JPH05163339A - Polycarbonate copolymer, its production and electrophotogsphic photorecptor containing same - Google Patents

Abstract

PURPOSE:To obtain the title copolymer which can give a coating fluid of an electrophotographic photoreceptor which does not gel and can keep excellent plate wear, etc., for a long time by reacting two specified bisphenols with a compound forming a carbonic ester. CONSTITUTION:A copolycarbonate comprising repeating units of formulas III and IV and having a content of repeating units of formulas III of 0.01-0.9 by a molar ratio and a reduced viscosity etasp/c of 0.3dl/g or above in a 0.5g/dl concentration in a methylene chloride solvent is obtained by reacting a bisphenol of formula I (wherein R<1>, R<2> and R<3> are each halogen, 1-6C alkyl or 6-12C aryl; n is 1 or 2; and a, b and c are each 0-4) and a bisphenol of formula II [wherein X is -CR<6>R<7>- (wherein R<6> and R<7> are each H, trifluoromethyl, 1-6C alkyl or 6-12C aryl), 5-11C 1,1-cycloalkylene, a single bond, a bivalent group such as O, S, SO or SO2, or the like; R<4> and R<5> are each halogen, 1-6C alkyl, 6-12C aryl or the like; and d and e are each 0-4] with a compound forming a carbonic ester.

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 photoreceptors, a laminated electrophotographic photoreceptor, that is,
The photosensitive layer is a charge generation layer (C
GL) and a charge-transporting layer (CTL) for transporting charges, which is a laminated organic electrophotographic photoreceptor (OP).
C) and a single-layer type electrophotographic photoreceptor in which the photosensitive layer is composed of a single layer in which a charge generating substance and a charge transporting substance are dispersed in a binder resin has been proposed and used. As the binder resin for the charge transport layer of the laminated electrophotographic photoreceptor and the binder resin of the photosensitive layer of the single-layer electrophotographic photoreceptor, both are bisphenol A.
Polycarbonate resin made from is 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 it 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 prepared from 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.

[0005]

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 suitable for EL materials and the like, and which is also excellent in functionality. The manufacturing method is provided.

[0007]

As a result of intensive studies to solve the above problems, the present inventors have found that an electrophotographic photoreceptor using a polycarbonate resin having a specific structure as a binder resin for a photosensitive layer is There is no problem as described above that is observed in a conventional electrophotographic photosensitive member using a polycarbonate resin made of bisphenol A as a binder resin, and the coating liquid is whitened (gelled) when the photosensitive member is manufactured. The present invention has been completed on the basis of this finding, since it was possible to maintain excellent mechanical strength and maintain excellent electrophotographic characteristics over a long period of use.

That is, the present invention has the general formula

[Chemical 5] (In the formula, R ¹ , R ² and R ³ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and n is 1 or 2, a, b and c represents an integer of 0 to 4) and a general formula.

[Chemical 6][In the formula, X is -CR⁶R⁷-(However, R⁶And R⁷Are each
Independently, hydrogen atom, trifluoromethyl group, carbon number 1 ~
An alkyl group having 6 or an aryl group having 6 to 12 carbon atoms
It ), 1,1-cycloalkylene having 5 to 11 carbon atoms
A group, an α, ω-alkylene group having 2 to 10 carbon atoms, a single bond,
-O-, -S-, -SO- or -SO ₂− And R^FourOver
And R^FiveAre each independently a halogen atom or an alkyl group having 1 to 6 carbon atoms.
Alkyl group, cycloalkyl group having 5 to 7 carbon atoms, 6 carbon atoms
To 12 aryl groups, and d and e are 0 to 4 respectively.
Indicates an integer. ] Having a repeating unit represented by the formula
The content of the repeating unit represented by [I] is a copolymer.
The molar ratio is 0.01 to 0.9 with respect to 1, and
Of a solution having a concentration of 0.5 g / dl in methylene chloride
Reduced viscosity [η_sp/ c] is 0.3 dl / g or more
To provide a polycarbonate copolymer characterized by
Is.

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. 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 terms of molar ratio.

The polycarbonate copolymer used in the present invention may have repeating units other than the above-mentioned ones within a range that does not impair the object 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 has, for example, the general formula

[Chemical 7] (Wherein R ¹ , R ² , R ³ , a, b, c and n are the same as above), and a divalent phenol represented by the general formula

[Chemical 8] [In the formula, X, R ⁴ , R ⁵ , d and e are the same as above. It can be produced by reacting a carbonic acid ester forming compound with the dihydric phenol represented by the formula (1).

This reaction is carried out in the presence of a suitable acid binder using various carbonyl dihalogenates such as phosgene, haloformates such as chloroformate compounds, or carbonate compounds as carbonate forming compounds. It is carried out by a condensation reaction or by a transesterification reaction using a bisaryl carbonate as a carbonic acid ester forming compound.

Typical examples of the dihydric phenol represented by the general formula [III] include 4,4 "-dihydroxy-p-terphenyl and 4,4""-dihydroxy-p. -Quotaphenyl and various nuclear substitution products thereof. Examples of the substituent include various substituents as described above, but a halogen atom, a methyl group, a phenyl group and the like are preferable.

Particularly preferably, 4,4 "-dihydroxy-p-terphenyl, 4,4" -dihydroxy-
p-Quaterphenyl is used.

Specific examples of the dihydric phenol represented by the 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 bisphenol compounds may be used alone or in combination of both. Particularly preferably, 2,2-bis (4-hydroxyphenyl) propane and 1,1-bis (4-hydroxyphenyl) cyclohexane are used.

The reaction in which polycondensation is carried out in the presence of an acid binder using the above-mentioned carbonyl dihalide, haloformate, carbonic acid ester compound or the like as the carbonic acid ester forming compound is usually 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 proportion of the acid binder used may be appropriately determined in consideration of the stoichiometric ratio (equivalent weight) of the reaction, similarly to the above.
Specifically, 2 equivalents or slightly excess amount of the acid binder is used with respect to the total number of moles of dihydric phenol [III] and divalent phenol [IV] used (usually 1 mole corresponds to 2 equivalents). It is preferable to use.

As the solvent, various solvents such as those used in the production of known polycarbonates 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.

Further, 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 consisting 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 material is 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. 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.

The reduced viscosity [η _sp / c] of the obtained polycarbonate copolymer can be controlled by various methods such as selection of the reaction conditions and adjustment of the amount of the molecular weight modifier used. 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 resin having a desired purity (purification degree) by subjecting to various post-treatments such as a known separation and purification method.

The present invention also relates to an electrophotographic photoreceptor having a photosensitive layer provided on a conductive substrate, wherein the polycarbonate copolymer obtained as described above is used as a binder resin of a charge transporting substance of the photosensitive layer. The present invention provides a characteristic electrophotographic photoreceptor. The electrophotographic photoreceptor of the present invention is not limited to any of various known electrophotographic photoreceptors of various types as long as the above-mentioned polycarbonate copolymer is used as a binder resin in single-layer type and laminated type photoreceptors. However, the photosensitive layer is preferably used as a binder resin for the charge transport layer in the laminated electrophotographic photosensitive member having at least one charge generation layer and at least one charge transport 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 vacuum deposition, sputtering 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. It should be noted that these may be used alone, or 2
It is also possible to use them in combination, such as by mixing two or more species.

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 a method for forming the charge transport layer, various methods such as a known method can be used. Usually, a coating solution prepared by dispersing or dissolving the charge transport material together with the polycarbonate copolymer in a suitable solvent is used. A method of coating on a substrate that serves as a predetermined base and drying it 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 transport material that can be used in the present invention include conventionally used electron transport materials and hole transport materials. 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-trinitrothioxanthone or 3,5-dimethyl-
There are electron withdrawing substances such as diphenoquinone derivatives such as 3 ′, 5′-di-t-butyl-4,4′-diphenoquinone and polymers obtained by polymerizing these electron withdrawing substances. In addition,
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. It should be noted that these may be used alone, or 2
You may use together, such as mixing 2 or more types.

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 as a mixed solvent.

The coating of each layer can be carried out by using various coating devices such as known ones. Specifically, for example, an applicator, a spray coater, a bar coater, a tip coater, a roll coater, a dip coater, a 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, within the range that does not impair the object of the present invention,
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 after repeated use 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.

[0043]

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 was allowed to stand and separate to obtain a methylene chloride solution of an oligomer of 2,2-bis (4-hydroxyphenyl) propane having a degree of polymerization of 2-4 in the organic phase and having a chloroformate group at the molecular end. It was Using the obtained oligomer solution, a small amount of p-tert-butylphenol was contained as a terminal stopper, and the molecular end had a chloroformate group of 2.
450 ml of a methylene chloride solution of an oligomer of 2-bis (4-hydroxyphenyl) propane was prepared. To this solution was added 4,4 ″ -dihydroxy-p-terphenyl 1
A solution prepared by dissolving 7.6 g 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. To the obtained reaction product, 1 liter of methylene chloride and 1.5 liter of water were added and stirred, then 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 a polycarbonate copolymer.

The copolymer thus obtained is a solution of methylene chloride in a solvent having a concentration of 0.5 g / dl at 20 ° C.
The reduced viscosity [η _sp / c] was 0.679 dl / g. As a result of IR spectrum analysis, 3030 cm ^-1 ,
1590 cm ^-1 and absorption by the benzene ring to 830 cm ^-1, absorption by carbonyl group 1650 cm ^-1, 124
Absorption due to an ether bond was observed at 0 cm ⁻¹ , and it was confirmed to have a carbonate bond.

[0045]

[Chemical 9]

Example 2 The same operation as in 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. And a polycarbonate copolymer ([η _sp /c]=0.676d consisting of the following repeating units:
1 / g) was obtained. When the structure and composition of this polycarbonate copolymer were confirmed by IR spectrum analysis, the same absorption as that of the polycarbonate of Example 1 was observed.

[0047]

[Chemical 10]

Example 3 4,4 ″ -dihydroxy-p-ter used in Example 1
17.6 g of phenyl was added to 4,4 "" dihydroxy-p-
Quarterphenyl (Journal of Chemical Society, 137
9 (1940). ) Changed to 22.6g
The same operation as in Example 1 was repeated except that the following was repeated.
Polycarbonate copolymer ([η_sp/
c] = 0.733 dl / g) was obtained. In addition, this polycarbonate
For carbonate copolymers, ¹Analysis by H-NMR
Then, 1.33 (0.21H, s), 1.70
(6H, s), 7.1-7.2 (4H, m), 7.25
~ 7.35 (4.05H, m), 7.35 (0.6H, m)
d), 7.42 (0.05H, d), 7.64 (0.6
H, d), 7.75 (0.6 H, d), 7.77 (0.
6H, d), all were ppm.

[Chemical 11]

Example 4 Using the following hydrazone derivative as a charge transport material,
A solution of charge transport material: the above-mentioned polycarbonate copolymer: methylene chloride = 1: 1: 8 (weight ratio) was prepared and used as a coating liquid. The coating liquid did not show cloudiness or gelation even after being left for one month. About 0.5 μm of oxotitanium phthalocyanine formed on a conductive substrate made of aluminum
This coating liquid was applied onto the charge generation layer by the dip coating method, dried and provided with a 20 μm charge transport layer to prepare a laminated electrophotographic photoreceptor. The charge transport layer did not crystallize during coating.

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

[Chemical 12]

Electrophotographic characteristics were evaluated by using an electrostatic charging tester EPA-8100 (manufactured by Kawaguchi Electric Co., Ltd.), corona discharge of -6 kV, initial surface potential (V ₀ ) and light irradiation (5 sec). The residual potential (V _R ) and half-exposure amount (E _1/2 ) of were measured. The results are shown in Table 1. The wear resistance of the charge transport layer was evaluated using a Suga abrasion tester (manufactured by Suga Test Instruments Co., Ltd.). The test conditions were such that the sample was reciprocated 1200 times on a worn paper under a load of 200 g, and the change in the amount of wear thereafter was measured. The results are shown in Table 2.

Example 5 Using the polycarbonate copolymer obtained in Example 2, a laminated electrophotographic photosensitive member was prepared in the same manner as in Example 4. The stability of the coating liquid, the evaluation result of crystallization at the time of coating,
All 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 6 Using the polycarbonate polymer obtained in Example 3,
A laminated electrophotographic photosensitive member was produced in the same manner as in Example 4. The stability of the coating liquid and the evaluation results of crystallization during coating were the same as in Example 1. Also, the electrophotographic characteristics,
The evaluation results of wear 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.

[0055]

[Chemical 13]

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 to give 4,4 ″ -p-ter. By the same operation as in Example 1 except that 35 g of 1,1-bis (4-hydroxyphenyl) cyclohexane was used instead of 17.6 g of phenyl, a polycarbonate polymer ([η _sp / c] = 0 consisting of the following repeating units was used. .84 dl / g)
Got

[0057]

[Chemical 14]

Using this polycarbonate polymer as a binder resin, a single-layer type 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 of this electrophotographic photosensitive member are shown in Tables 1 and 2.

[0059]

[Table 1] ─────────────────────────────────── Initial surface potential V ₀ (V) Residual potential V _R (V) Half exposure E _1/2 (lux ・ sec) ─────────────────────────────────── -Example 4-745-5 0.91 5 -792 -3 0.84 6 -748 -4 0.83 Comparative Example 1 -752 -3 0.84 2 -732 -4 0.85 ───── ──────────────────────────────

[0060]

[Table 2]

[0061]

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

Claims (3)

[Claims] 1. A general formula:(In the formula, R¹, R²And R³Are independently halogen sources
Child, an alkyl group having 1 to 6 carbon atoms or an alkyl group having 6 to 12 carbon atoms
Represents a reel group, n is 1 or 2, a, b and c are respectively
Is an integer of 0 to 4. ) And the general formula:[In the formula, X is -CR⁶R⁷-(However, R⁶And R⁷Are each
Independently, hydrogen atom, trifluoromethyl group, carbon number 1 ~
An alkyl group having 6 or an aryl group having 6 to 12 carbon atoms
It ), 1,1-cycloalkylene having 5 to 11 carbon atoms
A group, an α, ω-alkylene group having 2 to 10 carbon atoms, a single bond,
-O-, -S-, -SO- or -SO ₂− And R^FourOver
And R^FiveAre each independently a halogen atom or an alkyl group having 1 to 6 carbon atoms.
Alkyl group, cycloalkyl group having 5 to 7 carbon atoms, 6 carbon atoms
To 12 aryl groups, and d and e are 0 to 4 respectively.
Indicates an integer. ] Having a repeating unit represented by the formula
The content of the repeating unit represented by [I] is a copolymer.
The molar ratio is 0.01 to 0.9 with respect to 1, and
Of a solution having a concentration of 0.5 g / dl in methylene chloride
Reduced viscosity [η_sp/ c] is 0.3 dl / g or more
A polycarbonate copolymer characterized by: 2. A general formula:(In the formula, R¹, R²And R³Are independently halogen sources
Child, an alkyl group having 1 to 6 carbon atoms or an alkyl group having 6 to 12 carbon atoms
Represents a reel group, n is 1 or 2, a, b and c are respectively
Is an integer of 0 to 4. ) Dihydric phenol
And the general formula:[In the formula, X is -CR⁶R⁷-(However, R⁶And R⁷Are each
Independently, hydrogen atom, trifluoromethyl group, carbon number 1 ~
An alkyl group having 6 or an aryl group having 6 to 12 carbon atoms
It ), 1,1-cycloalkylene having 5 to 11 carbon atoms
A group, an α, ω-alkylene group having 2 to 10 carbon atoms, a single bond,
-O-, -S-, -SO- or -SO ₂− And R^FourOver
And R^FiveAre each independently a halogen atom or an alkyl group having 1 to 6 carbon atoms.
Alkyl group, cycloalkyl group having 5 to 7 carbon atoms, 6 carbon atoms
To 12 aryl groups, and d and e are 0 to 4 respectively.
Indicates an integer. ] With respect to the dihydric phenol represented by
Characterized by reacting a carbonic acid ester forming compound
The method for producing a polycarbonate copolymer according to claim 1. 3. An electrophotographic photosensitive member having a photosensitive layer provided on a conductive substrate, wherein the polycarbonate copolymer according to claim 1 is used as a binder resin of a charge transporting substance of the photosensitive layer. Electrophotographic photoreceptor.