JPH06248066A - Bisphenol copolymerization polycarbonate and electrophotographic sensitized material using the same - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer suitable for an electrophotographic sensitized material having excellent transparency, solubility, wear resistance, hardness, printing resistance and electrophotographic characteristics, comprising a repeating unit derived from a bisphenol such as bisphenol A and biphenol. CONSTITUTION:A solution obtained by dissolving 2,2-bis(4-hydroxyphenyl)propane in 6% aqueous solution of sodium hydroxide is mixed with methylene chloride. Phosgene is introduced into the solution and reacted while stirring under cooling to give a solution of an oligomer containing chloroformate group at the end of molecule, which is reacted with 4,4'-dihydroxybiphenyl and 1,1-bis(4- hydroxyphenyl)-1,1-diphenylmethane in the presence of a molecular weight modifier and an alkali to give the objective polycarbonate having repeating units of formula I [R<1> and R<2> are halogen, 1-6C alkyl, (substituted)aryl, etc.; (a) and (b) are 0-4; X is O, CO, SO2, CH2, etc.], formula II (R<3> and R<4> are as shown for R<1>; (c) and (d) are 0-4) and formula III.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel biphenol copolymerized polycarbonate and an electrophotographic photoreceptor using the same. More specifically, it relates to a polycarbonate having excellent abrasion resistance and solubility, and a practically excellent electrophotographic photoreceptor that maintains excellent mechanical strength and electrophotographic characteristics for a long period of time.

[0002]

2. Description of the Related Art Polycarbonate is used as an industrial material in a wide range of fields, but it is not sufficient in performance to use a general raw material such as bisphenol A. Development of more excellent polycarbonate is desired.

In recent electrophotographic photoreceptors,
Laminate type electrophotographic photoreceptor, that is, a laminate type organic electrophotographic in which the photosensitive layer has at least two layers of a charge generation layer (CGL) that generates charges by exposure and a charge transport layer (CTL) that transports charges. A photoconductor (OPC) and a single-layer type electrophotographic photoconductor in which a photosensitive layer is a single layer in which a charge generating substance and a charge transporting substance are dispersed in a binder resin have been proposed and used. As a binder resin for the charge transport layer of the laminated electrophotographic photoreceptor and the photosensitive layer of the single-layer electrophotographic photoreceptor, a polycarbonate resin containing bisphenol A or bisphenol Z as a raw material is widely used. Polycarbonate resin using bisphenol A or bisphenol Z as a raw material has good compatibility with a charge transporting substance, and therefore, when a photoconductor is produced by using this as a binder resin in a photosensitive layer, good electrical characteristics are obtained. A photoreceptor having relatively high mechanical strength can be obtained.

However, when a charge transport layer is formed by using a polycarbonate resin prepared from bisphenol A or bisphenol Z as a binder resin, it has been revealed that the following problems occur. 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, and it remains as an electric charge or a residual potential and appears as a defect in terms of image quality. A charge transport layer or a photosensitive layer using a polycarbonate resin made of bisphenol A or bisphenol Z as a binder resin has poor adhesion to the base and is easily peeled off, or is scratched due to insufficient surface hardness, or the surface is abraded. There is a drawback that the printing life is shortened. In general, the term "base" refers to a conductive substrate in a single-layer type photosensitive and reverse layer type photoreceptor, and a charge transport layer and a charge generation layer on the conductor as in a positive charging type electrophotographic photoreceptor. When the layers are sequentially laminated, the conductor serves as a base, and a blocking layer or an intermediate layer is provided between the conductor and the charge transport layer or the charge generation layer and the charge transport layer for the purpose of improving electrophotographic characteristics. If they do, they will be the groundwork. When preparing a coating solution using a polycarbonate resin containing bisphenol A as a raw material, a halogen-based solvent having a low boiling point such as dichloromethane is used because of problems of solubility and solution stability of the polycarbonate. However, when these are used as a solvent, there is a problem that the concentration of the coating liquid fluctuates because the solvent easily volatilizes, and a polycarbonate resin that can use chlorobenzene or toluene as a solvent has been demanded.

[0005]

The present invention has been made based on the above circumstances. An object of the present invention is to provide a biphenol copolymerized polycarbonate which is excellent in transparency and solubility in many solvents and is excellent in mechanical properties, particularly abrasion resistance, and bisphenol A or bisphenol as a binder resin for a photosensitive layer. In order to solve the above-mentioned problems observed in the conventional electrophotographic photoreceptor using a polycarbonate resin containing Z as a raw material, the coating liquid does not whiten (gel) during the production of the electrophotographic photoreceptor, An object of the present invention is to provide an electrophotographic photosensitive member which is excellent in mechanical strength (surface hardness, etc.) and has excellent printing durability and electrophotographic characteristics for a long time and which is remarkably excellent in practical use.

[0006]

As a result of intensive studies to solve the above problems, the present inventors have found that a specific aromatic compound having a repeating unit derived from biphenol and a repeating unit derived from bisphenol A. Biphenol copolymerized polycarbonate is excellent in abrasion resistance, solubility and transparency, and is preferably used as a binder resin for an electrophotographic photoreceptor, and an electrophotographic photoreceptor produced using the same has printing durability and electronic durability. They have found that they have excellent photographic characteristics, and have completed the present invention based on this finding.

That is, the present invention has the following general formula:

[0008]

[Chemical 3][In the formula, R¹And R²Are each independently a halogen atom or carbon
C1-C6 alkyl group, C5-C7 cycloalkyl
Group or substituted or unsubstituted aryl having 6 to 12 carbon atoms
A group, a and b each independently represent an integer of 0 to 4
X is -O-, -CO-, -SO-, -SO₂-,-
CR^FiveR⁶-(However, R^FiveAnd R⁶Are independently hydrogen
Child, trifluoromethyl group, alkyl having 1 to 6 carbon atoms
Group, substituted or unsubstituted aryl group having 6 to 12 carbon atoms
Indicates. ), Substituted or unsubstituted with 5 to 11 carbon atoms
1,1-cycloalkylene group, α, ω having 2 to 10 carbon atoms
-Alkylene group, fluorene group or divalent polydimethyl
Indicates a siloxane group (provided that a and b are 0 at the same time,
And R^FiveAnd R⁶Are not methyl groups at the same time
Yes. ), R³ And R^Four Are each independently a halogen atom or carbon
C1-C6 alkyl group, C5-C7 cycloalkyl
Group, substituted or unsubstituted aryl group having 6 to 12 carbon atoms
And c and d each independently represent an integer of 0 to 4. ]
The repeating units (I), (II) and (II
I) and a concentration of 0.
The reduced viscosity of a 5 g / dl solution at 20 ° C. is 0.2 to
Biphenol co-weight which is 10 dl / g
A composite polycarbonate is provided.

The above-mentioned biphenol copolymerized polycarbonate has the following general formulas (IV), (V) and (VI).

[0010]

[Chemical 4] [Wherein R ¹ , R ² , R ³ , R ⁴ , X, a, b, c and d are the same as defined above. ] It can manufacture by making the carbonic acid ester forming compound react with the dihydric phenol represented by these.

The present invention also provides an electrophotographic photosensitive member having a photosensitive layer provided on a conductive substrate, wherein the following general formula is used as the binder resin for the photosensitive layer.

[0012]

[Chemical 5] [Wherein R ¹ , R ² , R ³ , R ⁴ , X, a, b, c and d are the same as defined above. ] The repeating units (I) and (II) represented by
And (III), and a biphenol copolymerized polycarbonate having a reduced viscosity at 20 ° C. of 0.2 to 10 dl / g in a solution having a concentration of 0.5 g / dl in methylene chloride as a solvent is used. An electrophotographic photoreceptor is provided.

When the biphenol copolymerized polycarbonate of the present invention is used as a binder resin in an electrophotographic photoreceptor, the content of the repeating unit (I) is a molar ratio with respect to the total number of repeating units of the copolymer. 0.
It is preferably 1 to 90 mol%. If this molar ratio is less than 0.1 mol%, the solubility in a solvent may be insufficient. If it exceeds 90 mol%, the resin itself becomes opaque and may not be suitable for use as a photoreceptor. A more preferable range is 0.5 to 85 mol%, and a particularly preferable range is 1 to 80 mol%.

The content of the repeating unit (II) is 0.1 to 0.1 in terms of the molar ratio to the total number of repeating units of the copolymer.
It is preferably 70 mol%. This molar ratio is 0.1
If it is less than mol%, the solubility in a solvent may be insufficient. Further, the mechanical strength is not sufficient, and when it is used for an electrophotographic photoreceptor, printing durability and electrophotographic characteristics may be insufficiently improved. When it exceeds 70 mol%, the resin itself becomes opaque and may not be suitable for use as a photoreceptor. A more preferred range is 1 to 50 mol%, and a particularly preferred range is 5 to 40 mol%.

The content of the repeating unit (III) is preferably 1 to 99 mol%. This molar ratio is 1
If it is less than mol%, the solubility in a solvent may be insufficient. If it exceeds 99 mol%, the resin may crystallize and may not be suitable for use as a photoreceptor. Further, the mechanical strength is not sufficient, and when used in an electrophotographic photoreceptor, the printing durability and electrophotographic characteristics may not be improved sufficiently.
A more preferred range is 5 to 90 mol%.

The biphenol copolymerized polycarbonate of the present invention may have other repeating units other than those mentioned above within the range not impairing the object of the present invention, and may contain other polycarbonate components and additives. You may use it as a mixture added and compounded suitably.

The biphenol copolymerized polycarbonate of the present invention may be linear, branched or cyclic. As a branching agent when branched, 1,1,1-
There are tris (4-hydroxyphenyl) ethane, phloroglucin and the like, and 1,1,1-tris (4-hydroxyphenyl) ethane is preferable.

When the reduced viscosity [η _sp / c] of the biphenol copolymerized polycarbonate of the present invention is less than 0.2 dl / g, the mechanical strength of the biphenol copolymerized polycarbonate is low, especially as a binder for the photosensitive layer of an electrophotographic photoreceptor. When used, the surface hardness of the layer containing the biphenol copolymerized polycarbonate may be insufficient, and the photoreceptor may be worn to shorten the printing life. On the other hand, the reduced viscosity [η _sp /
When c] exceeds 10 dl / g, the solution viscosity of the biphenol copolymerized polycarbonate may increase, and it may be difficult to manufacture the photoreceptor by the solution coating method.

The synthesis reaction of the biphenol copolymerized polycarbonate of the present invention is carried out by using various carbonyl halides such as phosgene as a carbonic acid ester forming compound,
Carry out polycondensation reaction using haloformates such as chloroformate compounds or carbonic acid ester compounds in the presence of a suitable acid binder, or transesterification reaction using bisaryl carbonates as carbonic acid ester forming compounds. And the like.

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 (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-bis (3-phenyl-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-tert-butyl-4-hydroxy-5)
-Methylphenyl) isobutane, 1,1-bis (2-t
ert-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 , Screw (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 (3,5-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, 2,2-bis (4 −
(Hydroxyphenyl) hexafluoropropane, 1,1
-Bis (3-phenyl-4-hydroxyphenyl) cyclohexane, bis (3-phenyl-4-hydroxyphenyl) sulfone, 4,4 '-(3,3,5-trimethylcyclohexylidene) diphenol, terminal phenol poly Examples thereof include dimethyl siloxane and 4,4'-dihydroxybenzophenone. These dihydric phenols are 1
They may be used alone or in combination of two or more.

Particularly preferably, 1,1-bis (4-hydroxyphenyl) -1,1-diphenylmethane, 1,1
-Bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) sulfone, 1,1
-Bis (4-hydroxyphenyl) cyclohexane,
2,2-bis (3-methyl-4-hydroxyphenyl)
Propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 4,4 '-(3,3,5-trimethylcyclohexylidene) diphenol, 9,9-bis (4-hydroxyphenyl) Fluorene, terminal phenol dimethyl siloxane, etc. are used.

Specific examples of the dihydric phenol represented by the general formula (V) include 4,4'-dihydroxybiphenyl, 3,3'-dimethyl-4,4'-dihydroxybiphenyl and 3,5. , 3 ', 5'-tetramethyl-4,
4'-dihydroxybiphenyl, 3,3'-diphenyl-4,4'-dihydroxybiphenyl, 2,3,5
6,2 ', 3', 5 ', 6'-hexafluoro-4,
4'-dihydroxybiphenyl or the like is used.

The reaction in which polycondensation is carried out in the presence of an acid binder, using the above-mentioned carbonyl dihalide, haloformates, carbonic acid ester compounds and 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 ratio of the acid binder to be used may be appropriately determined in consideration of the stoichiometric ratio (equivalent amount) of the reaction, similarly to the above. Specifically, it is preferable to use 2 equivalents or slightly excess amount of the acid binder with respect to the total number of moles of dihydric phenol used (usually 1 mole corresponds to 2 equivalents).

As the solvent, various solvents such as those used in the production of known polycarbonates may be used alone or as a mixed solvent. Representative examples include hydrocarbon solvents such as xylene, 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 in order 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. If desired, a small amount of an antioxidant such as sodium sulfite and hydrosulfide may be added.
The reaction is usually performed 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 can be suitably used. The reaction time depends on the reaction temperature and the like, but is usually 0.5 minutes to 10 hours, preferably about 1 minute to 2 hours.

Further, dihydric phenols (IV), (V),
It is also possible to use a two-step method in which a part of the reaction raw material composed of (VI) is reacted with a carbonic acid ester-forming compound to form an oligomer, and then the remaining reaction raw materials are added to complete polycondensation. According to such a two-step method,
The reaction can be easily controlled, and highly precise molecular weight control can be performed.

A melt polycondensation method, a solid-phase polycondensation method and the like are preferable as a reaction method when the latter transesterification method of a dihydric phenol and a bisaryl carbonate is used. When the melt polycondensation method is carried out, the above monomers are mixed and reacted in a molten state at high temperature under reduced pressure. The reaction is usually 150 to 350 ° C., preferably 200 to 300.
It is carried out at temperatures in the range of ° C. When the solid-phase polycondensation method is carried out, the above-mentioned two or three kinds of monomers are mixed, and the polycondensation is carried out by heating to a temperature below the melting point of the produced polycarbonate copolymer in the solid-phase state. In either case, the degree of vacuum is preferably 1 mmHg at the final stage of the reaction.
In the following, 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 bring the reduced viscosity [η _sp / c] of the obtained biphenol copolymerized polycarbonate into the above range,
For example, it can be carried out by various methods such as selection of the reaction conditions and adjustment of the amount of the molecular weight regulator used. Also,
Depending on the case, the obtained biphenol copolymerized polycarbonate is appropriately subjected to physical treatment (mixing, fractionation, etc.) and / or chemical treatment (polymer reaction, crosslinking treatment, partial decomposition treatment, etc.) to obtain a desired reduced viscosity [η _sp / C] polycarbonate can also be obtained.

The obtained reaction product (crude product) can be subjected to various post-treatments such as a known separation and purification method, and recovered as a biphenol copolymerized polycarbonate having a desired purity (degree of purification).

The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member in which a photosensitive layer is provided on a conductive substrate, and the above-mentioned biphenol copolymerized polycarbonate is used as a binder resin in the photosensitive layer. .

The electrophotographic photoconductor of the present invention may be any known electrophotographic photoconductor of various types as long as the above-mentioned biphenol copolymerized polycarbonate is used as a binder resin. However, it is preferably used as a binder resin for the charge transport layer in a laminated electrophotographic photoreceptor having at least one charge generation layer and at least one charge transport layer.

The laminated electrophotographic photoreceptor may be one in which the charge transport layer is laminated on the charge generation layer in the photosensitive layer, or one in which the charge generation layer is laminated on the charge transport layer. Good. In addition, a conductive or insulating protective film may be formed on the surface layer as necessary. further,
An adhesive layer for improving the adhesiveness between the layers or an intermediate layer such as a blocking layer that plays a role of blocking charges may be formed.

In the electrophotographic photosensitive member of the present invention, the biphenol copolymerized polycarbonate may be used alone or in combination of two or more kinds. Further, if desired, other polycarbonate or the like may be contained as a binder resin component 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, and specifically, for example, aluminum,
Conductivity by coating a conductive material such as aluminum, nickel, chromium, palladium, graphite, etc. on a metal plate such as brass, copper, nickel, steel, metal drum or metal sheet, plastic sheet by vapor deposition, sputtering, coating, etc. It is possible to use those that have been subjected to a chemical treatment, those whose metal drum surface has been subjected to a metal oxide treatment such as electrode oxidation, or those whose substrates such as glass, plastic plates, cloth, and paper have been subjected to a conductive treatment. it can.

The charge generation layer of the laminated electrophotographic photosensitive member contains at least a charge generation substance, and this charge generation 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 the base or the base. 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 coating on a substrate which is a predetermined undercoat and drying it is preferably used.

The charge generating substance is not known.
Various types can be used, specifically, for example
For example, selenium simple substance such as amorphous selenium and trigonal selenium, selenium
Alloy of selenium such as N-tellurium, As₂ Se₃  Selenium, etc.
Compound or selenium-containing composition, zinc oxide, CdS-
Inorganic materials composed of Group II and Group IV elements such as Se,
Oxide semiconductors such as titanium oxide, amorphous silicon
Various inorganic materials such as silicon-based materials, metal or
Is a metal-free phthalocyanine, cyanine, anthracene,
Sazo compounds, pyrene, perylene, pyrylium salts, thia
Pyrylium salt, Polyvinylcarbazole, Square
Examples thereof include various organic materials such as a pigment.

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

The binder resin in the charge generation 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 biphenol copolymerized polycarbonate of the present invention can be used as the binder resin in the charge generation layer.

Next, the charge transport layer can be obtained by forming a layer formed by binding a charge transport substance using the biphenol copolymerized polycarbonate of the present invention as a binder resin on a base substrate. it can.

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 biphenol copolymerized polycarbonate of the present invention. A method in which the coating liquid thus prepared is applied onto a predetermined base substrate and dried, is used.

In the charge transport layer, the biphenol copolymerized polycarbonate of the present invention may be used alone or in combination of two or more. Further, another binder resin may be used in combination with the biphenol copolymerized polycarbonate 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, 2,3-dichloro-5,6-
Dicyano-p-benzoquinone, 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, 3,5-dimethyl-3 ', 5'. There are electron-withdrawing substances such as -di-tert-butyl-4,4'-diphenoquinone and polymers obtained by polymerizing these electron-withdrawing substances. In addition, these may be used individually by 1 type, or may be used together, such as mixing 2 or more types.

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 thiazoles, 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 (sec-butylphenyl) benzidine, N, N'-diphenyl-N, N'-bis (tert
-Butylphenyl) benzidine, N, N'-diphenyl-N, N'-bis (chlorophenyl) benzidine and other benzidine compounds, or butadiene compounds, triphenylamine, poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene , Polyvinyl acridine, 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, for example, benzene,
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, 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 is at least a biphenol copolymerized polycarbonate of the present invention,
It contains the charge transport material and the charge transport material. As the method for forming the photosensitive layer, various methods such as a known method can be used. Usually, for example, the charge generating substance and the charge transporting substance are dispersed or dissolved in a suitable solvent together with the copolymeric polycarbonate of the present invention. It is possible to suitably use a method in which the coating liquid thus obtained is applied on a substrate which is a predetermined undercoat and dried.

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 copolycarbonate of the present invention.

The electrophotographic photosensitive member of the present invention does not cause whitening (gelation) of the coating liquid at the time of its preparation, and has excellent mechanical durability such as excellent printing durability even when repeatedly used for a long time. It is an electrophotographic photosensitive member that is extremely excellent in practical use and maintains strength and electrophotographic characteristics, and can be suitably used in various electrophotographic fields.

[0056]

EXAMPLES The present invention will now be described in detail based on examples, but the present invention is not limited thereto.

Example 1 2,2-bis (4-hydroxyphenyl) propane 74
950 ml of phosgene gas in the liquid while cooling, while stirring a solution of g dissolved in 550 ml of a 6% concentration aqueous sodium hydroxide solution and 250 ml of methylene chloride.
Blow for 15 minutes at a rate of / minute. Then, the reaction solution was separated by standing to obtain a methylene chloride solution of an oligomer having a degree of polymerization of 2 to 4 in the organic layer and having a chloroformate group at the molecular end.

Methylene chloride was added to the resulting oligomer solution to bring the total amount to 450 ml, and then 8.3 g of 4,4'-dihydroxybiphenyl and 1,1-bis (4-hydroxyphenyl) -1,1-diphenylmethane 7 were added. 0.9 g was mixed with a solution prepared by dissolving 150% of 8% aqueous sodium hydroxide solution, and 1.0 g of p-tert-butylphenol, which is a molecular weight regulator, was added thereto. Then, while vigorously stirring the mixed solution, 2 ml of a 7% triethylamine aqueous solution was added as a catalyst, and the mixture was stirred at 25 ° C. for 1.5 minutes.
A time reaction was performed. After completion of the reaction, the reaction product was diluted with 1 liter of methylene chloride, then twice with 1.5 liter of water, 1 liter of 0.01N hydrochloric acid and 2 liters of 1 liter of water.
It was washed in order, and the organic phase was poured into methanol for reprecipitation purification.

The polymer thus obtained is 20 ° C. in a solution having a concentration of 0.5 g / dl using methylene chloride as a catalyst.
The reduced viscosity [η _sp / c] was 0.78 dl / g. The copolymer obtained here is shown in FIGS. 1 and 2.
¹ H-NMR spectrum analysis (solvent: methylene dichloride)
It was further confirmed that it was composed of the following repeating units.

[0060]

[Chemical 6]

The results of measuring the solubility and solution stability of this polycarbonate in chlorobenzene are shown in Table 1.

Example 2 2,2-bis (4-hydroxyphenyl) propane 61
g and 2,2-bis (3-methyl-4-hydroxyphenyl) propane 15 g dissolved in 550 ml of a 6% strength aqueous sodium hydroxide solution, and methylene chloride 250
Phosgene gas was blown into the liquid at a rate of 950 ml / min for 15 minutes while being mixed and stirred with cooling.
Then, this reaction solution was allowed to stand and separate, and the organic layer had a degree of polymerization of 2
A methylene chloride solution of an oligomer having a chloroformate group at the molecular end was obtained.

Methylene chloride was added to the obtained oligomer solution to make a total volume of 450 ml, and then 12 g of 4,4'-dihydroxybiphenyl was added to 8% sodium hydroxide aqueous solution 1
After mixing with a solution dissolved in 50 ml, 1.0 g of p-tert-butylphenol, which is a molecular weight regulator, was added thereto. Then, while vigorously stirring this mixed solution, 2 ml of a 7% triethylamine aqueous solution was added as a catalyst, and the mixture was added at 25 °
The reaction was carried out under stirring for 1.5 hours. After completion of the reaction, the reaction product was diluted with 1 liter of methylene chloride, washed twice with 1.5 liters of water, twice with 1 liter of 0.01N hydrochloric acid and twice with 1 liter of water, and the organic phase was dissolved in methanol. Then, it was re-precipitated and purified.

The polymer 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 0.87 dl / g. It was confirmed from ¹ H-NMR spectrum analysis that it was composed of the following repeating units. The results of the solubility test of this polycarbonate are shown in Table 1.

[0065]

[Chemical 7]

Example 3 A tetrahydrofuran solution having a concentration of 50 wt% and containing the following hydrazone compound as a charge transport material and the polycarbonate obtained in Example 1 in a weight ratio of 1: 1 was prepared. Even when the coating solution was allowed to stand for 1 month, no cloudiness or gel formation was observed. The conductive substrate is aluminum, and this coating solution is applied by dip coating on a charge generation layer of about 0.5 μm using oxotitanium furocyanine, and after drying, a charge transport layer of 20 μm is provided to form a stack type electron. A photographic photoreceptor was produced. The charge transport layer did not crystallize during coating. Further, the electrophotographic characteristics were measured using an electrostatic charging test device EPA-8100 (Kawaguchi Electric Co., Ltd.). Corona discharge of -6 kV was performed to obtain initial surface potential (V _O ), residual potential after light irradiation (10 Lux) (V _R ),
The half-exposure amount (E _1/2 ) was measured (Table 2). Furthermore, the wear resistance of this charge transport layer is measured by a Suga abrasion tester NUS-IS.
It evaluated using the O-3 type (made by Suga Test Instruments Co., Ltd.). The test conditions were such that the sample was reciprocated a certain number of times on a worn paper under a load of 200 g, and the change in the amount of wear thereafter was measured. The results of reciprocating 1200 times are shown in Table 3.

[0067]

[Chemical 8]

Example 4 Using the polycarbonate obtained in Example 2, a laminated type photoreceptor was prepared in the same manner as in Example 3. Stability of coating liquid,
The evaluation results of crystallization at the time of application were the same as in Example 3. The evaluation results of electrophotographic characteristics and abrasion resistance are shown in Tables 2 and 3, respectively.

Comparative Example 1 Using a commercially available polycarbonate ([η _sp /c]=0.78 dl / g) using 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), A laminated type photoreceptor was prepared in the same manner. 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 results of evaluation of solubility, electrophotographic properties and abrasion resistance are shown in Tables 1, 2 and 3.

Comparative Example 2 Example 3 was carried out using a commercially available polycarbonate ([η _sp /c]=0.75 dl / g) using 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z). A laminated type photoreceptor was prepared in the same manner. The stability of the coating liquid and the evaluation results of crystallization during coating were the same as in Example 1. The results of evaluation of solubility, electrophotographic properties and abrasion resistance are shown in Tables 1, 2 and 3.

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

[0074]

According to the present invention, a biphenol copolymerized polycarbonate having excellent transparency, abrasion resistance and solubility in a solvent can be obtained, and excellent printing durability and electrophotographic characteristics can be maintained for a long period of time. An electrophotographic photoreceptor can be obtained.

[Brief description of drawings]

FIG. 1 is a ¹ H-NMR spectrum of the copolymer obtained in Example 1, and FIG. 2 is a partially enlarged view thereof.

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[Procedure amendment]

[Submission date] July 22, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

1 is a ¹ H-NMR spectrum of the copolymer obtained in Example 1. FIG.

2 is a partially enlarged view of the ¹ H-NMR spectrum of the copolymer obtained in Example 1. FIG.

Claims (2)

[Claims] 1. The following general formula:[In the formula, R¹And R²Are each independently a halogen atom or carbon
C1-C6 alkyl group, C5-C7 cycloalkyl
Group or substituted or unsubstituted aryl having 6 to 12 carbon atoms
A group, a and b each independently represent an integer of 0 to 4
X is -O-, -CO-, -SO-, -SO₂-,-
CR^FiveR⁶-(However, R^FiveAnd R⁶Are independently hydrogen
Child, trifluoromethyl group, alkyl having 1 to 6 carbon atoms
Group, substituted or unsubstituted aryl group having 6 to 12 carbon atoms
Indicates. ), Substituted or unsubstituted with 5 to 11 carbon atoms
1,1-cycloalkylene group, α, ω having 2 to 10 carbon atoms
-Alkylene group, fluorene group or divalent polydimethyl
Indicates a siloxane group (provided that a and b are 0 at the same time,
And R^FiveAnd R⁶Are not methyl groups at the same time
Yes. ), R³ And R^Four Are each independently a halogen atom or carbon
C1-C6 alkyl group, C5-C7 cycloalkyl
Group, substituted or unsubstituted aryl group having 6 to 12 carbon atoms
And c and d each independently represent an integer of 0 to 4. ]
The repeating units (I), (II) and (II
I) and a concentration of 0.
The reduced viscosity of a 5 g / dl solution at 20 ° C. is 0.2 to
Biphenol co-weight which is 10 dl / g
Combined polycarbonate. 2. An electrophotographic apparatus in which a photosensitive layer is provided on a conductive substrate.
In the photoconductor, as the binder resin of the photosensitive layer,
General formula:[In the formula, R¹And R²Are each independently a halogen atom or carbon
C1-C6 alkyl group, C5-C7 cycloalkyl
Group or substituted or unsubstituted aryl having 6 to 12 carbon atoms
A group, a and b each independently represent an integer of 0 to 4
X is -O-, -CO-, -SO-, -SO₂-,-
CR^FiveR⁶-(However, R^FiveAnd R⁶Are independently hydrogen
Child, trifluoromethyl group, alkyl having 1 to 6 carbon atoms
Group, substituted or unsubstituted aryl group having 6 to 12 carbon atoms
Indicates. ), Substituted or unsubstituted with 5 to 11 carbon atoms
1,1-cycloalkylene group, α, ω having 2 to 10 carbon atoms
-Alkylene group, fluorene group or divalent polydimethyl
Indicates a siloxane group (provided that a and b are 0 at the same time,
And R^FiveAnd R⁶Are not methyl groups at the same time
Yes. ), R³ And R^Four Are each independently a halogen atom or carbon
C1-C6 alkyl group, C5-C7 cycloalkyl
Group, substituted or unsubstituted aryl group having 6 to 12 carbon atoms
And c and d each independently represent an integer of 0 to 4. ]
The repeating units (I), (II) and (II
I) and a concentration of 0.
The reduced viscosity of a 5 g / dl solution at 20 ° C. is 0.2 to
Biphenol copolymerized polycarbonate with 10 dl / g
An electrophotographic photosensitive member characterized by using a toner.