JP2008281805A - Image forming apparatus and process cartridge for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which avoids the occurrence of an abnormal image even in long-term repeated use and excels in durability and stability of image quality. <P>SOLUTION: The image forming apparatus includes: an electrophotographic photoreceptor; a charging means; an imagewise exposing means to form an electrostatic latent image; a developing means to develop the electrostatic latent image; and a transfer means to transfer a developed image, wherein the photoreceptor has on a conductive substrate a photosensitive layer containing at least a charge generating material, a specific naphthalenetetracarboxylic acid diimide type charge transport material and an o-hydroxyphenyltriazole compound. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile, a laser printer, and a direct digital plate making machine that performs an image forming operation using an electrophotographic process.

  The electrophotographic photoreceptors used in electrophotographic apparatuses applied to copying machines, laser printers, etc. have been mainly used for inorganic photoreceptors such as selenium, zinc oxide, cadmium sulfide, and so on. Organic photoreceptors (OPC), which are more advantageous than inorganic photoreceptors from the viewpoint of reducing load, reducing costs, and increasing design freedom, are widely used.

This organophotoreceptor can be classified by layer structure. For example, (1) a photoconductive resin represented by polyvinylcarbazole (PVK) and PVK-TNF (2,4,7-trinitrofluorenone). A homogeneous single layer type in which a charge transfer complex is provided on a conductive support, (2) a dispersed single layer type in which a pigment such as phthalocyanine or perylene is dispersed in a resin, and (3) The photosensitive layer provided on the conductive support is functionally separated into a charge generation layer (CGL) containing a charge generation material such as an azo pigment and a charge transport layer (CTL) containing a charge transport material such as triphenylamine. Can be classified into the laminated type.
In particular, the laminated type in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer as described above is advantageous for high sensitivity, and in addition, there is a high degree of freedom in design for high sensitivity and high durability. For this reason, many organic photoreceptors currently have this layer structure.

  The characteristics of these organic photoreceptors vary greatly depending on the material used, particularly the charge transport material. The charge transport material is roughly classified into a hole transport material having a function of transporting holes (holes) and an electron transport material having a function of transporting electrons. Among them, the demand for electron transport materials is increasing because they are positively charged in the above-described laminated structure, and are less susceptible to ozone generation and uneven charging than when negatively charged.

However, the reality is that very few electron transport materials are excellent as photosensitive material. Although it has excellent electron transport properties as a single material, there are many that have safety problems such as mutagenicity that causes mutation in cells, and many have not been put into practical use.
Although there is no problem in safety, many have problems in compatibility, film formability when forming a photosensitive layer, wear resistance, and the like.

Various types of organic photoconductor materials have been developed in the past. Sensitivity, receptive potential, potential retention, potential stability, residual potential, spectral characteristics, etc. are necessary to enable practical use of these materials. Various characteristics such as electrophotographic characteristics, mechanical durability such as wear resistance, chemical stability against heat, light, discharge products, and the like are required.
In particular, downsizing of the electrophotographic system is desired, and the photoconductor is forced to be reduced in diameter, and electrophotographic characteristics such as sensitivity, receptive potential, potential retention, potential stability, residual potential, and spectral characteristics as described above. In addition to this, it has become necessary to improve the durability against the deterioration phenomenon of the photoconductor which proceeds in accordance with the number of sheets passed.

The electrophotographic characteristics vary greatly depending on the materials used, and the charge transport material has a great influence on the characteristics. However, even if the charge transport material is excellent, it is exposed to ozone, NOx and other active gases generated during charging in the process of repeating electrophotographic processes such as charging and exposure, and also due to the effects of light fatigue and heat due to exposure and static elimination. Degradation progresses gradually. In addition to electrostatic deterioration, decomposition of structural components, reduction in hardness, discoloration, and the like were also observed. Thus, even if sufficient characteristics are initially obtained, sufficient durability due to repeated use is not obtained.
As a method for preventing the deterioration of the photoreceptor, a method of adding an antioxidant as proposed in Patent Document 1 (Japanese Patent Laid-Open No. 4-191754) is known. However, although the effect is exhibited, side effects such as an increase in residual potential have occurred.
JP-A-4-191754

  An object of the present invention is to provide an image forming apparatus excellent in durability and image quality stability that does not generate an abnormal image even when used repeatedly over a long period of time.

  In order to achieve the above-mentioned problems, the present inventors maintain the photoreceptor characteristics without impairing the initial electrophotographic characteristics even during repeated use, and do not cause abnormal images even under any usage environment. As a result of intensive studies on an electrophotographic photosensitive member having a high-quality photosensitive layer and an image forming apparatus using the same, an electrophotographic photosensitive member, a charging means for uniformly charging the surface of the photosensitive member, and uniform charging In an image forming apparatus comprising: an image exposure unit that performs image exposure later to form an electrostatic latent image; a developing unit that develops the electrostatic latent image; and a transfer unit that transfers the developed image. An image forming apparatus comprising a photosensitive layer containing at least a charge generation material, a charge transport material represented by the general formula (I), and a compound represented by the general formula (II) on a substrate. This In, be used repeatedly extended period to solve the above problems, found that the image forming apparatus can be obtained a good image can be output, it has led to the present invention.

In addition to having an excellent charge transport ability, the compound represented by the general formula (I) used in the electrophotographic photoreceptor used in the present invention is combined with the compound represented by the general formula (II), Even if light irradiation processes such as exposure and static elimination are repeated, the degree of reduction in chargeability is remarkably reduced.
In addition, since the compound represented by the general formula (II) has an ultraviolet absorbing effect, the characteristics are extremely deteriorated even when the photosensitive member or the process cartridge including the photosensitive member is detached during maintenance and exposed to a fluorescent lamp. There is also an advantage of less. Further, by adding the compound represented by the general formula (II), resistance to foreign matter adhesion is improved, specifically, cracks due to adhesion of oils and fats are greatly suppressed, resulting in foreign matter adhesion. Abnormal images do not occur, and the stability of the image forming apparatus is greatly improved. As described above, the excellent electrophotographic characteristics of the photoconductor, which is the key of the image forming apparatus, last for a long period of time, so that the durability of the entire image forming apparatus is enhanced. Moreover, it becomes possible to achieve both wear resistance and excellent electrostatic characteristics by using a polycarbonate resin as the binder resin used in the photosensitive layer in combination with the compounds of the general formula (I) and the general formula (II). A low exposed area potential can be maintained over a long period of time, and a good electrostatic contrast can be obtained.

  Further, by using phthalocyanine as the charge generation material used in the photosensitive layer, it is possible to obtain characteristics excellent in sensitivity characteristics with respect to a light source in a relatively long wavelength region such as a laser diode. Phthalocyanine is known in many types due to the presence of its central metal and crystal structure, but by using titanyl phthalocyanine in particular, it has excellent responsiveness and stable potential characteristics even during repeated use. Image formation with little deterioration in image quality is possible even when used for a long time. In particular, among titanyl phthalocyanine, it has a maximum diffraction peak at 27.2 ° as a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to CuKα (wavelength 1.542 mm). As a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to 1.542 mm, it has a maximum diffraction peak at least 27.2 ° and is further dominant at 9.4 °, 9.6 °, and 24.0 °. And a peak at 7.3 ° as the lowest diffraction peak, and no peak between the 7.3 ° peak and the 9.4 ° peak. This makes it possible to form a more stable image.

Furthermore, by providing a plurality of these image forming apparatuses as one unit, as a plurality of image forming groups called so-called tandem systems, images of different toner colors can be formed for each unit, and a full color image can be obtained in one cycle. One image forming apparatus can be obtained.
In addition to this, the image forming apparatus primarily transfers the toner image developed on the electrophotographic photosensitive member onto the intermediate transfer member, and then secondarily transfers the toner image on the intermediate transfer member onto the recording material. An image forming apparatus having an intermediate transfer unit, wherein a color image is formed by sequentially superimposing a plurality of color toner images on an intermediate transfer member, and the color image is secondarily transferred collectively onto a recording material. By using the image forming apparatus, it is difficult to be influenced by the thickness of the transfer paper and the carrier adhesion from the developing unit, and more stable image formation is possible.
Also, a process cartridge used in these image forming apparatuses, which at least includes a photosensitive member and one unit selected from a charging unit, an exposure unit, a developing unit, or a transfer unit, and is a detachable process. Maintenance can be easily performed by using a cartridge.

（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、０から１００までの整数を表す。）

（式中、Ｒ15は水素原子、ハロゲン原子、置換又は無置換のアルキル基、置換又は無置換のアリール基からなる群より選ばれる基を表し、Ｒ16、Ｒ17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、置換又は無置換のアリール基からなる群より選ばれる基を表す。）
（２）前記感光層において結着樹脂としてポリカーボネート樹脂が用いられることを特徴とする（１）記載の画像形成装置。
（３）前記電荷発生物質としてフタロシアニンを含有することを特徴とする（１）又は（２）に記載の画像形成装置。
（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（３）記載の画像形成装置。
（５）前記フタロシアニンが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結晶型を有するチタニルフタロシアニンであることを特徴とする（３）又は（４）記載の画像形成装置。 That is, according to the present invention,
(1) An electrophotographic photosensitive member, a charging unit 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 image forming apparatus comprising a developing means for developing and a transferring means for transferring a developed image, the photoreceptor is at least a charge generating material on a conductive substrate, a charge transport material represented by the following general formula (I), and An image forming apparatus having a photosensitive layer containing a compound represented by the following general formula (II).

Wherein R 1 and R 2 each independently represents a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group; , R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 are each independently a hydrogen atom, halogen atom, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted alkyl group Represents a group selected from the group consisting of a substituted or unsubstituted cycloalkyl group and a substituted or unsubstituted aralkyl group, n is a repeating unit, and represents an integer of 0 to 100.)

(In the formula, R15 represents a group selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group, and R16 and R17 each independently represents a hydrogen atom, a substituted or unsubstituted group. Represents a group selected from the group consisting of a substituted alkyl group and a substituted or unsubstituted aryl group.)
(2) The image forming apparatus according to (1), wherein a polycarbonate resin is used as a binder resin in the photosensitive layer.
(3) The image forming apparatus according to (1) or (2), wherein the charge generating substance contains phthalocyanine.
(4) The image forming apparatus according to (3), wherein the phthalocyanine is titanyl phthalocyanine.
(5) The 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 ray (wavelength 1.542 mm), and further 9.4 °. , 9.6 °, 24.0 °, and the lowest angle diffraction peak at 7.3 °, 7.3 ° and 9.4 ° The image forming apparatus according to (3) or (4), wherein the image forming apparatus is a titanyl phthalocyanine having a crystal type having no peak therebetween.

(6) The image forming apparatus according to any one of (1) to (5), wherein the image forming apparatus is a tandem type having a plurality of electrophotographic photosensitive members, a charging unit, a developing unit, and a transfer unit. .
(7) Intermediate transfer means for primary transfer of the toner image developed on the electrophotographic photosensitive member onto the intermediate transfer member by the image forming apparatus and then secondary transfer of the toner image on the intermediate transfer member onto the recording material A plurality of color toner images are sequentially superimposed on an intermediate transfer member to form a color image, and the color images are collectively transferred onto a recording material (secondary transfer). 6) The image forming apparatus described above.
(8) A process cartridge for an image forming apparatus, comprising at least one of a charging unit, an exposure unit, a developing unit, and a transfer unit and an electrophotographic photosensitive member, according to any one of (1) to (7) A process cartridge for an image forming apparatus.

  As described above, according to the present invention, it is possible to obtain a highly durable image forming apparatus that can obtain a stable image even during repeated use.

Next, the photoreceptor used in the image forming apparatus of the present invention will be described below.
In the photoreceptor used in the image forming apparatus of the present invention, as a conductive support, a conductor or an insulator subjected to a conductive treatment, for example, a metal such as Al, Fe, Cu, Au, or an alloy thereof, polyester, polycarbonate, A material in which a thin film of a metal such as Al, Ag, Au or a conductive material such as In ₂ O ₃ or SnO ₂ is formed on an insulating substrate such as polyimide or glass, paper subjected to a conductive treatment, or the like can be used. The shape of the conductive support is not particularly limited, and either a drum shape or a belt shape can be used.

Next, the photosensitive layer of the photoreceptor used in the image forming apparatus of the present invention will be described.
In the present invention, the photosensitive layer may be either a single layer type or a laminated type, and any of them can be used. For convenience of explanation, the photosensitive layer is first separated into a charge generation layer and a charge transport layer. The stacked type will be described. (An example is shown in FIG. 7)
First, the charge generation layer will be described. The charge generation layer is a layer mainly composed of a charge generation material, and a binder resin may be used as necessary. A known material can be used as the charge generating substance. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having carbazole skeleton, azo pigments having triphenylamine skeleton, azo pigments having diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having fluorenone skeleton, azo pigments having oxadiazole skeleton, azo pigments having bis-stilbene skeleton, azo pigments having distyryl oxadiazole skeleton, azo pigments having distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Jigoido based pigments, and bisbenzimidazole pigments. These charge generation materials can be used alone or as a mixture of two or more.
Among them, in particular, a titanyl phthalocyanine as shown in the following structural formula (1) having titanium as a central metal can make a photosensitive layer with particularly high sensitivity, and the electrophotographic apparatus can be further reduced in size and speed. It is possible to measure.

ただし、前記構造式（１）中、Ｘ₁、Ｘ₂、Ｘ₃、及びＸ₄は、互いに同一であってもよいし、異なっていてもよく、水素原子、各種ハロゲン原子、アルキル基、又はアルコキシ基を表す。ｎ、ｍ、ｌ、及びｋは、互いに同一であってもよいし、異なっていてもよく、０〜４の整数を表す。

However, in said structural formula (1), X < ₁ >, X < ₂ >, X < ₃ > and X < ₄ > may mutually be the same and may differ, and a hydrogen atom, various halogen atoms, an alkyl group, or Represents an alkoxy group. n, m, l, and k may be the same as or different from each other, and represent an integer of 0 to 4.

  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. JP-A 59-49544, JP-A 59-166959, JP-A 61-239248, JP-A 62-67094. JP-A-63-366, JP-A-63-116158, JP-A-64-17066, JP-A-2001-19871, etc. each describe titanyl phthalocyanine having a different crystal form. .

Among these crystal forms, titanyl phthalocyanine having a maximum diffraction peak at 27.2 ° with a Bragg angle 2θ exhibits particularly excellent sensitivity characteristics and potential stability during repeated use, and does not increase the potential of the exposed area. Therefore, it is used well. 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 it is repeatedly used and does not cause an increase in potential of the exposed portion.
In addition, by using the titanyl phthalocyanine crystal having an average particle size of 0.60 μm or less, it is possible to obtain a stable electrophotographic photosensitive member that does not cause deterioration in chargeability even after repeated use without losing high sensitivity. The background dirt property can be remarkably improved. This is because when the average particle size is larger than 0.60 μm, the contact area is lowered and the charge generation efficiency is lowered.

  The binder resin used as necessary for the charge generation layer includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, and poly-N-vinylcarbazole. Polyacrylamide is used. These binder resins can be used alone or as a mixture of two or more. Furthermore, you may add the electric charge transport material mentioned later as needed.

Examples of the method for forming the charge generation layer include a casting method from a solution dispersion system. 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 binder resin and a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone as necessary. The dispersion can be formed by appropriately diluting and applying. The coating can be performed using a dip coating method, a spray coating method, a bead coating method, or the like.
The thickness of the charge generation layer provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

Next, the charge transport layer will be described.
The charge transport layer is formed by dissolving, coating and forming a film using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone together with a charge transport material and a binder resin. As the coating method, dip coating, spray coating, bead coating, or the like can be used.
Binder resins that can be used for the charge transport layer include polycarbonate with good film properties (bisphenol A type, bisphenol Z type, bisphenol C type, or copolymers thereof), polyarylate, polysulfone, polyester, methacrylic resin, polystyrene, acetic acid. Vinyl, epoxy resin, phenoxy resin and the like are used, and among them, polycarbonate resin having excellent wear resistance is preferable in view of its properties. These binder resins can be used alone or as a mixture of two or more.

The charge transport material used in the present invention is represented by the aforementioned general formula (I). In the case of a laminated structure, the charge transport material of the general formula (I) is added to the charge transport layer in the photosensitive layer.
By incorporating the charge transport material represented by the general formula (I) into the photosensitive layer, long-term electrostatic stability, which is impossible with the conventional electrophotographic apparatus, that is, the charging potential and the exposure portion potential. As a result, it is possible to improve the electrical durability that keeps the so-called electrostatic contrast stable, and as a result, it is possible to realize an image forming apparatus that can stably obtain a high-quality image even in repeated use over a long period of time.

  In addition, the charge transport material represented by the general formula (I) is very stable with respect to an active gas such as ozone or nitrogen oxide gas, and is used in an electrophotographic apparatus in which such an active gas is generated from a charger. It is very advantageous to use. This is considered to be resistant to the gas as described above because of its strong N-basic molecular structure. That is, it is possible to obtain an electrophotographic apparatus that is very excellent in terms of chemical durability in addition to the mechanical durability and electrical durability described above. Therefore, when designing various electrophotographic image forming apparatuses, it is possible to prevent an increase in size and cost, and it is possible to provide a user with a machine that is inexpensive and easy to install.

  In the formula of the charge transport material represented by the general formula (I) used here, R 1 and R 2 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or R 3, R 4, R 5, R 6, R 7, R 8, R 9, R 10, R 11, R 12, R 13, R 14 are each independently a hydrogen atom, a halogen atom, or a cyano group, and represents a group selected from the group consisting of unsubstituted aralkyl groups. , A nitro group, an amino group, a hydroxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a group selected from the group consisting of a substituted or unsubstituted aralkyl group, n is a repeating unit; Represents an integer from 0 to 100.

  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- Linear groups 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.

The method for producing the charge transport material represented by the general formula (I) can be exemplified by the following two synthesis methods.
(N is a repeating unit and represents an integer from 0 to 100.)

（Ｒ3＝Ｒ7＝Ｒ11、Ｒ4＝Ｒ8＝Ｒ12、Ｒ5＝Ｒ9＝Ｒ13、Ｒ6＝Ｒ10＝Ｒ14の場合の合成例である。）

(This is a synthesis example when R3 = R7 = R11, R4 = R8 = R12, R5 = R9 = R13, and R6 = R10 = R14.)

More specifically, examples of the charge transport material represented by the general formula (1) include the following compounds (however, in each of the formulas, the terminal groups Me at both ends represent methyl groups).

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. The repeating unit n can be obtained by dividing the weight average molecular weight (Mw) in terms of standard polystyrene measured by GPC (gel permeation chromatography) by the molecular weight of the repeating unit.
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 with oligomers by appropriately selecting substituents for R 1 and R 2. 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.
In the electrophotographic characteristics, the charge transport materials represented by the above formulas (2) to (6) are particularly preferable from the viewpoints of the charging potential during repeated use and the stability of the exposed portion potential.

The charge transport material represented by the above formula (2) was produced by the following method.
First Step 200 ml In a 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-aminoheptane 2.14 g (18.6 mmol) and 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 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 100 ml Into a 4-neck 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 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. Further, the recovered product was recrystallized from toluene / ethyl acetate to obtain 0.668 g (yield 33.7%) of the compound represented by the formula (2).

The charge transport material represented by the above formula (3) was produced by the following method.
First Step In a 200 ml four-necked flask, 10 g (37.3 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 0.931 g (18.6 mmol) of hydrazine monohydrate, p- 20 mg of toluenesulfonic acid and 100 ml of toluene 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 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 50 ml Monoimide C 0.50 g (1.62 mmol) and DMF 10 ml were placed in a 50 ml four-necked flask and heated to reflux. To this, a mixture of 0.186 g (1.62 mmol) of 2-aminoheptane and 5 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 0.243 g (yield 22.4%) of the compound represented by the above formula (3).

The charge transport material represented by the above formula (4) was produced by the following method.
First Step 200 ml In a 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-aminopropane 1.10 g (18.6 mmol) and 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. Furthermore, the recovered product was recrystallized from toluene / hexane to obtain 2.08 g of monoimide B (yield 36.1%).
Second Step 100 ml Into a 4-neck 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 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. Further, the recovered product was recrystallized from toluene / ethyl acetate to obtain 0.810 g (yield 37.4%) of the charge transport material represented by the formula (4).

The charge transport material represented by the above formula (5) was produced by the following method.
First Step: The above-mentioned dimer C (5.0 g, 9.39 mmol) and DMF (50 ml) were placed in a 200 ml four-necked flask and heated to reflux. To this, a mixture of 1.08 g (9.39 mmol) DMF 25 ml of 2-aminoheptane 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 the charge transport material represented by the formula (5).

The charge transport material represented by the above formula (6) was produced by the following method.
First Step: The above-mentioned dimer C (5.0 g, 9.39 mmol) and DMF (50 ml) were placed in a 200 ml four-necked flask 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 charge transport material represented by the above formula (6).

  The content of the charge transport material represented by the general formula (I) is preferably 10 wt% to 70 wt%, more preferably 30 wt% to 60 wt%, based on the total solid content of the entire charge transport layer. If the added amount is too large, problems such as a decrease in wear resistance, a decrease in electric potential resistance, and an increase in dark decay may appear. If the added amount is too small, sufficient electrostatic contrast cannot be obtained, or abnormal There may be a problem that the image suppression effect is not sufficiently exhibited.

  Next, the compound represented by the general formula (II) used in the photosensitive layer in the present invention is preferably used in the charge transport layer in the case of a laminated structure. The compound represented by the general formula (II) is called benzotriazole and is known as an application of an ultraviolet absorber, and an example of addition to a photoreceptor is also known. (Patent Publication No. 2-7458, etc.) However, only by combining benzotriazole and a general charge transporting substance, an effect is initially seen when irradiated with light in the ultraviolet region, but in repeated use over a long period of time. The effect is not clear, and side effects such as increased residual potential occur.

When combined with the compound represented by the general formula (I) as in the present invention, the compound represented by the general formula (I) is extremely insensitive to the active gas such as ozone or nitrogen oxide gas as described above. Therefore, when combined with the compound represented by the general formula (II), there is an effect of further increasing the stability, and the chargeability does not decrease even during repeated use over a long period of time. A highly durable image forming apparatus can be obtained.
The proportion of the compound represented by the general formula (II) in the charge transport layer in the laminated structure is preferably 0.1% by weight or more and 20% by weight or less in the total weight of the charge transport layer. More preferably, they are 0.5 weight% or more and 10 weight% or less. When the amount is less than 0.5% by weight, the above effect is not sufficiently exhibited. When the amount is more than 10% by weight, the film strength becomes weak and a problem occurs in mechanical durability.
The thickness of the charge transport layer provided as described above is suitably 5 to 100 μm, and preferably 10 to 35 μm.

Specific examples of the compound represented by the general formula (II) include the following compounds.

  Moreover, you may add a leveling agent in a charge transport layer as needed to a charge transport layer. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain are used, and the amount used is 100 parts by weight of the binder resin. About 0 to 1 part by weight is appropriate.

The photoreceptor used in the image forming apparatus of the present invention can be provided with an intermediate layer (sometimes referred to as an undercoat layer) as appropriate between the conductive support and the photosensitive layer. (An example is shown in FIG. 8)
Although it is an intermediate layer that can be used, the intermediate layer is generally used based on a resin, but these resins are generally considered when a photosensitive layer is applied thereon using a solvent. It is desirable that the resin be highly soluble in 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 resin, melamine resin, and epoxy resin. And a curable resin that forms a three-dimensional network structure. In addition, metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide, etc., or fine powders such as metal sulfides and metal nitrides are added as fillers in the intermediate layer for further stability. The charged property can be maintained. These intermediate layers can be formed using an appropriate solvent and a coating method, and the film thickness is 0.1 to 20 μm, preferably 0.5 to 10 μm.

The electrophotographic photoreceptor of the present invention may be provided with a protective layer having a composition and composition ratio different from that of the photosensitive layer on the photosensitive layer for the purpose of protecting the photosensitive layer and improving printing durability. . (An example is shown in FIG. 9)
Materials used for the protective layer include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, Polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride And resins such as epoxy resins. It is also possible to add the above-described charge transport material to the protective layer. In the protective layer, a material in which an inorganic material such as titanium oxide, tin oxide, potassium titanate, or alumina is dispersed can be added. As a method for forming the protective layer, a normal coating method is employed. The thickness of the protective layer is suitably about 0.1 to 20 μm, preferably about 1 to 7 μm.

Next, the photosensitive layer when the photosensitive layer is a single layer type will be described.
When a single photosensitive layer is provided by a casting method or the like, the above-described charge generation material, the charge transport material represented by the general formula (I), and the compound represented by the general formula (II) are combined as described above. A single layer structure may be formed by forming a film using a material such as a resin. (An example is shown in FIG. 6)
In the case of a single layer structure, since the charge transport material represented by the general formula (I) is basically an electron transport material, it is preferable to use a hole transport material in combination for transporting holes. Any known material can be used as the hole-transporting substance. In particular, oxazole derivatives and oxadiazole derivatives (described in JP-A Nos. 52-139065 and 52-139066) imidazole derivatives (Japanese Patent Publication No. 34-10366) Described in the specification), a triphenylamine derivative (described in USP 3,180,730), a benzidine derivative (described in Japanese Patent Publication No. 58-32372), an α-phenylstilbene derivative (described in Japanese Patent Application Laid-Open No. 57-73075), Hydrazone derivatives (described in JP-A-55-154955, 55-156904, 55-52063, 56-81850, etc.), triphenylmethane derivatives (described in JP-B-51-10983), anthracene derivatives (JP-A-51 No. -94829), styryl derivatives (Japanese Patent Laid-Open No. 56-2924). , Described 58-198043), according to the carbazole derivative (JP-58-58552), pyrene derivatives (described in JP-A-2-190863 Pat) is preferred.
The thickness of the single photosensitive layer is suitably about 5 to 100 μm, and preferably about 10 to 30 μm.

In the single layer structure, the content of the charge transport material represented by the general formula (I) is preferably 8 wt% to 70 wt%, more preferably 10 wt% to 50 wt%, based on the total solid content of the entire photosensitive layer. is there. If the content is too large, problems such as a decrease in wear resistance, a decrease in electric potential resistance, and an increase in dark attenuation may appear. If the content is too small, sufficient electrostatic contrast cannot be obtained, or abnormal image suppression effect is exhibited. May cause problems such as not being fully demonstrated.
The content of the compound represented by the general formula (II) in the photosensitive layer having a single layer structure is preferably 0.1% by weight or more and 20% by weight or less based on the total solid content of the entire photosensitive layer. More preferably, they are 0.5 weight% or more and 10 weight% or less. If the amount is less than 0.1% by weight, the above-mentioned effect is small, and if it exceeds 20% by weight, crystallization occurs and the light attenuation characteristics deteriorate, the film strength becomes weak, and the mechanical durability decreases. Problem arises.
The content of the hole transport material is preferably 10% by mass to 70% by mass and more preferably 20% by mass to 50% by mass with respect to the total solid content of the entire photosensitive layer.
Even in a single layer structure, a leveling agent may be added to the photosensitive layer as necessary. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used as described above, and the amount used is 100 parts by weight of binder resin. About 0 to 1 part by weight is appropriate.
In the case where the photosensitive layer has a single layer structure, an intermediate layer (undercoat layer) and a protective layer can be provided on the photosensitive layer in exactly the same manner as in the case of the laminated structure.

Next, the image forming apparatus used in the present invention will be described with reference to the drawings. In any of the drawings, the photoconductor satisfies the requirements of the present invention.
FIG. 1 is a schematic diagram for explaining an example of an image forming element of an image forming apparatus according to the present invention, and modifications as described below also belong to the category of the present invention.
In FIG. 1, a photoconductor 11 is a photoconductor that satisfies the requirements of the present invention.
The photoconductor 11 has a drum shape, but may have a sheet shape or an endless belt shape.
As the charging means 12, known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used.
As the transfer means 16, the above charger can be generally used, but a combination of a transfer charger and a separation charger is effective.
Reference numeral 13 denotes exposure means, and a semiconductor laser (LD), a light emitting diode (LED), or the like can be used. In some cases, various 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. .

1A is a static elimination means, and is used according to necessity. Examples of the light source include fluorescent materials, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescence (ELs) and the like.
The toner 15 developed on the photoconductor by the developing means 14 is transferred to the image receiving medium 18, but not all is transferred, and some toner remains on the photoconductor. Such toner is removed from the photoreceptor by the cleaning means 17. As the cleaning means, a rubber cleaning blade, a brush such as a fur brush, a mag fur brush, or the like can be used. Thereafter, the transferred image on the image receiving medium 18 is fixed by the fixing means 19.

When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. When this is developed with negative (positive) polarity toner (electrodetection fine particles), a positive image can be obtained, and when developed with positive (negative) polarity toner, a negative image can be obtained. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.
In the present invention, a plurality of image forming elements as shown in FIG. 1 may be provided. In such a case, a plurality of these image forming elements are used in a horizontal or oblique arrangement.

FIG. 2 shows an example for explaining another example of the image forming apparatus according to the present invention. In FIG. 2, a photoconductor 11 is an electrophotographic photoconductor that satisfies the requirements of the present invention, and has an endless belt shape.
Driven by driving means 1C, charged by charging means 12, image exposure by exposure means 13, development (not shown), transfer by transfer means 16, exposure before cleaning by pre-cleaning exposure means 1B, cleaning by cleaning means 17, and charge removal The charge removal by means 1A is repeated. In FIG. 2, light irradiation for pre-cleaning exposure is performed from the support side of the photoreceptor (in this case, the support is translucent).
Also in the exposure means 13 of FIG. 2, a semiconductor laser (LD), a light emitting diode (LED), etc. can be used as a light source. In some cases, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range. .
In the present invention, a plurality of image forming apparatuses as shown in FIG. 2 may be provided. In this case, a plurality of these image forming apparatuses are arranged horizontally or diagonally.

  The image forming apparatus described above exemplifies the embodiment of the present invention, and other embodiments are of course possible. For example, in FIG. 2, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or image exposure and neutralization light irradiation may be performed from the support side. On the other hand, the light irradiation process is illustrated as image exposure, pre-cleaning exposure, and static elimination exposure. In addition, a pre-transfer exposure, a pre-exposure of image exposure, and other known light irradiation processes are provided to light the photosensitive member. Irradiation can also be performed.

Further, the image forming apparatus as described above may be fixedly incorporated in a copying machine, a facsimile machine, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge. A process cartridge is a single device (part) that contains a photosensitive member and includes a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit. There are many shapes and the like of the process cartridge, but a general example is shown in FIG. In FIG. 3, a photosensitive member 11, a developing roller 20 as an example of a developing unit, a cleaning brush 17 as an example of a cleaning unit, and a charging charger 12 as an example of a charging unit are provided, and a latent image is formed on the photosensitive member through an image exposure unit 13. It is formed.
These process cartridges are detachable and easy to maintain.
In the present invention, a plurality of image forming elements in the form of process cartridges as shown in FIG. 3 may be provided. In such a case, a plurality of these image forming apparatuses are used horizontally or diagonally.

4 and 5 show an example of the entire image forming apparatus corresponding to the full color according to the present invention. This image forming apparatus is a type using 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 11 used in this electrophotographic apparatus is an electrophotographic photoreceptor that satisfies the requirements of the present invention. Similarly, around each of the photoconductors 11Y, 11M, 11C, and 11Bk, a charging unit 12, an exposure unit 13, a developing unit 14, a cleaning unit 17, and the like are disposed.
Note that the exposure means 13 (13Y, 13M, 13C, 13Bk, 13Y, 13M, 13C, 13Bk in FIG. 5 is the same as described above). As described above, the light source is a semiconductor laser (LD) as a light source in the present invention. A diode (LED) or the like can be used. In some cases, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range. .

  In FIG. 4, a transfer transfer belt 1G as a transfer material carrier that comes in contact with and separates from the respective transfer positions of the respective photoconductors 11Y, 11M, 11C, and 11Bk arranged on a straight line is stretched by a driving unit 1C. Yes. A transfer unit 16 is disposed at a transfer position facing each of the photoreceptors 11Y, 11M, 11C, and 11Bk with the conveyance belt 1G interposed therebetween, and after being transferred to the image receiving medium 18 conveyed by the conveyance belt, the fixing device. 19 is fixed.

In FIG. 5, the toner images developed on the photoconductors 11Y, 11M, 11C, and 11Bk arranged on a straight line are positioned facing the photoconductors 11Y, 11M, 11C, and 11Bk. After the image is transferred to the image receiving medium 18 by the secondary transfer device 1E after the primary transfer is performed by the transfer device 1D via the intermediate transfer member (belt) 1F stretched by the drive device 1C, the fixing device 19 is fixed.
Also in the image forming apparatus as shown in FIGS. 4 and 5, it is possible to use the detachable process cartridge as described above as the image forming element for each color.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. In addition, all the parts used in an Example represent a weight part.
First, photoreceptors used in Examples 1 to 16 and Comparative Examples 1 to 7 were produced as follows.
<Photoconductor for Example 1>
The coating solution for coating each layer was adjusted by the method shown below.
(Intermediate layer coating solution)
The following resins were mixed by ball milling for 5 days in a ball mill apparatus (using φ5 mm alumina balls as media) to obtain an undercoat layer coating solution.
Alkyd resin 11 parts by weight (Beckolite M-6401-50, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 6 parts by weight (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
48 parts by weight of titanium oxide (CR-EL, manufactured by Ishihara Sangyo Co., Ltd.)
185 parts by weight of methyl ethyl ketone

(Coating solution for charge generation layer)
The resin shown below was mixed with a bead mill disperser (using a PSZ ball having a diameter of 0.5 mm as a medium) for 120 minutes to form a charge generation layer coating solution.
Metal-free phthalocyanine pigment, 12 parts by weight (Dainippon Ink Industries, Ltd .: Fastogen Blue 8120B)
9 parts by weight of polyvinyl butyral (Sekisui Chemical: BL-1)
270 parts by weight of cyclohexanone

(Coating liquid for charge transport layer)
The following resins and the like were stirred and dissolved to obtain a charge transport layer coating solution.
80 parts by weight of the charge transport material represented by the formula (2) synthesized by the above method 8 parts by weight of the compound represented by the above formula (II) -15 Z-type polycarbonate resin (viscosity average molecular weight; 50000) 100 parts by weight Tetrahydrofuran 1200 parts by weight 1% silicone oil tetrahydrofuran solution 2 parts by weight (silicone oil = KF50-100CS: manufactured by Shin-Etsu Chemical Co., Ltd.)

  Next, on the aluminum drum having a diameter of 30 mm and a length of 340 mm, the coating liquid for intermediate layer, the coating liquid for charge generation layer and the coating liquid for charge transport layer having the above composition are sequentially immersed in the dip coating method. The film was formed by coating at 150 ° C. for 20 minutes, 90 ° C. for 15 minutes, and 120 ° C. for 20 minutes. It should be noted that the undercoat layer was fabricated under the ascending / descending speed conditions such that the thickness was 3.5 μm, the charge generation layer was 0.15 μm, and the charge transport layer was 27.8 μm.

<Photoconductor for Example 2>
The photoconductor for Example 1 was exactly the same except that the compound represented by formula (II) -16 was used instead of the compound represented by formula (II) -15 used in the coating solution for the charge transport layer. Thus, a photoreceptor for Example 2 was produced.
<Photoreceptor for Example 3>
The photoconductor for Example 1 was exactly the same except that the compound represented by formula (II) -10 was used instead of the compound represented by formula (II) -15 used in the coating solution for the charge transport layer. Thus, a photoreceptor for Example 3 was produced.
<Photoreceptor for Example 4>
The photoconductor for Example 1 was exactly the same except that the compound represented by formula (II) -17 was used instead of the compound represented by formula (II) -15 used in the charge transport layer coating solution. Thus, a photoreceptor for Example 4 was produced.

<Photoreceptor for Example 5>
The same procedure as in Example 1 was carried out except that the amount of the compound represented by formula (II) -15 used in the charge transport layer coating solution was changed from 8 parts by weight to 0.7 parts by weight. A photoreceptor for Example 5 was prepared.
<Photoconductor for Example 6>
Example 6 In the same manner as in Example 1 except that the amount of the compound represented by formula (II) -15 used in the charge transport layer coating solution was changed from 8 parts by weight to 14 parts by weight. A photoconductor was prepared.
<Photoconductor for Example 7>
The photoconductor for Example 7 was exactly the same as the photoconductor for Example 1 except that the metal-free phthalocyanine pigment used in the charge generation layer coating solution was changed to titanyl phthalocyanine having X-ray diffraction as shown in FIG. Was made.

<Photoreceptor for Example 8>
The photoconductor for Example 8 was exactly the same as the photoconductor for Example 1 except that it was changed to a polyarylate resin (U-100 made by Unitika) instead of the Z-type polycarbonate resin used for the coating solution for the charge transport layer. Produced.
<Photoconductor for Example 9>
The photoconductor for Example 9 was exactly the same as the photoconductor for Example 7 except that it was changed to a polyarylate resin (U-100 manufactured by Unitika) instead of the Z-type polycarbonate resin used in the coating solution for the charge transport layer. Produced.
<Photoconductor for Example 10>
In the photoreceptor for Example 1, in place of the charge transport material represented by the formula (2) used in the coating solution for the charge transport layer, the charge transport material represented by the formula (3) synthesized according to the above-described method. A photoconductor for Example 10 was produced in the same manner as described above, except that:

<Photoreceptor for Example 11>
In the photoreceptor for Example 1, in place of the charge transport material represented by Formula (2) used in the coating solution for the charge transport layer, the charge transport material represented by Formula (4) synthesized according to the above-described method A photoconductor for Example 11 was produced in the same manner as described above, except that:
<Photoconductor for Example 12>
In the photoreceptor for Example 1, in place of the charge transport material represented by Formula (2) used in the coating solution for the charge transport layer, the charge transport material represented by Formula (5) synthesized according to the above-described method A photoconductor for Example 12 was prepared in exactly the same manner except that
<Photoreceptor for Example 13>
In the photoreceptor for Example 1, in place of the charge transport material represented by Formula (2) used in the coating solution for the charge transport layer, the charge transport material represented by Formula (6) synthesized according to the above-described method. A photoconductor for Example 13 was produced in the same manner as described above, except that
<Photoconductor for Example 14>
In the photoreceptor for Example 7, 8 parts by weight of the compound represented by the formula (II) -15 used in the coating solution for the charge transport layer, and 3 parts by weight of the compound represented by the formula (II) -11 A photoconductor for Example 14 was produced in the same manner as described above except that it was added.

<Photoconductor for Example 15>
In the photoreceptor for Example 1, the same procedure as in Example 1 was performed except that the titanyl phthalocyanine pigment produced according to the method of Synthesis Example 1 shown below was used instead of the metal-free phthalocyanine pigment used in the charge generation layer coating solution. A photoconductor for Example 15 was produced.
(Synthesis Example 1 of titanyl phthalocyanine used in Example 15)
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 (ion-exchanged water after washing). PH value was 6.8), and a titanyl phthalocyanine pigment wet cake (water paste) was obtained. 40 g of the obtained wet cake (water paste) was put into 200 g of tetrahydrofuran, stirred for 4 hours, filtered and dried to obtain titanyl phthalocyanine powder. This is designated as Pigment 1.
The solid content concentration of the wet cake was 15 wt%. The weight ratio of the crystal conversion solvent to the wet cake is 33 times. The obtained titanyl phthalocyanine powder was subjected to X-ray diffraction spectrum measurement under the following conditions. As a result, the Bragg angle 2θ with respect to the characteristic X-ray of Cu—Kα (wavelength: 1.542 mm) was 27.2 ± 0.2 ° with the maximum peak. Has a peak at the lowest angle of 7.3 ± 0.2 °, no peak between 7.3 ° peak and 9.4 ° peak, and no peak at 26.3 ° A titanyl phthalocyanine powder was obtained. The result of the X-ray diffraction is shown in FIG.

(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 The average particle size in the charge generation layer coating solution using titanyl phthalocyanine was measured by CAPA-700 manufactured by Horiba, Ltd. and found to be 0.29 μm.

<Photoconductor for Example 16>
A photoconductor for Example 16 was prepared in exactly the same manner as in the photoconductor for Example 15, except that the polyarylate resin (U-100 manufactured by Unitika) was used instead of the polycarbonate resin used in the coating solution for the charge transport layer. .

<Photoconductor for Comparative Example 1>
In the photoreceptor for Example 1, instead of the charge transport material represented by the formula (2) used in the charge transport layer coating solution, the charge transport material represented by the following structural formula (B) was used. A photoconductor for Comparative Example 1 was produced in exactly the same manner.

<Photoconductor for Comparative Example 2>
In the photoreceptor for Example 1, in place of the charge transport material represented by the formula (2) used in the charge transport layer coating solution, the charge transport material represented by the following structural formula (C) was used. A photoconductor for Comparative Example 2 was produced in exactly the same manner.

<Photoconductor for Comparative Example 3>
In the photoreceptor for Example 1, instead of the charge transport material represented by the formula (2) used in the coating solution for the charge transport layer, the charge transport material represented by the following structural formula (D) was changed. A photoconductor for Comparative Example 3 was produced in exactly the same manner.

<Photoconductor for Comparative Example 4>
A photoconductor for Comparative Example 4 was produced in the same manner as in the photoconductor for Example 1, except that the compound represented by formula (II) -15 used for the charge transport layer coating solution was not added.
<Photoconductor for Comparative Example 5>
In the photoreceptor for Example 1, in place of the compound represented by the formula (II) -15 used in the coating solution for the charge transport layer, except that it was changed to 2-hydroxy-4-methoxybenzophenone as a comparative compound A at all. Similarly, a photoconductor for Comparative Example 5 was produced.

<Photoconductor for Comparative Example 6>
In the photoreceptor for Example 1, instead of the compound represented by the formula (II) -15 used in the coating solution for the charge transport layer, the compound B was changed to 2-hydroxy-4-octyloxybenzophenone as the comparative compound B. A photoconductor for Comparative Example 6 was produced in exactly the same manner.
<Photoconductor for Comparative Example 7>
In the photoreceptor for Example 1, instead of the compound represented by the formula (II) -15 used in the coating solution for the charge transport layer, 2,4-bis [2-hydroxy-4-butoxyphenyl] as a comparative compound C was used. A photoconductor for Comparative Example 7 was produced in exactly the same manner except that it was changed to -6- (2,4-dibutoxyphenyl) -1,3-5 triazine.

<Examples 1 to 16 and Comparative Examples 1 to 7>
After the electrophotographic photoreceptors for Examples 1 to 16 and Comparative Examples 1 to 7 produced in this way were used for mounting, a power pack was formed based on the digital multifunction peripheral Imagio MF2700 [manufactured by Ricoh Co., Ltd.]. Evaluation was performed using an image forming apparatus that was changed and the charge polarity was modified to positive charge. Note that the toner and developer were changed from those for exclusive use of IMAGIO MF2700 to those having opposite polarities.

Using such an image forming apparatus, a paper copy test was conducted, and the following items were evaluated at the initial stage and after 10,000 sheets.
<Image quality>
The output image was comprehensively evaluated for the image density of the black solid portion, the presence or absence of abnormal images such as black spots, white spots, black stripes, and white stripes.
<Exposure part potential>
The exposed portion potential at the time of writing a solid black image (during full exposure) when the initial photoreceptor surface potential (charging potential) was 800 V was evaluated.
<Foreign substance resistance test>
After a 10,000-sheet paper copy test, a methanol solution containing 1% oleic acid was applied to the surface of the photoreceptor, and the surface of the photoreceptor was stored for 72 hours in an environment of 45 ° C. and 85% humidity. The presence or absence of occurrence was evaluated.
The evaluation results are shown in Table 1 below.

Next, photoreceptors used in Examples 17 to 32 and Comparative Examples 8 to 14 were produced as follows.
<Photoconductor for Example 17>
The photoreceptor used in Example 17 was produced as follows.
First, a photosensitive layer coating solution was prepared as shown below.
(Coating solution for photosensitive layer)
A photosensitive layer coating solution was prepared by the following procedure.
As a charge generation material, 30 parts by weight of a metal-free phthalocyanine pigment (Dai Nippon Ink Industry Co., Ltd .: Fastogen Blue 8120B) and 960 parts by weight of cyclohexane non were dispersed in a ball mill apparatus for 120 minutes to obtain a charge generation material dispersion. Separately from this, 340 parts by weight of tetrahydrofuran, 44 parts by weight of Z-type polycarbonate resin (viscosity average molecular weight; 50,000, manufactured by Teijin Chemicals Ltd.), 18 parts by weight of the charge transport material of the formula (2) synthesized by the method described above , 26 parts by weight of the charge transport material represented by the following structural formula (G), 9 parts by weight of the compound represented by the formula (II) -15 and silicone oil (KF50-100CS manufactured by Shin-Etsu Chemical Co., Ltd.) 0.1 Part by weight was dissolved, and 66.6 parts by weight of the above-described charge generating material dispersion was added and stirred to prepare a photosensitive layer coating solution.

次いで、φ３０ｍｍ、長さ２５６ｍｍのアルミニウムドラム上に、上記感光層用塗工液を浸漬塗工法にて塗工し成膜して、１２０℃で２０分乾燥した。なお感光層は乾燥後の膜厚が２８．８μｍとなるような昇降速度条件で作製し実施例１７用の感光体を作製した。

Subsequently, the photosensitive layer coating solution was applied by dip coating on an aluminum drum having a diameter of 30 mm and a length of 256 mm, and dried at 120 ° C. for 20 minutes. The photosensitive layer was produced under the ascending / descending speed conditions such that the film thickness after drying was 28.8 μm, and a photoreceptor for Example 17 was produced.

<Photoreceptor for Example 18>
In the photoreceptor for Example 17, the same procedure as in Example 17 was conducted except that the compound represented by formula (II) -16 was used instead of the compound represented by formula (II) -15 used in the photosensitive layer coating solution. Thus, a photoreceptor for Example 18 was produced.
<Photoconductor for Example 19>
In the photoreceptor for Example 17, the same procedure as in Example 17 was conducted except that the compound represented by formula (II) -10 was used instead of the compound represented by formula (II) -15 used in the photosensitive layer coating solution. Thus, a photoreceptor for Example 19 was produced.
<Photoconductor for Example 20>
In the photoconductor for Example 17, the same procedure as in Example 17 except that the compound represented by formula (II) -17 was changed to the compound represented by formula (II) -15 used in the photosensitive layer coating solution. Thus, a photoreceptor for Example 20 was produced.

<Photoconductor for Example 21>
The photoconductor for Example 17 was prepared in the same manner as in Example 21 except that the amount of the compound represented by formula (II) -15 used in the coating solution for the photosensitive layer was changed from 9 to 4 parts by weight. A photoconductor was prepared.
<Photoconductor for Example 22>
Example 22 was the same as Example 17 except that the amount of the compound represented by formula (II) -15 used in the photosensitive layer coating solution was changed from 9 parts by weight to 17 parts by weight. A photoconductor was prepared.
<Photoconductor for Example 23>
A photoreceptor for Example 23 was prepared in the same manner as in the photoreceptor for Example 17, except that the metal-free phthalocyanine pigment used in the coating solution for the photosensitive layer was changed to titanyl phthalocyanine having X-ray diffraction in FIG. .
<Photoconductor for Example 24>
A photoconductor for Example 24 was produced in the same manner as in the photoconductor for Example 17, except that the polyarylate resin (U-100 manufactured by Unitika) was used instead of the polycarbonate resin used in the coating solution for the photosensitive layer.

<Photoconductor for Example 25>
In the photoreceptor for Example 23, instead of the charge transport material represented by the structural formula (G) used in the photosensitive layer coating solution, a charge transport material represented by the following structural formula (H) was used. A photoconductor for Example 25 was prepared in exactly the same manner.

<Photoconductor for Example 26>
In the photoconductor for Example 17, instead of the charge transport material represented by the structural formula (G) used in the photosensitive layer coating solution, the charge transport material represented by the structural formula (H) was used. Were prepared in the same manner as above to prepare a photoreceptor for Example 26 <Photoconductor for Example 27>
In the photoreceptor for Example 17, in place of the charge transport material represented by the formula (2) used in the photosensitive layer coating solution, the charge transport material represented by the formula (3) synthesized according to the above-described method was used. A photoconductor for Example 27 was produced in exactly the same manner except for the change.
<Photoconductor for Example 28>
In the photoreceptor for Example 17, instead of the charge transport material represented by the formula (2) used in the coating solution for the photosensitive layer, the charge transport material represented by the formula (4) synthesized according to the above method was used. A photoconductor for Example 28 was produced in the same manner as described above, except for the changes.

<Photoconductor for Example 29>
In the photoreceptor for Example 17, instead of the charge transport material represented by the formula (2) used in the coating solution for the photosensitive layer, the charge transport material represented by the formula (5) synthesized according to the above-described method was used. A photoconductor for Example 29 was produced in the same manner as described above, except for the changes.
<Photoconductor for Example 30>
In the photoreceptor for Example 17, instead of the charge transport material represented by the formula (2) used in the coating solution for the photosensitive layer, the charge transport material represented by the formula (6) synthesized according to the above-described method was used. A photoconductor for Example 30 was produced in exactly the same manner except for the change.

<Photoconductor for Example 31>
In the photoreceptor for Example 25, except that the metal-free phthalocyanine pigment used in the coating solution for the photosensitive layer was changed to a titanyl phthalocyanine pigment (titanyl phthalocyanine having X-ray diffraction in FIG. 11) prepared according to the method of Synthesis Example 1. A photoconductor for Example 31 was produced in exactly the same manner.
<Photoconductor for Example 32>
In the photoreceptor for Example 17, except that the metal-free phthalocyanine pigment used in the coating solution for the photosensitive layer was changed to a titanyl phthalocyanine pigment (titanyl phthalocyanine having X-ray diffraction in FIG. 11) prepared according to the method of Synthesis Example 1. A photoconductor for Example 32 was produced in exactly the same manner.

<Photoconductor for Comparative Example 8>
In the photoreceptor for Example 17, in place of the charge transport material represented by the formula (2) used in the photosensitive layer coating solution, the charge transport material represented by the structural formula (B) was used. Similarly, a photoconductor for Comparative Example 8 was produced.
<Photoconductor for Comparative Example 9>
In the photoreceptor for Example 17, in place of the charge transport material represented by the formula (2) used in the photosensitive layer coating solution, the charge transport material represented by the structural formula (C) was used. Similarly, a photoconductor for Comparative Example 9 was produced.
<Photoconductor for Comparative Example 10>
In the photoreceptor for Example 17, in place of the charge transport material represented by the formula (2) used in the photosensitive layer coating solution, the charge transport material represented by the structural formula (D) was used. Similarly, a photoconductor for Comparative Example 10 was produced.
<Photoconductor for Comparative Example 11>
A photoconductor for Comparative Example 11 was produced in the same manner as in the photoconductor for Example 17, except that the compound represented by formula (II) -15 used for the coating solution for the photosensitive layer was not added.

<Photoconductor for Comparative Example 12>
The photoconductor for Example 17 was exactly the same except that the compound represented by formula (II) -15 used for the photosensitive layer coating solution was changed to 2-hydroxy-4-methoxybenzophenone as comparative compound A. Thus, a photoreceptor for Comparative Example 12 was produced.
<Photoconductor for Comparative Example 13>
In the photoreceptor for Example 17, instead of the compound represented by the formula (II) -15 used in the coating solution for the photosensitive layer, the compound was changed to 2-hydroxy-4-octyloxybenzophenone as the comparative compound B. Except for the above, a photoconductor for Comparative Example 13 was produced in the same manner.
<Photoconductor for Comparative Example 14>
In the photoreceptor for Example 17, in place of the compound represented by the formula (II) -15 used for the photosensitive layer coating solution, 2,4-bis [2-hydroxy-4-butoxyphenyl]- A photoconductor for Comparative Example 14 was produced in the same manner except that 6- (2,4-dibutoxyphenyl) -1,3-5 triazine was used.

<Examples 17 to 32 and Comparative Examples 8 to 14>
This is a full-color printer having a tandem mechanism and employing an intermediate transfer belt system after mounting the electrophotographic photosensitive members for Examples 17 to 32 and Comparative Examples 8 to 14 thus manufactured. The power pack was changed based on Ypsio CX400 [manufactured by Ricoh Co., Ltd.] and mounted on an image forming apparatus in which the charging polarity was modified to positive charging. The toner and developer were changed from those dedicated to Ypsio CX400 to those having opposite polarities.
Using such an image forming apparatus, a paper copy test was conducted, and the following items were evaluated at the initial stage and after 10,000 sheets.

<Image quality>
The output image was comprehensively evaluated for the image density of the black solid portion, the presence or absence of abnormal images such as black spots, white spots, black stripes, and white stripes.
<Exposure part potential>
The exposure portion potential at the time of writing a solid black image (at the time of whole surface exposure) when the initial photoreceptor surface potential (charging potential) was 600 V was evaluated.
<Foreign substance resistance test>
After a 10,000-sheet paper copy test, a methanol solution containing 1% oleic acid was applied to the surface of the photoreceptor, and the surface of the photoreceptor was stored for 72 hours in an environment of 45 ° C. and 85% humidity. The presence or absence of occurrence was evaluated.
These evaluation results are shown in Table 2 below.

  From the above results, in the case of an image forming apparatus satisfying the conditions of the present invention, both results are high in image quality and highly durable, but in the case of a comparative example that does not satisfy the requirements of the present invention, the initial or repeated use It can be seen that the image quality is poor at that time and sufficient durability cannot be obtained.

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 which shows another example of the electrophotographic apparatus which concerns on this 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 another example of the layer structure of the electrophotographic photoreceptor which concerns on this invention. It is sectional drawing which shows another example of the layer structure of the electrophotographic photoreceptor which concerns on this invention. It is sectional drawing which shows another example of the layer structure of the electrophotographic photoreceptor which concerns on this invention. 2 is an X-ray diffraction spectrum of titanyl phthalocyanine used in Examples. 2 is an X-ray diffraction spectrum of titanyl phthalocyanine prepared in Synthesis Example 1 of titanyl phthalocyanine of Example 15. FIG.

Explanation of symbols

11, 11Y, 11M, 11C, 11Bk... Photoconductor 12, 12Y, 12M, 12C, 12Bk... Charging means (charging charger)
13, 13Y, 13M, 13C, 13Bk... Exposure means (image exposure unit)
14, 14Y, 14M, 14C, 14Bk ... developing means 15 ... toner 16, 16Y, 16M, 16C, 16Bk ... transfer means 17, 17M, 17M, 17C, 17Bk ... cleaning means (cleaning brush) )
18. Image receiving medium (transfer material)
DESCRIPTION OF SYMBOLS 19 ... Fixing means 20 ... Developing roller 1A ... Static elimination means 1B ... Pre-cleaning exposure means 1C ... Driving means 1D ... Transfer means 1E ... Secondary transfer device 1F ... Intermediate transfer member (belt)
1G ... Conveyor belt

Claims (8)

An electrophotographic photosensitive member; a charging unit that uniformly charges the surface of the photosensitive member; an image exposing unit that forms an electrostatic latent image by performing image exposure after uniform charging; and a development that develops the electrostatic latent image And a transfer means for transferring a developed image. In the image forming apparatus, at least a charge generating material, a charge transport material represented by the following general formula (I), and a general formula represented by the following general formula: An image forming apparatus comprising a photosensitive layer containing the compound represented by (II).

Wherein R 1 and R 2 each independently represents a group selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aralkyl group; , R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 are each independently a hydrogen atom, halogen atom, cyano group, nitro group, amino group, hydroxyl group, substituted or unsubstituted alkyl group Represents a group selected from the group consisting of a substituted or unsubstituted cycloalkyl group and a substituted or unsubstituted aralkyl group, n is a repeating unit, and represents an integer of 0 to 100.)

(In the formula, R15 represents a group selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group, and R16 and R17 each independently represents a hydrogen atom, a substituted or unsubstituted group. Represents a group selected from the group consisting of a substituted alkyl group and a substituted or unsubstituted aryl group.)   2. The image forming apparatus according to claim 1, wherein a polycarbonate resin is used as a binder resin in the photosensitive layer.   The image forming apparatus according to claim 1, wherein the charge generating substance contains phthalocyanine.   The image forming apparatus according to claim 3, wherein the phthalocyanine is titanyl phthalocyanine.   The phthalocyanine has a maximum diffraction peak at 27.2 ° as a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to the Cu-Kα ray (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. 5. The image forming apparatus according to claim 3, wherein the image forming apparatus is a titanyl phthalocyanine having a crystal form having no peak.   6. The image forming apparatus according to claim 1, wherein the image forming apparatus is a tandem type having a plurality of electrophotographic photosensitive members, a charging unit, a developing unit, and a transfer unit.   An image having intermediate transfer means for secondarily transferring the toner image on the intermediate transfer member onto the recording material after the image forming apparatus primarily transfers the toner image developed on the electrophotographic photosensitive member onto the intermediate transfer member. 7. The forming apparatus according to claim 6, wherein a color image is formed by sequentially superposing a plurality of color toner images on an intermediate transfer member, and the color image is secondarily transferred collectively onto a recording material. Image forming apparatus.   A process cartridge for an image forming apparatus comprising at least one of a charging unit, an exposure unit, a developing unit, and a transfer unit and an electrophotographic photosensitive member, wherein the image forming apparatus according to any one of claims 1 to 7 is used. A process cartridge for an image forming apparatus, which is used.

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