Electro-conductive member for electrophotography, process cartridge, and electrophotographic image forming apparatus
Provided is an electro-conductive member including: an electro-conductive support; and a surface layer, in which: the surface layer has a three-dimensionally continuous skeleton and has pores communicating in a thickness direction thereof, and when an arbitrary 150-micrometer square region of the surface of the surface layer is equally divided into 3,600 squares, the number of squares each including a through-hole is 100 or less; the skeleton is non-electro-conductive; the skeleton includes a plurality of resin particles bonded to each other through necks; the resin particles each contain a radiation degradable resin; and an average D 1 of the circle-equivalent diameters of the resin particles is 0.1 μm or more and 20 μm or less.
1. An electro-conductive member for electrophotography, comprising:
an electro-conductive support; and
a surface layer formed on the electro-conductive support, the surface layer having a three-dimensionally continuous skeleton and pores communicating in a thickness direction thereof, wherein
when an arbitrary 150-micrometer square region of a surface of the surface layer is photographed and the region is equally divided into 3,600 squares by two sets of lines at right angles, a number of squares each including a through-hole is 100 or less,
the skeleton is non-electro-conductive and includes a plurality of resin particles bonded to each other through necks,
the resin particles each contains a radiation degradable resin comprising at least one selected from the group consisting of polyisobutylene, poly(α-methylstyrene), polybutyl methacrylate, polyisobutyl methacrylate and polyacetal, and
an average D 1 of circle-equivalent diameters of the resin particles is 0.1 to 20 μm.
2. An electro-conductive member for electrophotography according to claim 1 , wherein the radiation degradable resin has a glass transition temperature Tg of −150 to 100° C.
3. An electro-conductive member for electrophotography according to claim 1 , wherein an average D 2 of circle-equivalent diameters of sections of the necks is 0.1 to 0.7 times as large as the average D 1 .
4. An electro-conductive member for electrophotography according to claim 1 , wherein the surface layer has a thickness of 1 to 30 μm.
5. An electro-conductive member for electrophotography according to claim 1 , wherein the surface layer has a volume resistivity of 1×10 12 to 1×10 17 Ω·cm.
6. An electro-conductive member for electrophotography according to claim 1 , wherein the surface layer has a porosity of 20 to 80%.
7. An electro-conductive member for electrophotography according to claim 1 , wherein the electro-conductive member comprises a rigid structure configured to protect the surface layer.
8. An electro-conductive member for electrophotography, comprising in this order:
an electro-conductive support;
an intermediate layer; and
a surface layer, the surface layer having a three-dimensionally continuous skeleton and pores communicating in a thickness direction thereof, wherein
when an arbitrary 150-micrometer square region of a surface of the surface layer is photographed and the region is equally divided into 3,600 squares by two sets of lines at right angles, a number of squares each including a through-hole is 100 or less,
the skeleton is non-electro-conductive and includes a plurality of resin particles bonded to each other through necks,
an average D 1 of circle-equivalent diameters of the resin particles is 0.1 to 20 μm, and
the intermediate layer contains a radiation degradable resin and is non-electro-conductive.
9. An electro-conductive member for electrophotography according to claim 8 , wherein the intermediate layer has a volume resistivity of 1×10 12 to 1×10 17 Ω·cm.
10. An electro-conductive member for electrophotography according to claim 9 , wherein the intermediate layer has a volume resistivity of 1×10 15 to 1×10 17 Ω·cm.
11. An electro-conductive member for electrophotography according to claim 8 , wherein the radiation degradable resin comprises an acrylic resin having a constituent unit represented by formula (1)
where R 1 represents a hydrocarbon group having 1 to 6 carbon atoms.
12. An electro-conductive member for electrophotography according to claim 11 , wherein R 1 represents a linear or branched alkyl group having 2 to 6 carbon atoms.
13. An electro-conductive member for electrophotography according to claim 11 , wherein R 1 is at least one of —C(CH 3 ) 3 , —CH(CH 3 ) 2 , —CH(CH 3 )—C(CH 3 ) 3 or —C(CH 3 ) 2 —CH(CH 3 ) 2 .
14. An electro-conductive member for electrophotography according to claim 11 , wherein R 1 is —C(CH 3 ) 3 .
15. An electro-conductive member for electrophotography according to claim 8 , wherein the intermediate layer has a thickness of 1 to 5 μm.
16. An electro-conductive member for electrophotography according to claim 8 , wherein the resin particles forming the skeleton each contains a radiation degradable resin.
17. An electro-conductive member for electrophotography according to claim 8 , further comprising a rigid structure configured to protect the surface layer.
18. A process cartridge, which is removably mounted onto a main body of an electrophotographic apparatus, the process cartridge comprising:
(i) an electrophotographic photosensitive member; and
(ii) a charging member configured to charge the electrophotographic photosensitive member,
the charging member comprising an electro-conductive member for electrophotography comprising:
(i) an electro-conductive support; and
(ii) a surface layer formed on the electro-conductive support, the surface layer having a three-dimensionally continuous skeleton and pores communicating in a thickness direction thereof, wherein
when an arbitrary 150-micrometer square region of a surface of the surface layer is photographed and the region is equally divided into 3,600 squares by two sets of lines at right angles, a number of squares each including a through-hole is 100 or less,
the skeleton is non-electro-conductive and includes a plurality of resin particles bonded to each other through necks,
the resin particles each contain a radiation degradable resin comprising at least one selected from the group consisting of polyisobutylene, poly(α-methylstyrene), polybutyl methacrylate, polyisobutyl methacrylate and polyacetal, and
an average D 1 of circle-equivalent diameters of the resin particles is 0.1 to 20 μm.
19. An electrophotographic image forming apparatus, comprising:
(i) an electrophotographic photosensitive member; and
(ii) a charging member configured to charge the electrophotographic photosensitive member,
the charging member comprising an electro-conductive member for electrophotography comprising:
(i) an electro-conductive support; and
(ii) a surface layer formed on the electro-conductive support, the surface layer having a three-dimensionally continuous skeleton and pores communicating in a thickness direction thereof, wherein
when an arbitrary 150-micrometer square region of a surface of the surface layer is photographed and the region is equally divided into 3,600 squares by lines at right angles, a number of squares each including a through-hole is 100 or less,
the skeleton is non-electro-conductive and includes a plurality of resin particles bonded to each other through necks,
the resin particles each contain a radiation degradable resin comprising at least one selected from the group consisting of polyisobutylene, poly(α-methylstyrene), polybutyl methacrylate, polyisobutyl methacrylate and polyacetal, and
an average D 1 of circle-equivalent diameters of the resin particles is 0.1 to 20 μm.
20. An electro-conductive member for electrophotography according to claim 1 , wherein the radiation degradable resin comprises polyisobutylene.
21. An electro-conductive member for electrophotography according to claim 1 , wherein the radiation degradable resin comprises poly(α-methyl styrene).
22. An electro-conductive member for electrophotography according to claim 1 , wherein the radiation degradable resin comprises polyacetal.