JP3092270B2 - Method for producing novel dichlorotin phthalocyanine crystal and electrophotographic photoreceptor using the crystal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a novel dichlorotin phthalocyanine crystal and an electrophotographic photosensitive member using the novel dichlorotin phthalocyanine crystal.

[0002]

2. Description of the Related Art Phthalocyanines are used in paints, printing inks,
It is a useful material as a catalyst or electronic material.
In recent years, it has been widely studied as a material for an electrophotographic photosensitive member, a material for optical storage, and a photoelectric conversion material.

With regard to electrophotographic photoreceptors, in recent years, the photosensitive wavelength range of organic photoconductive materials conventionally proposed has been extended to the wavelength of near-infrared semiconductor lasers (780 to 830 nm), and digital recording by a laser printer or the like has been carried out. There is an increasing demand for use as a photoreceptor for photographic applications, and from this viewpoint, squarylium compounds (JP-A-49-10553)
Nos. 6 and 58-21416), triphenylamine-based trisazo compounds (JP-A-61-151659), and phthalocyanine compounds (JP-A-48-3418).
Nos. 9 and 57-148745) have been proposed as photoconductive materials for semiconductor lasers.

When an organic photoconductive material is used as a photosensitive material for a semiconductor laser, first, the photosensitive wavelength region extends to a long wavelength, and then, the sensitivity and durability of the formed photosensitive member are good. Is required. The organic photoconductive material described above does not always sufficiently satisfy these conditions. To overcome these drawbacks, the relationship between the crystal type and the electrophotographic properties of the organic photoconductive material has been studied, and many reports have been made on phthalocyanine compounds.

[0005] In general, phthalocyanine compounds 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 compound. . Regarding the crystal form of the phthalocyanine compound, for example, looking at copper phthalocyanine, in addition to the stable β form, α, π,
Crystal forms such as x, ρ, γ, and δ are known, and it is known that these crystal forms can be mutually transformed by mechanical tension, sulfuric acid treatment, organic solvent treatment, heat treatment, and the like. I have. (For example, U.S. Pat. Nos. 2,770,629, 3,1060,635, 3,708,292 and 3,357,989). Also, Japanese Patent Application Laid-Open
Japanese Patent No. 38543 describes the difference in crystal type of copper phthalocyanine and electrophotographic characteristics. On the other hand, JP-A-62-119547 describes an electrophotographic photoreceptor using dihalogenostin phthalocyanine as a charge generating material, and JP-A-1-14405 discloses an electrophotographic photoreceptor. A tin phthalocyanine compound having a specific diffraction peak and an electrophotographic photoreceptor using the same are described.

[0006]

However, the above-mentioned phthalocyanine compounds which have been conventionally developed have not been sufficiently satisfactory in light sensitivity and durability when used as a photosensitive material. The present invention has been made in view of the above-described circumstances in the related art. That is, an object of the present invention is to provide a method for producing a novel crystal of dichlorotin phthalocyanine useful as a photoconductive material having sensitivity in a long wavelength region. Another object of the present invention is to provide an electrophotographic photosensitive member having high sensitivity and durability using a novel crystal of dichlorotin phthalocyanine as a photoconductive material.

[0007]

The present inventors have studied the crystal system of dichlorotin phthalocyanine. As a result, the dichlorotin phthalocyanine has four crystal forms of type I to IV. Can be obtained by pulverizing the synthesized dichlorotin phthalocyanine or by milling with an organic solvent.
The type I and type IV crystals were found to be unstable compared to the type I and type II crystals, and were easily transformed into the type I crystals by treatment with a specific organic solvent. In addition, type III and
The type I crystal obtained through the type IV crystal has a powder X-ray diffraction peak almost identical to that of the type I crystal obtained without the type III and IV crystals, but the peak intensity ratio is quite low. They were found to be different and had excellent electrophotographic properties, and completed the present invention.

That is, according to the method for producing dichlorotin phthalocyanine of the present invention, the X-ray diffraction spectrum
= 1.5418A. U. Angle to CuKα radiation (hereinafter referred to as Bragg angle) (2θ ± 0.2 °) =
8.7 °, 9.9 °, 10.9 °, 13.1 °, 15.
2 °, 16.3 °, 17.4 °, 21.9 °, 25.5
A dichlorotin phthalocyanine crystal belonging to Form III having a strong diffraction peak at 0 ° or a Bragg angle (2θ ±
0.2 °) = 9.2 °, 12.2 °, 13.4 °, 1
Form IV dichlorotin phthalocyanine crystals having strong diffraction peaks at 4.6 °, 17.0 ° and 25.3 ° were converted into ketones, halogenated hydrocarbons and acetates.
Or dimethylformamide and pyridine?
Treatment in an organic solvent selected from the above, the Bragg angle (2θ
± 0.2 °) in the range of 25 ° to 30 °, 2
It is characterized by being transformed into a dichlorotin phthalocyanine crystal belonging to Form I having the strongest diffraction peak at 8.2 °. The electrophotographic photoreceptor of the present invention has a Bragg angle (2θ ±
0.2) in the range of 25 ° to 30 °.
A photosensitive layer containing a dichlorotin phthalocyanine crystal having the strongest diffraction peak at 2 ° is provided.

Hereinafter, the present invention will be described in detail. In the production method of the present invention, both the type III dichlorotin phthalocyanine crystal and the type IV dichlorotin phthalocyanine crystal, which are starting materials, are novel crystals and are produced as follows. That is, it can be produced by pulverizing dichlorotin phthalocyanine crystal produced by a known method using a ball mill or the like in a specific organic solvent. It can also be obtained by treating with a solvent after dry pulverization. The organic solvent used is II
In the case of type I dichlorotin phthalocyanine crystals, aromatic hydrocarbons such as toluene, xylene and chlorobenzene are used, and among them, chlorobenzene is most preferably used. In the case of IV-type dichlorotin phthalocyanine crystals, ethers such as tetrahydrofuran and 1,4-dioxane are used. Among them, tetrahydrofuran is preferably used.

For grinding, a sand mill,
A kneader or the like can be used, but is not limited thereto. Also, if necessary, glass beads,
Grinding media such as steel beads, or grinding aids such as salt and silica gel can be used. The pulverization treatment is carried out in a temperature range of 10 to 50 ° C, usually at room temperature, for 10 to 1
It is preferably performed for 00 hours.

As described above, the Bragg angle (2θ ±
0.2 °) = 8.7 °, 9.9 °, 10.9 °, 13.
1 °, 15.2 °, 16.3 °, 17.4 °, 21.9
III, a dichlorotin phthalocyanine crystal having strong diffraction peaks at 25.5 ° and a Bragg angle (2θ ±
0.2 °) = 9.2 °, 12.2 °, 13.4 °, 1
Form IV dichlorotin phthalocyanine crystals having strong diffraction peaks at 4.6 °, 17.0 °, and 25.3 ° are produced. These crystals are then treated in an organic solvent to give a Bragg angle (2θ ± 0.2 °) of 25 °.
From 30 to 30 ° to form I dichlorotin phthalocyanine crystals having the strongest diffraction peak at 28.2 °.

[0012] In the present invention, as the organic solvent, ketones such as acetone, methyl ethyl ketone (MEK), halogenated hydrocarbons such as methylene chloride, chloroform and the like,
Select from the group consisting of acetates such as ethyl acetate and butyl acetate, dimethylformamide (DMF) and pyridine
Those but is used, among these, acetic acid esters can be particularly preferably used.

At the time of the above-mentioned crystal transition, a binder resin may be blended in an organic solvent. In that case, by performing a dispersion treatment, crystal transition is performed, and the obtained dispersion can be directly used as a coating solution for forming a charge generation layer, which is advantageous in the production of an electrophotographic photoreceptor. is there. In the above-mentioned organic solvent treatment, if necessary, the treatment can be carried out while grinding using a grinding medium such as glass beads or steel beads.

The type I crystal obtained by the present invention has better electrophotographic characteristics than the type I crystal obtained without passing through the type III and type IV crystals, The peaks are almost identical to the type I crystal obtained without passing the type III and type IV crystals, but the peak intensity ratio is completely different. This is because during the transition from the type III or IV type crystal to the type I crystal, the volatile component incorporated in the type III or IV type crystal escapes, so that the crystal lattice is distorted and the crystal growth axis differs. This is presumed to affect the orientation.

Next, an electrophotographic photosensitive member using the dichlorotin phthalocyanine crystal obtained by the production method of the present invention as a photoconductive material in a photosensitive layer will be described. The electrophotographic photoreceptor of the present invention may have a single-layer photosensitive layer or a laminated structure in which a charge generation layer and a charge transport layer are functionally separated.

When the photosensitive layer has a laminated structure, the charge generation layer is composed of the above-mentioned I-type dichlorotin phthalocyanine crystal and a binder resin. The binder resin can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, and polyvinylpyrene.
Preferred binder resins include polyvinyl butyral, polyarylate (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, acrylic resin, polyacrylamide ,polyamide,
Polyvinyl pyridine, cellulosic resin, urethane resin, epoxy resin, casein, polyvinyl alcohol,
An insulating resin such as polyvinylpyrrolidone can be used.

The charge generation layer is prepared by dispersing the above-mentioned I-type dichlorotin phthalocyanine crystal in a solution in which the above-mentioned binder resin is dissolved in an organic solvent, and preparing a coating solution, and coating the solution on a conductive support. Can be formed by Alternatively, crystal transition may be performed in a coating solution using a type III or IV type crystal. In that case, the compounding ratio of the dichlorotin phthalocyanine crystal and the binder resin used is 40: 1 to 1:10,
Preferably it is 10: 1 to 1: 4. When the ratio of the dichlorotin phthalocyanine crystal is too high, the stability of the coating solution is lowered, and when it is too low, the sensitivity is lowered.

The solvent used is preferably selected from those which do not dissolve the undercoat layer or the charge transport layer. Specific organic solvents include alcohols such as methanol, ethanol, and isopropanol; acetone;
Ketones such as EK and cyclohexanone, DMF, N, N
-Amides such as dimethylacetamide, dimethylsulfoxides, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloride Aliphatic halogenated hydrocarbons such as ethylene, benzene, toluene, xylene, ligroin, monochlorobenzene,
Aliphatic and aromatic hydrocarbons such as dichlorobenzene can be used. Of these, acetates are particularly preferred.

The coating solution can be applied by a coating method such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wiper coating method, a blade coating method, a roller coating method, and a curtain coating method. The drying is preferably performed by touch drying at room temperature and then heating and drying. The heating and drying can be performed at a temperature of 30 to 200 ° C. for 5 minutes to 2 hours in a still or blown state. The thickness of the charge generation layer is usually 0.0
It is applied so as to have a thickness of about 5 to 5 μm.

The charge transport layer is composed of a charge transport material and a binder resin. Examples of the charge transport material include polycyclic aromatic compounds such as anthracene, pyrene, and phenanthrene; compounds having a nitrogen-containing heterocycle such as indole, carbazole and imidazole; pyrazoline compounds; hydrazone compounds; triphenylmethane compounds; and triphenylamine. Compounds, enamine compounds, stilbene compounds, etc.
Any known materials can be used. Furthermore, poly-N-vinyl carbazole, halogenated poly-N-vinyl carbazole, polyvinyl anthracene, poly-N-vinyl phenyl anthracene, polyvinyl pyrene, polyvinyl acenaphthylene, polyglycidicarbazole, pyrene-formaldehyde resin, ethyl carbazole -Photoconductive polymers such as formaldehyde resins, which may themselves form a layer. Further, as the binder resin, the same insulating resin as that used for the above-described charge generation layer can be used.

The charge transport layer can be formed by preparing a coating solution using the charge transport material, the binder resin, and the same organic solvent as described above, and then applying the same in the same manner. The mixing ratio (parts by weight) of the charge transport material and the binder resin is usually 5:
It is set in the range of 1-1: 5. The thickness of the charge transport layer is usually set to about 10 to 30 μm.

When the electrophotographic photosensitive member has a single-layer structure, the photosensitive layer comprises a photoconductive layer having a structure in which the above-mentioned dichlorotin phthalocyanine crystal is dispersed in a layer comprising a charge transport material and a binder resin. . In that case, the mixing ratio of the charge transport material and the binder resin is 1:20 to 5: 1,
The compounding ratio of the dichlorotin phthalocyanine crystal and the charge transport material is preferably set to about 1:10 to 10: 1. The same charge transport material and binder resin as described above are used, and the photoconductive layer is formed in the same manner as described above.

As the conductive support, any one can be used as long as it is known to be used as an electrophotographic photosensitive member. In the present invention, an undercoat layer may be provided on the conductive support. The undercoat layer is effective for preventing unnecessary charge injection from the conductive support, and has an effect of increasing the chargeability of the photosensitive layer. Further, it also has the effect of increasing the adhesion between the photosensitive layer and the conductive support. As a material constituting the undercoat layer, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine,
Cellulose ethers, cellulose esters, polyamide, polyurethane, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, polyacrylic acid, polyacrylamide, zirconium chelate compound, zirconium alkoxide compound, organic zirconium compound, titanyl chelate compound, Examples include titanyl alkoxide compounds, organic titanyl compounds, silane coupling agents, and the like. The thickness of the undercoat layer is 0.05
It is preferably set to about 2 μm.

[0024]

The present invention will be described below by way of examples. Synthesis Example 1 (Synthesis of dichlorotin phthalocyanine) 50 g of phthalonitrile and 27 g of anhydrous stannic chloride were added to
1-Chlornaphthalene in 350 ml, 195 ° C
After reacting for 5 hours, the product was separated by filtration, washed with 1-chloronaphthalene, acetone, methanol and then with water, and dried under reduced pressure to obtain 18.3 g (27%) of dichlorotin phthalocyanine crystals. . FIG. 1 shows a powder X-ray diffraction pattern of the obtained dichlorotin phthalocyanine crystal.

Synthesis Example 2 Dichlorotin phthalocyanine crystal 1 obtained in Synthesis Example 1
g in 100 ml of glass beads (1 mmφ) in 30 ml of chlorobenzene (hereinafter referred to as MCB) using a ball mill at room temperature for 72 hours. The obtained slurry is filtered, washed repeatedly with methanol, and dried under reduced pressure. 0.9 crystals of dichlorotin phthalocyanine
7 g were obtained. II of the obtained dichlorotin phthalocyanine
FIG. 2 shows a powder X-ray diffraction pattern of the type I crystal. FIG. 14 shows the results of the thermogravimetric analysis. At about 130 ° C., a weight loss of about 11% was observed (sample amount: 9.39 mg).

Synthesis Example 3 Synthesis Example 2 was repeated except that tetrahydrofuran (hereinafter referred to as THF) was used as a solvent for pulverization, to obtain dichlorotin phthalocyanine type IV crystal 0.9.
3 g were obtained. IV of the obtained dichlorotin phthalocyanine
FIG. 3 shows a powder X-ray diffraction pattern of the type crystal. FIG. 15 shows the result of the thermogravimetric analysis. About 7% weight loss was observed at about 150 ° C. (sample amount is 9.79 mg)

Synthetic Example 4 5 g of the dichlorotin phthalocyanine obtained in Synthetic Example 1 was put into an agate pot (500 ml) together with 500 g of agate ball (20 mmφ) and 400 rpm in a planetary ball mill (Fritsch: P-5). For 1 hour. Powder X of the obtained dichlorotin phthalocyanine crystal
The line diffraction diagram is shown in FIG.

Synthesis Example 5 Dichlorotin phthalocyanine crystal obtained in Synthesis Example 4 0.5
After milling at room temperature for 24 hours together with 15 ml of MCB and 30 g of glass beads, the glass beads were separated by filtration and dried to obtain a dichlorotin phthalocyanine type III crystal.
45 g were obtained. (X-rays are the same as in Fig. 2)

Synthesis Example 6 The MCB of Synthesis Example 5 was treated similarly in place of THF to obtain 0.43 g of type IV crystal of dichlorotin phthalocyanine.
(X-ray is the same as Fig. 3)

Example 1 0.5 g of the type III crystal of dichlorotin phthalocyanine obtained in Synthesis Example 2 was treated in the same manner as in Synthesis Example 5 using 15 ml of n-butyl acetate to give the dichlorotin phthalocyanine I
0.40 g of a type crystal was obtained. FIG. 5 shows a powder X-ray diffraction pattern of the obtained type I crystal of dichlorotin phthalocyanine.
FIG. 16 shows the result of the thermogravimetric analysis. Almost no change in weight was observed between 0 and 200 ° C (the sample amount was 9.7).
8 mg).

Example 2 0.42 g of the dichlorotin phthalocyanine type I crystal of the present invention was prepared in the same manner as in Example 1 except that 0.5 g of the dichlorotin phthalocyanine type IV crystal obtained in Synthesis Example 3 was used. Obtained. FIG. 6 shows a powder X-ray diffraction chart of the obtained type I crystal of dichlorotin phthalocyanine.

Comparative Example 1 Dichlorotin phthalocyanine crystal obtained in Synthesis Example 4 0.5
g was milled at room temperature for 24 hours together with 15 ml of butyl acetate and 30 g of glass beads. The glass beads were separated by filtration and dried to obtain 0.45 g of type I crystals of dichlorotin phthalocyanine. FIG. 7 shows a powder X-ray diffraction pattern of the obtained type I crystal of dichlorotin phthalocyanine.

Example 3 Dichlorotin phthalocyanine crystal 1 obtained in Synthesis Example 2
Part is polyvinyl butyral (trade name: Eslec BM-
1, 1 part of Sekisui Chemical Co., Ltd.) and 100 parts of n-butyl acetate, and after dispersing by treating with glass beads for 1 hour with a paint shaker, apply the obtained coating solution to an aluminum substrate by a dip coating method. Then, the resultant was dried by heating at 100 ° C. for 5 minutes to form a charge generation layer having a thickness of 0.2 μm. The solution was dried and powder X-ray diffraction was measured. As a result, it was found to be a type I crystal of dichlorotin phthalocyanine of the present invention as shown in FIG.

Next, the following structural formula

Embedded image

The following structural formula

Embedded image 3 parts of poly (4,4-cyclohexylidenediphenylene carbonate) shown in (1) is dissolved in 20 parts of monochlorobenzene, and the obtained coating solution is applied by dip coating on an aluminum substrate on which a charge generation layer is formed. And 1
The resultant was dried by heating at 20 ° C. for 1 hour to form a charge generation layer having a thickness of 20 μm.

The obtained electrophotographic photosensitive member was subjected to room temperature and normal humidity (2
0 ° C., 40 % RH) using an electrostatic copying tester (EPA-8100, manufactured by Kawaguchi Electric Co., Ltd.)
After performing corona discharge of 6 KV and charging the light, the light of the tungsten lamp was irradiated at 800 nm using a monochromator.
, And adjusted to 1 μW / cm ² on the surface of the photoreceptor and irradiated. Then, the surface potential is initially V ₀
(Volt) Exposure E _1/2 (erg
/ Cm ²⁾ was measured, then irradiated with tungsten light for 10 lux on a second surface of the photosensitive member was measured residual potential V _R. Furthermore, the above charge, V _0, E _1/2 after repeating 1000 times the exposure was measured V _R. Table 1 shows the results.

Example 4 A photoconductor was prepared and evaluated in the same manner as in Example 3, except that the dichlorotin phthalocyanine obtained in Synthesis Example 3 was used. Table 1 shows the results. Further, the CGL coating solution was dried and powder X-ray diffraction was measured. As a result, it was found to be a dichlorotin phthalocyanine type I crystal of the present invention as shown in FIG.

Comparative Example 2 A photoconductor was prepared and evaluated in the same manner as in Example 4 except that the dichlorotin phthalocyanine type I crystal obtained in Comparative Example 1 was used. Table 1 shows the results. Further, the CGL coating solution was dried, and the powder X-ray diffraction was measured. As a result, as shown in FIG.

Comparative Examples 3 to 5 Instead of n-butyl acetate as a CGL coating solvent, n-butyl acetate was used.
A photoconductor was prepared and evaluated in the same manner as in Example 4, except that butanol was used and the pigments (charge generating materials) shown in Table 1 were used. Further, each CGL coating solution was dried and powder X-ray diffraction was measured. The results are summarized in Table 1.

[0040]

[Table 1]

[0041]

According to the present invention, dichlorotin phthalocyanine having the strongest diffraction peak at 28.2 ° in a Bragg angle (2θ ± 0.2 °) range of 25 ° to 30 ° with a simple process. Is obtained. Dichlorotin phthalocyanine crystals obtained by the present invention,
It is very useful as a photoconductive material for an electrophotographic photosensitive member such as a printer using a semiconductor laser, and the obtained electrophotographic photosensitive member of the present invention has excellent sensitivity and durability.

[Brief description of the drawings]

FIG. 1 is a powder X-ray diffraction spectrum of a dichlorotin phthalocyanine crystal obtained in Synthesis Example 1.

FIG. 2 is a powder X-ray diffraction spectrum of a type III crystal of dichlorotin phthalocyanine obtained in Synthesis Example 2.

FIG. 3 is a powder X-ray diffraction spectrum of a type IV crystal of dichlorotin phthalocyanine obtained in Synthesis Example 3.

FIG. 4 is a powder X-ray diffraction spectrum of the dichlorotin phthalocyanine crystal obtained in Synthesis Example 4.

FIG. 5 is a powder X-ray diffraction spectrum diagram of Form I crystal of dichlorotin phthalocyanine obtained in Example 1.

FIG. 6 is a powder X-ray diffraction spectrum diagram of Form I crystal of dichlorotin phthalocyanine obtained in Example 2.

FIG. 7 is a powder X-ray diffraction spectrum diagram of Form I crystal of dichlorotin phthalocyanine obtained in Comparative Example 1.

FIG. 8 is a powder X-ray diffraction spectrum diagram of Form I crystal of dichlorotin phthalocyanine obtained in Example 3.

FIG. 9 is a powder X-ray diffraction spectrum diagram of Form I crystal of dichlorotin phthalocyanine obtained in Example 4.

FIG. 10 is a powder X-ray diffraction spectrum diagram of Form I crystal of dichlorotin phthalocyanine obtained in Comparative Examples 2 and 5.

FIG. 11 is a powder X-ray diffraction spectrum of the dichlorotin phthalocyanine crystal obtained in Comparative Example 3.

FIG. 12 is a powder X-ray diffraction spectrum of the dichlorotin phthalocyanine crystal obtained in Comparative Example 4.

FIG. 13 is an X-ray powder diffraction spectrum of a type II crystal of dichlorotin phthalocyanine.

FIG. 14 is a thermogravimetric analysis diagram of a type III crystal of dichlorotin phthalocyanine obtained in Synthesis Example 2.

FIG. 15 is a thermogravimetric analysis diagram of Form IV crystal of dichlorotin phthalocyanine obtained in Synthesis Example 3.

FIG. 16 is a thermogravimetric analysis diagram of Form I crystal of dichlorotin phthalocyanine obtained in Example 1.

Continued on the front page (72) Inventor Katsumi Daimon 1600 Takematsu, Fuji Xerox Co., Ltd., Takematsu Office, Minami Ashigara City, Kanagawa Prefecture (72) Inventor Masakazu Iijima 1600, Takematsu Office, Fuji Xerox Co., Ltd. ) Inventor Seika Mashimo 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd. Takematsu Office (56) References JP-A-5-140473 (JP, A) JP-A-5-66594 (JP, A) JP-A-3-93366 (JP, A) JP-A-3-73961 (JP, A) JP-A-1-210388 (JP, A) JP-A-1-133790 (JP, A) JP-A-57-148745 (JP, A) A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09B 67/50 G03G 5/06 371

Claims (4)

(57) [Claims] 1. In an X-ray diffraction spectrum, Bragg angles (2θ ± 0.2 °) = 8.7 °, 9.9 °, 10.9 °
°, 13.1 °, 15.2 °, 16.3 °, 17.4
Dichlorotin phthalocyanine crystal having strong diffraction peaks at °, 21.9 °, and 25.5 °, or Bragg angle (2θ ± 0.2 °) = 9.2 °, 12.2 °, 13.4
The dichlorotin phthalocyanine crystals having strong diffraction peaks at °, 14.6 °, 17.0 °, and 25.3 ° were converted to keto crystals.
, Halogenated hydrocarbons, acetates, dimethyl
Selected from the group consisting of ruformamide and pyridine
And treated with an organic solvent, a Bragg angle (2θ ± 0.2 °)
In the range of 25 ° to 30 °, a Bragg angle (2θ ± 2) characterized by transition to a dichlorotin phthalocyanine crystal having the strongest diffraction peak at 28.2 °.
0.2) in the range of 25 ° to 30 °.
A method for producing a dichlorotin phthalocyanine crystal having the strongest diffraction peak at 2 °. 2. The Bragg angle (2θ ± 0.2) according to claim 1, wherein the organic solvent contains a binder resin.
°) in the range of 25 ° to 30 °, a method for producing a dichlorotin phthalocyanine crystal having the strongest diffraction peak at 28.2 °. 3. The Bragg angle (2θ ± 0.2) according to claim 1, wherein the organic solvent is an acetic acid ester.
°) in the range of 25 ° to 30 °, a method for producing a dichlorotin phthalocyanine crystal having the strongest diffraction peak at 28.2 °. 4. A dichlorotin phthalocyanine having the strongest diffraction peak at 28.2 ° on a conductive support in a Bragg angle (2θ ± 0.2 °) range of 25 ° to 30 ° according to claim 1. An electrophotographic photoreceptor comprising a photosensitive layer containing crystals.