Electro-conductive member, process cartridge, and electrophotographic image forming apparatus
Used is an electro-conductive member for electrophotography including: a support having an electro-conductive outer surface; and an electro-conductive layer on the outer surface of the support, wherein the electro-conductive layer includes: a matrix containing a first crosslinked rubber product and having a volume resistivity greater than 1.0×10 12 Ωcm; and domains dispersed in the matrix, wherein the domain includes a second crosslinked rubber product and an electron conductive agent; and the electro-conductive layer includes a region T in which the volume resistivity of the matrix decreases in a depth direction from the outer surface of the electro-conductive member.
1. An electro-conductive member for electrophotography, comprising:
a support having an electro-conductive outer surface; and
an electro-conductive layer on the outer surface of the support, the electro-conductive layer comprising a matrix having domains dispersed therein;
the matrix containing a first crosslinked rubber product and having a volume resistivity greater than 1.0×10 12 Ωcm; and
the domains including a second crosslinked rubber product and an electron conductive agent, wherein
the electro-conductive layer includes a region T in which the volume resistivity of the matrix decreases in a depth direction from the outer surface of the electro-conductive member, and in which the volume resistivity of the domains increases from the outer surface toward the depth direction.
2. The electro-conductive member according to claim 1 , wherein a thickness t of region T is 20 to 200 μm.
3. The electro-conductive member for electrophotography according to claim 2 , wherein R1/r1>R2/r2
when R1 (Ωcm) represents the volume resistivity of the matrix in a first thickness region having a depth of 5 to 6 μm from the outer surface of the electro-conductive layer, r1 (Ωcm) represents the volume resistivity of the domains included in the first thickness region, R2 (Ωcm) represents the volume resistivity of the matrix in a second thickness region having a depth of t-1 to t μm from the outer surface of the electro-conductive layer, and r2 (Ωcm) represents the volume resistivity of the domains included in the second region.
4. The electro-conductive member according to claim 1 , wherein the volume resistivity pd of the domains existing in the electro-conductive layer is 1.0×10 1 to 1.0×10 4 Ωcm.
5. The electro-conductive member according to claim 1 , wherein a volume fraction p of the domains existing in the electro-conductive layer is 15 to 40%.
6. A process cartridge for electrophotography configured to be detachably attachable to a main body of an electrophotographic image forming apparatus, comprising an electro-conductive member for electrophotography, comprising:
a support having an electro-conductive outer surface; and
an electro-conductive layer on the outer surface of the support, the electro-conductive layer comprising a matrix having domains dispersed therein;
the matrix containing a first crosslinked rubber product and having a volume resistivity greater than 1.0×10 12 Ωcm; and
the domains including a second crosslinked rubber product and an electron conductive agent, wherein
the electro-conductive layer includes a region T in which the volume resistivity of the matrix decreases in a depth direction from the outer surface of the electro-conductive member, and in which the volume resistivity of the domains increases from the outer surface toward the depth direction.
7. An electrophotographic image forming apparatus comprising an electro-conductive member for electrophotography, comprising:
a support having an electro-conductive outer surface; and
an electro-conductive layer provided on the outer surface of the support, the electro-conductive layer comprising a matrix having a plurality of domains dispersed therein;
the matrix containing a first crosslinked rubber product and having a volume resistivity greater than 1.0×10 12 Ωcm; and
the domains including a second crosslinked rubber product and an electron conductive agent, wherein
the electro-conductive layer includes a region T in which the volume resistivity of the matrix decreases in a depth direction from the outer surface of the electro-conductive member, and in which the volume resistivity of the domains increases from the outer surface toward the depth direction.
8. The electro-conductive member according to claim 1 , wherein the matrix does not almost contain the electron conductive agent.