Electrophotographic member having bow-shaped resin particles defining concavity and protrusion at surface thereof

• US 9,599,914 B2
• Filed: 03/22/2016
• Issued: 03/21/2017
• Est. Priority Date: 04/03/2015
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yoshidome, Takeshi, Uematsu, Atsushi, Taniguchi, Tomohito, Watanabe, Masahiro, Miyagawa, Noboru, Sato, Taichi, Aoyama, Takehiko
• Primary Examiner(s): GRAINGER, QUANA MASHELLE
• Application Number:
  US15/077,167
• Publication Number:
  US 20160291487A1
• Time in Patent Office: 364 Days
• Field of Search: 399/176
• US Class Current: 1/1
• CPC Class Codes: G03G 5/043 Photoconductive layers characterised by having two or more layers or characterised by their composite structure
• CPC Class Codes: G03G 5/0525 Coating methods

Abstract

The electrophotographic member includes an electro-conductive substrate and an electro-conductive resin layer as the surface layer on the substrate. The electro-conductive resin layer contains a binder and a bowl-shaped resin particle; the surface of electrophotographic member has a concavity derived from the opening of the bowl-shaped resin particle, a protrusion derived from the edge portion of the opening and the electro-conductive resin layer; and when the surface of the member is observed using a scanning electron microscope at an accelerating voltage (1 kV) and a magnification (×2000) while applying a DC voltage (50 to 100 V) between an electrode disposed opposite to the electrophotographic member and the substrate, the brightness of the protrusion, K1, the brightness of the bottom of the concavity, K2, and the brightness of the exposed surface of the electro-conductive resin layer, K3, satisfy K2<K1, K3<K1 and 0.8≦K2/K3≦1.2.

Claims

1. An electrophotographic member comprising:

an electro-conductive substrate; and

an electro-conductive resin layer as a surface layer on the substrate, the electro-conductive resin layer comprising a binder and retaining a bowl-shaped resin particle having an opening that is exposed at a surface of the electrophotographic member;

the surface of the electrophotographic member comprising a concavity derived from the opening of the bowl-shaped resin particle exposed at the surface, and a protrusion derived from an edge of the opening of the bowl-shaped resin particle exposed at the surface; and

a part of the surface of the electrophotographic member is constituted by the electro-conductive resin layer, wherein

a brightness observed at a bottom of the concavity K2<

a brightness observed at the protrusion K1,

a brightness observed at an exposed surface of the electro-conductive resin layer K3 <

a brightness observed at the protrusion K1, and

0.8≦

K2/K3≦

1.2

when the surface of the electrophotographic member is observed with a scanning electron microscope at an accelerating voltage of 1 kV and a magnification of ×

2000 while applying a DC voltage of 50 to 100 V between an electrode disposed opposite to the electrophotographic member and the electro-conductive substrate.

2. The electrophotographic member according to claim 1 wherein a silicone oil is contained in the electro-conductive resin layer constituting a part of the surface of the electrophotographic member.

3. A method for producing an electrophotographic member comprising an electro-conductive substrate and an electro-conductive resin layer as a surface layer on the substrate, comprising the steps of:

(1) forming a coating layer of a composition comprising a hollow-shaped resin particle dispersed in a binder on the substrate;

(2) grinding a surface of the coating layer, and partly removing a shell of the hollow-shaped resin particle to form a bowl-shaped resin particle having an opening, and to make a concavity derived from the opening of the bowl-shaped resin particle and a protrusion derived from an edge of the opening on the surface of the coating layer;

(3) allowing an electro-conductive fine particle to be present at a surface of the concavity; and

regrinding the surface of the coating layer after the allowing an electro-conductive fine particle to be present at a surface of the concavity.

4. A method for producing an electrophotographic member comprising an electro-conductive substrate and an electro-conductive resin layer as a surface layer on the substrate, the method comprising the steps of:

forming a coating layer of a thermally crosslinkable rubber composition comprising an electro-conductive fine particle, a thermally crosslinkable rubber and a hollow-shaped resin particle on the substrate;

grinding a surface of the coating layer, and partly removing a shell of the hollow-shaped resin particle to form a bowl-shaped resin particle having an opening, and to make a layer retaining the bowl-shaped resin particle so that the opening is exposed at the surface thereof; and

thermally crosslinking the thermally crosslinkable rubber in the coating layer in the presence of oxygen to obtain an electrophotographic member having a concavity derived from the opening and a protrusion derived from an edge of the opening on the surface thereof, wherein

a part of the surface is constituted by the electro-conductive resin layer, and

oxygen transmission rate of the shell of the hollow-shaped resin particle is 140 cm³/(m²·

24 h·

atm) or less.

5. A process cartridge comprising an electrophotographic member and an electrophotographic photosensitive member and being configured to be attachable to and detachable from a main body of an electrophotographic apparatus, the electrophotographic member comprising:

an electro-conductive substrate; and

an electro-conductive resin layer as a surface layer on the substrate, the electro-conductive resin layer comprising a binder and retaining a bowl-shaped resin particle having an opening that is exposed at a surface of the electrophotographic member;

the surface of the electrophotographic member comprising a concavity derived from the opening of the bowl-shaped resin particle exposed at the surface, and a protrusion derived from an edge of the opening of the bowl-shaped resin particle exposed at the surface; and

a part of the surface of the electrophotographic member is constituted by the electro-conductive resin layer, wherein

a brightness observed at a bottom of the concavity K2 <

a brightness observed at the protrusion K1,

a brightness observed at an exposed surface of the electro-conductive resin layer K3 <

a brightness observed at the protrusion K1, and

0.8≦

K2/K3≦

1.2

when the surface of the electrophotographic member is observed with a scanning electron microscope at an accelerating voltage of 1 kV and a magnification of ×

2000 while applying a DC voltage of 50 to 100 V between an electrode disposed opposite to the electrophotographic member and the substrate.

6. An electrophotographic apparatus comprising an electrophotographic member and an electrophotographic photosensitive member, the electrophotographic member comprising:

an electro-conductive substrate; and

an electro-conductive resin layer as a surface layer on the substrate, the electro-conductive resin layer a bowl-shaped resin particle having an opening that is exposed at a surface of the electrophotographic member;

the surface of the electrophotographic member comprising a concavity derived from the opening of the bowl-shaped resin particle exposed at the surface, and a protrusion derived from an edge of the opening of the bowl-shaped resin particle exposed at the surface; and

a part of the surface of the electrophotographic member is constituted by the electro-conductive resin layer, wherein

a brightness observed at a bottom of the concavity K2 <

a brightness observed at the protrusion K1,

a brightness observed at an exposed surface of the electro-conductive resin layer K3 <

a brightness observed at the protrusion K1, and

0.8≦

K2/K3≦

1.2

when the surface of the electrophotographic member is observed with a scanning electron microscope at an accelerating voltage of 1 kV and a magnification of ×

2000 while applying a DC voltage of 50 to 100 V between an electrode disposed opposite to the electrophotographic member and the substrate.