JPS6029946B2 - Electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor using poly-9-pinylanthraceso as an organic photoconductor, and particularly to improvements in its sensitizer.

Traditionally, inorganic compounds such as selenium and cadmium sulfide have been mainly used as photoreceptors for electrophotography.
Many of these materials are designated as poisonous, deleterious substances, or specified chemical substances, and have the disadvantage of requiring care in their handling, especially in their disposal.

On the other hand, in contrast to photoreceptors using these inorganic materials, electrophotographic photoreceptors using organic photoconductors have recently been proposed as non-toxic and inexpensive photoreceptors. A number of organic compounds are known as suitable materials, such as sensitized poly-N-vinylcarbazole, polypynylanthracene, polyacenaphthylene, various phthalocyanine compounds, and the like. However, there are not many photoreceptors whose sensitivity is comparable to that of commercially available photoreceptors such as selenium, and which can produce good images, and the photosensitivity of these organic photoconductive materials themselves is on the short wavelength side of the visible region. or in the ultraviolet region, the degree of photosensitivity in the visible region is quite low.

For this reason, dyes and pigments such as crystal violet, methylene flue, rhodamine 83, rose bengal, and brilliant green have been used as sensitizers in order to shift the photosensitive characteristics from conventional to visible range. However, many of these have poor light resistance, which poses a major problem in practical use. An object of the present invention is to overcome the above-mentioned drawbacks, to provide a photosensitive plate for electrophotography that is simple to produce, has excellent light resistance and electrophotographic properties, is inexpensive, and is non-toxic.

As disclosed in Japanese Patent Publication No. 43-27587, Japanese Patent Publication No. 43-2758 & Japanese Patent Publication No. 43-2629, etc.
It is already known that the poly-9-vinylanthracene used in the present invention has photosensitive properties suitable for use as an electrophotographic photoreceptor.

The sensitizers include paraquinone, 2-methylanthraquinone, tetracyanoethylene, tetracyanoquinodimethane, chloranil, crystal violet,
Rhodamine 83, methyl violet, dichloroacetic acid,
Although various compounds such as trichloroacetic acid have been proposed, their light resistance has not been sufficiently investigated. The present invention provides a dispersion type photoreceptor made of poly-9-vinylanthracene, a Visoda resin, and a sensitizer, in which an electrophotographic photoreceptor using a phthalocyanine compound as a sensitizer uses a compound other than the phthalocyanine compound as a sensitizer. This is based on the discovery that it has superior electrophotographic properties and light resistance compared to electrophotographic photoreceptors containing it, and that images obtained by the Carlson method are also clearer.

The present invention will be explained in detail below using examples.

Example 1 Poly-9-vinylanthracene was synthesized by the following procedure.

Purified 9-vinyl anthracene was mixed with anhydrous benzene 2
5 and 0.05 titanium tetrachloride was added in a nitrogen atmosphere, and the mixture was allowed to react at room temperature for 8 hours. Thereafter, a pale yellow polymer is obtained by thoroughly washing with benzene and alcohol and then drying. The yield by this method was 90%. Next, the synthesized boly-9-vinylanthracene was mixed and ground with ethyl acetate in a ball mill for 100 hours, and then a polyurethane resin and a sensitizer were added to obtain a dispersion having the composition shown in Table 1. An electrophotographic photosensitive plate was prepared by coating the film on top.

As the polyurethane resin, a paint mixed in an equimolar ratio of Takelac U-25 (trade name of polyol for urethane resin manufactured by Takeda Pharmaceutical Company Ltd.) and Takenate D-110N (trade name of isocyanate for urethane resin manufactured by Takeda Pharmaceutical Company Ltd.) was used. there was. The electrophotographic properties of each of the obtained photosensitive plates were measured using an electrostatic recording paper tester SP-428 second model manufactured by Kawaguchi Denki ■.

Surface potential V when corona discharge of Juro V is performed for 1 hour of sulfuric acid
o, surface potential V when left in the dark for 10 seconds after charging,
o. After charging, apply 1 to the photosensitive plate using a white tungsten lamp.
Light of 0 lux was irradiated, and the exposure amount EI/2 when the surface potential attenuated to 1'2 was measured. The second measurement result
Shown in the table. Table 1 Table 2. Table 2. As is clear from this table, the phthalocyanine compounds (composition numbers 13 and 14) have a much greater sensitizing effect than other sensitizers.

In addition, after exposing the photosensitive plates of composition numbers 13 and 14 to direct sunlight for approximately 200 hours, the electrophotographic properties were measured again using the electrostatic recording paper tester described above, and no deterioration of the properties was observed. Proven to be excellent. Example 2 Poly-9-vinylanthracene synthesized by the same method as in Example 1 was mixed with Shin-Etsu Silicone KR-214 (trade name of polysiloxane resin containing OH groups manufactured by Shin-Etsu Chemical Co., Ltd.) and ethyl acetate at 100% After mixing and pulverizing with a ball mill for a time, the same polyurethane resin and sensitizer as used in Example 1 were added to obtain a dispersion having the composition shown in Table 3, which was coated on an aluminum plate. A photosensitive plate for electrophotography was created.

The electrophotographic properties of the obtained photosensitive plate were measured in the same manner as in Example 1, and the results shown in Table 3 were obtained. In the Examples of Table 3, metal-free phthalocyanine: C.I. 1. Pigment Blue 16 (C.1.74100
), but excellent sensitizing effects can also be obtained using other phthalocyanine compounds such as metal phthalocyanines and halogenated phthalocyanines.

In addition, phthalocyanine compounds include Q, 8 type, y,
The existence of crystalline forms such as 6, Go, Using the photosensitive plate obtained in Example 2, about 5. After giving a positive charge by the arc V corona discharger, 3
Exposure was performed for 1 second at an illuminance of 0 lux, and a developing toner was applied using a magnetic brush, resulting in a good image faithful to the original image.

From the above, it can be seen that in a dispersion type photoreceptor comprising poly-9-vinylanthracene, a binder resin, and a sensitizer, the photoreceptor in which the sensitizer is a phthalocyanine compound has excellent electrophotographic properties and light resistance.

Claims (1)

[Claims] 1. An electrophotographic photoreceptor comprising poly-9-vinylanthracene, a binder resin, and a sensitizer, wherein the sensitizer is a phthalocyanine compound.