JP4223908B2 - Electrophotographic photoreceptor - Google Patents

Description

  The present invention relates to an electrophotographic organic photoreceptor excellent in wear resistance and excellent in electrophotographic characteristics.

A typical configuration example of the organic photoreceptor is a laminated photoreceptor in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive substrate.
The charge transport layer is formed of a low molecular charge transport material and a binder resin, and many aromatic polycarbonate resins have been proposed as the binder resin.
Polycarbonate resin is suitable for the charge transport layer that is the outermost layer because it has high impact resistance and good light transmittance in the visible region. However, the inclusion of a low molecular charge transport material added for the purpose of imparting charge transportability reduces the inherent mechanical strength of the binder resin, which may cause wear deterioration, scratches, cracks, etc. of the photoreceptor. Thus, the durability of the photoreceptor is impaired.
In recent years, due to the desire to further reduce the running cost of the electrophotographic apparatus, improvement of the durability of the photoreceptor has been a major issue. Binder resins with as much wear resistance as possible even in contact with blades, toners, paper, brushes, etc. have been demanded, and various binder resins have been studied, but the wear resistance is greatly reduced by the inclusion of low molecular charge transport materials. Is inevitable.

On the other hand, polymer charge transport materials that do not use low molecular charge transport materials have been studied, and proposals have been made to improve wear resistance using polymer charge transport materials (see Patent Document 1).
However, in a polymer charge transport material, material purification is difficult as compared with low molecular weight compounds, and stable electrophotographic characteristics are hardly expressed, and it has not been put into practical use.
In recent years, it has been necessary to lower the toner fixing temperature from the viewpoint of energy saving, and in order to ensure toner fluidity when the softening temperature is lowered, a large amount of additives such as silica fine particles have been put into the toner. . This silica is sandwiched between the photoconductor and a cleaning blade, and the photoconductor is worn. Since the hardness of silica is extremely high compared to the surface of the organic photoreceptor, scratches and abrasion due to scratching are problematic.
Conventionally, various techniques using a polycarbonate resin as a binder material for a charge transport layer of an electrophotographic photosensitive member have been proposed (for example, see Patent Documents 1 and 2).
However, according to the polycarbonate resin having the specific structural formula shown in these proposals, the abrasion resistance of the electrophotographic photosensitive member is not yet satisfactory.

JP-A-6-110224 JP 2001-72756 A

  The present invention has been made in view of the above-described prior art, and the object thereof is an organic photoconductor for electrophotography having excellent wear resistance even in a system in which a low molecular charge transport material is mixed, particularly for scratch abrasion. It is to provide a strong organic photoreceptor.

  As a result of intensive studies, the inventors of the present invention have stronger abrasion resistance than conventional organic photoreceptors even in a system containing a low molecular charge transport material by using a polycarbonate resin containing a specific structural unit in the photosensitive layer. It has been found that it is possible to provide an organic photoconductor for electrophotography having good properties, especially scratch resistance.

That is, the above-mentioned problems are as follows : ( 1) A photosensitive layer containing, as an active ingredient, a polycarbonate resin comprising at least the structural units represented by the following general formula (1) and general formula (2) is provided on a conductive support. An electrophotographic photoreceptor characterized by:

（式中、Ｘは下記式で表わされる２価基を示す。）

(In the formula, X represents a divalent group represented by the following formula.)

（式中、Ｒ_１０１、Ｒ_１０２、Ｒ_１０３、Ｒ_１０４はハロゲン原子、炭素数１〜６の無置換もしくは置換のアルキル基又は無置換もしくは置換のアリール基（Ｒ_１０１、Ｒ_１０２、Ｒ_１０３、Ｒ_１０４が各々複数個存在するときは、同一であっても別異であってもよい）、ｏ、ｐは０〜４の整数、ｑ、ｒは０〜３の整数、Ｙは単結合、炭素数２〜４の直鎖状のアルキレン基、−Ｏ−、−Ｓ−又は下記式

(In the formula, R ₁₀₁ , R ₁₀₂ , R ₁₀₃ and R ₁₀₄ are each a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group (R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , When a plurality of R ₁₀₄ are present, they may be the same or different), o, p are integers of 0-4, q, r are integers of 0-3, Y is a single bond, C2-C4 linear alkylene group, -O-, -S- or the following formula

（式中、Ｒ_１０５はハロゲン原子、炭素数１〜６の無置換もしくは置換アルキル基、炭素数１〜６の無置換もしくは置換のアルコキシ基又は無置換もしくは置換アリール基を示し、Ｒ_１０６、Ｒ_１０７は水素原子、ハロゲン原子、炭素数１〜６の無置換もしくは置換アルキル基、炭素数１〜６の無置換もしくは置換のアルコキシ基又は無置換もしくは置換アリール基を示し、またＲ_１０６、Ｒ_１０７が結合して炭素数５〜１２の炭素環を形成してもよく、Ｒ_１０８、Ｒ_１０９、Ｒ_１１０、Ｒ_１１１は水素原子、ハロゲン原子、炭素数１〜６の無置換もしくは置換アルキル基、炭素数１〜６の無置換もしくは置換のアルコキシ基又は無置換もしくは置換アリール基を示す。）で表される２価基を示す。）」、
（２）「導電性支持体上に、前記一般式（１）で表わされる構成単位の組成比をＫ、前記一般式（２）で表わされる構成単位の組成比をＪとしたとき、０．３≦Ｋ／（Ｋ＋Ｊ）＜１．０であるポリカーボネート樹脂を有効成分として含有した感光層を設けたことを特徴とする前記第（１）項に記載の電子写真感光体」によって解決される。
また、上記課題は、本発明の（３）「導電性支持体上に、下記一般式（３）で表わされるポリカーボネート樹脂を有効成分として含有した感光層を設けたことを特徴とする電子写真感光体；

(Wherein R ₁₀₅ represents a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group, R ₁₀₆ , R ₁₀₇ represents a hydrogen atom, a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group; and R ₁₀₆ , R ₁₀₇ May combine to form a carbocyclic ring having 5 to 12 carbon atoms, R ₁₀₈ , R ₁₀₉ , R ₁₁₀ and R ₁₁₁ are a hydrogen atom, a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, A divalent group represented by a C1-C6 unsubstituted or substituted alkoxy group or an unsubstituted or substituted aryl group. ) ",
(2) “When the compositional ratio of the structural unit represented by the general formula (1) on the conductive support is K and the compositional ratio of the structural unit represented by the general formula (2) is J, 0. This is solved by the electrophotographic photosensitive member according to item (1) above, wherein a photosensitive layer containing a polycarbonate resin satisfying 3 ≦ K / (K + J) <1.0 as an active ingredient is provided .
Another object of the present invention is to provide an electrophotographic photosensitive material according to (3) of the present invention, wherein a photosensitive layer containing a polycarbonate resin represented by the following general formula (3) as an active ingredient is provided on a conductive support. body;

（式中、ｎは繰返し数を表わし、３０〜１００００の整数である。）」、
（４）「前記ポリカーボネート樹脂が、ポリスチレン換算重量平均分子量が７万以上であることを特徴とする前記第（３）項に記載の電子写真感光体」、
（５）「感光層が少なくとも電荷発生層、電荷輸送層の順に積層された構成を持ち、該ポリカーボネート樹脂が主に電荷輸送層に使用されていることを特徴とする前記第（３）項又は第（４）項に記載の電子写真感光体」、
（６）「電荷輸送層が二層以上の構成を持ち、該ポリカーボネート樹脂が最表面側の電荷輸送層に使用されていることを特徴とする前記第（５）項に記載の電子写真感光体」によって解決される。

(Where n represents the number of repetitions and is an integer from 30 to 10,000).
(4) "The polycarbonate resin is an electrophotographic photosensitive member according to prior Symbol first (3) term polystyrene equivalent weight average molecular weight and wherein the 70,000 der Turkey"
(5) "light-sensitive layer of at least a charge generating layer, has been configured laminated in this order of the charge transport layer, the second (3), characterized in that said polycarbonate resin is mainly used in the charge transport layer to claim or The electrophotographic photosensitive member according to item (4),
(6) The electrophotographic photosensitive member according to (5) above, wherein the charge transport layer has a structure of two or more layers, and the polycarbonate resin is used for the charge transport layer on the outermost surface side. Is solved by.

  The electrophotographic photosensitive member of the present invention has electrophotographic characteristics equivalent to those of conventional ones, but also has excellent wear resistance compared to conventional ones, and has high durability and long life. A photoconductor can be provided.

Details of the present invention will be described below.
(About polycarbonate resin used for photosensitive layer and its manufacturing method)
The polycarbonate resin used in the present invention is a polycarbonate resin composed of structural units represented by the general formula (1) and the general formula (2) and a polycarbonate resin represented by the general formula (3).

The manufacturing method of the polycarbonate resin used for this invention is demonstrated.
The polycarbonate resin used in the present invention can be produced by a method similar to the polymerization of bisphenol and a carbonic acid derivative known as a conventional method for producing a polycarbonate resin.
That is, using a diol represented by the following general formula (4), a transesterification method with bisaryl carbonate, a solution with a halogenated carbonyl compound such as phosgene or an interfacial polymerization method, or a bischloroformate derived from a diol It is manufactured by a method using chloroformate.
As the halogenated carbonyl compound, trichloromethyl chloroformate, which is a dimer of phosgene, and bis (trichloromethyl) carbonate, which is a trimer of phosgene, are also useful instead of phosgene, and halogens derived from halogens other than chlorine. Also useful are carbonyl chloride compounds such as carbonyl bromide, carbonyl iodide, carbonyl fluoride. These known production methods are described, for example, in a polycarbonate resin handbook (editor: Seiichi Honma, published by Nikkan Kogyo Shimbun).

A copolymer can be obtained by selecting an appropriate polymerization operation. For example, a random copolymer can be obtained by uniformly mixing the diol represented by the general formula (4) and the diol represented by the following general formula (5) from the beginning and performing a condensation reaction with phosgene.
A random block copolymer can be obtained by adding several kinds of diols in the middle of the reaction. An alternating copolymer can be obtained by performing a condensation reaction with a bischloroformate derivative derived from any diol. In the condensation reaction of these bischloroformates and diols, a random alternating copolymer can be obtained by using a plurality of bischloroformates and diols. A plurality of diols represented by the general formula (5) can be used and copolymerized with the diol represented by the general formula (4).

（式中、Ｘは下記式で表わされる２価基を示す。）

(In the formula, X represents a divalent group represented by the following formula.)

（式中、Ｒ_１０１、Ｒ_１０２、Ｒ_１０３、Ｒ_１０４はハロゲン原子、炭素数１〜６の無置換もしくは置換のアルキル基又は無置換もしくは置換のアリール基（Ｒ_１０１、Ｒ_１０２、Ｒ_１０３、Ｒ_１０４が各々複数個存在するときは、同一であっても別異であってもよい）、ｏ、ｐは０〜４の整数、ｑ、ｒは０〜３の整数、Ｙは単結合、炭素数２〜４の直鎖状のアルキレン基、−Ｏ−、−Ｓ−又は下記式

(In the formula, R ₁₀₁ , R ₁₀₂ , R ₁₀₃ and R ₁₀₄ are each a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group (R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , When a plurality of R ₁₀₄ are present, they may be the same or different), o, p are integers of 0-4, q, r are integers of 0-3, Y is a single bond, C2-C4 linear alkylene group, -O-, -S- or the following formula

（式中、Ｒ_１０５はハロゲン原子、炭素数１〜６の無置換もしくは置換アルキル基、炭素数１〜６の無置換もしくは置換のアルコキシ基又は無置換もしくは置換アリール基を示し、Ｒ_１０６、Ｒ_１０７は水素原子、ハロゲン原子、炭素数１〜６の無置換もしくは置換アルキル基、炭素数１〜６の無置換もしくは置換のアルコキシ基又は無置換もしくは置換アリール基を示し、またＲ_１０６、Ｒ_１０７が結合して炭素数５〜１２の炭素環を形成してもよく、Ｒ_１０８、Ｒ_１０９、Ｒ_１１０、Ｒ_１１１は水素原子、ハロゲン原子、炭素数１〜６の無置換もしくは置換アルキル基、炭素数１〜６の無置換もしくは置換のアルコキシ基又は無置換もしくは置換アリール基を示す。）で表される２価基を示す。）

(Wherein R ₁₀₅ represents a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group, R ₁₀₆ , R ₁₀₇ represents a hydrogen atom, a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group; and R ₁₀₆ , R ₁₀₇ May combine to form a carbocyclic ring having 5 to 12 carbon atoms, R ₁₀₈ , R ₁₀₉ , R ₁₁₀ and R ₁₁₁ are a hydrogen atom, a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, A divalent group represented by a C1-C6 unsubstituted or substituted alkoxy group or an unsubstituted or substituted aryl group. )

  In the case of a copolymer, the structural unit represented by the general formula (1) is preferably contained in an amount of 10 mol% or more, more preferably 30 mol% or more in terms of the composition ratio with other structural units. Furthermore, it is still more preferable to contain 50 mol% or more. In the resin of the present invention, the excellent abrasion resistance is expressed by the structural unit represented by the general formula (1), so that the effect is reduced when this concentration is lowered.

When interfacial polymerization is carried out in a method using a carbonyl halide compound or chloroformate, it is substantially insoluble in an alkaline aqueous solution of diol and water, and between two phases of an organic solvent that dissolves polycarbonate. The reaction is carried out in the presence of a carbonic acid derivative and a catalyst. At this time, a polycarbonate having a narrow molecular weight distribution can be obtained in a short time by emulsifying the reaction medium by high-speed stirring or addition of an emulsifying substance.
The base used in the alkaline aqueous solution is an alkali metal or an alkaline earth metal, and is usually a hydroxide such as sodium hydroxide, potassium hydroxide or calcium hydroxide, sodium carbonate, potassium carbonate, calcium carbonate, sodium hydrogen carbonate or the like. Carbonates and the like. These bases may be used alone or in combination.
A preferred base is sodium hydroxide or potassium hydroxide. The water used is preferably distilled water or ion exchange water.
Examples of the organic solvent include aliphatic halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, 1,2-dichloroethylene, trichloroethane, tetrachloroethane, and dichloropropane, aromatic halogenated hydrocarbons such as chlorobenzene and dichlorobenzene, or , A mixture of them. Moreover, the organic solvent which mixed aromatic hydrocarbons, such as toluene, xylene, and ethylbenzene, aliphatic hydrocarbons, such as hexane and a cyclohexane, etc. may be sufficient as them. The organic solvent is preferably an aliphatic halogenated hydrocarbon or an aromatic halogenated hydrocarbon, more preferably dichloromethane or chlorobenzene.

Polycarbonate-forming catalysts used in the production of polycarbonate are tertiary amines, quaternary ammonium salts, tertiary phosphines, quaternary phosphonium salts, nitrogen-containing heterocyclic compounds and salts thereof, imino ethers and salts thereof, amide groups And the like.
Specific examples of the polycarbonate formation catalyst include trimethylamine, triethylamine, tri-n-propylamine, tri-n-hexylamine, N, N, N ′, N′-tetramethyl-1,4-tetramethylenediamine, 4-pyrroline. Dinopyridine, N, N'-dimethylpiperazine, N-ethylpiperidine, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, tetramethylammonium chloride, tetraethylammonium bromide, phenyltriethylammonium chloride, triethylphosphine, triphenylphosphine, diphenylbutylphosphine , Tetra (hydroxymethyl) phosphonium chloride, benzyltriethylphosphonium chloride, benzyltriphenylphosphonium chloride 4-methylpyridine, 1-methylimidazole, 1,2-dimethylimidazole, 3-methylpyridazine, 4,6-dimethylpyrimidine, 1-cyclohexyl-3,5-dimethylpyrazole, 2,3,5,6-tetra Such as methylpyrazine.
These polycarbonate formation catalysts may be used alone or in combination. The polycarbonate-forming catalyst is preferably a tertiary amine, more preferably a tertiary amine having 3 to 30 carbon atoms, and particularly preferably triethylamine. These catalysts can be added before and / or after adding a carbonic acid derivative such as phosgene or bischloroformate to the reaction system.

  Further, an antioxidant such as hydrosulfite may be added in order to prevent oxidation of the diol in the alkaline aqueous solution. The reaction temperature is usually 0 to 40 ° C., the reaction time is several minutes to 5 hours, and the pH during the reaction is preferably kept at 10 or more.

  On the other hand, in the case of solution polymerization, it is obtained by dissolving a diol in a solvent, adding a deoxidizing agent, and adding bischloroformate, phosgene, or a phosgene multimer to this. As deoxidizers, tertiary amines such as trimethylamine, triethylamine, tripropylamine and pyridine are used. As the solvent used in the reaction, for example, halogenated hydrocarbons such as dichloromethane, dichloroethane, trichloroethane, tetrachloroethane, trichloroethylene and chloroform, and cyclic ether solvents such as tetrahydrofuran and dioxane, and pyridine are preferable. The reaction temperature is usually 0 to 40 ° C., and the reaction time is several minutes to 5 hours.

  It is also produced by a transesterification method. In this case, a diol and bisaryl carbonate are mixed in the presence of an inert gas, and are usually reacted at 120 to 350 ° C. under reduced pressure. The degree of vacuum is changed stepwise, and finally the phenols produced are distilled out of the system at 1 mmHg or less. The reaction time is usually about 1 to 4 hours. Moreover, you may add antioxidant as needed. Examples of the bisaryl carbonate include diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di-p-chlorophenyl carbonate, and dinaphthyl carbonate.

In order to adjust the molecular weight in all the polymerization operations described above, it is desirable to use a terminal terminator as the molecular weight regulator. Therefore, even if a substituent based on the terminator is bonded to the terminal of the polycarbonate resin used in the present invention. Good.
The terminal terminator used is a monovalent aromatic hydroxy compound, a haloformate derivative of a monovalent aromatic hydroxy compound, a monovalent carboxylic acid, a halide derivative of a monovalent carboxylic acid, or the like.
Monovalent aromatic hydroxy compounds include, for example, phenol, p-cresol, o-ethylphenol, p-ethylphenol, p-isopropylphenol, p-tert-butylphenol, p-cumylphenol, p-cyclohexylphenol, p -Octylphenol, p-nonylphenol, 2,4-xylenol, p-methoxyphenol, p-hexyloxyphenol, p-decyloxyphenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, p-bromophenol, Pentabromophenol, pentachlorophenol, p-phenylphenol, p-isopropenylphenol, 2,4-di (1′-methyl-1′-phenylethyl) phenol, β-naphthol, α-naphthol, p- (2 ', 4'4'-methyl chroma yl) phenol, 2- (4'-methoxyphenyl) -2- (4 "- hydroxy phenyl) phenols or alkali metal salts and alkaline earth metal salts thereof, such as propane.
The haloformate derivative of the monovalent aromatic hydroxy compound is the haloformate derivative of the above monovalent aromatic hydroxy compound.

Examples of monovalent carboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, 2,2-dimethylpropionic acid, 3-methylbutyric acid, 3,3-dimethylbutyric acid, 4- Fatty acids such as methyl valeric acid, 3,3-dimethyl valeric acid, 4-methyl caproic acid, 3,5-dimethyl caproic acid, phenoxyacetic acid, or alkali metal salts and alkaline earth metal salts thereof, benzoic acid, p- Benzoic acids such as methylbenzoic acid, p-tert-butylbenzoic acid, p-butoxybenzoic acid, p-octyloxybenzoic acid, p-phenylbenzoic acid, p-benzylbenzoic acid, p-chlorobenzoic acid or their alkalis Metal salts and alkaline earth metal salts. Examples of the monovalent carboxylic acid halide derivative include the above-described monovalent carboxylic acid halide derivatives.
These end-capping agents can arbitrarily adjust the molecular weight by adding them before the start of the reaction and during the reaction in the course of the polymerization operation. Furthermore, these end capping agents can also be used as end group protecting agents, and can be added after completion of the polymerization reaction to protect the end groups and add various functions.
These terminal blocking agents may be used alone or in combination. The end-capping agent is preferably a monovalent aromatic hydroxy compound, more preferably phenol, p-tert-butylphenol, p-cumylphenol or phenyl chloroformate.

  The molecular weight of the polycarbonate resin of the present invention is preferably 30000-300000, more preferably 70000-250,000 in terms of polystyrene-equivalent weight average molecular weight. If the molecular weight is too small, the mechanical strength becomes weak and the practicality is poor, such as cracking during film formation. On the other hand, if the molecular weight is too large, the solution viscosity becomes high and coating becomes difficult.

Also, a small amount of a branching agent can be added during the polymerization in order to improve the mechanical properties.
The branching agent used is a compound having three or more (same or different) reactive groups selected from an aromatic hydroxy group, a haloformate group, a carboxylic acid group, a carboxylic acid halide group, or an active halogen atom. is there.
Specific examples of the branching agent include phloroglucinol, 4,6-dimethyl-2,4,6-tris (4′-hydroxyphenyl) -2-heptene, 4,6-dimethyl-2,4,6-tris. (4′-hydroxyphenyl) heptane, 1,3,5-tris (4′-hydroxyphenyl) benzene, 1,1,1-tris (4′-hydroxyphenyl) ethane, 1,1,2-tris (4 '-Hydroxyphenyl) propane, α, α, α'-tris (4'-hydroxyphenyl) -1-ethyl-4-isopropylbenzene, 2,4-bis [α-methyl-α- (4'-hydroxyphenyl) ) Ethyl] phenol, 2- (4′-hydroxyphenyl) -2- (2 ″, 4 ″ -dihydroxyphenyl) propane, tris (4-hydroxyphenyl) phosphine, 1,1,4,4-tetrakis ( 4′-hydroxyphenyl) cyclohexane, 2,2-bis [4 ′, 4′-bis (4 ″ -hydroxyphenyl) cyclohexyl] propane, α, α, α ′, α′-tetrakis (4′-hydroxyphenyl) -1,4-diethylbenzene, 2,2,5,5-tetrakis (4′-hydroxyphenyl) hexane, 1,1,2,3-tetrakis (4′-hydroxyphenyl) propane, 1,4-bis (4 ', 4 "-dihydroxytriphenylmethyl) benzene, 3,3', 5,5'-tetrahydroxydiphenyl ether, 3,5-dihydroxybenzoic acid, 3,5-bis (chlorocarbonyloxy) benzoic acid, 4-hydroxy Isophthalic acid, 4-chlorocarbonyloxyisophthalic acid, 5-hydroxyphthalic acid, 5-chlorocarbonyloxyphthalic acid, trimesic acid Examples include lichloride and cyanuric acid chloride. These branching agents may be used alone or in combination.

  The polycarbonate resin obtained as described above is used after removing impurities such as catalyst and antioxidant used during polymerization, unreacted diol and terminal terminator, and inorganic salts generated during polymerization. Is done. These purification operations can also use known methods described in the previous polycarbonate resin handbook (editor: Seiichi Honma, issue: Nikkan Kogyo Shimbun). Moreover, additives such as an antioxidant, a light stabilizer, a heat stabilizer, a lubricant, and a plasticizer can be added to the polycarbonate resin produced according to the above-described method as necessary.

Hereinafter, the general formula (2) and the general formula (5) will be described in more detail.
In the explanation of R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , R ₁₀₄ ,
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the unsubstituted or substituted alkyl group having 1 to 6 carbon atoms include a linear, branched or cyclic alkyl group, and these alkyl groups include a fluorine atom, a cyano group, a phenyl group, a halogen atom, or a carbon number. It may contain a phenyl group substituted with 1 to 6 linear, branched or cyclic alkyl groups.
Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, trifluoromethyl group, 2-cyanoethyl group Benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, cyclopentyl group, cyclohexyl group and the like.
Examples of the unsubstituted or substituted aryl group include a phenyl group and a naphthyl group, which may have the same halogen atom and unsubstituted or substituted alkyl group having 1 to 6 carbon atoms as the substituent.

During the explanation of Y,
The linear alkylene group having 2 to 4 carbon atoms represents ethylene, propylene, butylene.

In the description of R _{105 to} R ₁₁₁ ,
A halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, and an unsubstituted or substituted aryl group are the same as those described for R ₁₀₁ , R ₁₀₂ , R ₁₀₃ , and R ₁₀₄ .
A substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms represents an alkoxy group having a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and specific examples thereof include a methoxy group, an ethoxy group, n -Propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, s-butoxy group, t-butoxy group, 2-hydroxyethoxy group, 2-cyanoethoxy group, benzyloxy group, 4-methylbenzyloxy Group, trifluoromethoxy group and the like.
_As the carbon ring of 5 to 12 carbon atoms R _{106, R 107} is formed by bonding, it represents cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, a cyclooctadiene decane.

  Specific examples of the diol represented by the general formula (5) include bis (4-hydroxyphenyl) methane, bis (2-methyl-4-hydroxyphenyl) methane, bis (3-methyl-4-hydroxyphenyl) methane, 1,1-bis <4-hydroxyphenyl) ethane, 1,2-bis (4-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,3-bis (4-hydroxyphenyl) -1,1-dimethylpropane, 2,2-bis (4-hydroxyphenyl) propane, 2- (4-hydroxy Phenyl) -2- (3-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2-me Rupropane, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-hydroxyphenyl) hexane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxy) Phenyl) nonane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-isopropyl-4-hydroxyphenyl) ) Propane, 2,2-bis (3-sec-butyl-4-hydroxyphenyl) propane, 2,2-bis (3-tert-butyl-4-hydroxy) Phenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2,2-bis (3-allyl-4-hydroxyphenyl) propane, 2,2-bis (3-phenyl-4-) Hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (3,5 -Dichloro-4-hydroxyphenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 2,2- Bis (4-hydroxyphenyl) hexafluoropropane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydride) Loxyphenyl) cyclohexane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5 -Dichloro-4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) cycloheptane, 2,2-bis (4-hydroxyphenyl) norbornane, 2,2-bis (4-hydroxyphenyl) adamantane, 4,4′-dihydroxydiphenyl ether, 1,3-bis (4-hydroxyphenoxy) benzene, 1,4-bis (3- Hydroxyphenoxy) benzene, 4,4′-dihydroxydiphenyl sulfide, 3 3'-dimethyl-4,4'-dihydroxydiphenyl sulfide, 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxydiphenyl sulfide, 3,3,3', 3'-tetramethyl-6 , 6′-Dihydroxyspiro (bis) indane, 3,3 ′, 4,4′-tetrahydro-4,4,4 ′, 4′-tetramethyl-2,2′-spirobi (2H-1-benzopyran) -7,7'-diol, trans-2,3-bis (4-hydroxyphenyl) -2-butene, 4,4'-dihydroxybiphenyl and the like.

(Photoreceptor configuration)
1 to 4 are sectional views of the photoreceptor of the present invention.
The photoreceptor of the present invention contains the above-described specific polycarbonate resin in the photosensitive layers (2a), (2b), (2c), and (2d). 2, 3 and 4 can be used.

The photoreceptor in FIG. 1 is dispersed in a charge transport medium (4) comprising a charge generating material (3) on a conductive support (1) and a low molecular charge transport agent mixed polycarbonate resin alone or in combination with a binder. A photosensitive layer (2a) is provided.
The low molecular charge transporting agent mixed polycarbonate resin here forms a charge transporting medium alone or in combination with a binder, while the charge generating substance (3) (charge generating substance such as an inorganic or organic pigment) Generate charge carriers. In this case, the charge transport medium (4) is mainly responsible for receiving and transporting charge carriers generated by the charge generating material (3).
In this photoreceptor, the basic condition is that the charge generation material and the low molecular charge transport agent mixed polycarbonate resin do not overlap with each other mainly in the visible region.
This is because it is necessary to transmit light to the surface of the charge generation material in order to efficiently generate charge carriers in the charge generation material (3). The low molecular charge transfer agent mixed polycarbonate resin used in the present invention has almost no absorption at a wavelength of 600 nm or more, generally absorbs light from the visible region to the near infrared region, and generates a charge carrier (3) When combined, the feature is that it works as a charge transport material particularly effectively.

2 includes a charge generation layer (5) mainly composed of a charge generation material (3) on a conductive support (1) and a low molecular charge transport agent mixed polycarbonate resin having charge transport ability. A photosensitive layer (2b) comprising a laminate with the charge transport layer (4) is provided. In this photoreceptor, the light transmitted through the charge transport layer (4) reaches the charge generation layer (5), where charge carriers are generated, while the charge transport layer (4) receives the charge carrier injection. The charge carriers necessary for light attenuation are generated by the charge generating material (3), and the charge carriers are transported by the charge transport layer (4). Such a mechanism is the same as that described for the photoconductor shown in FIG.
The charge transport layer (4) is formed by using a low molecular charge transport agent mixed polycarbonate resin alone or in combination with a binder used in the present invention. In order to increase the charge generation efficiency, the charge generation layer (5) may contain a low molecular charge transport agent mixed polycarbonate resin used in the present invention.
The same applies to photosensitive layers (2c) and (2d) described later.

The photoreceptor in FIG. 3 is obtained by further providing a second charge transport layer (4-2) on the first charge transport layer (4-1). This second charge transport layer is on the outermost surface of the photoreceptor and may be referred to as a protective layer in order to impart functions such as wear resistance. The protective layer in this case can be regarded as a part of the charge transport layer.
In the case of this configuration, a protective layer is formed on the first charge transport layer (4-1) in combination with the polycarbonate resin or binder used in the present invention. Of course, a low molecular charge transport material may be added. In that case, it is preferable to use a low molecular charge transport material in the range of 0 to 60% by weight.
Further, the lower charge transport layer (4-1), which is a lower layer, is mixed with a low molecular charge transport material at a high concentration, and is not used or lower in the second charge transport layer (4-2), which is an upper layer. More preferably, it is used at a concentration. A protective layer may be similarly provided on the photosensitive layer (2a) shown in FIG.

The photoconductor in FIG. 4 is obtained by reversing the stacking order of the charge generation layer (5) in FIG. 2 and the charge transport layer (4) containing a polycarbonate resin mixed with a low molecular charge transport agent, and the generation of the charge carriers. The transport mechanism can be the same as described above. In this case, the protective layer (6) is provided on the charge generation layer (5) in consideration of mechanical strength.
In FIG. 4, the polycarbonate resin used in the present invention can of course be used in the internal charge transport layer, but it can also be used as a binder for the protective layer by taking advantage of its excellent mechanical wear resistance.

  In order to actually produce the photoreceptor of the present invention, fine particles of the charge generating substance (3) are dissolved in a solution in which a low molecular charge transport material, a polycarbonate resin or a binder is used in combination, as long as the photoreceptor shown in FIG. Is coated on the conductive support (1) and dried to form the photosensitive layer (2a).

  Low molecular charge transport materials include, for example, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, benzidine compounds, pyrazolines Derivatives, stilbene compounds, amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly- Conventionally known materials such as 9-vinylanthracene can be used.

The thickness of the photosensitive layer (2a) is 3 to 50 μm, preferably 5 to 40 μm. The amount of the polycarbonate resin in the photosensitive layer (2a) is 20 to 70% by weight, the amount of the low molecular charge transport material is 30 to 70% by weight, and the charge generating material (3) in the photosensitive layer (2a). Is from 0.1 to 50% by weight, preferably from 1 to 20% by weight.
Examples of the charge generating substance (3) include inorganic materials such as selenium, selenium-tellurium, cadmium sulfide, cadmium sulfide-selenium, and α-silicon, and examples of organic materials include C.I. Pigment Blue 25 (Color Index CI21180) and C.I. Pigment Red. 41 (CI21200), CI Acid Red 52 (CI45100), CI Basic Red 3 (CI45210), an azo pigment having a carbazole skeleton (described in JP-A-53-95033), an azo pigment having a distyrylbenzene skeleton (special feature) No. 53-133445), an azo pigment having a triphenylamine skeleton (described in JP-A-53-132347), an azo pigment having a dibenzothiophene skeleton (described in JP-A-54-21728), Oxazi An azo pigment having a sol skeleton (described in JP-A No. 54-12742), an azo pigment having a fluorenone skeleton (described in JP-A No. 54-22834), an azo pigment having a bis-stilbene skeleton (Japanese Patent Laid-Open No. No. 17733), azo pigments having a distyryl oxadiazole skeleton (described in JP-A No. 54-2129), azo pigments having a distyrylcarbazole skeleton (described in JP-A No. 54-14967) ) Azo pigments, for example, phthalocyanine pigments such as C.I. Pigment Blue 16 (CI74100), indigo pigments such as C.I.But Brown 5 (CI73410), C.I. Indenseence scarlet R (manufactured by Bayer) etc. Perylene pigments. These charge generation materials may be used alone or in combination of two or more.

  Further, among the above charge generating materials, a highly sensitive and highly durable photoconductor can be obtained particularly by a combination with a phthalocyanine pigment. The phthalocyanine pigment is a compound having a phthalocyanine skeleton represented by the following general formula (N), and M (center metal) includes metal and nonmetal (hydrogen) elements.

ここで挙げられるＭは、Ｈ、Ｌｉ、Ｂｅ、Ｎａ、Ｍｇ、Ａｌ、Ｓｉ、Ｋ、Ｃａ、Ｓｃ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ、Ｇａ、Ｇｅ、Ｙ、Ｚｒ、Ｎｂ、Ｍｏ、Ｔｃ、Ｒｕ、Ｒｈ、Ｐｄ、Ａｇ、Ｃｄ、Ｉｎ、Ｓｎ、Ｓｂ、Ｂａ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｏｓ、Ｉｒ、Ｐｔ、Ａｕ、Ｈｇ、Ｔｌ、Ｌａ、Ｃｅ、Ｐｒ、Ｎｄ、Ｐｍ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙｂ、Ｌｕ、Ｔｈ、Ｐａ、Ｕ、Ｎｐ、Ａｍ等の単体、もしくは酸化物、塩化物、フッ化物、水酸化物、臭化物などの２種以上の元素からなる。中心金属は、これらの元素に限定されるものではない。
本発明におけるフタロシアニン骨格を有する電荷発生物質とは、少なくとも一般式（Ｎ）の基本骨格を有していればよく、２量体、３量体など多量体構造を持つもの、さらに高次の高分子構造を持つものでもかまわない。また基本骨格に様々な置換基があるものでもかまわない。

M mentioned here is H, Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y , Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, La, Ce Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Pa, U, Np, Am, etc., or oxides, chlorides, fluorides, It consists of two or more elements such as hydroxide and bromide. The central metal is not limited to these elements.
The charge generation material having a phthalocyanine skeleton in the present invention may have at least a basic skeleton of the general formula (N), a substance having a multimeric structure such as a dimer or trimer, and a higher order high-order substance. It may have a molecular structure. Also, the basic skeleton may have various substituents.

Of these various phthalocyanines, oxotitanium phthalocyanine having TiO as a central metal and metal-free phthalocyanine having H are particularly preferable in terms of photoreceptor characteristics.
These phthalocyanines are also known to have various crystal systems, such as α, β, γ, m, y type in the case of oxotitanium phthalocyanine, α, β, γ, etc. in the case of copper phthalocyanine. It has a polycrystal system. Even in a phthalocyanine having the same central metal, various properties change as the crystal system changes. Among them, it has been reported that the photoconductor characteristics also change with such a crystal system change. (Journal of Electrophotographic Society, Vol. 29, No. 4 (1990)) From this, each phthalocyanine has an optimum crystal system in terms of the characteristics of the photoreceptor, and in particular, in oxotitanium phthalocyanine, the y-type Crystalline systems are desirable.

In addition, these charge generation materials may be a mixture of two or more charge generation materials having a phthalocyanine skeleton. Further, it may be mixed with other charge generating materials.
In this case, examples of the charge transport material to be mixed include inorganic materials and organic materials.
Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.
On the other hand, organic materials include azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, azo pigments having a dibenzothiophene skeleton, fluorenone Azo pigment having skeleton, azo pigment having oxadiazole skeleton, azo pigment having bis stilbene skeleton, azo pigment having distyryl oxadiazole skeleton, azo pigment having distyryl carbazole skeleton, perylene pigment, anthraquinone or Polycyclic quinone pigments, quinone imine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments, etc. And the like.

Further, in order to produce the photoreceptor shown in FIG. 2, a charge generating material is vacuum-deposited on the conductive support (1), or a fine particle (3) of the charge generating material is dissolved in a suitable binder if necessary. A dispersion dispersed in a solvent is applied and dried, and if necessary, surface finishing and film thickness adjustment are performed by a method such as buffing to form a charge generation layer (5). A charge transport layer (4) may be formed by applying a solution dissolved together with a transport material, a polycarbonate resin, or a binder and drying it.
Here, the charge generation material used for forming the charge generation layer (5) is the same as described for the photosensitive layer (2a).
The thickness of the charge generation layer (5) is 5 μm or less, preferably 2 μm or less, and the thickness of the charge transport layer (4) is 3-50 μm, preferably 5-40 μm. When the charge generation layer (5) is of a type in which fine particles (3) of the charge generation layer material are dispersed in a binder, the ratio of the fine particles (3) of the charge generation material to the charge generation layer (5) Is about 10 to 100% by weight, preferably about 50 to 100% by weight. The amount of the polycarbonate resin in the charge transport layer (4) is 20 to 70% by weight.

To prepare the photoreceptor shown in FIG. 3, the polycarbonate resin used in the present invention alone or in combination with a binder is dissolved and coated on the photoreceptor shown in FIG. 2 together with a low molecular charge transport material. Then, a second charge transport layer (protective layer) (4-2) is provided by drying.
The thickness of the second charge transport layer (protective layer) is preferably 0.15 to 10 μm.
The amount of the polycarbonate resin used in the present invention in the second charge transport layer (protective layer) (4-2) is 20 to 100% by weight.

In order to produce the photoreceptor shown in FIG. 4, a solution dissolved together with a low molecular charge transporting material in combination with a binder resin or a binder is applied onto the conductive support (1), dried, and charged with a charge transporting layer ( 4) is formed, and then a dispersion in which fine particles of the charge generation layer material are dispersed in a solvent in which a binder is dissolved if necessary is applied and dried on the charge transport layer by a method such as spray coating. (5) is formed.
The amount ratio of the charge generation layer or the charge transport layer is the same as that described in FIG.
By forming the protective layer (6) containing the polycarbonate resin used in the present invention on the charge generation layer (5) of the photoreceptor thus obtained, the photoreceptor shown in FIG. 4 can be produced. . The amount of the polycarbonate resin used in the present invention in the protective layer (6) is 20 to 100% by weight.

  In any of these photoreceptors, a metal plate or a metal foil such as aluminum, a plastic film on which a metal such as aluminum is vapor-deposited, or paper subjected to a conductive treatment is used for the conductive support (1). It is done.

In addition, as the binder, a condensation resin such as polyamide, polyurethane, polyester, epoxy resin, polyketone, or polycarbonate, or a vinyl polymer such as polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, or polyacrylamide is used. As the insulating and adhesive resin, known resins can be used.
A plasticizer is added to the binder as necessary. Examples of such a plasticizer include halogenated paraffin, dimethylnaphthalene, and dibutyl phthalate. If necessary, additives such as an antioxidant, a light stabilizer, a heat stabilizer, and a lubricant can be added.

  Furthermore, the photoreceptor obtained as described above can be provided with an adhesive layer or a barrier layer between the conductive support and the photosensitive layer, if necessary. Materials used for these layers include polyamide, nitrocellulose, aluminum oxide, titanium oxide and the like, and the film thickness is preferably 0.2 μm to 20 μm.

  To perform copying using the photoreceptor of the present invention, the photosensitive surface is charged and exposed, then developed, and transferred to paper or the like as necessary. The photoreceptor of the present invention has high sensitivity and is excellent in mechanical strength and is extremely useful.

Hereinafter, the present invention will be described by way of examples.
(Material synthesis example)
Synthesis of Bisphenol Monomer and Synthesis of 4-Bromo-2-methylanisole 92 parts of o-anisole, 147 parts of N-bromosuccinimide and 270 parts of dehydrated acetonitrile were placed in a stirred reaction vessel and reacted at room temperature for 2 hours. After the reaction, carbon tetrachloride was added and succinimide was filtered. The filtrate was concentrated and subjected to column chromatography on silica gel using a cyclohexane solvent to obtain 125 parts of 4-bromo-2-methylanisole.
Synthesis of 4-methoxy-3-methylphenol 6.4 parts of 3-methyl-p-anisaldehyde, 13 parts of m-chloroperbenzoic acid and 200 parts of dichloromethane were placed in a stirred reaction vessel and refluxed for 11 hours under a nitrogen stream. I let you. After the reaction, the reaction mixture was cooled, ethyl acetate was added, and the organic layer was washed 5 times with 5% aqueous sodium hydrogen carbonate solution and once with saturated brine. Finally, it was dried over anhydrous magnesium sulfate and the filtrate was concentrated. 25 parts of methanol and 20 parts of a 10% aqueous potassium hydroxide solution were added to the filtrate and reacted at room temperature for 2 hours under a nitrogen stream. After the reaction, 50 parts of ethyl acetate was added and extracted. The organic layer was concentrated and subjected to column chromatography on silica gel using a toluene solvent to obtain 4 parts of 4-methoxy-3-methylphenol.
Synthesis of 4,4'-dimethoxy-3,3'-dimethyldiphenyl ether 28 parts 4-bromo-2-methylanisole, 29 parts 4-methoxy-3-methylphenol, 13 parts potassium hydroxide, 9 parts activated copper Was placed in a stirred reaction vessel and reacted at 220 ° C. under a nitrogen stream for 3 hours. After the reaction, the reaction mixture was cooled, toluene was added, and the mixture was filtered through celite. The filtrate was concentrated, and column chromatography with silica gel was performed twice using a toluene / n-hexane (1/1) mixed solvent, followed by using a solvent, and 4,4′-dimethoxy-3,3′-dimethyl. 21 parts of diphenyl ether were obtained.
Synthesis of 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether 11 parts of 4,4′-dimethoxy-3,3′-dimethyldiphenyl ether are dissolved in 70 parts of dichloromethane, put into a stirred reaction vessel, and under nitrogen flow A solution prepared by dissolving 20 parts of boron tribromide in 10 parts of dichloromethane at −5 ° C. was slowly added dropwise over 15 minutes. After dropping, the temperature was gradually returned to room temperature, and the reaction was further continued for 2 hours. After the reaction, the reaction solution was poured into 500 parts of ice water and stirred for 30 minutes. The organic layer was washed with water, 5% aqueous sodium hydrogen carbonate solution and water in this order, and finally dried over anhydrous magnesium sulfate. The filtrate was concentrated, and column chromatography with silica gel was performed using a toluene / ethyl acetate (4/1) mixed solvent, followed by recrystallization purification with toluene, and 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether. 7 parts were obtained. The melting point of this compound was 141.5 to 142.5 ° C., and the results of elemental analysis are shown in the following table, which agreed with the value calculated from the structural formula.

Synthesis of polycarbonate resin (Synthesis Example 1)
2.7 parts of 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether obtained in the above synthesis example and 0.141 part of 4-tert-butylphenol as a molecular weight regulator are placed in a container, and under a nitrogen stream. A solution prepared by dissolving 3.50 parts of sodium hydroxide and 0.15 parts of sodium hydrosulfite in 38 parts of water was added, dissolved by stirring, and cooled to 5 ° C.
On the other hand, 2.43 parts of bis (trichloromethyl) carbonate, which is a phosgene trimer, and 31 parts of dichloromethane were added to a reaction vessel, dissolved by stirring, and cooled to 5 ° C. Thereafter, an alkaline solution of the monomer was added to the phosgene solution and reacted while forming an emulsion with vigorous stirring. After stirring for 15 minutes, 0.01 part of triethylamine was added as a catalyst, and the reaction was stirred at 28 ° C. for 150 minutes.
After completion of the reaction, the organic layer was taken out, diluted with dichloromethane, washed in order with water and a 2% aqueous hydrochloric acid solution, and finally washed until the conductivity of the aqueous layer after washing with water was 2 μS or less. The obtained organic layer was dropped into isopropyl alcohol to obtain a colorless polycarbonate resin. The yield after filtration and drying was 2.87 parts, and the yield was 96%.
The obtained polycarbonate resin No. The structure of 1 is described below. When the molecular weight of this polycarbonate resin was measured by gel permeation chromatography, the molecular weight in terms of polystyrene was 75900 in terms of number average molecular weight and 185800 in terms of weight average molecular weight. Moreover, the glass transition temperature calculated | required from the differential scanning calorimetry was 101 degreeC. The results of elemental analysis are shown in the following table, which agreed with the values calculated from the structural formula.

(Synthesis Examples 2 to 4)
A polycarbonate resin No. 4 having a different molecular weight was prepared in the same manner as in Synthesis Example 1 except that the amount of 4-tert-butylphenol charged was changed. 2-No. 4 was obtained.

Resin No. 2
Weight average molecular weight: 70000
Glass transition temperature: 99 ° C

Resin No. 3
Weight average molecular weight: 113000
Glass transition temperature: 100 ° C

Resin No. 4
Weight average molecular weight: 148,000
Glass transition temperature: 100 ° C

(Synthesis Example 5)
Resin No. 1 was prepared in the same manner as in Synthesis Example 1 except that 50 mol% of 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether was replaced with 1,1-bis (4-hydroxyphenyl) cyclohexane. 5 was obtained.

重量平均分子量：１５８８００
ガラス転移温度：１４２℃

Weight average molecular weight: 158800
Glass transition temperature: 142 ° C

(Synthesis Example 6)
Resin No. 1 was prepared in the same manner as in Synthesis Example 1 except that 50 mol% of 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether was replaced with 2,2-bis (4-hydroxyphenyl) propane. 6 was obtained.

重量平均分子量：１３７０００
ガラス転移温度：１２７℃

Weight average molecular weight: 137,000
Glass transition temperature: 127 ° C

(Synthesis Example 7)
Resin No. 1 was prepared in the same manner as in Synthesis Example 1 except that 70 mol% of 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether was replaced with 2,2-bis (4-hydroxyphenyl) propane. 7 was obtained.

重量平均分子量：１５１２００
ガラス転移温度：１３９℃

Weight average molecular weight: 151200
Glass transition temperature: 139 ° C

(Synthesis Example 8)
Resin No. 1 was prepared in the same manner as in Synthesis Example 1 except that 30 mol% of 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether was replaced with 2,2-bis (4-hydroxyphenyl) propane. 8 was obtained.

重量平均分子量：１５０５００
ガラス転移温度：１１７℃

Weight average molecular weight: 150500
Glass transition temperature: 117 ° C

(Synthesis Example 9)
Resin No. was similarly prepared except that 30 mol% of 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether was replaced with 2,2-bis (3-methyl-4-hydroxyphenyl) propane in Synthesis Example 1. . 9 was obtained.

重量平均分子量：１４６０００
ガラス転移温度：１０８℃

Weight average molecular weight: 146000
Glass transition temperature: 108 ° C

(Synthesis Example 10)
Resin No. 1 was prepared in the same manner as in Synthesis Example 1 except that 30 mol% of 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether was replaced with 4,4′-dihydroxydiphenyl ether. 10 was obtained.

重量平均分子量：１５３７００
ガラス転移温度：１１３℃

Weight average molecular weight: 153700
Glass transition temperature: 113 ° C

Example 1
A polyamide resin (CM-8000: manufactured by Toray Industries, Inc.) solution dissolved in a methanol / butanol mixed solvent was applied on an aluminum plate with a doctor blade, and air dried to provide a 0.3 μm intermediate layer. A bisazo compound represented by the following formula as a charge generating material is pulverized with a ball mill in a mixed solvent of cyclohexanone and methyl ethyl ketone, and the resulting dispersion is applied with a doctor blade and naturally dried to generate a charge of 0.3 μm. A layer was formed.

Next, the resin No. obtained in Synthesis Example 1 was used. 1 polycarbonate resin and the following low-molecular charge transporting compound are dissolved in tetrahydrofuran at a weight ratio of 10: 7, this solution is applied onto the charge generation layer with a doctor blade, air-dried, and then at 120 ° C. for 20 minutes. A charge transport layer having a thickness of 20 μm was formed by drying to form a photoreceptor No. 1 was produced.
The photoreceptor No. thus produced was No. 1 was charged by applying a -6 kV corona discharge for 20 seconds in a dark place using a commercially available electrostatic copying paper testing apparatus [SP428 type manufactured by Kawaguchi Electric Mfg. Co., Ltd.], and then the surface potential Vm (- V) was measured, and after being left in a dark place for 20 seconds, the surface potential V0 (−V) was measured. Next, a tungsten lamp light is irradiated so that the illuminance on the surface of the photosensitive member becomes 4.5 lux, and a time (second) until V0 becomes 1/2 is obtained, and an exposure amount E1 / 2 (lux · sec) Was calculated. The results are shown in Table 3.

Further, the surface of the photoreceptor is subjected to a 3000 rotation wear test with a load of 1 kg using a CS-5 wear wheel made of a felt material with a Taber abrasion tester (manufactured by Toyo Seiki Co., Ltd.) in accordance with the industrial standard JIS K7204 (1995). It was.
In addition, a wear test of 1500 revolutions was performed at a load of 250 g using a CS-10 wear wheel made of a silica particle-containing rubber material. The amount of wear obtained in these tests is shown in Table 4.

Examples 2 to 4, Reference Examples 1 to 6
In Example 1, resin no. 1 except that the polycarbonate resin obtained in Synthesis Examples 2 to 10 was used instead of the polycarbonate resin of No. 1. 2-No. 10 were created and evaluated.

Comparative Examples 1-6
In Example 1, resin no. 1 instead of the polycarbonate resin No. 1 Photoreceptor No. 1 was used in the same manner except that polycarbonate resins 1 to 6 were used. 11-No. 16 were created and evaluated.

Ｍｗ：７６１００

Mw: 76100

Ｍｗ：１８０８００

Mw: 180800

Ｍｗ：１５１５００

Mw: 151500

Ｍｗ：１９０５００

Mw: 190500

Ｍｗ：７５０００

Mw: 75000

Ｍｗ：１２６０００

Mw: 126000

Ｍｗ：８１５００

Mw: 81500

Comparative Example 7
In Example 1, resin no. 1 instead of the polycarbonate resin No. 1 An attempt was made to produce a photoreceptor in the same manner using the polycarbonate resin No. 7, but the resin gelled and the photoreceptor could not be produced.

Example 5
Resin No. obtained in Synthesis Example 1 No. 1 polycarbonate resin and the above low-molecular charge transporting compound were dissolved in a mixed solvent of tetrahydrofuran and cyclohexanone at a weight ratio of 9: 1 at a weight ratio of 9: 1 to prepare a coating solution. The product was spray-coated on the body, allowed to dry naturally, and then dried at 130 ° C. for 20 minutes to form a protective layer having a thickness of 5 μm. 17 was produced. This was evaluated in the same manner as in Example 1.

Example 6
Comparative resin No. A charge transport layer was prepared in the same manner as in Comparative Example 3 except that the polycarbonate resin of No. 3 and the low molecular charge transporting compound were used in a weight ratio of 1: 1. Resin No. A protective layer was formed in the same manner as in Example 5 except that the polycarbonate resin of No. 1 and the low molecular charge transporting compound were used in a weight ratio of 10: 7. 18 was produced. This was evaluated in the same manner as in Example 1.

As shown in Examples 1 to 6 , the electrophotographic photosensitive member of the present invention has electrophotographic characteristics equivalent to those of the conventional ones, but has excellent wear resistance compared to the conventional ones, A highly durable electrophotographic photosensitive member can be provided.
The wear resistance of CS-10 wear wheel, which shows scratch wear characteristics, is superior to that of conventional photoconductors, and there is less wear due to scratches in the electrophotographic process with a lot of toner external additives, and it has a long life. The body can be provided.
Also, the wear resistance of the CS-5 wear wheel, which represents fatigue wear characteristics, is superior to that of conventional photoconductors, and it is due to fatigue even in an electrophotographic process equipped with a device that rubs the surface of the photoconductor by blade cleaning or the like. It is possible to provide an organic photoreceptor with little wear and long life.
The following points can be considered as the reason why the polycarbonate resin used in the present invention is excellent in wear resistance.
(1) The bisphenol body has a diphenyl ether structure, the molecular structure of the ether structure portion is good, and appropriate flexibility of the resin can be expressed.
(2) When there is no substituent other than the main chain bond on the benzene ring in the diphenyl ether structure site, a transparent amorphous film having strong crystallinity cannot be formed, whereas the resin used in the present invention has a substituent. Therefore, a stable amorphous film can be formed.
(3) One methyl group is attached as a substituent of the diphenyl ether ring, and due to moderate asymmetry, partial orientation hardly occurs, and a highly amorphous and flexible film can be formed.
(4) Even in a system in which a low molecular charge transporting compound is mixed as described above, it is compatible with each other and maintains high mechanical stability without impairing appropriate flexibility.

Moreover, when Reference Examples 1-6 and Examples 1-4 are compared, it turns out that the direction where the copolymerization seed | species is not included is more excellent in abrasion resistance. In particular, it is possible to provide a photoreceptor excellent in wear resistance due to CS-5 wear wheels and resistant to fatigue wear. Therefore, a longer life electrophotographic photosensitive member can be provided when the polycarbonate resin comprising the general formula (3) is used.

  In addition, in order to take advantage of the high wear resistance of the polycarbonate resin used in the present invention and the high wear resistance when a low molecular charge transport compound is mixed, the charge transport layer is the outermost surface as a photoreceptor structure The most excellent electrophotographic characteristics when applied to a functionally separated electrophotographic photosensitive member structure in which the charge generation layer and charge transport layer, which have been most practically used in the past and have been put into practical use, are stacked in this order. And an electrophotographic photosensitive member that can achieve both high wear resistance.

Moreover, the electrophotographic characteristics or the abrasion resistance can be further improved by forming the charge transport layer in a laminated structure and using the polycarbonate resin used in the present invention on the surface side. For example, as shown in Example 5 , a protective layer with a low content of a low-molecular charge transporting compound is laminated thinner than a normal charge transporting layer, so that the electrophotographic characteristics are not deteriorated so much that the wear resistance is further improved. Can be raised. Further, for example, as shown in Example 6 , the content of the low molecular charge transporting compound is increased to form a high mobility charge transporting layer, and a protective layer having excellent wear resistance is formed thereon, thereby forming an electrophotography. It is possible to provide an electrophotographic photoreceptor excellent in characteristics and excellent in abrasion resistance.

  In addition, it is known that the wear resistance of polycarbonate resin is abruptly lowered when the molecular weight is too small, and it is easily imagined that the same tendency is observed for the polycarbonate resin used in the present invention. As shown in Examples 1 to 4, the polycarbonate resin used in the present invention has a polystyrene-equivalent weight average molecular weight of 70,000 or more, and both show excellent wear resistance. Use such a resin. Can provide a long-life electrophotographic photosensitive member.

It is a figure which shows an example of the laminated constitution of the electrophotographic photoreceptor of this invention. It is a figure which shows the other example of a laminated constitution of the electrophotographic photoreceptor of this invention. It is a figure which shows the other example of a laminated constitution of the electrophotographic photoreceptor of this invention. It is a figure which shows the other example of a laminated constitution of the electrophotographic photoreceptor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive support body 2a, 2b, 2c, 2d Photosensitive layer 3 Charge generating substance 4 Charge transport layer (or charge transport medium)
4-1 First Charge Transport Layer 4-2 Second Charge Transport Layer 5 Charge Generation Layer 6 Protective Layer

Claims (4)

On a conductive support, a free polycarbonate resin represented by the following general formula (3), an electrophotographic photoreceptor, characterized in that a photosensitive layer containing a low-molecular charge transporting material.

(In the formula, n represents the number of repetitions and is an integer of 30 to 10,000.) The polycarbonate resin is, the electrophotographic photoreceptor according to claim 1, weight average molecular weight in terms of polystyrene is characterized and 70,000 der Turkey. Photosensitive layer of at least a charge generation layer has a structure laminated in the order of the charge transport layer, the electrophotographic photosensitive member according to claim 1 or 2 wherein the polycarbonate resin is characterized in that it is used in the charge transport layer . 4. The electrophotographic photosensitive member according to claim 3 , wherein the charge transport layer has a structure of two or more layers, and the polycarbonate resin is used for the charge transport layer on the outermost surface side.

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