EP1200203A2 - Coloring and/or effect-creating multilayer enamel coating, method for the production thereof and its use - Google Patents

Abstract

The invention relates to a coloring and/or effect-creating multilayer enamel coating ML which is provided for a primed or non-primed substrate and which contains, in an overlapping manner: (1) a filler coat FL which absorbs mechanical energy, and (2) a coloring and/or effect-creating finishing enamel coating DL; or (1) a filler coat FL which absorbs mechanical energy, (2) a coloring and/or effect-creating base enamel coating BL, and (3) a clear enamel coating KL; or (1) a coloring and/or effect-creating base enamel coating BL, and (2) a clear enamel coating KL. At least one coat, preferably at least two coats and especially all coats of the multilayer enamel coating ML is/are made of a coating material that contains at least one constituent (A) which can be produced in an aqueous medium by radically polymerizing: a) olefinically unsaturated monomers and; b) olefinically unsaturated monomers which are different from the olefinically unsaturated monomers cited in a) and which are of formula (I) R?1R2C=CR3R4¿, wherein the radicals R?1, R2, R3 and R4¿, independent of one another, represent hydrogen atoms or radicals of alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloalkylaryl, arylalkyl or arylcycloalkyl, whereby at least two are radicals of aryl, arylalkyl or arylcycloalkyl.

Description

Color and / or effect multi-layer coating, process for their preparation and their use

The present invention relates to a new color and / or effect multi-layer coating for a primed or unprimed substrate. Furthermore, the present invention relates to a new method for producing a color and / or effect multilayer coating on a primed or unprimed substrate. Last but not least, the present invention relates to the use of the new color and / or effect multi-layer coating and the new process for its production in automotive initial and repair painting, industrial painting, including container coating and coil coating, and furniture painting.

Color and / or effect multicoat paint systems for primed or unprimed substrates are known. They usually contain a filler layer that absorbs mechanical energy and a color and / or effect coating. In another variant, they contain a filler layer, a color and / or effect base coat and a clear coat. A multi-layer coating is also frequently used for the coating of plastics, which contains a color and / or effect-imparting base coating and a clear coating. Multilayer coatings of this type are frequently produced by the wet-on-wet process, in which in particular the basecoat film is merely dried but not cured before the clearcoat film is applied, and the basecoat film and the clearcoat film are cured together.

In the coating materials used to produce known multi-layer paint and / or effect coatings, components are often used which are produced by radical polymerization of olefinically unsaturated monomers. These ingredients are also called binders designated. In the majority of cases, the binders of the type mentioned are acrylate copolymers.

Acrylate copolymers and coating materials containing them are described, for example, in the patents EP-B-0 447 428, EP-B-0 593 454, EP-B-0 052 776 or DE-A-42 04 518.

Acrylate copolymers can be prepared in bulk, solution or emulsion by generally known polymerization processes. Polymerization processes for the preparation of acrylate copolymers, in particular polyacrylate resins, are generally known and have been described many times (see, for example: Houben Weyl, Methods of Organic Chemistry, 4th Edition, Volume 14/1, pages 24 to 255 (1961)).

Further examples of suitable copolymerization processes for the preparation of acrylate copolymers are described in the patents DE-A-197 09 465, DE-C-197 09 476, DE-A-28 48 906, DE-A-195 24 182, EP-A-0 554 783, EP-B-0 650 979 WO 95/27742, DE-A-38 41 540 or WO 82/02387.

Reactors for the copolymerization processes are the customary and known stirred kettles, stirred kettle cascades, tubular reactors, loop reactors or Taylor reactors, as described, for example, in the patents DE-B-1 071 241 or EP-A-0 498 583 or in the article by K. Kataoka in Chemical Engineering Science, Volume 50, No. 9, 1995, pages 1409 to 1416.

The radical polymerization used to prepare the acrylate copolymers is often very exothermic and difficult to control. For the implementation, this means that high concentrations of monomers and / or the so-called batch procedure, in which the entire amount of the monomers is placed in an aqueous medium, emulsified and then polymerized, must be avoided. The targeted adjustment of defined molecular weights, molecular weight distributions and other properties often causes difficulties. The targeted setting of a certain property profile of the acrylate copolymers is of great importance for their use as binders in coating materials, since this can directly influence the application properties profile of the coating materials.

There has been no shortage of attempts to regulate the radical copolymerization of olefinically unsaturated monomers in a targeted manner.

International patent application WO 98/01478 describes a process in which the copolymerization is carried out in the presence of a radical starter and a thiocarbonylthio compound as chain transfer agent.

International patent application WO 92/13903 describes a process for the preparation of copolymers with a low molecular weight by radical chain polymerization in the presence of a group transfer agent which has a carbon-sulfur double bond. These compounds not only act as chain transfer agents, but also as growth regulators, so that only low molecular weight copolymers result.

International patent application WO 96/15157 discloses a process for the preparation of copolymers with a comparatively narrow molecular weight distribution, in which a monomer is reacted with a vinyl-thinned macromonomer in the presence of a radical initiator. In addition, the international patent application WO 98/37104 discloses the preparation of acrylate copolymers with defined molecular weights by radical polymerization in the presence of a chain transfer agent with a CC double bond and with radicals which activate this double bond with regard to the radical addition of monomers.

Despite significant advances in this area, there is still a lack of a universally applicable process for controlled radical polymerization which provides chemically structured polymers, in particular acrylate copolymers, in a simple manner, and with the aid of which the profile of properties of the polymers with regard to their use in coating materials which Production of coloring and / or effect multi-layer coatings are used, can be set specifically.

Therefore, it is still necessary for others, e.g. T. more complex measures to match the property profiles and material compositions of the fillers, basecoats and clearcoats so that the color and / or effect multilayer coatings have the high optical quality and interlayer adhesion required by the market and no problems such as insufficient condensation resistance of the filler layers, crack formation ( mudcracking) in the basecoats or leveling more faults or surface structures in the clearcoats.

The object of the present invention is to provide new color and / or effect multilayer coatings and new processes for their production in which at least one layer of the color and / or effect multilayer coating is produced from a coating material which can be used in a simple manner as its respective Filler, basecoat and / or Clear varnish can be adjusted. This is to be accomplished in a simple manner by specifically adjusting the property profile of the coating materials, in particular through the use of chemically structured polymers which can be obtained by radical polymerization. The resulting new color and / or effect multi-layer coatings should no longer have the disadvantages of the prior art, but should have an excellent optical quality, interlayer adhesion and condensation resistance and should not show any mud cracking, flow problems or surface structures. These chemically structured polymers should also be usable as rubbing resins, which advantageously allow pigment pastes to be mixed in particularly well for the fillers, basecoats and clearcoats used to produce the new color and / or effect multicoat paint systems.

Accordingly, the new coloring and or effect-giving multilayer coating ML for a primed or unprimed substrate was found, in the order given

(1) a mechanical energy absorbing filler layer FL and

(2) a color and / or effect top coat DL

or

(1) a mechanical energy absorbing filler layer FL,

(2) a color and / or effect basecoat BL and

(3) a clear coat KL or

(1) a color and / or effect basecoat BL and

(2) a clear coat KL,

contains superimposed, with at least one layer FL and / or DL or BL and / or KL or FL, BL and / or KL, preferably at least two layers FL, BL and / or KL or all layers FL and DL or BL and KL or FL , BL and KL of the multilayer coating ML has been or are made from a coating material which contains at least one constituent (A) which is obtained by radical polymerization of

a) at least one olefinically unsaturated monomer and

b) at least one olefinically unsaturated monomer of the general formula I which is different from the olefinically unsaturated monomer (a)

R ¹ R ² C = CR ³ R ⁴ (I),

wherein the radicals R ¹ , R ² , R ³ and R ⁴ each independently represent hydrogen atoms or substituted or unsubstituted alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloalkylaryl, arylalkyl or arylcycloalkyl radicals with the proviso that at least two of the variables R ¹ , R ² , R ³ and R ⁴ stand for substituted or unsubstituted aryl, arylalkyl or arylcycloalkyl radicals, in particular substituted or unsubstituted aryl radicals; can be produced in an aqueous medium.

In the following, the new coloring and / or effect multilayer coating ML for a primed or unprimed substrate is referred to as "multilayer coating ML according to the invention".

In addition, the new process for producing a color and / or effect multilayer coating ML was carried out on a primed or unprimed substrate

(I) producing a filler lacquer layer by applying a filler to the substrate,

(II) hardening of the filler lacquer layer, resulting in the filler layer FL,

(III) Production of a solid-color topcoat by applying a solid-color topcoat to the filler layer FL and

(IV) curing the solid-color topcoat DL, resulting in the solid-color topcoat DL,

or

(I) producing a basecoat layer by applying a basecoat to the substrate,

(II) drying the basecoat film, (III) producing a clear coat by applying a clear coat to the basecoat and

(IV) joint hardening of the basecoat layer and the clearcoat layer, which results in the basecoating BL and the clearcoat KL,

or

(I) producing a filler lacquer layer by applying a filler to the substrate,

(II) hardening of the filler lacquer layer, resulting in the filler layer FL,

(III) producing a basecoat layer by applying a basecoat to the filler layer FL,

(IV) drying the basecoat film,

(V) producing a clear coat by applying a clear coat to the basecoat and

(VI) joint hardening of the basecoat layer and the clearcoat layer, which results in the basecoating BL and the clearcoat KL,

found, in which at least one of the coating materials used in each case contains at least one constituent (A) which is obtained by radical polymerization of

a) at least one olefinically unsaturated monomer and b) at least one olefinically unsaturated monomer of the general formula I which is different from the olefinically unsaturated monomer (a)

R ^ C ^ R ^ ⁴ (I),

wherein the radicals R ¹ , R ² , R ³ and R ⁴ each independently represent hydrogen atoms or substituted or unsubstituted alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloalkylaryl, arylalkyl or arylcycloalkyl radicals with the proviso that at least two of the variables R ¹ , R ² , R ³ and R ^{4 are} substituted or unsubstituted

Aryl, arylalkyl or arylcycloalkyl radicals, in particular substituted or unsubstituted aryl radicals;

can be produced in an aqueous medium.

The new process for producing a color and / or effect multilayer coating ML on a primed or unprimed substrate is referred to below as the “process according to the invention”.

With regard to the prior art, it was surprising that the complex task on which the present invention was based could be achieved with the aid of the method according to the invention and the multilayer lacquers ML according to the invention. It was particularly surprising that the multilayer coatings ML according to the invention have excellent optical quality, interlayer adhesion and condensation resistance and no longer show any crack formation (mud cracking), flow problems or surface structures. Even more surprising was the fact that the use of thixotropic agents or rheology aids in basecoats resulted in the production of pearlescent effects and / or dichroic effects, can be largely or possibly completely dispensed with.

According to the invention, at least one layer of the multilayer coating ML according to the invention is produced from a coating material which contains a constituent (A). According to the invention, it is advantageous if at least two layers, in particular all layers, of the multilayer coating ML according to the invention are produced from such coating materials.

According to the invention, component (A) is produced by controlled free-radical polymerization of at least one olefinically unsaturated monomer (a) and at least one olefinically unsaturated monomer (b), which is different from the monomer (a).

Examples of suitable monomers (a) are

al) essentially acid group-free (meth) acrylic esters such as (meth) acrylic or alkyl cycloalkyl esters with up to 20 carbon atoms in the alkyl radical, in particular methyl, ethyl, propyl, n-butyl, sec-butyl, tert-butyl -, hexyl, ethylhexyl, stearyl and

Lauryl acrylate or methacrylate; cycloaliphatic (meth) acrylic acid esters, especially cyclohexyl, isobornyl, dicyclopentadienyl, octahydro-4,7-methano-1H-indene methanol or tert-butylcyclohexyl (meth) acrylate; (Meth) acrylic acid oxaalkyl esters or oxacycloalkyl esters such as ethyl triglycol (meth) acrylate and methoxy oligoglycol (meth) acrylate with one

Molecular weight Mn of preferably 550 or other ethoxylated and / or propoxylated hydroxyl group-free (meth) acrylic acid derivatives. These can be used in minor amounts of higher functional (meth) acrylic acid alkyl or cycloalkyl esters such as ethylene glycol, propylene glycol, diethylene glycol, Dipropylene glycol, butylene glycol, pentane-1, 5-diol, hexane, 1,6-diol, octahydro-4,7-methano-1H-indene-dimethanol or cyclohexane-1,2-, 1,3 - or -l, 4-diol-di (meth) acrylate; Trimethylolpropane di or tri (meth) acrylate; or pentaerythritol di-, tri- or tetra (meth) acrylate. In the context of the present invention, minor amounts of higher-functional monomers are understood to mean those amounts which do not lead to crosslinking or gelling of the copolymers (A).

a2) Monomers which carry at least one hydroxyl group, amino group, alkoxymethylamino group or imino group per molecule and are essentially free of acid groups, such as hydroxyalkyl esters of acrylic acid, methacrylic acid or another alpha, beta-olefinically unsaturated carboxylic acid which are derived from an alkylene glycol which is associated with the Acid is esterified, or the unsaturated ones by reaction of the alpha, beta-olefin

Carboxylic acid with an alkylene oxide are available, in particular hydroxyalkyl esters of acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleic acid, fumaric acid or itaconic acid, in which the hydroxyalkyl group contains up to 20 carbon atoms, such as 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl-, 4-

Hydroxybutyl acrylate, methacrylate, ethacrylate, crotonate, maleate, timateate or itaconate; or hydroxycycloalkyl esters such as 1,4-bis (hydroxymethyl) cyclohexane, octahydro-4,7-methano-1H-indenedimethanol- or methylpropanediol monoacrylate, monomethacrylate, monoethacrylate, monocrotonate, monomaleinate, monofumarate or monoitaconate; or reaction products from cyclic esters, such as, for example, epsilon-caprolactone and these hydroxyalkyl or cycloalkyl esters; or olefinically unsaturated alcohols such as allyl alcohol or polyols such as trimethylolpropane mono- or dially lether or pentaerythritol mono-, di- or triallyl ether (with regard to these higher functional monomers (a2) the same applies analogously to the higher functional monomers (al)); N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate,

Allylamine or N-methyliminoethyl acrylate or N, N- di (memoxymethyl) aminoethyl acrylate and methacrylate or N, N-

Di (butoxymethyl) aminopropyl acrylate and methacrylate; Monomers of this type are preferably used for the production of self-crosslinking components (A).

a3) monomers which carry at least one acid group which can be converted into the corresponding acid anion group per molecule, such as acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleic acid, fumaric acid or itaconic acid; olefinically unsaturated sulfonic or phosphonic acids or their partial esters; or maleic acid mono (meth) acryloyloxyethyl ester, succinic acid mono (meth) acryloyloxyethyl ester or phthalic acid mono (meth) acryloyloxyethyl ester.

a4) vinyl esters of monocarboxylic acids with 5 to 18 carbon atoms in the molecule, branched in the alpha position. The branched monocarboxylic acids can be obtained by reacting formic acid or carbon monoxide and water with olefins in the presence of a liquid, strongly acidic catalyst; the olefins can be cracked products of paraffinic hydrocarbons, such as mineral oil fractions, and can contain both branched and straight-chain acyclic and / or cycloaliphatic olefins. In the implementation of such olefins with formic acid or with

Carbon monoxide and water form a mixture of carboxylic acids in which the carboxyl groups are predominantly located on a quaternary carbon atom. Other olefinic starting materials are, for example, propylene trimer, propylene tetramer and diisobutylene. The vinyl esters (a4) can also be used in a manner known per se from the acids, for example by allowing the acid to react with acetylene. Because of the good availability, vinyl esters of saturated aliphatic monocarboxylic acids with 9 to 11 carbon atoms which are branched on the alpha carbon atom, but in particular Versatic® acids, are particularly preferably used.

a5) reaction products of acrylic acid and / or methacrylic acid with the glycidyl ester of a monocarboxylic acid with 5 to 18 carbon atoms per molecule branched in the alpha position, in particular one Versatic® acid, or instead of the reaction product, an equivalent amount of acrylic and / or

Methacrylic acid, which is then reacted during or after the polymerization reaction with the glycidyl ester of a monocarboxylic acid with 5 to 18 carbon atoms per molecule, in particular a Versatic® acid, which is branched in the alpha position.

a6) Cyclic and / or acyclic olefins such as ethylene, propylene, but-1-ene, pent-1-ene, hex-1-ene, cyclohexene, cyclopentene, norbones, butadiene, isoprene, cyclopentadiene and / or dicyclopentadiene.

a7) (Meth) acrylic acid amides such as (meth) acrylic acid amide, N-methyl-, N, N-dimethyl-, N-ethyl-, N, N-diethyl-, N-propyl-, N, N-dipropyl-, N- Butyl, N, N-dibutyl, N-cyclohexyl, N, N-cyclohexyl-methyl and / or N-methylol, N, N-dimethylol, N-methoxymethyl, N, N-di (methoxymethyl ) -, N-ethoxymethyl and / or N, N-di (ethoxyethyl) - (meth) acrylic acid amide. Monomers of the latter type are used primarily for the production of self-crosslinking components (A). a8) Monomers containing epoxy groups, such as the glycidyl ester of acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleic acid, fumaric acid and / or itaconic acid.

a9) vinylaromatic hydrocarbons such as styrene, alpha-alkylstyrenes, in particular alpha-methylstyrene, and / or vinyltoluene; Vinylbenzoic acid (all isomers), N, N-diethylaminostyrene (all isomers), alpha-

Methyl vinylbenzoic acid (all isomers), N, N-diethylamino-alpha-methylstyrene (all isomers) and / or p-vinylbenzenesulfonic acid.

alO) nitriles such as acrylonitrile and / or methacrylonitrile.

al l) vinyl compounds, especially vinyl and / or vinylidene dihalides such as vinyl chloride, vinyl fluoride, vinylidene dichloride or vinylidene difluoride; N- vinylamides such as vinyl-N-methylformamide, N-vinylcaprolactam, 1-

Vinylimidazole or N-vinylpyrrolidone; Vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether and / or vinyl cyclohexyl ether; and / or vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate and / or the vinyl ester of 2-methyl-2-ethylheptanoic acid.

al2) allyl compounds, in particular allyl ethers and esters such as allymethyl, ethyl, propyl or butyl ether or allyl acetate, propionate or butyrate.

al3) polysiloxane macromonomers which have a number average molecular weight Mn of 1,000 to 40,000 and on average 0.5 to 2.5 ethylenically unsaturated double bonds per molecule; in particular

Polysiloxane macromonomers which have a number average molecular weight Mn of 2,000 to 20,000, particularly preferably 2,500 to 10,000 and in particular 3,000 to 7,000 and on average 0.5 to 2.5, preferably 0.5 to 1.5, ethylenically unsaturated double bonds per molecule, as described in DE-A-38 07 571 on pages 5 to 7 of DE -A 37 06 095 in columns 3 to 7, EP-B-0 358 153 on pages 3 to 6, in US-A 4,754,014 in columns 5 to 9, in DE-A 44 21 823 or in of international patent application WO 92/22615 on page 12, line 18, to page 18, line 10.

and or

al4) Acryloxysilane-containing vinyl monomers, producible by reaction of hydroxy-functional silanes with epichlorohydrin and subsequent

Implementation of the reaction product with (meth) acrylic acid and / or

Hydroxyalkyl and / or cycloalkyl esters of (meth) acrylic acid (cf. monomers a2).

Each of the above-mentioned monomers (al) to (al4) can be polymerized alone with the monomer (b). According to the invention, however, it is advantageous to use at least two monomers (a) because the property profile of the resulting constituents (A), ie the copolymers (A), varies very widely in a particularly advantageous manner and is specifically adapted to the particular intended use of the coating material can be. In particular, functional groups can be incorporated into the copolymers (A) in this way, making the copolymers (A) hydrophilic so that they can be dispersed or dissolved in aqueous media. In addition, functional groups (afg) can be incorporated which can undergo thermal crosslinking reactions with the complementary functional groups (bfg) of the crosslinking agents (B) described below. You can also create functional groups can be installed, which give component (A) self-crosslinking properties such as N-methylol or N-alkoxymethyl groups.

According to the invention, very particular advantages result if the monomers (a) and (a2) and optionally (a3) are used as monomers (a).

According to the invention, compounds of the general formula I are used as monomers (b).

In the general formula I, the radicals R ¹ , R ² , R ³ and R ⁴ each independently represent hydrogen atoms or substituted or unsubstituted alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloalkylaryl arylalkyl or arylcycloalkyl radicals, with the proviso that at least two of the variables R ¹ , R ² , R ³ and R ^{4 represent} substituted or unsubstituted aryl, arylalkyl or arylcycloalkyl radicals, in particular substituted or unsubstituted aryl radicals.

Examples of suitable alkyl radicals are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, amyl, hexyl or 2-ethylhexyl.

Examples of suitable cycloalkyl radicals are cyclobutyl, cyclopentyl or cyclohexyl.

Examples of suitable alkylcycloalkyl radicals are methylenecyclohexane, ethylenecyclohexane or propane-1,3-diylcyclohexane.

Examples of suitable cycloalkylalkyl radicals are 2-, 3- or 4-methyl-, ethyl-, propyl- or butylcyclohex-1-yl. Examples of suitable aryl radicals are phenyl, naphthyl or biphenylyl, preferably phenyl and naphthyl and in particular phenyl.

Examples of suitable alkylaryl radicals are benzyl or ethylene or propane-1,3-diylbenzene.

Examples of suitable cycloalkylaryl radicals are 2-, 3-, or 4-phenylcyclohex-l-yl.

Examples of suitable arylalkyl radicals are 2-, 3- or 4-methyl-, ethyl-, propyl- or butylphen-1-yl.

Examples of suitable arylcycloalkyl radicals are 2-, 3- or 4-cyclohexylphen-l-yl.

The radicals R ¹ , R ² , R ³ and R ⁴ described above can be substituted. For this purpose, electron-withdrawing or electron-donating atoms or organic residues can be used.

Examples of suitable substitutes are halogen atoms, in particular chlorine and fluorine, nitrile groups, nitro groups, partially or completely halogenated, in particular chlorinated and / or fluorinated, alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloalkylaryl, arylalkyl and Arylcycloalkyl radicals, including those exemplified above, in particular tert-butyl; Aryloxy, alkyloxy and cycloalkyloxy radicals, in particular phenoxy, naphthoxy, methoxy, ethoxy, propoxy, butyloxy or cyclohexyloxy; Arylthio, alkylthio and cycloacylthio radicals, in particular phenylthio, naphthylthio, methylthio, ethylthio, propylthio, butylthio or cyclohexylthio; hydroxyl groups; and / or primary, secondary and / or tertiary amino groups, in particular amino, N-methylamino, N-ethylamino, N-propylamino, N-phenylamino, N-cyclohexylamino, N, N-dimethylamino, N, N-diethylamino, N, N -Dipropylamino, N, N-diphenylamino, N, N-dicyclohexylamino, N-cyclohexyl-N-methylamino or N-emyl-N-memylamino.

Examples of monomers (b) used with particular preference according to the invention are diphenylethylene, dinaphthaleneethylene, trans-stilbene, vinylidene-bis (4-N, N-dimethylaminobenzene), vinylidene-bis (4-aminobenzene) or vinylidene-bis (4-nitrobenzene) ).

According to the invention, the monomers (b) can be used individually or as a mixture of at least two monomers (b).

With regard to the conduct of the reaction and the properties of the resulting copolymers (A), in particular the acrylate copolymer (A), diphenylethylene is of very particular advantage and is therefore used with particular preference in accordance with the invention.

The monomers (a) and (b) to be used according to the invention are reacted with one another to give the copolymer (A) in the presence of at least one radical initiator. Examples of initiators which can be used are: dialkyl peroxides, such as di-tert-butyl peroxide or dicumyl peroxide; Hydroperoxides, such as cumene hydroperoxide or tert-butyl hydroperoxide; Peresters, such as tert-butyl perbenzoate, tert-butyl perpivalate, tert-butyl per-3,5,5-trimethyl hexanoate or tert-butyl per-2-ethyl hexanoate; Potassium, sodium or ammonium peroxodisulfate; Azodinitriles such as azobisisobutyronitrile; C-C-cleaving initiators such as benzpmakolsilyl ether; or a combination of a non-oxidizing initiator with hydrogen peroxide.

Comparatively large amounts of free-radical initiator are preferably added, the proportion of the initiator in the reaction mixture being based in each case on the total amount of the monomers (a) and the initiator, particularly preferably 0.5 to 50% by weight, very particularly preferably 1 to 20% by weight and in particular 2 to 15% by weight.

The weight ratio of initiator to monomers (b) is preferably 4: 1 to 1: 4, particularly preferably 3: 1 to 1: 3 and in particular 2: 1 to 1: 2. Further advantages result if the initiator within the specified limits Excess is used.

The radical copolymerization is preferably carried out in the devices mentioned at the outset, in particular stirred tanks or Taylor reactors, the Taylor reactors being designed so that the conditions of the Taylor flow are met over the entire length of the reactor, even if the kinematic viscosity of the reaction medium changes greatly as a result of the copolymerization , especially increases.

According to the invention, the copolymerization is carried out in an aqueous medium.

The aqueous medium essentially contains water. The aqueous medium can in minor amounts the crosslinking agents (B), reactive thinners (F), paint additives (G) and / or organic solvents (H) and / or other dissolved solid, liquid or gaseous organic and / or inorganic solvents described below in detail , low and / or high molecular weight substances, in particular surface-active substances, if they do not negatively influence or even inhibit the copolymerization. In the context of the present invention, the term “minor amount” is understood to mean an amount which does not cancel out the aqueous character of the aqueous medium. However, the aqueous medium can also be pure water.

The copolymerization is preferably carried out in the presence of at least one base. Low molecular weight bases such as sodium hydroxide solution, potassium hydroxide solution, ammonia, diethanolamine, triemanolamine, mono-, di- and triemylamine, and / or dimethylethanolamine, in particular ammonia and / or di- and / or triethanolamine, are particularly preferred.

The copolymerization is advantageously carried out at temperatures above room temperature and below the lowest decomposition temperature of the monomers used in each case, a temperature range from 10 to 150 ° C., very particularly preferably 70 to 120 ° C. and in particular 80 to 110 ° C. being chosen.

If particularly volatile monomers (a) and / or (b) are used, the copolymerization can also be carried out under pressure, preferably under 1.5 to 3,000 bar, particularly 5 to 1,500 and in particular 10 to 1,000 bar.

With regard to the molecular weight distribution, component (A) is not subject to any restrictions. However, the copolymerization is advantageously carried out in such a way that a molecular weight distribution Mw / Mn measured using gel permeation chromatography using polystyrene as the standard of <4, preferably particularly preferably <2 and in particular <1.5 and in individual cases also 1.3. The molecular weights of the constituents (A) can be controlled within wide limits by the choice of the ratio of monomer (a) to monomer (b) to radical initiator. The content of monomer (b) in particular determines the molecular weight in such a way that the greater the proportion of monomer (b), the lower the molecular weight obtained. The component (A) resulting from the copolymerization is generally obtained in the form of a dispersion as a mixture with the aqueous medium. It can be processed further in this form or used as a macroinitiator for further reaction with at least one further monomer (a) in a second stage (ii). The component (A) resulting in the first stage (i) can, however, also be isolated as a solid and then reacted further.

The further reaction according to stage (ii) is preferably carried out under the usual conditions for free-radical polymerization, with suitable ones

Solvents (H) and / or reactive thinners (F) can be present. Steps (i) and (ii) can be carried out separately from one another both spatially and temporally within the scope of the method according to the invention. In addition, steps (i) and (ii) can also be carried out in succession in one reactor. For this purpose, first the monomer (b) with at least one monomer

(a) fully or partially implemented depending on the desired application and the desired properties, after which at least one further

Monomer (a) is added and polymerized by free radicals. In another

In the embodiment, at least two monomers (a) are used from the beginning, the monomer (b) first reacting with one of the at least two monomers (a) and then the resulting reaction product (A) above a certain molecular weight also with the further monomer (a) responding.

Depending on how the reaction is carried out, it is possible according to the invention to prepare functionalized polymers, block or multiblock and gradient (co) polymers, star-shaped polymers, graft copolymers and branched (co) polymers as constituents (A) on the end groups. Constituent (A) can contain at least one, preferably at least two, functional groups (afg) which can undergo thermal crosslinking reactions with complementary functional groups (bfg) of the optionally used crosslinking agents (B) described below. The functional groups (afg) can be introduced into component (A) via the monomers (a) or, after their synthesis, can be introduced by polymer-analogous reactions.

Examples of suitable complementary reactive functional groups (afg) and (bfg) which are to be used according to the invention and which undergo crosslinking reactions are summarized in the following overview. In the overview, the variable R ^{5 stands} for substituted or unsubstituted alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloalkylaryl, arylalkyl or arylcycloalkyl radicals; the variables R ⁶ and R ⁷ stand for identical or different alkyl, cycloalkyl, alkylcycloalkyl or cycloalkylalkyl radicals or are linked to one another to form an aliphatic or heteroaliphatic ring. Examples of suitable radicals of this type are those listed above for the radicals R ¹ , R ² , R ³ and R ⁴ .

Overview: Examples of complementary functional groups (afg) and (bfg) in

Component (A) and crosslinking agent (B) or

Crosslinking agent (B) and component (A)

-SH -C (O) -OH -NH ₂ -C (O) -OC (O) -

-OH -NCO

-O- (CO) -NH- (CO) -NH ₂ -NH-C (O) -OR ⁵

-O- (CO) -NH ₂ -CH ₂ -OH

-NH-C (O) -CH (-C (O) OR ⁵ ) ₂

-NH-C (O) -CH (-C (O) OR ⁵ ) (- C (O) -R ⁵ )

-NH-C (O) -NR ⁶ R ⁷

= Si (OR ⁵ ) ₂

O -CH-CH ₂

-C (O) -OH O -CH-CH ₂

-OC (O) -CR ⁵ = CH ₂ -OH

-O-CR = CH ₂ -NH ₂ -C (O) -CH ₂ -C (O) -R ⁵

-CH = CH ₂

The selection of the respective complementary groups (afg) and (bfg) depends on the one hand on the fact that they do not undergo any undesirable reactions during storage and / or, where appropriate, must not interfere with or inhibit curing with actinic radiation, and on the other hand in which Temperature range the thermal curing should take place.

Here, in particular with regard to thermally sensitive substrates such as plastics, it is advantageous according to the invention to choose a temperature range which does not exceed 100 ° C., in particular 80 ° C. With regard to these general conditions, hydroxyl groups and isocyanate groups or carboxyl groups and epoxy groups have proven to be advantageous as complementary functional groups, which is why they are preferably used according to the invention in the coating materials according to the invention, which are present as two- or multi-component systems. Particular advantages result if the hydroxyl groups are used as functional groups (afg) and the isocyanate groups as functional groups (bfg).

If higher crosslinking temperatures can be used, for example from 100 ° C. to 180 ° C., one-component systems are also suitable as coating materials, in which the functional groups (afg) are preferably thio, amino, hydroxyl, carbamate, allophanate, carboxy , and / or (meth) acrylate groups, but especially hydroxyl groups and the functional groups (bfg) preferably anhydride, carboxy, epoxy, blocked isocyanate, urethane, Methylol, methylol ether, siloxane, amino, hydroxy and / or beta-hydroxyalkylamide groups.

The component (A) or the coating material produced therewith can also film without a crosslinking agent (B) and form an excellent coating. In this case, component (A) is physically curing. In the context of the present invention, the physical hardening and the hardening via the complementary groups (afg) and (bfg) described above are summarized under the generic term “thermal hardening”.

The proportion of constituent (A) to be used according to the invention in the coating material can vary very widely and depends in particular on whether the coating material for the mechanical energy-absorbing filler layer FL, the color and / or effect top coat DL, the color and / or effect base coat BL or the clear coat KL should be used. The proportion is advantageously 1 to 90, preferably 2 to 80, particularly preferably 3 to 75 and in particular 4 to 70% by weight, in each case based on the total solids content of the coating material.

The coating material may further contain at least one component (A '), which is a customary and known binder (A') with at least one functional group (afg). Examples of suitable binders (A ') are linear and / or branched and / or block-like, comb-like and / or randomly constructed poly (meth) acrylates or acrylate copolymers, polyesters, alkyds, amino resins, polyurethanes, acrylated polyurethanes, acrylic polyesters, polylactones, polycarbonates, Polyethers, epoxy resin-amine adducts, (meth) acrylate diols, partially saponified polyvinyl esters or polyureas, which contain said functional groups (afg). If used, they are preferably in the coating material in an amount of 1 to 50, preferably 2 to 40, particularly preferably 3 to 30 and in particular 4 to 25 wt .-%, each based on the total solids content of the coating material.

The coating material may further contain at least one crosslinking agent (B) which contains at least two, in particular three, of the complementary functional groups (bfg) described in detail above.

If the coating material is a two- or multi-component system, polyisocyanates and / or polyepoxides, but especially polyisocyanates, are used as crosslinking agents (B).

Examples of suitable polyisocyanates (B) are organic polyisocyanates, in particular so-called lacquer polyisocyanates, with free, isocyanate groups bound to aliphatic, cycloaliphatic, araliphatic and / or aromatics. Polyisocyanates with 2 to 5 isocyanate groups per molecule and with viscosities of 100 to 10,000, preferably 100 to 5,000 and in particular 100 to 2,000 mPas (at 23 ° C.) are preferably used. If necessary, small amounts of organic solvent (H), preferably 1 to 25% by weight, based on pure polyisocyanate, can be added to the polyisocyanates in order to improve the incorporability of the isocyanate and, if appropriate, the viscosity of the polyisocyanate to a value within the above Lower areas. Solvents suitable as additives for the polyisocyanates are, for example, ethoxyethyl propionate, amyl methyl ketone or butyl acetate. In addition, the polyisocyanates (B) can be modified in a conventional and known manner to be hydrophilic or hydrophobic.

Examples of suitable polyisocyanates (B) are described, for example, in "Methods of Organic Chemistry", Houben-Weyl, Volume 14/2, 4th Edition, Georg Thieme Verlag, Stuttgart 1963, pages 61 to 70, and by W. Siefken, Liebigs Annalen der Chemie, volume 562, pages 75 to 136.

Further examples of suitable polyisocyanates (B) are polyisocyanates containing isocyanurate, biuret, AUophanat, iminooxadiazinedione, urethane, urea and / or uretdione groups. Polyisocyanates containing urethane groups are obtained, for example, by reacting some of the isocyanate groups with polyols, e.g. Trimethylolpropane and glycerin. Aliphatic or cycloaliphatic polyisocyanates, in particular hexamethylene diisocyanate, dimerized and trimerized hexamethylene diisocyanate, isophorone diisocyanate, 2-isocyanatopropylcyclohexyl isocyanate, dicyclohexylmethane-2,4'-diisocyanate, are preferably used.

Dicyclohexylmethane-4,4'-diisocyanate or 1,3-bis (isocyanatomethyl) cyclohexane (BIC), diisocyanates, derived from dirner fatty acids, as are sold under the trade name DDI 1410 by Henkel, 1,8-diisocyanato-4- Isocyanatomethyl-octane, 1, 7-diisocyanato-4-isocyanatomethyl-heptane or l-isocyanato-2- (3-isocyanatopropyl) cyclohexane or mixtures of these polyisocyanates.

Examples of suitable polyepoxides (B) are all known aliphatic and / or cycloaliphatic and / or aromatic polyepoxides, for example based on bisphenol-A or bisphenol-F. Also suitable as polyepoxides are, for example, the polyepoxides commercially available under the names Epikote® from Shell, Denacol® from Nagase Chemicals Ltd., Japan, such as Denacol EX-411 (pentaerytfirite polyglycidyl ether), Denacol EX-321 (trimethylolpropane polyglycidyl ether), Denacol EX-512 (polyglycerol polyglycidyl ether) and Denacol EX-521 (polyglycerol polyglycidyl ether). In the case of one-component systems, crosslinking agents (B) are used which react at higher temperatures with the functional groups of the binders in order to build up a three-dimensional network. Such crosslinking agents (B) can of course also be used in minor amounts in the multicomponent systems. In the context of the present invention, “minor amount” means a portion which does not interfere with the main crosslinking reaction or even prevents it altogether.

Examples of suitable crosslinking agents (B) of this type are blocked polyisocyanates. Examples of suitable polyisocyanates for the preparation of the blocked polyisocyanates are those described above.

Examples of suitable blocking agents are the blocking agents known from US Pat. No. 4,444,954, such as

i) phenols such as phenol, cresol, xylenol, nitrophenol, chlorophenol,

Ethylphenol, t-butylphenol, hydroxybenzoic acid, ester of this acid or

2,5-di-tert-butyl-4-hydroxytoluene;

ii) lactams, such as ε-caprolactam, δ-valerolactam, γ-butyrolactam or ß-propiolactam;

iii) active methylenic compounds such as diethyl malonate, dimethyl malonate, ethyl or methyl acetoacetate or acetylacetone;

iv) alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, n-amyl alcohol, t-amyl alcohol, lauryl alcohol, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, Ethylene glycol monobutyl ether, diethylene glycol monomethyl ether,

Diethylene glycol monoethyl ether, propylene glycol monomethyl ether,

Methoxymethanol, glycolic acid, glycolic acid ester, lactic acid, lactic acid ester, methylol urea, melolmelamine, diacetone alcohol, ethylene chlorohydrin, ethylene bromohydrin, 1,3-dichloro-2-propanol, 1,4-

Cyclohexyldimethanol or acetocyanhydrin;

v) mercaptans such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, t-dodecyl mercaptan, 2-mercaptobenzofhiazole, thiophenol, methylthiophenol or ethylthiophenol;

vi) acid amides such as acetoanilide, acetoanisidinamide, acrylamide, methacrylamide, acetic acid amide, stearic acid amide or benzamide;

vii) imides such as succinimide, phthalimide or maleimide;

viii) amines such as diphenylamine, phenylnaphthylamine, xylidine, N-phenylxylidine, carbazole, aniline, naphthylamine, butylamine, dibutylamine or butylphenylamine;

ix) imidazoles such as imidazole or 2-ethylimidazole;

x) ureas such as urea, thiourea, ethylene urea, ethylene thiourea or 1,3-diphenylurea;

xi) carbamates such as phenyl N-phenylcarbamate or 2-oxazolidone;

xii) imines such as emylemmin; xiii) oximes such as acetone oxime, formal doxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diisobutyl ketoxime, diacetyl monoxime,

Benzophenone oxime or chlorohexanone oximes;

xiv) salts of sulfurous acid such as sodium bisulfite or potassium bisulfite;

xv) hydroxamic acid esters such as benzyl methacrylohydroxamate (BMH) or allyl methacrylohydroxamate; or

xvi) substituted pyrazoles, imidazoles or triazoles; such as

Mixtures of these blocking agents, in particular dimethylpyrazole and triazoles, malonic esters and acetoacetic acid esters or dimethylpyrazole and succinimide.

Tris (alkoxycarbonylamino) triazines (TACT) of the general formula can also be used as crosslinking agents (B)

II o

be used. Examples of suitable tris (alkoxycarbonylamino) triazines (B) are described in the patents US-A-4,939,213, US-A-5,084,541 or EP-A-0 624577. In particular, the tris (methoxy-, tris (butoxy- and / or tris (2-ethylhexoxycarbonylamino) triazines are used.

The methyl-butyl mixed esters, the butyl-2-ethylhexyl mixed esters and the butyl esters are advantageous. Compared to the pure methyl ester, these have the advantage of better solubility in polymer melts and also have less tendency to crystallize out.

In particular, aminoplast resins, for example melamine resins, guanamine resins or urea resins, can be used as crosslinking agents (B). Any aminoplast resin suitable for transparent topcoats or clearcoats or a mixture of such aminoplast resins can be used. In addition, Römpp Lexikon Lacke und Drackfarben, Georg Thieme Verlag, 1998, page 29, "Aminoharze", and the textbook "Lackadditive" by Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998, pages 242 ff., Or on the book "Paints, Coatings and Solvents", second completely revised edition, Edit. D. Stoye and W. Freitag, Wiley-VCH, Weinheim, New York, 1998, pages 80 ff. Furthermore, the usual and known aminoplast resins come into consideration, the methylol and or methoxymethyl groups z. T. are defunctionalized by means of carbamate or allophanate groups. Crosslinking agents of this type are described in the patents US-A-4 710 542 and EP-B-0 245 700 and in the article by B. Singh and co-workers "Carbamylmethylated Melamines, Novel Crosslinkers for the Coatings Industry" in Advanced Organic Coatings Science and Technology Series, 1991, Volume 13, pages 193 to 207. Further examples of suitable crosslinking agents (B) are beta-hydroxyalkylamides such as N, N, ^N, N'-tetrakis (2-hydroxyethyl) adipamide or N, N, N ', N'-tetrakis (2-hydroxypropyl) adipamide.

Further examples of suitable crosslinking agents (B) are siloxanes, in particular siloxanes with at least one trialkoxy or dialkoxysilane group.

Further examples of suitable crosslinking agents (B) are polyanhydrides, in particular polysuccinic anhydride.

Further examples of suitable crosslinking agents (B) are compounds with an average of at least two groups capable of transesterification, for example malonic acid diesters and polyisocyanates, or reaction products of monoisocyanates with esters and partial esters of malonic acid with polyhydric alcohols, as described in European patent EP-A-0 596 460 are described;

The amount of crosslinking agent (B) in the coating material can - if used - vary widely and depends in particular on the one hand on the functionality of the crosslinking agent (B) and on the other hand on the number of crosslinking functional groups (afg) present in the binder (A) as well as the network density that you want to achieve. The person skilled in the art can therefore determine the amount of crosslinking agent (B) on the basis of his general specialist knowledge, if necessary with the aid of simple orienting experiments. The crosslinking agent (B) in the coating material according to the invention is advantageously in an amount of 1 to 60% by weight, particularly preferably 2 to 50% by weight and in particular 3 to 45% by weight, in each case based on the total solids content of the coating material, contain. It is also advisable to choose the amounts of crosslinking agent (B) and binder (A) so that in the Coating material the ratio of functional groups (bfg) in the crosslinking agent (B) and functional groups (afg) in the binder (A) between 2: 1 to 1: 2, preferably 1.5: 1 to 1: 1.5, particularly preferably 1 , 2: 1 to 1: 1.2 and in particular 1.1: 1 to 1: 1.1.

If the coating material is to be curable not only thermally but also with actinic radiation, in particular UV radiation and / or electron radiation (dual cure), it contains at least one constituent (C) which is curable with actinic radiation. However, if the coating material is to be curable predominantly (dual cure) or exclusively with actinic radiation, which is particularly suitable for clearcoats in the process according to the invention, it must contain a constituent (C).

In principle, all constituents (C) which can be used are all ohgomeric and polymeric compounds curable with actinic radiation, in particular UV radiation and / or electron radiation, as are conventionally used in the field of UV curable or electronically curable coating materials.

Radiation-curable binders are advantageously used as constituents (C). Examples of suitable radiation-curable binders (C) are (meth) acrylic-functional (meth) acrylic copolymers, polyether acrylates,

Polyester acrylates, unsaturated polyesters, epoxy acrylates, urethane acrylates, amino acrylates, melamine acrylates, silicone acrylates, isocyanato acrylates and the corresponding methacrylates. Binders (C) which are free from aromatic structural units are preferably used. Urethane (meth) acrylates and / or polyester (meth) acrylates are therefore preferably used, particularly preferably aliphatic urethane acrylates. If the constituents (C) are also used, they are each present in the coating material in an amount of preferably 1 to 80, preferably 1.5 to 70, particularly preferably 2 to 65 and in particular 2.5 to 60% by weight on the total solids content of the coating material.

The coating material may further contain at least one photoinitiator (D). If the coating material or the layers produced therefrom are to be crosslinked additionally (dual cure) or exclusively with UV radiation in the process according to the invention, the use of a photoinitiator (D) is generally necessary. If it is used, it is preferably present in the coating material according to the invention in proportions of 0.01 to 10% by weight, preferably 0.1 to 8% by weight and in particular 0.5 to 6% by weight on the total solids content of the coating material of the invention.

Examples of suitable photoinitiators (D) are those of the Norrish II type, the mechanism of action of which is based on an intramolecular variant of the hydrogen abstraction reactions, as occurs in a variety of ways in photochemical reactions (for example here on Römpp Chemie Lexikon, 9th extended and revised edition , Georg Thieme Verlag Stuttgart, Vol. 4, 1991) or cationic photoinitiators (for example, refer to Römpp Lexikon "Lacquers and Printing Inks" Georg Thieme Verlag Stuttgart, 1998, pages 444 to 446), in particular benzophenones, benzoins or benzoin ethers or phosphine oxides. Products which are commercially available under the names Irgacure® 184, Irgacure® 1800 and Irgacure® 500 from Ciba Geigy, Grenocure® MBF from Rahn and Lucirin® TPO from BASF AG can also be used. In addition to the photoinitiators (D), conventional sensitizers (D) such as anthracene can be used in effective amounts.

Furthermore, the coating material can contain at least one initiator of the thermal crosslinking (E). From 80 to 120 ° C these form radicals, which are the

Start crosslinking reaction. Examples of thermolabile free-radical initiators are organic peroxides, organic azo compounds or C-C-cleaving initiators such as dialkyl peroxides, peroxocarboxylic acids, peroxodicarbonates, peroxide esters,

Hydroperoxides, ketone peroxides, azodinitriles or benzpmakolsilyl ether. C-C-cleaving initiators are particularly preferred since their thermal cleavage does not form gaseous decomposition products which lead to disruptions in the

Paint layer could result. If they are used, their amounts are generally between 0.01 to 10% by weight, preferably 0.05 to 8% by weight and in particular 0.1 to 5% by weight, in each case based on the total solids content of the coating material of the invention.

In addition, the coating material can contain at least one reactive diluent (F) which is curable with actinic radiation and / or thermally.

Examples of suitable thermally crosslinkable reactive diluents (F) are branched, cyclic and / or acyclic C ₉ -C ₁₆ -alkanes which are functionalized with at least two hydroxyl groups, preferably dialkyloctanediols, in particular the positionally isomeric diethyloctanediols.

Further examples of suitable thermally crosslinkable reactive diluents (F) are oligomeric polyols which can be obtained from ohomeric intermediates, which are obtained by metathesis reactions of acyclic monoolefins and cyclic monoolefins, by hydroformylation and subsequent hydrogenation; Examples of suitable cyclic monoolefins are cyclobutene, cy- clopentene, cyclohexene, cyclooctene, cycloheptene, norbonen or 7-oxanorbonen; Examples of suitable acyclic monoolefins are contained in hydrocarbon mixtures obtained by cracking in petroleum processing (C ₅ cut); Examples of suitable oligomeric polyols to be used according to the invention have a hydroxyl number (OHZ) of 200 to 450, a number average molecular weight Mn of 400 to 1,000 and a mass average molecular weight Mw of 600 to 1,100.

Further examples of suitable thermally crosslinkable reactive diluents (F) are hyperbranched compounds with a tetrafunctional central group, derived from ditrimethylolpropane, diglycerol, ditrimethylolethane, pentaerythritol, tetrakis (2-hydroxyethyl) methane, tetrakis (3-hydroxypropyl) methane or 2,2-bis-hydroxymethyl -butanediol- (1,4) (homopentaerythritol). The making of this

Reactive diluents can be carried out using the customary and known methods of producing hyperbranched and dendrimeric compounds. suitable

Synthetic methods are described, for example, in the patent specifications WO 93/17060 or

WO 96/12754 or in the book by G.R. Newkome, C.N. Moorefield and F.

Vögtle, "Dendritic Molecules, Concepts, Syntheses, Perspectives", VCH, Weinheim,

New York, 1996.

Further examples of suitable reactive diluents (F) are polycarbonate diols, polyester polyols, poly (meth) acrylate diols or polyadducts containing hydroxyl groups.

Examples of suitable reactive solvents which can be used as reactive diluents (F) are butyl glycol, 2-methoxypropanol, n-butanol, methoxybutanol, n-propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether,

Diethylene glycol monoethyl ether, diethylene glycol diethyl ether, Diethylene glycol monobutyl ether, trimethylolpropane, ethyl 2-hydroxypropionate or 3-methyl-3-methoxybutanol and derivatives based on propylene glycol, for example isopropoxypropanol, are mentioned.

Reactive diluents (F) which can be crosslinked with actinic radiation are, for example, polysiloxane macromonomers, (meth) acrylic acid and their other esters, maleic acid and their esters or half esters, vinyl acetate, vinyl ether, vinyl ureas and others. used. Examples include alkylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, vinyl (meth) acrylate, allyl (meth) acrylate, glycerol-tri (meth) acrylate, trimethylolpropane tri (meth) acrylate , Trimethylolpropane di (meth) acrylate, tripropylene glycol diacrylate, styrene, vinyl toluene, divinylbenzene, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipropylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, ethyloxyethyl acrylate, ethoxyethylaethyl acrylate, ethoxyethyl acrylate , Hydroxyethyl (meth) acrylate, butoxyethyl acrylate, isobomyl (meth) acrylate, dimethylacrylamide and dicyclopentyl acrylate, and also the long-chain linear diacrylates described in EP-A-0 250 631 with a molecular weight of 400 to 4,000, preferably from 600 to 2,500 , For example, the acrylate groups can also be separated by a polyoxybutylene structure. It is also possible to use 1,12-dodecyl diacrylate and the reaction product of 2 moles of acrylic acid with one mole of a dimer fatty alcohol, which generally has 36 carbon atoms. Mixtures of the monomers mentioned are also suitable.

Mono- and / or diacrylates, such as isobomylacrylate, hexanediol diacrylate, tripropylene glycol diacrylate, Laromer® 8887 from BASF AG and Actilane® 423 from Akcros Chemicals Ltd., GB, are preferably used as reactive diluents (F). Isobomylacrylate, hexanediol diacrylate and tripropylene glycol diacrylate are particularly preferably used. If they are used, the reactive diluents (F) are used in an amount of preferably 1 to 70% by weight, particularly preferably 2 to 65% by weight and in particular 3 to 50% by weight, in each case based on the total solids content of the coating material of the invention applied.

The coating material can contain conventional paint additives (G) in effective amounts. The type and amount of the additives (G) depend primarily on the intended use of the coating material of the invention. Advantageously, the additives (G) are not volatile under the processing and application conditions of the coating material of the invention.

If the coating material is used as filler FL, solid-color topcoat DL and / or basecoat BL, it necessarily contains at least one filler and / or a coloring and / or effect-giving pigment (G) in customary and known, effective amounts as coating additives (G).

The coating material preferably contains the fillers and / or pigments (G) in amounts of 1 to 95% by weight, particularly preferably 2 to 90% by weight and in particular 3 to 85% by weight, in each case based on the total solids content of the the coating material.

The pigments (G) can consist of inorganic or organic compounds and can give effect and / or color. Because of this large number of suitable pigments (G), the coating material according to the invention therefore ensures a universal range of uses for the coating materials and enables a multitude of color tones and optical effects to be achieved. As the effect pigments (G), metal flake pigments such as commercially available aluminum bronzes, aluminum bronzes chromated according to DE-A-36 36 183, and commercially available stainless steel bronzes as well as non-metallic effect pigments, such as pearlescent or interference pigments, can be used. Examples of suitable inorganic color pigments (G) are titanium dioxide, iron oxides, Sicotrans yellow and carbon black. Examples of suitable organic coloring pigments (G) are indanthrene blue, cromophthal red, irgazin orange and heliogen green.

Furthermore, the coating material, in particular the filler FL, can contain organic and inorganic fillers (G) in customary and known, effective amounts. Examples of suitable fillers are chalk, calcium sulfate, barium sulfate, silicates such as talc or kaolin, silicas, oxides such as aluminum hydroxide or magnesium hydroxide or organic fillers such as textile fibers, cellulose fibers, polyethylene fibers or wood flour. In addition, reference is made to Römpp Lexikon Lacke und Drackfarben, Georg Thieme Verlag, 1998, pages 250 ff, »Füllstoffe«.

These additives (G) can also be incorporated into the coating materials by means of pigment pastes, the constituents (A) described above and, if appropriate, the constituents (A ') described above being particularly suitable as rubbing resins.

These additives (G) are omitted if the coating materials are used as clear coats KL in the process according to the invention.

Examples of suitable additives (G) which can be present both in the clear coats KL and in the fillers FL, solid-color top coats DL and base coats BL

UV absorbers; Light stabilizers such as HALS compounds, benzotriazoles or oxalanilides;

Radical scavengers;

Crosslinking catalysts such as dibutyltin dilaurate or lithium decanoate;

slip additives;

polymerization inhibitors;

defoamers;

Neutralizing agents such as ammonia or dimethylemanolamine;

Emulsifiers, especially nonionic emulsifiers such as alkoxylated alkanols and polyols, phenols and alkylphenols or anionic emulsifiers such as alkali salts or ammonium salts of alkane carboxylic acids, alkane sulfonic acids, and sulfonic acids of alkoxylated alkanols and

Polyols, phenols and alkylphenols;

Wetting agents such as siloxanes, fluorine-containing compounds, carboxylic acid half-esters, phosphoric acid esters, polyacrylic acids and their copolymers or polyurethanes;

Adhesion promoters such as tricyclodecanedimethanol;

Leveling agents; film-forming aids such as cellulose derivatives;

transparent fillers based on silicon dioxide, aluminum oxide or zirconium oxide; the Römpp Lexicon »Lacke und

Drackfarben «Georg Thieme Verlag, Stuttgart, 1998, pages 250 to 252;

Sag control agents such as ureas, modified ureas and / or silicas, as described, for example, in references EP-A-192 304,

DE-A-23 59 923, DE-A-18 05 693, WO 94/22968, DE-C-27 51 761, WO 97/12945 or "färbe + lack", 11/1992, pages 829 ff become;

rheology control additives such as those known from the patent specifications WO 94/22968, EP-A-0 276 501, EP-A-0 249 201 or WO 97/12945; crosslinked polymeric microparticles, such as are disclosed, for example, in EP-A-0 008 127; inorganic layered silicates such as

Aluminum-magnesium silicates, sodium-magnesium and

Montmorillonite type sodium magnesium fluorine lithium layered silicates; Silicas such as aerosils; or synthetic polymers with ionic and / or associative groups such as polyvinyl alcohol,

Poly (meth) acrylamide, poly (meth) acrylic acid, polyvinylpyrrolidone,

Styrene-maleic anhydride or ethylene-maleic anhydride copolymers and their derivatives or hydrophobically modified ethoxylated urethanes or polyacrylates;

Flame retardants and / or

Matting agent. Further examples of suitable paint additives (G) of this type are described in the textbook "Paint Additives" by Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998.

It is essential that the above-described paint additives (G), which may be present in the fillers, the solid-color top coats and the basecoats as well as in the clear coats, do not adversely affect the transparency and clarity of the coating material when it is used as the clear coat KL.

The coating material preferably contains these paint additives (G), which can be present both in the fillers, the solid-color top coats and the basecoats and in the clear coats, in amounts of up to 40% by weight, particularly preferably up to 30% by weight and in particular up to 20% by weight, in each case based on the total solids content of the coating material.

Last but not least, the coating materials, especially in the case of non-aqueous coating materials, can contain 1 to 70% by weight, preferably 2 to 60% by weight (based on the ready-to-use coating material) of water-miscible and water-immiscible organic solvents (H), such as, for example, Ahphatic, aromatic and / or cycloaliphatic hydrocarbons such as toluene or methylcylohexane or decalin, alkyl esters of acetic acid or propionic acid, alkanols such as ethanol, ketones such as methyl isobutyl ketone, glycol ether glycol ether esters, and / or ethers such as tetrahydrofuran. In the context of the present invention, carbon dioxide can also be used as solvent (H).

The coating material can be in various forms. Thus, with a corresponding choice of its constituents described above (A) and optionally at least one of its constituents (A '), (B), (C), (D), (E), (F) and / or (G) as liquid coating material is present which is essentially free of organic solvents and / or water (100% system).

However, the coating material can be a solution or dispersion of the components described above in organic solvents (H) and / or water. It is a further advantage of the coating material that solids contents of up to more than 80% by weight, based on the coating material, can be adjusted.

Furthermore, the coating material can be a powder coating if the components described above are selected accordingly. For this purpose, component (B) can be microencapsulated if it is a polyisocyanate. This powder coating can then optionally be dispersed in water, resulting in a powder slurry coating.

The coating material can be a two- or multi-component system in which at least the component (B) is stored separately from the other components and is only added to them shortly before use. In this case, the coating material of the invention can also be aqueous, the component (B) preferably being present in a component containing a solvent (H).

Furthermore, the coating material can be part of a so-called mixing system or module system, as described, for example, in the patents DE-A-41 10 520, EP-A-0 608 773, EP-A-0 614 951 or EP-A-0 471 972 to be discribed. The coating material according to the invention is preferably in the form of an aqueous solution, dispersion and / or emulsion, in particular dispersion, because in this case the isolation of the component (A) to be used according to the invention can be dispensed with.

The production of the coating material from its constituents (A) and optionally at least one of its constituents (A '), (B), (C), (D), (E), (F), (G) and / or (H) has no peculiarities, but takes place in a customary and known manner by mixing the constituents in suitable mixing units such as stirred kettles, dissolvers or extruders using the processes suitable for the production of the respective coating materials.

The coating material of the invention is used to produce the multilayer coatings ML of the invention on primed or unprimed substrates.

Suitable substrates are all surfaces to be painted, which are not damaged by curing the painting rods located thereon using heat and optionally actinic radiation. B. metals, plastics, wood, ceramics, stone, textiles, fiber composites, leather, glass, glass fibers, glass and rock wool, mineral and resin-bound building materials, such as plaster and cement boards or roof tiles, as well as composites of these materials. Accordingly, the multilayer coating ML according to the invention is also suitable for applications outside of automotive coating, in particular for the coating of furniture and industrial coating, including coil coating and container coating. As part of industrial painting, it is suitable for painting practically all parts for private or industrial use, such as radiators, household appliances, small parts made of metal, hubcaps or rims. In the case of electrically conductive substrates, primers can be used which are produced in a customary and known manner from electrocoat materials (ETL). Both anodic (ATL) and cathodic (KTL) electro-dip lacquers, but especially KTL, come into consideration.

With the multilayer coating ML according to the invention, primed or non-primed plastics such as. B. ABS, AMMA, ASA, CA, CAB, EP, UF, CF, MF, MPF, PF, PAN, PA, PE, HDPE, LDPE, LLDPE, UHMWPE, PET, PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PBT, PPE, POM, PUR-RIM, SMC, BMC, PP-EPDM and UP (short names according to DIN 7728T1) can be painted. The plastics to be painted can of course also be polymer blends, modified plastics or fiber-reinforced plastics. The plastics typically used in vehicle construction, in particular motor vehicle construction, can also be used.

In the case of non-functionalized and / or non-polar substrate surfaces, these can be subjected to a pretreatment, such as with a plasma or with flame treatment, or provided with a hydro primer in a known manner before the coating.

The multilayer coatings ML according to the invention can be produced in various ways by the method according to the invention.

In a first preferred variant, the process according to the invention comprises the following process steps:

(I) producing a filler lacquer layer by applying a filler to the substrate, (II) hardening of the filler lacquer layer, resulting in the filler layer FL,

(III) Production of a solid-color topcoat by applying a solid-color topcoat to the filler layer FL and

(IV) Hardening of the solid-color lacquer layer DL, whereby the solid-color lacquer DL results.

Another preferred variant of the method according to the invention comprises the method steps:

(I) producing a basecoat layer by applying a basecoat to the substrate,

(II) drying the basecoat film,

(III) producing a clear coat by applying a clear coat to the basecoat and

(IV) joint curing of the basecoat layer and the clearcoat layer, which results in the basecoat BL and the clearcoat KL (wet-on-wet process).

A third preferred variant of the method according to the invention comprises the method steps:

(I) producing a filler lacquer layer by applying a filler to the substrate, (II) hardening of the filler lacquer layer, resulting in the filler layer FL,

(III) producing a basecoat layer by applying a basecoat to the filler layer FL,

(IV) drying the basecoat film,

(V) producing a clear coat by applying a clear coat to the basecoat and

(VI) joint curing of the basecoat layer and the clearcoat layer, which results in the basecoat BL and the clearcoat KL (wet-on-wet process).

Which preferred variant is chosen depends on the intended use of the multilayer lacquers ML according to the invention. In particular, the third variant is particularly preferred for automotive series painting.

As a result, the multilayer coatings ML according to the invention can have a different structure.

In a first preferred variant of the multilayer coating ML according to the invention

(1) a mechanical energy absorbing filler layer FL and

(2) a color and / or effect top coat DL

on top of each other in the given order. In a second preferred variant of the multilayer coating ML according to the invention

(1) a mechanical energy absorbing filler layer FL,

(2) a color and / or effect base coat BL and

(3) a clear coat KL

on top of each other in the given order.

In a third preferred variant of the multilayer coating ML according to the invention

(1) a color and / or effect base coat BL and

(2) a clear coat KL

on top of each other in the given order. The third preferred variant is used in particular for plastic coating, μm

The coating material can be applied in the process according to the invention by all customary application methods, such as spraying, knife coating, brushing, pouring, dipping or rolling. Spray application methods are preferably used, such as, for example, compressed air spraying, airless spraying, high rotation, electrostatic spray application (ESTA), if appropriate combined with hot spray application such as hot air hot spraying. The applications can be used at temperatures of max. 70 to 80 ° C are carried out, so that suitable application viscosities are achieved without there being any change or damage to the coating material and its overspray, which may need to be reprocessed, in the event of a brief thermal load. For example, hot spraying can be designed in such a way that the coating material is heated only very briefly in or shortly before the spray nozzle.

The spray booth used for the application can be operated, for example, with a circulation that can be tempered, if necessary, which is equipped with a suitable absorption medium for the overspray, e.g. B. the coating material itself is operated.

If the coating material contains constituents (C) which can be crosslinked with actinic radiation, the application is carried out under illumination with visible light of a wavelength of over 550 nm or with exclusion of light. This avoids material changes or damage to the coating material and the overspray.

The application methods described above can be used to produce all layers FL, DL, BL and KL and, if appropriate, further layers of lacquer.

In the process according to the invention, the filler lacquer layer, top lacquer layer, basecoat layer and clear lacquer layer are applied in a wet layer thickness such that after hardening, layers FL, DL, BL and KL result with the layer thicknesses necessary and advantageous for their functions. In the case of the filler layer FL, this layer thickness is 10 to 150, preferably 15 to 120, particularly preferably 20 to 100 and in particular 25 to 90 μm, in the case of the topcoat DL it is 5 to 90, preferably 10 to 80, particularly preferably 15 up to 60, and in particular 20 to 50 μm, in the case of the base coat BL it is 5 to 50, preferably 10 to 40, particularly preferably 12 to 30 and in particular 15 to 25 μm, and in the case of the clear coats KL it is 10 to 100, preferably 15 to 80, particularly preferably 20 to 70 and in particular 25 up to 60 μm.

According to the invention, the filler coat, top coat, basecoat and clear coat can be cured thermally or thermally and with actinic radiation, depending on their material composition. According to the invention, it is advantageous not to harden the basecoat, or only partially, before applying the clearcoat, in order to subsequently harden it together with the clearcoat (wet-on-wet method).

The hardening can take place after a certain rest period. It can have a duration of 30 s to 2 h, preferably 1 min to 1 h and in particular 1 min to 30 min. The rest period is used, for example, for the course and degassing of the paint layers or for the evaporation of volatile constituents such as solvents, water or carbon dioxide if the coating material has been applied with supercritical carbon dioxide as the solvent (H). The rest period can be supported and / or shortened by the use of elevated temperatures up to 80 ° C, as long as there is no damage or changes to the lacquer layers, such as premature complete crosslinking.

The thermal hardening has no special features in terms of method, but takes place according to the customary and known methods such as heating in a forced air oven or irradiation with IR lamps. The thermal hardening can also be carried out in stages. The thermal curing is advantageously carried out at a temperature of 50 to 100 ° C., particularly preferably 80 to 100 ° C. and in particular 90 to 100 ° C. for a time of 1 minute to 2 hours, particularly preferably 2 minutes to 1 hour and in particular 3 min to 30 min. Become substrates used, which are thermally strong, the thermal crosslinking can also be carried out at temperatures above 100 ° C. In general, it is advisable not to exceed temperatures of 180 ° C., preferably 160 ° C. and in particular 140 ° C.

The thermal curing can be supplemented by curing with actinic radiation if the coating material has a suitable material composition, UV radiation and / or electron beams being able to be used. If necessary, it can be carried out or supplemented with actinic radiation from other radiation sources. In the case of electron beams, work is preferably carried out under an inert gas atmosphere. This can be ensured, for example, by supplying carbon dioxide and / or nitrogen directly to the surface of the lacquer layer.

In the case of curing with UV radiation, it is also possible to work under inert gas in order to avoid the formation of ozone.

The usual and known radiation sources and optical auxiliary measures are used for curing with actinic radiation. Examples of suitable radiation sources are high-pressure or low-pressure mercury vapor lamps, which may be doped with lead in order to open a radiation window up to 405 nm, or electron beam sources. Their arrangement is known in principle and can be adapted to the conditions of the workpiece and the process parameters. In the case of workpieces of complex shape, such as automobile bodies, the areas (shadow areas) which are not directly accessible to radiation, such as cavities, folds and other undercuts due to construction, can be cured with point, small area or all-round emitters combined with an automatic movement device for irradiating cavities or edges. The facilities and conditions of these curing methods are described, for example, in R. Holmes, UV and EB Curing Formulations for Printing Inks, Coatings and Paints, SITA Technology, Academic Press, London, United Kindom 1984.

The curing can take place in stages, i. H. by multiple exposure or exposure to actinic radiation. This can also take place alternately, i. that is, curing alternately with UV radiation and electron radiation.

If thermal curing and curing with actinic radiation are used together (dual cure), these methods can be used simultaneously or alternately. If the two curing methods are used alternately, thermal curing can be started, for example, and curing with actinic radiation can be ended. In other cases, it may prove advantageous to start and end the curing with actinic radiation. The person skilled in the art can determine the hardening method, which is particularly well suited to each individual case, on the basis of his general specialist knowledge, if necessary with the aid of simple preliminary tests.

The multilayer coatings ML according to the invention have an excellent profile of properties, which is very well balanced in terms of mechanics, optics, corrosion resistance and adhesion. For example, the multilayer coatings ML according to the invention have the high optical quality and interlayer adhesion required by the market and no longer pose problems such as a lack of condensation resistance in the filler layers, crack formation (mud cracking) in the base coats or flow problems or surface structures in the clear coats.

In particular, the multilayer coating ML according to the invention has an excellent, an excellent metallic effect, an excellent DOI (Distinctiveness of the Reflected Image) and an excellent surface smoothness. It is weather-resistant, resistant to chemicals and bird droppings and scratch-resistant and shows very good reflow behavior.

Another significant advantage is the very good paintability of the multilayer coating ML according to the invention, even without sanding. As a result, it can easily be coated with customary and known highly scratch-resistant coating materials based on organically modified ceramic materials.

Last but not least, it proves to be a very special advantage that the process according to the invention can be used to achieve a multi-layer coating which is based exclusively on aqueous coating materials.

Examples

Production Example 1

The preparation of a dispersion of a copolymer (A)

52.563 parts by weight of demineralized water were placed in a steel reactor, as is usually used for the preparation of dispersions, equipped with a stirrer, a reflux condenser and 3 feed vessels and heated to 90.degree. 10.182 parts by weight of acrylic acid, 18.345 parts by weight of methyl methacrylate and 1.493 parts by weight of diphenylethylene were placed in the first feed vessel. 9.914 parts by weight of 25 percent ammonia solution were placed in the second feed vessel. 5.25 parts by weight of demineralized water and 2.253 parts by weight of ammonium peroxodisulfate were placed in the third feed vessel. With intensive stirring of the initial charge in the steel reactor, the three feeds became simultaneous started. The first and second feed were metered in within one hour. The third feed was metered in within 1.25 hours. The resulting reaction mixture was kept at 90 ° C. for four hours and then cooled to below 40 ° C. and filtered through a 100 μm GAF bag. The resulting dispersion had a solids content of 32 to 34% by weight (1 hour, 130 ° C.) and a free monomer content of less than 0.2% by weight (determined by gas chromatography).

The dispersion (A) was used for the production of a block copolymer (A).

Preparation example 2

The preparation of a dispersion of a block copolymer (A)

In a steel reactor, as is usually used for the production of dispersions, equipped with a stirrer, a reflux condenser and an inlet vessel, 51.617 parts by weight of demineralized water and 9.907 parts by weight of the dispersion from preparation example 1 were introduced and heated to 90 ° C. with stirring. A mixture of 9.856 parts by weight of n-butyl methacrylate, 7.884 parts by weight of styrene, 12.661 parts by weight of hydroxyethyl methacrylate and 8.885 parts by weight of ethylhexyl methacrylate was then metered in from the feed vessel over the course of six hours. The resulting reaction mixture was stirred at 90 ° C for two hours. The resulting dispersion was then cooled below 40 ° C. and filtered through a 50 μm GAF bag. The dispersion (A) had a solids content of 41 to 42% by weight (1 hour, 130 ° C.) and a free monomer content of less than 0.2% by weight (determined by gas chromatography). example 1

The production of a multilayer coating ML according to the invention

1.1 The production of a filler containing component (A)

1.1.1 The manufacture of pigment paste

For the production of the filler, a pigment paste consisting of 3.8 parts by weight of carbon black, 32.87 parts by weight of barium sulfate (Blanc Fixe® Super-F), 1.73 parts by weight of talc, 1.04 parts by weight of Additol® XW395 (commercially available wetting agent) and 60. 56 parts by weight of dispersion (A) prepared according to Preparation Example 2. The mixture was predispersed in a dissolver for ten minutes and then ground on a sand mill to a Hegmann fineness <15 μm. The viscosity of the paste was 160 mPas at a shear rate of 100 s ^_1 and 23 ° C.

1.1.2 The manufacture of the fountain pen

The filler was produced by mixing 57.8 parts by weight of the pigment paste according to Examples 1.1.1 and 30 parts by weight of the dispersion (A) according to Preparation Example 2. It had a viscosity of 122 mPas at a shear rate of 100 s ^_1 and 23 ° C. The filler was adjusted to a spray viscosity of 55 mPas with water.

1.2 The production of a metallic basecoat containing constituent (A)

1.2.1 The production of a color paste For the production of the metallic basecoat, a color paste consisting of 50 parts by weight of the dispersion (A) according to Preparation Example 2, 2 parts by weight of Pluriol® P900 (BASF AG), 43 parts by weight of Sicopalgelb® Ll 100 (BASF AG), 0.4 parts by weight of Agitan® was first used 281 (commercially available defoaming agent; Münzing Chemie GmbH). The mixture was predispersed in a dissolver for ten minutes and then ground in a sand mill to a Hegmann fineness <5 μm. The viscosity of the resulting color paste was 424 mPas at a shear rate of 1,000 s ^_1 and 23 ° C.

For mixing with the metallic paste, 37.2 parts by weight of the color paste were mixed with 62.8 parts by weight of the dispersion (A) according to Preparation Example 2 and 5 parts by weight of water.

1.2.2 The preparation of a thixotropic agent

For the production of the metallic basecoat, a thixotropic agent was also produced from 94 parts by weight of demineralized water, 3.0 parts by weight of Laponite® RD (Solvay Alkali GmbH) and Pluriol® P900 (BASF AG).

1.2.3. The production of a polyester dispersion

For the production of the metallic basecoat, a polyester was further prepared in a customary and known manner from 23.23 parts by weight of dimer fatty acid (Pripol® 1009), 10.43 parts by weight of 1, 6-hexanediol, 6.28 parts by weight of hexahydrophthalic anhydride and 9.9 parts by weight of neopentyl glycol and 10.43 parts by weight of trimellitic anhydride. A part by weight of cyclohexane was used as an entrainer. The resulting polyester was dispersed in 17.48 parts by weight of demineralized water, 18.9 parts by weight of butyl glycol and 2.25 parts by weight of dimemylethanolamine.

1.2.4 The production of a metallic paste

A metallic paste comprising 378.7 parts by weight of the thixotropic agent according to Example 1.2.2, 74 parts by weight of a commercially available polyester (Maprenal® VM 3924), 70 parts by weight of butylglycol and 334.5 parts by weight of the dispersion (A) was used to produce the metallic basecoat. according to the production example 2, 5 parts by weight of a commercially available wetting agent (BYK® 346), 50.6 parts by weight of a commercially available aluminum paste (Stapa Hydrolux® 8154), 86 parts by weight of the polyester according to Example 1.2.3 and 33 parts by weight of demineralized water.

The pH of the metallic paste was adjusted to 7.8 with 10% dimethylethanolamine solution. The viscosity of the metallic paste was adjusted to 80 mPas by further addition of water.

1.2.5 The production of the metallic basecoat

The metallic basecoat was produced by mixing the color paste according to Example 1.2.1 and the metallic paste according to Example 1.2.4 in a weight ratio of 2:10.

1.2.6 The production of a clear lacquer containing component (A)

For the production of the multilayer coating ML according to the invention, a clear lacquer comprising 100 parts by weight of dispersion (A) according to the preparation example was used 2.5 parts by weight of a commercially available crosslinking agent based on tris (a] Jkoxycarbonylamino) triazines (Cylink® 2000; CYTEC) and 0.4 parts by weight of Agitan® 281. The low-viscosity mixture was homogenized with an Ultraturrax. The viscosity was 128 mPas at a shear rate of 1.00 s ^"1 and 23 ° C.

1.2.7 The coating of a substrate with the multilayer coating ML according to the invention

For the production of the multilayer coating ML according to the invention, customary and known test panels made of steel were used, which were coated with a commercially available electro-dip coating.

The test panels were pneumatically coated with the filler according to Example 1.1. The resulting filler coat was predried for ten minutes at room temperature and for ten minutes at 80 ° C. It was then baked at 100 ° C for 20 minutes and at 130 ° C for 20 minutes. The result was a filler layer FL with a layer thickness of 35 μm.

The metallic basecoat according to Example 1.2 was applied pneumatically to the filler layer FL. The resulting metallic basecoat was predried for ten minutes at room temperature and for ten minutes at 80 ° C.

The clearcoat according to Example 1.2.6 was applied to the predried metallic basecoat, after which the resulting clearcoat was flashed off at room temperature for 15 minutes. The metallic basecoat and the clearcoat were then baked at 140 ° C. for 30 minutes (wet-on-wet Method). The result was a metallic base coat BL with a layer thickness of 15 μm and a clear coat KL with a layer thickness of 35 μm.

The multilayer coating ML according to the invention produced in this way had an excellent overall optical impression, in particular an excellent metallic effect, an excellent D.O.I. (Distinctiveness of the Reflected Image) and an excellent surface smoothness. The clear coat KL was weather-resistant, resistant to chemicals and bird droppings and scratch-resistant and showed very good reflow behavior.

Another significant advantage was the very good overcoatability of the multilayer coating ML according to the invention, even without sanding. This made it easy to coat the KL clearcoat with the usual, well-known, highly scratch-resistant coatings based on organically modified ceramic materials.

Claims

Color and / or effect multicoat paint system, process for its production and its use

1. Coloring and / or effect-giving multilayer coating ML for a primed or unprimed substrate, comprising superimposed in the order given

(1) a mechanical energy absorbing filler layer FL and

(2) a color and / or effect top coat DL

or

(1) a mechanical energy absorbing filler layer FL,

(2) a color and / or effect base coat BL and

(3) a clear coat KL

or

(1) a color and / or effect base coat BL and

(2) a clear coat KL,

characterized in that at least one layer FL and / or DL or BL and / or KL or FL, BL and / or KL, preferably at least two Layers FL, BL and or KL or all layers FL and DL or BL and KL or FL, BL and KL of the multilayer coating ML has been or are made from a coating material which contains at least one component (A) which is obtained by free-radical polymerization of

a) at least one olefinically unsaturated monomer,

b) at least one olefinically unsaturated monomer of the general formula I which is different from the olefinically unsaturated monomer (a)

R * R ² C = CR ³ R ⁴ (I),

wherein the radicals R ¹ , R ² , R ³ and R ^{4 are} each independently of one another hydrogen atoms or substituted or unsubstituted alkyl,

Cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloalkylaryl, arylalkyl or arylcycloalkyl radicals, with the proviso that at least two of the variables R ¹ , R ² , R ³ and R ^{4 are} substituted or unsubstituted aryl, Arylalkyl or arylcycloalkyl radicals, in particular substituted or unsubstituted

Aryl residues, stand;

can be produced in an aqueous medium.

2. Process for producing a color and or effect-giving multilayer coating ML on a primed or unprimed substrate (I) producing a filler lacquer layer by applying a filler to the substrate,

(II) hardening of the filler lacquer layer, resulting in the filler layer FL,

(III) Production of a solid-color topcoat by applying a solid-color topcoat to the filler layer FL and

(IV) Hardening of the uni-lacquer layer DL, which causes the uni-lacquer layer

DL results

or

(I) producing a basecoat layer by applying a basecoat to the substrate,

(II) drying the basecoat film,

(III) producing a clear coat by applying a clear coat to the basecoat and

(IV) joint curing of the basecoat layer and the clearcoat layer, resulting in the basecoat BL and the clearcoat KL,

or (I) producing a filler lacquer layer by applying a filler to the substrate,

(II) hardening of the filler lacquer layer, resulting in the filler layer FL,

(III) producing a basecoat layer by applying a basecoat to the filler layer FL,

(IV) drying the basecoat film,

(V) producing a clear coat by applying a clear coat to the basecoat and

(VI) joint curing of the basecoat layer and the clearcoat layer, resulting in the basecoat BL and the clearcoat KL,

characterized in that at least one, preferably at least two and in particular all of the coating materials used in each case contain or contain at least one constituent (A) which is obtained by radical polymerization of

a) at least one olefinically unsaturated monomer,

b) at least one olefinically unsaturated monomer of the general formula I which is different from the olefinically unsaturated monomer (a) R ¹ R ² C = CR ³ R ⁴ (I),

wherein the radicals R ¹ , R ² , R ³ and R ⁴ each independently of one another represent hydrogen atoms or substituted or unsubstituted alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl,

Cycloalkylaryl, arylalkyl or arylcycloalkyl radicals, with the proviso that at least two of the variables R ¹ , R ² , R ³ and R ^{4 are} substituted or unsubstituted aryl, arylalkyl or arylcycloalkyl radicals, in particular substituted or unsubstituted aryl radicals;

can be produced in an aqueous medium.

3. The multilayer coating ML according spoke 1 and the method according addressed 2, characterized in that the component (A) of the coating material can be obtained by

(i) free-radically polymerizing at least one monomer (a) and at least one monomer (b) in an aqueous medium, after which

(ii) reacting the resulting reaction product with at least one further monomer (a) under radical conditions.

4. The multilayer coating ML according to claim 1 or 3 and the method according to claim 2 or 3, characterized in that the aryl radicals R ¹ , R ² , R ³ and / or R ^{4 of} the compound (b) are phenyl or Naphthyl residues, especially phenyl residues.

5. The multilayer coating ML according to one of claims 1, 3 or 4 and the method according to one of claims 2 to 4, characterized in that the substituents in the radicals R ¹ , R ² , R ³ and / or R ^{4 of} the compound ( b) electron-withdrawing or electron-donating atoms or organic radicals, in particular halogen atoms, nitrile, nitro, partially or completely halogenated alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloaucylaryl, arylalkyl and arylcycloalkyl radicals; Aryloxy, AUcyloxy and cycloalkyloxy radicals; Arylthio, alkylthio and cycloacylthio radicals, hydroxyl groups; and / or are primary, secondary and / or tertiary amino groups.

6. The multilayer coating ML according to one of claims 1 or 3 to 5 and the method according to one of claims 2 to 5, characterized in that as monomers (a)

al) essentially acid group-free (meth) acrylic acid esters;

a2) monomers which carry at least one hydroxyl group, amino group, alkoxymelxiylamino group or irino group per molecule and are essentially free of acid groups;

a3) monomers which carry at least one acid group which can be converted into the corresponding acid anion group per molecule;

a4) vinyl esters of monocarboxylic acids with 5 to 18 carbon atoms in the molecule which are branched in the alpha position; a5) reaction products of acrylic acid and / or methacrylic acid with the glycidyl ester of a monocarboxylic acid branched in the alpha position with 5 to 18 carbon atoms per molecule;

a6) cyclic and / or acyclic olefins;

a7) (meth) acrylic acid amides;

a8) monomers containing epoxy groups;

a9) vinyl aromatic hydrocarbons;

alO) nitriles;

al l) vinyl compounds, especially vinyl and / or

Vmylidenedihalogenide, N-vinylpynolidone, vinyl ether and or vinyl ester;

al2) allyl compounds, in particular allyl ethers and esters;

al3) polysiloxane macromonomers, which are a number average

Molecular weight Mn from 1,000 to 40,000 and on average 0.5 to 2.5 ethylenically unsaturated double bonds per molecule; and or

al4) Acryloxysilane-containing vinyl monomers, which can be prepared by reacting hydroxy-functional silanes with epichlorohydrin and then reacting the reaction product with (Meth) acrylic acid and / or hydroxyalkyl and / or cycloalkyl esters of (meth) acrylic acid (monomers a2);

be used.

7. The multilayer coating ML according to one of claims 1 or 3 to 6 and the method according to one of claims 2 to 6, characterized in that the coating material also contains at least one of the following components:

A ') at least one binder with at least one functional group (afg) which can undergo thermal crosslinking reactions with complementary functional groups (bfg) in the crosslinking agent (B);

B) at least one crosslinking agent with at least two functional groups (bfg) which can undergo thermal crosslinking reactions with complementary functional groups (afg) in component (A),

C) at least one component which can be crosslinked with actinic radiation,

D) at least one photoinitiator,

E) at least one initiator of the thermal crosslinking,

F) at least one reactive diluent curable with actinic radiation and / or thermally; G) at least one paint additive and / or

H) at least one organic solvent

contains.

8. Use of the multi-layer coating ML according to one of claims 1 or 3 to 7 or the multi-layer coating ML produced by the method according to one of claims 2 to 7 for automotive initial and refinishing, industrial painting, including coil coating and container coating Plastic painting and furniture painting.

9. Primed or unprimed substrates containing at least one multilayer coating ML according to one of claims 1 or 3 to 7 or at least one multilayer coating ML produced by the method according to one of claims 2 to 7.