JPH05100446A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance sensitivity and its stability in the electrophotographic sensitive body used for printers copying machine. CONSTITUTION:An electrolytic polymer is prepared in a sol. of propylene carbonate by using pyrrole as a monomer and sodium toluenesulfonate as an electrolyte, and crushing the solid of the electrolytic polymer into a fine power. Polycarbonate is used as a binder resin, hydrazone derivative is prepared by using dischloromethane at the wt. ratio of 2:3 to polycarbonate, electrolytic polymer power is mixed with the sol. in the amt. of 10wt.% based on the hydrazone derivative, and further the electrolytic polymer powder is sufficiently dispersed. A charge transfer layer is formed on the charge generating layer with this liquid dispersion, thus permitting sensitivity and its stability to be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoconductor for electrophotography using an organic photoconductor which is subjected to processes such as charging, exposure, development and charge elimination.

[0002]

2. Description of the Related Art Organic photoconductors (abbreviated as OPC) are capable of synthesizing materials having high sensitivity to various wavelengths by molecular design as compared with inorganic photoconductors, are non-polluting, have excellent productivity, are economical, and are inexpensive. It has such characteristics as, and active research and development is currently being conducted. Further, in terms of durability and sensitivity, which have hitherto been regarded as problems of organic photoconductors, significant improvements have been made, and some of them have been put into practical use, and are now becoming the main force of electrophotographic photoconductors.

OPC is usually used in a double layer structure of a charge generation layer (abbreviated as CGL) that absorbs light to generate carriers and a charge transfer layer (abbreviated as CTL) that moves generated carriers, and has high sensitivity. Is being promoted.

Materials used for CGL (abbreviated as CGM)
As such, various organic materials such as various perylene compounds, various phthalocyanine compounds, thiapyrylium compounds, anthanthrone compounds, squarylium compounds, bisazo compounds, trisazo pigments and azurenium dyes have been investigated.

On the other hand, various hydrazone compounds, oxazole compounds, triphenylmethane compounds, arylamine compounds, etc. have been developed as materials (abbreviated as CTM) used for CTL.

Further, in recent years, there has been an increasing demand for using these organic photoconductors in the near infrared region corresponding to semiconductor laser light (780-830 nm) as photoconductors for digital recording such as laser printers. In this area, the development of organic photoconductors having high sensitivity characteristics is active. As the photoconductor in such a region, the organic photoconductor is more advantageous than the inorganic photoconductor in terms of sensitivity. These materials are used with a binder polymer by a relatively simple coating method such as a drum, belt,
Etc. are formed on the substrate. Binder polymers used for such purpose include polyester resin, polycarbonate resin, acrylic resin, acrylic-styrene resin, and the like.

[0007]

Generally, in the double-layer structure, the CG layer is applied in a thickness of about 1 micron, while the CT layer is applied in a thickness of 10 to 20 micron in order to improve sensitivity. .. At this time, because of its strength, printing durability, etc., C
Normally, the G layer is formed on the substrate side, and the CT layer is formed on the front surface side. In such a configuration, only the CTM that operates by the movement of holes is put into practical use.
The multi-layer photoconductor is of a negative charging type. At present, there is a demand for further improvement in sensitivity, repeatability stability, and environmental resistance in a photoreceptor having such a structure.

In view of the above-mentioned conventional problems, the present invention has an object to improve sensitivity and stability in an organic photoconductor in which two layers of a charge generation layer and a charge transfer layer are essential components. Is.

[0009]

Means for Solving the Problems The present invention achieves the above object, and a technical means thereof is to have at least a charge transfer layer and a charge generation layer, wherein the charge transfer layer is one or more charge transfer materials. The electrophotographic photoreceptor is characterized by further containing an electropolymer.

[0010]

The organic photoreceptor having the charge transfer layer composed of the binder resin, the charge transfer material, and the electrolytic polymer as described above can be improved in sensitivity and stability in its characteristics. ..

As the electrolytic polymer, a 5-membered heterocyclic compound having a structure of the general formula as shown in (Chemical Formula 2) is preferable, and particularly polypyrrole and polythiophene compounds are excellent.

[0012]

[Chemical 2]

The electropolymer is easily formed into a film on the electrode of the anode by the electrolysis method, but a fine powder state is desirable for good dispersion and mixing with the photosensitive material and the binder resin. The oligomerization state of the electrolytic polymer is easy to carry out the pulverization treatment. The characteristics also differ depending on the anion being doped. By using an aromatic anion as the anion, not only the photosensitivity but also the stability is improved. As the aromatic anion, alkylbenzene sulfonic acid, alkylbenzene carboxylic acid, alkylnaphthalene sulfonic acid, and alkylnaphthalene carboxylic acid were particularly effective. As the alkyl group, the number of carbon atoms is from 1 to 6, and one or more may be attached to the aromatic ring. In this case, a hydrogen group may be used instead of the alkyl group.

The charge transfer material is not particularly limited, but it is required that the composite state of the binder resin and the electropolymer be uniform and have good dispersibility. As the charge transfer material, hydrazone compounds, oxazole compounds, triphenylmethane compounds, and aryl compounds which are already generally known.
It is selected from luamine compounds. With the charge generation layer thus produced, a photoreceptor having not only sensitivity characteristics but also repeated stability and image characteristics was obtained.

[0015]

EXAMPLES Examples of the present invention will be described below together with comparative examples.

Example 1 First, an electrolytic polymer was prepared in a solution of propylene carbonate using pyrrol as a monomer and sodium toluenesulfonate as an electrolyte. The solid substance of this electrolytic polymer was pulverized into a fine powder. Polycarbonate is used as the binder resin, and one of the hydrazone compounds, 1-phenyl-
1,2,3,4-Tetrahydroquinoline-6-carboxaldehyde 1 ′, 1′-diphenylhydrazone (CTC-236 manufactured by Anan Fragrance Co., Ltd.) was used in a weight ratio of 2: 3 with respect to the binder resin, polycarbonate, and dichloromethane. Made with this solution to 1 hydrazone compound
The electropolymer powder was mixed at a ratio of 0 wt% and further sufficiently dispersed. A charge transfer layer was formed on the charge generation layer from this solution. The charge generation layer was made of polybutyral and X-type phthalocyanine, and the thickness of the charge generation layer was set to 0.5 μm on the Al substrate. The charge transfer layer was formed so that the film thickness was 20 μm. At the same time, for the purpose of comparison, a charge transfer layer having the same constitution and containing no electrolytic polymer was prepared.

EPA- manufactured by Kawaguchi Electric Co., Ltd. is used to measure the photosensitivity.
It was performed using an 8100 Paper Analyzer. The results of the sensitivity characteristics are shown in (Table 1). Sensitivity is indicated by E1 / 2. The measurement wavelength is 780 nm. The first time as a result of the number of repetitions,
The results of the 1000th, 5000th and 10000th times are shown.

[0018]

[Table 1]

As can be seen from this (Table 1), polypyrro-
It can be seen that the addition of silane improves the sensitivity and improves the stability without deterioration due to repeated tests.

(Example 2) In the same manner as in Example 1, a polythiophene using sodium triisopropylnaphthalene sulfonate as an anion was prepared as an electrolytic polymer. The same binder resin as in Example 1 was used as the binder resin, and triphenylmethane was used as the charge transfer material, and polythiophene was used in an amount of 30 wt% for the charge transfer layer so that the charge transfer layer had a thickness of 20 μm. Was formed. As the charge generation layer, a perylene pigment and polybutyral were used to form a film having a thickness of 0.2 μm on an Al substrate. A photosensitive member was manufactured in the same manner as in Example 1 except for the above. The same experiment as in Example 1 was conducted using white light as the light source. The results are shown in (Table 2).

[0021]

[Table 2]

As can be seen from this (Table 2), by adding polythiophene, the sensitivity is improved and the stability is improved without deterioration by repeated tests.

[0023]

As described above, according to the present invention, the photosensitive resin and the stability thereof are improved by the constitution in which the electrolytic transfer polymer is further added to the binder resin and the charge transfer material as the charge transfer layer. It is possible to provide a photoconductor for electrophotography.

Claims (5)

[Claims] 1. A conductive support having at least two layers of a charge transfer layer and a charge generation layer, wherein the charge transfer layer further comprises an electropolymer in one or more charge transfer materials. A photoconductor for electrophotography. 2. The electrophotographic photoreceptor according to claim 1, wherein the electropolymer comprises a 5-membered heterocyclic compound having a structure represented by the general formula (1). [Chemical 1] 3. The electrophotographic photoconductor according to claim 1, wherein the anion in the electropolymer represented by the chemical formula 1 is an aromatic anion. 4. The electrophotographic photoreceptor according to claim 3, wherein the aromatic anion is any of alkylbenzene sulfonic acid, alkylnaphthalene sulfonic acid, alkylbenzene carboxylic acid, and alkylnaphthalene carboxylic acid. 5. The electrophotographic photoconductor according to claim 1, wherein the electropolymer is in an oligomer state.