Process cartridge and electrophotographic apparatus

• US 10,545,453 B2
• Filed: 11/20/2018
• Issued: 01/28/2020
• Est. Priority Date: 11/24/2017
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Iwasaki, Shuhei, Noguchi, Kazunori, Ogaki, Harunobu, Yamaai, Tatsuya, Miura, Daisuke, Sakakibara, Akira, Furukawa, Takumi, Tomomizu, Yuya
• Primary Examiner(s): Chapman, Mark A
• Application Number:
  US16/196,106
• Publication Number:
  US 20190163118A1
• Time in Patent Office: 434 Days
• Field of Search: 430 66
• CPC Class Codes: G03G 15/75 Details relating to xerographic drum, band or plate, e.g. replacing, testing electrographic recording members per se G03G5/00
• CPC Class Codes: G03G 21/1814 Details of parts of process cartridge, e.g. for charging, transfer, cleaning, developing G03G21/1835 takes precedence
• CPC Class Codes: G03G 5/0507 Inorganic compounds
• 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 5/14704 comprising inorganic material
• CPC Class Codes: G03G 5/14708 comprising organic material
• 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

Provided are a process cartridge and an electrophotographic apparatus each suppressed in fluctuation in charging potential at the time of its long-term use. The process cartridge includes: an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and a charging member configured to charge the electrophotographic photosensitive member, wherein an average of Martens hardnesses of the surface layer of the electrophotographic photosensitive member measured at a pushing force of 7 mN is 245 N/mm² or more, and wherein in a core defined by three-dimensional surface texture standards (ISO 25178-2:2012) of the surface of the charging member, an average of Martens hardnesses measured at a pushing force of 0.04 mN is 2 N/mm² or more and 20 N/mm² or less, and an average of adhesivenesses measured with a scanning probe microscope in a field of view of 2-micrometer square is 70 mV or less.

Claims

1. A process cartridge comprising:

an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and

a charging member configured to charge the electrophotographic photosensitive member, wherein

the surface layer has an average Martens hardness of 245 N/mm² or more measured at a pushing force of 7 mN, and

a core defined by three-dimensional surface texture standards (ISO 25178-2;

2012) of a surface of the charging member has an average Martens hardness of 2 to 20 N/mm² measured at a pushing force of 0.04 mN, and an average adhesiveness of 70 mV or less measured with a scanning probe microscope in a field of view of 2-micrometer square.

2. A process cartridge according to claim 1, wherein the resin comprises at least one member selected from the group consisting of formulae (I)-(III):

3. A process cartridge according to claim 2, wherein the resin comprises formula (I) and formula (II), and

the structure represented by formula (I) comprises at least one member selected from the group consisting of formulae (I-1)-(I-4):

4. A process cartridge according to claim 2, wherein formula (II) comprises at least one member selected from the group consisting of formulae (II-1)-(II-3):

5. A process cartridge according to claim 2, wherein the resin comprises formula (III), and

the structure represented by formula (III) comprises formula (III-1):

6. A process cartridge according to claim 5, wherein a ratio of formula (III-1) to formula (III) is 30 mol % or more.

7. A process cartridge according to claim 5, wherein the resin comprises at least one member selected from the group consisting of formulae (III-2-1)-(III-2-4):

8. A process cartridge according to claim 1, wherein the surface layer of the electrophotographic photosensitive member contains silica particles having an average primary particle diameter of 40 to 200 nm, and

a content of the silica particles is 1 to 10 mass % with respect to a solid content of the resin.

9. A process cartridge according to claim 1, wherein the surface of the charging member contains a vulcanizate of a rubber composition containing a polymer having a butadiene skeleton.

10. An electrophotographic apparatus, comprising a process cartridge and at least one of an exposing unit and a developing unit, said process cartridge comprising:

an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance, and

a charging member configured to charge the electrophotographic photosensitive member, wherein

the surface layer has an average Martens hardness of 245 N/mm² or more measured at a pushing force of 7 mN, and

a core defined by three-dimensional surface texture standards (ISO 25178-2;

2012) of a surface of the charging member has an average Martens hardness of 2 to 20 N/mm² measured at a pushing force of 0.04 mN, and an average adhesiveness of 70 mV or less measured with a scanning probe microscope in a field of view of 2-micrometer square.