Electrophotographic member, process cartridge, and electrophotographic image forming apparatus
An electrophotographic member, comprising: a support member having a conductive outer surface; and a conductive layer disposed on an outer surface of the support member, wherein the conductive layer comprises a matrix comprising a first rubber, and a plurality of domains dispersed in the matrix, volume resistivity of the matrix is 1.00×10 12 Ω·cm or less, the plurality of domains comprise at least one domain A, and the domain A satisfies specific conditions, in a case where impedance of the electrophotographic member is measured by applying specific AC voltage while changing frequency in a range of 1.0×10 −2 to 1.0×10 7 Hz and the specific plotting is done, a slope at a specific frequency is −0.80 to −0.30, and the impedance in a specific frequency is 1.00×10 3 to 1.00×10 7 Ω.
1 . An electrophotographic member, comprising:
a support member having a conductive outer surface; and a conductive layer disposed on an outer surface of the support member, wherein
the conductive layer comprises
a matrix comprising a first rubber, and
a plurality of domains dispersed in the matrix,
volume resistivity of the matrix is 1.00×10 12 Ω·cm or less,
the plurality of domains comprise at least one domain A, and
the domain A satisfies <Condition 1> to <Condition 3> below:
<Condition 1> the domain A comprises a second rubber and an electronic conductive agent;
<Condition 2> a centroid of volume of the domain A exists in the domain A;
<Condition 3> on a cross-section of the domain A passing through the centroid of volume, volume resistivity of an outer peripheral region, which is a region of a 100 nm distance from an outer edge of the domain A toward the centroid of volume, is more than 1.00×10 12 Ω·cm, and wherein
in a case where a platinum electrode is directly disposed on an outer surface of the electrophotographic member, impedance is measured by applying AC voltage having a 1V amplitude between the outer surface of the support member and the platinum electrode in an environment of a 23° C. temperature and 50% relative humidity, while changing frequency in a range of 1.0×10 −2 to 1.0×10 7 Hz, and the frequency is plotted on an abscissa and the impedance is plotted on an ordinate of a log-log graph, a slope at a frequency range of 1.0×10 5 to 1.0×10 6 Hz is −0.80 to −0.30, and the impedance in a frequency range of 1.0×10 −2 to 1.0×10 1 Hz is 1.00×10 1 to 1.00×10 7 Ω.
2 . The electrophotographic member according to claim 1 , wherein in at least eight samples out of cubic samples of which one side is 6 μm and are sampled from nine locations of the conductive layer, a ratio of the number of domains A with respect to a total number of plurality of domains is more than 50 quantity %.
3 . The electrophotographic member according to claim 1 , wherein
the domain A has a core-shell structure constituted of a core and a shell surrounding the core,
the shell comprises a third rubber,
the core comprises the second rubber and the electronic conductive agent in the second rubber, and
the third rubber and the second rubber are different from each other.
4 . The electrophotographic member according to claim 3 , wherein
volume resistivity of the core is 1.00×10 1 to 1.00×10 4 Ω·cm.
5 . The electrophotographic member according to claim 3 , wherein
a ratio of a cross-sectional area of the electronic conductive agent comprised in the core, with respect to a cross-sectional area of the core, is 20 area % or more.
6 . The electrophotographic member according to claim 3 , wherein the electronic conductive agent is carbon black.
7 . The electrophotographic member according to claim 3 , wherein
in a case where a circumference of the core is A and an envelope circumference of the core is B, A and B satisfy Expression (6) below:
1.
0
0
≤
A
/
B
≤
1
.10
.
(
6
)
8 . The electrophotographic member according to claim 3 , wherein
the domain A comprises a plurality of cores, and an arithmetic average value Dm of a distance between cores is 0.20 to 2.00 μm.
9 . The electrophotographic member according to claim 1 , wherein
the first rubber is at least one rubber selected from the group consisting of acrylonitrile-butadiene rubber, chloroprene rubber and hydrin rubber.
10 . The electrophotographic member according to claim 1 , wherein
the second rubber is at least one rubber selected from the group consisting of natural rubber, butadiene rubber, butyl rubber, acrylonitrile-butadiene rubber, urethane rubber, silicon rubber, fluoro rubber, isoprene rubber, chloroprene rubber, styrene-butadiene rubber, ethylene-propylene rubber and polynorbornene rubber.
11 . The electrophotographic member according to claim 3 , wherein
the third rubber is at least one rubber selected from the group consisting of natural rubber, butadiene rubber, butyl rubber, isoprene rubber, styrene-butadiene rubber and ethylene-propylene rubber.
12 . A process cartridge detachably attached to a main body of an electrophotographic image forming apparatus, wherein
the process cartridge comprises:
an electrophotographic photosensitive member; and a charging member arranged so as to be capable of charging the electrophotographic photosensitive member, and
the charging member is the electrophotographic member according to claim 1 .
13 . An electrophotographic image forming apparatus, comprising: an electrophotographic photosensitive member; and a charging roller arranged so as to be capable of charging the electrophotographic photosensitive member, wherein
the charging roller is the electrophotographic member according to claim 1 .