Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

• US 10,372,050 B2
• Filed: 05/17/2018
• Issued: 08/06/2019
• Est. Priority Date: 05/25/2017
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nishi, Masashi, Sekido, Kunihiko, Sekiya, Michiyo, Watanabe, Hiroyuki
• Primary Examiner(s): Rodee, Christopher D
• Application Number:
  US15/982,656
• Publication Number:
  US 20180341190A1
• Time in Patent Office: 446 Days
• CPC Class Codes: G03G 21/18 using a processing cartridge , whereby the process cartridge comprises at least two image processing means in a single unit
• CPC Class Codes: G03G 5/0535 Polyolefins; Polystyrenes; Waxes
• CPC Class Codes: G03G 5/0592 Macromolecular compounds characterised by their structure or by their chemical properties, e.g. block polymers, reticulated polymers, molecular weight, acidity
• CPC Class Codes: G03G 5/0651 containing four relevant rings
• CPC Class Codes: G03G 5/142 Inert intermediate layers

Abstract

The present invention provides an electrophotographic photosensitive member in which a photosensitive layer has strong close adhesiveness even when used repeatedly, and a positive ghost is reduced. An undercoat layer of the electrophotographic photosensitive member contains a cured product of an electron transport material having a polymerizable functional group; a polyolefin resin having at least one group/structure selected from the group consisting of a carboxyl group, an alkoxycarbonyl group and an anhydrous carboxylic acid structure, and a substituted or unsubstituted phenyl group; and an isocyanate compound having two or more isocyanate groups.

Claims

1. An electrophotographic photosensitive member comprising in this order:

a support;

an undercoat layer comprising a cured product of an electron transport material, a polyolefin resin and an isocyanate compound having two or more isocyanate groups;

a charge generation layer; and

a charge transport layer, wherein

the electron transport material has at least one member selected from the group consisting of a hydroxyl group, a thiol group, an amino group and a carboxyl group, and

the polyolefin resin has at least one member selected from the group consisting of a carboxyl group, an alkoxycarbonyl group and an anhydrous carboxylic acid structure and an optionally substituted phenyl group, the polyolefin resin having a structure represented by formula (B1) and a structure represented by formula (B2)

2. The electrophotographic photosensitive member according to claim 1, wherein the isocyanate compound is a biuret-type isocyanate compound.

3. The electrophotographic photosensitive member according to claim 1, wherein the electron transport material is represented by formula (A1)

4. The electrophotographic photosensitive member according to claim 1, wherein the electron transport material included in the undercoat layer has an amount of 45 to 55 mass % of the entire undercoat layer.

5. The electrophotographic photosensitive member according to claim 1, wherein the undercoat layer comprises silica particles having a number average particle diameter of 0.1 μ

m or less in an amount of 10.0 mass % or less of the entire undercoat layer.

6. The electrophotographic photosensitive member according to claim 1, wherein a ratio between a material amount of the isocyanate group included in a composition before curing the cured product included in the undercoat layer and a total of a material amount of a polymerizable functional group of the electron transport material and the carboxyl group, the alkoxycarbonyl group and the anhydrous carboxylic acid included in the polyolefin resin is 0.9 to 1.1 represented by (isocyanate group/(polymerizable functional group+carboxyl group±

alkoxycarbonyl group±

anhydrous carboxylic acid)).

7. The electrophotographic photosensitive member according to claim 1, wherein the polyolefin resin included in the undercoat layer has an amount of 0.2 to 8.0 mass % of the entire undercoat layer, and

the charge generation layer contains a phthalocyanine pigment and a resin at a ratio of 1.0 to 3.0 represented by (phthalocyanine pigment/resin).

8. A process cartridge, comprising:

an electrophotographic photosensitive member and at least one unit that is integrally supported being selected from the group consisting of a charging unit, a developing unit and a cleaning unit, said process cartridge being detachably attachable to an electrophotographic apparatus main body; and

the electrophotographic photosensitive member comprising in this order a support, an undercoat layer, a charge generation layer and a charge transport layer, said undercoat layer comprising a cured product of an electron transport material, a polyolefin resin and an isocyanate compound having two or more isocyanate groups, wherein

the electron transport material has at least one member selected from the group consisting of a hydroxyl group, a thiol group, an amino group and a carboxyl group, and

the polyolefin resin has at least one member selected from the group consisting of a carboxyl group, an alkoxycarbonyl group and an anhydrous carboxylic acid structure and an optionally substituted phenyl group, the polyolefin resin having a structure represented by formula (B1) and a structure represented by formula (B2)

9. An electrophotographic apparatus, comprising:

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

the electrophotographic photosensitive member comprising in this order a support, an undercoat layer, a charge generation layer and a charge transport layer, said undercoat layer comprising a cured product of an electron transport material, a polyolefin resin and an isocyanate compound having two or more isocyanate groups, wherein

the electron transport material has at least one member selected from the group consisting of a hydroxyl group, a thiol group, an amino group and a carboxyl group, and

the polyolefin resin has at least one member selected from the group consisting of a carboxyl group, an alkoxycarbonyl group and an anhydrous carboxylic acid structure and an optionally substituted phenyl group, the polyolefin resin having a structure represented by formula (B1) and a structure represented by formula (B2)