# US 12,181,823 B2 · Fixing film, heat fixing apparatus, and electrophotographic image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,823 B2 - Document ID: US12181823B2 - Status: Granted - Kind: B2 - Application number: 18/334,465 - Filed: 2023-06-14 - Published: 2024-02-08 - Granted: 2024-12-31 - Earliest claimed: 2022-06-21 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Akeshi Asaka; Ryunosuke Kawahara - Web page: https://patentgrep.com/patent/US12181823B2 ## CPC - G03G 15/2057: {relating to the chemical composition of the heat element and layers thereof} - G03G 2215/2035: the fixing nip having a stationary belt support member opposing a pressure member - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A fixing film having an endless shape, comprising at least a base material, an elastic layer, and a release layer in this order, the release layer comprising a tube containing a fluorine resin, and a value of Xe to Xm is 1.20 or more, where when, in a chart of an X-ray diffraction peaks obtained by measuring the release layer with a reflection X-ray diffraction method, a maximum X-ray diffraction strength at 2θ=17 to 19° is defined as Ic, a maximum X-ray diffraction strength at 2θ=39.5 to 40.5° is defined as Ia, and a value of Ic/Ia is defined as X, Xe represents an average value of X in an edge region, and Xm represents an average value of X in a central region. ## Claims ### Claim 1 A fixing film having an endless shape, comprising: at least a base material, an elastic layer, and a release layer in this order, the release layer comprising a tube containing a fluorine resin, a value of Xe/Xm is 1.20 or more, where when, in a chart of an X-ray diffraction peaks obtained by measuring the release layer with a reflection X-ray diffraction method, a maximum X-ray diffraction strength at 2θ=17 to 19° is defined as Ic, a maximum X-ray diffraction strength at 2θ=39.5 to 40.5° is defined as Ia, and a value of Ic/Ia is defined as X, and a length in a direction along a rotational axis of the fixing film is defined as L, Xe represents an average value of X in an edge region up to 0.15 L from each opposite edge in the direction along the rotational axis of the fixing film, and Xm represents an average value of X in a central region with a length in the direction along the rotational axis of 0.70 L present between the two edge regions. ### Claim 2 (depends on 1) The fixing film according to claim 1, wherein Xe/Xm is 1.20 to 5.00. ### Claim 3 (depends on 1) The fixing film according to claim 1, wherein Xe/Xm is 1.23 to 4.20. ### Claim 4 (depends on 1) The fixing film according to claim 1, wherein Xe/Xm is 1.25 to 2.00. ### Claim 5 (depends on 1) The fixing film according to claim 1, wherein Xe is 35.0 to 62.0. ### Claim 6 (depends on 1) The fixing film according to claim 1, wherein Xe is 37.0 to 50.0. ### Claim 7 (depends on 1) The fixing film according to claim 1, wherein Xe is 37.0 or more and less than 50.0. ### Claim 8 (depends on 1) The fixing film according to claim 1, wherein Xm is 10.0 to 35.0. ### Claim 9 (depends on 1) The fixing film according to claim 1, wherein the tube is a cylindrically extruded product. ### Claim 10 (depends on 1) The fixing film according to claim 1, wherein the fluorine resin is a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether. ### Claim 11 (depends on 1) The fixing film according to claim 1, wherein the tube is a cylindrically extruded product of a resin mixture comprising a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether. ### Claim 12 (depends on 1) The fixing film according to claim 1, wherein the release layer has a thickness of 10 to 45 μm. ### Claim 13 A heat fixing apparatus comprising a fixing film, wherein the fixing film has an endless shape, and comprises at least a base material, an elastic layer, and a release layer in this order, the release layer comprises a tube containing a fluorine resin, and a value of Xe/Xm is 1.20 or more, where when, in a chart of an X-ray diffraction peaks obtained by measuring the release layer with a reflection X-ray diffraction method, a maximum X-ray diffraction strength at 2θ=17 to 19° is defined as Ic, a maximum X-ray diffraction strength at 2θ=39.5 to 40.5° is defined as Ia, and a value of Ic/Ia is defined as X, and a length in a direction along a rotational axis of the fixing film is defined as L, Xe represents an average value of X in an edge region up to 0.15 L from each opposite edge in the direction along the rotational axis of the fixing film, and Xm represents an average value of X in a central region with a length in the direction along the rotational axis of 0.70 L present between the two edge regions. ### Claim 14 (depends on 13) The heat fixing apparatus according to claim 13, further comprising a heater, the heater being arranged so as to be in contact with an inner circumferential surface of the fixing film. ### Claim 15 (depends on 14) The heat fixing apparatus according to claim 14, further comprising a pressure roller, wherein the pressure roller and the heater are in pressure contact with each other with the fixing film interposed therebetween. ### Claim 16 An electrophotographic image forming apparatus comprising a heat fixing apparatus, wherein the heat fixing apparatus comprises a fixing film, the fixing film has an endless shape, and comprise at least a base material, an elastic layer, and a release layer in this order, the release layer comprises a tube containing a fluorine resin, and wherein a value of Xe/Xm is 1.20 or more, where when in a chart of an X-ray diffraction peaks obtained by measuring the release layer with a reflection X-ray diffraction method, a maximum X-ray diffraction strength at 2θ=17 to 19° is defined as Ic, a maximum X-ray diffraction strength at 2θ=39.5 to 40.5° is defined as Ia, and a value of Ic/Ia is defined as X, and a length in a direction along a rotational axis of the fixing film is defined as L, Xe represents an average value of the X in an edge region up to 0.15 L from each opposite edge in the direction along the rotational axis of the fixing film, and Xm represents an average value of the X in a central region with a length in the direction along the rotational axis of 0.70 L present between the two edge regions. ### Claim 17 (depends on 16) The electrophotographic image forming apparatus according to claim 16, wherein the heat fixing apparatus further comprises a heater, and the heater is arranged so as to be in contact with an inner circumferential surface of the fixing film. ### Claim 18 (depends on 17) The electrophotographic image forming apparatus according to claim 17, wherein the heat fixing apparatus further comprises a pressure roller, and the pressure roller and the heater are in pressure contact with each other with the fixing film interposed therebetween.