Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus
Provided is an electrophotographic photosensitive member that can achieve both of the suppression of a fluctuation in potential of the photosensitive member at the time of its repeated use, and the prevention of the occurrence of a black spot-like image defect at high levels. The electrophotographic photosensitive member includes in this order: a support; an intermediate layer; and a photosensitive layer, the intermediate layer containing particles each containing titanium oxide, and the particles having a mass increase ratio of 0.005% or more when heated under a nitrogen atmosphere from 300° C. to 900° C.
1. An electrophotographic photosensitive member comprising in this order:
a support;
an intermediate layer; and
a photosensitive layer,
wherein the intermediate layer contains particles each containing titanium oxide, and
wherein the particles have a mass increase ratio of 0.005% or more when heated under nitrogen atmosphere at a temperature from 300° C. to 900° C.
2. The electrophotographic photosensitive member according to claim 1 , wherein the particles each have a core containing titanium oxide, and a coating layer containing titanium oxide, the layer coating the core.
3. The electrophotographic photosensitive member according to claim 2 , wherein the coating layer containing titanium oxide contains titanium oxide doped with one of niobium and tantalum.
4. The electrophotographic photosensitive member according to claim 2 , wherein the cores have an average diameter 1 time or more and 30 times or less as large as an average thickness of the coating layers.
5. The electrophotographic photosensitive member according to claim 1 , wherein a ratio of a mass increase amount of the particles when heated under an oxygen atmosphere at a temperature from 300° C. to 900° C. to a mass increase amount of the particles when heated under the nitrogen atmosphere at a temperature from 300° C. to 900° C. is 1.0 or more and 7.0 or less.
6. The electrophotographic photosensitive member according to claim 1 , wherein a content of the particles in the intermediate layer is 20 vol % or more and 60 vol % or less.
7. A process cartridge 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,
the process cartridge integrally supporting the electrophotographic photosensitive member and the at least one unit, and being removably mounted onto a main body of an electrophotographic apparatus,
wherein the electrophotographic photosensitive member comprises an electrophotographic photosensitive member including a support, an intermediate layer, and a photosensitive layer in the stated order,
wherein the intermediate layer contains particles each containing titanium oxide, and
wherein the particles have a mass increase ratio of 0.005% or more when heated under a nitrogen atmosphere at a temperature from 300° C. to 900° C.
8. An electrophotographic apparatus comprising:
an electrophotographic photosensitive member;
a charging unit;
an exposing unit;
a developing unit; and
a transferring unit,
wherein the electrophotographic photosensitive member comprises an electrophotographic photosensitive member including a support, an intermediate layer, and a photosensitive layer in the stated order,
wherein the intermediate layer contains particles each containing titanium oxide, and
wherein the particles have a mass increase ratio of 0.005% or more when heated under a nitrogen atmosphere at a temperature from 300° C. to 900° C.