JP2011164157A - Electrophotographic photoreceptor, electrophotographic method, electrophotographic device and process cartridge for the electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high durability, even for long-term repeated use, suppressing image degradation due to decrease in image density or occurrence of image blurs, and thereby stably giving an image of high image quality. <P>SOLUTION: The electrophotographic photoreceptor includes at least a photosensitive layer on a conductive support. The photosensitive layer contains a naphthalene diimide-isoindole dimer derivative represented by general formula (1). In the general formula, R<SB>1</SB>, R<SB>2</SB>, R<SB>3</SB>, R<SB>4</SB>, R<SB>5</SB>and R<SB>6</SB>each represents a hydrogen atom, substituted or unsubstituted alkyl group, alkoxy group, substituted or unsubstituted aromatic hydrocarbon group, halogen atom, or nitro group, and they may be the same or different from one another; i and j represent integers of 1 to 4; and l, m, n represent integers of 1 to 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member containing at least one specific naphthalenediimide-isoindole dimer derivative in a photosensitive layer, and an electrophotographic method, an electrophotographic apparatus, and an electrophotographic method using the electrophotographic photosensitive member. The present invention relates to a process cartridge.

  In recent years, there has been a remarkable development in information processing system machines using electrophotography. In particular, laser printers and digital copying machines that convert information into digital signals and record information using light have significantly improved print quality and reliability. Furthermore, they have been applied to laser printers or digital copiers capable of full-color printing by fusing with high-speed technology. From such a background, it is particularly important to achieve both high image quality and high durability as a required photoreceptor function.

  As photoconductors used in these electrophotographic laser printers, digital copiers, etc., those using organic photosensitive materials (OPC) are generally widely used for reasons such as cost, productivity and non-pollution. Applied. The layer structure of the OPC photoreceptor is roughly divided into a single layer type and a function separation type laminated structure. The first practical OPC, the PVK-TNF charge transfer complex type photoreceptor, was the former single layer type.

  On the other hand, in 1968, Hayashi and Regensburger independently invented PVK / a-Se laminated photoreceptors, and later in 1977 by Melz et al. And in 1978 by Schlosser, an organic pigment dispersion layer and an organic low molecular weight dispersion polymer. Laminated photoreceptors have been announced in which all photosensitive layers, called layers, are made of organic materials. These are functionally separated from the concept of a charge generation layer (CGL) that absorbs light and generates charges, and a charge transport layer (CTL) that injects and transports charges generated by CGL and neutralizes surface charges. Also called a mold-laminated photoconductor.

  However, organic photoconductors have larger film scraping due to repeated use than inorganic ones. If the photoconductive layer is further scraped off, the surface of the photoconductor is deteriorated due to a decrease in charge potential, photosensitivity, or scratches on the surface of the photoconductor. There is a strong tendency to promote dirt, image density reduction or image quality degradation. Therefore, the wear resistance of organic photoreceptors has been cited as a major problem. Further, in recent years, with the increase in the speed of an electrophotographic apparatus or the reduction in the diameter of the photoreceptor accompanying the downsizing of the apparatus, it has become a more important issue to improve the durability of the photoreceptor.

  As a method for improving the abrasion resistance of the photoconductor, a method for imparting lubricity to the photosensitive layer, curing it, or containing a filler, or a low molecular charge transport material (CTM) molecular dispersed polymer layer can be used. Methods using polymer charge transport materials are widely known. However, a new problem arises when the abrasion of the photosensitive layer is suppressed by these methods. That is, ozone, NOx, and other oxidizing substances that are repeatedly used on the surface of the photosensitive layer and adsorbed by the surrounding environment are adsorbed. Depending on the repeated use and use environment, the resistance of the outermost surface is lowered, and image flow (image blur), etc. Known to cause problems. Conventionally, the problem has been avoided to some extent by removing the blur generating material little by little together with the photosensitive layer.

  However, as described above, in order to meet the recent demand for higher resolution and higher durability, a new method has to be provided. One method of reducing these effects is to mount a heater on the photoreceptor, which is a major obstacle to downsizing the apparatus and reducing power consumption. Additives such as antioxidants are also effective means, but mere additives are those that do not have photoconductivity. Therefore, addition of a large amount to the photosensitive layer can reduce the sensitivity and increase the residual potential. This leads to problems with photographic characteristics.

  As described above, electrophotographic photoconductors with high wear resistance or reduced shaving due to process design around the photoconductor have adverse effects on image quality, such as image blurring and reduced resolution. However, it has been difficult to achieve both high durability and high image quality. This is because a higher resistance is suitable for suppressing the occurrence of image blur, and a lower resistance is suitable for suppressing the increase in residual potential. This is because it makes it difficult to solve this problem.

  Most of the electrophotographic photoreceptors in practical use are function-separated type electrophotographic photoreceptors in which a charge generation layer and a charge transport layer are laminated on a conductive substrate. As a charge transport material contained in the charge transport layer, A hole transport material is used. These are used exclusively for negatively charged electrophotographic processes.

  In addition, a highly reliable charging method in the electrophotographic process is based on corona discharge, and this method is adopted in most copying machines and printers. However, as is well known, the negative corona discharge is unstable compared to the positive polarity, and for this reason, a scorotron charging method is adopted, which is a factor in increasing costs. The negative corona discharge is accompanied by a larger amount of ozone, a substance that causes chemical damage. Therefore, it is generated during the long-term oxidative degradation of the binder resin and charge transfer material due to ozone generated during charging, and is generated during charging. As a result, accumulation of ionic compounds such as nitrogen oxide ions, sulfur oxide ions, ammonium ions, etc. on the surface of the photoconductor causes a decrease in image quality, which is a problem. For this reason, ozone filters are often used in negatively charged copying machines and printers in order to prevent ozone from being discharged to the outside, which also increases the cost of the apparatus. Also, a large amount of ozone is a problem of environmental pollution.

  In order to solve these problems, development of a positively charged electrophotographic photosensitive member is underway. If the positive charging method is used, the generation amount of ozone, nitrogen oxide ions, etc. is suppressed, and the use of a two-component developer that is widely used at present makes the electrophotographic photosensitive member positively charged. A stable image with little environmental fluctuation can be obtained. From this aspect, a positively charged electrophotographic photosensitive member is desirable.

  However, positively charged single-layer and reverse-layer photoconductors have charge generating materials that are very sensitive to oxidizing substances such as ozone and nitrogen oxide ions near the surface. For example, there is a drawback that the characteristic fluctuation due to the exhaust gas from a blue heater or a car is large.

  On the other hand, in the case of a high-speed copying process, it is preferable to use a negative charging type rather than a positive charging type as described above. The reason for this is that organic materials exhibiting high charge mobility that does not interfere with high-speed copying processes are currently limited to hole transport materials that have only the property of hole transfer, and are therefore correct. This is because, in a forward layered electrophotographic photosensitive member in which a charge transporting layer formed using a hole transporting material is arranged on the surface side, the charging property is limited to negative charging on the principle of operation.

  As described above, regarding the charging polarity, if the electrophotographic photosensitive member can be used in both positive and negative polarities, the application range of the photosensitive member can be further expanded, and the cost can be reduced by reducing the number of photosensitive members. This is advantageous for speeding up.

  Under such circumstances, an electrophotographic photosensitive member capable of being charged in both polarities is disclosed in Patent Document 1. However, since the diphenoquinone derivative used as an electron transport material used therein has a slightly low charge mobility, it is used in a copying machine or a printer. When speeding up and downsizing are considered, the photosensitive member sensitivity characteristics are not sufficient, and further, there is a disadvantage that image blur is caused by repeated use.

Patent Document 2 discloses an aromatic compound having a dialkylamino group as an acid scavenger on a photoreceptor. This compound is effective for image quality after repeated use. However, since the charge transport ability is low, it is difficult to meet demands for high sensitivity and high speed, and there is a limit in the amount of addition.
Furthermore, the stilbene compounds having a dialkylamino group disclosed in Patent Document 3, Patent Document 4 and the like are also effective against image blur due to oxidation-resistant gas [Itami et al., Konica Technical Report, Vol. 13, 37 Page 2000].

  However, since this has a dialkylamino group that is a substituent of a strong mesomeric effect (+ M effect) at the resonance site of the triarylamine structure that is a charge transport site, the overall ionization potential value becomes abnormally small. Therefore, the charge retention ability of the photosensitive layer used alone as a hole transporting material is remarkably deteriorated from the beginning or by repeated use. Even when mixed with substances, the ionization potential values of the above stilbene compounds are much smaller than those, so the stilbene compounds become hole trap sites for mobile charges, resulting in an electrophotographic photosensitive member with significantly low sensitivity and a large residual potential. End up.

Further, Patent Document 5 proposes a photoreceptor that includes a stilbene compound and a specific diamine compound and has improved environmental resistance against repeated use and acid gas without causing a decrease in sensitivity.
However, it is not yet sufficient to realize downsizing of the apparatus accompanying high-speed printing or reduction in the diameter of the photoreceptor.
On the other hand, although a method for synthesizing 1,3-diphenyl-2-phthalimidoisoindole is disclosed in Non-Patent Document 1 for naphthalene diimide-isoindole dimer derivatives, it is not suggested to use it for an electrophotographic photoreceptor.

  An object of the present invention is to provide an electrophotographic photosensitive material that has high durability even for repeated use over a long period of time, suppresses image deterioration due to image density reduction or image blurring, and stably obtains high-quality images. To provide a body. In addition, it is possible to obtain photoconductors that are charged to either positive or negative polarity, and by using these photoconductors, it is not necessary to replace the photoconductors, and it is possible to reduce the size of the apparatus due to high-speed printing or reduction in the diameter of the photoconductor. Another object of the present invention is to provide an electrophotographic method, an electrophotographic apparatus, and an electrophotographic process cartridge that can be realized and can stably obtain a high-quality image even in repeated use.

As a result of investigations, the present inventors have been able to solve the above-mentioned problems by including a naphthalene diimide-isoindole dimer derivative having a specific structure in the photosensitive layer, and a photoreceptor that can cope with bipolar charging. The present invention has been completed.
That is, the present invention is as described below.

［式中、Ｒ_１、Ｒ_２、Ｒ_３、Ｒ_４、Ｒ_５、Ｒ_６は水素原子、置換もしくは無置換のアルキル基、アルコキシ基、置換もしくは無置換の芳香族炭化水素基、ハロゲン原子、ニトロ基を表し、それぞれ同一でも異なっていてもよい。また、i、ｊは１〜４の整数を、ｋ、ｌ、ｍ、ｎは１〜５の整数を表す。
（２）正および負のいずれの極性にも帯電することを特徴とする（１）に記載の電子写真感光体。
（３）前記感光層は、電荷輸送物質をさらに含むものであることを特徴とする（１）または（２）に記載の電子写真感光体。
（４）前記電荷輸送物質が下記一般式（２）で表される化合物であることを特徴とする（１）〜（３）のいずれかに記載の電子写真感光体。

［式中、Ｘは単結合もしくはビニレン基を表し、Ｒ_４は水素原子、置換もしくは無置換のアルキル基、または置換もしくは無置換の芳香族炭化水素基を表し、Ａｒ_１は置換もしくは無置換の芳香族炭化水素基を表し、Ｒ_５は水素原子、置換もしくは無置換のアルキル基、あるいは置換もしくは無置換の芳香族炭化水素基を表し、Ａｒ_１とＲ_５は共同で環を形成しても良い。Ａは下記一般式（３）で表される基、一般式（４）で表される基、９−アントリル基または置換もしくは無置換のカルバゾリル基を表す。

（ここでＲ_６は水素原子、アルキル基、アルコキシ基、ハロゲン原子または下記一般式（５）で表される基を表す。）

（ただし、Ｒ_７およびＲ_８は置換もしくは無置換のアルキル基、置換もしくは無置換の芳香族炭化水素基を示し、Ｒ_７およびＲ_８は同じでも異なっていてもよく、環を形成しても良い）を表し、ｍは１〜３の整数を表し、２以上の時Ｒ_６は同一でも異なっても良い。］
（５）前記電荷輸送物質が下記一般式（６）で表される化合物であることを特徴とする（１）〜（３）のいずれかに記載の電子写真感光体。

［式中、Ｒ_９、Ｒ_１１およびＲ_１２は水素原子、アミノ基、アルコキシ基、チオアルコキシ基、アリールオキシ基、メチレンジオキシ基、置換もしくは無置換のアルキル基、ハロゲン原子または置換もしくは無置換の芳香族炭化水素基を、Ｒ_１０は水素原子、アルコキシ基、置換もしくは無置換のアルキル基またはハロゲン原子を表す。また、ｋ，ｌ，ｍおよびｎは１、２、３または４の整数であり、それぞれが２、３または４の整数の時は、前記Ｒ_９、Ｒ_１０、Ｒ_１１およびＲ_１２は同じでも異なっていても良い。］
（６）前記電荷輸送物質が下記一般式（７）で表される化合物であることを特徴とする（１）〜（３）のいずれかに記載の電子写真感光体。

［式中、Ｘは単結合もしくはビニレン基を表し、Ｒ_１３は水素原子、置換もしくは無置換のアルキル基または置換もしくは無置換の芳香族炭化水素基を表し、Ａｒ_３は置換もしくは無置換の芳香族炭化水素基を表し、Ｒ_１４は水素原子、置換もしくは無置換のアルキル基、あるいは置換もしくは無置換の芳香族炭化水素基を表し、Ａｒ_３とＲ_１３は共同で環を形成しても良い。Ａｒ_２は下記一般式（８）または一般式（９）を表す。

ここでＲ_６は水素原子、アルキル基、アルコキシ基、ハロゲン原子を表し、ｍは１〜３の整数を表し、２以上の時Ｒ_６は同一でも異なっても良い。またＲ_１２は置換もしくは無置換のアルキル基、または置換もしくは無置換の芳香族炭化水素基を表す。］
（７）前記電荷輸送物質が下記一般式（１０）で表される化合物であることを特徴とする（１）〜（３）のいずれかに記載の電子写真感光体。

［式中、Ｘは単結合もしくはビニレン基を表し、Ｒ_１５は水素原子、置換もしくは無置換のアルキル基または置換もしくは無置換の芳香族炭化水素基を表し、Ａｒ_４は置換もしくは無置換の２価の芳香族炭化水素基を表し、Ｒ_１６は水素原子、置換もしくは無置換のアルキル基、あるいは置換もしくは無置換の芳香族炭化水素基を表し、Ａは一般式（３）、一般式（４）、９−アントリル基または置換もしくは無置換のカルバゾリル基を表す。

ここでＲ_６は水素原子、アルキル基、アルコキシ基、ハロゲン原子または一般式（５）を表す。

（但し、Ｒ_７およびＲ_８は置換もしくは無置換のアルキル基、置換もしくは無置換の芳香族炭化水素基を示し、Ｒ_７およびＲ_８は同じでも異なっていてもよく、環を形成しても良い）を表し、ｍは１〜３の整数を表し、２以上の時Ｒは同一でも異なっても良い。］
（８）前記電荷輸送物質が下記一般式（１１）で表される化合物であることを特徴とする（１）〜（３）のいずれかに記載の電子写真感光体。

（式中Ｒ_１７、Ｒ_１８は水素原子、置換もしくは無置換のアルキル基、置換もしくは無置換の芳香族炭化水素基を表し、それぞれ同じでも異なっていても良い。）
（９）前記電荷輸送物質が下記一般式（１２）で表される化合物であることを特徴とする（１）〜（３）のいずれかに記載の電子写真感光体。

〔式中、Ｒ_１９は置換基を有してもよいアルキル基、または置換基を有してもよいアリール基を示し、Ｒ_２０は置換基を有してもよいアルキル基、置換基を有してもよい芳香族炭化水素基、または下記式一般式（１３）で表される基を示す。

（Ｒ_２１は、置換基を有してもよいアルキル基、または置換基を有してもよいアリール基を示す。）
（１０）前記電荷輸送物質が下記一般式（１４）で表される化合物であることを特徴とする（１）〜（３）のいずれかに記載の電子写真感光体。

（式中Ｒ_２２、Ｒ_２３は水素原子、置換もしくは無置換のアルキル基、置換もしくは無置換の芳香族炭化水素基を表し、それぞれ同じでも異なっていても良い。）
（１１）前記電荷輸送物質が下記一般式（１５）で表される化合物であることを特徴とする（１）〜（３）のいずれかに記載の電子写真感光体。

（式中Ｒ_２４、Ｒ_２５は水素原子、置換もしくは無置換のアルキル基、置換もしくは無置換の芳香族炭化水素基を表し、それぞれ同じでも異なっていても良い。）
（１２）前記感光層は、少なくとも電荷発生層、電荷輸送層を順次積層したものであることを特徴とする（１）〜（１１）のいずれかに記載の電子写真感光体。
（１３）前記感光層は、少なくとも電荷輸送層、電荷発生層を順次積層したものであることを特徴とする（１）〜（１１）のいずれかに記載の電子写真感光体。
（１４）前記感光層は、単層型の感光層であることを特徴とする（１）〜（１１）のいずれかに記載の電子写真感光体。
（１５）電子写真感光体に、少なくとも帯電、画像露光、現像、転写が繰り返し行われる電子写真方法であって、該電子写真感光体は（１）〜（１４）のいずれかに記載の電子写真感光体であることを特徴とする電子写真方法。
（１６）電子写真感光体に、少なくとも帯電、画像露光、現像、転写を繰り返し行い、かつ画像露光の際にはＬＤあるいはＬＥＤ等によって感光体上に静電潜像の書き込みが行われる、デジタル方式の電子写真方法であって、該電子写真感光体は（１）〜（１４）のいずれかに記載の電子写真感光体であることを特徴とする電子写真方法。
（１７）少なくとも帯電手段、画像露光手段、現像手段、転写手段および電子写真感光体を具備してなる電子写真装置であって、該電子写真感光体は（１）〜（１４）のいずれかに記載の電子写真感光体であることを特徴とする電子写真装置。
（１８）少なくとも帯電手段、画像露光手段、現像手段、転写手段および電子写真感光体を具備してなる電子写真装置であって、画像露光手段にＬＤあるいはＬＥＤ等を使用することによって感光体上に静電潜像の書き込みが行われる、デジタル方式の電子写真装置であって、該電子写真感光体は（１）〜（１４）のいずれかに記載の電子写真感光体であることを特徴とする電子写真装置。
（１９）少なくとも電子写真感光体を具備してなる電子写真装置用プロセスカートリッジであって、該電子写真感光体は（１）〜（１４）のいずれかに記載の電子写真感光体であることを特徴とする電子写真装置用プロセスカートリッジ。 (1) An electrophotographic photosensitive member in which at least a photosensitive layer is provided on a conductive support, wherein the photosensitive layer contains a naphthalenediimide-isoindole dimer derivative represented by the following general formula (1) An electrophotographic photoreceptor, characterized in that

[Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ are a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted aromatic hydrocarbon group, a halogen atom, Represents a nitro group, which may be the same or different. I and j represent integers of 1 to 4, and k, l, m, and n represent integers of 1 to 5, respectively.
(2) The electrophotographic photosensitive member according to (1), wherein the electrophotographic photosensitive member is charged to both positive and negative polarities.
(3) The electrophotographic photosensitive member according to (1) or (2), wherein the photosensitive layer further contains a charge transport material.
(4) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the charge transport material is a compound represented by the following general formula (2).

[Wherein, X represents a single bond or a vinylene group, R ₄ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₁ represents a substituted or unsubstituted group. Represents an aromatic hydrocarbon group, R ₅ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₁ and R ₅ may form a ring together. good. A represents a group represented by the following general formula (3), a group represented by the general formula (4), a 9-anthryl group, or a substituted or unsubstituted carbazolyl group.

(Here, R ₆ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a group represented by the following general formula (5).)

(However, R ₇ and R ₈ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, and R ₇ and R ₈ may be the same or different and may form a ring. M represents an integer of 1 to 3, and R ₆ may be the same or different when 2 or more. ]
(5) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the charge transport material is a compound represented by the following general formula (6).

[Wherein R ₉ , R ₁₁ and R ₁₂ are a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom, or a substituted or unsubstituted group. R ₁₀ represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or a halogen atom. K, l, m, and n are integers of 1, 2, 3, or 4, and when each is an integer of 2, 3, or 4, R ₉ , R ₁₀ , R _11, and R ₁₂ are the same. It may be different. ]
(6) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the charge transport material is a compound represented by the following general formula (7).

[Wherein, X represents a single bond or a vinylene group, R ₁₃ represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₃ represents a substituted or unsubstituted aromatic group. R ₁₄ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₃ and R ₁₃ may form a ring together. . Ar ₂ represents the following general formula (8) or general formula (9).

Here, R ₆ represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, m represents an integer of 1 to 3, and R ₆ may be the same or different when 2 or more. R ₁₂ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group. ]
(7) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the charge transport material is a compound represented by the following general formula (10).

[Wherein, X represents a single bond or a vinylene group, R ₁₅ represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₄ represents a substituted or unsubstituted 2 group. R ₁₆ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and A represents a general formula (3) or a general formula (4 ), 9-anthryl group or a substituted or unsubstituted carbazolyl group.

Here, R ₆ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or general formula (5).

(However, R ₇ and R ₈ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, and R ₇ and R ₈ may be the same or different and may form a ring. M represents an integer of 1 to 3, and when 2 or more, Rs may be the same or different. ]
(8) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the charge transport material is a compound represented by the following general formula (11).

(Wherein R ₁₇ and R _{18 each} represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different.)
(9) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the charge transport material is a compound represented by the following general formula (12).

[Wherein R ₁₉ represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and R ₂₀ represents an alkyl group which may have a substituent or a substituent. An aromatic hydrocarbon group that may be used, or a group represented by the following general formula (13).

(R ₂₁ represents an alkyl group which may have a substituent, or an aryl group which may have a substituent.)
(10) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the charge transport material is a compound represented by the following general formula (14).

(Wherein R ₂₂ and R _{23 each} represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different.)
(11) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the charge transport material is a compound represented by the following general formula (15).

(Wherein R ₂₄ and R _{25 each} represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different.)
(12) The electrophotographic photosensitive member according to any one of (1) to (11), wherein the photosensitive layer is obtained by sequentially laminating at least a charge generation layer and a charge transport layer.
(13) The electrophotographic photosensitive member according to any one of (1) to (11), wherein the photosensitive layer is obtained by sequentially laminating at least a charge transport layer and a charge generation layer.
(14) The electrophotographic photosensitive member according to any one of (1) to (11), wherein the photosensitive layer is a single-layer type photosensitive layer.
(15) An electrophotographic method in which at least charging, image exposure, development, and transfer are repeatedly performed on an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is any one of (1) to (14) An electrophotographic method which is a photoconductor.
(16) A digital method in which at least charging, image exposure, development, and transfer are repeatedly performed on an electrophotographic photosensitive member, and an electrostatic latent image is written on the photosensitive member by an LD or an LED at the time of image exposure. An electrophotographic method according to claim 1, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of (1) to (14).
(17) An electrophotographic apparatus comprising at least a charging unit, an image exposing unit, a developing unit, a transferring unit, and an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is any one of (1) to (14) An electrophotographic apparatus comprising the electrophotographic photosensitive member described above.
(18) An electrophotographic apparatus comprising at least a charging means, an image exposing means, a developing means, a transferring means, and an electrophotographic photosensitive member, wherein an LD or LED is used as the image exposing means on the photosensitive member. A digital electrophotographic apparatus in which an electrostatic latent image is written, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of (1) to (14). Electrophotographic device.
(19) A process cartridge for an electrophotographic apparatus comprising at least an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of (1) to (14). A characteristic process cartridge for an electrophotographic apparatus.

  According to the present invention, by including the naphthalene diimide-isoindole dimer derivative represented by the general formula (1), the environmental resistance to repeated use and oxidizing gas is greatly reduced without causing a decrease in sensitivity. Therefore, it has become possible to obtain a photoconductor that has high durability and can obtain high-resolution image quality over a long period of time. According to the present invention, it is possible to achieve both high durability and high image quality of an electrophotographic photosensitive member, a high-quality image can be stably obtained over a long period of time, and furthermore, an electrophotographic photosensitive member that can handle bipolar charging, and An electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus using the same are provided.

1 is a cross-sectional view illustrating an electrophotographic photosensitive member of the present invention. 1 is a cross-sectional view illustrating an electrophotographic photosensitive member of the present invention. 1 is a cross-sectional view illustrating an electrophotographic photosensitive member of the present invention. 1 is a cross-sectional view illustrating an electrophotographic photosensitive member of the present invention. 1 is a cross-sectional view illustrating an electrophotographic photosensitive member of the present invention. 1 is a cross-sectional view illustrating an electrophotographic photosensitive member of the present invention. It is the schematic for demonstrating the electrophotographic process and electrophotographic apparatus of this invention. 3 is another example of an electrophotographic process according to the present invention. FIG. 3 is a schematic view for explaining an electrophotographic process cartridge according to the present invention. It is a figure which shows the powder XD spectrum of oxotitanium phthalocyanine. Exemplified Compound No. It is a figure which shows 12 IR spectra.

  The electrophotographic photosensitive member having at least a photosensitive layer on a conductive support according to the present invention contains the naphthalenediimide-isoindole dimer derivative represented by the general formula (1) in the photosensitive layer, thereby oxidizing. It is possible to solve problems such as image blur (image flow) due to a blur generating substance such as a property gas, and to deal with bipolar charging.

The reason why the naphthalene diimide-isoindole dimer derivative in the present invention is effective for maintaining the image quality by repeated use is not clear at present, but the amino group contained in the chemical structure is a strongly basic group. Therefore, it is presumed that there is an electrical neutralizing effect on the oxidizing gas that is considered to be a causative substance of image blur. In addition, the naphthalenediimide-isoindole dimer derivative in the present invention is further enhanced in sensitivity, repeat stability, and the like when used in combination with other charge transport materials.
In addition, since the naphthalene diimide-isoindole dimer derivative in the present invention is an ambipolar transporting substance, the photoconductor using the naphthalene diimide-isoindole dimer derivative can handle ambipolar charging regardless of the type of layer structure and the mixing of the transporting substance. A photoreceptor can also be obtained.

  Therefore, according to the present invention, it is possible to provide an electrophotographic photosensitive member that can be compatible with bipolar charging that can achieve both high durability and high image quality, and can stably obtain high-quality images even when used repeatedly. In addition, it has become possible to provide an electrophotographic method, an electrophotographic apparatus, and an electrophotographic process cartridge capable of stably obtaining a high-quality image even in repeated use.

Hereinafter, the electrophotographic photosensitive member of the present invention, the electrophotographic method using the same, the electrophotographic apparatus, and the electrophotographic process cartridge will be described in detail.
First, details of the naphthalene diimide-isoindole dimer derivative represented by the following general formula (1) to be contained in the photosensitive layer in the present invention will be described.

［式中、Ｒ_１、Ｒ_２、Ｒ_３、Ｒ_４、Ｒ_５及びＲ_６は水素原子、置換もしくは無置換のアルキル基、置換もしくは無置換の芳香族炭化水素基、ハロゲン原子、ニトロ基を表し、それぞれ同一でも異なっていてもよい。また、ｋ及びｌは１〜４の整数を、ｍ及びｎは１〜５の整数を表す。］

[Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a halogen atom or a nitro group. Each may be the same or different. Moreover, k and l represent the integer of 1-4, m and n represent the integer of 1-5. ]

The naphthalene diimide-isoindole dimer derivative represented by the general formula (1) is obtained by applying the production method described in Non-Patent Document 1.
Specifically, the method for producing a symmetrical naphthalene diimide-isoindole dimer derivative is obtained by reacting two equivalents of an N-amino-2,7-diphenylisoindole derivative with a naphthalene dianhydride derivative. The method for producing an asymmetric naphthalene diimide-isoindole dimer derivative is the first step; reacting one equivalent of N-amino-2,7-diphenylisoindole derivative with a naphthalene dianhydride derivative; In the step; taking out one of which is substituted with N-amino-2,7-diphenylisoindole derivative and reacting with another N-amino-2,7-diphenylisoindole derivative, The naphthalene diimide-isoindole dimer derivative represented by this can be produced.

The solvent is not particularly limited, and examples thereof include benzene, toluene, xylene, chloronaphthalene, acetic acid, pyridine, methylpyridine, N, N-dimethylformamide, N, N-dimethylacetamide, carbon tetrachloride and the like.
The reaction temperature is preferably 100 ° C. or higher.

Specific examples of the alkyl group in the description of the general formula (1) include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and an undecanyl group. In addition, aromatic hydrocarbon groups include aromatic ring groups such as benzene, biphenyl, naphthalene, anthracene, fluorene, and pyrene, and aromatic heterocyclic groups such as pyridine, quinoline, thiophene, furan, oxazole, oxadiazole, and carbazole. A halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of these substituents include those exemplified in the specific examples of the alkyl group, alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group, or the halogen atom, dialkylamino group, diphenylamino group, and the like. Examples thereof include a nitro group, the aromatic hydrocarbon group, and a heterocyclic group such as pyrrolidine, piperidine and piperazine.
Preferred examples of the compound represented by the general formula (1) are given below. However, the present invention is not limited to these compounds.

Next, the layer structure of the electrophotographic photosensitive member will be described.
FIG. 1 is a cross-sectional view showing an electrophotographic photosensitive member of the present invention. A photosensitive layer 33 mainly composed of a charge generating material and a charge transporting material is provided on a conductive support 31.

  FIG. 2 shows a structure in which a charge generation layer 35 mainly composed of a charge generation material and a charge transport layer 37 mainly composed of a charge transport material are laminated on a conductive support 31.

  In FIG. 3, a photosensitive layer 33 mainly composed of a charge generation material and a charge transport material is provided on a conductive support 31, and a protective layer 39 is further provided on the surface of the photosensitive layer. In this case, the naphthalene diimide-isoindole dimer derivative of the present invention may be contained in the protective layer 39.

  FIG. 4 shows a structure in which a charge generation layer 35 mainly composed of a charge generation material and a charge transport layer 37 mainly composed of a charge transport material are laminated on a conductive support 31. A protective layer 39 is provided on the transport layer. In this case, the naphthalene diimide-isoindole dimer derivative of the present invention may be contained in the protective layer 39.

  FIG. 5 shows a structure in which a charge transport layer 37 mainly composed of a charge transport material and a charge generation layer 35 mainly composed of a charge generation material are laminated on a conductive support 31.

  FIG. 6 shows a configuration in which a charge transport layer 37 mainly composed of a charge transport material and a charge generation layer 35 mainly composed of a charge generation material are laminated on a conductive support 31. A protective layer 39 is provided on the charge generation layer. In this case, the naphthalene diimide-isoindole dimer derivative of the present invention may be contained in the protective layer 39.

Examples of the conductive support 31 include those having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, indium oxide, etc. The metal oxide of the above is coated with film or cylindrical plastic or paper by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel or the like and extruded by drawing or drawing. After pipe formation, surface treatment pipes such as cutting, superfinishing, and polishing can be used. Further, an endless nickel belt or an endless stainless steel belt disclosed in Japanese Patent Publication No. 52-36016 can also be used as the conductive support 31.

  In addition, a material obtained by dispersing conductive powder in an appropriate binder resin and coating it on the support can also be used as the conductive support 31 of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support 31 of the present invention.

  Next, the photosensitive layer will be described. Although the photosensitive layer may be a single layer or a laminated layer, for convenience of explanation, a case where it is composed of the charge generation layer 35 and the charge transport layer 37 will be described first.

  The charge generation layer 35 is a layer mainly composed of a charge generation material. A known charge generation material can be used for the charge generation layer 35, and representative examples thereof include C-I Pigment Blue 25 (Color Index CI 21180), C-I Pigment Red 41 (CI 21200), and C-I Acid Red 52 (CI). 45100), CI Basic Red 3 (CI 45210), azo pigments having a carbazole skeleton (described in JP-A-53-95033), azo pigments having a distyrylbenzene skeleton (JP-A-53-133445), An azo pigment having a triphenylamine skeleton (described in JP-A No. 53-132347), an azo pigment having a dibenzothiophene skeleton (described in JP-A No. 54-21728), an azo pigment having an oxadiazole skeleton ( Described in Japanese Patent Laid-Open No. 54-12742 ), An azo pigment having a fluorenone skeleton (described in JP-A-54-22834), an azo pigment having a bis-stilbene skeleton (described in JP-A-54-17733), an azo having a distyryloxadiazole skeleton Azo pigments such as pigments (described in JP-A No. 54-2129), azo pigments having a distyrylcarbazole skeleton (described in JP-A No. 54-14967), and azo pigments having a benzanthrone skeleton. For example, CI Pigment Blue 16 (CI 74100), Y-type oxotitanium phthalocyanine (Japanese Patent Laid-Open No. 64-17066), A (β) -type oxotitanium phthalocyanine, B (α) -type oxotitanium phthalocyanine, I-type oxotitanium phthalocyanine (Described in JP-A-11-21466), type II chlorogallium phthalocyanine (Iijima et al., The 67th Annual Meeting of the Chemical Society of Japan, 1B4, 04 (1994)), type V hydroxygallium phthalocyanine (Damon et al., The Chemical Society of Japan) 67th Spring Annual Meeting, 1B4, 05 (1994)), phthalocyanine pigments such as X-type metal-free phthalocyanine (U.S. Pat. No. 3,816,118), C-Ibat Brown 5 (CI 73410), C-Ibat Dye (CI) 7330) and other indigo pigments, Lugo (manufactured by Bayer Co., Ltd.) Scarlet B, such as perylene pigment, such as in-closet Ren Scarlet R (manufactured by Bayer Co., Ltd.) and the like. These materials may be used alone or in combination of two or more.

  In the charge generation layer 35, a charge generation material is dispersed in a suitable solvent together with a binder resin as necessary using a ball mill, an attritor, a sand mill, an ultrasonic wave, etc., and this is applied onto a conductive support. It is formed by drying.

  As the binder resin used for the charge generation layer 35 as necessary, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N -Vinylcarbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, etc. Can be mentioned. The amount of the binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generating material. The binder resin may be added before or after dispersion.

  Examples of the solvent used here include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, and ligroin. In particular, ketone solvents, ester solvents, and ether solvents are preferably used. These may be used alone or in combination of two or more.

The charge generation layer 35 includes a charge generation material, a solvent, and a binder resin as main components, and includes any additive such as a sensitizer, a dispersant, a surfactant, and silicone oil. Also good.
As a coating method for the coating solution, a dip coating method, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used.
The thickness of the charge generation layer 35 is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

  The charge transport layer 37 is a layer mainly composed of a charge transport material. The charge transport material is divided into a hole transport material, an electron transport material, and a polymer charge transport material, which will be described below.

  Examples of the hole transport material include poly-N-carbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, imidazole Derivatives, triphenylamine derivatives, compounds represented by the general formulas (2), (6), (7) and (10) and compounds represented by the following general formulas (16) to (35) ( General formula (2) and general formula (27), and general formula (6) and general formula (32) are the same.)

（式中、Ｒ_２６はメチル基、エチル基、２−ヒドロキシエチル基または２−クロルエチル基を表し、Ｒ_２９はメチル基、エチル基、ベンジル基またはフェニル基を表し、Ｒ_２８は水素原子、塩素原子、臭素原子、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、ジアルキルアミノ基またはニトロ基を表す。）
一般式（１６）で表される化合物には、例えば、９−エチルカルバゾール−３−カルボアルデヒド１−メチル−１−フェニルヒドラゾン、９−エチルカルバゾール−３−カルボアルデヒド １−ベンジル−１−フェニルヒドラゾン、９−エチルカルバゾール−３−カルボアルデヒド １、１−ジフェニルヒドラゾンなどがある

(Wherein R ₂₆ represents a methyl group, an ethyl group, a 2-hydroxyethyl group or a 2-chloroethyl group, R ₂₉ represents a methyl group, an ethyl group, a benzyl group or a phenyl group, R ₂₈ represents a hydrogen atom, chlorine An atom, a bromine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a dialkylamino group, or a nitro group is represented.)
Examples of the compound represented by the general formula (16) include 9-ethylcarbazole-3-carbaldehyde 1-methyl-1-phenylhydrazone, 9-ethylcarbazole-3-carbaldehyde 1-benzyl-1-phenylhydrazone. , 9-ethylcarbazole-3-carbaldehyde 1,1-diphenylhydrazone, etc.

（式中、Ａｒ_５はナフタレン環、アントラセン環、ピレン環及びそれらの置換体あるいはピリジン環、フラン環、チオフェン環を表し、Ｒ_３０はアルキル基、フェニル基またはベンジル基を表す。）
一般式（１７）で表される化合物には、例えば、４−ジエチルアミノスチリル−β−カルボアルデヒド １−メチル−１−フェニルヒドラゾン、４−メトキシナフタレン−１−カルボアルデヒド １−ベンジル−１−フェニルヒドラゾンなどがある。

(In the formula, Ar ₅ represents a naphthalene ring, an anthracene ring, a pyrene ring and a substituted product thereof, or a pyridine ring, a furan ring, or a thiophene ring, and R ₃₀ represents an alkyl group, a phenyl group, or a benzyl group.)
Examples of the compound represented by the general formula (17) include 4-diethylaminostyryl-β-carbaldehyde 1-methyl-1-phenylhydrazone, 4-methoxynaphthalene-1-carbaldehyde 1-benzyl-1-phenylhydrazone. and so on.

（式中、Ｒ_３１はアルキル基、ベンジル基、フェニル基またはナフチル基を表し、Ｒ_３２は水素原子、炭素数１〜３のアルキル基、炭素数１〜３のアルコキシ基、ジアルキルアミノ基、ジアラルキルアミノ基またはジアリールアミノ基を表し、ｎは１〜４の整数を表し、ｎが２以上のときはＲ_３２は同じでも異なっていても良い。Ｒ_３３は水素原子またはメトキシ基を表す。）
一般式（１８）で表される化合物には、例えば、４−メトキシベンズアルデヒド １−メチル−１−フェニルヒドラゾン、２、４−ジメトキシベンズアルデヒド １−ベンジル−１−フェニルヒドラゾン、４−ジエチルアミノベンズアルデヒド １、１−ジフェニルヒドラゾン、４−メトキシベンズアルデヒド １−（４−メトキシ）フェニルヒドラゾン、４−ジフェニルアミノベンズアルデヒド １−ベンジル−１−フェニルヒドラゾン、４−ジベンジルアミノベンズアルデヒド １、１−ジフェニルヒドラゾンなどがある。

(In the formula, R ₃₁ represents an alkyl group, a benzyl group, a phenyl group or a naphthyl group, and R ₃₂ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group, a dialkyl group) Represents an aralkylamino group or a diarylamino group, n represents an integer of 1 to 4, and when n is 2 or more, R ₃₂ may be the same or different, and R ₃₃ represents a hydrogen atom or a methoxy group.
Examples of the compound represented by the general formula (18) include 4-methoxybenzaldehyde 1-methyl-1-phenylhydrazone, 2,4-dimethoxybenzaldehyde 1-benzyl-1-phenylhydrazone, 4-diethylaminobenzaldehyde 1,1. -Diphenylhydrazone, 4-methoxybenzaldehyde 1- (4-methoxy) phenylhydrazone, 4-diphenylaminobenzaldehyde 1-benzyl-1-phenylhydrazone, 4-dibenzylaminobenzaldehyde 1,1-diphenylhydrazone and the like.

（式中、Ｒ_３４は炭素数１〜１１のアルキル基、置換もしくは無置換のフェニル基または複素環基を表し、Ｒ_３５、Ｒ_３６はそれぞれ同一でも異なっていてもよく、水素原子、炭素数１〜４のアルキル基、ヒドロキシアルキル基、クロルアルキル基または置換もしくは無置換のアラルキル基を表し、また、Ｒ_３５とＲ_３６は互いに結合し窒素を含む複素環を形成していても良い。 Ｒ_３７は同一でも異なっていてもよく、水素原子、炭素数１〜４のアルキル基、アルコキシ基またはハロゲン原子を表す。）
一般式（１９）で表される化合物には、例えば、１、１−ビス（４−ジベンジルアミノフェニル）プロパン、トリス（４−ジエチルアミノフェニル）メタン、１、１−ビス（４−ジベンジルアミノフェニル）プロパン、２，２’−ジメチル−４，４’−ビス（ジエチルアミノ）−トリフェニルメタンなどがある。

(In the formula, R ₃₄ represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group or a heterocyclic group, and R ₃₅ and R ₃₆ may be the same or different, and each represents a hydrogen atom or a carbon number. Represents an alkyl group of 1-4, a hydroxyalkyl group, a chloroalkyl group, or a substituted or unsubstituted aralkyl group, and R ₃₅ and R ₃₆ may be bonded to each other to form a nitrogen-containing heterocyclic ring. ₃₇ may be the same or different and each represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group or a halogen atom.
Examples of the compound represented by the general formula (19) include 1,1-bis (4-dibenzylaminophenyl) propane, tris (4-diethylaminophenyl) methane, 1,1-bis (4-dibenzylamino). Phenyl) propane, 2,2′-dimethyl-4,4′-bis (diethylamino) -triphenylmethane, and the like.

（式中、Ｒ_３８は水素原子またはハロゲン原子を表し、Ａｒ_６は置換もしくは無置換のフェニル基、ナフチル基、アントリル基またはカルバゾリル基を表す。）
一般式（２０）で表される化合物には、例えば、９−（４−ジエチルアミノスチリル）アントラセン、９−ブロム−１０−（４−ジエチルアミノスチリル）アントラセンなどがある。

(In the formula, R ₃₈ represents a hydrogen atom or a halogen atom, and Ar ₆ represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group, or carbazolyl group.)
Examples of the compound represented by the general formula (20) include 9- (4-diethylaminostyryl) anthracene and 9-bromo-10- (4-diethylaminostyryl) anthracene.

（式中、Ｒ_３９は水素原子、ハロゲン原子、シアノ基、炭素数１〜４のアルコキシ基または炭素数１〜４のアルル基を表し、Ａｒ_７は下記一般式（２２）、一般式（２３）を表す。

(In the formula, R ₃₉ represents a hydrogen atom, a halogen atom, a cyano group, an alkoxy group having 1 to 4 carbon atoms, or an allyl group having 1 to 4 carbon atoms, and Ar ₇ represents the following general formula (22), general formula (23 ).

Ｒ_４０は炭素数１〜４のアルキル基を表す。

R ₄₀ represents an alkyl group having 1 to 4 carbon atoms.

Ｒ_４１は水素原子、ハロゲン原子、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基またはジアルキルアミノ基を表し、ｎは１または２であって、ｎが２のとき、Ｒ４１は同一でも異なっていてもよく、Ｒ_４２、Ｒ_４３は水素原子、炭素数１〜４の置換もしくは無置換のアルキル基または置換もしくは無置換のベンジル基を表す。）
一般式（２１）で表される化合物には、例えば、９−（４−ジメチルアミノベンジリデン）フルオレン、３−（９−フルオレニリデン）−９−エチルカルバゾールなどがある。

R ₄₁ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a dialkylamino group, n is 1 or 2, and when n is 2, R ₄₁ is R ₄₂ and R ₄₃ may be the same or different and each represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted benzyl group. )
Examples of the compound represented by the general formula (21) include 9- (4-dimethylaminobenzylidene) fluorene and 3- (9-fluorenylidene) -9-ethylcarbazole.

（式中、Ｒ_４４はカルバゾリル基、ピリジル基、チエニル基、インドリル基、フリル基あるいはそれぞれ置換もしくは非置換のフェニル基、スチリル基、ナフチル基、またはアントリル基であって、これらの置換基がジアルキルアミノ基、アルキル基、アルコキシ基、カルボキシ基またはそのエステル、ハロゲン原子、シアノ基、アラルキルアミノ基、Ｎ−アルキル−Ｎ−アラルキルアミノ基、アミノ基、ニトロ基及びアセチルアミノ基からなる群から選ばれた基を表す。）
一般式（２４）で表される化合物には、例えば、１、２−ビス（４−ジエチルアミノスチリル）ベンゼン、１、２−ビス（２、４−ジメトキシスチリル）ベンゼンなどがある。

Wherein R ₄₄ is a carbazolyl group, pyridyl group, thienyl group, indolyl group, furyl group or a substituted or unsubstituted phenyl group, styryl group, naphthyl group, or anthryl group, and these substituents are dialkyl Selected from the group consisting of amino group, alkyl group, alkoxy group, carboxy group or ester thereof, halogen atom, cyano group, aralkylamino group, N-alkyl-N-aralkylamino group, amino group, nitro group and acetylamino group Represents a group.
Examples of the compound represented by the general formula (24) include 1,2-bis (4-diethylaminostyryl) benzene and 1,2-bis (2,4-dimethoxystyryl) benzene.

（式中、Ｒ_４１は低級アルキル基、置換もしくは無置換のフェニル基、またはベンジル基を表し、Ｒ_４２、Ｒ_４３は水素原子、低級アルキル基、低級アルコキシ基、ハロゲン原子、ニトロ基、アミノ基あるいは低級アルキル基またはベンジル基で置換されたアミノ基を表し、ｎは１または２の整数を表す。）
一般式（２５）で表される化合物には、例えば、３−スチリル−９−エチルカルバゾール、３−（４−メトキシスチリル）−９−エチルカルバゾールなどがある。

(In the formula, R ₄₁ represents a lower alkyl group, a substituted or unsubstituted phenyl group, or a benzyl group, and R ₄₂ and R ₄₃ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, and an amino group. Alternatively, it represents an amino group substituted with a lower alkyl group or a benzyl group, and n represents an integer of 1 or 2.)
Examples of the compound represented by the general formula (25) include 3-styryl-9-ethylcarbazole and 3- (4-methoxystyryl) -9-ethylcarbazole.

（式中、Ｒ_４４は水素原子、アルキル基、アルコキシ基またはハロゲン原子を表し、Ｒ_４５およびＲ_４６は置換もしくは無置換のアリール基を表し、Ｒ_４７は水素原子、低級アルキル基または置換もしくは無置換のフェニル基を表し、また、Ａｒ_８は置換もしくは無置換のフェニル基またはナフチル基を表す。）
一般式（２６）で表される化合物には、例えば、４−ジフェニルアミノスチルベン、４−ジベンジルアミノスチルベン、４−ジトリルアミノスチルベン、１−（４−ジフェニルアミノスチリル）ナフタレン、１−（４−ジフェニルアミノスチリル）ナフタレンなどがある。

(Wherein R ₄₄ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, R ₄₅ and R ₄₆ represent a substituted or unsubstituted aryl group, and R ₄₇ represents a hydrogen atom, a lower alkyl group or a substituted or unsubstituted group. Represents a substituted phenyl group, and Ar ₈ represents a substituted or unsubstituted phenyl group or a naphthyl group.)
Examples of the compound represented by the general formula (26) include 4-diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolylaminostilbene, 1- (4-diphenylaminostyryl) naphthalene, 1- (4 -Diphenylaminostyryl) naphthalene.

（式中、ｎは０または１の整数、Ｒ_４８は水素原子、置換もしくは無置換のアルキル基、または置換もしくは無置換の芳香族炭化水素基を表し、Ａｒ_９は置換もしくは無置換の芳香族炭化水素基を表し、Ｒ_４９は水素原子、置換もしくは無置換のアルキル基、あるいは置換もしくは無置換の芳香族炭化水素基を表し、Ａｒ_９とＲ_４９は共同で環を形成しても良い。Ａ_２は下記一般式（３）で表される基、一般式（４）で表される基、９−アントリル基または置換もしくは無置換のカルバゾリル基を表す。

Wherein n represents an integer of 0 or 1, R ₄₈ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₉ represents a substituted or unsubstituted aromatic group. Represents a hydrocarbon group, R ₄₉ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₉ and R ₄₉ may form a ring together. A ₂ represents a group represented by the following general formula (3), a group represented by the general formula (4), a 9-anthryl group, or a substituted or unsubstituted carbazolyl group.

ここでＲ_６は水素原子、アルキル基、アルコキシ基、ハロゲン原子または一般式（５）を表す。

Here, R ₆ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or general formula (5).

（ただし、Ｒ_７およびＲ_８は置換もしくは無置換のアリール基を示し、Ｒ_７およびＲ_８は同じでも異なっていてもよく、環を形成しても良い）を表し、ｍが２以上の時Ｒ_６は同一でも異なっても良い。また、ｎが０の時、ＡとＲ１は共同で環を形成しても良い。）
一般式（２７）で表される化合物には、例えば、４‘−ジフェニルアミノ−α−フェニルスチルベン、４‘−ビス（４−メチルフェニル）アミノ−α−フェニルスチルベンなどがある。

Wherein R ₇ and R ₈ represent a substituted or unsubstituted aryl group, and R ₇ and R ₈ may be the same or different and may form a ring, and when m is 2 or more R ₆ may be the same or different. When n is 0, A and R1 may form a ring together. )
Examples of the compound represented by the general formula (27) include 4′-diphenylamino-α-phenylstilbene and 4′-bis (4-methylphenyl) amino-α-phenylstilbene.

（式中、Ｒ_５０、Ｒ_５１およびＲ_５２は水素原子、低級アルキル基、低級アルコキシ基、ハロゲン原子またはジアルキルアミノ基を表し、ｎは０または１を表す。）
一般式（２８）で表される化合物には、例えば、１−フェニル−３−（４−ジエチルアミノスチリル）−５−（４−ジエチルアミノフェニル）ピラゾリンなどがある。

(In the formula, R ₅₀ , R ₅₁ and R ₅₂ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom or a dialkylamino group, and n represents 0 or 1.)
Examples of the compound represented by the general formula (28) include 1-phenyl-3- (4-diethylaminostyryl) -5- (4-diethylaminophenyl) pyrazoline.

（式中、Ｒ_５３およびＲ_５４は置換アルキル基を含むアルキル基、または置換もしくは未置換のアリール基を表し、Ａは置換アミノ基、置換もしくは未置換のアリール基またはアリル基を表す。）
一般式（２９）で表される化合物には、例えば、２、５−ビス（４−ジエチルアミノフェニル）−１，３，４−オキサジアゾール、２−Ｎ、Ｎ−ジフェニルアミノ−５−（４−ジエチルアミノフェニル）−１，３，４−オキサジアゾール、２−（４−ジメチルアミノフェニル）−５−（４−ジエチルアミノフェニル）−１，３，４−オキサジアゾールなどがある。

(In the formula, R ₅₃ and R ₅₄ represent an alkyl group containing a substituted alkyl group or a substituted or unsubstituted aryl group, and A represents a substituted amino group, a substituted or unsubstituted aryl group or an allyl group.)
Examples of the compound represented by the general formula (29) include 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, 2-N, N-diphenylamino-5- (4 -Diethylaminophenyl) -1,3,4-oxadiazole, 2- (4-dimethylaminophenyl) -5- (4-diethylaminophenyl) -1,3,4-oxadiazole and the like.

（式中、Ｘは水素原子、低級アルキル基またはハロゲン原子を表し、Ｒ_５５は置換アルキル基を含むアルキル基、または置換もしくは無置換のアリール基を表し、 Ａは置換アミノ基または置換もしくは無置換のアリール基を表す。）
一般式（３０）で表される化合物には、例えば、２−Ｎ、Ｎ−ジフェニルアミノ−５−（Ｎ−エチルカルバゾール−３−イル）−１，３，４−オキサジアゾール、２−（４−ジエチルアミノフェニル）−５−（Ｎ−エチルカルバゾール−３−イル）−１，３，４−オキサジアゾールなどがある。

(In the formula, X represents a hydrogen atom, a lower alkyl group or a halogen atom, R ₅₅ represents an alkyl group containing a substituted alkyl group, or a substituted or unsubstituted aryl group, and A represents a substituted amino group or a substituted or unsubstituted group. Represents an aryl group of
Examples of the compound represented by the general formula (30) include 2-N, N-diphenylamino-5- (N-ethylcarbazol-3-yl) -1,3,4-oxadiazole, 2- ( 4-diethylaminophenyl) -5- (N-ethylcarbazol-3-yl) -1,3,4-oxadiazole.

（式中、Ｒ_５６は低級アルキル基、低級アルコキシ基またはハロゲン原子を表し、Ｒ_５７、Ｒ_５８は同じでも異なっていてもよく、水素原子、低級アルキル基、低級アルコキシ基またはハロゲン原子を表し、ｌ、ｍ、ｎは０〜４の整数を表す。）
一般式（３１）で表されるベンジジン化合物には、例えば、Ｎ，Ｎ’−ジフェニル− Ｎ，Ｎ’−ビス（３−メチルフェニル）−[１，１’−ビフェニル]−４，４’−ジアミン、３，３’−ジメチル−Ｎ，Ｎ，Ｎ’，Ｎ’−テトラキス（４−メチルフェニル）−[１，１’−ビフェニル]−４，４’−ジアミンなどがある。

(In the formula, R ₅₆ represents a lower alkyl group, a lower alkoxy group or a halogen atom, R ₅₇ and R ₅₈ may be the same or different, and each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom; l, m, and n represent an integer of 0 to 4.)
Examples of the benzidine compound represented by the general formula (31) include N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-. Examples include diamine, 3,3′-dimethyl-N, N, N ′, N′-tetrakis (4-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine.

（式中、Ｒ_５９、Ｒ_６１およびＲ_６２は水素原子、アミノ基、アルコキシ基、チオアルコキシ基、アリールオキシ基、メチレンジオキシ基、置換もしくは無置換のアルキル基、ハロゲン原子または置換もしくは無置換の芳香族炭化水素基を、Ｒ_６０は水素原子、アルコキシ基、置換もしくは無置換のアルキル基またはハロゲン原子を表す。また、ｋ，ｌ，ｍおよびｎは１、２、３または４の整数であり、それぞれが２、３または４の整数の時は、前記Ｒ_５９、Ｒ_６０、Ｒ_６１およびＲ_６２は同じでも異なっていても良い。）
一般式（３２）で表されるビフェニルアミン化合物には、例えば、４’−メトキシ−Ｎ，Ｎ−ジフェニル−［１，１’−ビフェニル］−４−アミン、４’−メチル− Ｎ，Ｎ−ビス（４−メチルフェニル）−［１，１’−ビフェニル］−４−アミン、４’−メトキシ−Ｎ，Ｎ−ビス（４−メチルフェニル）−［１，１’−ビフェニル］−４−アミン、Ｎ，Ｎ−ビス（３，４−ジメチルフェニル）−［１，１‘−ビフェニル］−４−アミンなどがある。

Wherein R ₅₉ , R ₆₁ and R ₆₂ are a hydrogen atom, amino group, alkoxy group, thioalkoxy group, aryloxy group, methylenedioxy group, substituted or unsubstituted alkyl group, halogen atom or substituted or unsubstituted R ₆₀ represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or a halogen atom, and k, l, m and n are integers of 1, 2, 3 or 4. And when each is an integer of 2, 3 or 4, the R ₅₉ , R ₆₀ , R ₆₁ and R ₆₂ may be the same or different.)
Examples of the biphenylamine compound represented by the general formula (32) include 4′-methoxy-N, N-diphenyl- [1,1′-biphenyl] -4-amine, 4′-methyl-N, N—. Bis (4-methylphenyl)-[1,1′-biphenyl] -4-amine, 4′-methoxy-N, N-bis (4-methylphenyl)-[1,1′-biphenyl] -4-amine N, N-bis (3,4-dimethylphenyl)-[1,1′-biphenyl] -4-amine and the like.

（式中、Ａｒ_１０は置換基を有してもよい炭素数１８個以下の縮合多環式炭化水素基を表し、また、Ｒ_６３およびＲ_６４は水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、アルコキシ基、置換もしくは無置換のフェニル基を表し、それぞれ同じでも異なっていても良い。ｎは１もしくは２の整数を表す。）
一般式（３３）で表されるトリアリールアミン化合物には、例えば、Ｎ，Ｎ−ジフェニル−ピレン−１−アミン、Ｎ，Ｎ−ジ−ｐ−トリル−ピレン−１−アミン、Ｎ，Ｎ−ジ−ｐ−トリル−１−ナフチルアミン、Ｎ，Ｎ−ジ（ｐ−トリル）−１−フェナントリルアミン、９，９−ジメチル−２−（ジ−ｐ−トリルアミノ）フルオレン、Ｎ，Ｎ，Ｎ‘，Ｎ’−テトラキス（４−メチルフェニル）−フェナントレン−９，１０−ジアミン、Ｎ，Ｎ，Ｎ’，Ｎ’−テトラキス（３−メチルフェニル）−ｍ−フェニレンジアミンなどがある。

(In the formula, Ar ₁₀ represents an optionally substituted condensed polycyclic hydrocarbon group having 18 or less carbon atoms, and R ₆₃ and R ₆₄ are hydrogen atoms, halogen atoms, substituted or unsubstituted groups. An alkyl group, an alkoxy group, a substituted or unsubstituted phenyl group, which may be the same or different, and n represents an integer of 1 or 2.)
Examples of the triarylamine compound represented by the general formula (33) include N, N-diphenyl-pyren-1-amine, N, N-di-p-tolyl-pyren-1-amine, and N, N- Di-p-tolyl-1-naphthylamine, N, N-di (p-tolyl) -1-phenanthrylamine, 9,9-dimethyl-2- (di-p-tolylamino) fluorene, N, N, N Examples include ', N'-tetrakis (4-methylphenyl) -phenanthrene-9,10-diamine and N, N, N', N'-tetrakis (3-methylphenyl) -m-phenylenediamine.

（式中、Ａｒ_１１は置換もしくは無置換の芳香族炭化水素基を表し、Ａは下記一般式（ａ）を表す。

(In the formula, Ar ₁₁ represents a substituted or unsubstituted aromatic hydrocarbon group, and A represents the following general formula (a).

（ただし、Ａｒ_１２は置換もしくは無置換の芳香族炭化水素基を表し、Ｒ_６５およびＲ_６６は置換もしくは無置換のアルキル基、または置換もしくは無置換のアリール基である。）
を表す。）
一般式（３４）で表されるジオレフィン芳香族化合物には、例えば、１、４−ビス（４−ジフェニルアミノスチリル）ベンゼン、１、４−ビス[４−ジ（ｐ−トリル）アミノスチリル]ベンゼンなどがある。

(However, Ar ₁₂ represents a substituted or unsubstituted aromatic hydrocarbon group, and R ₆₅ and R ₆₆ are a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.)
Represents. )
Examples of the diolefin aromatic compound represented by the general formula (34) include 1,4-bis (4-diphenylaminostyryl) benzene and 1,4-bis [4-di (p-tolyl) aminostyryl]. There is benzene.

（式中、Ａｒ_１２は置換もしくは無置換の芳香族炭化水素基を、Ｒ_６７は水素原子、置換もしくは無置換のアルキル基、または置換もしくは無置換のアリール基を表す。ｎは０または１、ｍは１または２であって、ｎ＝０、ｍ＝１の場合、Ａｒ_１２とＲ_６７は共同で環を形成しても良い。）
一般式（３５）で表されるスチリルピレン化合物には、例えば、１−（４−ジフェニルアミノスチリル）ピレン、１−（Ｎ，Ｎ−ジ−ｐ−トリル−４−アミノスチリル）ピレンなどがある。

(In the formula, Ar ₁₂ represents a substituted or unsubstituted aromatic hydrocarbon group, R ₆₇ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. N is 0 or 1, m is 1 or 2, and when n = 0 and m = 1, Ar ₁₂ and R ₆₇ may jointly form a ring.)
Examples of the styrylpyrene compound represented by the general formula (35) include 1- (4-diphenylaminostyryl) pyrene and 1- (N, N-di-p-tolyl-4-aminostyryl) pyrene.

Examples of the electron transport material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-indeno4H-indeno [1,2-b] thiophen-4-one, 1,3 , 7-trinitrodibenzothiophene-5,5-dioxide, and the compounds represented by the general formulas (11), (12), (14) and (15) and the following general formula Compounds represented by (36) to (39) can be preferably used (in addition, general formula (11), general formula (37), general formula (12), and general formula (39) It is the same thing.)
These charge transport materials may be used alone or in combination of two or more.

（式中Ｒ_６８、Ｒ_６９およびＲ_７０は水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、アルコキシ基、置換もしくは無置換のフェニル基を表し、それぞれ同じでも異なっていても良い。）

(Wherein R ₆₈ , R ₆₉ and R ₇₀ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted phenyl group, and may be the same or different.)

（式中Ｒ_７１、Ｒ_７２は水素原子、置換もしくは無置換のアルキル基、置換もしくは無置換の芳香族炭化水素基を表し、それぞれ同じでも異なっていても良い。）

(Wherein R ₇₁ and R _{72 each} represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different.)

（式中Ｒ_７３、Ｒ_７４およびＲ_７５は水素原子、ハロゲン原子、置換もしくは無置換のアルキル基、アルコキシ基、置換もしくは無置換のフェニル基を表し、それぞれ同じでも異なっていても良い。）

(Wherein R ₇₃ , R ₇₄ and R _{75 each} represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, or a substituted or unsubstituted phenyl group, and may be the same or different.)

〔式中、Ｒ_７６は置換基を有してもよいアルキル基、または置換基を有してもよいアリール基を示し、Ｒ_７７は置換基を有してもよいアルキル基、置換基を有してもよいアリール基、または下記一般式（ｂ）で表される基を示す。

[Wherein, R ₇₆ represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and R ₇₇ has an alkyl group which may have a substituent or a substituent. An aryl group which may be substituted, or a group represented by the following general formula (b) is shown.

〔Ｒ_７８は、置換基を有してもよいアルキル基、または置換基を有してもよいアリール基を示す。〕

[R ₇₈ represents an alkyl group which may have a substituent, or an aryl group which may have a substituent. ]

  As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin And thermoplastic or thermosetting resins such as phenol resins and alkyd resins.

  When the charge transport material and the naphthalene diimide-isoindole dimer derivative of the present invention are mixed and contained in the charge transport layer, the total amount is 20 to 300 parts by weight, preferably 40 to 40 parts by weight with respect to 100 parts by weight of the binder resin. 150 parts by weight is suitable. The thickness of the charge transport layer is preferably 25 μm or less from the viewpoint of resolution and responsiveness. Regarding the lower limit, although it differs depending on the system to be used (particularly the charging potential), 5 μm or more is preferable.

The amount of the naphthalenediimide-isoindole dimer derivative of the present invention is preferably 0.01 wt% to 150 wt% with respect to the charge transport material. If the amount is too small, the resistance to the oxidizing gas is insufficient. If the amount is too large, the residual potential increases greatly due to repeated use.
As the solvent used here, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used. The charge transport materials may be used alone or in combination of two or more.

As the antioxidant that can be used in the present invention, a general antioxidant described later can be used, and (c) hydroquinone-based compounds and (f) hindered amine-based compounds are particularly effective. However, the antioxidant used here is used for the alteration protection of the naphthalenediimide-isoindole dimer derivative used in the present invention, unlike the purpose described later.
For this reason, these antioxidants are preferably contained in the coating liquid in the step prior to containing the naphthalene diimide-isoindole dimer derivative of the present invention, and the addition amount is naphthalene diimide-isoindole dimer. A sufficient effect can be exhibited at 0.1 to 200 wt% with respect to the derivative.

  For the charge transport layer, a polymer charge transport material having a function as a charge transport material and a function as a binder resin is also preferably used. The charge transport layer composed of these polymer charge transport materials is excellent in wear resistance. As the polymer charge transport material, known materials can be used, and in particular, a polycarbonate containing a triarylamine structure in the main chain and / or side chain is preferably used. Among these, polymer charge transport materials represented by the structural formulas (I) to (XIII) are preferably used. These are illustrated below and specific examples are shown.

式中、Ｒ_７９，Ｒ_８０，Ｒ_８１はそれぞれ独立して置換もしくは無置換のアルキル基又はハロゲン原子、Ｒ_８４は水素原子又は置換もしくは無置換のアルキル基、Ｒ_８２，Ｒ_８３は置換もしくは無置換のアリール基、ｏ，ｐ，ｑはそれぞれ独立して０〜４の整数、ｋ，ｊは組成を表し、０．１≦ｋ≦１、０≦ｊ≦０．９、ｎは繰り返し単位数を表し５〜５０００の整数である。Ｘは脂肪族の２価基、環状脂肪族の２価基、または下記構造式（II）で表される２価基を表す。

In the formula, R ₇₉ , R ₈₀ and R ₈₁ are each independently a substituted or unsubstituted alkyl group or a halogen atom, R ₈₄ is a hydrogen atom or a substituted or unsubstituted alkyl group, and R ₈₂ and R ₈₃ are substituted or unsubstituted. Substituted aryl group, o, p and q are each independently an integer of 0 to 4, k and j are compositions, 0.1 ≦ k ≦ 1, 0 ≦ j ≦ 0.9, and n is the number of repeating units Represents an integer of 5 to 5000. X represents an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following structural formula (II).

式中、Ｒ_８４，Ｒ_８５は各々独立して置換もしくは無置換のアルキル基、アリール基またはハロゲン原子を表す。ｌ、ｍは０〜４の整数、Ｙは単結合、炭素原子数１〜１２の直鎖状、分岐状もしくは環状のアルキレン基、−Ｏ−，−Ｓ−，−ＳＯ−，−ＳＯ_２−，−ＣＯ−，−ＣＯ−Ｏ−Ｚ−Ｏ−ＣＯ−（式中Ｚは脂肪族の２価基を表す。）または、下記構造式（III）を表す。

In the formula, R ₈₄ and R ₈₅ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom. l and m are integers of 0 to 4, Y is a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —. , —CO—, —CO—O—Z—O—CO— (wherein Z represents an aliphatic divalent group) or the following structural formula (III).

（式中、ａは１〜２０の整数、ｂは１〜２０００の整数、Ｒ₈₆、Ｒ₈₇は置換または無置換のアルキル基又はアリール基を表す。）を表す。ここで、Ｒ₈₄とＲ₈₅，Ｒ₈₆とＲ₈₇は、それぞれ同一でも異なってもよい。

(Wherein, a represents an integer of 1 to 20, b represents an integer of 1 to 2000, R ₈₆ and R ₈₇ represent a substituted or unsubstituted alkyl group or aryl group). Here, R ₈₄ and R ₈₅ , R ₈₆ and R ₈₇ may be the same or different.

式中、Ｒ_８８，Ｒ_８９は置換もしくは無置換のアリール基、Ａｒ_１３，Ａｒ_１４，Ａｒ_１５は同一あるいは異なるアリレン基を表す。Ｘ，ｋ，ｊおよびｎは、上記構造式（Ｉ）式の場合と同じである。

In the formula, R ₈₈ and R ₈₉ represent a substituted or unsubstituted aryl group, and Ar ₁₃ , Ar ₁₄ , and Ar ₁₅ represent the same or different arylene groups. X, k, j and n are the same as those in the above formula (I).

式中、Ｒ_９０，Ｒ_９１は置換もしくは無置換のアリール基、Ａｒ_１６，Ａｒ_１７，Ａｒ_１８は同一あるいは異なるアリレン基を表す。Ｘ，ｋ，ｊおよびｎは、上記構造式（Ｉ）式の場合と同じである。

In the formula, R ₉₀ and R ₉₁ represent a substituted or unsubstituted aryl group, and Ar ₁₆ , Ar ₁₇ and Ar ₁₈ represent the same or different arylene groups. X, k, j and n are the same as those in the above formula (I).

式中、Ｒ₉₂，Ｒ₉₃は置換もしくは無置換のアリール基、Ａｒ₁₉，Ａｒ₂₀，Ａｒ₂₁は同一あるいは異なるアリレン基、ｐは１〜５の整数を表す。Ｘ，ｋ，ｊおよびｎは、上記構造式（I）式の場合と同じである。

In the formula, R ₉₂ and R ₉₃ are substituted or unsubstituted aryl groups, Ar ₁₉ , Ar ₂₀ and Ar ₂₁ are the same or different arylene groups, and p represents an integer of 1 to 5. X, k, j and n are the same as in the case of the above structural formula (I).

式中、Ｒ_９４，Ｒ_９５は置換もしくは無置換のアリール基、Ａｒ_２２，Ａｒ_２３，Ａｒ_２４は同一あるいは異なるアリレン基、Ｘ_１，Ｘ_２は置換もしくは無置換のエチレン基、又は置換もしくは無置換のビニレン基を表す。Ｘ，ｋ，ｊおよびｎは、上記構造式（Ｉ）式の場合と同じである。

In the formula, R ₉₄ and R ₉₅ are substituted or unsubstituted aryl groups, Ar ₂₂ , Ar ₂₃ and Ar ₂₄ are the same or different arylene groups, X ₁ and X ₂ are substituted or unsubstituted ethylene groups, or substituted or unsubstituted Represents a substituted vinylene group. X, k, j and n are the same as those in the above formula (I).

式中、Ｒ_９６，Ｒ_９７，Ｒ_９８，Ｒ_９９は置換もしくは無置換のアリール基、Ａｒ_２５，Ａｒ_２６，Ａｒ_２７，Ａｒ_２８は同一あるいは異なるアリレン基、Ｙ_１，Ｙ_２，Ｙ_３は単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表し同一であっても異なってもよい。Ｘ，ｋ，ｊおよびｎは、上記構造式（Ｉ）式の場合と同じである。

In the formula, R ₉₆ , R ₉₇ , R ₉₈ and R ₉₉ are substituted or unsubstituted aryl groups, Ar ₂₅ , Ar ₂₆ , Ar ₂₇ and Ar ₂₈ are the same or different arylene groups, and Y ₁ , Y ₂ and Y ₃ are A single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group may be the same or different. X, k, j and n are the same as those in the above formula (I).

式中、Ｒ_１００，Ｒ１０１は水素原子、置換もしくは無置換のアリール基を表し，Ｒ_１００とＲ_１０１は環を形成していてもよい。Ａｒ_２９，Ａｒ_３０，Ａｒ_３１は同一あるいは異なるアリレン基を表す。Ｘ，ｋ，ｊおよびｎは、上記構造式（Ｉ）式の場合と同じである。

_Wherein, R 100, R101 represents a hydrogen atom, a substituted or unsubstituted aryl _{group, R 100} and _{R 101} may form a ring. Ar ₂₉ , Ar ₃₀ and Ar ₃₁ represent the same or different arylene groups. X, k, j and n are the same as those in the above formula (I).

式中、Ｒ_１０２は置換もしくは無置換のアリール基、Ａｒ_３２，Ａｒ_３３，Ａｒ_３４，Ａｒ_３５は同一あるいは異なるアリレン基を表す。Ｘ，ｋ，ｊおよびｎは、上記構造式（Ｉ）式の場合と同じである。

In the formula, R ₁₀₂ represents a substituted or unsubstituted aryl group, and Ar ₃₂ , Ar ₃₃ , Ar ₃₄ , and Ar ₃₅ represent the same or different arylene groups. X, k, j and n are the same as those in the above formula (I).

式中、Ｒ_１０３，Ｒ_１０４，Ｒ_１０５，Ｒ_１０６は置換もしくは無置換のアリール基、Ａｒ_３６，Ａｒ_３７，Ａｒ_３８，Ａｒ_３９，Ａｒ_４０は同一あるいは又は異なるアリレン基を表す。Ｘ，ｋ，ｊおよびｎは、上記構造式（Ｉ）式の場合と同じである。

In the formula, R ₁₀₃ , R ₁₀₄ , R ₁₀₅ , and R ₁₀₆ represent substituted or unsubstituted aryl groups, and Ar ₃₆ , Ar ₃₇ , Ar ₃₈ , Ar ₃₉ , and Ar ₄₀ represent the same or different arylene groups. X, k, j and n are the same as those in the above formula (I).

式中、Ｒ_１０７，Ｒ_１０８は置換もしくは無置換のアリール基、Ａｒ_４１，Ａｒ_４２，Ａｒ_４３は同一あるいは異なるアリレン基を表す。Ｘ，ｋ，ｊおよびｎは、上記構造式（Ｉ）式の場合と同じである。

In the formula, R ₁₀₇ and R ₁₀₈ represent substituted or unsubstituted aryl groups, and Ar ₄₁ , Ar ₄₂ , and Ar ₄₃ represent the same or different arylene groups. X, k, j and n are the same as those in the above formula (I).

（式中、Ａｒ_４４、Ａｒ_４５、Ａｒ_４６、Ａｒ_４７およびＡｒ_４８は置換もしくは無置換の芳香環基、Ｚは芳香環基または―Ａｒ_４９―Ｚａ―Ａｒ_４９―を表し、Ａｒ_４９は置換もしくは無置換の芳香環基、ＺａはＯ、Ｓまたはアルキレン基、Ｒ１０９およびＲ_１１０は直鎖又は分岐鎖のアルキレン基を表す。ｍは０または１を表す。ｋ、ｊ、ｎ及びＸは前式と同じ。）

(In the formula, Ar ₄₄ , Ar ₄₅ , Ar ₄₆ , Ar ₄₇ and Ar ₄₈ represent a substituted or unsubstituted aromatic ring group, Z represents an aromatic ring group or —Ar ₄₉ —Za—Ar ₄₉ —, and Ar ₄₉ represents a substituted group. or unsubstituted aromatic ring group, Za is O, S or an alkylene group, R109 and _{R 110} are .k is .m representing an alkylene group having a straight or branched chain represents 0 or 1, j, n and X are pre Same as formula.)

The charge transport layer 37 can be formed by dissolving or dispersing a charge transport material alone or in a binder resin and an appropriate solvent, and applying and drying this on the charge generation layer. Further, if necessary, two or more kinds of plasticizers, leveling agents, antioxidants and the like can be added.
As a coating method of the coating liquid obtained as described above, conventional coating methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, and the like can be used.

Next, the case where the photosensitive layer has a single layer structure 33 will be described. A photoreceptor in which the above-described charge generating material is dispersed in a binder resin can be used. The photosensitive layer can be formed by dissolving or dispersing a charge generating substance, a charge transporting substance, and a binder resin in a suitable solvent, and applying and drying them.
Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.

  As the binder resin, in addition to the binder resin previously mentioned in the charge transport layer 37, the binder resin mentioned in the charge generation layer 35 may be mixed and used. Of course, the polymer charge transport materials mentioned above can also be used favorably. The amount of the charge generating material with respect to 100 parts by weight of the binder resin is preferably 5 to 40 parts by weight, and the amount of the charge transporting material is preferably 0 to 190 parts by weight, and more preferably 50 to 150 parts by weight. The photosensitive layer is formed by dip coating, spray coating, bead coating, a coating solution in which a charge generating material and a binder resin are dispersed together with a charge transporting material using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane. It can be formed by coating with a ring coat or the like. The film thickness of the photosensitive layer is suitably about 5 to 25 μm.

  In the photoreceptor of the present invention, an undercoat layer can be provided between the conductive support 31 and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, the resin may be a resin having high solvent resistance with respect to a general organic solvent. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. Further, a metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential.

These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. In addition, in the undercoat layer of the present invention, Al ₂ O ₃ is provided by anodization, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can also be used favorably. In addition, known ones can be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.

  In the photoreceptor of the present invention, the protective layer 39 may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer. Materials used for the protective layer 39 are ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene. , Polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, polyarylate, AS resin, butadiene-styrene copolymer, polyurethane, poly Examples thereof include resins such as vinyl chloride, polyvinylidene chloride, and epoxy resin. From the viewpoint of filler dispersibility, residual potential, and coating film defects, polycarbonate or polyarylate is particularly effective and useful.

  A filler material is added to the protective layer of the photoreceptor for the purpose of improving the wear resistance. As the solvent to be used, all solvents used in the charge transport layer 37 such as tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, and acetone can be used. However, a solvent having a high viscosity is preferable at the time of dispersion, but a solvent having high volatility is preferable at the time of coating. When there is no solvent satisfying these conditions, it is possible to use a mixture of two or more solvents having respective physical properties, which may have a great effect on filler dispersibility and residual potential. .

Further, the naphthalene diimide-isoindole dimer derivative of the present invention may be contained in the protective layer. Furthermore, the addition of the low molecular charge transport material or the polymer charge transport material mentioned in the charge transport layer 37 is effective and useful for reducing the residual potential and improving the image quality.
As a method for forming the protective layer, conventional methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, etc. can be used. preferable.

  In the photoreceptor of the present invention, an intermediate layer can be provided between the photosensitive layer and the protective layer. In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a generally used coating method as described above is employed. In addition, about 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer.

  In the present invention, in order to improve environmental resistance, in order to prevent a decrease in sensitivity and an increase in residual potential, oxidation is performed on each layer such as a charge generation layer, a charge transport layer, an undercoat layer, a protective layer, and an intermediate layer. Inhibitors, plasticizers, lubricants, UV absorbers and leveling agents can be added. Representative materials of these compounds are described below.

  Examples of the antioxidant that can be added to each layer include, but are not limited to, the following.

(A) Phenolic compounds 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, n-octadecyl -3- (4'-hydroxy-3 ', 5'-di-t-butylphenol), 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'- Methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis- (3-methyl) -6-tert-butylphenol), 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6- Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [meth -3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy-3′-t-butylphenyl) ) Butyric acid] cricol ester, tocopherols and the like.

(B) Paraphenylenediamines N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylene Diamine, N, N′-di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.

(C) Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2 -(2-octadecenyl) -5-methylhydroquinone and the like.

(D) Organic sulfur compounds dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.

(E) Organic phosphorus compounds Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine and the like.

(F) HALS (hindered amine)
Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6 6-tetramethylpyridine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy- 2,2,6,6-tetramethylpiperidine and the like.

  Examples of the plasticizer that can be added to each layer include, but are not limited to, the following.

(A) Phosphate ester plasticizer Triphenyl phosphate, tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, trichloroethyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, Triphenyl phosphate etc.

(B) Phthalate ester plasticizers Dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, phthalate Dinonyl acid, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate, butyl lauryl phthalate, methyl oleyl phthalate, octyl decyl phthalate, dibutyl fumarate, dioctyl fumarate Such.

(C) Aromatic carboxylic acid ester plasticizers Trioctyl trimellitic acid, tri-n-octyl trimellitic acid, octyl oxybenzoate, and the like.

(D) Aliphatic dibasic ester plasticizer dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, di-n-octyl adipate, adipic acid n-octyl-n-decyl Diisodecyl adipate, dicapryl adipate, di-2-ethylhexyl azelate, dimethyl sebacate, diethyl sebacate, dibutyl sebacate, di-n-octyl sebacate, di-2-ethylhexyl sebacate, di-2 sebacate -Ethoxyethyl, dioctyl succinate, diisodecyl succinate, dioctyl tetrahydrophthalate, di-n-octyl tetrahydrophthalate and the like.

(E) Fatty acid ester derivatives butyl oleate, glycerin monooleate, methyl acetylricinoleate, pentaerythritol ester, dipentaerythritol hexaester, triacetin, tributyrin and the like.

(F) Oxyacid ester plasticizers Methyl acetyl ricinoleate, butyl acetyl ricinoleate, butyl phthalyl butyl glycolate, tributyl acetyl citrate and the like.

(G) Epoxy plasticizer Epoxidized soybean oil, epoxidized linseed oil, butyl epoxy stearate, decyl epoxy stearate, octyl epoxy stearate, benzyl epoxy stearate, dioctyl epoxy hexahydrophthalate, didecyl epoxy hexahydrophthalate, etc. .

(H) Dihydric alcohol ester plasticizers such as diethylene glycol dibenzoate and triethylene glycol di-2-ethylbutyrate.
(I) Chlorinated plasticizer Chlorinated paraffin, chlorinated diphenyl, chlorinated fatty acid methyl, methoxychlorinated fatty acid methyl and the like.
(J) Polyester plasticizer Polypropylene adipate, polypropylene sebacate, polyester, acetylated polyester and the like.
(K) Sulfonic acid derivatives p-toluenesulfonamide, o-toluenesulfonamide, p-toluenesulfoneethylamide, o-toluenesulfoneethylamide, toluenesulfone-N-ethylamide, p-toluenesulfone-N-cyclohexylamide and the like.

(L) Citric acid derivatives Triethyl citrate, triethyl acetylcitrate, tributyl citrate, tributyl acetylcitrate, tri-2-ethylhexyl acetylcitrate, acetylcitrate-n-octyldecyl, and the like.
(M) Others Terphenyl, partially hydrogenated terphenyl, camphor, 2-nitrodiphenyl, dinonylnaphthalene, methyl abietate and the like.

  Examples of the lubricant that can be added to each layer include, but are not limited to, the following.

(A) Hydrocarbon compounds Liquid paraffin, paraffin wax, microwax, low-polymerized polyethylene and the like.
(B) Fatty acid compounds Lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and the like.
(C) Fatty acid amide compounds Stearylamide, palmitylamide, oleinamide, methylenebisstearamide, ethylenebisstearamide and the like.
(D) Ester compounds Lower alcohol esters of fatty acids, polyhydric alcohol esters of fatty acids, fatty acid polyglycol esters, and the like.

(E) Alcohol compounds Cetyl alcohol, stearyl alcohol, ethylene glycol, polyethylene glycol, polyglycerol and the like.
(F) Metal soap Lead stearate, cadmium stearate, barium stearate, calcium stearate, zinc stearate, magnesium stearate and the like.
(G) Natural wax Carnauba wax, candelilla wax, beeswax, whale wax, ivotaro, montan wax and the like.
(H) Others Silicone compounds, fluorine compounds, etc.

  Examples of the ultraviolet absorber that can be added to each layer include, but are not limited to, the following.

(A) Benzophenone series 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ′, 4-trihydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4- Such as methoxybenzophenone.

(B) Salsylate type Phenyl salsylate, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, and the like.

(C) benzotriazole (2′-hydroxyphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy3) '-Tert-butyl-5'-methylphenyl) 5-chlorobenzotriazole

(D) Cyanoacrylate-based ethyl-2-cyano-3,3-diphenyl acrylate, methyl 2-carbomethoxy-3- (paramethoxy) acrylate, and the like.

(E) Quencher (metal complex)
Nickel (2,2′thiobis (4-t-octyl) phenolate) normal butylamine, nickel dibutyldithiocarbamate, nickel dibutyldithiocarbamate, cobalt dicyclohexyldithiophosphate and the like.

(F) HALS (hindered amine)
Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6 6-tetramethylpyridine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy- 2,2,6,6-tetramethylpiperidine and the like.

Next, the electrophotographic method and the electrophotographic apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 7 is a schematic view for explaining the electrophotographic process and the electrophotographic apparatus of the present invention, and the following examples also belong to the category of the present invention.
In FIG. 7, the photosensitive member 1 has a drum shape, but may be a sheet shape or an endless belt shape. As the charging charger 3, the pre-transfer charger 7, the transfer charger 10, the separation charger 11, and the pre-cleaning charger 13, a corotron, a scorotron, a solid charger (solid state charger), a charging roller, or the like is used, and known means are used. All are usable.
As the transfer means, the above charger can be generally used. However, as shown in the figure, a combination of a transfer charger and a separation charger is effective.

  The light source such as the image exposure unit 5 and the charge removal lamp 2 emits light such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). All things can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

In addition to the steps shown in FIG. 7, the light source or the like is provided with a transfer step, a static elimination step, a cleaning step, or a pre-exposure step that uses light irradiation in combination to irradiate the photoreceptor with light.
The toner developed on the photosensitive member 1 by the developing unit 6 is transferred to the transfer paper 9, but not all is transferred, and some toner remains on the photosensitive member 1. Such toner is removed from the photoreceptor by the fur brush 14 and the cleaning blade 15. Cleaning may be performed only with a cleaning brush, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.

  When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. When this is developed with negative (positive) polarity toner (electrodetection fine particles), a positive image can be obtained, and when developed with positive (negative) polarity toner, a negative image can be obtained. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.

  FIG. 8 shows another example of the electrophotographic process according to the present invention. The photosensitive member 21 has at least a photosensitive layer, and is driven by driving rollers 22a and 22b. The photosensitive member 21 is charged by a charger 23, image exposure by a light source 24, development (not shown), transfer using a charger 25, and cleaning by a light source 26. Pre-exposure, cleaning with the cleaning brush 27, and static elimination with the light source 28 are repeated. In FIG. 8, the photoconductor 21 (of course, the support is translucent in this case) is irradiated with pre-cleaning exposure light from the support side.

The above illustrated electrophotographic process is illustrative of an embodiment of the present invention, and of course other embodiments are possible. For example, in FIG. 8, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or image exposure and neutralization light irradiation may be performed from the support side.
On the other hand, the light irradiation process is illustrated as image exposure, pre-cleaning exposure, and static elimination exposure. In addition, a pre-transfer exposure, a pre-exposure of image exposure, and other known light irradiation processes are provided to light the photosensitive member. Irradiation can also be performed.

  The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge. A process cartridge is a single device (part) that contains a photosensitive member and includes a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit. There are many shapes and the like of the process cartridge, but a general example is shown in FIG. The photoreceptor 16 has at least a photosensitive layer on a conductive support.

[Production example]
(Production Example of Exemplified Compound No. 12)
2-amino-1,3-diphenyl-5,6-dimethylisoindole 4.92 g (15.75 mmol), naphthalenetetracarboxylic dianhydride 2.01 g (7.5 mmol), N, N-dimethylformamide (dehydration) ) 100 ml and acetic acid 2 ml were added to the flask and heated to reflux for 4 hours. After cooling, the solvent was distilled off under reduced pressure. The residue was dissolved in a toluene / THF mixed solvent having a volume ratio of 100 to 1, and purified by alumina column chromatography. Further, recrystallization was performed with a toluene / THF mixed solvent to obtain 1.81 g (yield 28.1%) of naphthalenetetracarboxylic acid diimide bisindole as brownish green plate crystals.
The reaction formula is shown below. In addition, the obtained Exemplified Compound No. The IR spectrum of 12 is shown in FIG.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not restrict | limited by an Example. All parts are parts by weight.

[Example 1]
An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are sequentially applied onto an aluminum cylinder by dip coating and dried to obtain a 3.5 μm undercoat layer, 0. A 2 μm charge generation layer and a 23 μm charge transport layer were formed (photosensitive member No. 1).
◎ Undercoat layer coating liquid ・ Titanium dioxide powder (Ishihara Sangyo, Tybak CR-EL): 400 parts ・ Melamine resin (Dainippon Ink, Super Becamine G821-60): 65 parts ・ Alkyd resin (Dainippon Ink) Manufactured by Beckolite M6401-50): 120 parts ・ 2-butanone: 400 parts ◎ Charge generation layer coating solution Fluorenone bisazo pigment having the following structure: 12 parts

・ポリビニルブチラール（ユニオンカーバイド製、ＸＹＨＬ） ： ５部
・２−ブタノン ：２００部
・シクロヘキサノン ：４００部
◎電荷輸送層塗工液
・ポリカーボネート樹脂（Ｚポリカ、帝人化成製） ：１０部
・例示化合物Ｎｏ．１２のナフタレンジイミド−イソインドールダイマー誘導体
：１０部
・テトラヒドロフラン ：１００部

Polyvinyl butyral (manufactured by Union Carbide, XYHL): 5 parts 2-butanone: 200 parts Cyclohexanone: 400 parts Charge transport layer coating solution Polycarbonate resin (Z Polyca, manufactured by Teijin Chemicals): 10 parts Illustrative compound No . 12 naphthalene diimide-isoindole dimer derivatives
: 10 parts Tetrahydrofuran: 100 parts

  Ricoh's imagio MF2200 remodeling machine, in which the electrophotographic photosensitive member produced as described above is mounted on an electrophotographic process cartridge, the charging method is a positive charging corona charging method, and the image exposure light source is a 655 nm semiconductor laser (LD). After setting the dark part potential to 800 (V), a repeated test corresponding to printing a total of 100,000 sheets was continuously performed. At that time, the initial portion and the light portion potential (V) after repeated tests and images were evaluated. In addition, for image blur (dot resolution), ten consecutive dot images with a pixel density of 600 dpi × 600 dpi and an image density of 5% are printed out, and the dot shape is observed with a stereomicroscope. The evaluation was divided into five levels (5 is excellent and 1 is inferior).

(Dot image evaluation criteria)
5: The outline is clear and good.
4: Very slight blurring of outline is observed, but good.
3: Substantially blurred outlines are observed but substantially good.
2: Blurred outlines are observed, which may be a problem depending on the type of image.
1: The dot image cannot be identified.
The results are shown in Table 2.

[Examples 2 to 15]
In Example 1, Exemplified Compound No. In the same manner as in Example 1, except that the compounds shown in Table 2 were used instead of the naphthalene diimide-isoindole dimer derivative of No. 12, the electrophotographic photoreceptor No. 2 to 15 were prepared and evaluated. The results are also shown in Table 1.

[Example 16]
Except that the charge transport layer coating solution in Example 1 was changed to the one having the following composition, the same procedure as in Example 1 was carried out. 16 was produced.
The evaluation was performed in the same manner as in Example 1 except that the charging method was changed to a negatively charged corona discharge (scorotron method). The results are shown in Table 2.

・テトラヒドロフラン：１００部 Charge transport layer coating solution Polycarbonate resin (Z Polyca, manufactured by Teijin Chemicals): 10 parts Naphthalene diimide-isoindole dimer derivative of Exemplified Compound 12: 1 part Charge transport material No. 1 having the following structural formula 1: 9 copies

Tetrahydrofuran: 100 parts

[Examples 17 to 30]
In Example 16, Exemplified Compound No. 1 In the same manner as in Example 16, except that the naphthalene diimide-isoindole dimer derivative shown in Table 2 was used in place of the naphthalene diimide-isoindole dimer derivative of No. 12, the electrophotographic photoreceptor No. 17-30 were produced. The results are also shown in Table 2.

[Examples 31 to 34]
In Example 16, the contained naphthalene diimide-isoindole dimer derivative was replaced with those shown in Table 3, and the naphthalene diimide-isoindole dimer derivative and charge transport material No. Except that the amount of 1 was changed to the following amount, electrophotographic photoreceptors 31 to 34 were prepared and evaluated in the same manner as in Example 16. The results are also shown in Table 3.
Naphthalene diimide-isoindole dimer derivative: 1 part Charge transport material No. 1: 7 copies

[Examples 35 to 38]
In Examples 31-34, the charge transport material No. 1 is a charge transport material No. 1 below. 2 except that the electrophotographic photosensitive member No. 2 was changed in the same manner as in Examples 31-34. 35-38 were made and evaluated. The results are also shown in Table 4.
Charge transport material no. 2

[Examples 39 to 42]
In Examples 31-34, the charge transport material No. 1 is a charge transport material No. 1 below. Except for the change to 3 in the same manner as in Examples 31 to 34, the electrophotographic photoreceptor No. 39-42 were prepared and evaluated. The results are also shown in Table 5.
Charge transport material no. 3 Chemical structural formula

[Examples 43 to 46]
In Examples 31-34, the charge transport material No. 1 is a charge transport material No. 1 below. Except having changed to 4, it carried out similarly to Examples 31-34, and produced and evaluated the electrophotographic photoreceptors 43-46. The results are also shown in Table 6.

[Examples 47 and 48]
The naphthalene diimide-isoindole dimer derivative in Example 16 was replaced with the one shown in Table 7, and the same operation was performed except that the charge generation layer coating solution and the charge transport layer coating solution were changed to the following ones. Photoconductors 47 and 48 were prepared and evaluated. The results are also shown in Table 7.

<Manufacture of oxotitanium phthalocyanine>
In the same manner as in Synthesis Example 4 described in JP-A No. 2001-019871, 29.2 g of 1,3-diiminoisoindoline and 200 ml of sulfolane are mixed, and 20.4 g of titanium tetrabutoxide is added dropwise under a nitrogen stream. After completion of the dropwise addition, the temperature was gradually raised to 180 ° C., and the reaction was carried out by stirring for 5 hours while maintaining the reaction temperature between 170 ° C. and 180 ° C. After completion of the reaction, the mixture was allowed to cool, and then the precipitate was filtered, washed with chloroform until the powder turned blue, then washed several times with methanol, further washed several times with hot water at 80 ° C., and dried. Crude titanyl phthalocyanine was obtained. Dissolve the crude titanyl phthalocyanine in 20 times the amount of concentrated sulfuric acid, add dropwise to 100 times the amount of ice water with stirring, filter the precipitated crystals, and then repeat washing with water until the washing solution becomes neutral, wet cake of titanyl phthalocyanine pigment Got. The X-ray diffraction spectrum of the dried cake is shown in FIG. 2 g of the obtained wet cake was put into 20 g of carbon disulfide and stirred for 4 hours. 100 g of methanol was added thereto, and the mixture was stirred for 1 hour, then filtered and dried to obtain oxotitanium phthalocyanine crystal powder. This was made into the component of the coating liquid for charge generation layers. The powder XD spectrum of this crystal is shown in FIG.

・トルエン：７０部 ◎ Charge generation layer coating solution ・ Oxotitanium phthalocyanine: 8 parts ・ Polyvinyl butyral (BX-1): 5 parts ・ 2-butanone: 400 parts ◎ Charge transport layer coating liquid ・ Polycarbonate resin (Z polyca): 10 parts Naphthalene diimide-isoindole dimer derivative: 1 part-Charge transport material No. 1: 7 copies

-Toluene: 70 parts

ナフタレンジイミド−イソインドールダイマー誘導体Ｎｏ．１２： ２０部
ビスフェノールＺポリカーボネート（パンライトTS-2050、帝人化成製）： ５０部
テトラヒドロフラン ：５００部 (Example 49)
A photosensitive layer coating solution having the following composition was applied on an aluminum cylinder having a diameter of 100 mm and dried to form a 30 μm single layer photosensitive layer to obtain an electrophotographic photosensitive member. (Photoreceptor No. 49)
[Coating solution for photosensitive layer]
X-type metal-free phthalocyanine (FastogenBlue 8120B: manufactured by Dainippon Ink & Chemicals) 2 parts Charge transport material No. 1 represented by the following structural formula 2: 30 copies

Naphthalenediimide-isoindole dimer derivative no. 12: 20 parts Bisphenol Z polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals): 50 parts Tetrahydrofuran: 500 parts

The produced electrophotographic photosensitive member is positively charged with a remodeled imagio Neo 752 made by Ricoh using a corona charging method (scorotron type) as a charging method and a semiconductor laser (LD) having an image exposure light source of 780 nm. After setting to (V), a repeated test equivalent to printing a total of 100,000 sheets was continuously performed. At that time, the initial portion and the bright portion potential (V) image after the repeated test were evaluated. Further, the light potential after the repeated test was also measured. Further, image blur (dot resolution) was evaluated in the same manner as in Example 5.
The evaluation results are shown in Table 8.

(Examples 50 to 52)
Naphthalene diimide-isoindole dimer derivative No. 49 of Example 49 The electrophotographic photoreceptor of the present invention was prepared and evaluated in the same manner except that 12 was replaced with that shown in Table 8.

(Example 53)
The same photosensitive layer coating solution as in Example 49 was applied onto an aluminum cylinder with a diameter of 30 mm and dried to form a 30 μm single-layer photosensitive layer to obtain an electrophotographic photosensitive member (photosensitive member No. 53). ).
Further, the photoreceptor was evaluated in the same manner as in Example 16. The results are shown in Table 9.

(Examples 54 to 56)
Naphthalene diimide-isoindole dimer derivative No. 53 of Example 53 The electrophotographic photoreceptors of Examples 54 to 56 were prepared and evaluated in the same manner except that 12 was replaced with that shown in Table 9.

(Example 57)
A 20 μm charge transport layer and a 0.1 μm charge generation layer are formed by sequentially applying and drying a charge transport layer coating liquid and a charge generation layer coating liquid having the following composition on an aluminum cylinder having a diameter of 30 mm. Then, an electrophotographic photosensitive member was produced (photosensitive member No. 57) and evaluated in the same manner as in Example 53. Table 10 shows the evaluation results.

[Composition of coating solution for charge transport layer]
Bisphenol A polycarbonate (Panlite C-1400, manufactured by Teijin Chemicals): 10 parts Toluene: 100 parts Naphthalene diimide-isoindole dimer derivative No. 12: 10 parts [composition of coating solution for charge generation layer]
Polyvinyl butyral (XYHL, manufactured by UCC): 0.5 part Cyclohexanone: 200 parts Methyl ethyl ketone: 80 parts X-type metal-free phthalocyanine: 2 parts (FastogenBlue 8120B: manufactured by Dainippon Ink & Chemicals, Inc.)

(Examples 58 to 60)
Naphthalene diimide-isoindole dimer derivative No. 57 of Example 57 The electrophotographic photoreceptor of the present invention was prepared and evaluated in the same manner except that 12 was replaced with the one shown in Table 10.

(Example 61)
In Example 1, the evaluation was performed in the same manner as in Example 1 except that the charging method in Example 1 was replaced with a negatively charged corona discharge (scorotron method). The results are shown in Table 11.

(Examples 62 to 75)
In Examples 2 to 15, the operation was performed in the same manner as in Examples 2 to 15 except that the charging method used for the evaluation was changed to a negatively charged corona discharge (scorotron method). The results are also shown in Table 11.

・テトラヒドロフラン：１００部 (Example 76)
Except that the charge transport layer coating solution in Example 16 was changed to the one having the following composition, the same procedure as in Example 16 was carried out. 61 was produced. The evaluation was performed in the same manner except that the charging system in Example 16 was replaced with a positively charged corona discharge (scorotron system). . The results are also shown in Table 12.
Charge transport layer coating solution Polycarbonate resin (Z Polyca, manufactured by Teijin Chemicals): 10 parts Naphthalene diimide-isoindole dimer derivative of Exemplified Compound 8 Charge transport material having the following structural formula: 9 parts

Tetrahydrofuran: 100 parts

(Example 77)
Except that the charge transport material in Example 76 was changed to the one of the following structural formula, the electrophotographic photoreceptor No. 62 was produced.
All evaluations were made in the same manner as in Example 61. The results are also shown in Table 12.

(Example 78)
Except that the charge transport material in Example 76 was changed to the one of the following structural formula, the electrophotographic photoreceptor No. 63 was produced.
All evaluations were made in the same manner as in Example 61. The results are also shown in Table 12.

(Example 79)
Except that the charge transport material in Example 76 was changed to the one of the following structural formula, the electrophotographic photoreceptor No. 64 was produced.
All evaluations were made in the same manner as in Example 61. The results are also shown in Table 12.

[Comparative Example 1]
In Example 1, naphthalene diimide-isoindole dimer derivative no. Except that 12 was changed to the following benzoquinone derivative, the same procedure as in Example 1 was carried out. 1 was made and evaluated. The results are shown in Table 13.

[Comparative Example 2]
In Example 16, a comparative electrophotographic process was performed in the same manner as in Example 16 except that the naphthalenediimide-isoindole dimer derivative was not added to the coating solution for forming the charge transport layer and the weight of the charge transport material was 10 parts. Photoconductor No. 2 was prepared and evaluated. The results are shown in Table 11.

[Comparative Example 3]
In Example 35, except that the naphthalenediimide-isoindole dimer derivative was changed to the following tetraphenylmethane compound (described in JP-A No. 2000-231204), the same procedure as in Example 35 was carried out. 3 was made and evaluated. The results are shown in Table 13.

[Comparative Example 4]
In Example 47, except that the naphthalenediimide-isoindole dimer derivative was changed to the following hindered amine-based antioxidant, the same procedure as in Example 47 was carried out. 4 was prepared and evaluated. The results are shown in Table 13.

下記構造式で表わされる電荷輸送物質 ：２部

[Comparative Example 5]
In Example 49, naphthalene diimide-isoindole dimer derivative no. Except for using 12 and 20 parts of the following electron transport material, the same procedure as in Example 49 was conducted. 5 was prepared and evaluated in the same manner. The results are shown in Table 13.
18 parts of charge transport material represented by the following structural formula

Charge transport material represented by the following structural formula: 2 parts

[Comparative Example 6]
In Example 49, naphthalene diimide-isoindole dimer derivative no. Except for using 12 and 20 parts of the following electron transport material, the same procedure as in Example 49 was conducted. 6 was prepared and evaluated in the same manner. The results are shown in Table 13.
Charge transport material represented by the following structural formula: 20 parts

下記構造式で表わされる電荷輸送物質 １部

[Comparative Example 7]
In Example 57, naphthalene diimide-isoindole dimer derivative no. Comparative electrophotographic photosensitive member No. 12 was prepared in the same manner as in Example 57 except that 12 and 10 parts were used as the following electron transport materials. 7 was prepared and evaluated in the same manner. The results are shown in Table 13.
9 parts of charge transport material represented by the following structural formula

1 part of charge transport material represented by the following structural formula

  From the above evaluation results, it was confirmed that the bright portion potential increase was small even after printing 100,000 sheets, and that the photoconductor containing the naphthalenediimide-isoindole dimer derivative of the present invention can stably obtain a high-quality image. On the other hand, the comparative photoconductors 1, 3, and 4 have a very high bright portion potential from the beginning, causing a decrease in image density and a decrease in resolution, and the gradation is significantly decreased after printing 100,000 sheets. Image discrimination was impossible. Further, from the evaluation results of Tables 1 and 9, the photoreceptor of the present invention can obtain a good image even in the positive charging system, and the image quality is good even after printing 100,000 sheets, and the image blur (dot resolution) evaluation result. Was also good. Further, although the comparative photoconductors 2, 5, 6, and 7 have a relatively small increase in the bright portion potential, the resolution decrease due to repeated use is large as compared with the photoconductor of the present invention.

[Examples 80 to 86, Comparative Example 8]
Further, the electrophotographic photoreceptor of the present invention and the comparative photoreceptor 2 were left in a desiccator adjusted to a nitrogen oxide (NOx) gas concentration of 50 ppm for 4 days, and image evaluation was performed before and after.

  From the evaluation results shown in Table 14, it can be seen that the resistance to oxidizing gas, that is, the reduction in resolution, is greatly improved by incorporating the naphthalene diimide-isoindole dimer derivative of the present invention into the photoreceptor. On the other hand, the comparative photoconductor 2 has good initial image quality, but it can be seen that the resolution is significantly reduced by the oxidizing gas.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger charger 4 Eraser 5 Image exposure part 6 Developing unit 7 Charger before transfer 8 Registration roller 9 Transfer paper 10 Transfer charger 11 Separation charger 12 Separation nail 13 Charger before cleaning 14 Fur brush 15 Cleaning blade 16 Photoconductor 17 Charging Charger 18 Cleaning Brush 19 Image Exposure Unit 20 Developing Roller 21 Photoconductor 22a Drive Roller 22b Drive Roller 23 Charger Charger 24 Image Exposure Source 25 Transfer Charger 26 Pre-Cleaning Exposure 27 Cleaning Brush 28 Static Electricity Light Source 31 Conductive Support 33 Photosensitive Layer 35 charge generation layer 37 charge transport layer 39 protective layer

Japanese Patent No. 2732697 JP 2000-231204 A JP-A-60-196768 Japanese Patent No. 2884353 JP 2004-258253 A

D. W. Jones, Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry, 21, 2728 (1972).

Claims (19)

An electrophotographic photosensitive member having at least a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains a naphthalenediimide-isoindole dimer derivative represented by the following general formula (1). An electrophotographic photoreceptor characterized by the above.

[Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ are a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted aromatic hydrocarbon group, a halogen atom, Represents a nitro group, which may be the same or different. I and j represent integers of 1 to 4, and k, l, m, and n represent integers of 1 to 5, respectively. ]   2. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is charged to both positive and negative polarities.   The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer further contains a charge transport material. The electrophotographic photosensitive member according to claim 1, wherein the charge transport material is a compound represented by the following general formula (2).

[Wherein, X represents a single bond or a vinylene group, R ₄ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₁ represents a substituted or unsubstituted group. Represents an aromatic hydrocarbon group, R ₅ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₁ and R ₅ may form a ring together. good. A represents a group represented by the following general formula (3), a group represented by the general formula (4), a 9-anthryl group, or a substituted or unsubstituted carbazolyl group.

(Here, R ₆ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a group represented by the following general formula (5).)

(However, R ₇ and R ₈ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, and R ₇ and R ₈ may be the same or different and may form a ring. M represents an integer of 1 to 3, and R ₆ may be the same or different when 2 or more. ] The electrophotographic photosensitive member according to claim 1, wherein the charge transport material is a compound represented by the following general formula (6).

[Wherein R ₉ , R ₁₁ and R ₁₂ are a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom, or a substituted or unsubstituted group. R ₁₀ represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or a halogen atom. K, l, m, and n are integers of 1, 2, 3, or 4, and when each is an integer of 2, 3, or 4, R ₉ , R ₁₀ , R _11, and R ₁₂ are the same. It may be different. ] The electrophotographic photosensitive member according to claim 1, wherein the charge transport material is a compound represented by the following general formula (7).

[Wherein, X represents a single bond or a vinylene group, R ₁₃ represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₃ represents a substituted or unsubstituted aromatic group. R ₁₄ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₃ and R ₁₃ may form a ring together. . Ar ₂ represents the following general formula (8) or general formula (9).

Here, R ₆ represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, m represents an integer of 1 to 3, and R ₆ may be the same or different when 2 or more. R ₁₂ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group. ] The electrophotographic photoreceptor according to claim 1, wherein the charge transport material is a compound represented by the following general formula (10).

[Wherein, X represents a single bond or a vinylene group, R ₁₅ represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, and Ar ₄ represents a substituted or unsubstituted 2 group. R ₁₆ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, and A represents a general formula (3) or a general formula (4 ), 9-anthryl group or a substituted or unsubstituted carbazolyl group.

Here, R ₆ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or general formula (5).

(However, R ₇ and R ₈ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic hydrocarbon group, and R ₇ and R ₈ may be the same or different and may form a ring. M represents an integer of 1 to 3, and when 2 or more, Rs may be the same or different. ] The electrophotographic photosensitive member according to claim 1, wherein the charge transport material is a compound represented by the following general formula (11).

(Wherein R ₁₇ and R _{18 each} represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different.) The electrophotographic photoreceptor according to claim 1, wherein the charge transport material is a compound represented by the following general formula (12).

[Wherein R ₁₉ represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and R ₂₀ represents an alkyl group which may have a substituent or a substituent. An aromatic hydrocarbon group that may be used, or a group represented by the following general formula (13).

(R ₂₁ represents an alkyl group which may have a substituent, or an aryl group which may have a substituent.) The electrophotographic photoreceptor according to claim 1, wherein the charge transport material is a compound represented by the following general formula (14).

(Wherein R ₂₂ and R _{23 each} represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different.) The electrophotographic photoreceptor according to claim 1, wherein the charge transport material is a compound represented by the following general formula (15).

(Wherein R ₂₄ and R _{25 each} represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, which may be the same or different.) The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer is formed by sequentially laminating at least a charge generation layer and a charge transport layer. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer is obtained by sequentially laminating at least a charge transport layer and a charge generation layer. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer is a single-layer type photosensitive layer. An electrophotographic method in which at least charging, image exposure, development, and transfer are repeatedly performed on an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1. An electrophotographic method characterized by the above. Digital electrophotography in which at least charging, image exposure, development, and transfer are repeated on an electrophotographic photosensitive member, and an electrostatic latent image is written on the photosensitive member by an LD or LED during image exposure. A method, wherein the electrophotographic photoreceptor is the electrophotographic photoreceptor according to any one of claims 1 to 14. An electrophotographic apparatus comprising at least a charging unit, an image exposing unit, a developing unit, a transferring unit, and an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1. An electrophotographic apparatus characterized by being a body. An electrophotographic apparatus comprising at least a charging unit, an image exposing unit, a developing unit, a transferring unit, and an electrophotographic photosensitive member, wherein an electrostatic latent image is formed on the photosensitive member by using an LD or an LED as the image exposing unit. 15. An electrophotographic apparatus in which an image is written, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 14. An electrophotographic photosensitive member comprising at least an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 14. Process cartridge for equipment.

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