ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS

• US 20200133148A1
• Filed: 10/16/2019
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ikezue, Tatsuya, Takizawa, Kumiko, Kuroiwa, Ikuyo, Tanabe, Kan, Shimada, Tsuyoshi, Mitsuda, Haruhiko, Ueno, Takanori
• Granted Patent: US 10,838,314 B2
• Time in Patent Office: Days
• CPC Class Codes: G03G 5/0539 Halogenated polymers
• CPC Class Codes: G03G 5/056 Polyesters
• CPC Class Codes: G03G 5/0564 Polycarbonates
• CPC Class Codes: G03G 5/0596 Macromolecular compounds characterised by their physical properties
• CPC Class Codes: G03G 5/142 Inert intermediate layers
• CPC Class Codes: G03G 5/144 comprising inorganic material
• CPC Class Codes: G03G 5/14726 Halogenated polymers
• CPC Class Codes: G03G 5/14752 Polyesters
• CPC Class Codes: G03G 5/14756 Polycarbonates
• CPC Class Codes: G03G 5/14795 Macromolecular compounds characterised by their physical properties

Abstract

The electrophotographic photosensitive member includes an undercoat layer and a surface layer on or above a support in this order, in which the undercoat layer contains metal oxide particles and a specific binder resin, the surface layer contains a charge transporting substance, fluororesin particles, and a specific binder resin, an arithmetic average roughness Ra of a surface of the undercoat layer is 0.15 μm or less, a refractive index (a) of the metal oxide particles and a refractive index (b) of the binder resin contained in the undercoat layer satisfy a specific relationship, and a refractive index (c) of the binder resin contained in the surface layer and a refractive index (d) of the fluororesin particles satisfy a specific relationship.

Claims

1. An electrophotographic photosensitive member comprising:

an undercoat layer and a surface layer on or above a support in this order, wherein

the undercoat layer contains metal oxide particles and a binder resin,

the surface layer contains a charge transporting substance, fluororesin particles, and a binder resin,

an arithmetic average roughness Ra of a surface of the undercoat layer is 0.15 μ

m or less,

the binder resin contained in the undercoat layer contains at least one selected from the group consisting of a urethane resin, a polyamide resin, and a melamine-alkyd resin,

a refractive index (a) of the metal oxide particles and a refractive index (b) of the binder resin contained in the undercoat layer satisfy the following Equation (1);

0.70≤

(a)−

(b)≤

1.00 

 

Equation (1),

the binder resin contained in the surface layer contains at least one selected from the group consisting of a polycarbonate resin and a polyarylate resin, and

a refractive index (c) of the binder resin contained in the surface layer and a refractive index (d) of the fluororesin particles satisfy the following Equation (2);

0.20≤

(c)−

(d) 

 

Equation (2).

2. The electrophotographic photosensitive member according to claim 1, wherein a content of the metal oxide particles is 100% by mass or more and 500% by mass or less relative to the binder resin contained in the undercoat layer.

3. The electrophotographic photosensitive member according to claim 1, wherein a content of the fluororesin particles is 3.0% by mass or more and 20.0% by mass or less relative to a total mass of the surface layer.

4. The electrophotographic photosensitive member according to claim 1, wherein

in an any region including at least a part of each of the surface layer and the undercoat layer of a cut surface obtained by cutting the electrophotographic photosensitive member vertically from the surface layer toward the undercoat layer, when a ratio of a cross-sectional area of the metal oxide particles contained in the undercoat layer to a cross-sectional area of the undercoat layer is e %, and a ratio of a cross-sectional area of the fluororesin particles contained in the surface layer to a cross-sectional area of the surface layer is f %, e and f satisfy the following Equation (3):

5.0≤

e/f≤

15.0 

 

Equation (3).

5. The electrophotographic photosensitive member according to claim 1, wherein a number average primary particle diameter of the metal oxide particles is 10 nm or more and 100 nm or less.

6. The electrophotographic photosensitive member according to claim 1, wherein the metal oxide particles are strontium titanate or anatase type titanium oxide.

7. A process cartridge which integrally supports an electrophotographic photosensitive member and at least one unit selected from the group consisting of a charging unit, a developing unit, a transfer unit, and a cleaning unit, and is detachably attachable to a main body of an electrophotographic apparatus, wherein

the electrophotographic photosensitive member includes an undercoat layer and a surface layer on or above a support in this order,

the undercoat layer contains metal oxide particles and a binder resin,

the surface layer contains a charge transporting substance, fluororesin particles, and a binder resin,

an arithmetic average roughness Ra of a surface of the undercoat layer is 0.15 μ

m or less,

the binder resin contained in the undercoat layer contains at least one selected from the group consisting of a urethane resin, a polyamide resin, and a melamine-alkyd resin,

a refractive index (a) of the metal oxide particles and a refractive index (b) of the binder resin contained in the undercoat layer satisfy the following Equation (1);

0.70≤

(a)−

(b)≤

1.00 

 

Equation (1),

the binder resin contained in the surface layer contains at least one selected from the group consisting of a polycarbonate resin and a polyarylate resin, and

a refractive index (c) of the binder resin contained in the surface layer and a refractive index (d) of the fluororesin particles satisfy the following Equation (2);

0.20≤

(c)−

(d) 

 

Equation (2).

8. An electrophotographic apparatus comprising:

an electrophotographic photosensitive member, a charging unit, an exposing unit, a developing unit, and a transfer unit, wherein

the electrophotographic photosensitive member includes an undercoat layer and a surface layer on or above a support in this order,

the undercoat layer contains metal oxide particles and a binder resin,

the surface layer contains a charge transporting substance, fluororesin particles, and a binder resin,

an arithmetic average roughness Ra of a surface of the undercoat layer is 0.15 μ

m or less,

the binder resin contained in the undercoat layer contains at least one selected from the group consisting of a urethane resin, a polyamide resin, and a melamine-alkyd resin,

a refractive index (a) of the metal oxide particles and a refractive index (b) of the binder resin contained in the undercoat layer satisfy the following Equation (1);

0.70≤

(a)−

(b)≤

1.00 

 

Equation (1),

the binder resin contained in the surface layer contains at least one selected from the group consisting of a polycarbonate resin and a polyarylate resin, and

a refractive index (c) of the binder resin contained in the surface layer and a refractive index (d) of the fluororesin particles satisfy the following Equation (2);

0.20≤

(c)−

(d) 

 

Equation (2).