JP2005227580A - Electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor containing oxy-titanium phthalocyanine having high sensitivity in a long wavelength band, free of deterioration of electrical properties even when used repeatedly under environment of a low temperature and low humidity to high temperature and high humidity, and having such high stability in a coating liquid that the coating liquid can be used over a prolonged period of time. <P>SOLUTION: The electrophotographic photoreceptor has a photosensitive layer containing at least a charge generating agent, a charge transfer agent and a binder resin, laminated on an electrically conductive support, wherein the charge generating agent is oxy-titanium phthalocyanine having the highest peak at a Bragg angle (2θ±0.2°) of 7.5° in an X-ray diffraction spectrum using CuKα as a radiation source, while another diffraction peak intensity is ≤20% of the diffraction peak intensity at 7.5°, and the charge transfer agent contains a compound represented by formula 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrophotographic photoreceptor containing oxytitanium phthalocyanine having a specific crystal form as a charge generating agent and containing a specific compound as a charge transfer agent.

  In recent years, long-wavelength light sources such as semiconductor lasers and LEDs have been mainly used as exposure light sources for non-impact printers that employ electrophotography. Therefore, the electrophotographic photosensitive member generally uses a charge generating agent having sensitivity in a long wavelength region. Conventionally, phthalocyanine pigments are often used as such materials. It is well known that the sensitivity of this phthalocyanine pigment varies depending on its crystal form. Further, with the recent power saving, there is an increasing demand for high sensitivity in the electrophotographic photosensitive member in order to suppress the output of the exposure light source of the electrophotographic apparatus such as a printer.

Among the phthalocyanine pigments, oxytitanium phthalocyanine is mentioned as one having high sensitivity in the long wavelength region. Several crystal forms of oxytitanium phthalocyanine have been introduced. Among them, the one showing the maximum diffraction peak at 27.3 ° is considered to be highly sensitive. However, this oxytitanium phthalocyanine is highly environment-dependent, and is particularly unsuitable for color printers that require halftone reproducibility because the sensitivity changes with increasing and decreasing humidity. As other crystal types, α type showing main diffraction peaks at 7.6 ° and 28.3 ° and β type showing maximum diffraction peak at 26.3 ° are well known. The sensitivity is insufficient and is not practical (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 61-239248

  Accordingly, there is a need for an electrophotographic photosensitive member that has high sensitivity in the long wavelength region, excellent halftone reproducibility, and is constant. In addition, even if a charge generating agent having high charge generation efficiency is used, sufficient sensitivity cannot be obtained if the compatibility with the charge transfer agent is poor, and it is also high in various usage environments from high temperature and high humidity to low temperature and low humidity. Quality image is not obtained. The compatibility between the charge generating agent and the charge transfer agent has been studied from various viewpoints, but has not been clearly found at present.

  The problem of the present invention is that it has high sensitivity in a long wavelength range, excellent reproducibility of halftone, no deterioration of electrical characteristics even when used repeatedly in a low temperature and low humidity environment, and a coating solution. It is to provide an electrophotographic photosensitive member containing oxytitanium phthalocyanine which has a high stability and can be used for a long period of time.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used oxytitanium phthalocyanine exhibiting a specific X-ray diffraction peak as a charge generating agent, and an electrophotographic photoreceptor using a charge transfer agent of a specific compound However, the present inventors have found that the problems of the prior art are solved and have completed the present invention.

  The inventors of the present invention have focused on the fact that the potential variation of the photoconductor is small even with respect to the use environment variation by specifying the crystal form of oxytitanium phthalocyanine after being coated and formed as the photosensitive layer. Furthermore, it came to solve the conventional subject by combining with a specific charge transfer agent.

  Conventionally, X-ray diffraction spectra of oxytitanium phthalocyanine used in electrophotographic photoreceptors include powdered oxytitanium phthalocyanine having a desired crystal form after synthesis, or a resin or dispersion solvent created when forming a photosensitive layer. The sample was measured using a pellet of the coating solution.

  However, even if the X-ray diffraction spectrum of oxytitanium phthalocyanine is measured before the formation of the photosensitive layer, the crystal form of oxytitanium phthalocyanine contained in the photosensitive layer cannot be accurately determined. That is, there are various external factors in forming the photosensitive layer, and the diffraction spectrum may be different before and after the formation of the photosensitive layer.

  That is, in a laminate type photoreceptor in which a charge transfer layer is laminated on a charge generation layer, a coating solution containing a charge generation agent is applied and formed on a support, dried as necessary, and then the charge transfer agent is applied. Since the photosensitive layer is formed by applying a coating solution containing it to form a charge transfer layer and drying to fix each layer, it is used as a thermal external factor in the drying step, and a charge transfer layer forming coating solution. There is a possibility that the diffraction spectrum of the charge generating agent undergoes a crystal transition due to contact with a solvent or the like, and does not necessarily show the same crystal type as the diffraction spectrum in the state of the coating liquid and the diffraction spectrum in the final state of the photoreceptor. Therefore, in order to examine the diffraction spectrum of the charge generating agent actually functioning, it is necessary to take out and measure the charge generating agent after forming the photosensitive layer.

The present invention has been obtained from the above research results. The invention according to claim 1 is characterized in that a photosensitive layer containing at least a charge generator, a charge transfer agent, and a binder resin is provided on a conductive support. 8. In a laminated electrophotographic photosensitive member, the charge generator is oxytitanium phthalocyanine, and the oxytitanium phthalocyanine has a Bragg angle (2θ ± 0.2 °) in an X-ray diffraction spectrum using CuKα as a radiation source. An electrophotographic photosensitive member having main peaks at 0 ° and 27.3 ° and a charge transfer agent containing a compound represented by formula (I).
As peaks other than Bragg angle (2θ ± 0.2 °) 9.0 ° and 27.3 °, those shown at 7.0 °, 18.0 ° and 24.0 ° are preferable.

  When extracting oxytitanium phthalocyanine from the photosensitive layer, care must be taken not to crystallize the oxytitanium phthalocyanine. Further, the photosensitive layer contains a binder resin, a charge transfer agent, and the like, which are obstacles in measuring the X-ray diffraction spectrum. Therefore, it is necessary to appropriately select a solvent that removes the binder resin, the charge transfer agent, and the like and does not change the crystal form of oxytitanium phthalocyanine.

  As can be seen from the characteristic differences between the examples and comparative examples described later, the electrophotographic photosensitive member of the present invention has environment dependency and repetitive stability, and can meet high market demands.

  The electrophotographic photosensitive member of the present invention is obtained by containing oxytitanium phthalocyanine having a specific X-ray diffraction spectrum as a charge generating material in a photosensitive layer on a substrate.

A preferred embodiment of the electrophotographic photosensitive member according to the present invention will be described in detail. In the present invention, for example, a function-separated electrophotographic image in which a charge generation layer containing at least a charge generation agent is formed on a conductive support and a charge transfer layer containing at least a charge transfer agent is formed thereon. A photoreceptor is applied. In this case, a photosensitive layer is formed by the charge generation layer and the charge transfer layer.
Various methods can be used as the method for forming the charge generation layer. For example, a coating solution in which the phthalocyanine composition of the present invention is used as a charge generation agent and dispersed or dissolved in a suitable solvent together with a binder resin is used. It can apply | coat on the support body used as the foundation | substrate of this, and can dry and form as needed.

  The charge transfer layer has at least a charge transfer agent, which will be described later. This charge transfer layer is formed, for example, by binding the charge transfer agent on the charge generation layer serving as the base using a binder resin. be able to.

Various methods can be used as a method for forming the charge transfer layer. In general, a coating solution in which a charge transfer agent is dispersed or dissolved in a suitable solvent together with a binder resin is applied to the underlying charge generation layer. The method of apply | coating to and drying can be used.
Further, the present invention can also be applied to an inversely laminated electrophotographic photosensitive member in which a charge generation layer and a charge transfer layer are laminated upside down. Furthermore, the present invention can also be applied to a single layer type electrophotographic photosensitive member containing a charge generating agent and a charge transfer agent in the same layer.

  Examples of the conductive support that can be used in the present invention include aluminum, brass, stainless steel, nickel, chromium, titanium, gold, silver, copper, tin, platinum, molybdenum, indium, and other simple metals and alloys thereof. The body is mentioned. The shape may be any shape as long as it is a flexible shape such as a sheet shape, a film shape, or a belt shape, and may be endless or endless.

  Moreover, what formed the conductive layer in the flexible support body can be used. Examples of the flexible support include a non-conductive plastic sheet such as polyimide and polyethylene terephthalate (PET), a film, or a belt. In particular, polyimide is preferable because it has a small amount of deformation with respect to heat drying. . The film thickness of the flexible support can be 10 to 300 μm, preferably 70 to 150 μm. In that case, a conductive layer is formed on the front or back surface of the support by vapor deposition, plating, or the like. For example, a thin film of carbon or a metal such as chromium, aluminum, nickel, titanium or the like is formed on the front or back surface of the support by a method such as vapor deposition or plating, or a carbon-based paint or powder is applied. To provide conductivity.

Moreover, when using resin as a base | substrate, conductive agents, such as metal powder and conductive carbon, can be contained in resin, and conductive resin can also be used as base | substrate formation resin.
Further, when glass is used for the substrate, the surface thereof may be coated with tin oxide, indium oxide, or aluminum iodide so as to have conductivity.

  Further, the support surface may be anodized or a resin layer may be formed on the support. This resin layer has an adhesion improving function, a barrier function for preventing an inflow current from the aluminum tube, a defect covering function on the surface of the aluminum tube, and the like. Various resins such as polyethylene resin, acrylic resin, epoxy resin, polycarbonate resin, polyurethane resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, polyamide resin, nylon resin, alkyd resin, and melamine resin are used for this resin layer. be able to. These resin layers may be composed of a single resin or a mixture of two or more kinds of resins. Moreover, a metal compound, carbon, silica, resin powder, etc. can be dispersed in the layer. Furthermore, various pigments, electron accepting substances, electron donating substances, and the like can be contained for improving the characteristics.

  As the charge generating agent, oxytitanium phthalocyanine having main peaks at Bragg angles (2θ ± 0.2 °) of 9.0 ° and 27.3 ° in an X-ray diffraction spectrum using CuKα as a radiation source is used.

  The diffraction peaks shown above were measured in a state where oxytitanium phthalocyanine was extracted from the photosensitive layer after the photosensitive layer was formed. By using this oxytitanium phthalocyanine, it is possible to provide an electrophotographic photosensitive member having excellent sensitivity in a long wavelength region and exhibiting stable characteristics without being affected by the use environment, particularly humidity.

  In addition to the oxytitanium phthalocyanine of the present invention, oxytitanium phthalocyanine and azo pigments other than the present invention can be mixed in the photosensitive layer in order to obtain an appropriate photosensitivity wavelength and sensitizing action. These are desirable in terms of good sensitivity compatibility. Other examples include monoazo pigments, bisazo pigments, trisazo pigments, polyazo pigments, indigo pigments, selenium pigments, toluidine pigments, pyrazoline pigments, perylene pigments, quinacridone pigments, and pyrylium salts.

  As binder resin for forming the photosensitive layer, polycarbonate resin, styrene resin, acrylic resin, styrene-acrylic resin, ethylene-vinyl acetate resin, polypropylene resin, vinyl chloride resin, chlorinated polyether, vinyl chloride-vinyl acetate resin Polyester resin, furan resin, nitrile resin, alkyd resin, polyacetal resin, polymethylpentene resin, polyamide resin, polyurethane resin, epoxy resin, polyarylate resin, diarylate resin, polysulfone resin, polyethersulfone resin, polyallylsulfone resin, Silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin, EVA (ethylene-vinyl acetate) resin, ACS (acrylonitrile, chlorinated polyethylene, styrene) Resins, ABS (acrylonitrile butadiene styrene) is a resin and epoxy arylate such resins.

  They may be used alone or in combination of two or more. It is preferable to use a mixture of resins having different molecular weights because the hardness and wear resistance can be improved.

  In the case where the photosensitive layer comprises a charge generation layer and a charge transfer layer, the resin can be applied to either layer.

  Solvents used in the coating solution include alcohols such as methanol, ethanol, n-propanol, i-propanol and butanol, saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane and cycloheptane, toluene and xylene. Aromatic hydrocarbons such as dichloromethane, chlorinated hydrocarbons such as dichloromethane, dichloroethane, chloroform, chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran (THF), methoxyethanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone , Esters such as ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, diethyl ether, dimethoxyethane, tetrahydride Furan, dioxolane, dioxane or ether solvents such as anisole,, N, N-dimethylformamide, there are dimethyl sulfoxide and the like. Among these, ketone solvents, ester solvents, ether solvents, or halogenated hydrocarbon solvents are preferable, and these can be used alone or as a mixed solvent of two or more.

  The electrophotographic photoreceptor of the present invention contains a compound represented by formula (I) as a charge transfer agent.

Formula [I]


[Wherein R ₁ , R ₂ , R ₃ and R ₄ represent a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group or an aryl group, and R ₃ and R ₄ are bonded to each other to form a ring. May be formed. Z represents an atomic group necessary for forming a saturated 5- to 8-membered ring together with two carbon atoms of the indoline ring. ]

  The charge transfer agent has good compatibility with oxytitanium phthalocyanine and can provide an electrophotographic photosensitive member having high environmental resistance. Further, the charge transfer agent exhibits an excellent characteristic that, when a conductive support having a flexible belt shape is used, the problem that the end portion of the belt easily warps (curls) is eliminated.

Among the compounds represented by the general formula (I), the compounds represented by the formulas (Ia) to (If) are particularly preferable because of their good compatibility with oxytitanium phthalocyanine.
Specific compounds will be shown below, but are not limited thereto.

Formula [Ia]

Formula [Ib]

Formula [Ic]

Formula [Id]

Formula [Ie]

Formula [If]

In this case, the content of the compound represented by the general formula [I] in the charge transfer layer is preferably 0.3 to 2.0 parts by weight with respect to 1 part by weight of the binder resin. If the content of this compound is less than 0.3 parts by weight, the electrical characteristics deteriorate, for example, the residual potential increases. On the other hand, when the amount is more than 2.0 parts by weight, mechanical properties such as wear resistance are deteriorated.

Furthermore, the compound represented by the general formula [I] and other charge transfer agents can be mixed and used. In this case, the content ratio of the compound of the general formula [I] and the other compound is [I]: other compound = 3: 7 to 8: 2, preferably 5: 5 to 7: 3.

  Other charge transfer agents include polyvinyl carbazole, halogenated polyvinyl carbazole, polyvinyl pyrene, polyvinyl indoloquinoxaline, polyvinyl benzothiophene, polyvinyl anthracene, polyvinyl acridine, polyvinyl pyrazoline, polyacetylene, polythiophene, polypyrrole, polyphenylene, polyphenylene vinylene, poly Conductive polymer compounds such as isothianaphthene, polyaniline, polydiacetylene, polyheptadiene, polypyridinediyl, polyquinoline, polyphenylene sulfide, polyferrocenylene, polyperinaphthylene, and polyphthalocyanine can be used. In addition, as low molecular compounds, trinitrofluorenone, tetracyanoethylene, tetracyanoquinodimethane, quinone, diphenoquinone, naphthoquinone, anthraquinone and derivatives thereof, polycyclic aromatic compounds such as anthracene, pyrene, phenanthrene, indole, carbazole, Nitrogen-containing heterocyclic compounds such as imidazole, fluorenone, fluorene, oxadiazole, oxazole, pyrazoline, hydrazone, triphenylmethane, triphenylamine, enamine, stilbene and the like can be used. Further, a polymer solid electrolyte in which a polymer compound such as polyethylene oxide, polypropylene oxide, polyacrylonitrile, polymethacrylic acid or the like is doped with a metal ion such as Li ion can also be used. Furthermore, an organic charge transfer complex formed of an electron donating compound typified by tetrathiafulvalene-tetracyanoquinodimethane and an electron accepting compound, etc. can be used. Desired photoreceptor characteristics can be obtained by mixing and adding the above compounds.

  In the coating solution for producing the electrophotographic photosensitive member of the present invention, an antioxidant, an ultraviolet absorber, a radical scavenger, a softener, a curing agent, a crosslinking agent, etc. are added as long as the characteristics are not impaired. The characteristics, durability, and mechanical characteristics of the photoreceptor can be improved. In particular, phenolic antioxidants are useful because they contribute to improving the durability of the photoreceptor. Furthermore, the addition of a dispersion stabilizer, an anti-settling agent, an anti-coloring agent, a leveling agent, an antifoaming agent, a thickener, a matting agent, etc. can improve the finished appearance of the photoreceptor and the life of the coating solution.

  In addition, a thin film made of an organic thin film such as polyvinyl formal resin, polycarbonate resin, fluororesin, polyurethane resin, or silicone resin, or a siloxane structure formed from a hydrolyzate of a silane coupling agent is formed on the photosensitive layer. A surface protective layer may be provided as a film. In that case, the durability of the photoreceptor is improved, which is preferable. This surface protective layer may be provided in order to improve functions other than the durability improvement.

  As an electrophotographic apparatus on which the electrophotographic photosensitive member of the present invention is mounted, the charging method is usually a contact type such as a brush or a roller, a non-contact type such as a scorotron or a corotron, and any positive or negative charging method. It may be an electric charge. The exposure method may be either LED or LD. The development method may be two-component, one-component, or magnetic / non-magnetic. The transfer method may be either a roller or a belt.

  Hereinafter, although an example and a comparative example explain the present invention in detail, the present invention is not limited to this.

  An alkyd resin and a melamine resin are mixed at a polymerization ratio of 6/4, titanium oxide is prepared at a ratio of 1/3 by weight with respect to the mixed resin, dissolved and dispersed in methyl ethyl ketone, and an undercoat layer coating solution is prepared. Next, the undercoat layer coating solution was dip-coated on an endless belt-like support made of polyimide resin and dried at 130 ° C. for 20 minutes to form an undercoat layer having a thickness of 0.8 μm.

  Next, 10 g of β-type oxytitanium phthalocyanine powder having an X-ray diffraction peak shown in FIG. 2 is placed in a SUS pot together with glass beads, and dry pulverized with a sand mill dispersing device for 40 hours to form amorphous oxytitanium phthalocyanine. Next, 500 ml is prepared in a ratio of 1,1,2-trichloroethane / dichloromethane / tetrahydrofuran = 7/2/1. 5 g of polyvinyl butyral resin is dissolved in this, and after milling for 30 minutes, it is placed in the SUS pot and dispersed for 20 hours. Then, the obtained dispersion was filtered to remove the glass beads, and a charge generation layer coating solution was prepared. This was dip coated and then dried to form a charge generation layer having a thickness of 0.2 μm.

  Next, a polycarbonate resin as a binder resin, a compound represented by the formula [Ib] as a charge transfer agent, and 2,6-di-tert-butyl-4-methyl-phenol as an antioxidant, a weight ratio of 1 Prepared at 0.0: 1.0: 0.1 and dissolved in chloroform to prepare a charge transfer layer coating solution. The substrate on which the charge generation layer was formed was dip-coated in the charge transfer layer coating solution and dried at 100 ° C. for 60 minutes to form a charge transfer layer having a thickness of 25.0 μm, thereby producing an electrophotographic photosensitive member.

Preparation of specimen for X-ray diffraction Incision is made on the surface of the photoreceptor obtained in Example 1 in the circumferential direction and in the cylindrical axis direction intersecting with the office cutter to form a cut having a side of about 2 cm. The photosensitive film is peeled off using tweezers from the cut portion. 15 ml of 4-methoxy-4-methylpentanone is put into a 50 ml beaker, the release film is immersed in the beaker, and after the charge transfer layer is completely dissolved, it is stirred well and dispersed in a solvent as gel-like fine pieces. . This is suction filtered with a membrane filter (Pore size 0.2 μm) made of Teflon (registered trademark), and the filtrate is washed with 10 ml of PTX. Next, the membrane filter is closely attached to the silicon non-reflective plate so that the filtrate is inside, and only the membrane filter is peeled off to attach oxytitanium phthalocyanine to the silicon non-reflective plate. did.

X-ray diffraction When measuring the specimen sample prepared as described above, measurement was performed by a thin film method, CuKα (wavelength: 1.54178 mm) was used as an X-ray source, and an X-ray incident angle was set to 0.5 °. In addition, when measuring oxytitanium phthalocyanine powder, it measured by the powder method and used CuK (alpha) (wavelength 1.54178?) As an X-ray source. The X-ray diffraction pattern of the specimen sample is shown in FIG. According to FIG. 1, oxytitanium phthalocyanine extracted from the photosensitive layer has characteristic diffraction peaks at 9.0 ° and 27.3 °, and the other 7.0 °, 18.0 °, 24.0 °. Also have a diffraction peak.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transfer agent represented by the formula [Ic] was used instead of the charge transfer agent used in Example 1.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transfer agent represented by the formula [If] was used instead of the charge transfer agent used in Example 1.

An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the charge transfer agent was further added in the following formula [II] and the mixing ratio was changed to formula [Ib]: formula [II] = 6: 4. did.

Formula [II]

Comparative Example 1

  An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the charge transfer agent represented by the formula [III] was used instead of the charge transfer agent used in Example 1.

Formula [III]

Comparative Example 2

  An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the charge transfer agent represented by the formula [IV] was used instead of the charge transfer agent used in Example 1.

Formula [IV]

Comparative Example 3

  Instead of the charge generating agent used in Example 1, α-type oxytitanium phthalocyanine having a maximum peak at 7.6 ° shown in FIG. 3 was used as the charge generating agent, and the others were the same as in Example 1. An electrophotographic photoreceptor was prepared.

[Measurement of environmental dependency]
Using an electrophotographic photoreceptor evaluation apparatus (Eresia II manufactured by Trek), the electrophotographic photoreceptors produced according to the examples and comparative examples under the conditions of a photoreceptor rotational speed of 60 rpm, a scorotron charging method, and an exposure wavelength of 750 nm are obtained at low temperature and low humidity. After initial printing and after repeated printing (after printing 1,000 sheets) in each environment (10 ° C, 30% RH), normal temperature and normal humidity (25 ° C, 50% RH), high temperature and high humidity (35 ° C, 85% RH) The difference (ΔVL) in the surface potential (VL) after exposure was measured.

(End warp evaluation)
The electrophotographic photoreceptors produced in the examples and comparative examples were cut into 5 × 10 cm, the heights of the four corners were measured with a height gauge, and the total value was taken as the amount of turn. When the turning amount is 5 mm or less, ◎, when 10 mm or less, ◯, and when exceeding 10 mm, x. Table 1 shows the results of the electrostatic property measurement and the end warpage evaluation.

Table 1 shows that Examples 1-4 have little potential difference from low temperature and low humidity to high temperature and high humidity and little environmental dependency. In addition, as an effect of the charge transfer agent of the present invention, there is no warping of the end of the support, particularly in the case of a photoreceptor using a flexible belt-like support.
Comparative Examples 1 and 2 show examples using other charge transfer agents, and it can be seen that the potential difference at high temperature and high humidity is large. Moreover, the edge part curvature of the support body has generate | occur | produced and there existed a problem in use.
Comparative Example 3 uses a conventional α-type phthalocyanine as a charge generating agent, and has a large potential difference at high temperature and high humidity.

The X-ray diffraction pattern of the phthalocyanine composition of this invention is shown. The X-ray-diffraction figure of beta type oxytitanium phthalocyanine powder is shown. 2 shows an X-ray diffraction pattern of oxytitanium phthalocyanine used in Comparative Example 3. FIG.

Claims (4)

An electrophotographic photosensitive member in which a photosensitive layer containing at least a charge generator, a charge transfer agent, and a binder resin is laminated on a conductive support, wherein the charge generator is oxytitanium phthalocyanine, and the oxytitanium Phthalocyanine has main peaks at Bragg angles (2θ ± 0.2 °) of 9.0 ° and 27.3 ° in an X-ray diffraction spectrum using CuKα as a radiation source, and the charge transfer agent is represented by the general formula (I) An electrophotographic photoreceptor comprising a compound represented by:
Formula [I]

[Wherein R ₁ , R ₂ , R ₃ and R ₄ represent a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group or an aryl group, and R ₃ and R ₄ are bonded to each other to form a ring. May be formed. Z represents an atomic group necessary for forming a saturated 5- to 8-membered ring together with two carbon atoms of the indoline ring. ]   2. The electrophotographic photosensitive member according to claim 1, wherein the oxytitanium phthalocyanine has a Bragg angle (2θ ± 0.2 °) of 7.0 °, 9.0 °, 18.0 °, 24.0 ° and 27.3 °. An electrophotographic photosensitive member characterized by having a diffraction peak.   2. The electrophotographic photoreceptor according to claim 1, wherein the oxytitanium phthalocyanine is dispersed in the photosensitive layer together with at least a binder resin, and CuKα is used as a radiation source in a state extracted from the photosensitive layer after the photosensitive layer is formed. An electrophotographic photosensitive member characterized by having main peaks at Bragg angles (2θ ± 0.2 °) of 9.0 ° and 27.3 ° in an X-ray diffraction spectrum.   2. The electrophotographic photosensitive member according to claim 1, wherein a flexible belt is used as the conductive support.