JPH03220392A - Production of titanyl phthalocyanine by crystal transformation - Google Patents

Abstract

PURPOSE:To obtain the subject compound useful for a photosensitizer of an electrophotography by treating amorphous titanyl phthalocyanine with a heterocyclic ring-based organic solvent and transforming to a specific crystalline state. CONSTITUTION:Amorphous titanyl phthalocyanine expressed by the formula (X<1> to X<4> are H, halogen, alkyl or alkoxy; n, m, l, and k are 0-4) is treated with a heterocyclic ring-based organic solvent (e.g., thiophene or chloroethylene carbonate) to be transformed to a crystalline state exhibiting X-ray diffraction spectrum peaks by Cu-Kalpha line at 2theta=9.5+ or -0.2 deg., 24.1+ or -0.2 deg. and 27.2+ or -0.2 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for converting the crystal structure of titanyl 7-lycyanine into a specific useful form.

[Prior art]

Electrophotographic photoreceptors have traditionally been made of selenium, zinc oxide,
If inorganic photoreceptors with photosensitive layers mainly composed of inorganic photoconductive substances such as cadmium sulfide are widely used, selenium tends to deteriorate in properties due to crystallization due to heat or fingerprint stains.
Cadmium sulfide has problems such as poor moisture resistance and durability, and zinc oxide also has problems such as poor durability.In recent years, organic photoconductive materials with various advantages have been widely used in electrophotographic photoreceptors. It's here. Among them, phthalocyanine compounds have high photoelectric conversion quantum efficiency and exhibit high spectral sensitivity up to the near-infrared region, so they have attracted attention, especially as electrophotographic photoreceptors compatible with semiconductor laser light sources.

For such purposes, electrophotographic photoreceptors using copper 7-lycyanine, metal-free phthalocyanine, chloroindium phthalocyanine, chlorogallium phthalocyanine, etc. have been reported, but in recent years, titanyl phthalocyanine has attracted particular attention. , for example, JP-A-61-2392
No. 48, No. 62-670943, No. 62-27227
2 and No. 63-116158, many electrophotographic photoreceptors using various crystal forms of titanyl phthalocyanine have been disclosed.

[Problem that the invention seeks to solve]

In general, when a 7-lycyanine compound is used in an electrophotographic photoreceptor, its properties vary significantly depending on its crystalline state.
Controlling the crystalline state is an important technology. For this reason, various crystal forms of titanyl phthalocyanine have been developed as seen in the above-mentioned publications. As mentioned above, the properties of an electrophotographic photoreceptor vary significantly depending on the crystal type and also depending on the manufacturing conditions, so titanyl phthalocyanine for use in electrophotographic photoreceptors must have a crystal type with high sensitivity and excellent charging ability. At the same time, it is necessary that it can be produced in a stable state. Under such circumstances, the X-ray diffraction spectra for Cu- σ rays were 9.5±0.2°, 24.1±0.2°, 27.2
It has been found that a particularly markedly high sensitivity is achieved in the crystalline state exhibiting a peak at ±0.26. However, this particular crystalline state could not be stably produced by conventional solvent treatment or milling.

[Object of the Invention] The object of the present invention is to produce Cu-Ka, which is useful for electrophotographic photoreceptors.
9.5 ± 0.2° of the X-ray diffraction spectrum for the rays, 2
The object of the present invention is to provide a method for producing titanyl 7-thalocyanine having a crystalline state showing peaks at 4.1±0.2° and 27.2±0.2°.

[Structure and effects of the invention]

The production method targeted by the present invention involves converting titanyl phthalocyanine into an amorphous state or other thermally non-equilibrium crystalline state, and then treating it with a heterocyclic organic solvent in the presence of water.

Titanyl phthalocyanine is represented by the following general formula.

In the general formula, XI X2 X3 X4 represents a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group, and nS
m%Q represents an integer from 0 to 4.

The X-ray diffraction spectrum is measured under the following conditions, and the peak here is an acute-angled pyramidal projection that is clearly different from noise.

X-ray tube Cu voltage 40. Okv current
100 mA start angle 6.0 tleg.

Stop angle 35. Odeg.

Step angle 0.02 deg.

Measurement time 0.50 sec.

In the present invention, the amorphous state is a state in which the peak is generally broad or no peak is observed in the X-ray diffraction spectrum, and for example, titanyl phthalocyanine is dissolved in sulfuric acid and then poured into water to precipitate it. can be obtained by This method is called acid paste treatment, and the amorphous titanyl 7-lycyanine obtained by acid paste treatment generally has a peak in the 6-8° region of the X-ray diffraction spectrum.

The amount of water used can be selected within a wide range. The concentration of water in the immediate vicinity of titanyl phthalocyanine is important, so the wet paste immediately after acid paste treatment (
When a solid content concentration of 5 to 50% is used, the surface of titanyl 7-thalocyanine is moistened with water, so a very small amount of water relative to the total amount of the solvent is sufficient.

A method of converting into a similar crystal form using an aromatic hydrocarbon solvent instead of the heterocyclic organic solvent according to the present invention is already known. However, crystalline titanyl-7-thalocyanine obtained using an aromatic hydrocarbon solvent, similar to that of the present invention, has poorer performance when made into an electrophotographic photoreceptor than one obtained using a heterocyclic organic solvent. . This seems to be because the cleaning effect of the heterocyclic organic solvent leaves only a small amount of residual impurities.

Examples of the heterocyclic solvent used in the present invention include thiophene, 7-ran, N-methylpyrrolidone, pyridine, quinoline, 2-methylpyrazine, 3-methylpyrazole,
-Methylpyridazine, l-methyl-2-pyridone, 6-
Methyl-2-pyridinecarboxaldehyde, l-methylpyrrole, 6-methylquinoline, 2acetylpyridine, ■-acetyl-4-pyridone, 4-aminomol 7-olin, anabasine, anthranil, 1,3-benzodioxole, l, 4-benzodioxane, 2.3-benzofuran, benzothiazole, thiazole, oxazole,
Benzoxazole, 2,2'bithiophene, 3-bromo-2-coumaranone, coumarin, 3-bromo7rane, bromomaleic ambitrad, 5-bromo-1,3-
Benzodioxole, 2-brompridine, 2-bromothiazole, 2-bromothiophene, 1,4-butanesultone, γ-butyrolactone, catecholporan, 5-
Chlor-1,3-benzoxole, 2-chlorobenzothiazole, 2-chlorobenzoxazole, 3-chloro-2,5-dimethylpyrazine, chlorethylene carbonate, 2-chloro-6-methoxypyridine, chlorpyrazine, 2-chlorothiophene, 4-chromanone, citraconic anhydride, 2,3-cyclohexenopyridine, cyclohexene oxide, cyclohexene sulfide, 2,5-dibromothiophene, 2,6-difluorobyridine, 2,3-dihydrobenzofuran, dihydrocurarine , cis-4,7-sihydro-1,3-dioxepine, 2,3-dihydrofuran, 2,5-dihydro-7rane, 5,6-sihydro-4-methquin-2H-pyran, 4,5-dihydro-2- Methyl 7ran, 3.4-
dihydro-6-methyl-2H-pyran-2-one, 3.
4-dihydro-2H-pyran, 5,6-dihydro-2H
-pyran-2-one, 3,6-dihydro 4.6.6-1
-dimethyl-2H-bilan-2-one, 2,6-simethoxypyridine, tetrahydrofuran, 1,4-dioxane, 2,5-dimethoxytetrahydrofuran, 4-
[2-(dimethylamino)ethyl]mol 7 oline, 2-
(dimethylaminomethyl)thiophene, 2.5-dimethylfuran, 3.5-dimethylisoxazole, 2.5
-dimethylthiophene, l,3-dioxane, 1.7-
Cioxaspiro[5,5]undeceneepichlorohydrin, shrimp fluorohydrin, 1,2-epioxobutane, 1,4-epoxy-1,2,3,4-tetrahydronaphthalene, ethylene trithiocarbonate, glycol sulfide, 3 -Hydroxytetrahydrofuran, imidazolo[1,2-a]pyridine, 2-iodothiophene, inchroman, julolidine, 5-methylisoxazole, 1-morpholine-1-cyclohexene, phthalane, 2-picoline, 3-picoline, 4 -Picoline, 4
Examples include H-pyran-4-one, 2B-pyran-2-one, pyridine d3, pyrazole, pyrimidine, pyrrole and the like.

The processing method is to stir with a general stirring device, but it is also possible to use mechanical force using a homomixer, disperser, agitator, ball mill, sand mill, attritor, ultrasonic dispersion device, etc. .

The titanyl-7-thalocyanine thus obtained exhibits particularly excellent properties when used as a carrier generating material for electrophotographic photoreceptors. In such applications, titanyl-7-thalocyanine is first dispersed in a suitable solvent using a sand mill, ball mill, etc., and coated on a conductive support to form a carrier generation layer, and then carrier transport An electrophotographic photoreceptor can be manufactured by coating a solution in which a substance and a binder are dissolved in a solvent to form a carrier transport layer.

Next, specific examples of the present invention will be shown.

〔Example〕

(Synthesis of titanyl phthalocyanine) 1.3-diiminoisoindoline; 29.2 g and α-
Chlornaphthalene; 200+aff was mixed, titanium tetrabutoxide; 20.4 g was added, and heated at 140-150°C for 2 hours under nitrogen atmosphere, followed by 18
The reaction was carried out at 0°C for 3 hours. After cooling, the precipitate was collected by filtration.
Washing was performed with σ chlornaphthalene, then with chloroform, further with 2% aqueous hydrochloric acid, with water, and finally with methanol. After drying, 26.2 g (91.0%) of titanyl 7-talocyanine was obtained.

(Example 1) Titanyl 7-talocyanine: 100 g was dissolved in 2 kg of concentrated sulfuric acid, poured into 20Q water, precipitated and collected by filtration to obtain an amorphous wet paste.

Further, a part of this wet paste was dried to obtain an amorphous dry powder. The X-ray diffraction spectrum of the dry powder is shown in FIG.

Wet paste in amorphous state (solid content concentration lO
%); 7 runs; 200 aα was added to 100 g and stirred at room temperature for 2 hours. Then methanol i 400tm
(1), filtered, washed with methanol, and dried to obtain crystals having the X-ray diffraction pattern shown in FIG.

(Example 2) 200+m12 of 2-picoline was added to 20 g of the amorphous wet paste used in Example 1, and stirred for 1 hour while cooling with water. The mixture was diluted with methanol, filtered, washed with methanol, and dried to obtain crystals having the X-ray diffraction pattern shown in FIG.

(Example 3) Thiophene; 100 Otori Q was added to 1 g of the amorphous dry powder obtained in Example 1, and water; 100 tQ was added dropwise with stirring, followed by stirring at 50° C. for 3 hours. After cooling, the mixture was diluted with 400 ml of methanol, filtered, washed with methanol, and dried to obtain crystals having the X-ray diffraction pattern shown in FIG.

(Comparative Example) A crystal having the X-ray diffraction pattern shown in FIG. 5 was obtained by carrying out the same treatment except that the 7 runs used in Example 1 were replaced with benzene.

(Application example) Titanyl 7 thalocyanine shown in Figure 2 obtained in Example 1; 2 g
30 g of silicone resin KR-5240, 15% xylene-butanol solution (manufactured by Shin-Etsu Chemical Co., Ltd.) was dispersed using a sand mill in Improper Tool; A carrier generation layer having a thickness of 0.3 μl was formed by coating. Next, 1.2 g of N,N-diethylamino-p-benzaldehyde diphenylhydrazone as a carrier transport substance and polycarbonate resin “Nipiro:/Z-200J (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were added thereon.
; 1.5 g dissolved in 1,2-dichloroethane; 1OIIQ was coated with a blade coater to form a carrier transport layer with a thickness of 20 μm, thereby preparing an electrophotographic photoreceptor.

The photoreceptor thus obtained was evaluated as follows using a paper analyzer EPA-8100 (manufactured by Kawaguchi Electric Co., Ltd.). That is, the surface is negatively corona charged to about 1200V, the potential decay rate is determined for 5 seconds, and the surface is exposed to light such that the surface illuminance is 2 (lux). The exposure amount El/□ required to lower the value to 172 was determined.

As a result, it was D-21%, and E ryz-0-7C1
ux-sec) and exhibits excellent characteristics in both charging ability and sensitivity.

(Comparative Application Example) A dispersion liquid ① was obtained in the same manner except that the titanyl phthalocyanine shown in FIG. 2 obtained in Example 1 used in the application example was replaced with the titanyl phthalocyanine shown in FIG. 5 obtained in the comparative example. A photoreceptor was created.

Evaluate in the same way; Result: D-25%+EI/□-1,0
(1ux-sec) was 0

[Brief explanation of drawings]

The X-ray diffraction diagram of anine and FIGS. 2 to 4 are X-ray diffraction diagrams of titanyl phthalocyanine according to the present invention. FIG. 5 is an X-ray diffraction diagram of a comparative sample.

Claims (1)

[Claims] By treating amorphous titanyl phthalocyanine with a heterocyclic organic solvent in the presence of water, Cu-Ka
9.5 ± 0.2° of the X-ray diffraction spectrum for the rays, 2
A method for producing titanyl phthalocyanine, which comprises converting the titanyl phthalocyanine into a crystalline state exhibiting peaks at 4.1±0.2° and 27.2±0.2°.