WO2015094731A1

WO2015094731A1 - Aqueous epoxy composite dispersions

Info

Publication number: WO2015094731A1
Application number: PCT/US2014/069004
Authority: WO
Inventors: Jeff Anderson; Jodi Mecca; James Bohling; Ray Drumright
Original assignee: Dow Global Technologies Llc
Priority date: 2013-12-20
Filing date: 2014-12-08
Publication date: 2015-06-25

Abstract

Embodiments of the present disclosure are directed towards aqueous epoxy composite dispersions including an epoxy resin and a plurality of composite particles each including a respective inorganic pigment core having a number of adsorbing polymeric latex particles adsorbed thereto, wherein the aqueous epoxy composite dispersion has a pigment volume concentration in a range from five percent to fifty- five percent.

Description

AQUEOUS EPOXY COMPOSITE DISPERSIONS

Field of Disclosure

[001] Embodiments of the present disclosure are directed to aqueous epoxy composite dispersions, more specifically, embodiments are directed to aqueous epoxy composite dispersions including a plurality of composite particles each including a respective inorganic pigment core having a number of adsorbing polymeric latex particles adsorbed thereto.

Background

[002] Aqueous dispersions of epoxy resins are employed for various utilizations. An aqueous dispersion of epoxy resins can be applied to a surface and cured thereon to form a cured coating. The cured coating can provide functional properties and/or cosmetic properties for the various utilizations.

Summary

[003] The present disclosure provides an aqueous epoxy composite dispersion including an epoxy resin and a plurality of composite particles each including a respective inorganic pigment core having a number of adsorbing polymeric latex particles adsorbed thereto, wherein the aqueous epoxy composite dispersion has a pigment volume concentration in a range from five percent to fifty- five percent.

[004] The present disclosure provides a coated article including a substrate and a coating including the aqueous epoxy composite dispersion.

[005] The present disclosure provides a coated article including a substrate and a cured coating formed by curing the aqueous epoxy composite dispersion.

[006] The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list. Detailed Description

[007] Epoxy resins are reactive prepolymers, e.g., monomers or

oligomers, and/or polymers that contain epoxide groups. Epoxy resins may be reacted, which may be referred to as cross-linking or curing, to form a cured material, such as a cured coating. These cured materials are desirable for some applications due to improved mechanical properties and/or improved chemical resistance as compared to some other materials.

[008] Cured coatings formed from aqueous epoxy dispersions can include a number of components. For example, a cured coating may include an inorganic pigment. Inorganic pigments can be utilized to provide properties, e.g., opacity, to cured coatings. However, utilizing these inorganic pigments can be costly.

Therefore, for some applications it is desirable to use as little inorganic pigment as possible, e.g., to reduce costs, among other factors.

[009] Poor distribution of inorganic pigment particles in a cured coating can result in a less than a full potential contribution to the properties of the cured coatings, such as, for example, with regard to opacity, among others. Therefore, the poor distribution of inorganic pigment particles can result in increased usage of the inorganic pigment particles to achieve a desired property, such as a particular opacity. Poor distribution of inorganic pigment particles in a cured coating can also result in inferior performance properties, such as chemical and corrosion resistance, relative to similar coating having a good distribution of inorganic pigment particles.

[010] Advantageously the cured coatings formed from the aqueous epoxy composite dispersions, as disclosed herein, which include composite particles each including a respective inorganic pigment core having a number of adsorbing polymeric latex particles adsorbed thereto, provide improved pigment distribution as compared to cured coatings formed from compositions lacking the composite particles.

[01 1] Embodiments of the present disclosure provide that the aqueous epoxy composite dispersions can include a plurality of composite particles. Each of the plurality of composite particles can include a respective inorganic pigment core, e.g., respective inorganic pigment particles, having a number of adsorbing polymeric latex particles adsorbed thereto. For instance, the number of adsorbing polymeric latex particles can be adsorbed to a surface of the inorganic pigment core. [012] The respective inorganic pigment cores can include a metal oxide.

Examples of inorganic pigments include, but are not limited to, titanium dioxide, such as rutile titanium oxide or anatase titanium dioxide, for example; chromium oxide; cadmium sulfoselenide; cerium sulfide; iron oxide; cadmium sulfide; cadmium zinc sulfide; bismuth vanadate; and combinations thereof. Various particle sizes and/or particle size distributions of the inorganic pigment can be used for different applications. The respective inorganic pigment core may have a uniform

composition; however, some embodiments of the present disclosure provide that the respective inorganic pigment core may have a heterogeneous composition, e.g. with two or more phases. The respective inorganic pigment core may have a coating of silica, alumina, zinc oxide, zirconia, or a combination thereof. As is understood by those skilled in the art, the coatings of the inorganic pigment core may have different thickness for various applications.

[013] Embodiments of the present disclosure provide that the adsorbing polymeric latex particles can be formed by reacting, e.g. a polymerization reaction, a composition of monomers. The composition of monomers can be a homogenous mixture of monomers or a heterogeneous mixture of monomers. Examples of monomers that can utilized in the composition of monomers includes, but is not limited to, monoethylenically unsaturated monomers and multiethylenically unsaturated monomers. Various portions of monomers may be utilized for different applications.

[014] The adsorbing polymer latex particles useful in compositions of the present disclosure may be prepared from various polymerizable monomers, such as, for example, monoethylenically unsaturated monomers, including α,β- monoethylenically unsaturated monomers such as alkyl acrylates and methacrylates. Suitable monomers include styrene, butadiene, a-methyl styrene, vinyl toluene, vinyl naphthalene, ethylene, propylene, vinyl acetate, vinyl versatate, vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile, (meth)acrylamide, various Ci-C 40 alkyl esters of (meth)acrylic acid; for example, methyl (meth) acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth) acrylate, 2-ethylbexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl

(meth)acrylate, n-dodecyl (meth)acrylate, tetradecyl (meth)acrylate, n-amyl

(meth)acrylate, neopentyl (meth) acrylate, cyclopentyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth) acrylate, palmityl (meth)acrylate, and stearyl (meth)acrylate; other (meth)acrylates such as isobornyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, 2-bromoethyl (meth)acrylate, 2-phenylethyl (meth) acrylate, and 1 -naphthyl (meth)acrylate, alkoxyalkyl (meth)acrylate, such as ethoxyethyl (meth)acrylate, mono-, di-, trialkyl esters of ethylenically unsaturated di- and tricarboxylic acids and anhydrides, such as ethyl maleate, dimethyl fumarate, trimethyl aconitate, and ethyl methyl itaconate. The ethylenically unsaturated monomer may also include at least one multiethylenically unsaturated monomer, e.g, to raise a molecular weight and/or crosslink a two-phase polymer particle. Examples of multiethylenically unsaturated monomers that may be used include, but are not limited to, allyl (meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, 1 ,6-hexanediol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, polyalkylene glycol di(meth)acrylate, diallyl phthalate, trimethylolpropane tri(meth)acrylate,

divinylbenzene, divinyltoluene, trivinylbenzene, and divinyl naphthalene.

[015] Other useful types of polymerizable monomers include functional monomers, which may be included as polymerized units in the adsorbing polymer latex particles. For example, adhesion-promoting polymerizable monomers can also be included. Examples of other types of functional monomers include hydroxy- functional monomers such as, 2 -hydroxy ethyl (meth)acrylate, amino-functional monomers, such as glycidyl (meth)acrylate, (meth)acrylamide, substituted

(meth)acrylamide such as diacetone (meth)acrylamide, acetoacetoxyethyl

(meth)acrylate, acrolein, methacrolein, dicyclopentadienyl (meth)acrylate, dimethyl metaisopropenyl benzyl isocyanate, isocyanato ethyl methacrylate, N-vinyl pyrrolidone, N,N'-dimethylamino(meth)acrylate, and polymerizable surfactants, including, but not limited to, Trem LF-40 (Henkel Corporation). Methyl cellulose and hydroxyethyl cellulose may be included in the polymerization mixture.

[016] The adsorbing polymer latex particles may adsorb to an inorganic pigment particle, by attractive interactions, such as by covalent bonding, ionic bonding, attraction between opposite charges on the adsorbing polymer latex particles and the inorganic pigment particle, steric forces, or van der Waals's forces. The attachment of the adsorbing polymer latex particles to the inorganic pigment particle can be strong enough to form composite particles, which are colloidal stable in aqueous medium and wherein the adsorbing polymer latex particles do not desorb from the inorganic pigment particle in the presence of other components and in different conditions, such as components and conditions encountered in the manufacture, storage, and use of water-borne coatings.

[017] Adsorbing polymer latex particles can include chemical groups which provide adsorption to the inorganic pigment particle. For example, adsorbing polymer particles with phosphorus containing groups can absorb to titanium dioxide particles and may be prepared by polymerization of a mixture of ethylenically unsaturated monomers including phosphorus functional monomers.

[018] Suitable phosphorus acid monomers include dihydrogen phosphate- functional monomers such as dihydrogen phosphate esters of an alcohol in which the alcohol also contains a polymerizable vinyl or olefinic group, such as allyl phosphate, mono- or diphosphate of bis(hydroxy-methyl) fumarate or itaconate, derivatives of (meth)acrylic acid esters, such as, for examples phosphates of

hydroxyalkyl(meth)acrylates including 2 -hydroxy ethyl (meth)acrylate, 3- hydroxypropyl (meth)acrylates, and the like. Other suitable phosphorous acid monomers include CH₂=C(R)— C(O)— O— (R¹0)_n-P(0)(OH)₂, where R is H or CH₃ and R¹ is alkyl, such as SIPOMER™ PAM-100, SIPOMER™ PAM-200,

SIPOMER™ PAM-300, and SIPOMER™ PAM-4000, available from Rhodia, Inc., among others. Other suitable phosphorus acid monomers are phosphonate functional monomers. For example, a number of phosphonate functional monomers are discussed in publication WO 99/25780 Al . Phosphonate functional monomers include vinyl phosphonic acid, allyl phosphonic acid, 2-acrylamido-2- methylpropanephosphonic acid, a-phosphonostyrene, 2-methylacrylamido-2- methylpropanephosphonic acid. Further, suitable phosphorus functional monomers are Harcross T-Mulz 1228 and 1,2-ethylenically unsaturated

(hydroxy )phosphinylalkyl (meth)acrylate monomers, such as discussed in publicaiton U.S. Pat. No. 4,733,005, and include (hydroxy )phosphinylmethyl methacrylate. One or more embodiments of the present disclosure provide that phosphorus acid monomers are dihydrogen phosphate monomers, which include 2-phosphoethyl (meth)acrylate, 2-phosphopropyl (meth)acrylate, 3-phosphopropyl (meth)acrylate, and 3-phospho-2-hydroxypropyl (meth)acrylate. One or more embodiments of the present disclosure provide that phosphorus acid monomers are 2-phosphoethyl

(meth)acrylate, 2-phosphopropyl (meth)acrylate, 3-phosphopropyl (meth)acrylate, 3- phospho-2-hydroxypropyl (meth)acrylate, SIPOMER™ PAM-100, and SIPOMER™ PAM-200, or a combination thereof. [019] The adsorbing polymer latex particles may contain phosphorus functional monomers at in the range of 0.1 to 10 weight %, for example, from 0.5 to 5 weight %, from 1 to 3 weight %, or from 0.75 to 2.75 weight %, based on a weight of adsorbing polymer latex particles, as a chemical group which provides adsorption to the inorganic pigment particle.

[020] The adsorbing polymer latex particles may contain an oligomeric macromer of acid containing monomers. Some examples oligomeric macromers of acid containing monomers are described in publication U.S. Patent 6,214,467. The oligomeric macromers of acid containing monomers may provide adsorption properties to the inorganic pigment particles.

[021] In some embodiments of the present disclosure, the adsorbing polymer latex particles can include, e.g., as copolymerized units, from 0.01 % to 0.6 %, for example, from 0.1 % to 0.5 % by weight, based on a weight of an emulsion polymer, a second acid-containing monomer, or salts thereof. In some embodiments of the present disclosure, the second acid-containing monomer excludes phosphorous acid monomers and salts thereof, but includes both sulfur acid monomers and carboxylic acid monomers, and salts thereof. Second acid-containing monomers include (meth)acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and mono- ester derivatives of diacids, such as monomethyl itaconate, monomethyl fumarate, and monobutyl fumarate, among others. Also, maleic anhydride may be utilized for similar functionality. Examples of second acid-containing monomers containing sulfur acid groups include 2-acrylamido-2-methyl-l-propanesulfonic acid, sulfoethyl (meth)acrylate, and vinyl sulfonic acid and sodium styrene sulfonate.

[022] As mentioned, the adsorbing polymeric latex particles can be formed by reacting a composition of monomers. Embodiments of the present disclosure provide that the adsorbing polymeric latex particles are multistage latex

polymers. These adsorbing polymeric latex particles are formed by a multistage process. For example, the adsorbing polymeric latex particles can be formed by contacting, under emulsion polymerization conditions, a first portion of an acrylic monomer with a first portion of a phosphorus acid monomer to form a first stage polymer; and then contacting the first stage polymer with a second portion of an acrylic monomer and optionally a second portion of a phosphorus acid monomer under emulsion polymerization conditions to form adsorbing polymeric latex particles. Some embodiments of the present disclosure provide that an amount of the first portion of the phosphorus acid monomer is from 2 to 12 weight percent of the weight of the first stage polymer, and the first portion of the acrylic monomer is from 5 to 50 weight percent of the first and second portions of acrylic monomer. A first portion of a phosphorus acid or acrylic monomer refers to one or more of the specified monomers used in to make a first stage polymer. The acrylic and phosphorus acid monomers used in the first stage may be the same as or different from the acrylic and phosphorus acid monomers used to make the adsorbing polymeric latex particles. The first and second stage polymer can be formed in any order.

[023] Polymerization techniques, such as a multistage polymerization process, for preparing aqueous dispersions of the adsorbing polymeric latex particles from monomers can include one or more additional components including, but not limited to, polymerization initiators, catalysts, chain transfer agents, redox pairs, and surfactants, among others. The one or more additional components that can be utilized in the polymerization techniques are known to those skilled in the art.

Differing amounts of the one or more additional components may be utilized for various applications.

[024] The adsorbing polymeric latex particles can have a number average molecular weight in a range from 40000 to 10000000 Daltons, e.g., as measured by gel permeation chromatography. All individual values and subranges from and including 40000 to 10000000 Daltons are included; for example, the number average molecular weight can be from a lower limit of 40000, 500000 or 1000000 Daltons to an upper limit of 10000000, 9000000 or 8000000 Daltons.

[025] Examples of adsorbing polymeric latex particles useful for the present disclosure include, but are not limited to, multistage polymeric latex particles described in U. S. Patent 7, 179,531, publication WO 2012,016402, U.S. Publication 2012/0058277, among other publications.

[026] As mentioned, each respective inorganic pigment core can have a number of adsorbing polymeric latex particles adsorbed thereto. The composite particles, each having a respective inorganic pigment core with a number of adsorbing polymeric latex particles adsorbed thereto, can be formed by combining, e.g., admixing, the inorganic pigment and the adsorbing polymeric latex particles. For instance, inorganic pigment particles can be mixed with an aqueous dispersion of adsorbing polymeric latex particles, where each adsorbing polymeric latex particle has a greater negative surface potential than the inorganic pigment particles. The mixture of inorganic pigment particles and the adsorbing polymeric latex particles can be admixed, e.g., subjected to shear forces in a disperser, such that the adsorbing polymeric latex particles adsorb to the surfaces of the inorganic pigment particles to form discrete composite particles, e.g., without grit formation. Also, the composite particles can be formed by a number of processes known in the art. For example, some processes by which the composite particles can be formed are described in U.S. Patent 6,080,802 and U.S. Publication 2012/0058278.

[027] The inorganic pigment particles have a characteristic saturation, e.g., maximum, level for adsorption of the adsorbing polymeric latex particles. This adsorption saturation level can be determined empirically and may depend on a number of factors including geometric factors relating to the relative sizes and shapes of the inorganic pigment particles and adsorbing polymeric latex particles.

Preferably, the amount of adsorbing polymeric latex particles employed to form the composite particles is at least great enough to provide composite particles having adsorbing polymeric latex particles at this saturation level. However, some embodiments of the present disclosure provide the amount of adsorbing polymeric latex particles employed to form the composite particles will result in a number of the composite particles having adsorbing polymeric latex particles below the saturation level, for example as described in publication WO 2013159098. An amount of adsorbing latex utilized to reach the saturation level can be determined, for example, via a method described in the Experiment Methods section of U.S. Publication 2012/0058278.

[028] Embodiments of the present disclosure provide that the aqueous epoxy composite dispersions include an epoxy resin. The epoxy resin can be liquid, solid, semi-solid, or combinations thereof. The epoxy resin can be an aromatic epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, or a combination thereof.

[029] Examples of aromatic epoxy resins include, but are not limited to, divinylarene dioxide, glycidyl ether compounds of polyphenols, such as

hydroquinone, resorcinol, bisphenol A, bisphenol F, 4,4'-dihydroxybiphenyl, phenol novolac, cresol novolac, trisphenol (tris-(4-hydroxyphenyl)methane), l, l,2,2-tetra(4- hydroxyphenyl)ethane, tetrabromobisphenol A, 2,2-bis(4-hydroxyphenyl)-l, 1, 1, 3,3,3- hexafluoropropane, and 1,6-dihydroxynaphthalene. [030] Examples of alicyclic epoxy resins include, but are not limited to, polyglycidyl ethers of polyols having at least one alicyclic ring, or compounds including cyclohexene oxide or cyclopentene oxide obtained by epoxidizing compounds including a cyclohexene ring or cyclopentene ring with an oxidizer. Some particular examples include, but are not limited to, hydrogenated bisphenol A diglycidyl ether; 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexyl carboxylate; 3,4- epoxy-l-methylcyclohexyl-3,4-epoxy-l-methylhexane carboxylate; 6-methyl-3,4- epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexane carboxylate; 3,4-epoxy-3- methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexane carboxylate; 3,4-epoxy-5- methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexane carboxylate; bis(3,4- epoxycyclohexylmethyl)adipate; methylene-bis(3,4-epoxycyclohexane); 2,2-bis(3,4- epoxycyclohexyl)propane; dicyclopentadiene di epoxide; ethylene-bis(3,4- epoxycyclohexane carboxylate); dioctyl epoxyhexahydrophthalate; and di-2- ethylhexyl epoxyhexahydrophthalate.

[031] Examples of aliphatic epoxy resins include, but are not limited to, polyglycidyl ethers of aliphatic polyols or alkylene-oxide adducts thereof, polyglycidyl esters of aliphatic long-chain polybasic acids, homopolymers synthesized by vinyl-polymerizing glycidyl acrylate or glycidyl methacrylate, and copolymers synthesized by vinyl-polymerizing glycidyl acrylate or glycidyl methacrylate and other vinyl monomers. Some particular examples include, but are not limited to glycidyl ethers of polyols, such as 1 ,4-butanediol diglycidyl ether; 1,6- hexanediol diglycidyl ether; a triglycidyl ether of glycerin; a triglycidyl ether of trimethylol propane; a tetraglycidyl ether of sorbitol; a hexaglycidyl ether of dipentaerythritol; a diglycidyl ether of polyethylene glycol; and a diglycidyl ether of polypropylene glycol; polyglycidyl ethers of poly ether polyols obtained by adding one type, or two or more types, of alkylene oxide to aliphatic polyols such as propylene glycol, trimethylol propane, and glycerin; and diglycidyl esters of aliphatic long-chain dibasic acids.

[032] Embodiments of the present disclosure provide that the epoxy resin can be 10 to 60 weight percent of the aqueous epoxy composite dispersion based on a total weight of the aqueous epoxy composite dispersion. All individual values and subranges from and including 10 to 60 weight percent of aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion are included herein and disclosed herein; for example, the epoxy resin can be from a lower limit of 10 weight percent, 15 weight percent, or 20 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion to an upper limit of 60 weight percent, 50 weight percent, or 40 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion. Specific examples include the epoxy resin can be 15 to 50 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion or the epoxy resin can be 20 to 40 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion.

[033] Some embodiments of the present disclosure provide that the epoxy resins used to prepare the aqueous epoxy composite dispersions can be predispersed into aqueous epoxy dispersions. Aqueous epoxy dispersions can be formed by various processes recognized by those having skill in the art. For example, contents of the aqueous epoxy dispersion may be mixed by subjecting the contents to a sufficient amount of shear to form the aqueous epoxy dispersions. For instance, contents of the aqueous epoxy dispersions may be mixed at a temperature in a range from 10 °C to 150 °C via a shear providing mixer to form the aqueous epoxy dispersions. Processes by which aqueous epoxy dispersions disclosed herein can be formed are described, for example, in U.S. Patents 3,360,599; 3,503,917; 4,018,426; 4,123,403; 5,037,864; 5,250,576, and 5,539,021, among others. Some embodiments of the present disclosure provide that the aqueous epoxy dispersions can be formed via a BLUEWAVE™ process.

[034] Embodiments of the present disclosure provide that the aqueous epoxy composite dispersions include water. The water can be 10 to 60 weight percent of the aqueous epoxy composite dispersion based on a total weight of the aqueous epoxy composite dispersion. All individual values and subranges from and including 10 to 60 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion are included herein and disclosed herein; for example, water can be from a lower limit of 10 weight percent, 15 weight percent, or 20 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion to an upper limit of 60 weight percent, 50 weight percent, or 40 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion. Specific examples include the water can be 15 to 50 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion or the water can be 20 to 40 weight percent of aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion. The water can be incorporated into the aqueous epoxy composite dispersions from one or more sources. For example, the water can be incorporated into the aqueous epoxy composite dispersions via a composition, e.g. an aqueous dispersion including the plurality of composite particles and/or an aqueous dispersion including the epoxy resin. The water may be added to the aqueous epoxy composite dispersion as a separate component, among others.

[035] Embodiments of the present disclosure provide that the aqueous epoxy composite dispersions can include a solvent. Examples of the solvent include, but are not limited to butyrolactone, N-methyl pyrrolidone, alcohols, including glycols, glycol ethers, such as methoxypropanol, ethoxyethanol, phenoxyethanol and the like, and combinations thereof. The solvent, when utilized, can be 1 to 20 weight percent of the aqueous epoxy composite dispersion based on a total weight of the aqueous epoxy composite dispersion. All individual values and subranges from and including 1 to 20 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion are included herein and disclosed herein; for example, solvent can be from a lower limit of 1 weight percent, 2 weight percent, or 5 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion to an upper limit of 20 weight percent, 17.5 weight percent, or 15 weight percent of the aqueous epoxy composite dispersion based on the total weight of aqueous epoxy composite dispersion.

Specific examples include the solvent can be 2 to 17.5 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion or the solvent can be 5 to 15 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion.

[036] Embodiments of the present disclosure provide that the aqueous epoxy composite dispersions can include a polymeric latex binder, e.g., an acrylic latex binder. The polymeric latex binder is an emulsion of a polymer in water. The polymeric latex binder may facilitate adhesion of a cured coating formed from the aqueous epoxy composite dispersion to a substrate. Commercially available examples of the polymeric latex binder include, but are not limited to, Rhoplex™ MV-23, AVANSE™ MV-100, Rhoplex™ HG-706, Rhoplex™ HG-56 and Rhoplex™ AC261LF available from The Dow Chemical Company and PLIOTEC® PA90, available from OMNOVA Solutions, among others. The polymeric latex binder can be formed with a number of the monomers discussed herein via a single stage polymerization process, for example. Single stage polymerization processes are known by those skilled in the art.

[037] The polymeric latex binder, when utilized, can be 1 to 60 weight percent of the aqueous epoxy composite dispersion based on a total weight of the aqueous epoxy composite dispersion. All individual values and subranges from and including 1 to 60 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion are included herein and disclosed herein; for example, the polymeric latex binder can be from a lower limit of 1 weight percent, 2.5 weight percent, 5 weight percent, or 10 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion to an upper limit of 60 weight percent, 55 weight percent, 50 weight percent, or 45 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion. Specific examples include the polymeric latex binder can be 2.5 to 55 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion, the polymeric latex binder can be 5 to 50 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion, or the polymeric latex binder can be 10 to 45 weight percent of the aqueous epoxy composite dispersion based on the total weight of the aqueous epoxy composite dispersion.

[038] Embodiments of the present disclosure provide that the aqueous epoxy composite dispersions disclosed herein can have pigment volume concentration (PVC) in a range from 5 percent to 55 percent. All individual values and subranges from and including 5 to 55 weight percent are included; for example, the aqueous epoxy composite dispersions disclosed herein can have a PVC with a lower limit of 5 percent, 7 percent or 9 percent to an upper limit of 55 percent, 50 percent or 45 percent. Some specific examples include the aqueous epoxy composite dispersions disclosed herein can have a PVC in a range from 7 to 50 percent or from 9 to 45 percent. [039] PVC of the aqueous epoxy composite dispersion can be defined as a ratio, expressed as a percentage, of a volume of inorganic pigment to a volume of nonvolatile material in the aqueous epoxy composite dispersion. For example, PVC can be calculated as a product of one-hundred percent and a quotient of a volume of inorganic pigment divided by a sum of the volume of inorganic pigment plus a volume of adsorbing polymeric latex particles adsorbed to inorganic pigment plus a volume of epoxy resin plus a volume of polymeric latex binder. PVC of the aqueous epoxy composite dispersion can be expressed by the following formula:

PVC = -100%

B

[040] where A is a volume of inorganic pigment, and B is the volume of inorganic pigment + a volume of adsorbing polymeric latex particles adsorbed to the inorganic pigment + a volume of epoxy resin + a volume of polymeric latex binder.

[041] The aqueous epoxy composite dispersions can be formed by various processes recognized by those having skill in the art. For example, contents of the aqueous epoxy composite dispersion may be mixed by subjecting the contents to a sufficient amount of shear to form the aqueous epoxy composite dispersions. For instance, contents of the aqueous epoxy composite dispersions may be mixed at a temperature in a range from 10 °C to 150 °C via a shear providing mixer to form the aqueous epoxy composite dispersions. Processes by which aqueous epoxy composite dispersions disclosed herein can be formed are described, for example, in U.S. Patents 3,360,599; 3,503,917; 4,018,426; 4, 123,403; 5,037,864; 5,250,576, and 5,539,021, among others. Some embodiments of the present disclosure provide that the aqueous epoxy composite dispersions can be formed via a BLUEWAVE™ process.

[042] The aqueous epoxy composite dispersions disclosed herein can be utilized in coatings. For example, the aqueous epoxy composite dispersion can be mixed with a curing agent, e.g. a hardener, to form a curable composition, e.g., a curable aqueous epoxy composite dispersion. The curable composition can be applied to a substrate to form a coating.

[043] Embodiments of the present disclosure provide curable compositions that include the aqueous epoxy composite dispersions disclosed herein and a hardener. The hardener can be a carboxylic acid, a thiol, an amine, a phenolic, or a combination thereof. [044] Examples of carboxylic acids include polyfunctional acids such as dodecanedioic acid; phthalic acid; hexahydrophthalic acid; trimellitic acid;

copolymers synthesized by vinyl-polymerizing acrylic acid or methacrylic acid and other vinyl monomers.

[045] Examples of amines include, but are not limited to, ethylenediamine; diethylenetriamine; triethylenetetramine; trimethyl hexane diamine;

hexamethylenediamine; N-(2-aminoethyl)- 1 ,3 -propanediamine; Ν,Ν'- 1,2- ethanediylbis-l,3-propanediamine; dipropylenetriamine; m-xylylenediamine; p- xylylenediamine; 1,3-bisaminocyclohexylamine; isophorone diamine; 4,4'- methylenebiscyclohexaneamine; m-phenylenediamine; diaminodiphenylmethane; diaminodiphenylsulfone; N-aminoethylpiperazine; 3,9-bis(3-aminopropyl) 2,4,8,10- tetraoxaspiro(5,5)undecane; 4,7-dioxadecane-l, 10-diamine; 1-propanamine; (2, 1- ethanediyloxy)-bis-(diaminopropylated diethylene glycol) (ANCAMINE® 1922A); poly(oxy(methyl- 1 ,2-ethanediyl)), alpha-(2-aminomethylethyl)omega-(2- aminomethylethoxy) (JEFFAMINE® D-230, D-400); triethyleneglycoldiamine; and oligomers (JEFFAMINE® XTJ-504, JEFFAMINE® XTJ-512); poly(oxy(methyl-l,2- ethanediyl)), alpha,alpha'-(oxydi-2, 1 -etha nediyl)bis(omega-(aminomethylethoxy)) (JEFFAMINE® XTJ-51 1); bis(3-aminopropyl)polytetrahydrofuran 350; bis(3- aminopropyl)polytetrahydrofuran 750; poly(oxy(methyl-l,2-ethanediyl)); a-hydro-τσ- (2-aminomethylethoxy) ether with 2-ethyl-2-(hydroxymethyl)-l,3-propanediol (JEFFAMINE® T-403); diaminopropyl dipropylene glycol polyether adducts thereof; epoxy adducts thereof; amides thereof; polyamides thereof; Mannich bases thereof; and phenalkamines thereof; and combinations thereof

[046] Examples of phenolics include, but are not limited to bisphenols, novolacs, and resoles that can be derived from phenol and/or a phenol derivative, and combinations thereof.

[047] The hardener may be employed in an epoxy equivalent weight to amine hydrogen equivalent weight ratio of 1.0: 1.2 to 1.2: 1.0. For example, the hardener may be employed in an epoxy equivalent weight to amine hydrogen equivalent weight ratio of 1.0: 1.15, 1.0: 1.0, or 1.15: 1.0. Epoxy equivalent weight (EEW) may be calculated as the mass in grams of epoxy resin containing one mole of epoxide groups. Amine hydrogen equivalent weight (AHEW) may be calculated as mass in grams of hardener containing one mole of amine hydrogen atoms that are capable of opening an epoxy ring.

[048] Embodiments of the present disclosure provide that the curable composition can include one or more additives. Examples of the additive include, but are not limited to, extender and anti-corrosive pigments, surfactants, antifoam agents, mar and slip reagents, corrosion inhibitors, elastomers, stabilizers, extenders, plasticizers, antioxidants, leveling or thickening agents, co-solvents, wetting agents, co-surfactants, reactive diluents, fillers, catalysts, and combinations thereof, among others. Different amounts of the one or more additives can be utilized for various applications, as is recognized by those skilled in the art.

[049] As mentioned, the curable compositions can be applied to a substrate to form a coated article and be cured, e.g. crosslinked, to provide a cured coating on the substrate. Examples of the substrate include, but are not limited to concrete, composites, metals and metal alloys, such as aluminum, steel, iron, and plastics, among others.

[050] The curable compositions may be applied to the substrate by various methods; for example, via roller coating, spray coating, dip coating, wash coating, flow coating, draw down coating, and/or curtain coating, among others. The coating, e.g., the curable composition applied to the substrate, may have a thickness in the range of 0.01 millimeter (mm) to 2 centimeters (cm). All individual values and subranges from 0.01 mm to 2 cm are included herein and disclosed herein; for example, the coating may have a thickness from a lower limit of 0.01 mm, 0.05 mm, or 0.5 mm, to an upper limit of 2 cm, 1.5 cm, or 1cm. For example, the coating may have a thickness in the range of 0.01 mm to 2 cm; 0.05 mm to 1.5 cm; or, 0.5 mm to 1 cm.

[051] The curable composition, e.g. that is applied to the substrate, may be cured, e.g., to form a cured coating on the substrate. The curable composition may be cured at different temperatures and for different periods of time for various applications. For example, the curable composition may be cured at a temperature in a range of 10 °C to 375 °C for a period in a range from 5 minutes to 72 hours. The cured coating formed from the curable composition may have a thickness in the range of 0.01 millimeter (mm) to 2 centimeters (cm). All individual values and subranges from 0.01 mm to 2 cm are included herein and disclosed herein; for example, the cured coating may have a thickness from a lower limit of 0.01 mm, 0.05 mm, or 0.5 mm, to an upper limit of 2 cm, 1.5 cm, or 1cm. For example, the cured coating may have a thickness in the range of 0.01 mm to 2 cm; 0.05 mm to 1.5 cm; or, 0.5 mm to 1 cm.

[052] Embodiments of the present disclosure provide that the curable compositions and/or cured coatings disclosed herein can have PVC in a range from 5 percent to 55 percent. All individual values and subranges from and including 5 to 55 weight percent are included; for example, the curable compositions and/or cured coatings disclosed herein can have a PVC with a lower limit of 5 percent, 7 percent or 9 percent to an upper limit of 55 percent, 50 percent or 45 percent. Some specific examples include the curable compositions and/or cured coatings disclosed herein can have a PVC in a range from 7 to 50 percent or from 9 to 45 percent. PVC for the curable compositions and/or cured coatings can be expressed by the following formula:

PVC =—100%

D

[053] where C is a volume of inorganic pigment, and D is the volume of inorganic pigment + a volume of adsorbing polymeric latex particles adsorbed to the inorganic pigment + a volume of epoxy resin + a volume of hardener + a volume of polymeric latex binder + volume of additive. When determining PVC for a cured coating as disclosed herein, e.g., where the epoxy resin has reacted with the hardener to form a crosslinked material, D is a sum of components included in the crosslinked material, e.g., the volume of inorganic pigment + a volume of adsorbing polymeric latex particles adsorbed to the inorganic pigment + a volume of crosslinked material formed from the epoxy resin and the hardener + a volume of polymeric latex binder + a volume of additive.

[054] As mentioned, advantageously the cured coatings formed from the curable compositions that include the aqueous epoxy composite dispersions disclosed herein have a greater scattering coefficient, which corresponds to improved hiding, relative to cured coating formed from compositions lacking composite particles for similar PVC values. These greater scattering coefficients indicate that cured coatings formed from aqueous epoxy composite dispersions including composite particles, as disclosed herein, provide improved pigment distribution as compared to cured coatings formed from compositions lacking the composite particles. EXAMPLES

[055] In the Examples, various terms and designations for materials were used including, for example, the following:

[056] Inorganic pigment (titanium dioxide, Ti-Pure® R-746, available from

DuPont™); epoxy resin (bisphenol A epoxy resin, BECKOPOX™ VEP 2381, available from Cytec); thickening agent (ACRYSOL™ RM-825, available from the Dow Chemical Company); corrosion inhibitor (FLASH-X® 150, available from Halox); hardener (amine, ANQU AMINE® 401, available from Air Products); solvent (glycol ether, butyl CELLOSOLVE™, available from the Dow Chemical Company), DISPONIL® FES 993 (surfactant, available from BASF).

[057] Adsorbing polymeric latex particles

[058] Adsorbing polymeric latex particles were prepared via a multistage emulsion polymerization process as follows. A stage 1 monomer emulsion was prepared by mixing deionized water (200 grams (g)), DISPONIL® FES 993

Surfactant (24.3 g, 30% active), butyl acrylate (292.0 g), methyl methacrylate (186.2 g), methacrylic acid (4.17 g), and phosphoethyl methacrylate (39.11 g, 65% active). A stage 2 monomer emulsion was prepared by mixing deionized water (409.6 g), DISPONIL® FES 993 Surfactant (40.5 g, 30% active), butyl acrylate (681.3 g), methyl methacrylate (516.9 g), ureido methacrylate (17.4 g), and methacrylic acid (9.7 g). A 5-liter reactor, four-necked round bottom flask equipped with a paddle stirrer, a thermocouple, nitrogen inlet, and reflux condenser was assembled. To the flask was added deionized water (926.0 g) and 4.63 g of DISPONIL® FES 993 Surfactant (4.63 g, 30% active) and stirring was initiated. The contents of the flask were heated to 88 °C under a nitrogen atmosphere. A portion of the stage 1 monomer emulsion (1 10.1 g) was added to the kettle followed by a deionized water (25 g) rinse. The contents were stirred for 1 minute then a solution of sodium persulfate (3.55 g in deionized water (44 g) was added. After another 2 minutes monomer emulsion 1 was added to the flask over 40 minutes. Concurrently, a solution of sodum persulfate (1.58 g in deionized water (1 18 g)) was fed separately to the flask at a rate of 1.09 g/min. After completion of monomer emulsion 1 feed, monomer emulsion 2 was added over 70 minutes. The contents of the flask were maintained at 84 to 86 °C during the additions. The contents of the flask were rinsed with deionized water (50 g) and then cooled to 65 °C and partially neutralized with a solution of 15 g (28% cone.) aqueous ammonia (15 g, 28% concentration, in deionized water (22 g)) then a redox pair was added. Then the contents of the flask were cooled to room temperature; while cooling and at <50 °C, an aqueous solution of potassium hydroxide (196 g, 6.5 %) was added. The measured particle size of the adsorbing polymeric latex particles was 98 nm and solids were 45.1% with a pH of 7.9.

[059] Polymeric latex binder

[060] A polymeric latex binder was prepared via a single-stage emulsion polymerization process as follows. A monomer emulsion was prepared by mixing deionized water (525 g), DISPONIL® FES 993 Surfactant (64.8 g, 30% active), butyl acrylate (974.4 g), methyl methacrylate (703.9 g), methacrylic acid (13.89 g), phosphoethyl methacrylate (39.10 g, 65% active), and ureido methacrylate (17.4 g). A 5 -liter reactor, four-necked round bottom flask equipped with a paddle stirrer, a thermocouple, nitrogen inlet, and reflux condenser was assembled. To the flask was added deionized water (926.0 g) and 4.63 g of DISPONIL® FES 993 Surfactant (4.63 g, 30% active) and stirring was initiated. The contents of the flask were heated to 88 °C under a nitrogen atmosphere. A portion of the monomer emulsion (1 10.1 g) was added to the kettle followed by a deionized water (25 g) rinse. The contents were stirred for 1 minute then a solution of sodium persulfate (3.55 g in deionized water (44 g) was added). After another 2 minutes the remaining monomer emulsion and a solution of sodium persulfate (1.58 g in deionized water (1 18 g)) were separately fed to the flask over 1 10 minutes; the contents of the flask were maintained at 84 to 86 °C during the additions. The contents of the flask were rinsed with deionized water (50 g) and then cooled to 65 °C and partially neutralized with a solution of 15 g (28% cone.) aqueous ammonia (15 g, 28% concentration, in deionized water (22 g)) then a redox pair was added. Then the contents of the flask were cooled to room temperature; while cooling and at <50 °C, an aqueous solution of potassium hydroxide (196 g, 6.5 %) was added. The measured particle size of the polymeric latex binder was 101 nm and solids were 46.3% with a pH of 7.9.

[061] Aqueous epoxy resin mixture

[062] An aqueous epoxy resin mixture was prepared as follows.

BECKOPOX™ VEP 2381 (89.702 weight percent of the epoxy resin mixture), ACRYSOL™ RM-825 (2.225 weight percent of the epoxy resin mixture), FLASH- X® 150 (0.179 weight percent of the epoxy resin mixture), and water (7.894 weight percent of the epoxy resin mixture) were added to a container. The contents of the container were admixed to form the aqueous epoxy resin mixture. [063] Polymeric latex binder mixture

[064] A polymeric latex binder mixture was prepared as follows. Polymeric latex binder (98.887 weight percent of the polymeric latex binder mixture),

ACRYSOL™ RM-825 (0.143 weight percent of the polymeric latex binder mixture), FLASH-X® 150 (0.198 weight percent of the polymeric latex binder mixture), and water (0.772 weight percent of the polymeric latex binder mixture) were added to a container. The contents of the container were admixed to form the polymeric latex binder mixture.

[065] Example 1- Aqueous epoxy composite dispersion

[066] An aqueous epoxy composite dispersion, Example 1, was prepared as follows. Composite particles were prepared as follows. Adsorbing polymeric latex particles (9502 milligrams (mg)) and Ti-Pure® R-746 (9731 mg) were added to a container. The contents of the container were admixed to form composite particles, each having a respective inorganic pigment core having a number of polymeric latex particles adsorbed thereto. A portion of the aqueous epoxy resin mixture (7799 mg), was admixed with the contents of the container to form Example 1, which had a PVC of 20.85.

[067] Examples 2-5- Aqueous epoxy composite dispersions

[068] Aqueous epoxy composite dispersions, Examples 2-5, were formed as

Example 1 by utilizing different amounts of adsorbing polymeric latex particles, Ti- Pure® R-746, and the aqueous epoxy resin mixture, which are reported in Table 1. Additionally, the PVC for each of Examples 2-5 is reported in Table 1.

Table 1

[069] Example 6- Aqueous epoxy composite dispersion [070] An aqueous epoxy composite dispersion, Example 6, was prepared as follows. Composite particles were prepared as follows. Adsorbing polymeric latex particles (9671 mg) and Ti-Pure® R-746 (9715 mg) were added to a container. The contents of the container were admixed to form composite particles, each having a respective inorganic pigment core having a number of polymeric latex particles adsorbed thereto. A portion of the aqueous epoxy resin mixture (6354 mg) and polymeric latex binder mixture (1983 mg) were admixed with the contents of the container to form Example 6, which had a PVC of 20.00.

[071] Examples 7-12- Aqueous epoxy composite dispersions

[072] Aqueous epoxy composite dispersions, Examples 7-12, were formed as

Example 6 by utilizing different amounts of adsorbing polymeric latex particles, Ti- Pure® R-746, the aqueous epoxy resin mixture, and the polymeric latex binder mixture which are reported in Table 2. Additionally, the PVC for each of Examples 7-12 is reported in Table 2.

Table 2

[073] Example 13- Curable aqueous epoxy composite dispersion

[074] A curable aqueous epoxy composite dispersion, Example 13, was prepared as follows. Example 1, ANQUAMTNE® 401 (2124 mg), butyl

CELLOSOLVE™ (1377 mg), and water (1790 mg) were added to a container. The contents of the container were admixed at 20 °C with a FlakTec™ dual axis mixer via a mixing program of 15 seconds at 1500 rotations per minute followed by 30 seconds at 2000 rotations per minute with an acceleration of 1500 and a deceleration of 1000 to prepare Example 13, which had a PVC of 18.20.

[075] Examples 14-24- Curable aqueous epoxy composite dispersions

[076] Curable aqueous epoxy composite dispersions, Examples 14-24, were prepared as Example 13 with Examples 2-12 respectively replacing Example 1 and by utilizing different amounts of ANQUAMINE® 401, butyl CELLOSOLVE, and water, which are reported in Table 3. Additionally, the PVC for each of Examples 14-24 is reported in Table 3.

Table 3

[077] Comparative Example A

[078] A curable composition lacking composite particles, Comparative

Example A, was prepared as follows. A portion of the aqueous epoxy resin mixture (14099 mg), Ti-Pure® R-746 (9771 mg), ANQUAMINE® 401 (3542 mg), butyl CELLOSOLVE™ (1387 mg), and water (3034 mg) were added to a container. The contents of the container were admixed with a FlakTec™ dual axis mixer via a mixing program of 15 seconds at 1500 rotations per minute followed by 30 seconds at 2000 rotations per minute with an acceleration of 1500 and a deceleration of 1000 to prepare Comparative Example A, which had a PVC of 18.71.

[079] Comparative Example B-K

[080] Compositions lacking composite particles, Comparative Examples B-

K, were formed as Comparative Example A by utilizing different amounts of the aqueous epoxy resin mixture, Ti-Pure® R-746, ANQUAMINE® 401, butyl

CELLOSOLVE™, and water, which are reported in Table 4. Additionally, different amounts of the polymeric latex binder mixture, which are reported in Table 4, were added to the contents of the respective containers for Comparative Examples E-K prior to mixing. Additionally, the PVC for each of Comparative Examples B-K is reported in Table 4.

Table 4

Scattering Coefficients [082] Scattering coefficients for Examples 25-36, cured coatings formed from each of Examples 13-24 and Comparative Examples L-V, cured coatings formed from each of Comparative Examples A-K were determined as follows. Each of Examples 13-24 and Comparative Examples A-K was applied to a respective 5.08 centimeter by 10.16 centimeter portion of a Leneta Release Chart Form RC-B-1 (Leneta Release Chart Form RC-B-1 is equivalent to Leneta Release Chart Form RC- 5C except for size) via a doctor blade having a 0.0254 millimeter gap to form respective coatings. The respective coatings were cured in a room controlled to 50 percent relative humidity and 70 °C for 24 hours to form respective cured coatings.

[083] Y-reflectance was measured at four locations of a line along the center of each respective 5.08 centimeter by 10.16 centimeter portion using a colorimeter having an Ocean Optics ISP-REF Integrating Sphere with a 0.4 inch sampling aperture connected to an Ocean Optics USB 4000 Spectrometer via a fiber optic cable. The Y-reflectance measurements were performed with D65/10⁰ illumination and observer.

[084] Thickness of the respective cured coatings was measured using the coat weight of a respective center portion (2.54 centimeter by 5.08 centimeter) of each respective 5.08 centimeter by 10.16 centimeter portion. The respective center portions were cut with a die and clicker press, and then the respective center portions were weighed. Thereafter, the cured coatings were removed from each of the respective center portions and the substrate was weighed. Respective coat weights were determined by the difference of weights. Respective thicknesses were determined using a volume averaged density of solids in the coatings and the area of coating. Hiding was calculated with the Kubelka-Munk Equation:

where S is the scattering coefficient, X is thickness in mils (1 mil = 0.001 inch), R is Y-reflectance/ 100 at infinite thickness (herein estimated equal to 0.94), and RB is the Y-reflectance/ 100 of the coating created from the 0.0254 millimeter gap drawdown. Scattering coefficient per unit thickness for Examples 25-36 are reported in Table 5. Scattering coefficient per unit thickness for Comparative Examples L-V are reported in Table 6.

Table 5 Example S/mil Pigment

# (Scattering coefficient per Volume Concentration unit thickness)

Example 25

(Cured Coating formed from 5.49 18.20

Example 13)

Example 26

(Cured Coating formed from 4.27 14.40

Example 14)

Example 27

(Cured Coating formed from 4.40 14.12

Example 15)

Example 28

(Cured Coating formed from 4.49 13.97

Example 16)

Example 29

(Cured Coating formed from 2.89 9.89

Example 17)

Example 30

(Cured Coating formed from 5.71 18.11

Example 18)

Example 31

(Cured Coating formed from 4.31 13.92

Example 19)

Example 32

(Cured Coating formed from 2.97 9.89

Example 20)

Example 33

(Cured Coating formed from 6.16 18.27

Example 21)

Example 34

(Cured Coating formed from 5.04 14.06

Example 22)

Example 35

(Cured Coating formed from 5.11 14.06

Example 23)

Example 36

(Cured Coating formed from 3.58 9.94

Example 24)

Table 6 Comparative Example S/mil Pigment

(Scattering coefficient per Volume Concentration

#

unit thickness)

Comparative Example L

(Cured Coating formed from 2.72 18.71

Comparative Example A)

Comparative Example M

(Cured Coating formed from 2.21 14.33

Comparative Example B)

Comparative Example N

(Cured Coating formed from 1.83 11.92

Comparative Example C)

Comparative Example O

(Cured Coating formed from 1.55 10.02

Comparative Example D)

Comparative Example P

(Cured Coating formed from 2.44 18.40

Comparative Example E)

Comparative Example Q

(Cured Coating formed from 2.19 14.20

Comparative Example F)

Comparative Example R

(Cured Coating formed from 1.36 9.95

Comparative Example G)

Comparative Example S

(Cured Coating formed from 5.30 18.56

Comparative Example H)

Comparative Example T

(Cured Coating formed from 2.77 14.20

Comparative Example I)

Comparative Example U

(Cured Coating formed from 1.34 10.02

Comparative Example J)

Comparative Example V

(Cured Coating formed from 0.90 9.08

Comparative Example K)

[085] The data in Table 5 and Table 6 show that for similar pigment volume concentrations, similar epoxy concentrations, and similar epoxy/polymeric latex binder concentrations, each of Examples 25 through 36 have a greater scattering coefficient, which corresponds to improved hiding, relative to each of Comparative Examples L through V. For instance, for cured coatings having a pigment volume concentration of 10 (Example 29 PVC is 9.89 and Comparative Example O PVC is 10.02), Example 29 has a scattering coefficient of 2.89 and Comparative Example O has a scatting coefficient of 1.55. The greater scattering coefficients for each of Examples 25 through 36, relative respectively to each of Comparative Examples L through V, indicate that cured coatings formed from aqueous epoxy composite dispersions including composite particles, each having a respective inorganic core having a number of adsorbing polymeric latex particles adsorbed thereto, have improved pigment distribution as compared to cured coatings formed from compositions lacking the composite particles.

[086] Gloss Testing

[087] Gloss testing for each of Examples 25-26, 28-31, and 33-36 and

Comparative Examples L-V was performed using a BYK micro-TRI-gloss glossmeter. Gloss measurements were the average gloss at three locations on the cured coating. 60° Gloss and 20° Gloss for Examples 25-26, 28-31, and 33-36 are reported in Table 7. 60° Gloss and 20° Gloss for Comparative Examples L -V are reported in Table 8.

Table 7

Example 31

(Cured Coating formed from 49.03 6.00 Example 19)

Example 33

(Cured Coating formed from 77.94 51.12 Example 21)

Example 34

(Cured Coating formed from 79.31 48.40 Example 22)

Example 35

(Cured Coating formed from 74.94 39.23 Example 23)

Example 36

(Cured Coating formed from 80.39 45.71 Example 24)

Table 8

Comparative Example 60° Gloss 20° Gloss

#

Comparative Example L

(Cured Coating formed from 89.06 4.61 Comparative Example A)

Comparative Example M

(Cured Coating formed from 103.75 101.05 Comparative Example B)

Comparative Example N

(Cured Coating formed from 99.94 90.84 Comparative Example C)

Comparative Example O

(Cured Coating formed from 94.30 3.47 Comparative Example D)

Comparative Example P

(Cured Coating formed from 67.38 25.36 Comparative Example E)

Comparative Example Q

(Cured Coating formed from 31.00 7.56 Comparative Example F)

Comparative Example R

(Cured Coating formed from 33.45 8.00 Comparative Example G) Comparative Example S

(Cured Coating formed from 24.43 4.57

Comparative Example H)

Comparative Example T

(Cured Coating formed from 16.65 2.88

Comparative Example I)

Comparative Example U

(Cured Coating formed from 20.10 3.71

Comparative Example J)

Comparative Example V

(Cured Coating formed from 15.61 2.81

Comparative Example K)

[088] The data in Table 7 and Table 8 show that Examples 25-26, 28-31, and

33-36, which were each formed from curable aqueous epoxy composite dispersions including composite particles, each are having a respective inorganic pigment core having a number of adsorbing polymeric latex particles adsorbed thereto, have a desirable pigment distribution. The desirable pigment distribution is evidenced by non-decreasing 60° Gloss and non-decreasing 20° Gloss for Examples 25-26, 28-31, and 33-36, with increased pigment volume concentration for the tested Examples.

[089] Additionally, surprisingly, increasing the weight percent of epoxy resin in curable aqueous epoxy composite dispersions including composite particles each having a respective inorganic pigment core having a number of adsorbing polymeric latex particles adsorbed thereto can provide cured coatings having non- decreasing gloss with increased pigment volume concentrations. For instance, Examples 25, 26, 28, and 29, which each had an increased weight percent of epoxy resin compared to Examples 30, 31, and 33-36 and Comparative Examples P-V, have non-decreasing gloss with increased pigment volume concentration. In contrast to Examples 25, 26, 28, and 29, Comparative Examples L-O, have a decreasing gloss with increased pigment volume concentrations.

Claims

Claims What is claimed:

1. An aqueous epoxy composite dispersion comprising:

an epoxy resin; and

a plurality of composite particles each including a respective inorganic pigment core having a number of adsorbing polymeric latex particles adsorbed thereto, wherein the aqueous epoxy composite dispersion has a pigment volume concentration in a range from five percent to fifty- five percent.

2. The aqueous epoxy composite dispersion of claim 1, wherein the respective inorganic pigment cores comprise titanium dioxide.

3. The aqueous epoxy composite dispersion of any one of the preceding claims, wherein the number of adsorbing polymeric latex particles comprises phosphoethyl methacrylate.

4. The aqueous epoxy composite dispersion of any one of the preceding claims further comprising a polymeric latex binder.

5. The aqueous epoxy composite dispersion of any one of the preceding claims wherein the epoxy resin is selected from the group consisting of an aromatic epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, or a combination thereof.

6. A curable aqueous epoxy composite dispersion comprising the aqueous epoxy composite of any one of the preceding claims and a hardener.

7. The curable aqueous epoxy composite dispersion of claim 6, wherein the hardener is selected from the group consisting of an acid, an amine, a thiol, a phenolic, or a combination thereof,

8. A coated article comprising:

a substrate; and a cured coating on the substrate, wherein the cured coating is formed by curing a curable aqueous epoxy composite dispersion comprising:

an epoxy resin; and