JPH1017784A - Chlorogallium phthalocyanine crystal and production of dispersion liquid of the crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely and easily produce the subject crystal having excellent electrophotographic characteristics and useful as an electrophotographic receptor without causing the scattering of impurities by crushing a specific chlorogallium phthalocyanine crystal in a state wet with water, filtering the product and crushing in a state wet with an organic solvent to effect the conversion of the crystal form. SOLUTION: Chlorogallium phthalocyanine having strong diffraction peak at a Bragg angle (2θ) of 27.1±0.2 deg. by CuKαcharacteristic X-ray (e.g. an undried material produced by heating 1,3diiminoisoindoline and gallium trichloride in an organic solvent and washing the obtained condensation reaction product with refined water) is crushed in wet state together with re fined water, filtered and then crushed in wet state using an organic solvent such as n-butyl acetate or dimethyl sulfoxide to convert the original crystal form into the objective crystal form having strong diffraction peaks at 2θ=7.4±0.2 deg., 16.6±0.2' deg., 25.5±0.2 deg. and 28.3±0.2 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a chlorogallium phthalocyanine crystal having excellent electrophotographic properties, and a method for producing a crystal dispersion thereof.

[0002]

2. Description of the Related Art Various inorganic and organic photoconductive materials have been known as photoconductive materials for use in electrophotographic photosensitive members. When the organic photoconductive material is used for an electrophotographic photoreceptor, it has advantages such as transparency of a film, good film forming property and flexibility, non-pollution and relatively low cost. Therefore, various things have been conventionally proposed. In addition, by extending the photosensitive wavelength range of conventional organic photoconductive materials to the wavelength range of near-infrared semiconductor lasers, there is a demand for using them as photoconductors for digital recording such as laser printers, digital copiers, and facsimile machines. And several organic photoconductive materials for semiconductor lasers have been proposed. In particular, many reports have been made on the phthalocyanine compound regarding its crystal form and electrophotographic properties.

[0003] In general, phthalocyanine compounds are known to be divided into several crystal forms due to differences in the production method or treatment method, and that different crystal forms have a significant effect on the photoelectric conversion characteristics of the phthalocyanine compound. I have. Regarding the crystal form of the phthalocyanine compound,
For example, looking at metal-free phthalocyanine, α,
Crystal forms such as β, ε, π, τ, and x are known, but these are not sufficient in terms of photosensitivity, and no satisfactory repetition characteristics and environmental stability have been obtained.

On the other hand, with respect to chlorogallium phthalocyanine, many reports have been made on its crystal form and electrophotographic properties. JP-A-5-194523 and JP-A-5-98181 disclose CuKα characteristic X-rays. 7.4 ° of Bragg angle (2θ ± 0.2 °), 1
A highly sensitive chlorogallium phthalocyanine crystal having strong diffraction peaks at 6.6 °, 25.5 ° and 28.3 ° and an electrophotographic photoreceptor using the same are excellent in sensitivity, repetition characteristics and environmental stability. It is described.

As a typical method for producing the chlorogallium phthalocyanine crystal, a Bragg angle (2θ ± 2) with respect to CuKα characteristic X-ray obtained by heating and condensing 1,3-diiminoisoindoline with gallium trichloride in an organic solvent is used.
A method is known in which a chlorogallium phthalocyanine crystal having a strong diffraction peak at 27.1 ° (0.2 °) is dry-ground and then wet-ground in an appropriate organic solvent to convert the crystal.

[0006]

However, when dry grinding is performed in the crystal conversion step as in the above method,
1, contained in chlorogallium phthalocyanine crystal
Impurities such as 3-diiminoisoindoline, 3-iminoisoindoline, and phthalimide are exposed on the surface of the crystal particles by the pulverization. Therefore, if crystals are scattered and adhere to the human body or clothes during handling, the above impurities have strong skin irritation and skin sensitization, and may cause skin irritation and irritation. And had safety issues. In addition, a Bragg angle (2θ ± 0.2 °) of 7.4 °, 1
A chlorogallium phthalocyanine crystal having strong diffraction peaks at 6.6 °, 25.5 ° and 28.3 ° is a fine particle and easily floats even if washed with water, an organic solvent, or the like. In addition, there is a problem that handling of the dispersion is not easy.

[0007] The present invention has been made in view of the above-mentioned circumstances in the prior art. That is, an object of the present invention is to prevent the impurities contained in the chlorogallium phthalocyanine crystal from scattering, and to secure the safety during the handling operation by using the Bragg angle (2θ ± 0.2) for the CuKα characteristic X-ray.
°) 7.4 °, 16.6 °, 25.5 ° and 28.3.
It is an object of the present invention to provide a method for producing a chlorogallium phthalocyanine crystal having a strong diffraction peak at °. It is another object of the present invention to provide a safe and easy method for producing a dispersion containing the above-mentioned crystals, which has good electrophotographic properties and in which handling of crystal fine particles is difficult.

[0008]

Means for Solving the Problems The present inventors have developed a 1,3-
Bragg angle (2θ ± 0,5) for CuKα characteristic X-rays obtained from diiminoisoindoline and gallium trichloride.
Using a chlorogallium phthalocyanine crystal having a strong diffraction peak at 27.1 ° (2 °), under certain conditions,
A Bragg angle (2θ ± 0.2 °) of 7.4 ° or 16.6 obtained by performing a crystal conversion by performing a washing process and a pulverizing process.
The chlorogallium phthalocyanine crystal having strong diffraction peaks at °, 25.5 ° and 28.3 ° can be safely manufactured by performing washing and pulverization under specific processing conditions during the manufacturing process. ,Moreover,
It was confirmed that the crystals exhibited good electrophotographic properties, and the present invention was completed.

That is, according to the method for producing a chlorogallium phthalocyanine crystal of the present invention, chlorogallium phthalocyanine having a strong diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.1 ° with respect to CuKα characteristic X-rays is converted into purified water. And wet filtration using an organic solvent, thereby obtaining a Bragg angle (2θ ± 0.2 °) of 7.4 with respect to CuKα characteristic X-rays.
It is characterized in that it is converted into chlorogallium phthalocyanine crystals having strong diffraction peaks at °, 16.6 °, 25.5 ° and 28.3 °. 27.1 ° of the Bragg angle (2θ ± 0.2 °) with respect to the above-mentioned CuKα characteristic X-ray
Chlorogallium phthalocyanine having a strong diffraction peak is obtained by heating 1,3-diiminoisoindoline and gallium trichloride in an organic solvent and condensing the obtained reaction product with purified water. Is preferably used without drying. The method for producing a chlorogallium phthalocyanine crystal dispersion of the present invention is produced by heating and condensing 1,3-diiminoisoindoline and gallium trichloride in an organic solvent, and washing the obtained reaction product with purified water. Angle to the CuKα characteristic X-ray (2
The chlorogallium phthalocyanine crystal having a strong diffraction peak at 27.1 ° (θ ± 0.2 °) is subjected to a wet grinding treatment together with purified water without drying, followed by filtration.
An organic solvent solution of a synthetic resin is mixed and dispersed in a slurry obtained by wet grinding using an organic solvent.

[0010]

Embodiments of the present invention will be described below in detail. The present invention uses, as a raw material, a chlorogallium phthalocyanine crystal having a strong diffraction peak at 27.1 ° of the Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-rays, and the Bragg angle (2θ ± 0. 2 °) 7.4 °, 16.6 °, 25.5
A method for producing a chlorogallium phthalocyanine crystal having strong diffraction peaks at 0 ° and 28.3 °, and a method for producing a dispersion containing the obtained crystal.

[0011] In the present invention, the above-mentioned raw material CuK
As the chlorogallium phthalocyanine crystal having a strong diffraction peak at 27.1 ° of the Bragg angle (2θ ± 0.2 °) with respect to the α characteristic X-ray, 1,3-diiminoisoindoline is prepared by adding gallium trichloride and an organic solvent to each other. It is preferable to use one obtained by heat condensation. In particular, it is preferable to use wet cake-like chlorogallium phthalocyanine crystals obtained by filtering the reaction product solution, and then successively washing with an organic solvent and purified water. Organic solvents used for the production and washing of the raw material chlorogallium phthalocyanine crystal include α-chloronaphthalene, β-chloronaphthalene, methoxynaphthalene, diphenylethane,
Ethylene glycol, dialkyl ether, quinoline,
A reaction-inactive high-boiling point solvent such as sulfolane, dimethyl sulfoxide, dichlorobenzene, dichlorotoluene and the like is desirable. Further, the above heat condensation temperature is 130 to 22.
It is in the range of 0 ° C, preferably in the range of 140 to 180 ° C.

First, in the present invention, the above-mentioned raw material chlorogallium phthalocyanine crystal is washed with purified water, and then subjected to wet pulverization together with purified water without drying. In the wet grinding using the purified water, the use ratio of the chlorogallium phthalocyanine crystal and the purified water is such that 0.1 to 100 parts, preferably 1 to 10 parts, of the purified water is selected with respect to 1 part of the chlorogallium phthalocyanine crystal. . Examples of the apparatus used for wet pulverization include a vibration mill, an automatic mortar, a sand mill, a dyno mill, a Sueco mill, a Koball mill, an attritor, a planetary ball mill, a ball mill, a high-pressure homogenizer, and an ultrasonic disperser. Examples of the solvent used for wet pulverization include benzyl alcohol, isopropyl alcohol, n-butanol, glycerin, cyclohexanone, toluene, tetrahydrofuran, water, ethyl acetate, n-butyl acetate, dimethyl sulfoxide and the like. As purified water in washing and wet grinding, conductivity of pure, distilled water, ion-exchanged water or the like is 10.0 μS / cm or less, preferably 1.0 μS / cm.
S / cm or less can be used.

Next, after performing the above-mentioned wet pulverization treatment using purified water, the obtained pulverization treatment solution is separated by filtration.
By performing wet pulverization using an organic solvent, the crystallinity is good, and the Bragg angle (2θ ± 0.2 °) for CuKα characteristic X-rays having uniform particle diameters of 7.4 ° and 16.
A chlorogallium phthalocyanine crystal having strong diffraction peaks at 6 °, 25.5 ° and 28.3 ° can be obtained. Examples of the organic solvent used for this wet pulverization include n-butyl acetate, dimethyl sulfoxide and the like.
In wet grinding using an organic solvent, the use ratio of the chlorogallium phthalocyanine crystal and the organic solvent is not particularly limited, but a contact ratio of 1: 5 to 1: 100 is preferable from the viewpoint of the contact efficiency between the two. Further, as a device used for wet pulverization, a method in which the above-described pulverizing device is used or a method of stirring and mixing in a stirring tank is preferable.

According to the present invention, as described above, the raw material chlorogallium phthalocyanine crystal is wet-pulverized with purified water, separated by filtration, and then wet-pulverized with an organic solvent, whereby the crystal form is converted to CuKα. 7.4 of Bragg angle (2θ ± 0.2 °) with respect to characteristic X-ray
A chlorogallium phthalocyanine crystal having strong diffraction peaks at °, 16.6 °, 25.5 ° and 28.3 ° is obtained.

In the present invention, when the above-mentioned chlorogallium phthalocyanine crystal is produced, it is subjected to a wet pulverization treatment using an organic solvent, and then, without drying, the slurry obtained is mixed with an organic solvent solution of a synthetic resin. Are mixed and dispersed to obtain a Bragg angle (2θ ± 0.2 °) of 7.4 °, 16.6 °, 2 ° with respect to the CuKα characteristic X-ray.
A dispersion of chlorogallium phthalocyanine crystals having strong diffraction peaks at 5.5 ° and 28.3 ° is obtained. As the synthetic resin used, those well-known as a binder resin used in the charge generation layer of the electrophotographic photoreceptor, for example, polycarbonate, polystyrene, polyester, polyvinyl butyral, methacrylate polymer, vinyl acetate polymer, Or, a copolymer thereof, a cellulose ester, a cellulose ether, a polybutadiene, a polyurethane, an epoxy resin, and the like can be given.

Solvents used for dissolving the binder resin include methanol, ethanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, and n-butyl acetate. , Dioxane, tetrahydrofuran, methylene chloride, chloroform, benzene, toluene, xylene, chlorobenzene, dimethylformamide, dimethylacetamide and the like, or a mixed solvent thereof.

In the production method of the present invention, when the organic solvent used for the wet pulverization treatment is the same as the organic solvent used for the organic solvent solution of the binder resin, when forming the photoreceptor, the layer forming step is more simplified. This is preferable because it can be simplified.

Next, the case where the chlorogallium phthalocyanine crystal obtained by the production method of the present invention is used as a photoconductive substance in a photosensitive layer of an electrophotographic photosensitive member will be described. In the present invention, the chlorogallium phthalocyanine crystal may be any one such as a photosensitive layer of an electrophotographic photosensitive member having a single-layer structure or a laminated structure having a function separated into a charge generation layer and a charge transport layer. Can be applied. Any conductive support may be used as long as it is conventionally used. In addition, the surface of the conductive support may be subjected to various kinds of treatments, if necessary, within a range that does not affect the image quality, such as surface anodic oxidation treatment, surface roughening treatment by liquid honing, chemical treatment, coloring treatment, and the like. It can be performed.

In the case of a laminated photoreceptor, a photosensitive layer having at least a charge generation layer and a charge transport layer laminated on a conductive support is provided. Is also good. The charge generation layer is composed of the chlorogallium phthalocyanine crystal obtained by the above method and a suitable binder resin solution. As the charge generation material, other known charge generation materials may be used in addition to the chlorogallium phthalocyanine crystal. Further, as the binder resin, a known resin can be appropriately used. The compounding ratio of the charge generation material to the binder resin is from 40: 1 to 1: 4, preferably from 20: 1 to 1: 2. If the ratio of the charge generation material is too high, the stability of the coating solution is reduced, and
If the temperature is too low, the sensitivity is lowered. Therefore, it is preferable to set the temperature in the above range.

The solvent used for dispersing the charge generating material can be appropriately selected from those which dissolve the binder resin. The dispersing means include a sand mill, a colloid mill, an attritor, a ball mill, a dyno mill,
Devices such as a high-pressure homogenizer, an ultrasonic disperser, a coball mill, and a roll mill can be used. Application methods include blade coating, wire bar coating,
Spray coating, dip coating, bead coating, curtain coating, and other methods can be used. The thickness of the charge generation layer is 0.01 to 5
μm, preferably about 0.03 to 2 μm. Also,
The same conditions are employed when forming a charge generation layer using a dispersion of chlorogallium phthalocyanine crystals obtained by the production method of the present invention.

The charge transport layer is composed of a charge transport material and a binder resin, and known charge transport materials can be used as appropriate. Examples of the binder resin include polycarbonate, polyarylate, polystyrene, polyester, styrene-acrylonitrile copolymer, polysulfone, polymethacrylate, styrene-methacrylate copolymer, and polyolefin. The compounding ratio (weight) of the charge transport material and the binder resin is in the range of 5: 1 to 1: 5, preferably 3: 1 to 1: 1.
The range is 1: 3. If the ratio of the charge transporting material is too high, the mechanical strength of the charge transporting layer decreases, while if it is too low, the sensitivity decreases, so that it is preferable to set the ratio in the above range. When the charge transporting material has a film-forming property, the binder resin may not be used.

The charge transport layer is formed by dissolving the charge transport material and the binder resin in an appropriate solvent and applying the solution. The coating method is the same as that described for the charge generation layer. Can be used. The thickness of the charge transport layer is in the range of 5 to 50 μm, preferably 10 to 50 μm.
It is preferable to form it so as to have a range of 40 μm.

When the photosensitive layer of the electrophotographic photosensitive member has a single-layer structure, the photosensitive layer is formed of a chlorogallium phthalocyanine crystal and a photoconductive layer in which a charge transport material is dispersed in a binder resin. In this case, as the charge transporting material, known materials can be appropriately used, and as the binder resin,
Since the same material as described above can be used, the photosensitive layer can be formed by any of the methods described above. At this time, the blending (weight) ratio of the charge transporting material to the binder resin is preferably set in a range of 1:20 to 5: 1, and the blending (weight) of chlorogallium phthalocyanine and the charge transporting material is preferably set. The ratio is 1: 10-1
It is preferable to set the range of 0: 1.

The electrophotographic photosensitive member may be provided with an undercoat layer between the photosensitive layer and the support, if necessary.
The undercoat layer is effective for preventing unnecessary charge injection from the support, has an effect of improving the chargeability of the photoreceptor, and has a function of contacting the photosensitive layer with the conductive support. It also has the function of improving the adhesiveness. Further, a protective layer may be provided on the photosensitive layer in order to improve printing durability and the like.

[0025]

The present invention will be described below in detail with reference to examples. In Examples, “parts” means “parts by weight”. Synthesis Example 1 (Synthesis of raw material chlorogallium phthalocyanine crystal) 30 parts of 1,3-diiminoisoindoline and 9.1 parts of gallium trichloride were put in 230 parts of dimethyl sulfoxide, and reacted at 160 ° C. for 4 hours. The product was separated by filtration and washed with dimethyl sulfoxide and then with ion-exchanged water to obtain 30 parts of a chlorogallium phthalocyanine crystal in a wet cake form (solid content: 90%). FIG. 1 shows a powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal. This crystal has a Bragg angle (2θ ± 0.2 °) of 27 with respect to CuKα characteristic X-rays.
It had a strong diffraction peak at 1 °.

Example 1 2 parts of the wet cake-like chlorogallium phthalocyanine and 8 parts of ion-exchanged water obtained in the synthesis example were put together with 25 agate beads of 10 mmφ in an agate pot (capacity: 80 m).
l). This is a planetary ball mill (FRITSC)
H, manufactured by Puraerisette), wet pulverized for 100 hours, filtered, and washed with 600 parts of dimethyl sulfoxide. 17 parts of dimethyl sulfoxide was mixed with 8 parts of the obtained wet cake to obtain a slurry (solid content concentration: 8%). After 25 parts of the slurry was ball-milled at room temperature for 24 hours together with 100 parts of 5 mmφ glass beads, the slurry was separated by filtration and ion-exchanged water 600 parts.
Washed in part. By drying the obtained wet cake, 1.6 parts of chlorogallium phthalocyanine crystals were obtained. FIG. 2 shows an X-ray powder diffraction pattern of the obtained chlorogallium phthalocyanine crystal. This crystal has a Bragg angle (2θ ± 0.2 °) of 7.4 with respect to CuKα characteristic X-rays.
°, 16.6 °, 25.5 ° and 28.3 ° had strong diffraction peaks. In this production method, the chlorogallium phthalocyanine crystal powder was not scattered during the pulverization process and did not adhere to the worker or his clothes, and the crystal conversion could be performed safely.

Example 2 2 parts of the wet cake-like chlorogallium phthalocyanine and 8 parts of ion-exchanged water obtained in the synthesis example were put together with 25 agate beads of 10 mmφ in an agate pot (capacity: 80 m).
l). This is a planetary ball mill (FRITSC)
H, manufactured by Puraerisette), and wet-pulverized for 100 hours, filtered and then n-butyl acetate 600
Washed using 8 parts of acetic acid n-
17 parts of butyl were mixed to obtain a slurry (solid content concentration: 8%). 25 parts of this slurry was mixed with 5 mmφ glass beads 1
After ball milling at room temperature for 24 hours together with 00 parts, the mixture was separated by filtration to obtain a wet cake (solid content concentration: 40%). 2.5 parts of the obtained wet cake was previously mixed with a solution prepared by dissolving 1 part of polyvinyl butyral (trade name: Eslec BM-S, manufactured by Sekisui Chemical Co., Ltd.) in 49 parts of n-butyl acetate, and then sand-milled for 5 hours. And disperse this in n-acetic acid.
The solution was diluted with -butyl to prepare a charge generation layer coating solution having a solid content of 3.0% by weight. Note that the powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal after dispersion showed the same spectrum as in FIG. Also, during the process of preparing and dispersing the chlorogallium phthalocyanine crystal, the powder of the chlorogallium phthalocyanine crystal does not scatter and adhere to clothes or the human body, and a coating liquid for the charge generation layer of the chlorogallium phthalocyanine crystal is obtained safely. I was able to.

Comparative Example 2 parts of the wet cake-like chlorogallium phthalocyanine crystal obtained in the synthesis example were dried, and then placed in an agate pot (capacity: 80 ml) together with 25 agate beads of 10 mmφ. This is a planetary ball mill (FRITSCH, Pu
laelisette) and dry-pulverized for 60 hours to obtain 1.8 parts of chlorogallium phthalocyanine crystal. FIG. 3 shows a powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal.

One part of the obtained chlorogallium phthalocyanine crystal and 12 parts of dimethyl sulfoxide were subjected to ball milling together with 100 parts of 5 mmφ glass beads at room temperature for 24 hours. Next, after wet pulverization, it was washed with ion-exchanged water and the wet cake was dried to obtain 0.9 part of chlorogallium phthalocyanine crystal. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal showed the same spectrum as in FIG. In addition, in this production method, during the process, particularly when the chlorogallium phthalocyanine crystal after dry milling is taken out of the pot and put into the ball mill container, the powder of the chlorogallium phthalocyanine crystal is scattered and the surroundings are contaminated. In addition, it was confirmed that it adhered to workers and their clothes.

Production Example 1 First, polyvinyl butyral (trade name: Eslec BM)
(1. Sekisui Chemical Co., Ltd.) (8 parts) was added to n-butyl alcohol (152 parts) with stirring and dissolved to prepare a 5% by weight polyvinyl butyral solution. Next, 100 parts of a 50% toluene solution of tributoxy zirconium acetylacetonate (trade name: ZC540, manufactured by Matsumoto Kosho Co., Ltd.), γ-
Aminopropylethoxysilane (trade name: A1100,
10 parts by Nippon Unicar) and n-butyl alcohol 1
A solution obtained by mixing 30 parts was added to the polyvinyl butyral solution, and the mixture was stirred with a stirrer to prepare a coating liquid for forming an undercoat layer. This coating solution was applied onto a 40 × 319 mm aluminum pipe by dip coating, and dried by heating at 150 ° C. for 10 minutes to form an undercoat layer having a thickness of 1.0 μm.
In addition, 1 part of the above-mentioned polyvinyl butyral (trade name: Esrec BM-S, manufactured by Sekisui Chemical Co., Ltd.)
To a solution dissolved in 49 parts of butyl, 1 part of the chlorogallium phthalocyanine crystal obtained in Example 1 was added, dispersed by a sand mill for 5 hours, and then diluted with n-butyl acetate.
A coating solution for forming a charge generation layer having a solid content of 3.0% by weight was prepared. This coating solution was applied on the undercoat layer by a ring coater, and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.20 μm. In addition,
The chlorogallium phthalocyanine crystal after dispersion was confirmed to be the same as the crystal form before dispersion by its powder X-ray diffraction pattern. Next, a charge transport layer was formed on the charge generation layer. That is, N, N'-bis- (p-tolyl)
-N, N'-bis- (p-ethylphenyl) -3,3 '
4 parts of dimethylbenzidine as a charge transport material, together with 6 parts of polycarbonate Z resin,
0 parts, and the obtained solution is applied on the above-mentioned charge generating layer by a dip coating apparatus.
After heating and drying for a minute to form a charge transport layer having a thickness of 18 μm, an electrophotographic photosensitive member was produced.

Preparation Example 2 An electrophotographic photosensitive member was prepared in the same manner as in Preparation Example 1, except that the coating liquid obtained in Example 2 was used as a coating liquid for forming a charge generation layer. Production Example 3 In Production Example 1, instead of the chlorogallium phthalocyanine crystal obtained in Example 1 used as a charge generation material,
An electrophotographic photosensitive member was produced in the same manner as in Production Example 1, except that the chlorogallium phthalocyanine crystal obtained in Comparative Example was used.

In order to evaluate the electrophotographic characteristics of the electrophotographic photoreceptors obtained in Preparation Examples 1 to 3, the following measurements were performed using a laser printer (XP-11, manufactured by Fuji Xerox Co., Ltd.). This operation is performed under the environment of 20 ° C. and 50% RH by charging with a scorotron charger with a grid application voltage of −600 V (A), and using a 780 nm semiconductor laser, after 1 second, emitting 7.0 mJ / m ² of light. To discharge electricity (B), and after 3 seconds, irradiate red LED light of 50 mJ / m ² to remove electricity (C), and the potential of each part was measured. In this case, as for the electrophotographic photoreceptor, the higher the potential VH of (A), the higher the potential of the photoreceptor, the higher the contrast. Therefore, the lower the potential VL of (B), the lower the potential VH of (B). The photoreceptor has high sensitivity, and the lower the potential of (C) VRP, the lower the residual potential, and it can be evaluated that the photoreceptor has less image memory and less fog. In addition, the potential of each part after 10,000 times of repeated charging and exposure was also measured. Table 1 shows the results.

[0033]

[Table 1] In the table, ◎ indicates that the powder was not scattered, ○ indicates that the powder was almost not scattered, and X indicates that the powder was attached to the human body and clothes.

As shown in Table 1, the electrophotographic photoreceptor of Preparation Example 1 using the chlorogallium phthalocyanine crystal obtained in Example 1 for the photosensitive layer and the dispersion of the chlorogallium phthalocyanine crystal obtained in Example 2 were exposed to light. The electrophotographic photoreceptor of Production Example 2 used for the layer has good charging properties and photosensitivity, low residual potential, and excellent repetition characteristics. Further, when an electrophotographic photoreceptor was produced using the crystal and its dispersion, the powder was not scattered and was stable.

[0035]

According to the production method of the present invention, it is possible to prevent scattering of impurities in the chlorogallium phthalocyanine crystal during the production process of the chlorogallium phthalocyanine crystal, and to easily maintain the safety during the handling operation and easily maintain the chlorogallium phthalocyanine crystal. Can be manufactured. Further, the chlorogallium phthalocyanine crystal obtained by the production method of the present invention has excellent electrophotographic properties, and the electrophotographic photoreceptor containing this crystal in the photosensitive layer has high photosensitivity and good It has excellent chargeability and low residual potential, and exhibits excellent electrophotographic properties with good cycle stability.

[Brief description of the drawings]

FIG. 1 shows a powder X-ray diffraction diagram of a chlorogallium phthalocyanine crystal obtained in a synthesis example.

FIG. 2 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in Example 1.

FIG. 3 shows a powder X-ray diffraction diagram of a chlorogallium phthalocyanine crystal obtained in a comparative example.

Claims (3)

[Claims] 1. A chlorogallium phthalocyanine having a strong diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.1 ° with respect to CuKα characteristic X-rays is subjected to a wet pulverization treatment together with purified water, followed by filtration. By performing wet grinding using an organic solvent, a Bragg angle (2θ ± 0.2 °) of 7.4 ° and 16.6 with respect to CuKα characteristic X-rays is obtained.
A method for producing a chlorogallium phthalocyanine crystal, which comprises converting a chlorogallium phthalocyanine crystal having strong diffraction peaks at °, 25.5 ° and 28.3 °. 2. As chlorogallium phthalocyanine having a strong diffraction peak at 27.1 ° of Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-ray, 1,3-diiminoisoindoline and gallium trichloride are used as organic substances. The method for producing a chlorogallium phthalocyanine crystal according to claim 1, wherein the reaction product obtained by heat condensation in a solvent is washed with purified water, and the obtained product is used without drying. 3. A Bragg angle for CuKα characteristic X-rays produced by condensing 1,3-diiminoisoindoline and gallium trichloride by heating in an organic solvent, and washing the obtained reaction product with purified water. 2θ ± 0.2 °) 27.
A chlorogallium phthalocyanine crystal having a strong diffraction peak at 1 ° is subjected to wet grinding with purified water without drying, filtered, and then subjected to wet grinding with an organic solvent to obtain a slurry. A method for producing a chlorogallium phthalocyanine crystal dispersion, comprising mixing and dispersing an organic solvent solution of