JP4719616B2 - Image forming apparatus and process cartridge - Google Patents

Description

  The present invention relates to an image forming apparatus and a process cartridge.

  In recent years, there has been a remarkable development of information processing system machines using electrophotography. In particular, an optical printer that converts information into a digital signal and records information by light has a remarkable improvement in print quality and reliability. This digital recording technique is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. In addition, since a variety of information processing functions are added to a conventional copying machine equipped with this digital recording technology in analog copying, it is expected that its demand will increase further in the future. Further, with the spread of personal computers and the improvement in performance, the progress of digital color printers for performing color output of images and documents is rapidly progressing.

  The photoconductor used in these image forming apparatuses is an organic photoconductive material having superiority in sensitivity, thermal stability, toxicity, and the like, as a photoconductive material, over conventionally used inorganic materials such as Se, CdS, and ZnO. The ones that use sexual materials have become mainstream. The photoreceptor using the organic photoconductive material mainly includes a function-separated type photosensitive layer having a laminated structure including a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. It has been broken.

  On the other hand, a single-layer photoconductor including a charge generation material and a charge transport material in a single photosensitive layer can be produced by a simple manufacturing process, and has improved optical characteristics due to fewer layer interfaces. In recent years, it has been attracting attention because of its advantages such as being usable in the charging process.

  In general, an image forming apparatus irradiates a uniformly charged photosensitive member with writing light modulated by image data to form an electrostatic latent image on the photosensitive member. Toner is supplied to the formed photoreceptor by a developing unit to form and develop a toner image on the photoreceptor.

  As a charging method in an image forming apparatus, a corona charging method using a metal wire, a contact charging method in which a charging roller is brought into contact with a photosensitive member, and the like are known.

  In the contact charging method, since the photosensitive member and the charging member are in contact with each other, the voltage applied to the charging member can be lowered, and the generation amount of oxidizing gases such as ozone and NOx is smaller than that in the corona charging method. However, because the discharge energy is high, the hazard to the photoconductor is likely to be worn away, the followability of charging is poor when the process line speed is high, and a high voltage is directly applied to the photoconductor. There is a drawback that it is easy to cause electric discharge destruction.

  The corona charging method is superior to the contact charging method in terms of high-speed follow-up of charging, and since the electrostatic hazard given to the photoreceptor is small, it is advantageous for increasing the speed and durability of the device. By providing a plurality of corona charging devices, it is possible to obtain an image forming apparatus with high high-speed followability, but on the other hand, a large amount of oxidizing gas such as ozone and NOx is generated (100 times that of the contact charging method). )

  When the photoconductor is exposed to an oxidizing gas such as ozone or NOx, the charge generating material and charge transporting material in the photosensitive layer are subjected to a strong oxidizing action, causing a decrease in chargeability, an increase in residual potential, and a deterioration in sensitivity. As a result, image deterioration such as image density reduction and fogging is caused.

  In order to prevent deterioration due to these oxidizing gases, Patent Document 1 and the like describe a method of adding an antioxidant to the photosensitive layer. However, when an additive such as an antioxidant is contained in the photosensitive layer, there is an adverse effect that the residual potential is increased or sensitivity is deteriorated from the beginning or by repeated use, and the durability is still insufficient.

As described above, by using an image forming apparatus having a plurality of corona charging methods, a high-speed and highly durable image forming apparatus can be obtained. For this purpose, an oxidizing gas generated in large quantities by corona charging is used. On the other hand, a photoreceptor that does not cause deterioration such as charge reduction is required.
JP 57-122444 A

  The present invention provides an image forming apparatus and a process cartridge capable of suppressing deterioration of a photoreceptor due to an oxidizing gas and outputting a high-quality image over a long period of time, in view of the above-described problems of the prior art. The purpose is to do.

  As a result of diligent investigations to solve the above problems, the inventors of the present invention have made it possible to use a photoconductor containing a specific compound in a photosensitive layer in an image forming apparatus using a plurality of corona charging devices, thereby sensitizing with an oxidizing gas. It has been found that an image forming apparatus capable of outputting a high-quality image over a long period of time without deterioration of the body can be provided.

  Specifically, a photoconductor, a plurality of corona charging devices that charge the photoconductor, an image exposure device that performs image exposure on the charged photoconductor to form an electrostatic latent image, and the electrostatic latent image. In an image forming apparatus having at least a developing device for developing an image and a transfer device for transferring the developed image, the photosensitive member has at least a photosensitive layer on a conductive support, and the photosensitive layer has a charge. Generating material and general formula (1)

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表し、Ｒ_３、Ｒ_４、Ｒ_５、Ｒ_６、Ｒ_７、Ｒ_８、Ｒ_９及びＲ_１０は、それぞれ独立に、水素原子、ハロゲン基、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表す。）
又は一般式（２）

Wherein R ₁ and R ₂ are each independently a functional group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ are each independently a hydrogen atom, halogen group, cyano group, nitro group, amino group, hydroxyl group, This represents a functional group selected from the group consisting of a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group.
Or general formula (2)

（式中、Ｒ_１及びＲ_２は、それぞれ独立に水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表し、Ｒ_３、Ｒ_４、Ｒ_５、Ｒ_６、Ｒ_７、Ｒ_８、Ｒ_９、Ｒ_１０、Ｒ_１１、Ｒ_１２、Ｒ_１３及びＲ_１４は、それぞれ独立に、水素原子、ハロゲン基、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表し、ｎは、１以上１００以下の整数を表す。）
で表される電子輸送材料を含有することを特徴とする画像形成装置を用いることで、高速で長期に亘り、高品位な画像を出力することができる。

(Wherein R ₁ and R ₂ are each independently a functional group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are each independently a hydrogen atom, a halogen group, A functional group selected from the group consisting of a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group, and n is Represents an integer of 1 to 100)
By using the image forming apparatus characterized by containing the electron transport material represented by the above, a high-quality image can be output at a high speed over a long period of time.

  In the present invention, a plurality of corona charging devices are used as the charging device. Since corona charging is superior in high-speed followability compared to contact charging using a charging roller, it can cope with an increase in the speed of an electrophotographic apparatus. Corona charging has less electrostatic and physical hazards to the photoreceptor.

  In contact charging, the discharge energy is high, the electrostatic hazard to the photosensitive member is large, and the charging roller and the photosensitive member are in contact with each other, so that the photosensitive layer is greatly worn. Therefore, corona charging can extend the life of the photoreceptor.

  On the other hand, corona charging generates a large amount of oxidizing gas such as ozone and NOx. Therefore, the photoconductor is deteriorated by the generated oxidizing gas, and the charging property, residual potential, and sensitivity of the photoconductor are deteriorated. Arise.

  However, since the electron transport material represented by the general formula (1) or (2) used in the present invention itself has excellent stability against oxidizing gas, it is included in the photosensitive layer. Thus, even if a large amount of oxidizing gas is generated by a plurality of corona charges, the charging property, residual potential, and sensitivity of the photoreceptor are not deteriorated. This is considered to be resistant to oxidizing gas because of its strong N-basic molecular structure.

  In addition, since the electron transport material represented by the general formula (1) or (2) used in the present invention exhibits a very excellent electron transport property, it can be contained in the photosensitive layer with respect to the oxidizing gas. In addition to resistance, the photosensitive member is also highly sensitive in terms of electrostatic characteristics. Furthermore, the characteristics of the charge generation material are improved by using a specific material. In the present invention, a known material can be used as the charge generation material. Among them, a material having a phthalocyanine structure is preferable in view of the combination with the charge transport material used in the present invention.

  Among them, in particular, the structural formula having titanium as the central metal

に示すようなチタニルフタロシアニンとすることによって、感度が高い感光層とすることができ、画像形成装置として、高速化をより一層図ることが可能となる。

By using titanyl phthalocyanine as shown in (1), a photosensitive layer having high sensitivity can be obtained, and the image forming apparatus can be further increased in speed.

  References relating to the synthesis method and electrophotographic properties of titanyl phthalocyanine include, for example, JP-A-57-148745, JP-A-59-36254, JP-A-59-44054, JP-A-59-31965. JP, 61-239248, 62-67094, etc. are mentioned. In addition, various crystal systems are known for titanyl phthalocyanine, such as JP 59-49544, JP 59-166959, JP 61-239248, JP 62-67094. JP, 63-366, JP 63-116158, JP 64-17066, 2001-19871, etc. each describe titanyl phthalocyanine having a different crystal form. Yes.

  Among these crystal systems, titanyl phthalocyanine having a maximum diffraction peak at a Bragg angle 2θ of 27.2 ° exhibits particularly excellent sensitivity characteristics and is used favorably. In particular, it has a maximum diffraction peak at 27.2 ° described in JP-A-2001-19871, and further has main peaks at 9.4 °, 9.6 °, and 24.0 °. In addition, by using titanyl phthalocyanine having a peak at 7.3 ° and having no peak between the peak at 7.3 ° and the peak at 9.4 ° as the diffraction peak at the lowest angle side. Without losing high sensitivity, it is possible to obtain a stable photoconductor that does not cause a decrease in chargeability even when used repeatedly.

  Since the electron transporting material represented by the general formula (1) or (2) exhibits electron transporting properties, the laminated structure in the case where the photosensitive layer is provided in the order of the charge generation layer and the charge transport layer from the support side. Is a positively charged photoreceptor. In addition, when the photosensitive layer is used in a single layer configuration, it can be used in both positive and negative charges by using a hole transport material in combination, but the positive charge is more stable in chargeability, Further, it is preferable because less oxidizing gas is generated (about 1/10 of negative charging).

That is, this invention consists of the following aspects.
(1) a photosensitive member, a plurality of corona charging devices that charge the photosensitive member, an image exposure device that performs image exposure on the charged photosensitive member to form an electrostatic latent image, and the electrostatic latent image In an image forming apparatus having at least a developing device for developing and a transfer device for transferring the developed image, the photoreceptor has at least a photosensitive layer on a conductive support, and the photosensitive layer is a charge generating material. And a charge transport material represented by the general formula (1).
(2) a photosensitive member, a plurality of corona charging devices that charge the photosensitive member, an image exposure device that performs image exposure on the charged photosensitive member to form an electrostatic latent image, and the electrostatic latent image In an image forming apparatus having at least a developing device for developing and a transfer device for transferring the developed image, the photoreceptor has at least a photosensitive layer on a conductive support, and the photosensitive layer is a charge generating material. And general formula (2)
An image forming apparatus comprising: an electron transport material represented by:
(3) The image forming apparatus according to (1) or (2), wherein the charge generation material is phthalocyanine.
(4) The image forming apparatus according to (3), wherein the phthalocyanine is titanyl phthalocyanine.
(5) The titanyl phthalocyanine has a maximum diffraction peak at 27.2 ° as a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to the characteristic X-ray of CuKα, 9.4 °, 9.6 It has a peak at ° and 24.0 °, a peak at the lowest angle side at 7.3 °, and no peak between 7.3 ° and 9.4 ° The image forming apparatus according to (4).
(6) The photosensitive layer has the general formula (3)

（式中、Ｒ_１５及びＲ_１６は、それぞれ独立に、水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表し、Ｒ_１７、Ｒ_１８、Ｒ_１９及びＲ_２０は、それぞれ独立に、水素原子、ハロゲン基、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表す。）
で表される電子輸送材料をさらに含有することを特徴とする前記第（１）項乃至第（５）項のいずれか一項に記載の画像形成装置。
（７）前記コロナ帯電装置は、前記感光体を正に帯電することを特徴とする前記第（１）項乃至第（６）項のいずれか一項に記載の画像形成装置。
（８）前記感光体を複数有し、該複数の感光体に現像された像は、順次転写されて重ね合わせられることを特徴とする前記第（１）項乃至第（７）項のいずれか一項に記載の画像形成装置。
（９）前記感光体のプロセス線速は、１００ｍｍ／秒以上であることを特徴とする前記第（１）項乃至第（８）項のいずれか一項に記載の画像形成装置。
（１０）感光体を少なくとも有し、画像形成装置本体に着脱可能であるプロセスカートリッジにおいて、該画像形成装置は、前記第（１）項乃至第（９）項のいずれか一項に記載の画像形成装置であることを特徴とするプロセスカートリッジ。

Wherein R ₁₅ and R ₁₆ are each independently a functional group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. R ₁₇ , R ₁₈ , R ₁₉ and R ₂₀ each independently represent a hydrogen atom, halogen group, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted And a functional group selected from the group consisting of a substituted or unsubstituted aralkyl group.)
The image forming apparatus according to any one of (1) to (5), further including an electron transport material represented by:
(7) The image forming apparatus according to any one of (1) to (6), wherein the corona charging device charges the photoconductor positively.
(8) Any one of (1) to (7) above, wherein a plurality of the photosensitive members are provided, and the images developed on the plurality of photosensitive members are sequentially transferred and superimposed. The image forming apparatus according to one item.
(9) The image forming apparatus according to any one of (1) to (8), wherein a process linear velocity of the photoconductor is 100 mm / second or more.
(10) In a process cartridge having at least a photosensitive member and detachable from an image forming apparatus main body, the image forming apparatus includes the image described in any one of (1) to (9). A process cartridge which is a forming apparatus.

  According to the present invention, it is possible to provide an image forming apparatus and a process cartridge capable of suppressing deterioration of a photoreceptor due to an oxidizing gas and outputting a high-quality image over a long period of time.

  Next, the best mode for carrying out the present invention will be described.

  Hereinafter, the image forming apparatus of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an example of an image forming apparatus according to the present invention, and modifications as will be described later also belong to the category of the present invention.

  In FIG. 1, a photoreceptor 11 has at least a photosensitive layer on a conductive support, and includes at least a charge generation material and an electron transport material represented by the general formula (1) or (2) in the photosensitive layer. The photoconductor 11 has a drum shape, but may be a sheet shape or an endless belt shape.

  Since the charging unit 12 can obtain excellent charging stability even in a high-speed process with a process linear velocity of 100 mm / second or more, a plurality of corona charging devices such as corotron and scorotron are used.

  As a position where a plurality of corona charging devices are installed, it is necessary to install at least one charging device between the neutralizing unit 1A and the exposure unit 13, and it is also possible to install them side by side.

  In the present invention, the charge polarity can be positive or negative depending on the structure of the photoconductor. However, the positive charge is more stable than the negative charge, and an oxidizing gas such as ozone or NOx is used. This is desirable because the amount of generated is small.

  The transfer means 16 may be a known charger such as a corotron, scorotron, solid state charger, or charging roller. A combination of a transfer charger and a separation charger is effective. .

  The light source used for the exposure means 13, the neutralization means 1A, and the like is a luminescent material 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). General. 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.

  The toner 15 developed on the photoconductor by the developing means 14 is transferred to the image receiving medium 18, but not all is transferred, and some toner remains on the photoconductor. Such toner is removed from the photoreceptor by the cleaning means 17. As the cleaning means, a rubber cleaning blade, a brush such as a fur brush or a mag fur brush, or the like can be used.

  FIG. 2 shows another example of the image forming apparatus of the present invention. In FIG. 2, the photoreceptor 11 has a photosensitive layer on at least a conductive support, and includes at least a charge generation material and an electron transport material represented by the general formula (1) or (2) in the photosensitive layer. Endless belt-shaped. Driven by driving means 1C, charged by charging means 12, image exposure by exposure means 13, development (not shown), transfer by transfer means 16, exposure before cleaning by pre-cleaning exposure means 1B, cleaning by cleaning means 17, and charge removal The charge removal by means 1A is repeated. In FIG. 2, light irradiation for pre-cleaning exposure is performed from the support side of the photoreceptor (in this case, the support is translucent).

  The image forming process described above exemplifies the embodiment of the present invention, and other embodiments are possible. For example, although the pre-cleaning exposure is performed from the support side in FIG. 2, 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, in the light irradiation process, image exposure, pre-cleaning exposure, and static elimination exposure are shown in the figure. In addition, pre-exposure for transfer, pre-exposure for image exposure, and other known light irradiation processes are provided to light the photosensitive member. Irradiation can also be performed.

  Further, the image forming means as described above may be fixedly incorporated in a copying machine, 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 photoconductor and further includes a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, a neutralizing unit, and the like. Although there are many shapes and the like of the process cartridge, FIG. 3 shows an example of the process cartridge of the present invention. Also in this case, the photoreceptor 11 has at least a photosensitive layer on a conductive support, and includes at least a charge generation material and an electron transport material represented by the general formula (1) or (2) in the photosensitive layer. The photoconductor 11 has a drum shape, but may be a sheet shape or an endless belt shape.

  FIG. 4 shows another example of the image forming apparatus of the present invention. In this image forming apparatus, charging means 12, exposure means 13, black (Bk), cyan (C), magenta (M), and yellow (Y) toner developing means 14Bk, 14C, 14M and 14Y, an intermediate transfer belt 1F as an intermediate transfer member, and a cleaning unit 17 are arranged in this order. Here, the subscripts Bk, C, M, and Y shown in the figure correspond to the color of the toner described above, and subscripts are added as necessary, and are omitted as appropriate.

  The photoreceptor 11 has at least a photosensitive layer on a conductive support, and includes at least a charge generation material and an electron transport material represented by the general formula (1) or (2) in the photosensitive layer. Each color developing means 14Bk, 14C, 14M and 14Y can be controlled independently, and only the color developing means for image formation is driven. The toner image formed on the photoconductor 11 is transferred onto the intermediate transfer belt 1F by the first transfer unit 1D disposed inside the intermediate transfer belt 1F. The first transfer unit 1D is disposed so as to be able to come into contact with and separate from the photoconductor 11, and the intermediate transfer belt 1F is brought into contact with the photoconductor 11 only during the transfer operation. Each color image is sequentially formed, and the toner images superimposed on the intermediate transfer belt 1F are collectively transferred to the image receiving medium 18 by the second transfer unit 1E, and then fixed by the fixing unit 19 to form an image. The The second transfer unit 1E is also arranged so as to be able to contact and separate from the intermediate transfer belt 1F, and abuts on the intermediate transfer belt 1F only during the transfer operation.

  In the transfer drum type image forming apparatus, since the toner images of the respective colors are sequentially transferred onto the transfer material electrostatically attracted to the transfer drum, there is a limitation on the transfer material that cannot be printed on cardboard, as shown in FIG. Such an intermediate transfer type image forming apparatus is characterized in that the toner images of the respective colors are superimposed on the intermediate transfer body 1F, so that the transfer material is not limited. Such an intermediate transfer method is not limited to the apparatus shown in FIG. 4, but can be applied to the image forming apparatus shown in FIGS. 1, 2, 3 and FIG. 5 (a specific example is shown in FIG. 6) described later. it can.

  FIG. 5 shows another example of the image forming apparatus of the present invention. This image forming apparatus is a type that uses four colors of yellow (Y), magenta (M), cyan (C), and black (Bk) as toner, and an image forming unit is provided for each color. In addition, photoconductors 11Y, 11M, 11C, and 11Bk for the respective colors are provided. The photoreceptor 11 used in the image forming apparatus has at least a photosensitive layer on a conductive support, and at least a charge generation material and an electron transport material represented by the general formula (1) or (2) in the photosensitive layer. including. Around each of the photoconductors 11Y, 11M, 11C, and 11Bk, a charging unit 12, an exposure unit 13, a developing unit 14, a cleaning unit 17, and the like are disposed. Further, a transfer transfer belt 1G as a transfer material carrier that is brought into contact with and separated from the transfer positions of the respective photoconductors 11Y, 11M, 11C, and 11Bk arranged on a straight line is stretched by a driving unit 1C. A transfer unit 16 is disposed at a transfer position facing each of the photoreceptors 1Y, 1M, 1C, and 1Bk with the conveyance transfer belt 1G interposed therebetween.

  Subsequently, the electron transport material represented by the general formulas (1), (2) and (3) used in the present invention will be described.

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表し、Ｒ_３、Ｒ_４、Ｒ_５、Ｒ_６、Ｒ_７、Ｒ_８、Ｒ_９及びＲ_１０は、それぞれ独立に、水素原子、ハロゲン基、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表す。）

Wherein R ₁ and R ₂ are each independently a functional group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ are each independently a hydrogen atom, halogen group, cyano group, nitro group, amino group, hydroxyl group, This represents a functional group selected from the group consisting of a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group.

（式中、Ｒ_１及びＲ_２は、それぞれ独立に水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表し、Ｒ_３、Ｒ_４、Ｒ_５、Ｒ_６、Ｒ_７、Ｒ_８、Ｒ_９、Ｒ_１０、Ｒ_１１、Ｒ_１２、Ｒ_１３及びＲ_１４は、それぞれ独立に、水素原子、ハロゲン基、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表し、ｎは、１以上１００以下の整数を表す。）

(Wherein R ₁ and R ₂ are each independently a functional group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are each independently a hydrogen atom, a halogen group, A functional group selected from the group consisting of a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group, and n is Represents an integer of 1 to 100)

（式中、Ｒ_１５及びＲ_１６は、それぞれ独立に、水素原子、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表し、Ｒ_１７、Ｒ_１８、Ｒ_１９及びＲ_２０は、それぞれ独立に、水素原子、ハロゲン基、シアノ基、ニトロ基、アミノ基、水酸基、置換又は無置換のアルキル基、置換又は無置換のシクロアルキル基及び置換又は無置換のアラルキル基からなる群より選択される官能基を表す。）
一般式（２）で表される電子輸送材料の繰り返し単位ｎは、数平均分子量から求められる。ｎが１００を超えると、化合物の分子量が大きくなり、各種溶媒に対する溶解性が低下することがある。一方、ｎが１の場合は、ナフタレンカルボン酸の三量体であるが、Ｒ_１及びＲ_２の置換基を適切に選択することにより、オリゴマーでも優れた電子移動特性が得られる。このようにｎを変化させることにより、オリゴマーからポリマーまで幅広い範囲のナフタレンカルボン酸誘導体が合成される。分子量が小さいオリゴマー領域では、段階的に合成することで、単分散の化合物を得ることができる。また、分子量が大きいポリマー領域では、分子量に分布を有する化合物が得られる。

Wherein R ₁₅ and R ₁₆ are each independently a functional group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. R ₁₇ , R ₁₈ , R ₁₉ and R ₂₀ each independently represent a hydrogen atom, halogen group, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted And a functional group selected from the group consisting of a substituted or unsubstituted aralkyl group.)
The repeating unit n of the electron transport material represented by the general formula (2) is obtained from the number average molecular weight. When n exceeds 100, the molecular weight of the compound increases and the solubility in various solvents may decrease. On the other hand, when n is 1, it is a trimer of naphthalene carboxylic acid, but excellent electron transfer characteristics can be obtained even with oligomers by appropriately selecting substituents for R ₁ and R ₂ . By changing n in this way, a wide range of naphthalenecarboxylic acid derivatives from oligomers to polymers are synthesized. In an oligomer region having a small molecular weight, a monodispersed compound can be obtained by stepwise synthesis. In the polymer region having a large molecular weight, a compound having a distribution in molecular weight is obtained.

  As the substituted or unsubstituted alkyl group, an alkyl group having 1 to 25 carbon atoms, preferably 1 to 10 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, n -Linear alkyl group such as pentyl group, n-hexyl group, n-peptyl group, n-octyl group, n-nonyl group, n-decyl group, isopropyl group, s-butyl group, t-butyl group, A branched alkyl group such as methylpropyl group, dimethylpropyl group, ethylpropyl group, diethylpropyl group, methylbutyl group, dimethylbutyl group, methylpentyl group, dimethylpentyl group, methylhexyl group, dimethylhexyl group, alkoxyalkyl group, Monoalkylaminoalkyl group, dialkylaminoalkyl group, haloalkyl group, alkylcarbonylalkyl group, carboxyalkyl group Alkanoyloxy alkyl group, an aminoalkyl group, esterified optionally alkyl group substituted with a carboxyl group which have an alkyl group substituted by a cyano group are exemplified. The substitution position of these substituents is not particularly limited, and a functional group in which a part of carbon atoms of the alkyl group is substituted with a hetero atom (N, O, S, etc.) is also included in the substituted alkyl group. It is. As the substituted or unsubstituted cycloalkyl group, a cycloalkyl group having 3 to 25 carbon atoms, preferably 3 to 10 carbon atoms, specifically, a cycloalkyl group having the same group from a cyclopropyl group to a cyclodecyl group, Cycloalkyl groups having an alkyl substituent such as methylcyclopentyl group, dimethylcyclopentyl group, methylcyclohexyl group, dimethylcyclohexyl group, trimethylcyclohexyl group, tetramethylcyclohexyl group, ethylcyclohexyl group, diethylcyclohexyl group, t-butylcyclohexyl group, alkoxy Alkyl group, monoalkylaminoalkyl group, dialkylaminoalkyl group, haloalkyl group, alkoxycarbonylalkyl group, carboxyalkyl group, alkanoyloxyalkyl group, aminoalkyl group, halogen , An amino group, esterified carboxyl group which may be a cycloalkyl group substituted by a cyano group and the like. In addition, the substitution position of these substituents is not particularly limited, and a cycloalkyl group in which a functional group in which a part of carbon atoms of the cycloalkyl group is substituted with a hetero atom (N, O, S, etc.) is also substituted. include.

  Examples of the substituted or unsubstituted aralkyl group include a functional group in which the above-described substituted or unsubstituted alkyl group is substituted with an aromatic group, and an aralkyl group having 6 to 14 carbon atoms is preferable. Specifically, benzyl group, perfluorophenylethyl group, 1-phenylethyl group, 2-phenylethyl group, terphenylethyl group, dimethylphenylethyl group, diethylphenylethyl group, t-butylphenylethyl group, 3-phenylpropylene. Illustrative examples include a sulfur group, a 4-phenylbutyl group, a 5-phenylpentyl group, a 6-phenylhexyl group, a benzhydryl group, and a trityl group.

  Examples of the halogen group include a fluoro group, a chloro group, a bromo group, and an iodo group.

  Specifically, as the electron transport material represented by the general formula (1), the electron transport material represented by the structural formulas (1-1) to (1-7) has a high quality image. Is preferable.

一般式（１）で表される電子輸送材料の製造方法としては、上記のナフタレンカルボン酸若しくはその無水物をアミン類と反応させ、モノイミド化する方法、ナフタレンカルボン酸若しくはその無水物を緩衝液によりｐＨ調整してジアミン類と反応させる方法等が挙げられる。モノイミド化は、無溶媒若しくは溶媒存在下で行う。溶媒としては、特に制限はないが、ベンゼン、トルエン、キシレン、クロロナフタレン、酢酸、ピリジン、メチルピリジン、ジメチルホルムアミド、ジメチルアセトアミド、ジメチルエチレンウレア、ジメチルスルホキサイド等の原料や生成物と反応せず、５０〜２５０℃の温度で反応させられるものを用いるとよい。ｐＨ調整には、水酸化リチウム、水酸化カリウム等の塩基性水溶液をリン酸等の酸との混合により作製した緩衝液を用いる。カルボン酸とアミン類やジアミン類とを反応させて得られたカルボン酸誘導体脱水反応は、無溶媒若しくは溶媒存在下で行う。溶媒としては、特に制限は無いが、ベンゼン、トルエン、クロロナフタレン、ブロモナフタレン、無水酢酸等の原料や生成物と反応せず、５０〜２５０℃の温度で反応させられるものを用いるとよい。いずれの反応も、無触媒若しくは触媒存在下で行ってよく、特に限定されないが、例えば、モレキュラーシーブス、ベンゼンスルホン酸、ｐ−トルエンスルホン酸等を脱水剤として用いることが例示できる。

As a method for producing the electron transport material represented by the general formula (1), the above naphthalene carboxylic acid or its anhydride is reacted with amines to monoimidize, and the naphthalene carboxylic acid or its anhydride is buffered. The method of adjusting pH and making it react with diamines etc. are mentioned. Monoimidization is carried out without solvent or in the presence of a solvent. The solvent is not particularly limited, but it does not react with raw materials and products such as benzene, toluene, xylene, chloronaphthalene, acetic acid, pyridine, methylpyridine, dimethylformamide, dimethylacetamide, dimethylethyleneurea, dimethylsulfoxide and the like. It is good to use what is made to react at the temperature of 50-250 degreeC. For pH adjustment, a buffer solution prepared by mixing a basic aqueous solution such as lithium hydroxide or potassium hydroxide with an acid such as phosphoric acid is used. Carboxylic acid derivative dehydration reaction obtained by reacting carboxylic acid with amines or diamines is carried out without solvent or in the presence of a solvent. Although there is no restriction | limiting in particular as a solvent, It is good to use what reacts at the temperature of 50-250 degreeC, without reacting with raw materials and products, such as benzene, toluene, chloronaphthalene, bromonaphthalene, and acetic anhydride. Any reaction may be performed without a catalyst or in the presence of a catalyst, and is not particularly limited. For example, molecular sieves, benzenesulfonic acid, p-toluenesulfonic acid and the like can be used as a dehydrating agent.

  Naphthalenecarboxylic acid is synthesized by the following reaction according to a known synthesis method (for example, US Pat. No. 6,794,102, Industrial Organic Pigments 2nd edition, VCH, 485 (1997), etc.).

（式中、Ｒ_ｎは、Ｒ_３、Ｒ_４、Ｒ_７、Ｒ_８を表し、Ｒ_ｍは、Ｒ_５、Ｒ_６、Ｒ_９、Ｒ_１０を表す。）
構造式（１−４）で表される電子輸送材料は、下記の方法により製造することができる。
（第一工程）
２００ｍｌ４つ口フラスコに、１，４，５，８−ナフタレンテトラカルボン酸二無水物１０ｇ（３７．３ｍｍｏｌ）、ヒドラジン一水和物０．９３１ｇ（１８．６ｍｍｏｌ）、ｐ−トルエンスルホン酸２０ｍｇ、トルエン１００ｍｌを入れ、５時間加熱還流させる。反応終了後、容器を冷却し、減圧濃縮する。残渣をシリカゲルカラムクロマトグラフィーで精製する。さらに、回収品をトルエン／酢酸エチル混合溶媒により再結晶し、二量体Ｃを２．８４ｇ（収率２８．７％）が得られる。
（第二工程）
２００ｍｌ４つ口フラスコに、５．０ｇ（９．３９ｍｍｏｌ）の二量体Ｃ、ＤＭＦ５０ｍｌを入れ、加熱還流させる。これに、２−アミノヘプタン１．０８ｇ（９．３９ｍｍｏｌ）ＤＭＦ２５ｍｌの混合物を攪拌しながら滴下する。滴下終了後、６時間加熱還流させる。反応終了後、反応容器を冷却し、減圧濃縮する。残渣にトルエンを加え、シリカゲルカラムクロマトグラフィーで精製し、モノイミド体Ｄが１．６６ｇ（収率２８．１％）得られる。
（第三工程）
１００ｍｌ４つ口フラスコに、１．５ｇ（２．３８ｍｍｏｌ）のモノイミド体Ｄ、ＤＭＦ５０ｍｌを入れ、加熱還流させる。これに、２−アミノオクタン０．３０８ｇ（２．３８ｍｍｏｌ）とＤＭＦ１０ｍｌの混合物を攪拌しながら滴下する。滴下終了後、６時間加熱還流させる。反応終了後、反応容器を冷却し、減圧濃縮する。残渣にトルエンを加え、シリカゲルカラムクロマトグラフィーで精製する。さらに、回収品をトルエン／ヘキサン混合溶媒により再結晶し、構造式（１−４）で表される電子輸送材料０．３２８ｇ（収率１８．６％）が得られる。質量分析（ＦＤ−ＭＳ）において、Ｍ／ｚ＝７４０のピークが観測されることにより、目的物であると同定される。元素分析は、計算値が炭素６９．７２％、水素５．４４％、窒素７．５６％であるのに対し、実測値は、炭素６９．５５％、水素５．２６％、窒素７．３３％である。

(Wherein, _{R n represents R 3, R 4, R 7} , R 8, R m _{represents R 5, R 6, R 9} , R 10.)
The electron transport material represented by the structural formula (1-4) can be manufactured by the following method.
(First step)
In a 200 ml four-necked flask, 1,4,5,8-naphthalenetetracarboxylic dianhydride 10 g (37.3 mmol), hydrazine monohydrate 0.931 g (18.6 mmol), p-toluenesulfonic acid 20 mg, toluene Add 100 ml and heat to reflux for 5 hours. After completion of the reaction, the vessel is cooled and concentrated under reduced pressure. The residue is purified by silica gel column chromatography. Furthermore, the recovered product is recrystallized with a mixed solvent of toluene / ethyl acetate to obtain 2.84 g of dimer C (yield 28.7%).
(Second step)
In a 200 ml four-necked flask, 5.0 g (9.39 mmol) of Dimer C and 50 ml of DMF are placed and heated to reflux. A mixture of 1.08 g (9.39 mmol) of DMF 25 ml of 2-aminoheptane is added dropwise thereto while stirring. After completion of dropping, the mixture is heated to reflux for 6 hours. After completion of the reaction, the reaction vessel is cooled and concentrated under reduced pressure. Toluene is added to the residue and purified by silica gel column chromatography to obtain 1.66 g (yield 28.1%) of monoimide D.
(Third process)
In a 100 ml four-necked flask, 1.5 g (2.38 mmol) of monoimide D and 50 ml of DMF are placed and heated to reflux. A mixture of 2-aminooctane (0.308 g, 2.38 mmol) and DMF (10 ml) is added dropwise thereto while stirring. After completion of dropping, the mixture is heated to reflux for 6 hours. After completion of the reaction, the reaction vessel is cooled and concentrated under reduced pressure. Toluene is added to the residue and the residue is purified by silica gel column chromatography. Furthermore, the recovered product is recrystallized with a toluene / hexane mixed solvent to obtain 0.328 g (yield 18.6%) of an electron transport material represented by the structural formula (1-4). In mass spectrometry (FD-MS), when a peak of M / z = 740 is observed, it is identified as a target product. In the elemental analysis, the calculated values are 69.72% carbon, 5.44% hydrogen, and 7.56% nitrogen, whereas the measured values are 69.55% carbon, 5.26% hydrogen, and 7.33 nitrogen. %.

The electron transport material represented by Structural Formula (1-5) can be produced by the following method.
(First step)
In a 200 ml four-necked flask, 5.0 g (9.39 mmol) of Dimer C and 50 ml of DMF are placed and heated to reflux. A mixture of 1.08 g (9.39 mmol) of DMF 25 ml of 2-aminoheptane is added dropwise thereto while stirring. After completion of dropping, the mixture is heated to reflux for 6 hours. After completion of the reaction, the reaction vessel is cooled and concentrated under reduced pressure. Toluene is added to the residue and purified by silica gel column chromatography to obtain 1.66 g (yield 28.1%) of monoimide D.
(Second step)
In a 100 ml four-necked flask, 1.5 g (2.38 mmol) of monoimide D and 50 ml of DMF are placed and heated to reflux. To this, a mixture of 0.408 g (2.38 mmol) of 6-aminoundecane and 10 ml of DMF is added dropwise with stirring. After completion of dropping, the mixture is heated to reflux for 6 hours. After completion of the reaction, the reaction vessel is cooled and concentrated under reduced pressure. Toluene is added to the residue and the residue is purified by silica gel column chromatography. Furthermore, the recovered product is recrystallized with a toluene / hexane mixed solvent to obtain 0.276 g (yield 14.8%) of the electron transport material represented by the structural formula (1-5). In mass spectrometry (FD-MS), the peak of M / z = 782 is observed, and it is identified as the target product. In the elemental analysis, calculated values are 70.57% carbon, 5.92% hydrogen, and 7.16% nitrogen, whereas measured values are 70.77% carbon, 6.11% hydrogen, and 7.02 nitrogen. %.

  The following method can be illustrated as a manufacturing method of the electron transport material represented by General formula (2).

一般式（２）で表される電子輸送材料としては、構造式（２−１）〜（２−３）で表される電子輸送材料が例示できる。

Examples of the electron transport material represented by the general formula (2) include electron transport materials represented by the structural formulas (2-1) to (2-3).

一般式（３）で表される電子輸送材料としては、構造式（３−１）〜（３−３）で表される電子輸送材料が例示できる。

Examples of the electron transport material represented by the general formula (3) include electron transport materials represented by the structural formulas (3-1) to (3-3).

次に、本発明で用いられる感光体について詳細に説明する。

Next, the photoconductor used in the present invention will be described in detail.

  In the present invention, the photosensitive layer of the photoreceptor includes a stacked photosensitive layer in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated in this order, and a charge in a single layer. There is a single-layer type photosensitive layer containing a generating material and a charge transport material.

  7 and 8 are cross-sectional views showing an example of a photoreceptor used in the image forming apparatus of the present invention, FIG. 7 is an example of a photoreceptor of a laminated photosensitive layer, and FIG. 8 is a single-layer photosensitive layer. This is an example of the photoconductor.

  First, an example of each layer configuration of the laminated photosensitive layer will be described. In this example, an undercoat layer 24 is provided between the conductive support 21 and the charge generation layer 22, and a charge transport layer 23 is provided on the charge generation layer 22.

Examples of the conductive support 21 include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, and iron, tin oxide, and indium oxide. A film or cylindrical plastic, paper or the like coated by vapor deposition or sputtering, etc., a plate of aluminum, aluminum alloy, nickel, stainless steel, etc. It is possible to use a tube that has been surface-treated by cutting, super-finishing, polishing, or the like after being made into a raw tube by a method such as a method, an extruded drawing method, or a cutting method.

  First, the charge generation layer 22 among the layers in the multilayer photosensitive layer will be described. The charge generation layer is a layer mainly composed of a charge generation material, and a binder resin may be used as necessary. A known material can be used as the charge generation material used in the present invention. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having carbazole skeleton, azo pigments having triphenylamine skeleton, azo pigments having diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having fluorenone skeleton, azo pigments having oxadiazole skeleton, azo pigments having bis-stilbene skeleton, azo pigments having distyryl oxadiazole skeleton, azo pigments having distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigo Id based pigments, bisbenzimidazole pigments. These charge generation materials can be used alone or as a mixture of two or more.

  In the present invention, phthalocyanine pigments are preferable from the viewpoint of various properties necessary for the present invention. Among these, by using titanyl phthalocyanine having titanium as a central metal, a photosensitive layer having particularly high sensitivity can be obtained, and the speed of the image forming apparatus can be further increased. Further, among various crystal systems, titanyl phthalocyanine having a maximum diffraction peak at 27.2 ° with a Bragg angle 2θ exhibits particularly excellent sensitivity characteristics and is used favorably. In particular, it has a maximum diffraction peak at 27.2 ° described in JP-A-2001-19871, and further has main peaks at 9.4 °, 9.6 °, and 24.0 °. In addition, by using titanyl phthalocyanine having a peak at 7.3 ° and having no peak between the peak at 7.3 ° and the peak at 9.4 ° as the diffraction peak on the lowest angle side, Without losing high sensitivity, it is possible to obtain a stable photoconductor that does not cause a decrease in chargeability even after repeated use.

  The binder resin used as necessary for the charge generation layer includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, polyarylate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly (N- Vinylcarbazole), polyacrylamide and the like. These binder resins may be used alone or as a mixture of two or more.

  The binder resin is usually 0 to 500 parts by weight, and preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generating material.

  Moreover, a polymer charge transport material can be used as the binder resin of the charge generation layer. Furthermore, a charge transport material may be added as necessary.

  As a method of forming the charge generation layer, the above-described charge generation material is dispersed by a ball mill, an attritor, a sand mill, etc., if necessary, using a binder resin and a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone. The dispersion may be applied after being diluted appropriately. Application can be performed by dip coating, spray coating, bead coating, or the like.

  The thickness of the charge generation layer provided as described above is usually 0.01 to 5 μm, preferably 0.1 to 2 μm.

  Next, the charge transport layer 23 will be described.

  The charge transport layer can be formed by dissolving or dispersing a mixture or copolymer mainly composed of a charge transport component and a binder component in an appropriate solvent, and applying and drying the mixture.

  Examples of the polymer compound that can be used as the binder component of the charge transport layer include 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, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, silicone resin, fluororesin, epoxy resin And thermoplastic or thermosetting resins such as melamine resin, urethane resin, phenol resin, alkyd resin, etc., but are not limited thereto.

  These polymer compounds can be used singly or as a mixture of two or more kinds, as a copolymer comprising two or more of these raw material monomers, and further as a copolymer with a charge transport material.

  In order to improve the stability of the charge transport layer against environmental fluctuations, when an electrically inactive polymer compound is used, for example, polyester, polycarbonate, acrylic resin, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyethylene Polypropylene, fluororesin, polyacrylonitrile, acrylonitrile-styrene-butadiene copolymer, styrene-acrylonitrile copolymer, ethylene-vinyl acetate copolymer, and the like are effective.

  Here, as the electrically inactive polymer compound, a polymer compound that does not include a chemical structure exhibiting photoconductivity such as a triarylamine structure is exemplified.

  When these resins are used in combination with a binder resin as an additive, the addition amount is preferably 50% by weight or less because of restrictions on light attenuation sensitivity.

  In the present invention, as the charge transport material, it is essential to use an electron transport material represented by the general formula (1) or (2). In addition to this, a known charge transport material, that is, an electron is used. A transport material (acceptor) and a hole transport material (donor) can be used in combination.

  Examples of the electron transport material include chloroanil, bromanyl, 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-4H-indeno [1,2-b] thiophen-4-one, 1,3,7- Examples thereof include electron accepting substances such as trinitrodibenzothiophene-5,5-dioxide. These electron transport materials may be used alone or as a mixture of two or more.

  As the hole transport material, an electron donating substance is preferably used.

  Examples thereof are oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9-p-diethylaminostyrylanthracene, 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline. , Phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, and the like.

  These hole transport materials may be used alone or as a mixture of two or more.

  The addition amount of the charge transport material is usually 40 to 200 parts by weight, preferably 70 to 150 parts by weight with respect to 100 parts by weight of the resin component, and the general formula (1) with respect to the entire charge transport material. Alternatively, the electron transport material represented by (2) is preferably 50 to 100% by weight.

  Examples of the dispersion solvent that can be used in preparing the charge transport layer coating solution include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone, ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve, toluene, xylene, and the like. Examples thereof include aromatics, halides such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate. These solvents can be used alone or in combination.

  Moreover, low molecular weight compounds and leveling agents such as antioxidants, plasticizers, lubricants, and ultraviolet absorbers can be added to the charge transport layer as necessary. These compounds can be used alone or as a mixture of two or more. The usage-amount of a low molecular compound is 0.1-50 weight part normally with respect to 100 weight part of high molecular compounds, Preferably, it is 0.1-20 weight part. The amount of the leveling agent used is usually 0.001 to 5 parts by weight with respect to 100 parts by weight of the polymer compound.

  As the coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.

  The thickness of the charge transport layer is usually 15 to 40 μm, preferably 15 to 30 μm, and preferably 15 to 25 μm when resolution is required.

  In the photoreceptor used in the present invention, an undercoat layer 24 can be provided between the conductive support and the mixed photosensitive layer or the charge generation layer. The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving coatability of the upper layer, reducing residual potential, and preventing charge injection from the conductive support. The undercoat layer generally contains a resin as a main component, but these resins are resins having a high solubility resistance to a general organic solvent in consideration of applying a photosensitive layer thereon using a solvent. Desirably, 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 resins, and alkyd-melamine resins. And a curable resin that forms a three-dimensional network structure such as an epoxy resin. Further, fine powders such as metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide, metal sulfides, and metal nitrides may be added to the undercoat layer. These undercoat layers can be formed using an appropriate solvent and coating method, as in the case of the above-described photosensitive layer.

  Further, as the undercoat layer, a metal oxide layer formed by using, for example, a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is also useful. In addition to these, alumina provided by anodic oxidation, organic substances such as polyparaxylylene (parylene), and inorganic substances such as silicon oxide, tin oxide, titanium oxide, ITO, and ceria were provided by a vacuum thin film manufacturing method. It can be used well as a pulling layer.

  The thickness of the undercoat layer is usually 0.1 to 10 μm, preferably 1 to 5 μm.

  In the present invention, in order to improve the gas barrier property and environmental resistance of the surface layer of the photoreceptor, a known antioxidant, plasticizer, ultraviolet absorber, low molecular charge transport material, leveling agent, etc. are applied to each layer. Can be added.

  Further, in the present invention, by adding an electron transport material represented by the general formula (3) to the photosensitive layer, the photosensitive layer can be made dense, so that the gas barrier property is improved and generated by a charger or the like. It is possible to further suppress the deterioration of the photoreceptor mp due to the oxidizing gas. In addition, since shrinkage during film formation is relieved, when a flexible sheet such as an aluminum-deposited PET sheet or a nickel belt is used as a support, it is possible to reduce warpage generally referred to as curl, Occurrence of defects in the photoreceptor such as cracks can be suppressed.

  This is thought to be caused by the fact that the electron transport material represented by the general formula (3) has a low molecular weight and thus acts as a plasticizer in the photosensitive layer, but is represented by the general formula (3). The electron transport material has an electron transport ability and is a monomer of the electron transport material represented by the general formulas (1) and (2). Improvement and curl can be reduced.

  The addition amount of the electron transport material represented by the general formula (3) is usually 1 to 50% by weight with respect to the electron transport material represented by the general formula (1) or (2). If the amount added is less than 1% by weight, the desired effect may not be obtained. Moreover, since the electron transport material represented by General formula (3) is inferior to the electron transport material represented by General formula (1) or (2), its addition amount is more than 50% by weight. The sensitivity may decrease.

  Next, an example of a single-layer type photosensitive layer containing a charge generation material and a charge transport material in a single layer will be described.

  FIG. 8 is a cross-sectional view showing another example of a photoreceptor used in the image forming apparatus of the present invention. At least a charge generating material and a general formula (1) or (2) are formed on a conductive support 21. A photosensitive layer 25 containing the electron transport material represented is provided. Although not shown, it is also possible to provide an undercoat layer between the conductive support 21 and the photosensitive layer 25.

  As the charge generation material that can be used for the photosensitive layer having a single layer structure, a known material can be used as in the case of the laminated structure. However, as described above, phthalocyanine pigments are necessary for the present invention. It is preferable in terms of characteristics. Among them, as described above, by using titanyl phthalocyanine having titanium as a central metal, a photosensitive layer having particularly high sensitivity can be obtained, and the speed of the image forming apparatus can be further increased. Further, as in the case of the laminated structure, among various crystal systems, titanyl phthalocyanine having a maximum diffraction peak at 27.2 ° with a Bragg angle 2θ exhibits excellent sensitivity characteristics and is used favorably. In particular, it has a maximum diffraction peak at 27.2 ° described in JP-A-2001-19871, and further has main peaks at 9.4 °, 9.6 °, and 24.0 °, And, by using titanyl phthalocyanine having a peak at 7.3 ° and having no peak between the 7.3 ° peak and the 9.4 ° peak as the lowest diffraction peak, Without losing high sensitivity, it is possible to obtain a stable photoconductor that does not cause a decrease in chargeability even after repeated use.

  These pigments are preferably dispersed in advance by a ball mill, attritor, sand mill or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone. Moreover, you may disperse | distribute with binder resin as needed at the time of dispersion | distribution.

  It is essential to use the electron transport material represented by the general formula (1) or (2) as the charge transport material even in a single layer configuration. That is, it is possible to use an electron transport material (acceptor) and a hole transport material (donor) in the same manner as in the stacked structure.

  In the photosensitive layer having a single layer structure, the charge generation material is usually 0.1 to 30% by weight, preferably 0.5 to 10% by weight, based on the entire photosensitive layer. The electron transport material is usually 5 to 300 parts by weight, preferably 10 to 150 parts by weight with respect to 100 parts by weight of the binder resin component. However, the electron transport material represented by the general formula (1) or (2) is preferably 50 to 100% by weight with respect to the entire electron transport material. Moreover, a hole transport material is 5 to 300 weight part normally with respect to 100 weight part of binder resin components, Preferably it is 20 to 150 weight part. When the electron transport material and the hole transport material are used in combination, the total amount of the electron transport material and the hole transport material is usually 20 to 300 parts by weight with respect to 100 parts by weight of the binder resin component, preferably 30 -200 parts by weight.

  Examples of the solvent that can be used in preparing the photosensitive layer coating solution include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone, ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve, and aromatics such as toluene and xylene. , Halides such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate. These solvents can be used alone or in combination.

  If necessary, low-molecular compounds such as antioxidants, plasticizers, lubricants, ultraviolet absorbers and leveling agents can be added to the photosensitive layer. These compounds can be used alone or as a mixture of two or more. The usage-amount of a low molecular compound is 0.1-50 weight part normally with respect to 100 weight part of high molecular compounds, such as binder resin, Preferably, it is 0.1-20 weight part. The amount of the leveling agent used is usually 0.001 to 5 parts by weight with respect to 100 parts by weight of the polymer compound.

  Even in the case of a single layer structure, by adding an electron transport material represented by the general formula (3) to the photosensitive layer, the photosensitive layer can be made dense, so that the gas barrier property is improved, It is possible to further suppress the deterioration of the photoreceptor due to the generated oxidizing gas. In addition, since shrinkage during film formation is relieved, when a flexible sheet such as an aluminum-deposited PET sheet or a nickel belt is used as a support, it is possible to reduce warpage generally referred to as curl, Occurrence of defects in the photoreceptor such as cracks can be suppressed.

  In the photosensitive layer having a single layer structure, the addition amount of the electron transport material represented by the general formula (3) is usually 1 to 50 with respect to the electron transport material represented by the general formula (1) or (2). % By weight. If the amount added is less than 1% by weight, the desired effect may not be obtained. Moreover, since the electron transport material represented by General formula (3) is inferior to the electron transport material represented by General formula (1) or (2), its addition amount is more than 50% by weight. The sensitivity may decrease.

  As the coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.

  The film thickness of the photosensitive layer is usually 10 to 45 μm, preferably 15 to 32 μm, and when resolution is required, it is preferably 25 μm or less.

Hereinafter, the present invention will be described by way of examples. Note that this does not limit the scope of the present invention. All parts are parts by weight.
( Reference Example 1)
An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following compositions were prepared.
(Coating liquid for undercoat layer)
Alkyd resin (Dainippon Ink Co., Ltd .: Beccosol M-6401-50): 60 parts Melamine resin (Dainippon Ink Co., Ltd .: Super Becamine L-121-60): 40 parts Titanium oxide (Ishihara Sangyo Co., Ltd .: CR- EL): 400 parts Methyl ethyl ketone: 500 parts These were ball milled for 5 days with a ball mill apparatus (aluminum balls having a diameter of 10 mm were used as media) to obtain an undercoat layer coating solution.
(Coating solution for charge generation layer)
Metal-free phthalocyanine pigment: 12 parts (Dainippon Ink Industries, Ltd .: Fastogen
(Blue 8120B)
Polyvinyl butyral resin (Sekisui Chemical Co., Ltd .: ESREC BX-1): 5 parts 2-butanone: 200 parts Cyclohexanone: 400 parts These are put into a glass pot having a diameter of 9 cm and rotated using a PSZ ball having a diameter of 0.5 mm. Dispersion was performed at several 100 rpm for 5 hours to obtain a charge generation layer coating solution.
(Coating liquid for charge transport layer)
Electron transport material represented by structural formula (1-1): 10 parts Z-type polycarbonate resin (manufactured by Teijin Chemicals Ltd .: Panlite TS-2050): 10 parts Silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd .: KF50): 0. 01 parts Tetrahydrofuran: 80 parts These were stirred and dissolved to prepare a charge transport layer coating solution.

  Next, on an aluminum drum having a diameter of 30 mm and a length of 340 mm, the coating liquid for the undercoat layer, the coating liquid for the charge generation layer, and the coating liquid for the charge transport layer are sequentially applied by a dip coating method. Coating and drying were carried out to form an undercoat layer having a thickness of 4.5 μm, a charge generation layer having a thickness of 0.15 μm, and a charge transporting layer having a thickness of 25 μm to produce a photoreceptor. The drying temperature of each layer was 135 ° C. for 20 minutes, 80 ° C. for 15 minutes, and 120 ° C. for 20 minutes.

Two photoconductors as described above were prepared, and one was modified by a Ricoh laser printer (the charger was modified so that the scorotron was positively charged at two locations, the wavelength of the LD was 780 nm, the process linear velocity Was 175 mm / sec), and a continuous printing test was performed on 10,000 sheets of chart paper having a black solid portion of 5%. Image evaluation, dark part potential, and light part potential were evaluated before and after the test.
(Image evaluation)
An image for evaluation was output, and background stain, fogging, image density, and the like were visually evaluated.
(Dark part potential)
After the primary charging, the surface potential of the photosensitive member when moved to the developing unit position is adjusted. In the initial stage, the applied voltage of the charger is adjusted to +500 V, and thereafter, the applied voltage is constant until the end of the test. . The developing bias was + 350V.
(Bright part potential)
After primary charging, image exposure (entire exposure) was performed, and the surface potential of the photoconductor when moved to the developing unit position was determined.

An ozone exposure test was performed in which another produced photoreceptor was left in an environment with an ozone concentration of 10 ppm for 5 days. Similar to the printing durability test, image evaluation, dark part potential, and light part potential were evaluated before and after the ozone exposure test.
( Reference Example 2)
Metal-free phthalocyanine was dispersed under the following formulation and conditions to prepare a pigment dispersion.

Metal-free phthalocyanine pigment: 3 parts (Dainippon Ink Industries, Ltd .: Fastogen Blue 8120B)
Cyclohexanone: 97 parts The pigment dispersion was placed in a glass pot having a diameter of 9 cm and PSZ balls having a diameter of 0.5 mm were used for 5 hours at a rotation speed of 100 rpm.

  Next, using a pigment dispersion, dispersion was performed under the following composition and conditions to prepare a photoreceptor coating solution.

Pigment dispersion: 60 parts Structural formula

で表される正孔輸送材料：３０部
構造式（１−１）の電子輸送材料：２０部
Ｚ型ポリカーボネート樹脂（帝人化成製：パンライトＴＳ−２０５０）：５０部
シリコーンオイル（信越化学工業社製：ＫＦ５０）：０．０１部
テトラヒドロフラン：３５０部
こうして得られた感光層用塗工液を直径３０ｍｍ、長さ３４０ｍｍアルミニウムドラム上に、浸漬塗工法で塗布し、１２０℃で２０分間乾燥することにより、膜厚２５μｍの感光層を形成し、感光体を作製した。

Hole transport material represented by: 30 parts Electron transport material of structural formula (1-1): 20 parts Z-type polycarbonate resin (Teijin Chemicals: Panlite TS-2050): 50 parts Silicone oil (Shin-Etsu Chemical Co., Ltd.) Manufactured: KF50): 0.01 part Tetrahydrofuran: 350 parts The coating solution for photosensitive layer thus obtained is applied on an aluminum drum having a diameter of 30 mm and a length of 340 mm by dip coating, and dried at 120 ° C. for 20 minutes. Thus, a photosensitive layer having a film thickness of 25 μm was formed to prepare a photoreceptor.

Two photoreceptors as described above were prepared and evaluated in the same manner as in Reference Example 1.
( Reference Example 3)
Metal-free phthalocyanine (Fastogen)
Evaluation was performed in the same manner as in Reference Example 1 except that the titanyl phthalocyanine prepared in Pigment Synthesis Example 1 was used instead of Blue 8120B).
(Pigment synthesis example 1)
A pigment was produced according to the method described in the production example of JP-A-2-8256 (Japanese Patent Publication No. 7-91486). That is, 9.8 g of phthalodinitrile and 75 ml of 1-chloronaphthalene were mixed with stirring, and 2.2 ml of titanium tetrachloride was added dropwise under a nitrogen stream. After completion of the dropwise addition, the temperature was gradually raised to 200 ° C., and the reaction was carried out by stirring for 3 hours while maintaining the reaction temperature between 200 ° C. and 220 ° C. After completion of the reaction, the mixture was allowed to cool, and when it reached 130 ° C., it was filtered while hot, and washed with 1-chloronaphthalene until the powder turned blue. Next, it was washed several times with methanol, further washed several times with hot water at 80 ° C., and dried to obtain titanyl phthalocyanine.

  Using the obtained titanyl phthalocyanine powder, an X-ray diffraction spectrum was measured under the following conditions and confirmed to be the same as the spectrum described in the publication.

X-ray tube: Cu
Voltage: 50kV
Current: 30mA
Scanning speed: 2 ° / min Scanning range: 3-40 °
Time constant: 2 seconds ( Reference Example 4)
Metal-free phthalocyanine (Fastogen)
Evaluation was performed in the same manner as in Reference Example 2 except that the titanyl phthalocyanine prepared in Pigment Synthesis Example 1 was used instead of Blue 8120B).
( Reference Example 5)
Metal-free phthalocyanine (Fastogen)
Evaluation was performed in the same manner as in Reference Example 1 except that the titanyl phthalocyanine prepared in Pigment Synthesis Example 2 was used instead of Blue 8120B).
(Pigment synthesis example 2)
A pigment was prepared according to Japanese Patent Application Laid-Open No. 2001-19871. That is, 29.2 g of 1,3-diiminoisoindoline and 200 ml of sulfolane were mixed, and 20.4 g of titanium tetrabutoxide was added dropwise under a nitrogen stream. After completion of the dropping, the temperature was gradually raised to 180 ° C., and the reaction was carried out by stirring for 5 hours while keeping the reaction temperature between 170 ° C. and 180 ° C. After the reaction was completed, the mixture was allowed to cool, and the precipitate was filtered and washed with chloroform until the powder turned blue. Next, it was washed several times with methanol, and further washed several times with hot water at 80 ° C. and then dried to obtain crude titanyl phthalocyanine. Crude titanyl phthalocyanine was dissolved in 20 times the amount of concentrated sulfuric acid and dropped into 100 times the amount of ice water while stirring, and the precipitated crystals were filtered. Next, washing with water was repeated until the washing solution became neutral to obtain a titanyl phthalocyanine wet cake (water paste). 2 g of the obtained wet cake (water paste) was put into 20 g of tetrahydrofuran, stirred for 4 hours, filtered and dried to obtain titanyl phthalocyanine.

Using the obtained titanyl phthalocyanine powder, an X-ray diffraction spectrum was measured under the conditions of Pigment Synthesis Example 1, and the diffraction peak (±±) of the Bragg angle 2θ with respect to the Cu—Kα ray (wavelength 1.542Å) described in the publication 0.2 °) having a maximum diffraction peak at least 27.2 °, and further having main peaks at 9.4 °, 9.6 °, and 24.0 °, and the lowest angle side. As a diffraction peak, the titanyl phthalocyanine was confirmed to have a peak at 7.3 ° and no peak between the 7.3 ° peak and the 9.4 ° peak.
( Reference Example 6)
Metal-free phthalocyanine (Fastogen)
Evaluation was performed in the same manner as in Reference Example 2 except that titanyl phthalocyanine prepared in Pigment Synthesis Example 2 was used instead of Blue 8120B).

In addition, the electron transport material represented by Structural Formula (1-1) was manufactured by the following method.
(First step)
In a 200 ml four-necked flask, 5.0 g (18.6 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 2.14 g (18.6 mmol) of 2-aminoheptane and 25 ml of DMF was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the container was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Furthermore, the recovered product was recrystallized with a toluene / hexane mixed solvent to obtain 2.14 g (yield: 31.5%) of monoimide A.
(Second step)
In a 100 ml four-necked flask, 2.0 g (5.47 mmol) of monoimide A, 0.137 g (2.73 mmol) of hydrazine monohydrate, 10 mg of p-toluenesulfonic acid, and 50 ml of toluene are placed and heated to reflux for 5 hours. It was. After completion of the reaction, the container was cooled and concentrated under reduced pressure. The residue was purified by silica gel column chromatography. Furthermore, the recovered product was recrystallized with a mixed solvent of toluene / ethyl acetate to obtain 0.668 g (yield 33.7%) of an electron transport material represented by the structural formula (1-1). In mass spectrometry (FD-MS), the peak of M / z = 726 was observed, and it was identified as the target product. In the elemental analysis, the calculated values are 69.41% carbon, 5.27% hydrogen, and 7.71% nitrogen, whereas the measured values are 69.52% carbon, 5.09% hydrogen, and 7.93 nitrogen. %Met.
( Reference Example 7)
Evaluation was performed in the same manner as in Reference Example 5 except that the electron transport material represented by the structural formula (1-2) was used instead of the electron transport material represented by the structural formula (1-1). .
( Reference Example 8)
Evaluation was performed in the same manner as in Reference Example 6 except that the electron transport material represented by the structural formula (1-2) was used instead of the electron transport material represented by the structural formula (1-1). .

In addition, the electron transport material represented by Structural Formula (1-2) was manufactured by the following method.
(First step)
In a 200 ml four-necked flask, 1,4,5,8-naphthalenetetracarboxylic dianhydride 10 g (37.3 mmol), hydrazine monohydrate 0.931 g (18.6 mmol), p-toluenesulfonic acid 20 mg, toluene 100 ml was added and heated to reflux for 5 hours. After completion of the reaction, the container was cooled and concentrated under reduced pressure. The residue was purified by silica gel column chromatography. Furthermore, the recovered product was recrystallized with a mixed solvent of toluene / ethyl acetate to obtain 2.84 g of dimer C (yield 28.7%).
(Second step)
In a 100 ml four-necked flask, 2.5 g (4.67 mmol) of Dimer C and 30 ml of DMF were placed and heated to reflux. To this, a mixture of 2-aminopropane 0.278 g (4.67 mmol) and DMF 10 ml was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue and purified by silica gel column chromatography to obtain 0.556 g (yield 38.5%) of monoimide C.
(Third process)
In a 50 ml four-necked flask, 0.50 g (1.62 mmol) of monoimide C and 10 ml of DMF were placed and heated to reflux. To this, a mixture of 2-aminoheptane 0.186 g (1.62 mmol) and DMF 5 ml was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Furthermore, the recovered product was recrystallized with a toluene / hexane mixed solvent to obtain 0.243 g (yield 22.4%) of an electron transport material represented by the structural formula (1-2). In mass spectrometry (FD-MS), the peak of M / z = 670 was observed, and it was identified as the target product. In the elemental analysis, the calculated values are 68.05% carbon, 4.51% hydrogen, and 8.35% nitrogen, while the measured values are 68.29% carbon, 4.72% hydrogen, and 8.33 nitrogen. %Met.
( Reference Example 9)
Evaluation was performed in the same manner as in Reference Example 5 except that the electron transport material represented by the structural formula (1-3) was used instead of the electron transport material represented by the structural formula (1-1). .
( Reference Example 10)
Evaluation was performed in the same manner as in Reference Example 6 except that the electron transport material represented by the structural formula (1-3) was used instead of the electron transport material represented by the structural formula (1-1). .

In addition, the electron transport material represented by Structural Formula (1-3) was manufactured by the following method.
(First step)
In a 200 ml four-necked flask, 5.0 g (18.6 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 1.10 g (18.6 mmol) of 2-aminopropane and 25 ml of DMF was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the reaction vessel was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Furthermore, the recovered product was recrystallized with a toluene / hexane mixed solvent to obtain 2.08 g (yield 36.1%) of monoimide B.
(Second step)
In a 100 ml four-necked flask, 2.0 g (6.47 mmol) of monoimide B, 0.162 g (3.23 mmol) of hydrazine monohydrate, 10 mg of p-toluenesulfonic acid, and 50 ml of toluene were added and heated under reflux for 5 hours. I let you. After completion of the reaction, the container was cooled and concentrated under reduced pressure. The residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized with a mixed solvent of toluene / ethyl acetate to obtain 0.810 g (yield 37.4%) of an electron transport material represented by the structural formula (1-3). In mass spectrometry (FD-MS), the peak of M / z = 614 was observed, and it was identified as the target product. In the elemental analysis, the calculated values are 66.45% carbon, 3.61% hydrogen, and 9.12% nitrogen, whereas the measured values are 66.28% carbon, 3.45% hydrogen, and 9.33 nitrogen. %Met.
( Reference Example 11)
Evaluation was performed in the same manner as in Reference Example 5 except that the electron transport material represented by the structural formula (2-1) was used instead of the electron transport material represented by the structural formula (1-1). .
( Reference Example 12)
Evaluation was performed in the same manner as in Reference Example 6 except that the electron transport material represented by the structural formula (2-1) was used instead of the electron transport material represented by the structural formula (1-1). .

In addition, the electron transport material represented by Structural Formula (2-1) was manufactured by the following method.
(First step)
In a 200 ml four-necked flask, 5.0 g (18.6 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 1.62 g (18.6 mmol) of 2-aminopentane and 25 ml of DMF was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the container was cooled and concentrated under reduced pressure. Toluene was added to the residue, and the residue was purified by silica gel column chromatography. Furthermore, the recovered product was recrystallized with a toluene / hexane mixed solvent to obtain 3.49 g (yield: 45.8%) of monoimide E.
(Second step)
In a 100 ml four-necked flask, 3.0 g (7.33 mmol) of monoimide E, 0.983 g (3.66 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride, hydrazine monohydrate 368 g (7.33 mmol), p-toluenesulfonic acid 10 mg, and toluene 50 ml were added and heated to reflux for 5 hours. After completion of the reaction, the container was cooled and concentrated under reduced pressure. The residue was purified twice by silica gel column chromatography. Furthermore, the recovered product was recrystallized with a mixed solvent of toluene / ethyl acetate to obtain 0.939 g (yield 13.7%) of an electron transport material represented by the structural formula (2-1). In mass spectrometry (FD-MS), the peak of M / z = 934 was observed, and it was identified as the target product. In the elemental analysis, the calculated values are 66.81% carbon, 3.67% hydrogen, and 8.99% nitrogen, whereas the measured values are 66.92% carbon, 3.74% hydrogen, and 9.05 nitrogen. %Met.
(Example 13)
Electron transport material represented by structural formula (1-1): Instead of 10 parts, electron transport material represented by structural formula (1-1): 8 parts and represented by structural formula (3-1) Electron transport material: Evaluation was performed in the same manner as in Reference Example 5 except that 2 parts were used.
(Example 14)
Electron transport material represented by structural formula (1-1): Instead of 20 parts, electron transport material represented by structural formula (1-1): 15 parts and represented by structural formula (3-1) Electron transport material: Evaluation was performed in the same manner as in Reference Example 6 except that 5 parts were used.
(Comparative Example 1)
Instead of the electron transport material represented by the structural formula (1-1), the structural formula (A)

で表される化合物を用いたこと以外は、参考例５と同様にして評価を行った。
（比較例２）
構造式（１−１）で表される電子輸送材料の代わりに、構造式（Ａ）で表される化合物を用いたこと以外は、参考例６と同様にして評価を行った。
（比較例３）
構造式（１−１）で表される電子輸送材料の代わりに、構造式（Ｂ）

Evaluation was performed in the same manner as in Reference Example 5 except that the compound represented by formula (1) was used.
(Comparative Example 2)
Evaluation was performed in the same manner as in Reference Example 6 except that the compound represented by the structural formula (A) was used instead of the electron transport material represented by the structural formula (1-1).
(Comparative Example 3)
Instead of the electron transport material represented by the structural formula (1-1), the structural formula (B)

で表される化合物を用いたこと以外は、参考例５と同様にして評価を行った。
（比較例４）
構造式（１−１）で表される電子輸送材料の代わりに、構造式（Ｂ）で表される化合物を用いたこと以外は、参考例６と同様にして評価を行った。

Evaluation was performed in the same manner as in Reference Example 5 except that the compound represented by formula (1) was used.
(Comparative Example 4)
Evaluation was performed in the same manner as in Reference Example 6 except that the compound represented by the structural formula (B) was used instead of the electron transport material represented by the structural formula (1-1).

The evaluation results of Reference Examples 1 to 12, Examples 13 and 14, and Comparative Examples 1 to 4 are shown in Tables 1 and 2.

表１から、参考例１〜１２、実施例１３、１４では、繰り返しの使用によっても感光体の特性が安定しており、良好な画像が出力できることがわかる。また、表２から、参考例１〜１２、実施例１３、１４では、オゾン暴露によっても暗部電位がほとんど変化せず、酸化性ガスに対する安定性が優れていることがわかる。

From Table 1, it can be seen that in Reference Examples 1 to 12 and Examples 13 and 14, the characteristics of the photoreceptor are stable even after repeated use, and a good image can be output. In addition, Table 2 shows that in Reference Examples 1 to 12 and Examples 13 and 14, the dark portion potential hardly changes even when exposed to ozone, and the stability to oxidizing gas is excellent.

  On the other hand, in Comparative Examples 1 to 4, it can be seen from Table 1 that the dark portion potential of the photoreceptor is lowered by repeated use, and an abnormal image is generated. Further, in the ozone exposure test of Table 2, the dark portion potential is lowered and an abnormal image is generated, which indicates that the deterioration of the photosensitive member due to the oxidizing gas generated in large quantities by corona charging is caused.

It is a figure which shows an example of the image forming apparatus of this invention. It is a figure which shows the other example of the image forming apparatus of this invention. It is a figure which shows an example of the process cartridge of this invention. It is a figure which shows the other example of the image forming apparatus of this invention. It is a figure which shows the other example of the image forming apparatus of this invention. It is a figure which shows the other example of the image forming apparatus of this invention. 2 is a cross-sectional view showing an example of a photoreceptor used in the image forming apparatus of the present invention. FIG. It is sectional drawing which shows the other example of the photoreceptor used with the image forming apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Photoconductor 12 Charging means 13 Exposure means 14 Developing means 15 Toner 16 Transfer means 17 Cleaning means 18 Image receiving medium 19 Fixing means 1A Discharge means 1B Pre-cleaning exposure means 1C Driving means 1D First transfer means 1E Second transfer means 1F Intermediate transfer body 1G Image receiving medium carrier 21 Conductive support 22 Charge generation layer 23 Charge transport layer 24 Subbing layer 25 Photosensitive layer

Claims (8)

A photoreceptor, a belt collector means for charging the photosensitive member, an image exposure means for forming an electrostatic latent image by image exposure to the electrophotographic photosensitive member the charging, an electrostatic latent image formed on said photosensitive member an image forming apparatus for chromatic and developing means for developing with toner to form a toner image, a transfer means for transferring the image receiving medium the toner image formed on said photosensitive member,
Photoreceptor is sensitive light layer is formed on the conductive support,
The photosensitive layer comprises a charge generating material , general formula

(Wherein, R ₁ and R ₂ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group and substituted or unsubstituted selected Ru group from the group consisting of aralkyl groups in _{and, R 3, R 4, R} 5, R 6, R 7, R 8, R 9, R 10, R 11, R 12, R 13 and _{R 14} each independently represent a hydrogen atom, a halogen group, a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group and substituted or unsubstituted selected Ru group from the group consisting of aralkyl radical, n is 0 or more (It is an integer of 100 or less .)
Electron transport materials represented by the general formula

Wherein R ₁₅ and R ₁₆ are each independently a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. R ₁₇ , R ₁₈ , R ₁₉ and R ₂₀ are each independently a hydrogen atom, halogen group, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted It is a group selected from the group consisting of a cycloalkyl group and a substituted or unsubstituted aralkyl group.)
Containing in an electron transporting material represented,
The image forming apparatus , wherein the charging means is a plurality of corona charging devices. The image forming apparatus according to claim 1, wherein the charge generation material is phthalocyanine. The image forming apparatus according to claim 2 , wherein the phthalocyanine is titanyl phthalocyanine. The titanyl phthalocyanine has a maximum diffraction peak at 27.2 ° as a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to the characteristic X-ray of CuKα, and is 9.4 °, 9.6 ° and 24 °. which has a 2.0 ° peak has a peak of 7.3 ° lowest angle side, claim 3, characterized in that no peaks between the 7.3 ° and 9.4 ° The image forming apparatus described in 1. The corona charging device, an image forming apparatus according to any one of claims 1 to 4, characterized in Rukoto is positively charging the photosensitive member. A plurality of the photosensitive member, the charging unit, the image exposing unit, and the developing unit ;
The transfer means, the plurality of the first transfer means for the toner image formed on the photosensitive member Ru superimposed and transferred sequentially to the intermediate transfer member, the image-receiving medium the toner image superimposed on the intermediate transfer member the image forming apparatus according to any one of claims 1 to 5, characterized in that it has a second transfer unit for transferring the. The photoreceptor, an image forming apparatus according to any one of claims 1 to 6, characterized in that the process linear velocity is 100 mm / sec or more. A photosensitive member, have a charging means for charging the photosensitive member in a process cartridge which is detachably mountable to the main body of the image forming apparatus,
The photoreceptor has a photosensitive layer formed on a conductive support,
The photosensitive layer comprises a charge generating material, general formula

Wherein R ₁ and R ₂ are each independently a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are each independently a hydrogen atom, a halogen group, A group selected from the group consisting of a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group and a substituted or unsubstituted aralkyl group, and n is 0 or more (It is an integer of 100 or less.)
Electron transport materials represented by the general formula

Wherein R ₁₅ and R ₁₆ are each independently a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group. R ₁₇ , R ₁₈ , R ₁₉ and R ₂₀ are each independently a hydrogen atom, halogen group, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted It is a group selected from the group consisting of a cycloalkyl group and a substituted or unsubstituted aralkyl group.)
Containing an electron transport material represented by
The process cartridge is characterized in that the charging means is a plurality of corona charging devices .

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