Electrophotographic photosensitive member, manufacturing method of electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

• US 9,726,992 B2
• Filed: 01/12/2016
• Issued: 08/08/2017
• Est. Priority Date: 01/26/2015
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Fujii, Atsushi, Nakamura, Nobuhiro, Sakuma, Kazuko, Ishiduka, Yuka, Okuda, Atsushi, Noguchi, Kazunori, Yamamoto, Yuki, Maruyama, Akihiro
• Primary Examiner(s): LE, HOA VAN
• Application Number:
  US14/993,412
• Publication Number:
  US 20160216618A1
• Time in Patent Office: 574 Days
• CPC Class Codes: G03G 5/0436 combining organic and inorganic layers

Abstract

An electrophotographic photosensitive member comprises a support, an undercoat layer, a charge generation layer and a hole transporting layer disposed in this order. The undercoat layer contains silica particles and a polymer of a composition including an electron transporting material having a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, and a cross-linking agent. The content of the electron transporting material in the composition is 30 to 70 mass % relative to the total mass of the composition and the content of the silica particles in the undercoat layer is 1 to 30 mass % relative to the total mass of the electron transporting material.

Claims

1. An electrophotographic photosensitive member comprising:

a support, an undercoat layer, a charge generation layer adjacent to the undercoat layer, and a hole transporting layer disposed in this order,

the undercoat layer containing (1) silica particles and a polymerized product of a composition comprising an electron transporting material having a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, with a content of the electron transporting material in the composition being 30 to 70 mass % relative to the total mass of the composition;

or (2) silica particles and an electron transporting material comprising a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, and a binder resin, with a content of the electron transporting material in the undercoat layer being 30 to 70 mass % relative to the total mass of the electron transporting material and the binder resin, wherein

a content of the silica particles in the undercoat layer is 1 to 30 mass % relative to the total mass of the electron transporting material.

2. The electrophotographic photosensitive member according to claim 1, wherein the silica particles have an average primary particle diameter of 10 to 2000 nm.

3. The electrophotographic photosensitive member according to claim 1, wherein the silica particles have a hydrophobicity of 40% or less.

4. The electrophotographic photosensitive member according to claim 1, wherein the electron transporting material comprises at least 2 groups represented by formula (A):

-(α

¹)_l-(β

)_m-γ

 

 

(A)

wherein at least one of “

α

¹”

, “

β

” and

“

γ

”

is a group having the polar group, and l and m each independently represent 0 or 1, with a sum of l and m of 0 to 2;

“

α

¹”

represents a substituted or unsubstituted alkylene group having a main chain with 1 to 12 atoms, a group having a main chain with 1 to 12 atoms derived by replacing a methylene group in the main chain of a substituted or unsubstituted alkylene group with an oxygen atom, a group having a main chain with 1 to 12 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkylene group with a sulfur atom, or a group having a main chain with 1 to 12 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkylene group with NR¹;

a substituent of the substituted alkylene group is an alkyl group with 1 to 6 carbon atoms, a benzyl group, an alkoxycarbonyl group, or a phenyl group;

R¹ represents a hydrogen atom or an alkyl group;

“

β

”

represents a substituted or unsubstituted phenylene group, a substituted or unsubstituted cycloalkylene group, or a substituted or unsubstituted cycloalkylidene group;

a substituent of the substituted phenylene group, a substituent of the substituted cycloalkylene group, or a substituent of the substituted cycloalkylidene group is an alkyl group with 1 to 6 carbon atoms, a nitro group, a halogen group, or an alkoxy group;

“

γ

”

represents a hydrogen atom, a substituted or unsubstituted alkyl group having a main chain with 1 to 6 atoms, a group having a main chain with 1 to 6 atoms derived by replacing the methylene group in a main chain of a substituted or unsubstituted alkyl group with an oxygen atom, a group having a main chain with 1 to 6 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkyl group with a sulfur atom, or a group having a main chain with 1 to 6 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkyl group with NR²;

a substituent of the substituted alkyl group is an alkyl group having 1 to 6 carbon atoms or an alkoxycarbonyl group; and

R² represents a hydrogen atom or an alkyl group.

5. The electrophotographic photosensitive member according to claim 1, wherein the electron transporting material comprises each of a group represented by formula (A1) and a group represented by formula (A2):

-α

² 

 

(A1)

-(β

)_m-γ

 

 

(A2)

wherein “

α

²” and

“

γ

”

are groups having the polar group;

“

α

²”

represents a substituted or unsubstituted alkyl group having a main chain with 2 to 12 atoms, a group having a main chain with 2 to 12 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkyl group with an oxygen atom, a group having a main chain with 2 to 12 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkyl group with a sulfur atom, or a group having a main chain with 1 to 12 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkyl group with NR³;

a substituent of the substituted alkyl group is an alkyl group having 1 to 6 carbons or an alkoxycarbonyl group, except for the case of having two or more of the substituents on one carbon atom in the main chain of the alkyl group;

R³ represents a hydrogen atom or an alkyl group;

“

β

”

represents a substituted or unsubstituted phenylene group, a substituted or unsubstituted cycloalkylene group, or a substituted or unsubstituted cycloalkylidene group; and

a substituent of the substituted phenylene group, a substituent of the substituted cycloalkylene group, or a substituent of the cycloalkylidene group is an alkyl group having 1 to 6 carbons, a nitro group, a halogen group, or an alkoxy group, and m is 0 or 1, wherein

in the case of m=1, “

γ

”

represents a hydrogen atom, a substituted or unsubstituted alkyl group having a main chain with 1 to 6 atoms, a group having a main chain with 1 to 6 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkyl group with an oxygen atom, a group having a main chain with 1 to 6 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkyl group with a sulfur atom, or a group having a main chain with 1 to 6 atoms derived by replacing a methylene group in a main chain of a substituted or unsubstituted alkyl group with NR²;

a substituent of the substituted alkyl group is an alkyl group having 1 to 6 carbons or an alkoxycarbonyl group; and

R² represents a hydrogen atom or an alkyl group, and

in the case of m=0, “

γ

”

represents a substituted alkyl group having a main chain with 1 to 6 atoms, a group having a main chain with 1 to 6 atoms derived by replacing a methylene group in a main chain of a substituted alkyl group with an oxygen atom, a group having a main chain with 1 to 6 atoms derived by replacing a methylene group in a main chain of a substituted alkyl group with a sulfur atom, or a group having a main chain with 1 to 6 atoms derived by replacing a methylene group in a main chain of a substituted alkyl group with NR²; and

the substituted alkylene group has at least 2 substituents on one carbon atom in the main chain of the alkyl group, and the substituent is an alkyl group having 1 to 6 carbons or an alkoxycarbonyl group.

10. The electrophotographic photosensitive member according to claim 1, wherein the silica particles have the silanol group on its surface.

11. The electrophotographic photosensitive member according to claim 1, wherein the silica particles and the electron transporting materials are present in the vicinity of the interface with the photosensitive layer.

12. The electrophotographic photosensitive member according to claim 1, wherein the composition further comprises a cross-linking agent.

6. A method for manufacturing an electrophotographic photosensitive member having a support, an undercoat layer, a charge generation layer adjacent to the undercoat layer, and a hole transporting layer disposed in this order, comprising:

forming a coating film from a coating liquid for forming an undercoat layer containing (1) silica particles and a composition comprising an electron transporting material having a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, wherein a content of the electron transporting material in the composition is 30 to 70 mass % relative to the total mass of the composition and a content of the silica particles in the coating liquid for forming an undercoat layer is 1 to 30 mass % relative to the total mass of the electron transporting material;

or (2) silica particles and an electron transporting material comprising a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, and a binder resin, wherein a content of the electron transporting material in the coating liquid for forming an undercoat layer is 30 to 70 mass % relative to the total mass of the electron transporting material and the binder resin and a content of the silica particles in the coating liquid for forming an undercoat layer is 1 to 30 mass % relative to the total mass of the electron transporting material; and

forming the undercoat layer by heating and drying the coating film.

7. The method for manufacturing an electrophotographic photosensitive member according to claim 6, wherein the silica particles have a hydrophobicity of 40% or less.

8. A process cartridge detachably detachable to the main body of an electrophotographic apparatus comprising:

an electrophotographic photosensitive member and at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit integrally supported therein,

the electrophotographic photosensitive member comprising a support, an undercoat layer, a charge generation layer adjacent to the undercoat layer, and a hole transporting layer disposed in this order, the undercoat layer containing (1) silica particles and a polymerized product of a composition comprising an electron transporting material having a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, with a content of the electron transporting material in the composition being 30 to 70 mass % relative to the total mass of the composition;

or (2) silica particles and an electron transporting material comprising a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, and a binder resin, with a content of the electron transporting material in the undercoat layer being 30 to 70 mass % relative to the total mass of the electron transporting material and the binder resin, wherein

a content of the silica particles in the undercoat layer is 1 30 mass % relative to the total mass of the electron transporting material.

9. An electrophotographic apparatus comprising:

an electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit and a transferring unit,

the electrophotographic photosensitive member comprising a support, an undercoat layer, a charge generation layer adjacent to the undercoat layer, and a hole transporting layer disposed in this order, the undercoat layer containing (1) silica particles and a polymerized product of a composition comprising an electron transporting material having a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, with a content of the electron transporting material in the composition being 30 to 70 mass % relative to the total mass of the composition;

or

(2) silica particles and an electron transporting material comprising a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, and a binder resin, with a content of the electron transporting material in the undercoat layer being 30 to 70 mass % relative to the total mass of the electron transporting material and the binder resin; and

a content of the silica particles in the undercoat layer being 1 to 30 mass % relative to the total mass of the electron transporting material.