Patent ID: 11966174
Assignee: CANON KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An electrophotographic member comprising:
an electro-conductive substrate;
an elastic layer on the electro-conductive substrate; and
a surface layer on the elastic layer,
the surface layer containing a fine particle and a binder resin,
the surface layer having a thickness of less than 1.0 μm,
the fine particle having an average particle diameter of from 0.1 μm to 0.9 μm,
the fine particle having a volume occupancy of 60 vol % to 99 vol % with respect to 100 vol % of the binder resin in the surface layer,
wherein E1 and E2 satisfy relationships represented by the following formulae (1) and (2):

E1≥1,000 MPa  (1)

200 MPa≥E2≥2 MPa  (2),, where E1 denotes an elastic modulus of the fine particle and E2 denotes an elastic modulus of the binder resin, E1 and E2 being obtained by measurement of force curves with a SPM in a cross-section of a thickness-direction of the surface layer, and
wherein H1 and H2 satisfy relationships represented by the following formulae (3) and (4):

100°≥H1≥50°  (3)

H1−H2≥5°  (4), where H1 denotes an MD-1 hardness, which is measured by bringing a type C indenter into contact with a surface of the surface layer, the surface being opposite to a surface facing the elastic layer, at an indentation depth of 2 mm, and H2 denotes an MD-1 hardness, which is measured by peeling the surface layer from the electrophotographic member to expose a surface of the elastic layer, and bringing the type C indenter into contact with the exposed surface of the elastic layer at an indentation depth of 2 mm.