JP6949619B2 - Electrophotographic photosensitive members, process cartridges and electrophotographic equipment - Google Patents

Description

Related to electrophotographic photosensitive members, process cartridges and electrophotographic devices.

In recent years, the environment for outputting printers has diversified, and opportunities for printing in low humidity environments are increasing. In any environment, it is desired that the output image has a constant density and character quality. However, in a low humidity environment, the sensitivity of the electrophotographic photosensitive member (hereinafter, also referred to as a photosensitive member) becomes low, and character thinning may occur (Patent Document 1).

Patent Document 2 describes as a charge generating substance a titanyl phthalocyanine pigment (hereinafter, also referred to as Y-type TiOPc) having a maximum peak at a Bragg angle (2θ ± 0.2) of 27.3 ° in a powder X-ray diffraction spectrum. The photoconductor used is disclosed. In this case, although there is an advantage of high sensitivity, it is disclosed that the humidity influence of the sensitivity is large, and when the humidity is lowered, the amount of water taken up in the pigment is lowered and the sensitivity is lowered. Further, Patent Document 3 also discloses that the photoconductor using Y-type TiOPc deteriorates in chargeability with repeated use.

In response to the above problem, Patent Document 4 attempts to suppress the influence of humidity with Y-type TiOPc in which compounds for crystal type conversion are incorporated.
Further, in Patent Documents 5 and 6, when a resin having a specific structure is used for the photosensitive layer, the initial responsiveness is obtained in a low temperature and low humidity environment of 5 ° C./10% RH and a normal temperature and humidity environment of 23 ° C./50% RH. It is disclosed that it is excellent.

Japanese Unexamined Patent Publication No. 2005-221339 Japanese Unexamined Patent Publication No. 2014-197187 Japanese Unexamined Patent Publication No. 2015-92238 Japanese Patent No. 5900547 Japanese Unexamined Patent Publication No. 2003-82078 Japanese Unexamined Patent Publication No. 2005-189716

However, in the study by the present inventors, the photoconductor described in Patent Document 4 could not maintain the effect that the influence of humidity on the sensitivity was small for a long period of time. Further, even with the configurations described in Patent Documents 5 and 6, high sensitivity could not be maintained for a long period of time.

Therefore, an object of the present invention is to provide a highly sensitive electrophotographic photosensitive member in which the influence of a low humidity environment on sensitivity is small over a long period of time. Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member.

（一般式（Ｉ）において、Ｘ^１は、２価の基を表す。）

（一般式（ＩＩ）において、Ｘ^２は、単結合、酸素原子、２価のアルキレン基又は２価のシクロアルキレン基を表す。Ｒ^１１〜Ｒ^１８は、それぞれ独立に、水素原子又はアルキル基を表す。）

（一般式（ＩＩ−１）において、Ｒ^２１は、水素原子、メチル基、エチル基又はフェニル基を表す。Ｒ^２２は、メチル基又はエチル基を表す。Ｒ^２３は、炭素数１〜４のアルキル基を表す。Ｒ^２４〜Ｒ^２７は、それぞれ独立に、水素原子又はメチル基を表す。ｍは、括弧内のＣＨ _２ の繰り返し数を表し、０〜３の整数である。）

（一般式（ＩＩ−３）において、Ｒ ^２３１ 〜Ｒ ^２３４ は、それぞれ独立に、水素原子、メチル基又はエチル基を表す。） The above object is achieved by the following invention. That is, the electrophotographic photosensitive member according to the present invention includes a support, a charge generating layer containing a charge generating substance and a resin, and a charge transporting layer containing the charge transporting substance and the resin and adjacent to the charge generating layer. And, in this order, an electrophotographic photosensitive member.
Charge generation layer, a charge generating material, our Keru Bragg angle X-ray diffraction by CuKα-ray (2θ ± 0.2) is contained oxytitanium phthalocyanine showing a peak at 27.3 °,
Charge transport layer further contains a compound represented by the compound or the following formula represented by the following formula (P -2) (P-3 ),
The resin charge transport layer contains is a resin having the structure represented by the structure and the following general formula represented by the following general formula (I) (II), the resin of the charge transport layer contains the following as the structure represented by formula (II), which is an electrophotographic photosensitive member characterized by having a structure represented by the general formula structure and the following general formula represented by (II-1) (II- 3).

(In general formula (I), X ¹ represents a divalent group.)

(In the general formula (II), ^{X 2} represents a single bond, an oxygen atom, a divalent alkylene group or a divalent cycloalkylene group table to ^.R 11 ^{to R 18,} each independently, a hydrogen atom or Table to an alkyl group.)

(In the general formula ^{(II-1), R 21} is ^{.R 22} represents a hydrogen atom, a methyl group, an ethyl group or phenyl group, ^{.R 23} representing the ethyl group or methyl group, 1 to carbon atoms Table to ^.R 24 ^{to R 27} the alkyl groups of 4 each independently, also hydrogen atoms .m represents methyl group, and display the number of repetitions of CH ₂ in parenthesis, an integer from 0 to 3 .)

(In the general formula (II-3), R ^{231 to} R ²³⁴ independently represent a hydrogen atom, a methyl group, or an ethyl group.)

Further, the process cartridge according to the present invention integrally supports the electrophotographic photosensitive member and at least one means selected from the group consisting of charging means, developing means, transfer means, and cleaning means, and is an electrophotographic apparatus. The feature is that it can be attached to and detached from the main body.

Further, the electrophotographic apparatus of the present invention is characterized by having the electrophotographic photosensitive member, charging means, exposure means, developing means and transfer means.

According to the present invention, it is an object of the present invention to provide an electrophotographic photosensitive member which has high sensitivity in a low humidity environment and whose decrease in sensitivity is suppressed even after repeated use in a low humidity environment or after being left for a long period of time. Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member.

It is a figure which shows an example of the schematic structure of the electrophotographic apparatus including the process cartridge.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments.
As a result of the examination by the present inventors, it was found that the prior art has a technical problem that the influence on the sensitivity of the low humidity environment is insufficient in the initial stage and the long term.
In order to solve the above technical problems, by paying attention to the combination of photoconductor materials and selecting an appropriate material, it may be possible for the charge generating substance to achieve stable interaction with water over a long period of time. Thought. Specifically, in order for the charge generating substance to maintain water content in any environment, it is necessary to form hydrogen bonds around it and retain water reliably. An attempt was made to solve the above problem.
As a result of the examination, the charge transport layer was a charge transport layer containing a compound represented by the formula (P-2) or a compound represented by the formula (P-3) and a resin, and Y-type TiOPc was added to the charge generation layer. It was found that the technical problem that has occurred in the prior art can be solved by adopting the photoconductor configuration including the photoconductor.

（一般式（Ｉ）において、Ｘ^１は、２価の基を表す。）

（一般式（ＩＩ）において、Ｘ^２は、単結合、酸素原子、２価のアルキレン基又は２価のシクロアルキレン基を表す。Ｒ^１１〜Ｒ^１８は、それぞれ独立に、水素原子又はアルキル基を表す。）

（一般式（ＩＩ−１）において、Ｒ^２１は、水素原子、メチル基、エチル基又はフェニル基を表す。Ｒ^２２は、メチル基又はエチル基を表す。Ｒ^２３は、炭素数１〜４のアルキル基を表す。Ｒ^２４〜Ｒ^２７は、それぞれ独立に、水素原子又はメチル基を表す。ｍは、括弧内のＣＨ _２ の繰り返し数を表し、０〜３の整数である。）

（一般式（ＩＩ−３）において、Ｒ ^２３１ 〜Ｒ ^２３４ は、それぞれ独立に、水素原子、メチル基又はエチル基を表す。） Specifically, the configuration of the photoconductor according to the present invention is as follows. An electrophotographic photosensitive member having a support, a charge generating layer containing a charge generating substance and a resin, and a charge transporting layer containing a charge transporting substance and a resin and adjacent to the charge generating layer in this order. hand,
Charge generation layer, a charge generating material, our Keru Bragg angle X-ray diffraction by CuKα-ray (2θ ± 0.2) is contained oxytitanium phthalocyanine showing a peak at 27.3 °,
Charge transport layer further contains a compound represented by the compound or the following formula represented by the following formula (P -2) (P-3 ),
The resin charge transport layer contains is a resin having the structure represented by the structure and the following general formula represented by the following general formula (I) (II), the resin of the charge transport layer contains the following as the structure represented by formula (II), which is an electrophotographic photosensitive member characterized by having a structure represented by the general formula structure and the following general formula represented by (II-1) (II- 3).

(In general formula (I), X ¹ represents a divalent group.)

(In the general formula (II), ^{X 2} represents a single bond, an oxygen atom, a divalent alkylene group or a divalent cycloalkylene group table to ^.R 11 ^{to R 18,} each independently, a hydrogen atom or Table to an alkyl group.)

(In the general formula ^{(II-1), R 21} is ^{.R 22} represents a hydrogen atom, a methyl group, an ethyl group or phenyl group, ^{.R 23} representing the ethyl group or methyl group, 1 to carbon atoms Table to ^.R 24 ^{to R 27} the alkyl groups of 4 each independently, also hydrogen atoms .m represents methyl group, and display the number of repetitions of CH ₂ in parenthesis, an integer from 0 to 3 .)

(In the general formula (II-3), R ^{231 to} R ²³⁴ independently represent a hydrogen atom, a methyl group, or an ethyl group.)

The present inventors presume a mechanism capable of solving the above technical problems with such a configuration as follows.
Since the resin of the charge transport layer in the present invention has a large substituent in a part of the bisphenol structure, it has an action of making it difficult for the alkoxycarbonyl groups to aggregate with each other in the resin or between the resins. Therefore, it is presumed that the alkoxycarbonyl base is uniformly present in the membrane, and it is considered that the number of points where the alkoxycarbonyl base can interact with the water existing in the vicinity of the charge generating substance in the lower charge generating layer increases. .. As a result, as described in Patent Document 2, the decrease in humidity and the decrease in the amount of water taken up are suppressed by the interaction shown above, and the sensitivity is stabilized for a long period of time. Further, since the compound represented by the formula (P-2) or the compound represented by the formula (P-3) has a bulky substituent, the alkoxycarbonyl group portion in the resin of the charge transport layer is more aggregated. It becomes difficult.
On the other hand, it is represented by a case containing a resin having an alkoxycarbonyl group other than the resin having the charge transport layer according to the present invention, a compound represented by the formula (P-2) , or a compound represented by the formula (P-3). When no compound is contained, the alkoxycarbonyl base tends to aggregate. Therefore, it is presumed that the points that can interact with water in the vicinity of the charge generating substance are reduced, and the effect of the present invention cannot be obtained.

Further, even when a charge generating substance other than the charge generating substance according to the present invention is used, the effect of the present application cannot be obtained. The reason for this is that the stability of the charge generating substance itself is low in long-term use, so that the problem to be solved by the present invention cannot be solved by the interaction between the resin of the charge transport layer and the water content of the charge generating layer. I'm guessing.
As in the above estimation mechanism, the effects of the present invention can be achieved by synergistically exerting effects on each other.

[Electrophotophotoreceptor]
The electrophotographic photosensitive member according to the present invention is characterized by having a charge generation layer and a charge transport layer immediately above the charge generation layer on the support.

Examples of the method for producing the electrophotographic photosensitive member according to the present invention include a method in which a coating liquid for each layer described later is prepared, applied in the order of desired layers, and dried. At this time, examples of the coating liquid coating method include immersion coating, spray coating, inkjet coating, roll coating, die coating, blade coating, curtain coating, wire bar coating, and ring coating. Among these, dip coating is preferable from the viewpoint of efficiency and productivity.

Hereinafter, the support and each layer will be described.
<Support>
In the present invention, the electrophotographic photosensitive member has a support. In the present invention, the support is preferably a conductive support having conductivity. Further, examples of the shape of the support include a cylindrical shape, a belt shape, a sheet shape, and the like. Above all, a cylindrical support is preferable. Further, the surface of the support may be subjected to an electrochemical treatment such as anodic oxidation, a blast treatment, a cutting treatment or the like.
As the material of the support, metal, resin, glass and the like are preferable.
Examples of the metal include aluminum, iron, nickel, copper, gold, stainless steel, and alloys thereof. Above all, it is preferable that the support is made of aluminum using aluminum.
Further, the resin or glass may be imparted with conductivity by a treatment such as mixing or coating a conductive material.

<Conductive layer>
In the present invention, a conductive layer may be provided on the support. By providing the conductive layer, it is possible to conceal scratches and irregularities on the surface of the support and control the reflection of light on the surface of the support.
The conductive layer preferably contains conductive particles and a resin.

Examples of the material of the conductive particles include metal oxides, metals, and carbon black.
Examples of the metal oxide include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, magnesium oxide, antimony oxide, and bismuth oxide. Examples of the metal include aluminum, nickel, iron, nichrome, copper, zinc, silver and the like.
Among these, it is preferable to use a metal oxide as the conductive particles, and it is more preferable to use titanium oxide, tin oxide, and zinc oxide.

When a metal oxide is used as the conductive particles, the surface of the metal oxide may be treated with a silane coupling agent or the like, or the metal oxide may be doped with an element such as phosphorus or aluminum or an oxide thereof.
Further, the conductive particles may have a laminated structure having core material particles and a coating layer covering the particles. Examples of the core material particles include titanium oxide, barium sulfate, zinc oxide and the like. Examples of the coating layer include metal oxides such as tin oxide.
When a metal oxide is used as the conductive particles, its volume average particle size is preferably 1 nm or more and 500 nm or less, and more preferably 3 nm or more and 400 nm or less.

Examples of the resin include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, and alkyd resin.
Further, the conductive layer may further contain a hiding agent such as silicone oil, resin particles, and titanium oxide.
The average film thickness of the conductive layer is preferably 1 μm or more and 50 μm or less, and particularly preferably 3 μm or more and 40 μm or less.

The conductive layer can be formed by preparing a coating liquid for a conductive layer containing each of the above-mentioned materials and a solvent, forming this coating film, and drying it. Examples of the solvent used for the coating liquid include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents and the like. Examples of the dispersion method for dispersing the conductive particles in the coating liquid for the conductive layer include a method using a paint shaker, a sand mill, a ball mill, and a liquid collision type high-speed disperser.

<Underlay layer>
An undercoat layer may be provided on the support or the conductive layer. By providing the undercoat layer, the adhesive function between the layers is enhanced, and the charge injection blocking function can be imparted.
The undercoat layer preferably contains a resin. Further, an undercoat layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group.

Resins include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, polyvinylphenol resin, alkyd resin, polyvinyl alcohol resin, polyethylene oxide resin, polypropylene oxide resin, and polyamide resin. , Polyamic acid resin, polyimide resin, polyamideimide resin, cellulose resin and the like.

The polymerizable functional group of the monomer having a polymerizable functional group includes an isocyanate group, a blocked isocyanate group, a methylol group, an alkylated methylol group, an epoxy group, a metal alkoxide group, a hydroxyl group, an amino group, a carboxyl group and a thiol group. Examples thereof include a carboxylic acid anhydride group and a carbon-carbon double bond group.

Further, the undercoat layer may further contain an electron transporting substance, a metal oxide, a metal, a conductive polymer, or the like for the purpose of enhancing the electrical characteristics. Among these, it is preferable to use an electron transporting substance and a metal oxide.

Examples of the electron transporting substance include quinone compounds, imide compounds, benzimidazole compounds, cyclopentadienylidene compounds, fluorenone compounds, xanthone compounds, benzophenone compounds, cyanovinyl compounds, aryl halide compounds, silol compounds, and boron-containing compounds. ..

An undercoat layer may be formed as a cured film by using an electron transporting substance having a polymerizable functional group as the electron transporting substance and copolymerizing it with the above-mentioned monomer having a polymerizable functional group.

Examples of the metal oxide include indium tin oxide, tin oxide, indium oxide, titanium oxide, zinc oxide, aluminum oxide, silicon dioxide and the like. Examples of the metal include gold, silver and aluminum.

Further, the undercoat layer may further contain an additive.
The average film thickness of the undercoat layer is preferably 0.1 μm or more and 50 μm or less, more preferably 0.2 μm or more and 40 μm or less, and particularly preferably 0.3 μm or more and 30 μm or less.
The undercoat layer can be formed by preparing a coating liquid for an undercoat layer containing each of the above-mentioned materials and solvents, forming this coating film, and drying and / or curing. Examples of the solvent used for the coating liquid include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and the like.

<Photosensitive layer>
The photosensitive layer of the electrophotographic photosensitive member has a charge generating layer and a charge transporting layer immediately above the charge generating layer.

(Charge generation layer)
The charge generating layer preferably contains a charge generating substance and a resin.
The charge generating substance includes oxytitanium phthalocyanine, which shows a strong peak at a Bragg angle (2θ ± 0.2) of 27.3 ° in X-ray diffraction with CuKα rays.
The content of the charge generating substance in the charge generating layer is preferably 40% by mass or more and 85% by mass or less, and more preferably 50% by mass or more and 70% by mass or less with respect to the total mass of the charge generating layer. preferable.
Resins include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, polyvinyl alcohol resin, cellulose resin, polystyrene resin, polyvinyl acetate resin, and polyvinyl chloride. Examples include resin. Among these, polyvinyl acetal resin is preferable. Further, a polyvinyl acetal resin having an acetalization degree of 70 mol% or more and 90 mol% or less is preferable. It is considered that the reason for this is that since the polarity of the resin is lowered, the points where the resin in the charge transport layer directly above can directly interact with the water in the vicinity of the charge generating material are increased. Hydroxyl groups and water in the polyvinyl acetal resin also interact with each other, but since the resin is soft, it is considered difficult to maintain it stably for a long period of time. Specific examples thereof include KS10, KS1, KS3, and KS5 manufactured by Sekisui Chemical Co., Ltd., and MobileB30HH, MobileB60HH, and PioformBL16 manufactured by Kuraray Co., Ltd.

Further, as long as the effects of the present invention are satisfied, other charge generating substances include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, oxytitanium phthalocyanine pigments, chlorogallium phthalocyanine pigments, and hydroxygallium phthalocyanine pigments. May be good. Further, additives such as an antioxidant and an ultraviolet absorber may be further contained. Specific examples thereof include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, and benzophenone compounds.

The average film thickness of the charge generation layer is preferably 0.1 μm or more and 1 μm or less, and more preferably 0.15 μm or more and 0.4 μm or less.
The charge generation layer can be formed by preparing a coating liquid for a charge generation layer containing each of the above-mentioned materials and a solvent, forming the coating film, and drying the coating film. Examples of the solvent used for the coating liquid include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents and the like.

Examples of the dispersion method include a case where the charge generating substance is dispersed in the solvent and then the resin is added, and a method in which the charge generating substance is dispersed at the same time. When dispersed at the same time, the sensitivity stabilizes for a longer period of time. The reason for this is that the resin tends to exist near the charge generating substance and interacts with water in a more stable state.

（一般式（Ｐ）において、Ｗ^１は置換基としてカルボニルオキシ基を有してもよいアルキル基を表す。）

（一般式（Ｉ）において、Ｘ^１は、２価の基を表す。）

（一般式（ＩＩ）において、Ｘ^２は、単結合、酸素原子、２価のアルキレン基または２価のシクロアルキレン基を示す。Ｒ^１１〜Ｒ^１８は、それぞれ独立に水素原子またはアルキル基を示す。） (Charge transport layer)
The charge transport layer has a compound represented by the general formula (P), a resin having a structure represented by the general formula (I) and a structure represented by the general formula (II), and a charge transport substance.

(In the general formula (P), W ¹ represents an alkyl group which may have a carbonyloxy group as a substituent.)

(In general formula (I), X ¹ represents a divalent group.)

(In the general formula (II), X ² represents a single bond, an oxygen atom, a divalent alkylene group or a divalent cycloalkylene group. R ^{11 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group. .)

（一般式（ＩＩ−１）において、Ｒ^２１は、水素原子、メチル基、エチル基、フェニル基を表す。Ｒ^２２は、メチル基、エチル基を表す。Ｒ^２３は、炭素数１〜４のアルキル基を示す。Ｒ^２４〜Ｒ^２７は、それぞれ独立に水素原子またはメチル基を表す。ｍは、括弧内の繰り返し数を示し、０〜３の整数である。）

（式（ＩＩ−２）中、Ｒ^２２１、Ｒ^２２２はそれぞれ独立に水素原子、メチル基またはエチル基を示す。Ｒ^２２３〜Ｒ^２２６は、それぞれ独立に水素原子またはメチル基を表す。ｐは８〜１１の整数を表す。） Further, the structure represented by the general formula (II) has a structure represented by the general formula (II-1) or the general formula (II-2).

(In the general formula (II-1), R ²¹ represents a hydrogen atom, a methyl group, an ethyl group, and a phenyl group. R ²² represents a methyl group and an ethyl group. R ²³ has 1 to 4 carbon atoms. Indicates an alkyl group. R ^{24 to} R ²⁷ each independently represent a hydrogen atom or a methyl group. M indicates the number of repetitions in parentheses and is an integer of 0 to 3.)

(In formula (II-2), R ²²¹ and R ²²² independently represent a hydrogen atom, a methyl group or an ethyl group ^{, respectively. R 223 to} R ²²⁶ independently represent a hydrogen atom or a methyl group, respectively. P is 8 Represents an integer of ~ 11.

The ratio of the structure represented by the general formula (II-1) or the general formula (II-2) to the structure represented by the general formula (II) is preferably 30 mol% or more.

Specifically, as the structure represented by the general formula (I), it is more preferable to have at least one selected from the structures represented by the following formulas (I-1) to (I-4). In particular, it is more preferable to have at least the structure represented by the formula (I-1). It is considered that the reason for this is that having an ether structure further enhances the interaction with water in the vicinity of the charge generating substance.
From the viewpoint of coatability, the weight average molecular weight of the resin having the structure represented by the general formula (I) and the structure represented by the general formula (II) of the present invention is 50,000 or more and 150,000 or less. preferable.

It is considered that the resin having the structure represented by the general formula (II) has a bulky group, so that the alkoxycarbonyl group portion becomes more uniform, and thus the interaction with the water in the vicinity of the charge generating substance is further enhanced. Specific examples of the general formula (II-1) are shown in the following formulas (II-1-1) to (II-1-6). In particular, a resin having the structure of the formula (II-1-1) is preferable because the sensitivity is more stable over a long period of time.

Next, specific examples of the general formula (II-2) are shown in the following formulas (II-2-1) to (II-2-3). In particular, a resin having the structure of the formula (II-2-1) is preferable because the sensitivity is more stable over a long period of time.

（式（ＩＩ−３）中、Ｒ^２３１〜Ｒ^２３４はそれぞれ独立に水素原子、メチル基またはエチル基を表す。）

Further, it may have a structure represented by the general formula (II) other than the structure represented by the formula (II-1) or (II-2). In particular, the resins having the structures of the formulas (II-3-1), (II-3-2), and (II-3-3) having the structures represented by the following formulas (II-3) have long-term sensitivity. Is preferable from the viewpoint of stability. The reason is that since there is a tough biphenyl moiety, the alkoxycarbonyl base homogenized by the above general formula (II-1) and general formula (II-2) is hard to aggregate and continues to exist stably. Therefore, it is considered that the alkoxycarbonyl base can be uniformly and stably existed for a long period of time.

(In formula (II-3), R ^{231 to} R ²³⁴ independently represent a hydrogen atom, a methyl group, or an ethyl group.)

Other structures represented by the general formula (II) include structures represented by the following formulas (II-4-1) to (II-4-8).

（式（Ｑ）中、Ｒ^４１及びＲ^４３は、メチル基、エチル基、置換基を有してもよいアルケニル基、置換基を有してもよいアリール基を表し、該置換基はメチル基、エチル基またはフェニル基である。ｓ及びｔは１または２の整数を表す。Ｒ^４２及びＲ^４４はそれぞれ独立に置換基を有してもよいアリール基、置換基を有してもよいアルケニル基を表し、該置換基はメチル基、エチル基またはフェニル基である。） Examples of the charge transporting substance include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from these substances. Be done. Among these, a benzidine compound is preferable. In particular, a charge transporting substance having a structure represented by the general formula (Q) is preferable from the viewpoint of stabilizing the sensitivity over a long period of time. It is considered that the reason is that the presence of the tough charge transporting substance allows the alkoxycarbonyl base in the resin to be uniformly and stably present for a long period of time.

(In the formula (Q), R ⁴¹ and R ⁴³ represent a methyl group, an ethyl group, an alkenyl group which may have a substituent, and an aryl group which may have a substituent, and the substituent is a methyl group. , Ethyl group or phenyl group. S and t represent an integer of 1 or 2. R ⁴² and R ⁴⁴ may independently have an aryl group and an alkenyl group which may have a substituent. Represents a group, the substituent being a methyl group, an ethyl group or a phenyl group.)

The specific structure represented by the general formula (Q) is given below.

Other charge transport materials are listed below.

The content of the charge-transporting substance in the charge-transporting layer is preferably 25% by mass or more and 80% by mass or less, and more preferably 30% by mass or more and 55% by mass or less with respect to the total mass of the charge-transporting layer. preferable.

Other polyester resin, polycarbonate resin, acrylic resin, polystyrene resin and the like may be contained as long as the effects of the present invention are satisfied. Among these, other polyester resins are preferable. As the polyester resin, a polyarylate resin is particularly preferable.

（一般式（Ｐ）において、Ｗ^１は置換基としてカルボニルオキシ基を有してもよいアルキル基を表す。）
電荷輸送層中の一般式（Ｐ）で示される化合物の含有量は、電荷輸送層の全質量に対して、１質量％以上２０質量％以下であることが好ましく、３質量％以上１０質量％以下であることがより好ましい。 Further, in the present invention, the sensitivity is stabilized for a long period of time by containing the compound represented by the general formula (P) in the charge transport layer.

(In the general formula (P), W ¹ represents an alkyl group which may have a carbonyloxy group as a substituent.)
The content of the compound represented by the general formula (P) in the charge transport layer is preferably 1% by mass or more and 20% by mass or less, and 3% by mass or more and 10% by mass, based on the total mass of the charge transport layer. The following is more preferable.

The specific structure is shown below.

Further, additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a leveling agent, a slipper-imparting agent, and an abrasion resistance improving agent may be contained as long as the effects of the present invention are satisfied. Specifically, hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, boron nitride particles. Etc. may be contained.

The average film thickness of the charge transport layer is preferably 5 μm or more and 50 μm or less, more preferably 8 μm or more and 40 μm or less, and particularly preferably 10 μm or more and 30 μm or less.

The charge transport layer can be formed by preparing a coating liquid for a charge transport layer containing each of the above-mentioned materials and a solvent, forming the coating film, and drying the coating film.

Examples of the solvent used for the coating liquid include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Among these solvents, ketone solvents and ether solvents are preferable because their sensitivities are stable over a long period of time. Furthermore, it is more preferable to use at least one selected from cyclic ethers and cyclic ketones.

Specific examples thereof include tetrahydrofuran, cyclopentanone, cyclohexanone and the like. It is considered that the reason is that the ether bond portion and the ketone bond portion in the residual solvent participate in the interaction with the water in the vicinity of the charge generating substance. The total content of the cyclic ether or cyclic ketone in the charge transport layer is preferably 0.02% by mass or more and 2.0% by mass or less.

<Protective layer>
In the present invention, a protective layer may be provided on the photosensitive layer. Durability can be improved by providing a protective layer.
The protective layer preferably contains conductive particles and / or charge transporting material and a resin.
Examples of the conductive particles include particles of metal oxides such as titanium oxide, zinc oxide, tin oxide, and indium oxide.
Examples of the charge transporting substance include a polycyclic aromatic compound, a heterocyclic compound, a hydrazone compound, a styryl compound, an enamine compound, a benzidine compound, a triarylamine compound, and a resin having a group derived from these substances. Among these, triarylamine compounds and benzidine compounds are preferable.
Examples of the resin include polyester resin, acrylic resin, phenoxy resin, polycarbonate resin, polystyrene resin, phenol resin, melamine resin, epoxy resin and the like. Of these, polycarbonate resin, polyester resin, and acrylic resin are preferable.

Further, the protective layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group. Examples of the reaction at that time include a thermal polymerization reaction, a photopolymerization reaction, and a radiation polymerization reaction. Examples of the polymerizable functional group contained in the monomer having a polymerizable functional group include an acrylic group and a methacrylic group. As the monomer having a polymerizable functional group, a material having a charge transporting ability may be used.

The protective layer may contain additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a leveling agent, a slipper-imparting agent, and an abrasion resistance improver. Specifically, hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, boron nitride particles. And so on.

The average film thickness of the protective layer is preferably 0.5 μm or more and 10 μm or less, and preferably 1 μm or more and 7 μm or less.
The protective layer can be formed by preparing a coating liquid for a protective layer containing each of the above-mentioned materials and solvents, forming this coating film, and drying and / or curing it. Examples of the solvent used for the coating liquid include alcohol-based solvents, ketone-based solvents, ether-based solvents, sulfoxide-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.

[Process cartridge, electrophotographic equipment]
The process cartridge of the present invention integrally supports the electrophotographic photosensitive member described above and at least one means selected from the group consisting of charging means, developing means, transfer means and cleaning means, and is an electrophotographic apparatus. The feature is that it can be attached to and detached from the main body.

Further, the electrophotographic apparatus of the present invention is characterized by having the electrophotographic photosensitive member, charging means, exposure means, developing means and transfer means described above.

FIG. 1 shows an example of a schematic configuration of an electrophotographic apparatus having a process cartridge including an electrophotographic photosensitive member.
Reference numeral 1 denotes a cylindrical electrophotographic photosensitive member, which is rotationally driven at a predetermined peripheral speed in the direction of an arrow about a shaft 2. The surface of the electrophotographic photosensitive member 1 is charged to a predetermined positive or negative potential by the charging means 3. Although the roller charging method using the roller type charging member is shown in the figure, a charging method such as a corona charging method, a proximity charging method, or an injection charging method may be adopted. The surface of the charged electrophotographic photosensitive member 1 is irradiated with exposure light 4 from an exposure means (not shown) to form an electrostatic latent image corresponding to the target image information. The electrostatic latent image formed on the surface of the electrophotographic photosensitive member 1 is developed with the toner contained in the developing means 5, and the toner image is formed on the surface of the electrophotographic photosensitive member 1. The toner image formed on the surface of the electrophotographic photosensitive member 1 is transferred to the transfer material 7 by the transfer means 6. The transfer material 7 to which the toner image is transferred is conveyed to the fixing means 8, undergoes the fixing process of the toner image, and is printed out of the electrophotographic apparatus. The electrophotographic apparatus may have a cleaning means 9 for removing deposits such as toner remaining on the surface of the electrophotographic photosensitive member 1 after transfer. Further, a so-called cleanerless system may be used in which the above-mentioned deposits are removed by a developing means or the like without separately providing a cleaning means. The electrophotographic apparatus may have a static elimination mechanism for statically eliminating the surface of the electrophotographic photosensitive member 1 with preexposure light 10 from a preexposure means (not shown). Further, in order to attach / detach the process cartridge 11 of the present invention to / from the main body of the electrophotographic apparatus, a guide means 12 such as a rail may be provided.

The electrophotographic photosensitive member of the present invention can be used for laser beam printers, LED printers, copiers, facsimiles, and multifunction devices thereof.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. In the description of the following examples, the term "part" is based on mass unless otherwise specified.
The following Examples 1 to 17, 19, 21, and 24 are reference examples.

をジクロロメタンに溶解させ、酸ハロゲン化物溶液を調製した。また、別途、下記式（２）で示されるジオール１９．７ｇと下記式（３）で示されるジオール１８．５ｇと

を１０％水酸化ナトリウム水溶液に溶解させ、重合触媒としてトリブチルベンジルアンモニウムクロライドを添加して攪拌し、ジオール化合物溶液を調製した。 [Synthesis Example 1: Synthesis of Resin A]
Resin A was synthesized by the following method.
Dicarboxylic acid halide 26.2g represented by the following formula (1)

Was dissolved in dichloromethane to prepare an acid halide solution. Separately, 19.7 g of the diol represented by the following formula (2) and 18.5 g of the diol represented by the following formula (3)

Was dissolved in a 10% aqueous sodium hydroxide solution, tributylbenzylammonium chloride was added as a polymerization catalyst, and the mixture was stirred to prepare a diol compound solution.

Next, the acid halide solution was added to the diol compound solution with stirring to initiate polymerization. The polymerization was carried out for 3 hours with stirring while keeping the reaction temperature at 25 ° C. or lower. During the polymerization reaction, p-talshal butylphenol was added as a polymerization modifier. Then, the polymerization reaction was terminated by adding acetic acid, and washing with water was repeated until the aqueous phase became neutral. After washing, the dichloromethane solution was added dropwise to methanol under stirring to precipitate the polymer, and the polymer was vacuum dried to obtain 65.8 g of resin A. The obtained resin A has a partial structure represented by the formula (I-2), a partial structure represented by the formula (II-1-1), and a partial structure represented by the formula (II-4-3). It was a resin to have. The weight average molecular weight of the obtained resin A was 110,000.

[Synthesis Examples 2 to 17]
Resins B to Q shown in Table 1 were produced in the same manner as in Synthesis Example 1 except that the types and amounts of the dicarboxylic acid compounds and diols used in the synthesis were changed.

表１において、樹脂の重量平均分子量は、樹脂のポリスチレン換算重量平均分子量（Ｍｗ）を示す。

In Table 1, the weight average molecular weight of the resin indicates the polystyrene-equivalent weight average molecular weight (Mw) of the resin.

The ratio of the structure contained in the resin in the charge transport layer can be analyzed by a general analysis method. Further, the content of the resin of the present invention with respect to the total mass of the total resin in the charge transport layer can be analyzed by a general analysis method. An example of the analysis method is shown below.
First, the charge transport layer of the electrophotographic photosensitive member is dissolved with a solvent. After that, various materials contained in the charge transport layer are separated by a sorting device capable of separating and recovering each composition component such as size exclusion chromatography and high performance liquid chromatography. Nuclear magnetic resonance spectrum analysis and mass spectrometry are performed on the separated resin to calculate the number of structural repetitions and the molar ratio.
Alternatively, it is hydrolyzed in the presence of an alkali or the like to decompose into a carboxylic acid moiety and a bisphenol moiety. Nuclear magnetic resonance spectrum analysis and mass spectrometry are performed on the obtained bisphenol moiety to calculate the number of structural repetitions and the molar ratio.

<Manufacturing of electrophotographic photosensitive member>
(Example 1)
A cylinder made of an aluminum alloy having an outer diameter of 30 mm, a length of 260.5 mm, and a wall thickness of 0.75 mm whose surface was roughly cut was subjected to anodization treatment.
After that, the pores were sealed with a sealing agent containing nickel acetate as a main component to form an anodized film (anodized film) of about 6 μm, which was used as a support (conductive support).

Charge generation layer:
10 parts of Y-type oxytitanium phthalocyanine crystal (Y-type TiOPc) and 4-methoxy-4-that have a strong peak at 27.3 ° of Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction as a charge generating substance. Methylpentanone-2 150 parts were prepared. These were placed in a sand mill using glass beads having a diameter of 1 mm, and pulverized and dispersed by a sand grind mill for 1.5 hours.
Next, add 5 parts of polyacetal resin (trade name: Eslek BX-1, manufactured by Sekisui Chemical Co., Ltd., acetalization degree of about 66 mol%) to 100 parts of 4-methoxy-4-methylpentanone-2 in advance and dissolve. 105 parts of the prepared solution was added. Then, it was dispersed for 0.5 hours (hereinafter, also referred to as post-addition).
Then, 250 parts of 1,2-dimethoxyethane was added to prepare a coating liquid for a charge generation layer.
This coating liquid for a charge generating layer was immersed and coated on a support, and the obtained coating film was dried at 100 ° C. for 10 minutes to form a charge generating layer having a film thickness of 0.15 μm.

The X-ray diffraction measurement of the oxytitanium phthalocyanine crystal was performed under the following conditions.
[Powder X-ray diffraction measurement]
Measuring machine used: X-ray diffractometer RINT-TTRII manufactured by Rigaku Denki Co., Ltd.
X-ray tube: Cu
Tube voltage: 50KV
Tube current: 300mA
Scan method: 2θ / θ scan Scan speed: 4.0 ° / min
Sampling interval: 0.02 °
Start angle (2θ): 5.0 °
Stop angle (2θ): 40.0 °
Attachment: Standard Sample Holder Filter: Unused Incident Monochromator: Used Counter Monochromator: Unused Divergence Slit: Open Divergence Vertical Limit Slit: 10.00 mm
Scattering slit: Open light receiving slit: Open flat plate Monochromator: Used counter: Scintillation counter

Charge transport layer (surface layer):
5 parts of the amine compound represented by the above formula (T-1) as a charge transporting substance,
10 parts of the resin A obtained in Synthesis Example 1 and 0.3 parts of the compound represented by the above formula (P-2) (BASF Japan Ltd., trade name: Irganox 1076) were prepared as additives.
A coating liquid for a charge transport layer was prepared by dissolving these in a mixed solvent of 50 parts of methylal and 50 parts of chlorobenzene. The coating liquid for the charge transport layer was immersed and coated on the charge generation layer, and the obtained coating film was dried at 130 ° C. for 20 minutes to form a charge transport layer (surface layer) having a film thickness of 20 μm.

[evaluation]
As an evaluation machine, a laser beam printer (trade name: HP LaserJet Enterprise 500 Color M551, manufactured by Hewlett-Packard Co., Ltd., contact development method, printing speed: A4 length 30 sheets / minute) was modified to evaluate the sensitivity.
The environmental conditions were an environment of a temperature of 5 ° C. and a humidity of 10% RH (also referred to as L / L), and the sensitivity was measured after mounting the drum and acclimatizing to the environment (initial Vl / −V). Next, 500,000 images were formed in an intermittent mode in which an image having a printing ratio of 1% on A4 size plain paper was stopped every time two images were formed. Then, it was left for one month, and the sensitivity after leaving (Leave Vl / −V) was measured. Then, the difference between the neglected Vl and the initial Vl was set to ΔVl / −V.

(Examples 2 to 9)
In Example 1, the resin for the charge transport layer, the charge transport substance, the solvent used for preparing the coating liquid for the charge transport layer, the resin for the charge generation layer, the ratio of the charge transport substance to the resin for the charge transport layer, and the charge generation substance. The ratio of the resin for the charge generation layer was changed as shown in Table 2. Except for this, an electrophotographic photosensitive member was produced in the same manner as in Example 1.

(Example 10)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the method of dispersing the charge generating substance was changed in Example 9. The coating liquid for the charge generation layer was prepared as follows.
As a charge generating substance, 9 parts of Y-type oxytitanium phthalocyanine crystal having a strong peak at 27.3 ° of Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction, and 4-methoxy-4-methylpentanone- 2 150 copies were prepared. These were mixed with 105 parts of a solution prepared by adding 5 parts of a polyacetal resin (trade name: KS-1, manufactured by Sekisui Chemical Co., Ltd.) to 100 parts of 4-methoxy-4-methylpentanone-2 in advance. .. Then, it was pulverized and dispersed by a sand grind mill for 1.5 hours (hereinafter, also referred to as simultaneous addition). Then, 250 parts of 1,2-dimethoxyethane was added to prepare a coating liquid for a charge generation layer.

(Examples 11 to 24)
An electrophotographic photosensitive member was produced in the same manner as in Example 10 except that the resin for the charge transport layer, the charge transport substance, and the additive were changed as shown in Table 2. In Examples 16 and 17, the compound represented by the above formula (P-3) (BASF Japan Ltd., trade name: Irganox 1010) was used as an additive. The amount of solvent /% in Table 2 indicates the content of cyclic ether or cyclic ketone in the charge transport layer, and KS1 of the charge generation layer resin is a polyacetal resin (trade name: Eslek KS-1, Sekisui Chemical Industry Co., Ltd. Made by Co., Ltd., the degree of acetalization is about 74 mol%).
Headspace gas chromatography-mass spectrometry (GC-MS) was used as a method for measuring the content (solvent amount /%) of cyclic ether or cyclic ketone in the charge transport layer. A photoconductor was cut out as a sample and placed in a headspace vial, and the measurement was carried out at a temperature condition of 50 ° C. to 200 ° C. and a heating rate of 10 ° C./min.

(Comparative Example 1)
An electrophotographic photosensitive member was produced in the same manner as in Example 5 except that the resin for the charge transport layer was changed to the resin P in Example 5.

(Comparative Example 2)
An electrophotographic photosensitive member was produced in the same manner as in Example 5 except that the resin for the charge transport layer and the charge transport substance were changed as shown in Table 2.

(Comparative Example 3)
An electrophotographic photosensitive member was produced in the same manner as in Example 9 except that the method for preparing the coating liquid for the charge generation layer was changed as follows in Example 9.
As a charge generating substance, an oxytitanium phthalocyanine crystal (CGM-1) having strong diffraction peaks at Bragg angles (2θ ± 0.2 °) of 9.3 °, 10.6 ° and 26.3 ° in CuKα characteristic X-ray diffraction. ) (A type TiOPc) 9 parts were used. This was mixed with 150 parts of 4-methoxy-4-methylpentanone-2 and subjected to pulverization and dispersion treatment by a sand grind mill to produce a pigment dispersion liquid. This pigment dispersion is mixed with 100 parts of a 5 wt% 4-methoxy-4-methylpentanone-2 solution of a polyacetal resin (trade name: Eslek KS-1, manufactured by Sekisui Chemical Co., Ltd.) as a binder resin solution. (Post-addition). Further, an appropriate amount of 1,2-dimethoxyethane was added to finally prepare a coating liquid for a charge generation layer having a solid content concentration of 3.5%.

(Comparative Example 4)
An electrophotographic photosensitive member was produced in the same manner as in Example 9 except that the method for preparing the coating liquid for the charge generation layer was changed as follows in Example 9.
As a charge generating substance, an oxytitanium phthalocyanine crystal (CGM-1) having strong diffraction peaks at Bragg angles (2θ ± 0.2 °) of 9.3 °, 10.6 ° and 26.3 ° in CuKα characteristic X-ray diffraction. ) (A type TiOPc) 9 parts were used. This is mixed with 150 parts of 4-methoxy-4-methylpentanone-2, and 100 parts of 4-methoxy-4-methylpentanone-2 is mixed with a polyacetal resin (trade name: KS-1, Sekisui Chemical Co., Ltd.) in advance. ), 105 parts of the solution to which 5 parts were added and dissolved was mixed. Then, it was pulverized and dispersed by a sand grind mill for 1.5 hours (simultaneous addition). Further, an appropriate amount of 1,2-dimethoxyethane was added to finally prepare a coating liquid for a charge generation layer having a solid content concentration of 3.5%.

(Comparative Example 5, Comparative Example 6)
In Comparative Example 4, an electrophotographic photosensitive member was produced in the same manner as in Comparative Example 4 except that the resin for the charge transport layer was changed as shown in Table 2.

[evaluation]
The sensitivity of the electrophotographic photosensitive members obtained in Examples 2 to 24 and Comparative Examples 1 to 6 was evaluated in the same manner as in Example 1. The obtained results are shown in Table 3 together with the results for Example 1.

In Examples 1 to 24 according to the present invention, the initial sensitivity was high and the change in sensitivity in long-term use was small as compared with Comparative Examples 1 to 6 which did not satisfy the requirements of the present invention. Regarding the preparation of the coating liquid for the charge generation layer, the change in sensitivity of the electrophotographic photosensitive member obtained by the simultaneous addition of Example 10 was smaller than that of the post-addition of Example 9.

1 Electrophotographic photosensitive member 2 axes 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Guide means

Claims (6)

With the support
A charge generating layer containing a charge generating substance and a resin, and
A charge transport layer containing a charge transport substance and a resin and adjacent to the charge generation layer,
An electrophotographic photosensitive member having the above in this order.
Charge generation layer, a charge generating material, our Keru Bragg angle X-ray diffraction by CuKα-ray (2θ ± 0.2) is contained oxytitanium phthalocyanine showing a peak at 27.3 °,
The charge transport layer further contains a compound represented by the following formula (P-2) or a compound represented by the following formula (P-3).
The resin charge transport layer contains is a resin having the structure represented by the following general formula (I) structure and the following general formula represented by (II),
The resin in which the charge transport layer contains is a structure represented by the following formula (II), having a structure represented by the structure and the following general formula represented by the following general formula (II-1) (II- 3) An electrophotographic photosensitive member characterized by this.

(In general formula (I), X ¹ represents a divalent group.)

(In the general formula (II), ^{X 2} represents a single bond, an oxygen atom, a divalent alkylene group or a divalent cycloalkylene group table to ^.R 11 ^{to R 18,} each independently, a hydrogen atom or Table to an alkyl group.)

(In the general formula ^{(II-1), R 21} is ^{.R 22} represents a hydrogen atom, a methyl group, an ethyl group or phenyl group, ^{.R 23} representing the ethyl group or methyl group, 1 to carbon atoms Table to ^.R 24 ^{to R 27} the alkyl groups of 4 each independently, also hydrogen atoms .m represents methyl group, and display the number of repetitions of CH ₂ in parenthesis, an integer from 0 to 3 .)

(In the general formula (II-3), R ^{231 to} R ²³⁴ independently represent a hydrogen atom, a methyl group, or an ethyl group.) Wherein the resin charge transport layer contains is a structure represented by the general formula (I), the structure represented by the following formula (I-1), the structure represented by the following formula (I-2), the following equation ( structure represented by I-3), and the following formula (electrophotographic photosensitive member according to claim 1 having at least one kind of structure selected from the group consisting of structures represented by I-4).

The electrophotographic photosensitive member according to claim 2, wherein the resin contained in the charge transport layer has at least a structure represented by the general formula (I-1) as a structure represented by the general formula (I). The charge transport material, an electrophotographic photosensitive member according to any one of claims 1 to 3 which is a compound having a structure represented by the following general formula (Q).

(In the general formula (Q), R ⁴¹ and R ⁴³ are methyl group, an ethyl group, an alkenyl group which may have a substituent, or represents an aryl group having a substituent, the substituent , methyl group, ethyl group or a phenyl group .s and t is 1 or the ^{.R 42} and ^{R 44} represents 2, each independently, an optionally substituted aryl group, or a substituent the represents also an alkenyl group having the substituents include a methyl group, an ethyl group or a phenyl group.) An electrophotographic photosensitive member according to claim 1-4, whichever is first term, charging means, developing means, and at least one means selected from the group consisting of the transfer means and cleaning means, integrally supports a A process cartridge that is removable from the main body of the electrophotographic apparatus. The electrophotographic photosensitive member according to claim 1-4, whichever is first term, and a charging means, an exposure means, the electrophotographic apparatus, characterized in that it comprises a developing means and a transfer means.

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