JP2014055203A - Hydroxygallium phthalocyanine crystal and production method of the same, and electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel hydroxygallium phthalocyanine crystal capable of achieving high picture quality and high stability when the crystal is used as a charge generating material of an electrophotographic photoreceptor of an image forming apparatus.SOLUTION: The hydroxygallium phthalocyanine crystal shows, in an X-ray diffraction spectrum using CuKα characteristic X-rays, main diffraction peaks at 6.8° and 15.4° in Bragg angles (2θ±0.3°). Preferable aspects are, for example, that the crystal shows diffraction peaks at 6.8°, 7.4°, 7.7°, 15.4°, and 26.2° in the Bragg angles (2θ±0.3°) and that the crystal shows the most intense diffraction peak at 6.8° in the Bragg angles (2θ±0.3°).

Description

  The present invention relates to an electrophotographic photosensitive material, a photoelectric conversion element material, an organic semiconductor element material, a hydroxygallium phthalocyanine crystal useful as an optical recording material, a method for producing the same, and an electrophotographic photosensitive member.

Phthalocyanine compounds are useful materials that are widely used as paints and electronic materials. In recent years, phthalocyanine compounds have been widely studied as electrophotographic photosensitive materials, optical recording materials, and photoelectric conversion element materials.
As the electrophotographic photosensitive material, many phthalocyanine compounds having photosensitivity in the near-infrared wavelength region of a semiconductor laser have been proposed in order to achieve both improved sensitivity of the electrophotographic photosensitive member and improved stability over time. Studies on crystal forms of phthalocyanine compounds have been focused on.
In general, phthalocyanine compounds are known to exhibit a large number of crystal types due to differences in production methods and processing methods, and this difference in crystal types has a great influence on the photoelectric conversion efficiency and repeat stability of phthalocyanine compounds. It has been known. As the crystal form of the phthalocyanine compound, for example, copper phthalocyanine has crystal forms such as α, π, χ, ρ, γ, and δ in addition to the stable β form. These crystal forms include mechanical external force, sulfuric acid, and the like. It is known that they can be transferred to each other by treatment, organic solvent treatment, heat treatment or the like.

On the other hand, gallium phthalocyanine also has many reports on its crystal form (see, for example, Patent Documents 1 to 4). As a method for synthesizing hydroxygallium phthalocyanine, an acid paste method, that is, a method including a step of dissolving a precursor of hydroxygallium phthalocyanine in concentrated sulfuric acid and reprecipitation in water or the like has been proposed (Patent Documents 5 and 5). (See Patent Document 6).
However, in the method for producing hydroxygallium phthalocyanine by the acid paste method, a decomposition product is generated during hydrolysis using an acid, and this decomposition product may adversely affect the electrical characteristics of the electrophotographic photosensitive member. is there. In addition, the acid paste method has a difficulty in handling in manufacturing because a large amount of strong acid such as concentrated sulfuric acid is used.

  Therefore, in order to provide an electrophotographic photosensitive member that can realize high image quality and high stability when used as a charge generating material for an electrophotographic photosensitive member of an image forming apparatus, the development of a better charge generating material has been developed. The current situation is strongly desired.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide a novel hydroxygallium phthalocyanine crystal that can realize high image quality and high stability when used as a charge generation material of an electrophotographic photosensitive member of an image forming apparatus.

  The hydroxygallium phthalocyanine crystal of the present invention as a means for solving the above problems is obtained at an X-ray diffraction spectrum by CuKα ray at 6.8 ° and 15.4 ° out of Bragg angles (2θ ± 0.3 °). The main diffraction peak is shown.

  According to the present invention, the conventional problems can be solved, the object can be achieved, and when used as a charge generation material for an electrophotographic photosensitive member of an image forming apparatus, high image quality and high stability can be realized. A novel hydroxygallium phthalocyanine crystal can be provided.

FIG. 1 is a view showing an example of the layer structure of the electrophotographic photosensitive member of the present invention. FIG. 2 is a view showing another example of the layer structure of the electrophotographic photosensitive member of the present invention. FIG. 3 is a view showing another example of the layer structure of the electrophotographic photosensitive member of the present invention. FIG. 4 is a view showing another example of the layer structure of the electrophotographic photosensitive member of the present invention. FIG. 5 is a diagram showing an example of a process cartridge used in the present invention. FIG. 6 is a schematic view showing an example of an image forming apparatus used in the present invention. FIG. 7 is a schematic diagram illustrating an example of a state in which a gap forming member is provided on the charging roller. FIG. 8 is a schematic view showing another example of the image forming apparatus used in the present invention. FIG. 9 is a diagram showing a powder X-ray diffraction spectrum in Example 1. 10 is a view showing a powder X-ray diffraction spectrum in Example 2. FIG. FIG. 11 is a graph showing a powder X-ray diffraction spectrum in Example 3. 12 is a graph showing an X-ray powder diffraction spectrum in Example 4. FIG. FIG. 13 is a graph showing a powder X-ray diffraction spectrum in Example 5. 14 is a graph showing a powder X-ray diffraction spectrum in Comparative Example 1. FIG. FIG. 15 is a graph showing a powder X-ray diffraction spectrum in Comparative Example 2. FIG. 16 is a diagram illustrating an A4 size chart in which a character part and a halftone part used in the actual machine evaluation of the example are mixed.

(Hydroxygallium phthalocyanine crystal)
The hydroxygallium phthalocyanine crystal of the present invention is a novel compound showing main diffraction peaks at 6.8 ° and 15.4 ° of the black angle (2θ ± 0.3 °) in the X-ray diffraction spectrum by CuKα ray. is there.
The main diffraction peak means a peak having a diffraction intensity of 20% or more, more preferably 40% or more with respect to a peak having the strongest diffraction intensity and a peak having the strongest diffraction intensity among a plurality of diffraction peaks.
The hydroxygallium phthalocyanine crystal has diffraction peaks at 6.8 °, 7.4 °, 7.7 °, 15.4 ° and 26.2 ° out of Bragg angles (2θ ± 0.3 °). It is more preferable that it exhibits the strongest diffraction peak at 6.8 ° out of the Bragg angle (2θ ± 0.3 °), and has a structure represented by the following structural formula.

  The hydroxygallium phthalocyanine crystal of the present invention differs from the V-type hydroxygallium phthalocyanine crystal described in, for example, JP-A-5-263007 in the diffraction peak position of the X-ray diffraction spectrum. That is, the V-type hydroxygallium phthalocyanine crystal described in Japanese Patent Laid-Open No. 5-263007 has 7.5 °, 9.9 °, 12.5 °, 16 of Bragg angles (2θ ± 0.2 °). The crystal structure is different from the hydroxygallium phthalocyanine crystal of the present invention in that it has strong diffraction peaks at .3 °, 18.6 °, 25.1 ° and 28.3 °.

Here, the measurement of the powder X-ray diffraction spectrum of the hydroxygallium phthalocyanine crystal can be performed using CuKα characteristic X-rays under the following conditions.
・ Measurement device: RINT-TTRIII type wide-angle X-ray diffractometer manufactured by Rigaku Corporation ・ X-ray tube: Cu (wavelength 1.54 mm)
・ Voltage: 50kV
・ Current: 30mA
Scanning speed: 2 deg / min
Scan range: 2 deg to 35 deg
・ Time constant: 2 sec

(Method for producing hydroxygallium phthalocyanine crystal)
A conventionally known method for synthesizing a hydroxygallium phthalocyanine crystal is by hydrolyzing a gallium halide phthalocyanine, and the hydrolysis may be acid hydrolysis or alkali hydrolysis. .
Examples of the acid hydrolysis include a method of hydrolyzing chlorogallium phthalocyanine described in “Bull. Soc. Chim. France, 23 (1962)” using sulfuric acid.
Examples of the alkaline hydrolysis include a method of hydrolyzing with ammonia described in “Inlog. Chem. (19), 3131, (1980)”.

Examples of the halogenated gallium phthalocyanine include chlorogallium phthalocyanine, bromogallium phthalocyanine, iodine gallium phthalocyanine, and the like.
The chlorogallium phthalocyanine is synthesized, for example, by a method of reacting gallium trichloride and 1,3-diiminoisoindoline described in “DC Acad. Sci., (1965), 242, 1026”. be able to.
The bromogallium phthalocyanine can be synthesized, for example, by a method of reacting gallium tribromide and phthalonitrile described in JP-A No. 59-133551.
The iodine gallium phthalocyanine can be synthesized by, for example, a method of reacting gallium triiodide and phthalonitrile described in JP-A-60-59354.

  However, in the conventional method for producing a hydroxygallium phthalocyanine crystal, a decomposition product is generated during hydrolysis using an acid or an alkali. The generated decomposition product may adversely affect the electrical characteristics of the electrophotographic photosensitive member.

  In the method for producing a hydroxygallium phthalocyanine crystal of the present invention, as shown in the following reaction formula, 1,3-diiminoisoindoline and gallium hexafluoroacetylacetonate are reacted in an organic solvent. This effectively synthesizes the hydroxygallium phthalocyanine crystal of the present invention showing main diffraction peaks at 6.8 ° and 15.4 ° of the Bragg angle (2θ ± 0.3 °) in the X-ray diffraction spectrum by CuKα ray. can do.

<Reaction formula>

The method for producing a hydroxygallium phthalocyanine crystal according to the present invention uses a gallium hexafluoroacetylacetonate instead of a metal salt used for the synthesis of a generally known gallium halide phthalocyanine, and hydrolysis using an acid or an alkali. There is an advantage that hydroxygallium phthalocyanine can be obtained without any treatment.
In the conventional method for producing a hydroxygallium phthalocyanine crystal, the formation of a decomposition product due to hydrolysis treatment is unavoidable. However, since the production method for a hydroxygallium phthalocyanine crystal of the present invention does not produce a decomposition product, High-purity hydroxygallium phthalocyanine can be synthesized without adversely affecting the electrical properties of the body.

As said gallium hexafluoroacetylacetonate, what was synthesize | combined suitably may be used and a commercial item may be used.
The molar ratio (A: B) between the 1,3-diiminoisoindoline (A) and the gallium hexafluoroacetylacetonate (B) is not particularly limited and can be appropriately selected according to the purpose. 40:60 to 90:10 is preferable, and 70:30 to 85:15 is more preferable.
When (A) is less than 40:60 as the molar ratio (A: B), impurities derived from gallium hexafluoroacetylacetonate increase and the purity of the hydroxygallium phthalocyanine of the present invention may decrease. is there. This may have an adverse effect such as an increase in residual charge as an electrical characteristic of the electrophotographic photosensitive member. On the other hand, when (A) is more than 90:10 as the molar ratio (A: B), the product may contain metal-free phthalocyanine, and the ratio of hydroxygallium phthalocyanine of the present invention decreases. For this reason, sufficient stabilization may not be realized.

The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dehydrated dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, tetrahydrofuran, dioxane, 2- Butanone, cyclohexanone, chlorobenzene, dichlorobenzene, toluene, xylene, anisole, nitrobenzene, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethyl cellosolve, ethyl acetate, butyl acetate, dichloroethane, trichloroethane, pyridine, picoline, quinoline, etc. It is done. These may be used individually by 1 type and may use 2 or more types together. Among these, dehydrated dimethyl sulfoxide, N, N-dimethylformamide and chlorobenzene are preferable from the viewpoint of increasing the yield of the hydroxygallium phthalocyanine of the present invention.
There is no restriction | limiting in particular as reaction temperature, Although it can select suitably according to the objective, 0 to 200 degreeC is preferable and 20 to 150 degreeC is more preferable.
There is no restriction | limiting in particular as reaction time, Although it can select suitably according to the objective, 30 minutes-50 hours are preferable, and 1 hour-20 hours are more preferable.

  As a more specific synthesis method, for example, 1,3-diiminoisoindoline and gallium hexafluoroacetylacetonate are added to dehydrated dimethyl sulfoxide at a predetermined molar ratio, and an argon (Ar) stream is used. After reacting at 130 ° C. for 12 hours, the formed crystals are filtered off. The wet cake is washed with methyl ethyl ketone and N, N-dimethylformamide and then dried to obtain the hydroxygallium phthalocyanine crystal of the present invention.

  The hydroxygallium phthalocyanine crystal of the present invention has main diffraction peaks at 6.8 ° and 15.4 ° of the Bragg angle (2θ ± 0.3 °) in the X-ray diffraction spectrum by CuKα ray, and the photoconductor As a charge generating material for an electrophotographic photosensitive member, long-wavelength light can be suitably used in various fields such as an electrophotographic photosensitive member, a solar cell, a sensor, and a switching element. High-quality images can be stably formed in any of a normal temperature and normal humidity environment, a high temperature and high humidity environment, and a low temperature and low humidity environment. It is particularly preferably used for the electrophotographic photoreceptor of the present invention.

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor of the present invention comprises a support and at least a photosensitive layer on the support, and further comprises other layers as necessary.
In the electrophotographic photoreceptor, the photosensitive layer contains the hydroxygallium phthalocyanine crystal of the present invention.
The photosensitive layer may have any of a single layer structure and a laminated structure composed of a charge generation layer and a charge transport layer, but a photosensitive layer having a multilayer structure composed of a charge generation layer and a charge transport layer is particularly preferred.

<Support>
Examples of the support include those having a volume resistivity of 10 ¹⁰ Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, indium oxide, etc. The metal oxide of the above is coated by film or cylindrical plastic or paper by vapor deposition or sputtering, or a plate of aluminum, aluminum alloy, nickel, stainless steel, etc. After the conversion, a tube subjected to surface treatment such as cutting, superfinishing or polishing can be used. An endless nickel belt or an endless stainless steel belt can also be used as a support.

In addition, what coated and disperse | distributed electroconductive powder to the suitable binder resin on a support body can also be used as said support body.
Examples of the conductive powder include carbon black, acetylene black; metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver; metal oxide powder such as conductive tin oxide and ITO. Can be mentioned.
Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and polyacetic acid. Vinyl, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate, ethyl cellulose, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin , Phenol resin, alkyd resin, and the like. These may be used individually by 1 type and may use 2 or more types together.
The conductive layer can be formed by applying a coating solution in which the conductive powder and the binder resin are dispersed in a solvent. Examples of the solvent include tetrahydrofuran, dichloromethane, methyl ethyl ketone, toluene, and the like.
Furthermore, by a heat shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, polytetrafluoroethylene-based fluororesin on a cylindrical substrate. Those provided with a conductive layer can also be used favorably as the support.

<Photosensitive layer>
First, the laminated photosensitive layer will be described.
The photosensitive layer having the laminated structure is configured by sequentially laminating a charge generation layer and a charge transport layer.

<< Charge generation layer >>
The charge generation layer contains at least a charge generation material, preferably contains a binder resin, and further contains other components as necessary.

-Charge generation material-
As the charge generation material, the main diffraction at 6.8 ° and 15.4 ° of the Bragg angle (2θ ± 0.3 °) in the X-ray diffraction spectrum by CuKα ray, which is the hydroxygallium phthalocyanine crystal of the present invention. A hydroxygallium phthalocyanine crystal exhibiting a peak is used.
The charge generation material may be a mixture of the hydroxygallium phthalocyanine crystal of the present invention and a conventionally known charge generation material. Examples of the conventionally known charge generating materials include azo pigments such as monoazo pigments, disazo pigments, asymmetrical disazo pigments and trisazo pigments, phthalocyanine pigments such as titanyl phthalocyanine, copper phthalocyanine, vanadyl phthalocyanine, hydroxygallium phthalocyanine, and metal-free phthalocyanine. Perylene pigments, perinone pigments, indigo pigments, pyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squalium pigments, and the like. These may be used individually by 1 type and may use 2 or more types together.

-Binder resin-
There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, a polyamide resin, a polyurethane resin, an epoxy resin, a polyketone resin, a polycarbonate resin, a silicone resin, an acrylic resin, a polyvinyl butyral resin, polyvinyl Formal resin, polyvinyl ketone resin, polystyrene resin, polysulfone resin, poly-N-vinyl carbazole resin, polyacrylamide resin, polyvinyl benzal resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene Examples thereof include oxide resins, polyamide resins, polyvinyl pyridine resins, polyvinyl alcohol resins, polyvinyl pyrrolidone resins, cellulose resins, and caseins. These may be used individually by 1 type and may use 2 or more types together.
The content of the binder resin is preferably 500 parts by mass or less, and more preferably 10 parts by mass to 300 parts by mass with respect to 100 parts by mass of the charge generation material.

The charge generation layer is a charge generation layer coating solution obtained by dissolving or dispersing the charge generation material in a solvent together with the binder resin, if necessary, using a dispersion method such as a ball mill, an attritor, a sand mill, or an ultrasonic wave. It can be formed by coating on the support, or undercoat layer or intermediate layer and drying. The binder resin may be added before or after the charge generating material is dispersed.
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose.For example, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, mono Examples include chlorobenzene, cyclohexane, toluene, xylene, ligroin, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, ketone solvents, ester solvents, and ether solvents are particularly preferable.

The charge generation layer coating solution contains the charge generation material, and preferably contains a solvent and a binder resin, but includes any additive such as a sensitizer, a dispersant, a surfactant, and silicone oil as necessary. It may be.
The method for forming the charge generation layer using the charge generation layer coating liquid is not particularly limited and may be appropriately selected depending on the intended purpose. For example, dip coating, spray coating, bead coating, nozzle coating, Examples include spinner coats and ring coats.
There is no restriction | limiting in particular in the average thickness of the said charge generation layer, Although it can select suitably according to the objective, 0.01 micrometer-5 micrometers are preferable, and 0.1 micrometer-2 micrometers are more preferable. After coating, it is heated and dried in an oven or the like. There is no restriction | limiting in particular as a drying temperature of the said charge generation layer, Although it can select suitably according to the objective, 50 to 160 degreeC is preferable.

<< Charge transport layer >>
The charge transport layer contains a charge transport material and a binder resin, and further contains other components as necessary.

-Charge transport layer-
Examples of the charge transport material include a hole transport material and an electron transport material.
The hole transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include poly-N-vinylcarbazole or a derivative thereof, poly-γ-carbazolylethyl glutamate or a derivative thereof, and pyrene. -Formaldehyde condensate or derivative thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivative, oxadiazole derivative, imidazole derivative, monoarylamine derivative, diarylamine derivative, triarylamine derivative, stilbene derivative, α-phenylstilbene derivative, Benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives , Pyrene derivatives, bisstilbene derivatives, enamine derivatives, and the like. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as said electron transport material, According to the objective, it can select suitably, For example, chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1 , 2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, benzoquinone derivatives, and the like. These may be used individually by 1 type and may use 2 or more types together.
The content of the charge transport material is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 20 parts by mass to 300 parts by mass, and 40 parts by mass to 150 parts by mass with respect to 100 parts by mass of the binder resin. Part by mass is more preferable.

-Binder resin-
The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester , Polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate, ethyl cellulose, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly (N-vinyl carbazole) ), Acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, and the like. These may be used individually by 1 type and may use 2 or more types together.

  The charge transport layer is formed by applying a charge transport layer coating solution in which the charge transport material and the binder resin are dissolved or dispersed in a solvent on a charge generation layer, a support, or an undercoat layer, and then drying. It is formed. You may add additives, such as a plasticizer, a leveling agent, antioxidant, a lubricant, to the said charge transport layer coating liquid as needed.

  Examples of the solvent include tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, non-halogen solvents are preferable from the intention of reducing environmental burdens, and cyclic ethers such as tetrahydrofuran, dioxolane, and dioxane; aromatic hydrocarbons such as toluene and xylene, or derivatives thereof are particularly preferable.

The application method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a dip coating method, a spray coating method, a bead coating method, a nozzle coating method, a spinner coating method, and a ring coating method. Can be mentioned. Among these, the dip coating method is preferable because the charge transport layer needs to be thickened to some extent.
The formed charge transport layer is heated and dried by a heating means such as an oven. There is no restriction | limiting in particular in drying temperature, Although it can select suitably according to the objective, 80 to 200 degreeC is preferable and 110 to 170 degreeC is more preferable. There is no restriction | limiting in particular in drying time, Although it can select suitably according to the objective, 10 minutes or more are preferable and 20 minutes or more are more preferable.
The average thickness of the charge transport layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 μm to 50 μm, more preferably 15 μm to 35 μm from the viewpoint of resolution and responsiveness.

<Single layer photosensitive layer>
The photosensitive layer having a single layer structure is a photosensitive layer in which a charge generation material and a charge transport material are dispersed or dissolved in a binder resin to realize a charge generation function and a charge transport function in one layer.
As the charge generation material, the main diffraction at 6.8 ° and 15.4 ° of the Bragg angle (2θ ± 0.3 °) in the X-ray diffraction spectrum by CuKα ray, which is the hydroxygallium phthalocyanine crystal of the present invention. A hydroxygallium phthalocyanine crystal exhibiting a peak is used.

As for the charge transport material, binder resin, solvent and various additives used for the photosensitive layer having the single layer structure, any material contained in the charge generation layer and the charge transport layer can be used. is there.
The charge transport material preferably contains both the hole transport material and the electron transport material. A plasticizer, a leveling agent, an antioxidant and the like can be added as necessary.
As the binder resin, in addition to the binder resin mentioned in the charge transport layer, the binder resin mentioned in the charge generation layer may be mixed and used. The content of the charge generating material with respect to 100 parts by mass of the binder resin is not particularly limited and can be appropriately selected according to the purpose, but is preferably 5 parts by mass to 40 parts by mass, and 10 parts by mass to 30 parts by mass. More preferred. The content of the charge transport material is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0 part by mass to 190 parts by mass, and more preferably 50 parts by mass to 150 parts by mass.

The photosensitive layer having the single layer structure comprises a coating solution obtained by dissolving or dispersing the charge generation material, the charge transport material, and the binder resin in a solvent such as tetrahydrofuran, dioxane, dichloroethane, methyl ethyl ketone, cyclohexane, cyclohexanone, toluene, xylene. It can be formed by coating using a dip coating method, spray coating, bead coating, ring coating or the like.
There is no restriction | limiting in particular in the average thickness of the photosensitive layer of the said single layer structure, Although it can select suitably according to the objective, 5 micrometers-40 micrometers are preferable, and 10 micrometers-30 micrometers are more preferable.

<< undercoat layer >>
In the electrophotographic photoreceptor of the present invention, an undercoat layer can be provided between the support and the photosensitive layer.
The undercoat layer has a resin as a main component. The resin is preferably a resin having high solvent resistance against a general organic solvent in consideration of applying a photosensitive layer on the undercoat layer using a solvent. Examples of the resin include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate; alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon; polyurethane, melamine resin, phenol resin, alkyd-melamine resin, isocyanate And curable resins that form a three-dimensional network structure, such as epoxy resins.
The undercoat layer may contain fine powder pigments of metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide in order to prevent moire and reduce residual potential.
The undercoat layer may further contain a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like, if necessary.
The undercoat layer can be formed using a solvent and a coating method, similarly to the charge generation layer and the charge transport layer.

<< Protective layer >>
In the electrophotographic photosensitive member of the present invention, a protective layer can be provided on the outermost surface in order to improve wear resistance. Examples of the protective layer include a polymer charge transport material type obtained by polymerizing a charge transport component and a binder component, a filler dispersion type containing a filler, and a curable type obtained by curing a constituent material having a reactive functional group. is there.

<< Intermediate layer >>
In the electrophotographic photoreceptor of the present invention, an intermediate layer may be provided on the support, if necessary. The intermediate layer has a resin as a main component, and these resins are preferably resins having a high solvent resistance with respect to the solvent in view of applying the photosensitive layer thereon with a solvent. As the resin, the same resin as the undercoat layer can be appropriately selected and used.

  In the electrophotographic photosensitive member, in order to improve environmental resistance, in particular, for the purpose of preventing a decrease in sensitivity and an increase in residual potential, oxidation is performed on each layer such as a charge generation layer, a charge transport layer, an undercoat layer and a protective layer. Inhibitors, plasticizers, lubricants, ultraviolet absorbers, low molecular charge transport materials, leveling agents, and the like can be added.

Here, the layer structure of the electrophotographic photosensitive member will be described with reference to the drawings.
As shown in FIG. 1, an electrophotographic photosensitive member 201 of the present invention has a Bragg angle (2θ) in an X-ray diffraction spectrum by CuKα rays, which is the hydroxygallium phthalocyanine crystal of the present invention as a charge generation material on a support 202. A structure in which a charge generation layer 203 including a hydroxygallium phthalocyanine crystal having main diffraction peaks at 6.8 ° and 15.4 ° and a charge transport layer 204 containing a charge transport material are stacked. I am doing.
In the electrophotographic photosensitive member 201 of the present invention, an undercoat layer 206 or an intermediate layer may be formed between the support 202 and the charge generation layer 203 as shown in FIG.
In the electrophotographic photoreceptor 201 of the present invention, a protective layer 205 may be formed on the charge transport layer 204 as shown in FIG.
Further, as shown in FIG. 4, the electrophotographic photosensitive member 201 of the present invention has a Bragg angle in an X-ray diffraction spectrum by CuKα rays, which is the hydroxygallium phthalocyanine crystal of the present invention as a charge generation material on a support 202. (2θ ± 0.3 °) is a layer configuration including a hydroxygallium phthalocyanine crystal showing main diffraction peaks at 6.8 ° and 15.4 ° and a photosensitive layer 207 having a single-layer structure containing a charge transporting material. Also good.

<Process cartridge>
The process cartridge used in the present invention includes an electrophotographic photosensitive member, a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member using toner, and forms a visible image, a charging unit, and a cleaning unit. And at least one means selected from a transfer means and a static elimination means, and is detachable from the image forming apparatus main body.
As the electrophotographic photoreceptor, the electrophotographic photoreceptor of the present invention is used.
The process cartridge includes the electrophotographic photosensitive member of the present invention, and further includes at least one of a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit, and an image forming apparatus. It is a device (part) that is detachably attachable.

Here, FIG. 5 shows an example of a process cartridge used in the present invention.
For example, as shown in FIG. 5, the process cartridge includes an electrophotographic photosensitive member 101 and includes a charging unit 112, a developing unit 114, a transfer unit 118, and a cleaning unit 123. In FIG. 5, reference numeral 113 denotes exposure from the exposure means, and 117 denotes a recording medium. As the electrophotographic photosensitive member 101, the electrophotographic photosensitive member of the present invention is used.

  Next, the image forming process using the process cartridge shown in FIG. 5 will be described. The electrophotographic photosensitive member 101 is rotated while being charged by the charging unit 112 and exposed by the exposure unit (not shown) 113 so that an exposure image is formed on the surface. An electrostatic latent image corresponding to is formed. The electrostatic latent image is developed with toner by the developing unit 114, and the toner development is transferred to the recording medium 117 by the transfer unit 118 and printed out. Next, the surface of the electrophotographic photosensitive member 101 after the transfer is cleaned by the cleaning unit 123 and further discharged by the charge removing unit (not shown), and the above operation is repeated again.

<Image Forming Apparatus and Image Forming Method>
The image forming apparatus used in the present invention includes at least an electrophotographic photosensitive member, an electrostatic latent image forming unit, a developing unit, and a transfer unit, and other units appropriately selected as necessary. For example, the image forming apparatus includes a fixing unit, a discharging unit, a cleaning unit, a recycling unit, a control unit, and the like.
As the electrophotographic photoreceptor, the electrophotographic photoreceptor of the present invention is used.
The image forming method used in the present invention includes at least an electrostatic latent image forming step, a developing step, and a transfer step, and other steps appropriately selected as necessary, for example, a fixing step, a charge eliminating step, and a cleaning step. , Including recycling process, control process, etc.

  The image forming method used in the present invention can be suitably implemented by the image forming apparatus used in the present invention, and the electrostatic latent image forming step can be performed by the electrostatic latent image forming unit, and the development The step can be performed by the developing unit, the transfer step can be performed by the transfer unit, and the other steps can be performed by the other unit.

<Electrostatic latent image forming step and electrostatic latent image forming means>
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrophotographic photosensitive member.
The electrophotographic photoreceptor of the present invention is used as the electrophotographic photoreceptor (sometimes referred to as “electrostatic latent image carrier” or “photoreceptor”).

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrophotographic photosensitive member and then performing imagewise exposure, and can be performed by the electrostatic latent image forming unit. .
The electrostatic latent image forming means includes at least a charger that uniformly charges the surface of the electrophotographic photosensitive member and an exposure device that exposes the surface of the electrophotographic photosensitive member imagewise.

The charging can be performed, for example, by applying a voltage to the surface of the electrophotographic photosensitive member using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roller, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.

The shape of the charging means may take any form such as a magnetic brush or a fur brush in addition to a roller, and can be selected according to the specifications and form of the image forming apparatus. When using a magnetic brush, the magnetic brush is composed of, for example, various ferrite particles such as Zn-Cu ferrite as a charging means, a non-magnetic conductive sleeve for supporting it, and a magnet roll included therein. . Or, when using a brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound or attached to a metal or other conductive core. To make a charger.
The charger is not limited to the contact charger as described above. However, since an image forming apparatus in which ozone generated from the charger is reduced is obtained, a contact charger is used. preferable.

The exposure can be performed, for example, by exposing the surface of the electrophotographic photosensitive member imagewise using the exposure device.
The exposure device is not particularly limited as long as the surface of the electrophotographic photosensitive member charged by the charger can be exposed like an image to be formed, and can be appropriately selected according to the purpose. However, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, an optical backside system that performs imagewise exposure from the backside of the electrophotographic photosensitive member may be employed.

<Development process and development means>
The developing step is a step of developing the electrostatic latent image using the toner or developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, the toner or developer is accommodated. Preferred examples include those having at least a developing unit capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrophotographic photosensitive member, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted to the electrophotographic photosensitive member. Move to the surface of the body. As a result, the electrostatic latent image is developed with the toner to form a visible image with the toner on the surface of the electrophotographic photosensitive member.

  The developer accommodated in the developing device is a developer containing the toner, but the developer may be a one-component developer or a two-component developer.

<Transfer process and transfer means>
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the electrophotographic photosensitive member with the transfer charger using the visible image, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer unit (the primary transfer unit and the secondary transfer unit) includes at least a transfer unit that peels and charges the visible image formed on the electrophotographic photosensitive member toward the recording medium. preferable. There may be one transfer means or two or more transfer means. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. PET for OHP A base or the like can also be used.

<Other processes and other means>
-Fixing process and fixing means-
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing unit, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose, but a known heating and pressing unit is preferable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

-Static elimination process and static elimination means-
The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrophotographic photosensitive member, and can be suitably performed by a neutralization unit.
The neutralizing means is not particularly limited and may be appropriately selected from known neutralizers as long as it can apply a neutralizing bias to the electrophotographic photosensitive member. For example, a neutralizing lamp is preferably used. Can be mentioned.

-Cleaning process and cleaning means-
The cleaning step is a step of removing the toner remaining on the electrophotographic photosensitive member, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as the toner remaining on the electrophotographic photosensitive member can be removed, and can be appropriately selected from known cleaners. For example, a magnetic brush cleaner, a static cleaner Preferred examples include an electric brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

-Recycling process and recycling means-
The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

-Control process and control means-
The control step is a step of controlling each of the steps, and can be suitably performed by a control unit.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

Next, the image forming method and the image forming apparatus used in the present invention will be described in detail with reference to the drawings.
FIG. 6 is a schematic view showing an example of an image forming apparatus used in the present invention.
In the image forming apparatus of FIG. 6, the electrophotographic photosensitive member 1 has a drum shape, but may be a sheet shape or an endless belt shape.
As the charging roller 12, the transfer charger 18, and the separation charger 19, in addition to a corotron, a scorotron, a solid state charger (solid state charger), a roller-shaped charging unit or a brush-shaped charging unit is used. All means can be used.

As the charging means, a non-contact charging system such as corona charging or a contact charging system using a charging means using a roller or a brush is generally used, and any of them can be used effectively in the present invention. In particular, the charging roller 12 can significantly reduce the amount of ozone generated compared to corotron, scorotron, and the like, and is effective in stability during repeated use of the photoreceptor and prevention of image quality deterioration.
However, since the electrophotographic photosensitive member 1 and the charging roller 12 are in contact with each other, the charging roller is contaminated by repeated use, which affects the photosensitive member and promotes the generation of abnormal images and a decrease in wear resistance. It is a cause. In particular, when a photoconductor having high wear resistance is used, it is difficult to perform reface due to surface wear, and therefore it is necessary to reduce the contamination of the charging roller.

Therefore, as shown in FIG. 7, by providing gap forming members 12a at both ends of the charging roller 12 and disposing them close to each other through the gap with respect to the photosensitive member 1, contaminants are difficult to adhere to the charging roller 12, Or it becomes easy to remove and it is possible to reduce the influence.
In this case, the gap between the electrophotographic photosensitive member 1 and the charging roller 12 is preferably small, for example, 100 μm or less is preferable, and 50 μm or less is more preferable.
However, by making the charging roller non-contact, discharge may become non-uniform and charging of the photoreceptor may become unstable. Such a problem is caused by maintaining the charging stability by superimposing the alternating current component on the direct current component, thereby making it possible to simultaneously reduce the influence of ozone, the charging roller contamination and the charging effect. .

Examples of light sources such as the exposure unit 13 and the charge removal lamp 11 shown in FIG. 6 include a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). All luminescent materials such as can be used. Among these, a semiconductor laser (LD) and a light emitting diode (LED) are preferable.
Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
The light source or the like provides the electrophotographic photosensitive member 1 with light by providing a transfer step, a static elimination step, a cleaning step, or a pre-exposure step using light irradiation together. However, the exposure of the electrophotographic photosensitive member 1 in the static elimination process has a great influence of fatigue on the electrophotographic photosensitive member 1, and may cause a decrease in charging or an increase in residual potential. Therefore, there is a case where it is possible to eliminate static electricity by applying a reverse bias in the charging process or cleaning process instead of static elimination by exposure, which may be effective from the viewpoint of enhancing the durability of the photoreceptor.

When the electrophotographic photoreceptor 1 is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photoreceptor. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.
As the transfer means, the above-described charger can be generally used. However, as shown in FIG. 6, a combination of the transfer charger 18 and the separation charger 19 is effective.
Further, the toner image is directly transferred from the electrophotographic photosensitive member 1 to paper using such a transfer unit. In the present invention, the toner image on the photosensitive member is transferred to the intermediate transfer member, and then the intermediate transfer member. The intermediate transfer method for transferring the toner to the paper is more preferable from the viewpoints of high durability and high image quality of the photoreceptor.
Among contaminants adhering to the surface of the photoconductor, discharge substances generated by charging, external additives contained in the toner, etc. easily pick up the influence of humidity and cause abnormal images. Paper dust is one of the causative substances of such abnormal images, and when they adhere to the photoconductor, not only abnormal images are likely to be generated, but also the wear resistance is reduced or biased. There is a tendency to cause wear. Therefore, it is more preferable from the viewpoint of high image quality that the photoconductor and the paper are not in direct contact for the above reason.

  The intermediate transfer method is particularly effective for image forming apparatuses capable of full-color printing, and controls the prevention of color misregistration by forming a plurality of toner images on the intermediate transfer member and then transferring them to the paper at once. It is easy and effective for high image quality. However, the intermediate transfer method requires four scans to obtain one full-color image, so that the durability of the photoconductor is a serious problem. Since the image blur hardly occurs even without a drum heater, the photoconductor is easy to use in combination with an intermediate transfer type image forming apparatus, and is particularly effective and useful. The intermediate transfer member includes various materials or shapes such as a drum shape and a belt shape. In the present invention, any conventionally known intermediate transfer member can be used. Effective and useful for durability or high image quality.

The toner developed on the electrophotographic photosensitive member 1 by the developing means 14 shown in FIG. 6 is transferred to the recording medium 17, but not all is transferred, and the toner remaining on the electrophotographic photosensitive member 1 is not transferred. Also occurs.
Such residual toner is removed from the electrophotographic photosensitive member 1 by the cleaning brush 22 or the cleaning blade 23. The cleaning process may be performed only with a cleaning brush or may be performed in combination with a cleaning blade. As the cleaning brush, known ones such as a fur brush and a mag fur brush are used. As described above, the cleaning is a process of removing toner remaining on the electrophotographic photosensitive member 1 after the transfer. However, when the electrophotographic photosensitive member 1 is repeatedly rubbed by the cleaning blade 23 or the cleaning brush 22, Abnormal images may occur due to accelerated wear or scratches on the photographic photoreceptor 1.
Further, if the surface of the photoconductor is contaminated due to poor cleaning, it will not only cause an abnormal image, but also significantly reduce the life of the photoconductor. In particular, in the case of an electrophotographic photosensitive member provided with a protective layer as the outermost surface layer for improving wear resistance, it is difficult to remove contaminants adhering to the surface of the photosensitive member. Will be promoted. Therefore, improving the cleaning property of the electrophotographic photoreceptor 1 is very effective for improving the durability and image quality of the photoreceptor.

  As a means for improving the cleaning property of the electrophotographic photosensitive member 1, a method for reducing the coefficient of friction on the surface of the photosensitive member is known. Methods for reducing the coefficient of friction on the surface of the photoreceptor are classified into a method in which various lubricants are contained in the photoreceptor surface and a method in which the lubricant is supplied to the photoreceptor surface from the outside. The former is advantageous for small-diameter photoreceptors because of the high degree of freedom in layout around the engine, but the coefficient of friction increases remarkably with repeated use, and there remains a problem in its sustainability. On the other hand, the latter needs to be provided with a component for supplying a lubricating substance, but is effective for enhancing the durability of the photoreceptor because of high stability of the friction coefficient. Among them, the method of adhering to the photoreceptor during development by incorporating a lubricant into the developer is not restricted by the layout around the engine, and the effect of reducing the friction coefficient on the photoreceptor surface is high. Therefore, it is a very effective means for improving the durability and image quality of the photoreceptor.

  Examples of the lubricating substances include lubricating liquids such as silicone oil and fluorine oil, various fluorine-containing resins such as PTFE, PFA, and PVDF, silicone resins, polyolefin resins, silicone grease, fluorine grease, paraffin wax, and fatty acid esters. And fatty acid metal salts such as zinc stearate, lubricating liquids such as graphite and molybdenum disulfide, solids, powders, and the like. Among these, when mixed with a developer, it needs to be in a powder form, and zinc stearate has little adverse effect and can be used very effectively. When the zinc stearate powder is contained in the toner, it is necessary to consider the balance and the influence on the toner, and the content is preferably 0.01% by mass to 0.5% by mass with respect to the toner. 1 mass%-0.3 mass% is more preferable.

  The electrophotographic photosensitive member of the present invention can be applied to a small-diameter photosensitive member because it realizes high photosensitivity and high stability. An image forming apparatus in which the photosensitive member is used more effectively, or a method thereof, includes a plurality of corresponding photosensitive members for each developing unit corresponding to a plurality of color toners, thereby performing parallel processing. In other words, it is very effectively used in a so-called tandem image forming apparatus. The tandem image forming apparatus includes at least four color toners of yellow (C), magenta (M), cyan (C), and black (K) required for full-color printing and a developing unit that holds them. Further, by providing at least four photoconductors corresponding to them, full-color printing can be performed at a very high speed as compared with a conventional image forming apparatus capable of full-color printing.

Here, FIG. 8 is a schematic diagram showing an example of a tandem full-color electrophotographic apparatus used in the present invention.
In FIG. 8, photoconductors 1C (cyan), 1M (magenta), 1Y (yellow), and 1K (black) are drum-like photoconductors, and these photoconductors 1C, 1M, 1Y, and 1K are shown in FIG. The charging means 12C, 12M, 12Y, and 12K, the developing means 14C, 14M, 14Y, and 14K, and the cleaning means 15C, 15M, 15Y, and 15K are arranged at least in the order of rotation.

  The charging means 12C, 12M, 12Y, and 12K constitute a charging means for uniformly charging the surface of the photoreceptor 1. Laser beams 13C, 13M, 13Y, and 13K from an exposure unit (not shown) are irradiated from the back side of the photoreceptor between the charging units 12C, 12M, 12Y, and 12K and the developing units 14C, 14M, 14Y, and 14K. Thus, electrostatic latent images are formed on the photoreceptors 1C, 1M, 1Y, and 1K.

  Then, four image forming elements 10C, 10M, 10Y, and 10K centering on the photoreceptors 1C, 1M, 1Y, and 1K are juxtaposed along a conveyance belt 25 that is a recording medium conveyance unit. The conveyor belt 25 is provided between the developing units 14C, 14M, 14Y, and 14K of the image forming units (elements) 10C, 10M, 10Y, and 10K and the cleaning units 15C, 15M, 15Y, and 15K, and the photoreceptors 1C, 1M, and 15K. Transfer brushes 26 </ b> C, 26 </ b> M, 26 </ b> Y, and 26 </ b> K for applying a transfer bias are disposed on a surface (back surface) that is in contact with 1 </ b> Y and 1 </ b> K and that contacts the back side of the conveyance belt 25 on the photoconductor side. Each of the image forming elements 10C, 10M, 10Y, and 10K is different in the color of the toner inside the developing unit, and the rest is the same in configuration.

  In the color electrophotographic image forming apparatus having the configuration shown in FIG. 8, the image forming operation is performed as follows. First, in each of the image forming elements 10C, 10M, 10Y, and 10K, the photoreceptors 1C, 1M, 1Y, and 1K are charged by the charging units 12C, 12M, 12Y, and 12K that rotate in the direction of the arrow (the direction along with the photoreceptor). Next, an electrostatic latent image corresponding to each color image to be created is formed by laser beams 13C, 13M, 13Y, and 13K by exposure means (not shown) arranged outside the photoconductor.

  Next, the latent image is developed by the developing means 14C, 14M, 14Y, and 14K to form a toner image. Developing means 14C, 14M, 14Y, and 14K are developing means for developing with toners of C (cyan), M (magenta), Y (yellow), and K (black), respectively, and the four photosensitive members 1C, 1M, and 1Y. , 1K toner images are superimposed on the recording medium. The recording medium 17 is sent out from the tray by a paper feed roller 24, temporarily stopped by a pair of registration rollers 16, and sent to the transfer conveyance belt 25 in synchronism with the image formation on the photosensitive member. The recording medium 17 held on the conveyor belt 25 is conveyed, and the toner images of each color are transferred at the contact positions (transfer portions) with the photoreceptors 1C, 1M, 1Y, 1K.

The toner image on the photosensitive member is transferred onto the recording medium 17 by an electric field formed by a potential difference between the transfer bias applied to the transfer brushes 26C, 26M, 26Y, and 26K and the photosensitive members 1C, 1M, 1Y, and 1K. The Then, the recording medium 17 on which the four color toner images are superimposed through the four transfer portions is conveyed to the fixing means 27, where the toner is fixed, and is discharged to a discharge portion (not shown). Further, the residual toner that remains on the photoreceptors 1C, 1M, 1Y, and 1K without being transferred by the transfer unit is collected by the cleaning units 15C, 15M, 15Y, and 15K.
In the example of FIG. 8, the image forming elements are arranged in the order of C (cyan), M (magenta), Y (yellow), and K (black) from the upstream side to the downstream side in the recording medium conveyance direction. However, it is not limited to this order, and the color order is arbitrarily set. In addition, when a black-only document is created, it is particularly effective to use the present invention to provide a mechanism that stops the image forming elements 10C, 10M, and 10Y other than black.

Further, in FIG. 8, the charging means is in contact with the photosensitive member. However, by using a charging mechanism as shown in FIG. 7, an appropriate gap (about 10 μm to 200 μm) is provided between the two. The amount of wear of the toner can be reduced and toner filming on the charging means can be reduced so that it can be used satisfactorily.
The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge.

Since the tandem image forming apparatus can transfer a plurality of toner images at a time, high-speed full-color printing is realized. However, since at least four photoconductors are required, an increase in the size of the image forming apparatus is unavoidable, and depending on the amount of toner used, there is a difference in the amount of wear of each photoconductor, thereby causing the color to change. There are many problems such as a decrease in reproducibility of images and occurrence of abnormal images.
On the other hand, the electrophotographic photoreceptor of the present invention can be applied to a small-diameter photoreceptor by realizing high photosensitivity and high stability, and the influence of increase in residual potential, sensitivity deterioration, etc. is reduced. Even if the amounts of the four photoconductors are different, the difference in residual potential and sensitivity over time is small, and it is possible to obtain a full color image with excellent color reproducibility even when used repeatedly over a long period of time. .

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
-Synthesis of hydroxygallium phthalocyanine crystals-
100 parts by mass of dehydrated dimethyl sulfoxide, 25 parts by mass of 1,3-diiminoisoindoline (Tokyo Chemical Industry Co., Ltd.) (0.17 mol), gallium hexafluoroacetylacetonate (manufactured by Yamanaka Futec Co., Ltd.) 28 After adding a mass part (0.04 mol) and making it react at 150 degreeC for 12 hours under argon (Ar) stream, the produced | generated crystal | crystallization was separated by filtration. The obtained wet cake was washed with methyl ethyl ketone and N, N-dimethylformamide and then dried to obtain 10 parts by mass (41.7% by mass) of gallium phthalocyanine crystals.
The obtained gallium phthalocyanine crystal was analyzed as follows. Laser desorption ionization time-of-flight mass spectrum in positive mode (manufactured by autoflex speed Bruker Daltonics KK, hereinafter referred to as “LDI-TOF-MS (positive)”), m / z: 598.07 (theoretical value is 599.078: C ₃₂ H ₁₇ GaN ₈ O). In addition, elemental analysis was performed using a CHN coder MT-5 type manufactured by Yanaco Analytical Industries. The results are shown in Table 1.

From these results, it was confirmed that the obtained crystal was a hydroxygallium phthalocyanine crystal.
Furthermore, the powder X-ray diffraction spectrum of the obtained hydroxygallium phthalocyanine crystal was measured under the following conditions. The powder X-ray diffraction spectrum is shown in FIG.
・ Measurement device: RINT-TTRIII type wide-angle X-ray diffractometer manufactured by Rigaku Corporation ・ X-ray tube: Cu (wavelength 1.54 mm)
・ Voltage: 50kV
・ Current: 30mA
Scanning speed: 2 deg / min
Scan range: 2 deg to 35 deg
・ Time constant: 2 sec
From the powder X-ray diffraction spectrum of FIG. 9 obtained, a hydroxygallium phthalocyanine crystal having main diffraction peaks at 6.8 ° and 15.4 ° within the Bragg angle (2θ ± 0.3 °) was obtained. It was confirmed. In addition, diffraction peaks are also observed at 7.4 °, 7.7 °, and 26.2 ° out of the Bragg angle (2θ ± 0.3 °), and 6 out of the Bragg angle (2θ ± 0.3 °). It was confirmed that a hydroxygallium phthalocyanine crystal showing the strongest diffraction peak at 8 ° was obtained.

(Example 2)
-Synthesis of hydroxygallium phthalocyanine crystals-
100 parts by mass of chlorobenzene, 3.87 parts by mass of 1,3-diiminoisoindoline (manufactured by Tokyo Chemical Industry Co., Ltd.) (0.027 mol), and 28 parts by mass of gallium hexafluoroacetylacetonate (manufactured by Yamanaka Futec Co., Ltd.) Part (0.04 mol) was added and reacted under an argon (Ar) stream at 130 ° C. for 12 hours, and then the produced crystals were separated by filtration. The obtained wet cake was washed with methyl ethyl ketone and N, N-dimethylformamide and then dried to obtain 6 parts by mass (24.5% by mass) of gallium phthalocyanine crystals.
The obtained gallium phthalocyanine crystal was subjected to LDI-TOF-MS (positive) in the same manner as in Example 1, m / z: 598.07 (theoretical value was 599.078: C ₃₂ H ₁₇ GaN ₈ O) Admitted. Further, elemental analysis was performed in the same manner as in Example 1. The results are shown in Table 2.

From these results, it was confirmed that the obtained crystal was a hydroxygallium phthalocyanine crystal.
Further, with respect to the obtained hydroxygallium phthalocyanine crystal, a powder X-ray diffraction spectrum was measured in the same manner as in Example 1. The powder X-ray diffraction spectrum is shown in FIG. From the result of FIG. 10, it was found that the same diffraction peak as in Example 1 was exhibited.

(Example 3)
-Synthesis of hydroxygallium phthalocyanine crystals-
100 parts by mass of dehydrated dimethyl sulfoxide, 52 parts by mass (0.36 mol) of 1,3-diiminoisoindoline (manufactured by Tokyo Chemical Industry Co., Ltd.), and gallium hexafluoroacetylacetonate (manufactured by Yamanaka Futec Co., Ltd.) After 28 parts by mass (0.04 mol) was added and reacted at 170 ° C. for 12 hours under a stream of argon (Ar), the produced crystals were separated by filtration. The obtained wet cake was washed with methyl ethyl ketone and N, N-dimethylformamide and then dried to obtain 8 parts by mass (33.5% by mass) of gallium phthalocyanine crystals.
The obtained gallium phthalocyanine crystal was subjected to LDI-TOF-MS (positive) in the same manner as in Example 1, and m / z: 598.08 (theoretical value was 599.078: C ₃₂ H ₁₇ GaN ₈ O). Admitted. Further, elemental analysis was performed in the same manner as in Example 1. The results are shown in Table 3.

From these results, it was confirmed that the obtained crystal was a hydroxygallium phthalocyanine crystal.
Further, with respect to the obtained hydroxygallium phthalocyanine crystal, a powder X-ray diffraction spectrum was measured in the same manner as in Example 1. The powder X-ray diffraction spectrum is shown in FIG. From the result of FIG. 11, it was found that the same diffraction peak as in Example 1 was exhibited.

Example 4
-Synthesis of hydroxygallium phthalocyanine crystals-
100 parts by mass of N, N-dimethylformamide, 2.5 parts by mass of 1,3-diiminoisoindoline (manufactured by Tokyo Chemical Industry Co., Ltd.) (0.017 mol), gallium hexafluoroacetylacetonate (Yamanaka Futec Co., Ltd.) 28 parts by mass (0.04 mol) was added, and the mixture was reacted under an argon (Ar) stream at 150 ° C. for 12 hours, and then the produced crystals were separated by filtration. The obtained wet cake was washed with methyl ethyl ketone and N, N-dimethylformamide and then dried to obtain 5 parts by mass (20.4% by mass) of gallium phthalocyanine crystals.
The obtained gallium phthalocyanine crystal was subjected to LDI-TOF-MS (positive) in the same manner as in Example 1, m / z: 598.07 (theoretical value was 599.078: C ₃₂ H ₁₇ GaN ₈ O) Admitted. Further, elemental analysis was performed in the same manner as in Example 1. The results are shown in Table 4.

From these results, it was confirmed that the obtained crystal was a hydroxygallium phthalocyanine crystal.
Further, with respect to the obtained hydroxygallium phthalocyanine crystal, a powder X-ray diffraction spectrum was measured in the same manner as in Example 1. The powder X-ray diffraction spectrum is shown in FIG. From the results of FIG. 12, it was found that the same diffraction peak as in Example 1 was exhibited.

(Example 5)
-Synthesis of hydroxygallium phthalocyanine crystals-
100 parts by mass of dehydrated dimethyl sulfoxide, 110 parts by mass (0.76 mol) of 1,3-diiminoisoindoline (manufactured by Tokyo Chemical Industry Co., Ltd.), and gallium hexafluoroacetylacetonate (manufactured by Yamanaka Futec Co., Ltd.) 28 parts by mass (0.04 mol) was added, and the mixture was reacted at 150 ° C. for 12 hours under an argon (Ar) stream. The obtained wet cake was washed with methyl ethyl ketone and N, N-dimethylformamide and then dried to obtain 5 parts by mass (20.8% by mass) of gallium phthalocyanine crystals.
The obtained gallium phthalocyanine crystal was subjected to LDI-TOF-MS (positive) in the same manner as in Example 1, m / z: 598.07 (theoretical value was 599.078: C ₃₂ H ₁₇ GaN ₈ O) Admitted. Further, elemental analysis was performed in the same manner as in Example 1. The results are shown in Table 5.

From these results, it was confirmed that the obtained crystal was a hydroxygallium phthalocyanine crystal.
Further, with respect to the obtained hydroxygallium phthalocyanine crystal, a powder X-ray diffraction spectrum was measured in the same manner as in Example 1. The powder X-ray diffraction spectrum is shown in FIG. From the results of FIG. 13, it was found that the same diffraction peak as in Example 1 was exhibited.

(Comparative Example 1)
<Synthesis of hydroxygallium phthalocyanine>
(1) Synthesis of chlorogallium phthalocyanine To 200 parts by mass of dehydrated dimethyl sulfoxide, 30 parts by mass of 1,3-diiminoisoindoline (Tokyo Chemical Industry Co., Ltd.) and 8 parts by mass of gallium trichloride are added, and argon (Ar ) After reacting at 150 ° C. for 12 hours under an air stream, the produced chlorogallium phthalocyanine was separated by filtration. This wet cake was washed with methyl ethyl ketone and N, N-dimethylformamide and then dried to obtain 22 parts by mass (70.3% by mass) of chlorogallium phthalocyanine crystals.

(2) Acid paste of chlorogallium phthalocyanine Next, 5 parts by mass of the obtained chlorogallium phthalocyanine is dissolved in 150 parts by mass of ice-cooled concentrated sulfuric acid, and this sulfuric acid solution is gradually added to 500 parts by mass of ice-cooled ion-exchanged water. Crystals of hydroxygallium phthalocyanine were precipitated by dropping. After the crystals were filtered off, the obtained wet cake was washed with 500 parts by mass of 2% by mass of ammonia water, and then sufficiently washed with ion-exchanged water. By drying, 4.6 parts by mass of hydroxygallium phthalocyanine crystal was obtained.

Next, with respect to the obtained hydroxygallium phthalocyanine crystal, a powder X-ray diffraction spectrum was measured in the same manner as in Example 1. The powder X-ray diffraction spectrum is shown in FIG.
From the powder X-ray diffraction spectrum of FIG. 14, the Bragg angle (2θ ± 0.3 °) 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 °, It was confirmed that a hydroxygallium phthalocyanine crystal having a main diffraction peak at 28.3 ° was obtained.

(Comparative Example 2)
As Comparative Example 2, Y-type titanyl phthalocyanine (manufactured by Toyo Ink Manufacturing Co., Ltd., Riophoton-TOPA) was prepared.
For Y-type titanyl phthalocyanine, a powder X-ray diffraction spectrum was measured in the same manner as in Example 1. The powder X-ray diffraction spectrum is shown in FIG.
From the powder X-ray diffraction spectrum of FIG. 15, it was confirmed that main diffraction peaks were exhibited at Bragg angles (2θ ± 0.3 °) of 9.5 ° and 27.2 °.

(Example 6)
<Production of electrophotographic photoreceptor>
As a support, on an aluminum plate having a thickness of 2 mm (for evaluation of electrophotographic characteristics), and on a length of 380 mm and a diameter of 100 mm on an aluminum cylinder (for evaluation of an actual machine), each was applied using an intermediate layer coating solution having the following composition. Drying was performed at 130 ° C. for 20 minutes to form an intermediate layer having a thickness of 3.5 μm.
Next, the charge generation layer coating solution having the following composition is subjected to vibration mill dispersion for 6 hours together with zirconia balls having a diameter of 2 mm, and the prepared charge generation layer coating solution is applied onto the intermediate layer, followed by drying at 100 ° C. for 30 minutes. Then, a charge generation layer having a thickness of 0.3 μm was formed.
Next, a charge transport layer coating solution having the following composition was applied on the charge generation layer, and then dried at 130 ° C. for 20 minutes to form a charge transport layer having a thickness of 35 μm. Thus, an electrophotographic photosensitive member of Example 6 was produced.
Each coating solution was applied by a blade coating method (for electrophotographic characteristic evaluation) and a dip coating method (for actual machine evaluation).

[Composition of intermediate layer coating solution]
Titanium oxide (CR-EL, manufactured by Ishihara Sangyo Co., Ltd.) ... 50 parts by mass Alkyd resin (Beckolite M6401-50, solid content 50% by mass, manufactured by DIC Corporation) 15 parts by mass Melamine resin (L-145-60, solid content 60% by mass, manufactured by DIC Corporation) 8 parts by mass 2-butanone 120 parts by mass

[Composition of charge generation layer coating solution]
-Hydroxygallium phthalocyanine crystal of Example 1 ... 3 parts by mass-Polyvinyl butyral ("XYHL", manufactured by UCC) ... 2 parts by mass-Methyl ethyl ketone ... 150 parts by mass

[Composition of charge transport layer coating solution]
Polycarbonate (Z Polyca, Teijin Chemicals Ltd., Panlite TS-2050) ... 10 parts by mass Charge-transporting compound represented by the following structural formula: 7 parts by mass
・ Tetrahydrofuran ... 80 parts by mass Silicone oil (KF50-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.) ... 0.002 parts by mass

(Example 7)
-Production of electrophotographic photoreceptor-
In Example 6, the electrophotography of Example 7 was performed in the same manner as in Example 6 except that the hydroxygallium phthalocyanine crystal of Example 1 in the charge generation layer coating solution was replaced with the hydroxygallium phthalocyanine crystal of Example 2. A photoconductor was prepared.

(Example 8)
-Production of electrophotographic photoreceptor-
The electrophotography of Example 8 was carried out in the same manner as in Example 6 except that the hydroxygallium phthalocyanine crystal of Example 1 in the charge generation layer coating solution was replaced with the hydroxygallium phthalocyanine crystal of Example 3. A photoconductor was prepared.

Example 9
-Production of electrophotographic photoreceptor-
The electrophotography of Example 9 was performed in the same manner as in Example 6 except that the hydroxygallium phthalocyanine crystal of Example 1 in the charge generation layer coating solution was replaced with the hydroxygallium phthalocyanine crystal of Example 4. A photoconductor was prepared.

(Example 10)
-Production of electrophotographic photoreceptor-
The electrophotography of Example 10 was performed in the same manner as in Example 6 except that the hydroxygallium phthalocyanine crystal of Example 1 in the charge generation layer coating solution was replaced with the hydroxygallium phthalocyanine crystal of Example 5. A photoconductor was prepared.

(Comparative Example 3)
-Production of electrophotographic photoreceptor-
In Example 6, the hydroxygallium phthalocyanine crystal of Example 1 in the charge generation layer coating solution was replaced with the hydroxygallium phthalocyanine crystal obtained by the acid paste method of Comparative Example 1 in the same manner as in Example 6. Then, an electrophotographic photoreceptor of Comparative Example 3 was produced.

(Comparative Example 4)
-Production of electrophotographic photoreceptor-
In Example 6, except that the hydroxygallium phthalocyanine crystal of Example 1 in the charge generation layer coating solution was replaced with Y-type titanyl phthalocyanine of Comparative Example 2 (Ryophoton-TOPA, manufactured by Toyo Ink Manufacturing Co., Ltd.). In the same manner as in Example 6, an electrophotographic photoreceptor of Comparative Example 4 was produced.

  Next, for the produced electrophotographic photosensitive members of Examples 6 to 10 and Comparative Examples 3 to 4, electrophotographic characteristic evaluation and actual machine evaluation were performed as follows.

<Evaluation of electrophotographic characteristics>
Using the produced electrophotographic photoreceptors for evaluating the electrophotographic characteristics of Examples 6 to 10 and Comparative Examples 3 to 4, the electrophotographic characteristics were evaluated as follows. The results are shown in Table 6.
Using a commercially available electrostatic charge test device (manufactured by Kawaguchi Electric Manufacturing Co., Ltd., EPA8100 type), the surface potential Vm (-V) of the electrophotographic photosensitive member is charged after performing a -5 kV corona discharge for 20 seconds in the dark. It was measured. Further, after being left in a dark place for 20 seconds, the surface potential V30 (−V) of the electrophotographic photosensitive member was measured after irradiating with 780 nm monochromatic light having an amount of light of 5 μW / cm ^{2 on} the surface of the electrophotographic photosensitive member for 30 seconds. . Further, the exposure amount required for halving V0 (the surface potential of the electrophotographic photosensitive member immediately before irradiation with the monochromatic light) as sensitivity was measured as E1 / 2 (μJ / cm ² ). Note that a larger Vm indicates better chargeability. A smaller V30 indicates that the electrophotographic photoreceptor characteristics are better. The smaller E1 / 2 is, the smaller the electrophotographic photoreceptor characteristics are.

<Evaluation of actual machine>
The produced electrophotographic photoreceptors for actual device evaluation of Examples 6 to 10 and Comparative Examples 3 to 4 were mounted on a process cartridge and mounted on an image forming apparatus (RICOH Pro C900, manufactured by Ricoh Co., Ltd., production printer).
As the process conditions during the test, the applied voltage to the charging means was set so that the charged potential of the unexposed area was −800V. The development bias was set to -500V. As a sheet passing condition, 400,000 sheets of charts in which characters having an image area ratio equivalent to 6% were written on the entire A4 size were printed.
As test environments, normal temperature and normal humidity environment (temperature: 23 ° C., relative humidity: 55%), high temperature and high humidity environment (temperature: 30 ° C., relative humidity: 80%), and low temperature and low humidity environment (temperature: 10 ° C., The same printing test was performed under three environmental conditions (relative humidity: 15%).
In the image evaluation, after 400,000 images are printed, the voltage applied to the charging unit is set so that the charging potential of the unexposed portion becomes −700 V, and the voltage applied to the transfer unit is set so that the transfer current is 90 μA. The A4 size chart in which the character portion and the halftone portion shown in FIG. 16 are mixed is output. For the output image in each test environment, the degree of afterimage in the halftone portion was evaluated as follows. The results are shown in Table 7.

<< Degree of afterimage in halftone part of output image >>
The degree of afterimage in the halftone portion of the output image was visually evaluated in the following three stages.
〔Evaluation criteria〕
○: Good △: Slightly inferior ×: Inferior

The aspect of the present invention is as follows.
<1> In an X-ray diffraction spectrum using CuKα characteristic X-rays, hydroxy is characterized by showing main diffraction peaks at 6.8 ° and 15.4 ° out of Bragg angles (2θ ± 0.3 °). Gallium phthalocyanine crystal.
<2> In an X-ray diffraction spectrum using CuKα characteristic X-rays, 6.8 °, 7.4 °, 7.7 °, 15.4 ° and 26 of Bragg angles (2θ ± 0.3 °) The hydroxygallium phthalocyanine crystal according to <1>, which exhibits a diffraction peak at 2 °.
<3> In the X-ray diffraction spectrum using CuKα characteristic X-ray, any one of <1> to <2> showing the strongest diffraction peak at 6.8 ° out of Bragg angles (2θ ± 0.3 °) It is a hydroxygallium phthalocyanine crystal according to the above.
<4> The method for producing a hydroxygallium phthalocyanine crystal according to any one of <1> to <3>,
A method for producing a hydroxygallium phthalocyanine crystal, comprising reacting 1,3-diiminoisoindoline and gallium hexafluoroacetylacetonate in an organic solvent.
<5> The <4>, wherein the molar ratio (A: B) of the 1,3-diiminoisoindoline (A) to the gallium hexafluoroacetylacetonate (B) is 40:60 to 90:10. The method for producing a hydroxygallium phthalocyanine crystal as described in 1. above.
<6> The hydroxygallium phthalocyanine crystal according to any one of <4> to <5>, wherein the organic solvent is at least one selected from dehydrated dimethyl sulfoxide, N, N-dimethylformamide, and chlorobenzene. It is a manufacturing method.
<7> A support and at least a photosensitive layer on the support, wherein the photosensitive layer contains the hydroxygallium phthalocyanine crystal according to any one of <1> to <3>. An electrophotographic photoreceptor.
<8> The electrophotographic photosensitive member according to <7>, wherein the photosensitive layer has a laminated structure including a charge generation layer and a charge transport layer.
<9> An electrophotographic photosensitive member, electrostatic latent image forming means for forming an electrostatic latent image on the electrophotographic photosensitive member, and developing the electrostatic latent image with toner to form a visible image. An image forming apparatus having at least developing means and transfer means for transferring the visible image to a recording medium,
An electrophotographic photosensitive member according to any one of <7> to <8>, wherein the electrophotographic photosensitive member is an image forming apparatus.
<10> An electrophotographic photosensitive member, a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member using a toner to form a visible image, a charging unit, a cleaning unit, a transfer unit, and a discharging unit A process cartridge that can be attached to and detached from the image forming apparatus main body.
A process cartridge, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of <7> to <8>.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photosensitive member 1C, 1M, 1Y, 1K Electrophotographic photosensitive member 10C, 10M, 10Y, 10K Image forming element 11 Static elimination lamp 12 Charging roller 12a Gap forming member 12C, 12M, 12Y, 12K Charging means 13 Exposure means 13C, 13M, 13Y, 13K Laser light 14 Developing means 14C, 14M, 14Y, 14K Developing means 15C, 15M, 15Y, 15K Cleaning means 17 Recording medium 22 Cleaning brush 23 Cleaning blade 25 Conveying belt 27 Fixing means 101 Electrophotographic photosensitive member 112 Charging Means 113 Exposure by exposure means 114 Development means 117 Recording medium 118 Transfer means 123 Cleaning means 201 Electrophotographic photosensitive member 202 Support body 203 Charge generation layer 204 Charge transport layer 205 Protective layer 206 Undercoat layer 07 photosensitive layer of single-layer structure

Japanese Patent Laid-Open No. 5-98181 Japanese Patent Laid-Open No. 5-263007 JP 7-53892 A JP 2009-62475 A JP 2003-201414 A Japanese Patent No. 4109865

Claims (8)

  In a X-ray diffraction spectrum using CuKα characteristic X-ray, a hydroxygallium phthalocyanine crystal showing main diffraction peaks at 6.8 ° and 15.4 ° out of Bragg angles (2θ ± 0.3 °) .   In an X-ray diffraction spectrum using CuKα characteristic X-rays, 6.8 °, 7.4 °, 7.7 °, 15.4 ° and 26.2 ° out of Bragg angles (2θ ± 0.3 °) The hydroxygallium phthalocyanine crystal according to claim 1, which shows a diffraction peak.   3. The hydroxygallium according to claim 1, which shows the strongest diffraction peak at 6.8 ° out of the Bragg angle (2θ ± 0.3 °) in an X-ray diffraction spectrum using CuKα characteristic X-ray. Phthalocyanine crystals. A method for producing a hydroxygallium phthalocyanine crystal according to any one of claims 1 to 3,
A method for producing a hydroxygallium phthalocyanine crystal, comprising reacting 1,3-diiminoisoindoline and gallium hexafluoroacetylacetonate in an organic solvent.   5. The hydroxy according to claim 4, wherein a molar ratio (A: B) of the 1,3-diiminoisoindoline (A) to the gallium hexafluoroacetylacetonate (B) is 40:60 to 90:10. Method for producing gallium phthalocyanine crystal.   The method for producing a hydroxygallium phthalocyanine crystal according to any one of claims 4 to 5, wherein the organic solvent is at least one selected from dehydrated dimethyl sulfoxide, N, N-dimethylformamide, and chlorobenzene.   An electrophotographic photoreceptor comprising a support and at least a photosensitive layer on the support, wherein the photosensitive layer contains the hydroxygallium phthalocyanine crystal according to any one of claims 1 to 3.   The electrophotographic photosensitive member according to claim 7, wherein the photosensitive layer has a laminated structure having a charge generation layer and a charge transport layer.