MXPA97007985A - Coating compositions thermofraguadasteniendo better hardness - Google Patents

Abstract

The present invention relates to a crosslinkable coating composition comprising a mixture of: a. a poly (oligo) -meric polymeric component selected from the group consisting of di (poly) esters, polyesters, alkyd resins, acrylic resins, polyether polymers, polycarbonate resins and poly (oligo) méros containing a combination of two or more fractions ester , ether, carbonate, acrylic and alkyd in its structure, said polymeric component additionally characterized as having a number average molecular weight in the range of about 250 to about 20,000; and b. a phenolic alcohol ester having only one phenol group having at least one reactive phenolic hydroxyl, wherein the phenolic alcohol ester also has at least one aliphatic hydroxyl group and at least one esters, the phenolic hydroxyl and the aliphatic hydroxyl being effective for reaction with a linker cross section to cure the coating composition in a cure coating

Description

COATING COMPOSITIONS TER OFFRAGED HAVING IMPROVED HARDNESS Field of the Invention The present invention relates to transversely crosslinkable polymer compositions, to crosslinked solid polymeric compositions prepared therefrom, and to methods for improving the coating properties of films and surface coatings based thereon. Description of the Related Art Thermosetting coating formulations, particularly alkyd, acrylic, polyester or diester based coating compositions, are often the preferred materials for application to various substrates, particularly metal substrates, such as a paint or a protective coating . Such coatings can be formulated to provide a good balance of properties such as hardness, flexibility, solvent resistance, corrosion resistance, weathering and gloss. The improvement of these properties depends on many factors, including type, molecular weight, monomer composition, and glass transition temperature (Tg) of the resin; the type and amount of crosslinking agent; the curing conditions; the curing catalysts; pigments; fillings and additives. Variations of these parameters can be used to create a wide range of differences in film properties to meet the requirements of several diverse applications. However, it is not always possible to optimize all desirable properties simultaneously. The hardness of the thermoformed coating compositions can usually be increased either by providing a monomeric resin composition having a high glass transition temperature or by increasing the density of the crosslinking. The achievement of increased hardness by increasing the Tg of the polymer results in polymers having increased viscosity, which in turn may require the use of larger than desirable amounts of solvent to form suitable solutions for coating processes. On the other hand, an increase in the crosslinking density of di or polyhydroxy containing polymers containing a multifunctional crosslinking agent such as a multi-alkoxy methyl amino cross linking agent can be achieved by increasing the concentration of the hydroxy functional groups present in the polymer. For example, polyester polymers made by condensing a dibasic acid and an excess of diol and containing terminal hydroxy groups and having a low molecular weight contain a greater number of terminal hydroxy groups available as crosslinking sites than higher molecular weight materials. In this way, an increase in hardness of such resins can be achieved simultaneously with a reduction in viscosity and a reduction of the volatile solvent content of coating and paint formulations. However, a very high degree of transverse linkage tends to severely reduce the flexibility and can also affect other properties of the cured coating. Also, the use of high levels of crosslinking agents necessary for a high degree of crosslinking results in the formation of a large number of volatile side products of the crosslinking reaction, which is undesirable in such formulations. coating. A technique for improving the hardness and other properties of such coatings is the inclusion in the curable composition of about 1 to 60% by weight of a bis phenolic compound, for example bisphenol-A, as described in US Pat. 5166289. The polyhydric phenol component participates in the crosslinking reaction involving the base resin and the amino cross linker, thereby providing cured coatings of increased hardness. Nevertheless, bisphenols tend to be poorly-dissolvable in solvents normally used in such compositions, and additional amounts of solvent may be required to provide the required solubility. The inclusion of large amounts of solvent to provide more suscep-tibial viscosities to be worked also increases the content of the volatiles present in the composition, which is undesirable. US-A-4331782 discloses phenol functional polyester resins which are steam curable using isocyanate crosslinking agents. The phenol functional resins are prepared by first forming an ester-alcohol adduct of a hydroxybenzoic acid and an epoxy compound, and then forming the polyester by a polyesterification reaction, including the adduct, a polyol and a dibasic acid as reactants. Polyester resins are characterized by being topped by the functional phenol adduct. SUMMARY OF THE INVENTION The present invention provides crosslinkable coating formulations based on a mixture of a poly (oligo) -meric di or polyhydroxy functional component selected from the group consisting of di (poly) esters, polyesters, alkyd polymers, acrylic polymers, polyethers , polycarbonate and poly (oligó) mer polymers containing a combination of two or more ester, ether, carbonate, acrylic and alkyd fractions in their structure; a crosslinking agent and a reactive additive which is the ester reaction product of a phenolcarboxylic acid; and an epoxy compound. The preferred ester reaction products have the general formula A: where R4 is selected from the group consisting of hydrogen, halogen, hydroxyl, Cx to C8 alkyl, and alkoxy Q to Q, R, is a direct bond or an organic radical Cx to C20, which may incorporate another phenol or hydroxyl group aliphatic, ester, ether and / or carbonate in its structure, R6 is hydrogen or an organic radical Cx to C20 or a direct bond that can form with R7 part of a cyclic ring structure of 5 or 6 carbon atoms, R7 is CH2R8 , where Re is selected from the group consisting of hydroxy, OR9, OOCF ^ o and XR, wherein R is a primary or secondary aliphatic group containing 3 to 20 carbon atoms or an aromatic group containing 6 to 20 carbon atoms. R is a primary, secondary or tertiary aliphatic group containing 4 to 20 carbon atoms or an aromatic group containing 6 to 20 carbon atoms, and Ru is an organic radical C2 to C20 which can form with R6 part of a ring structure cyclic of 5 or 6 carbon atoms. More particularly, the present invention provides a crosslinkable coating composition comprising a mixture of: (a) an oligomeric or polymeric di or polyhydroxy functional component selected from the group consisting of a polyester, a diester of a di (poly) ol and a dicarboxylic acid, an alkyd resin, a polyether, an acrylic resin and a polycarbonate resin, said polymer component further characterized by having a number average molecular weight in the range of about 250 to about 20,000; (b) an ester reaction product of a phenol carboxylic acid and an epoxy functional compound; and (c) a cross-linking agent methylol (alkoxymethyl) amino present in an amount effective to crosslink the composition. The crosslinkable compositions of this invention can be used to prepare curable coating and paint formulations having workable viscosities (sprayable) and reduced volatile organic compound (VOC) content. The compositions may also contain other ingredients such as a crosslinking catalyst, fillers, pigments and the like. When cured, the coatings of this invention generally exhibit improved hardness properties when compared to cured coatings that do not contain the epoxy ester reaction product additive. The presence of the additive also serves to eliminate the problem of softening of coating when the coated substrate is baked for an extended period of time. These cured coatings also have good weathering, good corrosion resistance and hydrolytic stability, oxidative stability, good resistance to solvents and buckling and good adhesion properties. Detailed Description of the Invention The present invention is based on the fact that the low molecular weight reactive additives of the invention, when mixed with hydroxy functional polymers and the preferred curing agents of methylol (alkoxy methyl) amino, form linkable compositions transversally in which both the hydroxy functional polymers and the epoxy / phenol carboxylic acid reaction product participate in the crosslinking reaction under baking conditions. As a result, polymeric structures, including highly crosslinked polymer structures, can be formed under baking conditions with the use of very low molecular weight raw materials and low amounts of solvent. As indicated above, the oligomeric or polymeric component of the composition of this invention may comprise a di or polyhydroxy functional polymer including a polyester diester, an alkyd polymer, an acrylic polymer, a polyether, a polycarbonate polymer, or mixtures of two or more of these materials. Suitable diesters and polyesters are materials having the general formula I: i. 9 9 9 H0-R; -0-CR, -C-0- (R; -OCR, -CO) nR, -0H where n is 0 or an integer ranging from 1 to about 40, R2 is a divalent aliphatic or cycloaliphatic radical containing from 2 to about 40 carbon atoms or a mixture of such radicals, and R3 is a divalent aliphatic, cycloaliphatic or aromatic radical containing from 2 to about 40 carbon atoms, or a mixture of such radicals. Obviously, when n is 0 in formula I, a simple diester is represented. When n varies from 1 to about 40, a polyester is represented. In the most preferred embodiments of the invention, R2 is the divalent residue of a di (poly) ol containing from 2 to about 20 carbon atoms, more preferably from about 2 to 10 carbon atoms, and can also contain internal ester groups. Some preferred examples of the diols are one or more of the following: neopentyl glycol; ethylene glycol; hexamethylenediol; 1,2-cyclohexanedimethanol; 1,3-cyclohexanedimethanol; 1,4-cyclohexanedimethanol; diethylene glycol; triethylene glycol tetraethylene glycol; dipropylene glycol; polypropylene glycol hexylene glycol; 2-methyl-2-ethyl-l, 3-propanediol; 1,2-propanediol 1,2-butanediol; 1,3-butanediol; 2,3-butane diol; 1,4-butane-diol 2, 2, 4-trimethyl-1,3-pentanediol; 1,2-cyclohexanediol; 1,3-cyclohexanediol; 1,4-cyclohexanediol; neopentyl diol hydroxy methyl isobutyrate, and mixtures thereof. Examples of polyols include triols such as glycerin, trimethylol ethane, trimethylol propane, pentaerythritol, and the like. R3 is formula I above is the divalent residue of a dicarboxylic acid having from 2 to about 40 aliphatic carbon atoms, from about 5 to 40 cycloaliphatic carbon atoms, or from 6 to about 40 aromatic carbon atoms, as well as mixtures of these acids. The carboxyl groups may be present in the form of anhydride groups, lactone groups, or equivalent ester-forming derivatives such as the acid halide or methyl ester. Preferred dicarboxylic acids or derivatives are one or more of the following: phthalic anhydride, terephthalic acid, isophthalic acid, naphthalene dicarboxylic acids, adipic acid, succinic acid, glutaric acid, fumaric acid, maleic acid, cyclohexane dicarboxylic acid, acid azeleic, sebasic acid, dimeric acid, caprolactone, propiolactone, pyromellitic dianhydride, substituted maleic and fumaric acids such as citraconic, chloromaleic, mesaconic acid, and substituted succinic acids such as aconitic and itaconic acid, and mixtures thereof. Many commercially available polyesters are produced using a combination of aromatic and aliphatic dicarboxylic acids or a combination of cycloaliphatic and aliphatic dicarboxylic acids, or combinations of the three types. However, where polyesters having low viscosity and low solvent content are desired, the most preferred acids used for the purposes of this invention are linear, saturated or unsaturated aliphatic dicarboxylic acids, having from 2 to 10 carbon atoms such as succinic acid, glutaric, adipic and similar materials. The acrylic polymers that can be used as a polymer component in the present invention are acrylic copolymer resins. The acrylic copolymer resin is prepared from at least one hydroxy substituted alkyl meth (acrylate) and at least one non-hydroxy substituted alkyl (meth) acrylate. The hydroxy substituted alkyl (meth) acrylates which can be used as monomers comprise members selected from the group consisting of the following esters of acrylic or methacrylic acid and aliphatic glycols: 2-hydroxyethyl-acrylate, 3-chloro-2-hydroxypropyl acrylate; l-hydroxy-2-acryloxy propane; 2-hydroxypropyl acrylate; 3-hydroxypropylacrylate; 2,3-dihydroxypropylacrylate; 3-hydroxybutyl acrylate; 2-hydroxybutyl acrylate; 4-hydroxybutyl acrylate; diethylene glycol acrylate; 5-hydroxypentyl acrylate; 6-hydroxyhexyl acrylate; triethylene glycol acrylate; 7-hydroxyheptyl acrylate; 1-hydroxy-2-methacryloxy propane; 2-hydroxypropyl methacrylate; 2,3-dihydroxypropyl methacrylate; 2-hydroxybutyl methacrylate; 3-hydroxybutyl methacrylate; 2-hydroxyethyl methacrylate; 4-hydroxy-butyl methacrylate; 3, 4-dihydroxybutyl methacrylate; 5-hydroxy-pentyl methacrylate; and 7-hydroxyheptyl-5-methacrylate. Preferred hydroxy functional monomers for use in the preparation of acrylic resins are alkyl-II-hydroxy substituted (meth) acrylates having a total of 5 to 7 carbon atoms, ie esters of C2 to C3 dihydric alcohols and acids acrylics or methacrylics. Illustrative of the particularly suitable hydroxy-substituted alkyl (meth) acrylate monomers are 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, and 2-hydroxypropyl acrylate. Among the non-hydroxy substituted alkyl (meth) acrylate monomers that may be employed are the alkyl (meth) acrylates. Preferred non-hydroxy unsaturated monomers are esters of monohydric alcohols Cx to C12 and acrylic or methacrylic acids, for example methyl methacrylate, hexyl acrylate, 2-ethylhexyl acrylate, lauryl methacrylate, glycidyl methacrylate, etc. Examples of particularly suitable monomers are butyl acrylate, butyl methacrylate and methyl methacrylate. Additionally, the acrylic copolymer resins used in the present invention may include in their composition other monomers such as acrylic acid and methacrylic acid, monovinyl aromatic hydrocarbons containing from 8 to 12 carbon atoms (including styrene, alpha-methyl styrene, vinyl toluene , t-butyl styrene, chlorostyrene, and the like), vinyl chloride, vinylidene chloride, acrylonitrile, acrylics modified with epoxy and methacrylonitrile. The acrylic copolymer preferably has a number average molecular weight of not more than 20,000, more preferably between about 500 and 6,000, and most preferably between about 1,000 and 5,000. The alkyd polymers that can be used as the polymer component of the composition of this invention have a formula similar to formula I above, except that R2 is a divalent residue of a triol with a hydroxyl group esterified with a fatty acid. Typical triols are glycerin, trimethylol ethane and similar materials. These alkyd resins are oil-modified polyester resins and are largely the product of the reaction of a dihydric alcohol and a dicarboxylic acid or acid derivative of an oil, fat or carboxylic acid derived from such oil or fat, which acts as a modifier. Such modifiers are typically drying oils. The polyhydric alcohol used is suitably an aliphatic alcohol, and mixtures of the alcohols can also be used. The dicarboxylic acid, or corresponding anhydrides, may be selected from a variety of aliphatic carboxylic acids or mixtures of aliphatic and aromatic dicarboxylic acids. Suitable acid and acid anhydrides include, by way of example, succinic acid, adipic acid, phthalic anhydride, isophthalic acid, trimellitic acid (anhydride) and bis 3,3 ', 4,4'-benzophenone tetracarboxylic anhydride. Mixtures of these acids and anhydrides can be used to produce a balance of properties. A saturated or unsaturated fatty acid having from 12 to 22 carbon atoms or a corresponding triglyceride, that is to say a corresponding fat or oil, such as those contained in animal or vegetable fats or oils, is suitably used as the drying oil or fatty acid. Suitable fats and oils include tallow oil, castor oil, coconut oil, lard, linseed oil, palm oil, peanut oil, rapeseed oil, soy bean oil and beef tallow. Such fats and oils comprise mixed triglycerides of such fatty acids, such as caprylic, capric, lauric, myristic, palmic and stearic acids and such unsaturated fatty acids such as oleic, eracic, ricinoleic, linoleic and linolenic acids. Chemically, these oils and fats are usually mixtures of two or more members of the class. Alkyd resins made with saturated monocarboxylic acids and fats are preferable in cases where improved weather resistance is a primary concern. Oligomers or polycarbonate polymers which can be used in the preparation of the compositions of this invention with hydroxy-terminated polycarbonates having the general formula II: ?? or 0 0 9 HO-R2-0-C- (0-R2- - (C-R.} -C.-0-R2-0) n-C] q-0-R2-OH where q is an integer that varies from 1 to about 40, n is an integer that varies from 0 to 40, and R2 and R; they are as defined before. This formula includes diesters where n is 0, q is 1 or greater, which can be prepared by forming the condensation product of an aliphatic or cycloaliphatic diol having 2 to about 40 carbon atoms with a bisaryl ester of carbonic acid, such as carbonate of diphenyl, followed by the subsequent polycondensation reaction thereof as said diol. Also included in formula II are the elongated polyester diols via carbonate linkages and containing terminal carbonate groups that link end groups containing terminal hydroxy of the elongated diol polyester backbone, in which case n in formula II is equal to or greater that 1 and q is greater than 1. A third category of polycarbonate within the scope of formula II are polyester diols containing terminal carbonate groups that link the polyester diol backbone with hydroxy-containing end groups, in which case in formula II it is equal to 1 and n is greater than 1. These materials can be prepared by forming the condensation product of a polyester diol with a bisaryl ester of carbonic acid, such as diphenyl carbonate, to form the polyester-diol ester bis-carbonic acid, followed by polycondensation of this precursor with a diol to form hydroxy-terminated diesters. The polymeric component can also comprise poly (oligomers) which contain a combination of two or more ester, ether, carbonate, acrylic and alkyd moieties in their structure. Examples of such materials are poly (ether) esters, poly (ether) carbonates and poly (ether) or polyester acrylics. The diesters and polyesters can be prepared by means of well-known condensation processes using a molar excess of diol. Preferably, the molar ratio of diol to dicarboxylic acid is p + 1: p, where p represents the number of moles of dicarboxylic acid. The reaction can be conducted in the absence or in the presence of an aromatic or aliphatic solvent and in the absence or in the presence of a suitable polycondensation catalyst, as is known in the art. The preferred number average molecular weight (Mn) of the polymers can generally range from about 250 to about 20,000, more preferably from about 280 to about 10,000, and most preferably from about 300 to about 3,000 to 6,000. The glass transition temperatures (Tg) of these materials can generally vary from as low as -40 ° C to + 100 ° C or higher. The reactive additives used in the curable compositions of this invention are materials within the general structure of formula A above. The phenol carboxylic acid reagent used to prepare the ester reaction product of formula A has the general structure: where R4 and R5 are as described above. Examples of phenol carboxylic acids include hydroxybenzoic acids, acids wherein R is alkylene, such as phenyl acetic acid, hydroxy phenyl propionic acid, hydroxyphenyl stearic acid, and acids wherein R5 encompasses additional phenol functionality such as 4,4-bis-hydroxyphenyl pentanoic acid and the like . In a preferred embodiment of the invention, R 4 in formula A is hydrogen, R 5 is a direct bond, 6 R is hydrogen, and R is CH OH, a hydrocarbon fraction or an organic fraction containing ester or ether groups and containing 1 to about 20 carbon atoms, more preferably from about 3 to 20 carbon atoms. A particular advantage with the use of the reactive additives of this invention compared to, for example, the bisphenol-A type materials disclosed in US-A-5166289 is that the materials herein are generally more soluble in the solvents used conventionally in paint formulations and in many cases they are more compatible with other ingredients present in the formulation. In this way, low viscosity formulations that are solvent-free or contain lower amounts of solvent can be prepared, thereby reducing the content of volatile organic compounds (VOC) present in the formulation. Preferred reactive additives used in the curable compositions of this invention are the ester reaction products of a hydroxybenzoic acid and an epoxy compound. Suitable hydroxybenzoic acids include ortho-hydroxybenzoic acid (salicylic acid), meta-hydroxybenzoic acid and para-hydroxybenzoic acid (PHBA), para-hydroxybenzoic acid being most preferred. The epoxy compound can be selected from the group consisting of glycidyl esters, glycidyl alcohols, glycidyl ethers, linear epoxies and aromatic epoxies. These include glycidol, glycidyl ethers of the structure: CH2-CH-CH.OR9 glycidyl esters of the structure: CH H-CH2-0-C-R, or glycidyl or oxirane compounds having the structure: and cycloaliphatic epoxy compounds having the structures: where R12 is an organic radical having 1-12 carbon atoms which may include ether, ester, hydroxyl or epoxy groups, as well as other cycloaliphatic compounds having the structures: Other epoxy materials include epoxidized alpha-olefins and bis aromatic epoxies such as the reaction product of bisphenol A or F with epichlorohydrin. Suitable epoxy compounds include in particular monoepoxides containing a terminal glycidyl group or polyepoxides containing internal oxirane or glycidyl groups or terminal glycidyl groups. Suitable epoxy compounds include glycidol, glycidyl acrylate or methacrylate monomers, glycidyl alkyl ether monomers, and low molecular weight copolymers of one or more of these monomers with one or more ethylenically unsaturated monomers such as acrylates, methacrylates, vinyl aromatic monomers and Similar. Other suitable epoxy compounds include the ester reaction products of epichlorohydrin with aliphatic or aromatic carboxylic acids or anhydrides, mono or dibasic containing from about 1-20 carbon atoms. Included in such acids are the aliphatic acids such as acetic, butyric, isobutyric, lauric, stearic, maleic and myristic acids and aromatic acids such as benzoic, phthalic, isophthalic and terephthalic acids, as well as the corresponding anhydrides of such acids. Preferred acids are primary, secondary or tertiary aliphatic carboxylic acids containing from 5 to 13 carbon atoms. A preferred epoxy compound of this type is the glycidyl ester of an aliphatic, mixed, predominantly tertiary monocarboxylic acid, with an average of 9 to 11 carbon atoms such as those available from Exxon Chemical Company under the trademark Glydexx®, or from Shell Chemical Co. under the brand name Cardura® E for ester. Still other epoxy compounds include the reaction products glycidyl ether of epihalohydrin with aliphatic or aromatic alcohols or polyols containing from about 1 to 20 carbon atoms. Suitable alcohols include aromatic alcohols such as benzyl alcohol; aromatic polyols such as bisphenol, bisphenol A, bisphenol F, phenolphthalein and novolac resins; aliphatic alcohols such as ethanol, isopropanol, isobutyl alcohol, hexanol, stearyl alcohol and the like; and aliphatic polyols such as ethylene glycol, propylene glycol and butylene glycol. Other epoxy compounds that can be used include monoepoxides of alpha mono-olefins C8 to C20. The epoxy compound may also comprise epoxidized fatty compounds. Such epoxidized fatty compounds include epoxidized fatty oils, epoxidized fatty acid esters of monohydric alcohols, epoxidized fatty acid esters of polyhydric alcohols, epoxidized fatty nitrites, epoxidized fatty amides, epoxidized fatty amines, and epoxidized fatty alcohols. Suitable materials of alicyclic epoxide and polyepoxide include dicyclopentadiene diepoxide, limonene diepoxide, and the like. Additional useful epoxides include, for example, vinyl cyclohexane dioxide, bis (3,4-epoxycyclohexyl) adipate, 3,4-epoxycyclohexylmethyl-3,4-epoxy-cyclohexane carboxylate and 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-methadioxa-no. The preferred hydroxybenzoic acid / epoxy reaction product of this invention can be formed by reacting the hydroxybenzoic acid and the epoxy compound, optionally in a solvent therefor, at a temperature ranging from about 90 to about 120 ° C to Start such a reaction. Once the reaction is initiated, such a reaction is exothermic, and the reaction temperature can be raised to a level of about 150 to 175 ° C, usually without the application of external heat. The reaction temperature is then maintained at about 150-170 ° C (and preferably less than 200 ° C) until it has been determined that the reaction is substantially complete. Reduced discoloration reaction products can be produced by controlling the maximum temperature of the exothermic reaction. This can be achieved by the stepwise and / or incremental addition of one of the reagents, for example the epoxy reagent, so that the reaction temperature is maintained at a temperature of about 150 ° C or less. The remainder of that reagent can then be added in stages or continuously while maintaining the reaction temperature below about 150 ° C. This process modification results in reaction products that have lower values of the color index.

Approximately stoichiometric amounts of the epoxy compound and the phenol carboxylic acid are used in the reaction, although a slight molar excess of epoxy may be necessary to drive the reaction until it is consummated. The reaction product of phenol carboxylic acid / epoxy can be physically mixed with the base polymer at a physical mixing ratio of 1 to about 60% by weight of the reaction product, based on the weight of the base polymer and the cross linking agent taken together. More preferred compositions contain the reaction product at a level of from about 2 to about 40% by weight, and most preferably at a level of about 3 to 20% by weight, based on the weight of the polymer base and the transverse linkage agent taken together. Methylol crosslinking agents (Alkoxymethyl) amino acids used in the present invention are well known commercial products, and are generally made by the reaction of di (poly) amide (amine) compounds with formaldehyde and, optionally, a lower alcohol. Examples of suitable amino cross linker resins include one or a mixture of the following materials: Melamine Based Resins (ROCH2) 2N-C C-N (CH20R) 2 ? (CH2OR) 2 where R is as follows: R = CH3 (Cymel® 300, 301, 303); R = CH3, C2H5 (Cymel® 1116); R = CH3, C4H9 (Cymel® 1130, 1133); R = C4H9 (Cymel® 1156); or R = CH3H (Cymel® 370, 373, 380, 385). The preferred melamine is hexametoxymethyl melamine Benzosuanamine-based resins (ROCH2); N - - N (CH2OR) 2 where R = CH3, C2H5 (Cymel® 1123). Urea-based resins (ROCH; i; N-C-N (CH; OR): O where R = CH3 / H (Beetle 60, Beetle 65) or R = C4H9 (Beetle 80). Glycerin-based Resins where R = CH3, C2H5 (Cymel® 1171); or R = C4H9 (Cymel® 1170). In the present invention, the ratio of the active crosslinking groups, for example methylol (alkoxymethyl) groups of the cross-linking agent amino to the terminal hydroxy groups in the curable components is desirably from 1.0: 1.0 to 15.0: 1.0, with higher preference around 1.5: 1.0 to 5.0: 1.0, most preferably around 1.5: 1.0 to 4.0: 1.0. On a basis of weight, the amount of amino cross linker effective to cure the crosslinkable binder generally ranges from about 3 to about 60% by weight, more preferably from about 10 to about 50% by weight, based on the combined weight of the amino cross linker, polymer and any other crosslinkable polymer constituent of the composition. In general, the amounts of crosslinking agent required to cure the composition are inversely proportional to the numerical average molecular weight of the base polymer. Amounts of crosslinking agent in the upper side of this range are required to properly cure the polymer compositions having a relatively low numerical average molecular weight, for example from about 250 to about 3,000, while smaller amounts of the crosslinking agent are required to properly cure polymers having a higher numerical average molecular weight, for example from about 3,000 to about 20,000. The composition of the invention can also be cured using one or more multi-isocyanate crosslinking agents. Examples of such materials include di or aromatic and aliphatic polyisocyanates of the type described in US-A-4331782, the full disclosure of which is incorporated herein by reference. The amount of the crosslinking agent required to cure the base polymer depends on the hydroxyl equivalent weight of the base polymer. For bis-hydroxyl functional polymers (polyesters), the equivalent weight is equal to half the molecular weight. For polyfunctional polymers (acrylics), the equivalent weight is essentially independent of the molecular weight and depends on the concentration of the hydroxyl functional monomer in the structure of the polymer or copolymer. In general, the crosslinking agent and the ester reaction product of formula A above are present in the composition at a respective weight ratio of about 40 to 75 parts by weight of crosslinking agent by 60 to 25 parts by weight. weight of the ester reaction product, more preferably from 50 to 70 parts by weight of the first by 50 to 30 parts by weight of the last mentioned.

The present invention also provides a novel coating composition formed by combining the oligomeric or polymeric component, the phenol carboxylic acid / epoxy reaction product component, the crosslinking agent, and optionally a solvent. The application of the formulated coating can be done via conventional methods such as spraying, roller coating, dip coating, etc., and then the coated system can be cured by baking. Suitable optional solvents which may be included in the curable compositions of the invention comprise toluene, xylene, ethylbenzene, tetralin, naphthalene and solvents which are narrow-cut aromatic solvents comprising C8 to Q3 aromatics such as those sold by Exxon Chemical Company under the designations Aromatic 100, Aromatic 150 and Aromatic 200. Other suitable solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, methyl isoamyl ketone, methyl heptyl ketone, isophorone, isopro-panol, n-butanol, sec-butanol, isobutanol , amyl alcohol, isoamyl alcohol, hexanols and heptanols. Suitable oxygenated solvents include propylene ether monomethyl glycol acetate, propylene glycol propyl ether acetate, ethyl ethoxypropionate, dipropylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and the like. Other such solvents include alkyl esters such as ethyl acetate, n-propyl acetate, butyl acetate, amyl acetate, mixtures of hexyl acetates such as those sold by Exxon Chemical Company under the trademark Exxate® 600 and mixtures of acetates. of heptyl sold under the Exxate® 700 brand. The list should not be considered as limiting, but rather as examples of solvents that are useful in the present invention. The type and concentration of solvents are generally selected to obtain formulation viscosities and evaporation rates suitable for the application and baking of the coatings. Typical solvent concentrations in the formulations vary from 0 to about 75% by weight, with a preferred range between about 5 and 50% by weight, and a more preferred range between about 10 and 40% by weight. For the preparation of coatings with high solids content, the amount of solvent used in the coating formulation is preferably less than 40% of the weight of the formulation. The pigments are an additional component that may be present in the curable compositions of this invention. Generally, a weight ratio in the range of about 0.5 to about 5.0 to 1.0 of pigment to binder is included, the term binder referring to the total weight of the polymer plus the crosslinking agent. Suitable pigments which may be included in the compositions of this invention are those opacifying pigments normally used in formulations of paints and coatings, and include titanium dioxide, zirconium oxide, zircon, zinc oxide, iron oxides, antimony, carbon black, as well as yellows, greens and oranges of chromium, mixed metal oxides, ceramic pigments, and the like. Preferred pigments include rutile Ti02 and particularly coated, weather-resistant TiO2 types. The pigments can also be physically mixed with a suitable extender material that does not contribute significantly to the hiding power. Suitable extenders include silica, barites, calcium sulfate, magnesium silicate (talc), aluminum oxide, aluminum hydroxide, aluminum silicate, calcium silicate, calcium carbonate (mica), potassium aluminosilicate, and other clays or materials similar to clay. Successful baking schedules for the formulations of the present invention vary widely, including but not limited to low temperature baking of about 20 to 30 minutes at temperatures between 90 and 105 ° C for large equipment applications, and baked at high temperature for about 5 to 10 seconds in air at 300-375 ° C for coil coating applications. In general, the substrate and the coating must be baked at a sufficiently high temperature for a sufficiently long time so that essentially all the solvents are evaporated from the film and the chemical reactions between the polymer and the crosslinking agent continue to the desired degree of consummation. The desired degree of completion also varies widely and depends on the particular combination of cured film properties required for a given application. Acid catalysts can be used to cure systems containing hexamethoxymethyl melamine and other amino crosslinking agents, and a variety of suitable acid catalysts are known to those skilled in the art for this purpose. These include, for example, p-toluene sulfonic acid, methane sulfonic acid, nonylbenzene sulphonic acid, phosphoric acid, phosphorous acid, phenyl acid phosphate, butyl phosphate, butyl maleate and the like, or a compatible mixture thereof. These acid catalysts can be used in their clean, unblocked form, or combined with suitable blocking agents, such as amines. Typical examples of unblocked catalysts are the products of King Industries, Inc. under the K-Cure® brand. Examples of blocked catalysts are the products of King Industries, Inc. under the Nacure® brand. The amount of catalyst typically employed varies inversely with the severity of the baking program. In particular, lower concentrations of catalysts are usually required for higher baking temperatures or longer baking times. Typical catalyst concentrations for moderate baking conditions (15 to 30 minutes at 150 ° C) would be from about 0.2 to 0.5% by weight of catalyst solids per polymer solids plus cross-linking agent. Higher catalyst concentrations of up to about 2% by weight can be employed for curing at a lower temperature or shorter times. Formulations containing sufficient residual esterification catalyst, such as phosphorous acid, may not require the inclusion of any additional crosslinking catalyst to effect an appropriate cure at lower cure temperatures. In the case of formulations of this invention containing hexametoxymethyl melamine as the crosslinking agent and p-toluene sulfonic acid as the catalyst, the preferred conditions of curing at a dry film thickness of about one thousandth of an inch are catalyst concentration of between about 0.05 and 0.6% by weight, based on the polymeric solids plus the solids of the crosslinking agent, baking temperature of between 90 and 210 ° C, and baking time between about 5 and 60 minutes. The most preferred curing conditions are a catalyst concentration between about 0.05 and 0.5% by weight, baking temperature between about 120 and 180 ° C, and baking time between about 5 and 40 minutes. As described above, the formulations of this invention are characterized by improved weathering resistance. However, further improvements can be achieved in this and other properties including stabilizers and stabilization systems in the formulation. Among the compounds that provide improvements in weathering resistance are HALS (hindered amine light stabilizers), UV filters, and other anti-oxidants. Fluid modifiers, rheology modifiers, pigment dispersants and the like may also be included in the composition. The coating formulations of the present invention can be prepared first by forming a grinding base. The grinding base can be prepared by grinding a pigment mixture, resin and solvent in a high speed disk dispersant, such as the Dispermat®, model CV of By-Gardner, to form a pigment concentrate. This grinding base is then dropped (mixed) under mixing conditions with the remaining components of the formulation, which include additional resin, solvent, crosslinking agent, and catalyst. The coating compositions of the invention can be applied to substrates by any suitable conventional technique such as spraying, roller coating, dip coating, and the like. The composition can be applied in liquid form, and is preferably dispersed in an organic solvent. Typical solven-te concentrations in the formulations generally range from 0 to about 15% by weight, with a preferred range of between about 5 and 50% by weight, and a more preferred range of between about 10 and 40% by weight. weight. The crosslinking density and the degree of transverse linkage of the composition can be monitored by evaluating the impermeability of the coated coating to the organic solvent. A suitable test to evaluate this property is the rub test with MEK (methyl ethyl ketone), as described in paragraph 5.2 of the ASTM D3732 method. This test measures the number of double rubs of a swab soaked with methyl ethyl ketone (MEK) required to completely remove the cured coating of a substrate. In general terms, the coatings of this invention are cross-linked in sufficient manner such that rubbing values with MEK of more than about 5, more preferably about 15, and most preferably over 50 or 100 are achieved. Properly formulated binder paints and coatings comprising compounds of structure A above provide at least one of the listed improvements: improved hardness-flexibility balance, lower VOCs at a workable viscosity, improved adhesion, improved anti-corrosive properties, improved solvent resistance, and oxidative resistance. / oa improved location improved electrical resistance improved weather resistance The following examples illustrate the preparation of some preferred curing agents and their use as a physical blending component in the formation of curable polymeric compositions of the invention. The materials identified in the examples by trademarks or trade designations are the following: Glydexx N-10 glycidyl ester of a mixture of tertiary aliphatic acids having 9-11 carbon atoms, available from Exxon Chemical Company Glydexx ND-101 same as N-10, but less pure Araldite DY-025 a C8 glycidyl ether available from Ciba-Geigy Corp. Cyracure 6216 a linear epoxy C16 available from Union Carbide Cargill 57-5789 a hydroxy functional polyester having a molecular weight of 900-1,000, available from McWhorter Corp. Cargill 57-5742 an alkaline resin based oil tofa also available from McWhorter Corp. Rucoflex S107-210 neopentyl glycol adipate diester oligomer having a molecular weight of about 560 MIAK Methyl isoamyl ketone solvent mixture a mixture of methyl ethyl ketone, butyl acetate, xylene, butanol and Exxate® 600 present at a respective weight ratio of 2: 3: 3: 1: 1 HMMM transverse linker agent of hexametoxymethyl melamine BYK 300 silicone flow control agent by Byk-Chemie DC-57 silicone flow control agent by Dow Corning BYK 451 p-toluene sulfonic acid catalyst, blocked with amine, by Byk -Chemie Nacure 2500 blocked p-toluene sulfonic acid catalyst from King Industries Examples 1-4 below illustrate the preparation of four different PHBA ester reaction products and various epoxy compounds, and the properties of each.

Synthesis of Glycidyl Ester + PHBA Into a one liter flask equipped with agitator, nitrogen, heater and temperature probe, 326.6 g of Glydexx® glycidyl ester N-10 and 173.4 g of parahydroxy benzoic acid (PHBA) were charged. The mixture was heated to 110 ° C. At that point, an exothermic reaction takes place. The maximum temperature reached was 160 ° C. At that point, the solution was clear. The solution was then cooled and discharged. The physical properties are given below: Acid number 0 mg KOH / g Hydroxyl number 301.0 mg KOH / g NVM > 99% Color (3 Gardner Example 2 Synthesis of Glycidyl Ester and PHBA In a 3 liter flask equipped with heater, stirrer and nitrogen, 326.6 g of Glydexx® ND-101 and 173.4 g of parahydroxy benzoic acid (PHBA) were charged. The mixture was heated to 110 ° C with stirring. At approximately 110 ° C an exothermic reaction occurred. The mixture turned from a hazy solution to a clear solution as the temperature approaches a maximum of 158 ° C. The solution was cooled back to room temperature. The physical characteristics are given below: Acid number 2.5 mg KOH / g Hydroxyl number 417 mg KOH / g NVM 98.8% by weight Color (3 Gardner Example 3 Synthesis of Glycidyl Ether + PHBA 200 g of Araldite DY025 and 87.6 g of PHBA in a one-liter flask equipped with stirrer, heater and nitrogen.The mixture was heated to 135 ° C. An exothermic reaction occurred at 135 ° C. The maximum temperature reached was 172 ° C. At around 158 ° C. the solution turned from nebulous to clear.The reaction was then cooled back to room temperature.The physical characteristics are given below: SO 9.8 mg KOH / g Hydroxyl number 360.0 mg KOH / g NVM 96.01% by weight Example 4 Synthesis of Linear Epoxy + PHBA 250 g of Cyracure 6216 and 124.2 g of parahydroxy benzoic acid were charged into a one liter flask equipped with stirrer, heater and nitrogen.The reaction was heated to 150 ° C. At that temperature an exo reaction occurred. temperature and the temperature was increased to 159 ° C. The temperature was maintained at 160 ° C. The solution became clear. To bring the reaction to completion, the solution was maintained at 170 ° C for four hours. The solution was then cooled to room temperature. The physical properties are given below: TAN 10.5 mg KOH / g Hydroxyl number 294.0 mg KOH / g NVM 97.4% The paint formulations having compositions as outlined in the following examples were prepared by forming a grinding base composition and a composition of mixing by means of the general procedure described above. The test panels were prepared and evaluated as follows: Thin films of the various formulations were applied to steel test panels via stretch. The basic procedures are outlined in the ASTM D823-87 test procedure. The test panels are either cold rolled steel panels type S, untreated, obtained from Q-Panel Company, or Bonderite 1000 panels (iron phosphate treatment), polished, obtained from Advanced Coatings Technology Inc. The panel sizes are either 4 x 8 inches or 3 x 6 inches. Stretch rods wrapped in wire, and in some cases a stretch machine Precision Laboratory (both from Paul N. Gardner Company) are used to apply the films via hand stretches (method E). The target thicknesses of dry film are 1 mil. The evaluations of the film properties conducted on all cured panels were as follows: Knoop Hardness ASTM D-1474 Direct Impact ASTM D-2794 Inverse Impact ASTM D-2794 VOC EPA Method 24 Pencil Hardness ASTM D-3363 Flexibility (Bending in T) ASTM D-1737 Adhesion ASTM D-3359 Corrosion resistance (salt sprayed) ASTM B-117 Rubbing with MEK ASTM D-3732 Weathering (QUV) ASTM G-53 Buckling strength ASTM D-4400 In the case of tests of impact, a 5/8 inch punch was used with a 0.64 inch punch.

Example 5 (Control) A polyester paint was formulated as follows: Grinding Base Amount (s) Polyester (Cargill 57-5789) 15.8 Ti02 32.6 MIAK 1.6 Polyester Mix (Cargill 57-5789) 21.7 HMMM 9.0 BYK 451 0.8 BYK 300 0.1 MIAK 15.0 The resulting paint had a measured content of volatile organic compounds (VOC) of 3.2 lg / gallon at a viscosity of 29.8 seconds (Zahn, cup No. 2). The painting was baked at 177 ° C for 10 minutes. Paints with a dry film thickness of one thousandth of an inch were stretched over Bonderite 1000 panels. The results are given below: Dry Film Test Hardness of pencil 2H Knoop hardness 17.7 Direct impact (lb-in) 160 T-bend (uncollected) 2T Adhesion 5 Corrosion resistance, blister (salt spray, 144 hrs) 6 Double rubs with MEK 200 Gloss 600 97 Resistance to buckling (thousandths) 1.3 Example 6 The formulated paint of Example 5 was modified by adding the reaction product of parahydroxy benzoic acid (PHBA) and Glydexx® glycidyl ester N-10, made as described in Example 1. Grinding Base Amount (a) Polyester (Cargill 57-5789) 15.8 Ti02 32.6 MIAK 1.6 Polyester Mix (Cargill 57-5789) 14.2 HMMM 11.3 Reaction product Example 1 4.1 BYK 451 0.8 BYK 300 0.1 MIAK 14.2 Paint that had a content of VOCs measured 3.0 lb./galon at a viscosity of 28.4 seconds (Zahn No. 2) was baked at 177 ° C for 10 minutes. Paints with a dry film thickness of one thousandth of an inch were stretched over Bonderite 1000 panels. The test results are given below: Dry Film Testing Pencil hardness 2H Hardness Knoop 19.6 Direct impact (lb-in) 160 T-bend (uncollected) 2T Adhesion 5 Corrosion resistance, blistering (salt spray, 144 hrs) 10 Double rubs with MEK 200 Brightness 60 ° 98 Resistance to buckling (thousandths)} l.4 Example 7 (Control) The following painting was made using a short tofa oil alkyd. Base of Mold Quantity Alkyd (Cargill 57-5742) 15.0 Ti02 34.1 MIAK 1.8 Alkyd Mix (Cargill 57-5742) 20.6 HMMM 10.7 BYK 451 0.8 BYK 300 0.1 MIAK 16.9 The resulting paint had a measured VOC content of 3.1 lb / gal to a viscosity of 25.0 seconds (Zahn No. 2). The panels were made by stretching the paint over Bonderite 1000 panels. The panels were cured at 177 ° F for 10 minutes. The physical properties of the paint are given below: Dry Film Test Hardness of pencil 2H Hardness Knoop 16.5 Direct impact 70 T-bend (uncollected) 4T Adhesion 5 Double rubs with MEK 200 Gloss 60 ° 99 The alkyd formulation of Control Example 7 was modified to include the reaction product prepared in Example 1 in the formulation. Milling Base Amount (a) Alkyd (Cargill 57-5742) 15.0 Ti02 34.1 MIAK 1.8 Alkyd Mix (Cargill 57-5742) 13.5 HMMM 12.7 Reaction Product of Example 1 4.2 BYK 451 0.8 BYK 300 0.1 MIAK 15.8 The resulting paint had a measured VOC content of 2.9 lb / gal at a viscosity of 25.7 seconds (Zahn No. 2). The painted panels were made by stretching the paint on Bonderite 1000 panels and baking the panels for 10 minutes at 177 ° C. Paints of one thousandth of an inch of dry film thickness were made. The properties of the paint are given as follows: Dry Film Test Hardness of pencil 2H Knoop hardness 18.4 Direct impact (lb-in) 80 T-bend (uncollected) 4T Adhesion 5 Double rubs with MEK 200 Gloss 600 100 Example 9 (Control) A low VOC paint was made using the Rucoflex® S-107-210 polyester diol. The following formulation was used: Amount (s) Polyester diol (Rucoflex® S-107-210) 35.0 HMMM 17.5 Nacure® 2500 0.5 Mixture of solvents 6.7 Dow Corning® DC-57 0.1 The resulting paint had a measured VOC content of 1.8 lb / gallon at a viscosity of 21.7 seconds (Zahn No. 3). A one thousandth of an inch thick dry film was applied over Bonderite 1000 panels. The panels were cured for 10 minutes at 177 ° C. The results are given below: Dry film test Pencil hardness F Direct impact (lb-in) 120 T-bend (uncollected) 4T Adhesion 3 Double rubs with MEK 200 Example 10 A paint was made replacing 20% of the binder in Example 9 with the reaction product prepared in Example 1. The formulation used was as follows: Amount (a) Polyester diol (Rucoflex® S-107-210) 28.0 HMMM 19.0 Reaction product of Example 1 5.0 Nacure® 2500 0.5 Solvent Blend 7.9 Dow Corning DC-57 0.1 The resulting paint had a measured VOC content of 1.9 lb / gallon at a viscosity of 21.9 seconds (Zahn No. 3). A dry film one thousandth of thickness was applied to Bonderite 1000 panels. The panels were cured for 10 minutes at 177 ° C. The test results were as follows: Dry Film Test Pencil hardness 3H Direct impact (lb-in) 140 T-bend (uncollected) 4T Adhesion 3 Double rubs with MEK 200 Example 11 The polyester diol formulation of Example 9 was modified by addition of the reaction product of Example 2, as follows: Amount (s) Polyester diol (Rucoflex® S-107-210) 28.0 Reaction product of Example 2 5.05 HMMM 19.0 Nacure® 2500 0.25 DC-57 0.1 Solvent mixture 7.15 The resulting paint had a measured VOC content of 2.1 lb / gallon and a viscosity of 22.9 seconds (Zahn No. 3). A thousandth of an inch thick paint was applied to Bonderite 1000 panels. The panels were cured for 10 inutes at 177 ° C. The test results are as follows: Dry Film Test Hardness of pencil H Direct impact 140 Example 12 The polyester diol formulation of Example 9 was modified by the addition of the reaction product of Example 3, as follows: Amount (s) Polyester diol (Rucoflex® S-107-210) 28.0 HMMM 20.0 Reaction product of Example 3 5.20 Nacure ® 2500 0.65 DC-57 0.10 Solvent Blend 7.20 The resulting paint had a measured VOC content of 1.8 lb / gal and a viscosity of 22.1 seconds (Zahn No. 3). A paint of one thousandth of an inch of dry film thickness was applied to Bonderite 1000 panels. The panels were baked for 10 minutes at 177 ° C. The results are as follows: Dry Film Test Hardness of pencil H Double rubs with MEK 100 Example 13 The polyester diol formulation of Example 9 was modified by the addition of the reaction product of Example 4, as follows: Amount (s) Polyester diol (Rucoflex® S-107-210) 28.0 HMMM 19.0 Reaction product of Example 4 5.20 Nacure® 2500 0.65 DC-57 0.10 Solvent mixture 7.35 The resulting paint had a measured VOC content of 1.9 lb / gal and a viscosity of 24.8 seconds (Zahn No. 3). A thousandth of an inch thick dry paint was applied to Bonderite 1000 panels. The panels were baked for 10 minutes at 177 ° C. Dry Film Test Pencil hardness 2H Direct impact (lb-in) 100 Double rubs with MEK 200 Comparative Example 14 This example, which is outside the scope of the present invention, illustrates the preparation of a composition of the type described in Example 5 of US-A-5166289, where neopentyl glycol-bis para-hydroxy benzoic acid is used as a curing component.

The paint formulation of Example 9 was modified by inclusion of NPG-bis PHBA in the composition, as follows: Grinding Pass Amount (s) Polyester diol (Rucoflex® S-107-210) 31.5 HMMM 18.0 NPG-bis PHBA 4.0 Nacure® 2500 0.32 DC-57 0.1 Solvent Blend 8.7 The resulting paint had a VOC content of 2.1 lb / gal and a viscosity of 24.8 seconds (Zahn No. 3). A paint of one thousandth of an inch of dry film thickness was applied to Bonderite 1000 panels. The panels were baked for 10 minutes at 177 ° C. The test results were as follows: Pencil Hardness 2H Direct Impact (lb-in) 160 The analysis of the test results of the examples demonstrates that formulations within the scope of this invention have comparable hardness and impact properties with the achieved in US-A-5166289 and, at the same time, can be made from formulations having a lower content of volatile organic compounds and viscosities capable of being worked in the range of about 20-30 Zahn seconds.

The coatings and paints of the invention can be used for application by means of spraying, rolling or immersion to various metal surfaces such as automotive surfaces, building panels, metal furniture, household appliances and other metal surfaces and for applications of Coil coating, followed by proper baking to provide hard, durable and decorative finishes.

Claims (42)

1. REVIVAL APPLICATIONS 1. A crosslinkable coating composition comprising a mixture of: a. a poly (oligo) -meric polymeric component selected from the group consisting of di (poly) esters, polyesters, alkyd resins, acrylic resins, polyether polymers, polycarbonate resins, and poly (oligo) mers containing a combination of two or more ester, ether, carbonate, acrylic and alkyd fractions in their structure, said polymer component further characterized by having a number average molecular weight in the range of from about 250 to about 20,000; and b. an ester phenolic alcohol having only one phenol group having at least one reactive phenolic hydroxyl, wherein the phenolic alcohol ester also has at least one aliphatic hydroxyl group and at least one ester group, the phenolic hydroxyl and the aliphatic hydroxyl being effective for reaction with a cross slab to cure the coating composition in a cured coating.
2. 2. The composition of claim 1, which further contains: (c) a crosslinking agent for said polymer component.
3. The composition of claim 2, wherein the phenolic alcohol ester is the reaction product of a phenol carboxylic acid and an epoxy functional compound and said crosslinking agent is a cross-linking agent of methylol (alkoxymethyl) amino present in a effective amount to crosslink the composition.
4. 4. The composition of claim 3, wherein said phenolic alcohol ester has the structure: where R 4 is selected from the group consisting of hydrogen, halogen, hydroxyl, C x a alkyl and C alkoxy alkoxy. is a direct bond or an organic radical Q1 to C20, Rg is hydrogen or an organic radical C? to C20, which can form with R7 part of a cyclic ring structure of 5 or 6 carbon atoms, R7 is CH2R8, where R is selected from the group consisting of hydroxy, OR9, OOCR10 and Ru, where R9 is a group primary or secondary aliphatic containing 3 to 20 carbon atoms or an aromatic group containing 6 to 20 carbon atoms, R10 is a primary, secondary or tertiary aliphatic group containing 4 to 20 carbon atoms or an aromatic group containing 6 to 20 carbon atoms carbon, and Ru is a C2 to C20 organic radical that can form with R6 part of a cyclic ring structure of 5 or 6 carbon atoms.
5. The composition of claim 4, wherein R and R6 are each hydrogen, R5 is a direct bond, and R is selected from the group consisting of CH2OH, a hydrocarbon fraction containing 3 to about 20 carbon atoms and a fraction organic containing ester or ether groups and containing from 3 to about 20 carbon atoms.
6. 6. The composition of claim 3, wherein said phenol carboxylic acid is a hydroxybenzoic acid.
7. The composition of claim 3, wherein said epoxy functional compound is an ether or glycidyl ester containing a terminal epoxy group.
8. The composition of claim 3, wherein said phenol carboxylic acid is para-hydroxybenzoic acid.
9. The composition of claim 3, wherein said ester reaction product has a molecular weight in the range of about 250 to about 1,000.
10. The composition of claim 3, wherein said ester reaction product is the reaction product of para-hydroxybenzoic acid and a glycidyl ester of one or a mixture of aliphatic acids containing 5 to 13 carbon atoms.
11. The composition of claim 10, wherein said reaction product is the glycidyl ester of an aliphatic acid containing an average of 9 to 11 carbon atoms.
12. The composition of claim 3, wherein said ester reaction product is present in said composition at a level of from about 1 to about 60% by weight based on the combined weight of said polymer and amino crosslinking agent taken together.
13. 13. The composition of claim 12, wherein said ester reaction product is present at a level of from about 2 to about 30% by weight, based on the combined weight of said polymer and amino cross linker taken together.
14. The composition of claim 1, wherein said polymer component has a number average molecular weight in the range of about 250 to about 10,000.
15. 15. The composition of claim 14, wherein said molecular weight is in the range of about 250 to about 6,000.
16. The composition of claim 1, wherein said polymer component is a diester or polyester polymer having the structure: O O o o II II II II HO-Rj-O-C-Ra-C-O- (R-0-C-R3-C-0) B-R, -OH where n is 0 or an integer ranging from 1 to about 40, R2 is a divalent cycloaliphatic or aliphatic radical containing from 2 to about 40 carbon atoms or a mixture of such radicals, and R3 is an aliphatic, cycloaliphatic radical or divalent aromatic containing from 2 to about 40 carbon atoms, or a mixture of such radicals.
17. 17. The composition of claim 16, wherein n is 0.
18. 18. The composition of claim 16, wherein n ranges from 1 to about 40.
19. 19. The composition of claim 3, wherein said polymer component is an alkyd resin.
20. The composition of claim 3, wherein said polymer component is a polycarbonate polymer having the structure: O 0 0 or HO-R2-0-C II- [O-Rj-O- (CII-Rj-IIC-0-R-O) n-IIC], - 0-R2-OH where q is an integer ranging from 1 to about 40, n is an integer ranging from 0 to 40, R2 is a divalent aliphatic or cycloaliphatic radical containing from 2 to about 40 carbon atoms or a mixture of such radicals and R3 is a divalent aliphatic, cycloaliphatic or aromatic radical containing from 2 to about 40 carbon atoms, or a mixture of such radicals.
21. The composition of claim 17, wherein said polymer component is the condensation product neopentyl glycol diester and adipic acid present in a respective molar ratio of about 2 to 1.
22. The composition of claim 18, wherein said component polymeric is the polyester condensation product of neopentyl glycol and adipic acid, present at a respective molar ratio of p + 1 ap, where p is the number of moles of adipic acid.
23. The composition of claim 3, wherein said cross-linking agent methylol (alkoxymethyl) amino is present at a level of from about 3 to about 60% by weight, based on the combined weight of the linking agent components transverse and transversely linkable polymer.
24. The composition of claim 23, wherein said amino cross linker is hexametoxymethyl melamine or hexaethoxymethyl melamine.
25. 25. The composition of claim 1, further containing an organic solvent.
26. 26. The composition of claim 1, further containing pigment.
27. 27. A process for preparing a cured coating composition, comprising: a. applying the coating composition of claim 1 to a substrate; b. drying said coating; and c. heating said coated substrate for a time and a temperature sufficient to cure said coating.
28. 28. The process of claim 27, wherein said coating composition contains an organic solvent.
29. 29. A cured coating composition prepared by the process of claim 27.
30. 30. A process for preparing a crosslinkable coating composition, comprising forming a mixture comprising: a. a poly (oligo) -meric polymer component selected from the group consisting of di (poly) esters, polyesters, alkyd resins, acrylic resins, polyether polymers, polycarbonate resins, and poly (oligomers) containing a combination of two or more of ester, ether, carbonate, acrylic and alkyd fractions in its structure, said polymeric component further characterized by having a numerical average molecular weight in the range of about 250 to about 20,000; b. an ester phenolic alcohol, which is an ester reaction product of a phenol carboxylic acid and a mono glycidyl compound; and c. a transverse linkage agent for said polymer component.
31. 31. The process of claim 30, wherein said crosslinking agent is a cross-linking agent methylol (alkoxymethyl) amino present in an amount effective to crosslink the composition.
32. 32. The process of claim 31, wherein said ester reaction product has the structure: where R4 is selected from the group consisting of hydrogen, halogen, hydroxyl, Cv alkyl and alkoxy C ap, is a direct bond or an organic radical Cx to C20, Rg is hydrogen or an organic radical Cx to C20 which can form with R7 part of a cyclic ring structure of 5 or 6 carbon atoms, R7 is CH2R8 where R8 is selected from the group consisting of hydroxy, 0R9, OOCR and XR, wherein R is a primary or secondary aliphatic group containing 3 to 20 carbon atoms. carbon or an aromatic group containing 6 to 20 carbon atoms, R10 is a primary, secondary or tertiary aliphatic group containing 4 to 20 carbon atoms or an aromatic group containing 6 to 20 carbon atoms, and Ru is an organic radical C2 a C20 that can form with R € part of a cyclic ring structure of 5 or 6 carbon atoms.
33. The process of claim 32, wherein R4 and Rg are each hydrogen, R5 is a direct bond and R7 is selected from the group consisting of CH2OH, a hydrocarbon fraction containing from 3 to about 20 carbon atoms and a fraction organic containing ester or ether groups and containing from 3 to about 20 carbon atoms.
34. 34. The process of claim 33, wherein said phenol carboxylic acid is para-hydroxybenzoic acid.
35. 35. The process of claim 33, wherein said ester reaction product is the reaction product of para-hydroxybenzoic acid and a glycidyl ester of one or a mixture of aliphatic acids containing 5 to 13 carbon atoms.
36. 36. A crosslinkable coating composition comprising a mixture of: a. a poly (oligo) -meric polymer component selected from the group consisting of di (poly) esters, polyesters, alkyd resins, acrylic resins, polyether polymers, polycarbonate resins, and poly (oligomers) containing a combination of two or more ester, ether, carbonate, acrylic or alkyd fractions in structure, said polymer component further characterized as having a number average molecular weight in the range of about 250 to about 20,000; and b. an ester phenolic alcohol which is a reaction product of a phenol carboxylic acid and a mono glycidyl compound selected from the group consisting of a mono glycidyl ester and mono glycidyl ester.
37. 37. The crosslinkable coating composition, as defined in claim 36, wherein the phenolic alcohol ester has a molecular weight in the range of about 250 to about 100.
38. 38. The crosslinkable coating composition, as defined in claims 36 or 37, wherein the phenol carboxylic acid is hydroxybenzoic acid.
39. 39. The crosslinkable coating co-deposition, as defined in claim 38, wherein the phenol carboxylic acid is para-hydroxybenzoic acid.
40. 40. The crosslinkable coating composition, as defined in claims 36 or 37, wherein the mono glycidyl compound is a glycidyl ester which where R10 is a primary, secondary or tertiary aliphatic group having 4 to 20 carbon atoms.
41. 41. The crosslinkable coating composition, as defined in claim 38, wherein the mono glycidyl compound is a glycidyl ester having the formula C AH2 CHCH2- O! CR, wherein R10 is a primary, secondary or tertiary aliphatic group having 4 to 20 carbon atoms.
42. 42. A crosslinkable coating composition comprising a mixture of: a. a polymeric component having a number average molecular weight in the range of about 250 to about 20,000 and having a hydroxyl functionality that is effective for reaction with a cross-salt linking agent; and b. an ester phenolic alcohol that has the structure where R4 is selected from the group consisting of hydrogen, halogen, hydroxyl, alkyl Ca and alkoxy C ap, R is a direct bond or an organic radical C: a C20, Rg is hydrogen or an organic radical C: a C20 which can form with R7 part of a cyclic ring structure of 5 or 6 atoms of carbon, R7 is CH2R8, where R8 is selected from the group consisting of hydroxy, OR9, OOCR.0 and i, wherein R is a primary or secondary aliphatic group containing 3 to 20 carbon atoms or an aromatic group containing 6 to 20 carbon atoms, R10 is a primary, secondary or tertiary aliphatic group containing 4 to 20 carbon atoms or an aromatic group containing 6 to 20 carbon atoms, and Rn is an organic radical C2 to C20 which can form with R6 part of a cyclic ring structure of 5 or 6 carbon atoms. The present invention provides crosslinking amino-crosslinking formulations based on a mixture of a di or polyhydroxy functional polymer component selected from the group consisting of diesters, polyesters, alkyd polymers, acrylic polymers and polycarbonate polymers, a linking agent transverse such as a cross-linking agent of methylol (alkoxymethyl) amino, and a reactive additive which is the ester reaction product of a phenol carboxylic acid, preferably para-hydroxy benzoic acid, and an epoxy compound selected from glycidyl ethers, esters glycidyl, linear epoxies and aromatic epoxies. The cross-linkable compositions of this invention can be used to prepare curable coating and paint formulations, and may also contain other ingredients such as a crosslinking catalyst, fillers, pigments, and the like. When cured, the coatings of this invention exhibit improved physical and chemical properties compared to cured coatings that do not contain the additive of the ester reaction product.