MXPA98004970A - Coating containing silan polymer to improve the resistance to usual wear and attack by ac - Google Patents

Abstract

A coating composition containing a film-forming binder and a volatile liquid carrier for the binder is described, wherein the binder contains (a) an acrylic polymer of polymerized monomers selected from the group consisting of an alkyl methacrylate, an acrylate alkyl, each of which has from 1 to 12 carbon atoms in the alkyl group, isobornyl methacrylate, isobornyl acrylate, hydroxyalkyl methacrylate, hydroxyalkyl acrylate each of which has from 1 to 4 carbon atoms in the alkyl group , styrene and any mixture thereof: (b) an acrylosilane polymer of polymerized monomers selected from the group consisting of an alkyl methacrylate, and alkyl acrylate, each of which has from 1 to 12 carbon atoms in the group alkyl, isobornyl methacrylate, isobornyl acrylate, hydroxyalkyl methacrylate, hydroxyalkyl acrylate having each of 1 to 4 carbon atoms in the alkyl group, styrene and any mixtures thereof and an acrylosilane monomer with hydroxyl, ethylenically unsaturated functional group, and (c) an organic polyisocyanate. The clear coating has improved resistance to usual wear and tear, when exposed to natural environmental conditions

Description

COATING CONTAINING SILAN POLYMER TO IMPROVE THE RESISTANCE TO USUAL WEAR AND ATTACK BY ACID BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is directed to coating compositions or in particular to clear or transparent coating compositions used as a color coating on an automotive vehicle, which has improved resistance to the usual wear and tear and acid attack. by adding an acrylic polymer containing silane. 2. Description of the Prior Art.

Acid rain and other air pollutants have caused problems with spotting, water and acid attack of the finishes used in cars and trucks. The choice finish that is currently being used on the exterior of. .,the . Cars and Trucks., is a clear or transparent coating / color refinishing, in which a clear coating is applied over a colored coating, which is pigmented to provide protection to the colored coating. , and improve the appearance of the total finish such as luster and image distinctiveness. Another problem is the usual wear resistance of the clear coating finishes. The usual wear of the finish may be caused by the mechanical washing procedures used in a typical commercial car wash or by another mechanical marking of the finish. By introducing additives to improve resistance to acid attack, the usual wear resistance of the finish is often reduced. There is a need for an additive for clear coating compositions that will form finishes that are resistant to acid attack and water staining caused by acid rain, and will form finishes that are resistant to the usual desgiaste.

BRIEF DESCRIPTION OF THE INVENTION A coating composition containing 40-7.0% by weight of binder-film former and 30-60% by weight of a volatile liquid carrier for the binder; wherein the binder contains: a. 30-70% by weight, based on the weight of the binder, of an acrylic polymer of polymerized monomers selected from the group of an alkyl methacrylate, an alkyl alkyl acrylate. having each of 1 to 12 carbon atoms in the a.l.-alkyl, isobutyl, isobutyl acrylate, hydroxyalkyl methacrylate, acrylate. hydroxy-alkyl having each of from 1 to 4 atom atoms of carbon in the alkyl group, styrene or any mixtures of these manomers; b. 5-30% by weight, based on the weight of the binder, of an additive of a polymer of the polymerized monomer selected from the group of an alkyl methacrylate. of alkyl, each having 9-12 carbon atoms in the alkyl group, isobornyl methacrylate, isoborpyl acrylate, hydroxyalkyl methacrylate, hydroxy acrylate, alkyl that each have. one 1-4 carbon atoms in the alkyl group, styrene or any mixtures of these monomers and a monoethylenically unsaturated silane monomer; and c »25-50% by weight, based on the weight of the binder, of an organic polyisocyanate and d. 1-20% by weight, based on the weight of the binder, of a polyester resin consisting essentially of the esterification product of an aliphatic dicarboxylic acid, a polyol having at least three reactive hydroxyl groups, a diol, a cyclic anhydride and a cyclic alcohol, and having a number average molecular weight of 500-4,000.

DETAILED DESCRIPTION OF THE INVENTION The coating composition of this invention is generally used as a clear coating composition which is applied to a base coat which is a pigmented composition. The clear coating / basecoat finishes are conventionally used on the exterior of automobiles and trucks. The coating composition of this invention forms a clear finish, has improved resistance to acid attack, stain resistance, water resistance and usual wear resistance. In a typical body of a motor vehicle, such as an automobile or a truck, the substrate is steel or it can be a plastic or a composite .. If this is a steel substrate,. The same is first treated with an inorganic layer of zinc or iron phosphate to the oxidation test, and then a primer is applied by electroplating. Typically, these primers are resins modified with epoxy groups, .reticulated with a .po.liisocyanate and are applied by a cathodic coating process. Op.clanally, .can.be applied a. Aprestadox. On the electrodeposited dresser, to provide better. appearance and / or improved adhesion of the base coat to the dresser. A pigmented basecoat or color coating is then applied. A typical basecoat comprises the pigment which can include metallic pigments such as aluminum flakes, a film binder, which can be a polyurethane, an acrylourethane, an acrylic polymer. or a .silna polymer, and contains a crosslinking agent such as an aminoplast, typically, an alkylated melamine / formaldehyde crosslinking agent, or a polyisocyanate. The base coat may be carried by solvent or water, and may be in the form of a dispersion or solution. A clear topcoat is then applied (clear coating) to the basecoat before the basecoat is completely cured and the cover and basecoat are then completely cured. usually mediant. Ornate .a .1.0.0-.150 ° .C .por .15-45 -minutes .. The basecoat and the clearcoat are preferably coated with a dry coating of 2.5-75 microns and 25-100 microns, respectively. In the event that the clear coating / base coat finish is damaged, eg, in a collision, a refinishing base coat and then a clear coating is applied. It is applied, in general, the baking is not used to cure the finish, and the finish is cured at ambient temperatures - or at slightly elevated temperatures, for example 35 - The composition of Clear coating contains .40-70% by weight of a binder, film former and 30-70% of a volatile organic liquid carrier, which is usually a solvent for the binder and volatilizes to a 35 ° C and temperatures supericir.es ... .The clear coating can also be in the form of dispersion. The film-forming binder of the clear coating composition contains 30-70% by weight of an acrylic polymer having reagent nid axils, 5-30% by weight of a polymer additive. silane and .25-5.0.% in ..p.es.o. of. an organic polyisocyanate crosslinking agent. Silane polymers containing curable silane groups are used in the clear coating composition. These silane polymers are monomeric polymers of alkyl methacrylates, alkyl acrylate each having 1 to 12 carbon atoms in the alkyl, isobornyl methacrylate, acrylate Isobornyl, Hydroxyalkyl methacrylate., acrylate. of hydroxyalkyl, each having 1 to 4 carbon atoms in the alkyl group, styrene or a mixture of any of the foregoing manomers and a monomer of .sylamino-monoethically ins.atured.

These silane polymers have a weight average molecular weight of 1,000-10,000. All molecular weights described herein are determined by gel permeation chromatography (GPC) using a polystyrene standard, unless otherwise indicated. A preferred polymer is the polymerization product of the non-silane-containing monomers of an alkyl methacrylate, an alkyl acrylate having each of 1 to 8 carbon atoms in the alkyl group. isobornyl methacrylate, styrene, hydroxyalkyl methacrylate having from 1 to 4 carbon atoms in the alkyl group; and 5-40% by weight of a monomer containing a.soxane. The non-silane, ethylenically unsaturated, monomers typically useful are alkyl acrylates, alkyl methacrylates, wherein the alkyl groups have from 1.2 to 1.2 carbon atoms, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, ..pentyl methacrylate, ..me.acrylate of he-Kilo, octyl methacrylate, nonyl methacrylate, lauryl methacrylate; Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, acrylate of .isabutyl, acrylate of p.entyl, hexyl acrylate, octyl acrylate, nonyl acrylate, and acrylate. The cycloaliphatic methacrylates and acrylates can also be used, for example, such as the trimethylcyclohexyl meta.cr.ylate, trimethylcyclohexyl acrylate, and the. butyl butyl metacrlate. , .acrila.to. of tb.util-cyclohexyl, or t-butyl-cyclohexyl methacrylate. The .alpha.lacrylate and the .alpha.-acrylate can also be used, for example, such as benzyl acrylate and benzyl methacrylate. It is also possible to use isobornyl methacrylate and isobornyl acrylate. Mixtures of two or more of the aforementioned monomers are useful in the formulation of the polymer with the desired characteristics. In addition to the alkyl acrylates or methacrylates, other non-polymerizable monomers can be used which do not contain .alphane groups in amounts up to 50% by weight of the polymer, in a silane polymer. . to achieve the desired physical properties such as hardness, appearance, and wear resistance. Exemplary of other monomers of this type are styrene, methyl styrene, acrylamide, acrylonitrile, and methacrylonitrile. .E.1 is.wire.will.be.used in the range of 0-50% by weight. Monomers with hydroxyl functional groups can be incorporated into the silane polymer to produce a polymer having a hydroxyl number of 20 to 200. Hydraxyl-functional monomers, typically useful in hydroxyalkyl methacrylates and acrylates. such as n-methoxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylates, hydraxilsobutyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate. A monomer containing silane functional group, Suitable, in the formation of a silane polymer, is a silane having the following structural formula: R Q R'O-Si-CHz- CUaJ.n-O-C-C CH; .OR "where R is either CH3, CH3CH2, CH30, or CH3CH20, R1 and R2 are CH3 or CH3CH2, R3 is either H, CH3 or CH3CH2, and n is 0 or an integer from 1 to 10. Preferably, R is CH30.o CH3CH20 and n .es ..1 .. Typical examples of such silanes are alkoxysilanes of acrylates such as gamma-acryloxypropyltrimethoxy-silane and methacrylate-alkoxy-silanes, such as gamma-methacryloxypropyltrimethoxy. -silane, and the gamma-m «a.tacrilaxipro.pl.ltr.is (.2-methoxyethoxy) silane Other suitable silane monomers have the following structural formula: R OR ' wherein R, R1 and R2 are as described above and n is a positive integer of 1 to . Examples of such silanes are vinylalkoxy silanes, such as vinyltrimethoxy silane, vinyltriethoxysilane and vinyltris (2-methoxyethoxy) silane.

Other useful silane-containing monomers are acyloxysilanes, including acryllaxy-silane, methacrylate-silane, and vinylacetoxy-silanes, such as vinylmethyl-diacetoxy-silane, acrylate-propyl-triacetoxy-silane, and methacrylate propyltriacetoxy silane. Mixtures of the aforementioned monomers which contain ..silyne are also suitable. Consistent with the above components. The following is an example of a silane polymer useful in the composition of. coating. This invention, which contains the following constituents: 0-40% by weight of styrene, .0-40% .in that. methyl methacrylate, 10-40% by weight of ethylhexyl acrylate, 0-40% by weight of ... butyl acrylate, 0-40% by hydroxypropyl acrylate, 0- 40% by weight of Isomaltile methacrylic and 0.5-4.0% by weight of .gamma-methacryloxypropyltrimethoxysilane. The macromonomers of functional silane group can also be used in the formation of the silane polymer. For example, a macromonomer of this type is the reaction product of a compound containing. Silane, which has A reactive group such as epoxide or isocyanate, with a monomer containing no silane, ethylenically unsaturated having a reactive group, typically hydroxyl or an epoxide group, which is coreactive with the silane monomer. An example of a useful macromonomer is the reaction product of a monomer. ethylenically unsaturated with a hydroxyl functional group such as the hydroxyalkyl acrylate or methacrylate having from 1 to 4 carbon atoms, in the alkyl group and a isociety.taalkyl-alkoxysilane such as isocyanatopropyltriethoxysilane. Typical of the above-mentioned silane functional group macromonomers are those having the following structural formula: RJ H CH2 = C-C-0-R4-OCN- (CH2) n-Si-OR1 I OR2 wherein R, R1, R2 and R3 are as described above; R4 is an alkylene group, which has the β carbon atoms and n is a positive integer from 1 to 8. The silane polymer is prepared by a conventional solution polymerization process in which the monomers, the solvents and the Polymerization catalyst are heated at 120-160 ° C for 2-4 hours to form the polymers. The typical polymerization catalysts are azo-type catalysts such as azo-bis-isobutyronitrile, acetate catalysts such as t-butyl peracetate, di-t-butyl peroxide, perbenz, octorate of bu.ti.1.0 and t-butyl peroxylate. The typical solvents that may be used are ketones such as methyl amyl ketone, isobutyl ketone, methyl ethyl ketone, aromatic hydrocarbons such as toluene, .xylene, ethers, esters, alcohols, acetates and mixtures of any of the foregoing. The acrylic polymers which are used in the clear deposition composition are polymerized monomers of alkyl methacrylates, alkyl acrylates, each having 1 to 12 carbon atoms in the alkyl groups, isobarnyl methacrylate. Hydroxyalkyl acrylate, hydroxyalkyl acrylate each having 1 to 4 carbon atoms in the alkyl group, styrene or any mixture of the above monomers .. These polymers . Acrylics have a weight average molecular weight of 1,000 to 10,000.

Any of the aforementioned alkyl methacrylates, alkyl acrylates, methacrylates and hydroxyalkyl acrylates, and other non-silane-containing monomers, mentioned above can be used to form the acyl polymer. A particularly useful acrylic polymer is formed from the polymerized monomers of butyl acrylate, isobornyl methacrylate, hj.droxietilo methacrylate, me.tacrlla.to de. e.tila, methacrylate isobutyl and styrene, and has a number average molecular weight of 2,000 to 4,000. The coating composition may contain from 0.1% to 20% by weight of a polyester resin which is the esterification product of an aliphatic dicarboxylic acid, a polyol having at least three reactive hydroxyl groups, a diol, an anhydride cyclic and a cyclic alcohol, and having a number average molecular weight of 500 to 4,000. A preferred polyester resin is the esterification product of adipic acid, trimethylolpropane, hexanediol, hexahydrophthalic anhydride and cyclohexane-dimethalene. The coating composition also contains a polyisocyanate 1.6 crosslinking agent organic. Any of the adducts with functional, aromatic, cycloaliphatic, isocyanate, trifunctional isocyanate and isocyanate functional groups of a p.o.liol and a diisocyanate can be used. Typically useful diisocyanates are .diisocyanate of .1,., 6-hexamethylene, isophorone diisocyanate, 4,4'-bisphenylene diisocyanate, diisocyanate of toluene, diisocyanate. .bis-cyclohexyl, tetramethylene-xylene diisocyanate, ethyl-e.thylene di-isocyanate, 2,3-dimethyl-ethylene diisocyanate, 1-methyltrimethylene diisocyanate, diisocyanate of 1,3-elelopen ethylene, 1,4-cyclohexylene diisocyanate, 1,3-phenylene diisocyanate, 1,3-naphthalenediabis, .bis- (4-isocyanatocyclohexyl) -methane, 1,2,4-diisocyanate, and 4,4 '-diisocJj.anatodifenil-ether. The typical trifunctional isocyanates which can be used are triphenylmethane triphenyl, 1,3-, 5-benzene triisocyanate, and triacyanate of 2, 4, 6, 6. toluene .. The diisocyanate trimers may also be used, such as the trisomer of ethyl hexamethylene, which is sold under the tradename "Desmodur" N-3390.

Isocyanurates can be used, such as isocyanurate of isophorone diisocyanate. Adducts or addition complexes with an isocyanate functional group can be used, which can be formed from an organic polyisocyanate and a polyol. Any of the aforementioned polyisocyanates can be used with a polyo! To form an adduct. Polyols such as trimethylol alkanes such as trimethylolpropane or -ethane can also be used. A useful adduct is the reaction product of tetramethylxylidene diisocyanate and trimethylolpropane and is sold under the tradename "Cythane" 3160. A preferred polyisocyanate crosslinking agent is a mixture of the trimer of hexamethylene diisocyanate and the diisocyanate. of isocyanurate of isophorone. The curing catalysts are generally used in the coating composition in amounts of 0.01 to 2% by weight, based on the weight of the binder, to catalyze the crosslinking between the silane portions of the silane polymer and / or between the silane portions and other components of the composition including dibutyl tin dilaurate, dibutyltin diacetate, diututyltin dichloride, dibutyl tin dibromide, triphenyl boron, tetratrate teratocrylate, triethanolamine, dibutyl tin dioxide, dibyl tin dioctoate, tin., tin., tin, aluminum, aluminum chelates, zirconium chelate, and others such as catalysts or mixtures thereof, known to those of skill in the art. Tertiary amines and acids or combinations. thereof are also useful for catalyzing the silane linkage. Other silane-sizing catalysts are described in U.S. Patent No. 4,923.9.4.5., column 15. to column .17., incorporated by reference in the I presented. To improve the capacity of x.is.controls to the environmental conditions of the clear coating, they may be added stabilizers of ultraviolet light, or a combination of light stabilizers, ultraviolet to the clear coating composition in the amount of 0.1- 10% by weight, based on the weight of the binder ... .Such stabilizers include ultraviolet light absorbers, sunscreens, dampers, and specific hindered amine light stabilizers. Also, an antioxidant may be added, in the amount of 0.1-5% by weight, based on the weight of the binder. Typical ultraviolet light stabilizers, which are useful, include benzolenones, triazoles, triazines , benzoates, hindered amines and mixtures of the same ... The specific examples of ultraviolet light stabilizers are described in the North American Patent .No ... 4., .5.9.1, 53.3., The full description of which is incorporated by reference in the present .. For .the. Good durability, a mixture of "Tinuvin" 900 (.UV filter.) Is preferred. and "Tinuv.in" 1.23 .. (impeded mine), both commercially available from Ciba-Geigy. The clear coating composition can also include other stable, conventional formulation additives or flow control agents, for example, such as Resiflow® S (polybutylacrylate), B.YKRM 3.20 and 3.25 (high molecular weight polyacrylates).; and agents for the control of the reo.lagy, such as fumed silica. Conventional solvents and diluents are used to disperse and / or dilute the aforementioned polymers of the clear coating composition .... Typical solvents and diluents include toluene, xylene, butyl acetate, acetone, methyl -isobutyl ketone, methyl ethyl ketone, methane, .isaprapanol, butane, hexane, acetone, ethylene glycol, monoethyl ether, VM and P naphtha, mineral alcohol, heptane and other aliphatic hydrocarbons, cycloaliphatics. or aromatics, esters, ethers and ketones. The typical base coatings used in combination with the clear coating composition, comprise as the film-forming binder .. a paliuretane, an acrylonitrile, a silane. , an acrylic resin and a crosslinking agent such as a. .aliisoclana.to or a resin of alkylated melamine. The base coat may be a solution or dispersion based on water or solvent based. The base coat contains pigments such as those that are conventionally used, including metallic flake pigments such as aluminum flakes. Base coat and clear coat are applied by conventional techniques such as spraying, electrostatic spraying, immersion, wire application, and flow coating. The following examples illustrate the invention. All parts and percentages are on a weight basis unless otherwise indicated. The molecular weights san determined by GPC (Gel Permeation Chromatography) using polymethyl methacrylate as the standard.

EXAMPLE 1 The following polymers and resins were prepared and used in the Example.

Silane Polymer A The following constituents were loaded into a reactor equipped with a stirrer, nitrogen purge, condenser and thermometer: Portion 1 PARTS BY WEIGHT Xylene 617.5 Toluene 378.4 Portion1 2 PARTS BY WEIGHT Styrene monomer (S) 363.6 Methacrylate monomer .3.52 ... 1 methyl (MMA) Isobornyl methacrylate 352.1 monomer (IBMA) 163.6 butyl acrylate monomer (BA) 163.6 Ethylhexyl acrylate monomer (EHA) Monomer of acrylate of 181.8 hydroxypropyl (.HPA) Monomer of gamma-240.5 methacryloxypropyltrimethoxy-silane (TPM) Initiator of .9.0 ... 3 polymerization - 2.2 (2-methy1-butan-nitrile) Portion 3 PARTS BY WEIGHT 1- 5.4 polymerization initiator - described above Xylene 56 ... 4 Toluene 34.5 Ortho-formate 30.0 trimethyl Total 3029.8 Portion 1 was charged into the reactor and heated to its reflux temperature. Portion 2 was premixed and added at a uniform rate to the reactor over a period of 240 minutes, while maintaining the reaction mixture at its reflux temperature. Portion 3 was premixed and added to the reactor over a period of 30 minutes, and then portion 2 was added. The reaction mixture was maintained at 130 ° C for 30 minutes and then cooled. The resulting polymer solution had a polymeric solids content of 62.6% and the polymer had a composition of S / MMA / IBMA / BA / EHA / HPA / TPM of 20 / 19.4 / 19.4 / 9/9/10 / 13.2 and a viscosity of .Gardner Holdt of U and a weight average molecular weight of 8,000.

Styrene Acrylic Polymer B A styrene-acrylic polymer solution was prepared using a polymerization procedure similar to that described above. The polymer had the following composition: n-butyl acrylate / isobornyl methacrylate / 2-hydroxyethyl methacrylate / methyl methacrylate / isobutyl methacrylate / styrene in a ratio of 20. // 30.5/25/2/2/20 and which has a number average molecular weight of 3,000 and a Tg (glass transition temperature) of + 35 ° C and the polymer solution had a solids content of 65% by weight.

Polyester C The following polyester polymer solution was prepared using the conventional polymerization methods: adipic acid / trimethylolpropane / 1,6-hexanadial / hexahydrophthalic anhydride / 1,4-cyclohexanedimethanol in a weight ratio of 21.5 / 6.2 / 20.7 / 26.3/25.3 which has a number average molecular weight of 1500 and a Tg of -45 ° C and the polymer solution had a solids content of 80% by weight.

Two coating compositions were formulated by mixing together the following ingredients: Parts by weight Portion .1 .Invention. Control Polymer solution C 10.00 10.00 292 - .Sebacate of 0.80 0.80 bis- (N-meti 1-2, 2.6.6. -tetrame.ethyl-piper.idinyl.) "Tunuvin" 328-2- (2-hydroxy-0.80 0.80 3, 5-diter-amyl-phenyl) -2H-benzotriazole BYK 306 - Anti-crater agent 0.30 0.30 a copalimer. of dimethylpolysiloxane modified with polyether in a ratio of xylene / monophenylglycol 7: 2 Dilaura.to. dibutyl-tin ..0..02 -0..02 Catalyst DABCO - 1,4- 0.13 0.13 diazabicyclo- [2., 2, 2] -octane Parts by weight Invention Control Solution of .. Polymer of .Silane .1.2..5.0 .0.00 A (prepared above) Acetate e .butyl 7,10 7, -00 Xylene 7.10 7.00 Methyl-e.til-ce.tone .3 ... 0.0 .3., 00 Portion ____ 2_ "Desmodur" 3390 (trimer of 10.30 11.30 diisoc ^ anato of hexame.ethylene.) I IPDI-T1890E (isocyanurate of 10.30 11.30 diisocyanate) isoform total 100.00 100.00 Portion .1 was loaded into a mixing vessel and mixed, and then Portion .2 was added and mixed to form the coating compositions. Each of . The coating components were extended by a rod on a separate glass panel to form a film of 50.8 millimeters (2 mils) in thickness and hardness. Tukon was determined after the films had completely dried after 1 and 4 djias. For the swelling tests, films of 50.8 microns (2 mils. coating compositions, on separate TPO panels (pp.lio.lefina termop.lástlca) and the swelling in methylene chloride was determined after 1 and 4 days. For the flexibility test, films of 50.8 microns (2 mils) of each of the above coating compositions were spread on separate RIM panels (injection molded panel). reaction) and the flexibility was determined after 1 and 4 days. The temperature was determined free of unusual wear and stain - on separate steel panels, cathodically electrocoated, phased, each coated with 25.4 microns (1 mil) of a coating composition. , black, and then each was coated with 50.8 microns (2 mils.) of the above-prepared coating composition of the invention, and the control composition. The usual wear test was carried out after 14 days of drying at room temperature and the stain-free temperature test was carried out on prepared panels.

The following is a summary of the physical properties of the coating, determined by the previous test: Parts in Weight Properties .Inv.enció .Control n Resistance .al.desgaste ... us.ual in .4.4..0 .32 ... 0 Wet Hardness Tukon (knoops) 1 Day of healing time 3.3 1.8 4 Days. Of time-of-cure 6.7 .5.5 Touch-drying (minutes) 3.5 3.0 Swelling-in-methylene chloride 1 Day 1.79 1.76 4 Days 1.70 1 ... 64 Flexibility 1 Day Very Good Very Good 4 Days Very ... good. Very good Viscosity Zahn # 2 (seconds) 16.4 15.6 Temperature .free of stain .5.5 .4.0 (° C) The stain-free temperature test is run by exposing the coating to an aqueous solution of 10% sulfuric acid, and measuring the temperature at which acid attack occurs. The higher the temperature, the better the resistance of the coating to the attack by acid. The above test results show an improvement in, resistance to, wear, and the acid attack resistance of the coating composition of the invention, formulated by the silane polymer. Acrylic A, in comparison to the control, which did not contain the silane polymer.

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 manufacturing the objects. a .. that it refers Having described the invention as above, it does claim. like .. property. ontenido in the following:

Claims (10)

1. A coating composition comprising .40-70% by weight of a binder. film former and 30-60% by weight of a volatile liquid carrier for the binder; characterized the binder because it comprises a. 30-70% by weight, with base on the weight of the binder, of an acrylic polymer consisting essentially of monomers selected from the group consisting of an alkyl methacrylate, an acrylate .alkyl, each of which has 1-12 carbon atoms in the alkyl group, isobornyl ethacrylate, isobornyl acrylate, hydroxyalkyl methacrylate, hydroxyalkyl acrylate each of which has 1-4 carbon atoms. carbon in the alkyl group, styrene and any mixtures thereof and having a weight average molecular weight of from 1,000 to 10,000; , b. 5-30.%, In p.a., with base on the weight of the binder, of a silane polymer consisting essentially of polymerized monomers selected from the group consisting of an alkyl methacrylate, an alkyl acrylate, each of which has 1-12 carbon atoms in the alkyl group, isobornyl methacrylate, isobornyl acrylate, hydroxyalkyl methacrylate, hydroxyalkyl acrylate each having 1-4 carbon atoms in the alkyl group, styrene and any mixtures thereof and a monomer with monoethylenically unsaturated silane functional group and 0-50% by weight styrene monomer, and the polymer has a hydroxyl number of 20-200 and a molecular weight. weight average of 1,000 to 10,000; c. 25-50% by weight, based on the weight of the binder, of an organic polyisocyanate; and d. 1-20% by weight, based on the weight of the binder, of a polyester resin consisting essentially of the esterification product of an aliphatic dicarboxylic acid, a polyol having at least three reactive hydroxyl groups, a diol, an anhydride cyclic and a cyclic alcohol, and having a number average molecular weight of 500-4,000. The composition of the coating according to claim 1, characterized in that the silane polymer consists essentially of polymerized monomers of a methacrylate. of alkyl, an alkyl acrylate, each of which has 1-12 carbon atoms in the alkyl group, isobornyl methacrylate, styrene, hydroxyalkyl methacrylate having 1-4 carbon atoms in the alkyl group and a .manomex containing silane that has the following structural formula:

R O

R1O- H2 wherein: R is selected from the group consisting of CH3, CH3CH2, CH30 or CH3CH2O; R1 and R2 are individually selected from the group consisting of CH3, or CH3CH2; and R3 is selected from the group consisting of H, CH3 or CH3CH2; and n is 0 or a positive integer from 1 to 10. 3. The coating composition according to claim 2, characterized in that the silane is selected from the group consisting of methacrylate of gamma-trimethoxy-silyl-pr. ppyl and gamma-trimethoxy-silyl-propyl acrylate.

4. Compositing coating composition according to claim 1, characterized in that it contains 1-20% by weight, based on the weight of the binder, of a polyester resin, which essentially consists of the esterification product of an aliphatic dicarboxylic acid. ., a p.oliol containing at least three reactive hydroxyl groups, a diol, a cyclic anhydride, and a cyclic alcohol.

5. The coating composition according to claim 1, characterized in that the polyester resin is the product of the acidification of adipic acid, trimethylolprapane, hexanediol, hexahydrophthalic anhydride and cyclohexane-dimethoxy.

6. The coating composition according to claim 1, characterized in that the organic polyisocyanate is an aliphatic or cycloaliphatic polyisocyanate.

7. The coating composition according to claim 6., characterized in that the organic polyisocyanate is a mixture of the trimer of hexamethylene diisocyanate and the isocyanurate of isophorone diisocyanate.

8. The coating composition according to claim 1, characterized in that it contains, 0, 1, 10% by weight of ultraviolet light absorbers.

9. The coating composition according to claim 1, characterized in that the binder consists essentially of a. .25-50% by weight, with base on the weight of the binder, of an acrylic polymer consisting essentially of polymerized monomers of an alkyl methacrylate, an alkyl acrylate, each of. .the ... which .has. 1-.4 .. atoms of carbon in the alkyl group, isobornyl methacrylate, methacrylate dp.hydraxyalkyl, each .. .one of those which has .1 at 4 carbon atoms in the alkyl group, and styrene having an average molecular weight in number from 1,000 to 3,000; b. 5-20% by weight, based on the weight of the binder, of a silane polymer consisting essentially of polymerized monomers of a meta-saccharide, of alkylalkyl, an alkyl acrylate, which each have 1-8 carbon atoms in the alkyl group, isobornyl methacrylate, styrene, hydroxyalkyl methacrylate, having 1-4 carbon atoms in the group ... alkyl, a monomer what's wrong with it I silane of methacrylate of gamma-trimethoxy-silyl-propyl or acrylate d.e ..gamma-trimethoxy-silyl-propyl and having a number average molecular weight of 1 ^ .000 to 10,000; c. 1-20% by weight, based on the weight of the binder, of a polyester resin consisting essentially of the esterification product of a hydroxyacetic acid, a polyol! having at least three reactive hydroxyl groups, a diol, a cyclic anhydride, and a cyclic alcohol, and having a number average molecular weight of 500 to 4000; and d. .25-5.0% in weight with base on the weight of the binder, of organic polyisocyanate consisting essentially of a mixture of the hexamethylene diisocyanate trimer and the isocyanurate of diisocyanate and isophorone. .

10. A substrate, characterized in that it is covered with a basecoat. pigmented and coated on the upper part with a layer of the composition of the coating, in accordance with claim 1. SUMMARY OF THE INVENTION A coating composition containing a film-forming binder and a volatile liquid carrier for the binder is described, wherein the binder contains a. an acrylic polymer of polymerized monomers selected from the group consisting of an alkyl methacrylate, an alkyl acrylate, each of which has from 1 to 12 carbon atoms in the alkyl group, isobornyl methacrylate, isobornyl acrylate, methacrylate hydroxyalkyl, hydroxyalkyl acrylate each of which has from 1 to 4 carbon atoms in the alkyl group, styrene and any mixtures thereof; b. a silane polymer of polymerized monomers selected from the group consisting of an alkyl methacrylate, an alkyl acrylate, each having 1 to 12 carbon atoms in the alkyl group, isobornyl methacrylate, isobornyl acrylate, methacrylate of hydroxyalkyl, hydroxyalkyl acrylate each having 1 to 4 carbon atoms in the alkyl group, styrene and any mixtures thereof and a silane monomer with hydroxyl, ethylenically unsaturated functional group; and c. an organic polyisocyanate; and d. a polyester resin. The clear coating has improved resistance to wear and tear and acid attack, when exposed to natural environmental conditions.