JPH11218944A - Electrophotographic photoreceptor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance sensitivity and mechanical durability and to prevent deterioration of image quality and sensitivity by incorporating a specified polycarbonate copolymer resin and a specified compound in a photosensitive layer formed on a conductive substrate. SOLUTION: This photosensitive layer formed on the conductive substrate contains the polycarbonate copolymer resin having the terminal groups modified represented by formula I and the compound represented by formula II, and in formulae I and II, each of R1 -R3 is an optionally substituted alkyl or aryl or aralkyl or alkenyl group or the like; X is an alkylene, cycloalkylidene, arylene, sulfonyl, or carbonyl group; Z is an alkylene or arylene group or the like; Y is an alkyl or alkenyl group or the like; (n) is an integer of 10-200; Ar is an arylene group; each of R9 and R10 is an aryl group or an H atom or the like; (a) is an alkyl or alkoxy group or the like; (p) is 1, 2, 3, or 4; and (q) is 2, 3, or 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, and more particularly, to an organic photoconductive electrophotographic photosensitive member and a method for producing the same.

[0002]

2. Description of the Related Art In general, there are various systems in an electrophotographic process, and a direct system and a latent image transfer system are known as typical examples. In the electrophotographic photoreceptor used in these electrophotographic processes, basic properties required as a photoconductive layer material constituting the photoconductive layer include: 1) high chargeability of electric charge by corona discharge in a dark place. 2) The obtained charge due to corona discharge should have little attenuation in a dark place 3) The charge should be quickly dissipated by light irradiation 4) The residual charge after light irradiation should be small 5) The residual potential due to repeated use 6) There is little change in electrophotographic characteristics due to temperature and humidity.

As such materials, inorganic photoconductive materials such as zinc oxide (Japanese Patent Publication No. 57-19780), cadmium sulfide (Japanese Patent Publication No. 58-46018), and amorphous selenium alloy have been conventionally used. Although it has been used, various problems have been pointed out in recent years. That is, in the case of a zinc oxide-based material, the sensitizer causes charge deterioration due to corona discharge and photobleaching due to exposure, so that a stable image cannot be provided over a long period of time. In a cadmium sulfide-based material, stable sensitivity cannot be obtained under humid conditions. The selenium-based material has thermal stability, deterioration of characteristics due to crystallization, difficulty in production, and the like.

[0004] From a future perspective, electrophotography made of an organic material rather than an inorganic material, which has production problems due to resource depletion, concerns about pollution due to toxicity, and environmental problems. Research on photoconductors has been actively conducted, and as a result, electrophotographic photoconductors using various organic compounds have been studied. In particular, research and development in recent years have tended to actively introduce the concept of a function-separated type photoreceptor, and in particular, a charge generation layer and a hole-transporting charge transport layer on a conductive layer. Are stacked in order, and the charge transfer surface is negatively charged.

[0005] By separating the functions in this manner, it becomes possible to independently develop materials having the functions of charge generation and charge transfer, respectively.
Many charge generating materials and charge transfer materials having various molecular structures have been developed. An electrophotographic photoreceptor using these organic compounds is produced by coating a photosensitive layer on a conductive support. Known manufacturing methods include a baker applicator and a bar coater in the case of a sheet, and a spraying method, a vertical ring method, and a dip coating method in the case of a drum. The dip coating method is adopted.

Here, paying attention to the charge transfer materials, a typical one of them is classified according to the structural characteristics. The hydrazone type (JP-A-54-59143) and the stilbene-styryl type (JP-A-54-59143) JP-A-58-198043), triarylamines (JP-B-58-32372).
), Phenothiazines, triazoles, quinoxalines, oxadiazoles, oxazoles, pyrazolines, triphenylmethanes, dihydronicotinamide compounds, indoline compounds, semicarbazone compounds, and the like.

[0007]

However, despite the fact that a large number of organic compounds have been developed as charge transport materials, 1) low compatibility with binders 2) crystals are likely to be deposited 3) repetition There is no organic compound that satisfies all the problems such as sensitivity change when used, 4) poor charging ability and repetition characteristics, 5) poor residual potential characteristics, etc. At present, materials satisfying properties, furthermore, mechanical strength, high durability and the like have not yet been sufficiently obtained, and the development of more excellent organic photoconductive materials and photoreceptors has been desired.

Further, these function-separated type organic photoreceptors have heretofore mainly been provided with a thin carrier generation layer on a conductive support, mainly for negative charging, on which a carrier transport layer of an appropriate thickness is provided. Configuration has been taken.

As a binder resin used for such an organic photoreceptor, bisphenol A type polycarbonate is conventionally used in various electrophotographic characteristics (sensitivity, chargeability,
It has been generally known that the composition exhibits appropriate characteristics in terms of residual potential and repetition characteristics. However, the use of bisphenol A-type polycarbonate resin in recent years has led to the following problems.

1) When a polymer has high crystallinity and is made into a solution, a gelling phenomenon occurs immediately and the polymer becomes unusable. 2) At the time of film formation by coating, crystalline polycarbonate precipitates on the film surface, and the toner easily adheres to the uneven portions thereof, causing poor cleaning and causing image defects. 3) The surface of the photosensitive layer is easily damaged. 4) The photosensitive layer gradually wears as the number of copies increases.

In order to solve such problems, various methods, for example, a method using a specific polycarbonate resin for the surface layer of the photoreceptor (JP-A-63-14826).
No. 3, JP-B-2-57300, JP-A-2-2-2
No. 54466, JP-A-6-59471),
Methods for introducing various substituents into the monomer unit of bisphenol A (JP-A-60-172045, JP-A-63-65444, JP-A-60-148263)
However, as the speed is increased, the process speed is increased, the scattering of the toner is increased, and the cleaning failure is likely to occur.

As a countermeasure, some models use two-stage cleaning blades or increase the pressure. Therefore, at present, such improvement alone does not provide sufficient measures because the wear is large. Furthermore, some methods of providing an overcoat layer have been proposed,
In production by coating, it is difficult to select a solvent that does not dissolve the already coated photosensitive layer, and even when completed, it is difficult to design such that electrical characteristics are adversely affected. Further, some methods using two or more kinds of polycarbonates having different molecular weights have been proposed, but none of them can provide sufficient performance. There are still unresolved problems such as insufficient surface strength and surface smoothness, easy to scratch, deterioration of image quality due to repeated use, and decrease in sensitivity due to film thickness decrease due to wear. It is.

The object of the present invention is exactly at this point. The photosensitive member surface is worn or scratched even when it comes into contact with a toner, a developer, paper, a cleaning blade or the like with a highly sensitive and uniform coating film. To provide an electrophotographic photoreceptor that can be used repeatedly over a long period of time without causing coating film defects and has high mechanical durability of the photosensitive layer, good surface smoothness, low image quality, and low sensitivity deterioration. .

[0014]

Means for Solving the Problems The present inventors have developed a photoreceptor having a high sensitivity and a high mechanical durability of an electrophotographic photosensitive layer, a good flatness, a low image quality and a small deterioration in sensitivity. After conducting research, the photosensitive layer formed on the conductive support contains a polycarbonate copolymer resin having a terminal group modified by the following general formula (1), and the following general formula (2): The inventors have found that an electrophotographic photoreceptor characterized by incorporating a compound represented by (3), (4) or (5) is effective, and have completed the present invention.

[0015]

Embedded image

In the formula, R1 to R8 each have an alkyl group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, and a substituent. An aralkyl group having 7 to 17 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms,
X represents a halogen atom or a hydrogen atom, and X is a directly bonded or optionally substituted alkylene group having 1 to 10 carbon atoms, and 1 carbon atom which may have a substituent.
To 10 represents a cyclic alkylidene group, an optionally substituted arylene group having 6 to 12 carbon atoms, a sulfonyl group, or a carbonyl group, and Z represents an optionally substituted alkylene group having 1 to 5 carbon atoms. Y represents an arylene group having 6 to 12 carbon atoms, an arylene alkyl group having 7 to 17 carbon atoms, or a halogen atom, and Y represents an alkyl group having 1 to 5 carbon atoms which may have a substituent; Alkenyl group having 2 to 5 carbon atoms, alkoxy group having 1 to 5 carbon atoms, alkyl ester group having 1 to 5 carbon atoms which may have a substituent, 6 to 5 carbon atoms which may have a substituent 12 represents an aryl ester group, a carboxyl group, an aldehyde group, a hydroxyl group, a halogen atom or a hydrogen atom. n represents an integer of 10 to 200.

[0017]

Embedded image

In the formula, Ar is an arylene group having 6 to 12 carbon atoms which may have a substituent; R9 and R10 each represent an aryl group having 6 to 12 carbon atoms which may have a substituent; A heterocyclic group having 5 to 11 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, an alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. However, R9 and R10 exclude a hydrogen atom at the same time. a
Is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and p represents an integer of 1 to 4. However, when p is 2 or more, a may be the same or different. q represents an integer of 2 to 4.

[0019]

Embedded image

In the formula, Ar is an arylene group having 6 to 12 carbon atoms which may have a substituent; R11 represents an aryl group having 6 to 12 carbon atoms which may have a substituent; An optionally substituted heterocyclic group having 5 to 11 carbon atoms, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, an alkyl group having 1 to 5 carbon atoms, or a hydrogen atom;
R13 has 6 to 1 carbon atoms which may have a substituent.
Aryl group having 2 to 5 carbon atoms which may have a substituent
1 heterocyclic group, 7 to 17 carbon atoms which may have a substituent
May be an alkyl group having 1 to 5 carbon atoms, or R12 and R13 may be bonded to each other to form a fused heterocyclic ring. a is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and p represents an integer of 1 to 4. However, when p is 2 or more, a may be the same or different. q represents an integer of 2 to 4.

[0021]

Embedded image

In the formula, D is a group having 6 carbon atoms which may have a substituent.
To 12 arylene group, a divalent heterocyclic group which may have a substituent, an alkylene group having 1 to 10 carbon atoms which may have a substituent, and R14 and R15 each have a substituent An aryl group having 6 to 12 carbon atoms, a heterocyclic group having 5 to 11 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, 1 carbon atom And b is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and r is Represents an integer of 1 to 5. However, when r is 2 or more, b may be the same or different, and may be combined with each other to form a heterocyclic ring.

[0023]

Embedded image

In the formula, D represents an optionally substituted carbon number of 6
To 12 arylene group, a divalent heterocyclic group which may have a substituent, an alkylene group having 1 to 10 carbon atoms which may have a substituent, and R14 may have a substituent. An aryl group having 6 to 12 carbon atoms, a heterocyclic group having 5 to 11 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, 1 to 5 carbon atoms B is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and q
Is an integer of 2 to 4, and r represents an integer of 1 to 5.
However, when r is 2 or more, b may be the same or different, and may be combined with each other to form a heterocyclic ring.

In the present invention, X in the general formula (1) is a cyclic alkylidene group having 1 to 10 carbon atoms which may have a substituent, Z is a phenylene group, and Y is a hydrogen atom or a substituted Is an alkyl group having 1 to 5 carbon atoms which may have a group, X is directly bonded, Z is a phenylene group, and Y is a hydrogen atom or a carbon atom having 1 or 5 carbon atoms which may have a substituent.
To X, X is an aryl group having 6 to 12 carbon atoms which may have a substituent, Z is a phenylene group, and Y is a hydrogen atom or a group having a substituent. A good alkyl group having 1 to 5 carbon atoms, X is a sulfonyl group or a carbonyl group, Z is a phenylene group, and Y is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms which may have a substituent. Or Z is an alkylene group which may have a substituent and has 5 to 10 carbon atoms, and Y is an alkyl ester group or a substituent which may have a substituent and has 1 to 5 carbon atoms. It may have an arylester group having 6 to 12 carbon atoms or a hydrogen atom, or the structural unit of the general formula (1) is 1,1-bis (4-hydroxyphenyl) cyclohexanone, 1,1-bis (4 -Hydroxyphenyl-3-methyl Phenyl) cyclohexanone,
1,1-bis (4-hydroxyphenyl-3,5-dimethylphenyl) cyclohexanone is preferred.

In the present invention, by using the polycarbonate resin having both terminal groups modified as a binder resin for an electrophotographic photosensitive member, electrophotographic properties (sensitivity, chargeability, residual potential, repetition properties, etc.) are excellent, and fatigue deterioration is reduced. An electrophotographic photoreceptor exhibiting less stable characteristics can be provided.

Further, if necessary, other binder resins may be used together in a proportion that does not adversely affect the desired characteristics of the electrophotographic photosensitive member. In this case, the mixing ratio is preferably 50% by weight or less. If the content exceeds 50% by weight, the properties of the binder resin used in combination will be emphasized and lose the meaning of the original invention.

The polycarbonate resin having both terminal groups modified in the present invention can be easily synthesized by a general synthetic route using a divalent phenol derivative compound represented by the following general formula (6).

[0029]

Embedded image

In the formulas, R1 to R8 and X have the same meanings as in claim 1.

The polycarbonate resin of the present invention represented by the above general formula (1) having both terminal groups modified will be described in more detail.

The polycarbonate resin having both terminal groups modified in the present invention is obtained by polymerizing a divalent phenol derivative and a carbonate-forming compound, and has a structure in which a residue of a monofunctional compound is bonded to the terminal. Have.

Specific examples of the divalent phenol derivative (6) for synthesizing the polycarbonate resin having both terminal groups modified by the general formula (1) include the following compounds. Thus, the polycarbonate resin of the present invention in which both terminal groups are modified is not limited at all.

Bisphenol, bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, 1,1
-Bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4
-Hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4 -Hydroxy-
3-bromophenyl) propane, 2,2-bis (4-hydroxy-3-chlorophenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane,
2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) diphenylethane, 2,2-bis (4-
(Hydroxy-3-allylphenyl) propane, 1,1-
Bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) cyclohexane and the like.

In particular, from the viewpoint of reactivity, 2,2-bis (4-
(Hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4
-Hydroxy-3-methylphenyl) propane, 1,1
-Bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-
(3,5-dimethylphenyl) cyclohexane is more preferred. These may be used in combination of two or more.

Specific examples of the monofunctional compound that forms the polycarbonate resin having both terminal groups modified by the general formula (1) include the following compounds. The polycarbonate resin whose both terminal groups are modified is not limited at all.

Phenol, p-tert-butylphenol, o-cresol, p-cresol, m-cresol, thymol, naphthiol, carvacrol, p-cumylphenol, 2,3-xylenol, picric acid,
p-chlorophenol, o-chlorophenol, m-chlorophenol, p-bromophenol, o-bromophenol, m-bromophenol, eugenol, o-
Allylphenol, p-hydroxybenzoic acid, pn-
Butylphenol, p-ethoxyphenol, salicyl alcohol, p- (3-hydroxypropyl) phenol, vanillin, p-isopropenylphenol, guaiacol and the like. These may be used in combination of two or more. Among them, phenol, p-tert-
Butylphenol, o-allylphenol, p-hydroxybenzoic acid and salicyl alcohol are preferred.

Examples of the carbonate-forming compound include phosgene, diphenyl carbonate, bis-p-tolyl carbonate, phenyl-p-tolyl carbonate,
Bisaryl carbonates such as bis-p-chlorophenyl carbonate and bisnaphthyl carbonate are exemplified.

The method for producing the polycarbonate polymer represented by the general formula (1) of the present invention includes bisphenol A
Such as direct reaction of dihydric phenol with phosgene (phosgene method) or transesterification reaction of dihydric phenol with bisaryl carbonate (ester exchange method). A method can be adopted.

In the former phosgene method as a specific synthetic route, the dihydric phenol and the monofunctional compound are reacted with phosgene using an inert halogenated hydrocarbon such as dichloromethane, 1,2-dichloroethane or the like as a reaction solvent. Let it. As an acid trapping agent for hydrogen chloride gas produced as a by-product of the reaction, there is a method using an alkaline aqueous solution or an organic basic compound such as pyridine. When an aqueous alkaline solution is used as the acid trapping agent, a tertiary amine such as a trialkylamine (eg, trimethylamine, triethylamine, diisopropylethylamine) or a tetraalkylammonium halide (eg, tetraalkylammonium chloride, tributyl) is used as a co-catalyst. When a quaternary ammonium salt such as benzylammonium bromide) is used in combination, the reactivity increases. Further, if necessary for the purpose of controlling the molecular weight of the polycarbonate polymer in the present invention, a monovalent phenol derivative (for example, phenol, p-tert-butylphenol, pn-
Butyl phenol). If desired, a small amount of an antioxidant such as sodium sulfite or hydrosulfite or a branching agent such as phloroglucin or isatin bisphenol may be added. The reaction temperature is usually 0 to 1
Generally, the temperature is in the range of 50 ° C, preferably 5 to 40 ° C. The reaction time depends on the reaction temperature, but is usually 0.5 minutes to 10 hours, preferably 1 minute to 2 hours.
Time. During the reaction, the pH of the reaction system is preferably maintained at 10 or more.

On the other hand, in the latter transesterification method,
The dihydric phenol, the monofunctional compound and the bisaryl carbonate are mixed and reacted under reduced pressure and high temperature. The reaction temperature is usually 150 to 350 ° C., preferably 2
The reaction is carried out at a temperature in the range of from 00 to 300 ° C., and the pressure is finally reduced to preferably 1 mmHg or less to remove phenols derived from the bisaryl carbonate generated by the transesterification to the outside of the reaction system. The reaction time depends on the reaction temperature and the degree of pressure reduction, but is usually 1 to 4
Time. The reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen or argon, and the reaction may be carried out by adding an antioxidant or a branching agent as required.

Next, specific examples of the polycarbonate resin represented by the general formula (1) in which both terminal groups are modified are shown in Tables 1 and 2, but the present invention is not limited thereto.

[0043]

[Table 1]

[0044]

[Table 2]

Other binder resins which can be used in combination with the polycarbonate resin having both terminal groups modified according to the present invention used as the above-mentioned binder resin include the following resins.

Polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl butyral, polyvinyl formal, polystyrene, polyester, polyhydroxystyrene, methacrylic resin, acrylic resin, phenolic resin, styrene copolymer resin, acrylonitrile copolymer resin, chloride A vinyl-vinyl acetate copolymer, a vinyl chloride-vinyl acetate-maleic anhydride copolymer, a silicone resin, a silicone alkyd resin, and these binder resins have both terminal groups of the present invention either alone or as a mixture of two or more. It can be used in combination with a modified polycarbonate resin.

Next, the general formulas (2), (3), (4),
The charge transport material represented by (5) will be described.

[0048]

Embedded image

The substituents of the enamine group-containing compound represented by the general formula (2) will be described.
Arylene groups such as -phenylene, 3-methyl-p-phenylene, 3-methoxy-p-phenylene, 1,4-naphthylene, 3-methyl-1,4-naphthylene, 3-methoxy-1,4-naphthylene; R9 and R10 are phenyl, p-tolyl, 3,5-xylyl, p-methoxyphenyl, p-chlorophenyl, 1-
Aryl groups such as naphthyl, 9-anthracenyl, 2-methyl-1-naphthyl, 2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 2-pyridyl, 1-benzothiazole, 1-benzoxazole, etc. Heterocyclic group, benzyl, p-methoxybenzyl, p-methylbenzyl, p
Aralkyl groups such as -chlorobenzyl, methyl, ethyl,
n-propyl, iso-propyl, n-butyl, sec
An alkyl group such as -butyl and n-pentyl, or a hydrogen atom.

A represents methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl,
alkyl groups such as n-pentyl, methoxy, ethoxy, n
-Alkoxy groups such as -propyloxy and iso-propyloxy; dialkylamino groups such as dimethylamino, diethylamino, di-n-propylamino and diiso-propylamino; halogen atoms and hydrogen atoms such as fluorine, chlorine and bromine; .

Next, specific examples of the charge transporting material represented by the general formula (2) are shown in Table 3, but the present invention is not limited thereto.

[0052]

[Table 3]

[0053]

Embedded image

The substituents of the enamine group-containing hydrazone compound represented by the general formula (3) will be described. Ar is p-phenylene, 1,4-naphthylene, 9,1
And an arylene group such as 0-anthralene. R11 is phenyl, p-tolyl, 3,5-xylyl, p-
-Methoxyphenyl, 1-naphthyl, 2-naphthyl, 2
Aryl groups such as -methyl-1-naphthyl, 2-furyl,
A heterocyclic group such as 3-furyl, 2-thienyl, 3-thienyl, 2-pyridyl, 5-methyl-2-furyl, benzyl,
p-methoxybenzyl, p-methylbenzyl, 3,5-
Aralkyl groups such as dimethylbenzyl, methyl, ethyl,
n-propyl, iso-propyl, n-butyl, sec
An alkyl group such as -butyl, and a hydrogen atom;
R12 and R13 are each an aryl group such as phenyl, p-tolyl, 3,5-xylyl, p-methoxyphenyl, 1-naphthyl, 2-naphthyl, 2-methyl-1-naphthyl, 2-furyl, Frill, 2-thienyl,
Heterocyclic groups such as 2-pyridyl and 5-methyl-2-furyl;
Aralkyl groups such as benzyl, p-methoxybenzyl, p-methylbenzyl and 3,5-dimethylbenzyl; and alkyl groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl and sec-butyl. .

A represents methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl,
alkyl groups such as n-pentyl, methoxy, ethoxy, n
-Alkoxy groups such as -propyloxy and iso-propyloxy; dialkylamino groups such as dimethylamino, diethylamino, di-n-propylamino and diiso-propylamino; halogen atoms and hydrogen atoms such as fluorine, chlorine and bromine; .

Next, specific examples of the charge transporting material represented by the general formula (3) are shown in Table 4, but the present invention is not limited thereto.

[0057]

[Table 4]

[0058]

Embedded image

[0059]

Embedded image

The enamine group-containing compounds represented by the general formulas (4) and (5) will be described below. D is p-phenylene, m-phenylene, o-methyl-p
Arylene groups such as N-ethyl-2,7-carbazolylene; arylene groups such as ethylene and 1,2-dichloroethylene; and arylene groups such as ethylene and 1,2-dichloroethylene. As phenyl, p-tolyl, m-tolyl, p-methoxyphenyl,
Aryl groups such as 1-naphthyl, benzyl, methylbenzyl, aralkyl groups such as methoxybenzyl and methyl,
Alkyl group such as ethyl, 2-pyridyl, N-ethyl-3
-Heterocyclic groups such as carbazole, 2-furyl, 5-methyl-2-furyl and 2-thienyl; and b represents an alkyl group such as methyl, ethyl, n-propyl, iso-propyl, methoxy, ethoxy, etc. And dialkylamino groups such as dimethylamino and diethylamino, halogen atoms such as fluorine and chlorine, and hydrogen atoms.

R15 in the general formula (4) is phenyl, p-tolyl, p-methoxyphenyl,
-Aryl group such as naphthyl, 2-furyl, 5-methyl-
Examples include a heterocyclic group such as 2-furyl and 2-thienyl, an aralkyl group such as benzyl, methylbenzyl and methoxybenzyl, and an alkyl group such as methyl and ethyl.

Next, specific examples of the charge transporting materials represented by the general formulas (4) and (5) are shown in Tables 5 and 6, respectively, but the present invention is not limited thereto.

[0063]

[Table 5]

[0064]

[Table 6]

These general formulas (2), (3), (4),
Among the exemplary compounds represented by (5), particularly, electrophotographic properties,
In terms of cost and synthesis, one of R9 and R10 has a phenyl group, a p-methoxyphenyl group, or a p-methoxyphenyl group.
A tolyl group, one of which is a hydrogen atom;
13 is a phenyl group, a p-tolyl group, one is a methyl group, an ethyl group, a phenyl group,
Compounds in which both R14 and R15 are phenyl groups are exemplified.

The electrophotographic photoreceptor according to the present invention is obtained by containing one or more of the above-described charge transport materials, and as a result, has extremely high performance.

Various methods are conceivable for using such a polycarbonate resin and a charge transport material having both terminal groups modified as an electrophotographic photosensitive member. For example, a charge-transporting material and a sensitizing dye may be added, if necessary, with a chemical sensitizer or an electron-withdrawing compound to dissolve or disperse in the both-end-group-modified polycarbonate resin of the present invention. In the form of a photoreceptor provided on a body, or a laminated structure composed of a charge generation layer and a charge transport layer having high charge generation efficiency, a sensitizing dye or an azo pigment or a phthalocyanine pigment is typically represented on a conductive support. The charge transporting material of the present invention is required on the charge generating layer provided mainly with a pigment to be added, and an antioxidant compound or an electron withdrawing compound is added to the polycarbonate resin in which both terminal groups of the present invention are modified. There is a laminated photoreceptor which is dissolved or dispersed and provided as a charge transport layer, but any of these cases can be applied.

In order to easily form the polycarbonate resin of the present invention represented by the general formula (1) having both terminal groups modified by wet forming which is mainly used for the production of a photoreceptor, it is necessary to form the polycarbonate resin. It is desirable that the intrinsic viscosity is in the range of 0.1 to 2.0 dl / g. In order to obtain this intrinsic viscosity range, it is desirable that the polymerization degree n is 10 to 200.

The charge transporting material of the present invention is used in an amount of from 30 to 200 parts by weight based on 100 parts by weight of a binder resin mainly composed of a polycarbonate resin modified at both ends represented by the general formula (1). And more preferably in the range of 40 to 150 parts by weight. If the amount of the charge transporting material of the present invention is less than this range, the electrophotographic properties, particularly the decrease in photosensitivity and the accumulation of the residual potential will increase. Adverse effects such as image defects are likely to occur.

When a photoreceptor is prepared using the polycarbonate resin having both terminal groups modified according to the present invention and the charge transporting material according to the present invention, a conductive material such as a metal drum, a metal plate, a conductively processed paper, or a plastic film may be used. A photosensitive layer can be formed by coating on a photosensitive support. As a method of applying the coating solution for the charge transport layer, a spray method,
A bar coating method, a roll coating method, a blade method, a ring method, an immersion method and the like can be mentioned. In particular, the dip coating method is a method in which a photosensitive layer is formed by immersing a conductive support in a coating tank filled with a photoreceptor coating solution and then pulling the conductive support at a constant speed or a sequentially changing speed. And is excellent in productivity and cost. In this case, the coating property in the production of the photosensitive layer is largely controlled by the viscosity of the coating solution for the charge transport layer, and is 50 to 100 cps (20 ° C., solid content of 10 to 100 cps) which is suitable for forming a uniform film. (20% by weight), it is desirable that the concentration of the polycarbonate resin is 9% by weight or more and 13% by weight or less. Thus, the thickness of the charge transport layer is from 10 μm to 60 μm.
It is made with a thickness of μm, preferably 10 μm to 35 μm. If the thickness of the charge transport layer is smaller than this range, the electrophotographic properties, particularly the chargeability, will be reduced. If it is larger than this range, the adverse effect of increasing the accumulation of the residual potential tends to occur.

Next, sensitizing dyes added to the photosensitive layer include methyl violet, crystal violet,
Triphenylmethane dyes such as night blue and Victoria blue, erythrosine, rhodamine B, rhodamine 3R, acridine dyes such as acridine orange and flapeosin, thiazine dyes such as methylene blue and methylene green, and capri Blue, oxazine dyes represented by Meldora Blue, etc., other cyanine dyes, styryl dyes, pyrylium salt dyes,
And thiopyrylium salt dyes.

Further, in the photosensitive layer, various metal phthalocyanines, non-metal phthalocyanines, and non-metal phthalocyanines are used as photoconductive materials for generating electric charges with extremely high efficiency by light absorption.
Examples include phthalocyanine pigments such as halogenated metal-free phthalocyanine, perylene acid pigments such as perylene imide and perylene anhydride, azo pigments such as bisazo pigments and trisazo pigments, quinacridone pigments, and anthraquinone pigments. In particular, those using a metal-free phthalocyanine pigment, a titanyl phthalocyanine pigment, a fluorene, a bisazo pigment containing a fluorenone ring, a bisazo pigment composed of an aromatic amine, or a trisazo pigment as a pigment that generates electric charge exhibit excellent sensitivity. Give body.

The above-mentioned dye may be used as the charge generating material. These dyes may be used alone,
In many cases, electric charges are generated with higher efficiency by coexisting pigments.

Apart from the sensitizers mentioned above, it is necessary to add various chemical substances for the purpose of preventing an increase in the residual potential, a decrease in the charged potential, a decrease in the sensitivity and the like upon repeated use. It becomes. These added substances include 1-chloroanthraquinone, benzoquinone, 2, 3
-Dichloronaphthoquinone, naphthoquinone, 4,4'-dinitrobenzophenone, 4,4'-dichlorobenzophenone, 4-nitrobenzophenone, 4-nitrobenzalmalone dinitrile, α-cyano-β- (p-cyanophenyl) acrylic acid Ethyl, 9-anthracenylmethylmalondinitrile, 1-cyano-1- (p-nitrophenyl) -2- (p-chlorophenyl) ethylene, 2,7-
Electron-withdrawing compounds such as dinitrile fluorenone; In addition, an antioxidant, an anti-curl agent, a leveling agent, and the like can be added as necessary to the photoreceptor.

As coating materials, benzene, toluene,
Aromatic hydrocarbons such as xylene and monochlorobenzene, halogenated hydrocarbons such as dichloromethane and dichloroethane, solvents such as dioxane, dimethoxymethyl ether and dimethylformamide, alone or in combination of two or more, or, if necessary, alcohols And a solvent such as acetonitrile and methyl ethyl ketone.

The electrophotographic photoreceptor of the present invention has the general formula (2):
The charge transport materials shown in (3), (4), and (5) are used as charge transfer materials, and various modes are conceivable in this embodiment. The structure of the photoreceptor is schematically shown in FIGS.

FIG. 1 shows a charge generation layer 5 having a charge generation material 2 as a main component and dispersed in a binder, and a charge transport material 3 as a main component on a conductive support 1 as a photosensitive layer. This is a function-separated type photoreceptor comprising a laminate with a charge transport layer 6 dispersed in a photoreceptor, and shows the configuration of a photoreceptor using the charge transport material of the present invention as the charge transport material 3 in the charge transport layer 6. Things.

FIG. 2 shows the photosensitive layer 4 on the conductive support 1.
The symbol 'indicates the structure of a photoconductor composed of a single layer in which the charge generation material 2 and the charge transport material 3 are dispersed in a binder.

FIG. 3 shows a structure in which an intermediate layer 7 is provided between the conductive support 1 and the same photosensitive layer 4 as in FIG. It is.

FIG. 4 shows a single-layer photosensitive member in which an intermediate layer 7 is provided between the conductive support 1 and the same photosensitive layer 4 'as in FIG.

[0081]

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

(Example 1)

[0083]

Embedded image

An X-type metal-free phthalocyanine represented by the above structural formula (7) (manufactured by Dainippon Ink Co., Ltd.)
Fastogen Blue 8120) and 0.3 parts by weight of a vinyl chloride-vinyl acetate copolymer (manufactured by Sekisui Chemical Co., Ltd .; Eslec M) are added to 30 parts by weight of ethyl acetate, and a paint conditioner (manufactured by Red Level) is added. ) Was dispersed for about 2 hours together with glass beads having a diameter of 1.5 mm to prepare a charge generating material solution. Next, the dispersion liquid was applied by a doctor blade method using an aluminum-evaporated polyester film as a conductive support, and dried to form a charge generation layer. The film thickness after drying was 0.4 μm.

The charge transporting material No. of the present invention was placed on the charge generating layer. 2-3, 1 part by weight, and a polycarbonate resin 1-1 having both terminal groups modified according to the present invention as a binder resin
(Viscosity average molecular weight: about 40,000) A coating liquid for a charge transport layer, prepared by dissolving 1.2 parts by weight in methylene chloride to 15% by weight, was applied by a squeezing doctor method, and the dry film thickness was 25 μm
m of the charge transport layer was prepared. As described above, a function-separated laminated photoconductor sample 1 composed of the charge generation layer and the charge transport layer was obtained.

(Examples 2 to 10) The charge transporting materials of the present invention were used as the charge transporting materials No. 2-5, No. 2-9 and No.
4, No3-7, No3-9, No4-3, No4-
No. 6, No. 5-2, and No. 5-6, and in the same manner as in Example 1 to obtain function-separated-type laminated photoreceptors 2 to 10.

(Comparative Example 1) A commercially available bisphenol A type polycarbonate resin (Mo
Trademark from Bas Chemical Co; Madro
lon 5705) was obtained in the same manner as in Example 1 to obtain a function-separated laminated photoreceptor comparative sample 1.

(Comparative Example 2) A comparative sample of a function-separated type photoreceptor in the same manner as in Example 1 except that the binder of the charge transporting material was replaced with a commercially available bisphenol A-type polycarbonate resin (trade name of Sumitomo Dow Chemical; Caliber 300). 2 was obtained.

(Comparative Example 3)

[0090]

Embedded image

A function-separated laminated photoreceptor comparative sample 3 was obtained in the same manner as in Example 1 except that the charge transporting material was changed to the compound represented by the structural formula (8).

The thus-prepared function-separated type photoreceptor was manufactured by using an electrostatic recording paper test apparatus (manufactured by Kawaguchi Electric; SP-42).
8) The electrophotographic characteristics were evaluated. The measurement conditions were: applied voltage: -6 kV, static: No. 3 and white light irradiation (irradiation light: 5 lux) from -700 V to -100 V
Exposure E100 (Look-Sec) Required for Attenuation
And the initial potential V0 (-volt) was measured. Using the same apparatus, the same operation was performed 10,000 times with one cycle of charge-discharge (discharge light: irradiation with white light at 40 lux for 1 second), and the initial potential V0 (-volt) and E100 were obtained.
(Look second) was measured to examine changes in V0 and E100. In addition, a laser printer manufactured by Sharp (WD)
-580P), the photoreceptor was stuck to the drum portion, and continuous blank copy (Non Copy Aging) was performed 10,000 times, and then the degree of initial potential drop and sensitivity drop was examined.

Further, the wear resistance of the photoreceptor film thickness was evaluated using a wear tester manufactured by Suga Test Instruments Co., Ltd. The measurement conditions were as follows: abrasive = aluminum oxide # 2000, load = 200 g
f, the number of times of friction = 10000 times.

Table 7 shows the above measurement results.

[0095]

[Table 7]

(Embodiment 11)

[0097]

Embedded image

2 parts by weight of the charge generating material represented by the above structural formula (9), 1 part by weight of an epoxy resin (manufactured by Nippon Rika Co., Ltd .; Rica Resin BPO-20E), and 97 parts by weight of dimethoxyethane were dispersed for 6 hours using a paint shaker. The tank was filled with the coating solution prepared as described above, an aluminum cylindrical support (aluminum drum) having a diameter of 80 mm and a length of 348 mm was immersed, pulled up, dried at room temperature for 1 hour, and charged at a thickness of 0.2 μm. A generating layer was formed.

On the other hand, as a charge transport material, No. 1 of the present invention was used.
Polycarbonate resin No. 2-3 having both terminal groups modified according to the present invention using 100 parts by weight of 2-3 as a binder resin. 1-
100 parts by weight of 1 (viscosity average molecular weight = 40,000) was dissolved in 800 parts by weight of dichloromethane to prepare a coating solution for a charge transporting layer, and dip-coated on the charge generating layer formed above, followed by drying at 80 ° C. for 1 hour. Then, a charge transport layer having a thickness of 25 μm was formed to prepare a photosensitive drum. The sample thus produced was a uniform coating film. The photosensitive drum sample was mounted on a commercially available copying machine (SF8870, manufactured by Sharp Corporation), and a copying test was performed using A4 size paper. Initial and 40
After 000 uses, the image characteristics, the charged potential (V0), the potential (VL) and the residual potential (Vr) of the white original were measured.
Sufficient image characteristics were obtained both at the beginning and after repeated use, and almost no sensitivity deterioration due to a decrease in film thickness due to abrasion was observed.

Example 12 As a binder resin, polycarbonate resin No. 1 having both terminal groups modified according to the present invention was used.
A photoconductor drum sample was prepared and evaluated in the same manner as in Example 11 except that 1-2 (viscosity average molecular weight = 40,000) was used.

(Examples 13 to 16) The charge transporting material of the present invention was the same as the charge transporting material No. 2-9, no. 3-7, N
o. 4-3, no. A photoconductor drum sample was prepared and evaluated in the same manner as in Example 11 except that 5-2 was used.

Comparative Example 4 Example 11 was repeated except that the dichloromethane used for the coating solution for the charge transport layer was changed to 500 parts by weight.
A photosensitive drum sample was prepared and evaluated in the same manner as described above. The coating liquid had a very high viscosity and could not have a uniform film thickness, and the image had uneven density throughout.

Comparative Example 5 Example 1 was repeated except that the dichloromethane used in the coating solution for the charge transport layer was changed to 1100 parts by weight.
In the same manner as in Example 1, a photoreceptor drum sample was prepared and evaluated. The coating liquid had a very low viscosity and could not have a uniform film thickness, and only a charge transport layer having a film thickness of 10 μm was obtained.

Table 8 summarizes the above measurement results.

[0105]

[Table 8]

As can be seen from Tables 7 and 8, the electrophotographic photoreceptor of the present invention shows favorable values in the change in potential of the photoreceptor after aging and the amount of wear.

[0107]

The electrophotographic photoreceptor of the present invention has extremely good electrophotographic properties, has a uniform coating film, and has excellent durability against a cleaning blade, a developer, paper, etc., and can be used continuously. The electrophotographic properties are not changed even when the above method is performed, and the printing durability is more excellent as compared with the conventional one.

Further, according to the method for producing an electrophotographic photoreceptor of the present invention, since the coating solution has a viscosity suitable for the dip coating method, an electrophotographic photoreceptor having a uniform film thickness and having no coating film defects is produced. It is possible to do.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a layer configuration of a function-separated type photoconductor of the present invention.

FIG. 2 is a cross-sectional view schematically illustrating a layer configuration of a single-layer type photoconductor of the present invention.

FIG. 3 is a cross-sectional view schematically illustrating another layer configuration of the function-separated type photoconductor of the present invention.

FIG. 4 is a cross-sectional view schematically illustrating another layer configuration of the single-layer type photoconductor of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive support 2 charge generating material 3 charge transporting material 4, 4 ′ photosensitive layer 5 charge generating layer 6 charge transporting layer 7 intermediate layer

Claims (14)

[Claims] 1. A photosensitive layer formed on a conductive support contains a polycarbonate resin having a terminal group modified by the following general formula (1) and represented by the following general formula (2). An electrophotographic photoreceptor characterized in that it contains a compound. Embedded image (Wherein, R1 to R8 each may have an alkyl group having 1 to 5 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, X represents an aralkyl group having 7 to 17 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom or a hydrogen atom, and X is directly bonded or has a substituent. An alkylene group having 1 to 10 carbon atoms which may optionally have 1 to 10 carbon atoms which may have a substituent;
A cyclic alkylidene group having 6 carbon atoms which may have a substituent
To 12 represent an arylene group, a sulfonyl group, or a carbonyl group, and Z represents an alkylene group having 1 to 5 carbon atoms which may have a substituent, an arylene group having 6 to 12 carbon atoms, and an arylene having 7 to 17 carbon atoms. Represents an alkyl group or a halogen atom,
Y represents an alkyl group having 1 to 5 carbon atoms which may have a substituent, an alkenyl group having 2 to 5 carbon atoms which may have a substituent, an alkoxy group having 1 to 5 carbon atoms, and a substituent An alkyl ester group having 1 to 5 carbon atoms, an aryl ester group having 6 to 12 carbon atoms which may have a substituent, a carboxyl group, an aldehyde group, a hydroxyl group, a halogen atom or a hydrogen atom. n represents an integer of 10 to 200. ) (Wherein, Ar represents a C 6 to C 12 which may have a substituent)
R9 and R10 are an aryl group having 6 to 12 carbon atoms which may have a substituent, a heterocyclic group having 5 to 11 carbon atoms which may have a substituent, and a substituent, respectively. It represents an aralkyl group having 7 to 17 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or a hydrogen atom which may be possessed. However, R9 and R10 exclude a hydrogen atom at the same time. a represents 1 carbon atom
An alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms,
A dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and p represents an integer of 1 to 4. However, when p is 2 or more, a may be the same or different. q represents an integer of 2 to 4. ) 2. The photosensitive layer formed on a conductive support contains a polycarbonate resin having a terminal group modified by the general formula (1), and is represented by the following general formula (3). An electrophotographic photoreceptor characterized in that it contains a compound. Embedded image (Wherein, Ar represents a C 6 to C 12 which may have a substituent)
R11 is an aryl group having 6 to 12 carbon atoms which may have a substituent, a heterocyclic group having 5 to 11 carbon atoms which may have a substituent, And R12 and R13 are an aryl group having 6 to 12 carbon atoms and a substituent, each of which may have a substituent, each of which is an aralkyl group having 7 to 17 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. A heterocyclic group having 5 to 11 carbon atoms which may have a substituent, an aralkyl group having 7 to 17 carbon atoms which may have a substituent, an alkyl group having 1 to 5 carbon atoms, or R12 and R13 are bonded to each other. To form a fused heterocycle.
a is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms,
Is a halogen atom or a hydrogen atom, and p represents an integer of 1 to 4. However, when p is 2 or more, a may be the same or different. q represents an integer of 2 to 4. ) 3. The photosensitive layer formed on a conductive support contains a polycarbonate resin having a terminal group modified by the general formula (1) and is represented by the following general formula (4). An electrophotographic photoreceptor characterized in that it contains a compound. Embedded image (Wherein D is an arylene group having 6 to 12 carbon atoms which may have a substituent, a divalent heterocyclic group which may have a substituent, and a carbon atom having 1 to 1 carbon atoms which may have a substituent. 10 is an alkylene group, and R14 and R15 are an aryl group having 6 to 12 carbon atoms which may have a substituent, a heterocyclic group having 5 to 11 carbon atoms which may have a substituent, and a substituent. An aralkyl group having 7 to 17 carbon atoms, an alkyl group having 1 to 5 carbon atoms, and b is an alkyl group having 1 to 5 carbon atoms;
It is an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and r represents an integer of 1 to 5. However, when r is 2 or more,
b may be the same or different, and may combine with each other to form a heterocyclic ring. ) 4. A photosensitive layer formed on a conductive support contains a polycarbonate resin having a terminal group represented by the general formula (1) modified, and is represented by the following general formula (5). An electrophotographic photoreceptor characterized in that it contains a compound. Embedded image (Wherein D is an arylene group having 6 to 12 carbon atoms which may have a substituent, a divalent heterocyclic group which may have a substituent, and a carbon atom having 1 to 1 carbon atoms which may have a substituent. 10 is an alkylene group, and R14 has 6 to 1 carbon atoms which may have a substituent.
Aryl group having 2 to 5 carbon atoms which may have a substituent
1 heterocyclic group, 7 to 17 carbon atoms which may have a substituent
An aralkyl group, an alkyl group having 1 to 5 carbon atoms, and b is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or Is a hydrogen atom, q is an integer of 2 to 4, and r is an integer of 1 to 5. However, when r is 2 or more, b may be the same or different, and may be combined with each other to form a heterocyclic ring. ) 5. X in the general formula (1) is a cyclic alkylidene group having 1 to 10 carbon atoms which may have a substituent, and
5 is a phenylene group, and Y is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms which may have a substituent. body. 6. In the general formula (1), X is directly bonded, Z is a phenylene group, and Y is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms which may have a substituent. The electrophotographic photoreceptor according to any one of claims 1, 2, 3, and 4. 7. In the general formula (1), X is an aryl group having 6 to 12 carbon atoms which may have a substituent, Z is a phenylene group, and Y has a hydrogen atom or a substituent. 5. The electrophotographic photoreceptor according to claim 1, wherein the photoreceptor is an alkyl group having 1 to 5 carbon atoms. 8. In the general formula (1), X is a sulfonyl group or a carbonyl group, Z is a phenylene group, and Y is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms which may have a substituent. Claims 1, 2, 3,
4. The electrophotographic photoreceptor according to any one of 4. 9. Z in the general formula (1) is an alkylene group which may have a substituent and has 5 to 10 carbon atoms, and Y is an alkyl ester which may have a substituent and has 1 to 5 carbon atoms. The electrophotographic photoreceptor according to any one of claims 1, 2, 3, and 4, wherein the photoreceptor is a C6 to C12 aryl ester group or a hydrogen atom which may have a group or a substituent. 10. The electrophotographic photosensitive member according to claim 1, wherein the structural unit of the general formula (1) is 1,1-bis (4-hydroxyphenyl) cyclohexanone. . 11. The method according to claim 1, wherein the structural unit of the general formula (1) is 1,1-bis (4-hydroxyphenyl-3-methylphenyl) cyclohexanone.
3. The electrophotographic photosensitive member according to any one of items 3 and 4. 12. The method according to claim 1, wherein the structural unit of the general formula (1) is 1,1-bis (4-hydroxyphenyl-3,5-dimethylphenyl) cyclohexanone. Or the electrophotographic photoreceptor of the above. 13. The electrophotographic photoreceptor according to claim 1, wherein the intrinsic viscosity of the terminal modified polycarbonate resin is from 0.30 to 2.0 dl / g. . 14. A method for producing an electrophotographic photosensitive member in which a photosensitive layer is immersed and coated on a cylindrical conductive support, wherein the concentration of the terminal group-modified polycarbonate resin in the coating solution is 9% by weight or more. The method for producing an electrophotographic photoreceptor according to any one of claims 1, 2, 3, and 4, wherein the content is not more than% by weight.