CA1333432C - Coating agents based on polycondensation and/or addition products containing carboxyl groups and amino groups and use thereof - Google Patents
Coating agents based on polycondensation and/or addition products containing carboxyl groups and amino groups and use thereofInfo
- Publication number
- CA1333432C CA1333432C CA000592464A CA592464A CA1333432C CA 1333432 C CA1333432 C CA 1333432C CA 000592464 A CA000592464 A CA 000592464A CA 592464 A CA592464 A CA 592464A CA 1333432 C CA1333432 C CA 1333432C
- Authority
- CA
- Canada
- Prior art keywords
- component
- polyester
- preparation
- carboxyl
- coating agent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
- C09D133/04—Homopolymers or copolymers of esters
- C09D133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
- C09D133/062—Copolymers with monomers not covered by C09D133/06
- C09D133/066—Copolymers with monomers not covered by C09D133/06 containing -OH groups
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D163/00—Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D167/00—Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain; Coating compositions based on derivatives of such polymers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
Abstract
The present invention relates to a coating agent containing A) a component containing carboxyl and tertiary amino groups and a polyepoxy resin B). A) consists of 10 to 90% by weight of a carboxyl- and amino-containing polyacrylate (A1) having an acid number from 20 to 140 and an amine number from 5 to 60 and 90 to 10% by weight of a carboxyl- and amino-containing polyester (A2) having an acid number from 10 to 160 and an amine number from 3 to 90. (A2) is obtainable by reaction of a) poly-carboxylic acids or anhydrides thereof, if desired together with monocarboxylic acids, b) polyols, if desired together with monools, and c) further modifying components and, if desired, d) a component which reacts with the reaction product from a), b) and possibly c), with the proviso that the final product contains tertiary amino groups originating from component a) and/or b) and/or d), the sum of components (A1) to (A2) being 100% by weight. The coating agents of the invention are curable at room temperature or at slightly elevated temperatures and form coatings having improved resistance to long-term stress caused by chemicals and solvents.
Description
~ ~ 333432 BASF Lacke+Farben Aktiengesellschaft, Munster Coating agents based on polycondensation and/or addition products contA i n i ng carboxyl group~ and amino groups and use thereof The present invention relate~ to coating agents based on polycondensation and/or addition products COntA i n i ng carboxyl groups and amino y,oups and to the use thereof.
It is known that compounds which contain an epoxide ring react with carboxyl-contA i n i ng compounds with ring openi n~. If compounds having more than one epoxy group and more than one carboxyl group are used, the reaction proceeds with the formation of polymeric esters contain-ing secondary hydroxyl y~o~ps. This polymer formation isknown under the name of "acid-curing epoxy resins".
It is known that this epoxy/carboxyl reaction can be catalyzed by suitable basic compounds. Suitable basic catalysts are, for example, ~i~zAhicyclooctane, diaza-bicyclononene, diazabicycloundecene, imidazole deriva-tives, such as 3-methyl-, phenyl- or cyclohexyi~i~ole~
trialkylamine, such as triethylamine, tributylamine, tricyclohexylamine, N,N'-dialkylpiperazines, trialkylphosphi n~ and triarylphosrhine~, hydroxides, - 2 - 1 3 33~ 32 carbonates and alkali metal salts of organic acids, such a~ lithium hydroxide, potassium carbonate, sodium and lithium benzoate. Further suitable catalysts are chelates of magnesium, aluminum and titanium.
EP-B 51,275 has disclosed a reactive curable binder mixture based on special polycarboxylic acid units which i~ based on 1.) polymerization and/or con~n~Ation products in which carboxyl groups are formed, for ex-ample, by an addition reaction of cyclic carboxylic anhydrides with OH-acrylates and 2.) aliphatic or cyclo-aliphatic epoxy compounds. The advantage of the curable binder mixture is that a catalyst for the carboxyl/epoxy cro881i nki ng is present in the form of metal salts together with the binder, thus making an external cata-lyst unnecessary.
EP-A 123,793 has disclosed a composition which is cured at as low as room temperature and consi~ts of poly-epoxides and polymers which contain carboxyl groups and tertiary ~mino ~ ou~ and are formed by reaction of vinyl polymers contA;~;ng acid anhydride and carboxyl groups with compounds which contain at least one active hydrogen atom capable of reacting with acid anhydrides and at least one tertiary amino group, such a~, for example, tertiary amino alcohols. $he composition~ described have the advantage that they are cured at as low as room 133343.~
temperature, have good resistance to benzine, water and alkali and no undesirable discolorations owing to ter-tiary amino compounds occur.
However, the carboxyl-contAining acrylates of EP-A
123,793 have the disadvantage of being incompatible with polar epoxides (for example based on a reaction product of melamine resins with acrylamide with subsequent epoxidation of the acrylic double bond).
German Offenlegungsschrift 2,635,177 has disclosed compositions of acrylate resins and di- and polyepoxides.
~,~-Ethylenically unsaturated carboxylic acids have been incorporated into the acrylate resins by polymerization, and the resins have an acid number of 70 to 250. The compositions have a high solids content and give good results with respect to mechanical properties, resistance to chemicals and solvents and corrosion resistance.
JP-OS 76,338/?7 has disclosed a coating composition obtAi~Ahle by mixing acrylate copolymers of acrylic ester~, carboxyl-cont~i n i ~g monomer~ and acrylic monomers contAi~ing tertiary nitrogen, such as, for example, diethylaminoethyl acrylate, with polyepoxides. The coating compositions can be cured at low temperatures and have a high solids content.
133~432 WO 87/02041 has disclosed coating agents based on poly-epoxides and branched carboxyl- and amino-contAi~i~g acrylate resins, in which the acrylate resins have acid numbers between 15 and 200 and are prepared using more than 3 to 30% by weight of a monomer having at least two polymerizable, olefinically unsaturated double bond~.
These coating agents lead to coatings having good techni-cal properties, although they are in need of improvement with respect to solvent resistance.
German Offenlegungsschrift 2,161,253 has disclosed alkyd resins contAi n i ng tertiary amino groups and carboxyl y ou~ which are crosslinked with melamine resins.
Introduction of the tertiary amino groups into the alkyd resin is carried out by using 5 to 100% by weight, preferably 20 to 60% by weight, of nitrogen-contAining polyhydric alcohols in the polycondensation.
German Offenlegungsschrift 2,016,060 has disclosed that the compatibility with other resins is imp oved by incorporation of tertiary amino ylo~s in alkyd resins, thus making it possible also to prepare mixtures of polyesters contAi~i~g tertiary amino y~Ou~3 with thermo-plastic or heat-curable acrylic resins which, however, do not have tertiary amino y oup~. In contrast to the present invention, the curing of the resins or resin mixtures is carried out through a reaction with melamine 1~33~2 and not with epoxy resins.
The ob~ect of the present invention was to improve the properties of the coating agents or the coatings based on an epoxy/carboxyl crossli nki ng with respect to the S resistance to long-term stress caused by chemicals and solvents, with respect to the resistance to benzine, the elasticity of the coating~ obtAi~ by means of the coating agents, the gloss, corrosion resistance and with respect to the resistance to water and steam. In addition the compositions have to meet the requirement that they be curable, if necessary, at room temperature or at slightly elevated temperature and hence be usable, for example, in automotive repair coating.
An additional ob~ect is to provide those coating composi-tions which have such a low color number that they can be used as clearcoat in general or, in a multi-layer system, as clearcoat on top of a basecoat.
Furthermore, the polymers contAini ng carboxyl and ter-tiary amino groups must also be compatible with polar epoxides, that is to say, for example epoxides based on a reaction product of melamine resins with acrylamide with subsequent epoYi~Ation of the acrylic double bond.
133~32 Surprisingly, this ob~ect is achieved by a coating agent contA i n i r~g A) a carboxyl- and amino-contAini~g component (A), B) an epoxy resin as crosslinking agent having on average more than one epoxy group per molecule, C) one or more organic solvents, D) if desired, pigments, customary auxiliaries and addi-tives, and in which the ratio of the free carboxyl groups of component (A) to the number of epoxy groups is in the range from 1:3 to 3:1, the essential aspect according to the invention being that the component (A) consists of 1) 10 to 90% by weight of a carboxyl- and amino-contAining polyacrylate (A1) having an acid number of 20 to 140, preferably 30 to 90, an amine number of 5 to 60, preferably 10 to 40, 2) 90 to 10~ by weight of a carboxyl- and amino-contAini~g polyester (A2) having an acid number of 10 to 160, preferably 20 to 120, and an amine number of 3 to 90, preferably 10 to 60, where the polyester (A2) is obtAinAhl~ by reaction of a) polycarboxylic acids or anhydrides thereof, if de~ired together with monocarboxylic acids, b) polyols, if desired together with monools, and, if desired, c) further modifying components and, if desired, d) a component which reacts with the reaction product from a), b) and possibly c), 1333~13~
with the proviso that the final product contains tertiary amino groups originating from component a) and/or b) and/or d), the sum of the components (A1) to (A2) amounting to 100%
by weight.
The preparation of component (Al) can be carried out by different methods. Thus, the carboxyl y~o~s can be introduced into the polymer during the copolymerization by using carboxyl-contAining monomers.
Examples of suitable carboxyl-contAining monomers are acrylic acid, methacrylic acid, itaconic acid, crotonic acid, aconitic acid, maleic acid and fumaric acid and also their half esters, carboxyethyl acrylate, mono-2-methacryloyloxyethyl phthalate, mono-2-methacryloyloxy-ethyl hexahydrophthalate, mono-4-acryloyloxybutyl hexa-hydrophthalate and also caprolactone-modified acrylate monomers having COOH y- 0~3, such as, for example, the commercial product TONE ~XM 300 from Union Carbide Co./USA, a polyester acrylate based on caprolactone having a molecular weight of about 500 and a polymeriz-able double bond and a carboxyl group.
The introduction of the carboxyl y-O~p8 into the acrylate resin (Al) can also be carried out - as described in W0 87/02041 or in EP-B 51,275 - by first copolymerizing the ~RP~ P ~
- 8 - 1333~ 32 corresponding monomers in an organic solvent at 70 to 130C, preferably at 80 to 120C, using at least 0.5% by weight, preferably at least 2.5% by weight, relative to the total weight of the monomers, of a polymerization regulator and using polymerization initiators to give a precrosslinked, non-gelled hydroxyl-contAining product and, after the copolymerization is completed, carrying out the reaction with the cyclic acid anhydrides.
It is of course also possible to add cyclic acid anhyd-rides onto polyacrylates which apart from hydroxyl groups already contain carboxly groups. Examples of suitable acid anhydrides are listed in WO 87/02041.
The introduction of the tertiary amino groups can also be carried out during the copolymerization by using monomers having tertiary amino y o~ , such as is described, for example, in WO 87/02041. Example~ of suitable ethyleni-cally unsaturated compounds having a tertiary amino group are N,N'-dimethylaminoethyl methacrylate, N,N'-diethyl-aminoethyl methacrylate, 2-vinylpyridine, 4-vinylpyri-dine, vinylpyrroline, vinylquinoline, vinylisoquinoline, N,N'-dimethylaminoethyl vinyl ether and 2-methyl-5-vinylpyridine.
The introduction of the tertiary amino group~ into the polymer can preferably be carried out in such a way that a) an amino alcohol having a tertiary amino group or an 1333~3~
g equivalent compound i~ reacted with b) a polyi~ocyanate to give a compound which on the average contains 0.8 to 1.5, preferably 1, free isocyanate groups and at least one tertiary amino group per molecule. This compound is then added onto an acrylate having carboxyl and hydroxyl groups. Suitable diisocyanates are in particular those in which the isocyanate groups have different reactivities, such as, for example, isophorone diisocyanate. If poly-isocyanates having NCO groups of identical reactivity are used, it is preferred to use the polyisocyanate in excess and then to distill off the excess, thus obtAining a 1:1 adduct. A more detailed description of this preparation process can be found in German Patent Application 3,731,652 and also in German Offenlegungsschrift 2,836,830, in which this process for the introduction of tertiary amino groups into hydroxyl-contAi~ing polymers has been described for the preparation of binders for the cathodic electro-dipping process.
The introduction of the tertiary amino g~o~p~ into the polymer molecule can also be carried out by addition reaction of amino alcohols with polyacrylates contAi~ing glycidyl y ou~. This route has been described in German Offenlegungsschrift 2,900,592. The addition is followed by an addition reaction of cyclic carboxylic anhydrides.
1333~32 Preferably, a soluble, precrosslinked acrylate copolymer is used as polyacrylate (Al). These polymers are prepared by using more than 3 to 30% by weight of monomers having at least two polymerizable, olefinically unsaturated double bonds, relative to the total weight of the mono-mers. The tertiary amino group can be introduced into the precrosslinked polyacrylate by various methods, for example by using tertiary amines having a copolymerizable double bond. The soluble precrosslinked polyacrylates and their preparation are described in WO 87/02041. The advantage of these polyacrylates is, inter alia, that the resulting films have good resistance to solvents and water and dry relatively quickly.
Preferably, the acrylate copolymer (Al) has an OH number of more than 20 mg of ROH/g, since in this case a par-ticularly good compatibility with polar polyepoxides which were used as crosslinking agents is obtAin~.
Suitable polycarboxylic acids (component a)) for the preparation of the polyesters (A2) are, for example, phthalic acid, isophthAlic acid, terephthalic acid, halophthalic acids, such as tetrachloro- or tetrabromo-phthalic acid, hexahydrophthalic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, endomethylene-tetrahydrophthalic acid, 1,1,3-trimethyl-3-phenylin~An~-4',5-dicarboxylic acid, trimellitic acid and anhydrides 1333~32 of the acids mentioned, if they exist.
For the preparation of polyesters having the lowest possible color number, the use of aliphatic and cyclo-aliphatic polycarboxylic acids or their anhydrides, which are not prepared by the oxo process, is preferred.
Particular preference is given to the use of cyclohexAn~-dicarboxylic acid, since it leads to colorless polymers, which furthermore at the same time give good drying and development of hardness in the paint film. If desired, it is also possible to use monocarboxylic acids together with the polycarboxylic acids, such as, for example, benzoic acid, tert.-butylbenzoic acid, lauric acid, isononanoic acid and fatty acids of naturally occurring oils.
In a preferred embodiment, it i8 possible to use, inter alia, or exclusively ami~oc~rhoxylic acids having at least one tertiary amino group as component a) (carboxy-lic acid compo~ent). Examples of these are: pyridine-2-carboxylic acid, pyridine-3-carboxylic acid, pyridine-4-carboxylic acid and pyridine-2,6-dicarboxylic acid. Of the~e, nicotinic acid, that is, pyridine-3-carboxylic acid, i preferably used, because thi~ acid is a very reactive aminocarboxylic acid with respect to catalysis of the acid/epoxide reaction.
Advantageously, the reaction product of an amino alcohol having at least one. tertiary amino group and a polycar-boxylic anhydride can also be used as component a). An example of such a reaction product is the reaction product from 2-hydroxyethylpyridine with phthalic anhydride.
Furthermore, the reaction product from a polyamine having at least one tertiary and at least one primary or secon-dary, preferably secondary, amino group and a polycar-boxylic anhydride can be used as component a).
Suitable alcohol components b) for the preparation ofpolyester (A2) are polyhydric alcohols, such as ethylene glycol, propane diols, butane diols, pentane diols, heY~ diols, neopentyl glycol, diethylene glycol, cyclo-h~YAne~imethanol~trimethylpentA~e~iol~ditrimethylolpro-pane, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, trishydroxyethyl isocyanurate, polyethylene glycol, polyp~o~ylene glycol, if desired, together with monohydric alcohols, such as, for example, butanol, octanol, lauryl alcohol, and ethoxylated or propoxylated phenols.
Preferably, it is possible to use as alcohol component b), inter alia or even exclusively, amino alcohol~ having at least one tertiary amino group. Examples of these are 1333~3r?
2-hydroxyethylpyridine, dimethylaminopropanol, methyldiethanolamine, methyldipropanolamine and dihydroxyethylaniline. Reaction products of epoxy resins with carboxylic acids and/or amines are also preferably S used as alcohol component b).
Accordingly, the alcohol component b) used can be the reaction product of low-molecular-weight epoxy resins with polycarboxylic acids and/or polycarboxylic anhyd-rides and aminocarboxylic acids having at least one teriary amino group and/or polyamines having at least one tertiary and at least one primary or secondary amino group, this reaction product being subsequently, if desired, additionally esterified with the acid and the alcohol component and, if desired, modified with polyiso-cyanates. Low-molecular-weight epoxy resins are under-stood to mean epoxy resins having a molecular weight of less than about 2,000.
In the case of epoxy resin~, low-chlorine types should be used, since otherwise the products may become strongly discolored.
Preferably, polyisocyanates and/or diepoxy compounds, if desired also monoisocyanates and/or monoepoxy compounds, are used as modifying component c). Examples of suitable polyisocyanates are the toluylene diisocyanates, hexa-1333~32 methylene diisocyanate and also isophorone diisocyanate.
Diepoxy compounds are understood to mean epoxy resins having on average about two epoxy groups per molecule.
Examples of suitable monoepoxy compounds are olefin oxides, such as octylene oxide, butyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, p-butyl-phenol glycidyl ether, cresyl glycidyl ether, styrene oxide, glycidyl methacrylate, cycloheYenevinyl monoxide, dipentene monoxide, ~-pinene oxide and also glycidyl esters of tertiary carboxylic acids.
Preferably, monoisocyanates having at least one tertiary amino group are used as components (d) which are capable of reacting with the reaction product from a), b) and possibly c). These can be prepared, for example, by reaction of suitable diisocyanates, such as isophorone diisocyanate, with amino alcohols having a tertiary amino group, such as, for example, hydroxyethylpyridine or dimethylaminoethanol, or with polyamines having at least one tertiary and at least one secondary or primary amino group. The monoisocyanates are bound to the binder system by reaction with free hydroxyl g ou~ of the polyconden-sation and/or addition product with the formation of a urethane bond.
It is also possible to use polyamines having at least one tertiary and at least one primary or secondary amino 1333 13~J
group as component d). An example of a suitable polyamine is dimethylamino~lopylmethylamine.
It is also possible to use the ring-opened product of epoxy resins with compounds having active hydrogen atoms as alcohol component. Thus, for example, in a step-wise reaction fir~t diepoxides, such as the known Epikote types, can be reacted with dicarboxylic acids, such as, for example, pyridine-2,6-dicarboxylic acid, to give a precursor which is then used further as alcohol component.
Further components a) to d) suitable for the synthesis of the polyester resin (A2) can be obtAine~ from German Patent Application 3,629,470.
It is any casQ an essential aspect of the invention that the final product obtAine~ has an acid number in the range from 10 to 160, preferably from 20 to 120, and an amine number in the range from 3 to 90, preferably 10 to 60. By ~ing antioxidants or reducing agents, such as, for example, hypophosphorous acid, too strong a dis-coloration of the products during the con~s~tion isavoided.
The preparation of the polyesters and acrylates contain-ing carboxyl and tertiary amino groups is carried out in _ 16 -a conventional manner starting from the compounds mentioned.
In the case of all two-step variants in which a cyclic acid anhydride i8 added onto a hydroxyl-contAi n i ng polymer, it is preferred to carry out the partial dis-solution of the resin after the addition reaction not with primary but with secondary or tertiary alcohols, thus s~ppL~ssing the alcoholysis of the half ester bond which takes place as a side reaction.
It is an essential aspect of the invention that the carboxyl- and amino-contAining component (A) of the coating agent is a mixture of the acrylate resin (compo-nent Al) described having an acid number from 20 to 140, preferably 30 to 90, and an amine number from 5 to 60, preferably 10 to 40, and the polye~ter resin (component A2) described having an acid number of from 10 to 160, preferably 20 to 120, and an amine number from 3 to 90, preferably 10 to 60. The mixing ratio is 10 to 90% by weight of polyacrylate (A1) and 90 to 10% by weight of 20. polye~ter (A2). However, preferably the mixing ratio i5 40 to 90% by weight of polyacrylate (A1) and 10 to 60% by weight of polyester (A2), since these mixing ratios lead to coatings having particularly good properties.
`_ 133~432 The crosslinking agent cont~in~ in the coating agent according to the invention is an epoxy resin (B) having on average more than one epoxy group per molecule, in which the ratio of the free carboxly groups of component S (A) to the number of epoxy groups of the epoxy resin is in the range from 1:3 to 3:1. Examples of suitable epoxy resins are condensation products from epichlorohydrin and bisphenol A, for example cycloaliphatic bisepoxides, epoxydized polybutadienes formed by reaction of commer-cially available polybutadiene oils with peracids ororganic acid/H202 mixtures, epoxidation products of naturally occurring fats, oils, fatty acid derivatives, modified oils, epoxy-contAining novolaks, glycidyl ethers of a polyhydric alcohol, for example ethylene glycol diglycidyl ether, glycerol polyglycidyl ether, sorbitol polyglycidyl ether, trimethylolpropane polygycidyl ether and pentaerythritol polyglycidyl ether and also suitable acrylate resins having attenA~nt oxirane groups. Further-more it is also advantageous to use, ag crogglinki~g agents, reaction products of hydroxyl-cont~;ning poly-epoxides with di- or polyisocyanates, such as are formed, for example, by reaction of OH-functional epoxides, such as, for example, sorbitol polyglycidyl ethers, with isophorone A;; ~ocyanate.
Other crossl;~king agents which are preferably used are polar epoxides, for example based on a reaction product ~ 133~32 _ 18 -of melamine re~in~ with acrylamide with sub~equent epoxidation of the acrylic double bond. An example of this class of substances is the commercial product C Santolink LSE 4103 from Non~anto Co.~ in which the epoxy resin basic structure is a dinuclear melamine, the molecular weight is about 1200 and the epoxide equivalent weight about 300. Examples of suitable solvents (compo-nent C)) for the coating agents according to the inven-tion are toluene, xylene, butanol, ethyl acetate, butyl acetate, pentyl acetate, dimethyl glutarate, dimethyl succinate, l-methoxy-propyl 2-acetate, 2-ethylhe~y~Anol~
ethylene glycol diacetate, ethylene glycol monoethyl and monobutylether or acetates thereof, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ben-zines ContA i n i n~ aromatics, cycloheYAnone, methyl ethylketone, acetone, butyl acetoxyglycolate, ethyl acetoxy-glycolate.
These solvents can be used individually or also a~
mixtures of different solvents.
The coating~ agent~ according to the invention can furthermore contain, as component tD), if desired, pigments and also auxiliaries and additives. Suitable additives and auxiliaries are, for example, fillers, such as, for example, talcum, mica, kaolin, chalk, quartz powder, asbestos powder, barium sulfate, silicates, glass ~ ~ ~P ~
1~33~32 fibers, and anti-settling agents, such as, for example, finely dispersed silica, bentonite, colloidal silicates and the like.
The coating agents according to the invention can be applied to a large range of substrates. Examples of suitable substrates are metals, such as iron, zinc, titanium, copper, aluminum, steel, brass, bronze, mag-nesium or the like, furthermore ceramic, wood, glass, concrete and plastics.
The coating agents according to the invention are curable at relatively low temperature, that is, at room tempera-ture or slightly elevated temperatures. The low curing temperature and the short curing time are due to the presence of an internal catalyst in the binder system. If short curing times and low curing temperatures are desired, a component (A) having a relatively high amine number is used.
The coating agents according to the invention lead to coatings having improved resistance to water, steam and in particular to organic solvents and also to coatings having improved elasticity. Compared with coating agents based on polyester/epoxide contAining carboxyl and tertiary amino y-o~ or based on acrylate/epoxide contAi~ing carboxyl and tertiary amino yLo~p~, the 13~3,,7, combinations according to the invention are distinguished by a reduced viscosity compared to the mean value calculated arithmetically.
By suitable selection of the individual synthetic com-S ponents for the polyester and the acrylate resin and also by suitable selection of the mixing ratio, the properties of the final product can be controlled in a highly efficient manner.
Thus, the use of cycloh~YAnP~icarboxylic acid or other dicarboxylic acids which were not prepared by the oxo process lead to products having a particularly small color number, good drying and curing development in the paint film.
The concomitant use of suitable monocarboxylic acids for the synthesis of the polyester can also affect hardness and elasticity. The U8Q of benzoic acid gives relatively hard films, whereas the use of fatty acids gives signifi-cantly softer film~. The use of ~PYAn~Aiols as alcohol component leads to elastic films, whereas the use of neopentyl glycol and pentaerythritol leads to relatively hard coatings.
Aromatic tertiary amino y~O~8 in the binder system have a higher catalytic activity than aliphatic or araliphatic ` -- 21 - 1~3 3 3~32 amino groups.
Owing to the low curing temperatures and the short curing times, the coating agents according to the invention are preferably used for automotive repair coating.
S Furthermore they are highly suitable as topcoat, filler, clearcoat, primer or basecoat.
The selection of the epoxy resin depends on the int~n~
use. If used as topcoat, aliphatic epoxy resins are preferably employed, while for basecoats aromatic epoxy resins are also suitable.
The problem of discoloration, which may occur if they are used as clear coat, can be bypassed by preferably incor-porating aliphatic tertiary amino groups in the binder system. In the case of clear coats, low-chlorine or chlorine-free epoxy resins should be used; in this way, no discoloration phenomena occur.
If the curing is to be carried out under hAkinq condi-tions, that is, at temperatures of at least 100C, the coating agent according to the invention can additionally contain a hot-curable synthetic resin contA;ni~g ether and/or amino and/or OH y~Ou~ such as, for example, phenolic or amino resins.
-- 22 - 1 333~ ~2 The present invention also relates to a process for the preparation of coating agents ContA i n ing A) a carboxyl- and amino-contAi~ing component (A), B) an epoxy resin as crosslinking agent having on average more than one epoxy group per molecule, C) one or more organic solvents, D) if desired, pigments, customary auxiliaries and additives, in which the ratio of free carboxyl groups of com-ponent (A) to the number of epoxy groups is in the range from 1:3 to 3:1, wherein component (A) consists of 1) 10 to 90% by weight of a carboxyl- and amino-contAining polyacrylate (Al) having an acid number of 20 to 140, preferably 30 to 90, an amine number of 5 to 60, preferably 10 to 40, 2) 90 to 10% by weight of a carboxyl- and amino-contAining polye~ter (A2) having an acid number of 10 to 160, preferably 20 to 120, and an amine number of 3 to 90, preferably 10 to 60, where the polyester (A2) is obtAinAhle by reaction of a) polycarboxylic acids or anhydrides thereof, if desired together with monocarboxylic acids, b) polyols, if de~ired together with monools, and, if desired, c) further modifying component~ and, if de~ired, - 23 - 1 33~ 3~
d) a component which reacts with the reaction product from a), b) and possibly c), with the proviso that the final product contains tertiary amino groups originating from component a) and/or b) and/or d), the sum of the components (Al) to (A2) amounting to 100%
by weight.
The compounds which are suitable for use in the process according to the invention are the coating agents accor-ding to the invention already listed in the description.
The preparation of the polyester and acrylate resins used in the process according to the invention and cont~ining carboxyl and tertiary amino groups is also listed in the description of the coating agents according to the lS invention.
The preparation of the coating agents from components (A) to (D) is carried out in a known manner by mixing and, if necessary, dispersion of components (A) to (D).
Advantageous embodiments of the process according to the invention are evident from the qualitative and quantita-tive selection of specific aynthetic components for the coating agent which has already been mentioned in the description of the coating agents according to the - 24 - 1 3 ~ 3 1 3~
invention.
The coating agents prepared according to the invention lead to coatings having improved resistance to water, steam and in particular to organic solvents and also to S coatings having improved elasticity. Compared with coating agents based on polyester/epoxide contAining carboxyl and tertiary amino groups or based on acry-late/epoxide contA i n i ng carboxyl and tertiary amino glo~ps, the combinations according to the invention are distinguished by a reduced viscosity compared to the mean value calculated arithmetically.
The invention is illustrated in more detail below by means of examples. Parts are by weight, unless noted otherwise.
Example 1:
Preparation of the polyester resin I
446.0 parts of hexahydrophthalic anhydride, 480.8 parts of isophthalic acid, 330.6 parts of trimethylolpropane, 269.9 parts of pentaerythritol, 229.8 parts of methyl-diethanolamine, 196.3 parts of benzoic acid, 254.2 parts of isononanoic acid, 91.9 parts of xylene and 2.207 parts of trii~oAecyl phosphite are placed in a 4 liter polycon-densation kettle equipped with stirrer, steam-heated - 25 - 13~313~
column and water separator, and the mixture i8 ~ lowly heated. The condensation is carried out at a maximum temperature of 190C until an acid number of 20 mg of ROH/g and a viscosity of 7.9 dPas (50% strength in butyl glycol) have been reached, followed by cooling and partial dissolution of the reaction product with 410.0 parts of xylene at 130C. 307.23 parts of hexahydroph-thalic anhydride, 76.0 parts of xylene and 0.908 part of triisodecyl phosphite are then added to this solution.
The addition reaction of the anhydride is carried out at 120C until an acid number of 69.8 and a viscosity of 18 dPaæ (50% strength in butyl glycol) have been reached.
The product is then partially dissolved with 798.1 parts of xylene and 114.0 parts of secondary butanol. The poly-ester thus obtAin~A~ has a solids content of 59%, an acidnumber of 69.8, an amine number of 28.8 and a color number of 4-5 (Gardner-Holdt).
Example 2:
Preparation of the polyester resin II
482.2 parts of hexahydrophthalic anhydride, 585.3 parts of 1,4-cycloheYAneAicarboxylic acid, 611.8 parts of trimethylolpropane, 123.1 partg of 1,6-h~YAn~Aiol~
155.2 parts of methyldiethanolamine, 79.6 parts of benzoic acid, 206.1 part~ of isononanoic acid, 87.8 parts of xylene and 2.196 parts of triisodecyl phosphite are 13~313~
placed in a 4 liter polycondensation kettle equipped with stirrer, steam-heated column and water separator, and the mixture is slowly heated. The condensation is carried out at a maximum temperature of 190C until an acid number of 9.1 mg of ROH/g and a vi~cosity of 4.2 dPas (50% strength in butyl glycol) have been reached, followed by cooling and partial dissolution of the product with 387.4 parts of xylene at 130C. 367.0 parts of hexahydrophthalic anhydride, 80.9 parts of xylene and 0.742 part of triiso-decyl phosphite are then added to this solution. The addition reaction of the anhydride i8 carried out at 120C, until an acid number of 69.4 and a visco~ity of 8 dPaa (50~ strength in butyl glycol) have been reached.
The product is then partially dissolved with 718.6 parts of xylene and 182.1 parts of secondary butanol. The poly-ester thus obt~ has a solids content of 59.7%, an acid number of 67 (solid), an amine number of 31, a viscosity (original) of 27.5 dPas and a color number of 1-2 (Gardner-Holdt).
Example 3:
Preparstion of acrylate resin I
484.0 parts of xylene and 161.0 parts of l-metho~y~ o~yl 2-acetate are weighed in a 4 liter stainles~ steel polymerization kettle equipped with stirrer, reflux condenser, two monomer feeds and one initiator feed, and 1333~32 the mixture i~ heated to 110C. The following are weighed into the monomer feed A:
80.0 part~ of dimethylaminoethyl methacrylate 90.0 part~ of xylene 30.0 part~ of l-methoxypropyl 2-acetate The following are weighed into the monomer feed B:
143.0 part~ of methyl methacrylate 120.0 part~ of n-butyl acrylate 120.0 parts of cyclohexyl methacrylate 120.0 part~ of 4-hydroxybutyl acrylate 120.0 part~ of hydroxyethyl methacrylate 97.0 parts of divinylbenzene (62% strength in ethyl styrene) 22.4 part~ of mercaptoethanol lS 0.24 part of triisodecyl phosphite The following are weighed into the initiator feed :
19.2 part~ of 2,2'-azobi~(2-methylbutyronitrile) 58.0 parts of xylene 19.2 parts of l-methoxypropyl 2-acetate The addition of all feeds is started simultaneously; the two monomer feeds are evenly metered in over a period of 3 hour~ and the initiator feed i8 metered in over a period of 3.75 hours. During the polymerization, the temperature in the kettle i~ maint~in~ at 108 to 110C.
The polymerization i~ then allowed to continue for another 2 hour~. The acrylate re~in solution thu~
`- - 28 - 13~3~32 obtA i nP~ has a solids content of 51% and a viscosity of 24 dPas. 169.0 parts of hexahydrophthalic anhydride are then added, and the addition reaction with the acrylate resin is carried out at 110C. After the determination of the acid number in aqueous and alcoholic ROH gives the same values, the mixture i8 concentrated to a solids content of 55-56% by distilling off solvents and subse-quently diluted with secondary butanol to a solids content of 51%. The acrylate resin solution thus obt~inP~
has an acid number of 72 and a viscosity of 27 dPas and an amine number of 28.6.
Example 4:
Preparation of acrylate resin II
382.0 parts of xylene and 382.0 parts of l-methoxypropyl 2-acetate are weighed into a 4 liter stainless steel polymerization kettle e~lippe~ with stirrer, reflux condenser, two monomer feeds and one initiator feed, and the mixture is heated to 110C.
The following are weighed into the monomer feed A:
82.0 part~ of dimethylaminoethyl methacrylate 350.0 parts of mono-2-methacryloyloxyethyl hexahydro-phthalate 100.0 parts of xylene 100.0 parts of l-methoxypropyl 2-acetate 133~3~
The following are weighed into the monomer feed B:
148.0 parts of butylmethacrylate 124.0 parts of n-butyl acrylate 124.0 parts of cyclohexyl methacrylate 72.0 parts of hydroxypropyl methacrylate 100.0 parts of divinylbenzene (62% strength in ethyl styrene) 24.0 parts of mercaptoethanol 0.53 part of triisodecyl phosphite The following are weighed into the initiator feed:
20.0 part~ of 2,2'-azobis(2-methylbutyronitrile) 40.0 parts of xylene 40.2 parts of 1-methoxypropyl 2-acetate The addition of the monomer feeds is started simul-taneously and that of the initiator feed is started 10 minutes later. The two monomer feeds are evenly metered in over a period of 3 hours and the initiator feed is metered in over a period of 3.75 hours. During the polymerization, the temperature in the kettle is maint~i~e~ at 108-110C. The polymerization is then allowed to continue for another 2 hours. The mixture is concentrated to a solids content of about 60% by distil-ling off the solvents and then diluted with secondary butanol. The acrylate resin solution thus ob~ine~ has a solids content of 51% and an acid number of 67 and an amine number of 34.
30 1333~32 Example 5:
Preparation of coating agents These COOH polymers were crosslinked by means of an aliphatic epoxy resin having a molecular weight of about 1200 and an epoxide equivalent weight of about 300. The C ba~ic structure of this epoxy resin (commercial name LSE~
4103 from ~onsanto Co.) is a dinuclear melamine resin reacted with acrylamide followed by epoxidation of the acrylic double bonds.
Polyester resin II (lacquer 1), acrylate resin I (lacquer 2) and a 1:2 mixture (lacquer 3) of polyester and acry-late were mixed with this epoxy re~in. The lacquer mixtures thus prepared were applied as clear coating composition by the wet-in-wet process to a commercially available ~ilver metallic basecoat (bases CAB, polyester, melamine re~in, wax). The clear coats thus obt~i n~ were testercially availafor drying (dust-free, non-tacky), after drying for 24 hours at room temperature the pen-dulum hardne~s (according to Ronig) and after 3 days the elasticity by means of Erichsen indentation were deter-mined. Furthèrmore, the following tests were carried out:
1) A pressure test:
A sheet of absorbent paper is folded 8 times so that a small square (4 x 4 cm) is formed. Thi~ square is 6 ~
1333~2 laid on the film, and a weight of 500 g is placed on top of it. The film is then rated for marking or damage; 1 is very poor and 10 is very good - no marking.
2) A water drop test:
1 ml of distilled water is poured on the clear coat and allowed to interact for 4 hours in a 50C oven in the absence of circulating air. The film is rated on a scale from 1 to 10: 10 is without any marking, softening or other impairment of the film.
3) A benzine and xylene test:
1 ml of the solvent i8 allowed to flow down a board set up at an angle of 45. The film is rated for markings and softenings on a scale from 1 to 10, 10 denoting no impairment whatsoever.
Table 1: Lacquer formulations Lacquer 1 2 3 Polyester II 80.0 - 27.0 Acrylate I - 80.0 53.0 Epoxy resin 27.5 27.0 26.5 1-Nethoxy-2-propanol 2.0 2.0 2.0 Butyl acetate 85/100 11.5 11.5 11.5 Xylene 5.0 5.0 5.0 133~32 Silicone oil 0.5 0.5 0.5 Light ~tabilizer 1 0.6 0.6 0.6 Light ~tabilizer 2 0.4 0.4 0.4 Original viscosity (efflux time in a DIN 4 cup) 84" 140~ 94~
The mixture~ are ~et to 18" (efflux time DIN 4 cup) with solvent.
Solids content at sprayable vi~cosity 34.5% 27.6% 31.4%
Table 2: Test results Lacquer 1 2 3 Drying dust-free after 60' 30' 40' non-tacky after Sh20' 2h 3h30' Pre~sure test 6 8 8 Water drop test 5 7 6-7 Benzine test 8 7 8 Xylene te~t 8 6 9 Erichsen indentation (in mm) 9.0 7.7 9.9 Pendulum hardness (Konig) 74 n 118 N 84 Deg.--~ of glos~ (20) 94% 91% 93%
_ 33 _ 1333~32 As the experiment3 show, by mixing the acrylate resins with the polyester resins it is possible, surprisingly, to achieve an im~lovement in the performance. Thus, the resistance to chemicals is increased by the mixture according to the invention and the elasticity is better than that of the individual components. Surprisingly, owing to mixing, the viscosity of the lacquers becomes considerably more favorable than corresponds to the purely arithmetical mean value. Nean value of original viscosity: 120", found in the mixture 94"; mean value of the solids content at sprayable viscosity 29.9%, found in the mixture 31.4%.
It is known that compounds which contain an epoxide ring react with carboxyl-contA i n i ng compounds with ring openi n~. If compounds having more than one epoxy group and more than one carboxyl group are used, the reaction proceeds with the formation of polymeric esters contain-ing secondary hydroxyl y~o~ps. This polymer formation isknown under the name of "acid-curing epoxy resins".
It is known that this epoxy/carboxyl reaction can be catalyzed by suitable basic compounds. Suitable basic catalysts are, for example, ~i~zAhicyclooctane, diaza-bicyclononene, diazabicycloundecene, imidazole deriva-tives, such as 3-methyl-, phenyl- or cyclohexyi~i~ole~
trialkylamine, such as triethylamine, tributylamine, tricyclohexylamine, N,N'-dialkylpiperazines, trialkylphosphi n~ and triarylphosrhine~, hydroxides, - 2 - 1 3 33~ 32 carbonates and alkali metal salts of organic acids, such a~ lithium hydroxide, potassium carbonate, sodium and lithium benzoate. Further suitable catalysts are chelates of magnesium, aluminum and titanium.
EP-B 51,275 has disclosed a reactive curable binder mixture based on special polycarboxylic acid units which i~ based on 1.) polymerization and/or con~n~Ation products in which carboxyl groups are formed, for ex-ample, by an addition reaction of cyclic carboxylic anhydrides with OH-acrylates and 2.) aliphatic or cyclo-aliphatic epoxy compounds. The advantage of the curable binder mixture is that a catalyst for the carboxyl/epoxy cro881i nki ng is present in the form of metal salts together with the binder, thus making an external cata-lyst unnecessary.
EP-A 123,793 has disclosed a composition which is cured at as low as room temperature and consi~ts of poly-epoxides and polymers which contain carboxyl groups and tertiary ~mino ~ ou~ and are formed by reaction of vinyl polymers contA;~;ng acid anhydride and carboxyl groups with compounds which contain at least one active hydrogen atom capable of reacting with acid anhydrides and at least one tertiary amino group, such a~, for example, tertiary amino alcohols. $he composition~ described have the advantage that they are cured at as low as room 133343.~
temperature, have good resistance to benzine, water and alkali and no undesirable discolorations owing to ter-tiary amino compounds occur.
However, the carboxyl-contAining acrylates of EP-A
123,793 have the disadvantage of being incompatible with polar epoxides (for example based on a reaction product of melamine resins with acrylamide with subsequent epoxidation of the acrylic double bond).
German Offenlegungsschrift 2,635,177 has disclosed compositions of acrylate resins and di- and polyepoxides.
~,~-Ethylenically unsaturated carboxylic acids have been incorporated into the acrylate resins by polymerization, and the resins have an acid number of 70 to 250. The compositions have a high solids content and give good results with respect to mechanical properties, resistance to chemicals and solvents and corrosion resistance.
JP-OS 76,338/?7 has disclosed a coating composition obtAi~Ahle by mixing acrylate copolymers of acrylic ester~, carboxyl-cont~i n i ~g monomer~ and acrylic monomers contAi~ing tertiary nitrogen, such as, for example, diethylaminoethyl acrylate, with polyepoxides. The coating compositions can be cured at low temperatures and have a high solids content.
133~432 WO 87/02041 has disclosed coating agents based on poly-epoxides and branched carboxyl- and amino-contAi~i~g acrylate resins, in which the acrylate resins have acid numbers between 15 and 200 and are prepared using more than 3 to 30% by weight of a monomer having at least two polymerizable, olefinically unsaturated double bond~.
These coating agents lead to coatings having good techni-cal properties, although they are in need of improvement with respect to solvent resistance.
German Offenlegungsschrift 2,161,253 has disclosed alkyd resins contAi n i ng tertiary amino groups and carboxyl y ou~ which are crosslinked with melamine resins.
Introduction of the tertiary amino groups into the alkyd resin is carried out by using 5 to 100% by weight, preferably 20 to 60% by weight, of nitrogen-contAining polyhydric alcohols in the polycondensation.
German Offenlegungsschrift 2,016,060 has disclosed that the compatibility with other resins is imp oved by incorporation of tertiary amino ylo~s in alkyd resins, thus making it possible also to prepare mixtures of polyesters contAi~i~g tertiary amino y~Ou~3 with thermo-plastic or heat-curable acrylic resins which, however, do not have tertiary amino y oup~. In contrast to the present invention, the curing of the resins or resin mixtures is carried out through a reaction with melamine 1~33~2 and not with epoxy resins.
The ob~ect of the present invention was to improve the properties of the coating agents or the coatings based on an epoxy/carboxyl crossli nki ng with respect to the S resistance to long-term stress caused by chemicals and solvents, with respect to the resistance to benzine, the elasticity of the coating~ obtAi~ by means of the coating agents, the gloss, corrosion resistance and with respect to the resistance to water and steam. In addition the compositions have to meet the requirement that they be curable, if necessary, at room temperature or at slightly elevated temperature and hence be usable, for example, in automotive repair coating.
An additional ob~ect is to provide those coating composi-tions which have such a low color number that they can be used as clearcoat in general or, in a multi-layer system, as clearcoat on top of a basecoat.
Furthermore, the polymers contAini ng carboxyl and ter-tiary amino groups must also be compatible with polar epoxides, that is to say, for example epoxides based on a reaction product of melamine resins with acrylamide with subsequent epoYi~Ation of the acrylic double bond.
133~32 Surprisingly, this ob~ect is achieved by a coating agent contA i n i r~g A) a carboxyl- and amino-contAini~g component (A), B) an epoxy resin as crosslinking agent having on average more than one epoxy group per molecule, C) one or more organic solvents, D) if desired, pigments, customary auxiliaries and addi-tives, and in which the ratio of the free carboxyl groups of component (A) to the number of epoxy groups is in the range from 1:3 to 3:1, the essential aspect according to the invention being that the component (A) consists of 1) 10 to 90% by weight of a carboxyl- and amino-contAining polyacrylate (A1) having an acid number of 20 to 140, preferably 30 to 90, an amine number of 5 to 60, preferably 10 to 40, 2) 90 to 10~ by weight of a carboxyl- and amino-contAini~g polyester (A2) having an acid number of 10 to 160, preferably 20 to 120, and an amine number of 3 to 90, preferably 10 to 60, where the polyester (A2) is obtAinAhl~ by reaction of a) polycarboxylic acids or anhydrides thereof, if de~ired together with monocarboxylic acids, b) polyols, if desired together with monools, and, if desired, c) further modifying components and, if desired, d) a component which reacts with the reaction product from a), b) and possibly c), 1333~13~
with the proviso that the final product contains tertiary amino groups originating from component a) and/or b) and/or d), the sum of the components (A1) to (A2) amounting to 100%
by weight.
The preparation of component (Al) can be carried out by different methods. Thus, the carboxyl y~o~s can be introduced into the polymer during the copolymerization by using carboxyl-contAining monomers.
Examples of suitable carboxyl-contAining monomers are acrylic acid, methacrylic acid, itaconic acid, crotonic acid, aconitic acid, maleic acid and fumaric acid and also their half esters, carboxyethyl acrylate, mono-2-methacryloyloxyethyl phthalate, mono-2-methacryloyloxy-ethyl hexahydrophthalate, mono-4-acryloyloxybutyl hexa-hydrophthalate and also caprolactone-modified acrylate monomers having COOH y- 0~3, such as, for example, the commercial product TONE ~XM 300 from Union Carbide Co./USA, a polyester acrylate based on caprolactone having a molecular weight of about 500 and a polymeriz-able double bond and a carboxyl group.
The introduction of the carboxyl y-O~p8 into the acrylate resin (Al) can also be carried out - as described in W0 87/02041 or in EP-B 51,275 - by first copolymerizing the ~RP~ P ~
- 8 - 1333~ 32 corresponding monomers in an organic solvent at 70 to 130C, preferably at 80 to 120C, using at least 0.5% by weight, preferably at least 2.5% by weight, relative to the total weight of the monomers, of a polymerization regulator and using polymerization initiators to give a precrosslinked, non-gelled hydroxyl-contAining product and, after the copolymerization is completed, carrying out the reaction with the cyclic acid anhydrides.
It is of course also possible to add cyclic acid anhyd-rides onto polyacrylates which apart from hydroxyl groups already contain carboxly groups. Examples of suitable acid anhydrides are listed in WO 87/02041.
The introduction of the tertiary amino groups can also be carried out during the copolymerization by using monomers having tertiary amino y o~ , such as is described, for example, in WO 87/02041. Example~ of suitable ethyleni-cally unsaturated compounds having a tertiary amino group are N,N'-dimethylaminoethyl methacrylate, N,N'-diethyl-aminoethyl methacrylate, 2-vinylpyridine, 4-vinylpyri-dine, vinylpyrroline, vinylquinoline, vinylisoquinoline, N,N'-dimethylaminoethyl vinyl ether and 2-methyl-5-vinylpyridine.
The introduction of the tertiary amino group~ into the polymer can preferably be carried out in such a way that a) an amino alcohol having a tertiary amino group or an 1333~3~
g equivalent compound i~ reacted with b) a polyi~ocyanate to give a compound which on the average contains 0.8 to 1.5, preferably 1, free isocyanate groups and at least one tertiary amino group per molecule. This compound is then added onto an acrylate having carboxyl and hydroxyl groups. Suitable diisocyanates are in particular those in which the isocyanate groups have different reactivities, such as, for example, isophorone diisocyanate. If poly-isocyanates having NCO groups of identical reactivity are used, it is preferred to use the polyisocyanate in excess and then to distill off the excess, thus obtAining a 1:1 adduct. A more detailed description of this preparation process can be found in German Patent Application 3,731,652 and also in German Offenlegungsschrift 2,836,830, in which this process for the introduction of tertiary amino groups into hydroxyl-contAi~ing polymers has been described for the preparation of binders for the cathodic electro-dipping process.
The introduction of the tertiary amino g~o~p~ into the polymer molecule can also be carried out by addition reaction of amino alcohols with polyacrylates contAi~ing glycidyl y ou~. This route has been described in German Offenlegungsschrift 2,900,592. The addition is followed by an addition reaction of cyclic carboxylic anhydrides.
1333~32 Preferably, a soluble, precrosslinked acrylate copolymer is used as polyacrylate (Al). These polymers are prepared by using more than 3 to 30% by weight of monomers having at least two polymerizable, olefinically unsaturated double bonds, relative to the total weight of the mono-mers. The tertiary amino group can be introduced into the precrosslinked polyacrylate by various methods, for example by using tertiary amines having a copolymerizable double bond. The soluble precrosslinked polyacrylates and their preparation are described in WO 87/02041. The advantage of these polyacrylates is, inter alia, that the resulting films have good resistance to solvents and water and dry relatively quickly.
Preferably, the acrylate copolymer (Al) has an OH number of more than 20 mg of ROH/g, since in this case a par-ticularly good compatibility with polar polyepoxides which were used as crosslinking agents is obtAin~.
Suitable polycarboxylic acids (component a)) for the preparation of the polyesters (A2) are, for example, phthalic acid, isophthAlic acid, terephthalic acid, halophthalic acids, such as tetrachloro- or tetrabromo-phthalic acid, hexahydrophthalic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, endomethylene-tetrahydrophthalic acid, 1,1,3-trimethyl-3-phenylin~An~-4',5-dicarboxylic acid, trimellitic acid and anhydrides 1333~32 of the acids mentioned, if they exist.
For the preparation of polyesters having the lowest possible color number, the use of aliphatic and cyclo-aliphatic polycarboxylic acids or their anhydrides, which are not prepared by the oxo process, is preferred.
Particular preference is given to the use of cyclohexAn~-dicarboxylic acid, since it leads to colorless polymers, which furthermore at the same time give good drying and development of hardness in the paint film. If desired, it is also possible to use monocarboxylic acids together with the polycarboxylic acids, such as, for example, benzoic acid, tert.-butylbenzoic acid, lauric acid, isononanoic acid and fatty acids of naturally occurring oils.
In a preferred embodiment, it i8 possible to use, inter alia, or exclusively ami~oc~rhoxylic acids having at least one tertiary amino group as component a) (carboxy-lic acid compo~ent). Examples of these are: pyridine-2-carboxylic acid, pyridine-3-carboxylic acid, pyridine-4-carboxylic acid and pyridine-2,6-dicarboxylic acid. Of the~e, nicotinic acid, that is, pyridine-3-carboxylic acid, i preferably used, because thi~ acid is a very reactive aminocarboxylic acid with respect to catalysis of the acid/epoxide reaction.
Advantageously, the reaction product of an amino alcohol having at least one. tertiary amino group and a polycar-boxylic anhydride can also be used as component a). An example of such a reaction product is the reaction product from 2-hydroxyethylpyridine with phthalic anhydride.
Furthermore, the reaction product from a polyamine having at least one tertiary and at least one primary or secon-dary, preferably secondary, amino group and a polycar-boxylic anhydride can be used as component a).
Suitable alcohol components b) for the preparation ofpolyester (A2) are polyhydric alcohols, such as ethylene glycol, propane diols, butane diols, pentane diols, heY~ diols, neopentyl glycol, diethylene glycol, cyclo-h~YAne~imethanol~trimethylpentA~e~iol~ditrimethylolpro-pane, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, trishydroxyethyl isocyanurate, polyethylene glycol, polyp~o~ylene glycol, if desired, together with monohydric alcohols, such as, for example, butanol, octanol, lauryl alcohol, and ethoxylated or propoxylated phenols.
Preferably, it is possible to use as alcohol component b), inter alia or even exclusively, amino alcohol~ having at least one tertiary amino group. Examples of these are 1333~3r?
2-hydroxyethylpyridine, dimethylaminopropanol, methyldiethanolamine, methyldipropanolamine and dihydroxyethylaniline. Reaction products of epoxy resins with carboxylic acids and/or amines are also preferably S used as alcohol component b).
Accordingly, the alcohol component b) used can be the reaction product of low-molecular-weight epoxy resins with polycarboxylic acids and/or polycarboxylic anhyd-rides and aminocarboxylic acids having at least one teriary amino group and/or polyamines having at least one tertiary and at least one primary or secondary amino group, this reaction product being subsequently, if desired, additionally esterified with the acid and the alcohol component and, if desired, modified with polyiso-cyanates. Low-molecular-weight epoxy resins are under-stood to mean epoxy resins having a molecular weight of less than about 2,000.
In the case of epoxy resin~, low-chlorine types should be used, since otherwise the products may become strongly discolored.
Preferably, polyisocyanates and/or diepoxy compounds, if desired also monoisocyanates and/or monoepoxy compounds, are used as modifying component c). Examples of suitable polyisocyanates are the toluylene diisocyanates, hexa-1333~32 methylene diisocyanate and also isophorone diisocyanate.
Diepoxy compounds are understood to mean epoxy resins having on average about two epoxy groups per molecule.
Examples of suitable monoepoxy compounds are olefin oxides, such as octylene oxide, butyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, p-butyl-phenol glycidyl ether, cresyl glycidyl ether, styrene oxide, glycidyl methacrylate, cycloheYenevinyl monoxide, dipentene monoxide, ~-pinene oxide and also glycidyl esters of tertiary carboxylic acids.
Preferably, monoisocyanates having at least one tertiary amino group are used as components (d) which are capable of reacting with the reaction product from a), b) and possibly c). These can be prepared, for example, by reaction of suitable diisocyanates, such as isophorone diisocyanate, with amino alcohols having a tertiary amino group, such as, for example, hydroxyethylpyridine or dimethylaminoethanol, or with polyamines having at least one tertiary and at least one secondary or primary amino group. The monoisocyanates are bound to the binder system by reaction with free hydroxyl g ou~ of the polyconden-sation and/or addition product with the formation of a urethane bond.
It is also possible to use polyamines having at least one tertiary and at least one primary or secondary amino 1333 13~J
group as component d). An example of a suitable polyamine is dimethylamino~lopylmethylamine.
It is also possible to use the ring-opened product of epoxy resins with compounds having active hydrogen atoms as alcohol component. Thus, for example, in a step-wise reaction fir~t diepoxides, such as the known Epikote types, can be reacted with dicarboxylic acids, such as, for example, pyridine-2,6-dicarboxylic acid, to give a precursor which is then used further as alcohol component.
Further components a) to d) suitable for the synthesis of the polyester resin (A2) can be obtAine~ from German Patent Application 3,629,470.
It is any casQ an essential aspect of the invention that the final product obtAine~ has an acid number in the range from 10 to 160, preferably from 20 to 120, and an amine number in the range from 3 to 90, preferably 10 to 60. By ~ing antioxidants or reducing agents, such as, for example, hypophosphorous acid, too strong a dis-coloration of the products during the con~s~tion isavoided.
The preparation of the polyesters and acrylates contain-ing carboxyl and tertiary amino groups is carried out in _ 16 -a conventional manner starting from the compounds mentioned.
In the case of all two-step variants in which a cyclic acid anhydride i8 added onto a hydroxyl-contAi n i ng polymer, it is preferred to carry out the partial dis-solution of the resin after the addition reaction not with primary but with secondary or tertiary alcohols, thus s~ppL~ssing the alcoholysis of the half ester bond which takes place as a side reaction.
It is an essential aspect of the invention that the carboxyl- and amino-contAining component (A) of the coating agent is a mixture of the acrylate resin (compo-nent Al) described having an acid number from 20 to 140, preferably 30 to 90, and an amine number from 5 to 60, preferably 10 to 40, and the polye~ter resin (component A2) described having an acid number of from 10 to 160, preferably 20 to 120, and an amine number from 3 to 90, preferably 10 to 60. The mixing ratio is 10 to 90% by weight of polyacrylate (A1) and 90 to 10% by weight of 20. polye~ter (A2). However, preferably the mixing ratio i5 40 to 90% by weight of polyacrylate (A1) and 10 to 60% by weight of polyester (A2), since these mixing ratios lead to coatings having particularly good properties.
`_ 133~432 The crosslinking agent cont~in~ in the coating agent according to the invention is an epoxy resin (B) having on average more than one epoxy group per molecule, in which the ratio of the free carboxly groups of component S (A) to the number of epoxy groups of the epoxy resin is in the range from 1:3 to 3:1. Examples of suitable epoxy resins are condensation products from epichlorohydrin and bisphenol A, for example cycloaliphatic bisepoxides, epoxydized polybutadienes formed by reaction of commer-cially available polybutadiene oils with peracids ororganic acid/H202 mixtures, epoxidation products of naturally occurring fats, oils, fatty acid derivatives, modified oils, epoxy-contAining novolaks, glycidyl ethers of a polyhydric alcohol, for example ethylene glycol diglycidyl ether, glycerol polyglycidyl ether, sorbitol polyglycidyl ether, trimethylolpropane polygycidyl ether and pentaerythritol polyglycidyl ether and also suitable acrylate resins having attenA~nt oxirane groups. Further-more it is also advantageous to use, ag crogglinki~g agents, reaction products of hydroxyl-cont~;ning poly-epoxides with di- or polyisocyanates, such as are formed, for example, by reaction of OH-functional epoxides, such as, for example, sorbitol polyglycidyl ethers, with isophorone A;; ~ocyanate.
Other crossl;~king agents which are preferably used are polar epoxides, for example based on a reaction product ~ 133~32 _ 18 -of melamine re~in~ with acrylamide with sub~equent epoxidation of the acrylic double bond. An example of this class of substances is the commercial product C Santolink LSE 4103 from Non~anto Co.~ in which the epoxy resin basic structure is a dinuclear melamine, the molecular weight is about 1200 and the epoxide equivalent weight about 300. Examples of suitable solvents (compo-nent C)) for the coating agents according to the inven-tion are toluene, xylene, butanol, ethyl acetate, butyl acetate, pentyl acetate, dimethyl glutarate, dimethyl succinate, l-methoxy-propyl 2-acetate, 2-ethylhe~y~Anol~
ethylene glycol diacetate, ethylene glycol monoethyl and monobutylether or acetates thereof, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ben-zines ContA i n i n~ aromatics, cycloheYAnone, methyl ethylketone, acetone, butyl acetoxyglycolate, ethyl acetoxy-glycolate.
These solvents can be used individually or also a~
mixtures of different solvents.
The coating~ agent~ according to the invention can furthermore contain, as component tD), if desired, pigments and also auxiliaries and additives. Suitable additives and auxiliaries are, for example, fillers, such as, for example, talcum, mica, kaolin, chalk, quartz powder, asbestos powder, barium sulfate, silicates, glass ~ ~ ~P ~
1~33~32 fibers, and anti-settling agents, such as, for example, finely dispersed silica, bentonite, colloidal silicates and the like.
The coating agents according to the invention can be applied to a large range of substrates. Examples of suitable substrates are metals, such as iron, zinc, titanium, copper, aluminum, steel, brass, bronze, mag-nesium or the like, furthermore ceramic, wood, glass, concrete and plastics.
The coating agents according to the invention are curable at relatively low temperature, that is, at room tempera-ture or slightly elevated temperatures. The low curing temperature and the short curing time are due to the presence of an internal catalyst in the binder system. If short curing times and low curing temperatures are desired, a component (A) having a relatively high amine number is used.
The coating agents according to the invention lead to coatings having improved resistance to water, steam and in particular to organic solvents and also to coatings having improved elasticity. Compared with coating agents based on polyester/epoxide contAining carboxyl and tertiary amino y-o~ or based on acrylate/epoxide contAi~ing carboxyl and tertiary amino yLo~p~, the 13~3,,7, combinations according to the invention are distinguished by a reduced viscosity compared to the mean value calculated arithmetically.
By suitable selection of the individual synthetic com-S ponents for the polyester and the acrylate resin and also by suitable selection of the mixing ratio, the properties of the final product can be controlled in a highly efficient manner.
Thus, the use of cycloh~YAnP~icarboxylic acid or other dicarboxylic acids which were not prepared by the oxo process lead to products having a particularly small color number, good drying and curing development in the paint film.
The concomitant use of suitable monocarboxylic acids for the synthesis of the polyester can also affect hardness and elasticity. The U8Q of benzoic acid gives relatively hard films, whereas the use of fatty acids gives signifi-cantly softer film~. The use of ~PYAn~Aiols as alcohol component leads to elastic films, whereas the use of neopentyl glycol and pentaerythritol leads to relatively hard coatings.
Aromatic tertiary amino y~O~8 in the binder system have a higher catalytic activity than aliphatic or araliphatic ` -- 21 - 1~3 3 3~32 amino groups.
Owing to the low curing temperatures and the short curing times, the coating agents according to the invention are preferably used for automotive repair coating.
S Furthermore they are highly suitable as topcoat, filler, clearcoat, primer or basecoat.
The selection of the epoxy resin depends on the int~n~
use. If used as topcoat, aliphatic epoxy resins are preferably employed, while for basecoats aromatic epoxy resins are also suitable.
The problem of discoloration, which may occur if they are used as clear coat, can be bypassed by preferably incor-porating aliphatic tertiary amino groups in the binder system. In the case of clear coats, low-chlorine or chlorine-free epoxy resins should be used; in this way, no discoloration phenomena occur.
If the curing is to be carried out under hAkinq condi-tions, that is, at temperatures of at least 100C, the coating agent according to the invention can additionally contain a hot-curable synthetic resin contA;ni~g ether and/or amino and/or OH y~Ou~ such as, for example, phenolic or amino resins.
-- 22 - 1 333~ ~2 The present invention also relates to a process for the preparation of coating agents ContA i n ing A) a carboxyl- and amino-contAi~ing component (A), B) an epoxy resin as crosslinking agent having on average more than one epoxy group per molecule, C) one or more organic solvents, D) if desired, pigments, customary auxiliaries and additives, in which the ratio of free carboxyl groups of com-ponent (A) to the number of epoxy groups is in the range from 1:3 to 3:1, wherein component (A) consists of 1) 10 to 90% by weight of a carboxyl- and amino-contAining polyacrylate (Al) having an acid number of 20 to 140, preferably 30 to 90, an amine number of 5 to 60, preferably 10 to 40, 2) 90 to 10% by weight of a carboxyl- and amino-contAining polye~ter (A2) having an acid number of 10 to 160, preferably 20 to 120, and an amine number of 3 to 90, preferably 10 to 60, where the polyester (A2) is obtAinAhle by reaction of a) polycarboxylic acids or anhydrides thereof, if desired together with monocarboxylic acids, b) polyols, if de~ired together with monools, and, if desired, c) further modifying component~ and, if de~ired, - 23 - 1 33~ 3~
d) a component which reacts with the reaction product from a), b) and possibly c), with the proviso that the final product contains tertiary amino groups originating from component a) and/or b) and/or d), the sum of the components (Al) to (A2) amounting to 100%
by weight.
The compounds which are suitable for use in the process according to the invention are the coating agents accor-ding to the invention already listed in the description.
The preparation of the polyester and acrylate resins used in the process according to the invention and cont~ining carboxyl and tertiary amino groups is also listed in the description of the coating agents according to the lS invention.
The preparation of the coating agents from components (A) to (D) is carried out in a known manner by mixing and, if necessary, dispersion of components (A) to (D).
Advantageous embodiments of the process according to the invention are evident from the qualitative and quantita-tive selection of specific aynthetic components for the coating agent which has already been mentioned in the description of the coating agents according to the - 24 - 1 3 ~ 3 1 3~
invention.
The coating agents prepared according to the invention lead to coatings having improved resistance to water, steam and in particular to organic solvents and also to S coatings having improved elasticity. Compared with coating agents based on polyester/epoxide contAining carboxyl and tertiary amino groups or based on acry-late/epoxide contA i n i ng carboxyl and tertiary amino glo~ps, the combinations according to the invention are distinguished by a reduced viscosity compared to the mean value calculated arithmetically.
The invention is illustrated in more detail below by means of examples. Parts are by weight, unless noted otherwise.
Example 1:
Preparation of the polyester resin I
446.0 parts of hexahydrophthalic anhydride, 480.8 parts of isophthalic acid, 330.6 parts of trimethylolpropane, 269.9 parts of pentaerythritol, 229.8 parts of methyl-diethanolamine, 196.3 parts of benzoic acid, 254.2 parts of isononanoic acid, 91.9 parts of xylene and 2.207 parts of trii~oAecyl phosphite are placed in a 4 liter polycon-densation kettle equipped with stirrer, steam-heated - 25 - 13~313~
column and water separator, and the mixture i8 ~ lowly heated. The condensation is carried out at a maximum temperature of 190C until an acid number of 20 mg of ROH/g and a viscosity of 7.9 dPas (50% strength in butyl glycol) have been reached, followed by cooling and partial dissolution of the reaction product with 410.0 parts of xylene at 130C. 307.23 parts of hexahydroph-thalic anhydride, 76.0 parts of xylene and 0.908 part of triisodecyl phosphite are then added to this solution.
The addition reaction of the anhydride is carried out at 120C until an acid number of 69.8 and a viscosity of 18 dPaæ (50% strength in butyl glycol) have been reached.
The product is then partially dissolved with 798.1 parts of xylene and 114.0 parts of secondary butanol. The poly-ester thus obtAin~A~ has a solids content of 59%, an acidnumber of 69.8, an amine number of 28.8 and a color number of 4-5 (Gardner-Holdt).
Example 2:
Preparation of the polyester resin II
482.2 parts of hexahydrophthalic anhydride, 585.3 parts of 1,4-cycloheYAneAicarboxylic acid, 611.8 parts of trimethylolpropane, 123.1 partg of 1,6-h~YAn~Aiol~
155.2 parts of methyldiethanolamine, 79.6 parts of benzoic acid, 206.1 part~ of isononanoic acid, 87.8 parts of xylene and 2.196 parts of triisodecyl phosphite are 13~313~
placed in a 4 liter polycondensation kettle equipped with stirrer, steam-heated column and water separator, and the mixture is slowly heated. The condensation is carried out at a maximum temperature of 190C until an acid number of 9.1 mg of ROH/g and a vi~cosity of 4.2 dPas (50% strength in butyl glycol) have been reached, followed by cooling and partial dissolution of the product with 387.4 parts of xylene at 130C. 367.0 parts of hexahydrophthalic anhydride, 80.9 parts of xylene and 0.742 part of triiso-decyl phosphite are then added to this solution. The addition reaction of the anhydride i8 carried out at 120C, until an acid number of 69.4 and a visco~ity of 8 dPaa (50~ strength in butyl glycol) have been reached.
The product is then partially dissolved with 718.6 parts of xylene and 182.1 parts of secondary butanol. The poly-ester thus obt~ has a solids content of 59.7%, an acid number of 67 (solid), an amine number of 31, a viscosity (original) of 27.5 dPas and a color number of 1-2 (Gardner-Holdt).
Example 3:
Preparstion of acrylate resin I
484.0 parts of xylene and 161.0 parts of l-metho~y~ o~yl 2-acetate are weighed in a 4 liter stainles~ steel polymerization kettle equipped with stirrer, reflux condenser, two monomer feeds and one initiator feed, and 1333~32 the mixture i~ heated to 110C. The following are weighed into the monomer feed A:
80.0 part~ of dimethylaminoethyl methacrylate 90.0 part~ of xylene 30.0 part~ of l-methoxypropyl 2-acetate The following are weighed into the monomer feed B:
143.0 part~ of methyl methacrylate 120.0 part~ of n-butyl acrylate 120.0 parts of cyclohexyl methacrylate 120.0 part~ of 4-hydroxybutyl acrylate 120.0 part~ of hydroxyethyl methacrylate 97.0 parts of divinylbenzene (62% strength in ethyl styrene) 22.4 part~ of mercaptoethanol lS 0.24 part of triisodecyl phosphite The following are weighed into the initiator feed :
19.2 part~ of 2,2'-azobi~(2-methylbutyronitrile) 58.0 parts of xylene 19.2 parts of l-methoxypropyl 2-acetate The addition of all feeds is started simultaneously; the two monomer feeds are evenly metered in over a period of 3 hour~ and the initiator feed i8 metered in over a period of 3.75 hours. During the polymerization, the temperature in the kettle i~ maint~in~ at 108 to 110C.
The polymerization i~ then allowed to continue for another 2 hour~. The acrylate re~in solution thu~
`- - 28 - 13~3~32 obtA i nP~ has a solids content of 51% and a viscosity of 24 dPas. 169.0 parts of hexahydrophthalic anhydride are then added, and the addition reaction with the acrylate resin is carried out at 110C. After the determination of the acid number in aqueous and alcoholic ROH gives the same values, the mixture i8 concentrated to a solids content of 55-56% by distilling off solvents and subse-quently diluted with secondary butanol to a solids content of 51%. The acrylate resin solution thus obt~inP~
has an acid number of 72 and a viscosity of 27 dPas and an amine number of 28.6.
Example 4:
Preparation of acrylate resin II
382.0 parts of xylene and 382.0 parts of l-methoxypropyl 2-acetate are weighed into a 4 liter stainless steel polymerization kettle e~lippe~ with stirrer, reflux condenser, two monomer feeds and one initiator feed, and the mixture is heated to 110C.
The following are weighed into the monomer feed A:
82.0 part~ of dimethylaminoethyl methacrylate 350.0 parts of mono-2-methacryloyloxyethyl hexahydro-phthalate 100.0 parts of xylene 100.0 parts of l-methoxypropyl 2-acetate 133~3~
The following are weighed into the monomer feed B:
148.0 parts of butylmethacrylate 124.0 parts of n-butyl acrylate 124.0 parts of cyclohexyl methacrylate 72.0 parts of hydroxypropyl methacrylate 100.0 parts of divinylbenzene (62% strength in ethyl styrene) 24.0 parts of mercaptoethanol 0.53 part of triisodecyl phosphite The following are weighed into the initiator feed:
20.0 part~ of 2,2'-azobis(2-methylbutyronitrile) 40.0 parts of xylene 40.2 parts of 1-methoxypropyl 2-acetate The addition of the monomer feeds is started simul-taneously and that of the initiator feed is started 10 minutes later. The two monomer feeds are evenly metered in over a period of 3 hours and the initiator feed is metered in over a period of 3.75 hours. During the polymerization, the temperature in the kettle is maint~i~e~ at 108-110C. The polymerization is then allowed to continue for another 2 hours. The mixture is concentrated to a solids content of about 60% by distil-ling off the solvents and then diluted with secondary butanol. The acrylate resin solution thus ob~ine~ has a solids content of 51% and an acid number of 67 and an amine number of 34.
30 1333~32 Example 5:
Preparation of coating agents These COOH polymers were crosslinked by means of an aliphatic epoxy resin having a molecular weight of about 1200 and an epoxide equivalent weight of about 300. The C ba~ic structure of this epoxy resin (commercial name LSE~
4103 from ~onsanto Co.) is a dinuclear melamine resin reacted with acrylamide followed by epoxidation of the acrylic double bonds.
Polyester resin II (lacquer 1), acrylate resin I (lacquer 2) and a 1:2 mixture (lacquer 3) of polyester and acry-late were mixed with this epoxy re~in. The lacquer mixtures thus prepared were applied as clear coating composition by the wet-in-wet process to a commercially available ~ilver metallic basecoat (bases CAB, polyester, melamine re~in, wax). The clear coats thus obt~i n~ were testercially availafor drying (dust-free, non-tacky), after drying for 24 hours at room temperature the pen-dulum hardne~s (according to Ronig) and after 3 days the elasticity by means of Erichsen indentation were deter-mined. Furthèrmore, the following tests were carried out:
1) A pressure test:
A sheet of absorbent paper is folded 8 times so that a small square (4 x 4 cm) is formed. Thi~ square is 6 ~
1333~2 laid on the film, and a weight of 500 g is placed on top of it. The film is then rated for marking or damage; 1 is very poor and 10 is very good - no marking.
2) A water drop test:
1 ml of distilled water is poured on the clear coat and allowed to interact for 4 hours in a 50C oven in the absence of circulating air. The film is rated on a scale from 1 to 10: 10 is without any marking, softening or other impairment of the film.
3) A benzine and xylene test:
1 ml of the solvent i8 allowed to flow down a board set up at an angle of 45. The film is rated for markings and softenings on a scale from 1 to 10, 10 denoting no impairment whatsoever.
Table 1: Lacquer formulations Lacquer 1 2 3 Polyester II 80.0 - 27.0 Acrylate I - 80.0 53.0 Epoxy resin 27.5 27.0 26.5 1-Nethoxy-2-propanol 2.0 2.0 2.0 Butyl acetate 85/100 11.5 11.5 11.5 Xylene 5.0 5.0 5.0 133~32 Silicone oil 0.5 0.5 0.5 Light ~tabilizer 1 0.6 0.6 0.6 Light ~tabilizer 2 0.4 0.4 0.4 Original viscosity (efflux time in a DIN 4 cup) 84" 140~ 94~
The mixture~ are ~et to 18" (efflux time DIN 4 cup) with solvent.
Solids content at sprayable vi~cosity 34.5% 27.6% 31.4%
Table 2: Test results Lacquer 1 2 3 Drying dust-free after 60' 30' 40' non-tacky after Sh20' 2h 3h30' Pre~sure test 6 8 8 Water drop test 5 7 6-7 Benzine test 8 7 8 Xylene te~t 8 6 9 Erichsen indentation (in mm) 9.0 7.7 9.9 Pendulum hardness (Konig) 74 n 118 N 84 Deg.--~ of glos~ (20) 94% 91% 93%
_ 33 _ 1333~32 As the experiment3 show, by mixing the acrylate resins with the polyester resins it is possible, surprisingly, to achieve an im~lovement in the performance. Thus, the resistance to chemicals is increased by the mixture according to the invention and the elasticity is better than that of the individual components. Surprisingly, owing to mixing, the viscosity of the lacquers becomes considerably more favorable than corresponds to the purely arithmetical mean value. Nean value of original viscosity: 120", found in the mixture 94"; mean value of the solids content at sprayable viscosity 29.9%, found in the mixture 31.4%.
Claims (38)
1. A coating agent containing A) a carboxyl- and amino-containing component (A), B) an epoxy resin as crosslinking agent having on average more than one epoxy group per molecule, C) one or more organic solvents, and, if required D) pigments, customary auxiliaries and additives, in which the ratio of the free carboxyl groups of component (A) to the number of epoxy groups is in the range from 1:3 to 3:1, wherein component (A) consists of 1) 10 to 90% by weight of a carboxyl- and amino-containing polyacrylate (A1) having an acid number of 20 to 140 and an amine number of 5 to 60,
2) 90 to 10% by weight of a carboxyl- and amino-containing polyester (A2) having an acid number of 10 to 160 and an amine number of 3 to 90, wherein the polyester (A2) is obtainable by reaction of a) polycarboxylic acids or anhydrides thereof, if desired together with monocarboxylic acids, b) polyols, if required together with monools, and, c) further modifying components and, if desired, d) a component which reacts with the reaction product from a), b) and possibly c), with the proviso that the final product contains tertiary amino groups originating from component a) or b) or d), the sum of the components (A1) to (A2) amounting to 100% by weight.
2. A coating agent as claimed in claim 1, wherein component (A) consists of 1) 40 to 90% by weight of polyacrylate (A1) and 2) 10 to 60% by weight of polyester (A2), the sum of components (A1) to (A2) being 100% by weight.
2. A coating agent as claimed in claim 1, wherein component (A) consists of 1) 40 to 90% by weight of polyacrylate (A1) and 2) 10 to 60% by weight of polyester (A2), the sum of components (A1) to (A2) being 100% by weight.
3. A coating agent as claimed in claim 1 or 2, wherein the component a) used for the preparation of polyester (A2) comprises aminocarboxylic acids having at least one tertiary amino group.
4. A coating agent as claimed in claim 1 or 2, wherein component a) used for the preparation of polyester (A2) is cyclohexanedicarboxylic acid.
5. A coating agent as claimed in claim 1 or 2, wherein component a) used for the preparation of polyester (A2) is the reaction product of an amino alcohol containing at least one tertiary amino group with a polycarboxylic anhydride.
6. A coating agent as claimed in claim 1 or 2, wherein component b) used for the preparation of polyester (A2) comprises amino alcohols having at least one tertiary amino group.
7. A coating agent as claimed in claim 1 or 2, wherein component b) used for the preparation of polyester (A2) comprises reaction products of epoxy resins with carboxylic acids or amines.
8. A coating agent as claimed in claim 1 or 2, wherein component c) used for the preparation of polyester (A2) comprises polyisocyanates or diepoxy compounds, if desired also monoiso-cyanates or monoepoxy compounds.
9. A coating agent as claimed in claim 1 or 2, wherein component d) used for the preparation of polyester (A2) is a monoisocyanate having at least one tertiary amino group.
10. A coating agent as claimed in claim 1 or 2, wherein polyacrylate (A1) has an OH number of more than 20.
11. A coating agent as claimed in claim 1 or 2, wherein polyacrylate (A1) is prepared by reaction of a hydroxyl-containing acrylate resin with compounds containing on average 0.8 to 1.5 free isocyanate group and at least one tertiary amino group per molecule.
12. A coating agent as claimed in claim 1 or 2, wherein the polyacrylate (A1) used is a soluble precrosslinked acrylate copolymer.
13. A coating agent as claimed in claim 1 or 2, wherein the carboxyl groups are introduced into component (A) mainly or completely by addition of cyclic acid anhydrides onto an OH polymer and the partial dissolution the resin after this addition reaction is carried out using secondary or tertiary alcohols.
14. A process for the preparation of coating agents containing A) a carboxyl-and amino-containing component (A), B) an epoxy resin as crosslinking agent having on average more than one epoxy group per molecule, C) one or more organic solvents, and, if required D) pigments, customary auxiliaries and additives, in which the ratio of free carboxyl group of component (A) to the number of epoxy groups is in the range from 1:3 to 3:1, wherein component (A) consists of 1) 10 to 90% by weight of a carboxyl- and amino-containing polyacrylate (A1) having an acid number of 20 to 140 and an amine number of 5 to 60, 2) 90 to 10% by weight of a carboxyl- and amino-containing polyester (A2) having an acid number of 10 to 160 and an amine number of 3 to 90 wherein the polyester (A2) is obtain-able by reaction of a) polycarboxylic acids or anhydrides thereof, if desired together with monocarboxylic acids, b) polyols, if desired together with monools, and, c) further modifying components and, if required, d) a component which reacts with the reaction product from a), b) and possibly c), with the proviso that the final product contains tertiary amino groups originating from component a) or b) or d), the sum of the components (A1) to (A2) amounting to 100% by weight.
15. The process as claimed in claim 14, wherein component (A) consists of 1) 40 to 90% by weight of polyacrylate (A1) and 2) 10 to 60% by weight of polyester (A2), the sum of components (A1) to (A2) being 100% by weight.
16. The process as claimed in claim 14 or 15, wherein the component a) used for the preparation of polyester (A2) comprises aminocarboxylic acids having at least one tertiary amino group.
17. The process as claimed in claim 14 or 15, wherein component a) used for the preparation of polyester (A2) is cyclo-hexanedicarboxylic acid.
18. The process as claimed in claim 14 or 15, wherein component a) used for the preparation of polyester (A2) is the reaction product of an amino alcohol containing at least one tertiary amino group with a polycarboxylic anhydride.
19. The process as claimed in claim 14 or 15, wherein component b) used for the preparation of polyester (A2) comprises amino alcohols having at least one tertiary amino group.
20. The process as claimed in claim 14 or 15, wherein component b) used for the preparation of polyester (A2) comprises reaction products of epoxy resins with carboxylic acids or amines.
21. The process as claimed in claim 14 or 15, wherein component c) used for the preparation of polyester (A2) comprises polyisocyanates or diepoxy compounds, if desired also monoiso-cyanates or monoepoxy compounds.
22. The process as claimed in claim 14 or 15, wherein component d) used for the preparation of polyester (A2) is a monoisocyanate having at least one tertiary amino group.
23. The process as claimed in claim 14 or 15, wherein polyacrylate (A1) has an OH number of more than 20.
24. The process as claimed in claim 14 or 15, wherein polyacrylate (A1) is prepared by reaction of a hydroxyl-containing acrylate resin with compounds containing on average 0.8 to 1.5 free isocyanate group and at least one tertiary amino group per molecule.
25. The process as claimed in claim 14 or 15, wherein the polyacrylate (A1) used is a soluble precrosslinked acrylate copolymer.
26. The process as claimed in claim 14 or 15, wherein the carboxyl groups are introduced into component (A) mainly or completely by addition of cyclic acid anhydrides onto an OH polymer and the partial dissolution of the resin after this addition reaction is carried out using secondary or tertiary alcohols .
27. Use of the coating agents as claimed in claim 1 or 2 for repair coating of automotive bodies.
28. Use of the coating agents as claimed in claim 1 or 2 as topcoat, filler, clearcoat, primer or basecoat.
29. A coating agent as claimed in claim 1, wherein the carboxyl- and amino-containing polyacrylate (A1) has an acid number of 30 to 90 and an amine number of 10 to 40.
30. A coating agent as claimed in claim 1, wherein the carboxyl- and amino-containing polyester (A2) has an acid number of 20 to 120 and an amine number 10 to 60.
31. A coating agent as claimed in claim 1, wherein the carboxyl- and amino-containing polyester (A2) contains tertiary amino groups originating from component a), b) and d).
32. A coating agent as claimed in claim 1 or 2, wherein component b) used for the preparation of polyester (A2) comprises reaction products of epoxy resins with carboxylic acids and amines.
33. A coating agent as claimed in claim 1 or 2, wherein component c) used for the preparation of polyester (A2) comprises polyisocyanates and diepoxy compounds, if desired also monoisocyanates and monoepoxy compounds.
34. A process as claimed in claim 14, wherein the carboxyl-and amino-containing polyester (A2) contains tertiary amino groups originating from component a), b) and d).
35. A process as claimed in claim 14 or 15, wherein component b) used for the preparation of polyester (A2) comprises reaction products of epoxy resins with carboxylic acids and amines.
36. A process as claimed in claim 14 or 15, wherein component c) used for the preparation of polyester (A2) comprises polyisocyanates and diepoxy compounds, if desired also monoisocyanates and monoepoxy compounds .
37. A coating agent as claimed in claim 11, wherein polyacrylate (A1) is prepared by reaction of a hydroxyl-containing acrylate resin with compounds containing on average one free isocyanate group and at least one tertiary amino group per molecule.
38. A process as claimed in claim 24, wherein polyacrylate (A1) is prepared by reaction of a hydroxyl-containing acrylate resin with compounds containing on average one free isocyanate group and at least one tertiary amino group per molecule.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3806641.6 | 1988-03-02 | ||
| DE3806641A DE3806641A1 (en) | 1988-03-02 | 1988-03-02 | COATING AGENTS BASED ON CARBOXYL GROUPS AND POLYCONDENSATION AND / OR ADDITION PRODUCTS CONTAINING AMINO GROUPS AND THEIR USE |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1333432C true CA1333432C (en) | 1994-12-06 |
Family
ID=6348571
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000592464A Expired - Fee Related CA1333432C (en) | 1988-03-02 | 1989-03-01 | Coating agents based on polycondensation and/or addition products containing carboxyl groups and amino groups and use thereof |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US5283290A (en) |
| EP (2) | EP0330887B1 (en) |
| AT (1) | ATE82312T1 (en) |
| BR (1) | BR8907300A (en) |
| CA (1) | CA1333432C (en) |
| DE (2) | DE3806641A1 (en) |
| ES (1) | ES2035381T3 (en) |
| WO (1) | WO1989008132A1 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3908104A1 (en) * | 1989-03-13 | 1990-09-20 | Basf Lacke & Farben | COATING METHOD, METHOD FOR THE PRODUCTION THEREOF, AND THE USE OF THE COATING MACHINE, IN PARTICULAR FOR EXTERIOR LACQUERING OF DEEP-DRAWED CANS |
| DE3924618A1 (en) * | 1989-07-26 | 1991-01-31 | Basf Lacke & Farben | COATING AGENTS BASED ON CARBOXYL GROUP-CONTAINING POLYMERS AND EPOXY GROUP GROUPING NETWORKS, METHOD FOR PRODUCING THE COATING AGENT AND ITS USE |
| DE4119857A1 (en) * | 1991-06-17 | 1992-12-24 | Basf Lacke & Farben | COATING AGENTS BASED ON CARBOXYL GROUP-CONTAINING POLYMERS AND EPOXY RESINS |
| DE4134301A1 (en) * | 1991-10-17 | 1993-04-22 | Herberts Gmbh | METHOD FOR PRODUCING MULTILAYER COATINGS WITH CATIONIC FILLER LAYERS |
| DE4201376C1 (en) * | 1992-01-20 | 1993-01-28 | Herberts Gmbh, 5600 Wuppertal, De | |
| GB9210450D0 (en) * | 1992-05-15 | 1992-07-01 | Ici Plc | Aqueous coating composition |
| US5472999A (en) * | 1993-05-28 | 1995-12-05 | Kansai Paint Co., Ltd. | Aqueous resin dispersion containing an epoxy resin, an amine and an acrylic resin with a polydispersity of 1 to 1.2 |
| TW289044B (en) * | 1994-08-02 | 1996-10-21 | Ciba Geigy Ag | |
| CA2231574C (en) * | 1996-07-12 | 2005-08-30 | Kansai Paint Company, Limited | Cationic electrodeposition coating composition |
| SE515437C2 (en) * | 1997-10-22 | 2001-08-06 | Lars Andersson | Figure Painting |
| US6187374B1 (en) | 1998-09-02 | 2001-02-13 | Xim Products, Inc. | Coatings with increased adhesion |
| US8198370B2 (en) * | 2007-12-28 | 2012-06-12 | E I Du Pont De Nemours And Company | Coated substrate |
| US8030408B2 (en) * | 2008-08-29 | 2011-10-04 | E. I. Du Pont De Nemours And Company | Tricure acrylic resins |
| US20100055480A1 (en) * | 2008-08-29 | 2010-03-04 | Patricia Mary Ellen Sormani | Process for preparing tricure resins |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3575901A (en) * | 1969-04-04 | 1971-04-20 | Mobil Oil Corp | Polyester and alkyd resins including tertiary alkyl manoamine component |
| US4374716A (en) * | 1981-08-06 | 1983-02-22 | Eastman Kodak Company | Novel amorphous aromatic polyester modified with amine and UV curable composition containing the same |
| JPS59142220A (en) * | 1983-02-04 | 1984-08-15 | Dainippon Ink & Chem Inc | Room temperature-curable resin composition |
| DE3534858A1 (en) * | 1985-09-30 | 1987-04-02 | Basf Lacke & Farben | SOLUBLE ACRYLATE COPOLYMERISATE CONTAINING CARBOXYL GROUPS, METHOD FOR THE PRODUCTION THEREOF AND COATING AGENTS BASED ON THE ACRYLATE COPOLYMERISATE |
| JPH0791362B2 (en) * | 1986-07-21 | 1995-10-04 | 大日本インキ化学工業株式会社 | Curable resin composition |
| DE3629470A1 (en) * | 1986-08-29 | 1988-03-10 | Basf Lacke & Farben | CARBOXYL GROUPS AND TERTIAL AMINO GROUPS CONTAINING POLYCONDENSATION AND / OR ADDITION PRODUCT, COATING AGENTS BASED ON THE SAME AND THEIR USE |
| JP2927314B2 (en) * | 1992-03-27 | 1999-07-28 | 株式会社ピーエフユー | Double-sided reading device |
-
1988
- 1988-03-02 DE DE3806641A patent/DE3806641A1/en not_active Withdrawn
-
1989
- 1989-02-10 BR BR898907300A patent/BR8907300A/en not_active IP Right Cessation
- 1989-02-10 EP EP89102327A patent/EP0330887B1/en not_active Expired - Lifetime
- 1989-02-10 WO PCT/EP1989/000125 patent/WO1989008132A1/en not_active Application Discontinuation
- 1989-02-10 AT AT89102327T patent/ATE82312T1/en not_active IP Right Cessation
- 1989-02-10 ES ES198989102327T patent/ES2035381T3/en not_active Expired - Lifetime
- 1989-02-10 EP EP89902640A patent/EP0406254A1/en active Pending
- 1989-02-10 DE DE8989102327T patent/DE58902634D1/en not_active Expired - Lifetime
- 1989-03-01 CA CA000592464A patent/CA1333432C/en not_active Expired - Fee Related
-
1990
- 1990-08-31 US US07/573,037 patent/US5283290A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| EP0330887A1 (en) | 1989-09-06 |
| US5283290A (en) | 1994-02-01 |
| DE58902634D1 (en) | 1992-12-17 |
| BR8907300A (en) | 1991-03-19 |
| EP0330887B1 (en) | 1992-11-11 |
| ATE82312T1 (en) | 1992-11-15 |
| ES2035381T3 (en) | 1993-04-16 |
| DE3806641A1 (en) | 1989-09-14 |
| WO1989008132A1 (en) | 1989-09-08 |
| EP0406254A1 (en) | 1991-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1333432C (en) | Coating agents based on polycondensation and/or addition products containing carboxyl groups and amino groups and use thereof | |
| CA2062972C (en) | Coating agent based on polymers containing carboxyl groups and crosslinking agents containing epoxide groups, process for the preparation of the coating agent and its use | |
| US5179191A (en) | Polycondensation and/or addition product containing carboxyl groups and tertiary amino groups, coating agents based thereon, and the use thereof | |
| US5691419A (en) | Carboxyl-containing acrylate copolymer and epoxy resin | |
| US5686532A (en) | Binder composition, coating composition containing this binder, production and use thereof | |
| US6197883B1 (en) | Thermosetting coating compositions containing flow modifiers prepared by controlled radical polymerization | |
| EP1817386B1 (en) | Coating compositions and process for the production of multilayer coatings | |
| EP0134691B1 (en) | Compositions curable at ambient or slightly elevated temperatures comprising a polyhxdroxy compound together with a specified epoxide/carboxylic anhydride crosslinking system | |
| TW200303340A (en) | Two component coating compositions containing highly branched copolyester polyol | |
| KR100293403B1 (en) | Coating compositions with flow modifiers and the flow modifiers and multilayered coatings | |
| SK281260B6 (en) | Aqueous two-component polyurethane coating agent, process for preparing the same and its use | |
| JPH06299039A (en) | Water-dispersible hybrid polymer | |
| JP3588078B2 (en) | Block copolymer prepared by controlled radical polymerization and its use as flow modifier | |
| US5739216A (en) | Binder composition, coating compositions containing this binder composition, production and use thereof | |
| US5401795A (en) | Water-based physically drying coating agents, manufacture and use thereof | |
| AU689917B2 (en) | Water-dispersible resin composition and process for producing the same | |
| JP4005642B2 (en) | Coating composition, its manufacture and its use | |
| CN101977973A (en) | Process for producing a multilayer coating | |
| EP0770101B1 (en) | Catalytic compositions and coatings made therefrom | |
| US5214104A (en) | Compositions suitable as binders and their use in coating and sealing compositions | |
| JP2004531595A (en) | Reactive non-isocyanate coating composition | |
| AU2002251041A1 (en) | Reactive non-isocyanate coating compositions | |
| JP4065029B2 (en) | Binder composition, coating composition containing it, its production and its use | |
| EP0469646A1 (en) | Hybrid polymer, aqueous dispersions and coating composition therefrom | |
| KR20040061159A (en) | water soluble Thermosetting polyester resin composition and method of preparing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |