JPH03199268A - Crystal type titanyl phthalocyanine and preparation thereof - Google Patents

Abstract

PURPOSE:To stably prepare the subject compound providing highly sensitive photo-sensitizers in a high yield without requiring a crystallization process and a crystal-uniforming process by reacting O-phthalonitrile with titanium tetrachloride in a large amount of quinoline and subsequently hydrolyzing the reaction product. CONSTITUTION:O-Phthalonitrile is reacted with titanium tetrachloride in quinoline, the amount of the quinoline being >=7wt. times that of the O- phthalonitrile, followed by hydrolyzing the reaction product to provide the objective compound preferably having diffraction peaks at diffraction angles (2theta+ or -0.2 deg.) of 21.6 deg., 28 deg. by a powder X ray diffraction method.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing crystalline titanyl phthalocyanine and to crystalline titanyl phthalocyanine.

(Prior art and its problems) Phthalocyanine has recently attracted attention as an excellent photoconductive material. For example, as shown in FIG. The electrophotographic photoreceptor used for this purpose has been actively researched because it has high sensitivity up to long wavelengths. In particular, crystalline titanyl phthalocyanine has recently been taken up as a material with even higher sensitivity, and electrophotographic photoreceptors using this have already been commercialized.

Incidentally, titanyl phthalocyanine is generally produced by hydrolyzing dichlorotitanyl phthalocyanine obtained by reacting O-phthalonitrile and titanium tetrachloride in an inert solvent at a temperature of 170 to 300°C as shown in the following formula. .

However, the crystal form of titanyl phthalocyanine obtained by this method is a mixture of the well-known α type and β type, so
If this is used as it is, various problems arise due to instability of physical properties, for example, crystals of the α-form grow in aromatic solvents and the like over time and change to the β-form.

For this reason, there is a drawback that deterioration occurs over time, which hinders the stable supply of electrophotographic photoreceptors, and at the same time, the problem that stable production is likely to occur.

Therefore, it is necessary to carry out a step of converting it into the β form, for example, by recrystallization using an organic solvent. Moreover, when using it as a photoreceptor material, it is necessary to make the crystal type uniform, and various methods are used to achieve this, such as heating a phase synthesized product in an aromatic solvent to grow crystals, and then forming crystals with a hardness similar to that of common salt. Although a salt milling method has been proposed in which the powder is ground in a ball mill together with an inorganic salt having a high content, there are manufacturing difficulties such as the need for dedicated equipment and processes for each method, which is cumbersome.

(Objective of the Invention) The present invention provides a stable and high-yield production method capable of providing a new crystalline titanyl phthalocyanine having high sensitivity and uniform crystalline form by a method simpler than the conventional method described above.

(Means of the present invention for solving the problems) According to various experimental studies by the present inventors, O
- By setting the weight of the reaction solvent in which phthalonitrile and titanium tetrachloride are reacted to 7 times or more, particularly preferably 10 times or more, to 0-phthalonitrile, the conventional method can be improved as in the example described below. The present invention has been made based on the discovery that crystalline titanyl phthalonium can be produced stably and in large quantities without requiring a crystallization process or a crystal homogenization process, and can provide a highly sensitive photoreceptor.

Next, an example will be described.

(Example 1) Capacity 1 equipped with stirrer, reflux tube, thermometer and dropping funnel
0-phthalonitrile 64.4 in a four-loaf flask of N
to which 25.1 gr of titanium tetrachloride was added dropwise over about 5 minutes using a dropping funnel.

After dropping, heat at 200°C or higher using a mantle heater.
The reaction was completed by heating for a period of time, and after being allowed to cool, 100 Iui of methanol was added thereto, stirred, and filtered with suction, and the filtration residue was thoroughly washed with methanol. The obtained dichlorotitanyl phthalocyanine was heated to 1 ml under the boiling point with a mixture of 60 d of concentrated ammonia water and 60 d of ion-exchanged water.
After carrying out the hydrolysis reaction for 0 hours, the mixture was filtered under suction at room temperature and washed with ion-exchanged water until the washing liquid became neutral. After that, after further washing with methanol, 10 minutes with hot air at 90°C.
After drying for hours, 55.6 gr of blue-purple crystalline titanyl phthalocyanine powder was obtained.

(Example 2) The amount of quinoline in Example 1 was changed to 644 gr (10 times the amount)
By doing so, crystalline titanyl phthalocyanine 64
．． Got 6gr.

Next, it will be explained that the present invention is a new crystal type and that it is superior to conventional ones in terms of sensitivity, yield, etc.

As Reference Examples 1 and 2.3, the amount of quinoline in Example 1 was changed to 1 times, 3 times, and 5 times the amount of O-phthalonitrile, and the yields were determined to be 7.0 times the amount and 10 times the amount of O-phthalonitrile. When summarized together with the yields of Examples 1 and 2, the results are shown in Table 1. It can be seen from this that as the amount of quinoline increases, the yield also increases.

Table 1 Next, as a comparative example of Examples 1 and 2, α-type and β-type titanyl phthalocyanines made by the conventional method shown below were prepared, and Example 1.2, Comparative Example 1.2, and the above-mentioned Reference Example 1 were prepared. 2.
Comparing the X-ray diffraction patterns of No. 3 and No. 3, the following results were obtained.

(Comparative Example 1) 2g of titanyl phthalocyanine produced in Reference Example 1 above
is dissolved in 200 Inl of concentrated sulfuric acid, filtered with suction, and the filtrate is poured into 12 liters of water. Thereafter, the residue was filtered with suction and washed until the ion-exchanged water filtrate became neutral, and then dried with hot air at 90°C to obtain about 1.8 gr of α titanyl phthalocyanine.

(Comparative Example 2) 2g of titanyl phthalocyanine produced in Reference Example 1,
α-Chlornaphthalene 10 (200° with b++1
The mixture was heated and stirred at C for 1 hour, allowed to cool, filtered under suction, washed with 300°C of methanol, and dried with hot air at 90°C to obtain 1.9g of β-titanyl phthalocyanine.

Regarding the above two types of titanyl phthalocyanine and the titanyl phthalocyanine produced in Example 1.2 and Reference Examples 1 and 2.3, the wavelength (λ) ;/) (C
When X-ray diffraction was performed using uKα rays, the results shown in FIG. 2 were obtained. From now on, in Example 1.2, Comparative Examples 1 and 2
, a diffraction angle different from that of Reference Examples 1 and 2.3 (2θ±0.2°
) New diffraction peaks appear at 21.6 degrees and 28 degrees, indicating that the titanyl phthalocyanine of the present invention is novel and unprecedented.

Furthermore, the titanyl phthalocyanine produced in Examples 1 and 2 and Reference Examples 1 and 2.
After forming a charge generation layer by vapor deposition to a film thickness of 500 mm at a heating temperature of 500'' torr and a heating temperature of 500''C, 2-methyl-4-dihenzyl, aminobenzo-1-
A charge transfer layer consisting of 1 part by weight of polycarbonate was applied to 1 part by weight of 1-diphenylhydrazone to a thickness of 20 μm, and finally dried at 80°C for 1 hour to produce an electrophotographic photoreceptor. When the half-decreased exposure amount indicating the determination condition was compared for the photoreceptors of Example 12, Reference Examples 1 and 2.3, the results shown in FIG. 3 and Table 2 were obtained.

Note that the half-life exposure amount was measured as follows.

That is, the photoreceptor is negatively charged by corona discharge with an applied voltage set so that the corona current is 17 μA in a dark place, and then exposed to white light, and the amount of exposure is such that the surface potential is halved from 1,750 volts to 1,375 volts. (E/2) was calculated.

Table 2 FIG. 1 is a cross-sectional view of a functionally separated organic photoreceptor for electrophotography, FIG. 2 is an X-ray diffraction diagram of the present invention, and FIG. 3 is an exposure sensitivity curve of the present invention.

As is clear from the results shown in FIG. 3 and Table 2, it can be seen that the photoreceptor of Example 1.2 has a smaller half-life exposure amount and higher sensitivity than Reference Examples 1 and 2.3.

(Effects of the Invention) As described above, according to the present invention, it is possible to stably provide a high yield of crystalline titanyl phthalocyanine, which has high sensitivity for photoreceptors, without requiring a crystallization process or a crystal homogenization process. , it is highly effective when used in the production of electrophotographic photoreceptors.

[Brief explanation of drawings]

Claims (2)

[Claims] (1) In a method for producing titanyl phthalocyanine by reacting 0-phthalonitrile and titanium tetrachloride in quinoline and then hydrolyzing the same, the weight of the quinoline is reduced to 0.
- A method for producing titanyl phthalocyanine, characterized in that the amount is 7 times or more that of phthalonitrile. (2) The diffraction peak by powder X-ray diffraction is determined by the diffraction angle (2θ±
0.2°) Crystalline titanyl phthalocyanine characterized by a temperature of 21.6 degrees and 28 degrees.