JP6879071B2 - Electrophotographic photosensitive member, electrophotographic cartridge, and image forming apparatus - Google Patents

Description

The present invention relates to an electrophotographic photosensitive member used in a copier, a printer, or the like, a cartridge using the electrophotographic photosensitive member, and an image forming apparatus.

Electrophotographic technology is widely used as copiers, printers, and printing machines because high-quality images can be obtained immediately.

An electrophotographic photosensitive member (hereinafter, may be referred to as a “photoreceptor”), which is the core of electrophotographic technology, is an organic light having advantages such as pollution-free, easy film formation, and easy production. Photoreceptors using conductive materials are widely used.

An electrophotographic photosensitive member using an organic photoconducting substance has the above-mentioned advantages, but the photosensitive layer tends to be gradually deteriorated in repeated use in a copying machine or a printer. Therefore, it is desired that the damage due to repeated use is small, the residual potential is low, and the electrical characteristics are stable. These characteristics depend on the charge generating substance, the charge transporting substance, the binder resin, and the like contained in the photosensitive layer. Polycarbonate resin and polyarylate resin are preferably used as the binder resin used for the photosensitive layer, particularly the charge transport layer.

In order to enhance the electrical characteristics of the photoconductor, the charge transport layer contains a large amount of the charge transport substance. However, in this case, as the content of the binder resin decreases, the characteristics of the binder resin are impaired, and the wear resistance, scratch resistance, and the like tend to decrease.

Therefore, a charge transport material having a small ionization potential, that is, a HOMO energy level E_homo is relatively large, and the π-electron system is widely coupled and has a large polarizability, that is, a calculated polarizability αcal is used. (Patent Document 1). By using such a charge-transporting substance, in addition to being able to realize high electrical properties with a charge-transporting substance having a relatively low content, the properties of the binder resin are not impaired and wear resistance is exhibited. Can be made to.

Further, in recent years, the diameter of toner has been reduced due to the demand for higher image quality. Among them, chemical toner often has a shape close to a sphere, so that the toner remaining on the photoconductor is likely to slip through when it is cleaned with a blade, and as a result, image defects such as background stains may occur. The sex is high. Therefore, the cleaning blade is often brought into contact with the photoconductor with a strong pressure to prevent the toner from slipping through, and the process setting is such that the photoconductor is easily worn.

Therefore, as a means for improving the surface mechanical properties of the photoconductor, polyester resin, especially polyarylate resin, which is an all-aromatic polyester resin, has a high elastic deformation rate, and is therefore practically used as a means for meeting the demand for improvement of mechanical properties. (Patent Documents 2 and 3). On the other hand, it is generally known that a polyarylate resin is inferior in sensitivity and residual potential electrical characteristics when used as a photoconductor as compared with a polycarbonate resin. Therefore, in order to select a charge transporting substance having a low residual potential and a high charge mobility in the photosensitive layer containing the polyarylate resin, the above-mentioned HOMO energy level E_homo is relatively large and the polarizability is high. A charge transport material having a relatively large calculated value αcal is used (Patent Document 4).

Japanese Unexamined Patent Publication No. 2013-92760 Japanese Unexamined Patent Publication No. 2006-53549 Japanese Unexamined Patent Publication No. 10-288845 Japanese Unexamined Patent Publication No. 2011-170041 Japanese Unexamined Patent Publication No. 3-163556 Japanese Unexamined Patent Publication No. 9-80782

A charge transporting substance having a relatively large HOMO energy level E_homo and a relatively large calculated polarizability αcal, as described in Patent Documents 1 and 4, often becomes a large molecule. When such a charge-transporting substance is used, the shrinkage of the coating film becomes large due to the compatibility between the binder resin and the charge-transporting substance and the influence of the molecular entanglement between the binder resin and the charge-transporting substance. As a result, the adhesiveness of the charge transport layer to the substrate, the intermediate layer, the charge generation layer, and the like tends to decrease. Therefore, there is a problem that the film peels off or floats at the end of the photoconductor due to friction with a cleaning blade, a charging roller, or the like.

Further, in order to improve the adhesiveness of the electrophotographic photosensitive member, it has been studied to contain a rosin derivative (Patent Documents 5 to 6). However, when the rosin derivative is added to the electrophotographic photosensitive member, there is a problem that the electrical characteristics are deteriorated, and the electrical characteristics and the adhesiveness cannot be improved at the same time.

The present invention has been made in view of the background art, and an object of the present invention is an electrophotographic photosensitive member having simultaneously improved adhesiveness and electrical characteristics of a charge transport layer, an electrophotographic cartridge using the electrophotographic photosensitive member, and image formation. The subject is to provide the device.

It should be noted that the present invention is not limited to the purpose described here, and it is an action and effect derived by each configuration shown in the embodiment for carrying out the invention described later, and it is also possible to exert an action and effect that cannot be obtained by the conventional technique. It can be positioned as another purpose.

As a result of diligent studies to solve the above problems, the present invention provides an electrophotographic photosensitive member having a laminated photosensitive layer with other properties by containing a specific charge transporting substance, an adhesive aid, and a binder resin. It has been found that the adhesiveness of the photosensitive layer can be improved without damaging it.
That is, the gist of the present invention provides the following specific aspects.

[1] In an electrophotographic photosensitive member having a laminated photosensitive layer on a conductive support, the charge transporting layer of the laminated photosensitive layer contains a charge transporting substance, an adhesion aid, and a binder resin, and the charge transporting is performed. As a substance, the energy level E_homo of HOMO based on the structure optimization calculation by the density functional theory B3LYP / 6-31G (d, p) is -4.700 eV or more, and the density functional theory B3LYP / 6-31G ( ^{A compound having a calculated polarizability α of αcal of 90 Å 3} or more in a stable structure based on d, p) and HF / 6-31G (d, p)) is contained, and a loginate ester is used as the adhesion aid. An electrophotographic photosensitive member comprising.

[2] The electrophotographic photosensitive member according to [1], wherein the content of the rosin acid ester is 0.2 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin.
[3] The electrophotographic photosensitive member according to [1] or [2], wherein the rosin acid ester contains a disproportionated rosin acid ester and / or a hydride rosin acid ester.
[4] The electrophotographic photosensitive member according to any one of [1] to [3], wherein the rosin acid ester contains a rosin acid glycerin ester and / or a rosin acid pentaerythritol ester.

（一般式（１）中、Ａｒ¹〜Ａｒ⁴は、それぞれ独立に、置換基を有していてもよいアリーレン基を表し、Ｘ¹は、単結合、酸素原子、硫黄原子、下記式（２）で表される基、又は下記式（３）で表される基を示す。式（２）中のＲ¹及びＲ²は、それぞれ独立に、水素原子、アルキル基、又はアリール基を表し、Ｒ¹とＲ²とが結合して環を形成していてもよい。式（３）中のＲ³は、アルキレン基、アリーレン基、又は下記式（４）で表される基であって、式（４）中のＲ⁴及びＲ⁵は、それぞれ独立に、アルキレン基を表し、Ａｒ⁵は、アリーレン基を表す。ｋは、０以上の整数を表す。Ｙ¹は、単結合、酸素原子、硫黄原子、又は下記式（５）表される基であって、式（５）中、Ｒ⁶及びＲ⁷は、それぞれ独立に、水素原子、アルキル基、アルコキシ基、又はアリール基を表し、Ｒ⁶とＲ⁷とが結合して環を形成していてもよい。）

［７］前記バインダー樹脂が、芳香族ジヒドロキシ化合物に由来する構造単位を有するポリカーボネート樹脂を含有する、［１］〜［６］のいずれか一つに記載の電子写真感光体。
［８］前記電荷輸送物質の分子量が、６００以上１２００以下である、［１］〜［７］のいずれか一つに記載の電子写真感光体。 [5] The electrophotographic photosensitive member according to any one of [1] to [4], wherein the binder resin contains a polyarylate resin and / or a polycarbonate resin.
[6] The electrophotographic photosensitive member according to any one of [1] to [5], wherein the binder resin contains a polyarylate resin having a repeating unit represented by the following general formula (1).

(In the general formula (1), Ar ^{1 to} Ar ⁴ each independently represents an arylene group which may have a substituent, and X ¹ is a single bond, an oxygen atom, a sulfur atom, and the following formula (2). ) Or a group represented by the following formula (3). R ¹ and R ² in the formula (2) independently represent a hydrogen atom, an alkyl group, or an aryl group. R ¹ and R ² may be bonded to form a ring. R ³ in the formula (3) is an alkylene group, an arylene group, or a group represented by the following formula (4). ^{R 4} and R ⁵ in the formula (4) independently represent an alkylene group, Ar ⁵ represents an arylene group, k represents an integer of 0 or more, and Y ¹ represents a single bond and an oxygen atom. , A sulfur atom, or a group represented by the following formula (5), in formula (5), R ⁶ and R ⁷ each independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group. R ⁶ and R ⁷ may be combined to form a ring.)

[7] The electrophotographic photosensitive member according to any one of [1] to [6], wherein the binder resin contains a polycarbonate resin having a structural unit derived from an aromatic dihydroxy compound.
[8] The electrophotographic photosensitive member according to any one of [1] to [7], wherein the charge transporting substance has a molecular weight of 600 or more and 1200 or less.

[9] The electrophotographic photosensitive member according to any one of [1] to [8], a charging means for charging the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member are subjected to image exposure and electrostatically charged. An electrophotographic cartridge including at least one of an image exposure means for forming a latent image, a developing means for developing the electrostatic latent image with toner, and a transfer means for transferring the toner to a transfer target. ..
[10] An electrostatic latent image due to the electrophotographic photosensitive member according to any one of [1] to [8], a charging means for charging the electrophotographic photosensitive member, and exposure to the charged electrophotographic photosensitive member. An exposure means for forming the above, a developing means for developing the electrostatic latent image with toner, a transfer means for transferring the toner to a transfer target, and a fixing means for fixing the toner transferred to the transfer target. An image forming apparatus characterized by being provided.

According to the present invention, it is possible to provide an electrophotographic photosensitive member having simultaneously improved adhesiveness and electrical characteristics of a charge transport layer, an electrophotographic cartridge using the electrophotographic photosensitive member, and an image forming apparatus.

It is the schematic which shows an example of the image forming apparatus of embodiment. It is a figure which shows the powder X-ray diffraction spectrum by CuKα characteristic X-ray of oxytitanium phthalocyanine used in Example 1. FIG.

Hereinafter, embodiments for carrying out the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the gist thereof. In the present specification, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.

The electrophotographic photosensitive member of the present embodiment (hereinafter, may be referred to as “the present electrophotographic photosensitive member”) has a laminated photosensitive layer in which a charge generating layer and a charge transporting layer are laminated on a conductive support. It is an electrophotographic photosensitive member. In the present electrophotographic photosensitive member, the charge transport layer contains a charge transport substance, an adhesive aid, and a binder resin. Further, the present electrophotographic photosensitive member contains a compound having a specific parameter described later as a charge transporting substance. Further, in this electrophotographic photosensitive member, a rosin acid ester is contained as an adhesion aid. Hereinafter, each configuration of the electrophotographic photosensitive member will be described in detail.

[1. Electrophotographic photosensitive member]
The electrophotographic photosensitive member of the present embodiment includes a laminated photosensitive layer on a conductive support. The present electrophotographic photosensitive member may have a laminated structure in which an undercoat layer is provided on a conductive support and a laminated photosensitive layer is further provided on the undercoat layer.

[1-1. Laminated photosensitive layer]
The laminated photosensitive layer of the present embodiment is composed of two or more layers having at least a charge generating layer in which the charge generating substance is dispersed in the binder resin and a charge transporting layer in which the charge transporting substance is dispersed in the binder resin. It has a laminated structure. That is, the photosensitive layer of the present embodiment is a function-separated laminated photosensitive layer.

The laminated photosensitive layer includes a forward-laminated photosensitive layer in which a charge generating layer and a charge transporting layer are laminated in this order from the conductive support side, and a reverse lamination in which a charge transporting layer and a charge generating layer are laminated in this order. There is a type photosensitive layer, and any of them can be adopted. In the present embodiment, a forward-laminated photosensitive layer capable of exhibiting a well-balanced photoconductivity is preferable.

[1-2. Charge transport layer]
The charge transport layer of the present embodiment contains a charge transport substance, an adhesion aid, and a binder resin that simultaneously satisfy the values of E_homo and αcal, which will be described later. In this embodiment, a rosin ester resin is used as the adhesion aid. The charge transport layer may further contain other components as needed. In the charge transport layer, a charge transport substance, an adhesive aid, a binder resin, and, if necessary, other compounds are dissolved or dispersed in a solvent to prepare a coating liquid, and this coating liquid is coated on the charge generation layer. Can be obtained by drying.

The content of the charge transporting substance is not particularly limited, but is preferably 10 parts by mass or more, more preferably 30 parts by mass or more from the viewpoint of reducing the residual potential, and stability after repeated use. From the viewpoint of charge mobility, 35 parts by mass or more is more preferable. On the other hand, 100 parts by mass or less is preferable from the viewpoint of thermal stability, 80 parts by mass or less is more preferable from the viewpoint of compatibility between the charge transport substance and the binder resin, and 70 parts by mass or less is further preferable from the viewpoint of abrasion resistance. From the viewpoint of scratch resistance, 60 parts by mass or less is particularly preferable.

The content of the loginate ester is not particularly limited, but is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more from the viewpoint of adhesiveness, and from the viewpoint of strengthening the adhesiveness, with respect to 100 parts by mass of the binder resin. From 1 part by mass or more is more preferable. On the other hand, from the viewpoint of wear resistance, 30 parts by mass or less is preferable, from the viewpoint of scratch resistance, 20 parts by mass or less is more preferable, and from the viewpoint of stability after repeated use, 15 parts by mass or less is more preferable, and 10 parts by mass is more preferable. Part or less is particularly preferable.

The film thickness of the charge transport layer is not particularly limited, but from the viewpoint of long life and sensitivity, 5 μm or more is preferable, and 15 μm or more is more preferable. Further, from the viewpoint of high resolution and productivity, 40 μm or less is preferable, and 30 μm or less is more preferable.

<Binder resin>
Examples of the binder resin include polymers and copolymers of vinyl compounds such as butadiene resin, styrene resin, vinyl acetate resin, vinyl chloride resin, acrylic acid ester resin, methacrylic acid ester resin, vinyl alcohol resin, and ethyl vinyl ether, and polyvinyl. Butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal, polycarbonate resin, polyester resin, polyarylate resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicon resin, silicon-alkyd resin, poly-N-vinylcarbazole resin And so on. One of these binder resins may be used alone, or two or more of these binder resins may be used in combination in any combination.

Among these, polyarylate resin and polycarbonate resin are preferable, and polyarylate resin is more preferable. When a polyarylate resin or a polycarbonate resin is used, it is preferable to use a polyarylate resin or a polycarbonate resin having a specific structure described later. An electrophotographic photosensitive member having electrical properties, abrasion resistance, and adhesiveness by using a polyarylate resin or a polycarbonate resin, a loginate ester, and a charge transporting substance that simultaneously satisfies the values of E_homo and αcal, which will be described later. Can be provided. Above all, when a polyarylate resin is used, it tends to have excellent wear resistance and adhesiveness. Further, when the polycarbonate resin is used, the electrical characteristics tend to be excellent and the adhesiveness tends to be improved.

When the polyarylate resin or polycarbonate resin is used in combination with another resin, the total content of the polyarylate resin or polycarbonate resin contained in the entire binder resin used for the charge transport layer shall be 50% by mass or more. Is preferable, and 60% by mass or more is more preferable.

[Polyarylate resin]
A preferable example of the polyarylate resin used in the present embodiment is one having a repeating unit represented by the following general formula (1).

(In the general formula (1), Ar ^{1 to} Ar ⁴ each independently represents an arylene group which may have a substituent, and X ¹ is a single bond, an oxygen atom, a sulfur atom, and the following formula (2). ) Or a group represented by the following formula (3). R ¹ and R ² in the formula (2) independently represent a hydrogen atom, an alkyl group, or an aryl group. R ¹ and R ² may be bonded to form a ring. R ³ in the formula (3) is an alkylene group, an arylene group, or a group represented by the following formula (4). ^{R 4} and R ⁵ in the formula (4) independently represent an alkylene group, Ar ⁵ represents an arylene group, k represents an integer of 0 or more, and Y ¹ represents a single bond and an oxygen atom. , A sulfur atom, or a group represented by the following formula (5), in formula (5), R ⁶ and R ⁷ each independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group. R ⁶ and R ⁷ may be combined to form a ring.)

In the above general formula (1), the ^{number of carbon atoms of the arylene groups of Ar 1 to} Ar ⁴ is usually 6 or more, and the upper limit thereof is usually 20 or less, preferably 10 or less, more preferably 6. Is. If the number of carbon atoms is too large, the manufacturing cost will be high and the electrical characteristics may be deteriorated.

Specific examples of the arylene groups of Ar ^{1 to} Ar ⁴ include 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, naphthylene group, anthrylene group, phenylene group and the like. Of these, a 1,4-phenylene group is preferable from the viewpoint of electrical characteristics. One type of arylene group may be used alone, or two or more types may be used in any ratio and combination.

Specific examples of the substituents of Ar ^{1 to} Ar ⁴ include an alkyl group, an aryl group, a halogen atom, an alkoxy group and the like. Of these, the methyl group, ethyl group, propyl group, and isopropyl group are preferable as the alkyl group, and the aryl group is preferable in consideration of the mechanical properties as the binder resin for the photosensitive layer and the solubility in the coating liquid for forming the photosensitive layer. Is preferably a phenyl group or a naphthyl group, preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom as a halogen atom, and preferably a methoxy group, an ethoxy group, a propoxy group or a butoxy group as an alkoxy group. When the substituent is an alkyl group, the number of carbon atoms of the alkyl group is usually 1 or more, and usually 10 or less, preferably 8 or less, and more preferably 2 or less.

More specifically, Ar ³ and Ar ⁴ are independent of each other, and the number of substituents is preferably 0 or more and 2 or less, and it is more preferable to have substituents from the viewpoint of adhesiveness, and above all, from the viewpoint of abrasion resistance. It is particularly preferable that the number of substituents is one. Further, as the substituent, an alkyl group is preferable, and a methyl group is particularly preferable.
From the above viewpoint, it is preferable that at least one of ^{Ar 3} and Ar ^{4 is an arylene group having a substituent.}

On the other hand, Ar ¹ and Ar ² are independent of each other, and the number of substituents is preferably 0 or more and 2 or less, and more preferably no substituents from the viewpoint of wear resistance.

In the general formula (1), when k is 1 or more, X ¹ is a single bond, an oxygen atom, a sulfur atom, a group represented by the above formula (2), or a group represented by the above formula (3). Is shown. ^{R 1} and R ² in the formula (2) independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ¹ and R ² are bonded to form a ring such as a cycloalkylidene group. May be. ^{R 3} in the formula (3) is an alkylene group, an arylene group, or a group represented by the above formula (4), and R ^{4 and R 5} in the formula (4) are independently alkylene groups. And Ar ⁵ represents an arylene group.
In the general formula (1), suitable X ^{1 includes} an oxygen atom, a sulfur atom, a divalent organic residue having a structure represented by the formula (2), or a structure represented by the formula (3). ..

^{Examples of the alkyl group of R 1} and R ² in the formula (2) include a methyl group, an ethyl group, a propyl group, a butyl group and the like, and examples of the aryl group include a phenyl group and a naphthyl group. ^{Examples of the cycloalkylidene group formed by combining R 1} and R ² in the formula (2) include a cyclopentylidene group, a cyclohexylidene group, and a cycloheptilidene group. ^{Further, examples of the alkylene group of R 3} in the formula (3) include a methylene group, an ethylene group, a propylene group and the like. ^{Examples of the arylene group of R 3} in the formula (3) include a phenylene group and a terphenylene group.
Among these, X ¹ is preferably an oxygen atom. At that time, k is preferably 1.

Further, in the above general formula (1), Y ¹ is a single bond, an oxygen atom, a sulfur atom, or a group represented by the above formula (5).

^{R 6} and R ⁷ in the formula (5) each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or a cycloalkylidene group formed by bonding ^{R 6} and R ^7. Considering the mechanical properties of the binder resin for the photosensitive layer and the solubility in the coating liquid for forming the photosensitive layer, R ⁶ and R ⁷ in the formula (5) are preferably phenyl groups or naphthyl groups as aryl groups. As the alkoxy group, a methoxy group, an ethoxy group, and a butoxy group are preferable. The alkyl group preferably has an alkyl group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 2 carbon atoms. Considering the convenience of producing the divalent hydroxyaryl component used in producing the polyester resin, Y ¹ is single bond, −O−, −S−, −CH ₂₋ , −CH (CH ₃ ) −. , -C (CH ₃ ) ₂ −, cyclohexylene is preferable, more preferably −CH ₂ −, _{−CH (CH 3} ) −, −C (CH ₃ ) ₂ −, cyclohexylene, and even more preferably −. CH ₂ − and −CH (CH ₃ ) −.

As the polyarylate resin represented by the general formula (1), when k = 1, it is preferable that the polyarylate resin has a repeating unit represented by the following general formula (6).

(In the general formula (6), Ar ^{6 to} Ar ⁹ each independently represent an arylene group which may have a substituent, and R ⁸ represents a hydrogen atom or an alkyl group.)

In the above general formula (6), Ar ^{6 to} Ar ⁹ correspond to the above Ar ^{1 to} Ar ⁴ , respectively, and particularly preferably, they are phenylene groups which may have substituents, respectively. The preferred substituent is a hydrogen atom or an alkyl group, and particularly preferably a methyl group. Further, in the general formula (6), ^{it is particularly preferable that Ar 8} and Ar ⁹ are phenylene groups having a methyl group, and Ar ⁶ and Ar ⁷ are phenylene groups having no substituent. Further, R ⁸ represents a hydrogen atom or an alkyl group. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably a methyl group.

[Dicarboxylic acid residue of polyarylate resin]
The dicarboxylic acid component which is a dicarboxylic acid residue in the polyarylate resin is represented by the following general formula (7).

Ar ¹ , Ar ² , X ¹ , and k in the general formula (7) are as described above in the general formula (1), and * indicates a bond. As the dicarboxylic acid residue contained in the general formula (7), the structures represented by the following general formulas [I] to [VI] can be exemplified. Here, k is an integer of 0 or more, but an integer of 0 to 5 is preferable, and 0 or 1 is more preferable from the viewpoint of electrical characteristics and scratch resistance.

In the structure represented by the general formula (7), k is preferably 1 and X ¹ is an oxygen atom, which is the case represented by the following general formula (8).

Specific examples of the preferred dicarboxylic acid residue represented by the general formula (8) include diphenyl ether-2,2'-dicarboxylic acid residue, diphenyl ether-2,3'-dicarboxylic acid residue, and diphenyl ether-2,4'. Examples thereof include -dicarboxylic acid residue, diphenyl ether-3,3'-dicarboxylic acid residue, diphenyl ether-3,4'-dicarboxylic acid residue, diphenyl ether-4,4'-dicarboxylic acid residue and the like. Among these, considering the convenience of producing the dicarboxylic acid component, diphenyl ether-2,2'-dicarboxylic acid residue, diphenyl ether-2,4'-dicarboxylic acid residue, diphenyl ether-4,4'-dicarboxylic acid Residues are more preferred, with diphenyl ether-4,4'-dicarboxylic acid residues being particularly preferred.

Specific examples of the dicarboxylic acid residue represented by the general formula (7) and when k = 0 include a phthalic acid residue, an isophthalic acid residue, a terephthalic acid residue, and a toluene-2,5-dicarboxylic acid residue. , P-xylene-2,5-dicarboxylic acid residue, naphthalene-1,4-dicarboxylic acid residue, naphthalene-2,3-dicarboxylic acid residue, naphthalene-2,6-dicarboxylic acid residue, biphenyl-2 , 2'-dicarboxylic acid residue, biphenyl-4,4'-dicarboxylic acid residue, preferably phthalic acid residue, isophthalic acid residue, terephthalic acid residue, naphthalene-1,4-dicarboxylic acid. Residues, naphthalene-2,6-dicarboxylic acid residues, biphenyl-2,2'-dicarboxylic acid residues, biphenyl-4,4'-dicarboxylic acid residues, particularly preferably isophthalic acid residues, terephthalates. It is an acid residue, and it is also possible to use a plurality of these dicarboxylic acid residues in combination. The ratio of isophthalic acid residues to terephthalic acid residues is usually 50:50, but can be changed arbitrarily. In that case, the higher the ratio of terephthalic acid residues, the more preferable from the viewpoint of electrical characteristics.

As a specific example of the polyarylate resin represented by the general formula (1) when k = 0, a resin having a repeating unit represented by the following formula (9) can be mentioned.

The polyarylate resin used in the present embodiment may be a resin containing a dicarboxylic acid residue represented by the above general formula (7) in a part of the structure and also containing other dicarboxylic acid residues. Specific examples of other dicarboxylic acid residues include adipionic acid residue, suberic acid residue, sebacic acid residue, pyridine-2,3-dicarboxylic acid residue, pyridine-2,4-dicarboxylic acid residue, and pyridine. Included are −2,5-dicarboxylic acid residue, pyridine-2,6-dicarboxylic acid residue, pyridine-3,4-dicarboxylic acid residue, pyridine-3,5-dicarboxylic acid residue, and preferred. It is an adipic acid residue and a sebacic acid residue, and it is also possible to use a plurality of these dicarboxylic acid residues in combination.

When it has the dicarboxylic acid residue represented by the general formula (7) and the other dicarboxylic acid residue described above, it is represented by the general formula (7) constituting the polyarylate resin used in the present embodiment. The number of dicarboxylic acid residues is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more as the number of repeating units. Most preferably, the number of dicarboxylic acid residues represented by the general formula (7) is 100% as the number of repeating units.

The viscosity average molecular weight of the polyarylate resin used in the present embodiment is not particularly limited, but is preferably 10,000 or more, more preferably 20,000 or more, from the viewpoint of mechanical strength. Further, from the viewpoint of productivity such as dispersibility of the charge transporting substance and viscosity of the coating liquid, 80,000 or less is preferable, and 50,000 or less is more preferable. The viscosity average molecular weight can be measured by the method described in Examples using, for example, an Ubbelohde type capillary viscometer.

[Polycarbonate resin]
As the polycarbonate resin used in this embodiment, one produced by a known method can be used. The polycarbonate resin preferably has a structural unit derived from an aromatic dihydroxy compound. Examples of such a polycarbonate resin include those produced by a solvent method such as an interfacial method (intercondensation polycondensation method) or a solution method in which an aromatic dihydroxy compound and phosgene are reacted in a solution, or aromatic dihydroxy. Examples thereof include those produced by a melting method in which a compound and a carbonic acid diester are subjected to a polycondensation reaction by a transesterification reaction.

Among these, a polycarbonate resin produced by an interfacial method is preferable from the viewpoint of being able to increase the molecular weight, purifying by liquid-liquid washing, and being applicable to various types of aromatic dihydroxy compounds. On the other hand, from the viewpoint of safety, a polycarbonate resin produced by a melting method is preferable.

Examples of the aromatic dihydroxy compound include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A; BPA), 2,2-bis (3-methyl-4-hydroxyphenyl) propane) (bisphenol C; BPC), and the like. 1,1-bis (4-hydroxyphenyl) ethane (bisphenol E; BPE), bis (4-hydroxyphenyl) methane (bisphenol F; BPF), 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z; Known bisphenols such as BPZ) can be used.

As the polycarbonate resin used in the present embodiment, one type or a mixture of two or more types of polycarbonate resin obtained by copolymerizing bisphenol alone or two or more types can be used. Among bisphenols, bisphenol Z-type polycarbonate resin having a repeating unit derived from an aromatic dihydroxy compound represented by the following formula (11) is preferable from the viewpoints of electrical properties, surface hardness, elastic deformation rate, and adhesiveness. Used for.

The polycarbonate resin used in the present embodiment may be a homopolymer composed of a single unit represented by the above formula (11), or may be used by blocking or randomly copolymerizing with another bisphenol unit. Examples of bisphenol units that may be copolymerized are shown below. Regarding the copolymerization ratio of the structural unit represented by the above formula (11) and other bisphenol units, the ratio of the structural unit represented by the above formula (11) is preferably 50% by mass or more, preferably 60% by mass or more. Is more preferable.

The viscosity average molecular weight of the polycarbonate resin used in the present embodiment is not particularly limited, but is preferably 20,000 or more, more preferably 30,000 or more, still more preferably 40,000 or more, from the viewpoint of mechanical strength. Further, from the viewpoint of productivity such as dispersibility of the charge transporting substance and viscosity of the coating liquid, the upper limit is preferably 100,000 or less, more preferably 90,000 or less, further preferably 80,000 or less. The viscosity average molecular weight can be measured in the same manner as the polyarylate resin by using, for example, an Ubbelohde type capillary viscometer.

<Charge transport material>
In the charge transport layer according to the present embodiment, it is a requirement that a specific compound having parameters obtained by the specific calculation formula described below is used as the charge transport substance.

The charge transport material used in this embodiment usually has a HOMO energy level E_homo of -4.700 eV or higher based on the structure optimization calculation by the density functional theory B3LYP / 6-31G (d, p). -4.6600 eV or more is preferable, -4.550 eV or more is more preferable, -4.5500 eV or more is further preferable, and -4.450 eV or more is particularly preferable. Within the above range, the mobility of holes injected into the charge transport layer tends to increase, the traps of holes in the layer are small, and the residual potential tends to decrease. Further, since the holes injected into the charge transport layer are not trapped by impurities derived from the fluororesin particles and reach the surface of the photoconductor, the charge is not accumulated in the charge transport layer, so that the photoconductor is used repeatedly. Even in this case, it is possible to suppress an increase in the surface potential after exposure. On the other hand, the upper limit is not particularly limited, but from the viewpoint of improving gas resistance and preventing ghosts, it is preferably -4.150 eV or less, more preferably -4.20 eV or less, and further preferably -4.250 eV or less.

Further, the charge transport material used in this embodiment is a calculated value of polarizability in a stable structure based on density functional theory B3LYP / 6-31G (d, p) and HF / 6-31G (d, p) calculation. αcal is usually at 90 Å ³ or more, preferably 95 Å ³ or more, 100 Å ³ or more, and more preferably 105 Å ³ or more, particularly preferably 110 Å ³ or more, 115Å ³ or more is most preferable. A charge transport layer containing a charge transport substance having a large αcal exhibits high charge mobility, and by using this charge transport layer, an electrophotographic photosensitive member having excellent chargeability, sensitivity, and the like can be obtained. On the other hand, from the viewpoint of solubility, preferably 200 Å ³ or less, 170 Å ^3, more preferably less, more preferably 150 Å ³ or less, 130 Å ³ or less is particularly preferred.

In the present invention, the energy level E_homo of HOMO of the charge transport material can be obtained as a result of the structure optimization calculation using B3LYP / 6-31G (d, p). The energy level E_homo of this HOMO is B3LYP (AD Becke, J. Chem. Phys. 98, 5648 (1993), C. Lee, W. Yang, and RG Parr, Phys. Rev. B37, 785 (1988) and B. Miehlich, A. Savin, H. Stoll, and H. Preuss, Chem. Phys. Lett. 157, 200 (1989)) Obtained. At this time, 6-31G (d, p), which is a basis set with a polarization function added to 6-31G, was used (R. Ditchfield, WJ Hehre, and JA Pople, J. Chem. Phys. 54, 724 (1971). ), WJ Hehre, R. Ditchfield, and JA Pople, J. Chem. Phys. 56, 2257 (1972), PC Hariharan and JAPople, Mol. Phys. 27, 209 (1974), MS Gordon, Chem. Phys. Lett. 76, 163 (1980), PC Hariharan and JA Pople, Theo. Chim. Acta 28, 213 (1973), J. -P. Blaudeau, MP McGrath, LA Curtiss, and L. Radom, J. Chem. Phys 107, 5016 (1997), MM Francl, WJ Pietro, WJ Hehre, JS Binkley, DJ DeFrees, JA Pople, and MS Gordon, J. Chem. Phys. 77, 3654 (1982), RC Binning Jr. and LA Courtiss , J. Comp. Chem. 11, 1206 (1990), VA Rassolov, JA Pople, MA Ratner, and TL Windus, J. Chem. Phys. 109, 1223 (1998), and VA Rassolov, MARatner, JA Pople, See PC Redfern, and LA Curtiss, J. Comp. Chem. 22, 976 (2001)). In the present invention, the B3LYP calculation using 6-31G (d, p) is described as B3LYP / 6-31G (d, p).

In the present invention, the polarizability αcal of the charge transport material is calculated by HF / 6-31G (d, p) with respect to the stable structure obtained after the structure optimization calculation using B3LYP / 6-31G (d, p). Can be calculated by performing. This polarizability αcal is calculated by the restricted Hartree-Fock method (“Modern Quantum Chemistry”, A. Szabo and N.S. Ostlund) in the stable structure obtained by the structural optimization calculation by the above B3LYP / 6-31G (d, p). , McGraw-Hill publishing company, New York, 1989). At this time, the basis function used was 6-31G (d, p). In the present invention, the restricted Hartree-Fock calculation using 6-31G (d, p) is described as HF / 6-31G (d, p).

In the present invention, the program used for both B3LYP / 6-31G (d, p) calculation and HF / 6-31G (d, p) calculation is Gaussian 03, Revision D. 01 (MJ Frisch, GW Trucks, HB Schlegel, GE. Scuseria, MA Robb, JR Cheeseman, JA Montgomery, Jr., T. Vreven, KN Kudin, JC Burant, JM Millam, SS lyengar, J. Tomasi, V. Barone, B. Mennucci, M. Cossi, G. Scalmani, N. Rega, GA Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai , M. Klene, X. Li, JE Knox, HP Ilratchian, JB Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, RE Stratmann, O. Yazyev, AJ Austin, R. Cammi, C. Pomelli, JW Ochterski, PY Ayala, K. Morokuma, GA Voth, P. Salvador, JJ Dannenberg, VG Zakrzewski, S. Dapprich, AD Daniels, MCStrain, O. Farkas, DK Malick, AD Rabuck, K. Raghavachari, JB Foresman, JV Ortiz, Q. Cui, AG Baboul, S. Clifford, J. Cioslowski, BB Stefanov, G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, RL Martin, DJ Fox, T. Keith, MA Al-Laham, CY Peng, A. Nanayakkara, M. Challacombe, PMW Gill, B. Johnson, W. Chen, MW Wong, C. Gonzalez, and JA Pople, Gaussian, Inc., Wallingford CT, 2004. ).

Examples of charge transporting substances satisfying the above conditions include heterocyclic compounds such as carbazole derivatives, indol derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiazazole derivatives, and benzofuran derivatives, aniline derivatives, hydrazone derivatives, and aromatic amines. Derivatives, stylben derivatives, butadiene derivatives, enamine derivatives, and those in which a plurality of types of these compounds are bonded, or hole-transporting substances such as polymers having a group composed of these compounds in the main chain or side chain, and the like can be mentioned. Be done. Among these, from the viewpoint of electrical properties, carbazole derivatives, aromatic amine derivatives, stillben derivatives, butadiene derivatives, enamin derivatives, and those in which a plurality of types of these compounds are bound are preferable, and aromatic amine derivatives and enamin derivatives are more preferable. preferable. Any one of these charge transporting substances may be used alone, or two or more thereof may be used in combination in any combination. Specifically, the hole-transporting material represented by the following general formulas (21), (22), (23), (24), and (25) is particularly preferably used from the viewpoint of residual potential and response rate. ..

The molecular weight of the charge transporting substance is not particularly limited, but is preferably 600 or more, more preferably 700 or more, and even more preferably 750 or more. Further, 1200 or less is preferable, 1000 or less is more preferable, and 900 or less is further preferable. When the molecular weight of the charge-transporting substance is at least the above lower limit, the electrical characteristics of the charge-transporting layer are improved, and the elasticity of the charge-transporting layer is prevented from being lowered to improve the wear resistance. Further, when the molecular weight of the charge-transporting substance is not more than the above upper limit, the solubility of the charge-transporting substance becomes good and precipitation is prevented, and the adhesiveness tends to be improved by suppressing the shrinkage with the binder resin. is there.

[Material represented by the general formula (21)]
A preferable example of the charge transporting substance is a compound represented by the following formula (21).

(In the general formula (21), Ar ^{11 to} Ar ¹⁶ each independently represents an aryl group which may have a substituent. N ₁₀ represents an integer of 2 or more and 5 or less. Z is one. Indicates an organic residue of valence, m ₁₀ represents an integer from 0 to 4. ^{However, at least one of Ar 11 to Ar 12} is an aryl group having a substituent.)

In the above general formula (21), Ar ^{11 to} Ar ¹⁶ each independently represents an aryl group which may have a substituent. Of these, an aryl group having 6 to 20 carbon atoms is preferable, and an aryl group having 6 to 12 carbon atoms is more preferable. Specific examples thereof include a phenyl group, a naphthyl group, a fluorenyl group, an anthryl group, a phenanthryl group and a pyrenyl group, and preferably a phenyl group, a naphthyl group and a fluorenyl group. From the viewpoint of production cost, an aryl group having 6 to 10 carbon atoms such as a phenyl group and a naphthyl group is particularly preferable. Further, when it has a substituent, it is preferable that the substituent has 1 to 10 carbon atoms and the substituent constant σ _{p in Hammett's rule is 0.20 or less.} Here, Hammett's rule is an empirical rule used to explain the effect of substituents on aromatic rings on the electronic state of aromatic rings, and the substituent constant σ _p of substituted benzene is the electron donation of substituents. / It can be said that the degree of suction is quantified. If the σ _p value is positive, the substituted compound is more acidic than the non-substituted compound, that is, it becomes an electron-withdrawing substituent. Conversely, if the σ _p value is negative, it becomes an electron-donating substituent. Typical substituent σ _p values are described in "Chemical Handbook Basics II Revised 4th Edition" edited by The Chemical Society of Japan (Maruzen Co., Ltd., published on September 30, 1993, pp. 364-365). ing.

Examples of such a substituent include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylamino group having 2 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and the like. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, methoxy group, ethoxy group, propoxy group, butoxy group, N, N-dimethylamino group. , N, N-diethylamino group, phenyl group, 4-tolyl group, 4-ethylphenyl group, 4-propylphenyl group, 4-butylphenyl group, naphthyl group and the like. Of these, an alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group and an ethyl group are particularly preferable, from the viewpoint of electrical characteristics.

In the above general formula (21), n ₁₀ is usually an integer of 2 or more in that it improves the electrical characteristics of the electrophotographic photosensitive member, and there is no particular upper limit as long as it does not adversely affect the electrical characteristics, but it is 5 or less. An integer of 3 or less is preferable, and an integer of 3 or less is more preferable. From the viewpoint of compatibility with the photosensitive layer, manufacturing cost, and the like, n ₁₀ is preferably 2 or 3, and _{particularly preferably n 10} = 2.

In the above general formula (21), the monovalent organic residue Z includes, for example, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkylamino group having 2 to 4 carbon atoms, and a carbon number of carbon atoms. Examples thereof include 6 to 10 aryl groups, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, butoxy, N, N-dimethylamino. , N, N-diethylamino, phenyl, 4-tolyl, 4-ethylphenyl, 4-propylphenyl, 4-butylphenyl, naphthyl and the like. Of these, an alkyl group having 1 to 4 carbon atoms is particularly preferable from the viewpoint of electrical characteristics.

In the general formula (21), m ₁₀ is preferably an integer of 0 to 1, but from the viewpoint of manufacturing cost, m ₁₀ = 0 is particularly preferable.

Typical examples of the compound represented by the general formula (21) include the following exemplary compounds. However, the compound represented by the general formula (21) is not limited to these compounds.

[Material represented by the general formula (22)]
A preferable example of the charge transporting substance is a compound represented by the following general formula (22).

(In the general formula (22), R ^{11 to} R ¹⁷ independently represent a hydrogen atom, an alkyl group, an aryl group, or an alkoxy group. N ₁₁ represents an integer of 1 or more and 5 or less, and k ₁₁ ,. l ₁₁ , q ₁₁ , and r ₁₁ independently represent integers of 0 or more and 5 or less, and m ₁₁ , o ₁₁ , and p ₁₁ independently represent integers of 0 or more and 4 or less.)

In the above general formula (22), R ¹¹ and R ¹² independently represent a hydrogen atom, an alkyl group, an aryl group, or an alkoxy group, and specifically, the alkyl group includes a methyl group and an ethyl group. , N-propyl group, n-butyl group and other linear alkyl groups; branched alkyl groups such as isopropyl group and ethylhexyl group; cyclic alkyl groups such as cyclohexyl group and the like, and the aryl group has a substituent. Examples thereof include a phenyl group and a naphthyl group which may be used, and examples of the alkoxy group include a linear alkoxy group such as a methoxy group, an ethoxy group, an n-propoxy group and an n-butoxy group; an isopropoxy group and an ethylhexyloxy group. Branched alkoxy groups such as groups; cyclic alkoxy groups such as cyclohexyloxy groups can be mentioned. Among these, a hydrogen atom, a methyl group, an ethyl group, a methoxy group, and an ethoxy group are preferable from the viewpoint of versatility of the production raw material and charge transporting ability as a charge transporting substance. The bonding position of each substituent to the benzene ring can be usually at any of the ortho-position, meta-position, or para-position with respect to the styryl group, but from the viewpoint of ease of production, the ortho-position, Alternatively, either the para position is preferable.

In the above general formula (22), R ^{13 to} R ¹⁵ independently represent a hydrogen atom, an alkyl group, an aryl group, or an alkoxy group. Specifically, the alkyl group includes a methyl group and an ethyl group. , N-propyl group, n-butyl group and other linear alkyl groups, isopropyl group, ethylhexyl group and other branched alkyl groups; cyclohexyl groups and other cyclic alkyl groups, and aryl groups include substituents. Examples thereof include a phenyl group and a naphthyl group which may be used, and examples of the alkoxy group include a linear alkoxy group such as a methoxy group, an ethoxy group, an n-propoxy group and an n-butoxy group; an isopropoxy group and an ethylhexyloxy group. Branched alkoxy groups such as groups; cyclic alkoxy groups such as cyclohexyloxy groups can be mentioned. Among these, a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, and an alkoxy group having 1 to 8 carbon atoms are preferable from the viewpoint of versatility of the production raw material, and a hydrogen atom and an alkoxy group having 1 to 6 carbon atoms are preferable from the viewpoint of handleability at the time of production. Alkyl groups and alkoxy groups having 1 to 6 carbon atoms are more preferable, and hydrogen atoms and alkyl groups having 1 to 2 carbon atoms are more preferable from the viewpoint of light attenuation characteristics as an electrophotographic photosensitive member, and charges as a charge transporting material. A hydrogen atom is particularly preferable in terms of transport capacity.

In the above general formula (22), R ¹⁶ and R ¹⁷ each independently represent either a hydrogen atom, an alkyl group, an aryl group, or an alkoxy group. Specifically, the alkyl group includes a linear alkyl group such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group and an n-hexyl group; a branched alkyl group such as an isopropyl group and an ethylhexyl group; Examples thereof include a cyclic alkyl group such as a cyclohexyl group, examples of the aryl group include a phenyl group and a naphthyl group which may have a substituent, and examples of the alkoxy group include a methoxy group, an ethoxy group and an n-propoxy group. , A linear alkoxy group such as an n-butoxy group; a branched alkoxy group such as an isopropoxy group and an ethylhexyloxy group; a cyclic alkoxy group such as a cyclohexyloxy group. Among these, a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, and an alkoxy group having 1 to 8 carbon atoms are preferable from the viewpoint of versatility of the production raw material, and a hydrogen atom and 1 carbon number from the viewpoint of handleability at the time of production. Alkyl groups having ~ 6 and alkoxy groups having 1 to 6 carbon atoms are more preferable, and alkyl groups having 1 to 4 carbon atoms and alkoxy groups having 1 to 4 carbon atoms are more preferable from the viewpoint of light attenuation characteristics as an electrophotographic photosensitive member. More preferably, an alkyl group having 1 to 4 carbon atoms is particularly preferable from the viewpoint of resistance of the electrophotographic photosensitive member to ozone, and a methyl group or an ethyl group is most preferable from the viewpoint of charge transporting ability as a charge transporting substance. Furthermore, when R ₁₆ and R ₁₇ are alkyl groups or alkoxy groups, the bond position of each substituent to the benzene ring is usually at the ortho-position, meta-position, or para-position with respect to the bond of the nitrogen atom. However, from the viewpoint of ease of production, either the ortho position or the para position is preferable. When the total number of alkyl groups and alkoxy groups for one benzene ring is two or more, it is preferable to replace them with either the ortho-position or the para-position. From the viewpoint of electrophotographic photosensitive member characteristics, it is more preferable that one benzene ring is substituted with a total of two alkyl groups, and the two substituents are substituted at the para-position and the ortho-position, respectively. It is more preferable that, or both are replaced with ortho positions.

Although k ₁₁ , l ₁₁ , q ₁₁ , and r ₁₁ can take integers of 0 or more and 5 or less, 0 or more and 3 or less are preferable from the viewpoint of versatility of the manufacturing raw material, and the characteristics of the electrophotographic photosensitive member are improved. From 0 or more and 2 or less is more preferable. Further, m ₁₁ , o ₁₁ , and p ₁₁ can take integers of 0 or more and 4 or less, but for _{the same reason as k 11} , l ₁₁ , q ₁₁ , and r ₁₁ , 0 or more and 2 or less are used. Preferably, 0 or more and 1 or less are more preferable, and 0 is further preferable. ^{The plurality of R 11 to} R ¹⁷ bonded to the benzene ring may be the same or different, and k ₁₁ , l ₁₁ , m ₁₁ , o ₁₁ , p ₁₁ , q ₁₁ , and r ₁₁ are integers of 2 or more. In the case of, the plurality of R ^{11 to} R ¹⁷ bonded to the benzene ring may be the same or different from each other.

n ₁₁ represents an integer of 1 or more and 5 or less, more preferably 1 or more and 3 or less. n ₁₁ is preferably 1 or 2 from the viewpoint of solubility in the coating solvent, and more preferably 2 from the viewpoint of charge transporting ability as a charge transporting substance.

The arylene group moiety to which the diphenylamino group is bonded represents a _{phenylene group when n 11} = 1, a biphenylylene group when n ₁₁ = 2, and a terphenylylene group when n ₁₁ = 3. The position where the two diphenylamino groups bond with the arylene group is not particularly limited, but when n ₁₁ = 1, the two diphenylamino groups are meta at the bonding position of the phenylene group in terms of the chargeability of the electrophotographic photosensitive member. It is preferable to have a rank relationship. When n ₁₁ = 2, from the viewpoint of charge transporting ability as a charge transporting substance, the position where the diphenylamino group is bonded to the biphenylylene group is preferably bonded to the 4th and 4'positions of the biphenylylene group, and n ₁₁ = In the case of 3, the p-terphenylylene group is preferable among the terphenylylene groups from the viewpoint of versatility of the manufacturing raw material, and the bonding position of the diphenylamine group to the p-terphenylylene group is the 4-position and 4'from the viewpoint of the charge transporting ability as a charge transporting substance. It is preferable to bind to the'position.

Further, the electrophotographic photosensitive member of the present embodiment may contain a compound represented by the general formula (22) as a single component in the photosensitive layer, or may have a different structure represented by the general formula (22). It may be contained as a mixture of compounds. As a mixture, among the structures represented by the general formula (22), when a plurality of so-called positional isomers having different substitution positions of ^{R 11 to} R ^{17 are mixed, their electronic states are close to each other and charge transport} In addition to being less likely to be a trap, it is preferable from the viewpoint of suppressing crystal formation in the coating liquid or film. As the positional isomer, it is more preferable to mix and use those having different substitution positions of ^{R 11} and R ^{12 from the viewpoint of easiness of compound synthesis, and the substitution positions of R 11} and R ¹² are in the ortho position. It is most preferable to use a mixture of para-position compounds.

Typical examples of the compound represented by the general formula (22) include the following exemplary compounds. However, the compound represented by the general formula (22) is not limited to these compounds.

[Material represented by the general formula (23)]
A preferable example of the charge transporting substance is a compound represented by the following general formula (23).

(In the general formula (23), Ar ^{17 to} Ar ²¹ each independently represent an aryl group which may have a substituent, and Ar ^{22 to} Ar ²⁵ each independently have a substituent. Represents a optionally arylene group. M ₁₂ and n ₁₂ independently represent integers of 1 or more and 3 or less.)

In the above general formula (23), Ar ^{17 to} Ar ²¹ each independently represent an aryl group which may have a substituent, and specifically, a phenyl group, a naphthyl group, a biphenyl group, an indanyl group, and the like. Examples thereof include a tetralinyl group, an anthryl group and a phenylyl group. Among them, a phenyl group and a naphthyl group are preferable in consideration of the characteristics of the electrophotographic photosensitive member, and a phenyl group and a naphthyl group are more preferable, and a phenyl group is further preferable from the viewpoint of charge transporting ability. Examples of the substituent that Ar ^{17 to} Ar ²¹ may have include an alkyl group, an aryl group, an alkoxy group, a halogen atom and the like. Specifically, the alkyl group includes a methyl group, an ethyl group and an n-. Linear alkyl groups such as propyl group and n-butyl group; branched alkyl groups such as isopropyl group, t-butyl group and ethylhexyl group; cyclic alkyl groups such as cyclohexyl group can be mentioned, and the aryl group includes a substituent. Examples thereof include a phenyl group and a naphthyl group which may have a functional group, and examples of the alkoxy group include a linear alkoxy group such as a methoxy group, an ethoxy group, an n-propoxy group and an n-butoxy group; an isopropoxy group and an ethyl group. Branched alkoxy groups such as hexyloxy groups; cyclic alkoxy groups such as cyclohexyloxy groups; alkoxy groups having fluorine atoms such as trifluoromethoxy group, pentafluoroethoxy group and 1,1,1-trifluoroethoxy group can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom. Among these, an alkyl group having 1 to 20 carbon atoms and an alkoxy group having 1 to 20 carbon atoms are preferable from the viewpoint of versatility of the production raw material, and an alkyl group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms are preferable from the viewpoint of handleability at the time of production. Alkoxy groups of 1 to 12 are more preferable, and alkyl groups having 1 to 6 carbon atoms and alkoxy groups having 1 to 6 carbon atoms are further preferable from the viewpoint of light attenuation characteristics as an electrophotographic photosensitive member. When Ar ^{17 to} Ar ²¹ are phenyl groups, it is preferable to have a substituent from the viewpoint of charge transporting ability, and the number of substituents can be 1 to 5, but 1 from the viewpoint of versatility of the manufacturing raw material. ~ 3 is preferable, 1 to 2 is more preferable from the viewpoint of the characteristics of the electrophotographic photosensitive member, and when Ar ^{17 to} Ar ²¹ are naphthyl groups, the number of substituents is considered from the versatility of the manufacturing raw material. Is 2 or less, or preferably has no substituents, and more preferably the number of substituents is 1 or no substituents.

In the above general formula (23), Ar ^{22 to} Ar ²⁵ each independently represent an arylene group which may have a substituent, and specifically, a phenylene group, a biphenylylene group, a naphthylene group, an anthrylene group, and the like. An phenanthrylene group is given as an example, and among them, a phenylene group and a naphthylene group are preferable, and a phenylene group is more preferable in consideration of the characteristics of the electrophotographic photosensitive member. Examples of the substituent that Ar ^{22 to} Ar ²⁵ may have include an alkyl group, an aryl group, an alkoxy group, a halogen atom and the like, and specifically, the alkyl group includes a methyl group, an ethyl group and an n-propyl group. Examples thereof include a linear alkyl group such as a group and an n-butyl group; a branched alkyl group such as an isopropyl group and an ethylhexyl group; a cyclic alkyl group such as a cyclohexyl group, and the aryl group may have a substituent. Examples thereof include a good phenyl group and a naphthyl group, and examples of the alkoxy group include a linear alkoxy group such as a methoxy group, an ethoxy group, an n-propoxy group and an n-butoxy group; a branch of an isopropoxy group and an ethylhexyloxy group. A cyclic alkoxy group such as a cyclohexyloxy group; an alkoxy group having a fluorine atom such as a trifluoromethoxy group, a pentafluoroethoxy group and a 1,1,1-trifluoroethoxy group can be mentioned, and examples of the halogen atom include an alkoxy group having a fluorine atom. Examples include a fluorine atom, a chlorine atom and a bromine atom. Among these, an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms are preferable from the viewpoint of versatility of the production raw material, and an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms are preferable from the viewpoint of handleability at the time of production. Alkoxy groups 1 to 4 are more preferable, and methyl group, ethyl group, methoxy group, and ethoxy group are further preferable from the viewpoint of light attenuation characteristics as an electrophotographic photosensitive member.

If Ar ^{22 to} Ar ²⁵ have a substituent, the molecular structure is twisted, which may hinder the π-conjugated expansion in the molecule and reduce the electron transport capacity. Therefore, Ar ^{22 to} Ar ²⁵ are substituted. It is preferable to have no group, and from the viewpoint of electrophotographic photosensitive member characteristics, 1,3-phenylene group, 1,4-phenylene group, 1,4-naphthylene group, 2,6-naphthylene group, 2,8 The −naphthylene group is more preferred, and the 1,4-phenylene group is even more preferred.

m ₁₂ and n ₁₂ independently represent integers of 1 or more and 3 or less. As m ₁₂ and n ₁₂ increase, the solubility in the coating solvent tends to decrease, so that it is preferably 2 or less, and more preferably 1 from the viewpoint of charge transporting ability as a charge transporting substance. When m ₁₂ and n ₁₂ are 1, it represents an ethenyl group and has a geometric isomer, but from the viewpoint of electrophotographic photosensitive member characteristics, a trans structure is preferable. When m ₁₂ and n ₁₂ are 2, it represents a butadienyl group, which also has a geometric isomer, but from the viewpoint of storage stability of the coating liquid, a mixture of two or more kinds of geometric isomers is preferable.

Further, the electrophotographic photosensitive member of the present embodiment may contain a compound represented by the general formula (23) as a single component in the photosensitive layer, or a mixture of compounds represented by the general formula (23). It can also be contained as.

Typical examples of the compound represented by the general formula (23) include the following exemplary compounds. However, the compound represented by the general formula (23) is not limited to these compounds.

[Material represented by the general formula (24)]
A preferable example of the charge transporting substance is a compound represented by the following general formula (24).

(In the general formula (24), R ^{18 to} R ²³ independently represent an alkyl group, an alkoxy group, or an alkenyl group, and m ₁₃ , n ₁₃ , p ₁₃ , and q ₁₃ are independently 0. Integers of 5 or more, o ₁₃ and r ₁₃ independently represent integers of 0 or more and 4 or less, and when m ₁₃ , n ₁₃ , o ₁₃ , p ₁₃ , q ₁₃ and r ₁₃ are 2 or more, respectively. , Adjacent groups may bond to each other to form a ring structure.)

In the above general formula (24), R ^{18 to} R ²³ independently represent an alkyl group, an alkoxy group, and an alkenyl group, respectively. Specifically, as the alkyl group, a linear alkyl group such as a methyl group, an ethyl group, an n-propyl group or an n-butyl group; a branched alkyl group such as an isopropyl group or an ethylhexyl group; a cyclic such as a cyclohexyl group. Examples thereof include an alkyl group, and examples of the alkoxy group include linear alkoxy groups such as methoxy group, ethoxy group, n-propoxy group and n-butoxy group; branched alkoxy groups such as isopropoxy group and ethylhexyloxy group; cyclohexyl. Cyclic alkoxy groups such as siloxy groups; alkoxy groups having a fluorine atom such as trifluoromethoxy group, pentafluoroethoxy group and 1,1,1-trifluoroethoxy group can be mentioned, and examples of the alkenyl group include vinyl group and allyl group. Linear alkenyl groups such as 1-methylvinyl group, 1-methylallyl group, 1,1-dimethylallyl group, 2-methylallyl group, 1,2-dimethylallyl group and other branched alkenyl groups; styryl group, 1 , 2-Diphenylvinyl group, 2,2-diphenylvinyl group, 1-phenylallyl group, 2-phenylallyl group, 3-phenylallyl group, 3,3-diphenylallyl group and other aromatic substituted alkenyl groups. .. Among these, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and an aromatic-substituted alkenyl group having 1 to 20 carbon atoms are preferable from the viewpoint of versatility of the production raw material, and from the viewpoint of handleability at the time of production. , Alkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, and aromatic-substituted alkenyl groups having 1 to 14 carbon atoms are more preferable, and from the viewpoint of light attenuation characteristics as an electrophotographic photosensitive member, the number of carbon atoms is 1. Alkyl groups having ~ 6 and alkoxy groups having 1 to 6 carbon atoms are more preferable, alkyl groups having 1 to 3 carbon atoms and alkoxy groups having 1 to 3 carbon atoms are particularly preferable, and methyl groups, ethyl groups, and methoxy groups are most preferable. ..

m ₁₃ , n ₁₃ , p ₁₃ , and q ₁₃ can take integers of 0 or more and 5 or less, but 0 or more and 3 or less are preferable from the viewpoint of versatility of the manufacturing raw material, and the characteristics of the electrophotographic photosensitive member. From the above, 0 or more and 2 or less are more preferable. Further, o ₁₃ and r ₁₃ can take integers of 1 or more and 4 or less, but for _{the same reason as m 13} , n ₁₃ , p ₁₃ and q ₁₃ above, 0 or more and 2 or less are preferable, and 0 or more. 1 or less is more preferable, and 0 is further preferable. ^{Multiple R 18 to} R ²³ bonded to the benzene ring may be the same or different from each other, and when m ₁₃ , n ₁₃ , p ₁₃ , q ₁₃ , o ₁₃ and r ₁₃ represent an integer of 2 or more. , A plurality of R ^{18 to} R ²³ bonded to the benzene ring may be the same or different from each other.

When m ₁₃ , n ₁₃ , p ₁₃ , and q ₁₃ are 1 or more, the positions where R ¹⁸ , R ¹⁹ , R ²¹ , and R ²² replace each benzene ring are the ortho-position, meta-position, and para-position with respect to the nitrogen atom. Although it can be replaced with any of the positions, the ortho position or the para position is preferable from the viewpoint of the characteristics of the electrophotographic photosensitive member. Further, when m ₁₃ , n ₁₃ , o ₁₃ , p ₁₃ , q ₁₃ and r ₁₃ are 2 or more, the groups having adjacent substituents on the same benzene ring may be bonded to each other to form a ring structure. Good.

The bond positions of the two vinyl groups that replace the benzene ring that does not have a nitrogen atom as a substituent can be substituted at any of the ortho-position, meta-position, and para-position, respectively. It is preferable that it is in the para position.

Typical examples of the preferable compound represented by the general formula (24) include the following exemplary compounds. However, the compound represented by the general formula (24) is not limited to these compounds.

[Material represented by the general formula (25)]
A preferable example of the charge transporting substance is a compound represented by the following general formula (25).

(In the general formula (25), R ^{24 to} R ²⁸ independently represent a halogen atom, an alkyl group, an alkoxy group, an aryl group, a dialkylamino group, a diallylamino group, a dialalkylamino group, and a diheterocyclic amino group. Alternatively, it represents a diallylamino group, X ¹¹ represents a group represented by the following general formula (26), and X ¹² represents a group represented by the following general formula (27). K ₁₄ , l ₁₄ , m ₁₄ and n ₁₄ independently represent an integer of 0 or more and 5 or less, o ₁₄ represents an integer of 0 or more and 4 or less, and p ₁₄ represents an integer of 1 or more and 5 or less. ), (27), R ^{30 to} R ³⁹ independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or a heterocyclic group, and a pair consisting of ^{R 33} and R ^{34 , or R 38} , respectively. In the ^{pair consisting of R 39} , when either one is a hydrogen atom or an alkyl group, the other is an aryl group or a heterocyclic group. I ₁₄ represents an integer of 1 or 2, and h ₁₄ is 0. Represents an integer of 2 or more.)

In the above general formula (25), R ^{24 to} R ²⁸ independently represent a halogen atom, an alkyl group, an alkoxy group, an aryl group, a dialkylamino group, a diallylamino group, a dialalkylamino group, and a diheterocyclic amino group. Represents a substituted amino group such as a diallylamino group or a di-substituted amino group in which the above-mentioned substituents of the amino group are combined. Specifically, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, examples of the alkyl group include a methyl group, an ethyl group, a propyl group and an isopropyl group, and examples of the alkoxy group include a methyl group, an ethyl group, a propyl group and an isopropyl group. , Methoxy group, ethoxy group, propyloxy group and the like, examples of the aryl group include a phenyl group, a naphthyl group, a pyrenyl group and the like, and examples of the dialkylamino group include a dimethylamino group and the like, and a diarylamino group. Examples thereof include a diphenylamino group and the like, examples of the dialalkylamino group include a dibenzylamino group and the like, and examples of the diheterocyclic amino group include a dipyridylamino group and the like. Among these, an alkyl group and an aryl group are preferable, and a methyl group and a phenyl group are more preferable. These alkyl groups, alkoxy groups, and aryl groups may have a substituent, and the substituents include a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryloxy group, an arylalkoxy group, and an aryl group. , Arylvinyl group, acyl group, dialkylamino group, diarylamino group, dialalkylamino group, diheterocyclic amino group, diallylamino group, disubstituted amino group which is a combination of the above amino group substituents and the like. And so on. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group and an isopropyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propyloxy group and the like, and examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group and a naphthylmethyl group, and examples of the aryloxy group include an aryloxy group. , Phenoxy group, Triloxy group, benzyloxy group, phenethyloxy group and the like as the arylalkoxy group, phenyl group, naphthyl group and the like as the aryl group, and styryl as the arylvinyl group. Examples include a group, a naphthylvinyl group and the like, examples of the acyl group include an acetyl group and a benzoyl group, examples of the dialkylamino group include a dimethylamino group and a diethylamino group, and examples of the diarylamino group include a diphenylamino group. Examples thereof include a group, a dinaphthylamino group and the like, examples of the dialalkylamino group include a dibenzylamino group and a diphenethylamino group, and examples of the diheterocyclic amino group include a dipyridylamino group and a dithienylamino group. Be done. These substituents are fused with each other to form a carbon ring group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethyleneylene group, etc .; a heterocycle containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. A group may be formed.

In the general formulas (26) and (27), R ^{30 to} R ³⁹ independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, and a heterocyclic group, respectively. Specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group and the like, examples of the alkoxy group include a methoxy group and an ethoxy group, and examples of the aryl group include a phenyl group, a naphthyl group and an anthracenyl group. Examples thereof include a group, a pyrenyl group and the like, and examples of the heterocyclic group include a pyrrolyl group, a thienyl group, a furyl group, a carbazolyl group and the like. The heterocyclic group is preferably a heterocyclic group having aromaticity. These alkyl groups, alkoxy groups, aryl groups, and heterocyclic groups may have substituents, and the substituents include a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryloxy group, and an arylalkoxy group. Group, aryl group, aryl vinyl group, acyl group, dialkylamino group, diarylamino group, dialalkylamino group, diheterocyclic amino group, diallylamino group, disubstituted amino group which is a combination of the above amino group substituents, etc. Examples thereof include a substituted amino group of. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group and an isopropyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propyloxy group and the like, and examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group and a naphthylmethyl group, and examples of the aryloxy group include an aryloxy group. Examples thereof include a phenoxy group and a triloxy group, examples of the arylalkoxy group include a benzyloxy group and a phenethyloxy group, examples of the aryl group include a phenyl group and a naphthyl group, and examples of the arylvinyl group include styryl. Examples include a group, a naphthylvinyl group and the like, examples of the acyl group include an acetyl group and a benzoyl group, examples of the dialkylamino group include a dimethylamino group and a diethylamino group, and examples of the diarylamino group include a diphenylamino group. , Dinaphthylamino group and the like, examples of the dialalkylamino group include a dibenzylamino group and a diphenethylamino group, and examples of the diheterocyclic amino group include a dipyridylamino group and a dithienylamino group. Be done. These substituents are condensed with each other to form a carbon ring group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethyleneylene group, etc .; a heterocyclic group containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. Etc. may be formed. Further, when i ₁₄ = 2, the respective R ³⁰ and R ³¹ may be the same or different, and when h ₁₄ = 2, the respective R ³⁸ and R ³⁹ may be the same or different. Alternatively, the ^{pair consisting of R 33 and R 34} , or the pair consisting of R ³⁸ and R ³⁹ is condensed and has a carbon ring group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group, or the like. A heterocyclic group containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. may be formed, and those rings may have a substituent, and the substituents include a methyl group, an ethyl group, and the like. Alkyl groups such as propyl group, butyl group, hexyl group and isopropyl group; aryl groups such as phenyl group and naphthyl group; cyano group, alkoxycarbonyl group, aryloxycarbonyl group, nitro group; fluorine atom, chlorine atom, bromine atom, Examples include halogen atoms such as iodine atoms. However, when one of the pair consisting of ^{R 33} and R ^{34 or the pair consisting of R 38} and R ³⁹ is a hydrogen atom or an alkyl group, the other is an aryl group or a heterocyclic group.

Although k ₁₄ , l ₁₄ , m ₁₄ , and n ₁₄ can take integers of 0 or more and 5 or less, 0 or more and 3 or less are preferable from the viewpoint of versatility of the manufacturing raw material, and the characteristics of the electrophotographic photosensitive member are improved. From 0 or more and 2 or less is more preferable, and 0 or more and 1 or less is further preferable. Further, o ₁₄ can take an integer of 0 or more and 4 or less, but for _{the same reason as k 14} , l ₁₄ , m ₁₄ and n ₁₄ above, 0 or more and 2 or less are preferable, and an electrophotographic photosensitive member is used. From the viewpoint of the characteristics of, 0 or more and 2 or less are more preferable, and 0 or more and 1 or less are further preferable. ^{The plurality of R 24 to} R ²⁷ bonded to the benzene ring may be the same or different, and when k ₁₄ , l ₁₄ , m ₁₄ , n ₁₄ , and o ₁₄ represent integers of 2 or more, the benzene ring is used. The plurality of R ^{24 to} R ^{28 to} be combined may be the same or different from each other.

p ₁₄ represents an integer of 1 or more and 5 or less, more preferably 1 or more and 3 or less. p ₁₄ is preferably 1 or 2 from the viewpoint of solubility in the coating solvent, and more preferably 2 from the viewpoint of charge transporting ability as a charge transporting substance.

The arylene group moiety to which the diphenylamino group is bonded represents a _{phenylene group when p 14} = 1, a biphenylylene group when p ₁₄ = 2, and a terphenylylene group when p ₁₄ = 3. The position where the two diphenylamino groups bond with the arylene group is not particularly limited, but when p ₁₄ = 1, the two diphenylamino groups are paralyzed at the bonding position of the phenylene group from the viewpoint of chargeability of the electrophotographic photosensitive member. It is preferable to have a rank relationship. When p ₁₄ = 2, from the viewpoint of charge transporting ability as a charge transporting substance, the position where the diphenylamino group is bonded to the biphenylylene group is preferably bonded to the 4th and 4'positions of the biphenylylene group, and p ₁₄ = In the case of 3, the p-terphenylylene group is preferable among the terphenylylene groups from the viewpoint of versatility of the manufacturing raw material, and the bonding position of the diphenylamine group to the p-terphenylylene group is the 4-position and 4'from the viewpoint of the charge transporting ability as a charge transporting substance. It is preferable to bind to the'position.

Typical examples of the preferable compound represented by the general formula (25) include the following exemplary compounds. However, the compound represented by the general formula (25) is not limited to these representative examples.

[Other charge transport substances]
The charge-transporting substances represented by the general formulas (21), (22), (23), (24), and (25) may be used alone or in combination with other charge-transporting substances. Good. The charge transporting substance used together is not particularly limited, and any substance can be used. Examples include aromatic nitro compounds such as 2,4,7-trinitrofluorenone, cyano compounds such as tetracyanoquinodimethane, electron transporting substances such as quinone compounds such as diphenoquinone, carbazole derivatives, indol derivatives, and imidazole derivatives. , Oxazole derivatives, pyrazole derivatives, thiadiazol derivatives, benzofuran derivatives and other heterocyclic compounds, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, stillben derivatives, butadiene derivatives, enamine derivatives and a combination of these compounds, or Examples thereof include hole-transporting substances such as polymers having a group composed of these compounds in the main chain or the side chain. Among these, from the viewpoint of electrical properties, a carbazole derivative, an aromatic amine derivative, a stilbene derivative, a butadiene derivative, an enamine derivative, and a combination of a plurality of these compounds are preferable. When other charge transporting substances are used in combination, the above general formulas (21), (22), (23), (24), and (25) contained in the entire charge transporting substance are used from the viewpoint of sensitivity and residual potential. The total content of the represented charge transporting substances is preferably 50% by mass or more, and more preferably 60% by mass or more.

<Adhesive aid>
In the electrophotographic photosensitive member of the present embodiment, the charge transport layer contains an adhesion aid. The adhesive aid improves the adhesiveness of the charge transport layer containing the binder resin and the charge transport substance, and examples thereof include resins having adhesiveness at room temperature such as natural fuel resin and synthetic resin. In this embodiment, a rosin ester resin is used as the adhesion aid. That is, in the charge transport layer, the combination of the charge transport substance having the specific parameters described above and the rosin acid ester exerts the effect desired in the present invention.

The rosin acid ester is an esterified product of an alcohol and a rosin acid, and is preferably an esterified product of a polyhydric alcohol and a rosin acid.

Rosinic acid is a compound having a carboxy group contained in rosin. Examples of rosin include plant-derived natural rosins such as tall oil rosin, gum rosin, and wood rosin; purified rosin obtained by purifying natural rosin; hydrogenated rosin obtained by hydrogenating natural rosin; disproportionate natural rosin. Disproportionate rosin and the like obtained by reaction;

Specific examples of the rosin acid include, for example, abietic acid, neo-avietic acid, pulsetriic acid, pimaric acid, levopipmaric acid, isopimaric acid, dehydroabietic acid, sandaracopimaric acid and the like.

Examples of the polyhydric alcohol include dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol and neopentyl glycol; trihydric alcohols such as glycerin, trimethylolethane, trimethylolpropane and trimethylolbutane; pentaerythritol, diglycerin and the like. The tetrahydric alcohol of the above can be mentioned. Among these, trihydric alcohols, tetrahydric alcohols are preferable, glycerin and pentaerythritol are more preferable, and glycerin is further preferable.

Examples of the loginate ester include a loginic acid, a hydrogenated loginic acid obtained by hydrogenating the loginic acid, and a compound obtained by esterifying a disproportionated loginic acid obtained by disproportionating the loginic acid. Among them, a hydrogenated loginate ester which is a hydride and a disproportionated loginate ester which is a disproportionate are preferable, and a hydrogenated loginate ester is more preferable from the viewpoint of suppressing photodeterioration and coloring of the photoconductor. Further, as the rosin acid ester, a rosin glycerin ester which is an esterified product of glycerin and rosin acid and a rosinic acid pentaerythritol ester which is an esterified product of pentaerythritol and rosin acid are preferable. Further, rosin hydride glycerin ester, which is an esterified product of glycerin and rosin hydride or disproportionate rosin acid, or glycerin disqualified rosin acid ester is more preferable, and rosin hydride hydride is further preferable. .. Alternatively, pentaerythritol hydride or disproportionated pentaerythritol ester, which is an esterified product of pentaerythritol and hydride or disproportionated loginic acid, is more preferable, and pentaerythritol hydride is preferably. Is even more preferable. The rosin moiety in the loginate ester used in the present invention may or may not be plant-derived.

As a method for synthesizing a rosin acid ester, methods as described in JP-A-59-230072, JP-A-2002-201434, and JP-A-2001-316330 are generally known.

Commercially available rosin acid esters include Harima Chemicals'Hariester series, Neotor series, Haritac series, Tesspole series, Arakawa Chemicals' ester gum series, super ester series, pine crystal series, and pens. Examples include the cell series, the silverite series manufactured by Arizona Chemicals, the silver tack series, and the COMOTAC (R) series sold by Shinko Trading Co., Ltd. As the pine crystal, for example, products such as KE-100, KE-311, KE-359, and KE656 can be used, but the pine crystal is not limited thereto. Further, as the Haritac, for example, a product such as F85 can be used, but the present invention is not limited to this. Among these, KE-100 and KE-311 are preferable, and KE-100 is more preferable.

The structure of the rosin ester is not particularly limited, but a compound represented by the following general formula (31) is preferable.

(In the general formula (31), R ^{41 to} R ⁴³ each independently represent a hydrocarbon group which may have an ester moiety. R ⁴⁴ is a hydrocarbon group which may have a hydroxy group. N _{21 to} n ₂₃ are independently integers of 0 or more and 6 or less, and n ₂₄ is an integer of 1 or more and 30 or less. R ^{41 to} R ⁴³ are bonded to each other to form a ring. It may be formed. The broken line indicates that a carbon-carbon bond may be present there.)

In the above general formula (31), R ^{41 to} R ⁴³ each independently represent a hydrocarbon group which may have an ester moiety. Specifically, examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group and the like, and an alkyl group and an alkenyl group are preferable. The number of carbon atoms of the hydrocarbon group is not particularly limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, while usually 30 or less, preferably 20 or less, more preferably 15 or less, still more preferably 10. Hereinafter, it is particularly preferably 8 or less, and particularly preferably 6 or less. When R ^{41 to} R ⁴⁴ have an ester moiety, COOR ⁴⁴ is present at the end of the molecule. R ⁴⁴ is synonymous with ^{R 44,} which will be described later.

n _{21 to} n ₂₃ are independently integers of 0 or more and 6 or less. It is preferably 4 or less, more preferably 3 or less, still more preferably 2 or less, and particularly preferably 1 or less.
n ₂₄ is an integer of 1 or more and 30 or less. Usually 1 or more, preferably 2 or more, more preferably 3 or more, while usually 30 or less, preferably 20 or less, more preferably 15 or less, still more preferably 10 or less, still more preferably 8 or less, particularly preferably 6 or less. , Most preferably 5 or less.

In the above general formula (31), the broken line portion indicates that a carbon-carbon bond may be present there. That is, when a carbon-carbon bond is present in the broken line portion, it indicates that a carbon-carbon double bond is present in addition to the carbon-carbon bond in the solid line portion. The number of carbon-carbon bonds present in the broken line portion in the above formula (31) is not particularly limited, but is usually 0 or more, preferably 1 or more, while usually 9 or less, preferably 5 or less, more preferably 4 or less. It is more preferably 3 or less, and particularly preferably 2 or less.

Specific examples in parentheses in the general formula (31) are shown below. Although the broken line-wedge shape is not used in the following description, various stereoisomers exist in these specific examples, and the present invention includes these various stereoisomers.

Among these specific examples, the following structure is preferable.

Among these specific examples, it is more preferable to include at least one selected from the group consisting of an abietic acid structure, a neo-abietic acid structure, a dihydro-abietic acid structure, and a tetrahydro-abietic acid structure having the following structures.

R ⁴⁴ represents a hydrocarbon group which may have a hydroxy group. Specifically, the hydrocarbon group usually has 1 or more carbon atoms, preferably 2 or more carbon atoms, while usually 30 or less, preferably 20 or less, more preferably 15 or less, still more preferably 10 or less, and particularly preferably 8 or less. Is. The following general formula (32) can be mentioned as a specific example of ^{R 44.}

(In the general formula (32), R ⁵¹ independently represents hydrogen, a hydroxy group, a bond, or CH _2- R ^51. R ⁵² indicates a hydrogen, a hydroxy group, or a bond. * Indicates a bond. Indicates a hand. N ₃₁ is an integer greater than or equal to 1 and less than or equal to 30.)

It is preferable that at least one bond is present in the entire repeating structure represented by the _{parentheses and n 31} in the general formula (32). R ⁵² is preferably a bond.
In the general formula (32), the number of hydroxy groups is not particularly limited, but is usually 0 or more, preferably 1 or more, while usually 10 or less, preferably 8 or less, more preferably 6 or less, and particularly preferably 4 or less. , Most preferably 2 or less.
The number of bonds in the general formula (32) is not particularly limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, while usually 30 or less, preferably 20 or less, more preferably 15 or less, and further. It is preferably 10 or less, more preferably 8 or less, particularly preferably 6 or less, and most preferably 5 or less.
n ₃₁ is an integer of 1 or more and 30 or less. Usually 1 or more, preferably 2 or more, more preferably 3 or more, while usually 30 or less, preferably 20 or less, more preferably 15 or less, still more preferably 10 or less, still more preferably 8 or less, particularly preferably 6 or less. , Most preferably 5 or less.

Among the general formulas (32), the following general formulas (33-1), general formulas (33-2), general formulas (33-3), general formulas (33-4), general formulas (33-5), At least one selected from the group consisting of the general formula (34-1), the general formula (34-2), the general formula (34-3), the general formula (34-4), and the general formula (34-5). It is preferable to include, and two or more kinds may be included. General formula (33-3), general formula (33-4), general formula (33-5), general formula (34-2), general formula (34-3), general formula (34-4), and general formula It is more preferable to include at least one selected from the group consisting of the formula (34-5), and two or more thereof may be included. It is more preferable to include at least one selected from the group consisting of the general formula (33-3), the general formula (33-4), and the general formula (33-5), and two or more kinds may be included.

Further, the rosin acid ester preferably has a structure represented by the following general formulas (35) and (36), and more preferably a structure represented by the general formula (35).

In the general formula (35), R ^{61 to} R ⁶³ , R ^{64 to} R ⁶⁶ , and R ^{67 to} R ^{69 are the same as R 41 to} R ⁴³ in the general formula (31), respectively, and n _{31 to} n. ₃₃ , n _{34 to} n ₃₆ , and n _{37 to} n _{39 are the same as n 21 to} n ₂₃ in the above general formula (31), respectively. Further, R ⁶¹ , R ⁶⁴ , and R ⁶⁷ may be the same or different, R ⁶² , R ⁶⁵ , and R ⁶⁸ may be the same or different, respectively, and R ⁶³ , R ⁶⁶ , and R ⁶⁹ may be the same or different. They may be the same or different.

In the general formula (36), R ^{71 to} R ⁷³ , R ^{74 to} R ⁷⁶ , R ^{77 to} R ⁷⁹ , and R ^{80 to} R ^{82 are the same as R 41 to} R ⁴³ in the general formula (31), respectively. Yes, n _{41 to n 43} , n _{44 to} n ₄₆ , n _{47 to} n ₄₉ , and n _{50 to} n _{52 are the same as n 21 to} n ₂₃ in the above general formula (31), respectively. Further, R ⁷¹ , R ⁷⁴ , R ⁷⁷ , and R ⁸⁰ may be the same or different, and R ⁷² , R ⁷⁵ , R ⁷⁸ , and R ⁸¹ may be the same or different, respectively, and R ⁷³ and R may be different. ⁷⁶ , R ⁷⁹ , and R ⁸² may be the same or different, respectively.

[1-3. Charge generation layer]
The charge generating layer of the present embodiment contains a charge generating substance and a binder resin. The charge generation layer may further contain other components, if necessary. The charge generating layer is prepared by dissolving or dispersing the charge generating substance, the binder resin, and other compounds in a solvent as needed, and the coating liquid is applied onto the conductive support or the undercoat layer. It can be obtained by coating and drying.

Examples of the charge generating substance include inorganic photoconducting materials such as selenium and its alloys and cadmium sulfide, and organic photoconducting materials such as organic pigments. Organic photoconducting materials are preferable, and organic pigments are particularly preferable. Is preferable. Examples of the organic pigment include phthalocyanine pigment, azo pigment, dithioketopyrrolopyrrole pigment, squalene (squarylium) pigment, quinacridone pigment, indigo pigment, perylene pigment, polycyclic quinone pigment, antoanthron pigment, benzimidazole pigment and the like. .. Among these, phthalocyanine pigments are particularly preferable. When an organic pigment is used as a charge generating substance, fine particles of these organic pigments are usually used in the form of a dispersed layer bonded with various binder resins.

When a phthalocyanine pigment is used as a charge generating substance, specifically, metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, aluminum and other metals or their oxides, halides and water. Phthalocyanine dimers having each crystal form of coordinated phthalocyanines such as oxides and alkoxides, and phthalocyanine dimers using an oxygen atom or the like as a cross-linking atom are used. In particular, 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 crystal types. Phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, hydroxyindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as V type, μ-oxo-gallium phthalocyanine dimer such as G type and I type, type II, etc. The μ-oxo-aluminum phthalocyanine dimer of the above is suitable.

Among these phthalocyanines, A type (also known as β type), B type (also known as α type), and powder X-ray diffraction diffraction angle 2θ (± 0.2 °) are 27.1 ° or 27.3 °. It has the strongest peaks at D-type (Y-type) titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type and 28.1 °, which are characterized by showing a clear peak, and also has a peak at 26.2 °. Hydroxygallium phthalocyanine, G-type μ-, which has a clear peak at 28.1 ° and has a half-price width W of 25.9 ° of 0.1 ° ≤ W ≤ 0.4 °. Oxo-gallium phthalocyanine dimer and the like are particularly preferable.

The phthalocyanine compound may be a single compound, or may be in a mixed or mixed crystal state. As the phthalocyanine compound or the mixed state that can be placed in the crystalline state here, a mixture of each component may be used later, or the phthalocyanine compound may be mixed in the production / processing steps of the phthalocyanine compound such as synthesis, pigmentation, and crystallization. It may be the one that caused the state. As such a treatment, an acid paste treatment, a grinding treatment, a solvent treatment and the like are known. In order to generate a mixed crystal state, as described in Japanese Patent Application Laid-Open No. 10-48859, two types of crystals are mixed, mechanically ground, irregularized, and then converted to a specific crystal state by solvent treatment. There is a way to do it.

The binder resin used for the charge generation layer is not particularly limited, and examples thereof include polyvinyl butyral resin, polyvinyl formal resin, and polyvinyl acetal-based resins such as partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal or acetal. Resin, polyarylate resin, polycarbonate resin, polyester resin, modified ether-based polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide resin, polyamide Resin, polyvinylpyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicon resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, casein, vinyl chloride-vinyl acetate copolymer, hydroxy-modified vinyl chloride-vinyl acetate copolymer, Vinyl chloride-vinyl acetate copolymers such as carboxyl-modified vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, styrene-butadiene copolymers, vinylidene chloride-acrylonitrile copolymers, Examples thereof include insulating resins such as styrene-alkyd resin, silicon-alkyd resin and phenol-formaldehyde resin, and organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene and polyvinylperylene, but polyvinyl acetal resin is used. Particularly preferable, as the polyvinyl acetal resin, a polyvinyl butyral resin is preferable. Any one of these binder resins may be used alone, or two or more of these binder resins may be mixed and used in any combination.

In the charge generating layer, the content of the charge generating substance is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, preferably 500 parts by mass or less, and preferably 300 parts by mass or less with respect to 100 parts by mass of the binder resin. Is more preferable. If the ratio of the charge generating substance is too high, the stability of the coating liquid may decrease due to aggregation of the charge generating substance, etc., while if the ratio of the charge generating substance is too low, the sensitivity of the photoconductor may decrease. There is.

The film thickness of the charge generation layer is not particularly limited, but is usually in the range of 0.1 μm or more, preferably 0.15 μm or more, and usually 10 μm or less, preferably 0.6 μm or less.
Further, it is effective to refine the particles of the charge generating substance to a particle size in the range of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

[1-4. Undercoat layer]
An undercoat layer may be provided between the conductive support and the above-mentioned photosensitive layer in order to improve adhesiveness, blocking property, and the like. As the undercoat layer, a resin, a resin in which particles such as metal oxides are dispersed, or the like is used.

Examples of metal oxide particles used for the undercoat layer include metal oxide particles containing one kind of metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, and iron oxide, calcium titanate, and titanium. Examples thereof include metal oxide particles containing a plurality of metal elements such as strontium acid acid and barium titanate. These may use one kind of particles alone, or may use a plurality of kinds of particles in combination. 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 silicon. As the crystal type of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. Further, a plurality of crystalline states may be included.

Although various particle sizes of the metal oxide particles can be used, the average primary particle size is usually 1 nm or more, preferably 1 nm or more, from the viewpoint of electrical characteristics and stability of the coating liquid required for forming the undercoat layer. It is preferably 10 nm or more, and usually 100 nm or less, preferably 50 nm or less. The particle size of the metal oxide particles can be calculated based on the particle size measured from the observation region by observing the cut surface of the undercoat layer in the thickness direction with a transmission electron microscope (TEM).

It is desirable that the undercoat layer is formed by dispersing the metal oxide particles in the binder resin. As the binder resin used for the undercoat layer, resin materials such as polyvinyl acetal, polyamide resin, phenol resin, polyester, epoxy resin, polyurethane, and polyacrylic acid can be used. One of these binder resins may be used alone, or two or more of these binder resins may be used in combination in any combination. Among these, a polyamide resin having excellent adhesiveness to the support and having low solubility in the solvent used for the charge generation layer coating solution is preferable. Among the polyamide resins, a copolymerized polyamide having a cycloalcan ring structure as a constituent component is preferable, and a copolymerized polyamide having a cyclohexane ring structure as a constituent component is more preferable, and among them, it is particularly represented by the following general formula (41). A copolymerized polyamide resin having a diamine component as a constituent material is preferable.

(In the general formula (41), A and B each independently represent a cyclohexane ring which may ^{have a substituent, and X 21} represents a methylene group which may have a substituent.)

The ratio of inorganic particles used to the binder resin used for the undercoat layer can be arbitrarily selected, but from the viewpoint of stability and coatability of the dispersion, it is usually in the range of 10% by weight or more and 500% by weight or less. It is preferable to use in.

The film thickness of the undercoat layer can be arbitrarily selected, but from the viewpoint of improving the photoconductor characteristics and coatability, it is usually 0.01 μm or more, preferably 0.1 μm or more, usually 30 μm or less, preferably 20 μm or less. The range.

A known antioxidant or the like may be mixed in the undercoat layer. Further, the undercoat layer may contain pigment particles, resin particles and the like for the purpose of preventing image defects and the like.

[1-5. Other functional layers]
Further, in the laminated photoconductor, the photosensitive layer formed by the above procedure may be used as the uppermost layer, that is, the surface layer, but another layer may be provided on the photosensitive layer and used as the surface layer. For example, a protective layer may be provided for the purpose of preventing wear of the photosensitive layer and preventing / reducing deterioration of the photosensitive layer due to discharge products generated from a charger or the like. The photosensitive layer is preferably a surface layer because the number of production steps can be reduced. For the protective layer, for example, a conductive material is contained in an appropriate binder resin to form the protective layer, or a compound having a charge transporting ability such as a triphenylamine skeleton described in JP-A-9-1900004 of Japan is used. It can be formed using a copolymer.

[1-6. Conductive support]
As the conductive support used for the photoconductor, for example, a metal material such as aluminum, aluminum alloy, stainless steel, copper or nickel, or a conductive powder such as metal, carbon or tin oxide was added to impart conductivity. Resin materials and resins, glass, paper and the like obtained by depositing or coating a conductive material such as aluminum, nickel or ITO (indium tin oxide) on the surface thereof are mainly used. As the form, a drum shape, a sheet shape, a belt shape, or the like is used. For controlling conductivity, surface properties, etc., and for covering defects on conductive supports made of metallic materials. It may be coated with a conductive material having an appropriate resistance value.

When a metal material such as an aluminum alloy is used as the conductive support, it may be used after applying an anodic oxide film. When the anodic oxide film is applied, it is desirable to perform the hole sealing treatment by a known method.

For example, anodizing film is formed by anodizing in an acidic bath of chromic acid, sulfuric acid, oxalic acid, boric acid, sulfamic acid, etc., but the anodizing treatment in sulfuric acid gives better results. give away. In the case of anodizing 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 electrolytic voltage is 10 to 20 V, and the current density is 0.5 to 0.5. ^{It is preferably set within the range of 2} A / dm 2, but is not limited to the above conditions.

It is preferable to perform a pore-sealing treatment on the anodic oxide film thus formed. The pore-sealing treatment may be carried out by a known method. For example, a low-temperature pore-sealing treatment in which the material is immersed in an aqueous solution containing nickel fluoride as a main component, or a low-temperature pore-sealing treatment in which the material is immersed in an aqueous solution containing nickel acetate as a main component is used. It is preferable that a high temperature sealing treatment is applied.

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. Further, in order to smoothly proceed with the sealing treatment, the treatment temperature is 25 to 40 ° C., preferably 30 to 35 ° C., and the pH of the nickel fluoride aqueous solution is 4.5 to 6.5, preferably 5. It is recommended to process in the range of .5 to 6.0. 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 the film thickness. In addition, cobalt fluoride, cobalt acetate, nickel sulfate, a surfactant and the like may be added to the nickel fluoride aqueous solution in order to further improve the physical characteristics of the film. Then, 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 metal salt solution such as nickel acetate, cobalt acetate, lead acetate, nickel nickel-cobalt acetate, and barium nitrate can be used, but nickel acetate is particularly preferable. .. When the nickel acetate aqueous solution is used, the concentration is preferably in the range of 5 to 20 g / l. The treatment temperature is 80 to 100 ° C., preferably 90 to 98 ° C., and the pH of the nickel acetate aqueous solution is preferably 5.0 to 6.0. Here, as the pH adjuster, aqueous ammonia, sodium acetate or the like can be used. The treatment time is preferably 10 minutes or more, preferably 20 minutes or more. In this case as well, sodium acetate, an organic carboxylic acid, an anionic surfactant, a nonionic surfactant or the like may be added to the nickel acetate aqueous solution in order to improve the physical characteristics of the coating film. Then, it is washed with water and dried to finish the high temperature sealing treatment.

When the average film thickness is thick, strong sealing conditions are required due to high concentration of the sealing liquid and high temperature / long-term treatment. Therefore, the productivity is deteriorated, and surface defects such as stains, stains, and dusting are likely to occur on the surface of the coating film. From this point of view, the average film thickness of the anodized film is usually preferably 20 μm or less, particularly preferably 7 μm or less.

The surface of the support may be smooth, or may be roughened by using a special cutting method or by polishing. Further, the surface may be roughened by mixing particles having an appropriate particle size with the material constituting the support. Further, in order to reduce the cost, it is possible to use the drawn pipe as it is without cutting. In particular, when a non-cut aluminum support such as drawing, impact, or ironing is used, the treatment eliminates dirt, foreign matter, and other small scratches on the surface, and a uniform and clean support can be obtained. Therefore, it is preferable.

[1-7. How to form each layer]
For the undercoat layer according to the present embodiment and each layer constituting the photoconductor, a coating liquid obtained by dissolving or dispersing the substance contained in each layer in a solvent is immersed-coated, spray-coated, or nozzle-coated on the support. , Bar coat, roll coat, blade coating and the like, each layer is formed by repeating the coating and drying steps in sequence.

The solvent or dispersion medium used to prepare the coating liquid is not particularly limited, and specific examples thereof include alcohols such as methanol, ethanol, propanol and 2-methoxyethanol, tetrahydrofuran, 1,4-dioxane, dimethoxyethane and the like. Ethers, esters such as methyl formate, ethyl acetate, ketones such as acetone, methyl ethyl ketone, cyclohexanone, aromatic hydrocarbons such as benzene, toluene, xylene, dichloromethane, chloroform, 1,2-dichloroethane, 1,1, Chlorinated hydrocarbons such as 2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane, trichloroethylene, n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylenediamine, etc. Examples thereof include nitrogen-containing compounds, aprotic polar solvents such as acetonitrile, N-methylpyrrolidone, N, N-dimethylformamide, and dimethylsulfoxide. In addition, one of these may be used alone, or two or more thereof may be used in any combination and type.

The amount of the solvent or dispersion medium used is not particularly limited, but the physical properties such as the solid content concentration and viscosity of the coating liquid are appropriately within a desired range in consideration of the purpose of each layer and the properties of the selected solvent / dispersion medium. It is preferable to adjust. For example, in the case of a single-layer type photoconductor and a charge transport layer of a function-separated type photoconductor, the solid content concentration of the coating liquid is usually 5% by mass or more, preferably 10% by mass or more, and usually 40% by mass or less. , Preferably in the range of 35% by mass or less. The viscosity of the coating liquid is usually in the range of 10 cps or more, preferably 50 cps or more, and usually 500 cps or less, preferably 400 cps or less.

In the case of the charge generation layer of the laminated photoconductor, the solid content concentration of the coating liquid is usually 0.1% by mass or more, preferably 1% by mass or more, and usually 15% by mass or less, preferably 10% by mass. The range is% or less. The viscosity of the coating liquid is usually 0.01 cps or more, preferably 0.1 cps or more, and usually 20 cps or less, preferably 10 cps or less.

Examples of the coating method of the coating liquid include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, an air knife coating method, a curtain coating method and the like. , Other known coating methods can also be used.

[2. Image forming device, cartridge]
An image forming apparatus such as a copier or a printer using the electrophotographic photosensitive member of the present invention includes at least each process of charging, exposure, development, transfer, and static elimination, but any of the processes uses any of the commonly used methods. May be good. As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging apparatus 2, an exposure apparatus 3, and a developing apparatus 4, and if necessary, a transfer apparatus 5, a cleaning apparatus 6, and a fixing apparatus. 7 is provided.

Next, an embodiment of the image forming apparatus using the electrophotographic photosensitive member of the present invention will be described with reference to FIG. 1, which shows the main configuration of the apparatus. However, the embodiment is not limited to the following description, and can be arbitrarily modified and implemented as long as it does not deviate from the gist of the present invention.

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

The electrophotographic photosensitive member 1 is not particularly limited as long as it is the above-mentioned electrophotographic photosensitive member of the present invention, but as an example in FIG. 1, a drum having the above-mentioned photosensitive layer formed on the surface of a cylindrical conductive support. The shape of 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 arranged along the outer peripheral surface of the electrophotographic photosensitive member 1, respectively.

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. As the charging device, a corona charging device such as a corotron or a scorotron, a direct charging device (contact type charging device) in which a voltage-applied direct charging member is brought into contact with the surface of a photoconductor to charge the photoconductor is often used. Examples of the direct charging device include a charging roller, a charging brush and the like. Note that FIG. 1 shows a roller-type charging device (charging roller) as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. Further, as the voltage to be applied at the time of charging, only a direct current voltage can be applied, or an alternating current can be superimposed on the direct current. In the case of a corona charging device such as a corotron or a scorotron, ozone is particularly likely to be generated, so that the effect of the invention becomes remarkable.

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

The type of the developing device 4 is not particularly limited, and any device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, and two-component magnetic brush development, or a wet development method is used. be able to. In FIG. 1, the developing apparatus 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, if necessary, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4. This replenishment device is configured to be able to replenish the toner T from a container such as a bottle or a cartridge.

The supply roller 43 is formed of a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, nickel, or a resin roll obtained by coating such a metal roll with a silicon resin, a urethane resin, a fluororesin, or the like. If necessary, smoothing or roughening may be applied to the surface of the developing roller 44. The developing roller 44 is arranged between the electrophotographic photosensitive member 1 and the supply roller 43, and is in contact with the electrophotographic photosensitive member 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 brings it into contact with the surface of the electrophotographic photosensitive member 1.

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

The agitator 42 is rotated by a rotation drive 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, sizes, and the like.

The type of toner T is arbitrary, and in addition to powdery toner, polymerized toner using a suspension polymerization method, an emulsion polymerization method, or the like can be used. In particular, when polymerized toner is used, it is preferable that the toner has a small particle size of about 4 to 8 μm, and the shape of the toner particles is variously used, from one close to a spherical shape to one deviating from a potato-shaped spherical shape. be able to. The polymerized toner has excellent charge uniformity and transferability, and is suitably used for improving image quality.

The type of the transfer device 5 is not particularly limited, and a device using any method such as an electrostatic transfer method such as corona transfer, roller transfer, and belt transfer, a pressure transfer method, and an adhesive transfer method can be used. .. Here, it is assumed that the transfer device 5 is composed of a transfer charger, a transfer roller, a transfer belt, and the like arranged so as to face the electrophotographic photosensitive member 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 the recording paper (paper, medium) P. It is a thing.

The cleaning device 6 is not particularly limited, and any cleaning device such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, and a blade cleaner can be used. The cleaning device 6 scrapes off the residual toner adhering to the photoconductor 1 with a cleaning member and collects the residual toner. However, if the toner remaining on the surface of the photoconductor is small or almost nonexistent, the cleaning device 6 may be omitted.

The fixing device 7 is composed of 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. Note that FIG. 1 shows an example in which the heating device 73 is provided inside the upper fixing member 71. The upper and lower fixing members 71 and 72 are known heat fixing rolls such as stainless steel, aluminum and other metal tubes coated with silicon rubber, Teflon (registered trademark) resin-coated fixing rolls, and fixing sheets. Members can be used. Further, the fixing members 71 and 72 may be configured to supply a mold release agent such as silicone oil in order to improve the mold 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 after passing, it is cooled and cooled to the recording paper P. Toner is fixed on top.

The type of the fixing device is not particularly limited, and a fixing device by any method such as thermal roller fixing, flash fixing, oven fixing, pressure fixing, etc. can be provided in addition to the one used here.

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

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

In the developing apparatus 4, the toner T supplied by the supply roller 43 is thinned by the regulating member (development blade) 45, and has a predetermined polarity (here, the same polarity as the charging potential of the photoconductor 1, and has a negative electrode property). ) Is triboelectrically charged, and is conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoconductor 1.

When the charged toner T supported on the developing roller 44 comes into contact with the surface of the photoconductor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoconductor 1. Then, this toner image is transferred to the recording paper P by the transfer device 5. After that, the toner remaining on the photosensitive surface of the photoconductor 1 without being transferred is removed by the cleaning device 6.
After the toner image is transferred onto the recording paper P, the toner image is heat-fixed on the recording paper P by passing through the fixing device 7 to obtain a final image.

In addition to the above-described configuration, the image forming apparatus may have a configuration capable of performing, for example, a static elimination step. The static elimination step is a step of removing static electricity from the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the static elimination device. Further, the light used in the static elimination step is often light having an exposure energy of 3 times or more that of the exposure light in terms of intensity.

Further, the image forming apparatus may be further modified and configured, for example, a configuration capable of performing steps such as a pre-exposure step and an auxiliary charging step, a configuration capable of performing offset printing, and a plurality of types. A full-color tandem system using toner may be used.

In addition, the electrophotographic photosensitive member 1 is combined with one or two or more of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7, and an integrated cartridge ( Hereinafter, it may be appropriately configured as an “electrophotographic photosensitive member cartridge”), and the electrophotographic photosensitive member cartridge may be configured to be removable from the main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. In this case, for example, when the electrophotographic photosensitive member 1 or other members deteriorate, the electrophotographic photosensitive member cartridge is removed from the image forming apparatus main body, and another new electrophotographic photosensitive member cartridge is attached to the image forming apparatus main body. This facilitates maintenance and management of the image forming apparatus.

[3. Action and effect]
The electrophotographic photosensitive member of the present invention contains a charge transporting substance in which the charge transporting layer simultaneously satisfies the values of E_homo and αcal, a rosin acid ester, and a binder resin. In the charge transport layer, the rosin acid ester is compatible with the binder resin, and it is considered that the adhesiveness of the rosin acid ester also works usefully in the photosensitive layer. Thereby, the adhesiveness between the charge transport layer and the charge generation layer, the undercoat layer, or the substrate can be enhanced. At this time, by using a specific charge transporting substance in combination, the deterioration of the electrical characteristics due to the inclusion of the rosin ester and the deterioration of the adhesiveness due to the inclusion of the specific charge transporting substance can be compensated for each other. Therefore, the adhesiveness and electrical characteristics of the charge transport layer can be improved at the same time, the peeling of the charge transport layer can be reduced, and a high-performance electrophotographic photosensitive member can be provided.

Further, the electrophotographic photosensitive member of the present invention contains a polyarylate resin as a binder resin, and thus has excellent wear resistance in addition to adhesiveness and electrical properties.
Further, the electrophotographic photosensitive member of the present invention contains a polycarbonate resin as a binder resin, so that it has excellent adhesiveness and further enhanced electrical characteristics.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The following examples are shown for explaining the present invention in detail, and the present invention is not limited to the following examples as long as the gist of the present invention is not deviated. The "parts" used in this embodiment indicate "parts by mass" unless otherwise specified.

<Viscosity average molecular weight>
The polyarylate resin was dissolved in dichloromethane to prepare a sample solution having a concentration C of 6.00 g / L. Next, the flow time t of the sample solution was measured in a constant temperature water bath set at 20.0 ° C. using a Ubbelohde type capillary viscometer having a solvent (dichloromethane) flow time t _{0 of 136.16 seconds.} Further, the viscosity average molecular weight _Mv was calculated according to the following formula.
a = 0.438 × η _sp +1
b = 100 × η _sp / C
η _sp = t / t ₀ -1
C = 6.00 (g / L)
η = b / a
M _v = 3207 × η ^1.205

<Example 1>
(Formation of undercoat layer)
The coating liquid for the undercoat layer was prepared as follows. A rutile-type titanium oxide having an average primary particle diameter of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) in an amount of 3% by mass based on the titanium oxide are mixed with a honeyshell mixer. The surface-treated titanium oxide obtained by mixing was dispersed by a ball mill in a mixed solvent having a mass ratio of methanol / 1-propanol of 7/3 to obtain a dispersed slurry of surface-treated titanium oxide. The composition mol of the dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam / bis (4-amino-3-methylcyclohexyl) methane / hexamethylenediamine / decamethylenedicarboxylic acid / octadecamethylenedicarboxylic acid. By stirring and mixing the pellets of copolymerized polyamide having a ratio of 60% / 15% / 5% / 15% / 5% while heating to dissolve the polyamide pellets, and then performing ultrasonic dispersion treatment. , Methanol / 1-propanol / toluene with a mass ratio of 7/1/2 and surface-treated titanium oxide / copolymer polyamide with a mass ratio of 3/1, coating for undercoat layer with solid content concentration of 18.0% A liquid was prepared. This coating liquid is applied on a polyethylene terephthalate sheet (thickness 75 μm) on which aluminum is vapor-deposited on the surface of an aluminum plate with a wire bar so that the film thickness after drying is 1.2 μm, and the undercoat layer is provided by drying. It was.

(Formation of charge generation layer)
As a charge generating substance, 20 parts of Y-type titanyl phthalocyanine having a powder X-ray diffraction spectrum pattern shown in FIG. 2 and 280 parts of 1,2-dimethoxyethane are mixed and pulverized with a sand grind mill for 2 hours for atomization and dispersion treatment. went. Subsequently, 560 parts of a 2.5% 1,2-dimethoxyethane solution of polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name "Denka butyral"# 6000C) and 84 parts of 1,2-dimethoxyethane are mixed. To prepare a dispersion. This dispersion was applied onto the undercoat layer with a bar coater to form a charge generation layer so that the film thickness after drying was 0.4 μm.

(Formation of charge transport layer)
The coating liquid for the charge transport layer was prepared as follows. 100 parts of polyallylate resin-1 (viscosity average molecular weight: 36000) having a repeating unit represented by the following formula (A1) as a binder resin, and a charge transporting substance represented by the following formula (B1) as a charge transporting substance. 40 parts of -1, 1 part of Arakawa Kogyo Co., Ltd., trade name "Pine Crystal" KE-100 as a loginate ester, 2 parts of an antioxidant -1 represented by the following formula (C1) as an antioxidant. , 1 part of additive-1 represented by the following formula (D1), and 0.05 part of silicone oil (manufactured by Shinetsu Silicone Co., Ltd .: trade name KF-96) as a leveling agent, tetrahydrofuran (hereinafter abbreviated as THF as appropriate). ) And toluene (hereinafter abbreviated as TL as appropriate) in 640 parts of a mixed solvent (THF: 80% by mass, TL: 20% by mass) to prepare a coating liquid 1 for a charge transport layer.
This coating liquid was applied onto the charge generation layer with an applicator so that the film thickness after drying was about 20 μm to form a charge transport layer, and a photoconductor sheet A was prepared.

<Example 2>
In Example 1, a photoconductor sheet B was obtained in the same manner as in Example 1 except that the amount of KE-100 used as the rosin acid ester was 5 parts.

<Example 3>
In Example 1, a photoconductor sheet C was obtained in the same manner as in Example 1 except that “Pine Crystal” KE-311 manufactured by Arakawa Kogyo Co., Ltd. was used instead of KE-100 as the rosin acid ester.

<Example 4>
In Example 3, the same procedure as in Example 3 was carried out except that the amount of KE-311 used as the rosin ester was 5 parts, and a photoconductor sheet D was obtained.

<Comparative example 1>
In Example 1, the same procedure as in Example 1 was carried out except that the rosin acid ester was not used, to obtain a photoconductor sheet E.

<Example 5>
In Example 1, instead of the polyarylate resin-1, a polyallylate resin-2 (viscosity average molecular weight: 53000) having a repeating unit represented by the following formula (A2) was used as the charge transporting substance. A photoconductor sheet F was obtained in the same manner as in Example 1 except that the charge transporting substance-2 represented by the following formula (B2) was used instead of the charge transporting substance-1.

<Example 6>
In Example 5, a pine crystal KE-311 was used as the rosin acid ester instead of KE-100, and the same procedure as in Example 5 was carried out except that the amount used was 5 parts to obtain a photoconductor sheet G. ..

<Comparative example 2>
In Example 5, the same procedure as in Example 5 was carried out except that the rosin acid ester was not used, to obtain a photoconductor sheet H.

<Example 7>
In Example 1, instead of the polyarylate resin-1, a polyallylate resin-3 (viscosity average molecular weight: 40300) having a repeating unit represented by the following formula (A3) was used as the charge transporting substance. A photoconductor sheet I was obtained in the same manner as in Example 1 except that the charge transporting substance-3 represented by the following formula (B3) was used instead of the charge transporting substance-1.

<Comparative example 3>
In Example 7, the same procedure as in Example 7 was carried out except that the rosin acid ester was not used, to obtain a photoconductor sheet J.

<Example 8>
In Example 1, the same procedure as in Example 1 was carried out except that the charge transporting substance -4 represented by the following formula (B4) was used instead of the charge transporting substance -1, and the photoconductor sheet K was used. Got

<Comparative example 4>
In Example 8, the same procedure as in Example 8 was carried out except that the rosin acid ester was not used, to obtain a photoconductor sheet L.

<Example 9>
In Example 4, the same operation as in Example 4 was performed except that the charge-transporting substance-5 represented by the following formula (B5) was used instead of the charge-transporting substance-1 as the charge-transporting substance. Sheet M was obtained.

<Comparative example 5>
In Example 9, the same procedure as in Example 9 was carried out except that the rosin acid ester was not used, to obtain a photoconductor sheet N.

<Comparative Example 6>
In Example 1, a polycarbonate resin-1 (viscosity average molecular weight: 40,000) having a repeating unit represented by the following formula (E1) was used instead of the polyarylate resin-1 as the binder resin, and a loginate ester was used. The same procedure as in Example 1 was carried out except that the photoconductor sheet O was obtained.

<Comparative Example 7>
In Example 1, the same as in Example 1 except that the charge transporting substance-1 is replaced with the charge transporting substance-6 represented by the following formula (B6) and the rosin ester is not used. To obtain a photoconductor sheet P.

<Comparative Example 8>
In Comparative Example 7, the same procedure as in Comparative Example 7 was performed except that the charge transporting substance-7 represented by the following formula (B7) was used instead of the charge transporting substance-6, and the photoconductor sheet Q was used. Got

<Comparative Example 9>
In Comparative Example 7, the same procedure as in Comparative Example 7 was performed except that the charge transporting substance-8 represented by the following formula (B8) was used instead of the charge transporting substance-6, and the photoconductor sheet R was used. Got

<Comparative Example 10>
In Example 1, a photoconductor sheet S was obtained in the same manner as in Example 1 except that the above-mentioned charge-transporting substance-6 was used instead of the charge-transporting substance-1 as the charge-transporting substance-1.

<Comparative Example 11>
In Example 1, a photoconductor sheet T was obtained in the same manner as in Example 1 except that the above-mentioned charge-transporting substance-7 was used instead of the charge-transporting substance-1 as the charge-transporting substance-1.

<Comparative Example 12>
In Example 1, a photoconductor sheet U was obtained in the same manner as in Example 1 except that the above-mentioned charge-transporting substance-8 was used instead of the charge-transporting substance-1 as the charge-transporting substance-1.

<Calculated values of HOMO energy level and polarizability α of charge transport material>
Density functional theory calculation of charge transport material used in the above example and comparative example HOMO energy level E_homo obtained as a result of structural optimization calculation by B3LYP / 6-31G (d, p) and restriction Hartree in stable structure The values of αcal, which is the calculated value of the polarization rate α by the -Fock method calculation (basal function is 6-31G (d, p)), are shown in Tables 1 and 2 below.

<Electrical property test>
Each photoconductor sheet prepared in Examples and Comparative Examples was attached to an aluminum drum, the aluminum drum and the aluminum vapor deposition layer of the photoconductor were connected to each other, and then an electrophotograph prepared according to the measurement standard of the Electrophotographic Society. It was attached to a characteristic evaluation device (continued: Basics and Applications of Electrophotographic Technology, edited by Xerographic Society, Corona Publishing Co., Ltd., pp. 404-405) to evaluate electrical characteristics by a cycle of charging, exposure, potential measurement, and static elimination.

In the evaluation of electrical characteristics, in an environment of temperature 25 ° C. and humidity 50%, the photoconductor was first charged so that the initial surface potential was -700 V, and the light of the halogen lamp was converted to 780 nm monochromatic light by an interference filter. Was used as the exposure light. The surface potential when the exposure light was irradiated at 0.5 μJ / cm ² was defined as VL, and the time from exposure to potential measurement was defined as 60 milliseconds. LED light of 660 nm was used for the static elimination light. The smaller the absolute value of VL, the better the electrical characteristics. The results are shown in Tables 3-7.

<Adhesion test>
On the photoconductor sheets prepared in Examples and Comparative Examples, 6 vertical and 6 horizontal cuts were made at 2 mm intervals using an NT cutter (manufactured by NT) to prepare 25 cells of 5 × 5. .. A cellophane tape (manufactured by 3M) was closely attached from above, and the adhesive surface was pulled up to 90 ° to test the adhesiveness between the photosensitive layer (charge generation layer) and the undercoat layer. This was performed at two locations, and the ratio of the number of cells of the photosensitive layer remaining on the support to the total of 50 cells was evaluated as the residual rate. The larger the number of remaining cells, the higher the residual rate and the better the adhesiveness. The results are shown in Tables 3-7.

<Abrasion test>
The photoconductor sheets produced in Examples and Comparative Examples were cut into a circle having a diameter of 10 cm to prepare a test piece, which was subjected to a wear test using a Taber wear tester (manufactured by Toyo Seiki Co., Ltd.). The test conditions were measured by comparing the weights before and after the test with the amount of wear after rotating 700 times under a load of 500 g using a wear wheel CS-10F in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%. The smaller the amount of wear, the better the wear resistance (unit: mg). The results are shown in Tables 3-7.

From the data in Table 3, in Examples 1 to 4 using the polyarylate resin-1 and the charge transporting substance-1, the adhesiveness was improved by using the rosin acid ester as compared with Comparative Example 1. You can see that. Further, in Examples 1 to 4, it can be seen that the electrical characteristics and wear performance are kept stable. Further, from the results of Examples 1 to 4, it can be seen that the electrical characteristics are particularly excellent when the charge transporting substance-1 is used.

From the data in Table 4, in Examples 5 and 6 using the polyarylate resin-2 and the charge transporting substance-2, the adhesiveness was improved by using the rosin acid ester as compared with Comparative Example 2. You can see that. Further, in Examples 5 and 6, it can be seen that the electrical characteristics and wear performance are kept stable. Further, from Examples 5 and 6, it was confirmed that the same effect was exhibited even when the rosin acid ester was changed.

From the data in Table 5, in Examples 7 and 8 using the polyarylate resin-3 and the charge transporting substances-3 and 4, the adhesiveness was obtained by using the rosin acid ester as compared with Comparative Examples 3 and 4, respectively. Can be seen to be improving. Further, in Examples 7 and 8, it can be seen that the electrical characteristics and wear performance are kept stable.

From the data in Table 6, it can be seen that in Example 9 using the polyarylate resin-1 and the charge transporting substance-5, the adhesiveness was improved by using the rosin acid ester as compared with Comparative Example 5. Understand. Further, in Example 9, it can be seen that the electrical characteristics and wear performance are kept stable. Further, from Examples 4 and 9, it was confirmed that even when the charge transporting substance was changed, the effect of improving the adhesiveness was similarly exhibited.

From the data in Table 7, it can be seen that in Comparative Examples 7 to 9 using the polyarylate resin-1 and the charge transporting substances -6 to 8, the adhesiveness is good but the electrical characteristics are insufficient. Further, in Comparative Examples 10 to 12, a decrease in electrical characteristics was observed by using a rosin acid ester as compared with Comparative Examples 7 to 9. Compared with these Comparative Examples 7 to 12, in Example 1, the polyarylate resin-1, the charge transporting substance-1, and the rosin acid ester were used to obtain electrical properties, abrasion resistance, and adhesiveness. It can be seen that it has both. Further, the polyarylate resin generally tends to be inferior in electrical characteristics to the polycarbonate resin, but it can be seen that sufficient electrical characteristics can be realized by using the charge transporting substance-1 in Example 1.

<Example 10>
As the binder resin, 75 parts of polyallylate resin-4 (viscosity average molecular weight: 78000) having a repeating unit represented by the above formula (A1) and a polyallylate resin having a repeating unit represented by the above formula (A1)- 25 parts of 5 (viscosity average molecular weight: 37,000), 40 parts of the charge transporting substance-2 as a charge transporting substance, 5 parts of KE-311 as a loginate ester, and the antioxidant-1 as an antioxidant. 4 parts, 1 part of the above additive-1, and 0.05 part of silicone oil (KF-96) as a leveling agent, and a mixed solvent of tetrahydrofuran and toluene (THF: 80% by mass, TL: 20% by mass). ) 810 parts were mixed to prepare a coating liquid 2 for a charge transport layer.

Subsequently, the coating liquid for the undercoat layer of Example 1 was applied onto a 3003 aluminum alloy tube having a diameter of 30 mm, a length of 375 mm, and a wall thickness of 0.75 mm so that the film thickness after drying was about 1.5 μm. Was dipped and coated, dried at room temperature, and provided with an undercoat layer. Subsequently, the coating liquid for the charge generation layer of Example 1 was immersed and coated on the undercoat layer so that the film thickness after drying was about 0.3 μm, and dried at room temperature to provide the charge generation layer. It was. Further, the coating liquid 2 for the charge transport layer prepared above was dipped and coated on the charge generating layer so that the film thickness after drying was about 18 μm to obtain a photoconductor drum (1).

<Example 11>
In Example 10, instead of the polyarylate resins -4 and 5, a polycarbonate resin-2 having a repeating unit represented by the following formula (E2) was used as the binder resin, and the amount of the antioxidant-1 used was set to 0. A photoconductor drum (2) was obtained in the same manner as in Example 10 except that the portion was changed to 4.

<Printability test>
The photoconductor drums (1) and (2) obtained in the above examples were mounted on a black drum cartridge for the color printer MICROLINE Pro 9800PS-E manufactured by Oki Data Corporation. Next, the developing toner (volume average particle size 7.05 μm, Dv / Dn = 1.14, average circular shape) produced according to the method for producing the developing toner A (emulsion polymerization aggregation method) described in JP-A-2007-213050. The degree 0.963) was mounted on the black toner cartridge. These drum cartridges and toner cartridges were attached to the above printer.

(Specifications of MICROLINE Pro 9800PS-E)
Quadruple tandem color 36ppm, monochrome 40ppm
1200 dpi
Contact roller charging (DC voltage applied)
LED exposure with static elimination

When 10,000 halftone images were printed in an environment of a temperature of 25 ° C. and a humidity of 50%, uniform halftone images were obtained for both the photoconductor drums (1) and (2), and the end of the photoconductor was prevented from peeling off. I couldn't see any of them.

The present invention can be carried out in any field requiring an electrophotographic photosensitive member, and is preferably used in, for example, a copier, a printer, a printing machine, or the like.

1 Photoreceptor (electrophotograph photoconductor)
2 Charging device (charging roller; charging part)
3 Exposure device (exposure section)
4 Developing equipment (development unit)
5 Transfer device 6 Cleaning device 7 Fixing device 41 Developing tank 42 Agitator 43 Supply roller 44 Developing roller 45 Regulatory member 71 Upper fixing member (fixing roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper (paper, medium)

Claims (10)

In an electrophotographic photosensitive member having a laminated photosensitive layer on a conductive support, the charge transporting layer of the laminated photosensitive layer contains a charge transporting substance, an adhesion aid, and a binder resin.
As the charge transport material, the energy level E_homo of HOMO based on the structure optimization calculation by the density functional theory calculation B3LYP / 6-31G (d, p) is -4.70eV or more, and the density functional theory calculation B3LYP / Contains compounds with a ^{calculated polarization rate αcal of 90 Å 3} or higher in stable structures based on 6-31G (d, p) and HF / 6-31G (d, p) calculations.
An electrophotographic photosensitive member containing a rosin acid ester as the adhesive aid. The content of the rosin acid ester is 0.2 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin.
The electrophotographic photosensitive member according to claim 1. The rosinate contains a disproportionated rosinate and / or a hydride rosinate.
The electrophotographic photosensitive member according to claim 1 or 2. The rosin acid ester contains a rosin acid glycerin ester and / or a rosin acid pentaerythritol ester.
The electrophotographic photosensitive member according to any one of claims 1 to 3. The binder resin contains a polyarylate resin and / or a polycarbonate resin.
The electrophotographic photosensitive member according to any one of claims 1 to 4. The binder resin contains a polyarylate resin having a repeating unit represented by the following general formula (1).
The electrophotographic photosensitive member according to any one of claims 1 to 5.

(In the general formula (1), Ar ^{1 to} Ar ⁴ each independently represents an arylene group which may have a substituent, and X ¹ is a single bond, an oxygen atom, a sulfur atom, and the following formula (2). ) Or a group represented by the following formula (3). R ¹ and R ² in the formula (2) independently represent a hydrogen atom, an alkyl group, or an aryl group. R ¹ and R ² may be bonded to form a ring. R ³ in the formula (3) is an alkylene group, an arylene group, or a group represented by the following formula (4). ^{R 4} and R ⁵ in the formula (4) independently represent an alkylene group, Ar ⁵ represents an arylene group, k represents an integer of 0 or more, and Y ¹ represents a single bond and an oxygen atom. , A sulfur atom, or a group represented by the following formula (5), in formula (5), R ⁶ and R ⁷ each independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group. R ⁶ and R ⁷ may be combined to form a ring.)

The binder resin contains a polycarbonate resin having a structural unit derived from an aromatic dihydroxy compound.
The electrophotographic photosensitive member according to any one of claims 1 to 6. The molecular weight of the charge transporting substance is 600 or more and 1200 or less.
The electrophotographic photosensitive member according to any one of claims 1 to 7. The electrophotographic photosensitive member according to any one of claims 1 to 8, the charging means for charging the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member are subjected to image exposure to form an electrostatic latent image. An electrophotographic cartridge including an image exposure means, a developing means for developing the electrostatic latent image with toner, and a transfer means for transferring the toner to a transfer target. The electrophotographic photosensitive member according to any one of claims 1 to 8, a charging means for charging the electrophotographic photosensitive member, and an exposure means for forming an electrostatic latent image by exposure to the charged electrophotographic photosensitive member. It is characterized by including a developing means for developing the electrostatic latent image with toner, a transfer means for transferring the toner to a transfer target, and a fixing means for fixing the toner transferred to the transfer target. Image forming apparatus.

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