# US 11,441,052 B2 · Process for coating fiber composite panels at low baking temperatures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,052 B2 - Document ID: US11441052B2 - Status: Granted - Kind: B2 - Application number: 16/962,435 - Filed: 2019-01-18 - Published: 2021-03-04 - Granted: 2022-09-13 - Earliest claimed: 2018-01-18 - Assignees: BASF Coatings GmbH - Applicants: BASF Coatings GmbH - Inventors: Donald H Campbell; Colin Wade - Web page: https://patentgrep.com/patent/US11441052B2 ## CPC - C08G 18/67: Unsaturated compounds having active hydrogen - C09D 175/14: Polyurethanes having carbon-to-carbon unsaturated bonds - B05D 7/576: {each layer being cured, at least partially, separately} - C08G 18/227: {of antimony, bismuth or arsenic} - C08G 18/246: {containing also tin-carbon bonds} - C08G 18/792: {formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates} - C08G 18/809: {containing silicon} - B05D 7/572: {all layers being cured or baked together} - B05D 7/577: {some layers being coated "wet-on-wet", the others not} - B05D 2201/00: Polymeric substrate or laminate - 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) - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) ## Abstract Described herein is a process for producing a multilayer coating onto a fiber-reinforced composite material. Also described herein is a fiber-reinforced composite material coated with a multilayer coating obtainable by this process. ## Claims ### Claim 1 A process for producing a multilayer coating onto a fiber-reinforced composite material, comprising the steps of i. applying a primer composition onto the fiber-reinforced composite material to form a primer layer and at least partially drying the primer layer, ii. applying a basecoat composition onto the primer layer to form a basecoat layer and at least partially drying the basecoat layer, and iii. (a) applying a first clearcoat composition 1 onto the basecoat layer to form a first clearcoat layer 1 and curing the layers formed in steps i., ii. and the first clearcoat layer at a temperature of at least 80° C. and subsequently applying a second clearcoat composition 2 onto the thus cured layers to form a clearcoat layer 2 and curing clearcoat layer 2 at a temperature of more than 25° C. to less than 60° C. for 10 to 40 min; or (b) directly applying the clearcoat composition 2 onto the basecoat layer to form a single clearcoat layer 2 and curing the single clearcoat layer 2 at a temperature of more than 25° C. to less than 60° C. for 10 to 40 min followed by curing the primer, basecoat and clearcoat layer 2 at a temperature of at least 80° C. ### Claim 2 (depends on 1) The process according to claim 1, characterized in that the fiber-reinforced composite material comprises a polymer matrix and fibers. ### Claim 3 (depends on 1) The process according to claim 1, characterized in that the primer composition is a one-pack coating composition or a two-pack coating composition; and/or the basecoat composition is a one-pack coating compositions; and/or that clearcoat composition 1 is a one-pack coating composition or a two-pack coating composition; and/or clearcoat composition 2 is a two-pack coating compositions. ### Claim 4 (depends on 1) The process according to claim 1, characterized in that the primer composition is a solvent-borne or water-borne coating composition; the clearcoat compositions 1 and 2 are solvent-borne coating compositions; and/or the basecoat composition is a solvent-borne or water-borne coating composition. ### Claim 5 (depends on 1) The process according to claim 1, characterized in that no mechanical roughening step is required after curing clearcoat layer 1 in step iii.(a). ### Claim 6 (depends on 5) The process according to claim 5, wherein the mechanical roughening step is a sanding step. ### Claim 7 (depends on 5) The process according to claim 5, characterized in that no mechanical roughening step is required in or after any step of the process. ### Claim 8 (depends on 7) The process according to claim 7, wherein the mechanical roughening step is a sanding step. ### Claim 9 (depends on 1) The process according to claim 1, characterized in that step iii.(a) is followed by a second cure at a temperature of at least 80° C. for a time period of 10 to 40 min. ### Claim 10 (depends on 1) The process according to claim 1, characterized in that step iii.(b) subsequently to curing the single clearcoat layer 2 at a temperature of more than 25° C. to less than 60° C. for 10 to 40 min and before curing the primer, basecoat and clearcoat layer 2 at a temperature of at least 80° C., the coated fiber-reinforced composite material is cooled to a temperature in the range from 23° C. to below the curing temperature of clearcoat layer 2. ### Claim 11 (depends on 1) The process according to claim 1, characterized in that clearcoat layer 2 is cured at a temperature in the range from 30 to 55° C. for 15 to 35 min, or at a temperature in the range from 35 to 55° C. for 20 to 30 min. ### Claim 12 (depends on 3) The process according to claim 3, characterized in that the primer composition is a water-borne two-pack composition or a solvent-borne one-pack composition; the basecoat composition is a water-borne or a solvent-borne one-pack composition; and the clearcoat compositions 1 and 2 are solvent-borne two-pack compositions. ### Claim 13 (depends on 1) The process according to claim 1, wherein the primer composition and the basecoat composition comprise one or more polymeric polyols and one or more aminoplast resins; and/or the clearcoat composition 1 comprises one or more polymeric polyols and one or more isocyanato-group containing species. ### Claim 14 (depends on 1) The process according to claim 1, wherein clearcoat composition 2 comprises a master batch and a curing agent, the master batch comprising a polymeric polyol and the curing agent comprising a isocyanato-group containing species. ### Claim 15 (depends on 14) The process according to claim 14, wherein the polymeric polyol is selected from the group consisting of poly(meth)acrylate polyols and the isocyanato-group containing species is selected from the group consisting of diisocyanates and polyisocyanate. ### Claim 16 (depends on 15) The process according to claim 15, wherein the diisocyanates are selected from the group consisting of biuret dimers and uretdion dimers of diisocyanates. ### Claim 17 (depends on 15) The process according to claim 15, wherein the polyisocyanates are selected from the group consisting of trimers. ### Claim 18 (depends on 17) The process according to claim 17, wherein the trimers are selected from the group consisting of isocyanurate trimers and iminooxadiazindion trimers of diisocyanates. ### Claim 19 (depends on 14) The process according to claim 14, wherein the polymeric polyol has a weight-average molecular weight Mw in the range from 1,000 to 20,000 g/mol measure by means of gel permeation chromatography and/or exhibiting a theoretical glass transition temperature in the range from −100° C. to 100° C. and/or exhibiting hydroxyl number in the range from 60 to 250 mg KOH/g; and/or wherein the one or more isocyanato-groups of the isocyanato-group containing species are reacted to introduce one or more hydrolysable silane groups into the isocyanato-group containing species. ### Claim 20 (depends on 1) A fiber-reinforced composite material coated with a multilayer coating, obtainable in a process according to claim 1.