JPH05222181A - Polycarbonate copolymer, its production, and electrophotographic photoreceptor made by using - Google Patents

Abstract

PURPOSE:To obtain the title copolymer improved in mechanical strength and electrophotographic characteristics by reacting two specified dihydric phenols with a compound capable of forming a carbonic ester. CONSTITUTION:A dihydric phenol of formula I (wherein X is of any one of formulas II to V; R<1> and R<2> are each halogen, 1-6C alkyl or 6-12C aryl; R<3> and R<4> are each R<1>, 1-6C alkoxy, cyano or nitro; a, b and d are each 0 to 4; and c is 0 to 2) is reacted with a dihydric phenol of formula VI (wherein R<5> is R<1> or 5-7C cycloalkyl; e and f are each a; Y is -CR<7>R<8>-, 5-11C 1,1- cycloalkylene, 2-10C alpha,omega-alkylene, a single bond, -O-, -S-, -SO- or-SO2-; and R<7> and R<8> are each H, trifluoromethyl, 1-6C alkyl or 1-12C aryl) and a compound capable of forming a carbonic ester to give a polycarbonate copolymer which consists of repeating units of formula VII and those of formula VIII, with a molar ratio of the former units to the total of the former and latter units being 0.01 to 0.9, and has a reduced viscosity (0.5g/dl methylene chloride, 20 deg.C) of 0.3dl/g or higher.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel polycarbonate copolymer, a method for producing the same, and an electrophotographic photoreceptor using the same. More specifically, the present invention relates to an electrophotographic photosensitive member which maintains excellent mechanical strength and electrophotographic characteristics for a long time and can be suitably used in various electrophotographic fields.

[0002]

2. Description of the Related Art Polycarbonate is used as a raw material in various fields, and it is desired to develop one having higher performance as the fields of application are expanded.

In recent electrophotographic photosensitive members, a laminated electrophotographic photosensitive member, that is, a photosensitive layer is composed of a charge generating layer (CGL) for generating charges upon exposure and a charge transporting layer (CTL) for transferring charges. A laminated organic electrophotographic photoreceptor (OPC) having at least two layers, and a single-layer type electrophotographic photoreceptor having a photosensitive layer composed of a single layer in which a charge generating substance and a charge transporting substance are dispersed in a binder resin. Is being used. As the binder resin for the charge transport layer of the laminated electrophotographic photoreceptor and the photosensitive layer of the single-layer electrophotographic photoreceptor,
In both cases, polycarbonate resins made from bisphenol A are widely used.

Polycarbonate resin using bisphenol A as a raw material has good compatibility with a charge transporting substance, so that when it is used as a binder resin in a photoreceptor having a photosensitive layer, it has good electrical characteristics, and is relatively good. It has the feature of high mechanical strength.

However, it has been clarified that the following problems occur when the photosensitive layer is formed by using a polycarbonate resin containing bisphenol A as a binder resin. When a photosensitive layer is applied during preparation of a photoreceptor, the coating liquid may be whitened (gelled) or the photosensitive layer may be easily crystallized depending on the solvent used. In the part where this crystallization has occurred, there is no light attenuation, the electric charge remains as a residual potential, and it appears as a defect in terms of image quality. In the case of ordinary negative-charge type electrophotographic photoreceptors, the photosensitive layer using a polycarbonate resin made of bisphenol A as a raw material has poor adhesion to the base and is easily peeled off, scratched due to insufficient surface hardness, and the surface is abraded. Therefore, there is a drawback that the printing life is shortened. In general, the term "base" refers to a charge generation layer in a laminated photoreceptor and a conductive substrate in a single-layer photoreceptor and a reverse-layer photoreceptor.

[0006]

The present invention has been made based on the above circumstances. An object of the present invention is to solve the above problems found in a conventional electrophotographic photoreceptor using a polycarbonate resin made of bisphenol A as a binder resin for a photosensitive layer, and to provide a coating liquid when preparing an electrophotographic photoreceptor. Does not whiten (gelate),
Another object of the present invention is to provide an electrophotographic photosensitive member which is excellent in practical use and can maintain excellent mechanical strength such as printing durability for a long period of time and maintain excellent electrophotographic characteristics.

The present invention also provides a novel polycarbonate copolymer having a new chemical structure, which is preferably used as a binder resin for the above electrophotographic photoreceptor and also used for EL materials and the like, and which is also functionally excellent. The manufacturing method is provided.

[0008]

As a result of intensive studies to solve the above problems, the present inventors have found that an electrophotographic photoreceptor using a polycarbonate copolymer having a specific structure as a binder resin for a photosensitive layer. However, there is no problem as described above that is observed in a conventional electrophotographic photoreceptor using a polycarbonate resin using bisphenol A as a raw material as a binder resin, and the coating liquid is whitened (gelled) during the production of the photoreceptor. Based on this finding, the present invention has been completed based on the finding that the excellent mechanical strength can be maintained over a long period of use and excellent electrophotographic characteristics can be maintained.

That is, the present invention has the following general formula

[0010]

[Chemical 6] [Wherein X is

[0011]

[Chemical 7]

(However, R ¹ and R ² are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 6 to 12 carbon atoms.
R ³ and R ⁴ are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, a cyano group or a nitro group. And a, b and d are each independently an integer of 0 to 4, and c is independently an integer of 0 to 2. ). ] The repeating unit represented by

[0013]

[Chemical 8]

[In the formula, R ⁵ and R ⁶ are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms,
e and f are each independently an integer of 0 to 4, and Y is -CR.
⁷ R ⁸ — (wherein R ⁷ and R ⁸ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms), and 5 to 5 carbon atoms. 11
1,1-cycloalkylene group, α having 2 to 10 carbon atoms,
ω-alkylene group, single bond, -O-, -S-, -SO-
Or -SO ₂ - it is. ] The content ratio of the repeating unit represented by the general formula (I) is represented by the repeating unit represented by the general formula (I) and the general formula (I
I) in the range expressed by the following formula: 0.01 ≦ [(I) / {(I) + (II)}] ≦ 0.9 in terms of molar ratio with respect to the total of repeating units, and chloride Provided is a polycarbonate copolymer characterized in that a solution having a concentration of 0.5 g / dl in methylene as a solvent has a reduced viscosity [η _sp / c] at 20 ° C. of 0.3 dl / g or more.

When the content (molar ratio) of the repeating unit represented by the general formula (I) is less than 0.01, the effect of the present invention cannot be obtained, and the coating solution is whitened (gelled) and exposed to light. It becomes impossible to prevent crystallization of the layer or the charge transport layer and to improve the printing life. On the other hand, when this molar ratio exceeds 0.9, crystallization occurs in a part of the polycarbonate copolymer, which makes it unsuitable as a binder resin for an electrophotographic photoreceptor.

The content ratio of the repeating unit represented by the formula (I) is preferably 0.01 to 0.5 in the above molar ratio.

The polycarbonate copolymer used in the present invention may have other repeating units other than the above-mentioned ones within a range not hindering the purpose of the present invention, and other polycarbonate components or additives. It is also possible to appropriately add and blend the substances.

The polycarbonate copolymer used in the present invention has a concentration of 0.5 g / dl in methylene chloride as a solvent.
Solution has a reduced viscosity at 20 ° C. [η _sp / c] of 0.3.
dl / g or more, preferably 0.3 to 2.0 dl / g. When the reduced viscosity [η _sp / c] is less than 0.3 dl / g, the mechanical strength of the polycarbonate copolymer is low,
In particular, the surface hardness of the layer using the polycarbonate copolymer as a binder resin may be insufficient, and the photoreceptor may be worn to shorten the printing life. On the other hand, reduced viscosity [η _sp / c]
Is more than 2.0 dl / g, the solution viscosity of the polycarbonate copolymer may be increased, which may make it difficult to manufacture the photoreceptor by the solution coating method.

The polycarbonate copolymer of the present invention is, for example, a dihydric phenol represented by the following general formula HO-X-OH (III) (wherein X is the same as above) and the following general formula.

[0020]

[Chemical 9] (In the formula, R ⁵ , R ⁶ , e, f and Y are the same as above.) The dihydric phenol can be produced by reacting a carbonic acid ester forming compound.

In this reaction, various carbonic acid ester-forming compounds such as phosgene and various carbonyl dihalogenates, haloformates such as chloroformate compounds, or carbonic acid ester compounds are used in the presence of a suitable acid binder. It is carried out by a polycondensation reaction, or by a transesterification reaction using bisaryl carbonates as carbonic acid ester forming compounds.

Typical examples of the dihydric phenol represented by the general formula (III) include those having the following structures.

[0023]

[Chemical 10]

Among them, 2,3-bis (4-hydroxyphenyl) quinoxaline, 2,3-bis (4-hydroxyphenyl) -6-methylquinoxaline, 2,3-bis (4-hydroxyphenyl) -6, 7-Dimethylquinoxaline, 2,3-bis (4-hydroxyphenyl) pyrazine, 2,3-bis (4-hydroxyphenyl) benzo [g] quinoxaline and 2,3-bis (4-hydroxyphenyl) -7H, 12H. -Naphtho [2,3-f] quinoxaline-7,12-dione is preferably used.

Specific examples of the dihydric phenol represented by the above general formula (IV) include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane and 1,2- Bis (4-hydroxyphenyl)
Ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl)
Octane, 4,4-bis (4-hydroxyphenyl) heptane, 1,1-bis (4-hydroxyphenyl)-
1,1-diphenylmethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) -1-phenylmethane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis ( 3-methyl-4-hydroxyphenyl) propane, 2- (3-methyl-4-hydroxyphenyl) -2- (4-hydroxyphenyl) -1-phenylethane, bis (3-methyl-4-hydroxyphenyl) sulfide , Bis (3-methyl-4-hydroxyphenyl) sulfone, bis (3-
Methyl-4-hydroxyphenyl) methane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 2,2-bis (2-methyl-4-hydroxyphenyl) propane, 1,1-bis (2 -Butyl-4-hydroxy-5-methylphenyl) butane, 1,1-bis (2-tert-butyl-4-hydroxy-3-methylphenyl) ethane, 1,1-bis (2-tert-butyl-4) -Hydroxy-5-methylphenyl) propane,
1,1-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) butane, 1,1-bis (2-t
ert-butyl-4-hydroxy-5-methylphenyl) isobutane, 1,1-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) heptane,
1,1-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) -1-phenylmethane, 1,1
-Bis (2-tert-amyl-4-hydroxy-5-
Methylphenyl) butane, bis (3-chloro-4-hydroxyphenyl) methane, bis (3,5-dibromo-4)
-Hydroxyphenyl) methane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (3-fluoro-4-hydroxyphenyl) propane, 2,2-bis (3-bromo-) 4-hydroxyphenyl) propane, 2,2-bis (3,5-difluoro-4)
-Hydroxyphenyl) propane, 2,2-bis (3,3
5-dichloro-4-hydroxyphenyl) propane,
2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 2,2-bis (3-bromo-4-hydroxy-5-chlorophenyl) propane, 2,2-bis (3,5-dichloro) -4-hydroxyphenyl) butane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) butane, 1-phenyl-1,1-bis (3-
Fluoro-4-hydroxyphenyl) ethane, bis (3
-Fluoro-4-hydroxyphenyl) ether, 1,
1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxy-3,3'-dimethylbiphenyl, 4,4'-dihydroxy-2,2'- Dimethylbiphenyl, 4,4'-dihydroxy-3,3'-dicyclohexylbiphenyl, 3,3'-difluoro-4,
4'-dihydroxybiphenyl etc. are mentioned. These dihydric phenols can be used alone, or
Also, both can be used together.

Particularly preferably, 2,2-bis (4-hydroxyphenyl) propane and 1,1-bis (4-hydroxyphenyl) cyclohexane are used.

The amount of the dihydric phenol represented by the general formulas (III) and (IV) used is the same as that of the dihydric phenol represented by the general formula (III) and the dihydric phenol represented by the general formula (IV). The molar ratio of the dihydric phenol represented by the general formula (III) to the total amount of (III) / {(III) +
It is desirable that (IV)} be within the range of 0.01 to 0.9.

The reaction of polycondensation using the above-mentioned carbonyl dihalide, haloformates, carbonic acid ester compounds and the like as the carbonic acid ester forming compound is generally carried out in a solvent.

The proportion of the carbonic acid ester forming compound used is
It may be appropriately adjusted in consideration of the stoichiometric ratio (equivalent amount) of the reaction. When a gaseous carbonic acid ester-forming compound such as phosgene is used, a method of blowing it into the reaction system can be suitably adopted.

Examples of the acid binder include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide,
An alkali metal carbonate such as sodium carbonate or potassium carbonate, an organic base such as pyridine, or a mixture thereof is used.

The ratio of the acid binder to be used may be appropriately determined in consideration of the stoichiometric ratio (equivalent amount) of the reaction as in the above. Specifically, 2 equivalents or slightly excess amount of the acid binder is used with respect to the total number of moles of the dihydric phenol (III) and the dihydric phenol (IV) used (usually 1 mole corresponds to 2 equivalents). It is preferable to use.

As the solvent, various solvents such as those known in the production of polycarbonate may be used alone or as a mixed solvent. Typical examples include hydrocarbon solvents such as xylene and halogenated hydrocarbon solvents such as methylene chloride and chlorobenzene. The interfacial polycondensation reaction may be carried out using two kinds of solvents that are immiscible with each other.

In order to accelerate the polycondensation reaction, a catalyst such as a tertiary amine such as triethylamine or a quaternary ammonium salt, and to adjust the degree of polymerization,
It is desirable to carry out the reaction by adding a molecular weight modifier such as p-tert-butylphenol or phenylphenol. Further, if desired, a small amount of an antioxidant such as sodium sulfite and hydrosulfide may be added.
The reaction is usually carried out at a temperature in the range of 0 to 150 ° C, preferably 5 to 40 ° C. The reaction pressure may be any of reduced pressure, normal pressure, and increased pressure, but normally, normal pressure or the self-pressure of the reaction system is suitable. The reaction time depends on the reaction temperature and the like, but is usually 0.5 minutes to 10 hours, preferably 1 minute to 2 hours.

Further, first, a part of the reaction raw material composed of the dihydric phenol (III) and the dihydric phenol (IV) is reacted with a carbonate ester-forming compound to form an oligomer, and then the remaining reaction raw materials are added. It is also possible to use a two-step method in which the polycondensation is completed by the reaction. According to such a two-step method, the reaction can be easily controlled, and the molecular weight can be controlled with high accuracy.

Examples of the latter bisaryl carbonate used in the transesterification method between the dihydric phenol (III) and the dihydric phenol (IV) and the bisaryl carbonate include, for example, di-p-tolyl carbonate and phenyl-p-tolyl. Carbonate, di-p-chlorophenyl carbonate, dinaphthyl carbonate and the like can be mentioned. As a reaction mode of this method, a melt polycondensation method, a solid phase polycondensation method, and the like are suitable. When the melt polycondensation method is carried out, the above-mentioned three kinds of monomers are mixed and reacted in a molten state at a high temperature under reduced pressure. The reaction is usually 150-350.
C., preferably at a temperature in the range 200 to 300.degree. When the solid phase polycondensation method is carried out, the above-mentioned three kinds of monomers are mixed, and the polycondensation is carried out by heating to a temperature not higher than the melting point of the produced polycarbonate copolymer in the solid phase state. In any case, at the final stage of the reaction, the degree of pressure reduction is preferably set to 1 mmHg or less, and the phenols derived from the bisaryl carbonate produced by the transesterification reaction are distilled out of the system. Although the reaction time depends on the reaction temperature and the degree of reduced pressure, it is usually about 1 to 4 hours. The reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen or argon, and if desired, the reaction may be carried out by adding the above-mentioned molecular weight modifier or antioxidant.

In order to make the reduced viscosity [η _sp / c] of the obtained polycarbonate copolymer within the above range, for example, various methods such as selection of the above reaction conditions and adjustment of the use amount of the molecular weight modifier can be carried out. You can In addition, in some cases, the obtained polycarbonate copolymer is appropriately subjected to physical treatment (mixing, fractionation, etc.) and / or chemical treatment (polymer reaction, crosslinking treatment, partial decomposition treatment, etc.) to give a predetermined reduced viscosity [ It can also be obtained as a polycarbonate copolymer of [η _sp / c].

The obtained reaction product (crude product) can be recovered as a polycarbonate copolymer having a desired purity (purification degree) by subjecting to various post-treatments such as a known separation and purification method.

When a compound having an asymmetric molecule is used as the above-mentioned dihydric phenol in the production of a polycarbonate copolymer, the orientation of the obtained copolymer may be the same or random depending on the polymerization method. However, the polycarbonate copolymer of the present invention includes those in any orientation state.

The present invention also provides that in an electrophotographic photoreceptor having a photosensitive layer provided on a conductive substrate, the polycarbonate copolymer obtained as described above is used as a binder resin of a charge transport material of the photosensitive layer. The present invention provides a characteristic electrophotographic photoreceptor.

The electrophotographic photoreceptor of the present invention is not limited to various known electrophotographic photoreceptors of various types as long as the above polycarbonate copolymer is used as a binder resin in single-layer type and laminated type photoreceptors. However, it is preferable that the photosensitive layer is used as a binder resin for the charge transporting layer in the laminated electrophotographic photoreceptor having at least one charge generating layer and at least one charge transporting layer.

In the electrophotographic photosensitive member of the present invention, the polycarbonate copolymer of the present invention may be used alone or in combination of two or more kinds. Also,
If desired, other binder resin components such as polycarbonate may be contained within a range not impairing the object of the present invention. Further, additives such as antioxidants may be included.

As the conductive substrate material used in the electrophotographic photosensitive member of the present invention, various materials such as known materials can be used. Specifically, for example, aluminum,
Brass, copper, nickel, steel and other metal plates, drums or metal sheets, aluminum on plastic sheets,
Nickel, chromium, palladium, graphite or other conductive material that has been subjected to a conductive treatment by coating it by vapor deposition, sputtering, coating, or the like, or the surface of a metal drum that has been subjected to metal oxide treatment such as electrode oxidation, or It is possible to use a material such as glass, plastic plate, cloth, paper or the like that has been subjected to a conductive treatment.

The charge generating layer of the laminated electrophotographic photosensitive member contains at least a charge generating substance, and the charge generating layer is formed on the substrate which is the base thereof by a vacuum deposition method, a sputtering method or the like. It can be obtained by forming a layer formed by binding a charge-generating substance using a binder resin on a substrate which is a base or a base thereof. As the method for forming the charge generation layer using the binder resin, various methods such as a known method can be used. Usually, for example, a coating liquid in which the charge generation substance is dispersed or dissolved together with the binder resin in a suitable solvent is used. ,
A method of applying on a substrate which is a predetermined base and drying it is preferably used.

As the charge generating substance, various substances such as known substances can be used. Specifically, for example, selenium simple substance such as amorphous selenium and trigonal selenium, and selenium such as selenium-tellurium. Alloy, selenium compound such as As ₂ Se ₃ or selenium-containing composition, zinc oxide, CdS-
Inorganic materials composed of Group II and Group IV elements such as Se,
Various inorganic materials such as oxide-based semiconductors such as titanium oxide, silicon-based materials such as amorphous silicon, metal or metal-free phthalocyanine, cyanine, anthracene, bisazo compound, pyrene, perylene, pyrylium salt, thiapyrylium salt, polyvinylcarbazole, square Examples thereof include various organic materials such as a lithium pigment.

These may be used alone or in combination of two or more.

The binder resin in the charge generating layer is not particularly limited, and various known resins can be used. Specific examples include polystyrene, polyvinyl chloride, polyvinyl acetate, vinyl chloride-acetic acid. Vinyl copolymer, polyvinyl acetal, alkyd resin, acrylic resin, polyacrylonitrile, polycarbonate,
Thermoplastic resins such as polyamide, polyketone, polyacrylamide, butyral resin and polyester, and thermosetting resins such as polyurethane, epoxy resin and phenol resin can be used.

The polycarbonate copolymer may be used as the binder resin in the charge generation layer.

Next, the charge transport layer can be obtained by forming a layer obtained by binding a charge transport substance with a binder resin on a base substrate.

As the method for forming the charge transport layer, various methods such as a known method can be used. Usually, the charge transport material is dispersed or dissolved in a suitable solvent together with the above polycarbonate copolymer. A method in which a working solution is applied on a substrate serving as a predetermined base and dried is used.

In the charge transport layer, the above polycarbonate copolymers may be used alone or in combination of two or more. Further, another binder resin may be used in combination with the polycarbonate copolymer of the present invention within a range not impairing the object of the present invention.

Examples of the charge-transporting substance that can be used in the present invention include conventionally used electron-transporting substances and hole-transporting substances.

Specific examples of the electron-transporting substance include, for example, chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-.
Fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,7-trinitro-9-dicyanomethylenefluorenone, 2,4,5,7-tetranitroxanthone, 2,4,9-trinitro Thioxanthone or 3,5-dimethyl-3 ', 5'-di-t-butyl-
There are electron withdrawing substances such as diphenoquinone derivatives such as 4,4′-diphenoquinone and polymers obtained by polymerizing these electron withdrawing substances. These may be used alone or in combination of two or more.

As the hole transporting substance, pyrene, N-ethylcarbazole, N-isopropylcarbazole, N
-Methyl-N-phenylhydrazino-3-methylidene-
9-ethylcarbazole, N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N, N
-Diphenylhydrazino-3-methylidene-10-ethylphenothiazine, N, N-diphenylhydrazino-3
-Methylidene-10-ethylphenoxazine, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-N-α
-Naphthyl-N-phenylhydrazone, p-pyrrolidinobenzaldehyde-N, N-diphenylhydrazone,
1,3,3-Trimethylindolenine-ω-aldehyde-N, N-diphenylhydrazone, p-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 1-phenyl-1,2,3,4- Hydrazones such as tetrahydroquinoline-6-carboxaldehyde-1 ′, 1′-diphenylhydrazone, 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1-phenyl-3- ( p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [quinolyl (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [lepidil (2 )]-3- (p-
Diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [6-methoxy-pyridyl (2)]-3- (p-diethylaminostyryl) -5-
(P-Diethylaminophenyl) pyrazoline, 1- [pyridyl (5)]-3- (p-diethylaminophenyl)
Pyrazoline, 1- [pyridyl (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (p
-Diethylaminostyryl) -4-methyl-5- (p-
Diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (α-methyl-p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1-phenyl-3- (p-diethylaminostyryl)- 4-methyl-5- (p-diethylaminophenyl) pyrazoline, 1-phenyl-3- (α-benzyl-
Pyrazolines such as p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline and spiropyrazoline, 2- (p-diethylaminostyryl) -δ-
Oxazole compounds such as diethylaminobenzoxazole, 2- (p-diethylaminophenyl) -4- (p-dimethylaminophenyl) -5- (2-chlorophenyl) oxazole, 2- (p-diethylaminostyryl) -6-diethylaminobenzo Thiazole-based compounds such as thiazole, triarylmethane-based compounds such as bis (4-diethylamino-2-methylphenyl) -phenylmethane, 1,1-bis (4-N, N-diethylamino-)
Polyarylamines such as 2-methylphenyl) heptane and 1,1,2,2-tetrakis (4-N, N-dimethylamino-2-methylphenyl) ethane, N, N′-diphenyl-N, N ′ -Bis (methylphenyl) benzidine, N, N'-diphenyl-N, N'-bis (ethylphenyl) benzidine, N, N'-diphenyl-N, N '
-Bis (propylphenyl) benzidine, N, N'-diphenyl-N, N'-bis (butylphenyl) benzidine, N, N'-diphenyl-N, N'-bis (isopropylphenyl) benzidine, N, N ' -Diphenyl-
N, N'-bis (t-butylphenyl) benzidine,
N, N'-diphenyl-N, N'-bis (t-butylphenyl) benzidine, N, N'-diphenyl-N, N '
Benzidine compounds such as bis (chlorophenyl) benzidine, butadiene compounds, triphenylamine, poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine,
Examples thereof include poly-9-vinylphenylanthracene, organic polysilane, pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin and the like.

These may be used alone or in combination of two or more.

Specific examples of the solvent used for forming the charge generation layer and the charge transport layer include benzene and
Aromatic solvents such as toluene, xylene, chlorobenzene, ketones such as acetone, methyl ethyl ketone, cyclohexanone, alcohols such as methanol, ethanol, isopropanol, esters such as ethyl acetate, ethyl cellosolve, carbon tetrachloride, chloroform, dichloromethane, tetrachloroethane, etc. Examples thereof include halogenated hydrocarbons, ethers such as tetrahydrofuran and dioxane, dimethylformamide, dimethylsulfoxide, diethylformamide and the like.

These solvents may be used alone or in combination of two or more.

The coating of each layer can be carried out by using various coating devices such as known ones. Specifically, for example, applicator, spray coater, bar coater, chip coater, roll coater, dip coater, doctor blade, etc. Can be done using.

The photosensitive layer of the single-layer type electrophotographic photosensitive member contains at least the charge generating substance and the charge transporting substance in the polycarbonate copolymer as the binder resin. The method for forming the photosensitive layer is as follows. Although various methods such as known methods can be used, usually, for example, a coating liquid prepared by dispersing or dissolving a charge generating substance and a charge transporting substance together with a binder resin in a suitable solvent,
It is possible to preferably use a method of coating on a substrate that is a predetermined base and drying.

Further, to the extent that the object of the present invention is not impaired,
It is also possible to use other binder resins together with the polycarbonate copolymer of the present invention.

The electrophotographic photosensitive member of the present invention does not cause whitening (gelation) of the coating liquid during its preparation, and has excellent mechanical strength and electrophotographic characteristics even when it is repeatedly used for a long time. It is a remarkably excellent electrophotographic photosensitive member that maintains the above properties, and can be suitably used in various electrophotographic fields.

[0061]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples, and various modifications can be made without departing from the spirit of the present invention. And application is possible.

Example 1 2,2-bis (4-hydroxyphenyl) propane 74
g was dissolved in 550 ml of a 6% strength aqueous sodium hydroxide solution, and 250 ml of methylene chloride was added thereto. While stirring the obtained solution, phosgene gas was blown into the solution for 15 minutes at a rate of 950 ml / min while cooling. Then, the reaction solution is allowed to stand and separate, and the organic phase has a degree of polymerization of 2 to 4
And having a chloroformate group at the terminal of the molecule 2,2
A methylene chloride solution of an oligomer of -bis (4-hydroxyphenyl) propane was obtained.

Using the obtained oligomer solution, a small amount of p-tert-butylphenol was contained as a terminal stopper, and 2,2-bis (4) having a chloroformate group at the molecular end was used.
450 ml of a methylene chloride solution of an oligomer of -hydroxyphenyl) propane was prepared. 2,3-
A solution prepared by dissolving 21 g of bis (4-hydroxyphenyl) quinoxaline in 150 ml of a 2N sodium hydroxide aqueous solution was added and mixed, 5 ml of a 5 wt% concentration triethylamine aqueous solution was further added, and the mixture was vigorously stirred at room temperature for 1 hour. After adding 1 liter of methylene chloride and 1.5 liter of water to the obtained reaction product and stirring, the aqueous phase was separated, and the organic phase was washed once with 0.01N hydrochloric acid and three times with water.
This organic phase was dropped into methanol to obtain 81 g of a polycarbonate copolymer.

The copolymer obtained in this manner was used as a solution of 20 g of a solution containing methylene chloride as a solvent and having a concentration of 0.5 g / dl.
The reduced viscosity [η _sp / c] at 0 ° C was 0.617 dl / g. In addition, ¹ H-NMR spectrum confirmed that this copolymer was composed of the following repeating units.

[0065]

[Chemical 11]

The results of ¹ H-NMR spectrum analysis are shown below. ¹ H-NMR (CD ₂ Cl ₂ ): δ = 1.33 (0.21
H, s), 1.70 (6H, s), 7.1-7.2 (4
H, m), 7.25-7.35 (4.8H, m), 7.
42 (0.05 H, d, J = 9 Hz), 7.61 (0.
75H, d, J = 9 Hz), 7.75-7.85 (0.
38H, m), 8.1-8.2 (0.38H, m) pp
m

Example 2 The same as Example 1 except that 74 g of 2,2-bis (4-hydroxyphenyl) propane used in Example 1 was changed to 87 g of 1,1-bis (4-hydroxyphenyl) cyclohexane. A polycarbonate copolymer ([η _sp /c]=0.623 dl consisting of the following repeating units was operated.
/ G) 79 g was obtained. The structure and composition of this polycarbonate copolymer were also confirmed by ¹ H-NMR spectrum and found to have the following structure and composition.

[0068]

[Chemical 12]

Example 3 An example except that 21 g of 2,3-bis (4-hydroxyphenyl) quinoxaline used in Example 1 was changed to 22 g of 2,3-bis (4-hydroxyphenyl) -6-methylquinoxaline. The same operation as in 1 was carried out, and a polycarbonate copolymer ([η _sp / c] =
81 g (0.633 dl / g) was obtained. The structure and composition of this polycarbonate copolymer were also analyzed by ¹ H-NMR.
As a result of confirmation from the spectrum, it was found to have the following structure and composition.

[0070]

[Chemical 13]

Example 4 21 g of 2,3-bis (4-hydroxyphenyl) quinoxaline used in Example 1 was replaced with 23 g of 2,3-bis (4-hydroxyphenyl) -6,7-dimethylquinoxaline. The same operation as in Example 1 was carried out to give a polycarbonate copolymer ([η _sp
/c]=0.623 dl / g) 82 g was obtained. The structure and composition of this polycarbonate copolymer is ¹ H-
When confirmed from the NMR spectrum, it was found to have the following structure and composition.

[0072]

[Chemical 14]

Example 5 Example 1 was repeated except that 21 g of 2,3-bis (4-hydroxyphenyl) quinoxaline used in Example 1 was changed to 18 g of 2,3-bis (4-hydroxyphenyl) pyrazine.
Carrying out the same operation as above, a polycarbonate copolymer ([η _sp /c]=0.642 dl /
g) 75 g was obtained. The structure and composition of this polycarbonate copolymer were also confirmed by ¹ H-NMR spectrum and found to have the following structure and composition.

[0074]

[Chemical 15]

Example 6 An example except that 21 g of 2,3-bis (4-hydroxyphenyl) quinoxaline used in Example 1 was changed to 25 g of 2,3-bis (4-hydroxyphenyl) benzo [g] quinoxaline. The same operation as in 1 was carried out, and a polycarbonate copolymer ([η _sp / c] =
0.625 dl / g) 86 g was obtained. The structure and composition of this polycarbonate copolymer were also analyzed by ¹ H-NMR.
As a result of confirmation from the spectrum, it was found to have the following structure and composition.

[0076]

[Chemical 16]

Example 7 21 g of 2,3-bis (4-hydroxyphenyl) quinoxaline used in Example 1 was added to 2,3-bis (4-hydroxyphenyl) -7H, 12H-naphtho [2,3-f]. The same operation as in Example 1 was performed except that the amount of quinoxaline-7,12-dione was changed to 30 g, and a polycarbonate copolymer ([η _sp /c]=0.63) composed of the following repeating units was used.
80 g of 0 dl / g) was obtained. The structure and composition of this polycarbonate copolymer were also confirmed by ¹ H-NMR spectrum and found to have the following structure and composition.

[0078]

[Chemical 17]

Example 8 Using the following hydrazone derivative as a charge transport material,
Charge-transporting substance: Polycarbonate copolymer obtained in Example 1: Methylene chloride = 1: 1: 8 (weight ratio) was prepared as a coating solution. The coating liquid did not show cloudiness or gelation even after being left for one month. This coating solution was applied by dip coating onto a charge generation layer of oxotitanium phthalocyanine of about 0.5 μm formed on a conductive substrate made of aluminum, dried and then laminated with a charge transport layer of 20 μm. A type electrophotographic photosensitive member was produced. The charge transport layer did not crystallize during coating.

Charge transport material (1-phenyl-1,2,
3,4-tetrahydroquinoline-6-carboxaldehyde-1 ', 1'-diphenylhydrazone)

[0081]

[Chemical 18]

The electrophotographic characteristics of the obtained electrophotographic photosensitive member were evaluated by using an electrostatic charging tester EPA-8100 (manufactured by Kawaguchi Electric Mfg. Co., Ltd.) to carry out corona discharge of -6 kV to obtain an initial surface potential (V ₀ ), The residual potential (V _R ) after light irradiation (5 sec), and the half-exposure amount (E _1/2 ) were measured. The results are shown in Table 1.

The wear resistance of the charge transport layer was evaluated using a Suga abrasion tester (produced by Suga Test Instruments Co., Ltd.). The test conditions are 1200 samples on worn paper with a load of 200g.
It was reciprocated once and the change in the amount of wear thereafter was measured. The results are shown in Table 2.

Example 9 Using the polycarbonate copolymer obtained in Example 2, a laminated electrophotographic photoreceptor was prepared in the same manner as in Example 1.
The stability of the coating liquid and the evaluation results of crystallization during coating were the same as in Example 1. The evaluation results of electrophotographic characteristics and abrasion resistance are shown in Table 1 and Table 2, respectively.

Example 10 Using the polycarbonate copolymer obtained in Example 3, a laminated electrophotographic photosensitive member was produced in the same manner as in Example 1.
The stability of the coating liquid and the evaluation results of crystallization during coating were the same as in Example 1. The evaluation results of electrophotographic characteristics and abrasion resistance are shown in Table 1 and Table 2, respectively.

Example 11 Using the polycarbonate copolymer obtained in Example 4, a laminated electrophotographic photosensitive member was prepared in the same manner as in Example 1.
The stability of the coating liquid and the evaluation results of crystallization during coating were the same as in Example 1. The evaluation results of electrophotographic characteristics and abrasion resistance are shown in Table 1 and Table 2, respectively.

Example 12 Using the polycarbonate copolymer obtained in Example 5, a laminated electrophotographic photosensitive member was produced in the same manner as in Example 1.
The stability of the coating liquid and the evaluation results of crystallization during coating were the same as in Example 1. The evaluation results of electrophotographic characteristics and abrasion resistance are shown in Table 1 and Table 2, respectively.

Example 13 Using the polycarbonate copolymer obtained in Example 6, a laminated electrophotographic photosensitive member was produced in the same manner as in Example 1.
The stability of the coating liquid and the evaluation results of crystallization during coating were the same as in Example 1. The evaluation results of electrophotographic characteristics and abrasion resistance are shown in Table 1 and Table 2, respectively.

Example 14 Using the polycarbonate copolymer obtained in Example 7, a laminated electrophotographic photosensitive member was prepared in the same manner as in Example 1.
The stability of the coating liquid and the evaluation results of crystallization during coating were the same as in Example 1. The evaluation results of electrophotographic characteristics and abrasion resistance are shown in Table 1 and Table 2, respectively.

Comparative Example 1 Polycarbonate ([η _sp /c]=0.78 dl) composed of the following repeating unit using commercially available 2,2-bis (4-hydroxyphenyl) propane (bisphenol A)
/ G) in the same manner as in Example 1 to produce a laminated electrophotographic photosensitive member. As a result, the coating liquid became cloudy on the second day and gel was generated. In addition, part of the charge transport layer was crystallized (whitened) during coating. The evaluation results of electrophotographic characteristics and abrasion resistance are shown in Tables 1 and 2.

[0091]

[Chemical 19]

Comparative Example 2 74 g of 2,2-bis (4-hydroxyphenyl) propane used in Example 1 was added to 87 g of 1,1-bis (4-hydroxyphenyl) cyclohexane, and 2,3-bis (4-
The same operation as in Example 1 was conducted except that 21 g of hydroxyphenyl) quinoxaline was changed to 35 g of 1,1-bis (4-hydroxyphenyl) cyclohexane, and a polycarbonate ([η _sp / c] = 0.
84 dl / g) was obtained. The structure and composition of this polycarbonate were also confirmed by ¹ H-NMR spectrum and found to have the following structure and composition.

[0093]

[Chemical 20] Using this polycarbonate, a laminated electrophotographic photosensitive member was produced in the same manner as in Example 1. The stability of the coating liquid and the evaluation results of crystallization during coating were the same as in Example 1. The evaluation results of electrophotographic characteristics and abrasion resistance are shown in Table 1 and Table 2, respectively.

[0094]

[Table 1] Electrophotographic characteristics ────────────────────────────────── Initial surface potential V ₀ (V) Residual Potential V _R (V) Half exposure E _1/2 (lux · sec) ───────────────────────────────── --Example 8 -744 -3 0.92 Example 9 -762 -5 0.86 Example 10 -747 -7 0.82 Example 11 -739 -5 0.81 Example 12 -747 -80 .85 Example 13-736-3 0.87 Example 14-739-4 0.86 Comparative Example 1-752-3 0.84 Comparative Example 2-732-4 0.85 ───────── ───────────────────────────

[0095]

[Table 2] Wear characteristics ──────────────────────────── Wear amount (mg) Wear amount (mg) ─────── ───────────────────── Example 8 1.60 Example 13 1.60 Example 9 1.67 Example 14 1.66 Example 10 1. 69 Comparative Example 1 2.28 Example 11 1.63 Comparative Example 2 1.78 Example 12 1.58 ────────────────────────── ───

[0096]

INDUSTRIAL APPLICABILITY According to the present invention, a polycarbonate copolymer having a novel chemical structure having an excellent function is obtained, and the polycarbonate copolymer having this specific structure is used as a binder resin in the photosensitive layer of an electrophotographic photoreceptor. Since the coating liquid does not whiten (gel) during the production of the electrophotographic photoreceptor, the life of the electrophotographic photoreceptor can be extended and the surface hardness of the photoreceptor surface, that is, It is possible to provide an electrophotographic photoreceptor having improved abrasion resistance and excellent printing durability which maintains excellent electrophotographic characteristics even after repeated use for a long time.

Claims (3)

[Claims] 1. The following general formula: [In the formula, X is (However, R ¹ and R ² are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and R ³ and R ⁴ are each independently a halogen atom and 1 carbon atom. To a C6 alkyl group, a C6 to C12 aryl group, a C1 to C6 alkoxyl group, a cyano group or a nitro group, and a, b and d are each independently an integer of 0 to 4,
c is independently an integer of 0-2. ). ] And a repeating unit represented by the following general formula: [Wherein, R ⁵ and R ⁶ are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms, and e and f are Each independently is an integer of 0 to 4, Y is —CR ⁷ R ⁸ — (wherein R ⁷ and R ⁸ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms or a carbon number; 6-12
Is an aryl group. ), A 1,1-cycloalkylene group having 5 to 11 carbon atoms, an α, ω-alkylene group having 2 to 10 carbon atoms, a single bond, —O—, —S—, —SO— or —SO ₂
− ] The content ratio of the repeating unit represented by the general formula (I) is represented by the repeating unit represented by the general formula (I) and the repeating unit represented by the general formula (II). Is in a range represented by the following formula: 0.01 ≦ [(I) / {(I) + (II)}] ≦ 0.9, and 0.5 g / methylene chloride is used as a solvent. A polycarbonate copolymer having a reduced viscosity [η _sp / c] of 0.3 dl / g or more at 20 ° C. in a solution having a dl concentration. 2. The following general formula HO—X—OH (III) [wherein, X is (However, R ¹ and R ² are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and R ³ and R ⁴ are each independently a halogen atom and 1 carbon atom. To a C6 alkyl group, a C6 to C12 aryl group, a C1 to C6 alkoxyl group, a cyano group or a nitro group, and a, b and d are each independently an integer of 0 to 4,
c is independently an integer of 0-2. ). ] A dihydric phenol represented by the following formula and the following general formula: [Wherein, R ⁵ and R ⁶ are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms, and e and f are Each independently is an integer of 0 to 4, Y is —CR ⁷ R ⁸ — (wherein R ⁷ and R ⁸ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms or a carbon number; 6-12
Is an aryl group. ), A 1,1-cycloalkylene group having 5 to 11 carbon atoms, an α, ω-alkylene group having 2 to 10 carbon atoms, a single bond, —O—, —S—, —SO— or —SO ₂
− ] The carbonic acid ester forming compound is made to react with the dihydric phenol represented by these, The manufacturing method of the polycarbonate copolymer of Claim 1 characterized by the above-mentioned. 3. An electrophotographic photoreceptor having a photosensitive layer provided on a conductive substrate, wherein the polycarbonate copolymer according to claim 1 is used as a binder resin for the photosensitive layer. ..