Electrophotographic member, fixing member, fixing apparatus, image forming apparatus, and method of producing electrophotographic belt

A fixing apparatus for heat fixing a toner image comprising:

• a pressurizing member;
• and
• a fixing member, the fixing member disposed facing the pressurizing member, wherein the fixing member is
• an endless belt-shaped electrophotographic member comprising an endless belt-shaped substrate and a surface layer on the outer peripheral surface of the substrate,
• the surface layer comprises an ionizing radiation crosslinked product of a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer,
• the surface layer is formed by irradiation of electron beam to a resin layer provided on the substrate, the resin layer comprising the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer,
• the surface layer has a universal hardness HU at 200° C. of 18 N/mm2≤HU≤40 N/mm2, and
• when
• a degree of orientation of the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer in the resin layer in a direction orthogonal to the circumferential direction of the substrate is defined as Ri, and
• a degree of orientation of the crosslinked product of the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer in the surface layer in the direction orthogonal to the circumferential direction of the substrate is defined as Rf,
• Ri and Rf satisfy a relationship represented by expression (1):
• Ri×0.8≤Rf≤Ri (1)
• wherein Ri is represented by expression (2):
• Ri=AR0/AR90 (2)
• wherein when
• in polarized spectrum in the direction orthogonal to the circumferential direction of the substrate in an infrared-spectroscopic measurement of the resin layer, an absorption peak value at 640 cm−1 is defined as Abs640r0 and an absorption peak value at 993 cm−1 is defined as Abs993r0,
• AR0 is represented by expression (3):
• AR0=Abs640r0/Abs993r0 (3)
• and when
• in polarized spectrum in the circumferential direction of the substrate in an infrared-spectroscopic measurement of the resin layer, an absorption peak value at 640 cm−1 is defined as Abs640r90 and an absorption peak value at 993 cm−1 is defined as Abs993r90,
• AR90 is represented by expression (4):
• AR90=Abs640r90/Abs993r90 (4)
• and Rf is represented by expression (5):
• Rf=AS0/AS90 (5)
• wherein when
• in polarized spectrum in the direction orthogonal to the circumferential direction of the substrate in an infrared-spectroscopic measurement of the surface layer, an absorption peak value at 640 cm−1 is defined as Abs640s0 and an absorption peak value at 993 cm−1 is defined as Abs993s0,
• AS0 is represented by expression (6):
• AS0=Abs640s0/Abs993s0 (6)
• and when
• in polarized spectrum in the circumferential direction of the substrate in an infrared-spectroscopic measurement of the surface layer, an absorption peak value at 640 cm−1 is defined as Abs640s90 and an absorption peak value at 993 cm−1 is defined as Abs993s90,
• AS90 is represented by expression (7):
• AS90=Abs640s90/Abs993s90 (7).

A method of producing an electrophotographic belt comprising an endless belt-shaped substrate, and a surface layer covering an outer peripheral surface of the substrate, the method comprising:

• (i) providing an extruded cylindrical product of a resin material comprising a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer,
• (ii) covering the outer peripheral surface of the substrate with the extruded cylindrical product, and
• (iii) forming a surface layer through crosslinking of the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer in the extruded cylindrical product through irradiation of an outer surface of the extruded cylindrical product with ionizing radiation in a state where the extruded cylindrical product covering the outer peripheral surface of the substrate is heated to a temperature equal to or higher than a glass transition temperature (Tg) of the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer and lower than a melting point (Tm) of the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer,
• wherein the surface layer has a universal hardness HU at 200° C. of 18 N/mm2≤HU≤40 N/mm2, and
• when
• a degree of orientation of the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer in the extruded cylindrical product in a direction orthogonal to the circumferential direction of the substrate is defined as Ri, and
• a degree of orientation of a crosslinked product of the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer in the surface layer formed in the step (iii), in the direction orthogonal to the circumferential direction of the substrate is defined as Rf,
• Ri and Rf satisfy a relationship represented by expression (1):
• Ri×0.8≤Rf≤Ri (1)
• wherein Ri is represented by expression (2):
• Ri=AR0/AR90 (2)
• wherein when
• in polarized spectrum in the direction orthogonal to the circumferential direction of the substrate in an infrared-spectroscopic measurement of the extruded cylindrical product, an absorption peak value at 640 cm−1 is defined as Abs640r0 and an absorption peak value at 993 cm−1 is defined as Abs993r0,
• AR0 is represented by expression (3):
• AR0=Abs640r0/Abs993r0 (3)
• and when
• in polarized spectrum in the circumferential direction of the substrate in an infrared-spectroscopic measurement of the extruded cylindrical product, an absorption peak value at 640 cm−1 is defined as Abs640r90 and an absorption peak value at 993 cm−1 is defined as Abs993r90,
• AR90 is represented by expression (4):
• AR90=Abs640r90/Abs993r90 (4)
• and Rf is represented by expression (5):
• Rf=AS0/AS90 (5)
• wherein when
• in polarized spectrum in the direction orthogonal to the circumferential direction of the substrate in an infrared-spectroscopic measurement of the surface layer, an absorption peak value at 640 cm−1 is defined as Abs640s0 and an absorption peak value at 993 cm−1 is defined as Abs993s0,
• AS0 is represented by expression (6):
• AS0=Abs640s0/Abs993s0 (6)
• and when
• in polarized spectrum in the circumferential direction of the substrate in an infrared-spectroscopic measurement of the surface layer, an absorption peak value at 640 cm−1 is defined as Abs640s90 and an absorption peak value at 993 cm−1 is defined as Abs993s90,
• AS90 is represented by expression (7):
• AS90=Abs640s90/Abs993s90 (7).