CA2449209A1 - Coating materials that can be cured thermally and by actinic radiation, and the use thereof - Google Patents

Abstract

The invention relates to coating materials that can be cured thermally and by actinic radiation and that comprise (A) at least one binder, selected from the group including the random, alternating and block, linear, branched and comb polyaddition resins and polycondensation resins that can be cured thermally or thermally and by actinic radiation, and (co)polymers of olefinically unsaturated monomers, and (B) 0.01 to 3 % by weight, based on the solid content of the coating material, of at least one additive on the basis of at least one (meth)acrylate (co)polymer, selected from the group including (meth)acrylate (co)polymers of a number average molecular weight of from 4,000 to 100,000 daltons and having a low to high polarity. The invention relates to the use of the inventive coating materials for producing single-layer and multi-layer clearcoats and color- or effect-producing multi-layer coatings or as adhesives and sealing materials.

Description

COATING MATERIALS THAT CAN BE CURED THERMALLY AND BY
ACTINIC RADIATION, AND THE USE THEREOF
The present invention relates to novel coating materials which are curable thermally and with actinic radiation. The present invention also relates to the use of the novel coating materials curable thermally and with actinic radiation for producing single-coat and multicoat clearcoat systems and color and/or effect paint systems. The present invention additionally relates to the use of the novel coating materials curable thermally and with actinic radiation as adhesives and sealing compounds for producing adhesive films and seals.
Color and/or effect coatings of motor vehicle bodies, especially automobile bodies, nowadays consist preferably of- a plurality of coating films which are applied over one another and have different properties.
For example, an electrodeposition~coat (electrocoat) as primer, a primer-surfaces caat or antistonechip primer, a basecoat, and a clearcoat are applied in succession to a substrate. In this system, the electrocoat serves in particular to protect the sheet metal against corrosion. By those skilled in the art it is often also referred to as the primer. The primer-surfaces coat L

-serves to cover unevennesses in the substrate, and because of its elasticity imparts stonechip resistance.
Where present, the primer-surfacer coat may also serve to reinforce the hiding power and to deepen the shade of the paint system. The basecoat .'contributes the colors and/or optical effects. The clearcoat is used to intensify ,the optical effects and to protect the paint system against mechanical and chemical damage. Basecoat and clearcoat are frequently also referred to collectively as the topcoat. For further details, refer to Rompp Lexikon Lacke and Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, pages 99 and 51, "automotive finishes". In the text below, these multicoat paint systems are referred to as multicaat color and/or effect paint systems.
On account of their size and the fact that they almost always subsequently receive logos, inscriptions and/or blocks of color or images, commercial vehicles are frequently provided only with a pigmented coating, known as a solid-color topcoat.
More recently, the clearcoats in particular have been produced from clearcoat materials which are curable thermally and with actinic radiation. Here and below, actinic radiation means electromagnetic radiation, such as near infrared, visible light, UV radiation or x-rays, especially W radiation, and corpuscular radiation, such as electron beams. Combined curing by .. - 3 -means of heat and actinic radiation is also referred to by those skilled in the art as dual cure.
Dual-cure coating materials, especially dual-cure clearcoat materials, possess the key advantage that, even in the shadow zones of three-dimensional substrates of complex shape, such as autobodies, radiators or electrical wound articles, and even in the absence of optimum - in particular, complete - exposure E' 10 of the shadow zones to actinic radiation,, they provide coatings whose profile of performance properties at least comes close to that of the coatings outside of the shadow zones. As a result, the coatings in the shadow zones are also no longer readily damaged by mechanical and/or chemical attack, as may occur, for example, on the production line during the installation of further components of motor vehicles into the coated bodies.
Additionally, curing with actinic radiation may compensate incomplete ,thermal curing, if for example the dual-cure coating materials cannot be heated to the temperatures required for rapid progression of the thermal crosslinking reactions, owing to the temperature sensitivity of the coated substrates.
Dual-cure coating materials and ,their use to produce high-quality multicoat color and/or effect paint systems are known, for example, from the German patent applications DE 42 15 070 A1, DE 198 18 735 A1, DE 199 O8 018 A1, DE 199 30 665 A1, DE 199 30 067 A1, DE 1.99 30 664 Al, DE 199 29 674 A1, DE 199 20 799 AI, l99 58 726 A1 or DE 199 61 926 A1 or are described in the German patent applications DE 100 27 268.1, DE 100 42152.0, DE 100 47 989.8. or DE 100 55 549.7, unpublished at the priority date of the present specification. The use of additives based on a (meth)acrylate (co)polymer having a number-average molecular weight of from 5 000 to 100 000 daltons is not revealed by the patent applications.
The refinishing or repeat finishing of these high-quality multicoat color and/or effect paint systems imposes exacting demands on the refinish materials and the refinish process. This is particularly the case with the line refinishing of coated autobodies where the original (OEM) finish requires extensive or complete recoating (repeat finishing). The colors and/or optical effects in the refinish must not differ from those of the original finish. Moreover, the refinish must adhere firmly to the original finish.
I3owever, where the original finishes are produced. using the dual-cure clearcoat materials, which have particular technological advantages, adhesion problems arise which are attributable to the particularly high crosslinking density of the radiation-cured systems.
Effective adhesion in such cases is achievable only by 4.

a physical treatment, such as an ultrasound and/or heat treatment, a mechanical treatment, by sanding, polishing and/or buffing, for example, and/or a chemical treatment, such as incipient etching with appropriate chemicals, such as acids or bases, and/or by flaming. These measures may still be feasible in the refinishing of small .areas; on the industrial scale, they are completely impracticable because in that context they are too time-consuming and energy f consuming and in many cases give rise to safety objections. Where the measures are not taken, however, the repeat coatings and refinishes, particularly in the case of the following systems:
- clearcoat (original)/clearcoat (refinish), and - basecoat (original)/clearcoat (original)/basecoat (refinish)/clearcoat (refinish) It tend toward delamination, which with such high-quality products as motor vehicles is unacceptable. These key disadvantages are hindering the wide spread..of the dual-cure coating materials - which are otherwise so advantageous - within industrial coating.
These problems also arise with the refinishing or repeat finishing of solid-color topcoats produced from pigmented coating materials curable thermally and with actinic radiation.

i.

It is an object of the present invention to.find novel coating materials curable thermally and with actinic radiation (dual-cure coating materials) which provide novel coatings having improved performance properties.
In particular, the novel coatings, as single coats or as the topmost coat of a multicoat paint system, should permit extensive refinishing or repeat finishing without the need to take measures to promote adhesion, such as the abovementioned physical, mechanical and/or chemical surface treatments.
The invention accordingly provides the novel coating materials curable thermally and with actinic radiation, comprising (A) at least one binder selected from the group consisting of random, alternating and block, linear, branched and comb polyaddition resins, polycondensatian resins, and addition (co)polymers of olefinically unsaturated monomers, curable physically, thermally, with actinic radiation, and thermally and with actinic radiation;
and (B) from 0.01 to 3~ by weight,' based on the solids of the coating material, of at least one additive based on at least one (meth)acrylate (co)polymer selected from the group consisting of - _ '~
(meth)acrylate .(co)polymers having a number-average molecular weight of from 4 000 to 100 000 daltons and a low to high polarity.
In~the text below, the novel coating materials curable thermally and with actinic radiation are referred to as "coating materials of the invention".
Further subject matter of the invention will emerge k.
from the description.
In the light of the prior art it was surprising and unforeseeable for the skilled worker that the object on which the present invention is based could be achieved by the, inventive use of the additive (B) . A particular surprise was that the additive (B), as far as improving the wettability of the original finishes and the adhesion between original finish and refinish or repeat ( finish, was extraordinarily effective. even in small amounts, so that there was no longer any need to perform adhesion-promoting surface treatment of the original finishes, such as a physical treatment, by ultrasound and/or heat, for example, a mechanical treatment, by sanding, polishing and/or buffing, fvr example, and/or a chemical treatment, by incipient etching with appropriate chemicals, such as acids or bases, for example, and/or by flaming. It was also surprising that the coatings of the invention had a significantly reduced sensitivity toward fingerprints, .. _ which greatly facilitated .the .handling of substrates that had been coated with the coatings of the invention. Entirely surprising was that the coating .
materials of the invention could also be used as dual 5. cure adhesives and sealing compounds for producing adhesive films and seals.
The essential constituent of the coating material of the invention is at least one, especially one, additive (B) based on at least one, especially one, (meth)acrylate (co)polymer, particularly a (meth)acrylate copolymer, selected from the group consisting of (meth)acrylate (co)polymers With a number-average molecular. weight of from 4 000 to 100 000, preferably from 4 100 to 90 000, more preferably from 4 200 to 80 000, ~ with particular preference from 4 300 to 60 000, with very particular preference from 4 400 to 50 OOO,~and in particular from 4 500 to 40 000 daltons, and a low to high, in ( particular a low to moderate,~polarity.
In accordance with the invention, the additive (B) is present in the coating materials of the invention in an amount, based in each case on the solids of (B), of from O.Ol to 3%, preferably from 0.02 to 2.8%, more preferably from 0.03 to 2.6%, with particular preference from 0.04 to 2.4%, and in particular from 0.05 to 2.2.% by weight:

_ 9 _ The (meth)acrylate (co)polymer (B) for use in accordance with the invention may be added as it is to ' the coating materials of the invention. Tt is of advantage, however, to add the' (meth)acrylate (co)polymer (B) in the form of an organic solution.
Accordingly, the additive (B) for use in accordance with the invention preferably comprises at least one organic solvent. The amount of organic solvent may vary widely. The solvent content is preferably made such that the solids content of the additive (B), based on (B), is from 10 to 80~, more preferably from IS-to 75%, with particular preference from 20 to 700, with very particular preference from 25 to 65%, and in particular from 30 to 60~ by weight.
It is preferred to use organic solvents which do not inhibit the dual-cure crosslinking of the coating materials of the invention and/or do not enter into any ( disruptive interactions with constituents of the coating materials of the invention. The solvents may be inert or else may participate in the crosslinking reactions as reactive diluents which can be crosslinked thermally and/or with actinic radiation. The skilled worker will therefore select suitable solvents easily on the basis of their known solvency and their reactivity. Examples of suitable solvents are known from D. Stoye and W. Freitag (editors), "Paints, Coatings and Solvents", second, completely. revised edition, Wiley-VCFi, Weinheim, New York, 1998, "19.9.

R, - 10 -Solvent Groups", pages.327 to 373.
'The additives (B) are commercial products and are sold, for example, under the brand name BXK~ 354, 355, 357, 358, 380, 381 or 39Q, especially~358, by Byk Chemie.
The further essential constituent of .the coating materials of the invention is at least one binder (A).
Binders (A) are selected from the group consisting of random, alternating and block, linear, branched and comb 'addition (co)polymers of ethylenically unsaturated monomers, polyaddition resins .and/or polycondensation resins curable physically, thermally, or thermally and with actinic radiation. Regarding these terms, refer to Rompp Zexikon Zacke and Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 199$, page' 457,' "polyaddition" and "polyaddition resins (polyadducts)", and also pages 463 and 464, "polycondensates", "polycondensation", and ''polycondensation resins", and also pages 73 and 74, "binders".
Examples of suitable addition (co)polymers (A) are (meth) acrylate (co) polymers or partially sapoi~ified polyvinyl esters., especially (meth)acrylate copolymers.
Examples of suitable polyaddition resins and/or poly-condensation resins (A) are polyesters, alkyds, polyurethanes, polylactones, polycarbonates, poly-ethers, epoxy resin-amine adducts, polyureas, poly-amides, polyimides, polyester-polyurethanes, polyether-polyurethanes ox polyester-polyether-polyurethanes, especially polyesters.
Of these binders (A?, the (meth) acrylate copolymers and the polyesters, especially the (meth)acrylate copolymers, have particular advantages and are therefore used with particular preference.
y IO
The coating material for use in accordance with the invention accordingly comp.r.ises at least one, especially one, (meth)acrylate copolymer (A) as binder.
In some cases. however, it may be advantageous to use I5 at least two, especially two (meth)acrylate copolymers (A) which have a different profile of properties in terms of the preferred ranges of OH number, glass transitian temperature, and number-average and rnass-average molecular weight that are indicated below.
The (meth)acrylate copolymer (A) preferably has - an OH number of from 100 to 220, more preferably from 130 to 200, with particular preference from 140 to 190, and in particular. from 145 to 180 mg KOH/g, - a glass transition temperature of from -35. to t60°C,,in paxticular from -20 to +40°C, _ 12 - a number-average molecular weight of from 1 000 to 10 000 daltons, in particular from 1 500 to 000 daltons, and 5 - a mass-average molecular weight of from 2 000 to 40 000 daltons, in particular from 3 000 to 20 000 daltons.
The (meth)acrylate copolymer (A) preferably contains an amount corresponding to its OH number of hydroxyl- ( containing olefinically unsaturated monomers (a) in copolymerized form, of which (al) from 20 to 905, preferably from 22 to 85$, more preferably from 25 to 80°a, arid in particular from 28 to 75~ by weight, based.in each case on the , hydroxyl-containing monomers (a), are selected -from the group consisting of 4-hydroxybutyl (meth)acrylate and 2-alkylpropane-1,3-diol ( mono(meth)acrylates, and (a2) from 20 to 80g, preferably from 15 to 78%, more preferably from 20 to 750, and in particular from to ?2~ by weight, based in each case on the 25 hydroxyl-containing monomers (a), are selected from the group consisting of other hydroxyl-containing olefinically unsaturated monomers.

Examples of suitable 2-alkylpropane-1,3-diol mono-2-eth 1-, (-meth)acrylates (a1) are 2-methyl-, y 2-propyl-, 2-isopropyl- or 2-n-butylpropane-1,3-diol mono(meth)acrylate, of which 2-methylpropane-1,3-diol rnono(meth)acrylate is particularly advantageous and is used with preference.
Examples of suitable other hydroxyl-containing olefinically unsaturated monomers.(a2) are hydroxyalkyl esters of olefinically unsaturated carboxylic, sulfonic and phosphonic acids and acidic phosphoric and sulfuric esters, especially carboxylic acids, such as acrylic acid, beta-carboxyethyl acrylate, methacrylic acid, ethacrylic acid and crotonic acid, particularly acrylic acid and methacrylic acid. They are derived from an alkylene glycol, which is esterified with the acid,' or are obtainable by reacting the acid-with an alkylene oxide such as ethylene oxide or propylene oxide . It is preferred to use the hydroxyalkyl esters in which the hydroxyalkyl group contains up to 20 carbon 'atoms, particularly 2-hydroxyethyl or 3-hydroxypropyl acrylate or methacrylate; 1,4-bis(hydroxymethyl)cyclohexane or octahydro-4,7-methano-1H-indenedimethanol monoacrylate or monomethacrylate; or reaction products of cyclic esters, such as epsilon-caprolactone, for example, and these hydroxyalkyl esters; or olefinical.ly unsaturated alcohols such. as allyl alcohol: or polyols, such as " trimethylolpropane monoallyl or diallyl ether or pentaerythritol monoallyl, diallyl or triallyl ether.

- 14 ' 'These monomers (a2}~ of relatively high functionality are generally used only in mino r amounts. In the context 'of the present invention, minor amounts of moriomers (a2) of relatively high functionality are amounts which do not lead to crosslinking or gelling of the (meth}acrylate copolymers (A), unless the intention is that they should be in the form of crosslinked micro-gel particles.
i Also suitable as monomers (-a2) are ethoxylated and,/or~
propoxylated allyl alcohol, which is sold by Arco Chemicals, or 2-hydroxyalkyl a11y1 ethers; especially 2-hydroxyethyl a11y1 ether. . Where used, they are preferably employed not as sole monomers (a2} but in an amount of from 0.1 to 10% by weight, based on the (meth}acrylate copolymer (A).
Also suitable are reaction products of the olefinically unsaturated acids listed above, especially acrylic acid ;
and/or methacrylic acid, with the glycidyl ester of an alpha-branched monocarboxylic acid having from 5 to 1$ carbon atoms per molecule, in particular a Versatic~
acid, or, instead of the reaction products, an equivalent amount of the abovementioned olefinically unsaturated acids, especially acrylic acid and/or methacrylic acid, which is then reacted, during or after the polymerization. reaction, with the glycidyl ester of an alpha-branched monocarboxylic acid having from 5 to 18 carbon atoms per molecule, in particular a M _ 15 _ Versatic~ acid (cf. Rompp Lexikon Lacke and Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, "Versatic~ acids", pages 605 and 605)..
Not least, acryloyloxysilane-containing vinyl monomers are suitable as monomers (a2), being preparable by reacting hydroxy-functional silanes with epichloro-hydrin. and then reacting that reaction product with (meth)acrylic acid and/or with hydroxyalkyl and/or hydroxycycloalkyl esters of (meth)acrylic acid and/or other hydroxyl-containing monomers (a1j and..(a2).
Besides th.e hydroxyl, groups, the (meth)acrylate copolymers which are curable thermally. and/or with actinic radiation may contain on average.per molecule (l) at least one, in particular at least two, reactive functional groups) which are able to undergo thermally ,initiated crosslinking reactions with complementary reactive functional groups, and/or .
(ii) at least one, in particular at least two, reactive functional groups) having at least one, especially one, bond which can be activated with actinic radiation.
Examples of suitable complementary reactive functional groups (l) far use in accordance with the invention are ., _ Z 6 -compiled in the following overview. In the overview, the variable R stands for an acyclic or cyclic aliphatic radical,. an aromatic radical and/or aromatic-aliphatic (araliphatic) radical; the variables R' and R". stand for .identical or different aliphatic radicals or are linked with one another to form an aliphatic or heteroaliphatic ring.
Overview: Examples of complementary functional groups R
(i) Binder and crosslinking went or Crosslinkinq'aqent and binder , -SH -C (O).-OH
-NHz ~C (O) -0-C (0) --O- ( CO) -NH- ( CO ) -NH2 -NCO
-O- ( CO ) -NHZ -NH-C ( 0 ) -OR
>NH -CHz-OH
--CHZ-0-R ;;

-NH-CHI-OH
-N (-CH2-O-R) 2 -NH-C (O) -CH (-C (0) OR) Z
-NH-C (0) -CH (-C (0) OR) (-C (0) -R) -NH-C (0) -NR'R"
>Si (OR) z ." _ 17 _ C
~i C'~. .
-CH-CHi --C (O) -OH
-CH-~H
z -C,(O) -N (CH2-CHZ-OH) z The selection of the respective complementary reactive functional groups (i) is guided on the one hand by the consideration that during the preparation of the binders (A) and during the preparation, the storage, the application, and the curing.process they should not enter into any unwanted reactions, in particular no premature crosslinking, and/or should not disrupt or inhibit the actinic radiation cure, and secondly by the temperature range within which crosslinking is to take place.
Preferably, the complementary reactive functional groups (i) are selected on the one hand from the group consisting of thiol, amino, N-methylolamino, N-alkoxy-w ' ' -~ 18 methylamino, imino, carbamate, allophanate and/or carboxyl groups, and on the other hand from the group - consisting of anhydride, carboxyl, epoxy, blocked arid unblocked isocyanate, urethane, alkoxycarbonylamino, methylol, methylol ether, carbonate, amino and/or beta hydroxyalkylamide groups.
Self-crosslinking binders (A) contain, in particular, methylol, methylol ether and/or N-alkoxymethylamino groups ( l ) .
The complementary reactive functional groups (l) may be introduced into the (meth)acrylate copolymers with the aid of the olefinically unsaturated monomers (a3) described below, which contain the reactive functional groups (l) in question, or by means of polymer-analogous reactions.
Examples of suitable olefinically unsaturated monomers (a3) are (a31) monomers which carry per molecule at least one amino group, such as - aminoethyl acrylate, aminoethyl methacrylate, allylamine or N-methyliminoethyl acrylate;
and/or w _ 19 _ (a32) monomers which carry per molecule at least one acid group, such as ~ y - acrylic acid, beta-carboxyethyl acrylate, methacrylic acid, ethacrylic acid, erotonic acid, malic acid, fumaric acid or itaconic acid;
- olefinically unsaturated sulfonic or phosphonic acids or their partial esters;
- mono(meth)acryloyloxyethyl maleate.,.succinate or phthalate; or l5 - vinylbenzoic acid (all isomers), alpha-methylvinylbenzoic acid (all isomers) or vinylbenzenesulfonic acid (all isomers).
i . ..
(a33) Monomers' containing epoxide groups, suc°h as the glycidyl ester of acrylic -acid, methacrylic acid, ethacrylic acid, crotanic acid, malic acid, fumaric acid or itaconic acid, or allyl glycidyl ether. -One example of introducing reactive functional groups (i) by way of polymer-analogous reactions is the reaction of some of the hydroxyl groups present in the binder (A) with phosgene, to give resins containing chlorofo-rmate groups, and the polymer-analogous reaction of the chloroformate-functional resins with ammonia a.nd/or primary and/or secondary amines to give binders (A) containing carbamate groups. Further examples of suitable methods of this kind are kriowri from the patents US 4,758,632 A1, US 4,301,257 A1 and US 2,979,514 A1. It is possible, moreover, to introduce carboxyl groups by the polymer-analogous reaction of some of the hydroxyl groups with carboxylic anhydrides, (.
such as malic anhydride or phthalic anhydride.
Furthermore, the (meth)acrylate copal.ymers (A) may also contain at least one olefinieally unsaturated monomer (a4) which is substantially or entirely free from reactive functional groups, such as:
Monomers (a41 ) ;
Substantially acid-group-free (meth)acrylic esters such as (meth)acrylic acid alkyl or cycloalkyl esters having up to 20 carbon atoms in the alkyl radical, especiall y methyl, ethyl, n-propyl, n-butyl, sec-butyl, tert-butyl, hexyl, ethylhexyl, stearyl and lauryl acrylate, or lauryl methaerylate; cycloaliphatic (meth)acrylic esters, especially cyclohexyl, isobornyl, dicyclo-pentadienyl, octahydro-4,7-methano-1H-indenemethanol or tert-butylcyclohexyl (meth)acrylate; (meth)acrylic acid oxaalkyl esters or oxacycloalkyl esters such as ethoxytriglycol (meth)acrylate and methoxyoligoglycol (meth)acrylate having a molecular weight Mn of 21 _ _ preferably 550 or other ethoxylated and/or propoxy-lated,. hydroxyl-free (meth)acrylic~ acid derivatives (further examples of suitable monomers (32) of this kind are known from. the laid-.open specification DE 196 25 773~A1, column 3 line v65 to column 4 line 20). They may contain minor amounts of (meth)-acrylic acid alkyl or cycloalkyl esters of higher functionality, such as ethylene glycol, propylene glycol, diethylene glycol, di.propylene glycol, butylene glycol, pentane-1,5-diol, hexane-1,6-diol, octahydro-4,7-methano-1H-indenedimethanol or cyclohexane-1,2-, -1, 3- or -1, 9-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 monomers (a41) of higher functionality are amounts which do not lead to crosslinking or gelling of the copalymers, except where the intention is that they should be in the form of (,. . crosslinked microgel particles.
Monomers (a42):
Vinyl esters of alpha-branched monocarboxylic acids having from 5 to I8 carbon atoms in the molecule. The branched monocarboxylic acids may be obtained by reacting formic acid or carbon monoxide and water with olefins in the presence of a liquid, strongly acidic catalyst; the olefins may be cracking products of paraffinic hydrocarbons, such as mineral oil fractions, and may include both branched and straight-chain .. _ 22 _ - acyclic and/or cycloaliphatic olefins. The reaction of such olefins with formic acid or with carbon monoxide and water produces a mixture of carboxylic acids in which the carboxyl groups are.located~predominantly on a quaternary carbon atom, Other olefinic starting materials are propylene trimer, propylene tetramer, and diisobutylene, for example. The vinyl esters may, however, also .be prepared conventionally from the acids, for example, by reacting the acid with 1D acetylene. Particular preference - owing to their ready availability - ~is given to using vinyl esters of , saturated aliphatic monocarboxylic .acids having from 9 to 11 carbon atoms and being branched on the alpha carbon atom. Vinyl esters o~ this kind are sold under the brand name VeoVa~ (cf. also Rompp Lexikon Lacke and Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, page 598). , Monomers (a43) :, Diarylethylenes, especially those of the general formula I:
R1R2C=CR3R° ( I ) , in which the radicals Rl, R2, R3 and R9, in each case independently of one another,. stand for 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 Rlr R2, R3 and R4 stand for substituted or unsubstituted - '23 -aryl, arylalkyl or arylcycloalkyl radicals, especially substituted or unsubstituted aryl radicals. Examples 'of suitable alkyl radicals. are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, te~rt-butyl, amyl, hexyl arid 2-ethylhexyl. Examples of suitable cycloalkyl radicals are cyclobutyl, cyclopentyl and cycl.ohexyl.
.Examples of suitable alkylcycloalkyl radicals are methylenecyclohexane, ethylenecyclohexane, and propane-1,3-diylcyclohexane.. Examples of suitable cycloalkyl-alkyl .radicals are 2-, 3- or 9-methyl-, -ethyl-, -propyl- and -butylcyclohex-1-yl. Examples of suitable aryl radicals are phenyl, naphthyl, and biphenylyl, preferably phenyl and naphthyl, and especially phenyl.
Examples of suitable alkylaryl radicals are benzyl and ethylene- or propane-1,3-diylbenzene. Examples of suitable cycloalkylaryl radicals are' 2-, 3-, and 9-phenylcyclohex-1-yl. Examples of suitable arylalkyl radicals are 2-, 3- and 4-methyl-, -ethyl-, -propyl-, and -butylphen-1-yl. Examples of suitable arylcyclo-alkyl radicals are 2-, 3-, and 4--cyclohexylphen-1-yl.
The aryl radicals R1, R2, R3 a.nd/or R° are preferably phenyl or naphthyl radicals, especially phenyl radicals. The substituents that may be present in the radicals Rs, R2, R3 and/or. R4 are electron-withdrawing or electron-donating atoms or organic radicals, especially halogen atoms, nitrile, nitro, partially or fully halogenated alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloalkylaryl, arylalkyl, and ar.ylcyclo'alkyl radicals; aryloxy, alkyloxy and cycloalkyloxy radicals; and/or arylthio, alkylthio and -cycloalkylthio radicals. Particularly .advantageous are , diphenylethylene, dinaphthaleneethylene, cis- or trans-stilben.e or 5. vinylidenebis(4-nit.rob2nzene), especially diphenyl-ethylene (DPE), and so are used with preference. In the context of the present invention the monomers (a43) are used in order to regulate the copolymerization advantageously in such a way. that free-radical copolymerization~in batch mode is also possible, f Monomers (a49):
Vinylaromatic hydrocarbons such as styrene, vinyl toluene, diphenylethylene or alpha-alkylstyrenes, especially alpha-methylstyrene, Monomers (a45)~:
Nitrites such as acrylonit.rile and/or rnethacrylo-nitrile.
Monomers (a46) : . .
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-vinyl-caprolactam or N-vinylpyrrolidone; 1-vinylimidazole;
vinyl ethers. such as ethyl vinyl ether, n-propyT vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether and/or vinylcyclohexyl ether;

F"

'and/or vinyl esters such as vinyl acetate, ' vinyl propionate, vinyl butyxate,_ vinyl pivalate and/or the vinyl .ester of 2-methyl-2-ethylheptanoic acid. , Monomers (a47) : ~ ' .
Allyl compounds, especially allyl ethers 'and allyl esters such as allyl methyl, ethyl, propyl or butyl ether or allyl acetate, propionate or butyrate.
(. . . .
Monomers (a98): . .
Polysiloxane macromonomers which have a number-average molecular weight Mn of from 1 000 to 40 000 and contain on average from 0.5 to 2.5 ethylenically unsaturated double bonds per molecule; especially polysiloxane macromonomers which have a number-average molecular weight Mn of from 2 000 to 20 000, with particular preference from 2 500 to 10 000, and in particular from 3 000 to' 7 000, and contain on average per molecule from 0.5 to , 2.5, preferably from 0.5 to 1.5, ethylenically unsaturated double bonds, as are described in DE 38 07 571 A1 on pages 5 to 7, in DE 37 06 095 A1 in columns 3 to 7, in EP fl 358 153 B1 on pages 3 to 6, in US 9,759,014 A1 in columns 5 to 9, in DE 99 21 823 A1 or in the international patent application WO 92122515 on page 12 line l8 to page 18 line 10.
The monomers (a1) and (a2) and also (a3) and/or (a9) are selected so as. to give the OH numbers and glass - 2~ -transition temperatures. indicated above. Furthermore,.
the monomers (a~3) containing reactive fuwctional groups (i) are selected in their nature anal amount such that they do not inhibit or prevent entirely, the crosslinking reactions of the hydroxyl groups with the compounds (C) described below.
Fox adjusting the.glass transition temperatures, the skilled worker ma.y select the monomers (a) with the assistance of the following formula of Fox, with which the glass transition temperatures of poly-(meth).acrylates may be calculated approximately:
n=x 1lTg = ~ W11/ Tgn; ~a 1Nn = '( Tg .- glass transition temperature of the poly-(meth)acrylate:
Wn - weight fraction of the nth monomer;
Tgn - 'glass transition temperature of the homopolymer of the nth monomer; and x - number of different monomers.
The preparation of the (meth)acrylate copolymers (A) preferred for use has no special features in terms of its process technology but instead takes place with the aid of the methods of continuous or batchwise, free-radically initiated copolymerization that are customary _ 27 _ and. known i~n the plastics field, in bulk, solution, emulsion, miniemulsion . or microemulsion, under atmospheric pressure. or superatmospheric pressure, in stirred tanks, autoclaves, tube reactors, loop reactors or Taylor reactors, at temperatures of preferably~from '50 to 200°C.
Examples of suitable copolyrnerization processes are described in the patent applications DE 197 09 465 A1, DE 197 09 476 A1,. DE 28 98 906 A1, DE 195 24 182 A1, DE 198 28 742 Al, DE 196 28 193 A1, DE 196 28 142 A1., EP 0 f54 783 A1, WO 95/27742, W0 82/02387 and W0 98/02966. Alternatively, the copolymerization may be conducted in polyols (thermally curable reactive diluents) as the reaction medium, as is described, fox example, in the German ' patent application DE 298 .50 243 A1.
i. Examples af, suitable free-radical initiators are dialkyl peroxides, such as di-tert-butyl peroxide ox dicumyl peroxide; hydroperoxides, such as cumene hydroperoxide or tent-butyl hydroperaxide; perestexs, such as tent-butyl perbenzoate, tert-butyl perpivalate, tert-butyl per-3,5,5-trimethylhexanoate or tert -butyl per-2-ethylhexanoate; peroxodicarbonates; potassium, sodium or ammonium peroxodisulfate; azo initiators, examples being azo dinitriles such as a~obisiso-butyronitrile; C-C-cleaving initiators such as benzpinacol silyl ethers; or a combination of a non-w _ 2g _ oxidizing initiator with hydrogen peroxide. Combina-tions o.f the above-described initiators may also be used.
Further examples of suitable initiators are described in the German patent application DE 196 28 142 A1, page 3 line 49 to page 9 Line 6.
It is preferred to add comparatively large amounts of free-radical initiator, with the fraction .of ,the initiator in the reaction mixture,~based in each case on the overall amount of the monomers (a) and of the initiator, being with particular preference from 0.2 tc5 20~ by weight, with very particular preference from 0.5 to 15~ by.weight, and in particular from 1.0 to 10% by weight.
It is also possible to use thiocarbonylthio compounds or mercaptans such -as dodecyl mercaptan as chain -transfer agents or molecular weight regulators.
The nature and amount of the (meth)acrylate copolymers (A) are preferably selected in such a way that, following their curing,-the coating materials of the -invention have a storage modulus.E' in the rubber-elastic range of at least 10''5 Pa and a loss factor tan8 at 20°C of not more than 0.10, the storage modulus E' and the loss factor having been measured by dynamic mechanical thermoanalysis on free films with a 29 _ thickness of 90 t 10 um (cf. in this respect the German patent DE 197 09 467 C2) .
The reactive functional groups (ii) having at least one bond which can be activated with actinic'radiation may be present in the (meth)acrylate copolymers (A). Where the coating materials for use' in accordance with the invention include no other constituents which can be cured with actinic radiation, . the (meth)acrylate r ZO copolymers. (A) mandatorily contain these groups (ii).
In the context of the present invention, a bond which can be activated with actinic radiation is a bond which, on exposure to actinic radiation; becomes reactive and, together with other activated bonds of this kind, undergoes polymerisation reactions and/or crosslinking reactions which proceed~in accordance with free-radical and/or. ionic mechanisms. Examples of a. suitable bonds are carbon-hydrogen single bonds or carbon-carbon, carbon-oxygen, carbon-nitrogen, carbon-phosphorus or carbon-silicon single bonds or double bonds. Of these, the carbon-carbon double bonds are particularly advantageous and are therefore used with very particular preference in accordance with the invention. For the sake of brevity, they are referred to below as "double bonds".
Accordingly, the inventively preferred group (ii) contains one double bond or two, three or four double . ~ - 30 -bonds. Where more than one double bond is used, the double bonds may be conjugated. In accordance with the invention, however, it is of advantage if. the double bonds are present in isolation, in particular each terminally, in the gxoup (~.i)~ in question. It is of particular advantage in accordance with the invention to use two double bonds or, in particular, one double.
bond, The dual-cure binder (A) Contains on average at least one of the above-described groups (ii) which can be activated with actinic radiation. This means that the functionality of w the binder in this respect is integral, i.e., for example, is equal to two, three, four,, five or more, or is nonintegral, i.e., is equal for example to from 2.1 to 10.5 or more.
Where on average per molecule more than one group (ii)~
which can be activated with actinic radiation is employed, the groups (ii) are structurally different from one another or of the same structure.
Where they are structurally different from one another, this means i.n the context of. the present invention that two, three, four or more, but especially two, groups (ii) which can be activated with actinic radiation are used which derive from two, three, four or more, but especially two, monomer classes.

,: _ 33. _ Examples of suitable groups (ii) are (meth.)acrylate, ethacrylate, crotohate, cinnamate,, vinyl ether, vinyl ester, dicyclopentadienyl, norbornenyl, isoprenyl, iso-propenyl, allyl or butenyl groups; dicyclopentadienyl ether, norbornenyl ether, .isoprenyl ether, isopr,openyl J
ether, allyl ether or butenyl ether groups: or ~dicyclopentadienyl ester, norbornenyl ester, isoprenyl ester, isopropenyl ester, allyl ester or butenyl ester groups, but especially acrylate groups.
The groups (ii) are attached ,to respective parent structures. of the binders preferably by way of urethane, urea, allophanate, ester, ether and/or amide groups, but in particular by way of ester graups.
Normally this is effected by customary and known polymer-analogous reactions such as, for instance, the reaction of pendent glycidyl groups with the above-described olefinic ,unsaturated monomers containin g an (' acid group, of pendent hydroxyl groups with the halides of these .monomers, of hydroxyl groups with isocyanates containing double bonds, such as vinyl isocyanate, methacryloyl isocyanate and/or 1-(1-isocyanato 1-methylethyl)-3-(1-methylethenyl)benzene (TMx~ from CYTEC), or of isocyanate groups with the above described hydroxyl-containing monomers. .
The amount of the binders (A) in the coating materials of the invention may vary widely and is guided primarily by tha functionality of the binders (A), on ' - .32 the one whand,, and of the compounds (C), present if desired and described below, on the other. The amount, based on the solids of the coating material' of the invention, is preferably from 20 ~ to 99.8$, more.
5. preferably from 25 to 95~, with particular' preference from 30 to 90~, with very particular preference from 35, to 85~, and in particular from 40 to 80~ by weight.
Preferably, the coating materials of the invention further comprise at least one constituent selected fxom the group consisting of low molecular mass, oligomeric and polymeric compounds (C) other than the (meth) acrylate .copolymers . (A) , which contain on average per molecule a5 (i) at least one, preferably at least two, of the above-described reactive functional groups which are abl a to undergo thermally initiated cross-linking reactions with complementaryw reactive functional- groups, especially hydroxyl groups, and/or (ii) at least one, preferably at least two, of the above-described reactive ftanetional groups having at least one bond which can be activated with actinic radiation.
Where the above-described (meth)acrylate copolymer (A) contains none of the above-described, self-crosslinking ... . 3 3 reactive functional groups (i), the dual-cure coating material for use in accordance with the invention mandatorily comprises at least one, especially one, low molecular mass, aligpmeric and/or polymeric compound (C), in particular a low molecular mass or oligomeric compound (C), which has reactive functional groups (i) which are able to undergo thermally initiated crosslinking.reactions with hydroxyl groups. Suitable compounds (C) of this kind are customary and known crosslinking agents, such as are known, for example, from the German patent application DE 199 24 171 A1, page 7 line 38 to page 8 line 4~ in conjunction with page 3 line 43 to page 5 line 31. Preference is given to employing blocked, part-blocked or nonblocked 1S polyisocyanates.
Where the above-described (meth)acrylate copolymer (A) contains none of. the. above-described reactive functional groups (ii) having at least one bond which can be activated with~actinic radiation, the coating material of the invention mandatorily comprises at least, one low molecular mass, oligameric and/or polymeric compound (C) containing at least one, preferably at least two, .more preferably at least three, with particular preference at least four, and, in particular at least 'five, reactive functional graups (ii) .

., . - 3 ~ -Examples of suitable low molecular mass, oligomeric.
and/or polymeric compounds.(C) containing at least one group (ii) are. described in detail in Rompp Lexikon.
Lacke and Druckfarben, Georg Thieme Verlag,.Stuttgart, New York, 1998, "reactive diluents", pages 491'and 492, in the German patent application DE 199 OS 013 A1, column 6 line 63 to column 8 line 65, in the German patent application DE 199 08 018 A1, page 11 lines 31 to 33, in the German patent application a DE 198 18 735 Al,~column 7 lines 1 to 35, or in the German patent DE 197 09 467 C1, page 4- line 36 to page 5 line 56. Preference is given to using pentaerythritol tetxaacrylate, dipentaerythritol pentaacrylate, and/or aliphatic urethane acrylates containing six acrylate groups in the molecule.
Instead of or in addition to the compounds (C) described above, the coating materials of the invention may .contain at least one, in. particular at least two, low molecular mass, oligomeric and/or polymeric compounds) (C) containing at least one,.especially at least two, groups) _(i) and at least one, in particular at least two, groups) (ii). Examples of suitable compounds (C) of this kind are described in detail in the European patent~application EP 0 928 800 A1, page 3 Lines 17 to 54 and page 4 lines 41 to 54, or in the German patent application DE 198 18 735 Al, column 3 line l6,to column 6 line 33. Tt is preferred to use isocyanato acrylates, which are preparable from polyisocyanates and the above-described hydroxyl-containing monomers (al) and/or (a2).
The coating materials of the invenfiion preferably comprise at least one photoinitiator.~ preferabl y at least two and in particular three photoinitiators (D), in an amount of from 0.2 to 5~, preferably from 0.3 to 4.80, more preferably from 0.4 to 4.6~a, with particular preference from 0.5 to 4.5~, and in particular from 0.5 to 4.3~ by weight, based in each case Qn the solids of the coating material of the invention.
Examples of suitable photoir~itiators .(D) are described in Rompp I,exikon Lacke and Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, pages 444 to 446.
Photoinitiators (D) are commercially customary compounds and are sold, for example, by BASF
Aktiengesellschaft under the brand name LUCIRTN~, by Ciba Specialty Chemicals under the brand name IRGACURE~, and by Rahn under the brand name GENOCURE~.
Furthermore, the' coating materials of 'the invention may comprise at least .one additive (E) selected from .the group consisting of thermally curable reactive ~diluents; molecularly dispersely soluble dyes; light stabilizers, such as~ W absorbers and reversible free-radical scavengers (HALS); antioxidants; low-boiling and high-boiling ("long") organic solvents;

devolatilizers; ~ wetting agents; emulsifiers; slip additives; ~ polymexization inhibitors; thermal crosslinking catalysts; thermolabile free-radical initiators; adhesion promoters; leveling agents; film formation auxiliaries; rheological aids, such as thickeners and pseudoplastic sag control agents, SCAB;
flame retardants; corrosion inhibitors; free-flow aids;
waxes; siccatives; biocides, and flatting agents.
Examples of suitable additives (E) are described in -detail in the textbook "Lackadditive" [Additives for coatings] by Jahan Bieleman, Wiley-VGH, Weinheim, New Yor3c, 1998, in D. Stoye and W. Freitag (editors), "Paints, Coatings and Solvents", .second , completely revised edition, Wiley-VCH, Weinheim, New Xork, 1998, "14.9. solvent groups", pages 327 to 373, in the German patent application DE 199 14 896 A1, column 14 line 26 to 'column 15 line 46, or in the German patent application DE 199 08 018 Al, page 9 line 31 to page 8 i 2C1 line 30. For further details, refer to the German patent applications DE 199 04 317 A1 arid DE 198 55 125 A1.
The coating materials of the invention that comprise the above-described constituents (A) and (B) arid also, where appropriate, (C), (D) and/or (E) are used, in particular, as clearcoat materials of the invention fcr producing clearcoats.

., ~ ' ..
The pigmented coating materials of the invention further comprise at Least one pigment (F) selected from the group consisting of organic and inorganic, transparent and hiding, color and/or ~ effect, electrically conductive, magnetically shielding., and fluorescent pigments, fillers, and nanoparticles..
The pigmented coating materials of the invention are employed in particular as primer-surfacers, basecoat r materials and solid-color topcoat materials of the invention for producing ' primer-surfacer coats or antistonechip primer coats, basecoats, and solid-color topcoats of the invention, Z5 Where exclusively nonhiding, transparent pigments (F), especially nanoparticles (F), are used, the pigmented coating materials of the invention may also be used as clearcoat materials.
In terms of its method, the preparation of the coating materials of the invention has no special features but instead takes place by the mixing and homogenizing of the .above-described constituents using customary and known mixing techniques and equipment such as stirred vessels, stirred mills, extruders, kneaders, Ultraturrax, in-line dissolvers, static mixers, toothed-ring dispersers, pressure release nozzles and/or microfluidizers, preferably in the absence of actinic radiation.

_ gg _ The resulting coating materials of the invention. may be conventional coating materials, containing organic solvents, aqueous coating materials, substantially or fully solvent-free and water-free liquid coating materials (100 systems), substantially or fully solvent-free and water-free solid coating materials (powder coating materials}, or substantially or fully solvent-free powder coating suspensions (powder i slurries). Moreover, they may be one -component systems, in which the binders (A) and the crosslinking agents (C) are present alongside one another, or two-component or multicomponent' systems, in which the binders (A) and the crosslinking agents (C). are present separately from one another until shortly before application.
Tn terms of its method; the application of the dual-cure coating materials for use in the process of the invention has no special features but may instead take place by any customary and known application method suitable for' the coating material in question, such as electrodeposition coating, spraying, knife coating, brushing, flow coating, dipping, trickling ar rolling, for example. Preference is given to employing spray application methods, such as compressed air spraying, airless spraying, high-speed rotation, electrostatic spray application (ESTA), alone or in conjunction with hot spray application such as hot air sprayzng, for .L ._ 39 example,.except where the coating materials in question are powder coating materials:
i The application of the powder coating materials also has no special features in terms of its method but instead takes place, far example, by the customary and known fluidized bed techniques, such as are known, for example, from the BASF Coatings AG company brochures "Pulverlacke fur industrielle Anwendungen" [powder coating materials for industrial applications], January 2,000, or "Coatings Partner, Pulverlack Spezial"
[Coatings Partner, powder coatings special],1/2000, or RQmpp Zexikon ~ Lacke und_ Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, pages 187 and 188, I5 "electrostatic powder spraying", "electrostatic spraying", and "electrostatic fluidi.zed bath process".
In the course of application it is advisable to operate F, in the absence of actinic radiation in order to prevent premature crosslinking of the coating materials of the invention.
The curing of the dual-cure coating materials employed in the process of the invention generally takes place after a certain rest period or flash-off time. This may have a duration of 5 s to 2 h, preferably from l min to 2 h, and in~ particular from 1 min to 45 min. The rest period is used, for example, for leveling and devolatilization of the coating films and for the evaporation of volatile constituents such as any solvent and/or water present. Flashing off may be accelerated by an'inc.reased temperature, but .one less than that sufficient for curing, and/or by a reduced atmospheric humidity.
In the context of wet-on-wet techniques, this process measure also may be employed for the drying of applied coating films, particularly electrocoat, primer-surfacer and/or basecoat films, which are not to be cured or are to be only part-cured.
The thermal cure takes place, for example, with the aid of a gaseous, lit~uid and/or solid. hat medium, such as hot air, heated oil or heated rollers, or of microwave radiation, infrared light and/or near infrared (NTR) light. Heating preferably takes place in a forced air oven or by exposure to IR and/or NIR lamps. As in the case of the actinic radiation cure, the thermal cure may also take place in stages. Advantageously, the - thermal cure takes place at temperatures from worn temperature up to 200°C.
In the actinic radiation (especially UV radiation) cure it is preferred to employ a dose o,f from 500 to 4 000, more preferably from 1 000 to 2 900, with particular preference from 1 200 to 2 800, with very particular preference from 1 300 to 2 700, and in particular from 1 400 to 2 600 mJ/cm2.

The actinic radiation. cure is .carried out using the customary and 'known radiation sources and .optical auxiliary measures. Bxamples of suitable radiation sources are flash lamps from the company VISIT, high pressure or low-pressure mercury vapor lamps, with or without lead doping, in order to open up a radiation window of up to 405 nm, or electron beam sources. Their arrangement is known in principle and may be adapted to t:
the circumstances of the workpiece and the process parameters. In the case of workpieces of complex shape, such as those envisaged for automobile bodies, those areas which are not accessible to direct radiation (shadow areas), such as cavities, folds and other structural undercuts, may be cured using pointwise, small-area or all-round emitters, in conjunction with an automatic movement means for the. irradiation of cavities or edges.
y The equipment and conditions for these curing methods are described, for example, in R. Holmes, U.V. and,E.B.
Curing Formulations for Printing Inks, Coatings and Paints, STTA Technology, Academic Press, London, United Kingdom 1984, or in the German patent application DE 198 18 735 A1, column 10 line 31 to column 11 line 1.6.
Curing here may take place in stages, i.e., by multiple exposure to light or actinic radiation. It may also be - g2 -carried out alternatingly, i.e., by curing alternately with W radiation and electron beams, for example.
The thermal cure and actinic radiation cure may be employed simultaneously or in succession. Where the two methods of curing 'are employed in succession, it is possible, for example, to commence with the thermal cure and to end with the actinic radiation cure. In ather cases it may prove advantageous to begin and to end with the actinic radiation cure.
Preferably, curing with actinic radiation is carried out under inert gas to prevent ozone formation. Instead of a straight inert gas, an .oxygen-depleted atmosphere may be used.
"Oxygen-depleted" means that the oxygen content of the atmosphere is less than the oxygen content of -air (20.95% by volume). The maximum content in the oxygen-depleted atmosphere is preferably 18~, more preferably 16~, with particular preference 14~, with very particular preference 1Q°s, and in particular 6.0o by volume. The minimum oxygen content is preferably O.lfl, more preferably 0.5~, with particular preference 1.0%, with very particular preference 1.50, and in particular 2.0~ by volume.
The oxygen-depleted atmosphere may be provided in a variety of ways. For example, an appropriate gas mixture may be prepared and made available in pressure bottles. The depletion is preferably achieved by introducing .at least one inert gas in the requisite amounts into the air cushion located above 'the surface of the dual-cure films (2) that are to be cured. The oxygen content of the .atmosphere located above the surface in question may be measured continuously with the aid of customary .and known methods and equipment for determining elemental oxygen . and may, where 1Q appropriate, be adjusted automatically to the desired level. .
By inert gas is meant a gas which under the curing conditions employed is not decomposed by the actinic radiation, does not inhibit,.curing, and/or does' not react with the dual-cure coating material of the invention: Preference is given to using nitrogen, carbon dioxide, helium, ,neon or argon, especially nitrogen and/or carbon dioxide.
The above-described curing and application processes and apparatus may also be used for noninventive coating materials, such as electrocoat materials, primer-surfacers or basecoat materials, which are. used together with the coating materials of the invention. to produce multicoat clearcoat systems and multicoat color and/or effect paint systems.

Examples of suitable electrocoat materials and, where appropriate, of wet-on-wet techniques are described in the Japanese patent application 1975-142501 tJapanese laid-open specification JP~52-065534 A2, Chemical Abstracts report 'No. 87: 137427) or in the patents and patent applications US 4,375,498 A1, US 4,537,926 A1, US 4,761,212 Al, EP 0 529 335 A1, DE 41 25 459 A1, EP 0 595 186 A1, EP 0 074 634 A1, EP 0 505 445 A1, ,DE 42 35 778 A1, EP 0 646 420 A1, EP 0 639 660 A1, EP 0 817 698.A1, DE 195 12 017 Cl, EP 0 192 113 A2, DE 41 26 476 A1 and WO 98/07794.
Suitable primer-surfacers, especially aqueous primer-surfacers, Which are also referred to as antistonechip primer coats or functional coats, are known from the patents and patent applications US 4,537,926. A1, EP 0 52.9 335 A1, EP 0 595 186 A1, EP 0 639 660 A1, DE 44 38 504 A1, DE 43 37 961 A1, WO 89/10387, US 4,450,200 A1, US 4,614,683 A1 and WO 94/26827.
Suitable basecoat materials, especially aqueous basecoat materials, are known from the patent applications EP 0 089 497 A1, EP 0 256 540 A1, EP 0 260 447 A1, EP 0 297 576 A1, WO 96/12747, EP.O 523 610. A1, EP 0 228 003 A1, EP 0 397 806 Al, EP 0 574 917 A1, EP 0 531 510 A1, EP 0 581 211 A1, EP 0 708 7$8 A1, EP 0.593 454 A1, DE-A-43 28 092 A1, EP 0 299 148 A1, EP 0 399 737 A1, EP 0 590 484 A1, EP 0 234 362 A1, EP.O 234 361 Al, EP 0 593 817 A1, WO~95114721, _ _ _ EP 0 521 928AI, EP 0 420 Al., EP 0 522 419 Al, EP O 649 865A1',~ EP 0 712 A1, EP 0 596 460 A1, EP 0 596 461A1, EP- 0 818 A1, EP 0 669 356 A1, EP 0 634 431A1, EP 0 536 A1, EP 0 354 261 A1, EP 0 424 705A1, WO /49795, WO /49747, EP 0 401 565A1 and 0 684, column lines 31 ,to 45, The coatings, of the invention obtained, especially the single-coat or multicoat color and/or effect paint systems and clearcoats of the invention, are easy to produce and have outstanding optical properties and very high overbake stability, light stability,. chemical resistance, water resistance, condensation resistance, weathering stability, yellowing resistance, and etch resistance. In particular, they are free from turbidities and inhomogeneities. They have very good reflow properties and combine outstanding scratch s. resistance with high hardness.
The film thicknesses of the inventive and noninventive coatings are preferably situated within the ranges that are commonly employed:
Electrocoat:
Preferably from 10 to 60, more preferably from 15 to 50, and in particular from 15 to 40, um;

. .
Primer-surfacer coat:
Preferably~from 20 to~150, more preferably from 25 to 100, and.in particular from 30 to 80, Vim;
Basecoat:
Preferably from 5 to 30, more preferably from 7.5 to 25, and in particular from 10 to 20, um;
Solid-color topcoat:
'z Preferably from 10 to 60, more preferably from 15 to 50, and in particular Pram 15 to 40, um;
Clearcoat:
Preferably from 10 to 200, more preferably from 15 to.
80, and in particular from 20 t.o 70, um.
A further advantage of the coating materials of the invention is that, even in the shadow zones of three-dimensional substrates of complex shape, such as.
vehicle bodies, radiators or electrical wound products, and even without optimum, in particular, complete exposure of the shadow zones to actinic radiation, they give coatings whose profile of performance properties at least approaches that of the coatings outside of the shadow zones. As a result, the coatings present within the shadow zones are alsa no longer easily damaged by mechanical and/or chemical attack, as may occur, for example, on the line during the installation of further motor vehicle components into the coated bodies.

. _ 47 In particular, however, the coatings of 'the invention are notable for outstanding wettability, which makes it possible to . apply extensive refinishes and, repeat finishes without problems, and without the need to carry out the above-described physical, mechanical and/or chemical treatments beforehand. Clearcoat materials of the invention may be applied to inventive clearcoats or noninventive- or inventive basecoats and inventive cleareoats may be applied to the inventive clearcoat. In t.h.e same way, solid-color topcoats of the invention may be coated ,with inventive solid-color topcoats. Where necessary, it is also possible to incorporate the primer-surfacers into the refinish or repeat finish. Further possible combinations are obvious to the skilled worker and need not be recited explicitly.
The inventive ar noninventive coating materials used for the refinish or repeat finish need. not necessar~.ly be materially identical, or substantially identical, with those of the original finish. What is important is that they and the coatings produced from them have the same profile of performance properties, in order that, for example, there arise no deviations in shade between refinish or repeat finish on the one hand and original finish on the other.

_ qg The dual-mode curing results in refinishes and repeat finishes which adhere extremely firmly to the original finishes, do not delaminate even following condensation exposure, and have the same advantageous .properties as the original.finishes.
The coating materials of the invention may also, however, be used as adhesives and sealing compounds for producing adhesive films and seals of the invention and t may serve for the coating, bonding.and/or. sealing of primed or unprimed substrates made of metal, plastic, glass, wood, textile, leather, natural stone and artificial stone, concrete, cement, or composites of these materials.
The coating materials, adhesives or sealing compounds of the invention may therefore be used to coat, bond and seal motor vehicle bodies and parts thereof, the interior and exterior of motor vehicles, buildings inside and out, doors, windows, furniture, and for coating, bonding and sealing in the context of the industrial finishing of small parts, coils, containers, packaging, electrical components, and white goods, all with great success.
The substrates may have been primed.
In the case of plastics, customary and known primer coats or tie coats may be employed, or the surfaces of the plastic may have been given a firm-adhesion finish by flaming or etching with reactive compounds such as fluorine.
In the case of electrically conductive substrates, especially metals, the primers used may be those as described in Rompp Lexikon hacke and Druckfarben, Georg Thieme Verlag, Stuttgart, New- York, 1998, "primers", page 973, "wash primers", page 618, or "shop primers", page 230, ' In the ease of electrically conductive substrates based on aluminum, the primer ,coat used is preferably an aluminum oxide layer produced by anodic oxidation.

Owing to the outstanding performance properties of the coatings, adhesive films and seals of the invention, the substrates that are coated, bonded and/or sealed with them nave a particularly long service life and so are particularly valuable for users from an economic, environmental, and technical standpoint.
Inventive and comparative examples Preparation example 1 The preparation of a thermally curable bindex ~x, .. 5 O -In an appropriate reactor equipped with a stirrer, two dropping funnels for the monomer mixture and the initiator solution, a nitrogen inlet pipe, thermometer, heating system, and reflex condenser, 650 parts by weight of an aromatic hydrocarbon fraction with a boiling range from 158 to 172°C were weighed in. The solvent was heated to 140°C. Thereafter a. monomer mixture of 652 parts .by weight of ethylhexyl acrylate, 383 parts by weight of 2-hydroxyethyl methacrylate, 143 parts by weight of styrene, 212 parts by weight of 4-hydroxybutyl acrylate arid 21 parts by weight of acrylic acid .was metered into the initial charge at a uniform rate over the course of four hours and an initiator solution of 113 parts by weight of the aromatic solvent and 113 parts by weight of tert-butyl perethylhexanoate was .metered into the initial charge at a uniform rate over the course of 4.5 hours. The addition of the monomer mixture and of the initiator solution was commenced simultaneously. After the end of j the initiator feed, the resulting reaction mixture was heated at 140°C for two hours more, with stirring, and was then cooled. The resulting solution of the methacrylate copolyme r (A) was diluted with a mixture of 1-methoxypropyl 2-acetate, butyl glycol acetate and butyl acetate. The resulting solution had a solids content of 65°s by weight, determined in a forced air oven (one hour/130°C) and an acid number of 15 mg KOH/g solids.

4, - 51 -Inventive example l and comparative examples C1 and C2 The preparation of an inventive clearcoat material (example I) and of noninventive dual-cure clearcoat materials (examples Cl and C2) The dual-cure clearcoat materials 1, C1 and C2 were prepared by mixing the constituents indicated in the table, in the stated order, and homogenizing the ( 10 resulting mixture.
Table: The material compositions of the dual-cure clearcoat materials 1, C1 and C2 constituent Parts by weight Stock varnish:
Binder from preparation example 1 35.9 35.9 35.9 Dipentaerythritol pentaacrylate 20 20 20 UV absorber (substituted hydroxy-phenyltriazine) 1.0 7..0 1.0 HALS (N-methyl-2,2,6,6-tetramethyl-piperi~dinyl ester) 1.0 1.-0 1.0 Constituent Parts by ght wei Silicane additive (Byk~ 306 from Byk Chemie) - 0.4 -Additive (B) (8ykt~3 35$ from Byk Chemie) p.2 _ _ Butyl acetate 27.6 27:4 27.8 Solventnaphtha~ 10.8 10.8 10.8 Irgacure~ 184 (commercial photo- 2.0 2.0 2.0 ' initiator from Ciba Specialty.

Chemicals) Genocure~ MBF (commercial photo- 1.0 1.0 1.0 initiator from Rahn) Zucirin~ TPO (commercial photo-. 0.5 0.5 0.5 initiator from BASF AG) Total.: I00 100 x.00 Crosslinki.nq component (B) Crosslinkinc~ agent (B 1);
Isocyanato acrylate Roskydal~ UA VPLS
2337 from Bayer AG (basis: trimeric hexamethylene diisocyanate; isocyanate group content: 12~ by weight) 27.84 27.84 27..84 Crosslinking agent (B 2):
Isocyanato acrylate based on the trimer of isophorone diisocyanate (70.5 in butyl acetate; viscosity:
1 500 mPas; isocyanate group content:
6.7's by weight: prepared analogously to example 1 of EP 0 928 800 A1) 6.96 6.96 6.96 Diluent ~ 3.48 3.48 3.48 Total: 38.28 38.28 38.28 Inventive example 2 and comparative examples C3 and C~4 The production of an inventive multicoat paint system i, 5 (example 2) and of noninventive multiaoat paint systems (examples C3 and C4) For example 2, the clearcoat material from example 1 was used.
For example C3, the clearcoat material from example C1 was used.
For example C4, the clearcoat material from example C2 was used.

To produce the multicoat paint systems 2, C3 and C4, steel panels were coated in succession with an electrocoat, deposited cathodically and baked at 170°C
for 20 minutes, with a dry film thickness of from l8 to 22 um. The steel panels were then coated with a commercially customary two-component waterborne primer-surfacer from BASF Coatings AG, as is commonly used for plastics substrates. The resulting primer-surfacer film was baked at 90°C for 30 minutes so as to give a dry film thickness of from 35 to 40 um. Thereafter a commercially customary black aqueous basecoat material from BASF Coatings AG was applied with a film thickness of from 12 to 15 ~zm, after which the resulting aqueous basecoat films were flashed off at 80°C for ten .
minutes. The clearcoat materials were .then applied pneumatically using a gravity-feed cup gun in one cross pass, with a film thickness of from 40 to. ~!5 ~zm. The aqueous basecoat films and the clearcoat~ films were cured at room temperature for 5 minutes, at 80°C for 10 minutes, .followed by exposure to UV light in a dose of 1 500 mJ/cm2, and finally 'at 140°C~ for 20 minutes.
The multicoat paint systems 2, C3 and C9 had a very good profile of properties in terms of gloss, hardness, and scratch resistance.
They were very bright and had a gloss (20°) to DIN 67530 of 90. The micropenetration hardness (universal hardness at 25.6 mN, Fischerscope 100V with Vickers diamond pyramid) was 137 to 139.
The scratch resistance was assessed using the sand test tcf. the German patent application DE 198 39 453 A1, page 9 lines 1 to 63) on the basi s of the metal test panels described above. The loss of gloss was 10 units (20°) . _ The scratch resistance was also assessed using the brush test (cf. the German patent application DE 198 39 453 A1, page 9 lines 17 to 63) on .the basis of the metal test panels described above. The loss of gloss was 4 units (20°).
In the MB gradient oven test, which is known to those skilled in the art, initial damage to the inventive multicoat paint systems by sulfuric acid was evident only above a temperature of 53°C, and that caused by tree resin only above 55° Celsius. The etch resistance was also outstanding.
The multicoat paint systems 2 and C3 showed very good leveling and.a surface which was free from defects, without popping marks. The multicoat paint system C4 had pinholes in its surface, and other flow defects.
The intercoat adhesion was very good (cross-cut test in accordance with DIN EN ISO 2409: GTO-1).

Significant differences arose, however, with the adhesion between the inventive multicoat paint system 2 and its refinishes, on the one hand, and the noninventive multicoat paint systems C3 and C9 and their refinishes, on the other and also in the case of the systems - basecoat (original)/clearcoat (original)/basecoat (refinish) /clearcoat (refinish) (= 'repeat finish) and - basecoat (original)/clearcoat (original)/clear-I5 coat (refinish) (= clearcoat refinish), when the clearcoats of the original finishes had not been sanded prior to application of the refinishes.
r r Table 2 gives an overview of the results of the cross-cut test to DIN EN ISO 2909 following five-day aging of the metal test. panels. The adhesion in accordance with the cross-cut test was scored as follows:
GTO-1 - satisfactory, very little or no delamination (small splinters at the edges of the cut);
GT2 - still just satisfactory, slight delamination, about 15$ of the pieces;

~' CA 02449209 2003-11-26 y- 57 GT3-9 - unsatisfactory, extensive areas of delamination, from about 35 to 650 of the pieces;
GTS - complete delamination..
~ Table 2: Cross-cut test an metal test panels of inventive example 2 and camparative.exa;nples C3 and C4 System Example Repeat finish GT1-2 GT5 GTO-1 Clearcoat refinish GT2 n.m.a} GT2 a) not measurable, overcoating not possible because the refinish clearcoat did not wet the original Clearcoat

Claims (22)

What is claimed is:

1. A coating material curable thermally and with actinic radiation, comprising (A) at least one binder selected from the group consisting of random, alternating and block, linear, branched and comb polyaddition resins, polycondensation resins, and addition (co)polymers of olefinically unsaturated monomers, curable thermally, and thermally and with actinic radiation;
and (B) from 0.01 to 3% by weight, based on the solids of the coating material, of at least one additive based on at least one (meth)acrylate (co)polymer selected from the group consisting of (meth)acrylate (co)polymers having a number-average molecular weight of from 4 000 to 100 000 daltons and a low to high polarity.

2. The coating material as claimed in claim 2, wherein the additive comprises a (meth)acrylate copolymer (B).

3. The coating material as claimed in claim 1 or 2, wherein the (meth)acrylate copolymer (B) has a number-average molecular weight of from 4 500 to 40 000 daltons and a low to moderate polarity.

4. The coating material as claimed in any of claims 1 to 3, wherein the additive (B) comprises at least one organic solvent for the (meth)acrylate (co)polymer (B) .

5, The coating material as claimed in claim 4, wherein the solids content of the additive (B), based on its overall amount, is from 10 to 80% by weight.

6. The coating material as claimed in any of claims 1 to 5, wherein the binder (A) is selected from the group consisting of (meth)acrylate copolymers which have an OH number of from 100 to 220 mg KOH/g, a glass transition temperature of from -35 to +60°C, a number-average molecular weight of from 1 000 to 10 000 daltons and a mass-average molecular weight of from 2 000 to 40 000 daltons and which contain in copolymerized form an amount of hydroxyl-containing olefinically unsaturated monomers (a) that corresponds to the OH number, of which (a1) from 20 to 90% by weight, based on the hydroxyl-containing monomers (a), are selected from the group consisting of 4-hydroxybutyl (meth)acrylate and/or 2-alkylpropane-1,3-diol mono(meth)-acrylate, and (a2) from 10 to 80% by weight, based on the hydroxyl-containing monomers (a), are selected from the group consisting of other hydroxyl-containing olefinically unsaturated monomers.

7. The coating material as claimed in any of claims 1 to 6, wherein the 2-alkylpropane-1,3-dial mono-(meth)acrylates (a1) are selected from the group consisting of 2-methyl-, 2-ethyl-, 2-propyl-, 2-isopropyl-, and 2-n-butylpropane-1,3-diol mono(meth)acrylate.

8. The coating material as claimed in claim 7, wherein 2-methyl-1,3-diol mono(meth)acrylate (a1) is used.

9. The coating material as claimed in any of claims 1 to 8, wherein the monomers (a2) are selected from the group consisting of hydroxyalkyl esters of olefinically unsaturated carboxylic, sulfonic and phosphonic acids and acidic phosphoric and sulfuric esters, allyl alcohol, ethoxylated and propoxylated allyl alcohol and reaction products of olefinically unsaturated carboxylic, sulfonic and phosphoric acids and acidic phosphoric and sulfuric esters with the glycidyl ester of an alpha-branched monocarboxylic acid having from 5 to 18 carbon atoms in the molecule.

10. The coating material as claimed in any of claims 1 to 9, wherein the (meth)acrylate copolymers (A) contain on average per molecule (i) at least one nonhydroxyl, reactive functional group which undergoes thermally initiated crosslinking reactions with itself or with complementary reactive functional groups, and/or (ii) at least one reactive functional group having at least one bond which can be activated with actinic radiation.

11. The coating material as claimed in any of claims 1 to 10, wherein the coating materials further comprise at least one constituent selected from the group consisting of low molecular mass, oligomeric and polymeric compounds (C) other than the (meth)acrylate copolymers (A), which contain on average per molecule (i) at least one reactive functional group which can undergo thermally initiated crosslinking reactions with complementary reactive functional groups, and/or (ii) at least one reactive functional group having at least one bond which can be activated with actinic radiation.

12. The coating material as claimed in claim 10 or 11, wherein the bonds which can be activated with actinic radiation are selected from the group consisting of carbon-hydrogen single bonds or carbon-carbon, carbon-oxygen, carbon-nitrogen, carbon-phosphorus, and carbon-silicon single bonds and double bonds.

13. The coating material as claimed in claim 12, wherein the double bonds are carbon-carbon double bonds ("double bonds").

14. The coating material as claimed in claim 13, wherein the reactive functional groups (ii) are selected from the group consisting of (meth)acrylate, ethacrylate, crotonate, cinnamate, vinyl ether, vinyl ester, dicyclopentadienyl, norbornenyl, isoprenyl, isopropenyl, allyl, and butenyl groups;

dicyclopentadienyl ether, norbornenyl ether, isoprenyl ether, isopropenyl ether, allyl ether, and butenyl ether groups; and dicyclopentadienyl ester, norbornenyl ester, isoprenyl ester, isopropenyl ester,. allyl ester, and butenyl ester groups.

15. The coating material as claimed in claim 14, wherein acrylate groups (ii) are used.

16. The coating material as claimed in any of claims 10 to 15, wherein the complementary reactive functional groups (i) are selected on the one hand from the group consisting of thiol, amino, N-methylolamino, N-alkoxymethylamino, imino, carbamate, allophanate and/or carboxyl groups, and on the other hand from the group consisting of anhydride, carboxyl, epoxy, blocked and unblocked isocyanate, urethane, alkoxycarbonylamino, methylol, methylol ether, carbonate, amino and/or beta-hydroxyalkylamide groups.

17. The coating material as claimed in any of claims 1 to 18, containing from 0.2 to 5% by weight, based on the solids of the coating material, of at least one photoinitiator (D).

18. The coating material as claimed in any of claims 1 to 17, comprising at least one additive (E) different than the additives (B) and selected from the group consisting of binders other than the binders (A) and additives (B) and curable physically or by means of heat alone; thermally curable reactive diluents; molecularly dispersely soluble dyes: light stabilizers, such as UV absorbers and reversible free-radical scavengers (HALS); antioxidants; low-boiling and high-boiling ("long") organic solvents;
devolatilizers; wetting agents; emulsifiers; slip additives; polymerization inhibitors; thermal crosslinking catalysts; thermolabile free-radical initiators; adhesion promoters; leveling agents;
film formation auxiliaries; rheological aids, such as thickeners and pseudoplastic sag control agents, SCAs; flame retardants; corrosion inhibitors; free-flow aids; waxes; siccatives;
biocides, and flatting agents.

19. The coating material as claimed in any of claims 1 to 18, comprising at least one pigment (F) selected from the group consisting of organic and inorganic, transparent and hiding, color and/or effect, electrically conductive, magnetically shielding, and fluorescent pigments, fillers, and nanoparticles.

20. The use of the coating material as a coating material, adhesive or sealing compound.

21. The use as claimed in claim 20, wherein the coating material serves to produce single-coat or multicoat clearcoat systems and multicoat color and/or effect paint systems, the adhesive to produce adhesive films, and the sealing compound to produce seals.

22. The use as claimed in claim 20, wherein the coating material, adhesive or sealing compound is used to coat, bond and seal motor vehicle bodies and parts thereof, the interior and exterior of motor vehicles, buildings inside and out, doors, windows and furniture, and for coating, bonding and sealing in the context of the industrial coating of small parts, coils, containers, packaging, electrical components, and white goods.