Title of Invention	A CROSSLINKING COMPOSITION
Abstract	The invention relates to a crosslinking composition comprising and organic acid and a compound having the structure of Formula I: A'-N RA -RD where A' is a moiety derived from the group consisting of triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantonis, linear or cyclic carbamates and mixtures thereof, or a moiety comprising the structure (II):w here RA RD, hydrogen, an axyl of 1 to 20 carbon atoms, or taken together with A'forms a cyclic compound; RD is -CHRCORB, wherein RB, wherein RB is hydrogen, alkyl, aryl, aralkyl or an alkyl having from 1 to about 24 carbon atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, aloxyalkyl or an alkryl having from 1 to about 24 carbon atoms: A is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof; B is a residue of a poly (alkylaldehyde) with n aldehyde groups; n is an integer of 2 to about 8; Ra is Rd hydrogen, an alkyl of 1 to about 20 carbon atoms, or taken together with A forms a cyclic compound; where Rd is CHRcORb or (III) where Rb is hydrogen, alkyl, aryl, aralkyl having from 1 to about 24 carbon atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralyyl, alkoxyalkyl or an an alkaryl having from 1 to about 24 carbon atoms; and where the alkyl or aryl groups in each radivcal may optionally have heteroatoms in their structure and to a process for producing the crosslinking.

Title of Invention

A CROSSLINKING COMPOSITION

Abstract

The invention relates to a crosslinking composition comprising and organic acid and a compound having the structure of Formula I: A'-N RA -RD where A' is a moiety derived from the group consisting of triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantonis, linear or cyclic carbamates and mixtures thereof, or a moiety comprising the structure (II):w here RA RD, hydrogen, an axyl of 1 to 20 carbon atoms, or taken together with A'forms a cyclic compound; RD is -CHRCORB, wherein RB, wherein RB is hydrogen, alkyl, aryl, aralkyl or an alkyl having from 1 to about 24 carbon atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, aloxyalkyl or an alkryl having from 1 to about 24 carbon atoms: A is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof; B is a residue of a poly (alkylaldehyde) with n aldehyde groups; n is an integer of 2 to about 8; Ra is Rd hydrogen, an alkyl of 1 to about 20 carbon atoms, or taken together with A forms a cyclic compound; where Rd is CHRcORb or (III) where Rb is hydrogen, alkyl, aryl, aralkyl having from 1 to about 24 carbon atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralyyl, alkoxyalkyl or an an alkaryl having from 1 to about 24 carbon atoms; and where the alkyl or aryl groups in each radivcal may optionally have heteroatoms in their structure and to a process for producing the crosslinking.

Full Text	STABILIZED CROSSLINKING COMPOSITION FIELD OF THE INVENTION The invention is directed to aminoplast-based crosslinking compositions and their method of preparation. In particular, the invention relates to stabilized aminoplast-based crosslinking compositions, which are stabilized by organic acids and prepared by reacting amino compounds with mono(alkylaldehydes) and/or poly(alkylaldehydes) and alcohol. BACKGROUND OF THE INVENTION Traditional industrial coatings have for years been based in significant part on backbone resins having active hydrogen groups crosslinked with various derivatives of amino-1,3,5-triazines. Most notable among the amino-1,3,5-triazine derivatives are the aminoplasts such as the alkoxymethyl derivatives of melamine and guanamines which, while providing excellent results in a number of aspects, have the disadvantage of releasing formaldehyde as a volatile by-product under curing conditions and requiring relatively high temperatures to adequately crosslink the film. Despite the excellent film coating properties, which can be achieved with aminoplast crosslinked systems, the coatings industry is under great pressure to reduce the environmentally undesirable emission of formaldehyde. In addition, high temperature crosslinking systems require more energy to cure and/or crosslink slower resulting in less throughput. As a result, it has long been a desire of industry to find acceptable alternative crosslinkers and coatings systems, which emit no formaldehyde, or low amounts of formaldehyde, are soluble and/or stable in common solvents used in the coating industry and cure at relatively lower temperatures. U.S. Patent Nos. 3, 806, 508 and 4,180,488 disclose the preparation of resins prepared by reacting melamine with a mono(aikylaldehyde) and an alcohol. However, neither patent discloses nor teaches the use of organic acids to stabilize the resin composition. U.S. Patent No. 4,454,133 discloses the preparation of antimicrobial compounds prepared by reacting an amide or imide compound with poly(alkylaldehydes), e.g., glutaraldehyde. However, the patent neither discloses nor teaches reacting an amino- based compound with mono(alkylaldehydes) and/or poly(alkylaldehydes) and alcohol to form a crosslinking composition, nor discloses the use of organic acids to stabilize the composition. SUMMARY OF THE INVENTION This invention relates to a stabilized crosslinking composition comprising an organic acid and a compound having the structure of Formula I: where A' is a moiety derived from the group consisting of triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof, or a moiety comprising the structure: where RA is RD, hydrogen, an alkyl of 1 to 20 carbon atoms, or taken together with A' forms a cyclic compound; RD is -CHRC ORB , wherein RB is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to about 24 carbon atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to about 24 carbon atoms; A is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof; B is a residue of a poly(alkylaldehyde) with n aldehyde groups; n is an integer of 2 to about 8; Ra is Rd, hydrogen, an alkyl of 1 to about 20 carbon atoms, or taken together with A forms a cyclic compound; where Rd is CHRcORb or where Rb is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to about 24 carbon atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to about 24 carbon atoms; and where the alkyl or aryl groups in each radical may optionally have heteroatoms in their structure. This invention also relates to a process for producing the stabilized crosslinking composition by reacting an amino compound containing amino groups; a mono(alkylaldehyde) and/or a poly(alkylaldehyde), and an alcohol; and stabilizing the composition by adding an organic acid before, during and/or after the reaction where said amino compound is selected from the group consisting of: triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof. DETAILED DESCRIPTION OF THE INVENTION In the present invention, the term "mono(alkylaldehyde)" is an aldehyde having the general formula: R2-CHO, where R2 is alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl, having from 1 to about 24 carbon atoms or about 1 to 12 carbon atoms or about 1 to 4 carbon atoms. The term "poly(alkylaldehyde)" is an aldehyde having the general formula: B-[-CHO]n, where B is a organic residue of a poly(alkylaldehyde) with n aldehyde groups and n is an integer of 2 to about 8. A non-limiting example of a poly(alkylaldehyde) is glutaraldehyde having the structure OHC-(CH2)3-CHO, where B is -(CH2)3- and n is equal to 2. The term "and/or" means either or both. For example, "A and/or B" means A or B, or both A and B. The term "hydrocarbyl," as used herein, is a monovalent hydrocarbon group in which the valency is derived by extraction of a hydrogen from a carbon. Hydrocarbyl includes, for example, aliphatics (straight and branched chain), cycloaliphatics, aromatics and mixed character grups (e.g., aralkyl and alkaryl). Hydrocarbyl also includes groups with internal unsaturation and activated unsaturation. More specifically, hydrocarbyl includes, but is not limited to: alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkenyl, and alkynyl, typically having from 1 to about 24 carbon atoms, preferably having from 1 to about 12 carbon atoms or 1 to about 4 carbon atoms. A hydrocarbyl may contain one or more carbonyl groups (which is/are included in the carbon count) and/or a heteroatom or heteroatoms (such as at least one oxygen, nitrogen, sulfur, or silicon) in the chain or ring. In addition, a hydrocarbyl may have one or more of the hydrogens of the hydrocarbon group replaced by a functional group commonly found in organic molecules. The phrase "functional group commonly found in organic molecules" means non-hydrocarbyl groups that are typically found in organic molecules including, but not limited to, halides, cyano groups, amino groups, thiol groups, carboxylate groups, hydroxyl groups, sulfonate groups, nitroso groups, nitro groups, and the like. This invention relates to a stabilized crosslinking composition comprising an organic acid and a compound having the structure of Formula I: where A' is a moiety derived from the group consisting of triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof, or a moiety comprising the structure: where RA is RD, hydrogen, an alkyl of 1 to 20 carbon atoms, or taken together with A' forms a cyclic compound; RD is -CHRC ORB , where RB is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to about 24 carbon atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to about 24 carbon atoms; A is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof; B is a residue of a poly(alkylaldehyde) with n aldehyde groups; n is an integer of 2 to about 8; Ra is Rd, hydrogen, an alkyl of 1 to about 20 carbon atoms, or taken together with A forms a cyclic compound; where Rd is CHRcORb or where Rb is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to about 24 carbon atoms and Rc is an alkyl, halogenated aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to about 24 carbon atoms; and wherein the alkyl or aryl groups in each radical may optionally have heteroatoms in their structure. The amount of organic acid that may be used to stabilize the crosslinking composition ranges from a low of about 1:50, or about 1:20 or about 1:10 or about 1:5 or about 1:2.5 moles of organic acid to moles of amino compound used to derive the A' or A moieties to a high of about 1:2, or about 1:1, or about 1.5:1 or about 2:1 or about 4:1 or about 10:1, or about 20:1 or about 50:1 moles of organic acid to moles of amino compound used to derive the A' or A moieties. This invention also relates to a process for producing the crosslinking composition by reacting an amino compound containing amino groups; a mono(alkylaldehyde) and/or a poly(alkylaldehyde), and an alcohol; and stabilizing the composition by adding an organic acid before, during and/or after the reaction; where said amino compound is selected from the group consisting of: triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof. The above reaction may be prepared in an one-step or multi-step process. Preferably, the reaction is carried out in a multi-step process where the amino compound is first reacted with the mono and/or poly(alkylaldehydes). The reaction product is then reacted with an alcohol, optionally in the presence of an acid catalyst. As stated above, the amount of organic acid that may be used to prepare the stabilized crosslinking composition ranges from a low of about 1:50, or about 1:20 or about 1:10 or about 1:5 or about 1:2.5 moles of organic acid to moles of amino compound to about 1:2, or about 1:1, or about 1.5:1 or about 2:1 or about 4:1 or about 10:1 or about 20:1 or about 50:1 moles of organic acid to moles of amino compound. Generally, one -NH group from the amino compound reacts with an aldehyde group in the mono- or poly(alklyaldehydes) as set forth below. where A, B and R2 are defined above. During the etherification reaction, the hydroxyl groups may be etherified by the reacting alcohol (R1-OH) It should be noted that A and/or A' may be a monovalent or divalent radical depending on whether the amino group is linear or forms part of a cyclic ring respectively. The table below illustrates the numerous and diverse amino compounds that may be used in this invention. where R' and R are hydrogen or a hydrocarbyl group and R" is hydrogen, hydrocarbyl or -NR2. It should be noted that the disclosure of the above compounds are for illustrative purposes only, and should not be construed as limiting the scope of the present invention. Non-limiting examples of amide compounds that may be used are acrylamide adipamide, p-toluenesulfonamide, methyl acrylamide and the like. Examples of urea compounds that may be used in the present invention, include but are not limited to: urea, ethylene urea, dihydroxyethylene urea, dimethylurea and the like. Non-limiting examples of carbamate compounds that may be used are methyl carbamate, ethyl carbamate, butyl carbamate, trirnethyolpropane-triscarbamate, butane diol dicarbamate and the like. Examples of triazine compounds that may be used in the present invention, include but are not limited to meiamine, benzoguanamine, acetoguanamine, cyclohexylguanamine, di- or tri-alkylmelamines and the like. Non-limiting examples of hydantoin compounds that may be used are hydantoin, methyl hydantoin, ethyl hydantoin, propyl hydantoin, butyl hydantoin and other substituted hydantoins. Examples of glycoluril compounds that may be used in the present invention, include but are not limited to glycoluril, methyl glycoluril, ethyl glycoluril and other substituted glycolurils. Non-limiting examples of cyanuric acid compounds that may be used are cyanuric acid, methyl cyanuric acid, ethyl cyanuric acid and other substituted cyanuric acids. It should also be noted that more than one poly(alkylaldehyde) could react with an amino compound resulting in an oligomer. The term "oligomer" in this application means a compound having 2 or more amino compound repeating units. Preferably, the oligomer has a number average molecular weight of from about 200 to about 5000, or about 600 to about 3000, or about 600 to about 2000. Preferably, in the above Formula I; B is methylene, ethylene, propylene or a structure of the formula: which is the 1,4 Michael addition of crotonaldehyde with trimethylolpropane. Similarly, one may use the reaction product of crotonaldehyde and polyhydritic alcohols, such as glycerol, pentaerythritol, sorbitol, 1,4-butanediol, sugars, starches, cellulose and the like; or adducts and polymers of α, β-unsaturated aldehydes. Also, preferred is when Rc and RC are C1 to C8 alkyl, Rb and RB are C1 to C8 alkyl or C1 to C8 alkoxyalkyl and A and A' are moieties derived from urea, glycoluril or mixtures thereof. Also preferred is when Rb and RB are independently derived from methanol, ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol, monoalkyl ether of ethylene or propylene glycol and mixtures thereof. In addition, it is also preferred that about 10% to about 90% of the RD and Rd groups, or about 15% to about 70%, or about 30% to about 50% of the RD and Rd groups on a molar basis are -CHRC ORB and -CHRcORb, respectively. In another embodiment of the present invention, the stabilized crosslinking composition comprises an organic acid and the structure of Formula I: A'-NRA-RD wherein A' is a moiety derived from triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof: wherein RA is RD, hydrogen, an alkyl of 1 to about 20 carbon atoms, or taken together with A' forms a cyclic compound; RD is -CHRCORB , wherein RB is hydrogen, alkyl, aryl, aralkyl, or an alkaryl having from 1 to about 24 carbon atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to about 24 carbon atoms. Preferably, in this embodiment, the amino compound is melamine, guanamine, linear or cyclic ureas or mixtures thereof. Also, preferred is when RC is a C1 to C8 alkyl, RB is a C1 to C8 alkyl or C1 to C8 alkoxyalkyl. Also preferred is when RB is independently derived from methanol, ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol, monoalkyl ether of ethylene or propylene glycol and mixtures thereof. In addition, it is also preferred that about 10% to about 90% of the RD groups, or about 15% to about 70%, or about 30% to about 50% of the RD groups on a molar basis are -CHRC ORB . This invention also relates to a process for producing a stabilized crosslinking composition comprising reacting an amino compound containing amino groups; a mono(alkylaldehyde) and/or a poly(alkylaldehyde); and an alcohol; and stabilizing the composition by adding an organic acid before, during and/or after the reaction; where said amino compound is selected from the group consisting of: triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof. Another embodiment of this invention is a process for producing a stabilizing crosslinking composition comprising reacting an amino compound containing amino groups; a mono(alkylaldehyde); and an alcohol; and stabilizing the composition by adding an organic acid before, during and/or after the reaction; wherein said amino compound is selected from the group consisting of triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof. The organic acids that may be used in this invention to stabilize the crosslinking compositions include, but are not limited to organic compounds that contain at least one acidic functional group including RCO2H, RxSO3H, RxSO2H, RyOH, RxPO3H and RxPO2H, wherein R is hydrogen or a hydrocarbyl, Rx is hydrocarbyl and Ry is aryl. Examples of organic acids that may be used, include but are not limited to, acetic acid, (including glacial acetic acid and mono or polyhalogenated acetic acids), formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid, lactic acid, glycolic acid, glyoxylic acid, methanesulfonic acid, and p- toluenesulfonic acid or mixtures thereof. Preferably, the organic acid is a carboxylic acid (i.e., mono-, di-, tri- or polycarboxylic acids). Preferred carboxylic acid are acetic, formic and propionic acid. Non-limiting examples of mono(alkylaldehyde) that may be used in this invention are acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, chloral, caproaldehyde, octylaldehyde, acrolein and crotonaldehyde. Examples of poly(alkylaldehyde) which made be used in this invention include, but are not limited to glutaraldehyde; the reaction product of crotonaldehyde and polyhydritic alcohols, such as glycerol, pentaerythritol, trimethylolpropane, sorbitol, 1,4-butanediol, sugars, starches, cellulose and the like; or adducts and polymers of α, β-unsaturated aldehydes. Non-limiting examples of alcohols that may be used in this invention are methanol, ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol, monoalkyl ether of ethylene or propylene glycol and mixtures thereof. In the above reactions, the molar ratio of amino groups in all amino compounds to mono(alkylaldehyde) is about 1:0.1 to about 1:30, or about 1:0.25 to about 1:10 or about 1:0.5 to about 1:5. In this application "amino groups" include groups with primary and/or secondary amines, i.e., -NH2 and -NHR groups, respectively. In addition, the molar ratio of amino groups in the amino compounds to aldehyde groups in the poly(alkylaldehyde) is about 0.1:1 to about 50:1, or about 0.5:1 to about 25:1 or about 1:1 to about 10:1. The molar ratio of aldehyde groups in the mono(alkylaldehyde) and poly(alkylaldehyde) to alcohol is about 1:0.2 to about 1:50, or about 1.0.5 to about 1:5 or about 1:1 to about 1:3. The amount of organic acid that may be used to stabilize the crosslinking composition ranges from a low of about 1:50, or about 1:20 or about 1:10 or about 1:5 or about 1:2.5 moles of organic acid to moles of amino compound to a high of about 1:2, or about 1:1, or about 1.5:1 or about 2:1 or about 4:1 or about 10:1 or about 20:1 or about 50:1 moles of organic acid to moles of amino compound. It is believed that many of the amino-based crosslinking compositions derived from mono(alkylaldehydes) and/or poly(alkylaldehydes) are not very soluble and/or not stable in common solvents used in the coatings industry. Many of these amino-based compounds are not soluble or precipitate out over time leading to unstable compositions. The inventors of the present invention have discovered that the use of organic acids in these compositions better solubilizes the amino-based crosslinking compounds in the solvents leading to more stable compositions. Crosslinking solids concentration needed for coating applications is typically greater than about 20 wt.% based on the total weight of crosslinker and solvent. It should be noted that the above amounts are a general guide and the actual amount of the ingredients will depend on the type of reactants and conditions used to produce and stabilize the crosslinking composition. The reaction should be conducted to prevent gelation, which would have a deleterious effect on the crosslinking composition. For example, if the amino compounds contain a large number of amino groups, then a relative small amount of polyfunctional poly(alkylaldehydes) should be used in order to end-cap with amino groups to prevent an insoluble crosslinked gel from forming. Conversely, one can charge a large excess of poly(alkylaldehydes) to effectively end-cap with aldehydes in order to prevent gelation. In addition, higher reaction temperatures could also tend to lead to self-condensation and possibly gelation. One skilled in the art would be able to choose the proper reactant amounts and conditions to reduce or eliminate gel formation. The above process may be prepared in a one-step or multi-step process. In one embodiment of a multi-step process, the amino compounds are first reacted with the mono(alkylaldehyde) and/or poly(alkylaldehyde) compounds (alkylolation reaction), and then the etherification step would occur by the reaction with an alcohol. In another embodiment of a multistep reaction, the amino compounds are first reacted with a poly(alkylaldehyde) followed by an etherification step, then reacted with a mono(alkylaldehyde) followed by another etherification step. The alkylolation reaction is preferably conducted in the presence of a catalyst. An acid or base catalyst may be used. It should be noted that the above organic acids of this invention that are utilized to stabilize the crosslinking compositions may be added to the reaction as a catalyst for both the alkylolation and etherification steps. In general, the amount of the organic acids needed as catalyst will be less than the amount needed to stabilize the crosslinking composition. Non-limiting examples of base catalysts are inorganic basic salts such as the hydroxides, carbonates or bicarbonates of lithium, sodium, potassium, calcium and magnesium, or the organic bases and basic salts such as amines and guanidine, quaternary-ammonium or phosphonium hydroxide and (bi-)carbonate salts. The etherification reaction is preferably conducted in the presence of an acid catalyst. The same acid catalyst described above for the alkylolation reaction may also be used in the etherification reaction. The reaction is carried out at a temperature from about 0°C to about 125°C, or about 25°C to about 100°C or about 50°C to about 75°C for a time of about 0.5 hours to about 48 hours, or about 1 hour to about 24 hours or about 1 hour to about 12 hours. An important use of the compositions described herein is based on their ability to act as crosslinking agents in curable compositions, and especially those curable compositions which contain materials or polymers having active hydrogen groups. The crosslinkers of the present invention are capable of crosslinking active hydrogen containing materials or polymers. The active hydrogen-containing material of the curable compositions preferably contains at least one class of a reactive functionality such as hydroxy, carboxy, amino, amido, carbamate, mercapto, or a blocked functionality which is convertible to any of the preceding reactive functionalities. These active hydrogen-containing materials are those which are conventionally used in amino resin coatings, and in general are considered well-known to those of ordinary skill in the relevant art. Suitable active hydrogen-containing materials include, for example, polyfunctional hydroxy group containing materials such as polyols, hydroxyfunctional acrylic resins having pendant or terminal hydroxy functionalities, hydroxyfunctional polyester resins having pendant or terminal hydroxy functionalities, hydroxyfunctional polyurethane prepolymers, products derived from the condensation of epoxy compounds with an amine and mixtures thereof. Acrylic and polyester resins are preferred. Examples of the polyfunctional hydroxy group containing materials include DURAMAC® 203-1385 alkyd resin (Eastman Chemical Co.); Beckosol® 12035 alkyd resin (Reichhold Chemical Co. Durham, NC.)JONCRYL® 500 acrylic resin (S. C. Johnson & Sons, Racine, Wis.); AT-40C acrylic resin (Rohm & Haas, Philadelphia, Pa.); CYPLEX® polyester resin (Cytec Industries, West Paterson, N.J.); CARGILL® 3000 and 5776 polyester resins (Cargill, Minneapolis, Minn.); K-FLEX® XM-2302 and XM-2306 resins (King Industries, Norwalk, Conn.); CHEMPOL® 11-1369 resin (Cook Composites and Polymers (Port Washington, Wis.); CRYLCOAT® 3494 solid hydroxy terminated polyester resin (UCB CHEMICALS USA, Smyrna, Ga.); RUCOTE® 101 polyester resin (Ruco Polymer, Hicksville, N.Y.); JONCRYL® SCX-800-A and SCX-800-B hydroxyfunctional solid acrylic resins (S. C. Johnson & Sons, Racine, Wis.); and the like. Examples of carboxyfunctiona! resins include CRYLCOAT® solid carboxy terminated polyester resin (UCB CHEMICALS USA, Smyrna, Ga.). Suitable resins containing amino, amido, carbamate or mercapto groups, including groups convertible thereto, are in general well-known to those of ordinary skill in the art and may be prepared by known methods including copolymerizing a suitably functionalized monomer with a comonomer capable of copolymerizing therewith. The curable compositions may optionally further comprise a cure catalyst. The cure catalysts usable in the present invention include sulfonic acids, aryl, alkyl, and aralkyl sulfonic acids; aryl, alkyl and aralkyl acid phosphates; aryl, alkyl and aralkyl acid pyrophosphates; carboxylic acids; sulfonimides; mineral acids and a mixture thereof. Of the above acids, sulfonic acids are preferred when a catalyst is utilized. Examples of the sulfonic acids include benzenesulfonic acid, para-toluenesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, and a mixture thereof. Examples of the aryl, alkyl and aralkyl phosphates and pyrophosphates include phenyl, para-tolyl, methyl, ethyl, benzyl, diphenyl, di-para-tolyl, di- methyl, di-ethyl, di-benzyl, phenyl-para-tolyl, methyl-ethyl, phenyl-benzyl phosphates and pyrophosphates. Examples of the carboxylic acids include benzoic acid, formic acid, acetic acid, propionic acid, butyric acid, dicarboxylic acids such as oxalic acid, fluorinated acids such as trifluoroacetic acid, and the like. Examples of the sulfonimides include dibenzene sulfonimide, di-para-toluene sulfonimide, methyi-para-toluene sulfonimide, dimethyl sulfonimide, and the like. Examples of the mineral acids include nitric acid, sulfuric acid, phosphoric acid, poly-phosphoric acid, and the like. The curable composition may also contain other optional ingredients such as fillers, light stabilizers, pigments, flow control agents, plasticizers, mold release agents, corrosion inhibitors, and the like. It may also contain, as an optional ingredient, a medium such as a liquid medium to aid the uniform application and transport of the curable composition. Any or all of the ingredients of the curable composition may be contacted with the liquid medium. Moreover, the liquid medium may permit formation of a dispersion, emulsion, invert emulsion, or solution of the ingredients of the curable composition. Particularly preferred is a liquid medium, which is a solvent for the curable composition ingredients. Suitable solvents include aromatic hydrocarbons, aliphatic hydrocarbons, halogenated hydrocarbons, ketones, esters, ethers, amides, alcohols, water, compounds having a plurality of functional groups such as those having an ether and an ester group, and a mixture thereof. Preferably, the weight ratio of the active hydrogen-containing material to the crosslinking composition is in the range of from about 99:1 to about 0.5:1 or about 10:1 to about 0.8:1 or about 4:1 to about 0.8:1. The weight percent of the cure catalyst, if present, is in the range of from about 0.01 to about 3.0 wt % based on the weight of the crosslinker and active hydrogen- containing material components. The present coating compositions may employ a liquid medium such as a solvent, or it may employ solid ingredients as in powder coatings, which typically contain no liquids. Contacting may be carried out by dipping, spraying, padding, brushing, rollercoating, flowcoating, curtaincoating, electrocoating or electrostatic spraying. The liquid or powder coating compositions and a substrate to be coated are contacted by applying the curable composition onto the substrate by a suitable method, for example, by spraying in the case of the liquid compositions and by electrostatic spraying in the case of the powder compositions. In the case of powder coatings, the substrate covered with the powder composition is heated to at least the fusion temperature of the curable composition forcing it to melt and flow out and form a uniform coating on the substrate. It is thereafter fully cured by further application of heat, typically at a temperature in the range of about 120°C to about 220°C for a period of time in the in the range of about 5 minutes to about 30 minutes and preferably for a period of time in the range of 10 to 20 minutes. In the case of the liquid compositions, the solvent is allowed to partially evaporate to produce a uniform coating on the substrate. Thereafter, the coated substrate is allowed to cure at temperatures of about 20°C to about 150°C, or about 25°C to about 120°C for a period of time in the in the range of about 20 seconds to about 30 days depending on temperature to obtain a cured film. In a particularly advantageous embodiment, coating compositions formulated with crosslinker containing compositions of the present invention can be heat cured at lower temperatures preferably ranging from about 20°C to about 90°C. The heat cured compositions of this invention may be employed in the general areas of coatings such as original equipment manufacturing (OEM) including automotive coatings, general industrial coatings including industrial maintenance coatings, architectural coatings, powder coatings, coil coatings, can coatings, wood coatings, and low temperature cure automotive refinish coatings. They are usable as coatings for wire, appliances, automotive parts, furniture, pipes, machinery, and the like. Suitable surfaces include metals such as steel and aluminum, plastics, wood and glass. The curable compositions of the present invention are particularly well suited to coat heat sensitive substrates such as plastics and wood which may be altered or destroyed entirely at the elevated cure temperatures prevalent in the heat curable compositions of the prior art. The present invention will now be illustrated by the following examples. The examples are not intended to limit the scope of the present invention. In conjunction with the general and detailed descriptions above, the examples provide further understanding of the present invention. Example 1. Preparation of Tris(propylol)melamine Methyl Ether (TPMM) In a suitable flask was mixed 3026 grams of melamine (2.4 mole) with 1394 grams of propionaldehyde (24 moles), 1991 grams of methanol and 15.6 grams of acetic acid. The mixture was heated to 65°C, and kept for 2 hours. The solution cooled to precipitate solids, which were then separated by filtration. The solids had a melting point of about 152-154°C. Examples 2 and 2C. Solubility of Tris(propylol)melamine Methyl Ether in Ethyl Acetate The resin of Example 1 was placed in the following liquids Both compositions were heated to 80°C. The resin in Example 2 dissolved and the composition became homogenous (clear) and remained homogenous upon cooling. The resin in Example 2C did not dissolve upon heating and the composition did not become homogenous (not clear - hazy). Example 3. Solvent Resistance of Coatings Containing the Crosslinking Resins of Examples 2. A coating compositions containing the crosslinking composition of Examples 2 was prepared by mixing 36 parts crosslinking resin with 64 parts acrylic backbone resin (Joncryl® 500) on a dry weight basis and 1.0 parts dimethyl acid pyrophosphate catalyst in butanol. The formulation was applied on iron phosphate treated cold roll steel panels and baked at 105°C for 20 minutes. Solvent resistance of the baked film was measured using a methylethyl ketone (MEK) rub. The result is shown in Table 2 below. Solvent Resistance is measured by methyl ethyl ketone (MEK) double rubs to remove the coating. Example 3 demonstrates that a film with good solvent resistance may be formed by using an organic acid additive. Examples 4 to 8 and 4C to 8C. Solubility of Tris(propyIoI)melamine Methyl Ether in Other Common Coating Solvents The TPMM resin of Example 1 was contacted with additional solvents to determine their solubility in common solvents used in the coating industry. The compositions and the results of the solubility tests are disclosed in Table 3 below. The results show that without the glacial acetic acid, none of the solvents solubilized the TPMM resin. The use of glacial acetic acid allows the TPMM resin to be used as a crosslinker for coating applications. The invention described and claimed herein is not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. WE CLAIM: 1. A crosslinking composition comprising an organic acid and a compound having the structure of Formula I: A'-NRA-RD wherein the organic acid is selected from acetic acid, mono or polyhalogenated acetic acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid, lactic acid, glycolic acid, glyoxylic acid, and methanesulfonic acid, and mixtures thereof, and wherein A' is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid, the substituted cyanuric acids selected from methyl cyanuric acid and ethyl cyanuric acid, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof, or a moiety comprising the structure: wherein RA is RD, hydrogen, an alkyl of 1 to 20 carbon atoms, or taken together with A forms a cyclic compound; RD is -CHRC ORB, wherein RB is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to 24 carbon atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to 24 carbon atoms; A is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof; B is a residue of a poly(alkylaldehyde) with n aldehyde groups; n is an integer of 2 to 8; Ra is Rd, hydrogen, an alkyl of 1 to 20 carbon atoms, or taken together with A forms a cyclic compound; wherein Rd is CHRc ORb or wherein Rb is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to 24 carbon atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to 24 carbon atoms; wherein the molar ratio of said organic acid to amino compound used to derive the A or A moiety is from 1: 5 to 50 :1, and wherein the alkyl or aryl groups in each radical may optionally have heteroatoms in their structure. 2. The composition as claimed in claim 1, wherein said organic acid is a carboxylic acid selected from acetic acid, mono- or polyhalogenated acetic acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid, lactic acid, glycolic acid, glyoxylic acid, and mixtures thereof. 3.The composition as claimed in claim 1, wherein the molar ratio of said organic acid to amino compound used to derive the A or A' moiety is from 1: 5 to 20 :1. 4.The crosslinking composition as claimed in claim 1, wherein Rb and RB are independently derived from alcohols selected from the group consisting of: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol, monoalkyl ether of ethylene or propylene glycol and mixtures thereof. 5.The crosslinking composition as claimed in claim 1, wherein B is derived from glutaraldehyde, the reaction products of crotonaldehyde and polyhydritic alcohols or adducts and polymers of α,β-unsaturated aldehydes. 6. The crosslinking composition as claimed in claim 1, wherein Rc and Rc are independently C1 to C8 alkyl and Rb and RB are independently C1 to C8 alkyl or C1 to C8 alkoxyalkyl. 7. The composition as claimed in claim 2, wherein said carboxylic acid is acetic acid, formic acid, propionic acid or mixtures thereof. 8. The crosslinking composition as claimed in claim 1 wherein A' is a moiety derived from compounds selected from the group consisting of triazines, linear or cyclic ureas, cyanuric acid, the substituted cyanuric acids selected from methyl cyanuric acid and ethyl cyanuric acid, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof. 9.The composition as claimed in claim 8, wherein A' is derived from melamines, guanamines, linear and cyclic ureas and mixtures thereof. 10.The crosslinking composition as claimed in claim 8, wherein RB is derived from alcohols selected from the group consisting of: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol, monoalkyl ether of ethylene or propylene glycol and mixtures thereof. 11.The composition as claimed in claim 8, wherein said organic acid is a carboxylic acid selected from acetic acid, mono- or polyhalogenated acetic acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid, lactic acid, glycolic acid, glyoxylic acid, and mixtures thereof. 12.The composition as claimed in claim 8, wherein the molar ratio of said organic acid to amino compound used to derive the A' moiety is from 1: 20 to 20:1. 13.The crosslinking composition as claimed in claim 8, wherein Rc is a C1 to C8 alkyl and RB is a C1 to C8 alkyl or C1 to C8 alkoxyalkyl. 14.The composition as claimed in claim 11, wherein said carboxylic acid is acetic acid, formic acid, propionic acid or mixtures thereof. 15.A process for producing the crosslinking composition as claimed in claim 1, comprising reacting (i) an amino compound containing amino groups; (ii) a mono(alkylaldehyde) and/or a poly(alkylaldehyde); and (iii) an alcohol; wherein said amino compound is selected from the group consisting of: triazine, linear or cyclic ureas, cyanuric acid, the substituted cyanuric acids selected from methyl cyanuric acid and ethyl cyanuric acid, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof; and adding an organic acid selected from acetic acid, mono- or polyhalogenated acetic acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid, lactic acid, glycolic acid, glyoxylic acid, methane sulfonic acid, and p- toluenesulfonic acid and mixtures thereof. 16.The process as claimed in claim 15, wherein at least some of said organic acid is added before or during the reaction. 17.The process as claimed in claim 15, wherein at least some of said organic acid is added after the reaction. 18.The process as claimed in claim 15, wherein said alcohol is selected from the group consisting of: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol, monoalkyl ether of ethylene or propylene glycol and mixtures thereof. 19.The process as claimed in claim 15, wherein said poly(alkylaldehyde) is glutaraldehyde, the reaction product of crotonaldehyde and polyhydritic alcohols or adducts and polymers of α,β-unsaturated aldehydes. 20.The process as claimed in claim 15, wherein said mono(alkylaldehyde) is selected from the group consisting of acetaldehyde, propionaldehyde, n- butyraldehyde, isobutyraldehyde, valeraldehyde, chloral, caproaldehyde, octylaldehyde, acrolein and crotonaldehyde. 21.The process as claimed in claim 15, wherein the molar ratio of said amino group to mono(alkylaldehyde) is 1 : 0.1 to 1: 30, the molar ratio of amino group to the aldehyde groups in the poly(alkylaldehyde) is 0.1:1 to 50 : 1 and the molar ratio of aldehyde groups in said mono(alkylaldehyde) and said poly(alkylaldehyde) to alcohol is 1 : 0.2 to 1: 50. 22.The process as claimed in claim 15, wherein the molar ratio of said organic acid to amino compound is from 1: 20 to 20 :1. 23.The process as claimed in claim 15, wherein said organic acid is a carboxylic acid selected from acetic acid, mono- or polyhalogenated acetic acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid, lactic acid, glycolic acid, glyoxylic acid, and mixtures thereof. 24 .The process as claimed in claim 15, wherein in step (ii), a mono (alkylaldehyde) is used. 25.The process as claimed in claim 24, wherein the alcohol used in step (iii) is selected from the group consisting of: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol, monoalkyl ether of ethylene or propylene glycol and mixtures thereof. 26.The process as claimed in claim 24, wherein said mono(alkylaldehyde) is selected from the group consisting of acetaldehyde, propionaldehyde, n- butyraldehyde, isobutyraldehyde, valeraldehyde, chloral, caproaldehyde, octylaldehyde, acrolein and crotonaldehyde. 27.The process as claimed in claim 24, wherein at least some of said organic acid is added before or during the reaction. 28.The process as claimed in claim 24, wherein the molar ratio of said organic acid to amino compound is from 1: 50 to 50 :1. 29.The process as claimed in claim 24, wherein said organic acid is a carboxylic acid selected from acetic acid, mono- or polyhalogenated acetic acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid, lactic acid, glycolic acid, glyoxylic acid, and mixtures thereof. 30.The process as claimed in claim 24, wherein said amino compound is melamine, guanamine, linear and cyclic urea and mixtures thereof. 31.The process as claimed in claim 29, wherein said carboxylic acid is acetic acid, formic acid, propionic acid or mixtures thereof. ABSTRACT Title: A CROSSLINKING COMPOSITION The invention relates to a crosslinking composition comprising and organic acid and a compound having the structure of Formula I: A'-N RA -RD where A' is a moiety derived from the group consisting of triazines, linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantonis, linear or cyclic carbamates and mixtures thereof, or a moiety comprising the structure (II):w here RA RD, hydrogen, an axyl of 1 to 20 carbon atoms, or taken together with A'forms a cyclic compound; RD is -CHRCORB, wherein RB, wherein RB is hydrogen, alkyl, aryl, aralkyl or an alkyl having from 1 to about 24 carbon atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, aloxyalkyl or an alkryl having from 1 to about 24 carbon atoms: A is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof; B is a residue of a poly (alkylaldehyde) with n aldehyde groups; n is an integer of 2 to about 8; Ra is Rd hydrogen, an alkyl of 1 to about 20 carbon atoms, or taken together with A forms a cyclic compound; where Rd is CHRcORb or (III) where Rb is hydrogen, alkyl, aryl, aralkyl having from 1 to about 24 carbon atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralyyl, alkoxyalkyl or an an alkaryl having from 1 to about 24 carbon atoms; and where the alkyl or aryl groups in each radivcal may optionally have heteroatoms in their structure and to a process for producing the crosslinking.

Full Text

STABILIZED CROSSLINKING COMPOSITION
FIELD OF THE INVENTION
The invention is directed to aminoplast-based crosslinking compositions and their
method of preparation. In particular, the invention relates to stabilized aminoplast-based
crosslinking compositions, which are stabilized by organic acids and prepared by reacting
amino compounds with mono(alkylaldehydes) and/or poly(alkylaldehydes) and alcohol.
BACKGROUND OF THE INVENTION
Traditional industrial coatings have for years been based in significant part on
backbone resins having active hydrogen groups crosslinked with various derivatives of
amino-1,3,5-triazines. Most notable among the amino-1,3,5-triazine derivatives are the
aminoplasts such as the alkoxymethyl derivatives of melamine and guanamines which,
while providing excellent results in a number of aspects, have the disadvantage of
releasing formaldehyde as a volatile by-product under curing conditions and requiring
relatively high temperatures to adequately crosslink the film.
Despite the excellent film coating properties, which can be achieved with
aminoplast crosslinked systems, the coatings industry is under great pressure to reduce
the environmentally undesirable emission of formaldehyde. In addition, high temperature
crosslinking systems require more energy to cure and/or crosslink slower resulting in less
throughput. As a result, it has long been a desire of industry to find acceptable alternative
crosslinkers and coatings systems, which emit no formaldehyde, or low amounts of
formaldehyde, are soluble and/or stable in common solvents used in the coating industry
and cure at relatively lower temperatures.
U.S. Patent Nos. 3, 806, 508 and 4,180,488 disclose the preparation of resins
prepared by reacting melamine with a mono(aikylaldehyde) and an alcohol. However,
neither patent discloses nor teaches the use of organic acids to stabilize the resin
composition.
U.S. Patent No. 4,454,133 discloses the preparation of antimicrobial compounds
prepared by reacting an amide or imide compound with poly(alkylaldehydes), e.g.,
glutaraldehyde. However, the patent neither discloses nor teaches reacting an amino-
based compound with mono(alkylaldehydes) and/or poly(alkylaldehydes) and alcohol to

form a crosslinking composition, nor discloses the use of organic acids to stabilize the
composition.
SUMMARY OF THE INVENTION
This invention relates to a stabilized crosslinking composition comprising an
organic acid and a compound having the structure of Formula I:

where A' is a moiety derived from the group consisting of triazines, linear or cyclic ureas,
cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins,
linear or cyclic carbamates and mixtures thereof, or a moiety comprising the structure:

where RA is RD, hydrogen, an alkyl of 1 to 20 carbon atoms, or taken together with A'
forms a cyclic compound;

RD is -CHRC ORB , wherein RB is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to

about 24 carbon atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated
aralkyl, alkoxyalkyl or an alkaryl having from 1 to about 24 carbon atoms;
A is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid,
substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic
carbamates and mixtures thereof;
B is a residue of a poly(alkylaldehyde) with n aldehyde groups;
n is an integer of 2 to about 8;
Ra is Rd, hydrogen, an alkyl of 1 to about 20 carbon atoms, or taken together with A forms
a cyclic compound;
where Rd is CHRcORb or

where Rb is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to about 24 carbon
atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl
or an alkaryl having from 1 to about 24 carbon atoms; and where the alkyl or aryl groups
in each radical may optionally have heteroatoms in their structure.
This invention also relates to a process for producing the stabilized crosslinking
composition by reacting an amino compound containing amino groups; a
mono(alkylaldehyde) and/or a poly(alkylaldehyde), and an alcohol; and stabilizing the
composition by adding an organic acid before, during and/or after the reaction where said
amino compound is selected from the group consisting of: triazines, linear or cyclic ureas,
cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins,
linear or cyclic carbamates and mixtures thereof.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the term "mono(alkylaldehyde)" is an aldehyde having the
general formula: R2-CHO, where R2 is alkyl, halogenated alkyl, aryl, aralkyl, halogenated
aralkyl, alkoxyalkyl or an alkaryl, having from 1 to about 24 carbon atoms or about 1 to 12
carbon atoms or about 1 to 4 carbon atoms.
The term "poly(alkylaldehyde)" is an aldehyde having the general formula:
B-[-CHO]n, where B is a organic residue of a poly(alkylaldehyde) with n aldehyde groups
and n is an integer of 2 to about 8. A non-limiting example of a poly(alkylaldehyde) is
glutaraldehyde having the structure OHC-(CH2)3-CHO, where B is -(CH2)3- and n is
equal to 2.
The term "and/or" means either or both. For example, "A and/or B" means A or B,
or both A and B.
The term "hydrocarbyl," as used herein, is a monovalent hydrocarbon group in
which the valency is derived by extraction of a hydrogen from a carbon. Hydrocarbyl
includes, for example, aliphatics (straight and branched chain), cycloaliphatics, aromatics
and mixed character grups (e.g., aralkyl and alkaryl). Hydrocarbyl also includes groups

with internal unsaturation and activated unsaturation. More specifically, hydrocarbyl
includes, but is not limited to: alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkenyl,
and alkynyl, typically having from 1 to about 24 carbon atoms, preferably having from 1 to
about 12 carbon atoms or 1 to about 4 carbon atoms. A hydrocarbyl may contain one or
more carbonyl groups (which is/are included in the carbon count) and/or a heteroatom or
heteroatoms (such as at least one oxygen, nitrogen, sulfur, or silicon) in the chain or ring.
In addition, a hydrocarbyl may have one or more of the hydrogens of the hydrocarbon
group replaced by a functional group commonly found in organic molecules. The phrase
"functional group commonly found in organic molecules" means non-hydrocarbyl groups
that are typically found in organic molecules including, but not limited to, halides, cyano
groups, amino groups, thiol groups, carboxylate groups, hydroxyl groups, sulfonate
groups, nitroso groups, nitro groups, and the like.
This invention relates to a stabilized crosslinking composition comprising an
organic acid and a compound having the structure of Formula I:

where A' is a moiety derived from the group consisting of triazines, linear or cyclic ureas,
cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins,
linear or cyclic carbamates and mixtures thereof, or a moiety comprising the structure:

where RA is RD, hydrogen, an alkyl of 1 to 20 carbon atoms, or taken together with A'
forms a cyclic compound;
RD is -CHRC ORB , where RB is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to

about 24 carbon atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated
aralkyl, alkoxyalkyl or an alkaryl having from 1 to about 24 carbon atoms;
A is a moiety derived from the group consisting of linear or cyclic ureas, cyanuric acid,
substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic
carbamates and mixtures thereof;
B is a residue of a poly(alkylaldehyde) with n aldehyde groups;

n is an integer of 2 to about 8;
Ra is Rd, hydrogen, an alkyl of 1 to about 20 carbon atoms, or taken together with A forms
a cyclic compound;
where Rd is CHRcORb or

where Rb is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to about 24 carbon
atoms and Rc is an alkyl, halogenated aryl, aralkyl, halogenated aralkyl, alkoxyalkyl or an
alkaryl having from 1 to about 24 carbon atoms; and wherein the alkyl or aryl groups in
each radical may optionally have heteroatoms in their structure. The amount of organic
acid that may be used to stabilize the crosslinking composition ranges from a low of about
1:50, or about 1:20 or about 1:10 or about 1:5 or about 1:2.5 moles of organic acid to
moles of amino compound used to derive the A' or A moieties to a high of about 1:2, or
about 1:1, or about 1.5:1 or about 2:1 or about 4:1 or about 10:1, or about 20:1 or about
50:1 moles of organic acid to moles of amino compound used to derive the A' or A
moieties.
This invention also relates to a process for producing the crosslinking composition
by reacting an amino compound containing amino groups; a mono(alkylaldehyde) and/or
a poly(alkylaldehyde), and an alcohol; and stabilizing the composition by adding an
organic acid before, during and/or after the reaction; where said amino compound is
selected from the group consisting of: triazines, linear or cyclic ureas, cyanuric acid,
substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic
carbamates and mixtures thereof. The above reaction may be prepared in an one-step or
multi-step process. Preferably, the reaction is carried out in a multi-step process where
the amino compound is first reacted with the mono and/or poly(alkylaldehydes). The
reaction product is then reacted with an alcohol, optionally in the presence of an acid
catalyst.
As stated above, the amount of organic acid that may be used to prepare the
stabilized crosslinking composition ranges from a low of about 1:50, or about 1:20 or
about 1:10 or about 1:5 or about 1:2.5 moles of organic acid to moles of amino compound
to about 1:2, or about 1:1, or about 1.5:1 or about 2:1 or about 4:1 or about 10:1 or about
20:1 or about 50:1 moles of organic acid to moles of amino compound.

Generally, one -NH group from the amino compound reacts with an aldehyde
group in the mono- or poly(alklyaldehydes) as set forth below.

where A, B and R2 are defined above.
During the etherification reaction, the hydroxyl groups may be etherified by the
reacting alcohol (R1-OH)

It should be noted that A and/or A' may be a monovalent or divalent radical
depending on whether the amino group is linear or forms part of a cyclic ring respectively.
The table below illustrates the numerous and diverse amino compounds that may
be used in this invention.

where R' and R are hydrogen or a hydrocarbyl group and R" is hydrogen, hydrocarbyl or
-NR2. It should be noted that the disclosure of the above compounds are for illustrative
purposes only, and should not be construed as limiting the scope of the present invention.
Non-limiting examples of amide compounds that may be used are acrylamide
adipamide, p-toluenesulfonamide, methyl acrylamide and the like.
Examples of urea compounds that may be used in the present invention, include
but are not limited to: urea, ethylene urea, dihydroxyethylene urea, dimethylurea and the
like.
Non-limiting examples of carbamate compounds that may be used are methyl
carbamate, ethyl carbamate, butyl carbamate, trirnethyolpropane-triscarbamate, butane
diol dicarbamate and the like.
Examples of triazine compounds that may be used in the present invention,
include but are not limited to meiamine, benzoguanamine, acetoguanamine,
cyclohexylguanamine, di- or tri-alkylmelamines and the like.
Non-limiting examples of hydantoin compounds that may be used are hydantoin,
methyl hydantoin, ethyl hydantoin, propyl hydantoin, butyl hydantoin and other substituted
hydantoins.
Examples of glycoluril compounds that may be used in the present invention,
include but are not limited to glycoluril, methyl glycoluril, ethyl glycoluril and other
substituted glycolurils.
Non-limiting examples of cyanuric acid compounds that may be used are cyanuric
acid, methyl cyanuric acid, ethyl cyanuric acid and other substituted cyanuric acids.
It should also be noted that more than one poly(alkylaldehyde) could react with an
amino compound resulting in an oligomer. The term "oligomer" in this application means
a compound having 2 or more amino compound repeating units. Preferably, the oligomer

has a number average molecular weight of from about 200 to about 5000, or about 600 to
about 3000, or about 600 to about 2000.
Preferably, in the above Formula I; B is methylene, ethylene, propylene or a
structure of the formula:

which is the 1,4 Michael addition of crotonaldehyde with trimethylolpropane. Similarly,
one may use the reaction product of crotonaldehyde and polyhydritic alcohols, such as
glycerol, pentaerythritol, sorbitol, 1,4-butanediol, sugars, starches, cellulose and the like;
or adducts and polymers of α, β-unsaturated aldehydes.
Also, preferred is when Rc and RC are C1 to C8 alkyl, Rb and RB are C1 to C8 alkyl
or C1 to C8 alkoxyalkyl and A and A' are moieties derived from urea, glycoluril or mixtures
thereof. Also preferred is when Rb and RB are independently derived from methanol,
ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol,
monoalkyl ether of ethylene or propylene glycol and mixtures thereof.

In addition, it is also preferred that about 10% to about 90% of the RD and Rd

groups, or about 15% to about 70%, or about 30% to about 50% of the RD and Rd groups

on a molar basis are -CHRC ORB and -CHRcORb, respectively.
In another embodiment of the present invention, the stabilized crosslinking
composition comprises an organic acid and the structure of Formula I:
A'-NRA-RD
wherein A' is a moiety derived from triazines, linear or cyclic ureas, cyanuric acid,
substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic
carbamates and mixtures thereof: wherein RA is RD, hydrogen, an alkyl of 1 to about 20

carbon atoms, or taken together with A' forms a cyclic compound; RD is -CHRCORB ,

wherein RB is hydrogen, alkyl, aryl, aralkyl, or an alkaryl having from 1 to about 24 carbon

atoms and RC is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralkyl, alkoxyalkyl
or an alkaryl having from 1 to about 24 carbon atoms. Preferably, in this embodiment,
the amino compound is melamine, guanamine, linear or cyclic ureas or mixtures thereof.
Also, preferred is when RC is a C1 to C8 alkyl, RB is a C1 to C8 alkyl or C1 to C8 alkoxyalkyl.

Also preferred is when RB is independently derived from methanol, ethanol, propanol,
isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol, monoalkyl ether of
ethylene or propylene glycol and mixtures thereof.

In addition, it is also preferred that about 10% to about 90% of the RD groups, or

about 15% to about 70%, or about 30% to about 50% of the RD groups on a molar basis

are -CHRC ORB .
This invention also relates to a process for producing a stabilized crosslinking
composition comprising reacting an amino compound containing amino groups; a
mono(alkylaldehyde) and/or a poly(alkylaldehyde); and an alcohol; and stabilizing the
composition by adding an organic acid before, during and/or after the reaction; where said
amino compound is selected from the group consisting of: triazines, linear or cyclic ureas,
cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins,
linear or cyclic carbamates and mixtures thereof.
Another embodiment of this invention is a process for producing a stabilizing
crosslinking composition comprising reacting an amino compound containing amino
groups; a mono(alkylaldehyde); and an alcohol; and stabilizing the composition by adding
an organic acid before, during and/or after the reaction; wherein said amino compound is
selected from the group consisting of triazines, linear or cyclic ureas, cyanuric acid,
substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins, linear or cyclic
carbamates and mixtures thereof.
The organic acids that may be used in this invention to stabilize the crosslinking
compositions include, but are not limited to organic compounds that contain at least one
acidic functional group including RCO2H, RxSO3H, RxSO2H, RyOH, RxPO3H and RxPO2H,
wherein R is hydrogen or a hydrocarbyl, Rx is hydrocarbyl and Ry is aryl. Examples of
organic acids that may be used, include but are not limited to, acetic acid, (including
glacial acetic acid and mono or polyhalogenated acetic acids), formic acid, propionic acid,
butanoic acid, pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid,
oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid,
citric acid, lactic acid, glycolic acid, glyoxylic acid, methanesulfonic acid, and p-
toluenesulfonic acid or mixtures thereof. Preferably, the organic acid is a carboxylic acid
(i.e., mono-, di-, tri- or polycarboxylic acids). Preferred carboxylic acid are acetic, formic
and propionic acid.
Non-limiting examples of mono(alkylaldehyde) that may be used in this invention
are acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde,
chloral, caproaldehyde, octylaldehyde, acrolein and crotonaldehyde.

Examples of poly(alkylaldehyde) which made be used in this invention include, but
are not limited to glutaraldehyde; the reaction product of crotonaldehyde and polyhydritic
alcohols, such as glycerol, pentaerythritol, trimethylolpropane, sorbitol, 1,4-butanediol,
sugars, starches, cellulose and the like; or adducts and polymers of α, β-unsaturated
aldehydes.
Non-limiting examples of alcohols that may be used in this invention are methanol,
ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol,
monoalkyl ether of ethylene or propylene glycol and mixtures thereof.
In the above reactions, the molar ratio of amino groups in all amino compounds to
mono(alkylaldehyde) is about 1:0.1 to about 1:30, or about 1:0.25 to about 1:10 or about
1:0.5 to about 1:5. In this application "amino groups" include groups with primary and/or
secondary amines, i.e., -NH2 and -NHR groups, respectively.
In addition, the molar ratio of amino groups in the amino compounds to aldehyde
groups in the poly(alkylaldehyde) is about 0.1:1 to about 50:1, or about 0.5:1 to about 25:1
or about 1:1 to about 10:1.
The molar ratio of aldehyde groups in the mono(alkylaldehyde) and
poly(alkylaldehyde) to alcohol is about 1:0.2 to about 1:50, or about 1.0.5 to about 1:5 or
about 1:1 to about 1:3.
The amount of organic acid that may be used to stabilize the crosslinking
composition ranges from a low of about 1:50, or about 1:20 or about 1:10 or about 1:5 or
about 1:2.5 moles of organic acid to moles of amino compound to a high of about 1:2, or
about 1:1, or about 1.5:1 or about 2:1 or about 4:1 or about 10:1 or about 20:1 or about
50:1 moles of organic acid to moles of amino compound.
It is believed that many of the amino-based crosslinking compositions derived from
mono(alkylaldehydes) and/or poly(alkylaldehydes) are not very soluble and/or not stable
in common solvents used in the coatings industry. Many of these amino-based
compounds are not soluble or precipitate out over time leading to unstable compositions.
The inventors of the present invention have discovered that the use of organic acids in
these compositions better solubilizes the amino-based crosslinking compounds in the
solvents leading to more stable compositions. Crosslinking solids concentration needed
for coating applications is typically greater than about 20 wt.% based on the total weight of
crosslinker and solvent.
It should be noted that the above amounts are a general guide and the actual
amount of the ingredients will depend on the type of reactants and conditions used to
produce and stabilize the crosslinking composition.

The reaction should be conducted to prevent gelation, which would have a
deleterious effect on the crosslinking composition. For example, if the amino compounds
contain a large number of amino groups, then a relative small amount of polyfunctional
poly(alkylaldehydes) should be used in order to end-cap with amino groups to prevent an
insoluble crosslinked gel from forming. Conversely, one can charge a large excess of
poly(alkylaldehydes) to effectively end-cap with aldehydes in order to prevent gelation. In
addition, higher reaction temperatures could also tend to lead to self-condensation and
possibly gelation. One skilled in the art would be able to choose the proper reactant
amounts and conditions to reduce or eliminate gel formation.
The above process may be prepared in a one-step or multi-step process. In one
embodiment of a multi-step process, the amino compounds are first reacted with the
mono(alkylaldehyde) and/or poly(alkylaldehyde) compounds (alkylolation reaction), and
then the etherification step would occur by the reaction with an alcohol. In another
embodiment of a multistep reaction, the amino compounds are first reacted with a
poly(alkylaldehyde) followed by an etherification step, then reacted with a
mono(alkylaldehyde) followed by another etherification step.
The alkylolation reaction is preferably conducted in the presence of a catalyst. An
acid or base catalyst may be used.
It should be noted that the above organic acids of this invention that are utilized to
stabilize the crosslinking compositions may be added to the reaction as a catalyst for both
the alkylolation and etherification steps. In general, the amount of the organic acids
needed as catalyst will be less than the amount needed to stabilize the crosslinking
composition.
Non-limiting examples of base catalysts are inorganic basic salts such as the
hydroxides, carbonates or bicarbonates of lithium, sodium, potassium, calcium and
magnesium, or the organic bases and basic salts such as amines and guanidine,
quaternary-ammonium or phosphonium hydroxide and (bi-)carbonate salts.
The etherification reaction is preferably conducted in the presence of an acid
catalyst. The same acid catalyst described above for the alkylolation reaction may also
be used in the etherification reaction.
The reaction is carried out at a temperature from about 0°C to about 125°C, or
about 25°C to about 100°C or about 50°C to about 75°C for a time of about 0.5 hours to
about 48 hours, or about 1 hour to about 24 hours or about 1 hour to about 12 hours.
An important use of the compositions described herein is based on their ability to
act as crosslinking agents in curable compositions, and especially those curable

compositions which contain materials or polymers having active hydrogen groups. The
crosslinkers of the present invention are capable of crosslinking active hydrogen
containing materials or polymers.
The active hydrogen-containing material of the curable compositions preferably
contains at least one class of a reactive functionality such as hydroxy, carboxy, amino,
amido, carbamate, mercapto, or a blocked functionality which is convertible to any of the
preceding reactive functionalities. These active hydrogen-containing materials are those
which are conventionally used in amino resin coatings, and in general are considered
well-known to those of ordinary skill in the relevant art.
Suitable active hydrogen-containing materials include, for example, polyfunctional
hydroxy group containing materials such as polyols, hydroxyfunctional acrylic resins
having pendant or terminal hydroxy functionalities, hydroxyfunctional polyester resins
having pendant or terminal hydroxy functionalities, hydroxyfunctional polyurethane
prepolymers, products derived from the condensation of epoxy compounds with an amine
and mixtures thereof. Acrylic and polyester resins are preferred. Examples of the
polyfunctional hydroxy group containing materials include DURAMAC® 203-1385 alkyd
resin (Eastman Chemical Co.); Beckosol® 12035 alkyd resin (Reichhold Chemical Co.
Durham, NC.)JONCRYL® 500 acrylic resin (S. C. Johnson & Sons, Racine, Wis.); AT-40C
acrylic resin (Rohm & Haas, Philadelphia, Pa.); CYPLEX® polyester resin (Cytec
Industries, West Paterson, N.J.); CARGILL® 3000 and 5776 polyester resins (Cargill,
Minneapolis, Minn.); K-FLEX® XM-2302 and XM-2306 resins (King Industries, Norwalk,
Conn.); CHEMPOL® 11-1369 resin (Cook Composites and Polymers (Port Washington,
Wis.); CRYLCOAT® 3494 solid hydroxy terminated polyester resin (UCB CHEMICALS
USA, Smyrna, Ga.); RUCOTE® 101 polyester resin (Ruco Polymer, Hicksville, N.Y.);
JONCRYL® SCX-800-A and SCX-800-B hydroxyfunctional solid acrylic resins (S. C.
Johnson & Sons, Racine, Wis.); and the like.
Examples of carboxyfunctiona! resins include CRYLCOAT® solid carboxy
terminated polyester resin (UCB CHEMICALS USA, Smyrna, Ga.). Suitable resins
containing amino, amido, carbamate or mercapto groups, including groups convertible
thereto, are in general well-known to those of ordinary skill in the art and may be prepared
by known methods including copolymerizing a suitably functionalized monomer with a
comonomer capable of copolymerizing therewith.
The curable compositions may optionally further comprise a cure catalyst. The
cure catalysts usable in the present invention include sulfonic acids, aryl, alkyl, and aralkyl
sulfonic acids; aryl, alkyl and aralkyl acid phosphates; aryl, alkyl and aralkyl acid

pyrophosphates; carboxylic acids; sulfonimides; mineral acids and a mixture thereof. Of
the above acids, sulfonic acids are preferred when a catalyst is utilized. Examples of the
sulfonic acids include benzenesulfonic acid, para-toluenesulfonic acid,
dodecylbenzenesulfonic acid, naphthalenesulfonic acid, dinonylnaphthalenedisulfonic
acid, and a mixture thereof. Examples of the aryl, alkyl and aralkyl phosphates and
pyrophosphates include phenyl, para-tolyl, methyl, ethyl, benzyl, diphenyl, di-para-tolyl, di-
methyl, di-ethyl, di-benzyl, phenyl-para-tolyl, methyl-ethyl, phenyl-benzyl phosphates and
pyrophosphates. Examples of the carboxylic acids include benzoic acid, formic acid,
acetic acid, propionic acid, butyric acid, dicarboxylic acids such as oxalic acid, fluorinated
acids such as trifluoroacetic acid, and the like. Examples of the sulfonimides include
dibenzene sulfonimide, di-para-toluene sulfonimide, methyi-para-toluene sulfonimide,
dimethyl sulfonimide, and the like. Examples of the mineral acids include nitric acid,
sulfuric acid, phosphoric acid, poly-phosphoric acid, and the like.
The curable composition may also contain other optional ingredients such as
fillers, light stabilizers, pigments, flow control agents, plasticizers, mold release agents,
corrosion inhibitors, and the like. It may also contain, as an optional ingredient, a medium
such as a liquid medium to aid the uniform application and transport of the curable
composition. Any or all of the ingredients of the curable composition may be contacted
with the liquid medium. Moreover, the liquid medium may permit formation of a
dispersion, emulsion, invert emulsion, or solution of the ingredients of the curable
composition. Particularly preferred is a liquid medium, which is a solvent for the curable
composition ingredients. Suitable solvents include aromatic hydrocarbons, aliphatic
hydrocarbons, halogenated hydrocarbons, ketones, esters, ethers, amides, alcohols,
water, compounds having a plurality of functional groups such as those having an ether
and an ester group, and a mixture thereof.
Preferably, the weight ratio of the active hydrogen-containing material to the
crosslinking composition is in the range of from about 99:1 to about 0.5:1 or about 10:1 to
about 0.8:1 or about 4:1 to about 0.8:1.
The weight percent of the cure catalyst, if present, is in the range of from about
0.01 to about 3.0 wt % based on the weight of the crosslinker and active hydrogen-
containing material components.
The present coating compositions may employ a liquid medium such as a solvent,
or it may employ solid ingredients as in powder coatings, which typically contain no
liquids. Contacting may be carried out by dipping, spraying, padding, brushing,
rollercoating, flowcoating, curtaincoating, electrocoating or electrostatic spraying.

The liquid or powder coating compositions and a substrate to be coated are
contacted by applying the curable composition onto the substrate by a suitable method,
for example, by spraying in the case of the liquid compositions and by electrostatic
spraying in the case of the powder compositions. In the case of powder coatings, the
substrate covered with the powder composition is heated to at least the fusion
temperature of the curable composition forcing it to melt and flow out and form a uniform
coating on the substrate. It is thereafter fully cured by further application of heat, typically
at a temperature in the range of about 120°C to about 220°C for a period of time in the in
the range of about 5 minutes to about 30 minutes and preferably for a period of time in the
range of 10 to 20 minutes.
In the case of the liquid compositions, the solvent is allowed to partially evaporate
to produce a uniform coating on the substrate. Thereafter, the coated substrate is allowed
to cure at temperatures of about 20°C to about 150°C, or about 25°C to about 120°C for
a period of time in the in the range of about 20 seconds to about 30 days depending on
temperature to obtain a cured film. In a particularly advantageous embodiment, coating
compositions formulated with crosslinker containing compositions of the present invention
can be heat cured at lower temperatures preferably ranging from about 20°C to about
90°C.
The heat cured compositions of this invention may be employed in the general
areas of coatings such as original equipment manufacturing (OEM) including automotive
coatings, general industrial coatings including industrial maintenance coatings,
architectural coatings, powder coatings, coil coatings, can coatings, wood coatings, and
low temperature cure automotive refinish coatings. They are usable as coatings for wire,
appliances, automotive parts, furniture, pipes, machinery, and the like. Suitable surfaces
include metals such as steel and aluminum, plastics, wood and glass.
The curable compositions of the present invention are particularly well suited to
coat heat sensitive substrates such as plastics and wood which may be altered or
destroyed entirely at the elevated cure temperatures prevalent in the heat curable
compositions of the prior art.
The present invention will now be illustrated by the following examples. The
examples are not intended to limit the scope of the present invention. In conjunction with
the general and detailed descriptions above, the examples provide further understanding
of the present invention.

Example 1. Preparation of Tris(propylol)melamine Methyl Ether (TPMM)
In a suitable flask was mixed 3026 grams of melamine (2.4 mole) with 1394 grams
of propionaldehyde (24 moles), 1991 grams of methanol and 15.6 grams of acetic acid.
The mixture was heated to 65°C, and kept for 2 hours. The solution cooled to precipitate
solids, which were then separated by filtration. The solids had a melting point of about
152-154°C.
Examples 2 and 2C. Solubility of Tris(propylol)melamine Methyl Ether in Ethyl
Acetate
The resin of Example 1 was placed in the following liquids

Both compositions were heated to 80°C. The resin in Example 2 dissolved and
the composition became homogenous (clear) and remained homogenous upon cooling.
The resin in Example 2C did not dissolve upon heating and the composition did not
become homogenous (not clear - hazy).
Example 3. Solvent Resistance of Coatings Containing the Crosslinking Resins of
Examples 2.
A coating compositions containing the crosslinking composition of Examples 2 was
prepared by mixing 36 parts crosslinking resin with 64 parts acrylic backbone resin
(Joncryl® 500) on a dry weight basis and 1.0 parts dimethyl acid pyrophosphate catalyst
in butanol. The formulation was applied on iron phosphate treated cold roll steel panels
and baked at 105°C for 20 minutes. Solvent resistance of the baked film was measured
using a methylethyl ketone (MEK) rub. The result is shown in Table 2 below.

Solvent Resistance is measured by methyl ethyl ketone (MEK) double rubs to remove the
coating.
Example 3 demonstrates that a film with good solvent resistance may be formed
by using an organic acid additive.
Examples 4 to 8 and 4C to 8C. Solubility of Tris(propyIoI)melamine Methyl Ether in
Other Common Coating Solvents
The TPMM resin of Example 1 was contacted with additional solvents to determine
their solubility in common solvents used in the coating industry. The compositions and
the results of the solubility tests are disclosed in Table 3 below.

The results show that without the glacial acetic acid, none of the solvents
solubilized the TPMM resin. The use of glacial acetic acid allows the TPMM resin to be
used as a crosslinker for coating applications.
The invention described and claimed herein is not to be limited in scope by the
specific embodiments herein disclosed, since these embodiments are intended as
illustrations of several aspects of the invention. Any equivalent embodiments are
intended to be within the scope of this invention. Indeed, various modifications of the
invention in addition to those shown and described herein will become apparent to those

skilled in the art from the foregoing description. Such modifications are also intended to
fall within the scope of the appended claims.

WE CLAIM:
1. A crosslinking composition comprising an organic acid and a compound
having the structure of Formula I:
A'-NRA-RD
wherein the organic acid is selected from acetic acid, mono or
polyhalogenated acetic acids, formic acid, propionic acid, butanoic acid,
pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid,
oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid,
tartaric acid, citric acid, lactic acid, glycolic acid, glyoxylic acid, and
methanesulfonic acid, and mixtures thereof, and
wherein A' is a moiety derived from the group consisting of linear or cyclic
ureas, cyanuric acid, the substituted cyanuric acids selected from methyl
cyanuric acid and ethyl cyanuric acid, linear or cyclic amides, glycolurils,
hydantoins, linear or cyclic carbamates and mixtures thereof, or a moiety
comprising the structure:

wherein RA is RD, hydrogen, an alkyl of 1 to 20 carbon atoms, or taken
together with A forms a cyclic compound;

RD is -CHRC ORB, wherein RB is hydrogen, alkyl, aryl, aralkyl or an alkaryl
having from 1 to 24 carbon atoms and Rc is an alkyl, halogenated alkyl, aryl,
aralkyl, halogenated aralkyl, alkoxyalkyl or an alkaryl having from 1 to 24
carbon atoms; A is a moiety derived from the group consisting of linear or
cyclic ureas, cyanuric acid, substituted cyanuric acids, linear or cyclic amides,
glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof;
B is a residue of a poly(alkylaldehyde) with n aldehyde groups; n is an integer
of 2 to 8;
Ra is Rd, hydrogen, an alkyl of 1 to 20 carbon atoms, or taken together with A
forms a cyclic compound;
wherein Rd is CHRc ORb or

wherein Rb is hydrogen, alkyl, aryl, aralkyl or an alkaryl having from 1 to 24
carbon atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated
aralkyl, alkoxyalkyl or an alkaryl having from 1 to 24 carbon atoms;
wherein the molar ratio of said organic acid to amino compound used to
derive the A or A moiety is from 1: 5 to 50 :1,

and wherein the alkyl or aryl groups in each radical may optionally have
heteroatoms in their structure.
2. The composition as claimed in claim 1, wherein said organic acid is a
carboxylic acid selected from acetic acid, mono- or polyhalogenated acetic
acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic
acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid,
succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid,
lactic acid, glycolic acid, glyoxylic acid, and mixtures thereof.
3.The composition as claimed in claim 1, wherein the molar ratio of said
organic acid to amino compound used to derive the A or A' moiety is from 1:
5 to 20 :1.
4.The crosslinking composition as claimed in claim 1, wherein Rb and RB are
independently derived from alcohols selected from the group consisting of:
methanol, ethanol, propanol, isopropanol, butanol, isobutanol, cyclohexanol,
phenol, benzyl alcohol, monoalkyl ether of ethylene or propylene glycol and
mixtures thereof.

5.The crosslinking composition as claimed in claim 1, wherein B is derived
from glutaraldehyde, the reaction products of crotonaldehyde and
polyhydritic alcohols or adducts and polymers of α,β-unsaturated aldehydes.
6. The crosslinking composition as claimed in claim 1, wherein Rc and Rc are
independently C1 to C8 alkyl and Rb and RB are independently C1 to C8 alkyl
or C1 to C8 alkoxyalkyl.
7. The composition as claimed in claim 2, wherein said carboxylic acid is
acetic acid, formic acid, propionic acid or mixtures thereof.
8. The crosslinking composition as claimed in claim 1 wherein A' is a moiety
derived from compounds selected from the group consisting of triazines,
linear or cyclic ureas, cyanuric acid, the substituted cyanuric acids selected
from methyl cyanuric acid and ethyl cyanuric acid, linear or cyclic amides,
glycolurils, hydantoins, linear or cyclic carbamates and mixtures thereof.
9.The composition as claimed in claim 8, wherein A' is derived from
melamines, guanamines, linear and cyclic ureas and mixtures thereof.

10.The crosslinking composition as claimed in claim 8, wherein RB is derived
from alcohols selected from the group consisting of: methanol, ethanol,
propanol, isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl
alcohol, monoalkyl ether of ethylene or propylene glycol and mixtures
thereof.
11.The composition as claimed in claim 8, wherein said organic acid is a
carboxylic acid selected from acetic acid, mono- or polyhalogenated acetic
acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic
acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid,
succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid,
lactic acid, glycolic acid, glyoxylic acid, and mixtures thereof.
12.The composition as claimed in claim 8, wherein the molar ratio of said
organic acid to amino compound used to derive the A' moiety is from 1: 20 to
20:1.
13.The crosslinking composition as claimed in claim 8, wherein Rc is a C1 to
C8 alkyl and RB is a C1 to C8 alkyl or C1 to C8 alkoxyalkyl.
14.The composition as claimed in claim 11, wherein said carboxylic acid is
acetic acid, formic acid, propionic acid or mixtures thereof.

15.A process for producing the crosslinking composition as claimed in claim
1, comprising reacting
(i) an amino compound containing amino groups;
(ii) a mono(alkylaldehyde) and/or a poly(alkylaldehyde); and
(iii) an alcohol;
wherein said amino compound is selected from the group consisting of:
triazine, linear or cyclic ureas, cyanuric acid, the substituted cyanuric acids
selected from methyl cyanuric acid and ethyl cyanuric acid, linear or cyclic
amides, glycolurils, hydantoins, linear or cyclic carbamates and mixtures
thereof; and adding an organic acid selected from acetic acid, mono- or
polyhalogenated acetic acids, formic acid, propionic acid, butanoic acid,
pentanoic acid, hexanoic acid, benzoic acid, phthalic acid, carbonic acid,
oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, malic acid,
tartaric acid, citric acid, lactic acid, glycolic acid, glyoxylic acid,
methane sulfonic acid, and p- toluenesulfonic acid and mixtures thereof.
16.The process as claimed in claim 15, wherein at least some of said organic
acid is added before or during the reaction.
17.The process as claimed in claim 15, wherein at least some of said organic
acid is added after the reaction.

18.The process as claimed in claim 15, wherein said alcohol is selected from
the group consisting of: methanol, ethanol, propanol, isopropanol, butanol,
isobutanol, cyclohexanol, phenol, benzyl alcohol, monoalkyl ether of ethylene
or propylene glycol and mixtures thereof.
19.The process as claimed in claim 15, wherein said poly(alkylaldehyde) is
glutaraldehyde, the reaction product of crotonaldehyde and polyhydritic
alcohols or adducts and polymers of α,β-unsaturated aldehydes.
20.The process as claimed in claim 15, wherein said mono(alkylaldehyde) is
selected from the group consisting of acetaldehyde, propionaldehyde, n-
butyraldehyde, isobutyraldehyde, valeraldehyde, chloral, caproaldehyde,
octylaldehyde, acrolein and crotonaldehyde.
21.The process as claimed in claim 15, wherein the molar ratio of said amino
group to mono(alkylaldehyde) is 1 : 0.1 to 1: 30, the molar ratio of amino
group to the aldehyde groups in the poly(alkylaldehyde) is 0.1:1 to 50 : 1 and
the molar ratio of aldehyde groups in said mono(alkylaldehyde) and said
poly(alkylaldehyde) to alcohol is 1 : 0.2 to 1: 50.

22.The process as claimed in claim 15, wherein the molar ratio of said
organic acid to amino compound is from 1: 20 to 20 :1.
23.The process as claimed in claim 15, wherein said organic acid is a
carboxylic acid selected from acetic acid, mono- or polyhalogenated acetic
acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic
acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid,
succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid,
lactic acid, glycolic acid, glyoxylic acid, and mixtures thereof.
24 .The process as claimed in claim 15, wherein in step (ii), a mono
(alkylaldehyde) is used.
25.The process as claimed in claim 24, wherein the alcohol used in step (iii) is
selected from the group consisting of: methanol, ethanol, propanol,
isopropanol, butanol, isobutanol, cyclohexanol, phenol, benzyl alcohol,
monoalkyl ether of ethylene or propylene glycol and mixtures thereof.
26.The process as claimed in claim 24, wherein said mono(alkylaldehyde) is
selected from the group consisting of acetaldehyde, propionaldehyde, n-
butyraldehyde, isobutyraldehyde, valeraldehyde, chloral, caproaldehyde,
octylaldehyde, acrolein and crotonaldehyde.

27.The process as claimed in claim 24, wherein at least some of said organic
acid is added before or during the reaction.
28.The process as claimed in claim 24, wherein the molar ratio of said
organic acid to amino compound is from 1: 50 to 50 :1.
29.The process as claimed in claim 24, wherein said organic acid is a
carboxylic acid selected from acetic acid, mono- or polyhalogenated acetic
acids, formic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic
acid, benzoic acid, phthalic acid, carbonic acid, oxalic acid, malonic acid,
succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, citric acid,
lactic acid, glycolic acid, glyoxylic acid, and mixtures thereof.
30.The process as claimed in claim 24, wherein said amino compound is
melamine, guanamine, linear and cyclic urea and mixtures thereof.
31.The process as claimed in claim 29, wherein said carboxylic acid is acetic
acid, formic acid, propionic acid or mixtures thereof.

ABSTRACT

Title: A CROSSLINKING COMPOSITION
The invention relates to a crosslinking composition comprising and organic acid and a
compound having the structure of Formula I: A'-N RA -RD where A' is a moiety derived
from the group consisting of triazines, linear or cyclic ureas, cyanuric acid, substituted
cyanuric acids, linear or cyclic amides, glycolurils, hydantonis, linear or cyclic
carbamates and mixtures thereof, or a moiety comprising the structure (II):w here RA RD,
hydrogen, an axyl of 1 to 20 carbon atoms, or taken together with A'forms a cyclic
compound; RD is -CHRCORB, wherein RB, wherein RB is hydrogen, alkyl, aryl, aralkyl
or an alkyl having from 1 to about 24 carbon atoms and RC is an alkyl, halogenated alkyl,
aryl, aralkyl, halogenated aralkyl, aloxyalkyl or an alkryl having from 1 to about 24
carbon atoms: A is a moiety derived from the group consisting of linear or cyclic ureas,
cyanuric acid, substituted cyanuric acids, linear or cyclic amides, glycolurils, hydantoins,
linear or cyclic carbamates and mixtures thereof; B is a residue of a poly (alkylaldehyde)
with n aldehyde groups; n is an integer of 2 to about 8; Ra is Rd hydrogen, an alkyl of 1 to
about 20 carbon atoms, or taken together with A forms a cyclic compound; where Rd is
CHRcORb or (III) where Rb is hydrogen, alkyl, aryl, aralkyl having from 1 to about 24
carbon atoms and Rc is an alkyl, halogenated alkyl, aryl, aralkyl, halogenated aralyyl,
alkoxyalkyl or an an alkaryl having from 1 to about 24 carbon atoms; and where the alkyl
or aryl groups in each radivcal may optionally have heteroatoms in their structure and to
a process for producing the crosslinking.

Documents:

0905-kolnp-2007 abstrcat.pdf

0905-kolnp-2007 assignment.pdf

0905-kolnp-2007 claims.pdf

0905-kolnp-2007 correspondence others.pdf

0905-kolnp-2007 description(complete).pdf

0905-kolnp-2007 form-1.pdf

0905-kolnp-2007 form-2.pdf

0905-kolnp-2007 form-3.pdf

0905-kolnp-2007 form-5.pdf

0905-kolnp-2007 international publication.pdf

0905-kolnp-2007 international search authority report.pdf

0905-kolnp-2007 pct others.pdf

905-KOLNP-2007-(05-01-2012)-CORRESPONDENCE.pdf

905-KOLNP-2007-(05-01-2012)-OTHER PATENT DOCUMENT.pdf

905-KOLNP-2007-(09-07-2012)-CORRESPONDENCE.pdf

905-KOLNP-2007-(13-01-2012)-CORRESPONDENCE.pdf

905-KOLNP-2007-(13-01-2012)-PRIORITY DOCUMENT.pdf

905-KOLNP-2007-(19-12-2011)-ABSTRACT.pdf

905-KOLNP-2007-(19-12-2011)-AMANDED CLAIMS.pdf

905-KOLNP-2007-(19-12-2011)-DESCRIPTION (COMPLETE).pdf

905-KOLNP-2007-(19-12-2011)-EXAMINATION REPORT REPLY RECEIVED.pdf

905-KOLNP-2007-(19-12-2011)-FORM-1.pdf

905-KOLNP-2007-(19-12-2011)-FORM-2.pdf

905-KOLNP-2007-(19-12-2011)-FORM-3.pdf

905-KOLNP-2007-(19-12-2011)-FORM-5.pdf

905-KOLNP-2007-(19-12-2011)-OTHERS.pdf

905-KOLNP-2007-(19-12-2011)-PCT SEARCH REPORT.pdf

905-KOLNP-2007-CORRESPONDENCE.pdf

905-KOLNP-2007-EXAMINATION REPORT.pdf

905-KOLNP-2007-FORM 18 1.1.pdf

905-kolnp-2007-form 18.pdf

905-KOLNP-2007-FORM 3.pdf

905-KOLNP-2007-FORM 5.pdf

905-KOLNP-2007-GPA.pdf

905-KOLNP-2007-GRANTED-ABSTRACT.pdf

905-KOLNP-2007-GRANTED-CLAIMS.pdf

905-KOLNP-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

905-KOLNP-2007-GRANTED-FORM 1.pdf

905-KOLNP-2007-GRANTED-FORM 2.pdf

905-KOLNP-2007-GRANTED-SPECIFICATION.pdf

905-KOLNP-2007-OTHERS.pdf

905-KOLNP-2007-REPLY TO EXAMINATION REPORT.pdf

905-KOLNP-2007-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

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Patent Number

253198

Indian Patent Application Number

905/KOLNP/2007

PG Journal Number

27/2012

Publication Date

06-Jul-2012

Grant Date

04-Jul-2012

Date of Filing

14-Mar-2007

Name of Patentee

CYTEC TECHNOLOGY CORP.

Applicant Address

300 DELAWARE AVENUE, WILMINGTON, DE 19801.

Inventors:

#	Inventor's Name	Inventor's Address
1	LIN, LON-TANG, WILSON	3 FALLS LANE, BETHEL, CT 06801.
2	JAKOBS, WILLIAM, III:	9 OLD LATERN DRIVE, BETHEL, CT 06801,

PCT International Classification Number

C08L 61/28

PCT International Application Number

PCT/US2005/030853

PCT International Filing date

2005-08-29

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	10/953,025	2004-09-29	U.S.A.