Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus
An electrophotographic photosensitive member includes a surface layer containing a charge transporting material and a polyester resin having a specific structure.
1. An electrophotographic photosensitive member comprising:
a surface layer containing a charge transporting material and a polyester resin, the polyester resin including a structure represented by general formula (I) and a structure represented by general formula (II):
wherein X 1 represents a divalent group; and
wherein X 2 represents a member selected from the group consisting of a single bond, an oxygen atom, divalent alkylene groups, and divalent cycloalkylidene groups, and R 11 to R 12 each represent a member selected from the group consisting of a hydrogen atom and alkyl groups,
wherein the structure represented by general formula (I) includes a structure represented by formula (I-1):
and the structure represented by general formula (II) includes at least one of a structure represented by general formula (II-A) and a structure represented by general formula (II-B):
wherein R 211 and R 212 each represent a member selected from the group consisting of a hydrogen atom, a methyl group, and an ethyl group, and
wherein R 221 and R 222 each represent a member selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, and a phenyl group, and R 223 to R 226 each represent a member selected from the group consisting of a hydrogen atom, alkyl group having a carbon number of 1 to 5, and a phenyl group, at least one of R 223 to R 226 being one of an alkyl group having a carbon number of 2 or more and a phenyl group.
2. The electrophotographic photosensitive member according to claim 1 , wherein the proportion of the structure represented by formula (I-1) to all the structures represented by general formula (I) is 50% by mole or more in the polyester resin.
3. The electrophotographic photosensitive member according to claim 1 , wherein the proportion of the structure represented by general formula (II-A) or the structure represented by general formula (II-B) to all the structures represented by general formula (II) is 30% by mole or more in the polyester resin.
4. The electrophotographic photosensitive member according to claim 1 , wherein the structure represented by general formula (II) further includes a structure represented by general formula (II-2):
wherein R 31 to R 34 each represent a member selected from the group consisting of a hydrogen atom and alkyl groups, and Y l represents a member selected from the group consisting of a single bond, an oxygen atom, divalent alkylene groups, and divalent cycloalkylidene groups.
5. The electrophotographic photosensitive member according to claim 4 wherein Y l in general formula (II-2) represents a single bond.
6. A process cartridge capable of being removably attached to an electrophotographic apparatus, the process cartridge comprising:
an electrophotographic photosensitive member; and
at least one device selected from the group consisting of a charging device, a developing device, a transfer device, and a cleaning device, the at least one device being held together with the electrophotographic photosensitive member in one body,
wherein the electrophotographic photosensitive member includes a surface layer containing a charge transporting material and a polyester resin, the polyester resin including a structure represented by general formula (I) and a structure represented by general formula (II):
wherein X 1 represents a divalent group; and
wherein X 2 represents a member selected from the group consisting of a single bond, an oxygen atom, divalent alkylene groups, and divalent cycloalkylidene groups, and R H to R 18 each represent a member selected from the group consisting of a hydrogen atom and alkyl groups, and
wherein the structure represented by general formula (I) includes a structure represented by formula (I-1):
and the structure represented by general formula (II) includes at least one of a structure represented by general formula (II-A) and a structure represented by general formula (II-B):
wherein R 211 and R 212 each represent a member selected from the group consisting of a hydrogen atom, a methyl group, and an ethyl group, and
wherein R 221 and R 222 each represent a member selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, and a phenyl group, and R 223 to R 226 each represent a member selected from the group consisting of a hydrogen atom, alkyl group having a carbon number of 1 to 5, and a phenyl group, at least one of R 223 to R 226 being one of an alkyl group having a carbon number of 2 or more and a phenyl group.
7. An electrophotographic apparatus comprising:
an electrophotographic photosensitive member;
a charging device;
an exposure device;
a developing device; and
a transfer device,
wherein the electrophotographic photosensitive member includes a surface layer containing a charge transporting material and a polyester, the polyester resin including a structure represented by general formula (I) and a structure represented by general formula (II):
wherein X 1 represents a divalent group; and
wherein X 2 represents a member selected from the group consisting of a single bond, an oxygen atom, divalent alkylene groups, and divalent cycloalkylidene groups, and R 11 to R 18 each represent a member selected from the group consisting of a hydrogen atom and alkyl groups, and
wherein the structure represented by general formula (I) includes a structure represented by formula (I-1):
and the structure represented by general formula (II) includes at least one of a structure represented by general formula (II-A) and a structure represented by general formula (II-B):
wherein R 211 and R 212 each represent a member selected from the group consisting of a hydrogen atom, a methyl group, and an ethyl group, and
wherein R 221 and R 222 each represent a member selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, and a phenyl group, and R 223 to R 226 each represent a member selected from the group consisting of a hydrogen atom, alkyl group having a carbon number of 1 to 5, and a phenyl group, at least one of R 223 to R 226 being one of an alkyl group having a carbon number of 2 or more and a phenyl group.