# US 5,346,958 A · Curable coating compositions containing polystyrene microparticles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,346,958 A - Document ID: US5346958A - Status: Granted - Kind: A - Application number: 08/046,987 - Filed: 1993-04-16 - Granted: 1994-09-13 - Earliest claimed: 1992-04-20 - Assignees: Kansai Paint Co., Ltd. - Inventors: Yoshiyuki Yukawa; Motoshi Yabuta; Akimasa Nakahata; Yuzo Miyamoto; Masaaki Kobayashi; Naruhito Ueno - Web page: https://patentgrep.com/patent/US5346958A ## CPC - C09D 125/08: Copolymers of styrene (C09D129/08, C09D135/06, C09D155/02 take precedence) - C08L 25/14: with unsaturated esters - C08L 61/20: Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen (with aminophenols C08L61/04) - C08L 2205/18: Spheres - Y10T 428/29: Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof - Y10T 428/31855: Of addition polymer from unsaturated monomers - Y10T 428/31862: Melamine-aldehyde - 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) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A curable top coating composition essentially including (A) a hydroxyl-containing vinyl type resin containing 45 to 55% by weight of styrene monomer as a copolymerized unit of the resin, (B) at least one member selected from among amino resins and (blocked) polyisocyanate compounds, and (C) a microparticulate polymer having an average particle diameter within the range of 0.01 to 1 .mu.m and containing 40 to 60% by weight of styrene monomer as a copolymerized component of each particle, wherein the cured film from the coating composition contains the styrene-derived benzene ring in a proportion of 13 to 40% by weight of the total resin solids; a coating method using the above coating composition, and a coated article obtainable by using the above coating composition. ## Claims ### Claim 1 A curable top coating composition comprising: (A) a hydroxyl-containing vinyl resin containing 45 to 55% by weight of styrene monomer as copolymerized unit of the resin, (B) at least one crosslinking agent selected from the group consisting of amino resins, polyisocyanate compounds and blocked polyisocyanate compounds, and C) a microparticulate polymer having an average particle diameter within the range of 0.01 to 1 .mu.m and containing 40 to 60% by weight of styrene monomer as a copolymerized component of each particle, wherein the cured film from said coating composition contains the styrene-derived benzene ring in a proportion of 13 to 40% by weight of the total resin solids. ### Claim 2 (depends on 1) The top coating composition of claim 1 wherein said hydroxyl-containing vinyl resin has a weight average molecular weight in the range of 3000 to 30000. ### Claim 3 (depends on 1) The top coating composition of claim 1 wherein said hydroxyl-containing vinyl resin has a hydroxyl value in the range of 60 to 140 mg KOH/g. ### Claim 4 (depends on 1) The top coating composition of claim 1 wherein said hydroxyl-containing vinyl resin is a resin obtainable by copolymerizing a monomeric mixture consisting of 45 to 55% by weight of styrene monomer, 5 to 45% by weight of a hydroxyl-containing vinyl monomer and 1 to 45% by weight of a (meth)acrylic ester of a monoalcohol of 4 to 24 carbon atoms. ### Claim 5 (depends on 1) The top coating composition of claim 1 wherein said amino resin is at least one species selected from the group consisting of hexamethoxymethylmelamine and an etherified melamine resin prepared by partial or complete substitution of its methoxy groups with C.sub.4 or higher alcohols. ### Claim 6 (depends on 1) The top coating composition of claim 1 wherein, on the basis of the total weight of said components (A), (B) and (C), (A) accounts for 33 to 90% by weight, (B) for 7 to 33% by weight and (C) for 0.1 to 33% by weight. ### Claim 7 (depends on 4) The top coating composition of claim 4 wherein said hydroxyl-containing vinyl monomer is at least one species selected from the group consisting of 1,4-butanediol monoacrylate and .epsilon.-caprolactone-modified acrylate monomers. ### Claim 8 (depends on 1, 5) The top coating composition of claim 1 or 5 wherein the coating composition further comprises a curing catalyst for said amino resin which is selected from the group consisting of acids and amine salts of acids. ### Claim 9 (depends on 1) The top coating composition of claim 1 wherein the coating composition further comprises an organic solvent. ### Claim 10 (depends on 1) A coating method comprising using the coating composition of claim 1 as a top coating composition in a 2-coat/1-bake system wherein a substrate is coated with a colored base coat and a clear top coat in succession and then baked. ### Claim 11 (depends on 1) A coated article prepared by coating the coating composition of claim 1 on an article.