MXPA01010525A - Coating agents which can be used for multi-layer enameling - Google Patents

Abstract

The invention relates to coating agents containing organic solvents and/or water and optionally containing pigments and/or fillers and/or additives commonly used in enamels. The inventive coating agents also comprise a bonding agent/cross-linking system. The coating agents contain:A) 20 to 80 wt.%carboxyl-functional (meth)acrylic copolymers and/or carboxyl-functional polyesters which can be urethanized or modified using lactone and whose carboxyl-functionality corresponds to an acid number ranging from 15 to 300 mg KOH/g;B) 80 to 20 wt.%epoxide-functional (meth)acrylic copolymers with a calculated epoxide equivalent weight ranging from 200 to 700 g/mol, whereby the weight percentages of constituents A) and B) total 100 wt.%and the cross-linking ratio between the carboxyl groups of component A) and the epoxide groups of component B) lies between 1:1 and 1:3;C) 0 to 30 wt.%polymer polyols C) with regard to the solid weight total of constituents A) and B);D) 0 to 20 wt.%of additional cross-linkers D) with regard to the total of constituents A), B) and C);and E) 0 to 10 wt.%polyepoxides and/or monoepoxides with regard to the solid weight total of constituents A) and B), whereby the epoxide-functional (meth)acrylic copolymers B) have a branched molecular structure corresponding to a calculated branching equivalent weight ranging from 5000 to 60000 g/mol.

Description

ADEQUATE COATING COMPOUNDS FOR MULTIPLE LAYER LINKAGE DESCRIPTIVE MEMORY The invention relates to coating compositions and to the use thereof in the preparation of multilayer lacquers, for example, in the automotive sector, in particular in the preparation of two-coat lacquers of the base lacquer / clear lacquer type. Coating compositions which are cured with ester formation and which are based on a combination of epoxy functional component and carboxyl functional component are known, for example, from EP-A-0 598 280. Generally speaking, the compounds of Such coatings are characterized by good chemical and acid resistance of coatings prepared from them and baked, and are therefore particularly suitable as clear lacquers or topcoat lacquers in automotive OEM finish. The object of the invention is to provide interlaxable coating compounds by reaction of carboxyl and epoxy groups which are improved in terms of solvent resistance, in particular resistance to super-grade gasoline, particularly in the case of sub-home coatings. It should be possible to use the coating compounds to be found as coating compounds of nn-i ~ - ** -y ** - < • - * transparent lacquer for the production of two-coat lacquers of base lacquer / clear lacquer, of the type normally found in particular in the automotive finishing field. The object is achieved by curable coating compositions containing a binder / entanglement system, organic solvents and / or water, and optionally pigments and / or fillers and optionally additional conventional lacquer additives, in which the binder system / The entanglement agent contains from 20 wt% to 80 wt% of one or more functional carboxyl functional groups A) selected from carboxyl functional (meth) acrylic copolymers and / or carboxyl functional polyesters the carboxyl functionality of which corresponds in each case to a acid value of 15 to 300 mg KOH / g and 20% by weight to 80% by weight of one or more B) epoxy functional (meth) acrylic copolymers with a calculated epoxy equivalent of 200 g / mol to 700 g / mol, the percentages by weight adding up to 100% by weight, and in which the ratio of entanglement between carboxyl groups of components A) and epoxy groups of components B) is from 1: 1 to 1: 3, characterized in that the epoxy functional (meth) acrylic copolymers B) have a branched molecule structure corresponding to a calculated branching equivalent weight of 5000 g / mol to 60,000 g / mol. The binder / interlacing agent system of the coating compositions according to the invention contains components A) and B) as optional components and optionally components C), D) and / or E) which are explained below. For example, the coating compounds according to the invention can only contain components A) and B) as the binder / entangling agent system, or the binder / interlacing agent system of the coating compounds according to the invention additionally contains the optional components C), D) and / or E). The resin solids of the coating compounds according to the invention are formed from the sum of the resin solids or the non-volatile proportions of the components A), B) and the optional components C), D) and E ). The curing of the coating compounds according to the invention is based on the chemical reaction, which takes place during baking, of the reactive groups of components A) and B) which are complementary to one another; said reaction is the addition of the carboxyl groups to the epoxy groups with the formation of carboxylic acid ester bonding. The coating compounds according to the invention contain, as component A), one or more functional A) carboxyl components. The functional carboxyl component A) of the coating compounds according to the invention is carboxyl functional (meth) acrylic and / or carboxyl functional polyester copolymer, the carboxyl functionality of which corresponds in each case to an acid value of 15 to 300 mg KOH / g. The carboxyl functional (meth) acrylic copolymers and / or carboxyl functional polyesters can be urethanized and / or modified by reaction with lactones. The carboxyl functionalized (meth) acrylic copolymers optionally containing urethane group and / or modified by lactone of component A) preferably have a number average molecular weight (MWn) of 1000 g / mol to 30,000 g / mol. The functionalized carboxyl polyesters optionally containing urethane group and / or modified by lactone of component A) preferably have a calculated molecular weight of 500 g / mol to 4000 g / mol. The acid value is from 15 to 300 mg KOH / g in each case, preferably from 30 to 250 mg KOH / g. During the preparation of copolymers or polyesters (meth) acrylics containing carboxyl group of component A), which may optionally contain urethane groups in each case, the carboxyl groups can be introduced directly by the use of building blocks containing carboxyl group. Examples of suitable carboxyl group-containing monomers which can be used to construct (meth) acrylic copolymers containing carboxyl group include unsaturated carboxylic acids such as, for example, acrylic, methacrylic, itaconic, crotonic, isocrotonic, aconitic, maleic and fumaric acids, medium esters of maleic and fumaric acid and carboxyalkyl esters of methacrylic acid, for example beta-carboxylic acrylate and adducts of hydroxyalkyl (meth) acrylates with carboxylic acid anhydrides such as, for example, the ethyl ester of mono-2- acid (meth) acryloxyphthalic.

The (meth) acrylic expression is used in the present description and the patent claims. This means acrylic and / or methacrylic. However, during the preparation of (meth) acrylic copolymers or polyesters containing carboxyl group and optionally containing urethane group of component A), it is also possible to initially build a polymer containing hydroxyl groups and optionally already containing carboxyl groups and introduce the groups carboxyl completely or partially in a second step by reaction with carboxylic acid anhydrides. With this mode of operation, it is possible to operate with quantity ratios so that optionally sufficient hydroxyl groups remain to allow urethanization to be carried out. Carboxylic acid anhydrides suitable for addition to the hydroxyl group-containing polymers which may already contain carboxyl groups include the anhydrides of di- and polycarboxylic acids such as, for example, preferably anhydrous phthalic, tetrahydro-, methylhexahydro-, hexahydrophthalic and succinic . Examples of suitable monomers for the introduction of hydroxyl groups into (meth) acrylic copolymers optionally containing urethane group of component A) include hydroxyalkyl (meth) acrylates such as, for example, hydroxyethyl (meth) acrylate, and (met) isomeric hydroxypropyl acrylates in terms of the position of the hydroxyl group, hydroxybutyl (meth) acrylates, and reaction products of methacrylic acid with the glycidyl ester of a carboxylic acid with a tertiary alpha carbon atom. The formation of these latter reaction products can take place before, during or after the polymerization reaction. During the preparation of the (meth) acrylic copolymers of component A), additional olefinically unsaturated monomers can be used in addition to the monomers mentioned above, particularly those which, in addition to an olefinic double bond, do not contain additional functional groups. Examples of additional suitable olefinically unsaturated monomers include, in particular, alkyl esters of methacrylic acid containing, in the alkyl part, for example from 1 to 20 carbon atoms or more, such as, for example, methyl (meth) acrylate, (meth) ethyl acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, hexyl (meth) acrylate, (meth) cyclohexyl acrylate, 2-ethylhexyl (meth) acrylic, decyl (meth) acrylate, hexadecyl (meth) acrylate. Examples of additional suitable olefinically unsaturated monomers include the alkyl esters of maleic, fumaric, tetrahydrophthalic, crotonic, isocrotonic, vinylacetic and itaconic acids containing, in the alkyl part, for example from 1 to 20 carbon atoms or more. Moreover, small proportions of monomers having at least 2 olefinic, polymerizable double bonds can also be used. The proportion of these monomers is preferably less than 5% by weight, based on the total weight of the monomers. Examples of such compounds include hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexamethylene bis (meth) acrylate, trimethylolpropane tri (meth) acrylate, and divinyl benzene and similar compounds. The monovinyl aromatic compounds are an additional suitable component. They preferably contain from 8 to 9 carbon atoms per molecule. Examples of suitable compounds include alpha-methylstyrene and the isomeric methylstyrenes, particularly vinyl toluenes and styrene. The preparation of the (meth) acrylic copolymers of component A) carboxyl functional takes place by free radical copolymerization. It may be advantageous to add some of the monomers in stepwise intervals. In order to prepare the (meth) acrylic copolymers of component A), the monomers or the monomer mixture used can contain radical initiators. If the radical initiators are not contained in the monomer mixture, they can optionally be added at slightly staggered intervals or added separately to the monomer mixture. Post-polymerization can take place over a relatively long period, for example over a period of several hours. It is then possible to obtain the desired solids content for example, in the order of magnitude from 30% by weight to 80% by weight, for example, 50% by weight to 60% by weight, using a conventional lacquer solvent. This preparation takes place, for example, as polymerization of free radical solution known to the person skilled in the art, using, for example, from 0.1% by weight to 4% by weight based on the initial weight of monomers, of a radical initiator. Examples of radical initiators include dialkyl peroxide, diacyl peroxide, hydroperoxides, peresters, peroxydicarbonates, ketátalos, ketone peroxides; azo compounds such as 2,2'-azo-bis- (2,4-dimethylvaleronitrile), azo-bis-isobutyronitrile, C-C-cut initiators such as, for example, benzpinacol derivatives. For the possible urethanization of the carboxy functionalized (meth) acrylic copolymers of component A), the hydroxyl groups of the functionalized (meth) acrylic carboxy copolymers of component A) can be reacted with mono-, di-, tri- or polyisocyanates in an additional reaction step. Examples of isocyanates suitable for urethanization include phenyl isocyanate, and the polyisocyanates mentioned below by way of example in the description of additional entanglement agents D) and the products of defunctionalization thereof which can be obtained by reaction with less than stoichiometric amounts of monoalcohols, based on the isocyanate content. The amount of di-, tri- or polyisocyanates that are used for urethanization is selected in a manner known to those skilled in the art so that gelation is avoided. Naturally, it is also possible to urethane functional (meth) acrylic hydroxyl copolymers before the carboxyl groups are introduced by reaction with acid anhydrides. Polyesters containing carboxyl group and optionally containing urethane group of component A) can be constructed by conventional methods from aliphatic and / or cycloaliphatic alcohols dihydric, trihydric or higher, optionally together with monohydric alcohols and from aliphatic, carboxylic acids, aromatics and / or cycloaliphatics, particularly dicarboxylic acids, and polycarboxylic acids of higher valency. Examples of suitable alcohols include aliphatic diols such as ethylene glycol, propane-1,2-diol, propane-1,3-diol, 2,2-diethylpropane 1,3-diol, isomeric butane diols, pentane-1, 5- diol, 3-methylpentane-1,5-diol, hexane-1,6-diol, 2-ethylhexane-1,6-diol, 2,2,4-trimethylhexane-1,6-diol, 1,4-dimethylolcyclohexane , polyhydric aliphatic alcohols such as glycerol, trimethylolethane, ditrimethylolpropane, trimethylolpropane, pentaerythrotol and etherification products of diols and polyols, for example, di- and triethylene glycol, polyethylene glycol, neopentyl glycol esters of hydroxypivalic acid. Examples of suitable carboxylic acids include adipic acid, azelaic, 1,3- and 1,4-cydohexane dicarboxylic, tetrahydrophthalic, hexahydrophthalic, endomethyltetrahydrophthalic acid, isomeric italic acids and anhydrides thereof and derivatives thereof capable of esterification. Iguial that the carboxyl functional (meth) acrylic copolymers of component A) already described above, the carboxyl functional polyesters of component A) can be urethanized. The reaction conditions and the polyisocyanates that can be used are the same as for the (meth) acrylic copolymers. It is possible to introduce the urethane groups by reaction of the carboxyl and hydroxyl functional polyesters with higher mono-, di-, tri- or higher functionality polyisocyanates. It is also possible to introduce the urethane groups during the synthesis of the polyesters themselves. This takes place, for example, by exchanging di- or tricarboxylic acids completely or partially with di- or triisocyanates. For modification with lactones, the carboxyl groups of the carboxy functional (meth) acrylic copolymers and polyesters of components A) can be "chain extended" with a lactone. The same applies to hydroxyl groups optionally contained in the (meth) acrylic copolymers and polyesters of component A). The "chain extension" is obtained as a result of the addition of lactones to the carboxyl and / or hydroxyl groups that takes place with ring opening. Accordingly, the exposed carboxyl and hydroxyl end groups are obtained. The addition of lactones preferably takes place for carboxy functional (meth) acrylic copolymers and polyesters of component A) which are free of OH groups. The addition of the lactone preferably takes place as the final synthesis step during the preparation of the affected component A). An example of a lactone that is particularly preferred is epsilon caprolactone. The curable coating compositions according to the invention contain epoxy-functional (meth) acrylic B) copolymer with a calculated epoxy equivalent of 200 to 700 g / mol, preferably from 250 to 500 g / mol and particularly from 300 to 450 g / mol and a branched molecule structure corresponding to a branched equivalent weight calculated from 5000 to 60,000 g / mol, in each case based on the solids B). The number average molecular weight (PMn), determined by gel permeation chromatography with polystyrene standard of the epoxy functional (meth) acrylic copolymers B) can be, for example, 2500 to 10,000, preferably 3000 to 8000. The preparation of the epoxy functional (meth) acrylic copolymers of component B) takes place by free-radical polymerization, particularly solution polymerization, is well known to the person skilled in the art, for example, from the explanations mentioned above in connection with resins A) Functional carboxyl prepared by free radical polymerization. During free radical copolymerization, epoxy functional olefinically unsaturated monomers (I) capable of free radical polymerization and comonomers (II) capable of free radical copolymerization are used in a weight ratio so that (meth) acrylic copolymers B ) obtained have an epoxical equivalent of 200 to 700 g / mol, preferably 250 to 500 g / mol and particularly of 300 to 450 g / mol, and an equivalent branching weight calculated from 5000 to 60,000 g / mol, in each case in base to solids B). The term epoxy equivalent of (meth) acrylic copolymers B) means the amount of solids of B) in grams containing one mole of epoxy groups. The term branching equivalent weight of (meth) acrylic copolymers B) means the amount of solids B) in grams containing one mole of branches. The term "branching" within the meaning of the present invention means each individual binding site created by incorporating, by polymerization, di- or polyunsaturated comonomers, for example, of the type Ia described below, said binding sites lying between the structures of inherently linear polymer base which are substantially constructed from monounsaturated monomers (such as, for example, types I and IIb which are explained below). This is illustrated by the example of a (meth) acrylic copolymer B), which contains divinylbenzene as the only representative of comonomers that lead to branching and fully incorporated by polymerization: the amount of resin of solid B) in grams containing one mole of Fully incorporated divinylbenzene by polymerization corresponds to the branching equivalent weight of the (meth) acrylic copolymer B). Examples of epoxy functional, olefinically unsaturated monomers (I) capable of free-radical polymerization and suitable for the preparation of epoxy-functional (meth) acrylic copolymers (B) include (meth) allylicidyl ether, 3,4-epoxy-1 -vinylcyclohexane, epoxycyclohexyl (meth) acrylate, vinyl glycidyl ether, but particularly glycidyl (meth) acrylic acid. The epoxy functional (meth) acrylic copolymers B) are preferably glycidyl (meth) acrylate copolymers. During the preparation of the epoxy functional (meth) acrylic copolymers of component B), the comonomers (lia) used lead to a branched molecule structure of the (meth) acrylic copolymers corresponding to a calculated branching equivalent weight of 5000 to 60,000 g / mol, based on solids B). The comonomers (lia) are compounds having at least two olefinic double bonds capable of free radical polymerization in the molecule. Said comonomers are used, for example, in a proportion of 0.5% by weight to 5% by weight, based on the total weight of monomers used for the preparation of the (meth) acrylic copolymers of component B). Examples of comonomers (lia) having at least two olefinic double bonds capable of free-radical polymerization include hexane diol (meth) acrylate, ethylene glycol di (meth) acrylate, butane di (meth) acrylate, hexamethylene bis (meth) acrylamide, tri (meth) acrylate trimethylol propane, divinyl benzene. Examples of additions of comonomers (lia) include compounds that can be prepared by condensation or preferably by addition reaction of complementary compounds containing, in each case, in addition to one or more olefinic double bonds, one or more additional functional groups in the molecule . Additional functional groups of the individual complementary compounds are pairs of reactive groups that are complementary to one another, particularly groups that are capable of reacting together within the meaning of a possible condensation or addition reaction. The condensation or addition reaction, optionally catalyzed, can take place before or preferably during and / or after the copolymerization with complete consumption of one or both reactive groups which are complementary to each other. The comonomers (Na) which can be prepared by condensation or preferably by addition reaction of complementary compounds can also be prepared separately in the first instance before they are used in copolymerization for the preparation of the functional (meth) acrylic (B) epoxy copolymers.; they are preferably formed during copolymerization in situ and / or after the copolymerization has ended. In each case, the formation of comonomers (lia) occurs with the complete consumption of one or both of the complementary reactive groups. Within the context of the present invention, comonomers (lia) prepared by addition reaction are preferred. Non-limiting examples of comonomers (lia) containing more than one olefinic double bond and which are prepared by condensation reaction include reaction products formed from alkoxysilane functional (meth) acrylic monomers after hydrolysis with alcohol diisocytion and bridging of siloxane. Additional examples include reaction products formed from hydroxyalkyl (meth) acrylates and blocked olefinically unsaturated isocyanates on the isocyanate group such as isocyanate (meth) acrylate alkyl or isocyanate of N-α-propenyl-alpha, alpha-d-methylbenzyl, with dissociation of the blocking agent and formation of urethane groups. Non-limiting examples of comonomers (lia) containing more than one olefinic double bond and preferably prepared by addition reaction include addition products formed from hydroxyalkyl (meth) acrylics and olefinically unsaturated isocyanates such as (meth) acrylate isocyanatoalkyl or isocyanate of m-isopropenyl-alpha, alpha-dimethylbenzyl with the formation of a urethane group, or reaction products formed by adding ring opening of the epoxy group of unsaturated epoxy compounds to the carboxyl group of an unsaturated acid with the formation of an ester and a hydroxyl group. Within the context of the present invention, the addition product formed from glycidyl (meth) acrylate and (meth) acrylic acid are particularly preferred. In addition to the epoxy groups, the B) (meth) acrylic copolymers can contain hydroxyl groups, for example, corresponding to a hydroxyl value of up to 60 mg KOH / g, preferably from 0 to 40 mg KOH / g, based on the solids B). The hydroxyl groups can be originated, for example, from comonomers (lia) having at least two olefinic double bonds and at least one hydroxyl group in the molecule and / or hydroxyl-functional comonomers (llb) having only one olefinic double bond in the molecule are used. Comonomers (11b) suitable for the introduction of a suitable hydroxyl group contained in the epoxy functional (meth) acrylic copolymers of component B) include, for example, hydroxyalkyl (meth) acrylates such as, for example, (meth) acrylate hydroxyethyl, isomeric hydroxypropyl (meth) acrylates in terms of the position of the hydroxyl group, hydroxybutyl (meth) acrylates and reaction products of (meth) acrylic acid and the glycidyl ester of a carboxylic acid with a tertiary alpha carbon atom.

In addition to the epoxy functional, olefinically unsaturated monomers (I), the comonomers (Na) which lead to a branched molecule structure, and optionally contained functional hydroxyl comonomers (llb), the epoxy functional (meth) acrylic copolymers can contain additional comonomers (lie) capable of free radical copolymerization which, in addition to the olefinic double bond, do not contain functional groups that influence or disrupt the healing mechanism of the coating compounds according to the invention, in particular, no additional functional groups , for example, alkyl esters of (meth) acrylic acid containing, for example, from 1 to 20 carbon atoms or more in the alkyl part, such as, for example, methyl (meth) acrylate, (meth) acrylate ethyl, propyl (meth) acrylate, butyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, (met) acri hexyl latium, cyclohexyl alkyl (meth) acrylate, isobornyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, hexadecyl (meth) acrylate, lauryl (meth) acrylate, compounds monovinyl aromatics such as alpha-methylstyrene, isomeric methyl styrenes, vinyl toluenes, particularly styrene; alkylic esters of maleic, fumaric, tetrahydrophthalic, crotonic, isocrotonic, vinylacetic and itaconic acids containing, for example, from 1 to 20 carbon atoms or more in the alkyl part. Branched (meth) acrylic copolymers B) preferably contain, in addition to the epoxy groups and hydroxyl groups optionally contained, no additional functional group; expressly, they do not contain carboxyl groups or are devoid of carboxyl groups. Branched (meth) acrylic copolymers B) are particularly preferably those whose branches are derived from adducts of glycidyl (meth) acrylate / methacrylic acid as comonomer (lia), incorporated by polymerization in an amount ratio of 1 to 4% by weight , based on the total amount of olefinically unsaturated monomers used to prepare branched (meth) acrylic copolymers. During the preparation of the coating compounds according to the invention, the quantity ratios are selected such that the molar ratio of carboxyl to epoxy groups between the component A) containing carboxyl group and the (meth) acrylic copolymers B) epoxy functionalities is from 1: 1 to 1: 3, preferably 1: 1.2 to 1: 2.5. The coating compounds according to the invention may contain, in each case based on the solids content, from 0% by weight to 30% by weight, for example from 5% by weight to 30% by weight, of one or more polymer polyols C) which are different from components A) and B), based on the sum of the solids weights of components A) and B). Polyol polyols C) are, for example, polymer polyols selected from hydroxyl functional polyesters, polyurethanes and / or (meth) acrylic copolymers which are different from components A) optionally containing hydroxyl groups. The polymer polyols C) which are used in the coating compositions according to the invention have, for example, a number-average molecular weight (MWn) of from 500 to 10,000. The polymer polyols C) have at least two hydroxyl functions in the molecule. In addition to the hydroxyl groups corresponding to a hydroxyl value of, for example, 30 to 350 mg KOH / g, the polymer polyols C) may also contain carboxyl groups corresponding to an acid value of 0 to 15 mg KOH / g . The polymer polyols C) preferably contain, in addition to the hydroxyl groups and the carboxyl groups optionally present, no further functional groups, particularly no epoxy groups. In addition to the components A), B) and C), the coating compounds according to the invention may also contain one or more crosslinking agents D) which are different from the A components), B) and C) and allowing additional entanglement, particularly with the incorporation of hydroxyl groups, for example, hydroxyl groups which are present in the binder system and / or which are formed during baking during the course of the addition reaction of epoxide / carboxyl. The additional entanglement agents D) are contained in amounts proportions of, in total, from 0 wt% to 20 wt%, based on the sum of components A), B) and C), in each case based on the solid content. Examples of additional entanglement agents D) include conventional aminoplast coating resins, particularly melamine resins. Examples include butanol, isobutanol and / or methanol-etherified melamine resins. Additional examples of crosslinking agents D) include interlaced triazine-based components with ester group formation, particularly with the formation of urethane groups (carbamic acid ester groups), such as preferably tris (alkoxycarbonylamino) triazine. Additional examples of additional entanglement agents D) include conventional blocked polyisocyanates which can be prepared from free polyisocyanates by reaction with compounds capable of dissociation again under the baking conditions and containing an active hydrogen atom. Examples of suitable polyisocyanates include, in particular, cycloaliphatic and aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylene diisocyanate, cyclohexane-1, 3- and 1,4-diisocyanate, isophorone diisocyanate, biscyclohexylmethane diisocyanate and polyisocyanates derived therefrom, for example, of the type containing biuret, isocyanurate, uretidione, carbodiimide, urethane and / or allophanate groups. Well-known polyisocyanates which are commonly used in the preparation of lacquers are particularly suitable, for example, modification products of the above-mentioned simple polyisocyanates containing biuret, isocyanurate or urethane groups, particularly tris- (6-isocyanatohexyl) biuret, the isocyanurate isophorone diisocyanate derivative or hexane diisocyanate, or low molecular weight polyisocyanates containing urethane groups, of the type obtainable by reaction of isophorone diisocyanate which is used in excess with simple polyhydric alcohols on the molecular weight scale of 62 to 300, particularly with trimethylolpropane. Conventional blocking agents are used, for example, compounds having an active hydrogen atom, selected from CH-acid compounds such as acetyl acetone, acetic acid acetic acid alkyl esters, dialkyl malonic acid esters; alcohols, oximes such as methyl ethyl ketoxime; lactams such as epsilon caprolactam; imidazole or pyrazole derivatives. Additional examples of additional entanglement agents D) that may be contained in the coating compounds according to the invention include organic compounds having at least two cyclic carboxylic acid anhydride groups per molecule. The carboxylic acid anhydride group content of these compounds (formally calculated as C4O3, molecular weight = 96) is preferably from 5 wt% to 88 wt%, particularly preferably from 6 wt% to 30 wt%. Suitable examples include esters of trimethylic anhydride of ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, glycerol or trimethinolpropane, preferably prepared in a ratio of one mole of trimellitic anhydride per mole of hydroxyl groups. 1 Additional suitable polyanhydrides include, for example, benzophenotetracarboxylic acid dianhydride and 1,4,4,5-benzenetetracarboxylic acid dianhydride. Preferred polyanhydrides include copolymers of olefinically unsaturated monomers containing, per molecule, on a statistical average, at least two cyclic carboxylic acid anhydride groups. These are preferably copolymers of maleic anhydride and / or itaconic anhydride with conventional comonomers as described, for example, in relation to component A). Moreover, the coating compounds according to the invention may contain from 0 wt% to 10 wt% of one or more polyepoxide components that are different from the epoxy-functional (meth) acrylic copolymers B) and / or one or more monoepoxy compounds E), in each case based on the sum of the solids A) and B). Examples of polyepoxide components E) that are different from the epoxy functional (meth) acrylic copolymers of component B) include compounds having at least two epoxy functions in the molecule and a calculated epoxy equivalent of, for example, 200 to 700, preferably from 250 to 500, and particularly from 300 to 400, in each case based on the solid resin. The number average molecular weight (PMn) is preferably 200 to 10,000. Examples of polyepoxide components E) include conventional di- or polyepoxides, for example, polyglycidyl ethers based on diethylene glycol, dipropylene glycol, polypropylene glycol, bisphenol A or triglycidyl glycerol ethers. Additional examples of di- or polyepoxides include those based on di- or polyglycidyl esters. Examples thereof include reaction products of 1-hydroxy-2,3-epoxypropane with phthalic or terephthalic acid to bis (2,3-epoxypropyl ester) phthalic or terephthalic acid or a diglycidyl ether of bisphenol A with trimellitic anhydride polyesters, for example, having a number average molecular weight (MWn) of 500 to 2000. Preferred polyepoxide components E) include epoxy functional (meth) acrylic copolymers, particularly glycidyl (meth) acrylate copolymers with a structure unbranched of the macromolecule. The number average molecular weight (PMn) may be, for example, from 1,000 to 10,000, preferably from 2,000 to 5,000. The monoepoxides E) are substances that are substantially non-volatile under the baking conditions, for example, the volatile ratio is preferably less than 1% by weight, based on the total amount of monoepoxide E). The molecular weights of monoepoxides are more than 150 and compounds of this type having a number average molecular weight of up to 3000, particularly preferably below 1000 are preferred. Examples of such compounds include, for example, reaction products of a diglycidyl compound, for example, a diglycidyl ether such as one mole of diglycidyl ether of bisphenol A and one mole of a saturated or unsaturated monocarboxylic acid such as acetic acid, propionic acid or nonanoic acid. Additional examples include reaction products of di- or polyepoxides such as, for example, diethylene glycol-based polydiglycidyl ether, dipropylene glycol, with a number average molecular weight (PMn) of up to 2000 and triglycidyl ethers of glycerol and / or polyphenols such as bisphenol. A or F with the monocarboxylic acids mentioned above. The glycidyl ether of versatic acid is particularly preferred. The coating compositions according to the invention in the ready-to-use state have, for example, a solids content formed from the resin solids of the binder system / crosslinking agent and optionally contain no volatile constituent, of 35% in weight at 60% by weight. They contain, as volatile constituents, organic solvents of the type conventionally used in the preparation of coating compounds, for example, lacquers. The organic solvents can be added separately preferably during the preparation of the coating compounds according to the invention or they can be originated as a constituent from other components used in the preparation of the coating compounds according to the invention, by example, of the binder / entanglement agent system. Examples include glycol ethers such as ethoxypropanol, butoxypropanol, hexyl glycol, isopropyl glycol, methoxypropanol, methoxybutanol, butyl glycol, butyl diglycol, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol dimethyl ether, ether propylene glycol butyl, glycol ether esters such as ethyl glycol acetate, butyl glycol acetate, methyl glycol acetate, 3-methoxy-n-butyl acetate, butyl diglycol acetate, methoxypropyl acetate, ethyletoxy propionate, ethoxypropyl acetate, propylene glycol diacetate; esters such as butyrolactone, propylene carbonate, ethyl acetate, isobutyl acetate, isoamyl acetate; ketones such as methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, ethylamyl ketone, methyl isoamyl ketone, diisobutyl ketone, cyclohexanone, isophorone; alcohols such as methanol, ethanol, n- and isopropanol, n- and isobutanol 2-ethylhexanol, cyclohexanol, benzyl alcohol, isodecanol, isononyl alcohol, isotridecyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, hexylene glycol; aromatic hydrocarbons such as xylene, toluene, tetralin and mixtures of aromatic and araliphatic hydrocarbons on the boiling scale of 150 ° C to 270 ° C, eg, Solvesso 100 (registered trademark for a mixture of aromatic hydrocarbons with a boiling scale of 155 ° C to 185 ° C) and aliphatic hydrocarbons such as n-heptane, isoheptane, cyclohexane and mixtures of aliphatic hydrocarbons in the boiling range of 60 ° C to 250 ° C, for example gasoline and gasoline fractions. The coating compounds according to the invention may also be present in aqueous form in which case they may be free of organic solvents or contain a small proportion of organic solvents. The water content is, for example, 30% by weight to 70% by weight, the content of solvent other than water is, for example, from 0% by weight to 20% by weight. For the preparation of aqueous compositions it is possible, for example, to largely remove organic solvents from the functional carboxy functional component A, for example, by distillation, then neutralize part of the carboxyl groups, for example, with bases such as triethylamine or dimethylethanolamine and then form an emulsion in water. The other constituents of the coating compounds according to the invention can then be incorporated, optionally, in this emulsion in which component A) acts as an emulsification resin. The addition of all other constituents can also take place before the emulsification. It is also possible, for example, to mix the carboxyl functional resin of component A) from which the solvents have been greatly eliminated with the resin of component B) from which the solvent has been greatly removed, and to emulsify said resins in a water mixture. / emulsifier using a rotor / stator unit. It is also possible to emulsify the components separately and mix the emulsions. Suitable emulsifiers include, for example, ethoxylated sorbitan fatty acid esters. If the coating compounds according to the invention are to be used as pigmented topcoat lacquers, for example, in the preparation of the outer top layer of a multi-layered lacquer, they may contain pigments and optionally fillers. The weight ratio of pigment plus filler / resin solids is on the scale of, for example, 0.05 to 2: 1. Examples of pigments include inorganic and / or organic colored pigments and / or special effect pigments such as, for example, titanium dioxide, iron oxide pigments, carbon black, azo pigments, phthalocyanine pigments, quinacrodone pigments, pigments metallic, for example, titanium, aluminum or copper, interference pigments such as, for example, aluminum coated with titanium dioxide, coated mica, pigments with special effect type graphite effect, iron oxide in the form of flakes, pigments of phthalocyanine of copper in the form of scales. Examples of fillers include conventional lacquer fillers such as, for example, talc and silicates. Moreover, the coating compositions according to the invention which can be used as pigmented topcoat layers or preferably as clearcoats can contain conventional lacquer additives in conventional amounts, for example up to 5% by weight based on the total lacquer., for example, transparent pigments or fillers, leveling agents, reagent thinners, dyes, light stabilizers, antioxidants, rheology influencing agents such as, for example, disubstituted ureas, polymer microparticles, for example, epoxy-functional polymer microparticles. , compounds that produce formaldehyde in at least during baking, catalysts to catalyze the reaction of carboxyl and epoxy groups and / or to catalyze the additional entanglement optionally possible. The coating compounds according to the invention can be applied by known methods, particularly by spraying in layer thicknesses, for example, from 25 μm to 60 μm. After an evaporation phase, the applied coating composition is entangled by heating. The furnace temperatures are, for example, from 60 ° C to 180 ° C, preferably from 60 ° C to 160 ° C. The coating compositions according to the invention can be used, for example, for the preparation of the outer pigmented topcoat layer of a multilayer coating. In this regard, the present invention also relates to the use of the coating compounds according to the invention as topcoat lacquer compositions. The coating compositions according to the invention are preferably formulated as clear, clear lacquers which can be used for the preparation of the outer transparent lacquer layer of a multilayer lacquer. In this regard, the present invention also relates to the use of the coating compositions according to the invention as clearcoat coating compositions. For example, the clear lacquer coating composition according to the invention can be applied to a substrate provided with a pre-coating that imparts color and / or imparts special single layer or multiple layer effect and bakes. The baking temperatures of the clearcoat coating compositions according to the invention are, for example, 60 ° C to 160 ° C. For automotive applications they are, for example, 60 ° C to 160 ° C, for applications in automotive finishing, for example, in automotive OEM finishing, particularly from 80 ° C to 160 ° C and preferably from 120 ° C to 150 ° C. C. The clearcoat coating compositions according to the invention are preferably used for the preparation of a multi-coat lacquer base / clear lacquer. The application of a lacquer layer imparting color and / or imparting special effects to an optionally pre-coated substrate, particularly to pre-coated automotive bodies or parts thereof, takes place before the clear lacquer coating layer has been applied from a clear lacquer coating compound according to the invention and baked. The basecoat layer imparting color and / or imparting special effect can be baked prior to application of the clear lacquer layer of the clearcoat coating composition according to the invention, but the clearcoat coating composition according to the invention, it is preferably applied by the known wet wet method to the basecoat layer which determines the hue of the multi-layer lacquer. The application of the basecoat layer takes place by spraying from a basecoat that imparts color and / or imparts special effect transmitted by water or solvent-based in a dry layer thickness that depends on the shade, example, from 10 μm to 25 μm. After the application of the basecoat layer, after a brief instantaneous vaporization phase, for example at 20 ° C to 80 ° C, application of the clearcoat layer of the clearcoat clearcoat coating composition takes place. according to the invention, for example, by spraying, for example, in a dry layer thickness generally from 25 μm to 50 μm. Optionally, a brief instantaneous vaporization can be carried out. The substrate is then passed to the baking process in which the clear lacquer coating layer is baked together with the base lacquer layer at elevated temperatures, for example from 60 ° C to 160 ° C. The coating compounds according to the invention are not affected by undercoating conditions. It is possible, with the coating composition according to the invention, to prepare multi-layer lacquers, particularly two-coat lacquers of base lacquer / clear lacquer, particularly on motor vehicles and parts thereof with an outstanding optical / aesthetic impression , good resistance to acclimatization, good resistance to chemicals, acids and solvents.

EXAMPLE 1 Preparation of an unbranched epoxy functional methacrylic copolymer A charge of 1963 g of xylene was prepared and heated to reflux with stirring. A mixture of 327.6 g of butyl acrylate, 168.0 g of butyl methacrylate, 260.4 g of styrene, 1260.0 g of glycidyl methacrylate and 84.0 g of tertiary butyl perbenzoate was added dropwise within a period of 5 hours. The mixture was rinsed again with 168 g of xylene. The mixture was then post-polymerized under reflux for 6 hours. The branching equivalent weight calculated was infinite.

EXAMPLE 2 Preparation of a branched epoxy functional methacrylic copolymer The operations were washed out as in example 1, except that instead of 1260.0 g of glycidyl methacrylate, 1246.6 g of glycidyl methacrylate and 13.4 g of acrylic acid were used. The calculated branching equivalent weight was 11284.

EXAMPLE 3 Preparation of a branched epoxy functional methacrylic copolymer The operations were carried out as in Example 1, except that, instead of 1260.0 g of glycidyl methacrylate, 1239.8 g of glycidyl methacrylate and 20.2 g of acrylic acid were used. The branching equivalent weight calculated was 7485. The clear lacquers (A, comparison example, B and C, both according to the invention) were prepared by mixing the constituents (parts by weight) given in the following table. 1) Carboxyl functional polyester based on trimethylolpropane / 1,4-cyclohexanedicarboxylic acid / hexahydrophthalic anhydride / caprolactone, acid value 215 mg KOH / g. The clear lacquers were applied with a blade to glass sheets. The lacquers were then subjected to flash vaporization for 5 minutes and then baked for 10 minutes (first series at 125 ° C, second series at 130 ° C). High gloss clear lacquer films were obtained. The clear lacquer films obtained in this way were covered with filter paper on which xylene was sprayed. The evaporation of the xylene was prevented by covering with a glass. After 10 minutes, the filter paper was removed and the solvent residues were removed. The results of the measurement of pendulum hardness (Konig) on clear lacquer films not exposed before exposure to xylene and after 15 minutes and after 2 hours of recovery from xylene exposure can be derived from the following table. .alpha..

Claims (5)

NOVELTY OF THE INVENTION CLAIMS

1. A coating compound containing a binder / entanglement system, organic solvents and / or water, and optionally pigments and / or fillers and optionally additional conventional lacquer additives, characterized in that the binder / entanglement system contains: A) from 20% by weight to 80% by weight of one or more carboxyl functional components selected from carboxy functional (meth) acrylic esters and / or carboxyl functional polyesters, which in each case can be urethanized or modified with lactone and carboxyl functionality of which corresponds in each case to an acid value of 15 to 300 mg KOH / g, B) from 80% by weight to 20% by weight of one or more epoxy functional (meth) acrylic copolymers with a calculated epoxy equivalent from 200 g / mol to 700 g / mol, the percentages by weight of components A) and B) adding up to 100% by weight, and the ratio of entanglement between the carboxyl groups of component A) and the epoxy groups of component B) being from 1: 1 to 1: 3, C) from 0% by weight to 30% by weight of one or more polymer polyols C) which are different from components A) and B), based on the sum of the solids weights of components A) and B), D) from 0% by weight to 20% by weight of one or more additional interlacing agents D) that are different from the components A), B) and C), based on the sum of components A), B) and C), and E) from 0% by weight to 10% by weight of one or more polyepoxides and / or monoepoxides that are different from component B), based in the sum of the solid weights of components A) and B), characterized in that the epoxy-functional (meth) acrylic copolymers B) have a branched molecule structure corresponding to a calculated equivalent branching weight of 500 to 60,000 g / mol.

2. The coating composition according to claim 1, further characterized in that it is in aqueous form, the coating composition contains emulsifier or a part of the carboxyl groups of component A) are in neutralized form.

3. A process for lacquering multiple layers by applying a layer of base lacquer that imparts color and / or imparts special effect to an optionally pre-coated substrate and application of a clear lacquer coating layer, characterized in that a Clear lacquer coating layer is applied from a coating composition according to one of claims 1 or 2.

4. The use of coating compositions according to claim 1 or 2, as coating compositions of transparent or pigmented lacquer in the preparation of multiple coating lacquers.

5. The use according to claim 4, in the lacquering of automobiles. SUMMARY OF THE INVENTION The invention relates to coating agents containing organic solvents and / or water and optionally contain pigments and / or fillers and / or additives that are normally used in lacquering; The coating agents of the invention also comprise a binding / interlacing agent system; the coating agents contain; A) from 20 to 80% by weight of carboxy functional (meth) acrylic copolymers and / or carboxyl functional polyesters which can be urethanized or modified using lactone and whose carboxyl functionality corresponds to an acid number on the scale of 15 to 300 mg KOH / g; B) from 80 to 20% by weight of epoxy-functional (meth) acrylic copolymers with an equivalent weight of epoxide calculated on the scale from 200 to 700 g / mol, whereby the percentages by weight of constituents A) and B) total 100% by weight and the entanglement ratio between the carboxyl groups of component A) and the epoxide groups of component B) lies between 1: 1 and 1: 3; C) from 0 to 30% by weight of polymer polyols C) in relation to the total solid weight of constituents A) and B); D) from 0 to 20% by weight of additional interleavers D) in relation to the total of constituents A), B) and C); and E) from 0 to 10% by weight of polyepoxides and / or monoepoxides relative to the total solid weight of constituents A) and B), whereby the (meth) acrylic-B) epoxy functional copolymers have a corresponding branched molecular structure. to an equivalent branching weight calculated on the scale of 500 to 60000 g / mol. SR ald * mmf * eos * yac * P01 / 1410F