JP2012042628A - Electrophotographic photoreceptor, process cartridge, and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that sustainably exhibits relaxation effect for a contact stress of a contact member, and is excellent in potential stability at repeated usage, and to provide a process cartridge and an electrophotographic device having the electrophotographic photoreceptor.SOLUTION: A charge transport layer which is a surface layer of the electrophotographic photoreceptor has a matrix-domain structure composed of a matrix including a component β (at least one of a polycarbonate resin C having a specific structural repeating unit and a polyester resin D having a specific structural repeating unit), and a charge transport material; and a domain containing a component α (a polyester resin (A) having a specific structural repeating unit containing a specific siloxane site). The Martens hardness of the charge transport layer is 170 N/mmor higher and 210 N/mmor lower.

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

  2. Description of the Related Art An organic electrophotographic photoreceptor containing an organic photoconductive material (hereinafter also referred to as “electrophotographic photoreceptor”) has been actively developed as an electrophotographic photoreceptor mounted on an electrophotographic apparatus. However, an electrophotographic photoreceptor using an organic photoconductive material does not satisfy all of the characteristics required for an electrophotographic photoreceptor. In the electrophotographic process, various materials (hereinafter also referred to as “contact members”) such as a developer, a charging member, a cleaning blade, paper, and a transfer member come into contact with the surface of the electrophotographic photosensitive member. The characteristics required for the electrophotographic photoreceptor include reduction of image deterioration due to contact stress with these contact members and the like. In particular, as the durability of electrophotographic photoreceptors has improved in recent years, there is a demand for sustainability of the effect of reducing image deterioration due to contact stress.

  Regarding the continuous relaxation of contact stress, Patent Document 1 proposes a method of forming a matrix-domain structure in a surface layer using a siloxane resin in which a siloxane structure is incorporated in a molecular chain. Among them, it has been shown that by using a polyester resin incorporating a specific siloxane structure, it is possible to both relieve sustained contact stress and suppress potential fluctuation during repeated use of the photoreceptor.

  Patent Document 2 discloses an electrophotographic photosensitive member having a sea-island structure in which a domain is formed in a surface layer using a block copolymer resin material having a siloxane structure, and a low surface energy state is formed. It is disclosed. In the example of Patent Document 2, it is disclosed that the sea-island structure is formed by using only a resin having a low surface energy property and a matrix component in the same resin as the resin for the surface layer.

International Publication No. WO2010 / 008095 JP 2006-330251 A

However, although the electrophotographic photoreceptor disclosed in Patent Document 1 can achieve both maintenance of electrophotographic characteristics and continuous reduction of contact stress, as a result of investigations by the present inventors, the characteristics described above are achieved. In addition to the above, it was found that the durability of the electrophotographic photosensitive member can be further improved.
The material disclosed in Patent Document 2 is a resin having a component having a low surface energy and a matrix component in the same resin. The component having the low surface energy forms a domain, and the low surface energy state is low. It is shown that it is formed. In this configuration, since the photosensitive layer is formed only with the siloxane-containing resin which is inferior in strength, the durability is greatly inferior, and thus improvement has been desired.
An object of the present invention is to provide an electrophotographic photosensitive member that can continuously exert an effect of relieving contact stress with a contact member or the like in an electrophotographic photosensitive member and is excellent in durability during repeated use. There is to do. Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

The present invention relates to an electrophotographic photoreceptor having a support, a charge generation layer provided on the support, and a charge transport layer provided on the charge generation layer, wherein the charge transport layer is a surface layer. In
The charge transport layer has a matrix-domain structure composed of a matrix containing the following component [β] and a charge transport material and a domain containing the following component [α],
Martens hardness value of the charge transport layer, an electrophotographic photoreceptor, characterized in that at 170N / mm ² or more 210N / mm ² or less.
[Α] Polyester resin A having a repeating structural unit represented by the following formula (A) and a repeating structural unit represented by the following formula (B) and having a siloxane moiety content of 5% by mass or more and 40% by mass or less:

（式（Ａ）中、Ｘ^１は、ｍ−フェニレン基、ｐ−フェニレン基、または２つのｐ−フェニレン基が酸素原子を介して結合した２価の基を示す。ｎは、括弧内の構造の繰り返し数の平均値を示す。）

(In Formula (A), X ¹ represents an m-phenylene group, a p-phenylene group, or a divalent group in which two p-phenylene groups are bonded via an oxygen atom. N is a structure in parentheses. The average number of repetitions of.

（式（Ｂ）中、Ｒ^２１〜Ｒ^２４は、それぞれ独立に水素原子、またはメチル基を示す。Ｘ^２は、ｍ−フェニレン基、ｐ−フェニレン基、または２つのｐ−フェニレン基が酸素原子を介して結合した２価の基を示す。Ｙ^２は、エチリデン基、またはプロピリデン基を示す。）
〔β〕下記式（Ｃ）で示される繰り返し構造単位を有するポリカーボネート樹脂Ｃ、または下記式（Ｄ）で示される構造単位を有するポリエステル樹脂Ｄ：

(In formula (B), R ^{21 to} R ²⁴ each independently represents a hydrogen atom or a methyl group. X ² represents an m-phenylene group, a p-phenylene group, or two p-phenylene groups as an oxygen atom. (Y ² represents an ethylidene group or a propylidene group.)
[Β] Polycarbonate resin C having a repeating structural unit represented by the following formula (C), or polyester resin D having a structural unit represented by the following formula (D):

（式（Ｃ）中、Ｒ^３１〜Ｒ^３４は、それぞれ独立に水素原子、またはメチル基を示す。Ｙ^３は、エチリデン基、プロピリデン基、フェニルエチリデン基、シクロヘキシリデン基、または酸素原子を示す。）

(In the formula (C), R ^{31 to} R ³⁴ each independently represent a hydrogen atom or a methyl group. Y ³ represents an ethylidene group, a propylidene group, a phenylethylidene group, a cyclohexylidene group, or an oxygen atom. .)

（式（Ｄ）中、Ｒ^４１〜Ｒ^４４は、それぞれ独立に水素原子、またはメチル基を示す。Ｘ^４は、ｍ−フェニレン基、ｐ−フェニレン基、または２つのｐ−フェニレン基が酸素原子を介して結合した２価の基を示す。Ｙ^４は、単結合、エチリデン基、またはプロピリデン基を示す。）

(In formula (D), R ^{41 to} R ⁴⁴ each independently represents a hydrogen atom or a methyl group. X ⁴ represents an m-phenylene group, a p-phenylene group, or two p-phenylene groups as an oxygen atom. (Y ⁴ represents a single bond, an ethylidene group, or a propylidene group.)

Further, the present invention integrally supports the electrophotographic photosensitive member and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means, and is detachable from the main body of the electrophotographic apparatus. A process cartridge.
The present invention also provides an electrophotographic apparatus having the electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit, and a transfer unit.

  As described above, according to the present invention, it is possible to provide an electrophotographic photosensitive member that can continuously exert an effect of relieving contact stress with a contact member or the like and that is excellent in durability during repeated use. can do. According to the present invention, a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member can be provided.

1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having the electrophotographic photosensitive member of the present invention.

As described above, the electrophotographic photosensitive member of the present invention has a support, a charge generation layer provided on the support, and a charge transport layer provided on the charge generation layer, and the charge transport layer. In an electrophotographic photoreceptor in which is a surface layer,
The charge transport layer has a matrix-domain structure composed of a matrix containing the following component [β] and a charge transport material and a domain containing the following component [α],
Martens hardness value of the charge transport layer, an electrophotographic photoreceptor is 170N / mm ² or more 210N / mm ² or less.
[Α] Polyester resin A having a repeating structural unit represented by the following formula (A) and a repeating structural unit represented by the following formula (B) and having a siloxane moiety content of 5% by mass or more and 40% by mass or less:

（式（Ａ）中、Ｘ^１は、ｍ−フェニレン基、ｐ−フェニレン基、または２つのｐ−フェニレン基が酸素原子を介して結合した２価の基を示す。ｎは、括弧内の構造の繰り返し数の平均値を示す。）

(In Formula (A), X ¹ represents an m-phenylene group, a p-phenylene group, or a divalent group in which two p-phenylene groups are bonded via an oxygen atom. N is a structure in parentheses. The average number of repetitions of.

（式（Ｂ）中、Ｒ^２１〜Ｒ^２４は、それぞれ独立に水素原子、またはメチル基を示す。Ｘ^２は、ｍ−フェニレン基、ｐ−フェニレン基、または２つのｐ−フェニレン基が酸素原子を介して結合した２価の基を示す。Ｙ^２は、エチリデン基、またはプロピリデン基を示す。）
〔β〕下記式（Ｃ）で示される繰り返し構造単位を有するポリカーボネート樹脂Ｃ、または下記式（Ｄ）で示される構造単位を有するポリエステル樹脂Ｄ：

(In formula (B), R ^{21 to} R ²⁴ each independently represents a hydrogen atom or a methyl group. X ² represents an m-phenylene group, a p-phenylene group, or two p-phenylene groups as an oxygen atom. (Y ² represents an ethylidene group or a propylidene group.)
[Β] Polycarbonate resin C having a repeating structural unit represented by the following formula (C), or polyester resin D having a structural unit represented by the following formula (D):

（式（Ｃ）中、Ｒ^３１〜Ｒ^３４は、それぞれ独立に水素原子、またはメチル基を示す。Ｙ^３は、エチリデン基、プロピリデン基、フェニルエチリデン基、シクロヘキシリデン基、または酸素原子を示す。）

(In the formula (C), R ^{31 to} R ³⁴ each independently represent a hydrogen atom or a methyl group. Y ³ represents an ethylidene group, a propylidene group, a phenylethylidene group, a cyclohexylidene group, or an oxygen atom. .)

（式（Ｄ）中、Ｒ^４１〜Ｒ^４４は、それぞれ独立に水素原子、またはメチル基を示す。Ｘ^４は、ｍ−フェニレン基、ｐ−フェニレン基、または２つのｐ−フェニレン基が酸素原子を介して結合した２価の基を示す。Ｙ^４は、単結合、エチリデン基、またはプロピリデン基を示す。）

(In formula (D), R ^{41 to} R ⁴⁴ each independently represents a hydrogen atom or a methyl group. X ⁴ represents an m-phenylene group, a p-phenylene group, or two p-phenylene groups as an oxygen atom. (Y ⁴ represents a single bond, an ethylidene group, or a propylidene group.)

Below, the polyester resin A which is a component [(alpha)] is demonstrated.
The polyester resin A as the component [α] has a repeating structural unit represented by the above formula (A) and a repeating structural unit represented by the above formula (B).
In the above formula (A), n represents an average value of the number of repetitions of the structure in parentheses. n is Martens hardness values of the charge transport layer of the present invention is arbitrary within a range satisfying 170N / mm ² or more 210N / mm ² or less, n is preferably 20 or more and 100 or less. Furthermore, it is preferable that it is 40 or more and 60 or less.
Table 1 shows examples of the repeating structural unit represented by the above formula (A).

これらの中でも、上記式（Ａ−１）、（Ａ−３）、または（Ａ−５）で示される繰り返し構造単位であることが好ましい。
次に上記式（Ｂ）で示される繰り返し構造単位について説明する。
以下に、上記式（Ｂ）で示される繰り返し構造単位の例を示す。

Among these, a repeating structural unit represented by the above formula (A-1), (A-3), or (A-5) is preferable.
Next, the repeating structural unit represented by the above formula (B) will be described.
Examples of the repeating structural unit represented by the above formula (B) are shown below.

Among these, the repeating structural unit represented by the above formula (B-1), (B-4), or (B-7) is preferable.
Further, the polyester resin A as the component [α] in the present invention, the siloxane moiety relative to the total weight of the polyester resin A, Martens hardness values of the charge transport layer satisfies the 170N / mm ² or more 210N / mm ² or less Contains in a range. It is preferable to contain 10 mass% or more and 40 mass% or less of a siloxane site | part with respect to the total mass of the polyester resin A which is a component [(alpha)].

  In the present invention, the siloxane moiety is a moiety comprising silicon atoms at both ends constituting the siloxane moiety and groups bonded thereto, and oxygen atoms, silicon atoms and groups bonded to the silicon atoms sandwiched between the silicon atoms at both ends. is there. Specifically, in the present invention, the siloxane moiety is, for example, a moiety surrounded by a broken line below in the case of a repeating structural unit represented by the following formula (AS).

The content of the siloxane moiety relative to the total mass of the polyester resin A which is the component [α] of the present invention can be analyzed by a general analytical method. Examples of analysis methods are shown below.
The charge transport layer, which is the surface layer of the electrophotographic photosensitive member, is a preparative device capable of separating and recovering each composition component such as size exclusion chromatography and high performance liquid chromatography after dissolving the charge transport layer, which is the surface layer of the electrophotographic photoreceptor, with a solvent. Various materials contained in the transport layer are collected. The separated polyester resin A is hydrolyzed in the presence of alkali or the like to decompose into a carboxylic acid moiety and a bisphenol moiety. With respect to the obtained bisphenol moiety, the number of repetitions and the molar ratio of the siloxane moiety are calculated by nuclear magnetic resonance spectrum analysis and mass spectrometry, and converted to the content (mass ratio).

The polyester resin A which is the component [α] used in the present invention is a copolymer of a repeating structural unit represented by the above formula (A) and a repeating structural unit represented by the above formula (B). The copolymerization form may be any form such as block copolymerization, random copolymerization, and alternating copolymerization.
The weight average molecular weight of the polyester resin A, which is the component [α] used in the present invention, is 30,000 to 150,000 in terms of forming a domain structure in the matrix containing the component [β] and the charge transport material. It is preferable that Furthermore, it is more preferable that they are 40,000 or more and 100,000 or less.

In the present invention, the weight average molecular weight of the resin is a polystyrene equivalent weight average molecular weight measured by a conventional method, specifically, a method described in JP-A-2007-79555.
The copolymerization ratio of the polyester resin A, which is the component [α] used in the present invention, is a peak area ratio of hydrogen atoms (hydrogen atoms constituting the resin) by ¹ H-NMR measurement of the resin, which is a general technique. It can be confirmed by the conversion method.
The polyester resin A which is the component [α] used in the present invention can be synthesized by the method described in Patent Document 1.

Next, the component [β] will be described.
Component [β] of the present invention is a polycarbonate resin C having a repeating structural unit represented by the above formula (C) or a polyester resin D having a repeating structural unit represented by the above formula (D).
Hereinafter, the polycarbonate resin C having the repeating structural unit represented by the above formula (C) as the component [β] will be described.
Specific examples of the repeating structural unit represented by the above formula (C) are shown below.

Among these, the repeating structural unit represented by the above formula (C-1), (C-3), or (C-6) is preferable.
Hereinafter, the polyester resin D having the repeating structural unit represented by the above formula (D) as the component [β] will be described.
Specific examples of the repeating structural unit represented by the above formula (D) are shown below.

Among these, the repeating structural unit represented by the above formula (D-1), (D-3), (D-4), (D-6), or (D-7) is preferable.
The charge transport layer in the present invention has a matrix-domain structure composed of a matrix containing the component [β] and the charge transport material and a domain containing the component [α]. When the matrix-domain structure in the present invention is referred to as “sea-island structure”, the matrix corresponds to the sea and the domain corresponds to the island.

The domain containing the component [α] shows a granular (island) structure formed in a matrix containing the component [β] and the charge transport material. The domain containing the component [α] is separated from other domains in the matrix and each exists independently. Such a matrix-domain structure can be confirmed by observing the surface of the charge transport layer or observing the cross section of the charge transport layer.
The state observation of the matrix-domain structure or the measurement of the domain can be measured using, for example, a commercially available laser microscope, optical microscope, electron microscope, or atomic force microscope. Using the microscope, it is possible to observe the state of the matrix-domain structure or measure the domain structure at a predetermined magnification.

  The number average particle diameter of the domain containing the component [α] in the present invention is preferably 100 nm or more and 1,000 nm or less. Moreover, it is preferable that the particle size distribution of the particle size of each domain is narrow from the viewpoint of the uniformity of the effect of the coating film and stress relaxation. The number average particle size in the present invention is arbitrarily selected from 100 domains observed by microscopic observation of a cross section obtained by vertically cutting the charge transport layer of the present invention, and the maximum diameter of the cut domains is averaged. It is calculated by.

The content of the siloxane moiety of the polyester resin A which is the component [α] with respect to the total mass of all resins in the charge transport layer of the present invention is such that the Martens hardness value of the charge transport layer is 170 N / mm ² or more and 210 N / mm. Any range that satisfies ² or less is optional. In particular, the content of the siloxane moiety of the polyester resin A which is the component [α] with respect to the total mass of all the resins in the charge transport layer has a favorable matrix-domain structure that is 1% by mass or more and 20% by mass or less. Preferred for forming. More preferably, it is 2 mass% or more and 10 mass% or less.

Martens hardness value of the charge transporting layer of the electrophotographic photosensitive member of the present invention is 170N / mm ² or more 210N / mm ² or less. The Martens hardness value is a value measured by the following procedure based on the method disclosed in Japanese Patent Application Laid-Open No. 2007-233355.
In the present invention, the Martens hardness value of the surface of the electrophotographic photosensitive member is a value measured using a microhardness measuring apparatus Fischerscope H100V (manufactured by Fischer) in an environment of room temperature of 25 ° C. and relative humidity of 50%. . The Fischerscope H100V has a continuous hardness by contacting an indenter with a measurement object (the peripheral surface of the electrophotographic photosensitive member), continuously applying a load to the indenter, and directly reading the indentation depth under the load. It is a required device.

In the present invention, a Vickers quadrangular pyramid diamond indenter having a facing angle of 136 ° was used as an indenter, and the indenter was pressed against the peripheral surface of the charge transport layer of the electrophotographic photosensitive member.
Final load applied to the indenter continuously (final load): 6 mN
Time for holding a state where a final load of 6 mN is applied to the indenter (holding time): 0.1 seconds In addition, the measurement points were 273 points.
The Martens hardness value (HMk) was determined by the following formula from the indentation depth of the indenter when a final load of 6 mN was applied to the indenter. In the following formula, HMk represents the universal hardness value, F _f represents the final load, and S _f represents the surface area of the indented portion when the final load is applied. H _f represents the indentation depth (mm) of the indenter when the final load is applied.

  In general, it is known that the effect of alleviating contact stress can be obtained by having a structure of a siloxane moiety, but it is also known that the siloxane moiety has a structure inferior in hardness or strength. It is considered that the effect of alleviating contact stress at the siloxane site is due to the structure in which the siloxane structure can move relatively freely. A structure that can move freely, which is superior in stress relaxation, causes a decrease in hardness and strength. As a result, the durability of the charge transport layer of the electrophotographic photosensitive member is reduced. When the charge transport layer is formed only with a conventional resin containing a siloxane moiety, it is difficult to achieve both stress relaxation and durability. This is because if the introduction rate of the siloxane moiety in the resin is increased to alleviate the contact stress, the durability is remarkably lowered, and if the introduction rate is lowered to maintain the strength, the stress relaxation effect is reduced. In the charge transport layer of the present invention, the introduction rate of the siloxane moiety is increased by forming a domain containing the polyester resin A which is the component [α] having a siloxane moiety responsible for stress relaxation in the charge transport layer. Moreover, by maintaining the durability at the matrix site and adopting a configuration, it is possible to achieve both properties. Furthermore, since the charge transport layer has the Martens hardness value of the present invention, it is possible to effectively achieve both improvement in durability and stress relaxation.

Below, the synthesis example of the polyester resin A which is the component [(alpha)] used for this invention is shown.
The polyester resin A as the component [α] can be synthesized using the synthesis method described in Patent Document 1. In the present invention, the same synthesis method is used, and polyester resin A shown in the synthesis example of Table 2 is prepared using raw materials corresponding to the repeating unit represented by the above formula (A) and the structural unit represented by the above formula (B). Synthesized. Table 2 shows the weight average molecular weight of the synthesized polyester resin A and the content of the siloxane moiety in the polyester resin A.

The charge transport layer, which is the surface layer of the electrophotographic photoreceptor of the present invention, contains components [α] and [β] as resins, but other resins may be further mixed and used. Examples of other resins that may be used in combination include acrylic resins, polyester resins, and polycarbonate resins.
The charge transport layer which is the surface layer of the electrophotographic photoreceptor of the present invention contains a charge transport material. Examples of the charge transport material include a triarylamine compound or a hydrazone compound. Among these, it is preferable to use a triarylamine compound as a charge transport material from the viewpoint of improving electrophotographic characteristics.

Next, the configuration of the electrophotographic photosensitive member of the present invention will be described.
As described above, the electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member having a support, a charge generation layer provided on the support, and a charge transport layer provided on the charge generation layer. . The charge transport layer is an electrophotographic photosensitive member whose surface layer (uppermost layer) is an electrophotographic photosensitive member.
In addition, the charge transport layer of the electrophotographic photoreceptor of the present invention contains components [α], [β] and a charge transport material.
In addition, the charge transport layer may have a laminated structure. In that case, at least the charge transport layer on the most surface side has the matrix-domain structure.

In general, a cylindrical electrophotographic photosensitive member in which a photosensitive layer is formed on a cylindrical support is widely used as the electrophotographic photosensitive member. However, the electrophotographic photosensitive member may have a belt shape, a sheet shape, or the like. Is possible.
As the support, one having conductivity (conductive support) is preferable, and a metal support such as aluminum, aluminum alloy, and stainless steel can be used. In the case of a support made of aluminum or aluminum alloy, ED tube, EI tube, and these are cut, electrolytic composite polishing (electrolysis with an electrode having an electrolytic action and polishing with a grinding stone having a polishing action), wet or dry type A honing treatment can also be used. Further, a metal support or a resin support having a layer in which aluminum, an aluminum alloy, or an indium oxide-tin oxide alloy is formed by vacuum deposition can also be used. In addition, a support in which conductive particles such as carbon black, tin oxide particles, titanium oxide particles, and silver particles are impregnated in a resin, or a plastic having a conductive resin can also be used.
The surface of the support may be subjected to cutting treatment, roughening treatment, alumite treatment, or the like.

A conductive layer may be provided between the support and an intermediate layer or charge generation layer described later. This is a layer formed using a conductive layer coating liquid in which conductive particles are dispersed in a resin. Examples of the conductive particles include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, and metal oxide powder such as conductive tin oxide and ITO. Can be mentioned.
Examples of the resin include polyester resin, polycarbonate resin, polyvinyl butyral, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin.

Examples of the solvent for the conductive layer coating solution include ether solvents, alcohol solvents, ketone solvents, and aromatic hydrocarbon solvents.
The thickness of the conductive layer is preferably 0.2 μm or more and 40 μm or less, more preferably 1 μm or more and 35 μm or less, and further preferably 5 μm or more and 30 μm or less.

An intermediate layer may be provided between the support or the conductive layer and the charge generation layer.
The intermediate layer can be formed by applying an intermediate layer coating solution containing a resin on the conductive layer and drying or curing it.
Examples of the intermediate layer resin include polyacrylic acids, methylcellulose, ethylcellulose, polyamide resin, polyimide resin, polyamideimide resin, polyamic acid resin, melamine resin, epoxy resin, polyurethane resin, and polyolefin resin. The intermediate layer resin is preferably a thermoplastic resin. Specifically, a thermoplastic polyamide resin or a polyolefin resin is preferable. The polyamide resin is preferably a low crystalline or non-crystalline copolymer nylon that can be applied in a solution state. The polyolefin resin is preferably in a state usable as a particle dispersion. Furthermore, it is preferable that the polyolefin resin is dispersed in an aqueous medium.

The thickness of the intermediate layer is preferably 0.05 μm or more and 7 μm or less, and more preferably 0.1 μm or more and 2 μm or less.
Further, the intermediate layer may contain semiconductive particles, an electron transporting material, or an electron accepting material.

A charge generation layer is provided on the support, the conductive layer, or the intermediate layer.
Examples of the charge generating material used in the electrophotographic photoreceptor of the present invention include azo pigments, phthalocyanine pigments, indigo pigments and perylene pigments. These charge generation materials may be used alone or in combination of two or more. Among these, metal phthalocyanines such as oxytitanium phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine are particularly preferable because of their high sensitivity.

Examples of the resin used for the charge generation layer include polycarbonate resin, polyester resin, butyral resin, polyvinyl acetal resin, acrylic resin, vinyl acetate resin, and urea resin. Among these, a butyral resin is particularly preferable. These can be used singly or in combination of two or more as a mixture or copolymer.
The charge generation layer can be formed by applying a charge generation layer coating solution obtained by dispersing a charge generation material together with a resin and a solvent and drying the coating solution. The charge generation layer may be a vapor generation film of a charge generation material.

Examples of the dispersion method include a method using a homogenizer, an ultrasonic wave, a ball mill, a sand mill, an attritor, and a roll mill.
The ratio between the charge generating material and the resin is preferably in the range of 1:10 to 10: 1 (mass ratio), and more preferably in the range of 1: 1 to 3: 1 (mass ratio).
The solvent used for the charge generation layer coating solution is selected from the solubility and dispersion stability of the resin and charge generation material used. Examples of the organic solvent include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

The thickness of the charge generation layer is preferably 5 μm or less, and more preferably 0.1 μm or more and 2 μm or less.
In addition, various sensitizers, antioxidants, ultraviolet absorbers, plasticizers, and the like can be added to the charge generation layer as necessary. In addition, in order to prevent the flow of charges in the charge generation layer from stagnation, the charge generation layer may contain an electron transport material or an electron accepting material.

A charge transport layer is provided on the charge generation layer.
The charge transport layer which is the surface layer of the electrophotographic photoreceptor of the present invention contains a charge transport material. Examples of the charge transport material contained include a triarylamine compound or a hydrazone compound. Among these, it is preferable to use a triarylamine compound as a charge transport material from the viewpoint of improving electrophotographic characteristics.
Examples of charge transport materials are shown below.

The charge transport layer, which is the surface layer of the electrophotographic photoreceptor of the present invention, contains components [α] and [β] as resins, but as described above, other resins may be further mixed and used. Other resins that may be used in combination are as described above.
The charge transport layer can be formed by applying a charge transport layer coating solution obtained by dissolving a charge transport material and each of the above resins in a solvent, and drying it.
The ratio between the charge transport material and the resin is preferably in the range of 4:10 to 20:10 (mass ratio), and more preferably in the range of 5:10 to 12:10 (mass ratio).

Examples of the solvent used in the charge transport layer coating solution include ketone solvents, ester solvents, ether solvents, and aromatic hydrocarbon solvents. These solvents may be used alone or in combination of two or more. Among these solvents, it is preferable to use an ether solvent or an aromatic hydrocarbon solvent from the viewpoint of resin solubility.
The film thickness of the charge transport layer is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 35 μm or less.

In addition, an antioxidant, an ultraviolet absorber, a plasticizer, and the like can be added to the charge transport layer as necessary.
Various additives can be added to each layer of the electrophotographic photoreceptor of the present invention. Examples of the additive include deterioration inhibitors such as antioxidants, ultraviolet absorbers, and light stabilizers, and fine particles such as organic fine particles and inorganic fine particles. Examples of the deterioration inhibitor include hindered phenol antioxidants, hindered amine light stabilizers, sulfur atom-containing antioxidants, and phosphorus atom-containing antioxidants. Examples of the organic fine particles include polymer resin particles such as fluorine atom-containing resin particles, polystyrene fine particles, and polyethylene resin particles. Examples of the inorganic fine particles include metal oxides such as silica and alumina.

When applying the coating liquid for each of the above layers, a coating method such as a dip coating method (dip coating method), a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, or a blade coating method can be used. .
Moreover, you may form uneven | corrugated shape (concave shape, convex shape) on the surface of the electric charge transport layer which is a surface layer of the electrophotographic photoreceptor of this invention. A known method can be adopted as a method for forming the uneven shape. As a forming method, a method of forming a concave shape by spraying abrasive particles on the surface, a method of forming a concavo-convex shape by press-contacting a mold having a concavo-convex shape on the surface, a coating liquid for a coated surface layer Examples include a method of forming a concave shape by condensing the surface of the coating film and then drying it, a method of forming a concave shape by irradiating the surface with laser light.
Among these, a method of forming a concavo-convex shape by pressing a mold having a concavo-convex shape on the surface of the surface layer of the electrophotographic photosensitive member is preferable. Also preferred is a method of forming a concave shape by allowing the coating surface of the applied coating solution for the surface layer to condense and then drying.

FIG. 1 shows an example of a schematic configuration of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.
In FIG. 1, a cylindrical electrophotographic photosensitive member 1 is rotationally driven in a direction of an arrow about a shaft 2 at a predetermined peripheral speed.
The surface of the electrophotographic photosensitive member 1 that is rotationally driven is uniformly charged to a predetermined positive or negative potential by a charging unit (primary charging unit: charging roller or the like) 3. Next, exposure light (image exposure light) 4 output from exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images corresponding to the target image are sequentially formed on the surface of the electrophotographic photosensitive member 1.

  The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is developed with toner contained in the developer of the developing means 5 to become a toner image. Next, the toner image formed and supported on the surface of the electrophotographic photosensitive member 1 is sequentially transferred onto a transfer material (such as paper) P by a transfer bias from a transfer unit (such as a transfer roller) 6. The transfer material P is taken out from the transfer material supply means (not shown) between the electrophotographic photoreceptor 1 and the transfer means 6 (contact portion) in synchronization with the rotation of the electrophotographic photoreceptor 1 and fed. Is done.

The transfer material P that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member 1 and introduced into the fixing means 8 to receive the image fixing, and is printed out as an image formed product (print, copy). Is done.
The surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is cleaned by receiving a developer (toner) remaining after transfer by a cleaning means (cleaning blade or the like) 7. Next, after being subjected to charge removal processing by pre-exposure light (not shown) from pre-exposure means (not shown), it is repeatedly used for image formation. As shown in FIG. 1, when the charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not necessarily required.

  Of the above-described components such as the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6 and the cleaning unit 7, a plurality of components may be housed in a container and integrally combined as a process cartridge. Good. The process cartridge may be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. In FIG. 1, an electrophotographic photosensitive member 1, a charging unit 3, a developing unit 5 and a cleaning unit 7 are integrally supported to form a cartridge, and an electrophotographic apparatus is provided using a guide unit 10 such as a rail of the electrophotographic apparatus main body. The process cartridge 9 is detachable from the main body.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the technical scope of the present invention is not limited to these. In the examples, “part” means “part by mass”.

[Example 1]
An aluminum cylinder having a diameter of 24 mm and a length of 257 mm was used as a support.
Next, SnO ₂ coat-treated barium sulfate (conductive particles) 10 parts, titanium oxide (resistance control pigment) 2 parts, phenol resin 6 parts, silicone oil (leveling agent) 0.001 part and methanol 4 parts / methoxypropanol A conductive layer coating solution was prepared using 16 parts of a mixed solvent.
This conductive layer coating solution was dip-coated on a support and cured (thermosetting) at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 15 μm.

Next, an intermediate layer coating solution was prepared by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymer nylon in a mixed solvent of 65 parts of methanol / 30 parts of n-butanol.
This intermediate layer coating solution was dip coated on the conductive layer and dried at 100 ° C. for 10 minutes to form an intermediate layer having a thickness of 0.7 μm.

Next, 10 parts of hydroxygallium phthalocyanine (charge generating substance) was added to a solution obtained by dissolving 5 parts of polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) in 250 parts of cyclohexanone. This was dispersed for 1 hour in an atmosphere of 23 ± 3 ° C. by a sand mill apparatus using glass beads having a diameter of 1 mm. After dispersion, a coating solution for charge generation layer was prepared by adding 250 parts of ethyl acetate. In addition, hydroxygallium phthalocyanine is 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 °, and 28.3 at a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction. It is a crystalline form with a strong peak at °.
This charge generation layer coating solution was dip-coated on the intermediate layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.26 μm.

Next, 7 parts of a charge transport material having a structure represented by the above formula (1-1), 3 parts of a charge transport material having a structure represented by the above formula (1-2), and Component [α] in Synthesis Example 1 Polycarbonate containing 3 parts of the synthesized polyester resin A (1) and a repeating structure represented by the above formula (C-2) and a repeating structure represented by (C-5) as a component [β] in a ratio of 8: 2. A coating solution for a charge transport layer was prepared by dissolving 7 parts of Resin C (weight average molecular weight 80,000) in a mixed solvent of 30 parts of dimethoxymethane and 50 parts of orthoxylene.
This charge transport layer coating solution was dip-coated on the charge generation layer and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 14 μm. It was confirmed that the formed charge transport layer contained a domain structure containing the component [α] in a matrix containing the charge transport material and the component [β].

  In this manner, an electrophotographic photoreceptor having a charge transport layer as a surface layer was produced. Charge transport material contained in charge transport layer, components [α], [β], content A of siloxane moiety in polyester resin A, and content B of siloxane moiety in polyester resin A relative to the total mass of all resins Is shown in Table 3.

Next, evaluation will be described.
The evaluation is based on the relative value of the torque after initial use and after repeated use of 2,000 sheets, the initial measurement of the Martens hardness value of the surface layer of the photoreceptor, the observation of the surface of the electrophotographic photoreceptor during the torque measurement, and after 2,000 sheets The drum surface was scratched.
As an evaluation apparatus, a laser beam printer LBP-5050 manufactured by Canon Inc. was used. The evaluation was performed in an environment at a temperature of 23 ° C. and a relative humidity of 50%.

<Relative torque evaluation>
The driving current value (current value A) of the rotary motor of the electrophotographic photosensitive member was measured under the same conditions as the above-described potential fluctuation evaluation conditions. In this evaluation, the amount of contact stress between the electrophotographic photosensitive member and the cleaning blade is evaluated. The magnitude of the obtained current value indicates the magnitude of the contact stress amount between the electrophotographic photosensitive member and the cleaning blade.

Further, an electrophotographic photosensitive member serving as a control of the relative torque value was produced by the following method.
The component [α] of the charge transport layer of the electrophotographic photosensitive member of Example 1 was changed to the component [β] in Table 3 and changed to the configuration of only the component [β]. An electrophotographic photoreceptor was prepared and used as a control electrophotographic photoreceptor.
Using the produced control electrophotographic photoreceptor, the driving current value (current value B) of the rotary motor of the electrophotographic photoreceptor was measured in the same manner as in Example 1.

The thus obtained driving current value (current value A) of the electrophotographic photosensitive member using the component [α] according to the present invention and the electrophotographic photosensitive member not using the component [α] according to the present invention. The ratio with the drive current value (current value B) of the rotary motor was calculated. The obtained numerical value of (current value A) / (current value B) was compared as a relative value of torque. The relative value of the torque indicates the increase or decrease in the contact stress amount between the electrophotographic photosensitive member and the cleaning blade. The smaller the relative torque value, the smaller the contact stress amount between the electrophotographic photosensitive member and the cleaning blade. Indicates.
The results are shown in the relative values of the initial torque in Table 6.

  Subsequently, using A4 size plain paper, 2,000 images were continuously output. A test chart having a printing ratio of 5% was used. Thereafter, the relative value of torque after repeated use of 2,000 sheets was measured. The relative value of the torque after repeated use of 2,000 sheets was evaluated by the same evaluation as the relative value of the initial torque. In this case, the control electrophotographic photosensitive member was also used repeatedly for 2,000 sheets, and the relative value of the torque after the repeated use of 2,000 sheets was calculated using the driving current value at that time. The results are shown in Table 6 as relative values of torque after 2,000 sheets.

<Martens hardness evaluation>
For the electrophotographic photosensitive member produced by the above method, the Martens hardness value of the surface of the electrophotographic photosensitive member is a microhardness measuring device Fischerscope H100V (Fischer) in an environment of room temperature 25 ° C. and relative humidity 50%. The measurement was performed using A Vickers quadrangular pyramid diamond indenter having a facing angle of 136 ° was used as the indenter, and the indenter was pressed against the peripheral surface of the charge transport layer of the electrophotographic photosensitive member.
Final load applied to the indenter continuously (final load): 6 mN
Time for holding a state where a final load of 6 mN is applied to the indenter (holding time): 0.1 seconds In addition, the measurement points were 273 points.
The Martens hardness value (HMk) was determined by the above formula from the indentation depth of the indenter when a final load of 6 mN was applied to the indenter. The results are shown in Table 6.

<Evaluation of matrix-domain structure>
For the electrophotographic photosensitive member produced by the above method, the cross section of the charge transport layer obtained by cutting the charge transport layer in the vertical direction is cross sectioned using an ultradeep shape measuring microscope VK-9500 (manufactured by Keyence Corporation). Observations were made. At this time, the magnification of the objective lens is 50 times, and 100 μm square (10,000 μm ² ) of the surface of the electrophotographic photosensitive member is used for visual field observation, and the maximum diameter of 100 randomly selected domain parts in the visual field is selected. Was measured. An average value was calculated from the obtained maximum diameter, and was taken as the number average particle diameter. The results are shown in Table 6.

<Scratch depth evaluation>
The surface at a position of 120 mm from the upper end of the photoconductor was measured using a surface roughness measuring device (Surfcoder SE-3400, manufactured by Konishi Laboratories), and the ten-point average roughness in JIS B 0601: 2001 Evaluation based on (Rzjis) evaluation (evaluation length: 10 mm) was performed. The results are shown in Table 6.

[Examples 2 to 44]
In Example 1, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the charge transport materials and the components [α] and [β] in the charge transport layer were changed as shown in Table 3. . It was confirmed that the formed charge transport layer contained a domain structure containing the component [α] in a matrix containing the charge transport material and the component [β]. The results are shown in Table 6.

The weight average molecular weight of the polycarbonate resin C used as the component [β] is
(C-2) / (C-5) = 8/2: 80,000
(C-1): 60,000
(C-4) / (C-6) = 7/3: 60,000
(C-3): 80,000
Met.

[Examples 45-88]
In Example 1, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the charge transport materials and the components [α] and [β] in the charge transport layer were changed as shown in Table 4. . It was confirmed that the formed charge transport layer contained a domain structure containing the component [α] in a matrix containing the charge transport material and the component [β]. The results are shown in Table 7.

The weight average molecular weight of the polyester resin D used as the component [β] is
(D-2) / (D-5) = 5/5: 100,000
(D-1) / (D-4) = 5/5: 120,000
(D-7) = 120,000
(D-8) = 90,000
(D-1) / (D-3) / (D-4) / (D-6) = 3.5 / 1.5 / 3.5 / 1.5: 130,000
Met.
In Examples 67 and 70, polycarbonate resin C and polyester resin D were mixed and used as component [β] as shown in Table 4.

[Comparative Example 1]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the polyester resin A (1) as the component [α] in Example 1 was changed to the component [β] shown in Table 5. Table 5 shows the composition of the resin contained in the charge transport layer and the content of the siloxane moiety. Since the component [α] was not contained, the matrix-domain structure was not confirmed. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 8.

[Comparative Examples 2 to 4]
An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the component [α] was changed to the component [β] shown in Table 5 in Examples 21, 45 and 65. Table 5 shows the composition of the resin contained in the charge transport layer and the content of the siloxane moiety. Since the component [α] was not contained, the matrix-domain structure was not confirmed. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 8.

[Comparative Examples 5 to 8]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the component [α] was changed to a polyester resin (E (1): weight average molecular weight 60,000) in Example 1. The polyester resin E (1) contains a repeating structural unit represented by the above formula (A-1) and a repeating structural unit represented by the above formula (A-3), and the content of the siloxane moiety in the polyester resin is 2 % By mass. Table 5 shows the composition of the resin contained in the charge transport layer and the content of the siloxane moiety. In this case, the matrix-domain structure was not confirmed. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 8.

[Comparative Examples 9-12]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the component [α] was changed to the polyester resin (E (2): weight average molecular weight 70,000) in Example 1. The polyester resin E (2) contains a repeating structural unit represented by the above formula (A-1) and a repeating structural unit represented by the above formula (A-3), and the content of the siloxane moiety in the polyester resin is 50. % By mass. Table 5 shows the composition of the resin contained in the charge transport layer and the content of the siloxane moiety. The matrix-domain structure was confirmed. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 8.

[Comparative Examples 12 to 16]
In Example 1, the component [α] was changed to polyester resin (E (3): weight average molecular weight 100,000, terephthalic acid / isophthalic acid ratio was 1/1). Thus, an electrophotographic photosensitive member was produced. The polyester resin E (3) contains a repeating structural unit represented by the following formula (E-3), and the content of the siloxane moiety in the polyester resin is 30% by mass. Table 5 shows the composition of the resin contained in the charge transport layer and the content of the siloxane moiety. In this case, the matrix-domain structure was not confirmed. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 8.

[Comparative Examples 17-20]
In Example 1, component [α] was changed to polyester resin (E (4): weight average molecular weight 60,000, the ratio of terephthalic acid / isophthalic acid was 1/1). Thus, an electrophotographic photosensitive member was produced. The polyester resin E (4) contains a repeating structural unit represented by the following formula (E-3), and the content of the siloxane moiety in the polyester resin is 30% by mass. Table 5 shows the composition of the resin contained in the charge transport layer and the content of the siloxane moiety. The matrix-domain structure was confirmed. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 8.

[Comparative Example 21]
In Example 1, the component [β] was changed to the polyester resin E (5) having the same configuration as the polyester resin A (1) of Example 1, and the resin was only the component [α]. Similarly, an electrophotographic photosensitive member was produced. Table 5 shows the composition of the resin contained in the charge transport layer and the content of the siloxane moiety. At this time, the matrix-domain structure was not confirmed. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 8.

The “charge transport material” in Tables 3 to 4 means a charge transport material contained in the charge transport layer of the present invention. When the charge transport material is mixed and used, the type and mixing ratio of the charge transport material are shown.
“Component [α]” in Tables 3 to 4 means the configuration of the component [α].
The “siloxane content A (mass%)” in Tables 3 to 4 means the content (mass%) of the siloxane moiety in the polyester resin A.

“Component [β]” in Tables 3 to 4 means the structure of the component [β].
The “mixing ratio of component [α] and component [β]” in Tables 3 to 4 is the mixing ratio of component [α] and component [β] in the charge transport layer (component [α] / component [β]). Means.
“Siloxane content B (mass%)” in Tables 3 to 4 means the content (mass%) of the siloxane moiety in the polyester resin A with respect to the total mass of all the resins in the charge transport layer.

The “charge transport material” in Table 5 means a charge transport material contained in the charge transport layer of the present invention. When a charge transport material is mixed and used, it means the type and mixing ratio of the charge transport material.
“Resin E” in Table 5 means polyester resin E having a siloxane moiety.
“Siloxane content A (mass%)” in Table 5 means the content (mass%) of the siloxane moiety in the polyester resin E.

“Component [β]” in Table 5 means the constitution of component [β].
“Mixing ratio of resin E and component [β]” in Table 5 means a mixing ratio of polyester resin E and component [β] in the charge transport layer (resin E / component [β]).
“Siloxane content B (mass%)” in Table 5 means the content (mass%) of the siloxane moiety in the polyester resin E with respect to the total mass of all resins in the charge transport layer.

According to the comparison between the example and Comparative Examples 1 to 4, the comparative example does not contain the component [α] in the charge transport layer, so the strength is high, but the effect of stress relaxation is not obtained. This is shown by the fact that there is no torque reduction effect in the initial stage of this evaluation method and in the evaluation after 2,000 sheets.
By comparing the examples with comparative examples 5 to 8 and 13 to 16, in the comparative example, even if the charge transport layer contains a siloxane-containing resin, the Martens hardness value of the charge transport layer exceeds the range of the present invention. In some cases, sufficient contact stress mitigating effect is not obtained. This is shown by the fact that there is no torque reduction effect in the initial stage of this evaluation method and in the evaluation after 2,000 sheets. This result shows that if the content of the siloxane moiety in the component [α] is excessively reduced in order to increase the strength of the charge transport layer, a sufficient contact stress relaxation effect cannot be obtained. Therefore, it is important to design the component [α] so that the Martens hardness value satisfies the scope of the present invention.

By comparing the Examples with Comparative Examples 9 to 12 and 17 to 20, in the Comparative Example, the effect of stress relaxation can be obtained by including a siloxane-containing resin in the charge transport layer, but the charge transport layer has sufficient strength. I don't have it. This is shown by the Martens hardness value measurement and the flaw depth measurement. This result indicates that sufficient strength cannot be obtained if the content of the siloxane moiety in the component [α] is excessively increased in order to enhance the contact stress mitigating effect of the charge transport layer. Therefore, it is important to design the component [α] so that the Martens hardness value satisfies the scope of the present invention.
According to the comparison between the example and the comparative example 21, when the charge transport layer is formed only with the resin having a siloxane moiety, the stress relaxation effect can be obtained, but the charge transport layer does not have sufficient strength. It is shown.

Example 89
An aluminum cylinder having a diameter of 24 mm and a length of 246 mm was used as a support.
Next, SnO ₂ coat-treated barium sulfate (conductive particles) 10 parts, titanium oxide (resistance control pigment) 2 parts, phenol resin 6 parts, silicone oil (leveling agent) 0.001 part and methanol 4 parts / methoxypropanol A conductive layer coating solution was prepared using 16 parts of a mixed solvent.
This conductive layer coating solution was dip-coated on a support and cured (thermosetting) at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 15 μm.

Next, an intermediate layer was formed.
First, an aqueous dispersion of a polyolefin resin (Bondaine HX-8290, manufactured by Sumitomo Chemical Co., Ltd.) was synthesized by the method disclosed in Example 1 of JP-A-2009-288629.
Subsequently, 10 parts of titanium oxide (trade name: TTO55N specific gravity 4.2, manufactured by Ishihara Sangyo Co., Ltd.) and 90 parts of isopropanol (IPA) were dispersed by a ball mill for 72 hours to obtain a titanium oxide dispersion. The polyolefin resin particle dispersion was mixed with the titanium oxide dispersion so that the titanium oxide was 4.2 parts relative to 1 part of the solid content of the polyolefin resin of the polyolefin resin dispersion. Thereafter, a solvent was added so that the solvent ratio was 8/2 water / IPA and the solid content was 2.5%, and the mixture was stirred to obtain an aqueous dispersion. The produced aqueous dispersion was dip-coated on the conductive layer and dried at 100 ° C. for 30 minutes to form an intermediate layer having a thickness of 1.0 μm.

  Next, 10 parts of hydroxygallium phthalocyanine (charge generating substance) was added to a solution obtained by dissolving 5 parts of polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) in 250 parts of cyclohexanone. This was dispersed for 1 hour in an atmosphere of 23 ± 3 ° C. in a sand mill apparatus using glass beads having a diameter of 1 mm. After dispersion, a coating solution for charge generation layer was prepared by adding 250 parts of ethyl acetate. In addition, hydroxygallium phthalocyanine is 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 °, and 28.3 at a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction. It is a crystalline form with a strong peak at °.

This charge generation layer coating solution was dip-coated on the intermediate layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.26 μm.
Next, 7 parts of the charge transport material having the structure represented by the above formula (1-1) and 3 parts of the charge transport material having the structure represented by the above formula (1-2) using the same materials as in Example 21 3 parts of the polyester resin A (11) synthesized in Synthesis Example 11 as the component [α], and the repeating structure represented by the above formula (C-2) and the repeating structure represented by (C-5) as the component [β]. 7 parts of polycarbonate resin C (weight average molecular weight 80,000) contained in a ratio of 8: 2, and 0.02 parts of silica particles (average particle size 0.1 μm, trade name: Silica Doll 30G-100, manufactured by Nippon Chemical Industry Co., Ltd.) Was dissolved in a mixed solvent of 30 parts of tetrahydrofuran and 50 parts of toluene to prepare a coating solution for a charge transport layer.

The charge transport layer coating solution was dip coated on the charge generation layer and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 11 μm. It was confirmed that the formed charge transport layer contained a domain structure containing the component [α] in a matrix containing the charge transport material and the component [β].
The evaluation is the initial value and relative value of torque after repeated use of 1,000 sheets, measurement of the initial Martens hardness value of the surface layer of the photoreceptor, observation of the surface of the electrophotographic photoreceptor during torque measurement, and repeated 1,000 sheets. The drum surface was scratched after use.
As an evaluation apparatus, a laser beam printer LBP-3000 manufactured by Canon Inc. was used. The evaluation was performed in an environment at a temperature of 23 ° C. and a relative humidity of 50%.
Measurements were performed in the same manner as in Example 1. The results are shown in Table 9.

Example 90
In Example 89, electrophotography was performed in the same manner as in Example 89, except that the silica particles of the charge transport layer were changed to surface-treated silica (average particle size 0.1 μm, trade name: KMPX-100, manufactured by Shin-Etsu Chemical Co., Ltd.). Photoconductors were prepared and evaluated. The results are shown in Table 9.
Example 91
In Example 89, an electrophotographic photosensitive member was obtained in the same manner as in Example 89, except that the silica particles in the charge transport layer were changed to alumina particles (average particle size: 0.1 μm, trade name: LS-231, manufactured by Nippon Light Metal). Were made and evaluated. The results are shown in Table 9.

Example 92
In Example 89, an electrophotographic photosensitive member was produced in the same manner as in Example 89, except that the silica particles in the charge transport layer were changed to polytetrafluoroethylene particles (trade name: Lubron L2, manufactured by Daikin Corporation). ,evaluated. The results are shown in Table 9.
Example 93
In Example 89, the charge transport layer silica particles were changed to 2,6-di- (tertiary butyl) -p-cresol (BHT: manufactured by Tokyo Chemical Industry Co., Ltd.) which is a hindered phenol-based antioxidant. An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 89 except that. The results are shown in Table 9.

Example 94
An electrophotographic photoreceptor in the same manner as in Example 89 except that in Example 89, the silica particles in the charge transport layer were changed to IRGANOX 1330 (manufactured by Ciba Specialty Chemicals Co., Ltd.) which is a hindered phenol antioxidant. Were made and evaluated. The results are shown in Table 9.
Example 95
An electrophotographic photosensitive member was produced in the same manner as in Example 89 except that the silica particles in the charge transport layer were changed to TINUVIN 622LD (manufactured by Ciba Specialty Chemicals), which is a hindered amine antioxidant, in Example 89. And evaluated. The results are shown in Table 9.

Example 96
An electrophotographic photosensitive member was produced in the same manner as in Example 89 except that the silica particles in the charge transport layer were changed to TINUVIN 144 (manufactured by Ciba Specialty Chemicals), which is a hindered amine antioxidant, in Example 89. And evaluated. The results are shown in Table 9.
Example 97
In Example 89, an electrophotographic photosensitive member was produced in the same manner as in Example 89 except that the silica particles of the charge transport layer were changed to the terminal siloxane-modified polycarbonate resin described in Example 1 of Japanese Patent No. 0327816. evaluated. The results are shown in Table 9.

Example 98
In Example 89, the charge generation layer was manufactured in the same manner.
Next, 7 parts of the charge transport material having the structure represented by the above formula (1-1) and 3 parts of the charge transport material having the structure represented by the above formula (1-2) using the same materials as in Example 21 3 parts of the polyester resin A (11) synthesized in Synthesis Example 11 as the component [α], and the repeating structure represented by the above formula (C-2) and the repeating structure represented by (C-5) as the component [β] Is dissolved in a mixed solvent of 30 parts of dimethoxymethane, 45 parts of orthoxylene, and 5 parts of dipropylene glycol by dissolving 7 parts of polycarbonate resin C (weight average molecular weight 80,000) in a ratio of 8: 2. A transport layer coating solution was prepared.
This charge transport layer coating solution was dip coated on the charge generation layer and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 11 μm. It was confirmed that the formed charge transport layer contained a domain structure containing the component [α] in a matrix containing the charge transport material and the component [β]. In addition, an independent concave shape having an aperture diameter of 3 μm and a depth of 1 μm was formed on the surface of the charge transport layer.
Evaluation was performed in the same manner as in Example 89. The results are shown in Table 9.

Example 99
The surface of the electrophotographic photosensitive member of Example 21 was subjected to surface recess shape processing using the pressure contact shape transfer processing method and apparatus using a mold disclosed in Example 41 of International Publication WO2010 / 8094. An independent concave shape having an aperture diameter of 2 μm and a depth of 1 μm was formed on the processed surface.
Evaluation was performed in the same manner as in Example 89. The results are shown in Table 9.

[Examples 100 to 110]
In Examples 89 to 99, the charge transport material of the charge transport layer is composed of 9 parts of the charge transport material having the structure represented by the above formula (1-1) and the charge transport material having the structure represented by the above formula (1-2). Changed to 1 part material. Further, the component [β] is a polyester resin D (weight average molecular weight 120,000) containing a repeating structure represented by the above formula (D-1) and a repeating structure represented by (D-4) in a ratio of 5: 5. ). Except for these changes, electrophotographic photosensitive members were produced and evaluated in the same manner as in Examples 89 to 99. The results are shown in Table 9.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Axis 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Cleaning means 8 Fixing means 9 Process cartridge 10 Guide means P Transfer material

Claims (3)

In an electrophotographic photosensitive member having a support, a charge generation layer provided on the support, and a charge transport layer provided on the charge generation layer, wherein the charge transport layer is a surface layer.
The charge transport layer has a matrix-domain structure composed of a matrix containing the following component [β] and a charge transport material and a domain containing the following component [α],
The charge Martens hardness value of the transport layer, the electrophotographic photosensitive member, characterized in that at 170N / mm ² or more 210N / mm ² or less:
[Α] Polyester resin A having a repeating structural unit represented by the following formula (A) and a repeating structural unit represented by the following formula (B) and having a siloxane moiety content of 5% by mass or more and 40% by mass or less:

(In Formula (A), X ¹ represents an m-phenylene group, a p-phenylene group, or a divalent group in which two p-phenylene groups are bonded via an oxygen atom. N is a structure in parentheses. The average number of repetitions of.

(In formula (B), R ^{21 to} R ²⁴ each independently represents a hydrogen atom or a methyl group. X ² represents an m-phenylene group, a p-phenylene group, or two p-phenylene groups as an oxygen atom. (Y ² represents an ethylidene group or a propylidene group.)
[Β] Polycarbonate resin C having a repeating structural unit represented by the following formula (C), or polyester resin D having a structural unit represented by the following formula (D):

(In the formula (C), R ^{31 to} R ³⁴ each independently represent a hydrogen atom or a methyl group. Y ³ represents an ethylidene group, a propylidene group, a phenylethylidene group, a cyclohexylidene group, or an oxygen atom. .)

(In formula (D), R ^{41 to} R ⁴⁴ each independently represents a hydrogen atom or a methyl group. X ⁴ represents an m-phenylene group, a p-phenylene group, or two p-phenylene groups as an oxygen atom. (Y ⁴ represents a single bond, an ethylidene group, or a propylidene group.)   The electrophotographic photosensitive member according to claim 1 and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means are integrally supported and detachable from the main body of the electrophotographic apparatus. A process cartridge characterized by that.   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an exposure unit, a developing unit, and a transfer unit.

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