DE10128886A1 - Heat-cured or dual-cure aqueous coating material, used e.g. as a basecoat for painting cars, contains a polyurethane-(meth)acrylate binder and a special two-component melamine-formaldehyde resin crosslinker - Google Patents

Abstract

Aqueous coating material with a polyurethane-(meth)acrylate binder contains a specified amount of crosslinker comprising (b1) water-soluble melamine-formaldehyde (MF) resin with medium to high degree of alkylation (DA) and imino functionality (IF) which is catalysed with weak acid and (b2) insoluble MF resin with high DA and low IF which is catalysed with strong acid. Colored and/or effect-giving aqueous coating material (I) containing (A) anionically stabilized polyurethane-(meth)acrylate graft copolymer(s) as binder, (B) a crosslinker comprising (b1) water-soluble melamine-formaldehyde (MF) resin(s) with a medium to high degree of alkylation (DA) and a medium to high imino functionality (IF) which is/are catalysed with weak organic and/or inorganic acids and (b2) water-insoluble MF resin(s) with a high DA and a low IF which is/are catalysed with strong acids, (C) organic and/or inorganic acid catalyst(s), (D) pigment(s) and optionally (E) component(s) other than (A) which react with MF resins. The amount of (B) is 10-20 wt% based on the total amount of (B) plus (A) plus (E) (if present). Independent claims are also included for (1) a method for the production of single- or multi-coat, colored and/or effect-giving paint systems by applying layer(s) of (I) to an optionally primed substrate and then hardening the wet coating(s) by the application of heat or of heat and actinic radiation (2) a wet-in-wet method for the production of multi-coat systems by coating an optionally primed substrate with (I) in the form of an aqueous basecoat, air-drying and/or partly drying the basecoat, applying a clearcoat and then curing both wet layers with heat or with heat and light (3) a similar method in which a first aqueous basecoat is applied to an uncrosslinked or partly crosslinked electrophoretic primer on a substrate, the primer and basecoat are heat-cured and then a second basecoat and clearcoat are applied and cured as above, with material (I) being used for the first and/or second basecoat.

Description

The present invention relates to a new aqueous, color and / or effect coating material based on polyurethane and its use for the production of single and multi-layer, color and / or effect Coatings in automotive initial and refinishing, industrial Painting, including coil coating and container coating, the Plastic painting, furniture painting and painting white goods.

Thermally curable, aqueous, color and / or effect coating materials, which is a crosslinking agent and a saturated, unsaturated and / or with grafted olefinically unsaturated compounds, ionic and / or nonionic stabilized polyurethane based on aliphatic, cycloaliphatic, aliphatic cycloaliphatic, aromatic, aliphatic-aromatic and / or Cycloaliphatic aromatic polyisocanates contain, as well as the corresponding Coatings are known, for example, from the patent specifications EP 0 089 497 A1, DE 197 22 862 C2, DE 196 45 761 A1, DE 43 39 870 A1, DE 197 36 535 A1 or DE 44 37 535 A1 known. These known, aqueous coating materials, especially the water-based paints, and the one or Multi-layer paint and / or effect paint systems have very good application properties. They usually contain melamine Formaldehyde resins as crosslinking agents in an amount of more than 20% by weight, based on the total amount of melamine-formaldehyde resin and components, including binders that are reactive with melamine-formaldehyde resins.

Nowadays, more and more owners of automobiles lay down high pressure or High pressure steam cleaner for cleaning your motor vehicles too. Meanwhile, poses this type of cleaning significantly increased demands on the so-called Wet adhesion of all layers of those on the automobile Coating systems. The previously known, color and / or effect Multicoat paint systems based on previously known waterborne basecoats can delaminate under these cleaning conditions. It can be too a detachment of the clearcoat from the water-based paint or the Waterborne paint come from the filler paint. This problem will exacerbated by a high pigment content of the water-based paints.

The problem of unsatisfactory wet grip is even more serious Car refinishing, in which the multi-layer original paintwork with other color and / or effect multilayer coatings become. Here the delamination mostly occurs between the lower clear coat (Original paint) and the top basecoat (refinish).

Attempts have been made to address this serious problem through the Modification of certain binder properties, such as hydroxyl number and / or Functionality, the variation of the degree of crosslinking by catalysts and / or the use of different proportions of cross-linking agents, the degradation the pigment portion and / or the hydrophilic constituents and / or the Application of so-called adhesion promoters to solve. However, this is not in that succeeded in the desired scope.

With appropriate investigations, it has further been found that fumed silica the wet grip properties of the known Waterborne basecoats deteriorated. It therefore suggests itself that it should be used dispense. However, there are other disadvantages, such as one unsatisfactory stove stability.

In the unpublished German patent application DE 100 04 499.9 a thermally curable, aqueous, color and / or effect Coating material described as the binder two different, anionically stabilized polyurethane (meth) acrylate graft copolymers, at least one color and / or effect pigment as a crosslinking agent Melamine resin and monodisperse nanoparticles based on silicon dioxide contains. The coating material provides coatings with very good Wet adhesion properties even with high pigment contents Coating materials.

The object of the present invention is to create a new one, thermally or thermally and aqueous, color and / or effect curable with actinic radiation To provide coating material that is very good as a water-based paint or as Solid-color topcoat for the production of single and multi-layer, color and / or effect paints with wet adhesion properties that the increased Meet requirements, is suitable. The improvement of Wet adhesion properties should also with high pigment contents Water-based paints or solid-color top coats can be guaranteed. Beyond that the otherwise excellent, application properties of the previous known waterborne basecoats and solid-color topcoats are not affected become. Last but not least, the improvement in wet grip properties should also occur when using a wide variety of clear coats.

• A) als Bindemittel mindestens ein anionisch stabilisiertes Polyurethan- (Meth)Acrylat-Pfropfmischpolymerisat,
• B) als Vernetzungsmittel
  • 1. mindestens ein wasserlösliches, mit schwachen, organischen und/oder anorganischen Säuren katalysierbares Melamin- Formaldehyd-Harz, das einen mittleren bis hohen Alkylierungsgrad und eine mittlere bis hohe Iminofunktionalität aufweist, und
  • 2. mindestens ein wasserunlösliches, mit starken, organischen und/oder anorganischen Säuren katalysierbares Melamin-Formaldehyd-Harz, das einen hohen Alkylierungsgrad und eine niedrige Iminofunktionalität aufweist,
• C) mindestens eine organische und/oder anorganische Säure als Katalysator und
• D) mindestens ein Pigment sowie gegebenenfalls
• E) mindestens einen von den Bindemitteln (A) verschiedenen Bestandteil, der mit den Melamin-Formaldehyd-Harzen reaktiv ist,

enthält, wobei der Beschichtungsstoff die Vernetzungsmittel (B) in einer Menge von 10 bis 20 Gew.-%, bezogen auf die Menge an Vernetzungsmittel (B) und Bindemittel (A) sowie gegebenenfalls vorhandenem Bestandteil (E), enthält. Accordingly, the new, aqueous, color and / or effect coating material was found, the

• A) at least one anionically stabilized polyurethane (meth) acrylate graft copolymer as binder,
• B) as a crosslinking agent
  • 1. at least one water-soluble melamine-formaldehyde resin which can be catalyzed with weak, organic and / or inorganic acids and which has a medium to high degree of alkylation and a medium to high imino functionality, and
  • 2. at least one water-insoluble melamine-formaldehyde resin which can be catalyzed with strong, organic and / or inorganic acids and which has a high degree of alkylation and a low imino functionality,
• C) at least one organic and / or inorganic acid as a catalyst and
• D) at least one pigment and optionally
• E) at least one constituent different from the binders (A) and reactive with the melamine-formaldehyde resins,

contains, wherein the coating material contains the crosslinking agent (B) in an amount of 10 to 20 wt .-%, based on the amount of crosslinking agent (B) and binder (A) and any component (E) present.

The following is the new, watery, color and / or effect Coating material is referred to as "coating material according to the invention".

Further subject matter of the invention will emerge from the description below out.

In view of the prior art, it was surprising and for the One skilled in the art could not have foreseen that the object of the present invention is based, solved with the help of the coating material of the invention could be. In particular, it was surprising that this solution came with a decrease in the content of crosslinking agents, which leads to a lower Crosslink density of the coatings leads, could be solved; it stood there rather to be expected that through this measure essential to the invention The opposite, namely a deterioration in the wet grip properties, would occur.

The coating material according to the invention is thermally curing by crosslinking. Coating materials are referred to as external crosslinking, in which one type the complementary, reactive, functional groups in the binder, and the other type in a hardener or crosslinking agent. Complementary on Römpp "Lexicon Lacke und Druckfarben", Georg Thieme-Verlag, Stuttgart - New York, 1998, "Hardening", pages 274 to 276, especially page 275, below.

The coating material of the invention can also thermally and with actinic radiation can be curable, which is also called "dual cure" by experts referred to as. In the context of the present invention is under actinic Radiation electromagnetic radiation, such as near infrared (NIR), visible Light, UV radiation or X-rays, in particular UV radiation, and Understand corpuscular radiation, such as electron radiation.

The coating material of the invention is aqueous. This means that its Ingredients in water or in a mixture consisting of water and minor amounts of at least one water-miscible, organic Solvent is present, dissolved and / or dispersed. Here are under "Minor amounts" mean those amounts that are aqueous in nature do not destroy the mixture.

The coating material of the invention is a one-component (1K) system.

In the context of the present invention, one component (1K) is System a thermally or thermally and with actinic radiation curing To understand coating material in which the binder and the Crosslinking agents side by side, d. H. in one component. The prerequisite for this is that the two components only at higher Temperatures and / or when irradiated with actinic radiation with one another network.

The first, part of the invention essential to the invention Coating material is at least one, in particular a binder (A). According to the invention, this is an anionically stabilized one Polyurethane (meth) acrylate graft copolymer (A).

The polyurethane to be used according to the invention advantageously has (Meth) acrylate graft copolymer (A) has an acid number or amine number of 10 up to 250 mg KOH / g, an OH number of 30 to 350 mg KOH / g and a number average molecular weight of 1,500 to 100,000 daltons.

The polyurethane (meth) acrylate to be used according to the invention Graft copolymer (A) can be prepared in any way. It is preferably obtainable by using a in a first process step linear, branched or comb-like polyurethane with at least one produces lateral and / or terminal, olefinically unsaturated group.

• - mindestens eines Polyisocyanats, insbesondere eines Diisocyanats, mit
• - mindestens einem Polyol, insbesondere einem Diol,
• - mindestens einer Verbindung mit mindestens einer anionischen Gruppe und/oder mindestens einer in eine anionische Gruppe überführbaren, funktionellen Gruppe und mindestens einer isocyanatreaktiven, funktionellen Gruppe und
• - mindestens einer Verbindung mit mindestens einer olefinisch ungesättigten Gruppe und mindestens einer isocyanatreaktiven, funktionellen Gruppe sowie gegebenenfalls
• - mindestens einer Verbindung mit mindestens einer nichtionischen, hydrophilen Gruppe und mindestens einer isocyanatreaktiven, funktionellen Gruppe und
• - mindestens einem Kettenverlängerungsmittel

From a methodological point of view, the production of the polyurethanes to be used according to the invention has no special features, but takes place, for example, as in the patents EP 0 089 497 A1, DE 197 22 862 C2, DE 196 45 761 A1, DE 43 39 870 A1, DE 197 36 535 A1 or DE 44 37 535 A1, EP 0 522 419 A1 or EP 0 522 420 A1, by implementation

• - At least one polyisocyanate, in particular a diisocyanate, with
• at least one polyol, in particular a diol,
• at least one compound with at least one anionic group and / or at least one functional group which can be converted into an anionic group and at least one isocyanate-reactive functional group and
• - At least one compound with at least one olefinically unsaturated group and at least one isocyanate-reactive, functional group and optionally
• - At least one compound with at least one nonionic, hydrophilic group and at least one isocyanate-reactive, functional group and
• - at least one chain extender

Diisocyanates as well as are preferred for the production of the polyurethanes optionally in minor amounts of polyisocyanates for the introduction of Branches used. In the context of the present invention are under minor amounts to understand amounts that do not gel the Cause polyurethanes in their manufacture. The latter can also be done through the The use of small amounts of monoisocyanates can be prevented.

Examples of suitable diisocyanates are isophorone diisocyanate (= 5-isocyanato-1- isocyanatomethyl-1,3,3-trimethyl-cyclohexane), 5-isocyanato-1- (2-isocyanatoeth-1- yl) -1,3,3-trimethyl-cyclohexane, 5-isocyanato-1- (3-isocyanatoprop-1-yl) -1,3,3- trimethyl-cyclohexane, 5-isocyanato- (4-isocyanatobut-1-yl) -1,3,3-trimethylcyclohexane, 1-isocyanato-2- (3-isocyanatoprop-1-yl) cyclohexane, 1-isocyanato-2- (3-isocyanatoeth-1-yl) cyclohexane, 1-isocyanato-2- (4-isocyanatobut-1-yl) - cyclohexane, 1,2-diisocyanatocyclobutane, 1,3-diisocyanatocyclobutane, 1,2- Diisocyanatocyclopentane, 1,3-diisocyanatocyclopentane, 1,2- Diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4- Diisocyanatocyclohexane, dicyclohexylmethane-2,4'-diisocyanate, Trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, Hexamethylene diisocyanate, ethylethylene diisocyanate, trimethylhexane diisocyanate, Heptane methylene diisocyanate or diisocyanates derived from dimer fatty acids, as sold by the Henkel company under the trade name DDI 1410 and are described in the patent specifications WO 97/49745 and WO 97/49747, in particular 2-heptyl-3,4-bis (9-isocyanatononyl) -1-pentyl-cyclohexane, or 1,2-, 1,4- or 1,3-bis (isocyanatomethyl) cyclohexane, 1,2-, 1,4- or 1,3-bis (2- isocyanatoeth-1-yl) cyclohexane, 1,3-bis (3-isocyanatoprop-1-yl) cyclohexane, 1,2-, 1,4- or 1,3-bis (4-isocyanatobut-1-yl) cyclohexane, liquid bis (4- isocyanatocyclohexyl) methane with a trans / trans content of up to 30% by weight, preferably 25 wt .-% and in particular 20 wt .-%, as the Patents DE 44 14 032 A1, GB 1220717 A, DE 16 18 795 A1 or DE 17 93 785 A1 is described; Tetramethylxylylidene diisocyanate (TMXDI® from the company CYTEC), tolylene diisocyanate, xylylene diisocyanate, bisphenylene diisocyanate, Naphthylene diisocyanate or diphenylmethane diisocyanate.

Examples of suitable polyisocyanates based on those described above Diisocyanates are polyurethane prepolymers containing isocyanate groups, which are characterized by Reaction of polyols with an excess of at least one of the above described diisocyanates have been prepared, and / or isocyanurate, Biuret, allophanate, iminooxadiazinedione, urethane, urea and / or Polyisocyanates containing uretdione groups. Polyisocyanates are preferred used the statistical average of 2.5 to 5 isocyanate groups per molecule and Viscosities of 100 to 10,000, preferably 100 to 5000 mPa.s have. In addition, the polyisocyanates can be hydrophilic in the usual and known manner or be modified hydrophobically.

Mixtures of uretdione and / or are very particularly preferred Polyisocyanates containing isocyanurate groups and / or allophanate groups based on the diisocyanates described above, as obtained by catalytic Oligomerization of diisocyanates using suitable ones Catalysts are created, used. Examples of suitable manufacturing processes and polyisocyanates are, for example, from the patents CA 2,163,591 A, US-A-4,419,513, US 4,454,317 A, EP 0 646 608 A, US 4,801,675 A, EP 0 183 976 A1, DE 40 15 155 A1, EP 0 303 150 A1, EP 0 496 208 A1, EP 0 524 500 A. 1, EP 0 566 037 A1, US 5,258,482 A1, US 5,290,902 A1, EP 0 649 806 A1, DE 42 29 183 A1 or EP 0 531 820 A1.

Examples of suitable monoisocyanates are phenyl isocyanate and cyclohexyl isocyanate or stearyl isocyanate or vinyl isocyanate, methacryloyl isocyanate and / or 1- (1- Isocyanato-1-methylethyl) -3- (1-methylethenyl) benzene (TMI® from CYTEC).

• - gegebenenfalls sulfonierten, gesättigen und/oder ungesättigten Polycarbonsäuren oder deren veresterungsfähigen Derivaten, gegebenenfalls zusammen mit Monocarbonsäuren, sowie
• - gesättigten und/oder ungesättigten Polyolen, gegebenenfalls zusammen mit Monoolen,

hergestellt werden. Examples of suitable polyols are saturated or olefinically unsaturated polyester polyols which are obtained by reacting:

• optionally sulfonated, saturated and / or unsaturated polycarboxylic acids or their esterifiable derivatives, optionally together with monocarboxylic acids, and
• saturated and / or unsaturated polyols, optionally together with monools,

getting produced.

Examples of suitable polycarboxylic acids are aromatic, aliphatic and cycloaliphatic polycarboxylic acids. Aromatic and / or aliphatic polycarboxylic acids used.

Examples of suitable aromatic polycarboxylic acids are phthalic acid, Isophthalic acid, terephthalic acid, phthalic acid, isophthalic acid or Terephthalic acid monosulfonate or halophthalic acids, such as tetrachloro- or Tetrabromophthalic acid, of which isophthalic acid is advantageous and therefore is preferably used.

Examples of suitable, acyclic, aliphatic or unsaturated Polycarboxylic acids are oxalic acid, malonic acid, succinic acid, glutaric acid, Adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, Undecanedicarboxylic acid, dodecanedicarboxylic acid or dimer fatty acids or Maleic acid, fumaric acid or itaconic acid, of which adipic acid, glutaric acid, Azelaic acid, sebacic acid, dimer fatty acids and maleic acid are advantageous and therefore used preferentially.

Examples of suitable, cycloaliphatic and cyclic, unsaturated Polycarboxylic acids are 1,2-cyclobutanedicarboxylic acid, 1,3- Cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3- Cyclopentanedicarboxylic acid, hexahydrophthalic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-methylhexahydrophthalic acid, Tricyclodecanedicarboxylic acid, tetrahydrophthalic acid or 4-methyltetrahydrophthalic. These dicarboxylic acids can be used both in their cis and in their trans form as well as a mixture of both forms can be used.

The esterifiable derivatives of the above are also suitable Polycarboxylic acids, such as. B. their mono- or polyvalent esters with aliphatic Alcohols with 1 to 4 carbon atoms or hydroxy alcohols with 1 to 4 Carbon atoms. In addition, the anhydrides of the above Polycarboxylic acids are used if they exist.

If necessary, together with the polycarboxylic acids Monocarboxylic acids are used, such as benzoic acid, tert. Butylbenzoic acid, lauric acid, isononanoic acid, fatty acids, of course occurring oils, acrylic acid, methacrylic acid, ethacrylic acid or crotonic acid. Isononanoic acid is preferably used as the monocarboxylic acid.

Examples of suitable polyols are diols and triols, especially diols. Usually triols in addition to the diols in minor amounts used to introduce branches into the polyester polyols.

Suitable diols are ethylene glycol, 1,2- or 1,3-propanediol, 1,2-, 1,3- or 1,4- Butanediol, 1,2-, 1,3-, 1,4- or 1,5-pentanediol, 1,2-, 1,3-, 1,4-, 1,5- or 1,6- Hexanediol, hydroxypivalic acid neopentyl ester, neopentyl glycol, diethylene glycol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,2-, 1,3- or 1,4-cyclohexanedimethanol, Trimethylpentanediol, ethyl butyl propanediol, the positional isomers Diethyloctanediols 2-butyl-2-ethylpropanediol-1,3, 2-butyl-2-methylpropanediol-1,3, 2-phenyl-2-methylpropanediol-1,3, 2-propyl-2-ethylpropanediol-1,3, 2-di-tert-butylpropanediol-1,3, 2-butyl-2-propylpropanediol-1,3, 1-dihydroxymethyl-bicyclo [2.2.1] heptane, 2,2-diethylpropanediol-1,3, 2,2-dipropylpropanediol-1,3, 2-cyclohexyl-2-methylpropanediol-1,3 2,5-dimethylhexanediol-2,5, 2,5-diethylhexanediol-2,5, 2-ethyl-5-methylhexanediol-2,5, 2,4-dimethylpentanediol-2,4, 2,3-dimethylbutanediol-2,3, 1,4-bis (2'-hydroxypropyl) benzene or 1,3-bis (2'-hydroxypropyl) benzene. These diols can can also be used as such for the production of the polyurethanes.

Of these diols, hexanediol and neopentyl glycol are particularly advantageous and are therefore used with particular preference.

Examples of suitable triols are trimethylolethane, trimethylolpropane or Glycerin, especially trimethylolpropane.

The triols mentioned above can also be used as such for the preparation of the Polyurethanes are used (cf. patent specification EP 0 339 433 A1).

If necessary, minor amounts of monools can also be used become. Examples of suitable monools are alcohols or phenols such as ethanol, Propanol, n-butanol, sec-butanol, tert-butanol, amyl alcohols, hexanols, Fatty alcohols, allyl alcohol or phenol.

The polyester polyols can be prepared in the presence of small amounts suitable solvent as an entrainer. As an entrainer z. B. aromatic hydrocarbons, such as in particular xylene and (cyclo) aliphatic hydrocarbons, e.g. B. cyclohexane or methylcyclohexane, used.

Further examples of suitable polyols are polyester diols which are obtained by reacting a lactone with a diol. They are characterized by the presence of any hydroxyl groups and recurring polyester components of the formula - (- CO- (CHR ¹ ) _m -CH ₂ -O -) -. The index m is preferably 4 to 6 and the substituent R ¹ = hydrogen, an alkyl, cycloalkyl or alkoxy radical. No substituent contains more than 12 carbon atoms. The total number of carbon atoms in the substituent does not exceed 12 per lactone ring. Examples include hydroxycaproic acid, hydroxybutyric acid, hydroxydecanoic acid and / or hydroxystearic acid.

For the preparation of the polyester diols, the unsubstituted ### - caprolactone, in which m has the value 4 and all R ¹ substituents are hydrogen, is preferred. The reaction with lactone is started by low molecular weight polyols, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol or dimethylolcyclohexane. However, other reaction components, such as ethylenediamine, alkyldialkanolamines or urea, can also be reacted with caprolactone. Also suitable as higher molecular weight diols are polylactam diols which are produced by reacting, for example, epsilon-caprolactam with low molecular weight diols.

Further examples of suitable polyols are polyether polyols, in particular with a number average molecular weight from 400 to 5,000, in particular from 400 to 3,000. Suitable polyether diols are e.g. B. polyether diols of the general formula H - (- O- (CHR ² ) _o -) _p OH, where the substituent R ² = hydrogen or a lower, optionally substituted alkyl radical, the index o = 2 to 6, preferably 3 to 4 , and the index p = 2 to 100, preferably 5 to 50. Linear or branched polyether diols, such as poly (oxyethylene) glycols, poly (oxypropylene) glycols and poly (oxybutylene) glycols, are mentioned as particularly suitable examples.

On the one hand, the polyether diols should not have excessive amounts of ether groups bring in, because otherwise the using the polyurethane (meth) acrylate Graft copolymers (A) produced coatings by water be swollen. On the other hand, they can be used in quantities which stabilize the dispersions of the polyurethane (meth) acrylate Graft copolymers (A) contributes.

The polyurethane contains functional groups that are neutralized by Anions can be transferred, and / or anionic groups, in particular Carboxylic acid and / or carboxylate groups, and optionally nonionic, hydrophilic groups, especially poly (oxyalkylene) groups.

Examples of suitable functional groups to be used according to the invention, which can be converted into anions by neutralizing agents Carboxylic acid, sulfonic acid or phosphonic acid groups, in particular Carboxylic acid groups.

Examples of suitable anionic groups to be used according to the invention are carboxylate, sulfonate or phosphonate groups, in particular Carboxylate groups.

Examples of suitable neutralizing agents for anions convertible into functional groups are ammonia, ammonium salts, such as Ammonium carbonate or ammonium bicarbonate, as well as amines, such as. B. Trimethylamine, triethylamine, tributylamine, dimethylaniline, diethylaniline, Triphenylamine, dimethylethanolamine, diethylethanolamine, methyldiethanolamine, Triethanolamine and the like. The neutralization can be in the organic phase or take place in the aqueous phase. Preference is given to the neutralizing agent Dimethylethanolamine used.

The total amount used in the coating material of the invention of neutralizing agent is chosen so that 1 to 100 equivalents, preferably 50 up to 90 equivalents of the potentially anionic, functional groups of the Polyurethane are neutralized.

The introduction of (potentially) anionic groups into the polyurethane molecules is done by installing connections that are at least one opposite Isocyanate groups reactive and at least one, especially one for Group capable of anion formation contained in the molecule; the amount to be used can be calculated from the target acid number.

Suitable, isocyanate-reactive, functional groups are in particular Hydroxyl groups, thiol groups and primary and / or secondary Amino groups, of which the hydroxyl groups are preferably used.

Compounds which contain two groups which are reactive toward isocyanate groups in the molecule are particularly suitable. Accordingly, alkanoic acids with two substituents on the alpha carbon atom can be used, for example. The substituent can be a hydroxyl group, an alkyl group or preferably an alkylol group. These alkanoic acids have at least one, generally 1 to 3 carboxyl groups in the molecule. They have 2 to about 25, preferably 3 to 10, carbon atoms. Examples of suitable alkanoic acids are dihydroxypropionic acid, dihydroxysuccinic acid and dihydroxybenzoic acid. A particularly preferred group of alkanoic acids are the alpha, alpha-dimethylolalkanoic acids of the general formula R ³ -C (CH ₂ OH) ₂ COOH, where R ^{3 represents} a hydrogen atom or an alkyl group with up to about 20 carbon atoms. Examples of particularly suitable alkanoic acids are 2,2-dimethylol acetic acid, 2,2-dimethylol propionic acid, 2,2-dimethylol butyric acid and 2,2-dimethylol pentanoic acid. The preferred dihydroxyalkanoic acid is 2,2-dimethylol propionic acid. Compounds containing amino groups are, for example, alpha, omega-diaminovaleric acid, 3,4-diaminobenzoic acid, 2,4-diaminotoluenesulfonic acid and 2,4-diamino-diphenyl ether sulfonic acid.

The polyurethanes contain terminal and / or lateral, olefinically unsaturated Groups. Groups of this kind are introduced with the help of connections, which have at least one, in particular two, isocyanate-reactive group (s), especially hydroxyl groups, and at least one, especially one have olefinically unsaturated group. Connections can also be made be used, the at least one isocyanate group and at least one, in particular contain an olefinically unsaturated group. According to the invention preference is given to the first group of connections

Basically all groups can be considered as olefinically unsaturated groups, which contain at least one, especially a double bond. As part of In the present invention, a carbon bond is Understand carbon double bond. Examples of more suitable, olefinic unsaturated groups are (meth) acrylate, ethacrylate, crotonate, cinnamate, Vinyl ether, vinyl ester, vinyl, dicyclopentadienyl, norbornenyl, isoprenyl, Isopropenyl, allyl and / or butenyl groups; Dicyclopentadienyl, norbornenyl, Isoprenyl, isopropenyl, allyl or butenyl ether groups and / or Dicyclopentadienyl, norbornenyl, isoprenyl, isopropenyl, allyl and / or Butenyl. Of these are the accrylate, allyl and vinyl groups, especially allyl groups, particularly advantageous and therefore become special preferably used.

Examples of suitable compounds of this type are Trimethylolpropane monoallyl ether, trimethylolpropane mono (meth) acrylate or 1- (1- Isocyanato-1-methylethyl) -3- (1-methylethenyl) benzene (= Dimethyl-m-isopropenylbenzyl isocyanate), especially trimethylolpropane monoallyl ether.

The compounds described above, the olefinic introduction unsaturated groups in the polyurethanes are preferably used in Amounts used that have a statistical average of at least 0.5, preferably at least 1 and in particular at least 1.5 olefinic unsaturated double bonds in the molecule result.

The optionally present, non-ionically stabilizing poly (oxyalkylene) groups can be introduced into the polyurethane molecules as lateral or terminal groups. For this purpose, for example, alkoxypoly (oxyalkylene) alcohols with the general formula R ⁴ O - (- CH ₂ -CHR ⁵ -O-) _r H in R ⁵ for an alkyl radical having 1 to 6 carbon atoms, R ⁵ for a hydrogen atom or an alkyl radical with 1 to 6 carbon atoms and the index r stands for a number between 20 and 75. (see patent specifications EP 0 354 261 A1 or EP 0 424 705 A1).

Any free isocyanate groups still present in the polyurethanes can be reacted with polyols, polyamines and amino alcohols, resulting in leads to an increase in the molecular weight of the polyurethanes. The connections are therefore also called chain extenders.

Suitable polyols for chain extension are polyols with up to 36 carbon atoms per molecule, such as ethylene glycol, diethylene glycol, Triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butylene glycol, 1,6-hexanediol, trimethylolpropane, castor oil or hydrogenated castor oil, Ditrimethylolpropane ether, pentaerythritol, 1,2-cyclohexanediol, 1,4- Cyclohexanedimethanol, bisphenol A, bisphenol F, neopentyl glycol, Hydroxypivalic acid neopentylglycol ester, hydroxyethylated or hydroxypropylated bisphenol A, hydrogenated bisphenol A or mixtures thereof (see patent specifications EP 0 339 433 A1, EP 0 436 941 A1 or EP 0 517 707 A1).

Examples of suitable polyamines have at least two primary and / or secondary amino groups. Polyamines are essentially alkylene polyamines with 1 to 40 carbon atoms, preferably about 2 to 15 carbon atoms. she can carry substituents that are not reactive with isocyanate groups Have hydrogen atoms. Examples are polyamines with linear or branched, aliphatic, cycloaliphatic or aromatic structure and at least two primary amino groups.

Hydrazine, ethylenediamine, propylenediamine, 1,4- Butylenediamine, piperazine, 1,4-cyclohexyldimethylamine, 1,6-hexamethylenediamine, Trimethylhexamethylene diamine, methane diamine, isophorone diamine, 4,4'- Diaminodicyclohexylmethane and aminoethylenothanolamine. Preferred diamines are hydrazine, alkyl- or cycloalkyldiamines, such as propylenediamine and 1-amino-3- aminomethyl-3,5,5-trimethylcyclohexane.

It is also possible to use polyamines which have more than two amino groups contained in the molecule. In these cases, however - e.g. B. by using Monoamines - make sure that no cross-linked polyurethane resins are obtained become. Such useful polyamines are diethylene triamine, triethylene tetramine, Dipropylenediamine and dibutylenetriamine. In addition, Römpp "Lexicon Lacke and printing inks ", Georg Thieme-Verlag, 1998," Polyamine ", page 458, directed. An example of a monoamine is ethylhexylamine (cf. Patent EP-A-0 089 497).

Examples of suitable amino alcohols are ethanolamine or diethanolamine.

The production of the polyurethanes has no special features in terms of method, but takes place according to the usual and known methods, as described in the beginning cited prior art are described.

The polyurethanes are grafted with olefinically unsaturated monomers (a). Examples of suitable monomers (a) are:

Monomers a1)

Hydroxyalkyl esters of acrylic acid, methacrylic acid of another, alpha, beta ethylenically unsaturated carboxylic acid, which is derived from an alkylene glycol derived, which is esterified with the acid, or by reacting the acid with an alkylene oxide, in particular hydroxyalkyl esters of acrylic acid, Methacrylic acid or ethacrylic acid, in which the hydroxyalkyl group up to 20 Contains carbon atoms, such as 2-hydroxyethyl, 2-hydroxypropyl, 3- Hydroxypropyl, 3-hydroxybutyl, 4-hydroxybutyl acrylate, methacrylate, ethacrylate or crotonate; 1,4-bis (hydroxymethyl) cyclohexane, octahydro-4,7-methano-1H- inden dimethanol or methyl propanediol monoacrylate, monomethacrylate, monoethacrylate or monocrotonate; or reaction products from cyclic Esters such as B. ε-caprolactone and these hydroxyalkyl esters; or olefinic unsaturated alcohols such as allyl alcohol or polyols such as trimethylolpropane mono- or diallyl ether or pentaerythritol mono-, di- or triallyl ether. This higher functional monomers a1) are generally only in minor quantities used. Within the scope of the present invention here under minor amounts of higher functional monomers To understand amounts that are not used for crosslinking or gelling the Lead polyacrylate resins. For example, the share in Trimethylolpropane diallyl ether 2 to 10 wt .-%, based on the total weight of the Production of the polyacrylate resin used monomers a1) to a6).

Monomers a2)

(Meth) acrylic acid alkyl or cycloalkyl esters with up to 20 carbon atoms in 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-inden-methanol- or tert.- Butylcyclohexyl (meth) acrylate; (Meth) acrylic acid oxaalkyl ester or - oxacycloalkyl esters such as ethyl triglycol (meth) acrylate and Methoxyoligoglycol (meth) acrylate with a molecular weight Mn of preferably 550 or other ethoxylated and / or propoxylated, Hydroxyl group-free (meth) acrylic acid derivatives. These can be found in subordinate 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-1 H-indene-dimethanol- or cyclohexane-1,2-, 1,3- or -1,4-diol-di (meth) acrylate; Trimethylolpropane di- or tri (meth) acrylate; or pentaerythritol di-, tri- or tetra (meth) acrylate, contain. In the context of the present invention are here under minor amounts of higher functional monomers a2) such amounts to understand which is not for crosslinking or gelling the polyacrylate resins to lead.

Monomers a3)

At least one acid group, preferably one carboxyl group per molecule load-bearing, ethylenically unsaturated monomers or a mixture of such Monomers. Particularly preferred monomers a3) are acrylic acid, beta- Carboxyethyl acrylate and / or methacrylic acid used. But it can also other, ethylenically unsaturated carboxylic acids with up to 6 carbon atoms in the molecule be used. Examples of such acids are ethacrylic acid, crotonic acid, Maleic acid, fumaric acid and itaconic acid. Can also be ethylenic unsaturated sulfonic or phosphonic acids or their partial esters as a component a3) can be used. The following also come as monomers a3) Maleic acid mono (meth) acryloyloxyethyl ester, succinic acid mono (meth) acryloyloxyethyl ester and phthalic acid mono (meth) acryloyloxyethyl ester.

Monomers a4)

Vinyl esters of monocarboxylic acids branched in the alpha position with 5 to 18 C atoms in the molecule. The branched monocarboxylic acids can be obtained are by reacting formic acid or carbon monoxide and water with olefins in the presence of a liquid, strongly acidic catalyst; the olefins can crack products from paraffinic hydrocarbons, such as Mineral oil fractions, and can be both branched and straight-chain, acyclic and / or contain cycloaliphatic olefins. When implementing such olefins with formic acid or with carbon monoxide and water, a mixture is formed Carboxylic acids in which the carboxyl groups predominantly on a quaternary Carbon atom sit. Other olefinic starting materials are e.g. B. Propylene trimer, propylene tetramer and diisobutylene. The vinyl esters can can also be prepared in a manner known per se from the acids, e.g. B. by the acid is allowed to react with acetylene. Be particularly preferred - because of of good availability - vinyl esters of saturated, aliphatic Monocarboxylic acids with 9 to 11 carbon atoms located on the alpha carbon atom are branched, used.

Monomers a5)

Reaction product from acrylic acid and / or methacrylic acid with the Glycidyl ester of an alpha-branched monocarboxylic acid with 5 to 18 carbon atoms per molecule. The reaction of acrylic or methacrylic acid with the glycidyl ester a carboxylic acid with a tertiary alpha carbon atom can take place during or after the polymerization reaction. Is preferred as Component a5) with the reaction product of acrylic and / or methacrylic acid the glycidyl ester of Versatic® acid. This glycidyl ester is below the name Cardura® E10 commercially available. In addition, Römpp "Lexicon Lacke und Druckfarben", Georg Thieme-Verlag, Stuttgart - New York, 1998, Pages 605 and 606.

Monomers a6)

• - Olefine, wie Ethylen, Propylen, But-1-en, Pent-1-en, Hex-1-en, Cyclohexen, Cyclopenten, Norbornen, Butadien, Isopren, Cylopentadien und/oder Dicyclopentadien;
• - (Meth)Acrylsäureamide, wie (Meth)Acrylsäureamid, N-Methyl-, N,N- Dimethyl-, N-Ethyl-, N,N-Diethyl-, N-Propyl-, N,N-Dipropyl, N-Butyl-, N,N- Dibutyl-, N-Cyclohexyl- und/oder N,N-Cyclohexyl-methyl- (meth)acrylsäureamid;
• - Epoxidgruppen enthaltende Monomere, wie der Glycidylester der Acrylsäure, Methacrylsäure, Ethacrylsäure, Crotonsäure, Maleinsäure, Fumarsäure und/oder Itaconsäure;
• - vinylaromatische Kohlenwasserstoffe, wie Styrol, alpha-Alkylstyrole, insbesondere alpha-Methylstyrol und/oder Vinyltoluol;
• - Diarylethylene, insbesondere solche der allgemeinen Formel I:
  
  R⁶R⁷C=CR⁸R⁹ (I),
  
  worin die Reste R⁶, R⁷, R⁸ und R⁹ jeweils unabhängig voneinander für Wasserstoffatome oder substituierte oder unsubstituierte Alkyl-, Cycloalkyl-, Alkylcycloalkyl-, Cycloalkylalkyl-, Aryl-, Alkylaryl-, Cycloalkylaryl-, Arylalkyl- oder Arylcycloalkylreste stehen, mit der Maßgabe, daß mindestens zwei der Variablen R⁶, R⁷, R⁸ und R⁹ für substituierte oder unsubstituierte Aryl-, Arylalkyl- oder Arylcycloalkylreste, insbesondere substituierte oder unsubstituierte Arylreste, stehen. Beispiele geeigneter Alkylreste sind Methyl, Ethyl, Propyl, Isopropyl, n-Butyl, iso-Butyl, tert.-Butyl, Amyl, Hexyl oder 2-Ethylhexyl. Beispiele geeigneter Cycloalkylreste sind Cyclobutyl, Cyclopentyl oder Cyclohexyl. Beispiele geeigneter Alkylcycloalkylreste sind Methylencyclohexan, Ethylencyclohexan oder Propan-1,3-diyl-cyclohexan. Beispiele geeigneter Cycloalkylalkylreste sind 2-, 3- oder 4-Methyl-, -Ethyl-, -Propyl- oder -Butylcyclohex-1-yl. Beispiele geeigneter Arylreste sind Phenyl, Naphthyl oder Biphenylyl, vorzugsweise Phenyl und Naphthyl und insbesondere Phenyl. Beispiele geeigneter Alkylarylreste sind Benzyl oder Ethylen- oder Propan-1,3-diyl-benzol. Beispiele geeigneter Cycloalkylarylreste sind 2-, 3-, oder 4-Phenylcyclohex-1-yl. Beispiele geeigneter Arylalkylreste sind 2-, 3- oder 4-Methyl-, -Ethyl-, -Propyl- oder - Butylphen-1-yl. Beispiele geeigneter Arylcycloalkylreste sind 2-, 3- oder 4- Cyclohexylphen-1-yl. Vorzugsweise handelt es sich bei den Arylresten R⁶, R⁷, R⁸ und/oder R⁹ um Phenyl- oder Naphthylreste, insbesondere Phenylreste. Die in den Resten R⁶, R⁷, R⁸ und/oder R⁹ gegebenenfalls vorhandenen Substituenten sind elektronenziehende oder elektronenschiebende Atome oder organische Reste, insbesondere Halogenatome, Nitril-, Nitro-, partiell oder vollständig halogenierte Alkyl-, Cycloalkyl-, Alkylcycloalkyl-, Cycloalkylalkyl-, Aryl-, Alkylaryl-, Cycloalkylaryl-, Arylalkyl- und Arylcycloalkylreste; Aryloxy-, Alkyloxy- und Cycloalkyloxyreste; Arylthio-, Alkylthio- und Cycloalkylthioreste und/oder primäre, sekundäre und/oder tertiäre Amionogruppen. Besonders vorteilhaft sind Diphenylethylen, Dinaphthalinethylen, cis- oder trans-Stilben, Vinyliden-bis(4-N,N-dimethylaminobenzol), Vinyliden-bis(4-aminobenzol) oder Vinyliden-bis(4-nitrobenzol), insbesondere Diphenylethylen (DPE), weswegen sie bevorzugt verwendet werden. Vorzugsweise werden diese Monomeren a6) nicht als die alleinigen Monomere eingesetzt, sondern stets gemeinsam mit anderen Monomeren (a), wobei sie die Copolymerisation in vorteilhafter Weise derart regeln, daß auch eine radikalische Copolymerisation in Batch-Fahrweise möglich ist;
• - Nitrile, wie Acrylnitril und/oder Methacrylnitril;
• - Vinylverbindungen, wie Vinylchlorid, Vinylfluorid, Vinylidendichlorid, Vinylidendifluorid; N-Vinylpyrrolidon; Vinylether wie Ethylvinylether, n- Propylvinylether, Isopropylvinylether, n-Butylvinylether, Isobutylvinylether und/oder Vinylcyclohexylether; Vinylester wie Vinylacetat, Vinylpropionat, Vinylbutyrat, Vinylpivalat, Vinylester der Versatic®-Säuren, die unter dem Markennamen VeoVa® von der Firma Deutsche Shell Chemie vertrieben werden (ergänzend wird auf Römpp "Lexikon Lacke und Druckfarben", Georg Thieme-Verlag, Stuttgart - New York, 1998, Seite 598 sowie Seiten 605 und 606, verwiesen) und/oder der Vinylester der 2-Methyl-2-ethylheptansäure; und/oder
• - Polysiloxanmakromonomere, die ein zahlenmittleres Molekulargewicht Mn von 1.000 bis 40.000, bevorzugt von 2.000 bis 20.000, besonders bevorzugt 2.500 bis 10.000 und insbesondere 3.000 bis 7.000 und im Mittel 0,5 bis 2,5, bevorzugt 0,5 bis 1,5, ethylenisch ungesättigte Doppelbindungen pro Molekül aufweisen, wie sie in der DE 38 07 571 A1 auf den Seiten 5 bis 7, der DE 37 06 095 A1 in den Spalten 3 bis 7, der EP 0 358 153 B1 auf den Seiten 3 bis 6, in der US 4,754,014 A in den Spalten 5 bis 9, in der DE 44 21 823 A1 oder in der der internationalen Patentanmeldung WO 92/22615 auf Seite 12, Zeile 18, bis Seite 18, Zeile 10, beschrieben sind, oder Acryloxysilan-enthaltende Vinylmonomere, herstellbar durch Umsetzung hydroxyfunktioneller Silane mit Epichlorhydrin und anschließender Umsetzung des Reaktionsproduktes mit Methacrylsäure und/oder Hydroxyalkylestern der (Meth)acrylsäure.

Essentially acid-free, ethylenically unsaturated monomers, such as

• Olefins, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, cyclohexene, cyclopentene, norbornene, butadiene, isoprene, cyclopentadiene and / or dicyclopentadiene;
• - (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 and / or N, N-cyclohexyl-methyl- (meth) acrylic acid amide;
• 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;
• - Vinyl aromatic hydrocarbons, such as styrene, alpha-alkyl styrenes, in particular alpha-methyl styrene and / or vinyl toluene;
• - Diarylethylenes, in particular those of the general formula I:
  
  R ⁶ R ⁷ C = CR ⁸ R ⁹ (I),
  
  in which the radicals R ⁶ , R ⁷ , R ⁸ and R ⁹ 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 ⁶ , R ⁷ , R ⁸ and R ⁹ stand for 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, iso-butyl, 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-diyl-benzene. Examples of suitable cycloalkylaryl radicals are 2-, 3-, or 4-phenylcyclohex-1-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-1-yl. The aryl radicals R ⁶ , R ⁷ , R ⁸ and / or R ⁹ are preferably phenyl or naphthyl radicals, in particular phenyl radicals. The substituents optionally present in the radicals R ⁶ , R ⁷ , R ⁸ and / or R ⁹ are 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, cycloalkylaryl, arylalkyl and arylcycloalkyl radicals; Aryloxy, alkyloxy and cycloalkyloxy radicals; Arylthio, alkylthio and cycloalkylthio residues and / or primary, secondary and / or tertiary amino groups. Diphenylethylene, dinaphthaleneethylene, cis- or trans-stilbene, vinylidene-bis (4-N, N-dimethylaminobenzene), vinylidene-bis (4-aminobenzene) or vinylidene-bis (4-nitrobenzene), in particular diphenylethylene (DPE), are particularly advantageous. which is why they are preferred. These monomers a6) are preferably not used as the sole monomers, but always together with other monomers (a), and they regulate the copolymerization in such a way that radical copolymerization in batch mode is also possible;
• Nitriles, such as acrylonitrile and / or methacrylonitrile;
• Vinyl compounds, such as vinyl chloride, vinyl fluoride, vinylidene dichloride, vinylidene difluoride; 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; Vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl esters of Versatic® acids, which are sold under the brand name VeoVa® by Deutsche Shell Chemie (Römpp "Lexikon Lacke und Druckfarben", Lexikon Lacke und Druckfarben ", Georg Thieme-Verlag, Stuttgart - New York, 1998, page 598 and pages 605 and 606, referenced) and / or the vinyl ester of 2-methyl-2-ethylheptanoic acid; and or
• - Polysiloxane macromonomers which have a number average molecular weight Mn of 1,000 to 40,000, preferably from 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 Have unsaturated double bonds per molecule, as described in DE 38 07 571 A1 on pages 5 to 7, DE 37 06 095 A1 in columns 3 to 7, EP 0 358 153 B1 on pages 3 to 6, in which No. 4,754,014 A in columns 5 to 9, in DE 44 21 823 A1 or in international patent application WO 92/22615 on page 12, line 18 to page 18, line 10, or vinyl monomers containing acryloxysilane, can be produced by reacting hydroxy-functional silanes with epichlorohydrin and then reacting the reaction product with methacrylic acid and / or hydroxyalkyl esters of (meth) acrylic acid.

From these suitable monomers (a) described by way of example above the person skilled in the art can do that particularly well for the respective purpose suitable monomers (a) based on their known, physico-chemical Easily select properties and reactivities. If necessary, he can carry out a few preliminary tests for this purpose. In particular, he will make sure that the monomers (a) are none functional groups, especially (potentially) cationic, functional groups, contain the with the (potentially) anionic, functional groups in the Polyurethanes enter into undesirable interactions.

According to the invention, the monomers (a) are selected so that the Property profile of the grafted (co) polymers essentially from the (Meth) acrylate monomers (a) described above, wherein the other monomers (a) this property profile in an advantageous manner vary.

According to the invention, very special advantages result when mixtures of Monomers a1), a2) and a3) and optionally a6) can be used.

From a methodological point of view, the production of the polyurethane (meth) acrylate Graft copolymers (A) have no peculiarities, but are carried out according to usual and known methods of radical (co) polymerization in bulk, Solution or emulsion in the presence of at least one polymerization initiator.

If the (co) polymerization takes place in bulk or solution, the polyurethane (Meth) acrylate graft copolymer (A) dispersed in an aqueous medium, which results in a secondary dispersion.

The (co) polymerization is preferably carried out in emulsion, as described for example in the patent DE 197 22 862 C1 or the patent applications DE 196 45 761 A1, EP-A 522 419 A1 or EP 0 522 420 A1, or in a miniemulsion or microemulsion , The miniemulsion and microemulsion are supplementary to the patent applications and the references DE 196 28 142 A1, DE 196 28 143 A1 or EP 0 401 565 A1, "Emulsion Polymerization and Emulsion Polymers", editors. PA Lovell and Mohamed S. El-Aasser, John Wiley and Sons, Chichester, New York, Weinheim, 1997, pages 700 and following; Mohamed S. El-Aasser, "Advances in Emulsion Polymerization and Latex Technology", 30 ^th Annual Short Course, Volume 3, June 7-11, 1999, Emulsion Polymers Institute, Lehigh University, Bethlehem, Pennsylvania, USA, directed. In the (co) polymerization in emulsion, mini-emulsion or micro-emulsion, the graft copolymers are obtained in the form of primary dispersions.

The usual and. Come as reactors for the (co) polymerization processes known stirred tanks, stirred tank cascades, tubular reactors, loop reactors or Taylor reactors, as described, for example, in the patents DE-B-10 71 241 A1, EP 0 498 583 A1 or DE 198 28 742 A1 or in the article by K. Kataoka in "Chemical Engineering Science", volume 50, volume 9, 1995, pages 1409 to 1416.

The (co) polymerization is advantageously carried out at temperatures above the Room temperature and below the lowest decomposition temperature of each used monomers carried out, preferably a temperature range from 30 to 180 ° C, very particularly preferably 70 to 150 ° C and in particular 80 up to 110 ° C is selected.

When using particularly volatile monomers (a) and / or Emulsions can also be (co) polymerized under pressure, preferably under 1.5 to 3,000 bar, particularly preferably 5 to 1,500 and in particular 10 to 1,000 bar, be performed.

Examples of suitable polymerization initiators are free radicals Initiators such as 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-trimethylhexanoate or tert-butyl per-2-ethylhexanoate; Potassium, sodium or ammonium peroxodisulfate; Azodinitriles such as azobisisobutyronitrile; C-C-cleaving Initiators, such as benzpinacol silyl ether, or a combination of either oxidizing initiator with hydrogen peroxide. To be favoured water-insoluble initiators used. The initiators are preferred in one Amount from 0.1 to 25% by weight, particularly preferably from 2 to 10% by weight, based on the total weight of the monomers (a) used.

In the polyurethane (meth) acrylate graft copolymers (A) this can be done Quantity ratio of polyurethane to grafted monomers (a) wide vary, which is a particular advantage of polyurethane (meth) acrylate Graft copolymers (A). This ratio is preferably 1: 100 to 100: 1, preferably 1:50 to 50: 1, particularly preferably 30: 1 to 1:30, very particularly preferably 20: 1 to 1:20 and in particular 10: 1 to 1:10. Very special advantages result if this ratio is approximately at 3.5: 1 to 1: 3.5, in particular 1.5: 1 to 1: 1.5.

The proportion of the polyurethane (meth) acrylate to be used according to the invention Graft copolymers (A) on the coating materials of the invention can also vary widely and depends primarily on the Intended use of the coating materials and the functionality of the Polyurethane (meth) acrylate graft copolymers (A) with respect to Crosslinking reaction with those to be used according to the invention Crosslinking agents (B). According to the invention it is advantageous to Polyurethane (meth) acrylate graft copolymers (A) in an amount of 35 to 70, preferably 36 to 68, particularly preferably 38 to 66 and in particular 40 to 64 wt .-%, each based on the solid of the invention Coating material to use.

The further, essential component of the coating material of the invention are the crosslinking agents (B).

The coating material of the invention contains at least two Crosslinking agents of different reactivity with respect to the Crosslinking reaction (s) and of different solubility.

• 1. mindestens ein wasserlösliches, mit schwachen, organischen und/oder anorganischen Säuren katalysierbares Melamin-Formaldehyd-Harz, das einen mittleren bis hohen Alkylierungsgrad und eine mittlere bis hohe Iminofunktionalität aufweist, und
• 2. mindestens ein wasserunlösliches, mit starken, organischen und/oder anorganischen Säuren katalysierbares Melamin-Formaldehyd-Harz, das einen hohen Alkylierungsgrad und eine niedrige Iminofunktionalität aufweist.

According to the invention, the crosslinking agents (B) are:

• 1. at least one water-soluble melamine-formaldehyde resin which can be catalyzed with weak, organic and / or inorganic acids and which has a medium to high degree of alkylation and a medium to high imino functionality, and
• 2. at least one water-insoluble melamine-formaldehyde resin which can be catalyzed with strong, organic and / or inorganic acids and which has a high degree of alkylation and a low imino functionality.

In the context of the present invention, acids are among weak acids a pKs value> 4, in particular> 5. Examples of suitable weaker acids are carboxylic acids, which can also be blocked with amines and are only released during thermal hardening. Even those in the Polyurethane (meth) acrylate graft copolymers available Carboxyl groups can have a catalytic effect.

In the context of the present invention, acids are among strong acids a pKs value <3, in particular <2 to understand. Examples of more suitable, stronger ones Acids are phosphoric acid, alkyl and arylphosphonic acids or organic Sulfonic acids, such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid, Dinonylnaphthalenesulfonic acid or dinonylnaphthalenesulfonic acid, which too for example, can be blocked with amines and only when thermal Hardening can be released. Catalysts of this type are commercially available products (cf. the textbook "Lackadditive" by Johan Bieleman, Wiley-VCH, Weinheim - New York, 1998, page 247).

A medium to high degree of alkylation means that on average up to 70, preferably up to 65 and in particular up to 60 mol% of the available Methylol groups are etherified. A high degree of alkylation means that at least 70 mol%, in particular at least 80 mol% and in particular in substantially all or all of the methylol groups are etherified. The Ether groups methyl, propyl, isopropyl, n-butyl or isobutyl groups, especially methyl groups.

A low imino functionality means that the melamine in question Formaldehyde resin b2) on average less than 0.5, preferably less than 0.2 and especially less than 0.1 imino groups in the molecule contains. A high imino functionality means that the melamine in question Formaldehyde resin b1) on average more than 0.5, in particular more contains more than 0.7 and in particular more than 0.9 imino groups in the molecule.

Further details regarding the reactivity of the melamine-formaldehyde resins, are described in the textbook "Lackadditive" by Johan Bieleman, Wiley-VCH, Weinheim - New York, 1998, pages 242 to 250.

The melamine-formaldehyde resins are commercially available products. So sells for example the company Cytec Specialty Resins A.S. a melamine formaldehyde Resin b2) under the brand Cymel® 303 and a melamine-formaldehyde resin b1) under the brand Cymel® 327.

The content of the coating materials of the invention in the invention Crosslinking agents (B) to be used can vary widely. That in terms of Binder (A) The same applies here. Preferably contain the coating materials according to the invention the crosslinking agents (B) in one Amount of 5 to 15, preferably 5.2 to 14.8, particularly preferably 5.4 to 14.6, particularly preferred, 5.6 to 14.4 and in particular 5.8 to 14.2 wt .-%, each based on the solid of the coating material of the invention.

It is essential to the invention that the coating materials contain the crosslinking agents (B) in an amount of 10 to 20, preferably 12 to 19.5 and in particular 14 to 19% by weight, each based on the amount of crosslinking agent (B) and binders described above (A) and optionally existing components (E) described below.

Yet another essential part of the invention Coating material is at least one, preferably strong, organic and / or inorganic, optionally blocked acid, which is used as catalyst (C) acts. Examples of suitable acids are given above in the description the crosslinking agent (B) listed. In the invention Coating materials are preferably in an amount of 0.1 to 3, preferably 0.2 to 2.9, particularly preferably 0.3 to 2.8 and in particular 0.4 to 2.7% by weight, based in each case on the coating material of the invention, contain.

The fourth, essential component of the invention Coating material is at least one pigment (D) selected from the group consisting of color and / or effect, fluorescent, electrical conductive and magnetically shielding pigments, metal powders, organic and inorganic, transparent or opaque fillers and nanoparticles, contain.

Examples of suitable effect pigments are metal flake pigments, such as commercially available aluminum bronzes, chromated according to DE 36 36 183 A1 Aluminum bronze, and commercially available stainless steel bronze and non-metallic Effect pigments, such as pearlescent or interference pigments, platelet-like effect pigments based on iron oxide, which has a hue from pink to brownish red or liquid crystalline effect pigments. additional is published on Römpp "Lexicon Lacke und Druckfarben", Georg Thieme-Verlag, 1998, Pages 176, "Effect Pigments" and Pages 380 and 381 "Metal Oxide Mica Pigments "to" metal pigments ", and the patent applications and patents DE 36 36 156 A1, DE 37 18 446 A1, DE 37 19 804 A1, DE 39 30 601 A1, EP 0 068 311 A1, EP 0 264 843 A1, EP 0 265 820 A1, EP 0 283 852 A1, EP 0 293 746 A 1, EP 0 417 567 A1, US 4,828,826 A or US 5,244,649 A.

Examples of suitable inorganic color pigments are white pigments, such as titanium dioxide, zinc white, zinc sulfide or lithopone; Black pigments, such as carbon black, Iron-manganese black or spinel black; Colored pigments, such as chromium oxide, Chromium oxide hydrate green, cobalt green or ultramarine green, cobalt blue, ultramarine blue or manganese blue, ultramarine violet or cobalt and manganese violet, iron oxide red, Cadmium sulfoselenide, molybdate red or ultramarine red; Brown iron oxide, Mixed brown, spinel and corundum phases or chrome orange; or iron oxide yellow, Nickel titanium yellow, chrome titanium yellow, cadmium sulfide, cadmium zinc sulfide, chrome yellow or bismuth vanadate.

Examples of suitable organic coloring pigments are Monoazo pigments, bisazo pigments, anthraquinone pigments, Benzimidazole pigments, quinacridone pigments, quinophthalone pigments, Diketopyrrolopyrrole pigments, dioxazine pigments, indanthrone pigments, Isoindoline pigments, isoindolinone pigments, azomethine pigments, Thioindigo pigments, metal complex pigments, perinone pigments, perylene pigments, Phthalocyanine pigments or aniline black.

In addition, Römpp "Lexicon Lacke und Druckfarben", Georg Thieme- Verlag, 1998, pages 180 and 181, "Eisenblau-Pigments" to "Eisenoxidschwarz", pages 451 to 453 "Pigments" to "Pigment Volume Concentration", page 563 "Thioindigo Pigments", page 567 "Titanium dioxide pigments", pages 400 and 467 "Naturally occurring Pigments ", page 459" Polycyclic Pigments ", page 52" Azomethine Pigments "," Azo Pigments "and page 379" Metal Complex Pigments ", directed.

Examples of fluorescent pigments (daylight pigments) are Bis (azomethine) pigments.

Examples of suitable, electrically conductive pigments are titanium dioxide / tin oxide Pigments.

Examples of magnetically shielding pigments are pigments based on Iron oxides or chromium dioxide.

Examples of suitable metal powders are powders made of metals and Metal alloys aluminum, zinc, copper, bronze or brass.

Examples of suitable, organic and inorganic fillers are chalk, Calcium sulfate, barium sulfate, silicates such as talc, mica or kaolin, Silicas, oxides such as aluminum hydroxide or magnesium hydroxide or organic fillers such as plastic powder, in particular made of polylamide or Polyacrylonitrile. In addition, Römpp "Lexicon Lacke und Druckfarben", Georg Thieme-Verlag, 1998, pages 250 ff., "Fillers".

Examples of suitable, transparent fillers are those based on Silicon dioxide, aluminum oxide or zirconium oxide.

Suitable nanoparticles are selected from the group consisting of hydrophilic and hydrophobic, especially hydrophilic nanoparticles on the Base of silicon dioxide, aluminum oxide, zinc oxide, zirconium oxide and the Polyacids and heteropolyacids of transition metals, preferably of Molybdenum and tungsten, with a primary article size <50 nm, preferably 5 to 50 nm, in particular 10 to 30 nm. The hydrophilic ones are preferred Nanoparticles no matting effect. Nanoparticles are particularly preferred used on the basis of silicon dioxide.

Hydrophilic, pyrogenic silicon dioxides are very particularly preferred used, whose agglomerates and aggregates have a chain-like structure and that through the flame hydrolysis of silicon tetrachloride in one Oxyhydrogen flame can be produced. These are used, for example, by the company Degussa sold under the brand Aerosil®. Be particularly preferred also precipitated water glasses, such as nano-hectorite, for example from the company Südchemie under the Optigel® brand or from Laporte under the brand Laponite® are used.

Further suitable nanoparticles are described in US Pat. No. 4,652,470 A, Column 7, line 49, to column 13, line 36.

The proportion of pigments (D) in the coating material of the invention can vary widely and depends primarily on the opacity of the pigments (D), the desired color and the desired optical and / or other physical effect (s). The pigments (D) are preferably in the Contain coating material according to the invention in an amount that a Pigment-binder ratio of (D): (A) = 0.1: 1 to 2: 1 results.

In addition to the above-described ones to be used according to the invention, Essential components (A), (B), (C) and (D) can be the inventive Coating material still contain at least one component (E) with the Crosslinking agents (B) is reactive.

Examples of suitable constituents (E) are hydroxyl-containing and / or carbamate group-containing oligomers and polymers as well as reactive thinners for the thermal curing, such as poly (oxyalkylene) glycols or positional isomers Hyperbranched diethyloctanediols or hydroxyl groups Compounds or dendrimers or metathesis oligomers as described in the Patent applications DE 198 09 643 A1, DE 198 40 605 A1 or DE 198 05 421 A1 to be discribed.

In addition, the coating material of the invention can at least contain an additive (F) in conventional and known amounts.

Examples of suitable additives (F) are additional, customary and known Crosslinking agents such as tris (alkoxycarbonylamino) triazines, carbonate groups containing compounds or resins, blocked polyisocyanates or beta Hydroxyalkylamides, which - if used - in minor amounts are used, d. that is, the crosslinking properties are still in are essentially determined by the crosslinking agents (B).

Should the coating materials of the invention not only thermally but be curable with actinic radiation (Dual Cure), they contain the usual and known components (F) which can be activated with actinic radiation. UV light is particularly preferably used. Examples of suitable ingredients (E) which can be activated with actinic radiation are (meth) acrylic, allyl, vinyl or dicyclopentadienyl-functional (meth) acrylate copolymers or Polyether acrylates, polyester acrylates, unsaturated polyester acrylates, Epoxy acrylates, urethane acrylates, amino acrylates, melamine acrylates, silicone acrylates or the corresponding methacrylates, photoinitiators and coinitiators and / or reactive diluents which can be activated with actinic radiation.

• - niedrig siedende und hoch siedende ("lange"), organische Lösemittel;
• - UV-Absorber;
• - Radikalfänger;
• - Katalysatoren für die Vernetzung;
• - Slipadditive;
• - Polymerisationsinhibitoren;
• - Entschäumer;
• - Emulgatoren, insbesondere nicht ionische Emulgatoren, wie alkoxylierte Alkanole, Polyole, Phenole und Alkylphenole oder anionische Emulgatoren, wie Alkalisalze oder Ammoniumsalze von Alkancarbonsäuren, Alkansulfonsäuren, und Sulfosäuren von alkoxylierten Alkanolen, Polyolen, Phenolen und Alkylphenolen;
• - Netzmittel, wie Siloxane, fluorhaltige Verbindungen, Carbonsäurehalbester, Phosphorsäureester, Polyacrylsäuren und deren Copolymere, Decindiolderivate oder Polurethane;
• - Haftvermittler;
• - Verlaufmittel;
• - filmbildende Hilfsmittel, wie Cellulose-Derivate;
• - Flammschutzmittel;
• - rheologiesteuernde Additive, wie die aus den Patentschriften WO 94/22968, EP 0 276 501 A1, EP 0 249 201 A1 oder WO 97/12945 bekannten; vernetzte, polymere Mikroteilchen, wie sie beispielsweise in der EP 0 008 127 A1 offenbart sind; anorganische Schichtsilikate, wie Aluminium-Magnesium-Silikate, Natrium-Magnesium- und Natrium-Magnesium-Fluor-Lithium-Schichtsilikate des Montmorillonit-Typs; Kieselsäuren, wie Aerosile; oder synthetische Polymere mit ionischen und/oder assoziativ wirkenden Gruppen, wie Polyvinylalkohol, Poly(meth)acrylamid, Poly(meth)acrylsäure, Polyvinylpyrrolidon, Styrol-Maleinsäureanhydrid- oder Ethylen-Maleinsäureanhydrid-Copolymere und ihre Derivate oder assoziative Verdickungsmittel auf Polyurethanbasis, wie sie in Römpp "Lexikon Lacke und Druckfarben", Georg Thieme-Verlag, Stuttgart - New York, 1998, "Verdickungsmittel", Seiten 599 bis 600, und in dem Lehrbuch "Lackadditive" von Johan Bieleman, Wiley-VCH, Weinheim - New York, 1998, Seiten 51 bis 59 und 65, beschrieben werden, insbesondere hydrophob modifizierte, ethoxylierte Urethane.

Further examples of suitable additives (F) are:

• - low-boiling and high-boiling ("long"), organic solvents;
• - UV absorber;
• - radical scavenger;
• - crosslinking catalysts;
• - slip additives;
• - polymerization inhibitors;
• - defoamer;
• Emulsifiers, in particular nonionic emulsifiers, such as alkoxylated alkanols, polyols, phenols and alkylphenols or anionic emulsifiers, such as alkali metal salts or ammonium salts of alkane carboxylic acids, alkanesulfonic acids, and sulfonic acids of alkoxylated alkanols, polyols, phenols and alkylphenols;
• Wetting agents, such as siloxanes, fluorine-containing compounds, carboxylic acid half-esters, phosphoric acid esters, polyacrylic acids and their copolymers, decynediol derivatives or polyurethane;
• - adhesion promoter;
• - leveling agent;
• - Film-forming aids, such as cellulose derivatives;
• - flame retardants;
• rheology-controlling additives, such as those known from the patent specifications WO 94/22968, EP 0 276 501 A1, EP 0 249 201 A1 or WO 97/12945; crosslinked, polymeric microparticles, as disclosed, for example, in EP 0 008 127 A1; inorganic layered silicates such as aluminum-magnesium-silicates, sodium-magnesium and sodium-magnesium-fluorine-lithium layered silicates of the montmorillonite type; Silicas, such as aerosils; or synthetic polymers with ionic and / or associative groups, such as polyvinyl alcohol, poly (meth) acrylamide, poly (meth) acrylic acid, polyvinyl pyrrolidone, styrene-maleic anhydride or ethylene-maleic anhydride copolymers and their derivatives or associative polyurethane-based thickeners, such as them in Römpp "Lexicon Lacke und Druckfarben", Georg Thieme-Verlag, Stuttgart - New York, 1998, "Thickener", pages 599 to 600, and in the textbook "Lackadditive" by Johan Bieleman, Wiley-VCH, Weinheim - New York, 1998, pages 51 to 59 and 65, are described, in particular hydrophobically modified, ethoxylated urethanes.

Further examples of suitable additives (F) are in the textbook "Lackadditive" by Johan Bieleman, Wiley-VCH, Weinheim - New York, 1998, described.

The essential components of the invention described above Coating material is dispersed and / or dissolved in water. The The solids content of the coating material of the invention can be wide vary. It mainly depends on the storage, transport and the viscosity required for the application. On the one hand, this is intended to stop the Prevent components during storage and transportation. On the other hand, it should problem-free application with good flow of the resulting layers of paint guarantee. A solids content of 20 to 60 is preferred 22 to 58, particularly preferably 24 to 56 and in particular 26 to 54% by weight, each based on the coating material of the invention applied.

Seen methodologically, the preparation of the invention Coating material no special features, but was done by the Dispersing its constituents in the aqueous medium, being primary or Secondary dispersion process and conventional and known mixing units, such as Stirred kettles, dissolvers, agitator mills or extruders can be used. As an example, reference is made to the prior art cited at the beginning.

The coating material of the invention, in particular that of the invention Waterborne basecoat is excellent for the production of color and / or effect-giving multi-layer coatings on primed and unprimed Suitable substrates by the wet-on-wet method. Furthermore is the coating material according to the invention, in particular the coating material according to the invention Solid-color top coat, excellent for the production of single-layer, color and / or effect paint finishes.

The coating material of the invention exhibits particular advantages in its Use as a water-based paint in the wet-on-wet process, at which the waterborne basecoat is applied to the primed or unprimed substrate after which the water-based lacquer layer is dried, but not hardened, to the Waterborne basecoat applied a clear coat and the resulting Clear lacquer layer together with the water-based lacquer layer thermally or cures thermally and with actinic radiation (dual cure).

In the case of a primed substrate, the primer, in particular the Filler layer, in the not or only partially hardened state with the water-based lacquer according to the invention and the clear lacquer are overcoated, after which all three layers are baked together.

In a further variant of the wet-on-wet method, a first Waterborne basecoat on a substrate, not or only partially hardened primer, especially an electrocoat, applied, after which the two layers are thermally cured together. The resulting paint is then, as described above, with a second waterborne basecoat and clearcoat overlaid. Here, the first or the second water-based paint from an inventive Waterborne basecoat can be produced. However, both can Water-based paints from one and the same, according to the invention Waterborne basecoat or from two different materials according to the invention Waterborne basecoats are produced.

All surfaces that need to be painted come through as substrates of the layers thereon using heat or combined application of heat and actinic radiation (dual cure) is not be harmed. Suitable substrates are e.g. B. from metals, Plastics, wood, ceramics, stone, textile, fiber composite, leather, glass, Glass fibers, glass and rock wool, mineral and resin-bound building materials, such as Gypsum and cement boards or roof tiles, as well as composites of these materials.

Accordingly, the multicoat paint systems of the invention are also suitable for Applications outside of automotive OEM painting and Suitable for car refinishing. Here they come especially for the Painting of furniture, for industrial painting, including coil coating and Container coating, and the painting of white goods, including radiators, Boilers or refrigerator or washing machine panels. As part of industrial painting, they are suitable for painting practically all parts for private or industrial use, such as Household appliances or small parts made of metal, such as screws and nuts, Hubcaps or rims.

In the case of electrically conductive substrates, primers can be used which are produced in the usual and known manner from electrocoat materials (ETL) become. Both anodic (ATL) and cathodic (KTL) Electrodeposition paints, but especially KTL, into consideration. Usually, especially in automotive painting, followed by a filler paint or Stone chip protection primer applied as part of the primer is seen. Electrodeposition paints and fillers can also be applied wet-on-wet and thermally hardened together.

Primed or unprimed plastic parts can also be used, if under the applied thermal curing conditions are dimensionally stable. In the case of non-functionalized and / or non-polar Substrate surfaces can be coated in a known manner before coating Pretreatment, such as with a plasma or with flame, subjected to or with be provided with a hydro primer.

The application of the waterborne basecoats according to the invention can be done by all usual application methods, such as. B. spraying, knife coating, brushing, pouring, Dipping, watering, trickling or rolling. This can be too resting substrate as such, the application device or system is moved. However, the substrate to be coated, in particular a coil, are moved, the application system relative to the Substrate rests or is moved in a suitable manner. Contain the Waterborne basecoat components according to the invention, which contain actinic radiation can be activated, the application is preferably in the absence of light carried out.

Generally, the filler coat, waterborne paint coat and Clear coat applied in a wet coat thickness that after it has hardened Layers with the necessary and advantageous layer thicknesses for their functions result. In the case of the filler layer, this layer thickness is 10 to 150, preferably 10 to 120, particularly preferably 10 to 100 and in particular 10 to 90 microns, in the case of the basecoat it is 5 to 50, preferably 5 to 40, particularly preferably 5 to 30 and in particular 10 to 25 microns, and in the case the clearcoats, it is 10 to 100, preferably 15 to 80, particularly preferably 20 to 70 and in particular 25 to 60 microns. But it can also be done the European patent application EP 0 817 614 A1 known Multi-layer construction from an electro-dip coating, a first Basecoat, a second basecoat and a clear coat are applied, wherein the total layer thickness of the first and second Basecoat is 15 to 40 µm and the layer thickness of the first Base coat is 20 to 50% of said total layer thickness.

The waterborne basecoat becomes thermal or thermal and with actinic Radiation (dual cure) hardened.

Curing can take place after a certain period of rest. It can last from 30 s to 2 h, preferably 1 min to 1 h and in particular 1 min to 45 min to have. The rest period is used, for example, for the course and for degassing the Layers of paint or to evaporate volatile components such as solvents. The rest period can be increased by using elevated temperatures up to 90 ° C and / or by a reduced air humidity <10 g water / kg air, in particular <5 g / kg air, are supported and / or shortened, if none Damage or changes to the paint layers occur, for example one early, complete networking.

The thermal hardening has no special features in terms of method, but rather takes place according to the usual and known methods, such as heating in one Fan oven or irradiation with IR lamps. Here, the thermal hardening also take place gradually.

Thermal crosslinking at temperatures above 100 ° C. is preferred be performed. In general, it is advisable to use temperatures of Not to exceed 180 ° C., preferably 160 ° C. and in particular 155 ° C.

The curing with actinic radiation is preferably carried out with UV radiation and / or electron beams. A dose of 1,000 to 3,000, preferably 1,100 to 2,900, particularly preferably 1,200 to 2,800, very particularly preferably 1,300 to 2,700 and in particular 1,400 to 2,600 mJ / cm ² is preferably used here. If necessary, this hardening can be 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 layers. In the case of curing with UV radiation, too, it is possible to work under inert gas in order to avoid the formation of ozone.

For curing with actinic radiation, the usual and known Radiation sources and optical auxiliary measures applied. Examples of suitable ones Radiation sources are flash lamps from VISIT, high or low mercury low-pressure vapor lamps, which are optionally doped with lead, around a Open beam window up to 405 nm, or electron beam sources. their Arrangement is known in principle and can take into account the conditions of the workpiece and the process parameters are adjusted. For complicated shaped Workpieces, such as those intended for automobile bodies, cannot Areas accessible to direct radiation (shadow areas), such as cavities, Folds and other, design-related undercuts with point, Small area or all-round spotlights combined with an automatic Movement device for the irradiation of cavities or edges (partial) be cured.

The facilities and conditions of these hardening methods are, for example in R. Holmes, U. V. and E. B. Curing Formulations for Printing Inks, Coatings and Paints, SITA Technology, Academic Press, London, United Kingdom 1984, described.

The curing can take place in stages, i. H. through multiple Exposure or exposure to actinic radiation. This can also be the case alternate, d. that is, alternating with UV radiation and Electron radiation is cured.

Thermal curing and curing are combined with actinic radiation applied, these methods can be used simultaneously or alternately become. If the two hardening methods are used alternately, can for example, started with thermal hardening and with hardening actinic radiation. In other cases it can turn out to be prove advantageous to start curing with actinic radiation and to end here. Special advantages result when the Waterborne basecoat in two separate steps first with actinic radiation and then thermally cured.

In the coating process according to the invention, the Application and curing processes described above also for Manufacture of filler paints, solid-color top coats and clear coats be applied.

The single-coat and multi-coat coatings according to the invention have excellent properties optical, mechanical and chemical properties. So they are free from any surface defects, such as shrinking. They also point out a particularly high opacity and excellent, optical effects, in particular Metallic effects, on.

In particular, is due to the multi-layer coatings according to the invention their excellent wet adhesion properties no delamination of the Observe layers during high-pressure steam cleaning.

In addition, the coatings according to the invention offer further advantages. They are an effective physical barrier against the diffusion of Plasticizers, adhesives, antioxidants or solvents and of high Heat resistance. They have good anti-static properties and one significantly improved corrosion protection effect and significantly improved Wetting properties.

Examples Production Example 1 The production of a polyurethane-methacrylate graft copolymer (A)

First, a polyester diol was made from 40.7 parts by weight of a dimer fatty acid (Pripol® 1013), 22.4 parts by weight of 1,6-hexanediol and 12 parts by weight Isophthalic acid in 24 parts by weight of methyl ethyl ketone and 0.8 parts by weight Cyclohexane produced as an entrainer.

Furthermore, a polyurethane made of 2.42 parts by weight Dimethylolpropionic acid, 23.3 parts by weight of the polyester diol solution, 1.23 Parts by weight of trimethylolpropane monoallyl ether and 9.43 parts by weight Isophorone diisocyanate in the presence of 3 parts by weight of N-methylpyrrolidone, and 2.7 parts by weight of methyl ethyl ketone and 0.86 parts by weight Chain extender diethanolamine. After neutralizing the polyurethane with 0.1 Parts by weight of triethylamine were deionized in 52 parts by weight, with 3.9 Parts by weight of wetting agent solution dispersed in water.

50 parts by weight of the resulting polyurethane dispersion, 3.9 parts by weight a wetting agent solution and 28.3 parts by weight of deionized water were used as Template for the copolymerization of a monomer mixture from 3.745 Parts by weight of n-butyl acrylate, 5 parts by weight of methyl methacrylate, 3.745 Parts by weight of hydroxyethyl methacrylate and 5 parts by weight of styrene are used. 0.263 parts by weight of tert-butyl peroxy-2-ethylhexanoate were used as initiator used.

The resulting polyurethane-methacrylate graft copolymer (A) became Production of the invention and the non-invention Waterborne basecoats used.

Examples 1 to 3 and comparative tests V1 and V2 The production of waterborne basecoats and inventive multi-layer paint systems (Examples 1 to 3) and water-based paints not according to the invention and not inventive multi-layer paint systems (Comparative tests V1 and V2)

For example 1, a yellow, for example 2 a red, for example 3 a white, for comparative test V1 a red and for comparative test V2 a yellow waterborne basecoat was prepared by mixing the components listed in Table 1. The fillers and pigments were mixed in the form of aqueous pastes containing the polyurethane-methacrylate copolymer graft copolymer (A) from preparation example 1. The amounts of polyurethane-methacrylate copolymer graft copolymer (A) present in the pastes were included in the binder contents. Table 1 The material composition of the water-based lacquers according to the invention (examples 1 to 3) and of the water-based lacquers not according to the invention (comparative experiments V1 and V2)



a) melamine-formaldehyde resin b1) from Cytec Specialty Resins AS;
b) melamine-formaldehyde resin b2) from Cytec Specialty Resins AS;
c) Catalyst: blocked p-toluenesulfonic acid from King Industries;
d) associative thickener based on polyurethane; Serad® FX 1010 from Servo Delden BV;
e) commercially available, pyrogenic silicon dioxide;
f) wetting agent solution: tetramethyldecindiol, 52% by weight in butylglycol;
g) poly (oxypropylene) glycol from BASF Aktiengesellschaft;
h) commercial carbon black pigment;
i) titanium dioxide pigment;
j) iron oxide pigment from Bayer AG.

For testing the application properties of waterborne basecoats Table 1 were test tables in the usual and known manner Dimensions 10 × 20 cm. Steel panels were used for this (Body panels), with a usual and known, cathodic deposited and baked electro dip coating (KTL) coated with a commercially available thin film filler (Ecoprime® 60 from the company BASF Coatings AG) coated, after which the resulting filler layer during vented for five minutes at 20 ° C and a relative humidity of 65% and was dried in a forced air oven at 80 ° C for five minutes. hereafter the filler layer had a dry layer thickness of 15 µm.

After the test panels had cooled to 20 ° C., the waterborne basecoats of the Table 1 applied for five minutes at 20 ° C and a relative Humidity of 65% is vented and in a forced air oven for five minutes dried at 80 ° C, so that the dried basecoat layers a Had dry layer thickness of about 15 microns.

After the test panels had cooled again to 20 ° C., the Waterborne basecoats with a powder slurry clearcoat according to the international patent application WO 96/32452 overlaid. The resulting Powder slurry clearcoat layers were at 3 ° C for 3 minutes and one Relative humidity of 65% and vented in a forced air oven during dried at 55 ° C for five minutes. The dry film thickness of the resulting Clear lacquer layers were 55 to 57 µm.

After applying all three layers, they were together during Baked for 30 minutes at 135 ° C, whereby the inventive Multi-layer coatings of Examples 1 to 3 and those not according to the invention the comparison tests V1 and V2 resulted.

The resulting test panels are referred to below as "original panels". Before testing and applying the refinish, they were for 24 hours in a climate room at 23 ° C and a relative humidity stored by 50%.

Part of the original panels were repainted with a first refinish Provided with ISO 1520. These panels are referred to below as "1st repair panels" designated.

Part of these 1st repair panels were made according to ISO 1520 with a second one Provide repair paint. These boards are referred to as "2.- Repair boards ".

For testing the adhesion of the waterborne basecoats in Table 1 water-based paints produced on glass, the water-based paints were applied Glass plates applied and baked at 140 ° C for 30 minutes, so that Water-based paints with a layer thickness of 30 µm resulted. On the Waterborne basecoats were given water drops and for one hour let act. The adhesion of the waterborne basecoats was assessed the areas wetted with water drops compared to the adhesion to the non wetted places.

The original panels, the 1st repair panels and the 2nd repair panels were directly and after different pretreatment of the cross cut test Subject to ISO 2409: 1994-10.

Furthermore, the original panels and the 2nd repair panels were the Stone chip test subjected to VCKN4441 by NedCar. This stone chip test is in generally known to experts.

The results of these tests can be found in Table 2. They underpin the superior wet adhesion and stone chip resistance of the multi-layer coatings according to the invention produced from the waterborne basecoats of Examples 1 to 3 according to the invention. This superiority is unexpected insofar as the water-based lacquers of the multi-layer lacquers V1 and V2 not according to the invention had a higher crosslinking density because of their significantly higher proportion of crosslinking agents (B). TABLE 2 The adhesive strength of the inventive (Examples 1 to 3) and the non-inventive (comparative tests V1 and V2) multi-layer coatings

Claims (14)

1. Aqueous, color and / or effect coating material, containing: A) at least one anionically stabilized polyurethane (meth) acrylate graft copolymer as binder, B) as a crosslinking agent 1. at least one water-soluble melamine-formaldehyde resin which can be catalyzed with weak, organic and / or inorganic acids and which has a medium to high degree of alkylation and a medium to high imino functionality, and 2. at least one water-insoluble melamine-formaldehyde resin which can be catalyzed with strong, organic and / or inorganic acids and which has a high degree of alkylation and a low imino functionality, C) at least one organic and / or inorganic acid as a catalyst and D) at least one pigment and optionally containing E) at least one constituent different from the binders (A) and reactive with the melamine-formaldehyde resins, characterized in that the coating material contains the crosslinking agents (B) in an amount of 10 to 20% by weight, based on the amount of crosslinking agent (B) and binder (A) and any constituent (E) present. 2. Coating material according to claim 1, characterized in that it is the Crosslinking agent (B) in an amount of 14 to 19 wt .-%, based on the amount of crosslinking agent (B) and binder (A) and optionally present component (E). 3. Coating material according to claim 1 or 2, characterized in that the melamine-formaldehyde resins in the weight ratio of b1): b2) = 1.1: 1 to 2: 1. 4. Coating material according to one of claims 1 to 3, characterized characterized in that the pigment-binder ratio is 0.1: 1 to 2: 1 lies. 5. Coating material according to one of claims 1 to 4, characterized characterized in that, based on its total quantity, it has a Has solids content of 20 to 60 wt .-%. 6. Coating material according to one of claims 1 to 5, characterized characterized in that, based on its solid, it is 35 to 70% by weight of the binder (A) contains. 7. Coating material according to one of claims 1 to 6, characterized characterized in that, based on its solid, it is 5 to 15% by weight contains the crosslinking agent (B). 8. Coating material according to one of claims 1 to 7, characterized characterized in that it, based on its solid, 0.1 to 3 wt .-% of the catalyst (C) contains. 9. Coating material according to one of claims 1 to 8, characterized characterized in that it can be activated with actinic radiation (F) contains for crosslinking with actinic radiation. 10. Use of the aqueous coating material according to one of the Claims 1 to 9 for the production of single-layer or multi-layer, color and / or effect paint finishes for automotive first and - repair painting, industrial painting, including coil coating and Container coating, plastic painting, furniture painting and the Painting of white goods. 11. Use according to claim 10, characterized in that the aqueous Coating material as a water-based lacquer and solid-color topcoat in the Automotive initial and repair painting is used. 12. Process for producing a single or multi-layer, color and / or effect painting by applying at least one layer of Coating material according to one of claims 1 to 9 primed or unprimed substrate and thermal curing or Curing with heat and actinic radiation of the resulting Wet layer (s). 13. Process for producing a color and / or effect multi-layer coating by the wet-on-wet process by: A) application of a waterborne basecoat to a primed or unprimed substrate; B) flashing off and / or intermediate drying of the water-based lacquer layer; C) application of a clear lacquer layer on the water-based lacquer layer, and D) thermal curing or curing with heat and actinic radiation of the two wet layers, characterized in that the water-based lacquer layer is produced from the coating material according to one of claims 1 to 9. 14. Process for producing a color and / or effect multi-layer coating by the wet-on-wet method by: A) application of a first water-based lacquer layer to an electrodeposition lacquer layer which is on a substrate and is not or only partially cross-linked; B) thermal curing of the electrocoat layer and the first water-based lacquer layer; C) application of a second water-based lacquer layer; D) flashing off and / or intermediate drying of the second water-based lacquer layer; E) application of a clear lacquer layer on the second water-based lacquer layer, and F) thermal curing or curing with heat and actinic radiation of the two wet layers, characterized in that the first and / or second water-based lacquer layer is produced from the coating material according to one of claims 1 to 9.