JPS62121459A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the titled body capable of holding a high photosensitive characteristics and having improved electric charge fatigue and electrostatic properties by jointly using specific kinds of the electric charge transfer agents in a prescribed ratio. CONSTITUTION:A beta type copper phthalocyanine is used as the electric charge generating agent. The electric charge carrier layer comprises 0.8-5.0pts.wt. a compd. shown by formula (II) on the basis of 100pts.wt. a compd. shown by formula (I) as a main component. In formula I, R1 is 2-4C an alkyl group, R2 is an aryl or an alkyl substd. aryl group. In formula II, R1 is 2-4C an alkyl group, R2 is 2-4C an alkyl or an aryl or an alkyl substd. aryl group, R3 is an aryl or a benzyl group. Said two compds. are mixed with a small amount of a binding agent such as a polycarbonate resin etc., and chloroform to prepare a coating solution. The obtd. coating solution is coated on the surface of the electric charge generating layer, and dried to form the electric charge transfer layer.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an electrophotographic photoreceptor comprising a charge generation layer and a charge transport layer laminated on a conductive support.

Prior Art Electrophotographic photoreceptors using phthalocyanine compounds as charge generating agents (hereinafter referred to as CGM) are used in plain paper copying machines (PPC).
) is being put into practical use as a photoreceptor. It is also promising for use in laser printers. CGM is dispersed in a binding resin and coated on the surface of a conductive support to form a charge generation layer (hereinafter referred to as CGL). In order to improve functions such as photosensitivity, a charge transport layer (hereinafter referred to as (!TL)) is formed on CGL by binding a charge transport agent (hereinafter referred to as CTM) with resin. A photoconductor (hereinafter simply referred to as a photoconductor) for use in photoconductors has been announced.

CTM in photoreceptor using silver phthalocyanine as CGM
Many types are known as.

Built in Japanese Patent Publication No. 60-24553. 58-199353
It is disclosed in the publication No.

However, JP-A-57-79981. It is disclosed in Japanese Patent Publication No. 57-14844.

However, when each is used alone, although the photosensitivity is excellent, the charge fatigue due to repeated use is large, or the charge fatigue is good.

It has disadvantages of poor charging properties and light fatigue. The required performance as a photoreceptor is that the initial acceptance potential (Vo) is sufficiently high;
Low dark decay rate (D, D, R), low residual potential (V,), low half-life exposure (Ill), and durability during repeated use.

It is necessary to maintain the above initial characteristics.

Photoreceptors that have all of these characteristics are CGM and CT.
It is greatly influenced by the selection and combination of L.

Problems to be Solved by the Present Invention The present inventor conducted research with the aim of further improving the various characteristics of a photoreceptor using β-type steel phthalocyanine as CGM, and found that a combination of specific different types of CTM was used within a specific range. It has been found that by doing so, various properties can be synergistically improved.

Structure of the Invention The laminated electrophotographic photoreceptor of the present invention uses β-type copper phthalocyanine as a charge generating agent, and the main component constituting the charge transport layer is β-type copper phthalocyanine.

It is characterized in that 0.8 to 5.0 parts by weight of the compound represented by the general formula (I) is blended per 100 parts by weight of the compound represented by the following general formula (+).

General formula (1) General formula (II) This will be explained in more detail below. In the following description, the compounds of the general formula (+) are collectively abbreviated as APH2, and the compounds of the general formula (II) are collectively abbreviated as PSPZ.

In the photoreceptor of the present invention, a cGL is formed by thinly and uniformly applying ultrafine particles of β-type moiety phthalocyanine dispersed in a binder resin to the surface of a conductive support, and then the following is applied on the CGL. The CTL shown in FIG.

Examples of the conductive support include glass, a polymer film on which aluminum is vapor-deposited or aluminum foil is adhered, and an aluminum plate itself as a support.

Beta type steel phthalocyanine has a purity of 95% or more.

The average particle size is 0.1 μm or less, preferably 0.05 μm or less. β-type copper phthalocyanine is 69 by X-ray diffraction.
It has a diffraction pattern at 0, 730, and 780 cm-'. A saturated polyester resin or the like is used as the crystalline resin, kneaded with a solvent, and coated with 01 to 1 on the surface of the support.
Create a coating layer with a thickness of μm to create CGL.

In the present invention, a mixture of CTM, shiso, and two types of compounds with different structures, namely APH2 and pspz, is used in a ratio of 100:0.8 to 5.0.

The ratio was determined based on the viewpoint of comprehensive improvement of various properties. As for E'& characteristics, APH2 is better than PSPZ, but there is a region where the performance deteriorates synergistically when both are mixed.■R characteristics are that PSPZ is better than APHz, but when both are mixed, the performance is synergistically lower. There are areas where performance deteriorates.

VO properties synergistically improve performance through proper mixing. A particularly preferable ratio of APHz and PEIPZ is 10
0: 1.5 to 3°0 (parts by weight).

For both sides, a small amount of a binder such as a polycarbonate resin and chloroform are mixed to form a coating solution, and the coating solution is applied to the CGL surface to a thickness of about 10 to 30 μm.

Dry and use as OTL.

Effects and the like will be explained below based on Examples.

Example 9 parts by weight of a saturated polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) was added to 30 parts by weight of β-type copper phthalocyanine, and tetrahydrofuran was added so that the liquid concentration was Z77 parts by weight to dissolve the resin and make a paint conditioner. The mixture was kneaded for 1 hour to obtain a charge generating substance coating liquid. This coating liquid was applied with a wire bar onto a polyethylene terephthalate film on which aluminum was deposited to a thickness of about 100 μm so that the film thickness after drying would be 0.1 μm, and then dried.

Then p-diethylaminobenzaldehyde-diphenylhydrazone (APH2),! : 1-phenyl-5-
(p-diethylaminostyryl)-5-(p-diethylaminophenyl)-pyrazoline (pspz) was used alone at 2.02, and by varying the ratio of both, the total amount of 1 was reduced to 2.02.
．． 0? The resulting CTM was mixed with 2 g of polycarbonate resin and 12-chloroform to prepare a CTL coating liquid.

Each coating solution was applied onto the previously prepared charge generation layer using a doctor blade so that the film thickness after drying would be about 20 μm, and then dried.

The 8 types of electrophotographic photoreceptors created in this way were statically charged at a corona discharge voltage of -5 volts using a 5P428 electrostatic tester manufactured by Kawaguchi Electric, and after being held in a dark place for 5 seconds, It was exposed to light at an illuminance of 10 lux and its electrostatic properties were examined.

As for electrostatic characteristics, the initial potential is Vo (volt).

The attenuation rate of the potential for 5 seconds in the dark was evaluated as D, R, the half-decreased exposure amount as 8%4 (lux-sea), and the potential remaining after 10 seconds of light irradiation as VR (volt). The results are shown in the table.

10 conducted using photoreceptors A, D and E shown in Table 2.
The graph shows the change in residual potential vR after 00 repeated tests.

As is clear from the figure, the photoreceptor 9 of the present invention and E10
Even after repeated use 00 times.

Has excellent durability with almost no change in residual potential.

Effects of the present invention The present invention maintains or further improves the high photosensitivity characteristics of the compound of general formula (1) as a CTM.

Furthermore, an electrophotographic photoreceptor was obtained in which the disadvantageous charge fatigue characteristics were improved and the electrostatic characteristics were further improved.

[Brief explanation of drawings]

This figure shows the change in residual potential in repeated tests of a photographic photoreceptor made of 51 ml.

Claims (1)

[Scope of Claims] In a laminated electrophotographic photoreceptor using β-type copper phthalocyanine as a charge generating agent, the main component of the charge transport layer is a compound represented by the following general formula (I) per 100 parts by weight of a compound represented by the general formula (I). An electrophotographic photoreceptor comprising 0.8 to 5.0 parts by weight of the compound represented by (II). General formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (I) (In formula (I), R_1 is an alkyl group having 2 to 4 carbon atoms, and R_2 is an aryl group or an alkyl-substituted aryl group.) General formula ▲ Numerical formula , chemical formulas, tables, etc.▼(II) (In formula (II), R_1 is an alkyl group with 2 to 4 carbon atoms, R_2 is an alkyl group or aryl group with 2 to 4 carbon atoms, or an alkyl-substituted aryl group, and R_3 is an alkyl-substituted aryl group with 2 to 4 carbon atoms. (aryl group or benzyl group)