Electrophotographic photosensitive member, and electrophotographic apparatus and process cartridge each including the electrophotographic photosensitive member
Provided is an electrophotographic photosensitive member including a support, a charge-generating layer, a first hole-transporting layer, and a second hole-transporting layer, wherein the second hole-transporting layer contains a hole-transportable compound represented by the formula (1) (mass: W1, energy value of the highest occupied molecular orbital: CTM1HOMO), and a hole-transportable compound represented by the formula (2) (mass: W2) and/or a hole-transportable compound represented by the formula (3) (mass: W3) (energy value of the highest occupied molecular orbital: CTM2HOMO), wherein a value calculated from the expression (I) is from 0.05% by mass to 5.0% by mass, and wherein the expression (II) is satisfied: (W2+W3)/(W1+W2+W3)×100 (% by mass) . . . Expression (I); and 0.05 (eV)≤|CTM2HOMO|−|CTM1HOMO|≤0.30 (eV) . . . (II).
1 . An electrophotographic photosensitive member, comprising:
a support;
a charge-generating layer formed on the support;
a first hole-transporting layer formed on the charge-generating layer; and
a second hole-transporting layer formed on the first hole-transporting layer, the second hole-transporting layer being a surface layer and comprising a copolymer of a composition containing hole-transportable compounds represented by formulae (1) and (3), and optionally comprising a hole-transportable compound represented by formula (2)
where R 11 and R 12 independently represent an alkylene group having 2 to 6 carbon atoms, R 13 and R 14 independently represent a hydrogen atom or a methyl group, n 1 represents 1, R 15 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, x 11 represents an integer of from 0 to 5 and when x 11 represents an integer of from 2 to 5, R 15 s may be identical to or different from each other, R 16 represents an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, x 12 represents an integer of from 0 to 4 and when x 12 represents an integer of from 2 to 4, R 16 s may be identical to or different from each other, R 21 and R 22 independently represent an alkylene group having 2 to 6 carbon atoms, R 23 and R 24 independently represent a hydrogen atom or a methyl group, n 2 represents 1, R 25 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, x 21 represents an integer of from 0 to 5, and when x 21 represents an integer of from 2 to 5, R 25 s may be identical to or different from each other, R 26 represents an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, x 22 represents an integer of from 0 to 4 and when x 22 represents an integer of from 2 to 4, R 26 s may be identical to or different from each other, R 31 and R 32 independently represent an alkylene group having 2 to 6 carbon atoms, R 33 and R 34 independently represent a hydrogen atom or a methyl group, n 3 represents 1, R 35 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a substituted or unsubstituted phenyl group, x 31 represents an integer of from 0 to 5 and when x 31 represents an integer of from 2 to 5, R 35 s may be identical to or different from each other, R 36 represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and x 32 represents an integer of from 0 to 4 and when x 32 represents an integer of from 2 to 4, R 36 s may be identical to or different from each other, wherein
( W 2+ W 3)/( W 1+ W 2+ W 3)×100 (% by mass) is 0.05 to 5.0% by mass
when W1 is a mass of the hole-transportable compound represented by formula (1) in the composition, W2 is a mass of the hole-transportable compound represented by formula (2) in the composition, and W3 is a mass of the hole-transportable compound represented by formula (3) in the composition, and
0.05 (eV)≤|CTM2HOMO|−|CTM1HOMO|≤0.30 (eV)
when CTM1HOMO is an energy value of a highest occupied molecular orbital of the hole-transportable compound represented by formula (1) obtained as a result of energy calculation of the hole-transportable compound after structure optimization thereof by a density functional theory B3LYP/6-31G*, and
CTM2HOMO is an energy value of a highest occupied molecular orbital of the hole-transportable compound represented by formula (3) obtained as a result of energy calculation of the hole-transportable compound after structure optimization thereof by the density functional theory B3LYP/6-31G*.
2 . The electrophotographic photosensitive member according to claim 1 , wherein 0.15 (eV)≤|CTM2HOMO|−|CTM1HOMO|≤0.25 (eV).
3 . The electrophotographic photosensitive member according to claim 1 , wherein (W2+W3)/(W1+W2+W3)×100 (% by mass) is 0.1 to 2.0% by mass.
4 . The electrophotographic photosensitive member according to claim 3 , wherein (W2+W3)/(W1+W2+W3)×100 (% by mass) is 0.2 to 1.0% by mass.
5 . An electrophotographic apparatus, comprising:
an electrophotographic photosensitive member;
a charging unit;
an exposing unit;
a developing unit; and
a transferring unit;
the electrophotographic photosensitive member comprising a support, a charge-generating layer formed on the support, a first hole-transporting layer formed on the charge-generating layer, and a second hole-transporting layer formed on the first hole-transporting layer, the second hole-transporting layer being a surface layer of the electrophotographic photosensitive member and comprising a copolymer of a composition containing hole-transportable compounds represented by formulae (1) and (3), and optionally comprising at a hole-transportable compound represented by formula (2)
where R 11 and R 12 independently represent an alkylene group having 2 to 6 carbon atoms, R 13 and R 14 independently represent a hydrogen atom or a methyl group, n 1 represents 1, R 15 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, x 11 represents an integer of from 0 to 5 and when x 11 represents an integer of from 2 to 5, R 15 s may be identical to or different from each other, R 16 represents an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, x 12 represents an integer of from 0 to 4 and when x 12 represents an integer of from 2 to 4, R 16 s may be identical to or different from each other, R 21 and R 22 independently represent an alkylene group having 2 to 6 carbon atoms, R 23 and R 24 independently represent a hydrogen atom or a methyl group, n 2 represents 1, R 25 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, x 21 represents an integer of from 0 to 5, and when x 21 represents an integer of from 2 to 5, R 25 s may be identical to or different from each other, R 26 represents an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, x 22 represents an integer of from 0 to 4 and when x 22 represents an integer of from 2 to 4, R 26 s may be identical to or different from each other, R 31 and R 32 independently represent an alkylene group having 2 to 6 carbon atoms, R 33 and R 34 independently represent a hydrogen atom or a methyl group, n 3 represents 1, R 35 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a substituted or unsubstituted phenyl group, x 31 represents an integer of from 0 to 5 and when x 31 represents an integer of from 2 to 5, R 35 s may be identical to or different from each other, R 36 represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and x 32 represents an integer of from 0 to 4 and when x 32 represents an integer of from 2 to 4, R 36 s may be identical to or different from each other, wherein
( W 2+ W 3)/( W 1+ W 2+ W 3)×100 (% by mass) is 0.05 to 5.0% by mass
when W1 is a mass of the hole-transportable compound represented by formula (1) in the composition, W2 is a mass of the hole-transportable compound represented by formula (2) in the composition, and W3 is a mass of the hole-transportable compound represented by formula (3) in the composition, and
0.05 (eV)≤|CTM2HOMO|−|CTM1HOMO|≤0.30 (eV)
when CTM1HOMO is an energy value of a highest occupied molecular orbital of the hole-transportable compound represented by formula (1) obtained as a result of energy calculation of the hole-transportable compound after structure optimization thereof by a density functional theory B3LYP/6-31G*, and
CTM2HOMO is an energy value of a highest occupied molecular orbital of the hole-transportable compound represented by formula (3) obtained as a result of energy calculation of the hole-transportable compound after structure optimization thereof by the density functional theory B3LYP/6-31G*.
6 . 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, a transferring 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;
the electrophotographic photosensitive member comprising a support, a charge-generating layer formed on the support, a first hole-transporting layer formed on the charge-generating layer, and a second hole-transporting layer formed on the first hole-transporting layer,
the second hole-transporting layer being a surface layer of the electrophotographic photosensitive member and comprising a copolymer of a composition containing hole-transportable compounds represented by formulae (1) and (3), and optionally comprising a hole-transportable compound represented by formula (2)
where R 11 and R 12 independently represent an alkylene group having 2 to 6 carbon atoms, R 13 and R 14 independently represent a hydrogen atom or a methyl group, n 1 represents 1, R 15 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, x 11 represents an integer of from 0 to 5 and when x 11 represents an integer of from 2 to 5, R 15 s may be identical to or different from each other, R 16 represents an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, x 12 represents an integer of from 0 to 4 and when x 12 represents an integer of from 2 to 4, R 16 s may be identical to or different from each other, R 21 and R 22 independently represent an alkylene group having 2 to 6 carbon atoms, R 23 and R 24 independently represent a hydrogen atom or a methyl group, n 2 represents 1, R 25 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, x 21 represents an integer of from 0 to 5, and when x 21 represents an integer of from 2 to 5, R 25 s may be identical to or different from each other, R 26 represents an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, x 22 represents an integer of from 0 to 4 and when x 22 represents an integer of from 2 to 4, R 26 s may be identical to or different from each other, R 31 and R 32 independently represent an alkylene group having 2 to 6 carbon atoms, R 33 and R 34 independently represent a hydrogen atom or a methyl group, n 3 represents 1, R 35 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a substituted or unsubstituted phenyl group, x 31 represents an integer of from 0 to 5 and when x 31 represents an integer of from 2 to 5, R 35 s may be identical to or different from each other, R 36 represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and x 32 represents an integer of from 0 to 4 and when x 32 represents an integer of from 2 to 4, R 36 s may be identical to or different from each other, wherein
( W 2+ W 3)/( W 1+ W 2+ W 3)×100 (% by mass) is 0.05 to 5.0% by mass
when W1 is a mass of the hole-transportable compound represented by formula (1) in the composition, W2 is a mass of the hole-transportable compound represented by formula (2) in the composition, and W3 is a mass of the hole-transportable compound represented by formula (3) in the composition, and
0.05 (eV)≤|CTM2HOMO|−|CTM1HOMO|≤0.30 (eV)
when CTM1HOMO is an energy value of a highest occupied molecular orbital of the hole-transportable compound represented by formula (1) obtained as a result of energy calculation of the hole-transportable compound after structure optimization thereof by a density functional theory B3LYP/6-31G*, and
CTM2HOMO is an energy value of a highest occupied molecular orbital of the hole-transportable compound represented by formula (3) obtained as a result of energy calculation of the hole-transportable compound after structure optimization thereof by the density functional theory B3LYP/6-31G*.
7 . A method of producing an electrophotographic photosensitive member including a support, a charge-generating layer formed on the support, a first hole-transporting layer formed on the charge-generating layer, and a second hole-transporting layer formed on the first hole-transporting layer, the second hole-transporting layer being a surface layer, the method comprising:
forming a coat of an application liquid for the second hole-transporting layer containing hole-transportable compounds represented by formulae (1) and (3), and optionally comprising a hole-transportable compound represented by formula (2); and
copolymerizing a composition incorporated into the coat to form the second hole-transporting layer of the electrophotographic photosensitive member
where R 11 and R 12 independently represent an alkylene group having 2 to 6 carbon atoms, R 13 and R 14 independently represent a hydrogen atom or a methyl group, n 1 represents 1, R 15 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, x 11 represents an integer of from 0 to 5 and when x 11 represents an integer of from 2 to 5, R 15 s may be identical to or different from each other, R 16 represents an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, x 12 represents an integer of from 0 to 4 and when x 12 represents an integer of from 2 to 4, R 16 s may be identical to or different from each other, R 21 and R 22 independently represent an alkylene group having 2 to 6 carbon atoms, R 23 and R 24 independently represent a hydrogen atom or a methyl group, n 2 represents 1, R 25 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, x 21 represents an integer of from 0 to 5, and when x 21 represents an integer of from 2 to 5, R 25 s may be identical to or different from each other, R 26 represents an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, x 22 represents an integer of from 0 to 4 and when x 22 represents an integer of from 2 to 4, R 26 s may be identical to or different from each other, R 31 and R 32 independently represent an alkylene group having 2 to 6 carbon atoms, R 33 and R 34 independently represent a hydrogen atom or a methyl group, n 3 represents 1, R 35 represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a substituted or unsubstituted phenyl group, x 31 represents an integer of from 0 to 5 and when x 31 represents an integer of from 2 to 5, R 35 s may be identical to or different from each other, R 36 represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and x 32 represents an integer of from 0 to 4 and when x 32 represents an integer of from 2 to 4, R 36 s may be identical to or different from each other, wherein
( W 2+ W 3)/( W 1+ W 2+ W 3)×100 (% by mass) is 0.05 to 5.0% by mass
when W1 is a mass of the hole-transportable compound represented by formula (1) that is incorporated into the application liquid for the second hole-transporting layer, W2 is a mass of the hole-transportable compound represented by formula (2) that is incorporated into the application liquid for the second hole-transporting layer, and W3 is a mass of the hole-transportable compound represented by formula (3) that is incorporated into the application liquid for the second hole-transporting layer, and
0.05 (eV)≤|CTM2HOMO|−|CTM1HOMO|≤0.30 (eV)
when CTM1HOMO is an energy value of a highest occupied molecular orbital of the hole-transportable compound represented by formula (1) obtained as a result of energy calculation of the hole-transportable compound after structure optimization thereof by a density functional theory B3LYP/6-31G*, and
CTM2HOMO is an energy value of a highest occupied molecular orbital of the hole-transportable compound represented by formula (3) obtained as a result of energy calculation of the hole-transportable compound after structure optimization thereof by the density functional theory B3LYP/6-31G*.
8 . The electrophotographic photosensitive member according to claim 1 , wherein the second hole-transportable layer comprises the hole-transportable compound according to formula (2).
9 . The electrophotographic apparatus according to claim 5 , wherein the second hole-transportable layer comprises the hole-transportable compound according to formula (2).
10 . The process cartridge according to claim 6 , wherein the second hole-transportable layer comprises the hole-transportable compound according to formula (2).
11 . The method of producing an electrophotographic photosensitive member according to claim 7 , wherein the second hole-transportable layer comprises the hole-transportable compound according to formula (2).