WO2000027936A1

WO2000027936A1 - COATINGS COMPOSITIONS CONTAINING α-OLEFIN/VINYL OR VINYLIDENE AROMATIC AND/OR HINDERED ALIPHATIC OR CYCLOALIPHATIC VINYL OR VINYLIDENE INTERPOLYMERS

Info

Publication number: WO2000027936A1
Application number: PCT/US1999/025826
Authority: WO
Inventors: Stephen M. Hoenig; Thomas P. Schuman; Malcolm F. Finlayson; William L. Dechent; Shelby F. Thames; Oliver W. Smith; John O. Bieser
Original assignee: The Dow Chemical Company
Priority date: 1998-11-06
Filing date: 1999-11-03
Publication date: 2000-05-18
Also published as: AR021104A1; JP2002529573A; AU1711700A

Abstract

The present invention relates to a coating formulation comprising: (A) from 0.1 to 100 wt percent (based on the total weight of the coating formulation) of at least one substantially random interpolymer, which comprises: (1) polymer units derived from: (i) at least one vinyl or vinylidene aromatic monomer, or (iv) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or (v) a combination of at least one aromatic vinyl monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer; (2) polymer units derived from at least one of ethylene and/or a C3-20 α-olefin; and/or (4) polymer units derived from one or more of ethylenically unsaturated polymerizable monomers other than those derived from (1) and (2); (B) from 0 to 99.9 wt percent of an additional resin (based on the total weight of the coating formulation); (C) from 0 to 99.9 wt percent (based on the total weight of the coating formulation) of a solvent; and (D) from 0 to 99.9 wt percent (based on the total weight of the coating formulation) of one or more additives selected from the group consisting of binders, surfactants, thinners, adhesion promoters, fillers, tackifiers and processing aids, hardening resins, surface modifying additives, and combinations thereof.

Description

COATINGS COMPOSITIONS CONTAINING α-OLEFIN/VINYL OR VINYLIDENE AROMATIC AND/OR HINDERED ALIPHATIC OR CYCLOALIPHATIC VINYL OR VINYLIDENE INTERPOLYMERS

This invention describes the use of substantially random interpolymers such as the ethylene-styrene interpolymers (ESI) as a component in coatings such as paints and inks for substrates such as ESI, polyethylene, polystyrene, acrylonitrile/butadiene/styrene, polypropylene, other olefinic and styrenic substrates; as well as non-plastic substrates including wood, metal, paper and cement.

One of the attributes of a coating, such as a paint or ink, is that it has good adhesion to the substrate. Another attribute of such a coating is that it be able to hold high concentrations of filler or pigments for subsequent delivery to the substrate surface. In addition, a good coating should also allow control of the abrasion resistance, gloss, hardness, scratch resistance, low temperature flexibility, surface texture and filler holding capacity of the resulting coated surface.

In the case of polymer substrates, adhesion occurs through chemical bonding or mechanical interlocking of the coating and the substrate. In the case of mechanical interlocking, good swelling of the substrate by a coating solvent is generally a prerequisite of the interlocking mechanism. In the case of chemical bonding, the presence of a solvent for the coating is not a prerequisite, but can be advantageous.

Injection molded articles, such as toys, often require coatings for aesthetics.

To date, such toys are typically prepared either from styrenic polymers such as polystyrene, high impact polystyrene (HIPS), acrylonitrile/butadiene/styrene (ABS) or poly vinyl chloride (PVC) polymers (in the case of hard and stiff toys), or flexible poly vinyl chloride (f PVC) in the case of soft flexible toys. However, in multi- component articles requiring both soft and hard components, polystyrene cannot be used in combination with flexible PVC , as the plasticizer in the latter detrimentally impacts (causes crazing) in the physical properties of the styrenic component. Therefore to date, any multi-component toy having both hard and flexible parts must comprise f PVC and the more expensive ABS versus the less expensive f PVC PS combination.

In addition, for the styrenic-based substrates, a typical coating formulation would comprise an aromatic solvent (for example toluene, xylene, or ethylbenzene) with a styrenic block copolymer resin (for example SBS, SIS or SEBS). For the PVC-based substrates these coatings are unsuitable as they do not adhere to the substrate. Thus, most multi-component toys having both hard and flexible parts, in addition to requiring the more expensive polymer combinations, also typically require more than one coating formulation.

Articles prepared from other thermoplastic substrate combinations, including polyolefms, often require expensive and/or time-consuming pre-treatments to alter the surface chemistry, in order to render them coatable. Such pre-treatments include flame or corona-treatment (to oxidize the surface), or pre-coating with a primer to promote adhesion of the final coating.

Thus, it would be highly advantageous to develop a single coating formulation, which could coat a multi-component substrate comprising polystyrene as the hard component. It would be further advantageous if the single coating formulation did not require any pretreatment of the substrate prior to its use.

It would also be advantageous to develop a coating which allows control of properties, such as the abrasion resistance, gloss, hardness, scratch resistance, low temperature flexibility, surface texture and filler holding capacity, of the resulting coated surface.

Finally, it would also be advantageous to further improve the overall properties and performance of existing paint formulations in the areas of abrasion resistance, gloss, hardness, scratch resistance, low temperature flexibility, surface texture and filler holding capacity in order to further extend their range of application.

In one embodiment of the present invention, we have discovered coatings that have resin components which comprise one or more substantially random interpolymers which in turn comprise polymer units derived from ethylene and/or one or more α-olefin monomers with one or more vinyl or vinylidene aromatic monomers and/or aliphatic or cycloaliphatic vinyl or vinylidene monomers. The substantially random interpolymer can be the major resin component of the formulation or can be present as a minor resin component for example when being used as an adhesion promoter. Additionally the coatings of the present invention can further comprise an additional resin selected from the group consisting of styrenic homopolymers or copolymers, ethylene and/or α-olefin homopolymers or interpolymers, thermoplastic polyolefms (TPOs), engineering thermoplastics, styrenic block copolymers, elastomers, and the vinyl or vinylidene halide homopolymers and copolymers.

Depending on the application, the coatings of the present invention can further comprise a solvent system and one or more other additives including, but not limited to binders, surfactants, thinners, adhesion promoters, fillers, tackifiers and processing aids, antistatic agents hardening resins, surface modifying additives, and combinations thereof.

In another embodiment of the present invention we have surprisingly found that improved adhesion to styrene-containing substrates results from the use of coating formulations comprising solvents that are specific to the chemical composition of the substrate. Surprisingly, optimal adhesion occurred with the use of high boiling aromatic solvents. Solvents such as toluene generally give the lowest viscosity coating formulations and thus have potential for higher percent solids, better surface coverage, substrate hiding, and gloss. The preferred high boiling solvents include aromatic petroleum fractions boiling between 30 and 200°C, preferably propylbenzene and its isomers and isomers of butylbenzene.

In another embodiment of the present invention we have surprisingly found that the substantially random interpolymers may also be used as an additive in existing solvent borne coating formulations functioning as an adhesion promoter to low surface energy plastic substrates, such as ethylene-styrene copolymers or polyethylene, polystyrene, polypropylene, ABS, and other olefinic and styrenic substrates. In another embodiment of the present invention we have surprisingly found that coatings for substrates comprising substantially random ethylene-styrene interpolymers substrates exhibit enhanced adhesive properties if said coatings comprise styrenic polymers including, but not limited to, styrene-butadiene-styrene (SBS), styrene- isoprene-styrene (SIS), styrene-ethylene-butylene-styrene (SEBS), or styrene-ethylene- propylene (SEP) block copolymers, aromatic solvents and optionally an adhesion enhancing additive, such as one or more substantially random ethylene/styrene interpolymer.

In another embodiment of the present invention we have surprisingly found that the filler holding capacity of the substantially random interpolymers can be used to create a new, simplified paint or ink manufacturing process. In this process, colors are first added to the substantially random interpolymer (via compounding or other melt mixing techniques) and then the resulting pigment containing compound is added directly to the let down solution. This process represent a simplification over the more traditional paint or ink manufacturing processes which add the pigment via a mill base step.

Definitions

All references herein to elements or metals belonging to a certain Group refer to the Periodic Table of the Elements published and copyrighted by CRC Press, Inc., 1989. Also any reference to the Group or Groups shall be to the Group or Groups as reflected in this Periodic Table of the Elements using the IUPAC system for numbering groups.

Any numerical values recited herein include all values from the lower value to the upper value in increments of one unit provided that there is a separation of at least 2 units between any lower value and any higher value. As an example, if it is stated that the amount of a component or a value of a process variable such as, for example, temperature, pressure, and time is, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. are expressly enumerated in this specification. For values which are less than one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

The term "hydrocarbyl" as employed herein means any aliphatic, cycloaliphatic, aromatic, aryl substituted aliphatic, aryl substituted cycloaliphatic, aliphatic substituted aromatic, or aliphatic substituted cycloaliphatic groups.

The term "hydrocarbyloxy" means a hydrocarbyl group having an oxygen linkage between it and the carbon atom to which it is attached.

The term "interpolymer" is used herein to indicate a polymer wherein at least two different monomers are polymerized to make the interpolymer. This includes copolymers, terpolymers, etc.

The term "spray" is used herein to indicate that good atomization is possible with the coating formulations of the present invention with an application viscosity from 1 to 10 Poise.

The term "brush" is used herein to indicate that correct film thickness and yet proper leveling is possible with the coating formulations of the present invention with an application viscosity from 5 to 50 Poise.

The term "dip" is used herein to indicate that an excess coating of the coating formulations of the present invention runs off after removing from coating solution to give proper film thickness with an application viscosity intermediate between spray and brush (2 to 30 Poise), but formulated with 30 percent more volatile solvents content versus high boiling solvents in less viscous formulations (compared to brushing). Solvent volatility controls drip (set up) time and thus film thickness.

The term "ball jar or ball mill" (usually ceramic) is used herein to indicate ajar filled with grinding media and millbase to be ground into a fine dispersion. Grinding media is usually solid ceramic cylinders. The term "binder" is used herein to indicate the non-volatile portion of the liquid vehicle of a coating. It encompasses all polymer components of a coating formulation and functions to bind or cement the pigment particles together, and the coating film as a whole, to the material to which it is applied.

The term "coating" is used herein to indicate a clear or opaque surface coverage, which can be either water- or organic solvent-based and includes paints, inks, powder and architectural coatings.

The term "CPVC" is used herein to indicate the critical pigment volume concentration, which is the level of pigmentation in the dry paint, where just sufficient binder is present to fill the voids between the pigment particles.

The term "crystalline" is used herein to indicate the local or bulk material ordered molecular arrangement, the repeating pattern of which defines the crystal unit cell. The entropic ordering of a crystal corresponds to a material heat of transition (that occurs usually below melt, above glass transition temperature) and can be onset by thermal anneal (for example, during processing) in materials prone to crystalline ordering.

The term "dispersant" is used herein to indicate an additive that increases the stability of a suspension of powders in a liquid medium.

The term "dispersing resin" is used herein to indicate the, generally, higher molecular weight (polymeric) dispersant that has many pigment affinic sites along the polymeric chain, which bridge the surface tensions between the pigment and resin, and solvent.

The term "glass transition temperature" is used herein to indicate the temperature at which molecular motion (flow) of a material's amorphous regions begins, with the material becoming fluid-like.

The term "glove hand (feel)" is used herein to indicate the qualitative tactile test of touch sensation in comparison to kid-goatskin leather surface. The term "Hegman gauge" is used herein to indicate a device to measure the fineness of dispersion of a pigment based on drawing a paint down with a steel blade over a channel machined in a stainless steel block of tapered depth and observing the minimum depth at which pigment particles are observed to interfere with the smooth wet surface of the paint.

The term "letdown" is used herein to indicate the process of paint manufacturing in which the pigment paste (mill base) is reduced (let down) by the addition of the remaining ingredients of the formula. The definition is modified so that the correct application viscosity is obtained. Application viscosity is dependent on the method of application; spray, brush, or dip. Each method implies a shear rate range. Shear rate is important for materials that become less viscous under shear (pseudoplastic or thixotropic flow).

The term "leveling" is used herein to indicate the measure of the ability of a wet coating to flow out to a smooth dry film after application so as to obliterate any surface irregularities, such as brush marks, roller marks, orange peel from spraying, peaks or craters which have been produced by the mechanical process of applying the film.

The term " melt temperature" is used herein to indicate the transition of bulk material to a fluid state

The term "millbase" is used herein to indicate the portion of the coating formulation which is charged into the dispersion mill or appartus, and usually consists of pigments, dispersant(s), solvent(s), surface (processing) additives such as antifoaming agents, and possibly binder resin(s).

The term "PVC" is used herein to indicate the pigment volume concentration, which is the ratio of the volume of pigment to the volume of total non- volatile material (that is pigment and binder) present in the coating, usually expressed as a pecentage.

The term "vehicle" is used herein to indicate the liquid portion of a coating in which the pigment is dispersed. It is composed of binder and thinner. The term "substrate" as used herein to indicate the material of construction of an article which comprises any surface to be coated and includes, but is not limited to, the various plastics and polymers, metals, wood, paper, glass, cement and masonry.

The term "article" is used herein to indicate any structure prepared from a substrate which can be coated by a coating composition. These includes, but are not limited to, injection molded toys, durable goods, foams, films, sheets, fibers, injection molded, blow molded and calendered articles, flooring, wall coverings, decorative coatings and overlays.

The term "melt blending process" is used herein to indicate any mixing process in which one or more of the components to be mixed is in a molten state, and which processes include, but are not limited to, single and twin screw extrusion, Banbury mixing, Haake blending, calendering, melt milling and other thermoplastic processing operations.

The term "substantially random" (in the substantially random interpolymer comprising polymer units derived from ethylene and/or one or more α-olefin monomers with one or more vinyl or vinylidene aromatic monomers and/or aliphatic or cycloaliphatic vinyl or vinylidene monomers) as used herein means that the distribution of the monomers of said interpolymer can be described by the Bernoulli statistical model or by a first or second order Markovian statistical model, as described by J. C. Randall in POLYMER SEOUENCE DETERMINATION. Carbon- 1 NMR Method. Academic Press New York, 1977, pp. 71-78. Preferably, substantially random interpolymers do not contain more than 15 percent of the total amount of vinyl aromatic monomer in blocks of more than 3 units. This means that in the carbon^"13 NMR spectrum of the substantially random interpolymer, the peak areas corresponding to the main chain methylene and methine carbons, representing either meso diad sequences or racemic diad sequences, should not exceed 75 percent of the total peak area of the main chain methylene and methine carbons. The Coating Formulations of the Present Invention

For the coatings of the present invention comprise (A) one or more substantially random interpolymers. The substantially random interpolymer can be the major resin component of the coating formulation or can be present as a minor resin component, for example when being used as an adhesion promoter, or to impart specific enhancements to coating performance.

Additionally the coatings of the present invention can further comprise (B) one or more additional resin components selected from the group consisting of styrenic homopolymers or copolymers. ethylene and/or α-olefin homopolymers or interpolymers, thermoplastic polyolefms (TPOs), engineering thermoplastics, styrenic block copolymers, elastomers, and the vinyl or vinylidene halide homopolymers and copolymers. Depending on the application, the coatings of the present invention can optionally further comprise (C) a solvent system and (D) one or more other additives including, but not limited to, binders, thinners, adhesion promoters, fillers, tackifiers and processing aids, surfactants, hardening resins and other surface modifying additives.

The Substantially Random Interpolymers. (Component A).

The substantially random interpolymers used to prepare the coating compositions of the present invention, (Component A), include interpolymers prepared by polymerizing ethylene and/or one or more α-olefins with one or more vinyl or vinylidene aromatic monomers and/or one or more sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers, and optionally other polymerizable monomers.

Suitable α-olefins includes for example, α-olefins containing from 3 to about 20, preferably from 3 to 12, more preferably from 3 to 8 carbon atoms. Particularly suitable are propylene, butene-1, 4-methyl-l-pentene, heptene-1, hexene-1 or octene- 1. Also suitable is ethylene in combination with one or more α-olefins containing from 3 to 20 carbon atoms, and particularly ethylene in combination with one or more selected from propylene. butene-1, pentene-1, 4-methyl-l-pentene, hexene-1, heptene- 1 or octene-1. These α-olefins do not contain an aromatic moiety.

Other optional polymerizable ethylenically unsaturated monomer(s) include strained ring olefins such as norbornene and C,._I0 alkyl or C₆.₁₀ aryl substituted norbornenes, with an exemplary interpolymer being ethylene/styrene/norbornene.

Suitable vinyl or vinylidene aromatic monomers include, for example, those represented by the following formula:

Ar

I

(CH₂)_n

R^l — C = C(R²)₂ wherein R' is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R² is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, C -alkyl, and C -haloalkyl; and n has a value from zero to 4, preferably from zero to 2, most preferably zero. Exemplary vinyl aromatic monomers include styrene, vinyl toluene, α-methylstyrene, t-butyl styrene, chlorostyrene. including all isomers of these compounds,. Particularly suitable such monomers include styrene and lower alkyl- or halogen-substituted derivatives thereof. Preferred monomers include styrene, α-methyl styrene, the lower alkyl- (C, - C₄) or phenyl-ring substituted derivatives of styrene, such as for example, ortho-. meta-, and para-methylstyrene, the ring halogenated styrenes, para-vinyl toluene or mixtures thereof,. A more preferred aromatic vinyl monomer is styrene.

By the term '"sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene compounds", it is meant addition polymerizable vinyl or vinylidene monomers corresponding to the formula:

A'

I .

R^l _ C = C(R²)₂ wherein A¹ is a sterically bulky, aliphatic or cycloaliphatic substituent of up to 20 carbons, R¹ is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R² is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; or alternatively R¹ and A' together form a ring system. Preferred aliphatic or cycloaliphatic vinyl or vinylidene compounds are monomers in which one of the carbon atoms bearing ethylenic unsaturation is tertiary or quaternary substituted. Examples of such substituents include cyclic aliphatic groups such as cyclohexyl, cyclohexenyl, cyclooctenyl, or ring alkyl or aryl substituted derivatives thereof, tert-butyl, norbornyl,. Most preferred aliphatic or cycloaliphatic vinyl or vinylidene compounds are the various isomeric vinyl- ring substituted derivatives of cyclohexene and substituted cyclohexenes, and 5-ethylidene-2-norbornene. Especially suitable are 1-, 3-, and 4-vinylcyclohexene. α-Olefin monomers containing from 3 to 20 carbon atoms and having a linear aliphatic structure such as propylene, butene-1, hexene-1 and octene-1 are not considered as hindered aliphatic monomers.

The substantially random interpolymers may be modified by typical grafting, hydrogenation, functionalizing, or other reactions well known to those skilled in the art. This includes maleic anhydride- HDPE-,and polypropylene-grafted substantially random interpolymers. The substantially random interpolymers may also be readily sulfonated or chlorinated to provide functionalized derivatives according to established techniques.

One method of preparation of the substantially random interpolymers includes polymerizing a mixture of polymerizable monomers in the presence of one or more metallocene or constrained geometry catalysts in combination with various cocatalysts. The substantially random interpolymers include the pseudo random interpolymers prepared and described in EP-A-0,416,815 by James C. Stevens et al. and US Patent No. 5,703,187 by Francis J. Timmers. Preferred operating conditions for such polymerization reactions are pressures from atmospheric up to 3000 atmospheres and temperatures from -50°C to 200°C. Polymerizations and unreacted monomer removal at temperatures above the autopolymerization temperature of the respective monomers may result in formation of some amounts of homopolymer polymerization products resulting from free radical polymerization.

Examples of suitable catalysts and methods for preparing the substantially random interpolymers are disclosed in U.S. Application Serial No. 702,475, filed May 20, 1991 (EP-A-514,828); as well as U.S. Patents: 5,055,438; 5,057,475; 5,096,867; 5,064,802; 5,132,380; 5,189,192; 5,321,106; 5,347,024; 5,350,723; 5,374,696; 5,399,635; 5,470,993; 5,703,187; and 5,721,185.

The substantially random α-olefin/vinyl aromatic interpolymers can also be prepared by the methods described in JP 07/278230 employing compounds shown by the general formula

CP ¹ R ¹

/

\ /

R³ M

\ \

Cp² R²

where Cp¹ and Cp² are cyclopentadienyl groups, indenyl groups, fluorenyl groups, or substituents of these, independently of each other; R¹ and R² are hydrogen atoms, halogen atoms, hydrocarbon groups with carbon numbers of 1-12, alkoxyl groups, or aryloxyl groups, independently of each other; M is a group IV metal, preferably Zr or Hf. most preferably Zr; and R³ is an alkylene group or silanediyl group used to crosslink Cp' and Cp²).

The substantially random α-olefin/vinyl aromatic interpolymers can also be prepared by the methods described by John G. Bradfute et al. (W. R. Grace & Co.) in WO 95/32095; by R. B. Pannell (Exxon Chemical Patents, Inc.) in WO 94/00500; and in Plastics Technology, p. 25 (September 1992).

Also suitable are the substantially random interpolymers which comprise at least one α-olefin/vinyl aromatic/vinyl aromatic/α-olefin tetrad disclosed in U. S. Application No. 08/708.809 filed September 4. 1996 by Francis J. Timmers et al. These interpolymers contain additional signals in their carbon- 13 NMR spectra with intensities greater than three times the peak to peak noise. These signals appear in the chemical shift range 43.70 - 44.25 ppm and 38.0 - 38.5 ppm. Specifically, major peaks are observed at 44.1, 43.9. and 38.2 ppm. A proton test NMR experiment indicates that the signals in the chemical shift region 43.70 - 44.25 ppm are methine carbons and the signals in the region 38.0 - 38.5 ppm are methylene carbons.

It is believed that these new signals are due to sequences involving two head- to-tail vinyl aromatic monomer insertions preceded and followed by at least one α- olefin insertion, for example an ethylene/styrene/styrene/ethylene tetrad wherein the styrene monomer insertions of said tetrads occur exclusively in a 1 ,2 (head to tail) manner. It is understood by one skilled in the art that for such tetrads involving a vinyl aromatic monomer other than styrene and an α-olefin other than ethylene that the ethylene/vinyl aromatic monomer/vinyl aromatic monomer/ethylene tetrad will give rise to similar carbon- 13 NMR peaks but with slightly different chemical shifts.

These interpolymers can be prepared by conducting the polymerization at temperatures of from -30°C to 250°C in the presence of such catalysts as those represented by the formula

1

/ \

wherein: each Cp is independently, each occurrence, a substituted cyclopentadienyl group π-bound to M; E is C or Si; M is a group IV metal, preferably Zr or Hf, most preferably Zr; each R is independently, each occurrence, H, hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl, containing up to 30 preferably from 1 to 20 more preferably from 1 to 10 carbon or silicon atoms; each R is independently, each occurrence, H, halo, hydrocarbyl, hyrocarbyloxy, silahydrocarbyl, hydrocarbylsilyl containing up to 30 preferably from 1 to 20 more preferably from 1 to 10 carbon or silicon atoms or two R groups together can be a C ₀ hydrocarbyl substituted 1,3- butadiene; m is 1 or 2; and optionally, but preferably in the presence of an activating cocatalyst. Particularly, suitable substituted cyclopentadienyl groups include those illustrated by the formula:

wherein each R is independently, each occurrence, H, hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl, containing up to 30 preferably from 1 to 20 more preferably from 1 to 10 carbon or silicon atoms or two R groups together form a divalent derivative of such group. Preferably, R independently each occurrence is (including where appropriate all isomers) hydrogen, methyl, ethyl, propyl. butyl, pentyl, hexyl, benzyl, phenyl or silyl or (where appropriate) two such R groups are linked together forming a fused ring system such as indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl, or octahydrofluorenyl.

Particularly preferred catalysts include, for example, racemic- (dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl)zirconium dichloride. racemic- (dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl)zirconium 1 ,4-diphenyl- 1 ,3- butadiene, racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl)zirconium di- Cl-4 alkyl, racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl) zirconium di-Cl-4 alkoxide. or any combination thereof.

It is also possible to use the following titanium-based constrained geometry catalysts, [N-(l.l-dimethylethyl)-l,l-dimethyl-l-[(l,2,3,4,5-η)-l,5,6,7-tetrahydro-s- indacen-l-yl]silanaminato(2-)-N]titanium dimethyl; (l-indenyl)(tert-butylamido) dimethyl- silane titanium dimethyl; ((3-tert-butyl)(l,2,3,4,5-η)-l-indenyl)(tert- butylamido) dimethylsilane titanium dimethyl; and ((3-iso-propyl)(l,2,3.4,5-η)-l- indenyl)(tert-butyl amido)dimethylsilane titanium dimethyl, or any combination thereof. Further preparative methods for the interpolymers finding utility in the present invention have been described in the literature. United States patent number 5,652,315 issued to Mitsui Toatsu Chemicals. Inc. describes the copolymerization of ethylene and styrene. Longo and Grassi (Makromol. Chem.. Volume 191, pages 2387 to 2396 [1990]) and D'Anniello et al. (Journal of Applied Polymer Science, Volume 58, pages 1701-1706 [1995]) reported the use of a catalytic system based on methylalumoxane (MAO) and cyclopentadienyltitanium trichloride (CpTiCl₃) to prepare an ethylene- styrene copolymer. Xu and Lin (Polvmer Preprints, Am. Chem. Soc. Div. Polvm. Chem.) Volume 35, pages 686,687 [1994]) have reported copolymerization using a MgCl₂/TiCl₄/NdCl₃/ Al(iBu)₃ catalyst to give random copolymers of styrene and propylene. Lu et al (Journal of Applied Polvmer Science. Volume 53, pages 1453 to 1460 [1994]) have described the copolymerization of ethylene and styrene using a TiCl₄/NdCl₃/ MgCl₂/Al(Et)₃ catalyst. Sernetz and Mulhaupt, (Macromol. Chem. Phys.. v. 197, pp. 1071-1083, 1997) have described the influence of polymerization conditions on the copolymerization of styrene with ethylene using Me₂Si(Me₄Cp)(N- tert-butyl)TiCl₂/methylaluminoxane catalysts. Copolymers of ethylene and styrene produced by bridged metallocene catalysts have been described by Arai, Toshiaki and Suzuki (Polvmer Preprints. Am. Chem. Soc. Div. Polym. Chem.) Volume 38, pages 349, 350 [1997]). The manufacture of α-olefin/vinyl aromatic monomer inteφolymers such as propylene/styrene and butene/styrene are described in United States patent number 5,244,996, issued to Mitsui Petrochemical Industries Ltd or United States patent number 5,652,315 also issued to Mitsui Petrochemical Industries Ltd or as disclosed in DE 197 11 339 A 1 to Denki Kagaku Kogyo KK. The random copolymers of ethylene and styrene as disclosed in Polymer Preprints Vol 39, No. 1, March 1998 by Toru Aria et al. can also be employed as blend components of the present invention. Also included are the products of hydrogenation of random polymers of vinyl or vinylidene aromatic and diene monomers including but not limited to random styrene butadiene or styrene/isoprene copolymers.

The Additional Resin Component(s'). (Component B).

Additionally the coatings of the present invention can further comprise one or more additional resin components (Component B) selected from the group consisting of styrenic homopolymers or copolymers, ethylene and/or α-olefin homopolymers or inteφolymers, thermoplastic polyolefms (TPOs), engineering thermoplastics, styrenic block copolymers, elastomers, and the vinyl or vinylidene halide homopolymers and copolymers. The styrenic homopolymers or copolymers employed as component (B) of the coating compositions of the present invention are polymers of vinyl or vinylidene aromatic monomers and include homopolymers or copolymers of one or more vinyl or vinylidene aromatic monomers, or an copolymer of one or more vinyl or vinylidene aromatic monomers and one or more monomers copolymerizable therewith other than an aliphatic α-olefin. Suitable vinyl or vinylidene aromatic monomers are represented by the following formula:

Ar

I

R¹ — C = CH₂

Wherein R¹ is selected from the group of radicals consisting of hydrogen and alkyl radicals containing three carbons or less, and Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, C - alkyl, and C_M-haloalkyl. Exemplary vinyl or vinylidene aromatic monomers include styrene, para-vinyl toluene, α-methylstyrene, t-butyl styrene, chlorostyrene, including all isomers of these compounds, etc. Styrene is a particularly desirable vinyl aromatic monomer for the vinyl aromatic polymers used in the practice of the present invention.

A preferred polymer is atactic polystyrene. While preparing the substantially random inteφolymer component (A) of the present invention, atactic vinyl aromatic homopolymer may be formed due to homopolymerization of the vinyl aromatic monomer at elevated temperatures. For the puφose of the present invention, the atactic vinyl aromatic homopolymer, typically atactic polystyrene, constitutes at least part of the immiscible blend component (B).

Examples of suitable copolymerizable comonomers in Component (B), other than a vinyl or vinylidene aromatic monomer include, for example, C₄-C₆ conjugated dienes, especially butadiene or isoprene, n-phenyl maleimide, acrylamide. ethylenically- unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile, ethylenically- unsaturated mono- and difunctional carboxylic acids and derivatives thereof such as esters and, in the case of difunctional acids, anhydrides, such as acrylic acid, C,_,- alkylacrylates or methacrylates. such as n-butyl acrylate and methyl methacrylate, maleic anhydride, etc. In some cases it is also desirable to copolymerize a cross-linking monomer such as a divinyl benzene into the vinyl or vinylidene aromatic polymer. The polymers of vinyl or vinylidene aromatic monomers with other copolymerizable comonomers preferably contain, polymerized therein, at least 50 percent by weight and, preferably, at least 65 percent by weight of one or more vinyl or vinylidene aromatic monomers. Preferred styrenic copolymers are styrene/acrylonitrile (SAN) copolymers, styrene/maleic anhydride copolymers (SMA), styrene/methyl methacrylate copolymers (S-MMA) and the rubber modified copolymers such as acrylonitrile/butadiene/styrene copolymer (ABS). The number average molecular weight M_n of the styrenic homopolymers and copolymers used as blend components of the present invention is from 1000 to 1,000,000, preferably from 5,000 to 500.000, even more preferably from 10,000 to 350,000, and the molecular weight distribution M Mn is from 1.005 to 20.000.

Rubber modified vinyl aromatic polymers can be prepared by polymerizing the vinyl aromatic monomer in the presence of a predissolved rubber to prepare impact modified, or grafted rubber containing products, examples of which are described in US patents 3,123,655, 3,346,520, 3,639,522, and 4,409,369. The rubber is typically a butadiene or isoprene rubber, preferably polybutadiene. Preferably, the rubber modified vinyl aromatic polymer is high impact polystyrene (HIPS). Component (B) may also be a flame resistant rubber modified styrenic blend composition. The flame resistant compositions are typically produced by adding flame retardants to a high impact polystyrene (HIPS) resin. The addition of flame retardants lowers the impact strength of the HIPS which is restored back to acceptable levels by the addition of impact modifiers, typically styrene-butadiene-styrene (SBS) block copolymers. The final compositions are referred to as ignition resistant polystyrene (IRPS).

Suitable polymers to be employed as component (B) also include vinyl or vinylidene aromatic polymers having a high degree of isotactic or syndiotactic configuration. By a high degree of syndiotactic configuration is meant that the stereochemical structure is mainly of syndiotactic configuration, the stereostructure in which phenyl groups or substituted phenyl group as side chains are located alternately at opposite directions relative to the main chain consisting of carbon-carbon bonds. Tacticity is quantitatively determined by the 13C-nuclear magnetic resonance method, as is well known in the art. Preferably, the degree of syndiotacticity as measured by 13C NMR spectroscopy is greater than 75 percent r diad, more preferably greater than 90 percent r diad. Suitable examples of syndiotactic polymers include polystyrene, poly(alkylstyrene), poly(halogenated styrene), poly(alkoxystyrene), poly(vinylbenzoate), the mixtures thereof, and copolymers containing the above polymers as main components. Poly(alkylstyrene) includes poly(methylstyrene), poly(ethylstyrene) poly(isopropylstyrene), poly(tert-butylstyrene), etc., Poly(halogenated styrene) includes, poly(chlorostyrene), poly(bromostyrene), and poly(fluorostyrene), etc. Poly(alkoxystyrene) includes, poly(methoxystyrene), poly(ethoxystyrene), etc.

Preferred styrenic copolymers having tacticity and employed as component (B) are syndiotactic polystyrene (SPS) which usually has a weight-average molecular weight of 10,000 to 10,000,000, preferably 100,000 to 5,500,000 with a number-average molecular weight of 5,000 to 5,500,000, preferably 50,000 to 2,500,000. The syndiotactic polymer has a melting point of 160 to 310°C.

The ethylene and/or α-olefin homopolymers or inteφolymers can also be employed as component (B) of the coating compositions of the present invention. These are inteφolymers comprising ethylene and or C₃-C₂₀ α- olefins. The α-olefin homopolymers and inteφolymers include polypropylene, propylene/C₄-C₂₀ α- olefin copolymers, polyethylene, and ethylene/C₃-C₂₀ α- olefin copolymers. The inteφolymers can be either heterogeneous ethylene/α-olefin inteφolymers or homogeneous ethylene/α-olefin inteφolymers. including the substantially linear ethylene/α-olefin inteφolymers.

Also included are those aliphatic α-olefins having from 3 to 20 carbon atoms and containing polar groups. Suitable aliphatic α-olefin monomers which introduce polar groups into the polymer include, for example, ethylenically unsaturated nitriles such as acrylonitrile, methacrylonitrile, ethacrylonitrile. etc.; ethylenically unsaturated anhydrides such as maleic anhydride; ethylenically unsaturated amides such as acrylamide, methacrylamide etc.; ethylenically unsaturated carboxylic acids (both mono- and difunctional) such as acrylic acid and methacrylic acid, etc.; esters (especially lower, for example C,-C₆, alkyl esters) of ethylenically unsaturated carboxylic acids such as methyl methacrylate, ethyl acrylate, hydroxyethylacrylate, n-butyl acrylate or methacrylate, 2-ethyl- hexylacrylate etc.; ethylenically unsaturated dicarboxylic acid imides such as N- alkyl or N-aryl maleimides such as N-phenyl maleimide, etc. Preferably such monomers containing polar groups are acrylic acid, vinyl acetate, maleic anhydride and acrylonitrile. Exemplary polymer are ethylene vinyl acetate (EVA) and ethylene vinyl alcohol (EVOH). Halogen groups which can be included in the polymers from aliphatic α-olefin monomers include fluorine, chlorine and bromine; preferably such polymers are chlorinated polyethylenes (CPEs).

Heterogeneous inteφolymers are differentiated from the homogeneous inteφolymers in that in the latter, substantially all of the inteφolymer molecules have the same ethylene/comonomer ratio within that inteφolymer, whereas heterogeneous inteφolymers are those in which the inteφolymer molecules do not have the same ethylene/comonomer ratio. The term "broad composition distribution" used herein describes the comonomer distribution for heterogeneous inteφolymers and means that the heterogeneous inteφolymers have a "linear" fraction, multiple melting peaks (that is, exhibit at least two distinct melting peaks) by DSC and have a degree of branching less than or equal to 2 methyls/ 1000 carbons in 10 percent (by weight) or more, preferably more than 15 percent (by weight), and especially more than 20 percent (by weight of the polymer). The heterogeneous inteφolymers also have a degree of branching equal to or greater than 25 methyls/ 1000 carbons in 25 percent or less (by weight of the polymer), preferably less than 15 percent (by weight), and especially less than 10 percent (by weight of the polymer).

The Ziegler catalysts suitable for the preparation of the heterogeneous component of the current invention are typical supported, Ziegler-type catalysts which are particularly useful at the high polymerization temperatures of the solution process. Examples of such compositions are those derived from organomagnesium compounds, alkyl halides or aluminum halides or hydrogen chloride, and a transition metal compound. Examples of such catalysts are described in U.S. Pat Nos. 4,314,912 (Lowery, Jr. et al.), 4,547,475 (Glass et al.), and 4,612,300 (Coleman, III. Suitable catalyst materials may also be derived from a inert oxide supports and transition metal compounds. Examples of such compositions suitable for use in the solution polymerization process are described in U.S. Pat No. 5,420,090 (Spencer, et al).

The heterogeneous polymer component can be an ethylene and/or α-olefin homopolymer preferably polyethylene or polypropylene, or, preferably, an inteφolymer of ethylene with at least one C3-C20 oc-olefin and/or C4- 8 diolefins. Heterogeneous copolymers of ethylene and 1-butene, ethylene and 1-pentene, ethylene and 1-hexene and ethylene and 1-octene are especially preferred.

The relatively recent introduction of metallocene-based catalysts for ethylene/α-olefin polymerization has resulted in the production of new ethylene inteφolymers. Such polymers are known as homogeneous inteφolymers and are characterized by their narrower molecular weight and composition distributions relative to, for example, traditional Ziegler catalyzed heterogeneous polyolefin polymers. Substantially linear ethylene/α-olefin polymers and inteφolymers which can be employed as component (B) of the present invention are herein defined as in U.S. Patent No. 5,272,236 (Lai et al.), and in U.S. Patent No. 5,278,272.

The homogeneous polymer component can be an ethylene and/or α-olefin homopolymer preferably polyethylene or polypropylene, or, preferably, an inteφolymer of ethylene with at least one C3-C20 α-olefin and/or C4-C18 diolefins. Homogeneous copolymers of ethylene and one or more C3-C8 α-olefins are especially preferred.

Commercially available products to be employed as component (B) include ultralow density polyethylene (ULDPE). low density polyethylene (LDPE), linear low density polyethylene (LLDPE) medium density polyethylene (MDPE), high density polyethylene (HDPE), polyolefin plastomers, such as those marketed by The Dow Chemical Company under the AFFINITY™ tradename and polyethylene elastomers, such as those marketed under the ENGAGE™ tradename by Du Pont Dow Elastomers PLC. The molecular weight of the ethylene homopolymers and inteφolymers for use in the present invention is conveniently indicated using a melt flow measurement according to ASTM D-1238, Condition 190°C/2.16 kg (formerly known as "Condition (E)" and also known as I₂). Melt flow rate is inversely proportional to the molecular weight of the polymer. Thus, the higher the molecular weight, the lower the melt flow rate, although the relationship is not linear. The melt flow rate (12, ASTM D-1238, Condition 190°C/2.16 kg) for the ethylene homopolymers and inteφolymers useful herein is generally from 0.1 grams/ 10 minutes (g/10 min) to 1000 g/10 min, preferably from 0.5 g/10 min to 200 g/10 min, and especially from 1 g/10 min to 100 g/10 min.

The C3 α-olefin homopolymers or copolymers employed as component (B) of the coating compositions of the present invention are polypropylenes. The polypropylene is generally in the isotactic form of homopolymer polypropylene, although other forms of polypropylene can also be used (for example, syndiotactic or atactic). Polypropylene impact copolymers (for example, those wherein a secondary in-reactor copolymerization step reacting ethylene with the propylene is employed) and random copolymers (also reactor modified and usually containing 1.5-20 percent of ethylene or C4-C8 α-olefin copolymerized with the propylene), however, can also be used. A complete discussion of various polypropylene polymers is contained in

Modern Plastics Encvclopedia 89. mid October 1988 Issue, Volume 65, Number 11, pp. 86-92. The molecular weight of the polypropylene for use in the present invention is conveniently indicated using a melt flow measurement according to ASTM D-1238, Condition 230°C/2.16 kg (formerly known as "Condition (L)" and also known as 12). Melt flow rate is inversely proportional to the molecular weight of the polymer. Thus, the higher the molecular weight, the lower the melt flow rate, although the relationship is not linear. The melt flow rate for the polypropylene useful herein is generally from 0.5 grams/ 10 minutes (g/10 min) to 200 g/10 min, preferably from 1.0 g/10 min to 100 g/10 min, and especially from 2 g/10 min to 50 g/10 min. The thermoplastic polyolefms (TPOs) employed as component (B) of the coating compositions of the present invention are generally produced from propylene homo- or copolymers as described above, or blends of an elastomeric material such as ethylene/propylene rubber (EPM) or ethylene/propylene diene monomer teφolymer (EPDM) and a more rigid material such as isotactic polypropylene. Other materials or components can be added into the formulation depending upon the application, including oil, fillers, and cross-linking agents. In-reactor TPO's can also be used as blend components of the present invention.

The various engineering thermoplastics can also be employed as Component (B) of the coating compositions of the present invention. The third edition of the

Kirk-Othmer Encyclopedia of Science and Technology defines engineering plastics as thermoplastic resins, neat or unreinforced or filled, which maintain dimensional stability and most mechanical properties above 100°C and below 0°C. The terms "engineering plastics" and "engineering thermoplastics", can be used interchangeably. Engineering thermoplastics which can be employed as blend component (B) include polyoxymethylene-based resins such as acetal; acrylic resins (for example poly(methylmethacrylate, PMMA)); polyamides (for example nylon-4,6, nylon-6, nylon 6,6, and higher nylons), polyimides, polyetherimides, cellulosics, polyesters, poly(arylate); aromatic polyesters (for example polybutylene terephthalate and polyethylene terephthalate, and polycarbonate); liquid crystal polymers; blends, or alloys of the foregoing resins; and other resin types including for example rigid thermoplastic polyurethanes; high temperature polyolefms such as ethylene/norbornene copolymers, polycyclopentanes, its copolymers, and polymethylpentane and its copolymers. Also included are the aromatic polyethers including, for example, the poly(phenylene ether) (PPE) thermoplastic engineering resins which are well known, commercially available materials produced by the oxidative coupling polymerization of alkyl substituted phenols. They are generally linear, amoφhous polymers having a glass transition temperature in the range of 190°C to 235°C. Preferred PPE materials include those represented by the formula:

wherein Q is the same or different alkyl group having from 1 to 4 carbon atoms and n is a whole integer of at least 100, preferably from 150 to 1200. Examples of preferred polymers are poly(2,6-dialkyl-l,4-phenylene ether) such as poly(2,6-dimethyl-l,4- phenylene ether), poly(2-methyl-6-ethyl-l ,4-phenylene ether), poly(2-methyl-6- propyl-l,4-phenylene ether), poly-(2,6-dipropyl-l,4-phenylene ether) and poly (2- ethyl-6-propyl-l ,4-phenylene ether). A more preferred polymer is poly(2,6-dimethyl- 1 ,4-phenylene ether). These polymers are often sold as blends with polystyrene and high impact polystyrene, and other formulation components. Especially preferred engineering thermoplastics are acetal, polymethylmethacrylate,. poly(phenylene oxide), nylon-6, nylon 6,6, bisphenol A- poly(carbonate), poly(2,6-dimethyl-l,4-phenylene ether), and polybutylene terephthalate and polyethylene terephthalate,

Styrenic block copolymers which can be employed as component (B) of the coating compositions of the present invention are those having unsaturated rubber monomer units including, but not limited to, styrene-butadiene (SB), styrene- isoprene(SI), styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), α- methylstyrene-butadiene-α-methylstyrene and α-methylstyrene-isoprene-α- methylstyrene. The styrenic portion of the block copolymer is preferably a polymer or copolymer of styrene and its analogs and homologs including α-methylstyrene and ring-substituted styrenes, particularly ring-methylated styrenes. The preferred styrenics are styrene and α-methylstyrene, and styrene is particularly preferred.

Block copolymers with unsaturated rubber monomer units may comprise homopolymers of butadiene or isoprene or they may comprise copolymers of one or both of these two dienes with a minor amount of styrenic monomer. Preferred styrenic block copolymers which can be employed as Component (B) include at least one segment of a styrenic unit and at least one segment of an ethylene-butene or ethylene-propylene copolymer. Examples of such block copolymers with saturated rubber monomer units include styrene/ethylene-butene copolymers, styrene/ethylene-propylene copolymers, styrene/ethylene- butene/styrene (SEBS) copolymers, styrene/ethylene-propylene/styrene (SEPS) copolymers.

The elastomers which can be employed as component (B) of the coating compositions of the present invention include, but are not limited to, rubbers such as polyisoprene, polybutadiene, natural rubbers, ethylene/propylene rubbers, ethylene/propylene diene (EPDM) rubbers, silicone rubbers, styrene/butadiene rubbers and thermoplastic polyurethanes.

Vinyl or vinylidene halide homopolymers and copolymers can also be employed as component (B) of the coating compositions of the present invention and are a group of resins which use as a building block the structure CH₂=CXY, where X is selected from the group consisting of F, Cl, Br, and I and Y is selected from the group consisting of F, Cl, Br, I and H.

The vinyl or vinylidene halide polymer component of the blends of the present invention include but are not limited to homopolymers and copolymers of vinyl or vinylidene halides with copolymerizable monomers such as ethylene and/or α-olefins including but not limited to ethylene, propylene, vinyl esters of organic acids containing 1 to 18 carbon atoms, for example vinyl acetate, vinyl stearate and so forth; vinyl chloride, vinylidene chloride, symmetrical dichloroethylene; acrylonitrile, methacrylonitrile; alkyl acrylate esters in which the alkyl group contains 1 to 8 carbon atoms, for example methyl acrylate and butyl acrylate; the corresponding alkyl methacrylate esters; dialkyl esters of dibasic organic acids in which the alkyl groups contain 1 - 8 carbon atoms, for example dibutyl fumarate. diethyl maleate, and so forth.

Preferably the vinyl or vinylidene halide polymers are homopolymers or copolymers of vinyl chloride or vinylidene chloride. Poly (vinyl chloride) polymers (PVC) can be further classified into two main types by their degree of rigidity. These are "rigid" PVC and "flexible" PVC. Flexible PVC is distinguished from rigid PVC primarily by the presence of and amount of plasticizers in the resin. Flexible PVC typically has improved processability, lower tensile strength and higher elongation than rigid PVC. Of the vinylidene chloride homopolymers and copolymers (PVDC), typically the copolymers with vinyl chloride, acrylates or nitriles are used commercially and are most preferred. The choice of the comonomer significantly affects the properties of the resulting polymer. Perhaps the most notable properties of the various PVDC's are their low permeability to gases and liquids, barrier properties; and chemical resistance.

Also included in the family of vinyl halide polymers for use as blend components of the present invention are the chlorinated derivatives of PVC typically prepared by post chlorination of the base resin and known as chlorinated PVC, (CPVC). Although CPVC is based on PVC and shares some of its characteristic properties, CPVC is a unique polymer having a much higher melt temperature range (410 - 450°C) and a higher glass transition temperature (239 - 275°F) than PVC.

The Solvent System (Component Q.

Good compatibility of the binder system and the substrate is required for adhesion to occur. Solvent systems must function efficiently for both solvation of the coating polymer component of the binder and swelling of the substrate, even if the solubilities of the coating polymer and the substrate polymer are widely different. In systems comprising an adhesion promoter, compatibility of the adhesion polymer with the substrate polymer can be enhanced by the use of a solvent. Substantially random inteφolymers such as substantially random ethylene/styrene inteφolymers have demonstrated good compatibility with ESI, PE, PS, ABS, TPO and PP and thus adhesion to such substrates may be developed by selection of appropriate solvent(s).

Optimal adhesion occurs when the solvent system a good solvent for both the coating polymer and the substrate, the more critical being the extent of substrate solvency. However, the coating formulation's percent solids, hiding, coating thickness, is affected by viscosity and thus coating polymer solubility. Solvent selections for both coating polymer and substrate polymer should thus be made after determining percent solids and/or minimum viscosity trends for each pure material or material blend. Optimized solubility of both the coating polymer and substrate polymer corresponds with the most durable, measured adhesion.

Solvents in the formulation should include a high boiling aromatic solvent for ethylene-styrene substrates. For substrates other than ethylene-styrene, a solvent which softens/swells the interface of the plastic substrate is also preferred. We have found that optimal adhesion occurs when the solvent system is a good solvent for both the coating polymer (binder component) and the substrate, the more critical being the extent of substrate solubility. However, the coating formulation's percent solids, hiding ability, coating thickness, is affected by viscosity, and thus coating polymer solubility, and thus the coating adhesion does not only correlate with the solubility parameter.

For substantially random inteφolymer-based binders, solvents such as toluene generally give the lowest viscosity coating formulations and thus have potential for higher percent solids, better surface coverage, substrate hiding, and gloss. Better surface coverage and substrate hiding typically result from coating formulations of higher percent solids. We have also found that good adhesion to substrates comprising the substantially random inteφolymers results from the use of high boiling aromatic solvents in the coating composition. The preferred high boiling solvents include toluene, and aromatic petroleum fractions boiling between 30 and 200°C, preferably propylbenzene and its isomers and isomers of butylbenzene.

Alternatively, aqueous-based systems comprising water as the solvent may also be used. Such systems may also comprise a surfactant system to facilitate wetting of the substrate and wetting and dispersion of the binder. Such systems may also include the additional additives used to enhance the properties of coatings as described herein.

Other Additives (Component D).

Processing aids, which are also referred to herein as plasticizers, employed as Component D of the coating compositions of the present invention, include the phthalates, such as dioctyl phthalate and diisobutyl phthalate. natural oils such as lanolin, and paraffin, naphthenic and aromatic oils obtained from petroleum refining, and liquid resins from rosin or petroleum feedstocks. Exemplary classes of oils useful as processing aids include white mineral oil (such as Kaydol™ oil (available from and a registered trademark of Witco), and Shellflex™ 371 naphthenic oil (available from and a registered trademark of Shell Oil Company). Another suitable oil is Tuflo™ oil (available from and a registered trademark of Lyondell).

Hydrocarbon resins, most typically used as tackifiers in rubber compounding, can be added into the ESI and/or Kraton coatings which increase coating hardness, as measured by scratch resistance, without sacrificing flexibility and with improved adhesion to ESI substrates. Scratch resistance and compatibility were less in Kraton styrene block copolymers. The hydrocarbon resins are more advantageous to use, therefore, in ESI based coatings. The additives include, for example, coumarone- indene resins of glass transition temperatures greater than polystyrene, or other high glass transition temperature resins that associate with polystyrene endblocks. The tackifying resins should be completely compatible with coating solvents, dispersant(s), and other additives for optimal gloss, surface hardness, and adhesion. The preferred glass transition temperatures (T_g) of the tackifying resins are between 120 and 172°C. Lower T_g resins do not appreciably harden the surface but still improve adhesion. Specifically higher T_g resins (above 160°C) tend to be less compatible with Kraton, or styrene block copolymers. Compatibility, indicated by a clear solution of the tackifying resin with coating polymer, was necessary for improved surface hardness. Surface hardness was measured by a gloss change after abrasion.

A suitable tackifier may be selected on the basis of the criteria outlined by Hercules in J. Simons, Adhesives Age, "The HMDA Concept: A New Method for Selection of Resins", November 1996. This reference discusses the importance of the polarity and molecular weight of the resin in determining compatibility with the polymer. In the case of substantially random inteφolymers of at least one α-olefin and a vinyl aromatic monomer, preferred-tackifiers will have some degree of aromatic character to promote compatibility, particularly in the case of substantially random inteφolymers having a high content of the vinyl aromatic monomer.

Tackifying resins can be obtained by the polymerization of petroleum and teφene feedstreams and from the derivatization of wood, gum, and tall oil rosin. Several classes of tackifiers include wood rosin, tall oil and tall oil derivatives, and cyclopentadiene derivatives, such as are described in United Kingdom patent application GB 2,032,439A. Other classes of tackifiers include aliphatic C5 resins, polyteφene resins, hydrogenated resins, mixed aliphatic-aromatic resins, rosin esters, natural and synthetic teφenes, teφene- phenolics, and hydrogenated rosin esters.

Also included as Component D of the coating compositions of the present invention are the various organic and inorganic fillers, the identity of which depends upon the type of application for which the elastic film is to be utilized. The fillers can also be included in either blend Component A and/or blend Component B or the overall blend compositions employed to prepare the fabricated articles of the present invention. Representative examples of such fillers include organic and inorganic fibers such as those made from asbestos, boron, graphite, ceramic, glass, metals (such as stainless steel) or polymers (such as aramid fibers), talc, carbon black, carbon fibers, calcium carbonate, alumina trihydrate, glass fibers, marble dust, cement dust, clay, feldspar, silica or glass, fumed silica, alumina, magnesium oxide, magnesium hydroxide, antimony oxide, zinc oxide, barium sulfate, aluminum silicate, calcium silicate, titanium dioxide, titanates, aluminum nitride, B₂O₃, nickel powder or chalk.

Other representative organic or inorganic, fiber or mineral, fillers include carbonates such as barium, calcium or magnesium carbonate; fluorides such as calcium or sodium aluminum fluoride; hydroxides such as aluminum hydroxide; metals such as aluminum, bronze, lead or zinc; oxides such as aluminum, antimony, magnesium or zinc oxide, or silicon or titanium dioxide; silicates such as asbestos, mica, clay (kaolin or calcined kaolin), calcium silicate, feldspar, glass (ground or flaked glass or hollow glass spheres or microspheres or beads, whiskers or filaments). nepheline, perlite. pyrophyllite, talc or wollastonite; sulfates such as barium or calcium sulfate; metal sulfides; cellulose, in forms such as wood or shell flour; calcium terephthalate; and liquid crystals. Mixtures of more than one such filler may be used as well. The fillers can be used in a variety of particle sizes. Especially preferred are those fillers that are capable of being dispersed in "nano size" commonly referred to as nanofillers. Examples of such nanofillers include, but are not limited to, talc, clays such as montmorillonite and other aluminosilicates. mixed - metal and/or double layered hydroxides, mica, and organically treated analogs of said nanofillers.

Also included as Component D of the coating compositions of the present invention are hardening resins that associate with the styrene units in the polymer components and like the nanofillers, may be added to improve gloss and scratch resistance, for example, coumarone-indene, polystyrene, or polymethylstyrene resins.

Also included as Component D of the coating compositions of the present invention are the traditional coating binders which include, but are not limited to, styrne block copolymers, styrene acrylic copolymers, epoxies and epoxy hybrids, polyurethanes and polyurethane hybrids, polyesters, and acrylics.

Other ingredients included as Component D of the coating compositions of the present invention include colorants, organic and/or inorganic pigments, dispersing agents and/or resins, and surface control additives commonly used in coatings. In the case of dispersing resins, higher molecular weight dispersing agents, of good compatibility with the coating resins are preferred, because the coating resins themselves generally have poor dispersing qualities. Surface control additives include anti-foam, surface leveling, and mar-slip additives.

Additives such as antioxidants (for example, hindered phenols such as, for example, Irganox® 1010 a registered trademark of Ciba Geigy), phosphites (for example, Irgafos® 168 a registered trademark of Ciba Geigy), UN. stabilizers, antistatic agents (for example the quaternary ammonium salts), cling additives (for example, polyisobutylene), slip agents (such as erucamide and/or stearamide), antiblock additives, can also be included in the individual resin components of the coating formulation, or in their overall blend compositions. These additives are employed in functionally equivalent amounts known to those skilled in the art. For example, the amount of antioxidant employed is that amount which prevents the polymer or polymer blend from undergoing oxidation at the temperatures and environment employed during storage and ultimate use of the polymers. Such amount of antioxidants is usually in the range of from 0.01 to 10, preferably from 0.05 to 5, more preferably from 0.1 to 2 percent by weight based upon the weight of the polymer or polymer blend. Similarly, the amounts of any of the other enumerated additives are the functionally equivalent amounts such as the amount to render the polymer or polymer blend antiblocking, to produce the desired result, to provide the desired color from the colorant or pigment. Such additives can suitably be employed in the range of from 0.05 to 50, preferably from 0.1 to 35, more preferably from 0.2 to 20 percent by weight based upon the weight of the polymer or polymer blend.

Substrates To Be covered by the Coatings of the Present Invention.

The substrates to be covered by the coatings of the present invention include the normal materials of fabrication for articles to be painted, including metals, wood paper, glass, cement and masonry. The substrates can also be the various plastics and can include, but are not limited to, substantially random ethylene/styrene inteφolymers, one or more styrenic homopolymers or copolymers, ethylene and/or α- olefin homopolymers or copolymers, thermoplastic polyolefms, engineering thermoplastics, styrenic block copolymers, elastomers, or vinyl halide polymers, and blend combinations thereof.

General Procedure for the Preparation of Organic Solvent-Based Paint Compositions.

Such paint formulations are typically prepared in a two-step operation involving separate preparation of a "millbase" and a " letdown" . A typical millbase formulation is shown in Table 1. Table 1 Plastics Coating; Formulation Millbase

The ingredients are typically mixed in the following order; solvents, polymer and dispersants first, then pigment. The millbase is ground using a ball mill or similar pigment grinding apparatus to produce a fine dispersion of pigment, approximate particle size less than 37.5 μm as measured by a Hegman blade gauge. Millbase is used to disperse pigments for adding color or matting effects into the coating formulation. Typical wetting agents include maleic anhydride, trimellitic anhydride, or a naphthalenesulfonate. Dispersing resins as commonly used for styrene-acrylic coatings are ideal and produce high gloss, especially when the dispersant polarity was properly matched with the coating polymer (ESI or Kraton).

As a common coatings processing technique, some coating polymer (ESI or Kraton) or hardening additive in addition to the dispersing resins are typically added into the millbase to improve the millbase viscosity. The resins also contribute additional dispersion stability in a steric fashion, preventing pigment particle re- flocculation during the grinding process, thus accelerating the grinding process.

Letdown is produced separately and then blended with the millbase. Alternatively, the letdown may be applied alone as a clear coating. Overall percent solids of the coating formulation is 15 to 25 percent by weight. Lower percent solids are more conducive for spray application. Sufficient solvent must be used in the letdown to produce a clear, non-hazy solution of polymer or gloss will be affected. Pigment volume concentration (PVC) should be less than 15 percent of the coating solids to produce gloss (60°) values of 60 and less than 25 percent coating solids to produce gloss (60°) values of 20. Larger pigment volumes produce flatted films (60° gloss values near 0).

Relative weight ratios can be changed depending on the coating processing and desired viscosity and percent solids. For example, less polymer (resin) may be added to the grind stage by instead adding during the letdown (pigmented coatings), or more pigment can be used to make a less glossy coating but which then requires more dispersant. or less polymer may be used in the letdown to reduce viscosity. A typical letdown formulation is shown in Table 2.

Table 2: Plastics Coating; Formulation Letdown (parts by weight):

A Specific Coating Formulation

A specific millbase formulation is shown in Table 3.

Table 3. Plastics Coating; Formulation Millbase (parts by weight):

* Dispersing resins as commonly used for styrene-acrylic coatings tend to be ideal, producing optimum gloss.

Millbase ingredients are mixed, solvents, polymer and dispersants first, then pigment. The millbase is ground using a ball mill or similar pigment grinding apparatus to produce a fine dispersion of pigment, approximate particle size less than 37 μm (~1.5 mil) as measured by a Hegman blade gauge. Millbase is used to disperse pigments for adding color or matting effects into the coating formulation. Wetting agents typically comprise maleic anhydride, trimellitic anhydride, or a naphthalenesulfonate .

A specific letdown formulation is shown in Table 4.

Table 4. Plastics Coating; Formulation Letdown (parts by weight):

Composition Ranges of the Components of the Coating Compositions of the Present Invention.

It has been discovered that lower molecular weight, higher vinyl aromatic comonomer content substantially random inteφolymers give the lowest formulation viscosity and therefore can be formulated to higher percent solids than inteφolymers of lower melt index. Increasing the vinyl aromatic concentration in the substantially random inteφolymers lowers formulation viscosity by improving polymer solubility, allowing coating formulations of higher percent solids. The substantially random inteφolymer can be the major resin component of the formulation or can be present as a minor resin component for example when being used as an adhesion promoter especially when the substrates to be painted are themselves comprised of substantially random inteφolymers.

The substantially random inteφolymer is present in the wet aqueous or solvent-based coating formulation from 0.1 to 100 wt percent (in the case of a dry that is solvent free formulation) preferably from 0.1 to 50, preferably from 1 to 30, most preferably from 1 to 20 wt percent based on the total weight of the formulation.

The preferred substantially random inteφolymers contain from 0.5 mol percent to 65 mol percent (80 wt percent), preferably from 5 to 65 more preferably from 15 to 65 mole percent of at least one vinyl or vinylidene aromatic monomer and/or sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer and from 35 to 99.5, preferably from 35 to 95, more preferably from 35 to 85 mole percent of ethylene and/or at least one aliphatic α-olefin having from 3 to 20 carbon atoms.

The melt index (12) of the substantially random inteφolymer used in the paint formulations of the present invention is from 0.1 to 1000, preferably of from 1 to 500 more preferably of from 5 to 200 g/10 min.

The molecular weight distribution (M M of the substantially random inteφolymer used to prepare the elastic films of the present invention is from 1.5 to 20, preferably of from 1.8 to 10, more preferably of from 2 to 5.

Additionally the coatings of the present invention can further comprise an additional resin selected from the group consisting of styrenic block copolymers, polyurethanes, acrylics pigment(s), tackifiers and surface modifying additives.

The preferred solvents include water, toluene and high boiling aromatic petroleum fractions preferably boiling between 30 and 200°C, and more preferably propylbenzene and its isomers and isomers of butylbenzene.

The water or solvent component is present in the wet aqueous or solvent-based coating formulation from 50 to 99.9, preferably from 70 to 99, most preferably from 80 to 99 wt percent based on the total weight of wet formulation. Use Of Substantially Random Inteφolvmers As An Additive In Existing Solvent Borne Coating Formulations.

In another embodiment of the present invention we have suφrisingly found that the substantially random inteφolymers can be used as an additive in existing solvent borne coating formulations, functioning as an adhesion promoter to low surface energy plastic substrates, such as ethylene-styrene copolymers or polyethylene, polystyrene, polypropylene, ABS, and other olefinic and styrenic substrates.

The preferred ethylene-styrene inteφolymers include, but are not limited to, compositions of 20 to 80 percent styrene by weight of total monomer with a melt index (12) of between 0.1 and 200. Higher melt index polymers give the lowest formulation viscosity and therefore can be formulated to higher percent solids than polymers of lower melt index. Increasing the styrene concentration in the polymer improves polymer solubility, also allowing coating formulations of higher percent solids. Styrene content also improves gloss and pigment dispersion stability.

Glass transition temperature of the coating polymer has little affect on adhesion to the ethylene-styrene copolymer substrate, but does affect coating scratch resistance and flexibility. For example, higher glass transition temperature polymers (~20°C) have excellent scratch resistance. Rubbing with white paper does not affect gloss and, for pigmented systems, can instead improve gloss due to a burnishing effect. Practical coating flexibility at temperatures lower than the glass transition temperature is marginal.

Coating Formulations With Enhanced Adhesive Properties when Used for Coating Ethylene-Styrene Inteφolvmer Substrates.

In another embodiment of the present invention, coatings for ethylene-styrene inteφolymer substrates with enhanced adhesive properties have been discovered. The subject coatings are composed of coatings comprising styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), styrene-ethylene-butylene-styrene (SEBS), or styrene- ethylene-propylene (SEP) block copolymers, aromatic solvents and optionally an adhesion enhancing additive (such as the Dow Inteφolymer Binder (DIB)). Good adhesion to ethylene-styrene substrates results from the use of solvents that are specific to the chemical composition of the substrate, and/or the solubilized DIB (ethylene- styrene inteφolymer) in aromatic solvents. Suφrisingly, optimal adhesion occurred with the use of aromatic and high boiling aromatic solvents as noted below, although the use of a particular solvent combination did not ensure compatibility between the coating polymer and a given ESI substrate. As expected, aromatic solvents are good solvents for the coating polymer (binder) which affects viscosity and polymer chain mobility required for good coating gloss, flow, and substrate wetting but did not necessarily result in adhesive conditions. Solvents of low volatility maximize the time for polymer chain entanglement between the coating polymer and substrate polymer. Since the substrate polymer was a new composition and not a block copolymer, choice of solvent(s) was unknown and not predictable. Determination of solubility parameter was incorrect in predicting solubility and development of adhesion.

The preferred SBS polymers include, but are not limited to, those of 30+/- 5 percent styrene content. Increased styrene content creates harder, less flexible films, but apparently does not affect adhesion. Harder films can be subject to cracking when coated onto flexible substrates. SBS polymers, composed of unsaturated midblock monomers, have lower adhesion than polymers of saturated midblock on saturated polymer substrates, such as ethylene-styrene block inteφolymers (ESIs), especially those of critical surface tension less than 30.

The preferred SEBS and SEP polymers include, but are not limited to, those of 30+/-5 percent styrene content. Increased styrene content creates harder, less flexible films, but apparently does not affect adhesion. Harder films can be subject to cracking when coated onto flexible substrates.

ESI polymers were also found to be convenient and efficient as coatings polymers for ESI substrates. Being of similar composition, good compatibility with ESI substrates was suspected. However, solubility and high molecular weights of the ESI polymers made practical coatings formulation suspect, though the contrary has now been shown true. Variation of ESI polymer coating (material composition) separate from the substrate material was advantageous to alter gloss and other surface properties in appearance and resistance.

For example, when the substrate was low in styrene content, (for example, ESI inteφolymers with styrene contents of -30-40 weight percent), and was coated with a coating composition comprising higher styrene content ESI inteφolymers (with styrene contents of -60-70 wt percent), then gloss was improved from 10 or less units (60° gloss, ASTM D-523) to greater than 70 units relative to the uncoated material. Benefits in surface hardness (scratch or mar resistance) or glove feel (softness) of the surface can also be altered accordingly.

The preferred ESI polymers include, but are not limited to, those of melt index greater than 0.1 but less than 200. Higher melt index allows formulation of higher percent solids coatings at application viscosities for spray or brush. Surface properties can be altered by changing the coating polymer styrene content as noted above. Increased styrene content (>50 percent) creates harder, less flexible films, but apparently does not affect adhesion. Harder films can be subject to cracking when coated onto flexible substrates. However, doping the harder polymers with 5-10phr of softer ESI polymers, no limitations on melt index, dramatically improves low temperature flex cracking properties without significantly affecting scratch resistance or gloss. Dopant, flexible ESI polymers must still be compatible with coating solvents and substrate polymer for optimal formulation viscosity, substrate adhesion, scratch resistance, and gloss.

New. Simplified Paint Or Ink Manufacturing Process Utilizing The Filler Holding Capacity Of ESI.

In another embodiment of the present invention, the filler holding capacity of ESI's can be used to create a new, simplified paint or ink manufacturing process. In this process, colors are first added to the ESI (via compounding or other melt mixing techniques) and then the resulting pigment containing compound is added directly to the let down solution. This process represent a simplification over the more traditional paint or ink manufacturing processes which add the pigment via a mill base step. The following examples are illustrative of the invention, but are not to be construed as to limiting the scope thereof in any manner.

EXAMPLES

Test Methods

a) Melt Flow and Density Measurements

The molecular weight of the polymer compositions for use in the present invention is conveniently indicated using a melt index measurement according to ASTM D-1238, Condition 190°C/2.16 kg (formally known as "Condition (E)" and also known as 12) was determined. Melt index is inversely proportional to the molecular weight of the polymer. Thus, the higher the molecular weight, the lower the melt index, although the relationship is not linear.

Also useful for indicating the molecular weight of the substantially random inteφolymers used in the present invention is the Gottfert melt index (G, cm³/ 10 min) which is obtained in a similar fashion as for melt index (I₂) using the ASTM D1238 procedure for automated plastometers, with the melt density set to 0.7632, the melt density of polyethylene at 190°C.

The relationship of melt density to styrene content for ethylene-styrene inteφolymers was measured, as a function of total styrene content, at 190°C for a range of 29.8 percent to 81.8 percent by weight styrene. Atactic polystyrene levels in these samples was typically 10 percent or less. The influence of the atactic polystyrene was assumed to be minimal because of the low levels. Also, the melt density of atactic polystyrene and the melt densities of the samples with high total styrene are very similar. The method used to determine the melt density employed a Gottfert melt index machine with a melt density parameter set to 0.7632, and the collection of melt strands as a function of time while the 12 weight was in force. The weight and time for each melt strand was recorded and normalized to yield the mass in grams per 10 minutes. The instrument's calculated I2 melt index value was also recorded. The equation used to calculate the actual melt density is δ - δ₀₇₆₃₂ x l2 /l2 Gottfert

where δ _0.7632 ⁼ 0.7632 and 12 Gottfert ⁼ displayed melt index.

A linear least squares fit of calculated melt density versus total styrene content leads to an equation with a correlation coefficient of 0.91 for the following equation:

δ = 0.00299 x S + 0.723

where S = weight percentage of styrene in the polymer. The relationship of total styrene to melt density can be used to determine an actual melt index value, using these equations if the styrene content is known.

So for a polymer that is 73 percent total styrene content with a measured melt flow (the "Gottfert number"), the calculation becomes:

δ = 0.00299*73 + 0.723 = 0.9412

where 0.9412/0.7632 = If G# (measured) = 1.23

b^") Styrene Analyses

Inteφolymer styrene content and atactic polystyrene concentration can be determined using proton nuclear magnetic resonance (Η N.M.R) or by ¹³C nuclear magnetic resonance.

All proton NMR samples were prepared in 1, 1, 2, 2-tetrachloroethane-d₂ (TCE-d₂). The resulting solutions were 1.6 - 3.2 percent polymer by weight. Melt index (I₂) was used as a guide for determining sample concentration. Thus when the I₂ was greater than 2 g/10 min, 40 mg of inteφolymer was used; with an I₂ between 1.5 and 2 g/10 min, 30 mg of inteφolymer was used; and when the I₂ was less than 1.5 g/10 min, 20 mg of inteφolymer was used. The inteφolymers were weighed directly into 5 mm sample tubes. A 0.75 mL aliquot of TCE-d₂ was added by syringe and the tube was capped with a tight-fitting polyethylene cap. The samples were heated in a water bath at 85°C to soften the inteφolymer. To provide mixing, the capped samples were occasionally brought to reflux using a heat gun. Proton NMR spectra were accumulated on a Varian VXR 300 with the sample probe at 80°C, and referenced to the residual protons of TCE-d₂ at 5.99 ppm. The delay times were varied between 1 second, and data was collected in triplicate on each sample. The following instrumental conditions were used for analysis of the inteφolymer samples:

Varian VXR-300, standard Η: Sweep Width, 5000 Hz Acquisition Time, 3.002 sec Pulse Width, 8 μsec Frequency, 300 MHz

Delay, 1 sec Transients, 16 The total analysis time per sample was 10 minutes.

Initially, a Η NMR spectrum for a sample of the polystyrene, Styron™ 680 (available form the Dow Chemical Company, Midland, MI) was acquired with a delay time of one second. The protons were "labeled": b, branch; a, alpha; o, ortho; m, meta; p, para, as shown in Figure 1.

Figure 1.

Integrals were measured around the protons labeled in FIGURE 1 ; the 'A' designates aPS. Integral A₇ , (aromatic, around 7.1 ppm) is believed to be the three ortho/para protons: and integral A₆₆ (aromatic, around 6.6 ppm) the two meta protons. The two aliphatic protons labeled α resonate at 1.5 ppm; and the single proton labeled b is at 1.9 ppm. The aliphatic region was integrated from 0.8 to 2.5 ppm and is referred to as A_al. The theoretical ratio for A_{7 1}: A₆₆: A_al is 3: 2: 3, or 1.5: 1 : 1.5, and correlated very well with the observed ratios for the Styron™ 680 sample for several delay times of 1 second. The ratio calculations used to check the integration and verify peak assignments were performed by dividing the appropriate integral by the integral A₆₆ Ratio A. is A₇ , / A₆₆.

Region A₆₆ was assigned the value of 1. Ratio Al is integral A_a, / A₆₆. All spectra collected have the expected 1.5: 1: 1.5 integration ratio of (o+p): m: (α+b). The ratio of aromatic to aliphatic protons is 5 to 3. An aliphatic ratio of 2 to 1 is predicted based on the protons labeled α and b respectively in Figure 1. This ratio was also observed when the two aliphatic peaks were integrated separately.

For the ethylene/styrene inteφolymers, the 'H NMR spectra using a delay time of one second, had integrals C₇ ,, C₆₆, and C_a, defined, such that the integration of the peak at 7.1 ppm included all the aromatic protons of the copolymer as well as the o & p protons of aPS. Likewise, integration of the aliphatic region C_a, in the spectrum of the inteφolymers included aliphatic protons from both the aPS and the inteφolymer with no clear baseline resolved signal from either polymer. The integral of the peak at 6.6 ppm C₆₆ is resolved from the other aromatic signals and it is believed to be due solely to the aPS homopolymer (probably the meta protons). (The peak assignment for atactic polystyrene at 6.6 ppm (integral A₆₆) was made based upon comparison to the authentic sample Styron™ 680.) This is a reasonable assumption since, at very low levels of atactic polystyrene, only a very weak signal is observed here. Therefore, the phenyl protons of the copolymer must not contribute to this signal. With this assumption, integral A₆₆ becomes the basis for quantitatively determining the aPS content.

The following equations were then used to determine the degree of styrene incoφoration in the ethylene/styrene inteφolymer samples:

(C Phenyl).= C_{7 1} + A_{7 1} - ( 1.5 x A₆₆) (C Aliphatic) = C_a, - ( 1 5 x A₆₆) s_c = (C Phenyl) /5 e_c = (C Aliphatic - (3 x s_)) /4

E = e_c / (e_c + s_c)

S_c = s_c / (e_c + s_c) and the following equations were used to calculate the mol percent ethylene and styrene in the inteφolymers.

and

where: s_c and e_c are styrene and ethylene proton fractions in the inteφolymer, respectively, and S_c and E are mole fractions of styrene monomer and ethylene monomer in the inteφolymer, respectively.

The weight percent of aPS in the inteφolymers was then determined by the following equation:

The total styrene content was also determined by quantitative Fourier Transform Infrared spectroscopy (FTIR). Preparation of Substantially Random Ethylene/Styrene Inteφolvmers ("ESI's) Used in the Examples of the Present Invention.

ESI's 1 -6 were prepared by polymerizing a mixture of ethylene, styrene and hydrogen under solution process conditions in the presence of one or more metallocene or constrained geometry catalysts. The properties of ESI's 1 - 7 are summarized in Table 5.

Table 5. Properties of ESI #'s 1-7

* ESI 7 is a melt blend of 75 wt percent ESI 4 and 25wt percent Dowlex™ IP 60 (a product and trademark of The Dow Chemical Company.

Other materials employed in these studies are described in Table 6.

Table 6. Other Materials

Test parts and characterization data for the inteφolymers and their blends were generated according to the following procedures:

Injection Molding Method

ESI's 1 -7 were molded on a DEMAG Dl 50-275 injection molding machine at a barrel temperature of 160° - 170°C and a mold temperature of 10 - 20°C . The injection time was three seconds and the injection pressure was 2000 psi. A hold time of 15 second and a cooling time of 10 seconds was employed.

Examples

A series of experiments was conducted to study the effects of solvent on adhesion of a coating to an ESI substrate, ESI 7. Solvent blends of prescribed content according to the experimental design were made on a weight content basis. A list of solvent compositions is shown in Table 7.

Table 7. Solvent Compositions Used in Examples

Percent solids of materials, for coating and substrate polymers, was then measured as a indication of solubility and solvent susceptibility in a given solvent blend. Material was added to the above solvent blends in amounts as shown in Table 8.

Table 8. Saturated Solution Compositions

Polymer material was preweighed into glass vials and solvent pipetted in as a constant volume. Samples were shaken to mix and placed in a 50°C oven. Vials were removed from the oven, the contents manually stirred, and the vials replaced in the oven after 24 hours. Samples were removed from the oven after 48 hours and let stand at room temperature overnight (-15 hours) to equilibrate. [For baked coatings, samples would be equilibrated at the proposed baking temperature, instead of room temperature, until just before weighing.] Aliquots (~1.5g, net weight) were then removed from the clear, supernatant layer of each sample and placed into a preweighed (tare weight) aluminum pan, baked in a forced-air oven at 120°C overnight, cooled, and reweighed. Reheating and weighing produced no additional weight change. Percent solids was calculated from the difference in aliquot weights, pre- and post-bake. The percent solids data was entered into software and numerically solved for percent solids over solvent compositional space. Higher percent solids indicated better polymer solubility. Solubility data of polymers in solvent blends (percent solids by weight) is shown in Table 9. Table 9: Solubility

Aliquots from the samples (except ESI 7 solutions) were spray painted onto injection molded ASTM test samples of ESI 7 substrate, allowed to dry for three days. The resulting painted chips were then tested for paint adhesion following ASTM D 3359 - 95A, where grades were given according to the designations given in Table 10. In addition, a rub test using a Pink Pearl eraser (Eberhard Faser, Inc., 1 x 2 cm crossection) at 10 cycles of firm pressure further differentiated adhesive response of the solvent-polymer solution coatings to ESI 7. The rub test was conducted on the same portion of the plaques that was used for the earlier tape adhesion tests. In other words, the tape adhesion test was first conducted and the rub test was then conducted on the same area that had undergone the tape adhesion test. Results are shown in Table 11.

Table 10: Paint Adhesion rating Scheme

Tape test and rub test values of 4 or greater are considered good adhesion, 2 to 3 marginal, and 1 or less poor adhesion. A rating of 4 or greater for rub adhesion is considered as " durable" or wear resistant adhesion.

Table 11. Adhesion Data for Tape and Rub Tests (ASTM D3359)

The solubility and adhesion tests indicated that realtively high solubility greater than 13 percent solids in the coating solvents of substrate polymer (ESI 7), and coating polymer, ESI 1, generally gave adhesion values of 4 or greater (tape test) and 4 or greater (rub test). Kraton D-l 102 generally gave adhesion values 2 to 3 units lower than either ESI 1 or G-1726. Data showed that durable adhesion (rub > 4) was related to the quantity of high boiling aromatic solvent.

Adhesion to plastic substrates develops over a one to five day period, proportional to the quantity of high boiling aromatic solvent present. Pigmentation to 12 PVC reduces adhesion by 1-2 adhesion units. Adhesion measured before all high boiling solvent had evaporated demonstrated no adhesion (0) between the substrate and the coating polymer. Adhesion, upon thorough drying, increased with high boiling aromatic solvent content. In the absence of high boiling solvent, clear coatings of 3 adhesion were obtained. Increasing the weight percent of high boiling solvent to 20 percent (relative to total solvent) improved adhesion to 4, while solvent contents above 50 percent relative to the weight of solvent gave durable (5) adhesion.

Typically, the use of high boiling aromatic solvent increased dry time. Up to three days were required for durable adhesion while block resistance developed within 15 minutes at room temperature. All delamination (tape tests) occurred prior to 3 days drying time, although drying time can be reduced by baking the article at temperatures above ambient with fresh air circulated to the part surface.

Gloss values (measured by method ASTM D523) were - 60 for clear coatings with -30 percent solids or higher. Gloss values (measured by method ASTM D523) were - 80 units for clear coatings with -15-20 percent solids. Thus the percent solids of the coating formulation affects gloss.

Coatings Based On Solvents Comprising High Boiling Solvent

A separate study, using a combination of toluene and a high boiling aromatic solvent (Cyclosol 100™, available from Shell Chemical Company) was performed on the coating adhesion of three substantially random ethylene/styrene inteφolymers as compared to a Kraton G SEBS block copolymer. Room temperature saturated solutions of the test resins were prepared in various toluene/Cyclosol 100 mixtures as summarized in Table 12. The saturated solutions described in Table 12, were painted as coatings on injection molded plaques of ESI 7.

Table 12. Solubility in Toluene/Cyclosol 100 mixtures

The samples were allowed to dry for three days, and adhesion measured using the ASTM D-3359 Crosshatch tape test. Tape adhesion test results are given in Table 13. These data clearly show ESI containing coatings to be superior to the more traditional KRATON containing coatings - despite the higher solubility of KRATON in the solvent blends. Table 13: Adhesion (ASTM D-3359) of Coatings on ESI-7 Containing Substrate

Not an example of claimed invention

ESI clear coatings generally gave adhesion values of 4 or greater. (Durable adhesion was related to the quantity of high boiling aromatic solvent.)

Adhesion to ESI 7 developed over a one to five day period, and was proportional to both the quantity of high boiling solvent present and the relative evaporation rate of the solvent system. Pigmentation to 12 Pigment Volume Concentration (PVC) reduced adhesion by up to 1 - 2 adhesion units. Adhesion measured before all high boiling solvent had evaporated demonstrated no adhesion (0 rating) between the substrate and the coating polymer. Adhesion, upon thorough drying, generally increased with high boiling aromatic solvent content. Solvent with high boiling aromatic solvent content above 50 percent relative to the weight of solvent, gave durable (5) adhesion.

Gloss values (measured by method ASTM D523) were - 60 for clear coatings with -30 percent solids or higher. Gloss values (measured by method ASTM D523) were - 80 units for clear coatings with -15-20 percent solids. Percent solids of the coating formulation thus affects gloss. Gloss values were somewhat lower for ESI 3 compared to ESI's 1 and 2, thus higher mole percent ethylene content (or lower mol percent styrene content) in the ESI thus reduces gloss.

Example 15. ESI 2 Coating For Injection Molded ESI 7 Plaque.

A coatings was formulated at 17 wt percent ESI 2 solids and 12 pigment volume concentration (PVC) on an ESI 7 substrate, Table 14 describes the millbase and Table 15 describes the letdown.

Table 14. Millbase (by weight)

Ball mill to Hegman of greater than 5 (overnight), preferably greater than 7 (-2 days).

Table 15. Letdown (by weight)

Dissolve polymer completely in solvents, then add millbase to the following letdown.

This resulted in both good gloss (60 degree gloss of >60 units, ASTM D-503) and adhesion (5, ASTM D-3359). Coatings above 12 PVC caused significant loss of gloss. Semi gloss (60 degree gloss of -40 units) formulations are available at 20 PVC, and flat (60 degree gloss of <10 units) at >25 PVC.

Equivalent aromatic 100 solvent brands may be substituted for Cyclosol 100; additional dilution for spraying should be performed with toluene; minimum dry time is 3 days, tack free in <5 minutes. BYK-164 is a trademark standard dispersing resin manufactured by BYK Chemie, a high molecular weight block copolymer resin with pigment affinic groups for use in relatively non-polar media. Compatibility with non- polar media improved dispersion stability and development of coating gloss. CycloSol 100 is a trademark of Shell Chemical Co., consisting of a C₈+ (excluding ethylbenzene) aromatic fraction boiling between 150 and 175°C (300 and 350°F). Cypar 9 is a trademark of Shell Chemical Co., consisting of a C₈+ (excluding ethylbenzene) aromatic fraction boiling between 150 and 175°C (300 and 350°F).

Exs 16 - 29. Effect of ESI polymer properties on coating adhesion:

The effect of ESI polymer properties such as melt index (12) and percent styrene content on coating adhesion was evaluated. A base paint (without ESI) was produced and subsequently modified by the ESI's of Table 16.

Production of ESI free Base Paint.

The Base Paint was produced by making a paste, a solvent system and a resin system according to Table 16

Table 16. ESI free Base Paint Recipe

General Procedure: Mix up paste. Mix solvent systems. Dissolve resin and agents into solvent system. Blend Paste with solvent resin system.

ESI solutions were prepared for the puφose of modifying the base paint. These solutions were prepared by dissolving 10 percent ESI polymer into toluene. The solutions were made in a 1 liter resin kettle, with an air stirrer and a water cooled condenser. Temperature was controlled using an Omron E5EX temperature controller with the thermocouple in the solution. The maximum solution temperature was 108 C. The solution was allowed to heat and stir for 2-3 hr. To ensure complete dissolution of the polymer. The stirrer was turned off, the heating mantel removed, the stirrer turned back on and the solution allowed to cool to room temperature 25 C, taking approximately 3 hours. The ESI's are described in Table 17. Table 17. ESI Solutions Produced

The base paint described above was mixed with the ESI solutions from Table 17 and toluene as shown in Table 18.

Table 18. ESI based coatings on injection molded ESI 7

This data shows that the base paint does not adhere to the subject ESI substrate, but that by the addition of ESI solution the paint adhesion improves dramatically and steadily with increasing amounts of ESI solution. The results show that coating adhesion (at a given concentration of ESI solution) increases as the styrene content of the added ESI increases. The results also show that coating adhesion (at a given concentration of ESI solution) also increases as the melt index increases or molecular weight decreases. Exs 30 -31. Formulation of Tackifying Resins into Coatings for ESI substrates

Hardness, gloss, abrasion resistance and low temperature flexibility are generally desirable properties of coatings such as paint. A series of experiments, using coating formulations containing ESI 1 was conducted to determine the effect of several tackifying resins on coating properties such as hardness, gloss, adhesion and low temperature flexibility. These results are compared with coating formulations containing styrenic block copolymers. Compatibility was ascertained by clarity of the polymer and resin solution and of the resultant coating.

Table 19 shows gloss measured both before and after (numbers in parentheses) abrasion with white paper. An abrasion test was developed to measure the surface hardness of the polymer coatings. Standard long grain copier paper was used as the abrasive media. The sample was pulled against the grain of the paper 10 cycles while pressing the sample firmly into the paper. Gloss of the abraded sample was compared to the original gloss; less change in gloss indicated a harder, more scratch resistant coating.

The data shows that initial gloss is better with the ESI containing coatings and suφrisingly, the gloss is retained to a much higher degree for the ESI containing coating than for either of the styrene block copolymer containing coatings.

Table 19. Effect of Tackifying Resins On Gloss

Adhesion results are shown in Table 20. Even in the presence of tackifying resins the Styrene Block Copolymer resins exhibit poor adhesion to ESI 7. Excellent adhesion is achieved for the ESI containing coating.

Table 20. Tackifying Resins - Effect on Adhesion

Low temperature flexibility was measured by placing coated ESI 7 samples in a -5°C freezer for 0.5 hours. Samples were removed and immediately bent through 180°. Microscopic examination at 10 to 60X magnification showed presence/absence of crack defects and extent of failure. Coatings were assigned a pass (no defects) or fail (presence of any cracking due to flex) rating as shown in Table 21. Low temperature flexibility of Kraton containing coatings was unaffected by tackifier type or amount. In the case of ESI 1 containing coatings, low temperature flexibility is decreased in the presence of tackifying resins. This is expected since the hardness of these coatings increases in the presence of these same tackifying resins. Low temperature flexibility can be improved by utilizing a blend of ESI's in the coating formulation. For example, addition of 10 parts ESI 3 per 100 parts ESI 2 makes the microcracks invisible to the naked eye, with further improvements in flex at 20 and 30 phr ESπ. Table 21: Tackifying Resins - Effect on Low Temperature Flexibility*

*A rating of 1 = pass, 0 = fail

Claims

1. A coating formulation comprising;

(A) from 0.1 to 100 wt percent (based on the total weight of the coating formulation) of at least one substantially random inteφolymer, which comprises;

(1) polymer units derived from;

(i) at least one vinyl or vinylidene aromatic monomer, or (ii) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or (iii) a combination of at least one aromatic vinyl monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer;

(2) polymer units derived from at least one of ethylene and/or a C₃.₂₀ α- olefin; and/or (3) polymer units derived from one or more of ethylenically unsaturated polymerizable monomers other than those derived from (1) and (2);

(B) from 0 to 99.9 wt percent of an additional resin (based on the total weight of the coating formulation);

(C) from 0 to 99.9 wt percent (based on the total weight of the coating formulation) of a solvent; and

(D) from 0 to 99.9 wt percent (based on the total weight of the coating formulation) of one or more additives selected from the group consisting of binders, surfactants, thinners, adhesion promoters, fillers, tackifiers and processing aids, hardening resins, surface modifying additives, and combinations thereof.

2. The coating composition of Claim 1 wherein;

A) said one or more substantially random inteφolymers, Component A, has an I₂ of 0.1 to 1000 g/10 min, an M _v/M_n of 1.5 to 20. and present in an amount of from 0.1 to 50 percent by weight (based on the total weight of the coating formulation); and comprises;

(1) from 0.5 to 65 mol percent of polymer units derived from;

(a) at least one vinyl or vinylidene aromatic monomer, or (b) at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, or (c) a combination of at least one aromatic vinyl or vinylidene monomer and at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, and

(2) from 35 to 99.5 mol percent of polymer units derived from at least one of ethylene and/or a C₃.₂₀ α-olefin; and

(3) from 0 to 20 mol percent of polymer units derived from one or more of ethylenically unsaturated polymerizable monomers other than those derived from ( 1 ) and (2);

(B) said additional resin, Component B, is present in an amount of from 50 to 99.9 wt percent and is selected from the group consisting of styrenic homopolymers or copolymers, ethylene and/or α-olefin homopolymers or inteφolymers, thermoplastic polyolefms (TPOs), engineering thermoplastics, styrenic block copolymers, elastomers, and the vinyl or vinylidene halide homopolymers and copolymers;

(C) said solvent. Component C, is present in an amount of from 50 to 99.9 wt percent (based on the total weight of the coating formulation)and is selected from the group consisting of water, toluene and high boiling aromatic petroleum fractions preferably boiling between 30 and 200°C.

3. The coating composition of Claim 1 wherein;

A) said one or more substantially random inteφolymers. Component A, has an I₂ of 1 to 500 g/10 min. an M M_n of 1.8 to 10, and is present in an amount of from 1 to 30 percent by weight (based on the total weight of the coating formulation); and comprises;

(1) from 5 to 65 mol percent of polymer units derived from;

(2) from 35 to 95 mol percent of polymer units derived from at least one of ethylene and/or a C₃.₂₀ α-olefin; and

(4) from 0 to 20 mol percent of polymer units derived from one or more of ethylenically unsaturated polymerizable monomers other than those derived from (1) and (2);

(B) said additional resin, Component B, is present in an amount of from 70 to 99 wt percent and is one or more of polystyrene, high impact polystyrene, styrene/acrylonitrile (SAN) copolymers, styrene/maleic anhydride copolymers (SMA), styrene/methyl methacrylate copolymers (S-MMA), acrylonitrile/butadiene/styrene copolymer

(ABS), homogeneous and heterogeneous ethylene/C₃-C₈ alpha olefin copolymers, polyethylene, polypropylene, ethylene/propylene rubber (EPR), ethylene/propylene diene monomer (EPDM), acetal, polymethylmethacrylate, nylon-6, nylon -66, poly phenylene ether (PPE), polycarbonate, polyethylene terephthalate, styrene/ethylene- butene copolymers, styrene/ethylene-propylene copolymers, styrene/ethylene-butene/styrene (SEBS) copolymers, styrene/ethylene-propylene/styrene (SEPS), polyisoprene, polybutadiene, natural rubber, silicone rubber, styrene/butadiene rubbers, thermoplastic polyurethanes or poly vinyl chloride (PVC), flexible poly vinyl chloride (f PVC) or poly vinylidene chloride (PVDC) or combinations thereof; and (C) said solvent. Component C, is present in an amount of from 70 to 99 wt percent (based on the total weight of the coating formulation)and is one or more of water, toluene, propylbenzene and its isomers or butylbenzene and its isomers, or a combination thereof.

4. The coating composition of Claim 1 wherein;

A) said one or more substantially random inteφolymers, Component A, has an I₂ of 5 to 200 g/10 min, an MJM_n of 2 to 5; and comprises;

(1) from 15 to 65 mol percent of polymer units derived from;

(a) said vinyl or vinylidene aromatic monomer represented by the following formula;

Ar I R^l — c = CH₂ wherein R¹ is selected from the group of radicals consisting of hydrogen and alkyl radicals containing three carbons or less, and Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, C_M-alkyl, and C -haloalkyl; or (b) said sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer is represented by the following general formula;

A' Rⁱ — c = C(R )₂ wherein A¹ is a sterically bulky, aliphatic or cycloaliphatic substituent of up to 20 carbons, R¹ is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms; each R² is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms; or alternatively R¹ and A¹ together form a ring system; or c) a combination of a and b; and

(2) from 35 to 85 mol percent of polymer units derived from ethylene and/or said α-olefin which comprises at least one of propylene, 4- methyl-1-pentene, butene-1, hexene-1 or octene-1; and

(3) said ethylenically unsaturated polymerizable monomers other than those derived from (1) and (2) comprises norbornene, or a C,_₁₀ alkyl or C₆.₁₀ aryl substituted norbornene; and (B) said additional resin, Component B, is present in an amount of from

80 to 99 wt percent and is one or more of polystyrene, styrene/acrylonitrile (SAN) copolymers, styrene/maleic anhydride copolymers (SMA), acrylonitrile/butadiene/styrene copolymer (ABS), homogeneous and heterogeneous ethylene/octene copolymers, polyethylene, polypropylene, ethylene/propylene rubber

(EPR), ethylene/propylene diene monomer (EPDM), polymethylmethacrylate, styrene/ethylene-butene copolymers, styrene/ethylene-propylene copolymers, styrene/ethylene- butene/styrene (SEBS) copolymers, styrene/ethylene- propylene/styrene (SEPS), polyisoprene, thermoplastic polyurethanes or poly vinyl chloride (PVC), or combinations thereof; and (C) said solvent, Component C, is present in an amount of from 80 to 99 wt percent (based on the total weight of the coating formulation) and is one or more of water, toluene, propylbenzene and its isomers or butylbenzene and its isomers, or a combination thereof.

5. The coating composition of Claim 4 wherein said vinyl aromatic monomer, Component Al(a), is styrene; and said Component A2 is ethylene.

6. The coating composition of Claim 4 wherein said vinyl aromatic monomer,

Component A 1(a), is styrene; and said Component A2 is ethylene and at least one of propylene, 4-methyl-l-pentene, butene-1, hexene-1 or octene-1.

7. The coating composition of Claim 1 in the form of a paint.

8. The coating composition of Claim 1 in the form of an ink.

9. A process for preparing a coating composition, which process comprises A) preparing a pigment-containing compound by mixing a pigment and a substantially random inteφolymer, which comprises polymer units derived from;

(i) at least one vinyl or vinylidene aromatic monomer, or (ii) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or

(iii) a combination of at least one aromatic vinyl monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer; and B) adding said pigment containing compound directly to a let down solution.

10) The process of Claim 9 wherein said pigment and said substantially random inteφolymer are mixed by a melt blending process.

11) A process for improving the adhesion and/or gloss and/or abrasion resistance and/or filler pigment holding capacity of a coating to a substrate, which process comprises adding to said coating, an additive comprising a substantially random inteφolymer, which comprises polymer units derived from;

(iv) at least one vinyl or vinylidene aromatic monomer, or (v) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or (vi) a combination of at least one aromatic vinyl monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer.

12). The process of claim 10 wherein said substrate comprises a substantially random inteφolymer.

13) The process of claim 10 wherein said coating is in the form of a paint.

14). The process of claim 10 wherein said coating is in the form of an ink.

15). An article coated by the coating formulation of Claim 1.

16). The article of claim 15 in the form of an injection molded toy.