MXPA00011291A - High-solids binder compositions and their use - Google Patents

Abstract

The invention relates to a binder composition containing A) 50-90 parts by wt. of OH-functional graft copolymer resins prepared from a) 0.1 to 10 parts by wt. of polybutadiene, b) 5 to 60 parts by wt. of an unsaturated aromatic monomer ,c) 10 to 50 parts by wt. of a hydroxyalkyl ester of (meth)acrylic acid, d) 5 to 70 parts by wt. of a cycloaliphatic ester of (meth)acrylic acid, e) 5 to 50 parts by wt. of an aliphatic ester of (meth)acrylic acid, f) 0.1 to 5 parts by wt. of a mono-olifinically unsaturated mono- or dicarboxylic acid and/or maleic or fumaric acid half esters, B) 0.1 to 5 parts by wt. of a polyfunctional crosslinking agent.

Description

New solid-rich binder combinations and their use DESCRIPTION OF THE INVENTION The present invention relates to new combinations of polyolacrylate binders and crosslinkers, to a process for their preparation and to their use for the preparation of coatings.

New combinations of solid-rich binder are prepared by combining the binder components with constitutive OH functions of the invention with polyisocyanates, which can be hardened to valuable coatings. Together with outstanding film optics, as well as high resistance to solvents and chemicals, these coatings show very fast drying and chemical crosslinking at room temperature, as well as a good surface hardness.

The advantage of the polyacrylate resins rich in solids is in the reduction of the emission of organic compounds, preferably solvents, observed in the application of the varnish. To obtain these formulations of solids-rich varnishes, the corresponding low viscosity polyacrylate resins, that is to say of low molar mass, must be used.

It is known that for the preparation of low viscosity polymerisation the radical polymerization Ref: 125041 can be used (for example, in EP-A 408858, EP-A 398387, US-A-4,145,513). On the other hand, it is partially disadvantageous that the properties of the polymerizate are impaired by the use of considerable amounts of polymerization regulators, as well as by their resulting products. Especially, the thiols used as polymerization regulators may smell bad or even be toxic. In EP-A 225 808, EP-A 225 809 and EP-A 778 298, α-olefins such as 1-octene or 1-decene, which do not possess an unpleasant odor, are used as regulators. The 2K-PUR varnishes based on polyacrylate resin according to EP-A 225,809 and the aliphatic polyisocyanate varnishes, however, have a physical drying that is too slow to be used, for example for use in repair varnishes of automobiles and large vehicles. The drying of 2K-PUR varnishes according to EP-A 778,298 does not completely satisfy the current requirements in this respect either and is therefore in need of improvements.

EP-A 635,523 and EP-A 638,591 disclose solid-rich polyacrylate resins which are prepared by polymerizing substances and then diluted with a suitable solvent.

EP-A 635,523 describes the known effect in the solvent polymerization of the preparation of solid-rich polyacrylate resins distributed in a closely unimodal manner by the use of peroxides showing tertiary amyl groups, which are however transferred in the polymerization of substances. As expected, it was found that lower viscosity polyacrylate resins were prepared with peroxides showing tertiary amyl groups than with peroxides showing tertiary butyl groups. The advantages of this polymerization of substances against solvent polymerization are not, however, clearly recognizable, because the corresponding comparative tests are lacking. In practice, polymerization of substances used to have advantages compared to solvent polymerization in particular with regard to the elimination of the heat of reaction. The polyacrylate resins prepared in the examples show a solids content of 70% by weight, viscosities at 23 ° C between 2,790 and 9,130 mPa.s, which were therefore previously in the middle range instead of in the high range of solids and that no longer satisfy the current requirements of a varnish rich in solids.

EP-A 171,847 and EP-A 638,591 describe a solid-rich copolymer having a relatively low viscosity at high solids contents by the use of (meth) acrylate monomers with (cyclo) alkyl moieties with steric hindrance. The resistance to solvents and chemicals of said copolymer does not, however, fully meet the current requirements for a high strength varnish for automotive repair. In the preparation of the copolymer according to EP-A 638,591 by polymerization of substances, in all the cited examples, a monoepoxide (Cardura (R) E10) is presented as a reaction medium. This monoepoxide reacts during the polymerization with the (meth) acrylic acid administered and is therefore incorporated into the polyacrylate. By this reaction, secondarily bonded hydroxyl groups are formed, which are made available together with the primary hydroxyl groups (hydroxyethyl methacrylate) or secondary hydroxyl groups (hydroxypropyl methacrylate), introduced by hydroxyl functional monomers, for reaction with the polyisocyanate which serves as a crosslinking agent.

The secondary hydroxyl groups, however, have a significantly lower reactivity to the polyisocyanates than the primary hydroxyl groups. For this reason, 2K-PUR varnishes that harden at lower temperatures (repair varnish for cars and large vehicles, wood varnish) based on polyacrylate resins, mainly with secondary hydroxyl groups, reach a thickness of a few days after a few days. sufficient crosslinking and thus obtain a satisfactory resistance to solvents.

However, in the repair varnishing of automobiles and large vehicles it is absolutely necessary, together with a faster physical drying, also a rapid chemical crosslinking to enable a new use of the vehicle as quickly as possible.

Therefore, it is an object of the invention to provide new binder combinations based on copolymerized with functional hydroxyls and polyisocyanate (cyclo) aliphatic varnishes that provide high solids lacquers, which together with faster physical drying also show a rapid chemical crosslinking. In contrast to coatings with varnishes of the state of the art, with the new varnishes with high content of solids, valuable coatings can be obtained which show a remarkable resistance to solvents after a short hardening time, thus enabling rapid availability of use. of the vehicle, for example after repair.

Surprisingly it has now been found that varnishes based on binder combinations of special graft copolymers and polyisocyanates have a very high solids content in their ready-to-use state. These varnishes provide coatings that have a very fast physical drying at room temperature (23 ° C) and fast chemical crosslinking, that is, a remarkable resistance to solvents after 1 to 2 days. The very good general profile of properties of the varnish film obtained, such as hardness, elasticity, resistance to solvents, chemicals and at the same time, allows the use in the varnishing of vehicles, preferably in the repair varnish of automobiles and large vehicles. . Other fields of use are in the general fields of industrial varnishing, protection against corrosion, as well as wood and furniture varnishing, in which other crosslinking resins other than polyisocyanates can be used.

The object of the invention are binder combinations of A) from 90 to 50 parts by weight, preferably from 90 to 60 parts by weight, of functional OH graft copolymerized resins, prepared by copolymerization of a) from 0.1 to 10 parts by weight of at least one polybutadiene, optionally functional, with a molecular weight of 500 to 10,000 and at least 20% of 1,2-vinyl structure. b) from 5 to 60 parts by weight of at least one aromatic unsaturated monomer such as styrene, α-methylstyrene or vinyltoluene, c) from 10 to 50 parts by weight of at least one hydroxyalkyl ester of acrylic and / or methacrylic acid of 2 to 4 C atoms in the alkyl moiety and hydroxyl groups attached primarily, d) from 5 to 70 parts by weight of at least one cycloaliphatic ester of acrylic and / or methacrylic acid of 1 to 12 carbon atoms in the alcohol component, e) from 5 to 50 parts by weight of at least one aliphatic ester of acrylic and / or methacrylic acid of 1 to 8 carbon atoms in the alcohol component, f) from 0.1 to 5 parts by weight of at least one unsaturated mono- or dicarboxylic acid, 3-monoolefinic acid of 3 to 7 carbon atoms and / or at least one hemiside of maleic or fumaric acid of 1 to 14 atoms of C in the rest alcohol and g) from 0 to 40 parts by weight of other copolymerizable olefinic unsaturated compounds and from 10 to 50 parts by weight, preferably from 10 to 40 parts by weight, of a crosslinker with multifunctional or mixture of crosslinking agents, in which both the sum of the parts by weight of components A) and B), and the sum of the parts by weight of the components a) to g) respectively reaches a value of 100.

According to the invention, a large number of multifunctional crosslinkers are suitable, such as, for example, aminoplast resins, such as alkoxylated melamine resin, the melamine-formaldehyde condensation product, urea resin, guanidine resin, plastic phenol resin, resole resin and, preferably, polyfunctional isocyanates blocked, if appropriate, preferably oligomeric isocyanates with biuret, allophanate, uretdione, urethane and / or isocyanurate or iminooxadiazinedione structures.

It is also an object of the invention a process for the preparation of binder combinations according to the invention, characterized in that the graft copolymers described above A) are prepared by radical polymerization in organic solvents at temperatures between 150 and 240 ° C and are combined with the suitable crosslinking resin B).

It is also an object of the invention to prepare formulated varnishes prepared from the binder combinations according to the invention and their use in the varnishing of vehicles, especially in the repair varnish of automobiles and large vehicles, in the general industrial varnishing, of wood and furniture as well as the field of protection against corrosion.

The inventive graft copolymers of the invention A) of the binder combinations according to the invention differ in their chemical composition completely from both the polyolacrylates of EO-A 225.809 and EP-A 778.298 and the substance copolymerized documents. EP-A 635,523 and EP-A 638,591. Regarding the technical properties of varnishing, especially the drying value and the resistance to solvents, give rise to advantages over the products of the aforementioned documents as seen in the corresponding comparative examples.

Similarly, combinations of binder that are not identical are disclosed in EP 279,311. Otherwise, the binder combinations according to the invention are determined especially for the field of use that is not claimed in the aforementioned documents, because the varnishes described therein show a too long drying time and provide highly flexible varnish films of hardness Too low.

The preparation of the constitutive graft copolymer resins of the invention A) can be carried out by the copolymerization of components a) to g) by conventional methods. Radical polymerization in solution is preferred. For this, they are copolymerized at temperatures between 140 and 240 ° C from radical-forming monomers and oligomer units. The preferred polyacrylate resins A) are composed of: a) 0.2 to 8 parts by weight of one or more polybutadienes, optionally functional, with a molecular weight of 500 to 5,000 and at least 30% of structure 1 , 2 -vinyl. b) from 10 to 40 parts by weight of styrene, c) from 15 to 45 parts by weight of hydroxyethyl acrylate, hydroxyethyl methacrylate, butanediol-1,4 monoacrylate or mixtures thereof, d) from 10 to 50 parts by weight of at least one cycloaliphatic ester of acrylic and / or methacrylic acid of 1 to 12 carbon atoms in the alcohol component, e) from 10 to 40 parts by weight of at least one aliphatic ester of acrylic and / or methacrylic acid of 1 to 8 C atoms in the alcohol component, f) from 0.3 to 4 parts by weight of acrylic, methacrylic acid , maleic or fumaric acid of 1 to 8 C atoms in the alcohol components or their mixtures and g) from 0 to 25 parts by weight of acrylonitrile, methacrylonitrile, hydroxypropyl (meth) acrylate (up to 10 parts by weight), aliphatic vinyl ester, branched monocarboxylic acids, if appropriate, of 1 to 10 C atoms in the acid moiety, di (cyclo) alkyl ester of maleic acid and / or fumaric acid of 1 to 8 C atoms in the rest alcohol or its mixtures, reaching the sum of the parts by weight of the components a) to g) a value of 100.

Especially preferred polyacrylate resins A) are composed of: a) from 0.3 to 7.5 parts by weight of one or more polybutadienes, optionally functional, with a molecular weight of 500 to 3,000 and at least 40% of 1,2-vinyl structure. b) from 15 to 35 parts by weight of styrene, c) from 20 to 40 parts by weight of hydroxyethyl acrylate, hydroxyethyl methacrylate or mixtures thereof, d) from 15 to 45 parts by weight of isobornyl acrylate, isobornyl methacrylate, cyclohexyl (meth) acrylate, 3,5,5-trimethylcyclohexyl (meth) acrylate, 4-tert-butylcyclichexyl (meth) acrylate or its mixtures, e) from 10 to 40 parts by weight of at least one aliphatic ester of acrylic and / or methacrylic acid of 1 to 8 carbon atoms in the alcohol component, f) from 0.5 to 3 parts by weight of acrylic, methacrylic acid, or mixtures thereof and g) from 0 to 20 parts by weight of hydroxypropyl (meth) acrylate (up to 10 parts by weight), aliphatic vinyl ester, branched monocarboxylic acids, if appropriate, of 1 to 10 carbon atoms in the acid moiety, di ester (cyclo) ) alkyl of maleic acid and / or fumaric acid of 1 to 8 C atoms in the alcohol moiety or their mixtures, reaching the sum of the parts by weight of the components a) to g) a value of 100.

Especially preferred polyacrylate resins A) are composed of: a) from 0.4 to 6 parts by weight of one or more polybutadienes, optionally functional, with a molecular weight of 500 to 2,000 and at least 45% of 1,2-vinyl structure. b) from 15 to 25 parts by weight of styrene, c) from 25 to 35 parts by weight of hydroxyethyl acrylate, hydroxyethyl methacrylate or mixtures thereof, d) from 20 to 30 parts by weight of isobornyl acrylate, e) from 15 to 25 parts by weight of at least one aliphatic ester of acrylic and / or methacrylic acid of 1 to 4 carbon atoms in the alcohol component, f) from 0.5 to 2 parts by weight of acrylic, methacrylic acid, or mixtures thereof and g) from 0 to 10 parts by weight of hydroxypropyl (meth) acrylate (up to 5 parts by weight), aliphatic vinyl ester, acids monocarboxylic groups optionally branched from 1 to 9 carbon atoms in the acid moiety, di (cyclo) alkyl ester of maleic acid and / or fumaric acid of 1 to 6 carbon atoms in the alcohol moiety or mixtures thereof, reaching the sum of the parts by weight of the components a) to g) a value of 100.

As starting materials a) for the graft copolymers A) constituting the invention, essentially all polybutadienes possessing at least 20% of double 1,2-vinyl side bonds are suitable.

Polybutadienes with a content of vinyl double bonds = 30% are preferably suitable. For this, the remainder with double bonds can be composed of any proportion of 1,4-cis and 1,4-tran structures. Also suitable as component are a) polybutadienes that also show double bonds in cyclic structures. A very especially preferred starting material is a product with = 45% 1,2-vinyl double bonds.

In general, mixtures of polybutadiene isomers are used, for example polybutadienes showing from 30 to 90% of 1,2-vinyl double bonds, from 10 to 70% of 1,4-cis and 1,4-double bond mixtures. trans and from 0 to 30% of cyclical parts. In addition, the polybutadienes can optionally carry functional groups, for example hydroxyl groups, carboxyl groups, etc.

Said polybutadienes are known with different configurations, for example in "Makromoleküle" of H.G. Elias, 4th edition, Hüthig and Wepf-Verlag, Basel, Heidelberg, New York, pages 676 and 744 to 746 and 1012 et seq.

The monomers or oligomers a) to g) are generally incorporated in the same proportions used for the polymerization in the graft copolymers. The built-in units essentially have a statistical distribution.

Suitable solvents for the preparation of component A) are, for example, aliphatic, cycloaliphatic and / or aromatic hydrocarbons, such as alkylbenzenes, for example toluene, xylene; esters such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, acetate with long alcohol moieties, butyl propionate, pentyl propionate, ethylene glycol monoethyl ether acetate, the corresponding methyl ether acetate; ethers such as ethylene glycol monomethyl-, -ethyl- or -butyl ether; ketones such as methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, lactones or the like, or mixtures of such solvents.

The preparation of the graft copolymerized A) can be carried out continuously or discontinuously. In the continuous preparation, the monomer mixture and the initiator are simultaneously and continuously administered to a polymerization reactor and the corresponding amount of polymerized is continuously extracted continuously. Preferably, almost uniform copolymers can be prepared chemically. The almost uniform chemical copolymers can also be synthesized by batch preparation, by administering the monomer mixture and the initiator at constant speed in the polymerization reactor, without extracting the polymerized.

In general, graft copolymerization is carried out in the temperature range from 140 to 240 ° C, preferably from 160 to 210 ° C and particularly preferably from 165 to 200 ° C at a pressure up to 25 bar. The initiators are added in amounts of 0.05 to 15% by weight, preferably 1 to 10% by weight, especially 2 to 8% by weight, based on the total amount of components a) to g).

Suitable initiators for the preparation of the copolymer A) are conventional radical initiators based on azo or peroxide, however only those having a sufficiently long half-life in the temperature range for the polymerization indicated above from about 5 seconds to 30 minutes. Suitable are, for example, 2, 2'-azobis- (2-methylpropanonitrile), 2,2'-azobis- (2-methylbutanonitrile), 1,1'-azobis (cyclohexanecarbonitrile), 2-ethylhexanoate of tertiary butylperoxide, diethyl acetate of tert-butyl ether. butylperoxide, tert-butylperoxide isobutyrate, 1,1-ditert-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-ditert-butylperoxycyclohexane, 3,5,5-t-rimethexanoate tert-butylperoxide, tertiary-isopropylcarbonate butyl peroxide, tert-butyl peroxide acetate, tert-butyl peroxide benzoate, dicumyl peroxide, tert-butyl-oxyl peroxide, diterc-butyl peroxide and diterc-amyl peroxide.

The constituent graft copolymers A) of the invention represent valuable binder components for the combinations of solid-rich binders according to the invention (two component varnishes). By "two component varnishes" is meant in this respect also the "boiler system" as well as the "two boiler system". Since these are polymer resins according to the invention for binder components, they form part of the varnishes, together with the polymerized resins according to the invention (and, where appropriate, other polyhydroxyl compounds and / or amine reaction diluents), a hardener component. If this hardener is, for example, a polyisocyanate with free isocyanate groups, the coating compositions prepared for use shortly before processing can be prepared by mixing the components. In this case, it would be a "two boiler system".

However, in the case of a hardening compound which reacts with the polymer resins according to the invention at high temperature, for example polyisocyanate with blocked isocyanate groups, the hardener prepared can also be bound at room temperature with the polymerized resins in a "boiler system" at rest at room temperature.

In the use according to the invention of graft copolymers A) constituting the invention, these are used if appropriate mixed with other organic polyhydroxyl compounds known in the polyurethane technology, as a polyhydroxyl component and / or mixed with amine reaction diluents. These other polyhydroxyl compounds can be conventional polyol ester, polyether polyol, polyol carbonate, polyolurethane or polyolacrylate. Preferably they are used as other organic polyhydroxyl compounds, in case they are used together with the copolymerized component A) constituting the invention, the polyolacrylates and / or polyester polyols known in the state of the art. The amine reaction diluents can be products with blocked amino groups, such as aldimine, ketimine, oxazolan or those which, although free, show, however, amino groups attenuated in their reactivity, such as, for example, asparaginic acid ester. In all regulators, amine reaction diluents show more than one amino group (blocked), so that they contribute in the crosslinking reaction to the foil of the film lattice of the polymer lacquer.

In the use according to the invention of the graft copolymers A), these can be used mixed with up to 70, preferably up to 50% by weight, of other polyols and / or amine reaction diluents of the type named as an example. Particularly preferred, however, are the inventive graft copolymers of the invention as unique polyol components in the use according to the invention.

The content of hydroxyl groups of the graft copolymers A) is from 1.07 to 8.51% by weight, preferably from 1.77 to 7.77% by weight, with particular preference from 2.62 to 7.04% by weight and very particularly preferably from 3.27 to 6.31% by weight.

As reaction components B) for the graft copolymer resin A) containing the constitutive hydroxyls of the invention, for the preparation of binder combinations according to the invention for coatings and coatings, crosslinking reagents are taken into account which, by chemical reactions with the hydroxyl groups of the graft copolymer resin, the hardening of the coatings according to the invention, such as blocked or unblocked polyisocyanates, aminoplast resins, for example the corresponding melamine derivatives, such as alkoxylated melamine resin or the condensation product, results. of melamine-formaldehyde (for example, see document FR-A 943.411) of DH Solomon in "The Chemistry of Organic Filmformers", pages 235-240, John Wiley & Sons, Inc., New York, 1974) and conventional crosslinkers, for example with epoxides reactive with alcoholic hydroxyl groups, carboxylic acid anhydrides, phenol plastic resins, resole resins, urea resins or guanidine resins or mixtures thereof.

As a preferred reaction component B) for the graft copolymers A) constituting the reaction, for the preparation of the binder combinations according to the invention for coatings and coatings, the polyisocyanate lacquers, which are blocked, are used, the market, ie, mainly the modification products showing urethane, uretdione, allophanate and especially biuret, isocyanurate and iminooxadiazinedione groups known from simple diisocyanates, such as, for example, 1,6-diisocyanatohexane, l-isocyanate-3, 3, 5 trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate), 4,4'-diisocyanatodicyclohexylmethane, 1,4-diisocyanatocyclihexane, l-methyl-2,4-diisocyanatocyclohexane and mixtures thereof with up to 35% by weight, based on the total mixture, of -methyl-2,6-diisocyanatocyclohexane; 2,4-diisocyanatotoluene and its mixtures with up to 35% by weight, based on the total mixture, of 2,6-diisocyanotoluene or mixtures thereof. Particularly preferred "polyisocyanate varnishes" with free isocyanate groups attached in a cyclic and / or cycloaliphatic form are used. Another suitable polyisocyanate which does not contain the groupings indicated above is 4-isocyanatomethyl-1,8-octanediisocyanate. Suitable blockers for the blocked polyisocyanates used where appropriate are, for example, e-caprolactam, butanone oxime, triazole, phenol or phenol derivatives, secondary amines, alkyl esters of malonic acid, etc.

The "polyisocyanate varnishes" which include the urethane group include, for example, the reaction products of 2,4- and, where appropriate, 2,6-diisocyanotoluene or l-methyl-2,4- and, where appropriate, 1-methyl-2, 6-diisocyanatocyclohexane with deficient amounts of trimethylpropane, or mixtures thereof with simple diols, such as, for example, the isomers of propanediols or butanediols. The preparation of said polyisocyanate varnishes exhibiting urethane groups is described practically free from monomers, for example in DE-A 1,090,196.

Polyisocyanate varnishes containing biuret groups, which are especially preferred for use according to the invention, are particularly preferably those based on 1,6-diisocyanatohexane, their preparation being described, for example, in EP-A 0,003,505, DE-A 1,101,394, US-A 3,358,010 or US-A 3,903,127.

The polyisocyanate varnishes which also have particularly preferred isocyanurate groups include the trimerisates or trimerisation mixtures of the diisocyanates mentioned above, such as, for example, polyisocyanates containing isocyanurate groups based on diisocyanatotoluene according to GB-A 1,060-430, GB-A 1,506,373 or GB-A 1,485,564, the mixture of trimerisates of diisocyanotoluene with 1,6-diisocyanatohexine, which are accessible for example according to DE-A 1,644,809 or DE-A 3,144,672 and especially aliphatic, aliphatic-cycloaliphatic and cycloaliphatic trimerizates or mixtures of trimerisates based on 1,6-diisocyanatohexane and / or isophorone diisocyanate, which are obtained, for example, according to US-A 4,324,879, US-A 4,288,586, DE-A 3,100,262, DE-A 3,100,263, DE-A 3,033,860 or DE-A 3,144,672. The polyisocyanate varnishes used in the use according to the invention generally have an isocyanate content of 5 to 25% by weight, an average NCO functionality of 2.0 to 5.0, preferably 2.8 to 4.0, and content of monomeric diisocyanate residues used for their preparation below 2% by weight, preferably below 0.5% by weight. Of course, any mixtures of the polyisocyanate varnishes mentioned as an example can also be used.

In the two-component polyurethane varnishes rich in solids which are used for the use according to the invention, the polyol components and the polyisocyanate components are present in an equivalent ratio of isocyanate groups to hydroxyl groups of 5: 1 to 1: 2, preferably from 3: 1 to 1: 1.5 and with particular preference from 1.5: 1 to 1: 1.2 of the corresponding amounts. The two-component coating agent obtained by mixing both components has a limited processing time of about 1 to 24 hours and is processed as such (clear solvent-free varnish), or preferably however, by the joint use of adjuvants and conventional additives. These adjuvants and additives, if used together, can be added to the mixture or to the individual components of the mixture.

Suitable auxiliaries and additives are, for example, solvents, such as, for example, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, n-hexyl acetate, n-heptyl acetate, acetate. of 2-ethylhexyl, methoxypropyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, mixtures of higher aromatics, benzene for lacquers or any mixtures of these solvents.

Other adjuvants and additives which can be used together, if appropriate, are, for example, plasticizers, such as, for example, tricresyl phosphate, diester of phthalic acid, chloroparaffin; pigments and fillers, such as titanium dioxide, barium sulfate, gypsum, soot; catalysts such as, for example, N, N-dimethylbenzylamine, N-methylmorpholine, zinc octoate, tin octoate II or dibutyltin dilaurate; fluidifying agents; thickeners; in their case stabilizers such as substituted phenols; organofunctional silanes as adhesion agents, as well as photoprotection agents and UV absorbers. Said photoprotection agents are for example spherical hindered amines, as described in DE-A 2,417,353 (= US-A 4,123,418 and US-A 4,110,304) and DE-A 2,456,864 (= US). -A 3,993,655 and US-A 4,221,701). Especially preferred compounds are: bis- (1, 2,2,6,6-pentamethylpiperidyl-4) sebacate, (2, 2, 6,6-tetramethylpiperidyl-4) sebacate, bis- (1, 2, 2) ester. , 6, 6-pentamethylpiperidyl-4) of n-butyl- (3,5-di-tert-butyl-4-hydroxybenzyl) malonic acid.

The moisture adhered to the fillers and pigments can be removed by prior drying or by the joint use of water-absorbing compounds, such as for example zeolite molecular sieve.

The drying of the varnish film resulting from the use according to the invention can be carried out by using polyisocyanates free of blocking agents as a crosslinker at room temperature, and does not require a substantial increase in temperature in order to achieve the above-mentioned optimum properties. For the use of the binder as a repair varnish it is often advisable, however, to increase the temperature from approximately 60 to 100 ° C, preferably from 60 to 80 ° C, for a period of time of to 60 minutes, to shorten the drying and hardening time. With the use of blocked polyisocyanates or of the other groups of products indicated above as a crosslinker, higher temperatures, for example 100 to 240 ° C, preferably 110 to 220 ° C, should be used for the drying or hardening of the varnish film. and especially preferably from 120 to 180 ° C.

In the state prepared for the application, the varnishes based on binder combinations according to the invention are distinguished by a higher solids content or a lower solvent content. The resulting varnish films after curing have a high hardness, good elasticity and excellent resistance to weather, solvents and chemicals as well as a high gloss. The hardening times for both physical drying and chemical crosslinking are short, so that the corresponding coated use objects are resistant to solvents and chemicals and can be used very quickly.

The varnishes for use according to the invention are therefore suitable, in particular, for the varnishing of large vehicles, such as aircraft, railway and tramway cars, truck bodies and the like. Another preferred area of use is its use as a repair varnish for automobiles. In addition, the varnishes are suitable for use as protection against corrosion, as for example in the coating of bridges and electrical towers, for the general varnishing in industry, wood and furniture and for the previous varnishing in automobiles.

The application of the varnish according to the invention is carried out by conventional methods, for example by injection, pouring, dipping, rubbing, spraying or rolling. The varnishes according to the invention are suitable both for the preparation of first layers and for the preparation of double layers and especially for the preparation of coating layers on the painted substrates.

Examples The following examples serve as an explanation of the invention. All percentages data refer, unless otherwise indicated, to the weight.

EXAMPLE 1 Process for the general preparation of the constitutive graft copolymers of the invention A1 to A6 and of the comparative products VI to V3.

In a 5 1 stainless steel pressure reactor with stirrer, distillation device, collecting vessel for the monomer mixture and initiator, including dosing pumps as well as automatic temperature regulation, part I was placed and heated to the desired polymerization temperature (in the examples at 190 ° C). The general initial part II (monomer mixture) was then administered in separate times in 3 hours and part III (initiator) in 3.5 hours, keeping the polymerization temperature almost constant (+ 2 ° C). It was then stirred for 60 minutes at the polymerization temperature. It was then cooled to room temperature and the solids content was determined. The graft copolymers should have a solids content of 75 ± 1%. With a solids content = 73% it is subsequently activated with 5% of the original amount of initiator at 150 ° C for 30 minutes. With a solids content between 73 and 74%, up to 75 ± 1% is distilled. The graft copolymer is then filtered. with a filter (Seitz Supra 5500). The compositions of parts I to III, as well as the reference data of the product obtained, are indicated in table I.

Example 2 Adjustment of copolymer 2 of EP-A 638,591 as comparative example V4.

The copolymerized 2 of EP-A 638591 was adjusted exactly according to the preparation method and the composition. A product was obtained with the following reference data: Solids content: 74.2% Viscosity at 23 ° C: 8450 mPa. s acid index, Lff / FHA 7.5 / 10.1 hydroxyl index, Lff / FH'J 109/147 color index Hazen: 65 APHA Aspect: transparent Example 3 Adjustment of the copolymer A3 of EP A 778298 as a comparative example V5.

The A3 copolymer of EP-A 778298 was precisely adjusted according to the preparation process and the composition. A product with the following reference data was obtained: Solids content: 74.7% Viscosity at 23 ° C: 6180 mPa.s acid index, Lff / FH'J 12.1 / 16.2 hydroxyl index, Lf f / FH'J 98/131 Hazen color index: 60 APHA Appearance: transparent "Lff: Shape provided FH: Solid resin Table 2; Results of the 2K-PUR clear varnish test based on the polyols Al to A6 according to the invention and the comparative polyols VI to V5. fifteen Drying with TI sand, complete drying T3 (DIN 53.150 standard). me or V s iu? ~ a "?? u-uj .: < and J? \ / 5 = worst value (varnish film completely dissolved in the attacked site) 3) Before and after the QUV test (0 h / 1000 h) Example 4 (Use) This example describes the preparation of ready-to-use varnish based on the polyacrylates Al a A6 and VI to V5, its preparation and the test of the resulting varnish film.

In order to estimate the general properties of the varnish, transparent varnishes were prepared. For this, the polyols Al to A6 and VI to V5 were mixed with a polyisocyanate varnish, in which the NCO / OH ratio was maintained at approximately 1: 1. As the polyisocyanate varnish, Desmodur (R) N 3390, a polyisocyanate containing isocyanurate groups based on 1,6-diisocyanatohexane, dissolved at 90% in butyl acetate / Naphta 100 solvent (1: 1); NCO content of the solution: approximately 19.4% by weight, contained in the solution of 1,6-diisocyanatohexane free: below 0.5%. Referring to the solid resin (sum of the solid parts of polyol and polyisocyanate), the following additive parts were used.

Tngrprl -i p-rH- p. g% p > n < * gr? HP- a? L i rlrvci g-n P > 1? L "i Dabco 33 LVR) (PUR catalyst from Air Products, 10% in butyl acetate) 0.3 BYK (R) 331 (Plasticizer of BYK chemistry, 50% in butyl acetate) 0.3 Tinuvin (R) 1130 (UV absorber from Ciba Geigy, Basel, 50% in xylene) 2.0 Tinuvin < , 292 (Photoprotve agent of Ciba Geigy, Basel, 50% in xylene) 1.0 As the solvent, a mixture of methoxypropyl acetate, xylene and n-butyl acetate (1: 1: 1) was used. A content of: about 56% by weight of binder, about 2% by weight of additive, about 42% by weight of solvent.

The plasticizing time (DIN 53.211 standard, 4 mm nozzle) was between 20 and 26 seconds. Therefore, varnishes are largely regulated for injon and have a VOC (volatile organic compounds) value of 349 g / 1 (3.5 lbs / gal), which corresponds to 420 g of solvent per 1 kg of varnish.

With the varnish based on V4, only a plasticizing time of 26 seconds is reached and with the V5 varnish a plasticizing time of 24 seconds, with a solvent part of 42% by weight. These plastification times are too high for the application and explain that with these varnishes a VOC value of 3.5 349 g / 1 at 20 s of plasticizing time can not be reached.

The varnishes were coated on glass plates and dried both at room temperature and 30 minutes at 60 ° C, the drying speed was checked (DIN 53 150) and then allowed to stand for 7 days at room temperature. The thickness of the dried film reached approximately 40 to 50 μm.

The hardness was then tested according to Kónig (DIN 53157), the Gardner gloss at an angle of 60 ° (DIN 67.530 standard) and the solubility in super gasoline (after 1, 2, 3 and 4 days of rest at temperature environments). The depth of Erichsen was checked in the corresponding coated sheet test.

In addition, resistance to yellowing by light with short wave UV light was tested in the QUV (QUV-accelerated weather tester) test., ASTM G 53-77). For this, it was applied to an aluminum sheet (68 mm x 150 mm), which had been previously coated with a white base varnish layer, transparent varnish based on the polyols Al a A6 and VI a V5. After application and drying of the varnish (30 minutes at 60 ° C), it was left for 7 days at room temperature and then tested on a QUV (Q-Panel Company). It was then irradiated in cycles of 4 hours with UV light without intensive filtering in the wavelength range from about 280 to 370 nm (maximum at 313 nm) or left 4 hours in the dark, with a total duration of 1,000 hours. After washing the test, the general color difference dE (compared to the non-irradiated plate) was determined by means of a color measuring device as a measure of the yellowing produced.

The results of the tests of varnishes based on copolymerized Al a A6 and VI to V5 are presented in table 2.

Table 1; Compositions and reference data of the copolymers of inj al A to A6 and the comparative products VI to V3. 15 twenty "Commercial product of Nippon Soda Discussion of the results The 2K-PUR varnishes based on polyols Al to A6 have a fast drying at room temperature in the application despite the high solids content and are stable after 1 to 2 days against the effect of super gasoline. .. The brightness, elasticity and hardness of the film are at a high level, comparable with current standard systems that have an essentially lower solids content in the application. In comparison with the varnishes of the polyols Al to A6, the varnishes lacquers of the polyols VI to V3 have against a longer drying time and a worse resistance to super gasoline after one day, which improves after 2 days and It is correct after 3 days. The varnish based on polyol V4 has a slower drying and after a day a worse resistance to super gasoline, which improves after 2 and 3 days and is correct after 4 days. The varnish based on the comparison polyol V5 has a good resistance to super gasoline, but the drying is slower than in the varnishes according to the invention. The results of the tests clearly show, therefore, that the transparent varnish 2K-PUR rich in solids based on the polyols Al to A6 according to the invention shows a very fast drying, as well as a good resistance to super gasoline. and that for this reason the varnished objects of use, preferably vehicles, can after a shorter time, be taken to their intended use. / > ,! '; JO It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (12)

1. CLAIMS Having described the invention as above, property is claimed as contained in the following claims 1. Combinations of binder characterized because they are composed of A) from 90 to 50 parts by weight, preferably from 90 to 60 parts by weight, of functional OH graft copolymerized resins, prepared by copolymerization of a) from 0.1 to 10 parts by weight of at least one polybutadiene, optionally functional, with a molecular weight of 500 to 10,000 and at least 20% of 1,2-vinyl structure. b) from 5 to 60 parts by weight of at least one aromatic unsaturated monomer such as styrene, α-methylstyrene or vinyltoluene, c) from 10 to 50 parts by weight of at least one hydroxyalkyl ester of acrylic and / or methacrylic acid of 2 to 4 carbon atoms in the alkyl radical and hydroxyl groups primarily attached, d) from 5 to 70 parts by weight of less a cycloaliphatic ester of acrylic and / or methacrylic acid of 1 to 12 C atoms in the alcohol component, e) from 5 to 50 parts by weight of at least one aliphatic ester of acrylic and / or methacrylic acid of 1 to 8 carbon atoms in the alcohol component, f) from 0.1 to 5 parts by weight of at least one unsaturated mono- or dicarboxylic acid a, / 3-monoolefinic acid of 3 to 7 C atoms and / or at least one hemi-ester of maleic or fumaric acid of 1 to 14 C atoms in the alcohol residue and g) from 0 to 40 parts by weight of other copolymerizable olefinic unsaturated compounds and B) from 10 to 50 parts by weight, preferably from 10 to 40 parts by weight, of a crosslinker with multifunctional or mixture of crosslinking agents, Binder combinations according to claim 1, characterized in that the graft copolymer A) is composed of: a) from 0.2 to 8 parts by weight of one or more polybutadienes, optionally functional, with a molecular weight of 500 to 5,000 and at least 30% of 1,2-vinyl structure. b) from 10 to 40 parts by weight of styrene, c) from 15 to 45 parts by weight of hydroxyethyl acrylate, hydroxyethyl methacrylate, butanediol-1,4 monoacrylate or mixtures thereof, d) from 10 to 50 parts by weight of at least one cycloaliphatic ester of acrylic and / or methacrylic acid of 1 to 12 carbon atoms in the alcohol component, e) from 10 to 40 parts by weight of at least one aliphatic ester of acrylic and / or methacrylic acid of 1 to 8 carbon atoms in the alcohol component, f) from 0.3 to 4 parts by weight of acrylic, methacrylic, maleic or fumaric acid of 1 to 8 carbon atoms in the alcohol components or mixtures thereof and from 0 to 25 parts by weight of acrylonitrile, methacrylonitrile, hydroxypropyl (meth) acrylate (up to 10 parts by weight), aliphatic vinyl ester, branched monocarboxylic acids, if appropriate, of 1 to 10 C atoms in the acid moiety, di (cyclo) alkyl ester of maleic acid and / or fumaric acid of 1 to 8 C atoms in the rest alcohol or its mixtures, reaching the sum of the parts by weight of the components a) to g) a value of 100. Binder combinations according to claim 1, characterized in that the graft copolymer A) is composed of: a) from 0.3 to 7.5 parts by weight of one or more polybutadienes, optionally functional, with a molecular weight of 500 to 3,000 and at least 40% of 1,2-vinyl structure. b) from 15 to 35 parts by weight of styrene, c) from 20 to 40 parts by weight of hydroxyethyl acrylate, hydroxyethyl methacrylate or mixtures thereof, d) from 15 to 45 parts by weight of isobornyl acrylate, isobornyl methacrylate, cyclohexyl (meth) acrylate, (meth) acrylate of 3,5, 5-trimethylcyclohexyl, 4-tert-butylcyclohexyl (meth) acrylate or mixtures thereof, e) from 10 to 40 parts by weight of at least one aliphatic ester of acrylic and / or methacrylic acid of 1 to 8 carbon atoms in the alcohol component, f) from 0.5 to 3 parts by weight of acrylic, methacrylic acid, or mixtures thereof and g) from 0 to 20 parts by weight of hydroxypropyl (meth) acrylate (up to 10 parts by weight), aliphatic vinyl ester, branched monocarboxylic acids, if appropriate, of 1 to 10 carbon atoms in the acid moiety, di ester (cyclo) ) alkyl of maleic acid and / or fumaric acid of 1 to 8 C atoms in the alcohol moiety or their mixtures, reaching the sum of the parts by weight of the components a) to g) a value of 100. Binder combinations according to claim 1, characterized in that the graft copolymer A) is composed of: a) from 0.4 to 6 parts by weight of one or more polybutadienes, optionally functional, with a molecular weight of 500 to 2,000 and at least 45% of 1,2-vinyl structure. b) from 15 to 25 parts by weight of styrene, c) from 25 to 35 parts by weight of hydroxyethyl acrylate, hydroxyethyl methacrylate or mixtures thereof, d) from 20 to 30 parts by weight of isobornyl acrylate, e) from 15 to 25 parts by weight of at least one aliphatic ester of acrylic and / or methacrylic acid of 1 to 4 carbon atoms in the alcohol component, f) from 0.5 to 2 parts by weight of acrylic, methacrylic acid, or mixtures thereof and g) from 0 to 10 parts by weight of hydroxypropyl (meth) acrylate (up to 5 parts by weight), aliphatic vinyl ester, monocarboxylic acids, branched, if appropriate, from 1 to 9 carbon atoms in the acid moiety, di ester (cyclo) ) alkyl of maleic acid and / or fumaric acid of 1 to 6 carbon atoms in the alcohol moiety or their mixtures, reaching the sum of the parts by weight of the components a) to g) a value of 100. 5. Binder combinations according to claims 1 to 4, characterized in that the multifunctional crosslinking resin B) is an aminoplast resin. 6. Binder combinations according to claims 1 to 4, characterized in that the multifunctional crosslinking resin B) is an alkoxylated melamine resin, a melamine-formaldehyde condensation product, a urea resin, a guanidine resin or a mixture thereof. 7. Binder combinations according to claims 1 to 4, characterized in that the multifunctional crosslinking resin B) is a phenol resin, a resole resin or a mixture thereof. 8. Binder combinations according to claims 1 to 4, characterized in that the multifunctional crosslinking resin B) is a polyisocyanate and / or a mixture of polyisocyanates. 9. Binder combinations according to claims 1 to 8, characterized in that the multifunctional crosslinking resin B) is an aliphatic (cyclo) polyisocyanate with free isocyanate groups and with biuret, allophanate, uretdione, urethane, isocyanurate and / or iminooxadiazinedione structures and / or a mixture of said polyisocyanates. 10. Binder combinations according to claims 1 to 4 and 8, characterized in that the multifunctional crosslinking resin B) is 4-isocyanatomethyl-1, 8-octanediisocyanate. 11. Binder combinations according to claims 1 to 4, characterized in that the multifunctional crosslinking resin B) is a mixture of 4-isocyanatomethyl-1, 8-octanediisocyanate and at least one (cyclo) aliphatic polyisocyanate with free isocyanate groups and with biuret structures, allophanate , uretdione, urethane, isocyanurate and / or iminooxaydiazinedione structures. 12. Binder combination according to claims 1 to 4 and 8, characterized in that the multifunctional crosslinking resin B) is at least one (cyclo) aliphatic polyisocyanate with blocked isocyanate groups. Use of the binder combinations according to claims 1 to 12 for coating surfaces. Use of the binder combinations according to claims 1 to 12 for the coating of automobiles and automobile parts. Use of the binder combinations according to claims 1 to 12 in the varnishing of repairs of automobiles, large vehicles and automotive pre-coating. Use of the binder combinations according to claims 1 to 12 in the field of protection against corrosion in general industrial, wood and furniture varnishing.