Electrophotographic photosensitive member, process cartridge, electrophotographic apparatus, and method of manufacturing electrophotographic photosensitive member

An electrophotographic photosensitive member, comprising:

• a conductive support,
• a charge-generating layer which is provided on the conductive support and comprises a charge-generating substance, and
• a charge-transporting layer which is provided on the charge-generating layer and is a surface layer of the electrophotographic photosensitive member;
• wherein the charge-transporting layer has a matrix-domain structure having:
• a domain which comprises a polyester resin A having a repeating structural unit represented by the following formula (A) and a repeating structural unit represented by the following formula (B);
• and
• a matrix which comprises,
• at least one resin selected from the group consisting of a polycarbonate resin C having a repeating structural unit represented by the following formula (C) and a polyester resin D having a repeating structural unit represented by the following formula (D), and
• at least one charge-transporting substance selected from the group consisting of a compound represented by the following formula (1), a compound represented by the following formula (1′), a compound represented by the following formula (2), and a compound represented by the following formula (2′);
• wherein the content of a siloxane moiety in the polyester resin A is not less than 5.0% by mass and not more than 40% by mass relative to the total mass of the polyester resin A;
• wherein, in the formula (A),
• Y1 represents a single bond, a methylene group, an ethylidene group, a propylidene group, a phenylethylidene group, a cyclohexylidene group, or an oxygen atom;
• X1 represents a meta-phenylene group, a para-phenylene group, or a bivalent group having two para-phenylene groups bonded with an oxygen atom, and
• W1 represents a univalent group represented by the following formula (a), or a univalent group represented by the following formula (b);
• wherein, in the formulae (a) and (b),
• R41 represents a methyl group, or a phenyl group,
• R42 and R43 each independently represents an alkyl group having 1 to 4 carbon atoms,
• “n” represents the number of repetitions of a structure within brackets, an average of “n” in the polyester resin A ranges from 10 to 150;
• “m” and “k” each independently represents the number of repetitions of a structure within brackets, an average of “m+k” in the polyester resin A ranges from 10 to 150;
• wherein, in the formula (B),
• R51 to R54 each independently represents a hydrogen atom, or a methyl group,
• X2 represents a meta-phenylene group, a para-phenylene group, or a bivalent group having two para-phenylene groups bonded with an oxygen atom, and
• Y2 represents a single bond, a methylene group, an ethylidene group, a propylidene group, a phenylethylidene group, a cyclohexylidene group, or an oxygen atom;
• wherein, in the formula (C),
• R61 to R64 each independently represents a hydrogen atom, or a methyl group, and
• Y3 represents a single bond, a methylene group, an ethylidene group, a propylidene group, a phenylethylidene group, a cyclohexylidene group, or an oxygen atom;
• wherein, in the formula (D),
• R71 to R74 each independently represents a hydrogen atom, or a methyl group,
• X4 represents a meta-phenylene group, a para-phenylene group, or a bivalent group having two para-phenylene groups bonded with an oxygen atom, and
• Y4 represents a single bond, a methylene group, an ethylidene group, a propylidene group, a cyclohexylidene group, or an oxygen atom;
• wherein, in the formulae (1) and (1′),
• Ar1 represents a phenyl group, or a phenyl group substituted with a methyl group or an ethyl group,
• Ar2 represents a phenyl group, a phenyl group substituted with a methyl group, a phenyl group substituted with a univalent group represented by the formula “—CH═CH—Ta”, or a biphenyl group substituted with a univalent group represented by the formula “—CH═CH—Ta” (where, Ta represents a univalent group derived from a benzene ring of a triphenylamine by loss of one hydrogen atom, or derived from a benzene ring of a triphenylamine substituted with a methyl group or an ethyl group by loss of one hydrogen atom),
• R1 represents a phenyl group, a phenyl group substituted with a methyl group, or a phenyl group substituted with a univalent group represented by the formula “—CH═C(Ar3)Ar4” (where, Ar3 and Ar4 each independently represents a phenyl group or a phenyl group substituted with a methyl group), and
• R2 represents a hydrogen atom, a phenyl group, or a phenyl group substituted with a methyl group;
• wherein, in the formulae (2) and (2′),
• Ar21, Ar22, Ar24, Ar25, Ar27, and Ar28 each independently represents a phenyl group or a tolyl group,
• Ar23 and Ar26 each independently represents a phenyl group or a phenyl group substituted with a methyl group, and
• wherein the siloxane moiety in the polyester resin A is a moiety represented by one of the following formulae: