# US 10,865,303 B2 · Composite structure having an inorganic coating adhered thereto and method of making same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,303 B2 - Document ID: US10865303B2 - Status: Granted - Kind: B2 - Application number: 15/873,068 - Filed: 2018-01-17 - Published: 2018-07-26 - Granted: 2020-12-15 - Earliest claimed: 2011-07-01 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: James Frank Cordaro - Web page: https://patentgrep.com/patent/US10865303B2 ## CPC - C08L 63/00: Compositions of epoxy resins; Compositions of derivatives of epoxy resins - B05D 1/185: {applying monomolecular layers (B05D1/204 takes precedence)} - B05D 7/02: to macromolecular substances, e.g. rubber (treatment or coating of shaped articles made of macromolecular substances C08J7/00) - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - B82Y 40/00: Manufacture or treatment of nanostructures - C09D 1/04: with organic additives - C08K 5/544: containing nitrogen - C08K 5/5455: containing at least one [IMAGE cpc-sch-C08K-1012.gif] group - Y10T 428/31511: Of epoxy ether - Y10T 428/31515: As intermediate layer - Y10T 428/31522: Next to metal - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - 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) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present disclosure provides a composite structure and associated method for preparing a composite substrate comprising an inorganic coating that is adhered to an organic-based substrate via an adhesion promoting agent comprising a molecule having a urea moiety at one end of the molecule and an alkoxysilane moiety at the other end of the molecule. The use of adhesion promoting agent having at least one of an amine or imine moiety and an alkoxysilane moiety promotes tight adhesion of the inorganic coating to the substrate. ## Claims ### Claim 1 A method of preparing a composite structure comprising: providing a substrate comprising an epoxy-based matrix; humidifying an outer surface of the substrate to form chemisorbed water on or near said outer surface; applying a solution containing an adhesion promoting agent to said outer surface of the epoxy-based matrix, the adhesion promoting agent having the following formula: wherein X is an alkoxy group having from 1 to 3 carbon atoms; and n is a number from 1 to 5; drying the solution to form a layer containing the adhesion promoting agent; applying an inorganic coating over the layer of the adhesion promoting agent; and curing the inorganic coating to provide a composite substrate in which the inorganic coating layer is tightly adhered to the substrate. ### Claim 2 (depends on 1) The method of claim 1, wherein the solution containing the adhesion promoting agent comprises isopropyl alcohol. ### Claim 3 (depends on 1) The method of claim 1, wherein the adhesion promoting agent comprises a molecule having the following formula: ### Claim 4 (depends on 1) The method of claim 1, further comprising the step of humidifying the surface of the substrate prior to the step of applying the adhesion promoting agent. ### Claim 5 (depends on 1) The method of claim 1, wherein the step of applying an inorganic coating over the layer of the adhesion promoting agent comprises applying a first layer of inorganic coating as a mist coat. ### Claim 6 (depends on 5) The method of claim 5, further comprising the step of applying a second layer of inorganic coating, wherein the second layer of the inorganic coating is applied following at least 5 minutes after the application of the first layer of the inorganic coating. ### Claim 7 (depends on 1) The method of claim 1, wherein the inorganic coating has a pH greater than 7. ### Claim 8 (depends on 1) The method of claim 1, wherein the inorganic coating has a pH of about 11 or greater. ### Claim 9 (depends on 1) The method of claim 1, wherein the adhesion promoting agent is applied to the substrate by rubbing the adhesion promoting agent onto the surface of the substrate. ### Claim 10 (depends on 9) The method of claim 9, wherein the inorganic coating comprises a potassium silicate based resin. ### Claim 11 (depends on 1) The method of claim 1, wherein the epoxy-based matrix comprises glass fibers, carbon fibers, or a mixture thereof. ### Claim 12 A method of preparing a composite structure comprising: providing a substrate comprising an epoxy-based matrix; humidifying an outer surface of the substrate to form chemisorbed water on or near said outer surface; applying a solution containing an adhesion promoting agent to said outer surface of the epoxy-based matrix, the adhesion promoting agent having the following formula: wherein X is an alkoxy group having from 1 to 3 carbon atoms; and n is a number from 1 to 5; drying the solution to form a layer containing the adhesion promoting agent; applying an inorganic coating over the layer of the adhesion promoting agent; and curing the inorganic coating to provide a composite substrate in which the inorganic coating layer is tightly adhered to the substrate, wherein the adhesion promoting agent layer is disposed between and separates the outer surface of the substrate from the inorganic coating layer. ### Claim 13 (depends on 12) The method of claim 12, wherein the inorganic coating layer consists of one or more of potassium silicate, sodium silicate, a metal oxide based pigment in combination with a potassium or sodium silicate, or combinations thereof. ### Claim 14 (depends on 12) The method of claim 12, wherein the step of humidifying an outer surface of the substrate comprises exposing the outer surface to water or a humid environment. ### Claim 15 (depends on 12) The method of claim 12, wherein the adhesion promoting agent comprises a molecule having a following formula: ### Claim 16 (depends on 12) The method of claim 12, wherein the inorganic coating layer consists of potassium silicate. ### Claim 17 (depends on 12) The method of claim 12, wherein the epoxy-based matrix comprises glass fibers. ### Claim 18 (depends on 12) The method of claim 12, wherein the epoxy-based matrix comprises carbon fibers. ### Claim 19 (depends on 12) The method of claim 12, wherein the adhesion promoting agent layer has a thickness greater than 0.5 microns. ### Claim 20 (depends on 12) The method of claim 12, further comprising the step of depositing the epoxy-based matrix as a coating onto a surface of a non-epoxy based material.