DE19837063A1 - Use of aqueous dispersion of polyol comprising graft polyester polyacrylate copolymer and blocked aliphatic polyisocyanate in automotive series lacquering, especially stone chip barrier coat - Google Patents

Abstract

The use of an aqueous dispersion of a polyol component, comprising 20-60 wt.% unsaturated polyester polyol and 40-80 wt.% polyacrylate, and 1-70 wt.% (with respect to total solids) of a blocked aliphatic polyisocyanate component for light-stable, elastic, physically fast-drying coatings in series lacquering of cars is claimed. The use of an aqueous dispersion of (A) a polyol component and (B) a polyisocyanate component for light-stable, elastic, physically fast-drying coatings in series lacquering of cars is claimed. The polyol component comprises 20-60 wt.% polyester component (AI) with 10-60 wt.% units derived from 8-30 carbon (C) aliphatic (un)saturated monocarboxylic acid(s) and 0.4-5 wt.% units derived from 3-8 C alpha , beta -unsaturated mono- or dicarboxylic acid(s) or anhydride(s) capable of free radical polymerization and 40-80 wt.% polyacrylate component (AII). The polyisocyanate component (B) comprises blocked aliphatic polyisocyanate(s) and is used in an amount of 1-70 wt.% with respect to total solids in the dispersion.

Description

The invention relates to the use of an aqueous binder combination for Production of a physically fast drying and at the same time stone chip resistant and weather-resistant coating, preferably in automotive OEM coatings tion.

The automotive serial painting has a multi-layer structure on the deck layers established, increasingly by aqueous coating medium is realized. With such modern coatings, For economic efficiency. The goal is to coat in as much as possible to apply few and as inexpensive individual steps as possible.

In the usual paint build-up in the original car painting, cathodic paint is used Electrocoating (KTL) primed metal surface first a stone chip protective layer and a filler layer or a combination of both ("rockfall protective filler "). A pigmented basecoat is then applied to these layers, then a clear coat or alternatively a pigmented top coat is applied.

The stone chip protection and / or filler layer compensates for unevenness surface and causes high elasticity and deformability good resistance to stone chips. So far for this layer soft polyester or polyether polyurethanes as well as polyisocyanate or melamine crosslinker used. Before applying basecoat and clearcoat or topcoat the rockfall protection filler branded. This is necessary to get the topcoat level improve and remove the filler layer before applying the upper layers of paint grind. After the clearcoat or topcoat has been applied, it is then applied again burns. The disadvantage of this method is that two expensive baking processes are necessary. Physically, i.e. H. without stoving, quick-drying paints, how they can be formulated from polyacrylates, for example, does not show  required stone chip resistance, since they form brittle films during the baking process network.

The object of the present invention was to find a storage-stable binder which In addition to good stone chip resistance, it ensures rapid physical drying accomplishes. In addition, the binder should be lightfast to cover moderately even in the event the topcoats or basecoats or in places where there is a pigmentation Topcoat or basecoat is dispensed with, a weather-resistant coating produce. Accordingly, what was sought was an aqueous coating agent which was the essential properties of a stone chip protection filler and a top coat binder in unites and also dries physically quickly.

A proposed solution for stone chip-resistant coatings and / or filler layers The basis of aqueous binders is e.g. B. described in EP-A 330139. It is bean says that an OH- and COOH-functional polyester added a polyacrylate can be mixed. Corresponding exemplary embodiments are not described. A graft copolymerization of the polyacrylate onto a polyester as a graft base is not described. The claimed dispersions of acid-functional polyester are known to be poorly stable in storage because they undergo rapid chemical degradation by cleavage of ester bonds (e.g. Jones, T.E .; McCarthy, J.M., J. Coatings Technol. 76 (844), p. 57 (1995)).

It has now surprisingly been found that this problem can be solved by Use of a combination of special aqueous polyols and blocked Polyisocyanates. The polyol dispersions used according to the invention are thereby characterized in that they consist of graft copolymers based on polyester-polyacrylate exist, as the polyester component certain long-chain aliphatic mono carboxylic acids and polyesters containing a, b-unsaturated carboxylic acids are used become. The suitability of the polyol dispersions used according to the invention is therefore furthermore surprisingly, since polyols which contain a high proportion of polyacrylate at 1 stove enamels such as z. B. used for automotive fillers, so far not the high demands on z. B. meet elasticity and stone chip resistance.  

The invention accordingly relates to the use of an aqueous dispersion

• A) from a polyol component
  20 to 60, preferably 40 to 55% by weight of a polyester component AI), characterized in that AI) contains 10 to 60% by weight of units which are derived from one or more aliphatic, saturated or unsaturated monocarboxylic acids with 8 to 30 Derive carbon atoms and contains 0.4 to 5% units, which are derived from one or more, radically polymerized, a, b-unsaturated mono- or dicarboxylic acids with 3 to 8 carbon atoms or their anhydrides and
  40 to 80% of a polyacrylate component AII)
  such as
• B) a polyisocyanate component
  consisting of one or more blocked, preferably non-hydrophilized, aliphatic polyisocyanates, with component B) being present in parts by weight, based on the total solids content of the dispersion, of 1 to 70, preferably 20 to 50%,

for light-stable, elastic and physically fast drying coatings in the Automobile series painting.

An aqueous dispersion is preferably used for the use according to the invention

• A) a polyol component
  from 20 to 60% of a polyester component AI) with a molecular weight of 500 to 6000, an acid number <12 KOH / g and an OH number of 50 to 250 mg KOH / g, characterized in that AI) is obtainable by reaction of
  • 1. AI ₁₎ 10 to 60% of one or more aliphatic, saturated or unsaturated monocarboxylic acids with 8 to 30 carbon atoms
  • 2. AI ₂₎ 0.4 to 5% of an a, b-unsaturated mono- or dicarboxylic acid with 3 to 8 carbon atoms or their anhydrides
  • 3. AI ₃₎ 20 to 60% of one or more aliphatic, cycloaliphatic or aromatic di-, tri- or tetracarboxylic acids with 2 to 20 carbon atoms or their anhydrides
  • 4. AI ₄₎ 10 to 60% of one or more aliphatic alcohols with 1 to 4 OH groups per molecule
  • 5. AI ₅₎ 0 to 10% of an aromatic monocarboxylic acid
  • 6. AI ₆₎ 0 to 10% further acid or OH-reactive compounds such. B. epoxides, isocyanates or oxazolines with 1 to 4, preferably 1.9 to 2.5 functional groups per molecule
  and 40 to 80% of a polyacrylate component AII) obtainable by radical polymerization of a mixture of
  • 1. AII ₁₎ 20 to 70% of one or more non-functional esters of a, b unsaturated carboxylic acids with 3 to 12 carbon atoms and aliphatic or cycloaliphatic monoalcohols with 1 to 18 carbon atoms
  • 2. AII ₂₎ 1 to 10% of one or more a, b-unsaturated carboxylic acids with 3 to 12 carbon atoms or their anhydrides
  • 3. AII ₃₎ 0 to 95% of one or more hydroxy-functional, free-radically polymerizable monomers
  • 4. AII ₄₎ 0 to 20% of further free-radically polymerizable monomers
  in the presence of the polyester component AI) where it applies that the information given under AI and AII are based on weight and add up to 100% and
• B) a polyisocyanate component
  consisting of a blocked, non-hydrophilized aliphatic poly isocyanate, it being the case that component B) is present in parts by weight, based on the total solids content of the dispersion, of 1 to 70%.

To produce the polyol component A) used in accordance with the invention proceeded that first the polyester component AI) by conventional methods is synthesized. The production of polyesters AI) is known (see below).

As component AI ₁₎ , the polyester component of the polyol dispersion according to the invention contains one or more aliphatic monocarboxylic acids having 8 to 30 carbon atoms. Examples of saturated monocarboxylic acids with 8 to 30 carbon atoms are 2-ethylhexanoic acid, octanoic acid (caprylic acid), decanoic acid (capric acid), dodecanoic acid (lauric acid), hexadecanoic acid (cetylic acid) or octadecanoic acid (stearic acid). Also suitable are aliphatic, mono- or polyunsaturated monocarboxylic acids with 8 to 30 carbon atoms such as. As oleic acid, linoleic acid or linolenic acid. Mixtures of monocarboxylic acids such as those formed during the saponification of natural oils and fats are preferably used. Examples of such fatty acids are soybean oil fatty acid, tall oil fatty acid, linseed oil fatty acid, castor oil fatty acid, coconut oil fatty acid, peanut oil fatty acid or safflower oil fatty acid. Further suitable examples of monocarboxylic acids with 8 to 30 carbon atoms are hydrogenated fatty acids, synthetic fatty acids e.g. B. from paraffin oxidation or Koch synthesis (J. Falbe, New Syntheses with Carbon Monoxide, Berlin, Heidelberg, New York (1980)).

Further building blocks of the polyesters used according to the invention are a, b-unsaturated mono- or dicarboxylic acids having 3 to 8 carbon atoms Al ₂₎ . Examples of such carboxylic acids are acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid or tetrahydrophthalic acid. Instead of the free carboxylic acids, derivatives of carboxylic acids such as. B. anhydrides or esters can be used as starting material for the polyester production.

Examples of aliphatic, cycloaliphatic or aromatic di-, tri- or tetracar bonic acids with 2 to 20 carbon atoms AI ₃₎ are phthalic acid, isophthalic acid or terephthalic acid and pyromellitic acid, trimellitic acid and succinic acid, adipic acid, sebacic acid, azelaic acid. Dimer fatty acids made from natural or synthetic fatty acids are also suitable. Instead of the free carboxylic acids, derivatives of carboxylic acids such as. B. anhydrides or esters can be used as starting material for polyester production.

As OH components AI ₄₎ with 1 to 4 OH groups per molecule z. B. aliphatic monoalcohols such as butanol, pentanol or 2-ethylhexanol can be used. "Fatty alcohols", such as those formed in the reduction of fatty acids, are also suitable. Examples of alcohol components with 2 OH groups are ethylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, trimethylpentanediol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, tripropylene glycol or hydrogenated bisphenol. Preferred OH components AI _{4) are} trihydric and higher alcohol components, optionally in combination with dibasic alcohols. Examples include pentaerythritol, glycerol or trimethylolpropane.

As monocarboxylic acids AI ₅₎ z. B. benzoic acid or alkylbenzoic acids.

The polyester component AI) is usually prepared by polycondensation as in the literature (R. Dhein, K. Reuter, G. Ruf in "Houben-Weyl, Metho den der Organischen Chemie Bd E20 / 2", ed .: H. Bartl , J. Falbe, 4th edition pp. 1429-1435, Stuttgart, New York (1987)). However, it is also possible, additional Lich with other compounds AI ₆₎ , for. B. OH-reactive compounds such as poly isocyanates or COOH-reactive compounds such as epoxy, amino or oxazole-containing substances and thus incorporate urethane or amide groups in the polyester. Suitable polyisocyanates are aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, methylene bis (4-isocyanatocyclohexane), tetramethylxylylene diisocyanate or modified aliphatic types such as polyisocyanates containing isocyanurate, uretdione or biuret groups. Suitable epoxides are e.g. B. epoxy resins based on bisphenol A diglycyidyl ether or Cardura® E10 (Shell).

The polyacrylate component AII) is used for the use according to the invention a radical polymerization in the presence of the polyester component AI) Herge poses. In addition to component AI), organic solvents can also be used during the Polymerization will be present. Organic solvents are those for manufacturers development of polyacrylate resins customary and for the production of aqueous dispersion a suitable solvent. As an example of suitable solvents called: alkylbenzenes such as toluene, xylene or ethylbenzene, alcohols such as n-butanol, isopropanol, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, tri propylene glycol, 3-methyl-3-methoxybutanol or 1-methoxypropylacetate-2, Dipropylene glycol dimethyl ether. Acetone, butanone, ethanol, Propanol or hexane. The solvents used can be before, during or after the dispersion step in whole or in part, optionally azeotropically and / or by Applying a vacuum or an increased inert gas stream from the reaction mixture can be removed.  

In the radical polymerization z. B. How to proceed: The components AII ₁₎ to AII ₄₎ are added separately or together or also partially mixed at a suitable temperature to component AI) and, if appropriate, a solvent and polymerized there in the presence of a polymerization initiator. Compounds known per se are used as the polymerization initiator. For example, peroxides such as dibenzoyl peroxide, di-t-butyl peroxide or t-butylper 2-ethylhexanoate or azo initiators such as azo-bis-isobutyronitrile or azo-bis-isovaleronitrile are suitable. It is also possible to carry out the polymerization in the presence of regulators. Such compounds which reduce the molecular weight of the polymers by radical transfer are also known. Examples include n-dodecyl mercaptan or mercaptoacetic acid.

One or more monomers can be quick to achieve special properties It is slower, starts earlier and / or ends later than the other monomers be added.

Any copolymerizable (cyclo) alkyl ester of (meth) acrylic acid having 1 to 20 carbon atoms in the cycloalkyl radical or a mixture of such (meth) acrylic acid esters can be used as component AII ₁₎ . Particularly suitable are alkyl acrylates or methacrylates having 1 to 18 carbon atoms in the alkyl radical. Examples include his: methyl, ethyl, n-propyl, n-butyl, i-butyl, n-hexyl, 2-ethylhexyl, n-stearyl and n-lauryl acrylate and methacrylate as well as cycloali phatic (meth) acrylic acid esters such as cyclohexyl (meth) acrylate or nor bornyl (meth) acrylate. Esters of maleic or fumaric acid such as. B. maleic acid or fumaric acid dimethyl or diethyl ester.

Examples of suitable a, b-unsaturated carboxylic acids AII ₂₎ are e.g. As acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid or tetrahydrophthalic acid. Instead of the free carboxylic acids, their anhydrides can also be used as the starting substance.

Suitable hydroxy-functional monomers AII ₃₎ are preferably all hydroxyalkyl or hydroxycycloalkyl esters of the acids mentioned under AII ₂₎ . These hydroxy-functional esters are particularly preferably obtained by reacting the (meth) acrylic acid with an alkylene oxide or an aliphatic diol. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate or the reaction products of (meth) acrylic acid with monoepoxides such as. B. Cardura® E10 (Shell). The esters of (meth) acrylic acid and oligomeric or polymeric ethylene or propylene glycols are also suitable. Also suitable, but less preferred, are radical-polymerizable monomers containing OH groups and containing no structures derived from a, b-unsaturated carboxylic acids.

Examples of further radically polymerizable monomers AII ₄₎ are e.g. B. vinyl aromatic compounds such as styrene or a-methyl styrene, vinyl esters of carboxylic acids with 1 to 20 carbon atoms such as versatic acid, propionic acid or acetic acid, vinyl ether, vinyl pyrrolidone or compounds with two or more radically polymerizable double bonds such as. B. butanediol di (meth) acrylate, hexanediol di (meth) acrylate, divinylbenzene or polybutadiene.

To produce a polyol dispersion used according to the invention then the acid groups of the polyester-polyacrylate graft copolymer into the Salt form transferred. This is preferably done by reaction with an amine. Tertiary amines such as triethylamine, N, N-dimethylethanolamine are particularly preferred or N, N-dimethylisopropanolamine. Neutralization with z. B. Metal hydroxides such as potassium, sodium or lithium hydroxide or with primary or secondary amines and ammonia.

The hydrophilized resin is subsequently converted into an aqueous dispersion water is added to the resin with vigorous stirring. However, one can also ver drive that water submitted and metered the hydrophilized resin with stirring becomes. A less preferred method is to neutralize the Dissolve dispersing water and add the non-hydrophilized resin with stirring  or to submit the non-hydrophilized resin and stirring the solution of the new Add tralisationsamins in water.

The polyol dispersion prepared in this way can then together with crosslinker components to be formulated into a varnish. As a crosslinker component are before blocked blocked polyisocyanates used. To incorporate the blocked poly Isocyanate in the aqueous paint can be used so that a hydrophilizing blocked polyisocyanate is added to the polyol dispersion. A special one preferred method is to block one or more non-hydrophilized Mix polyisocyanates with the polyester polyacrylate resin before neutralization and to disperse this resin mixture together as described.

Examples of suitable poly on which the blocked polyisocyanates are based Isocyanates are cycloaliphatic or aliphatic polyisocyanates such as tetramethylene diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate, hexamethylene diisocyanate (HDI), 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), methylene bis (4-isocyanatocyclohexane), tetramethylxylylene diisocyanate (TMXDI). Polyisocyanates containing heteroatoms in which the Contain the rest containing isocyanate groups. Examples include carbodiimide groups, allophanate groups, isocyanurate groups, urethane groups and biuret group-containing polyisocyanates. Are particularly well suited for the invention the well-known polyisocyanates, which are mainly used in the manufacture of paints be set, e.g. B. Biuret isocyanurate or uretdione groups Modifi Ornamental products of the above simple polyisocyanates, especially the Hexamethylene diisocyanate or isophorone diisocyanate. Are also suitable low molecular weight polyisocyanates containing urethane groups, such as those obtained by reaction generation of excess IPDI or TDI with simple multi-valued ones Alcohols in the molecular weight range 62 to 300, especially with trimethy lolpropane or glycerin can be obtained. Of course you can too any mixtures of the polyisocyanates mentioned for the preparation of the Invention appropriate products are used.  

Suitable polyisocyanates are also the known terminal isocyanate groups having prepolymers, as they are in particular by implementing the above simple polyisocyanates, especially diisocyanates, with insufficient amounts of organic compounds with at least two isocyanate-reactive gene functional groups are accessible. Ent in these known prepolymers speaks the ratio of isocyanate groups to water reactive towards NCO Substance atoms 1.05: 1 to 10: 1, preferably 1.1: 1 to 3: 1, where the hydrogen atoms preferably come from hydroxyl groups. The type and proportions the starting materials used in the production of NCO prepolymers are preferably chosen so that the NCO prepolymers preferred have an average NCO functionality of 2 to 3 and a number average of the moles have mass from 500 to 10,000, preferably 800 to 4000.

The isocyanate groups of the polyisocyanates are completely blocked. As a blockage Conventional compounds can be used, for example be used in the paint sector. Examples of suitable blocking agents are Malonic acid dimethyl ester, malonic acid diethyl ester, acetoacetic acid ethyl ester, e-Capro lactam, acetanilide, secondary aliphatic amines and / or acetone oxime. Prefers butanone oxime, 3,5-dimethylpyrrazole or triazole are used.

The blocking of the polyisocyanates can e.g. B. by heating one or more Polyisocyanates with the blocking agent. For example, a or submitted several polyisocyanates and heated with stirring, for. B. about 80 ° C, and the blocking agent (for example, for about 10 min.) Metered become. The mixture is stirred until free isocyanate can no longer be detected. It it is also possible to use one or more polyisocyanates with a mixture of two or to block several blocking agents.

The blocked polyisocyanates described are preferably not hydrophilic put and the transfer into the aqueous dispersion is by mixing and dispersed together with the polyol resin melt. However, it is also possible to disperse the polyol alone and a solution to the aqueous phase  or to add a dispersion of a hydrophilized blocked polyisocyanate. Hydro Philated blocked polyisocyanates are known and z. B. described in EP-A 566 953.

The aqueous binders used according to the invention can be combined with other binders be combined. The combination with water-soluble or is preferred water-insoluble melamine resins and water-emulsifiable or water-dispersing possible polyester resins or polyester-polyurethane resins.

Customary additives (e.g. pigments, fillers, auxiliaries and Additives) are added, as are common in the paint sector. The amounts are in the usual range familiar to those skilled in the art.

The use according to the invention is the manufacture of physically lower Temperature-curable stoving lacquers, preferably used in automotive painting, particularly preferred for the production of rock-resistant barrier layers. For this you can NEN through the coating agents used for the invention Squeegee, dive, spray job such as compressed air or airless spraying, as well as by electrostatic application, for example high rotation bell application become. The dry film layer thickness can be, for example, 15 to 50 μm. It is advantageous that the binders of the invention initially at a low temperature maturity, e.g. B. dried at 80 ° C, whereupon the paint layer can be sanded. After painting with a basecoat / clearcoat or with a pigmented The topcoat then becomes the barrier layer together with clear in one baking process lacquer or top coat baked. This step is done e.g. B. by baking in 20 to 25 minutes at 135 to 145 ° C.

The coating produced in this way has optically and mechanically comparable results on like a lacquer structure, which instead of the aqueous barrier layer as usual set aqueous or solvent-based filler with e.g. B. 25 to 40 µm dry film Layer thickness with its own baking process, e.g. B. 20 to 25 minutes at 135 up to 165 ° C and in addition basecoat / clearcoat or topcoat.  

The coating agents used according to the invention have a very high storage stability act. The in aqueous polyester dispersions or solutions or polyester poly Urethane dispersions usually take place very quickly due to chemical degradation Cleavage of ester bonds in the polyester-polyacrylate according to the invention Dispersions not observed. At the same time, the from the invention Dispersions prepared paints for excellent stone chip resistance In the case of aqueous paints, only systems based on polyester or poly have so far been used urethane dispersions could be adjusted.

Examples example 1 Polyester resin

Into a 15 l reaction vessel with stirring, cooling and heating device as well as water 4041 g of peanut oil fatty acid, 4350 g of trimethylolpropane, 1131 g of tri ethylene glycol, 99 g maleic anhydride, 2035 g phthalic anhydride and 2008 g Weighed in adipic acid. Nitrogen is passed through the reaction mixture. The The batch is heated to 185 ° C. in 4 h. After 2 h at 185 ° C is then within heated to 220 ° C. for a further 2 h. At this temperature it becomes a strong stick material flow (approx. 30 l / h) through the batch until the acid number to 9 mg KOH / g fell. The OH number is 196 mg KOH / g.

Example 2 Polyester polyacrylate resin

In a 6 l four-necked flask with an internal thermometer, stirring device, dropping funnel, Gas inlet and reflux condenser are 500 g of the in a nitrogen atmosphere Polyester precursor from Example 1 and 33.4 g of butyl diglycol (diethylene glycol monobu tylether) submitted. A monomer mixture of 75 g of hydroxy is added to the dropping funnel ethyl methacrylate, 56 g butyl acrylate, 271 g methyl methacrylate and 50 g styrene prepared. At a temperature of 145 ° C half of the Monomer mixture added. In parallel, a solution of 10 g of di-t-butyl per oxide added in 40 g of butyl diglycol. Then the rest of the Monomermi 48 g of acrylic acid were added and mixed. The second mono made in this way The mixture is now metered in within 1.5 hours. In parallel, there will be a solution of 5 g of di-t-butyl peroxide in 20 g of butyl diglycol. Then becomes Reactivate a solution of 5 g di-t-butyl peroxide in 20 g butyl diglycol added.  

Example 3 Self-crosslinking polyester-polyacrylate dispersion

In a 4 l four-necked flask with internal thermometer, stirring device, gas inlet and reflux condenser are 600 g of polyester in a nitrogen atmosphere Polyacrylate precursor from Example 2 and 613 g Desmodur® BL 3175 (crosslinking Stoving urethane resin based on hexamethylene diisocyanate, 75% in solvent naphtha 100 dissolved) homogenized at 70 ° C. 61 g of N, N-dimethylethanolamine are added give and stir for 30 minutes. Then 1153 g of water are added. The Product is a milky aqueous dispersion with an average particle size of 213 nm (determined by laser correlation spectroscopy), a viscosity of 3574 mPa.s and a non-volatile content of 43.2%.

A film of self-crosslinking polyester-polyacrylate is placed on a glass plate. Dispersion applied with a wet film thickness of 210 microns and at 10 min Ambient temperature dried. Then it is forced for a further 30 min at 80 ° C dried.

After cooling to room temperature, the film is dry to pressure and easy to sand.

Claims (9)

1. Use of an aqueous dispersion

• A) a polyol component
  20 to 60 wt .-% of a polyester component AI), characterized in that AI) contains 10 to 60 wt .-% units which are derived from one or more aliphatic, saturated or unsaturated monocarboxylic acids with 8 to 30 carbon atoms and Contains 0.4 to 5% units derived from one or more, radically polymerized, a, b-unsaturated mono- or dicarboxylic acids with 3 to 8 carbon atoms or their anhydrides and
  40 to 80% of a polyacrylate component AII)
  such as
• B) a polyisocyanate component
  consisting of one or more blocked aliphatic poly isocyanates whereby component B) is present in parts by weight, based on the total solids content of the dispersion, of 1 to 70%

for light-stable, elastic and physically fast drying coatings in automotive OEM painting. 2. Use of an aqueous dispersion according to claim 1

• A) a polyol component
  from 20 to 60% of a polyester component AI) with a molecular weight of 500 to 6000, an acid number <12 KOH / g and an OH number of 50 to 250 mg KOHl g, characterized in that AI) is obtainable by reacting
  • 1. AI ₁₎ 10 to 60% of one or more aliphatic, saturated or unsaturated monocarboxylic acids having 8 to 30 carbon atoms
  • 2. AI ₂₎ 0.4 to 5% of an a, b-unsaturated mono- or dicarboxylic acid with 3 to 8 carbon atoms or their anhydrides
  • 3. AI ₃₎ 20 to 60% of one or more aliphatic, cycloaliphatic or aromatic di-, tri- or tetracarboxylic acids with 2 to 20 carbon atoms or their anhydrides
  • 4. AI ₄₎ 10 to 60% of one or more aliphatic alcohols with 1 to 4 OH groups per molecule
  • 5. AI ₅₎ 0 to 10% of an aromatic monocarboxylic acid
  • 6. AI ₆₎ 0 to 10% further acid or OH-reactive compounds such. B. epoxides, isocyanates or oxazolines with 1 to 4, preferably 1.9 to 2.5 functional groups per molecule
  and 40 to 80% of a polyacrylate component AI1) obtainable by radical polymerization of a mixture of
  • 1. AII ₁₎ 20 to 70% of one or more non-functional esters of a, b-unsaturated carboxylic acids with 3 to 12 carbon atoms and aliphatic or cycloaliphatic monoalcohols with 1 to 18 carbon atoms
  • 2. AII ₂₎ 1 to 10% of one or more a, b-unsaturated carboxylic acids with 3 to 12 carbon atoms or their anhydrides
  • 3. AII ₃₎ 0 to 95% of one or more hydroxy-functional, radically polymerizable monomers
  • 4. AII ₄₎ 0 to 20% of further free-radically polymerizable monomers in the presence of the polyester component AI) where it applies that the information given under AI and AII are based on weight and add up to 100%
    such as
• B) a polyisocyanate component
  consisting of a blocked, non-hydrophilized aliphatic polyisocyanate, it being the case that component B) in parts by weight, based on the total solids content of the dispersion. from 1 to 70% is present

for light-stable, elastic and physically fast drying coatings in automotive OEM painting. 3. Use of an aqueous dispersion according to claim 1, characterized records that the polyisocyanate component B) is a non-hydrophilized poly is isocyanate and is dispersed together with the polyol component A) for light-stable, elastic and physically fast drying coatings in automotive OEM painting. 4. Use of an aqueous dispersion according to claim 1, characterized in that the polyol component A) from 40 to 55% from the polyester com  component AI) with a molecular weight of 500 to 6000 is for light stable, elastic and physically fast drying coatings in the Automobile series painting. 5. Use of an aqueous dispersion according to claim 1, characterized in that the polyol component A) from 40 to 55% from the polyester com component AI) with a molecular weight of 1000 to 3000 exists for light stable, elastic and physically fast drying coatings in of automotive serial painting. 6. Use of an aqueous dispersion according to claim 1, characterized in that the polyester component AI) contains 30 to 50% building blocks of one or more aliphatic monocarboxylic acids AI ₁₎ with 8 to 30 C atoms for light-stable, elastic and physically fast-drying coatings in automotive OEM painting. 7. Use of an aqueous dispersion according to claim 1, characterized in that Al _{1) is} a mixture which is composed of 80 to 100% of aliphatic monocarboxylic acids having 12 to 20 carbon atoms and less than two double bonds per molecule for light-stable, elastic and physically quick-drying coatings in automotive OEM painting. 8. Use of an aqueous dispersion according to claim 1, characterized by polymerizing the polyacrylate component in two parts, the first part having an acid number of less than 10 mg KOH / g and the second part has an acid number of more than 20 mg KOH / g for lichtsta bile, elastic and physically fast drying coatings in the Automobile series painting. 9. Use of an aqueous dispersion according to claim 1 in combination with one or more water-dispersible melamine resins, hydrophilic ten polyisocyanates and polyester and / or polyester polyurethane resins  for light-stable, elastic and physically fast drying coatings in automotive OEM painting.