Electrophotographic member and electrophotographic image forming apparatus
An electrophotographic member comprising a base layer and a surface layer, the surface layer including at least one of an acrylic resin and a methacrylic resin, perfluoropolyether having a specified structure and a fluorine-containing copolymer, the fluorine-containing copolymer having a first polymerized unit of at least one of methyl acrylate and methyl methacrylate, and a second polymerized unit of at least one of methyl acrylate having a fluoroalkyl group and methyl methacrylate having a fluoroalkyl group, a molar ratio between the first polymerized unit and the second polymerized unit being 7 to 12, the fluorine-containing copolymer having Mw of 80000 or more and 150000 or less, and the ratio between Mn and Mw (Mw/Mn) being 3.0 or more and 6.5 or less.
1. An electrophotographic member comprising:
a base layer; and
a surface layer containing a perfluoropolyether (PFPE), a fluorine-containing copolymer and at least one of an acrylic resin and a methacrylic resin;
the PFPE having a structure represented by formula (1):
HO—H 2 C—(CF 2 O) p (CF 2 CF 2 O) q —CH 2 —OH (1)
where p and q each independently represent an integer of 1 or more,
the fluorine-containing copolymer having (i) a first polymerized unit of at least one of methyl acrylate (MA) and methyl methacrylate (MMA), and (ii) a second polymerized unit of at least one of methyl acrylate having a fluoroalkyl group (F-MA) and methyl methacrylate having a fluoroalkyl group (F-MMA), wherein
a molar ratio of the first polymerized unit and the second polymerized unit is 7 to 12,
the fluorine-containing copolymer having a weight average molecular weight (Mw) of 80000 to 150000, and a ratio between number average molecular weight (Mn) and Mw (Mw/Mn) being of 3.3 to 6.5, and
the content of the fluorine-containing copolymer in the surface layer is 11 to 30 mass % of the total solid content in the surface layer.
2. The electrophotographic member according to claim 1 , wherein the weight average molecular weight of the PFPE is 1000 or more and 9000.
3. The electrophotographic member according to claim 1 , wherein the surface layer has a matrix-domain structure having a domain containing the PFPE in the thickness direction.
4. The electrophotographic member according to claim 3 , wherein the standard deviation of the major diameter of the domain observed in the cross-section of the surface layer in the thickness direction is 1 to 50 nm.
5. The electrophotographic member according to claim 1 , wherein the electrophotographic member is an electrophotographic belt having an endless shape.
6. An electrophotographic image forming apparatus comprising:
an intermediate transfer member, which comprises an electrophotographic member having a base layer and a surface layer,
the surface layer containing a perfluoropolyether (PFPE), a fluorine-containing copolymer and at least one of an acrylic resin and a methacrylic resin;
the PFPE having a structure represented by formula (1):
HO—H 2 C—(CF 2 O) p (CF 2 CF 2 O) q —CH 2 —OH (1)
where p and q each independently represent an integer of 1 or more; and
the fluorine-containing copolymer having (i) a first polymerized unit of at least one of methyl acrylate (MA) and methyl methacrylate (MMA), and (ii) a second polymerized unit of at least one of methyl acrylate having a fluoroalkyl group (F-MA) and methyl methacrylate having a fluoroalkyl group (F-MMA), wherein
a molar ratio of the first polymerized unit to the second polymerized unit is 7 to 12,
the fluorine-containing copolymer has a weight average molecular weight (Mw) of 80000 to 150000, and a ratio between number average molecular weight (Mn) and Mw (Mw/Mn) of 3.3 to 6.5, and
the content of the fluorine-containing copolymer in the surface layer is 11 to 30 mass % of the total solid content in the surface layer.