MXPA97004807A - Coating composition cura - Google Patents

Abstract

A curable coating composition is disclosed which comprises: (A) a carbamate functional component, which is the reaction product of: (1) a compound having a plurality of oxyhydrogen groups, which is the reaction product of :( a) a compound comprising at least one epoxide group and (b) a compound selected from the group consisting of hydroxy acids, comprising at least one organic acid group and at least one hydroxyl group, polyacids comprising a plurality of groups of organic acid and mixtures thereof, (2) a component comprising a carbamate group, and (B) a component comprising a plurality of groups that are reactive with the carbamate functional groups in the component (

Description

CURABLE COATING COMPOSITION FIELD OF THE INVENTION This invention relates to curable coating compositions, particularly curable compositions utilizing a compound with carbamate functionality as one of the components of the composition.

BACKGROUND OF THE INVENTION Curable coating compositions, such as thermoset coatings, are widely used in the coating trade. They are frequently used for final coatings in the automotive and industrial coatings industry. Composite coatings plus transparent coatings are particularly useful as final coatings where exceptional gloss quality, sharpness of color, sharpness of the image or special metallic effects are desired. The automotive industry has extensively used these coatings for automotive body panels. However, color-plus-transparent composite coatings require an extremely high degree of clarity in the clear coat, to obtain the desired visual effect. High-gloss coatings also require a low degree of visual aberration on the surface of the coating, in order to obtain the desired visual effect, such as high image sharpness (DOI). These coatings are particularly susceptible to a phenomenon known as environmental degradation. Environmental degradation manifests as spots or marks on, or on, the finish of the coating, which frequently can not be easily removed by rubbing. Frequently, it is also desirable to provide options of different types of materials with sarbamate functionality, to provide coatings with a good combination of properties, such as durability, hardness, flexibility and resistance to scratching, wear, solvents and acids. Curable coating compositions based on curable components having carbamate functionality have been disclosed in the art to provide coatings resistant to degradation, for example, US Pat. UU 5,356,669 and WO 94/10211. Carbamate functional non-polymeric compounds, for coating compositions, have been described in 5,336,566 and EP 636,660, US Pat. In order to obtain the smooth finishes which are often highly desirable in the backing industry, the coating compositions preferably tend to be fluid in nature, and exhibit good flow. Good flow is observed when the coating composition is sufficiently fluid at a certain point, after it is applied to the substrate, and before it is cured on a hard film, so that the surface of the coating acquires a Smooth appearance. Some coating compositions exhibit good flow immediately upon application, and others exhibit good flow when they are heated. One way of imparting fluid characteristics and a good flow to a coating composition is by incorporating volatile organic solvents into the compositions. These solvents can provide the desired fluidity and flow during the coating process, after which they evaporate, leaving only the coating components. However, the use of said solvents also increases the volatile organic content (VOC) of the coating composition. Due to the adverse impact that VOC has on the environment, many government regulations impose limitations on the amount of solvent that can be used. Therefore, it would be desirable to use components of coating compositions that provide good flow and flow to the coating compositions, without the need for large amounts of solvent. Due to other beneficial properties, it would also be desirable to provide compounds with -carbamate functionality for use in coating compositions that do not require large amounts of solvent.

EXTRACT OF THE INVENTION According to the present invention, there is provided a curable coating csition cising: (A) a carbamate functional cnent, which is -the reaction product of: ti) a cund having a plurality of hydroxyl groups, which is the reaction product of: (a) a cund cising at least one epoxide group and (b) a cund selected from the group consisting of hydroxy acids, cising at least one organic acid group and, at least, an oxhydryl group, polyasides cising a plurality of organic acid groups and mixtures thereof, (2) a cund cising a carbamate group, and (B) a cnent cising a plurality of groups that are reactive with the groups with Carbamate functionality in cnent (A). The csitions of the present invention can reduce the need for organic solvents, and can also impart to the coating csitions the ability to be spray-applied at high viscosities, and still maintain the characteristics of good flow and appearance. Current invention provides coatings with a good combination of properties, such as durability, hardness and resistance to scratching, wear, solvents and acids. Coating csitions, according to the invention, can also provide low VOC levels, while maintaining other beneficial properties that are often found in coating csitions containing relatively high amounts of solvent, such as good sag resistance, leveling. , low orange peel, brightness, image sharpness (DOI), substrate wetting, and pigment loading and dispersion, and uniform curing.

DESCRIPTION OF PREFERRED EMBODIMENTS According to the invention, the cund (A) (1) cises a plurality of hydroxyl groups, and is the reaction product of (a) a cund cising at least one epidium group and (b) a cund cising at least one organic acid group and at least one hydroxyl group. It is believed that the reaction between the cunds - (a) and (b) is a ring opening reaction between the epoxy group and the organic acid group. This reaction frequently uses carboxylic acid groups, although other organic acids, such as the phenolic cunds, can also be used. The acid / epoxy reaction is well known in the chemical guild, and could proceed spontaneously under ambient conditions, either in solvent or undiluted, and could advantageously be accelerated with heat. The cund (A) ID could be a monoepoxide or a polyepodide. In the practice of the present invention, virtually any epoxide can be used. The epdxidos are well known in the guild, and could be characterized by the general formula: where R 1, R 2, R 3 and R 4 are each independently H (. with the proviso that at least one of R 1 -R 4 is other than H), an organic radical, which could be polymeric or non-polymeric and which could containing heteroatoms and / or unsaturation, or one of R 1 or R 2 together with one of R 3 or R 4 could form a cyclic ring, which could contain heteroatoms and / or unsaturation. Useful epdxides can be prepared from alcohols, for example, butanol, trimethylolpropane, by reaction with an epihalohydrin (for example, epichlorohydrin), or by reaction of an allyl group with peroxide. The epididy may be monofunctional or polyfunctional, which can be controlled by selection of the starting material. For example, a monoepoxide can be prepared by reacting a monoalcohol or monoacid with an epihalohydrin or a monounsaturated with -peroxide, and a polyepodide can be prepared by reacting a polyol (including diols, triols, and higher functional polyols) with an epihalohydrin or a polyunsaturated cund with perdioxide. Polyepdxidos -oligoméricos or polimérisos can also be used, such as oligomers or acrylic polymers containing glycidyl methacrylate or polyglycidyl ethers terminated with epoxy, such as the diglycidyl ether of bisphenol A (DGEBPA). Polyester resins or epoxidized polyurethane resins can be prepared by reacting polyesters or polyurethanes containing OH groups, as known in the art, with an epihalohydrin. Epdxides can also be prepared by reacting an isocyanate-terminated component with glycidol, such as a monomeric polyisocyanate (including isocyanates, for example, the isocyanurate of -isophorone diisocyanate), or a polymer or an oligomer. Other known polyepdxides, for example epoxy-novolacs, can also be used. In a preferred embodiment, the epoxide is a mono-epoxide, preferably an epoxy ester, also known as a glycidyl ester. The glycidyl esters can be prepared by reacting a monofunctional carboxylic acid (eg, octanoic acid, benzoic acid, benzylic acid, cyclohexanecarboxylic acid) with an epihalohydrin (eg, epichlorohydrin) under conditions well known in the art. Glycidyl esters can be obtained commercially, for example, as Cardura E from Shell -Oil Company, Glydexx® N-10 from Exxon, or Araldite® PT910 from Ciba-Geigy. Glycidyl steres can be described - by the formula where R is a hydrocarbon group, from 1 to 40 carbon atoms, preferably 1-20 carbon atoms, and more preferably 1-2 carbon atoms. This hydrocarbon group can be substituted, as is known in the guild. Polyglycidyl esters can also be used, and can be prepared by reacting a polyfunctional carboxylic acid (e.g., phthalic acid, thioglycolic acid, adipic acid) with an epihalohydrin. The polyglycidic steres can also be described by the formula indicated above, where-R is replaced by other glycidyl groups.

Another useful class of monoepoxides are glycidyl ethers. The glycidyl ethers can be prepared by the reaction of monofunctional alcohols (for example, n-butanol, propanol, 2-ethylhexanol, dodecanol, phenol, cresol, -cyclohexanol, benzyl alcohol) with an epihalohydrin (for example epichlorohydride. glycidyl ethers - useful are the glycidyl ether of 2-ethanolhexanol, the glycidyl ether of dodecanol, the glycidyl ether of phenol, and the like.These compounds can be obtained commercially under the Erisys family of products from CVC Specialties. polyglycidyl ethers, and can be prepared by reacting a polyfunctional alcohol (eg, bisphenol A, 1, 6-hexanediol) with an epihalohydrin.Epsods can also be prepared by reacting a compound containing one or more double bonds with - peroxide or peracetic acid under well-known conditions in the guild Virtually any compound containing double bond can be used. il of compounds containing double bond are the mono-saturated cycloaliphatic compounds, such as that can be sold like the Cyracure® products of Union Carbide. Among the other compounds containing unidn do ble, which may be used in the practice of the invention, are ethylene, propylene, styrene, styrene dioxide, cyclohexane, polybutadiene, and the like. The epoxide may also be an oligomer or polymer containing acrylic, preferably deriving its epoxy groups from the monomer of glycidyl methacrylate, glycidyl acrylate, ether-allyl glycidyl, monoepoxymethacrylate of cyclohexyl, the epidoxide of the cyclopentadiene methacrylate dimer or epoxidized butadiene, more preferably glycidyl methacrylate. The epdxides described above are reacted with-a compound Cb) comprising an acid selected from the group consisting of hydroxy acids having at least one organic acid group and at least one hydroxyl group, -polyacids comprising a plurality of acid groups or ganics, and which may or may not include hydroxyl groups and mixtures thereof. The use of a hydroxy acid or polyacid will provide a plurality of available hydroxyl groups for transesterification with the carbamate compound (A) (2), although a monoepoxide is used. Useful hydroxy acids include dimethylolpropidic acid, hydroxy pivalic acid, malic acid, tartaric acid and citric acid. Useful polyacids include tricarballyl acid, adipic acid, azelaic acid, trimellitic anhydride, citric acid, malic acid, tartaric acid, bisphenol F and bisphenol A. The reaction using a hydroxy acid is preferably carried out without a catalyst. , so that the undesired reaction of the hydroxyl groups with the epoxy groups is minimized. If the polyacid is reacted with a polyepdxide, the reaction conditions should be controlled in such a way as to avoid any undesired chain branching or extension, which could result in compounds with high molecular weight, which could increase the volatile organic content - (VOC) or cause gelatin. If the hydroxyl groups are present in the polyacid (for example citric acid), the reaction is preferably carried out without catalyst, in order to minimize the undesired reaction of the hydroxyl groups with the epoxy groups. The compound (A) (1) is reacted with a compound (A) (2) to form the compound (A) with carbamate functionality. In one embodiment, (A) (2) is cyanic acid, which can be formed by the well known reaction of the thermal composition of urea or by other methods, such as those described in US Patents 4,389,386 and 4,364,913. In another embodiment CA) (2) is a compound comprising a carbamate group. In this embodiment, it is considered that the reaction between (A) (1) and (A) C2) is a trans esterification between the OH groups in (A) (1) and the carbamate ester in the compound (A) C2 ). The carbamate in the compound (A) (2) can be any compound having a carbamate group capable of having a transesterification with the hydroxyl groups in the (A) CD component. These include, for example, methyl carbamate, butyl carbamate, propyl carbamate, 2-ethylhexyl carbamate, cyclohexyl carbamate, phenyl carbamate, hydroxypropyl carbamate, hydroxyethyl carbamate, and the like. Useful carbamate compounds can be characterized by the formula: R »- O - (C = 0) -NHR" where R 'is substituted or unsubstituted alkyl (preferably 1-8 carbon atoms), and R "is H, substituted or unsubstituted alkyl (preferably 1-8-carbon atoms), substituted or unsubstituted cycloalkyl ( preferably of 6-10 carbon atoms), or substituted or unsubstituted aryl (preferably of 6-10 carbon atoms) Preferably, R "is H. The transesterification reaction between the compounds (A) (1) and (A) (.2) can be carried out under typical transesterification conditions, for example, temperatures from ambient temperature to 150 ° C with transesterification-catalysts, such as calcium octoate, metal hydroxide C for example, KOH), metals of Group I and II (for example, Na, Li), metal carbonates (for example, -K CO_). which could be improved by use in combination with crown ethers, metal oxides (e.g., dibu azuletaño oxide), metal aldroxides (e.g., NaOCH-, Al (OC3H_) metallic esters (e.g., stannous octoate, calcium octoate) or practical acids (eg, H2SO.), MgCO ~ or Ph.Sbl. The reaction can also be carried out at room temperature, with a polymer-supported catalyst, such as Amberlyst-15 (Rohm &Haas), as described by R. Anand, Synthetic Communications, 24 (19), 2743-47 (1994), the disclosure of which is incorporated herein by reference The opening of the oxirane ring of an epoxide compound by a carboxylic acid results in a hydroxyester structure. Subsequent transesterification of the hydroxyl group in that structure, by the carbamate in the compound (A) (2) results in a component with carbamate functionality that can be represented by any of the structures: or a combination of these, where n is an integer of at least 1; R represents H, alkyl or cycloalkyl; R "represents alkyl, aryl or cycloalkyl; and X represents an organic radical which is a residue of the compound -epioxide. As used herein, it is to be understood that these alkyl, aryl or cycloalkyl groups can be substituted. For example, when a monoepoxide is reacted with a polyacid, R- in the structures indicated above would represent the polyacid residue, and would be replaced by -other (Cs) group of resulting carbamate Cs) of the other acid groups. in the polyacid reacting with the mono-epoxide, followed by transesterification with the carbamate in the -Ca compound) (2). The composition of the invention is cured by a reaction of the compound (A) with carbamate functionality with a component CB) which is a compound having a plurality of functional groups which are reactive with the groups of carbamate in the component ( TO) . Among said reactive groups are methylol or methylalkoxyl groups active in aminoplast crosslinking agents or in other compounds, such as phenol / formaldehyde adducts, siloxane or silane groups and anhydride groups. Among examples of CB compounds are melamine formaldehyde resin (including monomeric or polymeric melamine resin and partially or totally alkylated raelamine resin), C urea resins for example, methylolureas, such as ureaformaldehyde resin, alkoxyurea, such as butylated urea-formaldehyde resin), N-methyl-lacrylamide emulsions, isobutoxymethylacrylamide emulsions, polyanhydrides C for example, polysuccinic anhydride) and siloxanes or silanes (for example, dimethyldimethoxysilane). Aminoplast resins, such as melamine formaldehyde resin or ureaformaldehyde resin are particularly preferred. Also useful are aminoplast resins, where one or more of the aminic nitrogens is substituted with a carbamate group for use in a process with a curing temperature of less than 150 ° C, as described in US Patent 5,300,328. . A solvent could optionally be used in the coating composition used in the practice of the current invention. The coating composition, according to the present invention, it can be applied without solvent, especially if the degree of chain extension of the component (A) is limited. However, in many cases, it is also desirable to use a solvent in the backing composition. This solvent must act as a solvent, in relation to both the compound (A) with carbamate functionality, and with the component (B). In general, depending on the solubility characteristics of the components CA) and (B), the solvent can be any organic solvent and / or water. In a preferred embodiment, the solvent is a polar organic solvent. More preferably, the solvent may be polar aliphatic solvents or polar aromatic solvents. Still more preferably, the solvent is a ketone, ester, acetate, aprotic amide, aprotic sulphide or aprotic amine. Examples of useful solvents include methyl ethyl ketone, methyl isobutyl ketone, amyl acetate, ethylene glycol bityl ether acetate, propylene glycol monomethyl ether acetate, xylene, N-methylpyrrolidone or mixtures of aromatic hydrocarbons. In another embodiment, the solvent may be water or a water mixture with cosolvents. The coating composition used in the practice of the invention could include a catalyst for increasing or accelerating the curing reaction. For example, when the aminoplast compounds, particularly the monomeric melamines, are used as component CB), then a strong acid catalyst can be used to increase or accelerate the curing reaction. Such catalysts are well known in the trade and include, for example, β-toluene sulfonic acid, dinonylnaphthalenedisulphonic acid, dodecylbenzene sulfonic acid, phenyl acid phosphate, monobutyl maieate, butyl phosphate and hydroxyphosphate ester. Other catalysts that could be useful in the composition of the invention are Lewis acids, zinc salts and tin salts. Although a solvent may be present in the coating composition, in an amount of between about 0.01 percent, by weight, to about 99 percent, by weight, it is preferably present in an amount of less than 30%, more preferably less than -20%, and most preferably less than 10%. The coating composition preferably has a CVOC VOC is defined herein as the VOC according to ASTM D3960) of less than 3.8 3 pounds / galdn (455 kg / m), more preferably less than -3 3.0 pounds / galdn C359 kg / m), still more preferably - 3 less than 2.0 pounds / galdn (240 kg / m) and most preferably 3 less than 1.0 pounds / galdn (120 kg / m). The coating compositions can be reversed in the article by any of a number of techniques well known in the art. These include, for example, spray coating, dip coating, roll coating, curtain coating and the like. For automotive body panels, spray coating is preferred. An advantage that can be obtained with the coating compositions, according to the invention, is that coatings with a high degree of flexibility can be prepared. Therefore, in a preferred embodiment, the substrate on which the coating is applied is flexible, such as plastic, leather or fabric substrates. Any additional agent used, for example, -surfactants, fillers, stabilizers, wetting agents, dispersing agents, adhesion promoters, ultraviolet light absorbers, light stabilizers of the clogged amine, etc., could be incorporated into the composition of the dress Although the agents are well known in the art, the amount used must be controlled to avoid adversely affecting the characteristics of the coating. In a preferred embodiment, the composition of -coating, according to the invention, it is preferably used in a high gloss coating and / or as the transparent layer of a colored composite coating plus transparent layer. High gloss coatings, as used herein, are coatings with a gloss of 20 ° (ASTM D523-89) or an image sharpness (DOI) CASTM E430-91) of at least 80. In other preferred embodiments, You can use the coating composition to prepare low gloss or high gloss enamel coatings or printers. When the coating composition of the invention is used as a pigmented paint coating with high gloss, the pigment can be any organic or inorganic compound, or fillers or co-materials, metallic materials or other materials with inorganic flakes, such as mica or aluminum flakes, and other materials of the kind that the guild normally calls pigments. The pigments are generally used in the composition in an amount of 2% to 350%, based on the total weight Csin without including the solvent) of the components A and B (for example, a P: B ratio of 0.02 to 3.5) . When the coating composition, according to the invention, is used as the transparent layer of a colored composite coating plus a transparent layer, the composition of the pigmented base layer could be any of a number of well-known types in the composition. -the guild, and does not require detailed explanation -here. Polymers known in the art to be useful in basecoat compositions include acrylics, vinyls, polyurethanes, polycarbonates, polyesters, alkyd compounds, and siloxanes. Among the preferred polymers are acrylics and polyurethanes. In a preferred embodiment of the invention, the composition of the base layer also utilizes a functional acrylic polymer. carbamate The base layer polymers preferably have crosslinking capability and, therefore, include one or more types of crosslinkable functional groups. Among said groups are, for example, hydroxyl, isocyanate, amine, epoxy, acrylate, vinyl, silane and acetoasetate groups. These groups could be concealed or blocked in such a way that they are unblocked and available for the cross-linking reaction under the desired conditions of curing, generally at elevated temperatures. Among the useful functional groups with crosslinking capacity are the hydroxyl, epoxy, acid, anhydride, silane and acetoacetate groups. Among the preferred functional groups with cross-linking ability are the hydroxyl functional groups and the amine functional groups. The polymers of the base layer could have self-crosslinking capability, or they could require a separate crosslinking agent that is reactive with the functional groups of the polymer. When the polymer includes hydroxyl functional groups, for example, the crosslinking agent could be an aminoplast resin, isocyanates and isocyanates with blocking (including isocyanurates), and crosslinking agents with acid functionality or anhydride functionality.

The coating compositions described herein are preferably subjected to conditions for the coating layers to cure. Although various curing methods may be used, heat curing is preferred. Generally, heat cure is effected by exposing the coated article to elevated temperatures provided primarily by sources of radioactive heat. The curing temperatures will vary depending on the particular blocking groups used in the crosslinking agents; however, they are generally in a range between -93 ° C and 177 ° C. The coating composition, "with" the current invention, is curable even at relatively low curing temperatures. Therefore, in a preferred embodiment, the curing temperature is preferably between 115 ° C and 150 ° C, and more preferably at temperatures between 115 ° C and 138 ° C for a system catalysed with blocking acid. For a non-blocking acid catalyzed system, the curing temperature is preferably between 82 ° C and 99 ° C. The curing time will vary, depending on the particular components used and the physical parameters, such as the thickness of the layers; however, typical cure times have a range of 15 to 60 minutes and preferably 15-25 minutes for systems catalysed with -blocking acid and 10-20 minutes for systems catalyzed with -acid-free. In various embodiments in the present invention, the curable coating composition, when cured, can result in coatings having a surprising combination of high crosslinking density without being brittle. As used herein, the crosslink density is determined, as described in "Paint and Coatings Testing Manual", Gardner-S ard Handbook (Handbook Gardner-Sward), 14a. -ed. , chapter 46, p. 534, ASTM, 1995. Thus, a realization of the invention is directed to a coating-cured derived from the cured cladding compositions described above, with a crosslinking density of at least 3, and preferably, of at least 10. The invention is further described in the following Examples.

Preparation 1 In the first step, 120 parts of dimethylol-propidic acid (DMPA), an aliquot of 25% of the este-quiometric ratio, was charged with 943 parts of glycolid neodecanoate Glydexx N-10 to a reaction vessel. The mixture was heated to a temperature of 128 ° C. After a slight exothermic reaction, three more increments of 25% of 120 parts of DMPA were added, spaced over a period of 4 hours, and the temperature was maintained at 130 ° C. The reaction was monitored by means of the acid number, at a value of < 3 and - did not contain any residual epoxy group. In step two, 1211 parts of methyl carbamate, an excess of 50%, were added together with 10 parts of dibutyltin oxide catalyst and 950 parts of toluene. A reflux temperature of 109-117 ° C was maintained for 32 hours as the methanol was removed. The progress of the reaction was monitored by the hydroxyl number to at least 95% of the termination. The excess of methyl carbamate and solvent was removed and -450 parts of amyl acetate was added to reduce to a non-volatile content of 80%.

Preparation 2 In the first step, 89 parts of citric acid, an aliquot of 25% of the stoichiometric ratio, was charged with 1470 parts of glycidyl neodecanoate Glydexx® N-10 to a reaction vessel. The mixture was heated to a temperature of 128 ° C. After a slight exothermic reaction, three more increments of 25% of 89 parts of citric acid were added, spaced over a period of 4 hours, and the temperature was maintained at 130 ° C. The reaction was monitored by means of the acid number, at a value of <; 3 and did not contain any residual epoxy group. In step two, 840 parts of methyl carbamate were added, an excess of 50%, together with 12.8 parts of dibutyltin catalyst and 1200 parts of toluene. A reflux temperature of 109-117 ° C was maintained for 32 hours as the methanol was removed. The progress of the reaction was monitored by the hydroxyl number to at least 95% of the termination. The excess of methyl carbamate and solvent was removed and 425 parts of amyl acetate were added to reduce to a non-volatile content of 80%.

EXAMPLE 1 A coating composition was prepared, racking 84 parts of the product of Preparation 1, with 27 parts of a commercially available liquid hexamethoxymethylmelamine resin. In addition, 4 parts of blocked dodecylbenzenesulfadic acid catalyst, together with 22 parts of amyl acetate, were added to yield a coating composition with a non-volatile content of 61% by weight. The coating composition was sprayed on a panel, on a conventional high-solids basecoat, which contained a hydroxyl-functional acrylic polymer and a melamine resin curing agent, and was cured for 20 minutes at a time. metal temperature of 132 ° C. The resulting coating exhibited good film properties as measured by moisture resistance, solvent resistance, hardness, resistance to degradation, gravametry and weathering resistance, EXAMPLE 2 A coating composition was prepared by mixing 97 parts of the product of Preparation 2 with 19 parts of a commercial liquid hexametoxymethylmelamine resin. In addition, 4 parts of blocked dodecylbenzenesulfadic acid catalyst, together with 20 parts of amyl acetate, were added to yield a coating composition with a non-volatile content of 64%, by weight. The coating composition was sprayed on a panel, on a conventional base coat with high solids content, containing an acrylic polymer with hydroxyl functionality and a melamine resin curing agent, and cured for 20 minutes, a metal temperature of 132 ° C. The resulting coating exhibited good film properties as measured by moisture resistance, solvent resistance, hardness, resistance to degradation, grametry and weathering resistance. The invention has been described in detail in relation to the preferred embodiments thereof. However, it should be understood that variations and modifications may be made within the spirit and scope of the invention.

Claims (25)

1. A curable coating composition comprising: (A) a carbamato-functional component, which is the reaction product of: Cl) a compound having a plurality of hydroxyl groups, which is the reaction product of: a) a compound comprising at least one epoxide group and (b) a compound selected from the group consisting of hydroxy acids, comprising at least one organic acid group and at least one hydroxyl group, polyacids comprising a plurality of organic acid groups and mixtures thereof, (2) a compound comprising a carbamate group, and (B) a component - comprising a plurality of groups that are reactive with the carbamate functional groups in component (A) .

2. A curable coating composition, according to claim 1, wherein said compound (A) - (1) (a) is a glycidyl ester.

3. A curable coating composition, according to claim 1, wherein said compound (A) -Cl) (a) is a glycidyl ether.

4. A curable coating composition, according to claim 3, wherein said glycidyl ester has the formula: where R is a hydrocarbon group of 1 to 40 carbon atoms,

5. A curable coating composition, according to claim 3, wherein R is a hydrocarbon group of 1 to 12 carbon atoms.

6. A curable coating composition, according to claim 1, wherein said compound (A) Cl) (a) comprises a plurality of epididy groups.

7. A curable coating composition, according to claim 1, wherein said compound (A) (1) (a) comprises a single epoxide group.

8. A curable coating composition, according to claim 1, wherein said compound (A) (1) (a) is the glycidyl ester of neodecanoic acid.

9. A curable coating composition, according to claim 1, wherein said compound (A) (.1) Cb) is a polyacid comprising at least one hydroxyl group.

10. A curable coating composition according to claim 1, wherein said compound (A) (1) (b) is a hydroxy acid comprising a plurality of hydroxyl groups.

11. A curable coating composition, according to claim 1, wherein said organic acid is a carboxyl group.

12. A curable coating composition according to claim 1, wherein said compound (A > (1) (b) is a hydroxy acid comprising a plurality of carboxyl groups

13. A curable coating composition, in accordance with claim 1, wherein said hydroxyl group in compound (A) (1) (b) is a primary hydroxyl group

14. A curable coating composition, according to claim 1, wherein component (B) is a resin aminoplastic

15. A curable coating composition, according to claim 11, wherein said amino-plastic resin is a melamine resin

16. A curable coating composition, according to claim 1, having an organic content. 3 Volatile Mechanic (VOC) of less than 3.8 pounds / feet (455 kg /

17. A curable coating composition, according to claim 1, having a volatile organic content (VOC) of less than 3.0 pounds / feet C359 kg / m3)

18. A curable coating composition, according to claim 1, having an organic volatile CVOC content of less than 2.0 pounds / feet (240 kg /

19. A curable coating composition, according to claim 1, having a volatile organic content (VOC) of less than 1.0 pounds / feet (.120 kg / m).

20. A cured coating composition, comprising the reaction product of a coating composition according to claim 1.

21. A cured coating, according to claim 20, having a crosslinking density of at least 3.

22. A cured coating, according to claim 20, with a crosslink density of at least 10.

23. A coating, according to claim 20, with a brightness of 20 °, as defined by ASTM D523-89, of minus 80.

24. A coating, according to claim 20, with an image sharpness (DOI), as defined by ASTM E430-91, of at least 80.

25. A composite coating of color plus ca-pa transparent, wherein the transparent layer is derived from a coating composition according to claim 1.