JP2765399B2 - Method for producing hydroxygallium phthalocyanine 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 novel method for producing hydroxygallium phthalocyanine crystals.

[0002]

2. Description of the Related Art Phthalocyanines are used in paints, printing inks,
It is a useful material as a catalyst or an electronic material. Particularly, in recent years, it has been widely studied as a material for an electrophotographic photosensitive member, a material for optical recording, and a photoelectric conversion material. In general, the phthalocyanine compound, the production method, due to the difference in the treatment method,
It shows a large number of crystal forms, and it is known that the difference between these crystal forms greatly affects the photoelectric conversion characteristics of the phthalocyanine compound. Regarding the crystal form of the phthalocyanine compound, for example, in the case of copper phthalocyanine, in addition to the stable β form, crystal forms such as α, π, x, ρ, γ, and δ are known. Are known to be mutually reversible by mechanical strain, sulfuric acid treatment, organic solvent treatment, heat treatment and the like (see, for example, US Pat.
No. 70,629, No. 3,160,635, No. 3,
708,292 and 3,357,989). JP-A-50-38543 describes the relationship between the crystal form of copper phthalocyanine and electrophotographic characteristics. Furthermore, besides copper phthalocyanine,
With respect to metal-free phthalocyanine, hydroxygallium phthalocyanine, chloroaluminum phthalocyanine, chloroindium phthalocyanine and the like, it has been proposed to use various types of crystals for the electrophotographic photosensitive member. The crystal form and electrophotographic properties of hydroxygallium phthalocyanine are described in Japanese Patent Application Laid-Open (JP-A) No. 1-222159, which is obtained by the acid pasting method.

[0003] As a result of further studies, the present inventors have found that
For hydroxygallium phthalocyanine, five new crystal forms have been discovered and they have been found to be excellent electrophotographic photoreceptors. (Japanese Patent Application 3-1
No. 22812) hydroxygallium phthalocyanine
First, a gallium phthalocyanine halide can be synthesized and hydrolyzed by acid pasting to synthesize the gallium phthalocyanine. As a method for synthesizing a gallium phthalocyanine halide, for example, one of the chlorogallium phthalocyanines is, for example, 3 A method of reacting gallium chloride with diiminoisoindoline (DCR AcadSci., 1956, 242;
1026) A method of reacting gallium trichloride with phthalonitrile (Japanese Patent Publication No. Hei 3-30854), a method of reacting gallium trichloride and phthalonitrile in butyl cellosolve,
Method of reacting in the presence of a catalyst (Japanese Patent Laid-Open No. 22145/1990)
No. 9) A method of reacting gallium trichloride with phthalonitrile in quinoline (Inorg. Chem. 19).
80, 19, 3131) and the like.

[0004]

However, when chlorogallium phthalocyanine synthesized by these known methods is hydrolyzed by acid pasting, the obtained hydroxygallium phthalocyanine exhibits an electrophotographic characteristic of chlorogallium phthalocyanine used. It is greatly affected by the method of synthesizing phthalocyanine, and even when the crystal type is the same, when used as an electrophotographic photoreceptor, the chargeability and dark decay rate are particularly large, making it difficult to obtain stable characteristics. There was a problem that it was. The present invention has been made in view of the above-described circumstances in the related art.
Therefore, an object of the present invention is to produce hydroxygallium phthalocyanine having stable electrophotographic properties by employing a synthesis method different from the conventional method.

[0005]

As a result of the study, the present inventors have found that hydrolyzing chlorogallium phthalocyanine synthesized using a specific solvent has stable electrophotographic characteristics, and in particular, improves sensitivity. It has been found that the obtained hydroxyphthalocyanine can be obtained, and the present invention has been completed. That is, the present invention relates to a method for producing hydroxygallium phthalocyanine, which comprises reacting gallium trihalide with phthalonitrile or diiminoisoindoline in an aromatic hydrocarbon solvent to obtain chlorogallium phthalocyanine. It is characterized by hydrolysis.

Hereinafter, the present invention will be described in detail. In the present invention, first, chlorogallium phthalocyanine is synthesized from gallium trichloride and phthalonitrile or diiminoisoindoline. At that time, phthalonitrile or diiminoisoindoline is used at least 4 times the amount of gallium trichloride. It is preferably used in the range of 4 to 10 equivalents. In addition, the aromatic hydrocarbon solvent used in the reaction preferably has a boiling point of 150 ° C. or higher from the viewpoint of the production rate of chlorogallium phthalocyanine. For example, α- and β-chloronaphthalene, o-
And halogenated aromatic hydrocarbon solvents such as p-dichlorobenzene and trichlorobenzene are particularly preferred. These aromatic hydrocarbons can be used in a range of 0.2 to 20 times the amount of phthalonitrile or diiminoisoindoline. If the amount is too small, it is difficult to stir. , Because it is uneconomical, usually 0.3
It is preferable to use in the range of 10 to 10 times. The reaction can be carried out by heating under an inert atmosphere such as nitrogen in the range of 100 ° C. to the boiling point of the solvent.

[0007] The chlorogallium phthalocyanine obtained by the above synthesis reaction is then subjected to solvent washing. As the solvent to be used, amide solvents such as DMF and NMP are particularly preferable. In this solvent washing treatment, after the reaction product is separated by filtration, the obtained filter cake may be dispersed in an amide solvent and stirred. The stirring may be performed while heating. Alternatively, the filter cake may be simply washed with an amide solvent. As the amide solvent, dimethylformamide, N-methylpyrrolidone and the like can be used.

Next, the chlorogallium phthalocyanine obtained as described above is hydrolyzed using an acid. That is, a solution of chlorogallium phthalocyanine dissolved in an acid is poured into a suitable solvent to precipitate hydroxygallium phthalocyanine. As the acid, trichloroacetic acid, trifluoroacetic acid, phosphoric acid, methanesulfonic acid, hydrochloric acid, sulfuric acid, nitric acid, etc. having high solubility in chlorogallium phthalocyanine can be used. It is easy to handle because it does not have any. The amount of the acid used for the hydrolysis is usually in the range of 2 to 70 parts, preferably in the range of 10 to 50 parts with respect to 1 part of chlorogallium phthalocyanine. The temperature at which chlorogallium phthalocyanine is dissolved is as follows:
0-100 ° C, preferably 5-80 ° C is employed. Examples of the solvent into which the solution in which the chlorogallium phthalocyanine is dissolved include water, a mixed solvent of water and an organic solvent, and an alkaline aqueous solution. The amount of the solvent is in the range of 2 to 70 parts, preferably 5 to 50 parts with respect to 1 part of the acid used. It is preferable to use a solvent kept at 10 ° C. or lower in order to avoid heat generation during precipitation.

The hydroxygallium phthalocyanine obtained as described above can be converted into a desired crystal form by treating it in various solvents. For example, amides (N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc.), esters (ethyl acetate, n-butyl acetate, iso-amyl acetate, etc.), ketones (acetone, methyl ethyl ketone) , Methyl iso-butyl ketone, etc.) and 7.5 ° of the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum;
9 °, 12.5 °, 16.3 °, 18.6 °, 25.1
A hydroxygallium phthalocyanine crystal having strong diffraction peaks at ° and 28.3 ° can be obtained. Similarly, using alcohols (methanol, ethanol, etc.), polyhydric alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.), sulfoxides (dimethyl sulfoxide, etc.), aromatics (toluene, chlorobenzene, etc.), X 7.7 °, 16.5 °, 2 of the Bragg angle (2θ ± 0.2 °) in the line diffraction spectrum
A hydroxygallium phthalocyanine crystal having strong diffraction peaks at 5.1 ° and 26.6 ° was obtained by using an aromatic alcohol (such as benzyl alcohol) to obtain a Bragg angle (2θ ±
0.2 °) 7.0 °, 7.5 °, 10.5 °, 11.
7 °, 12.7 °, 17.3 ° 18.1 °, 24.5
The hydroxygallium phthalocyanine crystal having strong diffraction peaks at 0 °, 26.2 ° and 27.1 ° is converted to a Bragg angle (2θ) in the X-ray diffraction spectrum by using polyhydric alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.). (± 0.2 °).
Hydroxygallium phthalocyanine crystals having strong diffraction peaks at 8 °, 12.8 °, 15.8 ° and 26.0 ° can be produced. In addition, amides (N, N
-Dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc., organic amines (pyridine, piperidine, etc.), sulfoxides (dimethylsulfoxide, etc.), etc., can be used to obtain the Bragg angle (2θ) in the X-ray diffraction spectrum. 7.9 ° of ± 0.2 °),
Hydroxygallium phthalocyanine crystals having strong diffraction peaks at 16.5 °, 24.4 ° and 27.6 ° can be produced. These solvent treatments are from 0 to 15
In the temperature range of 0 ° C., it can be carried out in the range of 1 to 200 parts with respect to 1 part of hydroxygallium phthalocyanine crystal.

[0010]

The present invention will be described below by way of examples. In the examples and comparative examples, “parts” means “parts by weight”. (Synthesis example of chlorogallium phthalocyanine) Example 1 1500 ml of α-chloronaphthalene, gallium trichloride 1
00 parts and 291 parts of phthalonitrile in a nitrogen stream 2
After reacting at 00 ° C. for 4 hours, the generated chlorogallium phthalocyanine crystal was separated by filtration. The obtained filter cake was dispersed in 1000 ml of dimethylformamide (DMF), and heated and stirred at 150 ° C. for 30 minutes. The filter cake obtained by filtration was sufficiently washed with methanol, and then dried to obtain 156 parts (44.1%) of chlorogallium phthalocyanine crystals.

Example 2 100 ml of α-chloronaphthalene, phthalonitrile 2
After 9.1 parts of the mixture were thoroughly stirred at room temperature under a nitrogen stream, 10 parts of gallium trichloride was added as a lump, and reacted at 200 ° C. for 24 hours under a nitrogen stream, and the formed chlorogallium phthalocyanine crystal was filtered off. . The obtained filter cake was dispersed in 100 ml of DMF, and heated and stirred at 150 ° C. for 30 minutes. The filter cake obtained by filtration was sufficiently washed with methanol, and then dried to obtain 28.9 parts (82.5%) of chlorogallium phthalocyanine crystals.

Example 3 100 ml of o-dichlorobenzene 10 gallium trichloride
Parts and 29.1 parts of phthalonitrile in a stream of nitrogen under a stream of nitrogen.
After heating under reflux for a period of time, the generated chlorogallium phthalocyanine crystals were separated by filtration. The obtained filter cake was dispersed in 100 ml of DMF, and heated and stirred at 150 ° C. for 30 minutes. The filter cake obtained by filtration was sufficiently washed with methanol, and then dried to obtain 12.2 parts (34.6%) of chlorogallium phthalocyanine crystals.

Example 4 A reaction was carried out in the same manner as in Example 3 except that p-dichlorobenzene was used instead of o-dichlorobenzene, washed and 5.1 parts (14.5%) of chlorogallium phthalocyanine crystal was obtained.
I got

Example 5 (Comparative Example) 30 parts of 1,3-diiminoisoindoline and 9.1 parts of gallium trichloride were placed in 230 parts of quinoline, reacted at 200 ° C. for 3 hours under a nitrogen stream, and formed. The chlorogallium phthalocyanine crystals thus obtained were separated by filtration, washed with acetone and methanol, and then the wet filter cake was dried to obtain 28 parts of chlorogallium phthalocyanine crystals.

Example 6 (Comparative Example) After reacting 29.1 parts of phthalonitrile and 10 parts of gallium trichloride in a 300 ml flask under a nitrogen stream at 300 ° C. for 4 hours, the resulting blue lump was placed in a mortar. The mixture was pulverized well, suspended in 200 ml of DMF, and heated to reflux for 1.5 hours under a nitrogen stream. The obtained chlorogallium phthalocyanine crystal was separated by filtration, washed, and this DMF washing was further repeated twice, and finally, washed with 600 ml of methanol three times, and dried to obtain 25.1 parts of chlorogallium phthalocyanine crystal. Obtained. Elemental analysis values of the obtained chlorogallium phthalocyanine crystal were as follows. From the result of the Mass spectrum measurement, it was found that the chlorogallium phthalocyanine crystal was a mixture of phthalocyanine rings having 0 to 4 Cl atoms substituted.

Elemental analysis value (%) (C ₃₂ H ₁₆ N ₈ GaC
calculated as C: 62.22 H: 2.61 N: 18.1
4 Cl: 5.74 Found C: 60.80 H: 2.43 N: 17.1
5 Cl: 6.95

Example 7 (comparative example) 1.3 33 parts of diiminoisoindoline, 10 parts of gallium chloride and 150 parts of N-methylpyrrolidone were added.
After reacting at 00 ° C. for 3 hours, the product is filtered off,
Wash with acetone, water, DMF, methanol, then
After drying the wet cake, 17 parts of chlorogallium phthalocyanine crystals were obtained.

Example 1 3 parts of the chlorogallium phthalocyanine crystal obtained in the above Example 1 was dissolved in 90 parts of concentrated sulfuric acid at 0 ° C., and dropped into 450 parts of 5 ° C. distilled water to reprecipitate the crystal. Was. After sufficiently washing with distilled water, the powder X-ray diffraction spectrum was measured. The result is shown in FIG. Further, the substrate was washed with dilute aqueous ammonia. Then suspended in 100 ml of 2% aqueous ammonia,
Stirred at room temperature for 1 hour. When 2% aqueous ammonia was added, the hue changed from dark green to dark blue. Further, after sufficiently washing with distilled water, drying was performed to obtain 0.5 part of hydroxygallium phthalocyanine crystal. The powder X-ray diffraction spectrum is shown in FIG. 0.5 parts of the obtained hydroxygallium phthalocyanine crystal was mixed with N, N-dimethylformamide 1
5 parts and 2 parts together with 30 parts of 1 mm diameter glass beads.
After milling for 4 hours, the crystals were separated, washed with methanol and dried to obtain hydroxygallium phthalocyanine crystals. The powder X-ray diffraction pattern is shown in FIG.

Examples 2 to 4 and Comparative Examples 1 to 3 Same as Example 1 except that the chlorogallium phthalocyanine crystals obtained in Examples 2 to 7 were used instead of the chlorogallium phthalocyanine crystals obtained in Example 1. To obtain hydroxygallium phthalocyanine crystals. Example 2
The powder X-ray diffraction patterns of Sample No. 4 and Comparative Examples 1 and 3 were the same as in FIG. The powder X-ray diffraction chart of Comparative Example 2 is shown in FIG.

Application Examples 1-4 and Reference Examples 1-3 On an aluminum substrate, 10 parts of a zirconium compound (trade name; Organix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and a silane compound (trade name: A1110, manufactured by Junker Japan) 1 And a solution consisting of 40 parts of i-propanol and 20 parts of butanol by dip coating.
It was dried by heating at 50 ° C. for 10 minutes to form an undercoat layer having a thickness of 0.5 μm. Next, 0.1 part of the hydroxygallium phthalocyanine crystal obtained in Example 1 was mixed with 0.1 part of polyvinyl butyral (trade name; Esrec BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 10 parts of n-butyl acetate. After mixing and treating with a glass shaker for 1 hour using a paint shaker and dispersing, the obtained coating solution was placed on the undercoat layer using a wire bar No. 5 at 100 ° C for 1
By heating and drying for 0 minutes, a charge generation layer having a thickness of about 0.15 μm was formed. Further, it was confirmed by X-ray diffraction that the crystal form of the hydroxygallium phthalocyanine crystal after dispersion did not change compared to the crystal form before dispersion. Next, 2 parts of a compound represented by the following structural formula (I) and 3 parts of a polycarbonate having a repeating unit represented by the following structural formula (II) are dissolved in 20 parts of monochlorobenzene, and the obtained coating solution is charged. It was applied on the aluminum substrate on which the generating layer was formed by dip coating, and dried by heating at 120 ° C. for 1 hour to form a 20 μm-thick charge transport layer.

[0021]

Embedded image

The electrophotographic characteristics of the electrophotographic photoreceptor thus obtained were measured using a flat plate scanner manufactured in-house under an environment of normal temperature and normal humidity (20 ° C., 40% RH). The sample was charged by performing a corona discharge of 0.5 μA (V0 (V)) and left for 1 second to measure the potential: VDDP (V), and the dark decay rate: DDR (DDR = (V0−VDDP))
/ V0 x 100 (%)). After that, the light of the tungsten lamp was changed to 780 n using a monochromator.
m monochromatic light, and 0.25 μW / cm ² on the photoreceptor surface
And irradiate to obtain an initial sensitivity: dV / dE
(V-cm ² / erg) was measured. Table 1 shows the results. Using the hydroxygallium phthalocyanine crystals obtained in Examples 2 to 4 and Comparative Examples 1 to 3, similar photoconductors were produced and evaluated. Table 1 shows the results.

[0023]

[Table 1]

[0024]

According to the present invention, the hydroxygallium phthalocyanine crystal produced by the present invention can be easily converted into a crystal form useful for an electrophotographic photosensitive member having a low dark decay rate and a high sensitivity, and the obtained electrophotographic photosensitive member is obtained. Shows stable electrophotographic characteristics without variation in chargeability and dark decay rate.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction diagram of hydroxygallium phthalocyanine immediately after hydrolysis in Example 1.

FIG. 2 is an X-ray diffraction diagram of the neutralized hydroxygallium phthalocyanine of Example 1.

FIG. 3 is an X-ray diffraction diagram of hydroxygallium phthalocyanine of Example 1.

4 is an X-ray diffraction diagram of a hydroxygallium phthalocyanine crystal of Comparative Example 2. FIG.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // G03G 5/06 371 G03G 5/06 371 (72) Inventor Yasuo Sakaguchi 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Fujize Rocks Co., Ltd. (56) References JP-A-6-73303 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09B 67/50 C09B 47/04-47/32 C07D 487/22 G03G 5/06 371

Claims (3)

(57) [Claims] 1. A hydroxygallium phthalocyanine crystal characterized by reacting gallium trihalide with phthalonitrile or diiminoisoindoline in an aromatic hydrocarbon solvent to hydrolyze the obtained chlorogallium phthalocyanine. Production method. 2. The method for producing a hydroxygallium phthalocyanine crystal according to claim 1, wherein the aromatic hydrocarbon solvent is a halogenated aromatic hydrocarbon having a boiling point of 150 ° C. or higher. 3. The method for producing a hydroxygallium phthalocyanine crystal according to claim 1, wherein the gallium trihalide is gallium trichloride.