JPH1160979A - Treatment of phthalocyanine pigment and electrophotographic photoreceptor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a phthalocyanine pigment enabling adjustment of sensitivity in phthalocyanine pigment in wide range, excellent in dispersibility in resin dispersion and storage stability of dispersion, having good electrophotographic characteristics, simple in production process and free from cost up and provide its treating method and obtain an electrophotographic photoreceptor having good resolving power, excellent in tone property and capable of forming image having vivid image quality. SOLUTION: Crude phthalocyanine compound is subjected to exposing treatment under ozone atmosphere before or after subjecting crude phthalocyanine compound to grinding treatment to produce pigment. For example, the crude phthalocyanine compound is subjected to acid paste treatment and then, subjected to exposing treatment under ozone atmosphere and grinding treatment. Phthalocyanine treated thus is included in a photosensitive layer of electrophotographic photoreceptor to provide the objective electrophotographic photoreceptor adjusted in sensitivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a phthalocyanine pigment and an electrophotographic photosensitive member containing a phthalocyanine pigment obtained by the method in a photosensitive layer.

[0002]

2. Description of the Related Art Phthalocyanine compounds are used as functional materials in various fields, and are used as blue or green pigments and dyes, as well as electrophotographic photoreceptors, optical disks, solar cells, sensors, deodorants, and antibacterial agents. Research and development are being actively conducted in a wide range of fields such as agents and nonlinear optical materials. In particular, for phthalocyanine pigments used in electrophotographic photoreceptors, the photosensitive wavelength range has been extended to the wavelength of near-infrared semiconductor lasers, and those having high sensitivity have already been put into practical use, such as laser printers and full-color copiers. Numerous reports have been made on charge generation materials for photoconductors for digital recording, focusing on their crystal forms and electrophotographic properties.

[0003] In general, phthalocyanine pigments exhibit several crystal forms depending on the production method and treatment method, and it is known that the difference in crystal form has a great effect on the photoelectric conversion characteristics of the phthalocyanine pigment. Regarding the crystal form of the phthalocyanine pigment, for example, looking at the copper phthalocyanine pigment, in addition to the stable β form, α, ε, χ,
Crystal forms such as γ and δ are known, and these crystal forms are
It is known that mutual transformation is possible by mechanical strain, sulfuric acid treatment, organic solvent treatment, heat treatment and the like (for example, U.S. Pat. Nos. 2,770,629 and 3,160,300).
Nos. 635, 3,708,292 and 3,35
7,989). Further, among metal-free phthalocyanine pigments, crystal forms such as α, β, γ, ε, δ and X are known. Further, with respect to gallium phthalocyanine pigment, many reports have been made on its crystal form and electrophotographic properties. JP-A-5-98181 discloses a chlorogallium phthalocyanine pigment having a diffraction peak at a specific Bragg angle, The electrophotographic photoreceptor used is further described in JP-A-5-263007 and JP-A-7-53892, which describe a very sensitive hydroxygallium phthalocyanine pigment and a highly sensitive electrophotographic photoreceptor using the same. Have been.

[0004]

Generally, the sensitivity of an electrophotographic photoreceptor using a phthalocyanine pigment as a charge generating material is substantially determined by the phthalocyanine pigment used. It is necessary to select a phthalocyanine pigment that meets the sensitivity required by the electrophotographic process. However, in some cases,
The required sensitivity of the electrophotographic process and the sensitivity of the electrophotographic photoreceptor do not always match, and the problem of thickening or thinning of thin lines or fogging may occur.In order to achieve high quality image formation, charge generation is required. There were restrictions on the choice of materials. Furthermore, for electrophotographic photoreceptors for general-purpose small laser printers used in the market of individual users and small offices and for full-color copying machines requiring high resolution, high-sensitivity electrophotographic photoreceptors are used. In such a case, there is a problem that the resolution is lowered or the reproducibility of halftone is deteriorated. Therefore, there is a limitation in using a high-sensitivity phthalocyanine pigment as it is as a charge generation material. In order to adjust the electrophotographic photosensitive member to a desired sensitivity, for example, when a charge generation material is used in a resin dispersion system, a method of changing a binder resin or a solvent to be used is known. The solvent and the solvent are restricted by the configuration or production of the photoreceptor and can be used, so that it is difficult to adjust the sensitivity to the actually required sensitivity. On the other hand, it has been reported that the sensitivity is adjusted by using a mixture of a plurality of phthalocyanine pigments. For example, JP-A-62-2
No. 7227 discloses the use of α-type and β-type titanyl phthalocyanine pigments.
No. 1 discloses a Bragg angle (2θ) = 7.6 °, 10.
2 °, 12.6 °, 13.2 °, 15.2 °, 16.2
°, 18.4 °, 22.5 °, 24.2 °, 25.4 °
And mixing a titanyl phthalocyanine pigment having a crystal giving a diffraction peak at 28.7 ° with a titanyl phthalocyanine pigment having a crystal type giving a peak at 27.3 °, and titanyl phthalocyanine pigments having different crystal types are described. It is known that the sensitivity is adjusted by changing the mixing ratio of the two. JP-A-2-280169 discloses that sensitivity is adjusted by mixing various kinds of phthalocyanine pigments such as a metal-free phthalocyanine pigment and a copper phthalocyanine pigment with a titanyl phthalocyanine pigment.

However, the electrophotographic photosensitive members disclosed in the above publications do not always have a sufficient sensitivity adjustment range, and when used in a resin dispersion system, dispersibility and storage stability of the dispersion can be practically satisfied. However, there are problems such as large fluctuations in the potential upon repeated use, and large fluctuations in characteristics under high and low humidity environments. In addition, there are problems that the manufacturing process becomes complicated and the cost increases.

The present invention has been made to solve the above-mentioned problems in the prior art. That is, an object of the present invention is to adjust the sensitivity of a phthalocyanine pigment in a wide range, to have excellent dispersibility in a resin dispersion and storage stability of the dispersion, to have good electrophotographic properties, and to simplify the production process. Accordingly, an object of the present invention is to provide a phthalocyanine pigment which does not increase the cost and a method for treating the same. Another object of the present invention is to provide an electrophotographic photosensitive member capable of adjusting the sensitivity of the electrophotographic photosensitive member to a required sensitivity of an electrophotographic process so that a clear image of an image can be obtained. .

[0007]

Means for Solving the Problems The present inventor controlled the sensitivity of a phthalocyanine pigment by providing a step of processing under an ozone atmosphere during the step of pulverizing a phthalocyanine compound, thereby achieving the required sensitivity of an electrophotographic process. The inventors have found that stable electrophotographic characteristics can be obtained without deteriorating the dispersibility in a resin dispersion and storage stability, and have completed the present invention.

That is, the present invention relates to a method for treating a phthalocyanine pigment in which the crude phthalocyanine compound is pulverized into fine particles by pulverizing the crude phthalocyanine compound under ozone atmosphere before or after the crude phthalocyanine compound is pulverized. The ozone exposure treatment is performed. The phthalocyanine pigment of the present invention is obtained by the processing method described above, and the electrophotographic photoreceptor of the present invention contains the phthalocyanine pigment in a photosensitive layer provided on a conductive substrate. It is characterized by.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The method for treating a phthalocyanine pigment of the present invention includes a step of performing an ozone exposure treatment for exposing the crude phthalocyanine compound to an ozone atmosphere before or after the pulverization treatment during the phthalocyanine compound pigmentation step.
As a method for treating a phthalocyanine pigment for an electrophotographic photoreceptor, a method of subjecting a crude phthalocyanine to an acid paste treatment, followed by a wet treatment, a method of pulverizing a crude phthalocyanine compound obtained by synthesis, and a method of pulverizing a crude phthalocyanine compound are used. The main treatment method is a method of subjecting the phthalocyanine pigment to wet treatment, and the like.In the treatment method of the phthalocyanine pigment of the present invention, an ozone exposure treatment step is provided in the pigmentation process by the above-mentioned pulverization treatment. Specifically, (1) the crude phthalocyanine compound is subjected to an acid paste treatment, then to an ozone exposure treatment in an ozone atmosphere, and then to a pulverization treatment.
The crude phthalocyanine compound is subjected to an ozone exposure treatment in an ozone atmosphere and then pulverized. (3) The crude phthalocyanine compound is pulverized and pulverized, and then subjected to an ozone exposure treatment in an ozone atmosphere and then wet-treated. I can give you a case.

In the present invention, the raw phthalocyanine compound to be treated is synthesized by a known method. For example, as a method of synthesizing a crude metal phthalocyanine compound, a diiminoisoindoline method in which diiminoisoindoline and a metal chloride are heated in the presence of an organic solvent, phthalonitrile and a metal chloride are heated and melted or an organic solvent is used. Phthalonitrile method of heating in the presence of, phthalic anhydride and urea and metal chloride are heated and melted or the Wiler method of heating in the presence of an organic solvent, a method of reacting cyanobenzamide and a metal salt at a high temperature, dilithium phthalocyanine And a metal salt. The crude metal-free phthalocyanine can be synthesized by, for example, reacting o-phthalodinitrile or diiminoisoindoline with a suitable solvent in the presence of a strong base catalyst. Solvents used in these synthesis methods include α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenylethane, ethylene glycol, dialkyl ether, quinoline, sulfolane, dichlorobenzene, dimethylformamide, dimethyl sulfoxide. ,
A reaction-inactive high-boiling solvent such as dimethylsulfamide is preferred.

[0011] The present invention provides an ozone exposure treatment step under an ozone atmosphere during the process of converting the crude phthalocyanine compound obtained by the above synthesis method into a pigment for use as a pigment for an electrophotographic photosensitive member. Is provided. Ozone treatment equipment for performing ozone exposure treatment
For example, a processing vessel 1 provided with a stirring blade 6 as shown in FIG. 1 is used. That is, the phthalocyanine compound 7 to be treated is charged into the treatment vessel 1 provided with the stirring blade 6, the air containing ozone generated from the ozone generator 2 is fed, and the ozone concentration in the air discharged from the exhaust port is reduced. The ozone exposure treatment is performed while measuring with the ozone concentration meter 3. 4 is an ozone filter and 5 is a motor. In order to treat the phthalocyanine compound more efficiently, an ozone treatment device having a mechanism in which the whole container vibrates or rotates may be used.

The concentration of ozone in the ozone atmosphere is not particularly limited, but the higher the ozone concentration, the more the sensitivity tends to decrease, so that the ozone exposure treatment can be performed in a short time. The practical ozone concentration is preferably 0.01 ppm or more, more preferably in the range of 0.1 ppm to 500 ppm. On the other hand, the time required for the ozone exposure treatment is appropriately determined depending on the type and weight of the phthalocyanine compound to be treated. For example, when the ozone concentration is 0.1 ppm, the treatment time is 1 minute or more, preferably 10 minutes or more. Is preferred.

In one embodiment of the present invention, a phthalocyanine pigment having excellent dispersibility can be obtained by subjecting the phthalocyanine compound to pulverization by subjecting the phthalocyanine compound to a pulverization treatment after the ozone exposure treatment according to the above method. If
This involves crystal transformation by the pulverization process. The pulverization treatment includes dry pulverization without using a solvent and wet pulverization using a solvent. In the present invention, any method can be used. Examples of the apparatus used for dry pulverization include a vibration mill, an automatic mortar, a sand mill, a dyno mill, a co-ball mill, an attritor, a planetary ball mill, and a ball mill. The average particle size of the phthalocyanine pigment after the dry pulverization is adjusted to be 0.5 μm or less, preferably 0.3 μm or less by adjusting the pulverization time. On the other hand, as an apparatus used for wet pulverization, an apparatus for the above-mentioned dry pulverization can be used, and a stirring tank, an ultrasonic disperser, a high-pressure homogenizer, and the like can be used. Solvents that can be used for wet grinding include benzyl alcohol, isopropyl alcohol, cyclohexanone, methyl ethyl ketone, toluene, monochlorobenzene, n-butyl acetate, dimethyl sulfoxide, N, N-dimethylformamide, water, and two or more of these solvents. Known solvents such as a mixture can be used. These solvents are used in an amount of 1 to 200 parts by weight, preferably 10 to 100 parts by weight, based on 1 part by weight of the phthalocyanine pigment. Also,
The processing time of the wet pulverization is adjusted so that the average particle size becomes 0.5 μm or less, preferably 0.3 μm or less, similarly to the dry pulverization. The temperature of the wet treatment is selected from the range of 0 ° C to the boiling point of the solvent, preferably 10 to 80 ° C.

[0014] In another embodiment of the present invention,
After the crude phthalocyanine compound is pulverized and pulverized,
An ozone exposure treatment can be performed in an ozone atmosphere, followed by a wet treatment. The crude phthalocyanine compound obtained by synthesis is subjected to wet treatment after being pulverized into fine particles by a pulverization treatment, thereby facilitating the crystal conversion of the phthalocyanine pigment, and by selecting a solvent used in the wet treatment, a wide range from high sensitivity to low sensitivity is obtained. Although a phthalocyanine pigment can be produced, in the present invention,
By performing the ozone exposure treatment under an ozone atmosphere as a pre-process of the wet treatment, the sensitivity can be more finely adjusted, and the sensitivity can be controlled to the optimum. At this time, the pulverizing treatment, the ozone exposure treatment, and the wet treatment can be performed in the same manner as in the above-described method.

[0015] In yet another embodiment of the present invention,
After the crude phthalocyanine compound has been subjected to the acid paste treatment, it may be subjected to an ozone exposure treatment in an ozone atmosphere, followed by a wet treatment. By subjecting the crude phthalocyanine compound to an acid paste treatment, the crude phthalocyanine compound can be converted into an amorphous or low-crystallinity phthalocyanine crystal at the same time as being atomized. The phthalocyanine pigment can be produced by further performing a wet treatment to crystallize it. In the present invention, the sensitivity is finely adjusted by performing an ozone exposure treatment in an ozone atmosphere after the acid paste treatment. And the sensitivity can be controlled to the optimum sensitivity. The above-mentioned acid paste treatment means a method in which a crude phthalocyanine compound is dissolved in sulfuric acid or a sulfated salt is poured into an aqueous alkali solution, water or ice water and reprecipitated. As the sulfuric acid used for the acid paste treatment, one having a concentration of 70 to 100%, preferably 95 to 100% is used. Acid
The ozone exposure treatment and the wet treatment in an ozone atmosphere after the paste treatment can be performed in the same manner as described above.

According to the present invention, an ozone exposure treatment step is provided in the process of converting the crude phthalocyanine compound into a pigment as described above, and the sensitivity can be adjusted to an arbitrary value by adjusting the ozone exposure treatment conditions. It becomes possible. In the phthalocyanine pigment subjected to the ozone exposure treatment, a part of the pigment is oxidized by reacting with ozone, so that the photoelectric conversion efficiency is lowered and the sensitivity is lowered. The higher the ozone concentration during ozone exposure treatment, the longer the treatment time, the greater the rate of reaction with ozone. Therefore, the sensitivity can be controlled by adjusting the ozone exposure treatment conditions. In addition, the phthalocyanine pigment that has been subjected to the ozone exposure treatment has no change in properties other than sensitivity, such as the crystal type or particle size, so that the ozone exposure treatment reduces the dispersibility of the coating solution and the environmental stability of the electrophotographic photoreceptor. The sensitivity can be reduced without causing a decrease.

Next, an electrophotographic photosensitive member containing a phthalocyanine pigment obtained by the processing method of the present invention in a photosensitive layer will be described. In the electrophotographic photoreceptor of the present invention, the phthalocyanine pigment obtained by providing the ozone exposure treatment step in the production step is contained in the photosensitive layer. In the present invention, as the phthalocyanine pigment used as the charge generating material, any known phthalocyanine pigment can be used, and among them, X-type metal-free phthalocyanine pigment, chlorogallium phthalocyanine pigment, hydroxygallium phthalocyanine pigment and titanyl phthalocyanine pigment are preferable. Among them, X-type metal-free phthalocyanine pigments, chlorogallium phthalocyanine pigments having a specific crystal form, hydroxygallium phthalocyanine pigments and titanyl phthalocyanine pigments are particularly preferred.

The X-type metal-free phthalocyanine pigment used in the electrophotographic photoreceptor of the present invention can be obtained by using a crude β
A non-metallic phthalocyanine or a crude α-metal-free phthalocyanine is subjected to an acid paste treatment to obtain an α-metal-free phthalocyanine pigment, which is then subjected to an ozone exposure treatment, followed by a solvent treatment.

The chlorogallium phthalocyanine pigment used in the electrophotographic photoreceptor of the present invention includes a Bragg angle (2θ).
± 0.2 °) having strong diffraction peaks at 7.4 °, 16.6 °, 25.5 ° and 28.3 °, and the crude chlorogallium phthalocyanine produced by a known method is It can be manufactured by mechanically dry pulverizing using a known pulverizing apparatus, or by dry pulverizing and then performing wet processing using the above processing apparatus together with a solvent, and ozone exposure processing is performed before dry pulverization or wet pulverization. It may be performed before processing.

The hydroxygallium phthalocyanine pigment used in the electrophotographic photoreceptor of the present invention includes a Bragg angle (2θ ± 0.2 °) of 7.5 °, 9.9 °, 12.5 °.
°, 16.3 °, 18.6 °, 25.1 ° and 28.
It has a strong diffraction peak at 3 °, and can be produced by subjecting crude chlorogallium phthalocyanine produced by a known method to acid / paste treatment, followed by ozone exposure treatment, and further solvent treatment. . In the present invention, the ozone exposure treatment can be performed before the acid paste treatment, but it is more effective to perform the treatment after the acid paste treatment because the sensitivity control range is slightly narrowed.

The titanyl phthalocyanine pigment used in the electrophotographic photoreceptor of the present invention includes a Bragg angle (2θ ± 0.
2 °), which has a strong diffraction peak at 27.3 °. The crude titanyl phthalocyanine produced by a known method is subjected to an acid paste treatment, followed by an ozone exposure treatment, and further using a specific solvent. And can be produced by performing a solvent treatment.

In the present invention, the phthalocyanine pigment and the binder resin solution are mixed and dispersed to prepare a coating solution for coating the photosensitive layer. As the binder resin used for the photosensitive layer of the electrophotographic photoreceptor of the present invention, well-known ones, for example,
Polycarbonate, polystyrene, polysulfone, polyester, polyimide, polyester carbonate, polyvinyl butyral, methacrylate polymer, vinyl acetate polymer or copolymer, cellulose ester or ether, polybutadiene, polyurethane, phenoxy resin, epoxy resin, silicone resin, fluorine Examples thereof include resins and the like and partially crosslinked cured products thereof, and these can be used alone or in combination of two or more. The mixing ratio of the phthalocyanine pigment and the binder resin is 40: 1 to 1: 4,
Preferably it is 20: 1 to 1: 2. If the ratio of the phthalocyanine pigment is too high, the stability of the coating solution is reduced. If the ratio is too low, the sensitivity is reduced. Therefore, it is preferable to set the ratio within the above range. As a solvent used for dispersion, methanol, ethanol, n-butanol, benzyl alcohol, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, toluene, xylene, chlorobenzene, dimethyl Examples thereof include various solvents such as formamide, dimethylacetamide, water and the like, and mixtures thereof. As a dispersing means, methods such as a sand mill, a colloid mill, an attritor, a dyno mill, a coball mill, a roll mill, an ultrasonic disperser, and a high-pressure homogenizer can be used.

In the present invention, in the case of an electrophotographic photosensitive member having a laminated structure in which the photosensitive layer is functionally separated into a charge generating layer and a charge transporting layer, the charge generating layer is formed by applying the above coating solution directly or under the conductive substrate. It is formed by coating through a pull layer. Further, it may be formed by coating on a charge transport layer described later. At this time, the thickness of the charge generation layer is
It is about 0.01 to 5 μm, preferably about 0.03 to 2 μm.

As the electroconductive substrate in the electrophotographic photoreceptor of the present invention, any one can be used as long as it is usually used for an electrophotographic photoreceptor. In addition, the surface of the conductive substrate can be subjected to various kinds of processing as needed within a range that does not affect the image quality. For example, surface anodic oxidation treatment, surface roughening treatment by liquid honing, chemical treatment, coloring treatment, and the like can be performed.

The charge transport layer comprises a charge transport material and a film-forming resin. Any known charge transporting material can be used. Examples of the film-forming resin include, for example, polycarbonate, polyarylate, polystyrene, polyester, styrene-acrylonitrile copolymer, polysulfone, polymethacrylate, styrene-methacrylate copolymer, silicone resin,
Known resins such as a fluorine resin and a phenol resin are used. The compounding ratio of the charge transport material and the film-forming resin is 5: 1 to 1
1: 5, preferably 3: 1 to 1: 3. When the ratio of the charge transporting material is too high, the mechanical strength of the charge transporting layer is reduced, and when it is too low, the sensitivity is reduced. When the charge transporting material has a film forming property, the film forming resin can be omitted. The charge transport layer is formed by dissolving the above-described charge transport material and the film-forming resin in an appropriate solvent and applying the solution. The film is formed to have a thickness of 5 to 50 μm, preferably 10 to 40 μm. Is preferred. In the present invention, the charge transport layer preferably contains a hindered amine compound or a hindered phenol compound as an antioxidant. Since the hindered amine compound and the hindered phenol compound are not affected by a modifying substituent, known compounds can be widely used. The total amount of the antioxidant added is preferably in the range of 0.01 to 10% by weight of the whole layer to be added.

In the case where the photosensitive layer has a single-layer structure, the photosensitive layer is formed by adding the phthalocyanine pigment, the charge transporting material, and the film-forming resin prepared by providing the above-mentioned ozone exposure treatment step during the manufacturing process. The film is formed by mixing, dispersing, and applying the solution, but is preferably formed to have a thickness of 5 to 50 μm, preferably 10 to 40 μm. Also, the compounding ratio between the charge transport material and the film forming property is as follows:
It is preferable to set the compounding ratio of the phthalocyanine pigment to the charge transporting material to about 1:10 to 10: 1.

As a coating method for forming the above-mentioned photosensitive layer, known methods such as a spray coating method, a wire bar coating method, a dip coating method, a bead coating method and a curtain coating method can be used. An undercoat layer may be provided on the conductive substrate as needed. As the undercoat layer, for example, an anodized aluminum film, aluminum oxide, inorganic layers such as aluminum hydroxide, polyvinyl alcohol, polyethylene, polyacrylic acid, celluloses, organic layers such as polyurethane, polyimide, polyamide, zirconium chelate compound, A layer made of a known material such as an organic metal compound such as a zirconium alkoxide compound, a titanyl chelate compound, or a titanyl alkoxide compound, or a silane coupling agent can be used. The thickness of the undercoat layer is 0.0
It is most effective to set the thickness in the range of 1 to 20 μm, preferably 0.0.1 to 10 μm.

In the present invention, if necessary, a protective layer may be coated on the surface of the photosensitive layer. The protective layer is formed by including a conductive material in a suitable binder resin. As the conductive material, metallocene compounds such as dimethylferrocene,
Aromatic amino compounds such as N, N'-bis- (m-tolyl) benzidine, and metal oxides such as antimony oxide, tin oxide, titanium oxide, indium oxide, and tin oxide-antimony oxide can be used. However, the present invention is not limited to this. Further, as the binder resin used for the protective layer, those exemplified above as the binder resin can be used. The protective layer has an electric resistance of 10 ⁹ to 10.
It is preferable to configure so as to be ¹⁴ Ω · cm. The thickness of the protective layer is 0.5 to 20 μm, preferably 1 to 10 μm
Is set in the range.

[0029]

The present invention will be described below in more detail with reference to examples. In the examples and the like, all “parts” mean “parts by weight”. Synthesis Example 1 (Synthesis of α-type metal-free phthalocyanine) 100 parts of o-phthalodinitrile and 10 parts of piperidine were added in 300 parts of chlorotoluene at 200 ° C.
The reaction was carried out with stirring for a period of time to obtain reddish purple crystals. Then, after washing with acid and alkali, methanol, N,
After washing with N-dimethylformamide and N-methylpyrrolidone, drying was performed to obtain a crude metal-free phthalocyanine.
10 parts of the obtained crude metal-free phthalocyanine was sufficiently dissolved in 200 parts of sulfuric acid (concentration: 97%) cooled to 0 to 5 ° C.
It was dropped into 000 parts of pure water and reprecipitated. This was filtered, washed with an alkali, methanol, N, N-dimethylformamide, and N-methylpyrrolidone, and then dried to obtain 90 parts of α-type metal-free phthalocyanine.

Example 1 10 parts of the α-type metal-free phthalocyanine obtained in Synthesis Example 1 was added to an ozone treatment apparatus having a structure shown in FIG.
And then pulverizing with a magnetic ball mill for 4 days together with 0.5 part of an X-type metal-free phthalocyanine pigment to obtain an X-type metal-free phthalocyanine pigment having an average particle size of 0.10 μm.

Examples 2 to 6 In Example 1, the conditions for the ozone exposure treatment were 0.1 pp.
m · 10 minutes, 0.5 ppm · 30 minutes, 1.0 ppm
・ 30 minutes, 10 ppm ・ 30 minutes, 50 ppm ・ 30
Except that the average particle size was 0.1 minute.
A 10 μm X-type metal-free phthalocyanine pigment was prepared. Comparative Example 1 An X-type metal-free phthalocyanine pigment having an average particle size of 0.10 μm was prepared in the same manner as in Example 1 except that the ozone exposure treatment was not performed.

Example A Polyvinyl butyral resin (trade name: Eslec BM-
8 parts of n-butyl alcohol 1
A 50% toluene solution of tributoxyzirconium acetylacetonate (trade name:
100 parts of ZC-540, manufactured by Matsumoto Kosho Co., Ltd., 10 parts of γ-aminopropyltriethoxysilane (trade name: A1100, manufactured by Nippon Unicar) and n-butyl alcohol 13
The solution obtained by mixing 0 parts was added to the above-mentioned polyvinyl butyral resin solution and stirred to prepare a coating liquid for an undercoat layer. This coating solution was dip-coated on an aluminum sheet having a thickness of 50 μm and dried by heating at 150 ° C. for 10 minutes to form an undercoat layer having a thickness of 1.0 μm. On the other hand, a solution prepared by dissolving 1 part of a polyvinyl butyral resin (trade name: ESLEC BM-S, manufactured by Sekisui Chemical Co., Ltd.) in 100 parts of n-butyl acetate and 1 part of the X-type metal-free phthalocyanine pigment obtained in Example 1 were used. The mixture was mixed and dispersed with a glass bead for 3 hours using a sand mill to prepare a coating solution for forming a charge generation layer.
The obtained coating solution was applied onto the undercoat layer by dip coating,
The resultant was dried by heating at 0 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.20 μm. Next, a charge transport layer was formed on the formed charge generation layer. That is, N, N'-diphenyl-
N, N'-bis (3-methylphenyl)-[1,1'-
Biphenyl] -4,4'-diamine is used as a charge transporting material, dissolved together with 6 parts of a polycarbonate Z resin in 40 parts of monochlorobenzene, and the obtained solution is applied on the charge generating layer by a dip coating apparatus. 40 at 120 ° C
After heating and drying for 20 minutes, a charge transport layer having a thickness of 20 μm was formed, and an electrophotographic photosensitive member was produced.

Examples BF Similar to Example A except that the X-type metal-free phthalocyanine pigments of Examples 2 to 6 were used in place of the X-type metal-free phthalocyanine pigment of Example 1. Thus, electrophotographic photoreceptors were respectively manufactured. Comparative Example A An electrophotographic photosensitive member was prepared in the same manner as in Example A, except that the X-type metal-free phthalocyanine pigment of Comparative Example 1 was used instead of the X-type metal-free phthalocyanine pigment of Example 1. Produced.

The following measurements were performed to evaluate the electrophotographic characteristics of the electrophotographic photosensitive member. Using an electrophotographic paper tester (EPA 8200: manufactured by Kawaguchi Electric Co., Ltd.), a 20 mmφ small area mask was used for the electrophotographic photosensitive member of the sample.
In an environment of 0 ° C. and 50% RH, the electrophotographic photoreceptor is negatively charged by corona discharge of −5.0 kV, and then halogen lamp light separated to 780 nm using an interference filter is applied to the surface of the photoreceptor for 5 hours. Irradiation was carried out by adjusting to be 0.0 μW / cm ² . The initial surface potential V0 (V) at that time and the half-exposure amount E1 / to 1/2 of V0.
2 (μJ / cm ² ) and the residual potential VR (V) 10 seconds after exposure were measured. Further, V0, E1 / 2 and VR after repeating the above charging and exposure 1000 times were also measured. Further, 1 of the coating solution for the charge generation layer
The condition after storage for months was observed. Table 1 shows the results.

[0035]

[Table 1] Synthesis Example 2 (Synthesis of type I chlorogallium phthalocyanine) 30 parts of 1,3-diiminoisoindoline and 9.1 parts of gallium trichloride were placed in 230 parts of dimethyl sulfoxide, reacted at 150 ° C. for 4 hours, and formed. The product was filtered off, washed with methanol and dried to give
28 parts of crude crystals of type chlorogallium phthalocyanine were obtained.

Example 7 The crude type I chlorogallium phthalocyanine 1 obtained in Synthesis Example 2
0 parts were exposed to ozone at 50 ppm for 30 minutes using the same ozone treatment apparatus as that used in Example 1, and then 1 part.
It was placed in an alumina pot together with 100 parts of 2 mmφ alumina beads. This was mounted on a vibration mill (MB-1 type, manufactured by Chuo Kakoki Co., Ltd.) and subjected to dry pulverization for 100 hours to obtain a chlorogallium phthalocyanine pigment having an average particle size of 0.02 μm. FIG. 2 shows a powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine pigment.

Example 8 Crude I-chlorogallium phthalocyanine 1 obtained in Synthesis Example 2
0 parts were dry-pulverized by a vibration mill in the same manner as in Example 7 without performing the ozone exposure treatment. After 5 parts of the obtained chlorogallium phthalocyanine pigment was subjected to an ozone exposure treatment at 50 ppm for 30 minutes using the same ozone treatment apparatus as that used in Example 1, the glass beads 60 of 5 mmφ were used.
In 50 parts of dimethylsulfoxide at room temperature for 24 hours.
After washing in a part, II was dried to obtain an average particle size of 0.08 μm.
4.5 parts of chlorogallium phthalocyanine type pigment were obtained.

Comparative Example 2 A chlorogallium phthalocyanine pigment having an average particle size of 0.08 μm was prepared in the same manner as in Example 7 except that the ozone exposure treatment was not performed. Comparative Example 3 A chlorogallium phthalocyanine pigment having an average particle size of 0.08 μm was prepared in the same manner as in Example 8, except that the ozone exposure treatment was not performed.

Examples G and H Examples A and H were prepared in the same manner as in Example A except that the chlorogallium phthalocyanine pigment of Example 7 or 8 was used instead of the X-type metal-free phthalocyanine pigment of Example 1. An electrophotographic photoreceptor was produced in the same manner. Comparative Examples B and C In Example A, except that the chlorogallium phthalocyanine pigment of Comparative Example 2 or Comparative Example 3 was used instead of the X-type metal-free phthalocyanine pigment of Example 1, each was performed in the same manner as in Example A. An electrophotographic photosensitive member was manufactured.

The evaluation of the electrophotographic photosensitive member was performed by the method described above. Table 2 shows the results.

[Table 2] Synthesis Example 3 (Synthesis of type I hydroxygallium phthalocyanine) After dissolving 3 parts of crude crystals of type I chlorogallium phthalocyanine prepared in Synthesis Example 2 in 90 parts of concentrated sulfuric acid, the obtained solution was mixed with 180 parts of 25% aqueous ammonia. And 60 parts of distilled water were dropped into a mixed solution to precipitate crystals. The precipitated hydroxygallium phthalocyanine was sufficiently washed with distilled water, dried and dried.
Got a part.

Example 9 Two parts of the type I hydroxygallium phthalocyanine prepared in Synthesis Example 3 were exposed to ozone at 100 ppm for 60 minutes using the same ozone treatment apparatus as used in Example 1, and then N, N- A wet pulverization treatment was performed for 24 hours with a ball mill together with 38 parts of dimethylformamide. Next, after washing with ethyl acetate, drying was performed to obtain an average particle size of 0.1.
1.9 parts of a 10 μm V-type hydroxygallium phthalocyanine pigment were obtained. Comparative Example 4 A V-type hydroxygallium phthalocyanine pigment having an average particle diameter of 0.10 μm was prepared in the same manner as in Example 9 except that the ozone exposure treatment was not performed.

Example I A 40 mmφ × 319 mm aluminum pipe was subjected to a wet honing treatment so that the center line average roughness Ra was 0.15 μm.
The surface was roughened so that Next, the undercoat layer coating solution used in Example A was applied thereon in the same manner as in Example A to form an undercoat layer. Next, the V-type hydroxygallium obtained in Example 9 was added to a solution in which 2 parts of a vinyl chloride-vinyl acetate copolymer resin (trade name: VMCH, manufactured by Union Carbide) was dissolved in 100 parts of n-butyl acetate. 2 parts of a phthalocyanine pigment were added, dispersed by a sand mill for 24 hours, and the resulting solution was diluted with n-butyl acetate to prepare a coating solution for forming a charge generation layer having a solid content of 3% by weight. The obtained coating solution was applied on the undercoat layer by a ring coating machine,
Heated and dried at 00 ° C for 10 minutes to a film thickness of 0.17 µm
Was formed. Further, the coating solution for a charge transport layer used in Example A was applied on the charge generation layer in the same manner as in Example A to form a charge transport layer, thereby producing an electrophotographic photoreceptor.

Comparative Example D An electrophotograph was prepared in the same manner as in Example I, except that the V-type hydroxygallium phthalocyanine pigment of Comparative Example 4 was used instead of the V-type hydroxygallium phthalocyanine pigment of Example 9. A photoreceptor was produced.

In order to evaluate the above electrophotographic photosensitive member, a laser printer (XP-11, manufactured by Fuji Xerox Co., Ltd.) was used.
The following measurement was performed using. This operation is performed in a low-temperature, low-humidity environment (10 ° C., 15% RH) under a grid applied voltage−
Charged with a 600 V scorotron charger (A), 780
5.0 mJ / s after one second using a semiconductor laser
The potential of each part was measured by a process of irradiating m ² light to perform exposure (B), and further irradiating 50 mJ / m ² of red LED light to remove electricity after 2 seconds (C). In this case, the higher the potential VH in (A), the higher the receptive potential of the photoreceptor, the higher the contrast, and the lower the potential VL in (B), the higher the sensitivity.
The lower the potential VRP of (C), the lower the residual potential, and it can be evaluated that the electrophotographic photosensitive member has less image memory and less fog. Next, the same measurement was performed in a high-temperature and high-humidity environment (30 ° C., 90% RH) to measure environmental fluctuation. The image quality (resolution) of these electrophotographic photosensitive members was evaluated using a laser printer (XP-15, manufactured by Fuji Xerox Co., Ltd.). Furthermore, in order to evaluate the dispersibility of the coating solution for the charge generation layer, a charge generation layer is formed on a glass plate, and those in which no aggregate is observed by microscopic observation are good, and an aggregate is observed. Those having a rough coating film surface were regarded as defective. Table 3 shows the results.

[0045]

[Table 3] Synthesis Example 4 (Synthesis of amorphous titanyl phthalocyanine) 3 parts of 1,3-diiminoisoindoline and 1.7 parts of titanium tetrabutoxide were placed in 20 parts of 1-chloronaphthalene, and reacted at 190 ° C. for 5 hours. , After filtering the product and washing with ammonia water, water and acetone,
Drying gave 4.0 parts of crude titanyl phthalocyanine. After dissolving 2.0 parts of the obtained crude titanyl phthalocyanine in 100 parts of 97% concentrated sulfuric acid, the mixture is poured into 1300 parts of ice water,
The precipitate of titanyl phthalocyanine was filtered, washed with dilute aqueous ammonia and water, and dried to obtain 1.6 parts of amorphous titanyl phthalocyanine.

Example 10 Amorphous titanyl phthalocyanine prepared in Synthesis Example 4
0 parts were exposed to ozone at 200 ppm for 30 minutes using the same ozone treatment apparatus as used in Example 1.
Thereafter, the mixture was stirred at 50 ° C. for 1 hour in a mixed solvent of 10 parts of water and 1 part of monochlorobenzene, then filtered, washed with methanol and water, and dried, to obtain a Bragg angle (2θ ± 0.
2 °) at least 9.5 °, 14.3 °, 18.0
°, 24.0 ° and 27.3 ° showing diffraction peaks,
As a result, 0.9 part of a titanyl phthalocyanine pigment having an average particle size of 0.09 μm and having no diffraction peaks at 6.8 °, 7.5 °, 11.7 ° and 28.6 ° was obtained.

Comparative Example 5 A titanyl phthalocyanine pigment having an average particle size of 0.09 μm was prepared in the same manner as in Example 10, except that the ozone exposure treatment was not performed. Comparative Example 6 0.5 part of α-type titanyl phthalocyanine pigment not subjected to ozone exposure treatment and 0.5 part of β-type titanyl phthalocyanine pigment 0.5
Were mixed to prepare 1 part of a mixed pigment of titanyl phthalocyanine having an average particle size of 0.09 μm.

Example J An electrophotographic photoreceptor was prepared in the same manner as in Example I, except that the titanyl phthalocyanine pigment of Example 10 was used instead of the V-type hydroxygallium phthalocyanine pigment of Example 9. Produced.

Comparative Example E An electrophotographic photosensitive member was prepared in the same manner as in Example I except that the titanyl phthalocyanine pigment of Comparative Example 5 was used instead of the V-type hydroxygallium phthalocyanine pigment of Example 9. Produced. Comparative Example F In Example I, instead of the V-type hydroxygallium phthalocyanine pigment of Example 9, the α-type titanyl phthalocyanine pigment of Comparative Example 6 not subjected to the ozone exposure treatment was added.
An electrophotographic photoreceptor was prepared in the same manner as in Example I, except that a mixture of 1 part by weight and 0.5 part of β-type titanyl phthalocyanine pigment was used.

The evaluation of the above electrophotographic photosensitive member was performed by the above-described method. Table 4 shows the results.

[0051]

[Table 4]

[0052]

The phthalocyanine pigment produced according to the present invention has a sensitivity that can be adjusted over a wide range, is excellent in dispersibility in a resin dispersion and storage stability of the dispersion, and has good electrophotographic properties. I have. In the method for treating a phthalocyanine pigment of the present invention, the treatment process is simple, and the sensitivity can be adjusted without increasing the cost. Therefore, according to the present invention, it is possible to adjust the sensitivity of the electrophotographic photoreceptor to the required sensitivity of the electrophotographic process so that a clear image can be obtained. Further, the electrophotographic photoreceptor of the present invention has good resolution, excellent gradation,
This shows a clear image. Therefore, the electrophotographic photoreceptor of the present invention is a laser printer, an LED,
The present invention can be applied to various printers such as a printer and a CRT printer, a copying machine, a facsimile, a digital multifunction machine, a digital electrophotographic apparatus such as a full-color copying machine, and other electrophotographic application fields.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an ozone treatment apparatus.

FIG. 2 is a powder X-ray diffraction diagram of the chlorogallium phthalocyanine pigment obtained in Example 7.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing container, 2 ... Ozone generator, 3 ... Ozone concentration meter, 4 ... Ozone filter, 5 ... Motor, 6 ... Stirring blade, 7 ... Phthalocyanine compound.

Claims (5)

[Claims] Claims: 1. A method for treating a phthalocyanine pigment in which a crude phthalocyanine compound is pulverized to form fine particles,
A method for treating a phthalocyanine pigment, comprising subjecting the crude phthalocyanine compound to ozone exposure treatment in an ozone atmosphere before or after pulverizing the crude phthalocyanine compound. 2. The method according to claim 1, wherein the crude phthalocyanine compound is subjected to an acid paste treatment, followed by an ozone exposure treatment in an ozone atmosphere, followed by a pulverization treatment.
A method for treating the phthalocyanine pigment described in the above. 3. The method for treating a phthalocyanine pigment according to claim 1, wherein the crude phthalocyanine compound is subjected to a pulverization treatment, followed by an ozone exposure treatment in an ozone atmosphere, followed by a wet treatment. 4. A phthalocyanine pigment obtained by the treatment method according to claim 1. 5. An electrophotographic photosensitive member having a photosensitive layer on a conductive substrate, wherein the photosensitive layer contains the phthalocyanine pigment according to claim 4.