JP2005055888A - Electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high sensitivity electrophotographic photoreceptor which has excellent electric characteristics in high speed response and is high in stability/durability. <P>SOLUTION: In an electrophotographic photoreceptor having a photosensitive layer on a conductive support, the photosensitive layer is made to contain a charge transport substance chosen from the group consisting of the compound expressed in general formula (1). In this formula (1), Ar<SP>1</SP>represents an arylene radical and Ar<SP>2</SP>is aryl or univalent heterocyclic group which may have a substituent. m<SB>1</SB>denotes an integer of 1-3, and n<SB>1</SB>is 0 or 1, provided m<SB>1</SB>+n<SB>1</SB>≥2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrophotographic photoreceptor having a photosensitive layer formed on a conductive support. More specifically, the present invention relates to an electrophotographic photoreceptor having high sensitivity, excellent electrical characteristics such as high-speed response, and excellent stability and durability.

  In recent years, electrophotographic technology has been widely used and applied not only in the field of copying machines but also in the fields of various printers and printing presses because of its immediacy and high quality images.

  For photoconductors that are the core of electrophotographic technology, photoconductors that use conventional photoconductive materials such as selenium, arsenic-selenium alloys, cadmium sulfide, and zinc oxide (inorganic photoconductors) are used. Recently, the use of a photoconductor (organic photoconductor) using an organic photoconductive material having advantages such as pollution-free, easy film formation, and easy manufacture has become the mainstream.

  As the main layer structure of the organic photoreceptor, a so-called single-layer photoreceptor in which a charge generation material is dispersed in a binder resin and a laminated photoreceptor in which a charge generation layer and a charge transfer layer are laminated are known. . Multilayer photoconductors can provide highly sensitive and stable photoconductors by combining highly efficient charge generating materials and charge transfer materials into separate layers and combining them optimally. It is often used because it is easy to adjust. Single layer type photoconductors are slightly inferior to multilayer photoconductors in terms of electrical characteristics, and material selectivity is narrow, but high resolution can be achieved by generating charges in the vicinity of the photoconductor surface. Since the image is not blurred, high printing durability can be achieved by increasing the film thickness. In addition, the single-layer type photosensitive member requires less coating processes, is advantageous for interference fringes and tube defects derived from a conductive substrate (support), and can be used with a low-priced substrate such as a non-cutting tube. It has advantages such as cost reduction.

In addition, since the electrophotographic photosensitive member is repeatedly used in an electrophotographic process, that is, a cycle of charging, exposure, development, transfer, cleaning, static elimination, and the like, it is deteriorated by various stresses during that time. Among them, strongly oxidizing ozone or NO _x that as the chemical degradation arising from a corona charger which is normally used as, for example, the charger is useless in the photosensitive layer - include giving di, if used repeatedly, the charging Deterioration in electrical stability such as increase in residual potential and increase in residual potential, and accompanying image defects may occur. These are largely derived from chemical deterioration of charge transport materials contained in the photosensitive layer in a large amount.

  Furthermore, with the recent increase in the speed of the electrophotographic process, it is essential to increase the sensitivity and speed of the electrophotographic photosensitive member. Among these requirements, in order to achieve high sensitivity, it is necessary not only to optimize the charge generation material, but also to develop a charge transport material with good matching with the charge generation material. In order to achieve high-speed response, it is necessary to develop a charge transport material that exhibits high mobility and exhibits a sufficiently low residual potential during exposure.

  Triarylamines such as triphenylamine have attracted attention as examples of charge transport materials that lead to improved durability and higher sensitivity of electrophotographic photoreceptors. For example, Patent Document 1 describes that a styryltriphenylamine compound having a specific structure is used as a charge transport material.

Japanese Patent Laid-Open No. 06-118667

  However, there are still few examples of charge transport materials that can achieve improved durability, higher sensitivity, and faster response of the electrophotographic photosensitive member. Under such circumstances, there is a need for an excellent charge transport material that has little chemical degradation, good matching with a charge generation material, high mobility, and a sufficiently low residual potential upon exposure.

  The present invention was devised in view of the above-mentioned problems, and aims to provide an electrophotographic photosensitive member having high sensitivity, excellent electrical characteristics such as high-speed response, and good stability and durability. To do.

  As a result of diligent research on a charge transport material that satisfies the above requirements, the present inventors have used an arylamine compound having an aryl group having a specific structure as a charge transport material, so that the sensitivity and electrical characteristics of the electrophotographic photosensitive member can be improved. The present invention was completed by finding that the stability and durability were improved.

（一般式（１）において、Ａｒ¹は、置換基を有していてもよいアリーレン基を表わす。Ａｒ²は、置換基を有していてもよい、アリール基又は１価の複素環含有基を表わす。複数のＡｒ²は同一でもよく、互いに異なっていてもよい。ｍ₁は１〜３の整数を、ｎ₁は０又は１を表わす。但し、ｍ₁＋ｎ₁≧２である。ｍ₁が２以上の場合、複数のＡｒ¹は同一でもよく、互いに異なっていてもよい。）

（一般式（２）において、Ａｒ²は、置換基を有していてもよい、アリール基又は１価の複素環含有基を表わす。複数のＡｒ²は同一でもよく、互いに異なっていてもよい。Ａｒ³は、少なくとも１つの置換基又は縮合環を有するアリーレン基を表わす。）

（一般式（３）において、Ａｒ¹は、置換基を有していてもよいアリーレン基を表わす。Ａｒ²は、置換基を有していてもよい、アリール基又は１価の複素環含有基を表わす。Ａｒ⁴は、少なくとも１つの置換基又は縮合環を有するアリール基、又は、１価の複素環含有基を表わす。）

（一般式（４）において、Ａｒ¹は、置換基を有していてもよいアリーレン基を表わす。Ａｒ²は、置換基を有していてもよい、アリール基又は１価の複素環含有基を表わす。複数のＡｒ²は同一でもよく、互いに異なっていてもよい。ｍ₂は１又は２を、ｎ₂は０又は１を表わす。但し、ｍ₂＋ｎ₂≧２である。ｍ₂が２の場合、複数のＡｒ¹は同一でもよく、互いに異なっていてもよい。）

（一般式（５）において、Ａｒ³は、少なくとも１つの置換基又は縮合環を有するアリーレン基を表わす。Ｃｎは２価の連結基を表わす。）

（一般式（６）において、Ａｒ²は、置換基を有していてもよい、アリール基又は１価の複素環含有基を表わす。複数のＡｒ²は同一でもよく、異なっていてもよい。Ａｒ³は、少なくとも１つの置換基又は縮合環を有するアリーレン基を表わす。）

（一般式（７）において、Ａｒ¹は、置換基を有していてもよいアリーレン基を表わす。Ａｒ²は、置換基を有していてもよい、アリール基又は１価の複素環含有基を表わす。Ａｒ⁵は、少なくとも１つのアルコキシ基、ハロゲン基若しくは縮合環を有するアリール基又は１価の複素環含有基を表わす。）

（一般式（８）において、Ａｒ¹は、置換基を有していてもよいアリーレン基を表わす。Ａｒ²は、置換基を有していてもよい、アリール基又は１価の複素環含有基を表わす。ｎ₃は１又は２を表わす。） That is, the gist of the present invention is that, in an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, the photosensitive layer has the following general formula (1), general formula (2), general formula (3), Containing at least one charge transporting material selected from the group consisting of compounds represented by general formula (4), general formula (5), general formula (6), general formula (7) or general formula (8). It exists in the characteristic electrophotographic photoreceptor.

(In General Formula (1), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. A plurality of Ar ² may be the same or different from each other, m ₁ represents an integer of ₁ to 3, n ₁ represents 0 or 1, provided that m ₁ + n ₁ ≧ 2. _{When 1} is 2 or more, the plurality of Ar ¹ may be the same or different from each other.

(In General Formula (2), Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. A plurality of Ar ² may be the same or different from each other. Ar ³ represents an arylene group having at least one substituent or a condensed ring.)

(In General Formula (3), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. Ar ⁴ represents an aryl group having at least one substituent or a condensed ring, or a monovalent heterocyclic ring-containing group.

(In General Formula (4), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. A plurality of Ar ² may be the same or different from each other, m ₂ represents 1 or 2, n ₂ represents 0 or 1, provided that m ₂ + n ₂ ≧ 2, where m ₂ is In the case of 2, the plurality of Ar ¹ may be the same or different from each other.)

(In the general formula (5), Ar ³ represents an arylene group having at least one substituent or a condensed ring. Cn represents a divalent linking group.)

(In General Formula (6), Ar ² represents an aryl group or a monovalent heterocyclic-containing group which may have a substituent. The plurality of Ar ² may be the same or different. Ar ³ represents an arylene group having at least one substituent or a condensed ring.)

(In General Formula (7), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. Ar ⁵ represents at least one alkoxy group, a halogen group, an aryl group having a condensed ring, or a monovalent heterocyclic-containing group.

(In General Formula (8), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. N ₃ represents 1 or 2)

  According to the present invention, by incorporating a triarylamine compound having a specific structure in the photosensitive layer as a charge transport material, it has high sensitivity, excellent electrical characteristics such as high-speed response, and is also stable and durable. A good electrophotographic photoreceptor is realized.

  Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following descriptions, and various modifications can be made within the scope of the gist of the present invention.

  The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, and the photosensitive layer contains a specific charge transport material. In the following description, the charge transport material used in the electrophotographic photosensitive member of the present invention (hereinafter, abbreviated as “charge transport material of the present invention” as appropriate) will be described first, and then the electrophotography of the present invention. Let's move on to the explanation of the photoreceptor.

[1. Charge transport material]
The charge transport material of the present invention includes the following general formula (1), general formula (2), general formula (3), general formula (4), general formula (5), general formula (6), and general formula (7). ) And the general formula (8), specifically, a N, N-bis (3,4-dimethylphenyl) arylamine compound.

In the general formula (1), Ar ¹ represents an arylene group. The kind of the arylene group is not particularly limited, and may be a single ring or a condensed two or more rings. Specific examples include o-phenylene group, p-phenylene group, m-phenylene group, 1,3-naphthylene group, 1,4-naphthylene group and the like. Among these, a p-phenylene group, an m-phenylene group, and a 1,4-naphthylene group are preferable from the viewpoint of reducing the molecular size as much as possible and reducing the intramolecular steric repulsion. On the other hand, using an arylene group in which three or more rings such as a fluorene residue or a phenanthrene residue are used is disadvantageous in terms of production due to excessive molecular size, and the effect of the hydrazone structure cannot be obtained. This is not preferable because the effect of the above may not be sufficiently obtained.

The arylene group for Ar ¹ may have a substituent. The type of the substituent is not particularly limited as long as it does not depart from the spirit of the present invention, but preferred specific examples include alkyl groups such as methyl group, ethyl group, propyl group and allyl group, methoxy group, ethoxy group and propoxy group. And the like. The presence of these substituents may provide an effect of increasing charge mobility due to an electron donating effect. However, if the size of the substituent is too large, the charge mobility is decreased due to the distortion of the conjugated surface in the molecule and the steric repulsion between the molecules. Therefore, the substituent having 3 or less carbon atoms is preferable. A methyl group and a methoxy group are preferred. Also, the number of substituents is arbitrary, but if it is too large, the charge mobility is reduced for the same reason, so it is preferably 3 or less, more preferably 2 or less.

m ₁ represents an integer of 1 to 3. When m ₁ is 2 or more, the plurality of Ar ¹ may be the same or different from each other.
n ₁ represents 0 or 1. However, m ₁ + n ₁ ≧ 2.

Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group. Several Ar < ² > may be the same and may mutually differ. However, since the aryl group has a great effect of expanding the conjugated system and increasing the charge mobility, it is desirable that at least one of the plurality of Ar ² is an aryl group.

  The kind of the aryl group is not particularly limited, and may be a single ring or a condensed two or more rings. Specific examples include phenyl group, naphthyl group, acenaphthyl group, pyrenyl group and the like. Among these, a phenyl group and a naphthyl group are preferable, and a phenyl group and an α-naphthyl group are particularly preferable from the viewpoint of conjugation extension in the molecule and reduction of the permanent dipole moment of the molecule. On the other hand, the use of an aryl group condensed with three or more rings such as a fluorene residue or a phenanthrene residue is disadvantageous in terms of production because the molecular size becomes too large. By repulsion, the charge mobility is decreased, and the effect as a charge transport material may not be sufficiently obtained.

  The type of the monovalent heterocyclic ring-containing group is not particularly limited as long as it is a monovalent organic group containing a heterocyclic ring, but it is usually monovalent to a monovalent heterocyclic group or a divalent linking group. It is a monovalent organic group to which the heterocyclic group is bonded. Specific examples of the monovalent heterocyclic group include a furyl group, a thienyl group, and a pyridyl group. Of these, a thienyl group is preferable and an α-thienyl group is preferable from the viewpoints of intramolecular conjugation extension and reduction of the permanent dipole moment of the molecule. The type of the divalent linking group is not particularly limited, but a saturated or unsaturated alkylene group having about 1 to 4 carbon atoms is preferable, and specific examples include a methylene group, an ethylene group, a propylene group, and a vinylene group. . However, from the viewpoint of reducing the steric repulsion between molecules by reducing the molecular size as much as possible and improving the charge mobility, a divalent linking group is not present or even a methylene group is preferred.

The aryl group or heterocycle-containing group for Ar ² may further have a substituent. The type of the substituent is not particularly limited as long as it does not depart from the spirit of the present invention, but preferred specific examples include alkyl groups such as methyl group, ethyl group, propyl group and allyl group, methoxy group, ethoxy group and propoxy group. And the like. The presence of these substituents may provide an effect of increasing charge mobility due to an electron donating effect. However, if the size of the substituent is too large, the charge mobility is decreased due to the distortion of the conjugated surface in the molecule and the steric repulsion between the molecules. Therefore, the substituent having 3 or less carbon atoms is preferable. A methyl group and a methoxy group are preferred. Also, the number of substituents is arbitrary, but if it is too large, the charge mobility is reduced for the same reason, so it is preferably 3 or less, more preferably 2 or less.

In the general formula (2), Ar ² represents the same group as the group having the same sign in the general formula (1). Several Ar < ² > may be the same and may mutually differ.

Ar ³ represents an arylene group having at least one substituent or condensed ring. The kind of the arylene group is not particularly limited, and may be a single ring or a condensed two or more rings. However, in the case of an arylene group having a single ring, at least a substituent described later is used. One needs to have. Specific examples of the arylene group having a single ring include an o-phenylene group, a p-phenylene group, and an m-phenylene group. Specific examples of the arylene group having a condensed ring include a 1,3-naphthylene group and a 1,4-naphthylene group. Among these, a p-phenylene group, an m-phenylene group, and a 1,4-naphthylene group are preferable from the viewpoint of reducing the molecular size as much as possible and reducing the intramolecular steric repulsion. If an arylene group condensed with 3 or more rings is used, the molecular size becomes too large, which is disadvantageous in terms of production. On the other hand, charge mobility is reduced due to distortion of the conjugated surface in the molecule and steric repulsion between molecules. This is not preferable because the effect as a charge transport material may not be sufficiently obtained.

The kind of the substituent that the arylene group of Ar ³ has is not particularly limited as long as it does not depart from the spirit of the present invention. Preferred specific examples include alkyl groups such as methyl, ethyl, propyl, and allyl groups, methoxy And alkoxy groups such as an ethoxy group and a propoxy group. The presence of these substituents may provide an effect of increasing charge mobility due to an electron donating effect. However, if the size of the substituent is too large, the charge mobility is decreased due to the distortion of the conjugated surface in the molecule and the steric repulsion between the molecules. Therefore, the substituent having 3 or less carbon atoms is preferable. A methyl group and a methoxy group are preferred. Also, the number of substituents is arbitrary, but if it is too large, the charge mobility is reduced for the same reason, so it is preferably 3 or less, more preferably 2 or less.

In the general formula (3), Ar ¹ and Ar ² each represent the same group as the group having the same sign in the general formula (1).
Ar ⁴ represents an aryl group having at least one substituent or a condensed ring, or a monovalent heterocyclic ring-containing group.

When Ar ⁴ is an aryl group, the type of the aryl group is not particularly limited, and may be a single ring or a condensed two or more rings, but in the case of an aryl group having a single ring Must have at least one substituent described below. Specific examples of the aryl group having a single ring include a phenyl group. Specific examples of the aryl group having a condensed ring include a naphthyl group, an acenaphthyl group, and a pyrenyl group. Among these, a phenyl group and a naphthyl group are preferable, and a phenyl group and an α-naphthyl group are particularly preferable from the viewpoint of conjugation extension in the molecule and reduction of the permanent dipole moment of the molecule. On the other hand, the use of an aryl group condensed with three or more rings such as a fluorene residue or a phenanthrene residue is disadvantageous in terms of production because the molecular size becomes too large. By repulsion, the charge mobility is decreased, and the effect as a charge transport material may not be sufficiently obtained.

The type of the substituent that the aryl group of Ar ⁴ has is not particularly limited as long as it does not depart from the spirit of the present invention, but preferred specific examples include alkyl groups such as methyl, ethyl, propyl, and allyl groups, methoxy Group, alkoxy groups such as ethoxy group and propoxy group, and halogen groups such as chloro group and bromo group. The presence of these substituents may provide an effect of increasing charge mobility due to an electron donating effect. However, if the size of the substituent is too large, the charge mobility is reduced due to the distortion of the conjugate plane in the molecule and the steric repulsion between the molecules, so the alkyl group or alkoxy group having 3 or less carbon atoms, Alternatively, a halogen group is preferable, and among them, a methyl group, a methoxy group, and a chloro group are preferable. Also, the number of substituents is arbitrary, but if it is too large, the charge mobility is reduced for the same reason, so it is preferably 3 or less, more preferably 2 or less.

When Ar ⁴ is a monovalent heterocyclic ring-containing group, the type is not particularly limited as long as it is a monovalent organic group containing a heterocyclic ring, but usually a monovalent heterocyclic group or a divalent linking group Is a monovalent organic group having a monovalent heterocyclic group bonded thereto. Specific examples of the monovalent heterocyclic group include a furyl group, a thienyl group, and a pyridyl group. Of these, a thienyl group is preferable and an α-thienyl group is preferable from the viewpoints of intramolecular conjugation extension and reduction of the permanent dipole moment of the molecule. The type of the divalent linking group is not particularly limited, but a saturated or unsaturated alkylene group having about 1 to 4 carbon atoms is preferable, and specific examples include a methylene group, an ethylene group, a propylene group, and a vinylene group. . However, from the viewpoint of reducing the steric repulsion between molecules by reducing the molecular size as much as possible and improving the charge mobility, a divalent linking group is not present or even a methylene group is preferred.

The heterocycle-containing group for Ar ⁴ may further have a substituent. The type of the substituent is not particularly limited as long as it does not depart from the spirit of the present invention, but preferred specific examples include alkyl groups such as methyl group, ethyl group, propyl group and allyl group, methoxy group, ethoxy group and propoxy group. And the like. The presence of these substituents may provide an effect of increasing charge mobility due to an electron donating effect. However, if the size of the substituent is too large, the charge mobility is decreased due to the distortion of the conjugated surface in the molecule and the steric repulsion between the molecules. Therefore, the substituent having 3 or less carbon atoms is preferable. A methyl group and a methoxy group are preferred. Also, the number of substituents is arbitrary, but if it is too large, the charge mobility is reduced for the same reason, so it is preferably 3 or less, more preferably 2 or less.

In the general formula (4), Ar ¹ and Ar ² each represent the same group as the group having the same sign in the general formula (1). Several Ar < ² > may be the same and may mutually differ.

m ₂ represents 1 or 2, and n ₂ represents 0 or 1. However, m ₂ + n ₂ ≧ 2. That is, as combinations of m ₂ and n ₂ , there are three combinations of m ₂ = 1 and n ₂ = 1, m ₂ = 2 and n ₂ = 0, m ₂ = 2 and n ₂ = 1. . When m ₂ is 2, the plurality of Ar ¹ may be the same or different from each other.

In the general formula (5), Ar ³ represents the same group as the group having the same sign in the general formula (2).
Cn represents a divalent linking group. The type of the linking group is arbitrary, but a saturated or unsaturated alkylene group is preferable. The carbon number of Cn is usually 3 or less. If the length is too long, the strain in the molecule increases, so it is not preferable to have 4 or more carbon atoms. Specific examples include a methylene group, vinylene group, ethylene group, ethylidene group, propylene group, and isopropylene group. From the viewpoint of suppressing intramolecular distortion and increasing charge mobility, a methylene group and vinylene group are preferable. .

In the general formula (6), Ar ² represents the same group as the group having the same sign in the general formula (1). A plurality of Ar ² may be the same or different.
Ar ³ represents the same group as the group having the same sign in the general formula (2).

In General Formula (7), Ar ¹ and Ar ² each represent the same group as the group having the same sign in General Formula (1).
Ar ⁵ represents an aryl group having at least one alkoxy group or halogen group, or a monovalent heterocyclic ring-containing group.

When Ar ⁵ is an aryl group, the type of the aryl group is not particularly limited, and may be a single ring or a condensed two or more rings. Specific examples include phenyl group, naphthyl group, acenaphthyl group, pyrenyl group and the like. Among these, a phenyl group and a naphthyl group are preferable, and a phenyl group and an α-naphthyl group are particularly preferable from the viewpoint of conjugation extension in the molecule and reduction of the permanent dipole moment of the molecule. On the other hand, the use of an aryl group condensed with three or more rings such as a fluorene residue or a phenanthrene residue is disadvantageous in terms of production because the molecular size becomes too large. By repulsion, the charge mobility is decreased, and the effect as a charge transport material may not be sufficiently obtained.

The type of alkoxy group or halogen group contained in the aryl group of Ar ⁵ is not particularly limited. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group. However, if the size of the alkoxy group is too large, the charge mobility is decreased due to the distortion of the conjugate plane in the molecule and the steric repulsion between the molecules. Therefore, the alkoxy group having 3 or less carbon atoms is preferable. A methoxy group is preferred. Specific examples of the halogen group include a chloro group and a bromo group. Among them, a chloro group is preferable. The number of alkoxy groups or halogen groups is also arbitrary, but if it is too large, the charge mobility is reduced for the same reason, so it is preferably 3 or less, more preferably 2 or less. Moreover, it may have only one of an alkoxy group or a halogen group, and may have both.

When Ar ⁵ is a monovalent heterocyclic ring-containing group, the type is not particularly limited as long as it is a monovalent organic group containing a heterocyclic ring, but usually a monovalent heterocyclic group or a divalent linking group. Is a monovalent organic group having a monovalent heterocyclic group bonded thereto. Specific examples of the monovalent heterocyclic group include a furyl group, a thienyl group, and a pyridyl group. Of these, a thienyl group is preferable and an α-thienyl group is preferable from the viewpoints of intramolecular conjugation extension and reduction of the permanent dipole moment of the molecule. The type of the divalent linking group is not particularly limited, but a saturated or unsaturated alkylene group having about 1 to 4 carbon atoms is preferable, and specific examples include a methylene group, an ethylene group, a propylene group, and a vinylene group. . However, from the viewpoint of reducing the steric repulsion between molecules by reducing the molecular size as much as possible and improving the charge mobility, a divalent linking group is not present or even a methylene group is preferred.

The hetero ring-containing group for Ar ⁵ may further have a substituent. The type of the substituent is not particularly limited as long as it does not depart from the spirit of the present invention, but preferred specific examples include alkyl groups such as methyl group, ethyl group, propyl group and allyl group, methoxy group, ethoxy group and propoxy group. And the like. The presence of these substituents may provide an effect of increasing charge mobility due to an electron donating effect. However, if the size of the substituent is too large, the charge mobility is decreased due to the distortion of the conjugated surface in the molecule and the steric repulsion between the molecules. Therefore, the substituent having 3 or less carbon atoms is preferable. A methyl group and a methoxy group are preferred. Also, the number of substituents is arbitrary, but if it is too large, the charge mobility is reduced for the same reason, so it is preferably 3 or less, more preferably 2 or less.

In the general formula (8), Ar ¹ and Ar ² each represent the same group as the group having the same sign in the general formula (1).
N ₃ represents 1 or 2.

  General formula (1), general formula (2), general formula (3), general formula (4), general formula (5), general formula (6), general formula (7) and general formula (8) explained above As a charge transport material, this compound exhibits hole transportability, has little chemical degradation, good matching with a charge generation material, high mobility, and a sufficiently low residual potential upon exposure. It has favorable characteristics. Therefore, by using these compounds as a charge transport material in the photosensitive layer, it is possible to obtain an electrophotographic photosensitive member with high sensitivity, excellent electrical characteristics such as high-speed response, and good stability and durability. It becomes.

Compounds of general formula (1), general formula (2), general formula (3), general formula (4), general formula (5), general formula (6), general formula (7) and general formula (8) The reason for the excellent properties as a charge transport material is not clear, but can be considered as follows. That is, these compounds have a sufficiently long conjugated system extending from an arylene group such as Ar ¹ and Ar ³ to an aryl group and heterocycle-containing group such as Ar ² , Ar ⁴ and Ar ⁵ in the intramolecular structure. And free charge transfer within the molecule is ensured. Further, since the intramolecular homogeneity of the conjugated system is high and there is no intramolecular twist that cuts the conjugated system, it is considered that the above-described excellent characteristics can be obtained.

  Among the above-mentioned compounds, from the viewpoint of ensuring a sufficiently long conjugated system, the general formula (1), the general formula (2), the general formula (3), the general formula (4), and the general formula (5 ), A compound which is a group represented by any one of the general formula (6) and the general formula (7) is preferable as the charge transport material.

General formula (1), general formula (2), general formula (3), general formula (4), general formula (5), general formula (6), general formula (7) and general formula (8) Specific examples are shown below.

  As a general method for producing the charge transport material of the present invention, a secondary amine bis (3,4-dimethylphenyl) amine is reacted with a halogenated aryl compound using a known reaction such as an Ullmann reaction, Examples thereof include a method in which the obtained triarylamine compound is formylated by a Vilsmeier reaction, and a conjugated system such as stilbene or hydrazone is imparted to the formyl body using a known reaction. The charge transport material of the present invention can also be obtained by an Ullmann reaction between an aminoaryl compound that is a primary amine and 3,4-dimethylhalogenobenzene.

  The charge transport material of the present invention is used in a photosensitive layer provided on a conductive support (substrate) in the electrophotographic photoreceptor of the present invention to be described subsequently.

[2. Electrophotographic photoreceptor]
The structure of the electrophotographic photosensitive member of the present invention is not particularly limited as long as the photosensitive layer containing the above-described charge transporting material of the present invention is provided on a conductive support.

  As the conductive support, for example, a metal material such as aluminum, aluminum alloy, stainless steel, copper, nickel, or a resin material imparted with conductivity by adding conductive powder such as metal, carbon, tin oxide, Resins, glass, paper, and the like, which are formed by depositing or coating a conductive material such as aluminum, nickel, ITO (indium oxide tin oxide alloy) on the surface, are mainly used. As a form, a drum shape, a sheet shape, a belt shape or the like is used. A conductive material having an appropriate resistance value may be coated on a conductive support made of a metal material in order to control conductivity and surface properties or to cover defects.

  When a metal material such as an aluminum alloy is used as the conductive support, it may be used after anodizing. When the anodizing treatment is performed, it is desirable to perform a sealing treatment by a known method.

For example, an anodic oxidation film is formed by anodizing in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, boric acid, sulfamic acid, etc. give. In the case of anodic oxidation in sulfuric acid, the sulfuric acid concentration is 100 to 300 g / l, the dissolved aluminum concentration is 2 to 15 g / l, the liquid temperature is 15 to 30 ° C., the electrolysis voltage is 10 to 20 V, and the current density is 0.5 to Although it is preferable to set within the range of ² A / dm ² , it is not limited to the above conditions.

  It is preferable to perform a sealing treatment on the anodic oxide film thus formed. The sealing treatment may be performed by a known method. For example, it is immersed in an aqueous solution containing nickel fluoride as a main component, or immersed in an aqueous solution containing nickel acetate as a main component. A high temperature sealing treatment is preferably performed.

  The concentration of the nickel fluoride aqueous solution used in the case of the low-temperature sealing treatment can be appropriately selected, but more preferable results can be obtained when it is used in the range of 3 to 6 g / l. In order to smoothly proceed with the sealing treatment, the treatment temperature is usually 25 ° C. or higher, preferably 30 ° C. or higher, and usually 40 ° C. or lower, preferably 35 ° C. or lower, and a nickel fluoride aqueous solution. The pH is usually 4.5 or more, preferably 5.5 or more, and usually 6.5 or less, preferably 6.0 or less. As the pH adjuster, oxalic acid, boric acid, formic acid, acetic acid, sodium hydroxide, sodium acetate, aqueous ammonia and the like can be used. The treatment time is preferably in the range of 1 to 3 minutes per 1 μm of film thickness. In order to further improve the physical properties of the film, cobalt fluoride, cobalt acetate, nickel sulfate, a surfactant or the like may be added to the nickel fluoride aqueous solution. Subsequently, it is washed with water and dried to finish the low temperature sealing treatment. As the sealing agent in the case of the high temperature sealing treatment, an aqueous solution of a metal salt such as nickel acetate, cobalt acetate, lead acetate, nickel acetate-cobalt, barium nitrate can be used, and it is particularly preferable to use nickel acetate. . The concentration in the case of using an aqueous nickel acetate solution is preferably 5 to 20 g / l. The treatment temperature is usually 80 ° C. or higher, preferably 90 ° C. or higher, and usually 100 ° C. or lower, preferably 98 ° C. or lower, and the pH of the nickel acetate aqueous solution is 5.0 to 6.0. Is preferred. Here, ammonia water, sodium acetate, or the like can be used as the pH adjuster. The treatment time is 10 minutes or longer, preferably 20 minutes or longer. In this case as well, sodium acetate, organic carboxylic acid, anionic and nonionic surfactants may be added to the nickel acetate aqueous solution in order to improve the film properties. Subsequently, it is washed with water and dried to finish the high temperature sealing treatment. When the average film thickness is thick, stronger sealing conditions are required due to the higher concentration of the sealing liquid and high temperature / long-time treatment. Accordingly, productivity is deteriorated and surface defects such as spots, dirt, and dusting are likely to occur on the coating surface. From such a point, it is preferable that the average film thickness of the anodic oxide coating is usually 20 μm or less, particularly 7 μm or less.

  The support surface may be smooth, or may be roughened by using a special cutting method or polishing. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without cutting. Especially when using non-cutting aluminum supports such as drawing, impact processing, ironing, etc., the process eliminates dirt, foreign matter, etc. on the surface, small scratches, etc., and a uniform and clean support can be obtained. Therefore, it is preferable.

  The surface of the support may be smooth, or may be roughened by using a special cutting method or performing a polishing treatment. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without performing the cutting process.

  An undercoat layer may be provided between the conductive support and the photosensitive layer in order to improve adhesion and blocking properties. As the undercoat layer, a resin, a resin in which particles such as a metal oxide are dispersed, or the like is used.

  Examples of metal oxide particles used for the undercoat layer include metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, titanium Examples thereof include metal oxide particles containing a plurality of metal elements such as strontium acid and barium titanate. Only one type of particle may be used, or a plurality of types of particles may be mixed and used. Among these metal oxide particles, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance such as stearic acid, polyol, or silicone. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. A thing of a several crystalline state may be contained.

  In addition, various particle diameters of the metal oxide particles can be used. Among these, from the viewpoint of characteristics and liquid stability, the average primary particle diameter is usually 1 nm or more, particularly 10 nm or more, and usually 100 nm or less. The range of 50 nm or less is particularly preferable.

  The undercoat layer is preferably formed in a form in which metal oxide particles are dispersed in a binder resin. Examples of the binder resin used for the undercoat layer include phenoxy, epoxy, polyvinyl pyrrolidone, polyvinyl alcohol, casein, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, and polyamide. These may be used alone or in combination of two or more. Moreover, you may use with the hardening | curing form with the hardening | curing agent. Among these, alcohol-soluble copolymerized polyamide, modified polyamide, and the like are preferable because they exhibit good dispersibility and coating properties.

  The addition ratio of the inorganic particles to the binder resin used in the undercoat layer may be arbitrarily selected, but it is usually used in the range of 10% by weight or more and 500% by weight or less for the stability of the dispersion and the coating property. It is preferable in terms of

  Although the thickness of the undercoat layer can be arbitrarily selected, it is usually preferably in the range of 0.1 μm or more and 20 μm or less from the viewpoint of improving the photoreceptor characteristics and applicability. Further, a known antioxidant or the like may be added to the undercoat layer.

  The type of the photosensitive layer formed on the conductive support includes a single layer type in which the charge generation material and the charge transport material are present in the same layer and dispersed in the binder resin, and the charge generation material in the binder resin. The charge generation layer and the charge transport layer in which the charge transport material is dispersed in a binder resin may be used. In general, it is known that the charge transport material exhibits the same performance as a charge transfer function regardless of whether it is a single layer type or a multilayer type.

  Examples of charge generation materials include selenium and its alloys, cadmium sulfide, and other inorganic photoconductive materials, phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, and perylene pigments. Various photoconductive materials such as organic pigments such as polycyclic quinone pigments, anthanthrone pigments, and benzimidazole pigments can be used. Of these, organic pigments are preferred.

  When organic pigments are used as the charge generating material, these fine particles are converted into, for example, polyvinyl acetate, polyacrylic acid ester, polymethacrylic acid ester, polyester, polycarbonate, polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, phenoxy resin, epoxy resin. , Urethane resin, cellulose ester, cellulose ether, and other binder resins. In the case of a multilayer photoreceptor, the organic pigment is used in a range of usually 30 parts by weight or more and 500 parts by weight or less with respect to 100 parts by weight of the binder resin, and its film thickness is usually 0.1 μm or more, preferably A range of 0.15 μm or more, usually 1 μm or less, preferably 0.6 μm or less is suitable. In the case of a single layer type photoreceptor, the range is usually 0.1 parts by weight or more, preferably 1 part by weight or more, and usually 30 parts by weight or less, preferably 10 parts by weight or less with respect to 100 parts by weight of the binder resin. Used in.

  When an organic pigment is used as the charge generating material, a phthalocyanine pigment or an azo pigment is particularly preferable. The phthalocyanine pigment provides a photosensitive material with high sensitivity to a laser beam having a relatively long wavelength, and the azo pigment has a sufficient sensitivity to white light and a laser beam having a relatively short wavelength. , Each is excellent.

  When a phthalocyanine compound is used as the charge generation material, specifically, a metal such as metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, or an oxide, halide, hydroxide thereof And various crystal forms of coordinated phthalocyanines such as alkoxides. Particularly, titanyl phthalocyanines (also known as oxytitanium) such as X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), and D-type (also known as Y-type), which are highly sensitive crystalline Phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and type I, μ-oxo such as type II -Aluminum phthalocyanine dimer is preferred. Among these phthalocyanines, A-type (β-type), B-type (α-type) and D-type (Y-type) titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type hydroxygallium phthalocyanine, G-type μ-oxo-gallium A phthalocyanine dimer and the like are particularly preferable.

  Further, among phthalocyanines, oxytitanium phthalocyanine having a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of X-ray diffraction spectrum with respect to CuKα characteristic X-ray of 27.3 ° is 9.3 °, 13. Oxytitanium phthalocyanine showing main diffraction peaks at 2 °, 26.2 ° and 27.1 °, dihydroxysilicon having main diffraction peaks at 9.2, 14.1, 15.3, 19.7, 27.1 ° Phthalocyanine, dichlorotin phthalocyanine showing major diffraction peaks at 8.5 °, 12.2 °, 13.8 °, 16.9 °, 22.4 °, 28.4 ° and 30.1 °, 7.5 ° , 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 °, hydroxy potassium phthalocyanine showing main diffraction peaks, and 7.4 °, 16. °, chlorogallium phthalocyanine preferably exhibits a diffraction peak at 25.5 ° and 28.3 °. Among these, oxytitanium phthalocyanine showing a main diffraction peak at 27.3 ° is particularly preferable, and in this case, oxytitanium phthalocyanine showing main diffraction peaks at 9.5 °, 24.1 ° and 27.3 ° is particularly preferable. .

  As the phthalocyanine compound, only a single compound may be used, or several mixed or mixed crystal states may be used. As the mixed state that can be placed in the phthalocyanine compound or crystal state here, the respective constituent elements may be mixed and used later, or the mixed state in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, crystallization, etc. It may be generated. As such treatment, acid paste treatment, grinding treatment, solvent treatment and the like are known. In order to generate a mixed crystal state, as described in JP-A-10-48859, two types of crystals are mixed, mechanically ground and made amorphous, and then converted into a specific crystal state by solvent treatment. The method of doing is mentioned.

When an azo pigment is used as the charge generating substance, specific examples include monoazo, bisazo, trisazo, polyazos, etc. Among them, conventionally known various bisazo pigments and trisazo pigments are preferably used.
Examples of preferred azo pigments are shown below.

  As the charge transport material, the above-described charge transport material of the present invention is used. Any one of the charge transport materials of the present invention may be used alone, or two or more thereof may be used in any combination and ratio. That is, the above general formula (1), general formula (2), general formula (3), general formula (4), general formula (5), general formula (6), general formula (7) and / or general formula Among the compounds represented by (8), any one can be used alone, or two or more can be used in any combination.

  In addition to the charge transport material of the present invention, other known charge transport materials may be used in combination. When other charge transport materials are used in combination, the kind thereof is not particularly limited. For example, carbazole derivatives, hydrazone compounds, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, and those obtained by bonding a plurality of these derivatives are preferable. More specifically, compounds described in JP-A-2-230255, JP-A-63-225660, JP-A-58-198043, JP-B-58-32372, and JP-B-7-21646 Are preferably used.

  In forming the photosensitive layer, a binder resin is used to ensure film strength. In this case, the photosensitive layer can be obtained by applying and drying a coating solution obtained by dissolving or dispersing the charge transport material and the binder polymer in a solvent. Examples of the binder resin include polymers and copolymers of vinyl compounds such as butadiene, styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinyl alcohol, and ethyl vinyl ether, polyvinyl butyral, polyvinyl formal, and partially modified polyvinyl. Examples include acetal, polycarbonate, polyester, polyarylate, polyamide, polyurethane, cellulose ether, phenoxy resin, silicon resin, epoxy resin, and poly-N-vinylcarbazole resin. Of these, polycarbonate and polyarylate are particularly preferred. These can also be used after being crosslinked with heat, light or the like using an appropriate curing agent or the like. These binders can also be used by blending two or more.

  The ratio between the binder resin and the charge transporting material is usually 20 parts by weight or more with respect to 100 parts by weight of the binder resin in both the single layer type and the laminated type, and more preferably 30 parts or more from the viewpoint of reducing the residual potential. From the viewpoint of stability and charge mobility, 40 parts or more is more preferable. On the other hand, from the viewpoint of thermal stability of the photosensitive layer, it is usually 150 parts by weight or less, more preferably 110 parts by weight or less from the viewpoint of compatibility between the charge transport material and the binder resin, and 80 weights from the viewpoint of printing durability. Part or less is more preferable, and from the viewpoint of scratch resistance, 70 parts by weight or less is most preferable. The film thickness is usually 5 μm or more and usually 50 μm or less, preferably 10 μm or more and 45 μm or less from the viewpoint of long life and image stability, and from the viewpoint of high resolution, the range is 10 μm or more and 30 μm or less. More preferred.

  The photosensitive layer has well-known antioxidants, plasticizers, ultraviolet absorbers, electron-withdrawing compounds to improve film-forming properties, flexibility, coating properties, stain resistance, gas resistance, light resistance, etc. Further, additives such as a leveling agent may be contained.

  In the case of a single-layer type photoreceptor, the above-described charge generating material is further dispersed in the charge transport medium having the above-described blending ratio. In this case, the particle size of the charge generating material needs to be sufficiently small, and is preferably 1 μm or less, more preferably 0.5 μm or less. When the amount of the charge generating material dispersed in the photosensitive layer is too small, sufficient sensitivity cannot be obtained. On the other hand, when the amount is too large, there are problems such as a decrease in chargeability and a decrease in sensitivity. It is used in the range of not less than wt%, preferably not less than 1 wt%, and usually not more than 50 wt%, preferably not more than 20 wt%. The film thickness of the single-layer type photosensitive layer is usually 5 μm or more, preferably 10 μm or more, and usually 100 μm or less, preferably 50 μm or less.

  A protective layer is provided on the laminated or single-layered photosensitive layer for the purpose of preventing the photosensitive layer from being worn out or preventing or reducing the deterioration of the photosensitive layer due to discharge products generated from a charger or the like. Also good.

  The layer that contacts the surface of the photoreceptor may contain a fluorine resin, a silicone resin, or the like for the purpose of reducing frictional resistance and wear on the surface of the photoreceptor. Moreover, you may contain the particle | grains which consist of these resin, and the particle | grains of an inorganic compound.

  Each layer constituting these photoreceptors is formed by immersing, coating, spraying, nozzle coating, bar coating, roll coating, blade coating, etc., on a support, a coating solution obtained by dissolving or dispersing a substance to be contained in a solvent. Are formed by sequential application by the known method.

  Examples of the solvent or dispersion medium used for preparing the coating liquid include alcohols such as methanol, ethanol, propanol, and 2-methoxyethanol, ethers such as tetrahydrofuran, 1,4-dioxane, and dimethoxyethane, methyl formate, and acetic acid. Esters such as ethyl, ketones such as acetone, methyl ethyl ketone, cyclohexanone, aromatic hydrocarbons such as benzene, toluene, xylene, dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, 1, Chlorinated hydrocarbons such as 1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane, trichloroethylene, n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylene Examples include nitrogen-containing compounds such as amines, and aprotic polar solvents such as acetonitrile, N-methylpyrrolidone, N, N-dimethylformamide, and dimethyl sulfoxide. These are used alone or in combination of two or more. It is done.

  In the preparation of the coating liquid or dispersion, in the case of a single layer type photosensitive layer and a charge transport layer of a laminated type photosensitive layer, the solid content concentration is preferably 10% by weight or more, and preferably 40% by weight. Hereinafter, it is more preferably in the range of 35% by weight or less, the viscosity is preferably in the range of 50 cps or more, and preferably in the range of 400 cps or less. In the case of the charge generation layer of the laminated photosensitive layer, the solid content concentration is preferably Is 1% by weight or more, preferably 15% by weight or less, more preferably 10% by weight or less, and the viscosity is preferably 0.1 cps or more, and preferably 10 cps or less.

[3. Image forming apparatus and image forming method]
Next, an embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

  As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6 and a fixing device as necessary. A device 7 is provided.

  The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are disposed along the outer peripheral surface of the electrophotographic photosensitive member 1.

  The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2, but other corona charging devices such as corotron and scorotron, and contact-type charging devices such as charging brushes are often used.

  In many cases, the electrophotographic photosensitive member 1 and the charging device 2 are designed to be removable from the main body of the image forming apparatus as a cartridge including both of them (hereinafter, appropriately referred to as a photosensitive cartridge). For example, when the electrophotographic photoreceptor 1 or the charging device 2 deteriorates, the photoreceptor cartridge can be removed from the image forming apparatus main body, and another new photosensitive cartridge can be mounted on the image forming apparatus main body. ing. Also, the toner described later is often stored in the toner cartridge and designed to be removable from the main body of the image forming apparatus. When the toner in the used toner cartridge runs out, this toner cartridge is removed. It can be removed from the main body of the image forming apparatus and another new toner cartridge can be mounted. Further, a cartridge equipped with all of the electrophotographic photosensitive member 1, the charging device 2, and the toner may be used.

  The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary. For example, the exposure may be performed using monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength slightly shorter than 600 nm to 700 nm, or monochromatic light with a short wavelength of 380 nm to 500 nm. .

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component conductive toner development, two-component magnetic brush development, or a wet development method can be used. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

  The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicone resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.

  The developing roller 44 is disposed between the electrophotographic photoreceptor 1 and the supply roller 43 and is in contact with the electrophotographic photoreceptor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photosensitive member 1.

  The regulating member 45 is formed of a resin blade such as a silicone resin or a urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such a metal blade with a resin. The regulating member 45 contacts the developing roller 44 and is pressed against the developing roller 44 side with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

  The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.

  The type of the toner T is arbitrary, and in addition to the powdery toner, a polymerized toner using a suspension polymerization method, an emulsion polymerization method, or the like can be used. In particular, when a polymerized toner is used, a toner having a small particle diameter of about 4 to 8 μm is preferable, and the toner particles are used in various shapes ranging from a nearly spherical shape to a shape outside the spherical shape on the potato. be able to. The polymerized toner is excellent in charging uniformity and transferability and is suitably used for high image quality.

  The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like that are disposed to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is.

  There is no restriction | limiting in particular about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner. However, when there is little or almost no toner remaining on the surface of the photoreceptor, the cleaning device 6 may be omitted.

  The fixing device 7 includes an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. Each of the upper and lower fixing members 71 and 72 includes a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, and a fixing sheet. A member can be used. Further, each of the fixing members 71 and 72 may be configured to supply a release agent such as silicone oil in order to improve releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P.
The type of the fixing device is not particularly limited, and a fixing device of any type such as heat roller fixing, flash fixing, oven fixing, pressure fixing, etc. can be provided including those used here.

  In the electrophotographic apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed by a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.

  Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1.

  The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ), And conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoreceptor 1.

  When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6.

  After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.

  In addition to the above-described configuration, the image forming apparatus may have a configuration capable of performing, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

  The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited to a following example, unless it deviates from the summary.

<Manufacture of charge transport materials>
[Production Example 1]
(Production of charge transport material (1))
55.8 g of aniline and 349.5 g of 4-iodo-o-xylene were heated and stirred at 150 ° C., 45.7 g of copper powder and 99.4 g of potassium carbonate were added thereto, and the temperature was 195 ° C. to 200 ° C. under a nitrogen flow. After reacting under conditions for 24 hours, 4-iodo-o-xylene was distilled off under reduced pressure. The remaining product was cooled to room temperature and dissolved by adding 620 ml of tetrahydrofuran. The obtained tetrahydrofuran solution was poured into a mixture of methanol 1984 ml / water 496 ml, and the resulting precipitate was filtered to obtain 144 g of crude N, N-bis (3,4-dimethylphenyl) aniline.

  9.34 g of this crude N, N-bis (3,4-dimethylphenyl) aniline was dissolved in 30 ml of N, N-dimethylformamide, and 7.67 g of phosphorus oxychloride was slowly added dropwise to the resulting solution at room temperature. Then, it stirred for 3 hours, heating at 60 to 70 degreeC. After allowing to cool, 100 ml of toluene and 100 ml of water were added, and the resulting mixture was discharged while cooling into a solution of 13.8 g of sodium hydroxide dissolved in 100 ml of water. After the toluene layer was separated and washed, toluene was distilled off to obtain 8.23 g of p- [N, N-bis (3,4-dimethylphenyl) amino] benzaldehyde.

  6.5 g of this crude product of p- [N, N-bis (3,4-dimethylphenyl) amino] benzaldehyde was dissolved in 20 ml of tetrahydrofuran, and 13.3 g of diethyl p-methoxydiphenylmethyl phosphite and tert- 4.5 g of butoxy potassium was added and stirred at room temperature for 2 hours. The reaction solution was concentrated, dissolved in toluene, washed with water, and purified by silica gel chromatography to obtain 7.2 g of a charge transport material (1) having a structure represented by the following chemical formula.

When mass analysis and elemental analysis were performed on the obtained product, the respective results were as follows: mass analysis (m / Z): M ⁺ = 509 (theoretical value 509) and elemental analysis (C ₃₇ H ₃₅ NO) : C, 87.37; H, 6.99; N, 2.82; O, 3.32 (theoretical: C, 87.19; H, 6.92; N, 2.75; O, 3.32. 14). This confirmed that the product was a charge transport material (1).

[Production Example 2]
(Synthesis of charge transport material (2))
Instead of the intermediate product p- [N, N-bis (3,4-dimethylphenyl) amino] benzaldehyde by changing aniline to m-toluidine in the procedure of Preparation Example 1, p- [N, N- Bis (3,4-dimethylphenyl) amino] -o-methylbenzaldehyde could be obtained.

  6.86 g of the obtained p- [N, N-bis (3,4-dimethylphenyl) amino] -o-methylbenzaldehyde was dissolved in 30 ml of tetrahydrofuran, to which 12.2 g of diethyl diphenylmethylphosphite and tert-butoxy were added. 4.5 g of potassium was added and stirred at room temperature for 2 hours. The reaction solution was concentrated, dissolved in toluene, washed with water, and purified by silica gel chromatography to obtain 7.9 g of a charge transport material (2) having a structure represented by the following chemical formula.

When mass analysis and elemental analysis were performed on the obtained product, each result was as follows: mass analysis (m / Z): M ⁺ = 493 (theoretical value 493) and elemental analysis (C ₃₇ H ₃₅ N) : C, 90.14; H, 7.10; N, 2.77 (theoretical value: C, 90.02; H, 7.15; N, 2.84). This confirmed that the product was a charge transport material (2).

[Production Example 3]
(Synthesis of charge transport material (4))
According to the procedure of Preparation Example 1, an intermediate product p- [N, N-bis (3,4-dimethylphenyl) amino] benzaldehyde was synthesized. This crude 9.8 g of p- [N, N-bis (3,4-dimethylphenyl) amino] benzaldehyde was dissolved in 30 ml of tetrahydrofuran, and 1 mol / l of a solution of methylmagnesium bromide in tetrahydrofuran was added thereto at room temperature. After stirring for 1 hour, it stirred at 50-60 degreeC for 1 hour. The reaction mixture was cooled and then added to an aqueous ammonium chloride solution. After stirring, the organic layer was separated. 100 ml of acetic acid was added to the organic layer and stirred at 80 ° C. for 1 hour. After cooling, the reaction mixture is poured into water, extracted with toluene, the toluene layer is washed with water, dried, purified by silica gel column chromatography, and p- [N, N-bis (3,4-dimethylphenyl) amino. ] 6.2 g of styrene was obtained.

  6.2 g of this p- [N, N-bis (3,4-dimethylphenyl) amino] styrene is dissolved in 30 ml of N, N-dimethylformamide, and 4.35 g of phosphorus oxychloride is slowly added to the resulting solution at room temperature. After dripping, it stirred for 3 hours, heating at 60-70 degreeC. After allowing to cool, 100 ml of toluene and 100 ml of water were added, and the resulting mixture was discharged with cooling into a solution of 4.6 g of sodium hydroxide in 50 ml of water. The toluene layer was separated and washed, and then toluene was distilled off to obtain 4.3 g of 3- {p- [N, N-bis (3,4-dimethylphenyl) amino] phenyl} acrolein.

  4.3 g of this 3- {p- [N, N-bis (3,4-dimethylphenyl) amino] phenyl} acrolein was dissolved in 100 ml of tetrahydrofuran, and 7.36 g of diethyl diphenylmethyl phosphite and tert- 2.72 g of butoxy potassium was added and stirred at room temperature for 2 hours. The reaction solution was concentrated, dissolved in toluene, washed with water, and purified by silica gel chromatography to obtain 4.8 g of a charge transport material (4) having a structure represented by the following chemical formula.

When mass analysis and elemental analysis were performed on the obtained product, the respective results were as follows: mass analysis (m / Z): M ⁺ = 505 (theoretical value 505) and elemental analysis (C ₃₈ H ₃₅ N) : C, 90.38; H, 6.90; N, 2.72 (theoretical value: C, 90.25; H, 6.98; N, 2.77). This confirmed that the product was a charge transport material (4).

[Production Example 4]
(Synthesis of charge transport material (5))
In a nitrogen atmosphere, 5.5 g of N-3,4-dimethylphenyl-3,4-xylidine and 4.2 g of an iodobenzene compound having the structure represented by the following chemical formula (i) were added together with Cu 0.07 g and anhydrous potassium carbonate 1.66 g. Heated at 195-200 ° C. for 24 hours.

  After cooling to 110 ° C., 150 ml of toluene was added, and the reaction mixture was filtered through a celite bed as it was. The filtrate was washed with water, and the organic layer was dried over anhydrous sodium sulfate. Next, after toluene in the organic layer was distilled off, 100 ml of tetrahydrofuran was added again, and this was added to methanol cooled to 5 ° C. The precipitated solid was dried, dissolved in toluene, and purified by silica gel column chromatography to obtain a charge transport material (5) having a structure represented by the following chemical formula.

When mass analysis and elemental analysis were performed on the obtained product, the results were as follows: mass analysis (m / Z): M ⁺ = 517 (theoretical value 517) and elemental analysis (C ₃₉ H ₃₅ N>) : C, 90.60; H, 6, 73; N, 2.64 (theoretical: C, 90.48; H, 6.81; N, 2.71). Was confirmed to be a charge transport material (5).

[Production Example 5]
(Synthesis of charge transport material (42))
According to the procedure of Preparation Example 1, an intermediate product p- [N, N-bis (3,4-dimethylphenyl) amino] benzaldehyde was synthesized. A crude product of 6.5 g of p- [N, N-bis (3,4-dimethylphenyl) amino] benzaldehyde is dissolved in 30 ml of tetrahydrofuran, 7.78 g of benzyltriphenylphosphonium chloride, and a methanol solution of sodium methoxide. 7 g (containing 1.42 g of sodium methoxide) was added and stirred at room temperature for 2 hours. The reaction solution was concentrated, dissolved in toluene, washed with water, and purified by silica gel chromatography to obtain 7.3 g of a charge transport material (42) having a structure represented by the following chemical formula.

When mass analysis and elemental analysis were performed on the obtained product, the results were as follows: mass analysis (m / Z>: M ⁺ = 403 (theoretical value 403) and elemental analysis (C ₃₀ H ₂₉ N) : C, 89.45: H, 7.18; N, 3.37 (theoretical: C, 89.29; H, 7.24; N, 3.47). Was confirmed to be a charge transport material (42).

[Production Example 6]
(Synthesis of charge transport material (19))
In the procedure of Preparation Example 1, except that m-toluidine was used instead of aniline, the same procedure was followed. Instead of p- [N, N-bis (3,4-dimethylphenyl) amino] benzaldehyde, an intermediate product was used. p- [N, N-bis (3,4-dimethylphenyl) amino] -o-methylbenzaldehyde was synthesized. 4.2 g of this p- [N, N-bis (3,4-dimethylphenyl) amino] -o-methylbenzaldehyde is dissolved in 15 ml of tetrahydrofuran, and 3.45 g of 1,1-diphenylhydrazine is dissolved in 10 ml of methanol. The resulting solution was added dropwise at room temperature, and then heated and stirred at 50 to 60 ° C. for 1 hour. After allowing to cool, 85 ml of methanol was added, and the filtrated substance obtained by filtration was purified by silica gel chromatography to obtain 6.02 g of a charge transport material (19) having a structure represented by the following chemical formula.

When mass analysis and elemental analysis were performed on the obtained product, the results were as follows: mass analysis (m / Z): M ⁺ = 509 (theoretical value 509) and elemental analysis (C ₃₆ H ₃₅ N ₃ ): C, 84.73: H, 6.85; N, 8.41 (theoretical value: C, 84.83; H, 6.92; N, 8.24). This confirmed that the product was a charge transport material (19).

[Production Example 7]
(Synthesis of charge transport material (20))
3.8 g of p- [N, N-bis (3,4-dimethylphenyl) amino] benzaldehyde synthesized according to the procedure of Preparation Example 1 was dissolved in 15 ml of tetrahydrofuran, and N-phenyl-N- (2-thienylmethyl) was dissolved therein. ) A solution prepared by dissolving 3.45 g of hydrazine in 10 ml of methanol was added dropwise at room temperature, followed by heating and stirring at 50 to 60 ° C. for 1 hour. After allowing to cool, 85 ml of methanol was added, and the filtrated product obtained by filtration was purified by silica gel chromatography to obtain 4.08 g of a charge transport material (20) having a structure represented by the following chemical formula.

When mass analysis and elemental analysis were performed on the obtained product, the respective results were as follows: mass analysis (m / Z): M ⁺ = 515 (theoretical value 515) and elemental analysis (C ₄₁ H ₃₇ N ₃ S ₁ ): C, 79.09: H, 6.58; N, 8.22: S, 6.11 (theoretical: C, 79.18; H, 6.45; N, 8.15: S 6.22). This confirmed that the product was a charge transport material (20).

[Production Example 8]
(Synthesis of charge transport material (30))
4.5 g of 4- [N, N-bis (3,4-dimethylphenyl) amino] -1-naphthaldehyde was dissolved in 15 ml of tetrahydrofuran, and 3.45 g of 1,1-diphenylhydrazine was dissolved in 10 ml of methanol. The solution was added dropwise at room temperature, and then heated and stirred at 50 to 60 ° C. for 1 hour. After allowing to cool, 85 ml of methanol was added, and the filtrated product obtained by filtration was purified by silica gel chromatography to obtain 5.36 g of a charge transport material (30) having a structure represented by the following chemical formula.

When mass analysis and elemental analysis were performed on the obtained product, the results were as follows: mass analysis (m / Z): M ⁺ = 545 (theoretical value 545) and elemental analysis (C ₃₉ H ₃₅ N ₃ ): C, 86.02: H, 6.36; N, 7.62 (theoretical value: C, 85.84; H, 6.46; N, 7.70). This confirmed that the product was a charge transport material (30).

<Manufacture of electrophotographic photoreceptors A1 to A13, P1 to P8>
[Example 1]
(Charge transport material (1) / charge generation material: D-type titanyl phthalocyanine)
In an X-ray diffraction spectrum, 10 parts by weight of D-type titanyl phthalocyanine showing a maximum diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.3 ° is added to 150 parts by weight of 4-methoxy-4-methylpentanone-2. Then, the mixture was pulverized and dispersed in a sand grind mill for 1 hour to prepare a pigment dispersion.

  In addition, 100 parts by weight of 5% by weight 1,2-dimethoxyethane solution of polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: Dencaptilal # 6000C) and phenoxy resin (trade name PKHH, manufactured by Union Carbide) A binder solution was prepared by mixing 100 parts by weight of a 5% by weight 1,2-dimethoxyethane solution.

  100 parts by weight of the above-mentioned binder solution and an appropriate amount of 1,2-dimethoxyethane are added to 160 parts by weight of the previously prepared pigment dispersion, and finally the dispersion (charge generation layer having a solid content concentration of 4.0% by weight) is added. Coating solution) was prepared.

  Using a 75 μm thick polyethylene terephthalate film with aluminum deposited on the surface as a conductive support (substrate), the above dispersion was applied onto the film and dried to form a 0.3 μm thick charge generation layer. Provided.

  Next, 50 parts by weight of a charge transport material (1) represented by the following chemical formula, 100 parts by weight of a polycarbonate resin (m: n = 51: 49, viscosity average molecular weight 30000) represented by the following structural formula (X), an antioxidant (Product name: IRGANOX 1076, manufactured by Ciba Geigy) and 0.03 part by weight of silicone oil as a leveling agent were dissolved in 640 parts by weight of a tetrahydrofuran / toluene mixed solvent (weight ratio 80:20) to obtain a solution (charge transport). Layer coating solution).

  This solution was applied on the charge generation layer provided on the above film and dried at 125 ° C. for 20 minutes to provide a charge transport layer having a thickness of 25 μm, thereby producing an electrophotographic photoreceptor A1.

[Example 2]
(Charge transport material (2) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor A2 was produced in the same procedure as in Example 1 except that the charge transport material (2) represented by the following chemical formula was used in place of the charge transport material (1).

[Example 3]
(Charge transport material (4) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor A3 was produced in the same procedure as in Example 1 except that the charge transport material (4) represented by the following chemical formula was used in place of the charge transport material (1).

[Example 4]
(Charge transport material (5) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor A4 was produced in the same procedure as in Example 1 except that the charge transport material (5) represented by the following chemical formula was used in place of the charge transport material (1).

[Example 5]
(Charge transport material (19) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor A5 was produced in the same procedure as in Example 1 except that the charge transport material (19) represented by the following chemical formula was used in place of the charge transport material (1).

[Example 6]
(Charge transport material (20) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor A6 was produced in the same procedure as in Example 1 except that the charge transport material (20) represented by the following chemical formula was used in place of the charge transport material (1).

[Example 7]
(Charge transport material (24) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photosensitive member A7 was produced in the same procedure as in Example 1 except that the charge transport material (24) represented by the following chemical formula was used instead of the charge transport material (1).

[Example 8]
(Charge transport material (30) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photosensitive member A8 was produced in the same procedure as in Example 1 except that the charge transport material (30) represented by the following chemical formula was used instead of the charge transport material (1).

[Example 9]
(Charge transport material (34) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor A9 was produced in the same procedure as in Example 1 except that the charge transport material (34) represented by the following chemical formula was used in place of the charge transport material (1).

[Example 10]
(Charge transport material (37) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor A10 was produced in the same procedure as in Example 1 except that the charge transport material (37) represented by the following chemical formula was used in place of the charge transport material (1).

[Example 11]
(Charge transport material (39) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor A11 was produced in the same procedure as in Example 1 except that the charge transport material (39) represented by the following chemical formula was used instead of the charge transport material (1).

[Example 12]
(Charge transport material (42) / charge generation material: D-type titanyl phthalocyanine)
In place of the charge transport material (1), an electrophotographic photoreceptor A12 was produced in the same procedure as in Example 1 except that the charge transport material (42) represented by the following chemical formula was used.

[Example 13]
(Charge transport material (45) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor A13 was produced in the same procedure as in Example 1 except that the charge transport material (45) represented by the following chemical formula was used in place of the charge transport material (1).

[Comparative Example 1]
(Charge transport material (a) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor P1 was produced in the same procedure as in Example 1 except that the charge transport material (a) represented by the following chemical formula was used in place of the charge transport material (1).

[Comparative Example 2]
(Charge transport material (b) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photosensitive member P2 was produced in the same procedure as in Example 1 except that the charge transport material (b) represented by the following chemical formula was used in place of the charge transport material (1).

[Comparative Example 3]
(Charge transport material (c) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor P3 was produced in the same procedure as in Example 1 except that the charge transport material (c) represented by the following chemical formula was used instead of the charge transport material (1).

[Comparative Example 4]
(Charge transport material (d) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor P4 was produced in the same procedure as in Example 1 except that the charge transport material (d) represented by the following chemical formula was used in place of the charge transport material (1).

[Comparative Example 5]
(Charge transport material (e) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor P5 was produced in the same procedure as in Example 1 except that the charge transport material (e) represented by the following chemical formula was used in place of the charge transport material (1).

[Comparative Example 6]
(Charge transport material (f) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor P6 was produced in the same procedure as in Example 1 except that the charge transport material (f) represented by the following chemical formula was used instead of the charge transport material (1).

[Comparative Example 7]
(Charge transport material (g) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photoreceptor P7 was produced in the same procedure as in Example 1 except that the charge transport material (g) represented by the following chemical formula was used instead of the charge transport material (1).

[Comparative Example 8]
(Charge transport material (h) / charge generation material: D-type titanyl phthalocyanine)
An electrophotographic photosensitive member P8 was produced in the same procedure as in Example 1 except that the charge transport material (h) represented by the following chemical formula was used in place of the charge transport material (1).

<Test of electrophotographic photoreceptors A1 to A13, P1 to P8>
Using the electrophotographic characteristic evaluation apparatus ("Continuing Electrophotographic Technology Basics and Applications" edited by the Electrophotographic Society, Corona, pages 404-405) prepared according to the Electrophotographic Society measurement standard, the above-mentioned electrophotographic photoreceptor A1 ~ A13, P1 to P8 are each attached to an aluminum drum to form a cylindrical shape, and the aluminum drum and the aluminum substrate of each photoconductor are electrically connected, and then the drum is charged while rotating at a constant rotational speed. An electrical property evaluation test was performed by a cycle of exposure, potential measurement, and static elimination. The initial surface potential was −700 V, monochromatic light of 780 nm was used for exposure, and 660 nm was used for charge removal.

In the electrical property evaluation test, the surface potential at the time of irradiating 1.0 μJ / cm ² of monochromatic light with a wavelength of 780 nm (hereinafter, referred to as “VL” as appropriate) and the surface potential as half as −350 V as an index representing sensitivity (Hereinafter referred to as “half exposure amount” or “E _1/2 ” as appropriate). In the VL measurement, the time required from the exposure to the potential measurement was 100 ms. The measurement environment was a temperature of 25 ° C. and a relative humidity of 50%.
The results are shown in Table 1. It shows that an electrical property is so favorable that the absolute value of the value of VL and a half exposure amount is small.

  From the results of Table 1, the electrophotographic photoreceptors A1 to A13 using the charge transport material of the present invention have a half-exposure amount and a VL of VL compared with the electrophotographic photoreceptors P1 to P8 using the conventional charge transport material. Since the absolute value is small, it can be seen that it has high sensitivity, excellent high-speed response, and exhibits good electrical characteristics.

[Example 14]
A charge generating layer coating produced in the same manner as in Example 1 on a conductive support having a diameter of 30 mm and a length of 254 mm, which was anodized on the surface of an aluminum alloy non-cut tube and further sealed. A coating layer and a charge transport layer coating solution are sequentially applied by a dip coating method and dried to form a photosensitive layer formed by laminating a charge generation layer having a thickness of about 0.3 μm and a charge transport layer having a thickness of about 25 μm in this order. An electrophotographic photoreceptor B1 having a layer was produced.

  This electrophotographic photosensitive member is mounted on a laser printer, Laser Jet 4 (LJ4) manufactured by Hewlett-Packard Company, and an initial image (after 100 times of image formation) and an image after 10,000 times of continuous image formation are visually evaluated. did. The results are shown in Table 2.

[Examples 15 to 21]
Instead of the charge transport material (1) used in Example 14, the charge transport materials (2), (4), (5), (19), (20), (24), and (42) were respectively used. The electrophotographic photoreceptors B2 to B8 used were prepared. Each electrophotographic photosensitive member was subjected to image formation in the same manner as in Example 14, and the obtained image was visually evaluated. The results are shown in Table 2.

[Comparative Example 9]
Instead of anodizing and sealing treatment on the surface of an aluminum alloy non-cutting tube similar to that used in Example 14, an undercoat layer formed by the following procedure was used as a conductive support. It was. On this conductive support, a photosensitive layer was formed in the same manner as in Example 14 to produce an electrophotographic photoreceptor Q1. The photoreceptor Q1 was subjected to image evaluation in the same manner as in Example 14. The results are shown in Table 2.

(Preparation of dispersion for undercoat layer)
A rutile type titanium oxide having an average primary particle size of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.), 3% by weight of methyldimethoxysilane with respect to the titanium oxide, and a ball mill together with 2 times by weight of methanol with respect to the titanium oxide The obtained slurry was dried, heat-treated at 120 ° C. to 140 ° C. for 30 minutes, further washed with methanol, and dried, the hydrophobic treated titanium oxide was mixed with methanol / 1-propanol (weight ratio: 7/3) was dispersed by a ball mill to obtain a dispersion slurry of hydrophobically treated titanium oxide.

  This dispersion slurry, methanol / 1-propanol / toluene mixture (weight ratio: 7/1/2), ε-caprolactam / bis (4-amino-3-methylphenyl) methane / hexamethylenediamine / decamethylenedicarboxylic The polyamide pellets were dissolved by stirring and mixing with the copolyamide pellets of acid / octadecamethylenedicarboxylic acid (composition molar ratio: 75 / 9.5 / 3 / 9.5 / 3) while heating. Thereafter, ultrasonic dispersion treatment was performed to obtain a dispersion for an undercoat layer having a solid content concentration of 18.0% containing a hydrophobically treated titanium oxide / copolymerized polyamide at a weight ratio of 3/1. The structures of the polyamide raw materials used here are as follows.

(Coating formation of undercoat layer)
The undercoat layer dispersion described above was applied to the surface of an aluminum alloy non-cutting tube similar to that used in Example 14 by a dip coating method so that the film thickness after drying was 1.25 μm. And dried to form an undercoat layer.

[Comparative Examples 10 to 16]
Instead of the charge transport material (1) used in Comparative Example 9, charge transport materials (2), (4), (5), (19), (20), (24), and (42) were respectively used. The electrophotographic photoreceptors Q2 to Q8 used were prepared. Each electrophotographic photosensitive member was subjected to image formation in the same manner as in Comparative Example 9, and the obtained image was visually evaluated. The results are shown in Table 2.

  As is apparent from Table 2, an electrophotographic photosensitive member using a conductive support obtained by anodizing and sealing the surface of an aluminum alloy support is excellent in image stability.

[Example 22]
A charge generation layer produced in the same manner as in Example 2 on a conductive support having a diameter of 20 mm and a length of 251 mm, which had been subjected to anodizing, and further subjected to sealing treatment. By sequentially applying and drying the coating liquid for coating and the coating liquid for charge transport layer by the dip coating method, a charge generation layer having a thickness of about 0.3 μm and a charge transport layer having a thickness of about 15 μm are laminated in this order. An electrophotographic photosensitive member C1 having a photosensitive layer was prepared.

  When four electrophotographic photoconductors were mounted on a Fuji Xerox tandem color laser printer, C1616, and image formation was performed, a good image free from image defects and noise was obtained. Subsequently, continuous image formation of 10,000 sheets was performed, and the formed image was stable with no image deterioration such as ghost, black spots, and fog.

[Comparative Example 17]
Instead of anodizing treatment and sealing treatment, a conductive support similar to that used in Example 22 was used except that an undercoat layer formed in the following procedure was used as the conductive support. In the same manner as in Example 22, a photosensitive layer was formed to produce an electrophotographic photoreceptor R1. When the image of the photoreceptor R1 was evaluated in the same manner as in Example 14, a good image was initially formed, but the image after 10,000 consecutive image formations had many black spots. A visible and degraded image was formed.

  The photoconductor of the present invention is excellent in stability and durability, and a good image can be stably printed by a copying machine using this photoconductor or a printer using a photoconductor cartridge.

  As described above, according to the present invention, by incorporating a triarylamine compound having a specific structure in the photosensitive layer as a charge transport material, high sensitivity, excellent electrical characteristics such as high-speed response, stability, An electrophotographic photoreceptor excellent in durability can be realized. Therefore, the present invention can be suitably used in various fields in which the electrophotographic photosensitive member is used, for example, various fields such as a copying machine, a printer, and a printing machine.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus including an electrophotographic photosensitive member of the present invention.

Explanation of symbols

1 Photoconductor 2 Charging device (charging roller)
DESCRIPTION OF SYMBOLS 3 Exposure apparatus 4 Developing apparatus 5 Transfer apparatus 6 Cleaning apparatus 7 Fixing apparatus 41 Developing tank 42 Agitator 43 Supply roller 44 Developing roller 45 Control member 71 Upper fixing member (fixing roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper (paper, medium)

Claims (11)

An electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains one or more charge transport materials selected from the group consisting of compounds represented by the following general formula (1). An electrophotographic photoreceptor.

(In General Formula (1), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. A plurality of Ar ² may be the same or different from each other, m ₁ represents an integer of ₁ to 3, n ₁ represents 0 or 1, provided that m ₁ + n ₁ ≧ 2. _{When 1} is 2 or more, the plurality of Ar ¹ may be the same or different from each other. An electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains one or more charge transport materials selected from the group consisting of compounds represented by the following general formula (2). An electrophotographic photoreceptor.

(In General Formula (2), Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. A plurality of Ar ² may be the same or different from each other. Ar ³ represents an arylene group having at least one substituent or a condensed ring.) An electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains one or more charge transport materials selected from the group consisting of compounds represented by the following general formula (3). An electrophotographic photoreceptor.

(In General Formula (3), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. Ar ⁴ represents an aryl group having at least one substituent or a condensed ring, or a monovalent heterocyclic ring-containing group. An electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains one or more charge transport materials selected from the group consisting of compounds represented by the following general formula (4). An electrophotographic photoreceptor.

(In General Formula (4), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. A plurality of Ar ² may be the same or different from each other, m ₂ represents 1 or 2, n ₂ represents 0 or 1, provided that m ₂ + n ₂ ≧ 2, where m ₂ is In the case of 2, the plurality of Ar ¹ may be the same or different from each other.) An electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains one or more charge transport materials selected from the group consisting of compounds represented by the following general formula (5). An electrophotographic photoreceptor.

(In the general formula (5), Ar ³ represents an arylene group having at least one substituent or a condensed ring. Cn represents a divalent linking group.) An electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains one or more charge transport materials selected from the group consisting of compounds represented by the following general formula (6). An electrophotographic photoreceptor.

(In General Formula (6), Ar ² represents an aryl group or a monovalent heterocyclic-containing group which may have a substituent. The plurality of Ar ² may be the same or different. Ar ³ represents an arylene group having at least one substituent or a condensed ring.) An electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains one or more charge transport materials selected from the group consisting of compounds represented by the following general formula (7). An electrophotographic photoreceptor.

(In General Formula (7), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. Ar ⁵ represents at least one alkoxy group, a halogen group, an aryl group having a condensed ring, or a monovalent heterocyclic-containing group. An electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains one or more charge transport materials selected from the group consisting of compounds represented by the following general formula (8). An electrophotographic photoreceptor.

(In General Formula (8), Ar ¹ represents an arylene group which may have a substituent. Ar ² represents an aryl group or a monovalent heterocyclic ring-containing group which may have a substituent. N ₃ represents 1 or 2)   The electrophotographic photosensitive member according to any one of claims 1 to 8, wherein the photosensitive layer further contains a phthalocyanine charge generating substance.   The electrophotographic photosensitive member according to claim 9, wherein the phthalocyanine compound is titanyl phthalocyanine. The titanyl phthalocyanine is a crystalline form of titanyl phthalocyanine having peaks at 9.5 °, 24.1 ° and 27.3 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum. The electrophotographic photosensitive member according to claim 10.

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