JP2008009070A - Aromatic polycarbonate, electrophotographic photoreceptor, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new aromatic polycarbonate having proper charge transporting performance, superior mechanical strength, electrical characteristics, such as charging potential and sensitivity, and durability, and is capable of being suitably used. <P>SOLUTION: The aromatic polycarbonate comprises a constitutional unit represented by general Formula (1), wherein Ar<SB>1</SB>represents an aryl group or a heterocyclic group; Ar<SB>2</SB>and Ar<SB>3</SB>each represents an arylene group or a divalent heterocyclic group; Ar<SB>4</SB>represents an arylene group or a divalent heterocyclic group; Ar<SB>5</SB>represents H, an aryl group, an aralkyl group or an alkyl group; R<SB>1</SB>represents H, an aryl group or an alkyl group; R<SB>2</SB>and R<SB>3</SB>each represents H, an alkyl group, an aryl group, a heterocyclic group or an aralkyl group; and n represents an integer of 0-2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an aromatic polycarbonate, an electrophotographic photosensitive member, and an image forming apparatus.

  Conventionally, in electrophotographic image forming apparatuses such as copying machines, printers, facsimiles, etc., the surface layer of an electrophotographic photosensitive member for forming an electrostatic latent image has high mechanical strength, wear resistance, and dimensions. Polycarbonate is used because of its excellent stability and wear resistance. In particular, in a function-separated electrophotographic photosensitive member in which a charge generating layer containing a charge generating material and a charge transporting layer containing a charge transporting material are sequentially laminated on a conductive support, the charge transporting layer which is the outermost layer includes Polycarbonate is often used as a binder resin for holding the charge transport material in the layer.

  Examples of the polycarbonate include bisphenol A polycarbonate obtained by reacting 4,4 ′-(1-methylethylidene) bisphenol (bisphenol A) and phosgene, and 4,4′-cyclohexene having excellent wear resistance and solubility. Aromatic polycarbonates such as Z-type polycarbonates synthesized from silidenebisphenol (bisphenol Z) are known as typical ones. These polycarbonates are generally superior in mechanical strength (especially mechanical strength at low temperatures) and superior in weather resistance compared to other thermoplastic resins.

  By the way, in order to maintain the electric characteristics required for the electrophotographic photosensitive member, the charge transport layer contains the same amount of charge transport material as polycarbonate which is a binder resin. However, the amount ratio between the polycarbonate and the charge transporting material is combined with the fact that the charge transporting material is a low molecular weight compound having low compatibility with the polycarbonate. Is a cause of damage.

  For this reason, attempts have been made to improve the durability of the charge transport layer by reducing the amount of charge transport material added while improving the electrical characteristics of the charge transport material while maintaining the electrical characteristics of the electrophotographic photoreceptor. Has been made. This attempt has further improved the sensitivity and mobility of the charge transport material. However, the charge transport materials that have been proposed so far require an addition amount that has an adverse effect on the durability of the charge transport layer in order to obtain desired electrical characteristics. Therefore, it is very difficult to achieve both electrical characteristics and durability.

  In order to solve the above problems, attempts have been made to impart a charge transport function to the binder resin and reduce the amount of charge transport material added. For example, a binder resin containing a structural unit having a charge transporting function, a so-called polymer photoconductive material is being developed. Specific examples of the binder resin include a carbazole-based polycarbonate having a carbazole ring in the main chain (see, for example, Patent Document 1), a polyvinyl carbazole having a carbazole ring in a side chain (see, for example, Patent Document 2), and the like. These carbazole polymers have drawbacks that they are poor in flexibility, have low mechanical strength, and easily form structural traps, which is one of the causes for reducing charge transport ability.

  Moreover, as binder resin other than the above, a polystyrene compound having a hydrazone side chain (for example, see Patent Document 3), an arylamine compound having a tertiary amine structure in the main chain (for example, see Patent Documents 4 to 6), and a side chain Examples include (meth) acrylic acid copolymers having a tertiary amine structure (triphenylamine skeleton) (see, for example, Patent Document 7). These polymers are not fully satisfactory in terms of charge transport ability, mechanical strength, and the like.

  In addition, although the polymers described in Patent Documents 1 to 7 are all π electron conjugated systems, polysilanes having a conduction mechanism through a σ electron conjugated system different from that (for example, see Patent Documents 8 to 9) and the like. Can be mentioned. Although polysilane is excellent in charge transporting ability, it has not been put into practical use because it is easily decomposed by ultraviolet light and has poor mechanical strength.

  In addition, for the purpose of improving mechanical strength, a polycarbonate copolymer obtained by monomerizing a charge transport material and copolymerizing this monomer and a polycarbonate monomer (for example, Patent Documents 10 to 11 and Non-Patent Document 1) can be given. reference). However, such a copolymer is not at a sufficiently satisfactory level for both charge transporting ability and mechanical strength.

  Moreover, the aromatic polycarbonate formed by making the enamine compound (for example, refer patent documents 12-13) excellent in charge transport ability into a monomer, and copolymerizing this enamine monomer and a polycarbonate monomer is mentioned (for example, refer patent document 14). However, this aromatic polycarbonate has a high structure symmetry and tends to cause crystallization. For this reason, when used as a photosensitive layer resin of an electrophotographic photosensitive member, there is a disadvantage that the crystallized portion becomes an image defect.

  In addition, as a means for improving the mechanical strength of a photosensitive layer such as a charge transport layer, a surface protective layer is laminated on the photosensitive layer. This surface protective layer usually contains a conductive substance and a binder resin. As the binder resin, for example, a polycarbonate having a polar group (see, for example, Patent Document 15), a polycarbonate having a fluorine-substituted alkyl group (see, for example, Patent Document 16), and the like have been proposed. However, in such an electrophotographic photoreceptor, a potential barrier is formed at the interface between the surface protective layer and the charge transport layer due to incompatibility between the charge transport material in the charge transport layer and the conductive material in the surface protective layer. . This potential barrier causes a reduction in sensitivity when charge injection is insufficient. Also, peeling and / or cracking may occur during manufacturing due to the difference in shrinkage caused by the difference in material between the two layers. Therefore, sufficient performance cannot be realized.

  Recently, a surface protective layer made of a siloxane resin has been proposed (see, for example, Patent Document 17). However, in order to form a surface protective layer using a siloxane resin, it is necessary to heat cure the siloxane resin. However, the material in the photosensitive layer may be deteriorated by heating. The siloxane resin itself is an insulator. Therefore, it is necessary to add a low molecular compound having a charge transporting ability. However, it is the same as in the case of the charge transport layer that the addition of such a low molecular weight compound causes a decrease in the mechanical strength of the surface protective layer.

JP-A-4-183719 JP 50-82056 A Japanese Patent Laid-Open No. 3-50555 JP-A-1-13061 JP-A-1-19049 JP-A-5-40350 JP-A-5-66598 JP-A 63-285552 Japanese Patent Laid-Open No. 5-19497 Japanese Patent Laid-Open No. 3-221522 JP-A-4-11627 Japanese Patent Laid-Open No. 6-43674 Patent Registration No. 3580426 JP 2004-269813 A U.S. Pat. No. 4,260,671 JP-A-10-158380 JP 2000-241919 “Prospects for Development and Practical Use of Charge-Transporting Polymers”, Katsumi Nukata, Functional Materials, October 1999, Vol. 19, no. 10, pages 52-59, published by CMC Publishing

  The problems of the present invention are that (1) excellent mechanical strength, (2) very good electrical characteristics, (3) high charging potential and sensitivity, (4) voltage application, laser light Changes in various properties when repeated irradiation, toner adhesion, heating and pressurization, etc., and (5) a novel aromatic polycarbonate capable of providing a long-term stable high-quality image to an electrophotographic photoreceptor. An electrophotographic photosensitive member using the aromatic polycarbonate, and an image forming apparatus using the electrophotographic photosensitive member.

  As a result of intensive studies to solve the above problems, the present inventor has found that an aromatic polycarbonate containing an asymmetric bishydroxy compound as a structural unit can solve the above problems, thereby completing the present invention.

  Thus, according to the present invention, the following general formula (1)

(In the formula, Ar ₁ represents an aryl group which may have a substituent or a heterocyclic group which may have a substituent. Ar ₂ and Ar ₃ may be different from each other and have a substituent. A divalent heterocyclic group which may have a good arylene group or substituent, and two Ar _{4 s} are the same or different and have an arylene group or a substituent which may have a substituent; The two Ar _{5 s} are the same or different and each represents a hydrogen atom, an aryl group which may have a substituent, an aralkyl group or a substituent which may have a substituent; R ₁ represents a hydrogen atom, an aryl group which may have a substituent, or an alkyl group which may have a substituent, 2n R ₂ and R ₃ are , The same or different, a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a substituent A heterocyclic group which may have a substituent or an aralkyl group which may have a substituent, n represents an integer of 0 to 2, and z is a value sufficient to obtain a number average molecular weight of 5,000 to 500,000. )
The aromatic polycarbonate containing the structural unit represented by these is provided.

Furthermore, according to the present invention, there is provided an electrophotographic photosensitive member characterized by having a photosensitive layer containing the aromatic polycarbonate on a conductive support.
In addition, according to the present invention, there is provided an electrophotographic photosensitive member comprising a photosensitive layer and a surface protective layer containing the aromatic polycarbonate on a conductive support.
Further, according to the present invention, the electrophotographic photosensitive member, a charging means for charging the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member are exposed with light according to image information to form an electrostatic latent image. An exposure unit that forms an image; a developing unit that develops the electrostatic latent image formed on the electrophotographic photosensitive member into a visible image; and a visible image developed by the developing unit on a recording medium. An image forming apparatus including a transfer means for transferring is provided.

According to this invention, the homopolymer containing the structural unit represented by General formula (1), or the structural unit represented by General formula (1) and the structural unit represented by General formula (4) is included. An aromatic polycarbonate that is a copolymer is provided.
The aromatic polycarbonate not only has good charge transport performance, but also has excellent mechanical strength, electrical characteristics, durability, and the like. Therefore, it can be suitably used as a binder resin for a photosensitive layer in a single layer type electrophotographic photosensitive member, a charge transport layer in a multilayer type electrophotographic photosensitive member, and a surface protective layer in single layer type and multilayer type electrophotographic photosensitive members. Furthermore, the aromatic polycarbonate of the present invention can be used as a charge transport material in a photosensitive layer, a charge transport layer and the like. In this case, even if the aromatic polycarbonate of the present invention and another aromatic polycarbonate are used as the binder resin, the compatibility between them is good, so that uniform charge transport performance can be exhibited in the photosensitive layer, the charge transport layer, etc. .

The aromatic polycarbonate of the present invention can be used not only as a charge transport material, a charge transport layer and a binder resin for a single-layer type photosensitive layer in an electrophotographic photoreceptor, but also as a sensor material, an organic electroluminescence (EL) element, an organic It can also be suitably used as a constituent for photorefractive elements.
In consideration of stability that it is difficult to be decomposed or altered as a chemical substance, availability, production cost, and the like, the structural unit of the general formula (2) is preferable, and the structural unit of the general formula (3) is more preferable.
An aromatic polycarbonate further containing the structural unit of the general formula (5) is preferable because it can further improve mechanical strength, durability, weather resistance, chemical resistance, and the like.

According to the present invention, there is provided an electrophotographic photoreceptor containing the aromatic polycarbonate of the present invention in a photosensitive layer, a surface protective layer or the like. This electrophotographic photosensitive member has various performances such as charge transport performance, mechanical strength, electrical characteristics, and durability (including wear resistance) at a very high level. Therefore, when this electrophotographic photosensitive member is used, even when 100,000 or more images are formed, the amount of film loss is very small, and the electric characteristics are almost the same as in the initial state. In addition, a high-quality image free from image defects such as white spots can be stably formed.
According to the present invention, an image forming apparatus including an electrophotographic photosensitive member capable of stably forming the high-quality image can be provided.

(Aromatic polycarbonate)
The aromatic polycarbonate of the present invention is a homopolymer containing a structural unit represented by the following general formula (1), or represented by the structural unit represented by the general formula (1) and the following general formula (4). And a structural unit. Among the structural units represented by the general formula (1), from the viewpoint of easy acquisition or synthesis of raw materials, low raw material costs, and high stability as a compound, the following general formula (2 ) Including a structural unit represented by the following general formula (3) is particularly preferable. Similarly, among the structural units represented by the general formula (4), those including a structural unit represented by the following general formula (5) are preferable.

  Although the content ratio of the structural units of the general formulas (1) and (4) is not particularly limited, the general formula (1): general formula (4) = 5 to 95:95 to 5 (molar ratio) is usually preferable. More preferably, it is 20-60: 40-80 (molar ratio), More preferably, it is 30-45: 70-55 (molar ratio). If it is the ratio of the range of 5-95: 95-5, there exists an effect of coexistence of mechanical strength and an electrical property.

The ratio of the aromatic polycarbonate of the present invention in the homopolymer and copolymer is preferably 50% by weight or more, more preferably 80% by weight or more, and preferably 100% by weight. Particularly preferred.
Moreover, it is preferable that the aromatic polycarbonate copolymer has a number average molecular weight (Mn) of 5,000 to 500,000. When Mn is smaller than 5000, the film strength becomes weak, which is not preferable. When it exceeds 500,000, solubility in a solvent becomes poor at the time of manufacture, which is not preferable. More preferable Mn is 10,000 to 100,000, and more preferable Mn is 15,000 to 60,000.

  Furthermore, the polycarbonate copolymer preferably has a weight average molecular weight (Mw) of 5,000 to 500,000. When Mw is less than 5000, the film strength becomes weak, which is not preferable. When it exceeds 500,000, solubility in a solvent becomes poor at the time of manufacture, which is not preferable. More preferable Mw is 10,000 to 300,000, and further preferable Mw is 20000 to 150,000.

Here, Mn and Mw are the polystyrene-equivalent number average molecular weight and weight average molecular weight measured by gel permeation chromatography (GPC).
In the general formulas (1) to (3), the symbol z is a value sufficient to obtain a number average molecular weight of 1000 to 500,000. In general formula (1) and (2), the code | symbol n is an integer of 0-2.

In the general formulas (1) to (3), examples of the aryl group in the symbol Ar ₁ include phenyl, naphthyl, biphenylyl, and the like. When the aryl group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. As the aryl group, phenyl, tolyl, methoxyphenyl, naphthyl and the like are preferable.
In addition, examples of the heterocyclic group in the symbol Ar ₁ include thienyl, benzothiazolyl, and the like. When the heterocyclic group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms. As the heterocyclic group, a thiophene ring, a benzothiazole ring and the like are preferable.

In the general formula (1), examples of the arylene group in the symbols Ar ₂ and Ar ₃ and the symbols Ar ₄ in the general formulas (1) and (2) include phenylene, naphthylene, benzoxazolen, biphenylylene, and the like. When the arylene group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms. As the arylene group, p-phenylene, m-phenylene, methyl-p-phenylene, methoxy-p-phenylene, 1,4-naphthylene, benzoxazolen, biphenylylene and the like are preferable, and p-phenylene, m-phenylene, methyl -P-phenylene, methoxy-p-phenylene, 1,4-naphthylene and the like are more preferable, and p-phenylene, 1,4-naphthylene is particularly preferable.

In the general formula (1), the divalent heterocyclic groups in the symbols Ar ₂ and Ar ₃ and the symbols Ar ₄ in the general formulas (1) and (2) are 1,4-furandyl, 1, 4-thiophenediyl, 2,5-benzofurandyl, 2,5-benzoxazolediyl, carbazole-3,6-diyl group, and the like can be mentioned. When the divalent heterocyclic group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms. As the divalent heterocyclic group, 1,4-furandiyl, 1,4-thiophenediyl, 2,5-benzofurandyl, 2,5-benzoxazolediyl and N-ethylcarbazole-3,6-diyl groups are preferable. .

In the general formula (1), when one of the symbols Ar ₂ and Ar ₃ is p-phenylene and the other is 1,4-naphthylene, that is, in the case of the general formula (2), the raw material is obtained at low cost. It is particularly preferable because it can be easily synthesized.
In the general formula (1), examples of the aryl group in the symbol Ar ₅ include phenyl and naphthyl. When the aryl group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms and a dialkylamino group having 2 to 8 carbon atoms. As the aryl group, phenyl, p-tolyl and the like are preferable.

Examples of the aralkyl group in the symbol Ar ₅ include benzyl and naphthylmethyl. When the aralkyl group has a substituent, the substituent is a linear or branched alkyl group having 1 to 4 carbon atoms selected from methyl, ethyl, isopropyl, tert-butyl, etc., cycloalkyl such as cyclohexyl, cyclopentyl, etc. You can choose from groups. As the aralkyl group, benzyl, p-methylbenzyl, 1-naphthylmethyl and the like are preferable.

In the general formulas (1) to (3), examples of the aryl group in the symbol R ₁ include phenyl and naphthyl. When the aryl group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms. As the aryl group, phenyl and p-tolyl are preferable.
Examples of the alkyl group in the symbol R ₁ include a linear or branched alkyl group having 1 to 4 carbon atoms. When the alkyl group has a substituent, the substituent can be selected from a halogen atom. As the alkyl group, methyl, ethyl, n-propyl, isopropyl, trifluoromethyl and the like are preferable.

In the general formula (1), examples of the alkyl group in the symbols R ₂ and R ₃ include a linear or branched alkyl group having 1 to 4 carbon atoms. When the alkyl group has a substituent, the substituent can be selected from a halogen atom (for example, a fluorine atom and a chlorine atom) and an aryl group (for example, a phenyl group). As the alkyl group, methyl, ethyl, n-propyl, isopropyl, fluoromethyl, phenylmethyl and the like are preferable.
Examples of the aryl group in the symbols R ₂ and R ₃ include phenyl and naphthyl. When the aryl group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms. As the aryl group, phenyl and tolyl are preferable, and a phenyl group is more preferable.

Examples of the heterocyclic group in the symbols R ₂ and R ₃ include thienyl, furyl, benzofuryl, benzoxazolyl and carbazolyl groups. When the heterocyclic group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms. As the heterocyclic group, a thienyl group is preferable.
Examples of the aralkyl group in the symbols R ₂ and R ₃ include benzyl and naphthylmethyl. When the aralkyl group has a substituent, the substituent is a linear or branched alkyl group having 1 to 4 carbon atoms selected from methyl, ethyl, isopropyl, tert-butyl, etc., cycloalkyl such as cyclohexyl, cyclopentyl, etc. You can choose from groups. As the aralkyl group, benzyl is preferable.

The terminal structure of the aromatic polycarbonate is preferably a structure derived from para-hydroxybenzoic acid-n-butyl, parahydroxy-n-propyl, ethyl parahydroxybenzoate, or the like.
The aromatic polycarbonate preferably has a solubility capable of dissolving 10 to 30 g in 100 g of an organic solvent such as tetrahydrofuran. The aromatic polycarbonate having such solubility has an effect that it is easy to form a layer using the polycarbonate by a coating method.

(Method for producing aromatic polycarbonate)
Among the aromatic polycarbonates of the present invention, a homopolymer composed of the structural unit represented by the general formula (1) is, for example, an asymmetric bishydroxy compound which may have charge transporting ability as a raw material compound (monomer). It can be produced in the same manner as a conventional polycarbonate except that one or more kinds and one or more kinds of carbonate compounds are used.
Moreover, the copolymer which consists of a structural unit represented by General formula (1) and General formula (4) is 1 of the asymmetric bishydroxy compound which may have a charge transport ability as a raw material compound (monomer), for example. It can be produced in the same manner as a conventional polycarbonate except that one or more species, one or more carbonate compounds, and one or more dihydroxy compounds are used.

(Asymmetric bishydroxy compound)
Known asymmetric bishydroxy compounds can be used. Among these, for example, an asymmetric bishydroxy compound having a charge transporting ability represented by the following general formula (6) (hereinafter referred to as “asymmetric bishydroxy compound (6)”) is preferable.

  Among the asymmetric bishydroxy compounds (6), an asymmetric bishydroxy compound represented by the following general formula (7) (hereinafter referred to as “asymmetric bishydroxy compound (7)”) is more preferable, and represented by the following general formula (8). The asymmetric bishydroxy compound (hereinafter referred to as “asymmetric bishydroxy compound (8)”) is particularly preferred.

(In the formula, Ar ₁ , Ar ₂ , Ar ₃ , Ar ₄ , Ar ₅ , R ₁ , R ₂ , R ₃ and n are the same as above.)
The asymmetric bishydroxy compound (6) can be produced, for example, by the method shown in the following reaction process formula. That is, it can be produced by producing an ether compound (12a) or (12b) of an asymmetric bishydroxy compound according to the following reaction process formula, and further deprotecting the hydroxyl protecting group represented by the symbol R ₅ .
[Reaction process]

(In the formula, Ar ₁ , Ar ₂ , Ar ₃ , Ar ₄ , Ar ₅ , R ₁ , R ₂ , R ₃ , and n are the same as above. Two R _{4 s} are the same or different and have a substituent. R ₅ represents the same or different, an alkyl group which may have a substituent, or an aralkyl which may have a substituent. Ar ₆ represents an aryl group which may have a substituent or a heterocyclic group which may have a substituent.
In this reaction process formula, examples of the alkyl group in the symbols R ₄ and R ₅ include a linear or branched alkyl group having 1 to 4 carbon atoms. When the alkyl group has a substituent, the substituent can be selected from a halogen atom (for example, a fluorine atom and a chlorine atom) and an aryl group (for example, a phenyl group). As the alkyl group, methyl, ethyl, n-propyl, isopropyl and the like are preferable.

Examples of the aryl group in the symbol R ₄ include phenyl and naphthyl. When the aryl group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms. As the aryl group, phenyl and p-tolyl are preferable, and a phenyl group is more preferable.
Examples of the aralkyl group in the symbol R ₅ include benzyl and naphthylmethyl. When the aralkyl group has a substituent, the substituent is a linear or branched alkyl group having 1 to 4 carbon atoms selected from methyl, ethyl, isopropyl, tert-butyl, etc., cycloalkyl such as cyclohexyl, cyclopentyl, etc. You can choose from groups. As the aralkyl group, benzyl is preferable.

Examples of the aryl group which may have a substituent in the symbol Ar ₆ include phenyl, naphthyl, biphenylyl and the like. When the aryl group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. As the aryl group, phenyl, tolyl, methoxyphenyl, naphthyl and the like are preferable.
Examples of the heterocyclic group in the symbol Ar ₆ include thienyl and benzothiazolyl. When the heterocyclic group has a substituent, the substituent can be selected from an alkyl group having 1 to 4 carbon atoms. As the heterocyclic group, a thiophene ring, a benzothiazole ring and the like are preferable.
Each reaction in this reaction process equation can be carried out, for example, as follows.

(Production of biscarbonyl intermediate represented by general formula (10))
(A) Bisformylation of the amine compound represented by the general formula (9) (hereinafter referred to as “amine compound (9)”) can be carried out, for example, according to the Vilsmeier reaction. Specifically, it can be carried out by heating the amine compound (9) and the Vilsmeier reagent with stirring, followed by hydrolysis.

As the Vilsmeier reagent, known ones can be used, and examples thereof include Vilsmeier reagent obtained by reacting phosphorus oxychloride with one or more of formamides in a suitable solvent.
Examples of the solvent include N, N-dimethylformamide, 1,2-dichloroethane and the like. N, N-dimethylformamide can also be used as formamides to be reacted with phosphorus oxychloride. Examples of formamides include N, N-dimethylformamide, N-methyl-N-phenylformamide, N, N-diphenylformamide, and the like.

  The use ratio of the amine compound (9) and the Vilsmeier reagent is not particularly limited, but considering the reaction efficiency and the like, the Vilsmeier reagent is used in an amount of 2.0-2. About 3 equivalents are preferably used. This reaction is preferably carried out with stirring and heating at 60 to 110 ° C., and is usually completed in about 2 to 8 hours.

By carrying out hydrolysis by adding an alkali to the reaction mixture after completion of the reaction, two of the biscarbonyl intermediates represented by the general formula (10) (hereinafter referred to as “biscarbonyl intermediate (10)”) A compound in which R ₁ is a hydrogen atom (hereinafter referred to as “biscarbonyl intermediate (10a)”) is obtained by precipitation. Here, general alkalis such as sodium hydroxide and potassium hydroxide can be used as the alkali. Moreover, an alkali is normally used with the form of aqueous solution, and the density | concentration of the alkali in this aqueous solution should just be about 1-8N.

  (B) The bisacylation of the amine compound (9) can be performed, for example, according to the Friedel-Crafts reaction. Specifically, the reaction can be carried out by reacting the amine compound (9) with a Friedel-Crafts reaction reagent in a suitable solvent and further hydrolyzing the reaction product. Here, the solvent is not particularly limited as long as it is inert to the reaction and can dissolve or disperse the amine compound (9) and Friedel-Crafts reaction reagent, and examples thereof include 1,2-dichloroethane. A well-known thing can be used as a Friedel-Crafts reaction reagent, For example, what is obtained by making aluminum chloride and an acid chloride react is mentioned. Here, as an acid chloride, acetyl chloride etc. are mentioned, for example.

  The use ratio of the amine compound (9) and the Friedel-Crafts reaction reagent is not particularly limited, but considering the reaction efficiency and the like, the Friedel-Crafts reaction reagent is used in an amount of 2. for 1 equivalent of the amine compound (9). It is preferable to use about 0 to 2.3 equivalents. This reaction is preferably performed with stirring and at a temperature of -40 to 80 ° C, and is usually completed in about 2 to 8 hours.

By carrying out hydrolysis by adding an alkali to the reaction mixture after completion of the reaction, among the biscarbonyl intermediate (10), two R ₁ are groups other than hydrogen atoms (hereinafter referred to as “biscarbonyl intermediate (10b)”. ) ") Is obtained. The hydrolysis with alkali can be carried out in the same manner as the hydrolysis for obtaining the biscarbonyl intermediate (10a).

(Production of ether compound represented by formula (12a) or (12b))
Further, the biscarbonyl intermediate (10) is subjected to a Wittig-Horner reaction, and the biscarbonyl intermediate (10) is reacted with a Wittig reagent to thereby produce an asymmetric bishydroxy compound (6). An ether compound represented by the general formula (12a) or (12b) (hereinafter referred to as “ether compound (12a) or (12b)”), which is an ether compound serving as a precursor, is obtained.

Here, examples of the Wittig reagent include compounds represented by the general formula (11a) or (11b) (hereinafter referred to as “Wittig reagent (11a) or (11b)”). In the Wittig reagents (11a) and (11b), the hydroxyl group bonded to the substituent represented by the symbol Ar ₄ is protected by the substituent represented by the symbol R ₅ .

By reacting the biscarbonyl intermediate (10) with the Wittig reagent (11a), an ether compound (12a) is obtained, and further, the protecting group represented by the symbol R ₅ is deprotected, whereby the asymmetric bishydroxy compound (6) In which n = 0 is obtained (hereinafter referred to as “asymmetric bishydroxy compound (6a)”).
Further, by reacting the biscarbonyl intermediate (10) with the Wittig reagent (11b), an ether compound (12b) is obtained, and further, the protecting group represented by the symbol R ₅ is deprotected, whereby an asymmetric bishydroxy compound ( In 6), a compound in which n = 1 or 2 (hereinafter referred to as “asymmetric bishydroxy compound (6b)”) is obtained.
The Wittig-Horner reaction for the biscarbonyl intermediate (10) can be carried out according to a known method. For example, the biscarbonyl intermediate (10) and the Wittig reagent (11a) or (11b) may be reacted in a suitable solvent in the presence of a catalyst such as a metal alkoxide base.

  The solvent is not particularly limited as long as it is inert to the reaction and can dissolve or disperse the reaction substrates (biscarbonyl intermediate (10) and Wittig reagent (11)) and catalyst. Examples thereof include aromatic hydrocarbons such as toluene and xylene, ethers such as diethyl ether, tetrahydrofuran and ethylene glycol dimethyl ether, amides such as N, N-dimethylformamide, and sulfoxides such as dimethyl sulfoxide. A solvent can be used individually by 1 type, or can mix and use 2 or more types as needed. The amount of the solvent used is not particularly limited, and the amount by which the reaction smoothly proceeds may be appropriately selected according to the reaction conditions such as the amount of the reaction substrate used, the reaction temperature, and the reaction time.

  A well-known thing can be used as a metal alkoxide base, For example, alkali metal alkoxide bases, such as potassium t-butoxide, sodium ethoxide, sodium methoxide, etc. are mentioned. A metal alkoxide base can be used individually by 1 type, or can use 2 or more types together. The amount of the reaction substrate and the catalyst used is not particularly limited and can be appropriately selected from a wide range depending on the reaction conditions and the like. However, considering the smooth progress of the reaction, etc., preferably 1 equivalent of the biscarbonyl intermediate (10) On the other hand, the Wittig reagent (11a) or (11b) may be used in an amount of about 2.0 to 2.3 equivalents, and the catalyst may be used in an amount of about 2.0 to 2.5 equivalents. This reaction is preferably carried out with stirring and at room temperature or under heating at 30 to 60 ° C., and is usually completed in about 2 to 8 hours. By this reaction, the ether compound (12a) or (12b) is obtained.

  Deprotection of the ether compound (12a) or (12b) can be carried out according to a known method. For example, it can be carried out by reacting the ether compound (12a) or (12b) with a deprotecting agent in a suitable solvent. Here, known deprotecting agents can be used, for example, hydrogen halides such as hydrogen bromide and hydrogen iodide, aluminum halides such as aluminum chloride and aluminum bromide, boron tribromide, and ethanethiol sodium. Examples include salts. A deprotecting agent can be used individually by 1 type, or can use 2 or more types together. The amount of the deprotecting agent to be used is not particularly limited, but is preferably about 2.0 to 3.0 equivalents, more preferably 2.2 to 2.6 with respect to 1 equivalent of the ether compound (12a) or (12b). What is necessary is just to use about an equivalent.

  Considering the smooth progress of the reaction and the easy isolation and purification of the target compound after completion of the reaction, the solvent for deprotection is inert to the reaction and can stably dissolve or disperse the reaction substrate. Anything can be used without particular limitation. Examples include aromatic hydrocarbons such as benzene and nitrobenzene, halogenated aromatic hydrocarbons such as chlorobenzene, formamides such as N, N-dimethylformamide, acetic anhydride, and methylene chloride. It may be appropriately selected and used depending on the situation. For example, when hydrogen halide is used as the deprotecting agent, acetic anhydride is preferred. When aluminum halide is used, aromatic hydrocarbons, halogenated aromatic hydrocarbons and the like are preferable. When using boron tribromide, methylene chloride is preferred. When ethanethiol sodium salt is used, formamides are preferred. The amount of the solvent used is not particularly limited, and can be appropriately selected from a wide range according to the reaction conditions such as the kind of the reaction substrate and the deprotecting agent, the amount used, and the reaction temperature. This deprotection reaction can be performed under cooling or from room temperature to solvent reflux, and is usually completed in about 0.5 to 24 hours. In addition, what is necessary is just to select suitably reaction temperature that the deprotection reaction advances smoothly. By this reaction, an asymmetric bishydroxy compound (6) is obtained.

In addition, the target compound produced | generated in each said reaction can be used for next reaction, without isolating from the reaction mixture after completion | finish of reaction, or isolating. The target compound can be isolated from the reaction mixture according to general purification means such as extraction, chromatography, centrifugation, recrystallization, and washing.
Specific examples of the asymmetric bishydroxy compound (6) include those described in Table 1 below.

(Carbonate compound)
In addition, as the carbonate compound used together with the asymmetric bishydroxy compound in the production of the aromatic polycarbonate, any of those used for the production of the polycarbonate can be used. For example, bisaryl carbonates such as bisphenyl carbonate, halogenated formates such as bischloroformate, phosgene, trichloromethyl chloroformate (phosgene dimer), bis (trichloromethyl) carbonate (phosgene trimer) ), Halogenated carbonates such as phosgene multimers, and the like. The phosgene trimer is advantageous in that it is thermally and chemically stable and easy to control and handle. Halogenated formates can be derived from the following dihydroxy compounds.

  Examples of the dihydroxy compound include a dihydroxy compound (hereinafter referred to as “dihydroxy compound (15)”) represented by the general formula (15) HO—X—OH (wherein X is the same as above). The mechanical strength of the aromatic polycarbonate containing the structural unit of the general formula (1) and the general formula (4) obtained by using the dihydroxy compound (15) is compared with the mechanical strength of the aromatic polycarbonate containing only the structural unit (1). It can be further improved than the strength.

  Specific examples of the dihydroxy compound (15) include, for example, 4,4 ′-(1-methylethylidene) bisphenol, 4,4 ′-(1-methylethylidene) bis (2-methylphenol), 4,4′- Cyclohexylidene bisphenol, 4,4-ethylidene bisphenol, 4,4 ′-(1,3-dimethylbutylidene) bisphenol, 4,4 ′-(1-methylethylidene) bis (2,6-dimethylphenol), 4 , 4 ′-(1-phenylethylidene) bisphenol, 4,4 ′-(2-ethylhexylidene) bisphenol, 5,5 ′-(1-methylethylidene) (1,1′-biphenyl) -2-ol 1,1′-biphenyl-4,4′-diol, 4,4′-methylidene bisphenol, 4,4′-methylene bis [2- (2-propenyl) phenol] 4,4′-methylidenebis (2-methylphenol),

4,4'-propanediylbisphenol, 4,4 '-(1-methylpropylidene) bisphenol, 4,4'-(2-methylpropylidene) bisphenol, 4,4 '-(3-methylbutylidene) bisphenol 4,4′-cyclopentylidene bisphenol, 4,4 ′-(phenylmethylidene) bisphenol, 4,4 ′-(1-methylheptylidene) bisphenol, 4,4′-cyclohexylidene bis (3- Methylphenol), 4,4 ′-(1-methylethylidene) bis [2- (2-propenyl) phenol], 4,4 ′-(1-methylethylidene) bis [2- (1-methylethyl) phenol] 4,4 ′-(1-methyloctylidene) bisphenol, 4,4 ′-(1-phenylethylidene) bis (2-methylphenol), 4,4′-cyclo Hexylidenebis (2,6-dimethylphenol),

4,4 ′-(1-methyl) nonylidene bisphenol, 4,4′-decylidene bisphenol, 4,4 ′-(1-methylethylidene) bis [2- (1,1-methylpropyl) phenol], 4 , 4 ′-(1-methylethylidene) bis [2- (1,1-dimethylethyl) phenol], 4,4 ′-(diphenylmethylidene) bisphenol, 4,4′-cyclohexylidenebis [2- ( 1,1-dimethylethyl) phenol], 4,4 ′-(2-methylpropylidene) bis [3-methyl-6- (1,1-dimethylethyl) phenol], 4,4 ′-(1-methyl) Ethylidene) bis (2-cyclohexylphenol), 4,4′-methylene-bis [2,6-bis (1,1-dimethylethyl) phenol], 4,4′-methylenebis (2,6-di-sec-) Spotted Phenol),

5,5 ′-(1,1-cyclohexylidene) bis- (1,1′-biphenyl) -2-ol, 4,4′-cyclohexylidenebis (2-cyclohexylphenol), 2,2′- Methylenebis (4-nonylphenol), 4,4 ′-(1-methylethylidene) bis [2,6-bis (1,1-dimethylethyl) phenol], 5,5 ′-(1-phenolethylidene) (1, 1'-biphenyl) -2-ol, bis (4-hydroxyphenyl) methanone, 4,4'-methylenebis (2-fluorophenol), 4,4 '-[2,2,2-trifluoro-1- ( Trifluoromethyl) ethylidene] bisphenol, 4,4′-isopropylidenebis (2-fluorophenol), 4,4 ′-[(4-fluorophenyl) methylene] bis (2-fluorophenol) , 4,4 '- (phenylmethylene) bis (2-fluorophenol),

4,4 ′-[(4-fluorophenyl) methylene] bisphenol, 4,4 ′-(1-methylethylidene) bis (2-chloro-6-methylphenol), 4,4 ′-(1-methylethylidene) Bis (2,6-dichlorophenol), 4,4 ′-(1-methylethylidene) bis (2-chlorophenol), 4,4′-methylenebis (2,6-dibromophenol), 4,4 ′-( 1-methylethylidene) bis (2,6-dibromophenol), 4,4 ′-(1-methylethylidene) bis (2-nitrophenol), 3,3′-dimethyl-1,1′-biphenyl-4, 4′-diol, 3,3 ′, 5,5′-tetramethyl-1,1′-biphenyl-4,4′-diol, 3,3 ′, 5,5′-tetra-t-butyl-1, 1′-biphenyl-4,4′-diol, 3,3′-di Examples include fluoro-1,1′-biphenyl-4,4′-diol, 3,3 ′, 5,5′-tetrafluoro-1,1′-biphenyl-4,4′-diol, and the like.

  Two or more kinds of the dihydroxy compound (15) may be used in combination. In particular, from the viewpoint of reactivity, 4,4 ′-(1-methylethylidene) bisphenol, 4,4 ′-(1-methylethylidene) bis (2-methylphenol), 4,4′-cyclohexylidenebisphenol, etc. preferable.

(Polymerization method)
The polymerization method of an asymmetric bishydroxy compound and a carbonate compound, and the polymerization method of an asymmetric bishydroxy compound, a carbonate compound and a dihydroxy compound are described in, for example, “Plastic Materials Course, Polycarbonate Resin” (Matsuo Matsugane, Shogo Tahara, Shuji Kato, Nikkan). The method can be carried out according to known methods described in documents such as those published by Kogyo Shimbun, published in 1969.
For example, when a halogenated carbonate is used as the carbonate compound, an aromatic polycarbonate can be obtained by an interfacial polymerization method, a solution polymerization method, or the like. Moreover, when using bisaryl carbonate as a carbonate compound, an aromatic polycarbonate can be obtained by transesterification.

[Interfacial polymerization method]
More specifically, according to the interfacial polymerization method, an aqueous phase containing an asymmetric bishydroxy compound and an oil phase containing a carbonate compound and a polycarbonate-forming catalyst, and further containing a dihydroxy compound, if necessary, are mixed between the two phases. The aromatic polycarbonate of the present invention can be produced by polymerizing these compounds.

  The asymmetric bishydroxy compound can be dissolved in water under alkaline conditions. A common base can be used to make the water alkaline. Known bases can be used, for example, alkali metal or alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, calcium carbonate, sodium bicarbonate, etc. And alkali metal or alkaline earth metal carbonates. Among these, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferable. A base can be used individually by 1 type or can use 2 or more types together. The water used here is distilled water, ion-exchanged water or the like. The aqueous phase may contain an aqueous medium such as alcohol. The amount of the base used may be such that the total amount of the asymmetric bishydroxy compound used is stably dissolved in the water used.

  As the organic solvent constituting the oil phase, those commonly used in this field, that is, those having a low solubility in water so as not to adversely affect the polymerization reaction and those capable of dissolving the produced aromatic polycarbonate can be used. For example, halogenated aliphatic hydrocarbons such as dichloromethane, 1,2-dichloroethane, 1,2-dichloroethylene, trichloroethane, tetrachloroethane, dichloropropane, halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene, halogenated fats A mixture of two or more of aromatic hydrocarbons, a mixture of two or more of halogenated aromatic hydrocarbons, one or more of halogenated aliphatic hydrocarbons and one of halogenated aromatic hydrocarbons Or the mixture with 2 or more types is mentioned. Among these, dichloromethane, chlorobenzene and the like are preferable. Furthermore, you may mix 1 type, or 2 or more types chosen from aromatic hydrocarbons, such as toluene, xylene, and ethylbenzene, alicyclic hydrocarbons, such as hexane and a cyclohexane, with the said organic solvent. Although the amount of the organic solvent used is not particularly limited, an amount that allows the polymerization reaction to proceed smoothly may be appropriately selected according to reaction conditions such as the type and amount of each monomer, the type of organic solvent, the reaction temperature, and the reaction time. .

As the polycarbonate forming catalyst, those commonly used in this field can be used. Examples include tertiary amines, quaternary ammonium salts, tertiary phosphines, quaternary phosphonium salts, nitrogen-containing heterocyclic compounds and salts thereof, imino ethers and salts thereof, amide group-containing compounds, and the like. Among these, tertiary amines are preferable, tertiary amines having 3 to 30 carbon atoms are more preferable, and triethylamine is particularly preferable. The timing for adding the polycarbonate-forming catalyst to the reaction system may be either before or after the carbonate compound is added to the reaction system, or twice before and after the addition.
The proportions of the asymmetric bishydroxy compound, dihydroxy compound and carbonate compound used are not particularly limited, but it is preferable to obtain an aromatic polycarbonate in which the molar ratio of the general formulas (1) and (4) to the structural unit is within the above range. It is preferable to set so that

  In the interfacial polymerization reaction, the molecular weight can be adjusted by the following method. That is, the molecular weight of the polycarbonate to be produced is tracked by a technique such as chromatography, and when the desired molecular weight is reached, the molecular weight is adjusted by adding a terminal terminator as a molecular weight regulator to the reaction system. is there. As the end capping agent, those commonly used in this field can be used. For example, 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 and the like can be mentioned. Among these, monovalent aromatic hydroxy compounds are preferable, and phenol, p-tert-butylphenol, p-cumylphenol and the like are more preferable. When a terminal terminator is used, a monovalent substituent derived from the terminal terminator is usually bonded to the C-terminal and O-terminal of the resulting aromatic polycarbonate.

  In the interfacial polymerization reaction, an appropriate amount of a branching agent can be added in order to further improve the mechanical properties of the resulting aromatic polycarbonate. As a branching agent, those commonly used in this field can be used. For example, 3 or the same or different reactive groups selected from phenolic hydroxyl group, haloformate group, carboxylic acid group, carboxylic acid halide group, active halogen atom and the like can be used. Compounds having two or more.

In the interfacial polymerization reaction, it is also possible to obtain an aromatic polycarbonate having a narrow molecular weight distribution in a short time by emulsifying the reaction medium by high-speed stirring, addition of an emulsifier, or the like.
The interfacial polymerization reaction is performed, for example, at a temperature of 0 to 40 ° C. and is completed in about several minutes to 5 hours. In addition, the pH of the aqueous phase is usually preferably maintained at 10 or more, for example, by adding a base.

[Solution polymerization method]
In addition, according to the solution polymerization method, an aromatic bishydroxy compound and a carbonate compound and, if necessary, a monomer composed of a dihydroxy compound are polymerized in an appropriate solvent in the presence of a deoxidizing agent. Polycarbonate can be produced. More specifically, an asymmetric bishydroxy compound and, if necessary, a dihydroxy compound are dissolved in a solvent, a deoxidizing agent is added to this solution, bischloroformate, phosgene, a phosgene dimer, phosgene An aromatic polycarbonate is obtained by adding a carbonate compound such as a multimer and carrying out a polymerization reaction.
The proportions of the asymmetric bishydroxy compound, dihydroxy compound and carbonate compound are not particularly limited, but preferably aromatics in which the molar ratio of the structural units represented by the general formulas (1) and (4) is within the above range. It is preferable to set so that a polycarbonate can be obtained.

As the solvent, those commonly used in this field and inert to the polymerization reaction and capable of dissolving or dispersing the three types of monomers and the deoxidizer can be used. Examples thereof include halogenated hydrocarbons such as dichloromethane, dichloroethane, trichloroethane, tetrachloroethane, trichloroethylene, and chloroform, cyclic ethers such as tetrahydrofuran and dioxane, pyridine, and the like. As the deoxidizer, those commonly used in this field can be used. For example, tertiary amines such as trimethylamine, triethylamine and tripropylamine, pyridine and the like can be mentioned.
Furthermore, as in the case of interfacial polymerization, a molecular weight regulator, a branching agent and the like can be added.
This method is usually performed at a temperature of 0 to 40 ° C. and is completed in about several minutes to 5 hours.

[Transesterification method]
Furthermore, according to the transesterification method, for example, an asymmetric bishydroxy compound and a bisaryl carbonate (carbonate compound) and, if necessary, a dihydroxy compound are mixed in an inert gas atmosphere, usually under reduced pressure and at 120 to 350 ° C. Aromatic polycarbonate is obtained by reacting at a temperature of. It is preferable to change the degree of vacuum stepwise and finally to 1 mmHg or less to distill off by-produced phenols out of the system. The reaction time is usually about 1 to 4 hours. Moreover, you may add a molecular weight regulator, antioxidant, etc. as needed.
In each of the above polymerization reactions, a random copolymer, an alternating copolymer, a block copolymer, a random alternating copolymer or a random block copolymer can be selectively produced by appropriately selecting a polymerization operation. .

  For example, a random copolymer can be obtained by uniformly mixing an asymmetric bishydroxy compound and a dihydroxy compound and then performing a condensation reaction with a carbonate compound such as phosgene. When several kinds of asymmetric bishydroxy compounds are further added to the reaction system during the polymerization reaction, a random block copolymer is obtained. An alternating copolymer can be obtained by conducting a condensation reaction between a bischloroformate derived from a dihydroxy compound and an asymmetric bishydroxy compound. Conversely, an alternating copolymer can be obtained in the same manner by a condensation reaction of bischloroformate derived from an asymmetric bishydroxy compound with a dihydroxy compound. A random alternating copolymer is obtained by a condensation reaction using two or more bischloroformates and an asymmetric bishydroxy compound or dihydroxy compound.

The aromatic polycarbonate thus obtained can be easily isolated and purified from the reaction mixture after completion of the polymerization reaction by a general purification means such as extraction, chromatography, centrifugation, recrystallization, washing and the like.
One or more selected from general resin additives such as antioxidants, light stabilizers, heat stabilizers, lubricants, and plasticizers can be added to the aromatic polycarbonate of the present invention as necessary. .

(Electrophotographic photoreceptor)
The configuration is not particularly limited as long as the aromatic polycarbonate is contained in the electrophotographic photosensitive member.
1 to 8 are cross-sectional views schematically showing the configuration of the main part of the electrophotographic photosensitive member. The electrophotographic photosensitive member shown in FIGS. 1 to 4 is a single layer type electrophotographic photosensitive member characterized in that the photosensitive layer 2 is composed of one layer. The electrophotographic photoreceptor shown in FIGS. 5 to 8 is a function-separated or laminated electrophotographic photoreceptor in which the photosensitive layer 2 a is composed of the charge generation layer 3 and the charge transport layer 4.
The electrophotographic photosensitive member shown in FIG. 1 includes a conductive support (electrophotographic photosensitive member tube) 1 and a photosensitive layer 2 formed on the surface of the conductive support 1.

The electrophotographic photoreceptor shown in FIG. 2 includes a conductive support 1, a photosensitive layer 2 formed on the surface of the conductive support 1, and a surface protective layer 5 formed on the surface of the photosensitive layer 2.
The electrophotographic photoreceptor shown in FIG. 3 includes a conductive support 1, an undercoat layer 6 formed on the surface of the conductive support 1, and a photosensitive layer 2 formed on the surface of the undercoat layer 6. .
The electrophotographic photoreceptor shown in FIG. 4 includes a conductive support 1, an undercoat layer 6 formed on the surface of the conductive support 1, a photosensitive layer 2 formed on the surface of the undercoat layer 6, and a photosensitive layer. And a surface protective layer 5 formed on the surface of the layer 2.
The electrophotographic photosensitive member shown in FIG. 5 includes a conductive support 1, a charge generation layer 3 formed on the surface of the conductive support 1, and a charge transport layer 4 formed on the surface of the charge generation layer 3. Including.

The electrophotographic photoreceptor shown in FIG. 6 includes a conductive support 1, a charge generation layer 3 formed on the surface of the conductive support 1, a charge transport layer 4 formed on the surface of the charge generation layer 3, And a surface protective layer 5 formed on the surface of the charge transport layer 4.
The electrophotographic photosensitive member shown in FIG. 7 includes a conductive support 1, an undercoat layer 6 formed on the surface of the conductive support 1, a charge generation layer 3 formed on the surface of the undercoat layer 6, And a charge transport layer 4 formed on the surface of the charge generation layer 3.
The electrophotographic photosensitive member shown in FIG. 8 includes a conductive support 1, an undercoat layer 6 formed on the surface of the conductive support 1, a charge generation layer 3 formed on the surface of the undercoat layer 6, A charge transport layer 4 formed on the surface of the charge generation layer 3 and a surface protective layer 5 formed on the surface of the charge transport layer 4 are included.
Specifically, the layers constituting the electrophotographic photoreceptor shown in FIGS. 1 to 8 are as follows.

[Conductive support]
The electroconductive support body 1 is comprised with metal materials, such as aluminum, aluminum alloy, copper, zinc, stainless steel, titanium, for example. Further, without being limited to these metal materials, a metal foil laminated on a substrate surface made of a synthetic resin such as polyethylene terephthalate, polyester, polyoxymethylene, polystyrene, hard paper, glass, etc., or a metal material was deposited. It is also possible to use those obtained by depositing or applying a layer of a conductive compound such as a conductive polymer, tin oxide, indium oxide, carbon particles, or metal particles.

  If necessary, the surface of the conductive support 1 is irregularly reflected within a range that does not affect the image quality, such as anodized film treatment, surface treatment with chemicals, hot water, coloring treatment, and surface roughening. Processing may be performed. The irregular reflection treatment is particularly effective when an electrophotographic photosensitive member is used in an electrophotographic process using a laser as an exposure light source. That is, in the electrophotographic process using a laser as an exposure light source, the laser light has the same wavelength, so that the incident laser light and the light reflected in the electrophotographic photosensitive member interfere with each other, and interference fringes due to this interference are imaged. Appearing above may cause image defects. By subjecting the surface of the conductive support to the irregular reflection treatment as described above, it is possible to prevent image defects due to the interference of laser light having the same wavelength.

[Photosensitive layer]
The photosensitive layer 2 includes a charge generating material and the aromatic polycarbonate of the present invention. In the photosensitive layer 2, the aromatic polycarbonate functions as a charge transport material and a binder resin. The photosensitive layer 2 may contain a charge transport material other than the aromatic polycarbonate of the present invention, a binder resin other than the aromatic polycarbonate of the present invention, an antioxidant, and the like, if necessary.

  The charge generation material is a material that generates a charge by absorbing light. As the charge generating material, those commonly used in this field can be used. For example, azo pigments (monoazo pigments, bisazo pigments, trisazo pigments, etc.), indigo pigments (indigo, thioindigo, etc.), perylene pigments (peryleneimide, perylene acid anhydride, etc.), polycyclic quinone pigments (anthraquinone) , Pyrenequinone, etc.), phthalocyanine pigments (metal phthalocyanine, metal-free phthalocyanine, etc.), triphenylmethane dyes (methyl violet, crystal violet, night blue, Victoria blue, etc.), acridine dyes (erythrosine, rhodamine B, rhodamine 3R Acridine orange, frappeosin, etc.), thiazine dyes (methylene blue, methylene green, etc.), oxazine dyes (capri blue, meldra blue, etc.), squarylium dyes, pyrylium salts, thiopyrylium salts, thioy Organics such as digo dyes, bisbenzimidazole dyes, quinacridone dyes, quinoline dyes, lake dyes, azo lake dyes, dioxazine dyes, azurenium dyes, triallylmethane dyes, xanthene dyes, cyanine dyes Examples thereof include pigments, dyes, and inorganic materials such as amorphous silicon, amorphous selenium, tellurium, selenium-tellurium alloy, cadmium sulfide, antimony sulfide, zinc oxide, and zinc sulfide. One charge generating substance is used alone, or two or more kinds are used in combination.

The aromatic polycarbonate of the present invention is one kind selected from a homopolymer of the structural unit represented by the general formula (1) and a copolymer containing the structural units of the general formulas (1) and (4). Or 2 or more types can be used.
Other charge transport materials are used, for example, to further improve the electrical characteristics of the photosensitive layer 2. The charge transport material includes a hole transport material and an electron transport material.

  As the hole transport material, those commonly used in this field can be used, for example, carbazole derivatives, pyrene derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives. , Bisimidazolidine derivatives, styryl compounds, hydrazone compounds, polycyclic aromatic compounds, indole derivatives, pyrazoline derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, triarylamines Derivatives, triarylmethane derivatives, phenylenediamine derivatives, stilbene derivatives, enamine derivatives, benzidine derivatives, combinations thereof Polymers having a group derived from the main chain or side chain (poly-N-vinylcarbazole, poly-1-vinylpyrene, ethylcarbazole-formaldehyde resin, triphenylmethane polymer, poly-9-vinylanthracene, etc.), polysilane, etc. Is mentioned.

  As the electron transport material, those commonly used in this field can be used, for example, benzoquinone derivatives, tetracyanoethylene derivatives, tetracyanoquinodimethane derivatives, fluorenone derivatives, xanthone derivatives, phenanthraquinone derivatives, phthalic anhydride derivatives, Examples thereof include organic compounds such as diphenoquinone derivatives, inorganic materials such as amorphous silicon, amorphous selenium, tellurium, selenium-tellurium alloy, cadmium sulfide, antimony sulfide, zinc oxide, and zinc sulfide. One charge transport material can be used alone, or two or more charge transport materials can be used in combination.

Other binder resins are used, for example, to improve the mechanical strength, durability, etc. of the photosensitive layer 2. As other binder resins, those having excellent compatibility with the aromatic polycarbonate of the present invention are preferably used. Specific examples thereof include, for example, vinyl resins such as polymethyl methacrylate, polystyrene, and polyvinyl chloride, polycarbonate, polyester, polyester carbonate, polysulfone, polyarylate, polyamide, methacrylic resin, acrylic resin, polyether, polyacrylamide, and polyphenylene. Examples thereof include thermoplastic resins such as oxide, thermosetting resins such as phenoxy resin, epoxy resin, silicone resin, polyurethane and phenol resin, and partially cross-linked products of these resins. Among these, polystyrene, polycarbonate, polyarylate, and polyphenylene oxide have a volume resistance of 10 ¹³ Ω or more, have excellent electrical insulation properties, and are excellent in film formability, potential characteristics, etc., and thus are suitable as binder resins. Can be used. Furthermore, polycarbonate can be particularly preferably used. Other binder resins can be used alone or in combination of two or more.

  The antioxidant can reduce the deterioration of the surface layer due to the adhesion of active substances such as ozone and NOx generated when the electrophotographic photosensitive member is charged, and can improve the durability when the electrophotographic photosensitive member is repeatedly used. Further, the antioxidant can improve the stability of the coating solution for forming a photosensitive layer, which will be described later, and can extend the life of the solution. In addition, the electrophotographic photosensitive member produced with this coating solution can also improve durability because impurities are reduced.

  Examples of the antioxidant include hindered phenol derivatives and hindered amine derivatives. The amount of the antioxidant used is not particularly limited, but is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the charge transport material. If the amount of the antioxidant used is less than 0.1 parts by weight, the effect of improving the stability of the coating solution for forming a photosensitive layer, which will be described later, and the durability of the electrophotographic photosensitive member are insufficient, such being undesirable. On the other hand, if it exceeds 10 parts by weight, the electrical characteristics of the electrophotographic photosensitive member may be adversely affected.

  The photosensitive layer 2 is obtained by dissolving and / or dispersing a charge generating material, the aromatic polycarbonate of the present invention, and other charge transporting materials, other binder resins, and antioxidants in an applicable organic solvent as necessary. It can be formed by preparing a coating liquid for formation, applying this coating liquid to the surface of the conductive support 1 or the undercoat layer 6 described later, and drying to remove the organic solvent.

  Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, tetralin, diphenylmethane, dimethoxybenzene and dichlorobenzene, halogenated hydrocarbons such as dichloromethane and dichloroethane, tetrahydrofuran (THF), Ethers such as dioxane, dibenzyl ether and dimethoxymethyl ether, ketones such as cyclohexanone, acetophenone and isophorone, esters such as methyl benzoate and ethyl acetate, sulfur-containing compounds such as diphenyl sulfide, fluorine such as hexafluoroisopropanol Compounds, aprotic polar compounds such as N, N-dimethylformamide, mixtures of two or more of these compounds, one or more of these compounds with alcohols, acetonitrile or Mixtures plus ethyl ketone and the like.

  The film thickness of the photosensitive layer is not particularly limited, but is preferably 5 to 100 μm, more preferably 10 to 50 μm. If the film thickness is less than 5 μm, the charge holding ability on the surface of the electrophotographic photosensitive member may be lowered, which is not preferable. When the film thickness exceeds 100 μm, the productivity of the electrophotographic photosensitive member may be lowered, which is not preferable.

[Charge generation layer and charge transport layer]
The photosensitive layer 2 a is a laminate including the charge generation layer 3 and the charge transport layer 4.
The charge generation layer 3 contains a charge generation material and a binder resin.
As the charge generation material, one or more of the same charge generation materials as those contained in the photosensitive layer 2 can be used.

  As the binder resin, those commonly used as a matrix resin for the charge generation layer can be used. For example, thermoplastic resins such as polyester, polystyrene, acrylic resin, methacrylic resin, polycarbonate (including the aromatic polycarbonate of the present invention), and polyarylate. , Polyurethane, phenol resin, alkyd resin, melamine resin, epoxy resin, silicone resin, phenoxy resin, polyvinyl butyral, polyvinyl formal, and other thermosetting resins, and a co-polymer containing two or more of the structural units contained in these resins. Polymer resin (insulating resin such as vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, acrylonitrile-styrene copolymer resin) and the like. Among these, polyvinyl butyral is preferable. Binder resin can be used individually by 1 type, or can use 2 or more types together.

  Although the content ratio of the charge generation material and the binder resin is not particularly limited, the charge generation material is preferably contained in an amount of 10 to 99% by weight in the total amount of the charge generation material and the binder resin. If the ratio of the charge generation material is less than 10% by weight, the sensitivity may be lowered, which is not preferable. If the ratio of the charge generation material exceeds 99% by weight, (1) the film strength of the charge generation layer 3 may decrease, and (2) the dispersibility of the charge generation material decreases and coarse particles increase, thereby exposing the light. This is not preferable because the surface charge other than the portion to be erased may decrease. A decrease in film strength or a decrease in surface charge is one of the causes of image defects, particularly image fogging called black spots where toner adheres to a white background and minute black spots are formed.

  In addition to the two essential components, the charge generation layer 3 may be one or more selected from a hole transport material, an electron transport material, an antioxidant, a dispersion stabilizer, a sensitizer, and the like as necessary. Each of the other additives may contain an appropriate amount. As a result, the potential characteristics are improved, the stability of the coating solution for forming a charge generation layer, which will be described later, is increased, fatigue deterioration during repeated use of the electrophotographic photosensitive member can be reduced, and durability can be improved.

  The charge generation layer 3 is prepared by, for example, preparing a charge generation layer forming coating solution by dissolving or dispersing a charge generation material, a binder resin and other additives as required in a suitable organic solvent. Is applied to the surface of the conductive support 1 or the undercoat layer 6 described later, and dried to remove the organic solvent. Specifically, for example, a charge generation layer forming coating solution is prepared by dissolving or dispersing a charge generation substance and other additives as required in a resin solution obtained by dissolving a binder resin in an organic solvent. Is done.

  Examples of the organic solvent include halogenated hydrocarbons such as tetrachloropropane and dichloroethane, ketones such as isophorone, methyl ethyl ketone, acetophenone and cyclohexanone, esters such as ethyl acetate, methyl benzoate and butyl acetate, tetrahydrofuran (THF) ), Ethers such as dioxane, dibenzyl ether, 1,2-dimethoxyethane, dioxane, aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, tetralin, diphenylmethane, dimethoxybenzene, dichlorobenzene, diphenyl sulfide, etc. And fluorine-containing compounds such as hexafluoroisopropanol, aprotic polar compounds such as N, N-dimethylformamide or N, N-dimethylacetamide, and the like. Moreover, the mixed solvent which mixed 2 or more types of these compounds can also be used.

Prior to dissolving or dispersing the charge generation material or the like in the resin solution, the charge generation material and other additives may be pre-ground. The preliminary pulverization is performed using, for example, a general pulverizer such as a ball mill, a sand mill, an attritor, a vibration mill, and an ultrasonic disperser.
The dissolution or dispersion of the charge generating substance or the like in the resin solution is performed using a general dispersing machine such as a paint shaker, a ball mill, or a sand mill. At this time, it is preferable to appropriately select the dispersion conditions so that impurities are generated by abrasion or the like from the container that contains the resin solution, the charge generation material, and the like and the members constituting the disperser and are not mixed into the coating liquid. .

Examples of the method for applying the charge generation layer forming coating liquid include roll coating, spray coating, blade coating, ring coating, and dip coating.
The thickness of the charge generation layer 3 is not particularly limited, but is preferably 0.05 to 5 μm or less, more preferably 0.1 to 1 μm. If the thickness of the charge generation layer is less than 0.05 μm, the light absorption efficiency is lowered and the sensitivity may be lowered, which is not preferable. If the film thickness of the charge generation layer exceeds 5 μm, the charge transfer inside the charge generation layer becomes a rate-determining step in the process of erasing the charge on the surface of the electrophotographic photosensitive member, and the sensitivity may be lowered.

  The charge transport layer 4 can be composed of the aromatic polycarbonate of the present invention having the ability to accept and transport charges generated by the charge generating material. Furthermore, the charge transport layer 4 can contain other charge transport materials, other binder resins, antioxidants, and the like. The charge transport layer 4 may include other charge transport materials and other binder resins as essential components, and may further include an additive such as an antioxidant as necessary. The aromatic polycarbonate of the present invention is preferably contained in the charge transport layer 4 in the range of 50 to 75% by weight.

The aromatic polycarbonate of the present invention is 1 selected from a homopolymer comprising a structural unit represented by the general formula (1) and a copolymer comprising the structural units represented by the general formulas (1) and (4). Species or two or more can be used.
In addition, as other charge transport materials, other binder resins, and antioxidants, the same materials as those used in the photosensitive layer 2 can be used in the same amounts.

  The charge transport layer 4 is used for forming a charge transport layer by, for example, dissolving or dispersing the aromatic polycarbonate of the present invention, if necessary, other charge transport materials, other binder resins, and antioxidants in a suitable organic solvent. It can be formed by preparing a coating solution, applying this coating solution for forming a charge transport layer to the surface of the charge generation layer 3, and removing the organic solvent by drying.

  As the organic solvent used here, the same organic solvent used for forming the photosensitive layer 2 can be used. There is no restriction | limiting in particular as a coating method to the charge generation layer 3 surface of the coating liquid for charge transport layer formation, For example, dip coating, roll coating, inkjet coating etc. are mentioned. The drying may be performed by appropriately selecting a temperature at which the organic solvent contained in the coating liquid is removed and the charge transport layer 4 having a uniform surface can be formed.

  The thickness of the charge transport layer 4 is not particularly limited, but is preferably 5 to 50 μm, more preferably 10 to 40 μm. If the thickness of the charge transport layer is less than 5 μm, the charge holding ability on the surface of the electrophotographic photosensitive member may be lowered, which is not preferable. If the thickness of the charge transport layer exceeds 50 μm, the resolution of the electrophotographic photosensitive member may be lowered, which is not preferable.

[Surface protective layer]
The surface protective layer 5 has a function of improving the durability of the photosensitive layers 2 and 2a, for example. The surface protective layer 5 is formed, for example, by applying a resin solution obtained by dissolving a binder resin (including the aromatic polycarbonate of the present invention) in an appropriate organic solvent to the surface of the photosensitive layers 2 and 2a and removing the organic solvent by drying. it can. As the binder resin and the organic solvent used here, the same amount as that used in the charge transport layer 4 can be used in the same amount. The aromatic polycarbonate of the present invention is preferably contained in the surface protective layer 5 in the range of 70 to 90% by weight.

  The thickness of the surface protective layer 5 is not particularly limited, but is preferably 0.5 to 10 μm or less, more preferably 1 to 5 μm. If the thickness of the surface protective layer 5 is less than 0.5 μm, the surface resistance of the electrophotographic photosensitive member is inferior and the durability may be insufficient. If it exceeds 10 μm, the resolution of the electrophotographic photoreceptor may be lowered, which is not preferable.

[Underlayer]
The undercoat layer 6 has a function of preventing charge injection from the conductive support 1 to the photosensitive layers 2 and 2a. As a result, a decrease in chargeability of the photosensitive layers 2 and 2a can be suppressed, a decrease in surface charge other than a portion to be erased by exposure can be suppressed, and image defects such as fogging can be prevented from occurring. In particular, when an image is formed by the reversal development process, it is possible to prevent the occurrence of image fogging called black spots in which minute black dots made of toner are formed on a white background portion. Further, by covering the surface of the conductive support 1 with the undercoat layer 6, the degree of unevenness that is a defect on the surface of the conductive support 1 can be reduced to flatten the surface. Therefore, since the film formability of the photosensitive layers 2 and 2a on the undercoat layer 6 can be improved, the adhesion between the conductive support 1 and the photosensitive layers 2 and 2a can be improved.

  The undercoat layer 6 is prepared, for example, by preparing a coating solution for forming an undercoat layer in which a resin material is dissolved in an appropriate solvent, applying the coating solution to the surface of the conductive support 1, and applying the coating solution by heating. It can be formed by removing the solvent in the working liquid. The resin material constituting the resin layer includes polyethylene, polypropylene, polystyrene, acrylic resin, vinyl chloride resin, vinyl acetate resin, polyester, polycarbonate, polyester carbonate, polysulfone, polyvinyl butyral, polyamide, polyarylate, and other thermoplastic resins, polyurethane , Epoxy resins, melamine resins, phenoxy resins, silicone resins and other thermosetting resins, copolymer resins containing two or more of the structural units contained in these thermoplastic resins or thermosetting resins, casein, gelatin Natural polymer materials such as polyvinyl alcohol and ethyl cellulose. Examples of the solvent for dissolving or dispersing the resin material include water, alcohols such as methanol, ethanol and butanol, and glymes such as methyl carbitol and butyl carbitol. Is mentioned.

  Furthermore, metal oxide particles may be added to the undercoat layer forming coating solution. By adding metal oxide particles, the volume resistance value of the undercoat layer 6 can be easily adjusted, charge injection from the conductive support 1 to the photosensitive layers 2 and 2a can be further suppressed, and the electrophotographic photoreceptor can be used in various environments. Electrical characteristics can be maintained. Examples of the metal oxide particles include particles of titanium oxide, aluminum oxide, aluminum hydroxide, tin oxide, and the like. Examples of the apparatus for dispersing the metal oxide particles in the coating liquid for forming the undercoat layer include general particle dispersion apparatuses such as a ball mill, a sand mill, an attritor, a vibration mill, and an ultrasonic disperser.

  When the total content of the resin material and the metal oxide particles in the coating solution for forming the undercoat layer containing the resin material and the metal oxide particles is C, and the content of the solvent is D, the ratio between the two (C / D) is preferably 1/99 to 40/60 (= 0.01 to 0.67, weight ratio), more preferably 2/98 to 30/70 (= 0.02 to 0.43, Weight ratio). The ratio (E / F) between the resin material content (E) and the metal oxide particle content (F) is preferably 1/99 to 90/10 (= 0.01 to 9.0, weight ratio). And more preferably 5/95 to 70/30 (= 0.05 to 2.33, weight ratio).

The thickness of the undercoat layer 6 is not particularly limited, but is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm. When the film thickness is less than 0.01 μm, the undercoat layer 6 does not substantially function, and a uniform surface cannot be obtained by covering the defects of the conductive support 1, and the conductive support 1 is exposed to the photosensitive layer 2. , 2a cannot be prevented from being injected. As a result, the chargeability of the photosensitive layers 2 and 2a may be lowered, which is not preferable. When the film thickness exceeds 20 μm, it is not preferable because uniform formation of the undercoat layer 6 is difficult and the sensitivity of the electrophotographic photosensitive member may be lowered.
In addition, a layer containing alumite (alumite layer) can be formed on the surface of the conductive support 1, and this layer can be used as the undercoat layer 6.

(Image forming device)
FIG. 9 is a side view illustrating a simplified configuration of the image forming apparatus 20 of the present invention. The image forming apparatus 20 includes an electrophotographic photosensitive member 21 having any one of the configurations shown in FIGS. The image forming apparatus 20 will be described with reference to FIG. Note that the image forming apparatus of the present invention is not limited to the following description.
The image forming apparatus 20 includes an electrophotographic photosensitive member 21 rotatably supported by an apparatus main body (not shown), a charger 24, an exposure unit 28, a developing unit 25, a transfer unit 26, a cleaner 27, and a fixing unit. Device 31.

  The electrophotographic photosensitive member 21 is rotationally driven around the rotation axis 22 in the direction of the arrow 23 by a driving unit (not shown). The drive means includes, for example, an electric motor and a reduction gear. The driving means transmits the driving force to the conductive support constituting the core of the electrophotographic photosensitive member 21, thereby rotating the electrophotographic photosensitive member 21 at a predetermined peripheral speed. The charger 24, the exposure unit 28, the developing unit 25, the transfer unit 26, and the cleaner 27 are arranged along the outer peripheral surface of the electrophotographic photosensitive member 21 from the upstream side in the rotation direction of the electrophotographic photosensitive member 21 indicated by the arrow 23. In this order towards the side.

  The charger 24 is a charging unit that charges the outer peripheral surface of the electrophotographic photosensitive member 21 to a predetermined potential. In FIG. 9, the charger 24 is realized by a contact-type charging roller 24a and a bias power source 24b that applies a voltage to the charging roller 24a. A charger wire can also be used as the charging means. In particular, the former charging roller requires a high abrasion resistance on the surface of the photoreceptor, so that the electrophotographic photoreceptor on which the surface protective layer is formed exhibits a great effect by improving the durability.

  The exposure unit 28 includes, for example, a semiconductor laser as a light source. Light 28 a such as a laser beam output from a light source can be irradiated between the charger 24 and the developer 25 of the electrophotographic photosensitive member 21 by the exposure unit 28. As a result, it is possible to expose the outer peripheral surface of the charged electrophotographic photosensitive member 21 according to the image information. Usually, the light 28a is repeatedly scanned in the main scanning direction in the direction in which the rotation axis 22 of the electrophotographic photosensitive member 21 extends, whereby an electrostatic latent image can be sequentially formed on the surface of the electrophotographic photosensitive member 21.

  The developing device 25 is a developing unit that develops the electrostatic latent image formed on the surface of the electrophotographic photosensitive member 21 by exposure with a developer. The developing device 25 is provided facing the electrophotographic photosensitive member 21, and includes a developing roller 25 a that supplies toner to the outer peripheral surface of the electrophotographic photosensitive member 21 and a casing 25 b. The casing 25b supports the developing roller 25a so as to be rotatable about a rotation axis parallel to the rotation axis 22 of the electrophotographic photosensitive member 21, and accommodates a developer containing toner in the internal space thereof.

  The transfer unit 26 transfers a toner image, which is a visible image formed on the outer peripheral surface of the electrophotographic photosensitive member 21 by development, between the electrophotographic photosensitive member 21 and the transfer unit 26 from the direction of the arrow 29 by a conveying unit (not shown). Transfer means for transferring onto a transfer paper 30 as a recording medium supplied to the printer. The transfer unit 26 is, for example, a non-contact type transfer unit that includes a charging unit and transfers a toner image onto the transfer paper 30 by applying a charge having a polarity opposite to that of the toner to the transfer paper 30.

  The cleaner 27 is a cleaning unit that removes and collects toner remaining on the outer peripheral surface of the electrophotographic photosensitive member 21 after the transfer operation by the transfer unit 26. The cleaner 27 includes a cleaning blade 27a that peels off the toner remaining on the outer peripheral surface of the electrophotographic photosensitive member 21, and a recovery casing 27b that stores the toner peeled off by the cleaning blade 27a. Further, the cleaner 27 may be provided together with a static elimination lamp (not shown).

  Further, the image forming apparatus 20 includes a fixing device 31 that is a fixing unit that fixes the transferred image on the downstream side where the transfer paper 30 that has passed between the electrophotographic photosensitive member 21 and the transfer device 26 is conveyed. It may be provided. The fixing device 31 includes a heating roller 31a having a heating unit (not shown), and a pressure roller 31b that is provided to face the heating roller 31a and is pressed by the heating roller 31a to form a contact portion.

The image forming operation by the image forming apparatus 20 is performed as follows.
First, when the electrophotographic photosensitive member 21 is rotationally driven in the direction of the arrow 23 by the driving unit, a charger provided on the upstream side in the rotational direction of the electrophotographic photosensitive member 21 with respect to the imaging point of the light 28a by the exposure unit 28. 24, the surface of the electrophotographic photosensitive member 21 is uniformly charged to a predetermined positive or negative potential.

Next, light 28 a corresponding to image information is irradiated from the exposure unit 28 to the surface of the electrophotographic photosensitive member 21. By this exposure, the surface charge of the part irradiated with the light 28a is removed from the electrophotographic photosensitive member 21, and the surface potential of the part irradiated with the light 28a is different from the surface potential of the part not irradiated with the light 28a. And an electrostatic latent image is formed.
Toner is supplied to the surface of the electrophotographic photosensitive member 21 on which the electrostatic latent image is formed from a developing unit 25 provided downstream of the image forming point of the light 28a by the exposure means 28 in the rotation direction of the electrophotographic photosensitive member 21. The electrostatic latent image is developed to form a toner image.

In synchronization with the exposure of the electrophotographic photosensitive member 21, the transfer paper 30 is supplied between the electrophotographic photosensitive member 21 and the transfer unit 26. The transfer device 26 applies a charge having a polarity opposite to that of the toner to the supplied transfer paper 30, and the toner image formed on the surface of the electrophotographic photosensitive member 21 is transferred onto the transfer paper 30.
The transfer paper 30 onto which the toner image has been transferred is conveyed to a fixing device 31 by a conveying means, and is heated and pressurized when passing through a contact portion between a heating roller 31a and a pressure roller 31b of the fixing device 31, and toner The image is fixed on the transfer paper 30 and becomes a robust image. The transfer paper 30 on which the image is formed in this way is discharged to the outside of the image forming apparatus 20 by the conveying means.

On the other hand, the toner remaining on the surface of the electrophotographic photosensitive member 21 even after the transfer of the toner image by the transfer device 26 is separated from the surface of the electrophotographic photosensitive member 21 by the cleaner 27 and collected. The charge on the surface of the electrophotographic photosensitive member 21 from which the toner has been removed in this manner is removed by the light from the static elimination lamp, and the electrostatic latent image on the surface of the electrophotographic photosensitive member 21 disappears. Thereafter, the electrophotographic photosensitive member 21 is further rotationally driven, and a series of operations starting from charging is repeated to form images continuously.
Since the image forming apparatus of the present invention includes an electrophotographic photosensitive member having appropriate conductivity and excellent durability, it is possible to form a high-quality image under various environments.

Hereinafter, the present invention will be specifically described with reference to production examples, examples, and comparative examples. However, the following examples do not limit the present invention. Hereinafter, “part” means “part by weight”.
In addition, the molecular weight measurement and elemental analysis of the compounds obtained in the following production examples or examples were measured with the following apparatuses and conditions.

(Molecular weight measurement)
Molecular weight measuring device: LC-MS (manufactured by ThermoQuest, Finnegan LCQ Deca mass spectrometer system).
LC column GL-Sciences Inertsil ODS-3 2.1 × 100mm
Column temperature 40 ° C
Eluent methanol: water = 90: 10
Sample injection volume 5μl
Detector UV 254nm and MS ESI
(Elemental analysis)
Elemental analysis device: Perkin Aelmer, Elemental Analysis 2400
Sample amount: Weigh accurately about 2 mg Gas flow rate (ml / min): He = 1.5, O ₂ = 1.1, N ₂ = 4.3
Combustion tube temperature setting: 925 ℃
Reduction tube temperature setting: 640 ° C
The elemental analysis was a simultaneous determination method of carbon (C), hydrogen (H) and nitrogen (N) by a differential thermal conductivity method.

(Production Example 1)
In accordance with the following reaction process formula, Exemplified Compound No. 1 (compound (6a)) was produced.

[Production of Amine-Bisaldehyde Intermediate (10a)]
In 100 ml of anhydrous N, N-dimethylformamide (abbreviation DMF), 18.4 g (2.4 equivalents) of phosphorus oxychloride was gradually added under ice cooling and stirred for about 30 minutes to prepare a Vilsmeier reagent. To this solution, 15.5 g (1.0 equivalent) of N-α-naphthyl-N-phenyl-p-toluidine (9a) was gradually added under ice cooling. Then, it heated gradually, raised reaction temperature to 110 degreeC, and stirred for 3 hours, heating so that 110 degreeC might be maintained. After completion of the reaction, the reaction solution was allowed to cool and gradually added to 800 ml of a cold 4N aqueous sodium hydroxide solution. The resulting precipitate was collected by filtration, washed thoroughly with water, and then a mixed solvent of ethanol and ethyl acetate (ethanol: Recrystallization with ethyl acetate = 8: 2 to 7: 3) gave 14.6 g of a yellow powdery compound.

As a result of analysis of the obtained yellow powdery compound, a peak corresponding to the molecular ion [M + H] ⁺ in which a proton was added to the compound of the chemical structural formula (10a) (calculated molecular weight: 365.14) was 366.4. From the observation, it was found that the compound was an amine-bisaldehyde intermediate (10a) represented by the chemical structural formula (10a) (yield: 80% by weight).
Moreover, from the analysis result of HPLC at the time of LC-MS measurement, the purity of the obtained amine-bisaldehyde intermediate (10a) was 97.2%.

[Production of Asymmetric Bisalkoxyamine Compound (12aa)]
7.26 g (1.0 eq) of amine-bisaldehyde intermediate (10a) and 12.41 g (2.4 eq) of diethyl-p-methoxybenzylphosphonate (11aa) were dissolved in 80 ml of anhydrous DMF and dissolved in the solution. 5.6 g (2.5 equivalents) of potassium t-butoxide was gradually added at 0 ° C. Thereafter, the mixture was allowed to stand at room temperature for 1 hour, further heated to 50 ° C., and stirred for 5 hours while heating to maintain 50 ° C. The reaction mixture was allowed to cool and then poured into excess methanol. The precipitate was collected and dissolved in toluene to obtain a toluene solution. The toluene solution was transferred to a separatory funnel and washed with water. Then, the organic layer was taken out, and the taken out organic layer was dried over magnesium sulfate. After drying, the organic layer from which the solid was removed was concentrated and subjected to silica gel column chromatography to obtain 9.75 g of yellow crystals.

As a result of analyzing the obtained yellow crystals by LC-MS, a peak corresponding to a molecular ion [M + H] ⁺ in which a proton was added to the compound represented by the chemical structural formula (12aa) (calculated molecular weight: 573.27). Was observed at 574.5. From this fact, the crystals are exemplified by Compound Nos. 1 was found to be an asymmetric bisalkoxyamine compound (12aa) which is a precursor of No. 1 (yield: 85% by weight). Moreover, the purity of the obtained compound was 97.7% from the analysis result of HPLC at the time of LC-MS measurement.

[Production of Asymmetric Bishydroxy Compound (6a) (Exemplary Compound No. 1)]
5.7 g (1.0 equivalent) of the asymmetric bisalkoxyamine compound (9a) and 6.39 g (7.0 equivalent) of ethanethiol sodium salt were suspended in 130 ml of N, N-dimethylformamide and stirred under a nitrogen gas stream. While gradually heating, foaming started at 130 ° C. After foaming subsided, the temperature was further raised and heated to reflux for 4 hours. After cooling to room temperature, the reaction mixture was poured into 600 ml of ice water, and neutralized by adding 3.2 ml of concentrated hydrochloric acid with stirring. This was extracted with 400 ml of ethyl acetate, and the extract was washed with water, dried over anhydrous magnesium sulfate, removed by filtration, and then the solvent was distilled off to obtain 6.71 g of crude crystals. This was recrystallized with a mixed solvent of ethanol and ethyl acetate (ethanol: ethyl acetate = 8: 2 to 7: 3) to obtain 5.04 g of a yellow powdery compound.

The elemental analysis values of this yellow powdery compound were as follows.
<Exemplary Compound No. Elemental analysis value of 1>
Theoretical value C: 85.84%, H: 5.73%, N: 2.57%
Actual value C: 84.95%, H: 5.18%, N: 2.22%
Further, as a result of analyzing the obtained yellow powdery compound by LC-MS, molecular ion obtained by adding a proton to the compound represented by the target chemical structural formula (6a) (calculated molecular weight: 545.24) [ A peak corresponding to M + H] ⁺ was observed at 546.8.
From the results of elemental analysis and LC-MS analysis, the resulting yellow powdery compound was found to be Exemplified Compound No. 1 asymmetric bishydroxy compound (6a) (yield: 88%). Moreover, the purity of the obtained compound (6a) was 99.0% from the analysis result of HPLC at the time of LC-MS measurement.

(Production Examples 2 and 3)
Exemplified Compound No. Synthesis of 2 and 3 The same operation as in Production Example 1 was carried out using each raw material compound shown in the following Table 2 instead of the compound represented by the general formula (11aa) as a Wittig reagent. 2 and 3 were produced respectively. In Table 2, Exemplified Compound No. 1 raw material compounds are also shown.

  In addition, Table 3 shows elemental analysis values, calculated molecular weight values, and LC-MS actual measurement values [M + H] of each of the exemplary compounds obtained in Production Examples 1 to 3 above.

Production Example 4 Synthesis of Aromatic Polycarbonate (P-1) Asymmetric bis obtained in Production Example 1 in an aqueous solution prepared by dissolving 1.62 g of sodium hydroxide and 0.075 g of sodium hydrosulfite in 60 ml of water. Hydroxy compound (6a) (Exemplary Compound No. 1) 2.73 g (5.0 mmol), 4,4 ′-(1-methylethylidene) bisphenol 1.48 g (6.5 mmol) and 4-tert-butylphenol 0 0.030 g was added and stirred under an argon gas stream. To this mixed solution, a solution of 2.11 g of triphosgene in 40 ml of dichloromethane was gradually added dropwise under ice cooling and vigorous stirring, and the reaction was carried out while forming an emulsion. After completion of the dropwise addition, the reaction solution was returned to room temperature, 0.25 g of sodium hydroxide was added, and 0.45 ml of triethylamine was further added. Thereafter, the reaction was carried out for 3 hours while maintaining the liquid temperature in the range of 25 to 30 ° C. After completion of the reaction, 200 ml of dichloromethane was added to extract the organic layer. This organic layer was washed successively with 3% aqueous sodium hydroxide, 2% aqueous hydrochloric acid and ion-exchanged water, and then reprecipitated in methanol, and the structural unit (1) shown in Table 4 (corresponding to general formula (1)) ) And structural unit (4) (corresponding to general formula (4)) 3.74 g of aromatic polycarbonate (P-1) was obtained.

When the molecular weight of this aromatic polycarbonate was measured by gel permeation chromatography, it was a number average molecular weight 28600 and a weight average molecular weight 74000 (both in terms of polystyrene). In addition, in the infrared absorption spectrum of this product, absorption based on C═O stretching vibration of carbonate was observed at 1775 cm ⁻¹ . Moreover, from the area ratio of the signal by a < ¹ > H-NMR measurement, exemplary compound No. The structural unit (1) derived from 1 and the structural unit (4) derived from 4,4 ′-(1-methylethylidene) bisphenol are polymerized at a ratio of 0.34 / 0.66 (molar ratio). I understood.

(Production Example 5) Synthesis of aromatic polycarbonate (P-2) As a bisphenol component, 4,4′-cyclohexylene was used instead of 1.48 g (6.5 mmol) of 4,4 ′-(1-methylethylidene) bisphenol. 3. Aromatic polycarbonate (P-2) comprising the structural unit (1) and the structural unit (4) shown in Table 4 in the same manner as in Production Example 4 except that 1.98 g (6.5 mmol) of denbisphenol is used. 21 g was obtained.

When the molecular weight of this aromatic polycarbonate was measured by gel permeation chromatography, it was a number average molecular weight 29700 and a weight average molecular weight 73800 (both in terms of polystyrene). In addition, in the infrared absorption spectrum of this product, absorption based on C═O stretching vibration of carbonate was observed at 1775 cm ⁻¹ . Moreover, from the area ratio of the signal by a < ¹ > H-NMR measurement, exemplary compound No. It was found that the structural unit (1) derived from 1 and the structural unit (4) derived from 4,4′-cyclohexylidenebisphenol were polymerized at a ratio of 0.35 / 0.65 (molar ratio). .

(Production Example 6) Synthesis of Aromatic Polycarbonate (P-3) Asymmetric bishydroxy compound (6a) (Exemplary Compound No. 1) Instead of 3.24 g (5.0 mmol), Exemplified Compound No. shown in Table 1 . Aromatic polycarbonate (P-3) comprising the structural unit (1) and the structural unit (4) shown in Table 4 in the same manner as in Production Example 4 except that 2.99 g (5.0 mmol) of 2 is used. 4.08 g was obtained.

When the molecular weight of this aromatic polycarbonate was measured by gel permeation chromatography, it was a number average molecular weight 26300 and a weight average molecular weight 69200 (both in terms of polystyrene). In addition, in the infrared absorption spectrum of this product, absorption based on C═O stretching vibration of carbonate was observed at 1775 cm ⁻¹ . Moreover, from the area ratio of the signal by a < ¹ > H-NMR measurement, exemplary compound No. It was found that the structural unit (1) derived from 62 and the structural unit (4) derived from 4,4′-cyclohexylidenebisphenol were polymerized at a ratio of 0.40 / 0.60 (molar ratio). .

(Production Example 7) Synthesis of aromatic polycarbonate (P-4) Asymmetric bishydroxy compound (6a) (Exemplary Compound No. 1) Instead of 3.24 g (5.0 mmol), Exemplified Compound No. shown in Table 1 . 3, 4.25 g (5.0 mmol) was used, and 4,4′-cyclohexylidene was used instead of 1.48 g (6.5 mmol) of 4,4 ′-(1-methylethylidene) bisphenol as the bisphenol component. 2. Aromatic polycarbonate (P-4) comprising the structural unit (1) and the structural unit (4) shown in Table 4 in the same manner as in Production Example 4 except that 1.98 g (6.5 mmol) of bisphenol is used. 98 g was obtained.

When the molecular weight of this aromatic polycarbonate was measured by gel permeation chromatography, it was a number average molecular weight 29100 and a weight average molecular weight 73300 (both in terms of polystyrene). In addition, in the infrared absorption spectrum of this product, absorption based on C═O stretching vibration of carbonate was observed at 1775 cm ⁻¹ . Moreover, from the area ratio of the signal by a < ¹ > H-NMR measurement, exemplary compound No. It was found that the structural unit (1) derived from 1 and the structural unit (4) derived from 4,4'-cyclohexylidenebisphenol were polymerized at a ratio of 0.38 / 0.62 (molar ratio). .

(Production Example 8) Synthesis of Comparative Aromatic Polycarbonate (P-5) In place of 3.24 g (5.0 mmol) of asymmetric bishydroxy compound (6a) (Exemplary Compound No. 1), JP-A No. 2004-269377 The reaction was carried out in the same manner as in Production Example 4 except that 2.92 g (5.0 mmol) of a symmetric bishydroxyenamine compound represented by the following chemical structural formula (20) described in the publication was used. 3.84 g of aromatic polycarbonate (P-5) composed of the structural unit (1 ′) and the structural unit (4) derived from the hydroxyenamine compound (20) was obtained.

When the molecular weight of this aromatic polycarbonate was measured by gel permeation chromatography, it was a number average molecular weight 28000 and a weight average molecular weight 71000 (both in terms of polystyrene). In addition, in the infrared absorption spectrum of this product, absorption based on C═O stretching vibration of carbonate was observed at 1775 cm ⁻¹ . Moreover, from the area ratio of the signal measured by ¹ H-NMR, the structural unit (1 ′) derived from the symmetric bishydroxyenamine compound (20) and 4,4 ′-(1-methylethylidene) bisphenol were 0.42 / It was found that polymerization was carried out at a ratio of 0.58 (molar ratio).

(Example 1)
7 parts of titanium oxide (trade name: TTO55A, manufactured by Ishihara Sangyo Co., Ltd.) and 13 parts of copolymer nylon resin (trade name: CM8000, manufactured by Toray Industries, Inc.) are mixed solvent of 159 parts of methyl alcohol and 106 parts of 1,3-dioxolane. In addition to the above, dispersion treatment was performed for 8 hours with a paint shaker to prepare a coating solution for forming an undercoat layer. The coating solution for forming the undercoat layer is filled in a coating tank, an aluminum drum-like support (conductive support) having a diameter of 30 mm and a length of 340 mm is dipped, pulled up and dried naturally, and an undercoat layer having a thickness of 1 μm. Formed.

  Next, 1 part of titanyl phthalocyanine and a butyral resin (trade name: # 6000) having an X-ray diffraction spectrum in which the Bragg angle (2θ ± 0.2 °) with respect to X-ray of CuKα1.541Å has a main peak at 27.3 °. -C, manufactured by Denki Kagaku Kogyo Co., Ltd.) was mixed with 98 parts of methyl ethyl ketone and dispersed with a paint shaker to prepare a coating solution for forming a charge generation layer. This charge generation layer forming coating solution was applied to the surface of the undercoat layer in the same manner as in the formation of the undercoat layer, and naturally dried to form a charge generation layer having a thickness of 0.4 μm.

  Next, a 21 wt% tetrahydrofuran solution of the aromatic polycarbonate (P-1) of Production Example 4 was prepared and used as a coating solution for forming a charge transport layer. The charge transport layer forming coating solution is applied to the surface of the charge generation layer in the same manner as in the case of forming the undercoat layer, and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 21 μm. A multilayer electrophotographic photosensitive member having a multilayer structure of 6 was produced.

(Example 2)
A laminated electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the aromatic polycarbonate (P-2) of Production Example 5 was used instead of the aromatic polycarbonate (P-1).

(Example 3)
A laminated electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the aromatic polycarbonate (P-3) of Production Example 6 was used instead of the aromatic polycarbonate (P-1).

Example 4
A laminated electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the aromatic polycarbonate (P-4) of Production Example 7 was used instead of the aromatic polycarbonate (P-1).

(Example 5)
In the same manner as in Example 1, an undercoat layer having a thickness of 1 μm and a charge generation layer having a thickness of 0.4 μm were sequentially formed on the surface of an aluminum drum-shaped support having a diameter of 30 mm and a total length of 340 mm.
Subsequently, 100 parts of the following butadiene compound (21) (1,1-bis (p-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene, trade name: T405, manufactured by Takasago Chemical Co., Ltd.), 22) 100 parts of Z-type polycarbonate (Iupilon Z400, manufactured by Mitsubishi Gas Chemical Company) and 5 parts of 2,6-bis-tert-butyl-4-methylphenol (trade name: Sumilizer BHT, manufactured by Sumitomo Chemical Co., Ltd.) Then, a coating solution for forming a charge transport layer having a solid content of 21% by weight was prepared using tetrahydrofuran as a solvent. This charge transport layer coating solution was applied on the charge generation layer previously provided in the same manner as the above intermediate layer, and then dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 21 μm.

  Next, a 21 wt% tetrahydrofuran solution of the aromatic polycarbonate (P-3) of Production Example 6 was prepared and used as a coating solution for forming a surface protective layer. This surface protective layer forming coating solution is applied to the surface of the charge transport layer in the same manner as in the case of forming the undercoat layer in Example 1, and dried at 110 ° C. for 1 hour to form a surface protective layer having a thickness of 4 μm. Thus, a multilayer electrophotographic photosensitive member having the multilayer structure of FIG. 8 was produced.

(Comparative Example 1)
A laminated electrophotographic photosensitive member was produced in the same manner as in Example 4 except that the surface protective layer was not provided.

(Comparative Example 2)
In the same manner as in Example 1, an undercoat layer having a thickness of 1 μm, a charge generation layer having a thickness of 0.4 μm, and a charge transport layer having a thickness of 21 μm were formed on the surface of an aluminum drum-shaped support having a diameter of 30 mm and a total length of 340 mm. Sequentially formed.
Next, a 10 wt% tetrahydrofuran solution of Z-type polycarbonate (trade name: Iupilon Z800, manufactured by Mitsubishi Gas Chemical Company) was prepared and used as a coating solution for forming a surface protective layer. This surface protective layer forming coating solution is applied to the surface of the charge transport layer in the same manner as in the case of forming the undercoat layer in Example 1, and dried at 110 ° C. for 1 hour to form a surface protective layer having a thickness of 4 μm. Thus, a multilayer electrophotographic photosensitive member having the multilayer structure of FIG. 8 was produced.

(Comparative Example 3)
In the formation of the charge transport layer, a laminated electrophotographic photosensitive member is obtained in the same manner as in Example 1 except that the aromatic polycarbonate (P-5) of Production Example 8 is used instead of the aromatic polycarbonate (P-1). The body was made.

(Image evaluation)
The laminated electrophotographic photoreceptors obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were mounted on a commercial copying machine (trade name: AR-451N, manufactured by Sharp Corporation), and halftone images were confirmed. The image state after copying 100,000 sheets was evaluated.
In addition, after the initial and 100,000 copies, the developer tank is taken out from the development site of the evaluation copier, and a surface potential meter (trade name: Model 344, manufactured by Trek) is set instead. The electrical characteristics were evaluated by measuring V0 (V), the surface potential VH (V) when copying a halftone document, and the surface potential VL (V) when copying a black solid document.

(Durability evaluation)
The laminated electrophotographic photoreceptors obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were mounted on a commercial copying machine (trade name: AR-451N, manufactured by Sharp Corporation), and 100,000 images were copied. . The total film thickness T1 and T2 on the drum support in the electrophotographic photosensitive member before and after image copying are measured with a film thickness measuring device (trade name: MCPD1100, manufactured by Otsuka Electronics Co., Ltd.), and the wear amount ΔT (= T1-T2) was determined. It was evaluated that the greater the amount of wear, the lower the durability.
The results are shown in Table 5.

In Examples 1 to 4 in which the aromatic polycarbonate of the present invention is used for the charge transport layer and Example 5 in which the surface protective layer is used, the image state is good even after repeated use (100,000 copies), and wear is also reduced. There were few.
On the other hand, in Comparative Example 1, although the image state was good at the initial stage, the image was fogged after repeated use. In addition, the wear was large and the chargeability was significantly reduced.
In Comparative Example 2, the initial charging characteristics were good, but the potential was not attenuated by exposure, so the image density was low and the image was thin. Furthermore, the image hardly appeared after repeated use. This is presumably because the surface protective layer does not have a charge transporting ability and the charge cannot be erased even when charged.
In Comparative Example 3, black spots occurred. This is because a known aromatic polycarbonate is used for the charge transport layer, but the structural unit (1 ′) of the aromatic polycarbonate has high chemical structural objectivity, so it has low solubility and is insoluble in a solvent. Is left in the charge transport layer in a crystalline state, and this portion is considered to have appeared as a black spot in the image.

1 is a cross-sectional view schematically showing a configuration of a main part of a single layer type electrophotographic photosensitive member of the present invention. 1 is a cross-sectional view schematically showing a configuration of a main part of a single layer type electrophotographic photosensitive member of the present invention. 1 is a cross-sectional view schematically showing a configuration of a main part of a single layer type electrophotographic photosensitive member of the present invention. 1 is a cross-sectional view schematically showing a configuration of a main part of a single layer type electrophotographic photosensitive member of the present invention. FIG. 2 is a cross-sectional view schematically showing a configuration of a main part of the multilayer electrophotographic photosensitive member of the present invention. FIG. 2 is a cross-sectional view schematically showing a configuration of a main part of the multilayer electrophotographic photosensitive member of the present invention. FIG. 2 is a cross-sectional view schematically showing a configuration of a main part of the multilayer electrophotographic photoreceptor of the present invention. FIG. 2 is a cross-sectional view schematically showing a configuration of a main part of the multilayer electrophotographic photosensitive member of the present invention. FIG. 3 is a side view illustrating a simplified configuration of the image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive support body 2,2a Photosensitive layer 3 Charge generation layer 4 Charge transport layer 5 Surface protective layer 6 Undercoat layer 20 Image forming apparatus 21 Electrophotographic photosensitive member 24 Charger 25 Developer 26 Transfer device 27 Cleaner 28 Exposure means 30 Transfer paper 31 Fixing device

Claims (12)

An electrophotographic photosensitive member having a photosensitive layer or a photosensitive layer and a surface protective layer in this order on a conductive support, wherein the photosensitive layer, the surface protective layer, or both layers are represented by the following general formula (1 )

(In the formula, Ar ₁ represents an aryl group which may have a substituent or a heterocyclic group which may have a substituent. Ar ₂ and Ar ₃ may be different from each other and have a substituent. A divalent heterocyclic group which may have a good arylene group or substituent, and two Ar _{4 s} are the same or different and have an arylene group or a substituent which may have a substituent; The two Ar _{5 s} are the same or different and each represents a hydrogen atom, an aryl group which may have a substituent, an aralkyl group or a substituent which may have a substituent; R ₁ represents a hydrogen atom, an aryl group which may have a substituent, or an alkyl group which may have a substituent, 2n R ₂ and R ₃ are , The same or different, a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a substituent A heterocyclic group which may have a substituent or an aralkyl group which may have a substituent, n represents an integer of 0 to 2, and z is a value sufficient to obtain a number average molecular weight of 5,000 to 500,000. )
An electrophotographic photosensitive member comprising an aromatic polycarbonate containing a structural unit represented by: The structural unit represented by the general formula (1) is represented by the general formula (2).

(In the formula, Ar ₁ , Ar ₄ , n and z are the same as above.)
The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is a structural unit represented by: The structural unit represented by the general formula (1) is represented by the general formula (3).

(In the formula, Ar ₁ , Ar ₄ and z are the same as above.)
The electrophotographic photosensitive member according to claim 2, wherein the electrophotographic photosensitive member is a structural unit represented by: The aromatic polycarbonate has the following general formula (4) together with the structural unit represented by the general formula (1).

(In the formula, X represents a group -YZ- or group -ZY-. Here, Y represents a substituted or unsubstituted chain aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group. A group, a substituted or unsubstituted aromatic divalent group, a substituted or unsubstituted heterocyclic divalent group, or a divalent group formed by bonding two or more of these groups, Z represents an oxygen atom or a sulfur atom; .)
The electrophotographic photosensitive member according to claim 1, comprising a structural unit represented by: In the structural unit represented by the general formula (4), the X represents the general formula (5).

(In the formula, 1 R ₅ and m R ₆ are the same or different and each represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having 1 to 4 carbon atoms, or a halogen atom. Y is a single bond, an oxygen atom, a sulfur atom, a substituted or unsubstituted chain aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, or a divalent group formed by bonding two or more of these groups. L and m are the same or different and represent an integer of 1 to 4)
The electrophotographic photosensitive member according to claim 4, which is a divalent group represented by the formula:   An electrophotographic photosensitive member according to any one of claims 1 to 5, a charging means for charging the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member with light corresponding to image information. An exposure means for forming an electrostatic latent image, a developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member into a visible image, and a visible image developed by the developing means. An image forming apparatus comprising: transfer means for transferring onto a recording medium.   The image forming apparatus according to claim 6, wherein the charging unit is a contact charger. The following general formula (1)

(In the formula, Ar ₁ represents an aryl group which may have a substituent or a heterocyclic group which may have a substituent. Ar ₂ and Ar ₃ may be different from each other and have a substituent. A divalent heterocyclic group which may have a good arylene group or substituent, and two Ar _{4 s} are the same or different and have an arylene group or a substituent which may have a substituent; The two Ar _{5 s} are the same or different and each represents a hydrogen atom, an aryl group which may have a substituent, an aralkyl group or a substituent which may have a substituent; R ₁ represents a hydrogen atom, an aryl group which may have a substituent, or an alkyl group which may have a substituent, 2n R ₂ and R ₃ are , The same or different, a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a substituent A heterocyclic group which may have a substituent or an aralkyl group which may have a substituent, n represents an integer of 0 to 2, and z is a value sufficient to obtain a number average molecular weight of 5,000 to 500,000. )
An aromatic polycarbonate containing a structural unit represented by: The structural unit represented by the general formula (1) is represented by the general formula (2).

(In the formula, Ar ₁ , Ar ₄ , n and z are the same as above.)
The aromatic polycarbonate according to claim 8, wherein the aromatic polycarbonate is a structural unit represented by: The structural unit represented by the general formula (1) is represented by the general formula (3).

(In the formula, Ar ₁ , Ar ₄ and z are the same as above.)
The aromatic polycarbonate according to claim 9, which is a structural unit represented by: The aromatic polycarbonate has the following general formula (4) together with the structural unit represented by the general formula (1).

(In the formula, X represents a group -YZ- or group -ZY-. Here, Y represents a substituted or unsubstituted chain aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group. A group, a substituted or unsubstituted aromatic divalent group, a substituted or unsubstituted heterocyclic divalent group, or a divalent group formed by bonding two or more of these groups, Z represents an oxygen atom or a sulfur atom; .)
The aromatic polycarbonate as described in any one of Claims 8-10 containing the structural unit represented by these. In the structural unit represented by the general formula (4), the X represents the general formula (5).

(In the formula, 1 R ₅ and m R ₆ are the same or different and each represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having 1 to 4 carbon atoms, or a halogen atom. Y is a single bond, an oxygen atom, a sulfur atom, a substituted or unsubstituted chain aliphatic divalent group, a substituted or unsubstituted cyclic aliphatic divalent group, or a divalent group formed by bonding two or more of these groups. L and m are the same or different and represent an integer of 1 to 4)
The aromatic polycarbonate according to claim 11, which is a divalent group represented by:

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