JPH04224872A - Preparation of titanylphthalocyanine crystal - Google Patents

Abstract

PURPOSE:To prepare the title crystal with a specific crystal structure having good electrophotographic properties i.e., a crystal structure having main peaks at Bragg angles 2theta of 9.5 deg. and 27.2 deg. in the X-ray diffraction spectrum using Cu Kalpha radiation, industrially stably with a high reproducibility. CONSTITUTION:An amorphous titanylphthalocyanine obtd. by an acid paste treatment is treated with a solvent such as a ketone, an alcohol, an ester, or an ether without being dried in the presence of water to convert the amorphous phthalocyanine into the title crystal to thereby deposit it.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial method for producing titanyl phthalocyanine crystals used in photoelectric conversion devices such as electrophotography.

0002

[Prior Art] Inorganic photoconductive materials such as selenium, zinc oxide, and cadmium sulfide have long been known as electrophotographic photoreceptors, but they are sensitive to semiconductor lasers whose emission wavelength is in the near-infrared region. In recent years, photoreceptors using phthalocyanines have attracted attention. Among them, titanyl phthalocyanine has several crystal forms.
No. -239248, No. 62-67094, JP-A-63
-218768 etc. Among these, the one with particularly high sensitivity is titanyl phthalocyanine crystal, which has main peaks at Bragg angles 2θ; 9.5 ± 0.2° and 27.2 ± 0.2° in the X-ray diffraction spectrum, and has already been
apan Hardcopy'89” (Collection of papers 10
(page 3).

0003

[Problems to be Solved by the Invention] However, this titanyl phthalocyanine crystal with excellent electrophotographic performance has been disclosed in Japanese Patent Application No. 1-161177, No. 1-170358, No. 1
As described in No. 170355, although a product with sufficient performance has been obtained on a laboratory-level manufacturing scale, there are many problems that need to be improved as an industrial manufacturing method.

One of the methods is to dry the amorphous titanyl phthalocyanine, which is originally a fine particle obtained through acid paste treatment (a process of dissolving it in concentrated sulfuric acid and pouring it into water to make it amorphous), and to convert it into crystals after pulverizing it again. That's a problem.

[0005] Although this problem can be solved by using the wet paste as it is, there are several industrial problems such as the odor of the solvent, toxicity, and production stability. That is, the aromatic solvents (for example, orthodichlorobenzene) described in JP-A No. 63-20365 may cause neurotoxicity if used in large quantities in a poorly ventilated place.

Furthermore, in the method described in JP-A-2-28265, the wet paste is treated with THF (tetrahydrofuran), which is a solvent that is miscible with water as it is, and variations in the amount of water in the wet paste cause fluctuations in production stability. It has the potential to be a factor. Furthermore, the special application 1986-1
Although the example of No. 70355 shows that alkyl halides can be used as a crystal conversion solvent, this is not environmentally preferable due to the nature of alkyl halides that are poorly degradable by microorganisms.

[0007]

OBJECT OF THE INVENTION The object of the present invention is to obtain a Bragg angle of 2θ; 9.5.
The present invention provides a means for stably and safely producing titanyl phthalocyanine crystals having excellent electrophotographic performance and having two main peaks at 27.2° and 27.2°.

[0008]

DESCRIPTION OF THE INVENTION The production method of the present invention involves dissolving titanyl phthalocyanine in sulfuric acid to make it amorphous, and then dissolving the titanyl phthalocyanine in a water-immiscible ketone solvent, alcohol solvent, ester solvent, etc. in the presence of water. After treatment with an ether solvent, the Bragg angle 2θ of the X-ray diffraction spectrum for the Cu-Kα line was 9.5±0.2°, 27.2±0.
This invention provides a method for producing titanyl phthalocyanine crystals having a main peak at 2°.

In the embodiment of the present invention, the titanyl phthalocyanine chlorine content in the acid paste treatment is 0.
It is preferably 2% or less, and it is preferably obtained via 1,3-diiminoisoindoline as an intermediate.

Titanyl phthalocyanine has the following general formula (
1).

[0011]

[Chemical formula 1]

In the formula, R1 to R16 represent a hydrogen atom or a substituent, and examples of the substituent include a halogen atom, an alkyl group,
Examples include alkoxyl groups.

[0013] The X-ray diffraction spectrum is determined by "JDX-8200
” (manufactured by JEOL Ltd.) under the following conditions.

X-ray tube Cu voltage
40.0
KV current
100 mA starting angle 6.0 d
eg. Stop angle 35.0
deg. step angle
0.02 deg. Measurement time 0.50
sec. The titanyl phthalocyanine according to the present invention has a Bragg angle 2θ of 9.5±0.2° and 27.2±0.2°.
Two clear peaks are shown at °. The two clear peaks are 27 in the region of 2θ from 6.0° to 33.0°.
．． The X-ray diffraction intensity at 17°, which is near the center of 2° and 9.5° and has no peak, is taken as the baseline, and 27
．． It means that the peak intensity at 9.5 ± 0.2° is in the 40 to 150% region based on the peak intensity at 2°, and the intensity of other peaks is less than that at 9.5°. do.

[0015] The acid paste treatment referred to in the present invention is one of the means for making phthalocyanine amorphous.
This is a method of making amorphous pigments by dissolving them in sulfuric acid and pouring them into water.

Various known methods can be used to synthesize the phthalocyanine (hereinafter referred to as crude titanyl phthalocyanine for convenience) prior to acid paste treatment. For example, titanium tetrachloride and phthalonitrile are reacted at a high temperature of around 200° C. to obtain an intermediate dichlorotitanium phthalocyanine, which is then hydrolyzed. Alternatively, it can also be obtained directly from a titanium coupling agent such as diiminoisoindoline and alkoxytitanium. Among these synthesis methods, the method using diiminoisoindoline has fewer impurities, probably because the reaction is conducted under mild conditions. Therefore, when the titanyl phthalocyanine crystal obtained according to the crystal conversion method of the present invention using the crude titanyl phthalocyanine obtained by this method as a raw material is used in an electrophotographic photoreceptor, it exhibits excellent performance.

In the present invention, the crude titanyl phthalocyanine is dissolved in sulfuric acid and poured into water to make it amorphous.
By mixing this with an organic solvent in the presence of water, a specific crystalline titanyl phthalocyanine is obtained.

Among these organic solvents, ketone solvents have carbon atoms in the range of 4 to 15, such as methyl ethyl ketone (4 carbon atoms), 3-pentanone (5 carbon atoms), and cyclopentanone (5 carbon atoms). , cyclohexanone (6 carbon atoms), methyl isobutyl ketone (6 carbon atoms)
, diisobutyl ketone (9 carbon atoms), and the like.

[0019] The alcohol solvent has 4 to 15 carbon atoms.
Among them, linear ones are more preferable. For example, butanol (4 carbon atoms), amyl alcohol (5 carbon atoms)
), hexanol (6 carbon atoms), pentanol (7 carbon atoms), nonyl alcohol (9 carbon atoms), and the like.

Ester solvents include those having 3 to 15 carbon atoms, such as ethyl acetate (4 carbon atoms), butyl acetate (6 carbon atoms), isobutyl acetate (6 carbon atoms), and cyclohexyl acetate (8 carbon atoms). , hexyl acetate (8 carbons)
, methyl propionate (4 carbon atoms), butyl acrylate (7 carbon atoms), and the like.

As the ether solvent, butyl ether (
carbon number 8), tetrahydropyran (carbon number 5), ethylene glycol dibutyl ether (carbon number 10), and the like.

[0022] All of the above-mentioned solvents have a certain limit of solubility in water, and cannot be mixed in arbitrary proportions. Therefore, since excess water is expelled from the system, the amorphous paste obtained by acid paste treatment becomes crystals consisting of water/organic solvent/titanyl phthalocyanine at a constant ratio regardless of manufacturing variations in water content. It can provide a platform for transformation.

The amount of the solvent is desirably 5 times or more, preferably 5 to 100 times the volume of the solid content of titanyl phthalocyanine. If the amount is too small, stirring will not be sufficient and it will be difficult to obtain uniform crystals. Furthermore, when the amount of solvent is large, the performance of the crystals produced is satisfactory, but the production cost is high.

The solvent, water, and amorphous titanyl phthalocyanine may be added in any order. When stirring is sufficient on a small scale, use a wet paste of amorphous titanyl phthalocyanine (if it contains a large amount of water, you can leave it as is or add more water)
The solvent may be added in the order in which the solvent is added. In addition, in the case of large-scale production where stirring is a problem, there is a method in which the solvent is placed in the reaction vessel and the wet paste of amorphous titanyl phthalocyanine is added little by little afterwards.

In order to further ensure the presence of water, which is a key point, there is also a method in which water is added together with the solvent into the reaction vessel, and amorphous titanyl phthalocyanine is added to the organic solvent saturated with water from an early stage.

The temperature for crystal conversion may be within a range where water exists as a liquid, preferably 0 to 100°C, preferably 15°C.
~80°C can be used.

[0027] There is no particular restriction on the time, but it is preferable that stirring can be done in a sufficiently uniform state. In a short time, the degree of crystal growth between particles varies, which is unfavorable in terms of electrophotographic performance.

[0028] The titanyl phthalocyanine crystal (X-ray diffraction spectrum has main peaks at Bragg angles 2θ; 9.5±0.2° and 27.2±0.2°) obtained by the synthesis method of the present invention. Various applications can be considered in the field of dyes and pigments. In particular, when used as photoelectric conversion elements such as electrophotographic photoreceptors and solar cells, the titanyl phthalocyanine synthesized according to the present invention exhibits excellent properties that cannot be obtained by other synthesis methods.

[0029]

[Examples] Examples and application examples will be described below, but the present invention is not limited to these.

Example 1 (1) Synthesis of titanyl phthalocyanine wet paste product 29.2 g of 1,3-diiminoisoindoline was dispersed in 200 ml of orthodichlorobenzene, 20.4 g of titanium tetrabutoxide was added, and nitrogen was added. Under the atmosphere 1
It was heated at 50-160°C for 5 hours. After cooling, the precipitated crystals were filtered, washed with chloroform, washed with 2% aqueous hydrochloric acid, washed with water, washed with methanol, and dried to yield 26.2 g (
91.0%) of crude titanyl phthalocyanine was obtained. The crystal form of this product is shown in FIG. Next, 20.0 g of this crude titanyl phthalocyanine was added to 200 ml of concentrated sulfuric acid at 5°C or below.
Stir for 1 hour to dissolve, and pour into 4 liters of water at 20°C. The precipitated crystals were filtered and thoroughly washed with water to obtain 180 g of a wet paste product. The crystal form of this substance is shown in Figure 2.
As shown, it is in an almost amorphous state.

(2) Creation of titanyl phthalocyanine crystals of the present invention In a beaker, 60 ml of methyl ethyl ketone and 20 ml of water were added, and the above-mentioned titanyl phthalocyanine wet paste product 40 was placed in a beaker.
g (solid content: 11%), stirred at room temperature for 8 hours, and left overnight. Add 500ml of methanol to this viscous mixture.
In addition, crystals are precipitated. Filter, wash with methanol, and dry to obtain the desired titanyl phthalocyanine crystals.
4.2g was obtained. The crystal form of this product is shown in FIG. It is characterized by significantly developed peaks at Bragg angles 2θ; 9.5° and 27.2°.

Example 2 In a beaker, 60 ml of 3-pentanone, 20 ml of water, and 40 g of the aforementioned titanyl phthalocyanine wet paste product (
Solid content: 11%) was added, stirred at room temperature for 8 hours, and left overnight. Add 300ml of isopropanol to this viscous mixture.
1 to precipitate crystals. Filter, wash with methanol, and dry to obtain the desired titanyl phthalocyanine crystal 4.
．． Obtained 0g. The crystal form of this product is shown in FIG. It is characterized by significantly developed peaks at Bragg angles 2θ; 9.5° and 27.2°.

Examples 3 to 25 In the same manner, the solvent for crystal transformation (corresponding to 3-pentanone in Example 2) was changed one after another, and there were significantly developed peaks at Bragg angle 2θ; 9.5° and 27.2°. Crystalline titanyl phthalocyanine was synthesized.

Example Solvent name
X-ray diffraction diagram 3 Methyl isobutyl ketone Figure 5 4
cyclopentanone
Figure 6 5
cyclohexanone
Figure 7 6
diisobutyl ketone
Figure 8 7 Diisopropyl ketone
Figure 9 8 Butanol

Figure 10 9 Amyl alcohol
Figure 11 10 Hexanol

Figure 12 11 Heptanol
Figure 13 12 Nonyl alcohol
Figure 14 13 Ethyl acetate

Figure 15 14 Propyl acetate
Figure 16 15 Butyl acetate
Figure 17 16 Butyl acrylate
Figure 18 17 Methyl propionate
Figure 19 18 Cyclohexyl acetate
Figure 20 19 Hexyl acetate
Figure 21 20 Isobutyl acetate
Figure 22 21 Butyl ether
Figure 23 22 Tetrahydropyran
Figure 24 23 Ethylene glycol dibutyl ether Figure 25 Application examples 1 to 5 Titanyl phthalocyanine crystals having the X-ray diffraction pattern shown in Figure 3 obtained in Example 1; 1 part, silicone modified resin "KR-5240" (Shin-Etsu) as binder resin; Kagakusha); 1 part, t-butyl acetate as dispersion medium; 100
The mixture was dispersed using a sand mill. This was applied onto a polyester base coated with aluminum using a wire bar to form a carrier generation layer having a thickness of 0.2 μm. Next, 1 part of a styryl-triphenylamine compound represented by the following structural formula (1), 1.5 parts of polycarbonate resin "Iupilon Z200" (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and a trace amount of silicone oil "KF54" (manufactured by Shin-Etsu Chemical Co., Ltd.) 1,2-dichloroethane) was dissolved in 10 parts of 1,2-dichloroethane, and this solution was applied onto the carrier generation layer using a blade coater to form a carrier transport layer having a thickness of 20 μm after drying. The photoreceptor thus obtained is referred to as sample 1.

[0035]

[Case 2]

4 to 7 similarly described in Examples 2 to 5
Samples 2 to 5 were made using titanyl phthalocyanine crystals having an X-ray diffraction pattern of .

The samples obtained as described above were evaluated as follows using a paper analyzer EPA-8100 (manufactured by Kawaguchi Electric Co., Ltd.).

First, corona charging was performed for 5 seconds under the condition of -80 μA, and the surface potential Va immediately after charging and the surface potential Vi after being left for 5 seconds were determined.
x), and the exposure amount E1/2 required to set the surface potential to 1/2Vi was determined.

[0039] Also, D=100(Va-Vi)/Va(%
) The dark decay rate D was determined from the equation. The results are shown in Table 1. It can be seen that the dark decay rate is low and the sensitivity is also good.

[0040]

[Table 1]

Application Examples 8 to 10 Titanyl phthalocyanine crystal having the X-ray diffraction pattern shown in FIG. 10 obtained in Example 8: 1 part, butyral resin "S-LEC BL-1" (Sekisui Chemical) 1 part as a binder resin, dispersion As a medium, 100 parts of t-butyl acetate was dispersed using a sand mill. This was applied as an undercoat layer onto a polyester base coated with polyamide resin "CM-8000" (Toray) and deposited with aluminum using a wire bar to form a carrier generation layer with a thickness of 0.2 μm. Next, 1 part of a styryl-triphenylamine compound represented by the following structural formula (1) and a polycarbonate resin ``
1.5 parts of ``Iupilon Z200'' (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and a trace amount of silicone oil ``KF54'' (manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in 10 parts of 1,2-dichloroethane, and this solution was used to generate the above carrier. The layer was coated using a blade coater to obtain a carrier transport layer having a thickness of 20 μm after drying. The photoreceptor thus obtained is designated as sample 8.

FIG. 11 similarly described in Examples 9 and 10
Samples 9 and 10 were made using titanyl phthalocyanine crystals having X-ray diffraction patterns of ~12.

The samples obtained as described above were evaluated as follows using Paper Analyzer EPA-8100 (manufactured by Kawaguchi Electric Co., Ltd.).

First, corona charging was carried out for 5 seconds under the condition of -80 μA, and the surface potential Va immediately after charging and the surface potential Vi after being left for 5 seconds were determined.
x), and the exposure amount E1/2 required to set the surface potential to 1/2Vi was determined.

[0045] Also, D=100(Va-Vi)/Va(%
) The dark decay rate D was determined from the equation. The results are shown in Table 2. It can be seen that the dark decay rate is low and the sensitivity is also good.

[0046]

[Table 2]

Application Examples 13 to 17 Titanyl phthalocyanine crystal having the X-ray diffraction pattern shown in FIG. 15 obtained in Example 13; 2 parts, butyral resin "S-LEC BL-1" (Sekisui Chemical) 1 part as a binder resin, dispersion As a medium, 100 parts of t-butyl acetate was dispersed using a sand mill. This was applied as an undercoat layer onto a polyester base coated with polyamide resin CM-8000 (Toray) and deposited with aluminum using a wire bar to form a carrier generation layer with a thickness of 0.2 μm. Next, 1 part of a styryl-triphenylamine compound represented by the following structural formula (2) and a polycarbonate resin ``
1.5 parts of ``Iupilon Z200'' (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and a trace amount of silicone oil ``KF54'' (manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in 10 parts of 1,2-dichloroethane, and this solution was used to generate the above carrier. The layer was coated using a blade coater to obtain a carrier transport layer having a thickness of 20 μm after drying. The photoreceptor thus obtained is referred to as sample 13.

[0048]

[Chemical formula 3]

FIG. 1 similarly described in Examples 14 to 17
Samples 14 to 17 were made using titanyl phthalocyanine crystals having the X-ray diffraction patterns shown in Figures 6 to 19.

The samples obtained as described above were evaluated as follows using a paper analyzer EPA-8100 (manufactured by Kawaguchi Electric Co., Ltd.).

First, corona charging was performed for 5 seconds under the condition of -80 μA, and the surface potential Va immediately after charging and the surface potential Vi after being left for 5 seconds were determined.
), and the exposure amount E600/100 required to lower the surface potential from -600V to -100V was determined. Further, the dark decay rate D was determined from the formula D=100(Va-Vi)/Va(%). The results are shown in Table 3. It can be seen that the dark decay rate is low and the sensitivity is also good.

[0052]

[Table 3]

Application Examples 21 to 22 Titanyl phthalocyanine crystal having the X-ray diffraction pattern shown in FIG. 23 obtained in Example 21; 1 part; silicone modified resin "KR-5240" (Shin-Etsu Chemical Co., Ltd.) as a binder resin; 2 parts , t-butyl acetate as dispersion medium; 10
0 parts were dispersed using a sand mill. This was applied onto a polyester base coated with aluminum using a wire bar to form a carrier generation layer having a thickness of 0.2 μm. Next, 1 part of the styryl-triphenylamine compound represented by the structural formula (2), 1.5 parts of polycarbonate resin "Iupilon Z200" (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and a trace amount of silicone oil "KF54" (manufactured by Shin-Etsu Chemical Co., Ltd.) company)
was dissolved in 10 parts of 1,2-dichloroethane, and this solution was applied onto the carrier generation layer using a blade coater to obtain a carrier transport layer having a thickness of 20 μm after drying. The photoreceptor thus obtained is designated as sample 21. Similarly, sample 22 was prepared using the titanyl phthalocyanine crystal having the X-ray diffraction pattern shown in FIG. 24 obtained in Example 22.
made.

The samples obtained as described above were evaluated as follows using a paper analyzer EPA-8100 (manufactured by Kawaguchi Electric Co., Ltd.).

First, corona charging was performed for 5 seconds under the condition of -80 μA, and the surface potential Va immediately after charging and the surface potential Vi after being left for 5 seconds were determined.
x) Exposure amount required to reduce the surface potential from -600V to -100V E600/100
I asked for Also, D=100(Va-Vi)/Va(%)
The dark decay rate D was determined from the equation.

The results are shown in Table 4. It can be seen that the dark decay rate is low and the sensitivity is also good.

[0057]

[Table 4]

[0058]

Effects of the Invention: It is possible to industrially produce titanyl phthalocyanine crystals having a specific crystal structure with good electrophotographic performance, that is, main peaks at Bragg angles 2θ of 9.5° and 27.2°, in a stable manner and with good reproducibility. can.

[Brief explanation of the drawing]

The drawings explained below show Cu-Kα of titanyl phthalocyanine crystals synthesized in Examples and Comparative Examples according to the present invention.
It is an X-ray diffraction spectrum for rays. Figure 1; Crude titanyl phthalocyanine in Example 1 Figure 2
Wet paste titanyl phthalocyanine in Example 1 Figure 3; Final finished titanyl phthalocyanine crystal in Example 1 (same below) (Figure number) (Example number) Figure 4 2 Figure 5 3 Figure 6 4 Figure 7 5 Figure 8 6 Figure 9 7 Figure 10 8 Figure 11 9 Figure 12 10 Figure 13 11 Figure 14 12 Figure 15 13 Figure 16 14 Figure 17 15 Figure 18 16 Figure 19 17 Figure 20 18 Figure 21 19 Figure 22 20 Figure 23 21 Figure 24 22 Figure 25 23

Claims (6)

[Claims] Claim 1: A method for converting amorphous titanyl phthalocyanine obtained by acid paste treatment into crystals by treating it with a ketone solvent having 4 to 15 carbon atoms in the presence of water without drying it. - Bragg angle 2θ of X-ray diffraction spectrum for Kα ray; 9.5±0.
A method for producing titanyl phthalocyanine crystals having main peaks at 2° and 27.2±0.2°. 2. Cu, characterized in that amorphous titanyl phthalocyanine obtained by acid paste treatment is treated with an alcoholic solvent having 4 to 15 carbon atoms in the presence of water to convert it into crystals without drying it. - Bragg angle 2θ of X-ray diffraction spectrum for Kα ray; 9.5±
A method for producing titanyl phthalocyanine crystals having main peaks at 0.2° and 27.2±0.2°. 3. Cu, characterized in that amorphous titanyl phthalocyanine obtained by acid paste treatment is treated with an ester solvent having 3 to 15 carbon atoms in the presence of water without drying to convert it into crystals. -Bragg angle 2θ of X-ray diffraction spectrum for Kα ray; 9.5±0
．． A method for producing titanyl phthalocyanine crystals having main peaks at 2° and 27.2±0.2°. 4. Cu, characterized in that amorphous titanyl phthalocyanine obtained by acid paste treatment is treated with an ether solvent having 4 to 15 carbon atoms in the presence of water without drying to convert it into crystals. -Bragg angle 2θ of X-ray diffraction spectrum for Kα ray; 9.5±0
．． A method for producing titanyl phthalocyanine crystals having main peaks at 2° and 27.2±0.2°. 5. The method for producing titanyl phthalocyanine crystals according to claim 1, wherein the titanyl phthalocyanine subjected to acid paste treatment has a chlorine content of 0.2% or less. 6. The Cu-Kα according to claim 1, wherein the titanyl phthalocyanine is obtained via 1,3-diiminoisoindoline as an intermediate.
Bragg angle 2θ of the X-ray diffraction spectrum with respect to the line; 9.
A method for producing titanyl phthalocyanine crystals having main peaks at 5±0.2° and 27.2±0.2°.