JP4739100B2 - Electrophotographic equipment - Google Patents

Description

  The present invention relates to an electrophotographic apparatus using a photosensitive member containing a specific charge transport material in an intermediate transfer type electrophotographic apparatus.

  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 technology 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 for analog copying, it is expected that its demand will increase further in the future. In addition, 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.

  In recent years, many systems using an intermediate transfer member for color printers and copying machines have been put on the market. An intermediate transfer type electronic device that sequentially superimposes toner images of respective colors on an intermediate transfer body, for example, an intermediate transfer belt, and performs primary transfer, and then secondary transfer the primary transfer image on the intermediate transfer body onto a transfer material. Photographic devices are known. In particular, the intermediate transfer method is used as a superimposing transfer method for each color toner image in a so-called full-color electrophotographic apparatus that reproduces a color-separated original image using subtractive color mixing with toners such as black, cyan, magenta, and yellow. (See Patent Document 1). In such a full-color electrophotographic apparatus, by using the intermediate transfer member, it is possible to improve the superposition of the respective color toner images and obtain an image without color misregistration.

  In addition, an electrophotographic apparatus using an intermediate transfer body is compared with an electrophotographic apparatus of a system in which a transfer material is attached or adsorbed to a transfer drum or a transfer belt, and a toner image on a photoconductor is directly transferred to the transfer material. Color misregistration is unlikely to occur when superimposing toner images of each color, and the transfer material does not require any processing or control (for example, gripping, adsorbing, giving curvature, etc.) to the transfer material, and transferring the image from the intermediate transfer member Therefore, the transfer material is excellent in that a wide variety of transfer materials can be selected.

  On the other hand, the intermediate transfer method tends to promote image quality degradation in the first transfer process in the second transfer process. Further, 100% of the same toner image cannot be transferred at the time of transfer, and the outline of the dot becomes slightly blurred. Therefore, in order to output a high-definition image with high resolution, it is necessary that the toner image on the photoreceptor is high-definition and has a good image quality.

  In recent years, as a full-color electrophotographic apparatus, a tandem system including a plurality of image forming elements including a photosensitive member is mainly used because it can cope with a high speed. In such a tandem system, the number of specific colors (for example, only black) often increases depending on the ratio of colors to be output, and there is a problem that the load on each photoconductor is not uniform. In such a case, the characteristics of only some of the photoconductors are deteriorated, resulting in a change in color tone when a full color image in which colors are superimposed is output during repeated use. Therefore, it is necessary for the photoreceptor to be stable without changing its characteristics even after repeated use.

JP 2002-169344 A

  An object of the present invention is to provide an electrophotographic apparatus capable of outputting high-definition and high-quality images over a long period of time.

  As a result of intensive studies to solve the above problems, the present inventors have found that in an electrophotographic apparatus of an intermediate transfer method, a photosensitive layer containing a specific charge transporting material is used in a photosensitive layer, thereby achieving high definition and high performance over a long period. It has been found that an electrophotographic apparatus capable of outputting a quality image can be provided.

That is, the said subject is solved by (1)-(9) of this invention shown below.
(1) “At least the photosensitive member, a charging device that uniformly charges the surface of the photosensitive member, an image exposure unit that performs image exposure after uniform charging to form an electrostatic latent image, and the electrostatic latent image In an electrophotographic apparatus having a developing means for developing and a transferring means for transferring a developed image, the electrophotographic apparatus primarily transfers the toner image developed on the photoreceptor onto the intermediate transfer body, and then the intermediate transfer An electrophotographic apparatus having intermediate transfer means for secondary transfer of a toner image on a body onto a recording material, wherein the photosensitive member has a photosensitive layer on at least a conductive support, and at least in the photosensitive layer An electrophotography comprising a charge generation material and an electron transport material represented by the following general formula (1) , preferably at least one of electron transport materials represented by the following structural formulas (a) to (g) apparatus.

なお、上記一般式（１）において、Ｒ１、Ｒ２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、置換又は無置換のアラルキル基からなる群より選ばれる基を表わし、Ｒ３、Ｒ４、Ｒ５、Ｒ６、Ｒ７、Ｒ８、Ｒ９、Ｒ１０はそれぞれ独立に水素原子、ハロゲン原子、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、置換又は無置換のアラルキル基からなる群より選ばれる基を表わす。」
（２）少なくとも感光体と、該感光体の表面を一様に帯電する帯電装置と、一様帯電後に像露光を行ない静電潜像を形成する像露光手段と、前記静電潜像を現像する現像手段と、現像像を転写する転写手段とを有する電子写真装置において、前記電子写真装置が、感光体上に現像されたトナー画像を中間転写体上に一次転写したのち、該中間転写体上のトナー画像を記録材上に二次転写する中間転写手段を有する電子写真装置であって、前記感光体が、少なくとも導電性支持体上に感光層を有し、該感光層中に少なくとも電荷発生材料と下記一般式（A）で表わされる電子輸送材料を含むことを特徴とする電子写真装置。

In the general formula (1) , R1 and R2 are each independently 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. R3, R4, R5, R6, R7, R8, R9, R10 are each independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted group Or a group selected from the group consisting of an unsubstituted cycloalkyl group and a substituted or unsubstituted aralkyl group. "
(2) At least a photoconductor, a charging device that uniformly charges the surface of the photoconductor, an image exposure unit that performs image exposure after uniform charging to form an electrostatic latent image, and develops the electrostatic latent image In the electrophotographic apparatus having the developing means for transferring and the transferring means for transferring the developed image, the electrophotographic apparatus primarily transfers the toner image developed on the photoreceptor onto the intermediate transfer body, and then the intermediate transfer body An electrophotographic apparatus having intermediate transfer means for secondary transfer of the toner image on a recording material, wherein the photoreceptor has a photosensitive layer on at least a conductive support, and at least a charge is contained in the photosensitive layer. An electrophotographic apparatus comprising a generating material and an electron transport material represented by the following general formula (A).

式中、Ｒ１、Ｒ２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、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、Ｒ３、Ｒ４、Ｒ５、Ｒ６、Ｒ７、Ｒ８、Ｒ９、Ｒ１０、Ｒ１１、Ｒ１２、Ｒ１３、Ｒ１４はそれぞれ独立に水素原子、ハロゲン原子、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、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、ｎは繰り返し単位であり、１から１００までの整数を表す。

（３）「前記電荷発生材料がフタロシアニンであることを特徴とする前記第（１）項又は第（２）項に記載の電子写真装置」
（４）「前記フタロシアニンがチタニルフタロシアニンであることを特徴とする前記第（３）項に記載の電子写真装置」
（５）「前記チタニルフタロシアニンがＣｕ−Ｋα線（波長１．５４２Å）に対するブラッグ角２θの回折ピーク（±０．２゜）として、少なくとも２７．２°に最大回折ピークを有し、更に９．４゜、９．６゜、２４．０゜に主要なピークを有し、かつ最も低角側の回折ピークとして７．３゜にピークを有し、７．３゜のピークと９．４゜のピークの間にピークを有さないことを特徴とする前記第（４）項に記載の電子写真装置」
（６）前記感光層中に更に下記一般式Bで表される電子輸送材料を含有することを特徴とする前記第（１）項乃至第（５）項のいずれかに記載の電子写真装置。

In the formula, R 1 and R 2 each independently represent a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aralkyl group, R 3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 are each independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, A group selected from the group consisting of a substituted or unsubstituted cycloalkyl group and a substituted or unsubstituted aralkyl group is represented, n is a repeating unit, and represents an integer of 1 to 100.

(3) “The electrophotographic apparatus according to (1) or (2), wherein the charge generation material is phthalocyanine”
(4) “Electrophotographic apparatus according to item (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 Cu—Kα rays (wavelength 1.542 mm). It has major peaks at 4 °, 9.6 ° and 24.0 °, and has a peak at 7.3 ° as the lowest diffraction peak, a peak at 7.3 ° and 9.4 °. The electrophotographic apparatus according to item (4), wherein there is no peak between the peaks of
(6) The electrophotographic apparatus according to any one of (1) to (5), wherein the photosensitive layer further contains an electron transport material represented by the following general formula B.

式中、Ｒ１５、Ｒ１６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、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、Ｒ１７、Ｒ１８、Ｒ１９、Ｒ２０はそれぞれ独立に水素原子、ハロゲン原子、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、置換又は無置換のアラルキル基からなる群より選ばれる基を表す。
（７）「正帯電で帯電プロセスを行なうことを特徴とする前記第（１）項乃至第（６）項のいずれかに記載の電子写真装置」
（８）「前記電子写真装置が複数の感光体を具備してなり、それぞれの感光体上に現像された単色のトナー画像を順次重ね合わせてカラー画像を形成することを特徴とする前記第（１）項乃至第（７）項のいずれかに記載の電子写真装置」
（９）「少なくとも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、該感光体が前記第（１）項乃至第（８）項のいずれかに記載の電子写真装置に用いられ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」

In the formula, R15 and R16 each independently represent a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aralkyl group, and R17, R18, R19 and R20 are each independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aralkyl group. Represents a group selected from the group consisting of
(7) “Electrophotographic apparatus according to any one of items (1) to (6), wherein the charging process is performed with positive charging”
(8) “The electrophotographic apparatus includes a plurality of photoconductors, and a single color toner image developed on each photoconductor is sequentially overlapped to form a color image. The electrophotographic apparatus according to any one of 1) to 7)
(9) “A process cartridge for an electrophotographic apparatus comprising at least a photoconductor, wherein the photoconductor is used in the electrophotographic apparatus according to any one of (1) to (8). Process cartridge for electrophotographic apparatus characterized in that "

  According to the present invention, it is possible to provide an electrophotographic apparatus capable of outputting high-definition and high-quality images over a long period of time.

  Specifically, at least a photoconductor, a charging device that uniformly charges the surface of the photoconductor, an image exposure unit that performs image exposure after uniform charging to form an electrostatic latent image, and the electrostatic latent image In the electrophotographic apparatus having a developing means for developing the toner and a transferring means for transferring the developed image, the electrophotographic apparatus primarily transfers the toner image developed on the photosensitive member onto the intermediate transfer member, and then In an electrophotographic apparatus having an intermediate transfer means for secondary transfer of a toner image on a transfer material onto a recording material, the photosensitive member has at least a photosensitive layer on a conductive support, and at least charge is generated in the photosensitive layer. By using an electrophotographic apparatus including the material and the electron transport material represented by the general formula (1) or the general formula (A), a high-definition and high-quality image can be output over a long period of time. .

In the present invention, an intermediate transfer system is used. As described above, the intermediate transfer method is mainly used in full-color electrophotographic apparatuses because color misregistration hardly occurs when toner images of respective colors are superimposed to output a color image.
Further, since the degree of freedom of the transfer material is increased and the transfer material and the photosensitive member are not in direct contact with each other, the adhesion of paper dust is suppressed. Therefore, the transfer material can be favorably used in a monochrome machine that does not require toner overlap.

In addition, since the electron transport material represented by the general formula (1) or the general formula (A) used in the present invention exhibits a very excellent electron transport property, it can be contained in the photosensitive layer as a charge transport material. It becomes a highly sensitive photoconductor.
In addition, a photoreceptor using the electron transport material represented by the general formula (1) or the general formula (A) as a charge transport material has not only sensitivity but also good chargeability and a small accumulation of residual potential. Furthermore, since the change in characteristics is small even after repeated use, it is possible to output a high-quality image without abnormal images over a long period of time, and there is no change in color tone even by repeated use by using it in a tandem full-color electrophotographic apparatus. An electrophotographic apparatus can be obtained.
Further, 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 generating material, but among them, a material having a phthalocyanine structure is preferable in combination with the charge transporting material used in the present invention.

  Among them, in particular, by using titanyl phthalocyanine as shown in the following structural formula (1) having titanium as a central metal, it is possible to obtain a photosensitive layer with particularly high sensitivity and to output a high-definition image. .

  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, and JP-A-59-31965. JP, 61-239248, JP, 62-67094, A, etc. are mentioned. In addition, various crystal systems are known for titanyl phthalocyanine, such as JP-A-59-49544, JP-A-59-416169, JP-A-59-166959, JP-A-61-239248, The crystal forms are different from those of JP-A-62-67094, JP-A-63-366, JP-A-63-116158, JP-A-64-17066, JP-A-2001-19871, etc. Titanyl phthalocyanine has been described.

  Of these crystal forms, 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 ° as the diffraction peak on the lowest angle side and having no peak between the 7.3 ° peak and the 9.4 ° peak, Without losing sensitivity, it is possible to obtain a stable electrophotographic photosensitive member that does not cause a decrease in chargeability even when used repeatedly.

  Since the electron transport material represented by the general formula (1) or the general formula (A) exhibits an electron transport property, a laminated structure in which 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 for both positive and negative charges by using a hole transport material in combination, but the positive charge is more stable in chargeability and is generated. This is preferable because less oxidizing gas is used (about 1/10 of negative charging).

Hereinafter, the electrophotographic apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view for explaining an electrophotographic apparatus of the present invention, and modifications as will be described later also belong to the category of the present invention.
In FIG. 1, the photoreceptor (11) has at least a photosensitive layer on a conductive support, and at least the charge generating material and the electron transport material represented by the general formula (1) or (A) in the photosensitive layer. including. Although the photoconductor (11) has a drum shape, it may have a sheet shape or an endless belt shape.

As the charging means (charging device) (12), known means such as a corotron, a scorotron solid state charger (solid state charger), and a charging roller are used.
As the first transfer means (1D) and the second transfer means (1E), known chargers such as corotron, scorotron, solid state charger (solid state charger), and charging roller can be used.
Light sources used for the exposure means (13), the charge removal means (1A), etc. include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), and electroluminescence (ELs). Examples of luminescent materials such as 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 (11) by the developing means (14) is transferred to the image receiving medium (18), but not all is transferred and remains on the photoconductor (11). Toner is also generated. Such toner is removed from the photoreceptor (11) by the cleaning means (17). As the cleaning means, a rubber cleaning blade, a brush such as a fur brush, a mag fur brush, or the like can be used.

  The toner image formed on the photoreceptor (11) is transferred onto the intermediate transfer belt (1F) by the first transfer means (1D) disposed inside the intermediate transfer belt (1F). The first transfer means (1D) is arranged so as to be able to come into contact with and separate from the photoreceptor (11), and the intermediate transfer belt (1F) is brought into contact with the photoreceptor (11) only during the transfer operation. The toner image transferred to the intermediate transfer belt (1F) after image formation is transferred to the image receiving medium (18) by the second transfer means (1E) and then fixed by the fixing means (19). A fixed image is formed. The second transfer means (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.

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 photosensitive member and includes any one or more of charging means, exposure means, developing means, transfer means, cleaning means, and discharging means. It is. There are many shapes and the like of the process cartridge, but a general example is the one shown in FIG. The process cartridge of the example in this figure has a built-in photoreceptor (11), and further has a charging means (12), a developing means (14), and a cleaning means (17). The exposure of the photosensitive member is performed through the image exposure unit (16) from the exposure means in the apparatus.
These process cartridges are detachable and easy to maintain.

  FIG. 3 shows another example of the electrophotographic apparatus according to the present invention. In this electrophotographic apparatus, charging means (charging device) (12), exposure means (13), black (Bk), cyan (C), magenta (M), and yellow (Y) are disposed around the photoreceptor (11). Developing means (14Bk, 14C, 14M, 14Y) for each color toner, an intermediate transfer belt (1F) as an intermediate transfer member, and a cleaning means (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, and are added or omitted as appropriate.

  The photoreceptor (11) is an electrophotographic photoreceptor that satisfies the requirements of the present invention. Each color developing means (14Bk, 14C, 14M, 14Y) can be controlled independently, and only the color developing means for image formation is driven. The toner image formed on the photoreceptor (11) is transferred onto the intermediate transfer belt (1F) by the first transfer means (1D) disposed inside the intermediate transfer belt (1F). The first transfer means (1D) is arranged so as to be able to come into contact with and separate from the photoreceptor (11), and the intermediate transfer belt (1F) is brought into contact with the photoreceptor (11) only during the transfer operation. The respective color images are 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 means (1E) and then fixed by the fixing means (19). The image is formed by fixing. The second transfer means (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.

  FIG. 4 shows another example of the electrophotographic apparatus according to the present invention. This electrophotographic 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, 11Bk) for each color are provided. The photoreceptor used in this electrophotographic apparatus is a photoreceptor that satisfies the requirements of the present invention. Around each photoconductor (11Y, 11M, 11C, 11Bk), charging means (12Y, 12M, 12C, 12Bk), exposure means (13Y, 13M, 13C, 13Bk), developing means (14Y, 14M, 14C, 14Bk), cleaning means (17Y, 17M, 17C, 17Bk) and the like are provided.

  Each color image forming section can be controlled independently, and only the color image forming section for image formation is driven. The toner image formed on the photoconductor (11Y, 11M, 11C, 11Bk) for each color is transferred to the intermediate transfer belt (1F) by the first transfer means (1D) arranged inside the intermediate transfer belt (1F). Transcribed above. The first transfer means (1D) is arranged so as to be able to come into contact with and separate from the photoreceptor (11), and the intermediate transfer belt (1F) is brought into contact with the photoreceptor (11) only during the transfer operation. The respective color images are 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 means (1E) and then fixed by the fixing means (19). The image is formed by fixing. The second transfer means (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.

Next, the electrophotographic photosensitive member used in the present invention will be described in detail.
The photosensitive layer of the electrophotographic photoreceptor according to the present invention includes a multilayer 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 single layer. There is a single-layer type photosensitive layer containing a charge generation material and a charge transport material.

5 and 6 are cross-sectional views schematically showing an example of an electrophotographic photoreceptor used in the electrophotographic apparatus of the present invention. FIG. 5 shows an example of a photoreceptor of a laminated photosensitive layer, and FIG. 6 shows a single layer type. It is an example of the photoreceptor of a photosensitive layer.
First, an example of each layer structure 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). The structure of the photosensitive layer.
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, iron, tin oxide, An oxide such as indium oxide coated with film or cylindrical plastic or paper by vapor deposition or sputtering, or a plate of aluminum, aluminum alloy, nickel, stainless steel, etc., and drawing ironing method or impact ironing method It is possible to use pipes that have been surface-treated by cutting, superfinishing, polishing, etc. after being made into raw pipes by methods such as the Extruded Ironing method, Extruded Drawing method, and cutting method.

(Charge generation layer)
First, the charge generation layer (22) among the layers in the multilayer photoconductor 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. As the charge generation material used in the present invention, a known material can be used. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzo An azo pigment having a thiophene skeleton, an azo pigment having a fluorenone skeleton, an azo pigment having an oxadiazole skeleton, an azo pigment having a bis-stilbene skeleton, an azo pigment having a distyryl oxadiazole skeleton, an azo pigment having a distyrylcarbazole skeleton Perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Jigoido pigments, bisbenzimidazo - such as Le based pigments. These charge generation materials can be used alone or as a mixture of two or more.

In the present invention, phthalocyanine pigments are particularly preferable from the viewpoint of various properties necessary for the present invention.
Among these, in particular, titanyl phthalocyanine having titanium as a central metal makes it possible to obtain a photosensitive layer having particularly high sensitivity, and it is possible to further increase the speed of an electrophotographic apparatus. Further, among various crystal forms, 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 ° as the diffraction peak on the lowest angle side and having no peak between the 7.3 ° peak and the 9.4 ° peak, Without losing sensitivity, it is possible to obtain a stable electrophotographic photosensitive member that does not cause a decrease in chargeability even when used repeatedly.

Such titanyl phthalocyanine can be synthesized as follows (see Pigment Synthesis Example 2 described below). That is,
<Synthesis example>
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.
2 g of the obtained wet cake was put into 20 g of an organic solvent shown in Table 7 and stirred for 4 hours. 100 g of methanol was added to this and stirred for 1 hour, followed by filtration and drying to obtain a titanyl phthalocyanine crystal powder used in the present invention.
The obtained titanyl phthalocyanine crystal powder was subjected to X-ray diffraction spectrum measurement under the following conditions.
X-ray tube: Cu, voltage: 50 kV,
Current: 30 mA
Scanning speed: 2 ° / min,
Scanning range: 3 ° -40 °
Time constant: 2 seconds FIG. 7 shows an X-ray diffraction spectrum of the pigment prepared in the synthesis example.

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-. Examples thereof include vinyl carbazole and polyacrylamide.
These binder resins may be used alone or as a mixture of two or more.
The binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight, per 100 parts by weight of the charge generating material.
Further, 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 for forming the charge generation layer, a casting method from a solution dispersion system is preferable. In order to provide a charge generation layer by a casting method, the above-described charge generation material is dispersed by a ball mill, an attritor, a sand mill, or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone together with a binder resin if necessary. What is necessary is just to apply the dispersion liquid after diluting it appropriately. Application can be performed by dip coating, spray coating, bead coating, or the like.
The film thickness of the charge generation layer provided as described above is usually 0.01 μm to 5 μm, preferably 0.1 μm to 2 μm.

(Charge transport layer)
Next, the charge transport layer (23) will be described.
The charge transport layer is formed by dissolving or dispersing a mixture or copolymer containing a charge transport component and a binder component as main components in a suitable 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 , 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 alone or as a mixture of two or more kinds, or as a copolymer comprising two or more kinds of raw material monomers, and further copolymerized with a charge transporting material.

For the purpose of ensuring the stability of the charge transport layer against environmental fluctuations, when using an electrically inactive polymer compound, 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, the electrically inactive polymer compound refers to a polymer compound that does not include a chemical structure exhibiting photoconductivity such as a triarylamine structure.
When these resins are used in combination with a binder resin as an additive, the addition amount is preferably 50 wt% or less because of restrictions on light attenuation sensitivity.

In the present invention, as a material that can be used for the charge transport material, it is essential to use the electron transport material represented by the general formula (1) or the general formula (A) described above. A charge transport material, that is, an electron transport material (acceptor) and a hole transport material (donor) can be used in combination.
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-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron accepting substances such as nitrodibenzothiophene-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 include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, Examples include styrylpyrazolines, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, and thiophene derivatives.
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 suitably 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) or general formula ( The electron transport material represented by A) 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, halogenated hydrocarbons 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 and ultraviolet absorbers and leveling agents described later can be added to the charge transport layer. These compounds can be used alone or as a mixture of two or more. The amount of the low molecular compound used is 0.1 to 50 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the polymer compound, and the amount of the leveling agent used is 100 parts by weight of the polymer compound. On the other hand, about 0.001 to 5 parts by weight is appropriate.

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 suitably about 15 to 40 μm, preferably about 15 to 30 μm, and when resolution is required, 25 μm or less is appropriate.

(Underlayer)
In the electrophotographic photoreceptor used in the present invention, an undercoat layer (24) may be provided between the conductive support (21) and the mixed photosensitive layer (25) or the charge generation layer (22). 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. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is applied on the resin using a solvent, the resin is a resin having high resistance to general organic solvents. 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, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin.
In addition, a fine powder such as a metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, or indium oxide, or a metal sulfide or metal nitride 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 this, 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 an undercoat layer.
The thickness of the undercoat layer is suitably from 0.1 to 10 μm, more preferably from 1 to 5 μm.
In the present invention, a known antioxidant, plasticizer, ultraviolet absorber, low molecular charge transporting material and leveling agent are added to each layer in order to improve the gas barrier property and the environmental resistance of the photoreceptor surface layer. can do.

Further, in the present invention, the photosensitive layer can be made dense by adding the electron transport material represented by the general formula (B) to the photosensitive layer, so that the gas barrier property is improved and generated by a charger or the like. It is possible to prevent deterioration of the photoreceptor 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 nickel belt is used as a support, it is possible to reduce warpage generally referred to as curl, Occurrence of photoreceptor defects can be prevented.
This is because the electron transport material represented by the general formula (B) has a low molecular weight, and thus acts as a plasticizer in the photosensitive layer, but the electron transport material represented by the general formula B is Since it is an electron transporting material monomer that has electron transporting ability and is represented by general formula (1) and general formula (A), there is almost no side effect such as residual potential, and improvement of gas barrier properties and curling are reduced. Can be made.
The electron transport material represented by the general formula (B) is suitably 1 to 50% by weight with respect to the electron transport material represented by the general formula (1) or the general formula (A). If the amount is too small, the desired effect cannot be obtained, and the electron transport material represented by the general formula (B) has an electron transport ability as compared with the electron transport materials represented by the general formula (1) and the general formula (A). Since it is inferior, when too much, sensitivity will fall.

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. 6 is a cross-sectional view schematically showing an example of an electrophotographic photosensitive member used in the electrophotographic apparatus of the present invention. At least a charge generating material on the conductive support (21) and the general formula (1). Alternatively, a photosensitive layer (25) containing a charge transport material represented by the general formula (A) is provided.
Although not shown, an undercoat layer may be provided between the conductive support (21) and the photosensitive layer (25).

As the charge generating 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, the phthalocyanine pigment has various characteristics necessary for the present invention. Is particularly preferred.
Among them, as described above, particularly titanyl phthalocyanine having titanium as a central metal makes it possible to obtain a photosensitive layer with particularly high sensitivity, and it is possible to further increase the speed of an electrophotographic apparatus. Further, among various crystal forms as in the case of lamination, 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 ° as the diffraction peak on the lowest angle side and having no peak between the 7.3 ° peak and the 9.4 ° peak, Without losing sensitivity, it is possible to obtain a stable electrophotographic photosensitive member that does not cause a decrease in chargeability even when used repeatedly.
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.

As a material that can be used for the charge transport material even in the case of a single layer configuration, it is essential to use the electron transport material represented by the general formula (1) or the general formula (A), but in addition to this, A known charge transporting material as described above, that is, an electron transporting material (acceptor) and a hole transporting material (donor) can be used in the same manner as in the lamination.
In the photosensitive layer having the single layer structure, the charge generating material is suitably 0.1 to 30% by weight, preferably 0.5 to 10% by weight, based on the entire photosensitive layer. The electron transport material is suitably 5 to 300 parts by weight, preferably 10 to 150 parts by weight, based on 100 parts by weight of the binder resin component. However, it is preferable that the electron transport material represented by General formula (1) or General formula (A) is 50 to 100 weight% with respect to the whole electron transport material. The hole transport material is suitably 5 to 300 parts by weight, preferably 20 to 150 parts by weight with respect to 100 parts by weight of the binder resin component. 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 20 to 300 parts by weight, preferably 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin component. It is.

  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. , Halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate. These solvents can be used alone or in combination.

  Further, if necessary, low-molecular compounds such as antioxidants, plasticizers, lubricants and 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 amount of the low molecular compound used is 0.1 to 50 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the polymer compound such as a binder resin. The amount of the leveling agent used is the polymer compound. About 0.001 to 5 parts by weight is appropriate for 100 parts by weight.

Even in the case of a single layer structure, by adding an electron transport material represented by the general formula (B) to the photosensitive layer, the photosensitive layer can be made dense, so that the gas barrier property is improved, Photoconductor deterioration due to the generated oxidizing gas can be prevented. In addition, since shrinkage during film formation is relieved, when a flexible sheet such as an aluminum-deposited PET sheet or nickel belt is used as a support, it is possible to reduce warpage generally referred to as curl, Occurrence of photoreceptor defects can be prevented.
In the photosensitive layer having a single layer structure, the electron transport material represented by the general formula (B) is suitably 1 to 50% by weight based on the electron transport material represented by the general formula (1) or the general formula (A). It is. If the amount is too small, the desired effect cannot be obtained, and the electron transport material represented by the general formula (B) has an electron transport ability as compared with the electron transport materials represented by the general formula (1) and the general formula (A). Since it is inferior, when too much, sensitivity will fall.

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 suitably about 10 to 45 μm, preferably about 15 to 32 μm, and when resolution is required, 25 μm or less is appropriate.

  The electron transport materials represented by the general formula (1), general formula (A), and general formula (B) used in the present invention have the structural skeleton shown below.

式中、Ｒ１、Ｒ２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、置換又は無置換のアラルキル基からなる群より選ばれる基を表わし、Ｒ３、Ｒ４、Ｒ５、Ｒ６、Ｒ７、Ｒ８、Ｒ９、Ｒ１０はそれぞれ独立に水素原子、ハロゲン原子、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、置換又は無置換のアラルキル基からなる群より選ばれる基を表わす。

In the formula, R1 and R2 each independently represent a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aralkyl group, R3, R4, R5, R6, R7, R8, R9, R10 are each independently a hydrogen atom, halogen atom, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group Represents a group selected from the group consisting of a substituted or unsubstituted aralkyl group.

式中、Ｒ１、Ｒ２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、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、Ｒ３、Ｒ４、Ｒ５、Ｒ６、Ｒ７、Ｒ８、Ｒ９、Ｒ１０、Ｒ１１、Ｒ１２、Ｒ１３、Ｒ１４はそれぞれ独立に水素原子、ハロゲン原子、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、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、ｎは繰り返し単位であり、１から１００までの整数を表す。

In the formula, R 1 and R 2 each independently represent a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aralkyl group, R 3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 are each independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, A group selected from the group consisting of a substituted or unsubstituted cycloalkyl group and a substituted or unsubstituted aralkyl group is represented, n is a repeating unit, and represents an integer of 1 to 100.

式中、Ｒ１５、Ｒ１６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、置換又は無置換のアラルキル基からなる群より選ばれる基を表し、Ｒ１７、Ｒ１８、Ｒ１９、Ｒ２０はそれぞれ独立に水素原子、ハロゲン原子、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、置換又は無置換のアラルキル基からなる群より選ばれる基を表す。

In the formula, R15 and R16 each independently represent a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aralkyl group, and R17, R18, R19 and R20 are each independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aralkyl group. Represents a group selected from the group consisting of

  The substituted or unsubstituted alkyl group is 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- Straight chain such as butyl group, n-pentyl group, n-hexyl group, n-peptyl group, n-octyl group, n-nonyl group, n-decyl group, i-propyl group, s-butyl group, t -Branched group such as butyl group, methylpropyl group, dimethylpropyl group, ethylpropyl group, diethylpropyl group, methylbutyl group, dimethylbutyl group, methylpentyl group, dimethylpentyl group, methylhexyl group, dimethylhexyl group, alkoxy Alkyl group, monoalkylaminoalkyl group, dialkylaminoalkyl group, halogen-substituted alkyl group, alkylcarbonylalkyl group, Kishiarukiru group, alkanoyloxy 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 group in which a part of carbon atoms of the substituted or unsubstituted alkyl group is substituted with a hetero atom (N, O, S, etc.) is also substituted. Included in the alkyl group.

  The substituted or unsubstituted cycloalkyl group includes a cycloalkyl ring having 3 to 25 carbon atoms, preferably 3 to 10 carbon atoms, specifically, a homocyclic ring from cyclopropane to cyclodecane, methylcyclo Those having an alkyl substituent such as pentane, dimethylcyclopentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, tetramethylcyclohexane, ethylcyclohexane, diethylcyclohexane, t-butylcyclohexane, alkoxyalkyl groups, monoalkylaminoalkyl groups, dialkylamino Alkyl group, halogen-substituted alkyl group, alkoxycarbonylalkyl group, carboxyalkyl group, alkanoyloxyalkyl group, aminoalkyl group, halogen atom, amino group, esterified Which may be a carboxyl group, a cycloalkyl group substituted by a cyano group and the like. The substitution position of these substituents is not particularly limited, and a group in which a part of carbon atoms of the substituted or unsubstituted cycloalkyl group is substituted with a hetero atom (N, O, S, etc.) is also substituted. It is included in the cycloalkyl group.

Examples of the substituted or unsubstituted aralkyl group include groups in which an aromatic ring is substituted on the above-described substituted or unsubstituted alkyl group, and an aralkyl group having 6 to 14 carbon atoms is preferable. More specifically, benzyl group, perfluorophenylethyl group, 1-phenylethyl group, 2-phenylethyl group, terphenylethyl group, dimethylphenylethyl group, diethylphenylethyl group, t-butylphenylethyl group, 3- Examples thereof include a phenylpropyl group, a 4-phenylbutyl group, a 5-phenylpentyl group, a 6-phenylhexyl group, a benzhydryl group, and a trityl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  Specifically, as the electron transport material represented by the general formula (1), electron transport materials represented by the following structural formulas (2) to (8) are preferable in that the obtained image has high quality. In the formula, Me represents a methyl group.

Examples of the method for producing the electron transport material represented by the general formula (1) include the following methods.
That is, naphthalenecarboxylic acid is synthesized from the following reaction formula according to a known synthesis method (for example, US Pat. No. 6,794,102, Industrial Organic Pigments 2nd edition, VCH, 485 (1997)).

式中、ＲｎはＲ３、Ｒ４、Ｒ７、Ｒ８を表わし、ＲｍはＲ５、Ｒ６、Ｒ９、Ｒ１０を表わす。

In the formula, Rn represents R3, R4, R7, R8, and Rm represents R5, R6, R9, R10.

  The electron transport material represented by the general formula (1) used in the present invention is a method of reacting the above naphthalenecarboxylic acid or its anhydride with amines to monoimidize, and using a buffer solution for naphthalenecarboxylic acid or its anhydride. It is obtained by a method of adjusting pH and reacting with diamines. 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 or products such as benzene, toluene, xylene, chloronaphthalene, acetic acid, pyridine, methylpyridine, dimethylformamide, dimethylacetamide, dimethylethyleneurea, dimethylsulfoxide, and the like. It is good to use what can be made to react at the temperature of -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 to 250 degreeC, without reacting with raw materials and products, such as benzene, toluene, chloronaphthalene, bromonaphthalene, and acetic anhydride. Any reaction may be performed in the absence of 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.

The electron transport material represented by the above structural formula (2) was produced 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. Further, the recovered product was recrystallized from toluene / hexane to obtain 2.14 g of monoimide A (yield 31.5%).
<Second step>
Into 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 were heated and refluxed 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. Further, the recovered product was recrystallized from toluene / ethyl acetate to obtain 0.668 g (yield 33.7%) of the compound represented by the structural formula (2). In mass spectrometry (FD-MS), a peak of M / z = 726 was observed and identified as a target product. In the elemental analysis, calculated values were 69.41% carbon, 5.27% hydrogen, and 7.71% nitrogen, and the measured values were 69.52% carbon, 5.09% hydrogen, and 7.93% nitrogen.

The electron transport material represented by the above structural formula (3) 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. The recovered product was recrystallized from 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 the residue was purified by silica gel column chromatography to obtain 0.556 g of monoimide C (yield 38.5%).
<Third step>
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. Further, the recovered product was recrystallized from toluene / hexane to obtain 0.243 g (yield 22.4%) of the compound represented by the structural formula (3). In mass spectrometry (FD-MS), the peak was identified as M / z = 670, and the product was identified as the target product. In the elemental analysis, the calculated values were 68.05% carbon, 4.51% hydrogen, and 8.35% nitrogen, and the measured values were 68.29% carbon, 4.72% hydrogen, and 8.33% nitrogen.

The electron transport material represented by the above structural formula (4) was produced 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 from toluene / hexane to obtain 2.08 g of monoimide B (yield 36.1%).
<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 are heated and refluxed 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. Further, the recovered product was recrystallized from toluene / ethyl acetate to obtain 0.810 g (yield 37.4%) of the compound represented by the structural formula (4). In mass spectrometry (FD-MS), the peak of M / z = 614 was observed and identified as the target product. In the elemental analysis, the calculated values were 66.45% carbon, 3.61% hydrogen, and 9.12% nitrogen, and the measured values were 66.28% carbon, 3.45% hydrogen, and 9.33% nitrogen.

The electron transport material represented by the above structural formula (5) was produced by the following method.
<First step>
In a 200 ml four-necked flask, 5.0 g (9.39 mmol) of the above-mentioned dimer C and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 2-aminoheptane 1.08 g (9.39 mmol) DMF 25 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 to obtain 1.66 g (yield 28.1%) of monoimide D.
<Second step>
A 100 ml four-necked flask was charged with 1.5 g (2.38 mmol) of monoimide D and 50 ml of DMF and heated to reflux. To this, a mixture of 2-aminooctane 0.308 g (2.38 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 the residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized from toluene / hexane to obtain 0.328 g (yield 18.6%) of an electron transport material represented by the structural formula (5). In mass spectrometry (FD-MS), the peak of M / z = 740 was observed and identified as the target product. In the elemental analysis, the calculated values were 69.72% carbon, 5.44% hydrogen, and 7.56% nitrogen, and the measured values were 69.55% carbon, 5.26% hydrogen, and 7.33% nitrogen.

The electron transport material represented by the above structural formula (6) was produced by the following method.
<First step>
In a 200 ml four-necked flask, 5.0 g (9.39 mmol) of the above-mentioned dimer C and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 2-aminoheptane 1.08 g (9.39 mmol) DMF 25 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 to obtain 1.66 g (yield 28.1%) of monoimide D.
<Second step>
A 100 ml four-necked flask was charged with 1.5 g (2.38 mmol) of monoimide D and 50 ml of DMF and heated to reflux. To this, a mixture of 0.408 g (2.38 mmol) of 6-aminoundecane and 10 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. Further, the recovered product was recrystallized from toluene / hexane to obtain 0.276 g (yield 14.8%) of the electron transport material represented by the structural formula (6) described above. In mass spectrometry (FD-MS), the peak of M / z = 782 was observed and identified as the target product. In the elemental analysis, the measured values were 70.77% carbon, 6.11% hydrogen, and 7.02% nitrogen while the calculated values were 70.57% carbon, 5.92% hydrogen, and 7.16% nitrogen.

  The electron transport material represented by the general formula (A) is mainly synthesized by the following two synthesis methods.

  These synthesis methods include those suitable for obtaining a monodispersed compound by performing stepwise synthesis as shown below, as variations (applied synthesis methods).

The repeating unit n of the electron transport material represented by the general formula (A) is an integer of 1 to 100.
The repeating unit n is determined from the weight average molecular weight (Mw). That is, the compound exists with a distribution in molecular weight. When n exceeds 100, the molecular weight of the compound increases and the solubility in various solvents decreases, so 100 or less is preferable.
On the other hand, when n is 1, for example, it is a trimer of naphthalene carboxylic acid, but excellent electron transfer characteristics can be obtained even for oligomers by appropriately selecting substituents for R1 and R2. In this way, a wide range of naphthalenecarboxylic acid derivatives from oligomers to polymers are synthesized depending on the number of repeating units n.
In the range where the molecular weight of the oligomer region is small, monodispersed compounds can be obtained by stepwise synthesis. In the case of a compound having a large molecular weight, a compound having a distribution in molecular weight is obtained.
Specific examples of the electron transport material represented by the general formula (A) include the following.

  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.

Electron transport material synthesis example 1
<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. Further, the recovered product was recrystallized from toluene / hexane to obtain 2.14 g of monoimide A (yield 31.5%).
<Second step>
Into 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 were heated and refluxed 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. Further, the recovered product was recrystallized with toluene / ethyl acetate to obtain 0.668 g (yield 33.7%) of the electron transport material represented by the structural formula (2) (referred to as electron transport material 1).
In mass spectrometry (FD-MS), a peak of M / z = 726 was observed and identified as a target product. In the elemental analysis, calculated values were 69.41% carbon, 5.27% hydrogen, and 7.71% nitrogen, and the measured values were 69.52% carbon, 5.09% hydrogen, and 7.93% nitrogen.

Electron transport material synthesis example 2
<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. The recovered product was recrystallized from 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 the residue was purified by silica gel column chromatography to obtain 0.556 g of monoimide C (yield 38.5%).
<Third step>
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. Further, the recovered product was recrystallized with toluene / hexane to obtain 0.243 g (yield 22.4%) of the electron transport material represented by the structural formula (3) (referred to as electron transport material 2).
In mass spectrometry (FD-MS), the peak was identified as M / z = 670, and the product was identified as the target product. In the elemental analysis, the calculated values were 68.05% carbon, 4.51% hydrogen, and 8.35% nitrogen, and the measured values were 68.29% carbon, 4.72% hydrogen, and 8.33% nitrogen.

Electron transport material synthesis example 3
<First step>
In a 200 ml four-necked flask, 5.0 g (9.39 mmol) of the above-mentioned dimer C and 50 ml of DMF were placed and heated to reflux. To this, a mixture of 2-aminoheptane 1.08 g (9.39 mmol) DMF 25 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 to obtain 1.66 g (yield 28.1%) of monoimide D.
<Second step>
A 100 ml four-necked flask was charged with 1.5 g (2.38 mmol) of monoimide D and 50 ml of DMF and heated to reflux. To this, a mixture of 2-aminooctane 0.308 g (2.38 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 the residue was purified by silica gel column chromatography. Further, the recovered product was recrystallized with toluene / hexane to obtain 0.328 g (yield 18.6%) of the electron transport material represented by the structural formula (5) (referred to as electron transport material 3).
In mass spectrometry (FD-MS), the peak of M / z = 740 was observed and identified as the target product. In the elemental analysis, the calculated values were 69.72% carbon, 5.44% hydrogen, and 7.56% nitrogen, and the measured values were 69.55% carbon, 5.26% hydrogen, and 7.33% nitrogen.

Electron transport material synthesis example 4
<First step>
A 200 ml four-necked flask was charged with 5.0 g (18.6 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 50 ml of DMF 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. Further, the recovered product was recrystallized from toluene / hexane to obtain 3.49 g of monoimide E (yield 45.8%).
<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, 0. 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. Further, the recovered product was recrystallized with toluene / ethyl acetate to obtain 0.939 g (yield 13.7%) of an electron transport material represented by the structural formula (A-1) (referred to as electron transport material 4).
In mass spectrometry (FD-MS), the peak of M / z = 934 was observed and identified as the target product. In the elemental analysis, the calculated values were 66.92% carbon, 3.67% hydrogen, and 8.99% nitrogen, and the measured values were 66.92% carbon, 3.74% hydrogen, and 9.05% nitrogen.

(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 are stirred and mixed, and 2.2 ml of titanium tetrachloride is added dropwise under a nitrogen stream. After completion of the dropping, 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 to 130 ° C. and filtered while hot, then washed with 1-chloronaphthalene until the powder turned blue, then washed several times with methanol, and further with hot water at 80 ° C. After washing twice, it was dried to obtain a pigment (referred to as Pigment 1).
The obtained titanyl phthalocyanine powder was subjected to X-ray diffraction spectrum measurement under the following conditions and confirmed to be the same as the spectrum described in the publication.
(X-ray diffraction spectrum measurement conditions)
X-ray tube: Cu
Voltage: 50kV
Current: 30mA
Scanning speed: 2 ° / min Scanning range: 3 ° -40 °
Time constant: 2 seconds

(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 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. (Water paste) was obtained. 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 powder (referred to as pigment 2).

  The obtained titanyl phthalocyanine powder was subjected to X-ray diffraction spectrum measurement under the conditions of Pigment Synthesis Example 1, and a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to Cu—Kα rays (wavelength 1.542 mm) described in the publication. ) Having a maximum diffraction peak at least 27.2 °, and further having main peaks at 9.4 °, 9.6 °, and 24.0 °, and the diffraction peak at the lowest angle side as 7. It was confirmed that the titanyl phthalocyanine had a peak at 3 ° and no peak between the peak at 7.3 ° and the peak at 9.4 °.

Photoconductor Preparation Example 1
An undercoat layer coating solution, a charge generation layer coating solution and a charge transport layer coating solution having the following composition were prepared.
(Coating liquid for undercoat layer)
Alkyd resin 60 parts (Dainippon Ink Co., Ltd .: Beccosol M-6401-50)
40 parts of melamine resin (Dainippon Ink Co., Ltd .: Super Becamine L-121-60)
Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd .: CR-EL) 400 parts Methyl ethyl ketone 500 parts These were ball milled for 5 days in a ball mill apparatus (using φ10 mm alumina balls as media) to give an undercoat layer coating solution.

(Coating solution for charge generation layer)
Metal-free phthalocyanine pigment 12 parts (Dainippon Ink Industries, Ltd .: Fastogen Blue 8120B)
5 parts of polyvinyl butyral resin (Sekisui Chemical Co., Ltd .: ESREC BX-1)
2-butanone 200 parts cyclohexanone 400 parts These were dispersed in a glass pot with a diameter of 9 cm using PSZ balls with a diameter of 0.5 mm for 5 hours at a rotation speed of 100 rpm to obtain a coating solution for a charge generation layer.

(Coating liquid for charge transport layer)
Electron transport material 1 10 parts Z-type polycarbonate resin (Teijin Chemicals: Panlite TS-2050) 10 parts Silicone oil (Shin-Etsu Chemical Co., Ltd .: KF50) 0.01 parts Tetrahydrofuran 80 parts

These were stirred and dissolved to obtain a charge transport layer coating solution.
Then, on the aluminum drum having a diameter of 30 mm and a length of 256 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 immersed in the dip coating method. And dried to form a 4.5 [mu] m undercoat layer, 0.15 [mu] m charge generation layer, and 25 [mu] m charge transport layer (referred to as "photoreceptor 1"). The drying temperature of each layer was 135 ° C. for 20 minutes, 80 ° C. for 15 minutes, and 120 ° C. for 20 minutes.

Photoconductor Preparation Example 2
Metal-free phthalocyanine was dispersed under the following composition and conditions to prepare a pigment dispersion.
3 parts of metal-free phthalocyanine pigment (Dainippon Ink and Chemicals Co., Ltd .: Fastogen Blue 8120B)
97 parts of cyclohexanone Using a PSZ ball of φ0.5 mm in a glass pot of φ9 cm, dispersion was performed at a rotation speed of 100 rpm for 5 hours.

A photoconductor coating solution having the following composition was prepared using the dispersion.
60 parts of the above dispersion liquid hole transport material of the following structural formula (9) 25 parts electron transport material 1 25 parts Z type polycarbonate resin 50 parts (Teijin Chemicals: Panlite TS-2050)
0.01 parts of silicone oil (Shin-Etsu Chemical Co., Ltd .: KF50)
Tetrahydrofuran 350 parts

こうして得られた感光層用塗工液をφ３０ｍｍ、長さ２５６ｍｍアルミニウムドラム上に、浸漬塗工法にて塗布、１２０℃で２０分間乾燥し、２５μｍの感光層を形成し、感光体を作製した（感光体２とする）。

The photosensitive layer coating solution thus obtained was applied on an aluminum drum having a diameter of 30 mm and a length of 256 mm by a dip coating method and dried at 120 ° C. for 20 minutes to form a photosensitive layer of 25 μm, thereby preparing a photoreceptor ( Photoconductor 2).

Photoconductor Preparation Example 3
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 1 except that titanyl phthalocyanine of Pigment 1 was used instead of X-type metal-free phthalocyanine (Fastogen Blue 8120B) in Photoconductor Preparation Example 1 (Photoconductor) 3).

Photoconductor Preparation Example 4
A photoconductor was prepared in exactly the same manner as in Photoconductor Preparation Example 2 except that the charge generating material in Example 2 was replaced with X-type metal-free phthalocyanine (Fastogen Blue 8120B) and titanyl phthalocyanine of Pigment 1 was used. 4).

Photoconductor Preparation Example 5
A photoconductor was prepared in exactly the same manner as in Photoconductor Preparation Example 1 except that the charge generating material in Example 1 of the photoconductor was replaced by X-type metal-free phthalocyanine (Fastogen Blue 8120B) and titanyl phthalocyanine of Pigment 2 was used (Photoconductor) 5).

Photoconductor Preparation Example 6
A photoconductor was prepared in exactly the same manner as in Photoconductor Preparation Example 2 except that the charge generating material in Example 2 was replaced with X-type metal-free phthalocyanine (Fastogen Blue 8120B) and titanyl phthalocyanine of Pigment 2 was used (Photoconductor) 6).

Photoconductor Preparation Example 7
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 5 except that the electron transport material 2 was used instead of the electron transport material 1 in Photoconductor Preparation Example 5 (referred to as Photoconductor 7).

Photoconductor Preparation Example 8
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 6 except that the electron transport material 2 was used in place of the electron transport material 1 in Photoconductor Preparation Example 6 (referred to as Photoconductor 8).

Photoconductor Preparation Example 9
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 5 except that the electron transport material 3 was used instead of the electron transport material 1 in Photoconductor Preparation Example 5 (referred to as Photoconductor 9).

Photoconductor Preparation Example 10
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 6 except that the electron transport material 3 was used instead of the electron transport material 1 in Photoconductor Preparation Example 6 (referred to as Photoconductor 10).

Photoconductor Preparation Example 11
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 5 except that a compound of the following structural formula (10) was used in place of the electron transport material 1 in Photoconductor Preparation Example 5 (referred to as Photoconductor 11).

Photoconductor Preparation Example 12
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 6 except that the compound of the structural formula (10) was used in place of the electron transport material 1 in Photoconductor Preparation Example 6 (referred to as Photoconductor 12).

Photoconductor Preparation Example 13
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 5 except that a compound of the following structural formula (11) was used in place of the electron transport material 1 in Photoconductor Preparation Example 5 (referred to as Photoconductor 13).

Photoconductor Preparation Example 14
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 6 except that the compound of the structural formula (11) was used instead of the electron transport material 1 in Photoconductor Preparation Example 6 (referred to as Photoconductor 14).

Photoconductor Preparation Example 15
A photoconductor was prepared in the same manner as in photoconductor preparation example 5 except that the electron transport material 4 was used instead of the electron transport material 1 (referred to as photoconductor 15).

Photoconductor Preparation Example 16
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 6 except that the electron transport material 4 was used instead of the electron transport material 1 (referred to as photoconductor 16).

Photoconductor Preparation Example 17
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 5, except that 1:10 parts of the electron transport material was changed to 1: 8 parts of the electron transport material and 2 parts of the electron transport material of the following structural formula (B-1). (Referred to as photoconductor 17).

Photoconductor Preparation Example 18
A photoconductor was prepared in the same manner as in Photoconductor Preparation Example 6 except that 1:10 parts of the electron transport material was changed to 1: 8 parts of the electron transport material and 2 parts of the electron transport material of the above structural formula (B-1). (Referred to as photoreceptor 18).

Examples 1-14 and Comparative Examples 1-4
After mounting the photoconductors 1 to 14 prepared as described above, a tandem type and intermediate transfer type full-color electrophotographic apparatus (IPCO CX400 remodeling machine manufactured by Ricoh, remodeled to be positively charged by replacing the power pack, Further, a printing durability test was performed in which a total of 10,000 sheets were printed using a chart with a writing rate of 5%.
The toner and developer used were changed from those dedicated to IPSiO CX400 to toner and developer having opposite polarity.
The test environment is 23 ° C. and 55% RH.
Image evaluation and resolution evaluation were performed before the printing durability test (initial stage) and after the printing durability test.
Image evaluation: An image for evaluation was output, and the rank was evaluated comprehensively with respect to background dirt, fogging, image density, and the like.
-Resolution: A halftone image was output and the dot formation state (dot dispersion and dot reproducibility) was observed.
In any case, the evaluation rank is as follows.
：: Very good ○: Good △: Slightly inferior ×: Very bad The results of Examples 1 to 14 and Comparative Examples 1 to 4 are shown in Table 1.

Examples 15-21
After mounting the photoconductors 2, 4, 6, 8, 10, 16, 18 for mounting, a full color electrophotographic apparatus of a tandem type and an intermediate transfer type (Ricoh's IPSiO CX400 remodeling machine, LD wavelength used for writing is 780 nm) A printing press test was performed to print a total of 10,000 sheets using a 5% writing rate chart.
The test environment is 23 ° C. and 55% RH.
Image evaluation and resolution evaluation were performed before the printing durability test (initial stage) and after the printing durability test.
Image evaluation: An image for evaluation was output, and the rank was evaluated comprehensively with respect to background dirt, fogging, image density, and the like.
-Resolution: A halftone image was output and the dot formation state (dot dispersion and dot reproducibility) was observed.
In any case, the evaluation rank is as follows.
A: Very good B: Good B: Somewhat inferior X: Very bad The results of Examples 15 to 21 are shown in Table 2.

表１、２の結果から、本発明の要件を満たす実施例では、繰り返し使用によっても異常画像がなく、また、高精細な画像が出力できることがわかる。

From the results of Tables 1 and 2, it can be seen that in the examples satisfying the requirements of the present invention, there is no abnormal image even when used repeatedly, and a high-definition image can be output.

(Examples 22 to 25)
The photoconductors 5, 6, 17 and 18 were subjected to an ozone exposure test in which they were left in an environment with an ozone concentration of 10 ppm for 5 days. Image evaluation and resolution evaluation were performed after the ozone exposure test.
Evaluation was performed using the electrophotographic apparatus used in (Examples 1 to 14 and Comparative Examples 1 to 4).

(Image evaluation)
An image for evaluation was output, and the rank was evaluated comprehensively with respect to background dirt, fogging, image density, and the like.
(resolution)
A halftone image was output, and the dot formation state (dot dispersion and dot reproducibility) was observed.
In any case, the evaluation rank is as follows.

◎: Very good ○: Good △: Slightly inferior ×: Very bad The evaluation results of Examples 22 to 25 are shown in Table 3 above.

1 is a schematic cross-sectional view illustrating an example of an electrophotographic apparatus according to the present invention. It is a schematic cross section showing an example of a process cartridge according to the present invention. It is a schematic cross section which shows another example of the electrophotographic apparatus which concerns on this invention. It is a schematic cross section which shows another example of the electrophotographic apparatus which concerns on this invention. It is sectional drawing which shows the example of the layer structure of the electrophotographic photoreceptor which concerns on this invention. It is sectional drawing which shows the example of another layer structure of the electrophotographic photoreceptor which concerns on this invention. It is a X-ray diffraction spectrum figure of the titanyl phthalocyanine synthesize | combined by the synthesis example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Electrophotographic photoreceptor 12 ... Charging means 13 ... Exposure means 14 ... Development means 15 ... Toner 16 ... Image exposure part 17 ... Cleaning means 18 ... Image receiving medium DESCRIPTION OF SYMBOLS 19 ... Fixing means 1A ... Static elimination means 1C ... Driving means 1D ... 1st transfer means 1E ... 2nd transfer means 1F ... Intermediate transfer body 21 ... Conductive support Body 22 ... charge generation layer 23 ... charge transport layer 24 ... undercoat layer 25 ... photosensitive layer

Claims (7)

At least a photosensitive member, a charging device that uniformly charges the surface of the photosensitive member, an image exposure unit that performs image exposure after uniform charging to form an electrostatic latent image, and a developing unit that develops the electrostatic latent image And a transfer means for transferring the developed image, wherein the electrophotographic apparatus primarily transfers the toner image developed on the photosensitive member onto the intermediate transfer member, and then the toner on the intermediate transfer member. An electrophotographic apparatus having intermediate transfer means for secondary transfer of an image onto a recording material, wherein the photosensitive member has a photosensitive layer on at least a conductive support, and at least a charge generating material in the photosensitive layer. An electrophotographic apparatus comprising at least one electron transport material represented by the following structural formulas (a) to (g) .

The electrophotographic apparatus according to claim 1 , wherein the charge generation material is phthalocyanine. The electrophotographic 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 Cu-Kα rays (wavelength 1.542 mm), and further 9.4 °, 9 It has major peaks at .6 ° and 24.0 ° and has a peak at 7.3 ° as the lowest angled diffraction peak, between the 7.3 ° peak and the 9.4 ° peak. The electrophotographic apparatus according to claim 3 , wherein the electrophotographic apparatus has no peak. The electrophotographic apparatus according to any one of claims 1 to 4, characterized by performing the charging process in positively charged. It comprises a said electrophotographic apparatus a plurality of photosensitive member, more of claims 1 to 5 sequentially superposing toner images of a single color that is developed on each photoreceptor and forming a color image An electrophotographic apparatus according to claim 1. An electrophotographic apparatus process cartridge comprising at least a photoconductor, wherein the photoconductor is used in the electrophotographic apparatus according to any one of claims 1 to 6. .

Images