# US 6,294,619 B1 · Stable powder coating compositions which produce consistent finishes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,294,619 B1 - Document ID: US6294619B1 - Status: Granted - Kind: B1 - Application number: 09/431,790 - Filed: 1999-11-02 - Granted: 2001-09-25 - Earliest claimed: 1999-11-02 - Assignees: PPG Industries Ohio, Inc. - Inventors: Anthony M. Chasser; Ronald R. Ambrose; Barbara A. Greigger; William H. Retsch - Web page: https://patentgrep.com/patent/US6294619B1 ## CPC - C08G 18/8067: {phenolic compounds} - C08G 18/4661: {containing three nitrogen atoms in the ring} - C08G 18/8016: {Masked aliphatic or cycloaliphatic polyisocyanates} - C09D 167/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds (C09D167/06 takes precedence) - C08G 2150/20: Compositions for powder coatings - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) ## Abstract The invention provides powder coatings that consistently produce durable finishes when cured, and are stable when uncured. These powder coatings of the invention include novel film forming systems. The novel film forming system, in turn, includes a polymer component and a crosslinker component. In one embodiment, the polymer component is novel; and, in another embodiment, both the polymer and crosslinker components are novel. The novel polymer component includes a novel polyester polyol. This novel polyester polyol includes the reaction product of a cycloaliphatic component and a polyfunctional isocyanurate component. The novel crosslinker component which can be used when practicing certain embodiments of this invention includes a novel, polyfunctional isocyanate compound which is at least partially blocked with at least one of the following: a polyhydroxy aromatic compound, or a mixture of a polyhydroxy aromatic compound and a hydroxy-functional ester compound. ## Claims ### Claim 1 A powder coating composition comprising a film forming resin system, wherein said film forming resin system comprises: a. a polymer component comprising a polyester polyol which comprises the reaction product of: i. a cycloaliphatic component which comprises the reaction product of: (1) a cycloaliphatic acid, and (2) a cyclic polyol, and ii. a polyfunctional isocyanurate component which comprises at least one compound that has at least two groups reactive towards carboxylic groups, and b. a crosslinker component capable of crosslinking said polyester polyol, said crosslinker component comprising a polyfunctional isocyanate which is at least partially blocked with at least one of the following: i. a polyhydroxy aromatic compound having at least one of the following structures: HO—Φ1—R1—Φ1—OH where Φ1 consists of a phenylene group, and Rh is an alkylene group having 0 to 4 carbon atoms, or HO—Φ2—OH where Φ2 consists of a phenylene group or a naphthylene group, or ii. a mixture of the polyhydroxy aromatic compound and a hydroxy-functional ester compound. ### Claim 2 (depends on 1) The powder coating composition recited in claim 1, wherein the cycloaliphatic acid comprises at least one compound selected from the group consisting of: the 1,2-isomer of hexahydrophthalic acid, the 1,3- isomer of hexahydrophthalic acid; and the 1,4-isomer of hexahydrophthalic acid. ### Claim 3 (depends on 1) The powder coating composition recited in claim 1, wherein the cycloaliphatic acid comprises hexahydrophthalic anhydride. ### Claim 4 (depends on 1) The powder coating composition recited in claim 1, wherein the amount of the cycloaliphatic acid employed is at least about 40 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 5 (depends on 1) The powder coating composition recited in claim 1, wherein the amount of the cycloaliphatic acid employed is at most about 55 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 6 (depends on 1) The powder coating composition recited in claim 1 wherein the cyclic polyol comprises at least one compound selected from the group consisting of: cyclohexanie dimethanol and cyclohexane diol. ### Claim 7 (depends on 1) The powder coating composition recited in claim 1, wherein the amount of the cyclic polyol employed is at least about 10 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 8 (depends on 1) The powder coating composition recited in claim 1, wherein the amount of the cyclic polyol employed is at most about 70 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 9 (depends on 1) The powder coating composition recited in claim 1, wherein the amount of the cycloaliphatic component employed is at least about 60 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 10 (depends on 1) The powder coating composition recited in claim 1, wherein the amount of the cycloaliphatic component employed is at most about 99 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 11 (depends on 1) The powder coating composition recited in claim 1, wherein the polyfunctional isocyanurate component comprises at least one compound selected from the group consisting of: tris(hydroxyethyl) isocyanurate and triglycidyl isocyanurate. ### Claim 12 (depends on 1) The powder coating, composition recited in claim 1, wherein the amount of the polyfunctional isocyanurate component employed is at least about 1 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 13 (depends on 1) The powder coating composition recited in claim 1, wherein the amount of the polyfunctional isocyanurate component employed is at most about 40 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 14 (depends on 1) The powder coating composition recited in claim 1, wherein the polyfunctional isocyanate comprises at least one compound selected from the group consisting of: isocyanurates from isophoronie diisocyanate, isocyanurates from hexamethylene diisocyanate, and biurets from hexamethylene diisocyanate. ### Claim 15 (depends on 1) The powder coating composition recited in claim 1, wherein the crosslinker component comprises triisocyanates or a mixture of diisocyanates and triisocyanates. ### Claim 16 (depends on 1) The powder coating composition recited in claim 1, wherein the polyhydroxy aromatic compound comprises at least one compound selected from the group consisting of: diphenols, dihydroxynaphthalene, and hydroxy phenols. ### Claim 17 (depends on 1) The powder coating composition recited in claim 1, wherein the hydroxy-functional ester compound comprises compounds having at least one of the following structure: COOR2—Φ2—OH where, R2 is an alkyl group having from 1 to 4 carbon atoms, and Φ2 consists of a phenylene group or a naphthylene group. ### Claim 18 (depends on 1) The powder coating composition recited in claim 1, wherein the hydroxy-functional ester compound comprises at least one compound selected from the group consisting of: methyl 4-hydroxy benzoate, and methyl 3-hydroxy benzoate. ### Claim 19 (depends on 1) The powder coating composition recited in claim 1, wherein the polyfunctional isocyanate is at least partially blocked with a blend of a polyhydroxy aromatic compound and a hydroxy-functional ester compound, and wherein the ratio of the polyhydroxy aromatic compound to the hydroxy-functional ester compound ranges from about 0.01:1 to about 1.4:1. ### Claim 20 A powder coating composition comprising a film forming resin system, wherein said film forming resin system comprises: a. a polymer component comprising a polyester polyol which comprises the reaction product of: i. a cycloaliphatic component which comprises the reaction product of: (1) hexahydrophthalic anhydride, and (2) a cyclic polyol, and ii. a polyfunctional isocyanurate component which comprises at least one compound that has at least two groups reactive towards carboxylic groups, and b. a crosslinker component capable of crosslinking said polyester polyol. ### Claim 21 (depends on 20) The powder coating composition recited in claim 20, wherein the amount of hexahydrophthalic anhydride employed is at least about 40 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 22 (depends on 20) The powder coating composition recited in claim 20, wherein the amount of hexahydrophthalic anhydride employed is at most about 55 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 23 (depends on 20) The powder coating composition recited in claim 20, wherein the cyclic polyol comprises at least one compound selected from the group consisting of: cyclohexanie dimethanol and cyclohexane diol. ### Claim 24 (depends on 20) The powder coating composition recited in claim 20, wherein the amount of the cyclic polyol employed is at least about 10 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 25 (depends on 20) The powder coating composition recited in claim 20, wherein the amount of the cyclic polyol employed is at most about 70 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 26 (depends on 20) The powder coating composition recited in claim 20, wherein the amount of the cycloaliphatic component employed is at least about 60 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 27 (depends on 20) The powder coating composition recited in claim 20, wherein the amount of the cycloaliphatic component employed is at most about 99 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 28 (depends on 20) The powder coating composition recited in claim 20, wherein the polyfunctional isocyanurate component comprises at least one compound selected from the group consisting of: tris(hydroxyethyl) isocyanurate and triglycidyl isocyanurate. ### Claim 29 (depends on 20) The powder coating composition recited in claim 20, wherein the amount of the polyfunctional isocyanurate component employed is at least about 1 weight percent, said weight percentage being based upon the total weight of the polyester polyol. ### Claim 30 (depends on 20) The powder coating composition recited in claim 20, wherein the amount of the polyfunctional isocyanurate component employed is at most about 40 weight percent, said weight percentage being based upon the total weight of the polyester polyol.