JP2013082783A - Novel hydroxy gallium phthalocyanine crystal, electrophotographic photoreceptor using the same, image forming method, image forming apparatus, and process cartridge for image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a novel hydroxy gallium phthalocyanine crystal not generating image degradation such as afterimages in a long-term repeated use, and achieving stable sensitivity characteristics and charging characteristics; an electrophotographic photoreceptor using the same; an image forming method; an image forming apparatus; and a process cartridge for the image forming apparatus.SOLUTION: The hydroxy gallium phthalocyanine crystal shows a main diffraction peak at a Bragg angle (2θ±0.3°) of 8.0° and 28.0° in an X-ray diffraction spectrum with a CuKα ray.

Description

  The present invention relates to a hydroxygallium phthalocyanine crystal having a novel crystal type, an electrophotographic photoreceptor using the crystal, an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus.

  In recent years, long-wavelength light sources such as semiconductor lasers and LEDs have been mainly used as exposure light sources for laser printers employing an electrophotographic system. The light emission wavelength region of the LD that is most often used in digital recording at present is in the near infrared light region (780 nm), which is longer than the light emission wavelength of LED, 650 nm. For this reason, in addition to the requirements for the electrophotographic photoreceptor, it is desired to have high sensitivity from the visible light region to the near infrared light region. From this point of view, squarylium dyes, triphenylamine trisazo pigments, phthalocyanine pigments (JP-A-48-34189 of Patent Document 1 and JP-A-57-14874 of Patent Document 2), etc. It has been proposed as a photoconductor for use. Phthalocyanine pigments are especially popular as photoconductors for digital recording because they have a photosensitive wavelength range up to a long wavelength range, high photosensitivity, and variations in various characteristics depending on the type of central metal and crystal form. Research has been conducted. Known phthalocyanine pigments exhibiting good sensitivity are ε-type copper phthalocyanine (Japanese Patent Publication No. 51-1662 of Patent Document 3), X-type metal-free phthalocyanine (US Pat. No. 3,816, Patent Document 4). , 118 specification), τ-type metal-free phthalocyanine (Japanese Patent Laid-Open No. 58-182039), A (β) -type titanyl phthalocyanine, B (α) -type titanyl phthalocyanine, Y-type titanyl phthalocyanine [non-patent Y. of reference 1. Fujimaki, Proc. IS & T's 7th International Congress on Advances in Non-Impact Printing Technologies, 1,269], type II chlorogallium phthalocyanine (JP-A-5-98181 of Patent Document 6), V-type hydroxygallium phthalocyanine [Patent Document 7 No. 5-263007, Non-Patent Document 2, k. Daimon, et al. : J. Imaging Sci. Technol. , 40, 249] and the like.

  The spectral wavelength range of these phthalocyanine pigments has reached the near infrared range, and exhibits extremely high sensitivity to light sources such as the semiconductor laser. However, when the above phthalocyanine pigment is used for an electrophotographic photosensitive member, the sensitivity is sufficient, but the chargeability is reduced due to repeated fatigue, and the temperature and humidity dependency is large. Many problems remain in practice, such as the occurrence of abnormal images such as afterimages.

  The present invention relates to a novel hydroxygallium phthalocyanine crystal that does not generate an abnormal image such as an afterimage in repeated use over a long period of time and realizes stable sensitivity characteristics and charging characteristics, and an electrophotographic photosensitive member and an image forming method using the same. An object of the present invention is to provide an image forming apparatus and a process cartridge for the image forming apparatus.

As a result of intensive studies, the present inventors have found that “hydroxygallium phthalocyanine crystal”, “electrophotographic photosensitive member”, “image forming method”, “image forming apparatus” described in the following items (1) to (6) and The present invention including the “process cartridge for image forming apparatus” has been found to solve the above problems, and the present invention has been achieved.
(1) “Hydroxygallium phthalocyanine crystal showing main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 8.0 ° and 28.0 ° in an X-ray diffraction spectrum by CuKα rays.”
(2) “Bragg angle (2θ ± 0.3 °) 8.0 °, 10.4 °, 13.3 °, 16.6 °, 22.5 °, 24.5 in X-ray diffraction spectrum by CuKα ray The hydroxygallium phthalocyanine crystal according to (1), which exhibits a diffraction peak at ° and 28.0 °. "
(3) “Hydroxygallium phthalocyanine according to the above item (1) or (2)” in the multilayer electrophotographic photosensitive member provided with a charge generation layer and a charge transport layer on a conductive support. An electrophotographic photosensitive member characterized by containing crystals. "
(4) “An image forming method using the electrophotographic photosensitive member according to item (3)”.
(5) “An image forming apparatus comprising the electrophotographic photosensitive member according to item (3)”.
(6) “A process cartridge for an image forming apparatus comprising the electrophotographic photosensitive member according to (3)”.

  As will be understood from the following detailed and specific description, according to the present invention, a novel hydroxy group that does not generate an abnormal image such as an afterimage in repeated use over a long period of time and realizes stable sensitivity characteristics and charging characteristics. The gallium phthalocyanine crystal, an electrophotographic photoreceptor using the crystal, an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus are provided with an extremely excellent effect.

1 is a schematic cross-sectional view showing one configuration example of an electrophotographic photosensitive member according to the present invention. It is a cross-sectional schematic diagram which shows another one structural example of the electrophotographic photoreceptor which concerns on this invention. It is a cross-sectional schematic diagram which shows another example of 1 structure of the electrophotographic photoreceptor which concerns on this invention. It is a cross-sectional schematic diagram which shows another example of 1 structure of the electrophotographic photoreceptor which concerns on this invention. 1 is a schematic diagram for explaining an electrophotographic process and an image forming apparatus of the present invention. It is a schematic diagram showing an example of a charging unit used in the image forming apparatus of the present invention. 1 is a schematic view for explaining an example of a tandem-type full-color electrophotographic apparatus of the present invention. It is a schematic diagram showing an example of a process cartridge of the present invention. 2 is a powder X-ray diffraction spectrum diagram of a hydroxygallium phthalocyanine crystal of the present invention according to Synthesis Example 1. FIG. 4 is a powder X-ray diffraction spectrum diagram of a hydroxygallium phthalocyanine crystal of the present invention according to Synthesis Example 2. FIG. 6 is a powder X-ray diffraction spectrum diagram of a hydroxygallium phthalocyanine crystal of the present invention according to Synthesis Example 3. FIG. 6 is a powder X-ray diffraction spectrum diagram of a hydroxygallium phthalocyanine crystal of the present invention according to Synthesis Example 4. FIG. It is a figure which shows the A4 chart in which the character part and halftone part which were output for the afterimage evaluation by a real machine are mixed after 400,000 sheets run.

Hereinafter, the present invention will be described in detail and specifically.
The hydroxygallium phthalocyanine of the present invention is a novel compound, and as described above, the main diffraction peaks at black angles (2θ ± 0.3 °) of 8.0 ° and 28.0 ° in the X-ray diffraction spectrum by CuKα ray. It is a compound which shows. The hydroxygallium phthalocyanine crystal of the present invention is different from the V-type hydroxygallium phthalocyanine described in JP-A-5-263007 of Patent Document 7 in the X-ray diffraction spectrum.
In the X-ray diffraction spectrum of the CuKα ray of the present invention, a method for producing a hydroxygallium phthalocyanine crystal showing main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 8.0 ° and 28.0 ° includes gallium halide phthalocyanine or Hydroxygallium phthalocyanine of the present invention can be produced by hydrolyzing a sulfonic acid ester derivative that can be synthesized by reacting hydroxygallium phthalocyanine and a sulfonic acid derivative in an organic solvent. Examples of the halogenated gallium phthalocyanine include chlorogallium phthalocyanine, bromogallium phthalocyanine, iodine gallium phthalocyanine, and the like, which can be synthesized by a known method. For example, chlorogallium phthalocyanine is disclosed in D.C. C. Acad. Sci. , (1965), 242, 1026, and the method of reacting gallium trichloride with diiminoisoindoline.

  Bromogallium phthalocyanine can be synthesized by a method of reacting gallium tribromide and phthalonitrile described in JP-A-59-133551 of Patent Document 8. Iodine gallium phthalocyanine can be synthesized by a method of reacting gallium triiodide and phthalonitrile described in JP-A-60-59354 of Patent Document 9. Hydroxygallium phthalocyanine can be obtained by hydrolyzing the above-mentioned gallium halide phthalocyanine. Hydrolysis may be acid hydrolysis or alkaline hydrolysis. Regarding acid hydrolysis, see, for example, Bull. Soc. Chim. France, 23 (1962), and can be obtained by a method of hydrolyzing chlorogallium phthalocyanine using sulfuric acid. Regarding alkaline hydrolysis, Inlog. Chem. (19), 3131, (1980) can be obtained by the method of hydrolysis using ammonia.

  Next, the gallium phthalocyanine compound of the general formula (A) can be synthesized by reacting the obtained gallium halide phthalocyanine or hydroxygallium phthalocyanine with a sulfonic acid derivative. Can be used. As described above, this is due to the production method, and in the production method of hydroxygallium phthalocyanine, generation of decomposition products is unavoidable when the hydrolysis treatment using acid or alkali is performed.

  In contrast, halogenated gallium phthalocyanine can be produced without providing a hydrolysis step. Therefore, in the present invention, there is no generation of a decomposition product as a synthesis raw material, and halogen having a small production step. Gallium phthalocyanine can be favorably used.

［但し、一般式（Ａ）中、Ｘは置換基を有してもよいアルキル基、置換基を有してもよいアルケニル基、置換基を有してもよいアルキニル基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基を表わす。置換基としては、アルコキシ基、アルキルチオ基、アルキル基、ハロゲン原子、ニトロ基、アミノ基、アリール基、カルボキシ基、シアノ基などがあげられる。Ｒ１〜Ｒ１６はそれぞれ独立して、水素、アルコキシ基、アルキルチオ基、アルキル基、ハロゲン原子、ニトロ基、アリール基、などが挙げられる。ｎは１から２の整数である。］

[In the general formula (A), X has an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, and a substituent. An aralkyl group which may be substituted, or an aryl group which may have a substituent; Examples of the substituent include an alkoxy group, an alkylthio group, an alkyl group, a halogen atom, a nitro group, an amino group, an aryl group, a carboxy group, and a cyano group. R1 to R16 each independently include hydrogen, an alkoxy group, an alkylthio group, an alkyl group, a halogen atom, a nitro group, an aryl group, and the like. n is an integer of 1 to 2. ]

  Examples of the sulfonic acid derivatives used here include methanesulfonic acid, ethanesulfonic acid, butanesulfonic acid, pentanessulfonic acid, hexanesulfonic acid, heptanesulfonic acid, octanessulfonic acid, hexadecanesulfonic acid, trifluoromethanesulfonic acid, nonafluoro -1-butanesulfonic acid, heptadecafluorooctanesulfonic acid, 2-chloroethanesulfonic acid, 2-bromoethanesulfonic acid, vinylsulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, p-chlorobenzenesulfonic acid, nitrobenzenesulfonic acid , Pyridinesulfonic acid, 1-naphthalenesulfonic acid, 4-aminonaphthalene-1-sulfonic acid, anthraquinone-2-sulfonic acid, 1,3-benzenedi Rufon acid, 1,5-naphthalenedicarboxylic sulfonic acid, 1,3-propane-di sulfonic acid, 1,4-butane-di sulfonic acid and the like. Although the reason is not clear, in order to obtain a hydroxygallium phthalocyanine crystal showing main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 8.0 ° and 28.0 ° in the X-ray diffraction spectrum by CuKα ray of the present invention. Methane sulfonic acid, ethane sulfonic acid, butane sulfonic acid, pentanes sulfonic acid, hexane sulfonic acid, heptane sulfonic acid, octanes sulfonic acid, hexadecane sulfonic acid, trifluoromethane sulfonic acid, nonafluoro-1-butane sulfonic acid, heptadecafluoro Octane sulfonic acid, 2-chloroethanesulfonic acid, 2-bromoethanesulfonic acid, 1,3-propanedisulfonic acid, 1,4-butanedisulfonic acid and the like are suitable.

As for the quantitative ratio of the halogenated gallium phthalocyanine or hydroxygallium phthalocyanine to the sulfonic acid derivative, when n in the general formula (A) is 2, about 1/2 mole of the sulfonic acid derivative is suitable. When n in the general formula (A) is 1, the sulfonic acid derivative is suitably equimolar or more, and varies depending on the reactivity of the sulfonic acid derivative used, etc. Yes. In the case of a liquid at the reaction temperature, it may be used as a solvent. Examples of the organic solvent used here include dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, tetrahydrofuran, dioxane, 2-butanone, cyclohexanone, monochlorobenzene, dichlorobenzene, toluene, xylene, anisole, Examples thereof include nitrobenzene, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethyl cellosolve, ethyl acetate, butyl acetate, dichloroethane, trichloroethane, pyridine, picoline or quinoline.
The reaction can be carried out by reacting at a temperature of 0 ° C. to 200 ° C., preferably 20 ° C. to 150 ° C. for 30 minutes to 50 hours.

Next, hydrolysis of the obtained sulfonic acid ester derivative will be described. A base using an organic solvent for producing hydroxygallium phthalocyanine showing main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 8.0 ° and 28.0 ° in the X-ray diffraction spectrum by CuKα ray of the present invention Hydrolytic hydrolysis is suitable.
Suitable organic solvents are, for example, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, ethyl cellosolve, ethyl acetate, monochlorobenzene, toluene, xylene, nitrobenzene, pyridine, picoline or quinoline and mixtures thereof A solvent etc. are mentioned.

Suitable bases as catalysts include diazabicyclooctene, diazabicycloundecene, 4-dimethylaminopyridine, dimethylpyridine, pyridine, N, N-dimethylformamide, N, N-dimethylacetamide, triethylamine, diethylamine, dibutylamine Etc. can be used.
Further, N, N-dimethylformamide and N, N-dimethylacetamide which are also used as a reaction solvent are particularly suitable.
The amount of water used for hydrolysis may be equimolar or more with respect to the gallium phthalocyanine compound represented by formula (A).
The reaction temperature varies depending on the hydrolyzability of the gallium phthalocyanine compound represented by the general formula (A) and the presence or absence of a catalyst, but is 0 to 300 ° C, preferably 20 to 250 ° C, and the heating time is 30 minutes to 20 hours. Is desirable.

  Next, the configuration of the electrophotographic photoreceptor will be described in detail below with reference to the drawings. As shown in FIG. 1, the photoreceptor (1) of the present invention comprises, on a conductive support (2), a charge generation layer (3) containing a charge generation material as a main component and a charge transport material as a main component. The charge transport layer (4) to be stacked is laminated.

As shown in FIG. 2, the photoreceptor (1) of the present invention has an undercoat layer (6) or an intermediate layer between the conductive support (2) and the charge generation layer (3). It may be formed.
In the photoreceptor (1) of the present invention, a protective layer (5) may be formed on the charge transport layer (4) as shown in FIG.
Further, as shown in FIG. 4, the photoreceptor (1) of the present invention has a single photosensitive layer (7) containing a charge generation substance and a charge transport substance on a conductive support (2). You may make the aspect of a layer type photoreceptor.

[Conductive support]
Examples of the conductive support include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum, tin oxide, and indium oxide. Metal oxide coated by film or cylindrical plastic or paper by vapor deposition or sputtering, or a plate made 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. Endless nickel belts and endless stainless steel belts can also be used as the conductive support.
In addition, the conductive support dispersed in an appropriate binder resin on the support can be used as the conductive support of the present invention.

Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done.
The binder resin used at the same time includes polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine Thermoplastic, thermosetting resin or photo-curing resin such as resin, urethane resin, phenol resin, alkyd resin and the like can be mentioned.
Such a conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.
Furthermore, 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, and polytetrafluoroethylene-based fluororesin on a suitable cylindrical substrate. Those provided with a conductive layer can be used favorably as the conductive support of the present invention.

[Photosensitive layer]
Next, the photosensitive layer will be described. The laminated photosensitive layer is constituted by sequentially laminating at least a charge generation layer and a charge transport layer.

[Charge generation layer]
The charge generation layer is a layer containing a charge generation material. As the charge generation material, at least a hydroxygallium phthalocyanine crystal having main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 8.0 ° and 28.0 ° in the X-ray diffraction spectrum by CuKα ray used in the present invention is used. contains.

  The charge generating material includes a hydroxygallium phthalocyanine crystal having main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 8.0 ° and 28.0 ° in the X-ray diffraction spectrum of the CuKα ray of the present invention, and a conventionally known charge generation material. You may mix and use a substance. Examples of 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, Examples include perylene pigments, perinone pigments, indigo pigments, pyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, and squalium pigments.

  Binder resins used in the charge generation layer include polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N-vinylcarbazole, polyacrylamide. , Polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone and the like. The amount of the binder resin is preferably 0 to 500 parts by mass and more preferably 10 to 300 parts by mass with respect to 100 parts by mass of the charge generation material.

The charge generation layer disperses the charge generation material in a suitable solvent together with a binder resin as necessary using a known dispersion method such as a ball mill, an attritor, a sand mill, or an ultrasonic wave. Alternatively, it is formed by applying on an undercoat layer or an intermediate layer and drying. The binder resin may be added before or after the charge generating material is dispersed.
Examples of the solvent used for forming the charge generation layer include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin. Although generally used organic solvents such as ketone solvents, ketone solvents, ester solvents, and ether solvents are particularly preferable. These may be used alone or in combination of two or more.
The coating solution for forming the charge generation layer is mainly composed of a charge generation material, a solvent and a binder resin, and includes any additive such as a sensitizer, a dispersant, a surfactant, and silicone oil. May be included.
As a method for coating the charge generation layer using the coating solution, known methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, and the like can be used.
The thickness of the charge generation layer is preferably from 0.01 to 5 μm, more preferably from 0.1 to 2 μm. After coating, it is heated and dried in an oven or the like. The drying temperature of the charge generation layer in the present invention is preferably 50 ° C. or higher and 160 ° C. or lower.

[Charge transport layer]
Next, the charge transport layer will be described. The charge transport layer is formed by applying and drying a coating liquid in which a charge transport material and a binder resin are dissolved or dispersed in a solvent. Moreover, you may add additives, such as a plasticizer, a leveling agent, antioxidant, a lubricant, etc. individually or in 2 types or more to the coating liquid of a charge transport layer as needed.
Examples of the charge transport material include a hole transport material and an electron transport material. Examples of the hole transport material include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc., bisstilbene derivatives, enamine derivatives, etc. Other known materials may be mentioned. These charge transport materials may be used alone or in combination of two or more.
Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.
These charge transport materials may be used alone or in combination of two or more. The content of the charge transport material is usually 20 to 300 parts by weight and preferably 40 to 150 parts by weight with respect to 100 parts by weight of the binder resin.
Binder resins include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, poly Vinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly (N-vinylcarbazole), acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, Examples thereof include thermoplastic or thermosetting resins such as phenol resins and alkyd resins.
As the solvent, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone or the like is used. Among them, the use of a non-halogen solvent is desirable for the purpose of reducing the environmental load. Specifically, cyclic ethers such as tetrahydrofuran, dioxolane and dioxane, aromatic hydrocarbons such as toluene and xylene, and derivatives thereof are preferably used. Two or more of these may be used in combination.
The film thickness of the charge transport layer is preferably 10 to 50 μm, more preferably 15 to 35 μm, from the viewpoint of resolution and responsiveness.
As a coating method, known methods such as 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 used, but the charge transport layer has a certain thickness. Since it is necessary to apply thickly, it is preferable to apply the dip coating method with a highly viscous liquid.
The charge transport layer after coating is heated and dried by a thermal means used in the charge generation layer. Although drying temperature changes also with the solvent contained in a coating liquid, it is preferable that it is 80-200 degreeC, and 110-170 degreeC is more preferable. The drying time is preferably 10 minutes or more, more preferably 20 minutes or more.

[Single layer]
Next, the case where the photosensitive layer has a single layer structure will be described. This is a photoreceptor in which the above-described charge generation material and 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.
In the photosensitive layer, a charge generating substance, a charge transporting substance and a binder resin are dissolved or dispersed in a solvent such as tetrahydrofuran, dioxane, dichloroethane, methyl ethyl ketone, cyclohexane, cyclohexanone, toluene, xylene, etc., and this is dip coating, spray coating, bead coating. It can be formed by coating using a conventionally known method such as ring coating.
The charge transport material preferably contains both the hole transport material and the electron transport material described above. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.
Regarding the charge generating substance, charge transporting substance, binder resin, organic solvent and various additives used in the single photosensitive layer, any material contained in the above-described charge generating layer and charge transporting layer should be used. Is possible.
As the binder resin, in addition to the binder resin previously mentioned in the charge transport layer, the binder resin mentioned in the charge generation layer may be mixed and used. The amount of the charge generating material with respect to 100 parts by mass of the binder resin is preferably 5 to 40 parts by mass, and more preferably 10 to 30 parts by mass. The amount of the charge transport material is preferably 0 to 190 parts by mass, and more preferably 50 to 150 parts by mass. Further, the film thickness of the photosensitive layer is preferably 5 to 40 μm, more preferably 10 to 30 μm.

[Underlayer]
In the photoreceptor of the present invention, an undercoat layer can be provided between the conductive support and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, in consideration of applying a photosensitive layer using a solvent thereon, such a resin is a resin having high solvent resistance to a general organic solvent. Preferably there is. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resins, phenol resins, alkyd-melamine resins, and isocyanates. And curable resins that form a three-dimensional network structure, such as epoxy resins.
Further, a fine powder pigment of a metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, or indium oxide may be added to the undercoat layer in order to prevent moire and reduce residual potential.
Moreover, it can form using a solvent and a coating method similarly to the above-mentioned charge generation layer and charge transport layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer.

[Protective layer]
In the present invention, a protective layer can be provided on the outermost surface of the photoreceptor in order to improve wear resistance. As the protective layer, a polymer charge transport material type obtained by polymerizing a charge transport component and a binder component, a filler dispersion type containing a filler, a curable type obtained by curing a constituent material having a reactive functional group, and the like are known. However, in the present invention, any conventionally known protective layer can be used.

[Image forming apparatus]
Next, the electrophotographic method and the image forming apparatus of the present invention will be described in detail with reference to the drawings. FIG. 5 is a schematic view for explaining the electrophotographic process and the image forming apparatus of the present invention, and the following examples also belong to the category of the present invention.
As shown in FIG. 5, the photoconductor (1) has a drum shape, but may be a sheet or an endless belt. For charging roller (12), pre-transfer charger (15), transfer charger (18), separation charger (19), pre-cleaning charger (21), in addition to corotron, scorotron, solid state charger (solid state charger) A roller-shaped charging member or a brush-shaped charging member is used, and all known means can be used.
As the charging member, a non-contact charging method such as corona charging or a contact charging method using a charging member 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 can significantly reduce the amount of ozone generated compared to corotron, scorotron, etc., and is effective in stability and prevention of image quality deterioration when the photoreceptor is used repeatedly.
However, due to the contact between the photoconductor and the charging roller, the charging roller is contaminated by repeated use, which affects the photoconductor and contributes to the occurrence of abnormal images and reduced wear resistance. It was.
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 contamination of the charging roller.

Therefore, as shown in FIG. 6, the charging roller (12) is provided with a gap forming member (12a) and is disposed close to the photoreceptor (1) via the gap, so that contaminants adhere to the charging roller. It is difficult or easy to remove, and the influence thereof can be reduced.
In this case, the gap between the photosensitive member and the charging roller 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. .

On the other hand, the light source such as the image exposure unit (13) and the charge removal lamp (11) shown in FIG. 5 includes a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), All luminescent materials such as electroluminescence (EL) can be used. Among these, a semiconductor laser (LD) and a light emitting diode (LED) are mainly used.
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.
From the light source or the like, the photosensitive member (1) is irradiated with light in a transfer process, a static elimination process, a cleaning process, or a pre-exposure process using light irradiation. However, the exposure of the photoreceptor (1) in the charge eliminating step is greatly affected by fatigue on the photoreceptor 1, and may cause a decrease in charge and 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 photosensitive member (1) is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. 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. 5, a combination of the transfer charger (18) and the separation charger (19) is effective.
Further, the toner image is directly transferred from the photosensitive member to the paper using such a transfer unit. In the present invention, the toner image on the photosensitive member is once transferred to the intermediate transfer member, and then from the intermediate transfer member to the paper. An intermediate transfer method for transferring the toner to the photoconductor is more preferable for enhancing the durability or improving the image quality of the photoreceptor.

  Among the contaminants that adhere to the surface of the photoconductor, discharge substances generated by charging and external additives contained in the toner are easy to pick up the effects of humidity and cause abnormal images. Paper powder is one of the causative substances, and when they adhere to the photoreceptor, abnormal images are more likely to occur, as well as a tendency to reduce wear resistance and cause uneven wear. Is seen. 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 has been a big problem. The photoconductor of the present invention is particularly effective and useful since it is easy to use in combination with an intermediate transfer type image forming apparatus because image blurring hardly occurs even without a drum heater. 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. It is effective and useful for achieving high quality or high image quality.

The toner developed on the photosensitive member (1) by the developing unit (14) shown in FIG. 5 is transferred to the transfer paper (17), but not all of the toner is transferred to the photosensitive member (1). The toner remaining in the toner is also generated.
Such toner is removed from the photoreceptor (1) by the fur brush (22) or the cleaning blade (23). This cleaning process may be performed only with a cleaning brush or may be performed in combination with a blade, and known cleaning brushes 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 photosensitive member (1) after the transfer. However, the photosensitive member (1) is repeatedly rubbed by the cleaning blade (23) or the fur brush (22). As a result, wear of the photoconductor (1) is promoted, or an abnormal image may be generated due to scratches.
In addition, if the surface of the photoconductor is contaminated due to poor cleaning, it not only causes an abnormal image, but also significantly reduces the life of the photoconductor.
In particular, in the case of a photoconductor with a protective layer on the outermost layer to improve wear resistance, it is difficult to remove contaminants adhering to the surface of the photoconductor, which promotes the generation of filming and abnormal images. Will do. Therefore, improving the cleaning property of the photoconductor is very effective for improving the durability and image quality of the photoconductor.
As means for improving the cleaning property of the photosensitive member, a method of 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.

  These lubricants include lubricating fluids 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, fatty acid esters , Fatty acid metal salts such as zinc stearate, lubricating liquids such as graphite and molybdenum disulfide, solids, powders, and the like, but particularly when mixed with a developer, it must be in the form of a powder, especially stearic acid Zinc 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 to 0.5% by mass with respect to the toner. 3 mass% is more preferable.

  The photoconductor according to the present invention can be applied to a small-diameter photoconductor because high photosensitivity and high stability are realized. Accordingly, as an image forming apparatus or method using the above photoreceptor more effectively, each developing unit corresponding to a plurality of colors of toner is provided with a plurality of corresponding photoreceptors, thereby performing parallel processing. It is very effectively used in a so-called tandem type 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.

FIG. 7 is a schematic diagram for explaining the tandem-type full-color electrophotographic apparatus of the present invention, and the following modifications also belong to the category of the present invention. In FIG. 7, photoconductors (1C) (cyan), (1M) (magenta), (1Y) (yellow), and (1K) (black) are drum-like photoconductors (1), and these photoconductors. (1C), (1M), (1Y), (1K) rotate in the direction of the arrow in the figure, and charging members (12C), (12M), (12Y), (12K), Developing members (14C), (14M), (14Y), (14K), and cleaning members (15C), (15M), (15Y), (15K) are arranged.
The charging members (12C), (12M), (12Y), and (12K) constitute a charging device for uniformly charging the surface of the photoreceptor (1). From the back side of the photoreceptor (1) between the charging members (12C), (12M), (12Y), (12K) and the developing members (14C), (14M), (14Y), (14K). Then, laser beams (13C), (13M), (13Y), and (13K) from an exposure member (not shown) are irradiated, and electrostatic latent images are formed on the photoreceptors (1C), (1M), (1Y), and (1K). Is to be formed.
Then, the four image forming elements (10C), (10M), (10Y), and (10K) centering on such photoconductors (1C), (1M), (1Y), and (1K) serve as transfer materials. It is juxtaposed along the transfer and transport belt (25) which is a transport means. The transfer conveyance belt (25) includes developing members (14C), (14M), (14Y), and (14K) of the image forming units (elements) (10C), (10M), (10Y), and (10K), Between the cleaning members (15C), (15M), (15Y), and (15K), the photosensitive members (1C), (1M), (1Y), and (1K) are in contact with the transfer conveyance belt (25). Transfer brushes (26C), (26M), (26Y), and (26K) for applying a transfer bias are disposed on a surface (back surface) that is in contact with the back side of the photoconductor (1). Each of the image forming elements (10C), (10M), (10Y), and (10K) is different in the color of the toner inside the developing device, and the others are the same in configuration.

In the color electrophotographic apparatus having the configuration shown in FIG. 7, the image forming operation is performed as follows. First, in each of the image forming elements (10C), (10M), (10Y), (10K), the photoconductors (1C), (1M), (1Y), (1K) are in the direction indicated by the arrows (photoconductor (1)). Exposure unit (not shown) which is charged by charging members (12C), (12M), (12Y) and (12K) which rotate in the rotation direction and then arranged outside the photoreceptor (1). Thus, an electrostatic latent image corresponding to each color image to be created is formed by the laser beams (13C), (13M), (13Y), and (13K).
Next, the latent image is developed by developing members (14C), (14M), (14Y), and (14K) to form a toner image. Development members (14C), (14M), (14Y), and (14K) are development members that perform development with toners of C (cyan), M (magenta), Y (yellow), and K (black), respectively. The toner images of the respective colors produced on the two photoconductors (1C), (1M), (1Y), and (1K) are superimposed on the transfer paper. The transfer paper (17) is fed out from the tray by the paper feed roller (24), and is temporarily stopped by the pair of registration rollers (16). The transfer paper (17) is transferred to the transfer conveyance belt (25) in synchronization with the image formation on the photoconductor. Sent.
The transfer paper (17) held on the transfer / conveying belt (25) is conveyed, and each color at the contact position (transfer portion) with each photoconductor (1C), (1M), (1Y), (1K). The toner image is transferred.
The toner image on the photoconductor includes the transfer bias applied to the transfer brushes (26C), (26M), (26Y), and (26K) and the photoconductors (1C), (1M), (1Y), and (1K). The image is transferred onto the transfer paper (17) by an electric field formed from the potential difference. Then, the recording paper (17) on which the four color toner images are passed through the four transfer portions is conveyed to the fixing device (27), where the toner is fixed, and is discharged to a paper discharge portion (not shown). The Further, the residual toner remaining on each of the photoconductors (1C), (1M), (1Y), and (1K) without being transferred by the transfer unit is removed from the cleaning devices (15C), (15M), (15Y), ( 15K).
In the example of FIG. 7, 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 transfer paper conveyance direction. However, it is not limited to this order, and the color order is arbitrarily set. Further, 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, although the charging member is in contact with the photosensitive member in FIG. 7, by using a charging mechanism as shown in FIG. 6, an appropriate gap (about 10 to 200 μm) is provided between them. In addition, the wear amount of the both can be reduced, and toner filming on the charging member can be reduced and the toner 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.
The process cartridge includes the photoelectric conversion element 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 is detachable from the image forming apparatus. Device (parts).
An example of the process cartridge is shown in FIG. 8, but the neutralizing means is not described here.
The above-described tandem image forming apparatus can transfer a plurality of toner images at a time, so that high-speed full-color printing is realized.
However, since at least four photoconductors are required, an increase in the size of the apparatus is unavoidable, and depending on the amount of toner used, there is a difference in the wear amount of each photoconductor, thereby reproducing the color. There are many problems such as a decrease in performance and occurrence of abnormal images.
On the other hand, the photosensitive member according to the present invention can be applied to a small-diameter photosensitive member by realizing high photosensitivity and high stability, and the influence of increase in residual potential, sensitivity deterioration, etc. is reduced. Even if the amount of the photoconductor used is different, the difference in residual potential and sensitivity over time is small, and a full color image having excellent color reproducibility can be obtained even when used repeatedly for a long time.

  Hereinafter, the present invention will be described in more detail and specifically based on examples, but these examples are for facilitating understanding of the present invention and are intended to limit the present invention. It is not a thing. In the following description, “parts” and “%” represent “parts by mass” and “mass%” unless otherwise specified.

[Reference Synthesis Example 1]
[Synthesis of chlorogallium phthalocyanine]
First, in the X-ray diffraction spectrum by CuKα ray of the present invention, chlorogallium phthalocyanine used as a raw material for hydroxygallium phthalocyanine crystal showing main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 8.0 ° and 28.0 °. A synthesis example is shown. In the following description, “part” means “part by weight”.
After adding 30 parts of 1,3-diiminoisoindoline and 8 parts of gallium trichloride to 200 parts of dehydrated dimethyl sulfoxide and reacting at 150 ° C. for 12 hours under an Ar stream, the produced chlorogallium phthalocyanine is filtered off. did. The wet cake was washed with methyl ethyl ketone and N, N-dimethylformamide and then dried to obtain 22 parts (70.3%) of chlorogallium phthalocyanine crystals.

[Synthesis of hydroxygallium phthalocyanine]
The above-mentioned 5 parts of chlorogallium phthalocyanine was dissolved in 150 parts of concentrated ice-cooled sulfuric acid, and this sulfuric acid solution was gradually added dropwise to 500 parts of ice-cooled ion-exchanged water to precipitate hydroxygallium phthalocyanine crystals. After the crystals were separated by filtration, the wet cake was washed with 500 parts of 2 wt% ammonia water, and then thoroughly washed with ion-exchanged water. By drying, 4.6 parts of hydroxygallium phthalocyanine crystals were obtained.

[(Synthesis Example 1]
[(1) Synthesis of gallium phthalocyanine compound of general formula (A) (n = 1)]
Next, a Bragg angle (2θ ± 0.3 °) of 8.0 ° in the X-ray diffraction spectrum by CuKα ray of the present invention obtained by hydrolyzing the gallium phthalocyanine compound represented by the general formula (A), A synthesis example of a hydroxygallium phthalocyanine crystal showing a main diffraction peak at 28.0 ° is shown.
To 100 ml of dimethyl sulfoxide, 1.24 parts of chlorogallium phthalocyanine and 20.0 parts of heptadecafluorooctane sulfonic acid were added, heated to 110 ° C. and reacted for 7 hours. After cooling to room temperature, a trace amount of insoluble part was removed by filtration. About 150 ml of ion-exchanged water was added to the resulting solution, and the mixture was stirred at room temperature for 6 hours. The produced crystals were filtered, washed thoroughly with ion-exchanged water, and dried to obtain 1.94 parts (90%) of a gallium phthalocyanine compound.
The following analysis was performed on this compound. LDI-TOFMS (positive) confirmed m / z: 1079.92 (theoretical value was 1080.01: C40H16F17GaN8O3S). The results of further elemental analysis are shown in the table below.

  From these results, it was confirmed that it was a gallium phthalocyanine compound of the following formula (G).

[(2) Hydrolysis of gallium phthalocyanine compound of the above formula (G)]
2.16 parts of the gallium phthalocyanine compound of the formula (G) and 0.2 parts of water were added to 100 parts of N, N-dimethylformamide and reacted for 6 hours under reflux. After cooling, the obtained crystals were collected by filtration, washed twice with 100 parts of N, N-dimethylformamide, once with 100 parts of methyl ethyl ketone, and twice with 100 parts of ion-exchanged water, and then dried. 11 parts (92%) of hydroxygallium phthalocyanine were obtained.
The following analysis was performed on this compound. By LDI-TOFMS (positive), m / z: 598.07 (theoretical value is 598.078: C32H17GaN8O) was recognized. From this result, it was confirmed that it was hydroxygallium phthalocyanine.
Furthermore, the powder X-ray diffraction spectrum of this hydroxygallium phthalocyanine was measured under the following conditions. The powder X-ray diffraction spectrum is shown in FIG.
X-ray tube: Cu (wavelength 1.54 mm)
Voltage: 50kV
Current: 30mA
Scanning speed: 2 deg / min
Scanning range: 2 to 35 deg
Time constant: 2 sec

  From this spectrum, it was confirmed that a hydroxygallium phthalocyanine crystal having main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 7.82 ° and 27.88 ° was obtained. Further, hydroxygallium phthalocyanine crystals having diffraction peaks at Bragg angles (2θ ± 0.3 °) of 10.18 °, 13.18 °, 16.46 °, 22.60 °, and 24.40 ° are also obtained. I confirmed that.

[Synthesis Example 2]
[(1) Synthesis of gallium phthalocyanine compound of general formula (A) (n = 1)]
To 100 ml of dimethyl sulfoxide, 1.24 parts of chlorogallium phthalocyanine and 6.0 parts of trifluoromethanesulfonic acid were added, heated to 110 ° C. and reacted for 7 hours. After cooling to room temperature, a trace amount of insoluble part was removed by filtration. About 100 ml of ion exchange water was added to the resulting solution, and the mixture was stirred at room temperature for 3 hours. The produced crystals were filtered, washed thoroughly with ion exchange water, and then dried to obtain 1.43 parts (98%) of a gallium phthalocyanine compound. A part of the obtained product was recrystallized from N, N-dimethylformamide, and the following analysis was performed.
By LDI-TOFMS (negative), m / z: 730.07 (theoretical value is 730.03: C33H16F3GaN8O3S) was recognized. The results of further elemental analysis are shown in the table below.

これらの結果より、下記式（Ｄ）のガリウムフタロシアニン化合物であることを確認した。

From these results, it was confirmed that it was a gallium phthalocyanine compound of the following formula (D).

[(2) Hydrolysis of gallium phthalocyanine compound of the above formula (D)]
0.73 parts of the gallium phthalocyanine compound of the formula (D) and 0.1 part of water were added to 60 parts of N, N-dimethylformamide, and reacted for 7 hours under reflux. After cooling, the obtained crystals were collected by filtration, washed twice with 60 parts of N, N-dimethylformamide, once with 60 parts of methyl ethyl ketone, and three times with 60 parts of ion-exchanged water, and then dried to give a 0.1% solution. 49 parts (81%) of hydroxygallium phthalocyanine were obtained.
The following analysis was performed on this compound. By LDI-TOFMS (positive), m / z: 598.06 (theoretical value is 598.078: C32H17GaN8O) was recognized. From this result, it was confirmed that it was hydroxygallium phthalocyanine.
The powder X-ray diffraction spectrum of this compound is shown in FIG. From this spectrum, it was confirmed that a hydroxygallium phthalocyanine crystal having main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 7.82 ° and 27.86 ° was obtained. Further, hydroxygallium phthalocyanine crystals having diffraction peaks at Bragg angles (2θ ± 0.3 °) of 10.12 °, 13.16 °, 16.38 °, 22.58 °, and 24.26 ° are also obtained. I confirmed that.

[Synthesis Example 3]
[(1) Hydrolysis of gallium phthalocyanine compound of formula (D)]
Add 1.10 parts of the gallium phthalocyanine compound of formula (D), 0.10 parts of 4-dimethylaminopyridine, and 0.1 parts of water to 100 parts of N, N-dimethylformamide, react at 7O 0 C for 7 hours. I let you. After cooling, the obtained crystals were collected by filtration, washed 3 times with 100 parts of N, N-dimethylformamide, once with 100 parts of methyl ethyl ketone, and twice with 100 parts of ion-exchanged water, and then dried to give a 0.1% solution. 81 parts (90%) of hydroxygallium phthalocyanine were obtained.
The following analysis was performed on this compound. By LDI-TOFMS (positive), m / z: 598.06 (theoretical value is 598.078: C32H17GaN8O) was recognized. From this result, it was confirmed that it was hydroxygallium phthalocyanine.
The powder X-ray diffraction spectrum of this compound is shown in FIG. From this spectrum, it was confirmed that hydroxygallium phthalocyanine crystals having new main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 7.84 ° and 27.84 ° were obtained. In this synthesis example, [JP-A-5-263007 of the Patent Document 7 and k. Daimon, et al. : J. Imaging Sci. Technol. , 40, 249], diffraction peaks such as 7.50 ° and 28.38 ° based on the V-type hydroxygallium phthalocyanine crystal described above were also observed, confirming that the crystal types were mixed.

[Synthesis Example 4]
[(1) Synthesis of gallium phthalocyanine compound of general formula (A) (n = 1)]
To 100 ml of dimethyl sulfoxide, 1.24 parts of chlorogallium phthalocyanine and 6.0 parts of nonafluoro-1-butanesulfonic acid were added, heated to 110 ° C. and reacted for 7 hours. After cooling to room temperature, a trace amount of insoluble part was removed by filtration. About 100 ml of ion exchange water was added to the resulting solution, and the mixture was stirred at room temperature for 4 hours. The produced crystals were filtered, washed thoroughly with ion exchange water, and dried to obtain 1.67 parts (95%) of a gallium phthalocyanine compound.
A part of the resulting product was dissolved in dimethyl sulfoxide and subjected to adsorption treatment with silica gel. Silica gel was separated by filtration, and dimethyl sulfoxide obtained by filtration was added with an approximately equal amount of ion-exchanged water to precipitate crystals. This was filtered, washed thoroughly with ion-exchanged water, dried, and purified.
The following analysis was performed on this compound. By LDI-TOFMS (positive), m / z: 879.97 (theoretical value is 880.02: C36H16F9GaN8O3S) was recognized. The results of further elemental analysis are shown in the table below.

  From these results, it was confirmed that it was a gallium phthalocyanine compound of the following formula (F).

[(2) Hydrolysis of gallium phthalocyanine compound of the above formula (F)]
0.88 part of the gallium phthalocyanine compound of the formula (F) and 0.1 part of water were added to 60 parts of N, N-dimethylformamide and reacted for 6 hours under reflux. After cooling, the obtained crystals were collected by filtration, washed twice with 60 parts of N, N-dimethylformamide, once with 60 parts of methyl ethyl ketone, and twice with 60 parts of ion-exchanged water, and then dried to give a solution of 0. 53 parts (88%) of hydroxygallium phthalocyanine were obtained.
The following analysis was performed on this compound. By LDI-TOFMS (positive), m / z: 598.07 (theoretical value is 598.078: C32H17GaN8O) was recognized. From this result, it was confirmed that it was hydroxygallium phthalocyanine.
The powder X-ray diffraction spectrum of this compound is shown in FIG. From this spectrum, it was confirmed that hydroxygallium phthalocyanine crystals showing new main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 8.16 ° and 28.06 ° were obtained. In this synthesis example, [JP-A-5-263007, k. Daimon, et al. : J. Imaging Sci. Technol. , 40, 249], a diffraction peak such as 7.86 ° based on the V-type hydroxygallium phthalocyanine crystal was also observed, and it was confirmed that the crystal types were mixed.

[Synthesis Example 5]
[(1) Synthesis of gallium phthalocyanine compound of general formula (A) (n = 1)]
To 100 ml of dimethyl sulfoxide, 1.24 parts of chlorogallium phthalocyanine and 3.8 parts of methanesulfonic acid were added, heated to 110 ° C. and reacted for 9 hours. After cooling to room temperature, a trace amount of insoluble part was removed by filtration. About 150 ml of ion exchange water was added to the resulting solution, and the mixture was stirred at room temperature for 3 hours. The produced crystals were filtered, washed thoroughly with ion exchange water, and dried to obtain 1.25 parts (92%) of a gallium phthalocyanine compound. A part of the obtained product was recrystallized from N, N-dimethylformamide, and the following analysis was performed.
L / TOFMS (negative) confirmed m / z: 676.19 (theoretical value was 676.06: C33H19GaN8O3S). The results of further elemental analysis are shown in the table below.

  From these results, it was confirmed that it was a gallium phthalocyanine compound of the following formula (C).

[(2) Hydrolysis of gallium phthalocyanine compound of the above formula (C)]
0.68 part of the gallium phthalocyanine compound of the formula (C) and 0.1 part of water were added to 60 parts of N, N-dimethylformamide and reacted for 7 hours under reflux. After cooling, the obtained crystals were collected by filtration, washed with 60 parts of N, N-dimethylformamide three times, once with 60 parts of methyl ethyl ketone, and twice with 60 parts of ion-exchanged water, and then dried to give a 0.1% solution. 43 parts (71%) of hydroxygallium phthalocyanine were obtained. The following analysis was performed on this compound.
By LDI-TOFMS (positive), m / z: 598.07 (theoretical value is 598.078: C32H17GaN8O) was recognized. From this result, it was confirmed that it was hydroxygallium phthalocyanine.
The powder X-ray diffraction spectrum of this compound is the same as that in FIG. 11 of [Synthesis Example 3], and shows new main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 7.92 ° and 27.82 °. It was confirmed that a hydroxygallium phthalocyanine crystal was obtained.

[Example of electrophotographic photosensitive member]
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not restrict | limited by these Examples. All parts are parts by weight.

[Electrophotographic Photoconductor Example 1]
After coating with an intermediate layer coating solution having the following composition on a 2 mm thick aluminum plate (for electrophotographic characteristic evaluation) and 380 mm long, φ100 mm aluminum cylinder (for actual machine evaluation), 130 ° C./20 minutes Drying was performed to form an intermediate layer of about 3.5 μm. Subsequently, the coating solution for the charge generation layer having the following composition was subjected to vibration mill dispersion for 6 hours together with zirconia balls having a diameter of 2 mm. After coating using this coating solution, drying was performed at 100 ° C./30 minutes, and the coating solution was about 0.3 μm. A charge generation layer was formed. Furthermore, after coating using a coating solution for a charge transport layer having the following composition, drying was performed at 130 ° C./20 minutes to form a charge transport layer of about 35 μm, and an electrophotographic photoreceptor of Example 1 was produced. For coating, a blade coating method (for electrophotographic characteristic evaluation) and a dip coating method (for actual machine evaluation) were used.

(Intermediate layer coating solution)
Titanium oxide CR-EL (manufactured by Ishihara Sangyo Co., Ltd.): 50 parts alkyd resin Beckolite M6401-50 (solid content 50% by weight, manufactured by Dainippon Ink & Chemicals, Inc.): 15 parts melamine resin L-145-60 (solid content 60) % By weight, manufactured by Dainippon Ink & Chemicals, Inc.): 8 parts 2-butanone: 120 parts

(Coating solution for charge generation layer)
Hydroxygallium phthalocyanine obtained in Synthesis Example 1: 3.0 parts polyvinyl butyral (manufactured by “XYHL” UCC): 2 parts methyl ethyl ketone: 150 parts

(Coating liquid for charge transport layer)
Polycarbonate Z polycarbonate (manufactured by Teijin Chemicals Ltd .; Panlite TS-2050): 10 parts Charge transporting compound (1) represented by the following structural formula: 7 parts Tetrahydrofuran: 80 parts Silicone oil (KF50-100cs, manufactured by Shin-Etsu Chemical Co., Ltd.) ): 0.002 part

[Electrophotographic Photoconductor Example 2]
The electrophotographic photosensitive member example 2 is the same as the electrophotographic photosensitive member example 1 except that the hydroxygallium phthalocyanine of the coating solution for the charge generation layer used in the electrophotographic photosensitive member example 1 is changed to that of the synthetic example 2. An electrophotographic photoreceptor was prepared.

[Electrophotographic Photoconductor Example 3]
The electrophotographic photosensitive member example 3 is the same as the electrophotographic photosensitive member example 1, except that the hydroxygallium phthalocyanine of the coating solution for the charge generation layer used in the electrophotographic photosensitive member example 1 is changed to that of the synthetic example 3. An electrophotographic photoreceptor was prepared.

[Electrophotographic Photoconductor Example 4]
The electrophotographic photoreceptor Example 4 was the same as the electrophotographic photoreceptor Example 1 except that the hydroxygallium phthalocyanine of the charge generation layer coating solution used in the electrophotographic photoreceptor Example 1 was changed to that of Synthesis Example 4. An electrophotographic photosensitive member was produced.

[Electrophotographic Photoconductor Example 5]
The electrophotographic photoreceptor Example 5 was the same as the electrophotographic photoreceptor Example 1 except that the hydroxygallium phthalocyanine of the charge generation layer coating solution used in the electrophotographic photoreceptor Example 1 was changed to that of Synthesis Example 5. An electrophotographic photosensitive member was produced.

[Electrophotographic photoreceptor comparative example 1]
Electrophotographic process similar to electrophotographic photoreceptor example 1 except that hydroxygallium phthalocyanine in the coating solution for charge generation layer used in electrophotographic photoreceptor example 1 is changed to hydroxygallium phthalocyanine obtained by the acid paste method. An electrophotographic photosensitive member of Comparative Example 1 was prepared.

[Electrophotographic photoreceptor comparative example 2]
Electrophotographic photoconductor Example 1 except that hydroxygallium phthalocyanine in the coating solution for charge generation layer used in electrophotographic photoconductor Example 1 was changed to Y-type titanyl phthalocyanine (manufactured by Toyo Ink Co., Ltd .; Riophoton-TOPA). Similarly, an electrophotographic photosensitive member of Comparative Example 2 was prepared.

[Electrophotographic characteristic evaluation]
Electrophotographic photosensitive member produced on an aluminum plate For the photosensitive members of Examples 1 to 5 and the electrophotographic photosensitive members of Comparative Examples 1 and 2, a commercially available electrostatic charging test apparatus (EPA8100 type manufactured by Kawaguchi Electric Manufacturing Co., Ltd.) was used. After charging for 5 seconds with a -5 KV corona discharge in the dark, the surface potential Vm (-V) of the electrophotographic photosensitive member was measured, and after being left in the dark for 20 seconds, the electrophotographic photosensitive member was The surface potential V0 (−V) was measured to determine the dark decay rate V0 / Vm. Next, after irradiating with 780 nm monochromatic light having a light amount of 5 μW / cm ^{2 on} the surface of the electrophotographic photosensitive member for 30 seconds, the surface potential V30 (−V) of the electrophotographic photosensitive member was measured. Further, as the sensitivity, the exposure amount required for halving V0 was measured as E1 / 2 (μJ / cm ² ). The results are shown in Table 5.

After obtaining the initial characteristics in this way, the fatigue characteristics were measured as follows. Using an electrostatic charge test device, tungsten light irradiation and corona charging are performed simultaneously, and charging exposure is performed for 2 hours while adjusting the amount of light and the corona discharge voltage so that the surface potential of the photoconductor is −800 V and the charging current is 7 μA. It was. Vm (−V), V0 (−V), V0 / Vm, V30 (−V), and E1 / 2 (μJ / cm ² ) were measured for this sample in the same manner as the initial characteristics. The results are shown in Table 6.

[Evaluation of actual machine]
The previously prepared photoreceptors of Examples 1 to 12 and the electrophotographic photoreceptors of Comparative Examples 1 to 5 were mounted on a process cartridge and mounted on a RICOH Pro C900 (Ricoh production printer).
As a process condition at the time of the test, the applied voltage to the charging member was set so that the charged potential of the unexposed portion was −800V. The development bias was set to -500V. As a sheet passing condition, 400,000 sheets of charts on which characters with an image area ratio equivalent to 6% were written on the entire A4 surface were printed. The test environment is normal temperature and humidity as temperature: 23 ° C., relative humidity: 55%, high temperature and high humidity environment as temperature: 30 ° C., relative humidity: 80%, and low temperature and low humidity environment as temperature: 10 ° C., relative humidity: 15%. The same printing test was conducted under the three environmental conditions.
The image evaluation was performed after the printing of 400,000 images. 5-2 was output, and the image density, resolution, and color color reproducibility were evaluated. These image evaluations were carried out in four stages. Very good ones were indicated by ◎, good ones were indicated by ○, slightly inferior ones by Δ, and bad ones by x. Further, as an evaluation of the afterimage, after printing 400,000 images, the applied voltage to the charging member is set so that the charged potential of the unexposed portion becomes −500 V, and the applied voltage to the transfer member is set so that the transfer current becomes 100 μA. The A4 chart in which the character portion and the halftone portion shown in FIG. 13 are mixed is output. The degree of afterimage in the halftone part of the output image was evaluated in four stages, and very good ones were indicated by ◎, good ones by ○, slightly inferior by Δ, and bad ones by x. The results are shown in Table 7.

  From the above results, the photoconductor of the present invention uses a novel hydroxygallium phthalocyanine crystal and does not generate abnormal images such as afterimages after repeated use over a long period of time, and realizes stable sensitivity characteristics and charging characteristics. I understand that there is.

DESCRIPTION OF SYMBOLS 1 Photoconductor 1C, 1M, 1Y, 1K Photoconductor 2 Conductive support 3 Charge generation layer 4 Charge transport layer 5 Protective layer 6 Undercoat layer 7 Single layer type photosensitive layer 10C, 10M, 10Y, 10K Image forming element 11 Static elimination Lamp 12 Charging roller 12a Gap forming member 12C, 12M, 12Y, 12K Charging member 13 Image exposure unit 13C, 13M, 13Y, 13K Laser beam 14 Developing unit 14C, 14M, 14Y, 14K Developing member 15 Pre-transfer charger 15C, 15M, 15Y, 15K Cleaning member 16 Registration roller 17 Transfer paper 18 Transfer charger 19 Separation charger 20 Separation claw 21 Charger before cleaning 22 Fur brush 23 Cleaning blade 24 Feed roller 25 Transfer conveyance belts 26C, 26M, 26Y, 26K Transfer brush 27 Fixing device

JP 48-34189 A Japanese Patent Laid-Open No. 57-14874 Japanese Patent Publication No.51-1662 US Pat. No. 3,816,118 JP 58-18239 A Japanese Patent Laid-Open No. 5-98181 Japanese Patent Laid-Open No. 5-263007 JP 59-133551 A JP 60-59354 A

Y. Fujimaki, Proc. IS & T's 7th International Congress on Advances in Non-Impact Printing Technologies, 1,269 k. Daimon, et al. : J. Imaging Sci. Technol. , 40, 249 D. C. Acad. Sci. , (1965), 242, 1026 Bull. Soc. Chim. France, 23 (1962) Inlog. Chem. (19), 3131, (1980)

Claims (6)

  A hydroxygallium phthalocyanine crystal showing main diffraction peaks at Bragg angles (2θ ± 0.3 °) of 8.0 ° and 28.0 ° in an X-ray diffraction spectrum by CuKα ray.   Bragg angles (2θ ± 0.3 °) 8.0 °, 10.4 °, 13.3 °, 16.6 °, 22.5 °, 24.5 °, 28. X-ray diffraction spectrum by CuKα ray. The hydroxygallium phthalocyanine crystal according to claim 1, which shows a diffraction peak at 0 °.   An electrophotographic photosensitive member having a charge generation layer and a charge transport layer provided on a conductive support, wherein the charge generation layer contains the hydroxygallium phthalocyanine crystal according to claim 1 or 2. Photoconductor.   An image forming method using the electrophotographic photosensitive member according to claim 3.   An image forming apparatus comprising the electrophotographic photosensitive member according to claim 3.   A process cartridge for an image forming apparatus, comprising the electrophotographic photosensitive member according to claim 3.

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