Patent ID: 11879066
Assignee: CHEMOURS-MITSUI FLUOROPRODUCTS CO., LTD.
Field: Basic materials chemistry (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 3:
4. A method of forming the coating film on the substrate according to claim 1, comprising the steps of: coating a fluororesin coating composition for forming a topcoat, comprising a crystalline tetrafluoroethylene and perfluoro(ethyl vinyl ether) copolymer having a perfluoro(ethyl vinyl ether) content of 8 to 20 mass % based on the total mass of said copolymer on a substrate; and then performing heat treatment on the coated substrate, wherein said heat treatment is carried out at the melting point or higher of said crystalline tetrafluoroethylene and perfluoro(ethyl vinyl ether) copolymer, and wherein said substrate is primer coated or the surface of said substrate is chemically treated prior to being coated with said coating film, wherein the crystalline tetrafluoroethylene and perfluoro(ethyl vinyl ether) copolymer consists of tetrafluoroethylene, perfluoro(ethyl vinyl ether), and optionally a monomer selected from the group consisting of a perfluoroalkene including 3 to 6 carbon atoms, a perfluoro(alkyl vinyl ether) including 1 to 6 carbon atoms other than perfluoro(ethyl vinyl ether), chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride, ethylene, propylene, butylene, pentene, hexene, styrene, acetylene, propyne, and combinations thereof.