Polyarylate resin and electrophotographic photosensitive member
A polyarylate resin includes repeating units represented by formulas (1), (2), and (4). The polyarylate resin further includes a repeating unit represented by formula (3) and a percentage of the number of repeats of the repeating unit represented by formula (3) relative to the total number of repeats of the respective repeating units represented by formulas (1) and (3) is greater than 0% and less than 50%. Or, the polyarylate resin does not include the repeating unit represented by formula (3). In formula (1), R 1 and R 2 each represent, independently of one another, a hydrogen atom or a methyl group and X represents a divalent group represented by formula (X1) or (X2). In formula (3), R 5 and R 6 each represent, independently of one another, a hydrogen atom or a methyl group.
1 . A polyarylate resin comprising
repeating units represented by formulas (1), (2), (3) and (4), wherein
a percentage of a number of repeats of the repeating unit represented by the formula (3) relative to a total number of repeats of the respective repeating units represented by the formulas (1) and (3) is greater than 0% and less than 50%,
where in the formula (1), R 1 and R 2 each represent, independently of one another, a hydrogen atom or a methyl group and X represents a divalent group represented by formula (X1) or (X2), and
in the formula (3), R 5 and R 6 each represent, independently of one another, a hydrogen atom or a methyl group,
where in the formula (X1), t represents an integer of at least 1 and no greater than 3 and * represents a bond, and
in the formula (X2), R 3 and R 4 each represent, independently of one another, a hydrogen atom or an alkyl group with a carbon number of at least 1 and no greater than 4 and * represents a bond,
the polyarylate resin does not comprise a repeating unit represented by formula (5):
wherein the repeating unit represented by the formula (3) includes a repeating unit represented by formula (3-1), and
the repeating unit represented by the formula (1) includes a repeating unit represented by formula (1-1):
2 . The polyarylate resin according to claim 1 , wherein
the percentage of the number of repeats of the repeating unit represented by the formula (3) is greater than 0% and no greater than 30%.
3 . An electrophotographic photosensitive member comprising:
a conductive substrate; and
a photosensitive layer, wherein
the photosensitive layer contains a charge generating material, a hole transport material, and a binder resin, and
the binder resin includes the polyarylate resin according to claim 1 .
4 . The electrophotographic photosensitive member according to claim 3 , wherein
the hole transport material includes a compound represented by formula (20), (21), or (22):
where in the formula (20): R 21 and R 22 each represent, independently of one another, a phenyl group, an alkyl group with a carbon number of at least 1 and no greater than 8, or an alkoxy group with a carbon number of at least 1 and no greater than 8; R 23 to R 29 each represent, independently of one another, a hydrogen atom, an alkyl group with a carbon number of at least 1 and no greater than 8, a phenyl group optionally substituted with an alkyl group with a carbon number of at least 1 and no greater than 8, or an alkoxy group with a carbon number of at least 1 and no greater than 8; any adjacent two of chemical groups R 25 to R 29 may be bonded to form a ring; and a1 and a2 each represent, independently of one another, an integer of at least 0 and no greater than 5,
in the formula (21): R 31 to R 36 each represent, independently of one another, a phenyl group or an alkyl group with a carbon number of at least 1 and no greater than 8; R 37 and R 38 each represent, independently of one another, a hydrogen atom, a phenyl group, or an alkyl group with a carbon number of at least 1 and no greater than 8; b1, b2, b3, and b4 each represent, independently of one another, an integer of at least 0 and no greater than 5; b5 and b6 each represent, independently of one another, an integer of at least 0 and no greater than 4; and d and e each represent, independently of one another, 0 or 1, and
in the formula (22): R 41 to R 46 each represent, independently of one another, a phenyl group, an alkyl group with a carbon number of at least 1 and no greater than 8, or an alkoxy group with a carbon number of at least 1 and no greater than 8; f1, f2, f4, and f5 each represent, independently of one another, an integer of at least 0 and no greater than 5; and f3 and f6 each represent, independently of one another, an integer of at least 0 and no greater than 4.
5 . The electrophotographic photosensitive member according to claim 3 , wherein
the hole transport material includes a compound represented by formula(HTM-1), (HTM-2), (HTM-3), (HTM-4), (HTM-5), or (HTM-6):
6 . The electrophotographic photosensitive member according to claim 3 , wherein
the photosensitive layer includes a charge generating layer containing the charge generating material and a charge transport layer containing the hole transport material and the binder resin, and
the charge transport layer is a single layer serving as an outermost layer.
7 . An electrophotographic photosensitive member comprising:
a conductive substrate; and
a photosensitive layer, wherein
the photosensitive layer contains a charge generating material, a hole transport material, and a binder resin, and
the binder resin includes a polyarylate resin,
wherein
the photosensitive layer includes a charge generating layer containing the charge generating material and a charge transport layer containing the hole transport material and the binder resin, and
the charge transport layer is a single layer serving as an outermost layer,
wherein the polyarylate resin comprises repeating units represented by formulas (1), (2), (3) and (4),
wherein a percentage of a number of repeats of the repeating unit represented by the formula (3) relative to a total number of repeats of the respective repeating units represented by the formulas (1) and (3) is greater than 0% and less than 50%,
where in the formula (1), R1 and R2 each represent, independently of one another, a hydrogen atom or a methyl group and X represents a divalent group represented by formula (X1) or (X2), and
in the formula (3), R5 and R6 each represent, independently of one another, a hydrogen atom or a methyl group,
where in the formula (X1), t represents an integer of at least 1 and no greater than 3 and * represents a bond, and
in the formula (X2), R3 and R4 each represent, independently of one another, a hydrogen atom or an alkyl group with a carbon number of at least 1 and no greater than 4 and * represents a bond,
the repeating unit represented by the formula (3) includes a repeating unit represented by formula (3-1), and
the repeating unit represented by the formula (1) includes a repeating unit represented by formula (1-1):
8 . The electrophotographic photosensitive member according to claim 7 , wherein the percentage of the number of repeats of the repeating unit represented by the formula (3) is greater than 0% and no greater than 30%.