# US 5,705,017 A · Method for the production of steel sheet coated with a fluororesin film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,705,017 A - Document ID: US5705017A - Status: Granted - Kind: A - Application number: 08/549,789 - Filed: 1995-12-05 - Granted: 1998-01-06 - Earliest claimed: 1993-06-10 - Assignees: Kawatetsu Galvanizing Co., Ltd. - Inventors: Yasuhei Sakamoto; Toshio Irie; Hideshi Fujisawa; Koji Seto; Morimasa Kuroda - Web page: https://patentgrep.com/patent/US5705017A ## CPC - B32B 15/08: of synthetic resin - B32B 15/18: comprising iron or steel {(B32B15/011, B32B15/012 and B32B15/013 take precedence)} - B32B 37/04: characterised by the partial melting of at least one layer - B32B 37/06: characterised by the heating method - B32B 38/0036: {Heat treatment (for heating or cooling of layers during lamination B32B37/06, B32B37/08)} - B32B 2310/0812: using induction - B32B 2311/30: Iron, e.g. steel - B32B 2327/12: containing fluorine - B32B 2327/18: PTFE, i.e. polytetrafluoroethylene - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM ## Abstract A method of producing a steel sheet coated with a fluororesin film by heat-fusing the fluororesin film onto a surface of the steel sheet, comprising heating the surface of the steel sheet to a temperature higher by 30-120 degrees C. than a melting point of the fluororesin of the fluororesin film, and contact bonding the fluororesin film onto the steel sheet surface between a pair of rolls, while a surface of a roll facing the fluororesin film, in the pair of rolls, is heated to a temperature lower by 100-210 degrees C. than the melting point of the fluororesin of the fluororesin film. ## Claims ### Claim 1 A method of producing a steel sheet coated with a fluororesin film by heat-fusing the fluororesin film onto a surface of the steel sheet, comprising: heating the surface of the steel sheet to a temperature higher by 30.degree.-120.degree. C. than a melting point of the fluororesin of said fluororesin film; and contact bonding the fluororesin film onto the steel sheet surface between a pair of rolls, while a surface of a roll facing the fluororesin film, in said pair of rolls, is heated to a temperature lower by 100.degree.-210.degree. C. than the melting point of the fluororesin of the fluororesin film. ### Claim 2 (depends on 1) A method of producing a steel sheet coated with a fluororesin film according to claim 1, wherein a primer comprised of a mixed resin of fluororesin and thermal-resistant resin is applied onto the surface of the steel sheet and dried, prior to contact-bonding of the fluororesin film to the steel sheet, the primer having a thickness of 3-15 g/m.sup.2 after drying. ### Claim 3 (depends on 1) A method of producing a steel sheet coated with a fluororesin film according to claim 1, wherein at least one of the steel sheet surface and the roll surface facing the fluororesin film is heated using induction heating. ### Claim 4 (depends on 2) A method of producing a steel sheet coated with a fluororesin film according to claim 2, wherein at least one of the primer which has been applied to the steel sheet surface and the roll surface facing the fluororesin film is heated using induction heating. ### Claim 5 (depends on 1) A method of producing a steel sheet coated with a fluororesin film according to claim 1, wherein the steel sheet comprises a member selected from the group consisting of galvanized steel sheet, hot dip zinc-5% aluminum alloy plated steel sheet, hot dip galvannealed steel sheet, zinc-nickel alloy plated steel sheet, hot dip aluminum plated steel sheet, hot dip aluminum-silicon alloy plated steel sheet, 55% aluminum-zinc alloy plated steel sheet, and stainless steel sheet. ### Claim 6 (depends on 5) A method of producing a steel sheet coated with a fluororesin film according to claim 5, wherein the thickness of the steel sheet is from about 0.5 to about 1.6 mm. ### Claim 7 (depends on 1) A method of producing a steel sheet coated with a fluororesin film according to claim 1, wherein the fluororesin film comprises a fluororesin containing 2 or more fluorine atoms per 1 molecule unit. ### Claim 8 (depends on 7) A method of producing a steel sheet coated with a fluororesin film according to claim 7, wherein the fluororesin film comprises a member selected from the group consisting of ethylene tetrafluoride-perfluoroalkylvinyl ether copolymer resin, ethylene tetrafluoride-propylene hexafluoride copolymer resin and ethylene tetrafluoride-ethylene copolymer resin. ### Claim 9 (depends on 7) A method of producing a steel sheet coated with a fluororesin film according to claim 7, wherein the thickness of the fluororesin film is from 10 to 100 .mu.m. ### Claim 10 (depends on 2) A method of producing a steel sheet coated with a fluororesin film according to claim 2, wherein the primer comprises a mixed resin comprising a fluororesin powder and a thermal-resistant resin and wherein: A) the fluororesin powder comprises a member selected from the group consisting of polyethylene tetrafluoride, ethylene tetrafluoride-perfluoroalkylvinyl ether copolymer resin, ethylene tetrafluoride-propylene hexafluoride copolymer resin, ethylene tetrafluoride-ethylene copolymer resin, chlorotrifluoroethylene, and polyvinylidene fluoride; and B) the thermal-resistant resin comprises a heat-resistant resin comprising a member selected from the group consisting of polyether sulfone, polyphenylene sulfide, polyimide, polyamideimide, epoxy resin, silicone resin and phenolic resin. ### Claim 11 (depends on 10) A method of producing a steel sheet coated with a fluororesin film according to claim 10, wherein a mixing ratio of the fluororesin powder to heat-resistant resin is in the range of from 1:99 to 95:5, by weight.