JP2548175B2 - Electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor. More specifically, it relates to an electrophotographic photoreceptor containing a specific polysilane.

(Prior Art) Phthalocyanine-based dyes, diazo-based dyes, electrophotographic photoreceptors composed of organic compounds such as polyvinylcarbazole, oxadiazole, hydrazone, and pyrazoline in combination with various dyes such as selenium, Compared with an electrophotographic photosensitive member made of an inorganic photoconductive compound such as cadmium sulfide, various combinations have been proposed that have advantages such as no pollution and high productivity, and have high sensitivity and excellent durability.

[Problems to be solved by the invention]

The above various pigments or organic compounds alone did not form a good film, and it was necessary to use various binders in combination. Therefore, there are various problems such as deterioration of photoconductive characteristics and deterioration of durability. On the other hand, a method of utilizing a polymer such as polyvinylcarbazole as a photoconductive or electron or hole conductor and not using a binder is also known. However, there were problems such as poor film forming properties.

[Means for solving problems]

The present inventors diligently studied a method for solving the above-mentioned problems, and found that an electrophotographic photoreceptor having high sensitivity and good characteristics can be obtained by using a specific compound, and completed the present invention.

That is, the present invention is an electrophotographic photosensitive member characterized by containing a polysilane containing silicon and boron in the main chain of a polymer and having at least one hydrocarbon residue per silicon atom.

The electrophotographic photoreceptor of the present invention may be of a function separation type (multilayer type having at least two layers of a charge generation layer and a charge transfer layer) or a single layer type, and any of the polysilanes defined in the present invention may be used. It is also effective for improving the performance of the electrophotographic photoconductor even when it is used in the layer.

What is important in the present invention is to use polysilane containing silicon and boron in the main chain of the polymer and having at least one hydrocarbon residue per silicon atom as one component of the photoreceptor.

In the present invention, the polysilane containing silicon and boron in the polymer main chain and having at least one hydrocarbon residue per silicon atom is preferably a dihalogenosilane having at least one hydrocarbon residue and / or 1,2- It is obtained by dehalogenating polycondensation of dihalogenodisilane in the presence of boron halide. Specifically, dimethyldichlorosilane, methylphenyldichlorosilane, diphenyldichlorosilane, diethyldichlorosilane, ethylphenyldichlorosilane, dipropyldichlorosilane, dipropylsilane such as propylphenyldichlorosilane, and tetramethyldichlorosilane. Chlordisilane, trimethylphenyldichlorodisilane, dimethyldiphenyldichlorodisilane, dimethyldiethyldichlorodisilane, dichlorodisilane such as trimethylethyldichlorodisilane and their fluoride derivatives and boron halides, specifically trichloroboron, methyl Dichloroboron, ethyldichloroboron, ropyldichloroboron, butyldichloroboron, hexyldichloroboron, phenyldichloroboron, or nuclear substitution products thereof,
Examples thereof include those compounds obtained by substituting chlorine, fluorine, bromine and iodine for these compounds, or those obtained by dehalogenating polycondensation of a mixture thereof. The method for producing polysilane by dehalogenation polycondensation is not particularly limited, but the above boron halide and dihalogenosilane and / or
A method of heat-contacting 1,2-dihalogenodisilane and an alkali metal can be preferably exemplified (for example, RCWes
t, Comprehensive Organic Chemistry, Vol.2, Chaptor 9.
4, P365-387 (1982), edited by G. Wilkinson et al.,
Pergamon Press, New York, Polymer Preprints 1986 27
(2) 261 Ming-ta S.Hsu et al.] As the polysilane, an asymmetric one such as amorphous polysilastyrene which is soluble in an organic solvent is preferably used, and usually, as a content of boron. Is for 1 atom of boron
A boron unit having an atomic ratio of about 0.0001 to 0.10 is preferably used.

In the present invention, the polysilane is a multi-layer type as a dispersion medium of a pigment in a charge generation layer, and as a dispersion medium of various unsaturated group-containing organic compounds in a charge transfer layer, and a single-layer type is a pigment. It is used as necessary and as a dispersion medium for the unsaturated group-containing organic compound.

In the present invention, various types can be used as the charge generation layer, and there is no particular limitation, and many known pigments for electrophotography can be exemplified. For example, azo pigments such as Sudan Red, Diane Blue, and Genus Green B,
Quinone pigments such as algor yellow, pyrene quinone, indanthrene brilliant, violet RRP, quinocyanine pigments, indigo pigments such as indigo and thioindigo, bisbenzimidazole pigments such as indo fast orange, phthalocyanine pigments such as copper phthalocyanine, Examples thereof include quinacridone pigments such as quinacridone.

In the present invention, the above-mentioned pigment is simply dispersed in the above-mentioned polysilane, and if necessary, 2,4,7-trinitrofluorenone, dicyanobenzene, tetracyanoethylene, aromatic dicarboxylic acid ester, triphenylamine, triphenylamine and triphenylamine. An electrophotographic photoreceptor can be obtained by coating and forming a film on the conductive support layer in combination with phenylmethane and the like.

In the present invention, a charge transfer layer may be further formed on the layer in which the above pigment is dispersed to obtain an electrophotographic photoreceptor. In the case of a single-layer type, the layer in which the pigment is dispersed has a thickness of several μ to several tens of μ, and the ratio of the pigment to the total solid content is 0.05 to
The thickness is about 0.5, the thickness of the multi-layer type is 0.005 to several μ, and the ratio of the pigment is about 0.1 to 0.9. The charge generation layer is a multi-layer type and has a relatively high pigment concentration and other binders such as polyester, polyvinyl butyral, polycarbonate, polystyrene, polyvinyl chloride, methyl cellulose, and polyacryl are used. Such an organic compound may be dispersed in polysilane and used. Examples of the organic compound that can be used in the charge transfer layer include polycyclic aromatic compounds such as anthracene, piene, and phenanthrene, or indole, carbazole, oxazole, isoxazole, thiazole, imidazole, pyrazole, oxadiazole, pyrazoline, thiazole, and the like. A nitrogen-containing cyclic compound can be illustrated.

In the present invention, the charge generation layer and the conductive support layer provided thereunder are prevented from injecting free charges from the conductive support layer into the charge generation layer, and the adhesion between the charge generation layer and the conductive support layer is prevented. A layer made of aluminum oxide, indium oxide, tin oxide, polypropylene resin, acrylic resin, methacrylic resin, polyvinyl chloride resin, epoxy resin, polyester resin, alkyd resin, polyurethane resin, polyimide resin or the like may be provided to improve it can.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples.

Example 1 β-type copper phthalocyanine (manufactured by Toyo Ink Mfg. Co., Li
99 parts by weight of toluene was added to 1 part by weight of onol Blue NCB Tonor), and ultrasonic dispersion was performed for 24 hours. Next, a coating solution prepared by mixing 50 parts by weight of a 10% tetrahydrofuran solution of a saturated polyester resin (manufactured by Toyobo Co., Ltd., Byron 200) and the above dispersion liquid was applied onto an aluminum plate having a thickness of 100 μ using a film applicator and dried. Thus, a charge generation layer having a thickness of 0.5 μm was formed.

Dimethyldichlorosilane, methylphenyldichlorosilane and trichloroboron 1: 1: 0.
A solution of 1 part by weight of polysilane having an average molecular weight of 70,000 and a boron content of 0.02 mol ratio with respect to silicon, obtained by polycondensation with metallic sodium in toluene in a weight ratio of 05, was applied in 10 parts by weight of toluene and dried. Then, a charge transfer layer having a thickness of 8 μ was formed.

The characteristics of the laminated electrophotographic photoconductor prepared in this manner are confirmed by the electrostatic paper analider EPA-8.
It was measured using 100 (manufactured by Kawaguchi Electric Co., Ltd.). First, −6
After performing kV corona discharge for 2 seconds and measuring the initial surface potential, leave it in the dark for 2 seconds, then pass it through a color glass filter IR-80 (manufactured by Hoya Glass Co., Ltd.) and apply light with an illuminance of 20lux. The half-dose exposure was measured. The results are shown in Table 1 with the initial voltage as V ₀ and the half-exposure amount as E _1/2 (lux · sec).

Examples 2 to 3 2,4,7-trinitrofluorenone (1/20 weight ratio to polysilane, Example 2) and m-dicyanobenzene (1/20 weight ratio to polysilane, Example 3) were added to polysilane. A laminated electrophotographic photosensitive member was manufactured in the same manner as in Example 1 except that the above was performed, and the characteristics of the obtained photosensitive member were measured in the same manner as in Example 1. The results are shown in Table 1.

Examples 4 and 5 99 parts by weight of toluene was added to 1 part by weight of τ-type phthalocyanine "Liophoton" (trademark, manufactured by Toyo Ink Mfg. Co., Ltd.) to prepare 24
Time ultrasonic dispersion was performed. Next, a coating solution prepared by mixing 1 part by weight of polysilastyrene obtained in Example 1 in 9 parts by weight of tetrahydrofuran and 10 parts by weight of the above dispersion liquid to give a thickness of
After coating with a film applicator on a 100μ aluminum plate, it is dried in the dark at 80 ° C for 1 hour to give a film thickness of 7
A μ photosensitive layer was formed.

The characteristics of the electrophotographic photosensitive member thus prepared were measured. First. −6 kV (Example 4) or +6 kV (Example 5)
The corona discharge of No. 2 was performed for 2 seconds, the initial surface potential was measured, and the sample was left in the dark for 2 seconds. Then, a half-exposure amount was measured by irradiating light with an illuminance of 5.0 lux through a color glass filter IR-80 (manufactured by Hoya Glass Co., Ltd.). Table 2 shows the results.

Comparative Examples 1 and 2 Instead of polysilane, polyester resin (Vylon 200
When the same procedure as in Example 1 or 5 was carried out except that Toyobo Co., Ltd. was used, the surface potential did not decrease (Comparative Example 1), or it was as large as 2.8 lux · sec (Comparative Example 2). Met.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in a wide range of electrophotographic application fields such as laser printers, CRT printers and electrophotographic plate making systems, and is industrially valuable. .

Claims (2)

(57) [Claims] 1. An electrophotographic photoreceptor comprising a polysilane containing silicon and boron in the main chain of a polymer and having at least one hydrocarbon residue per silicon atom. 2. A polysilane containing silicon and boron in the main chain of a polymer and having at least one hydrocarbon residue per silicon atom is a dihalogenosilane having at least one hydrocarbon residue and / or 1,2-. The electrophotographic photoreceptor according to claim 1, which is obtained by dehalogenation polycondensation of dihalogenodisilane and boron halide.