JPS61270766A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophtographic sensitive body superior in coatability, sensitivity, durability, and the like by incorporating a specified hydrazone compd. and a specified polycarbonate resin in a photosensitive layer and using coating solutions of both of them good in storage stability and usable for a long period. CONSTITUTION:The electrophotographic sensitive body high in sensitivity, superior in residual potential, and good in mechanical strength and durability an the like can be obtained by coating an electrostatic charge generating layer with a coating solution as a charge transfer layer contg. the hydrozone compd. represented by formula (R1 is CH3, C2H5, CH2CH2Cl, R2, R3 are each optionally substd. alkyl, aralkyl, or aryl, and R4 is H, Cl, Br, alkyl, alkoxy, dialkylamino, or NO2) and the polycarbonate resin represented by formula II in which (n) is an average polymerization degree of 50-500.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and particularly to an electrophotographic photoreceptor suitable for repeated use in an electrophotographic copying machine.

[Conventional technology]

Conventional electrophotographic photoreceptors include those using inorganic photoconductive materials such as selenium, cadmium sulfide, zinc oxide, and amorphous silicon, as well as those using poly-N-vinylcal-p4-nol, ? Photoreceptors using various low-molecular organic photoconductive substances such as photoconductive I sumers such as libinylanthracene or hydrazone compounds such as diethylaminobenzaldehyde and -N,N-diphenylhydrazone are known.

Among these, regarding hydrazone compounds, JP-A-54-
No. 59143, JP-A-54-150128, JP-A-5
5-52064, etc., and the sensitivity and stability of bright area potential upon repeated charging exposure were disclosed in JP-A No. 5-52064.
The hydrazone compound disclosed in No. 7-101844 is very excellent.

By the way, since the hydrazone compound itself cannot be formed into a film with a low molecular weight, a resin having film-forming properties is used as a binder to form a photosensitive layer. Therefore, the properties of the photosensitive layer are greatly influenced not only by the hydrazone compound but also by the binder resin. In other words, if the combination with the binder resin is poor, not only will the characteristics of the hydrazone compound not be exhibited, but the crystals of the hydrazone compound will precipitate, the photosensitive layer will become cloudy and the image quality will deteriorate, and the coating solution will not be as good when coating the photosensitive layer. Separated particles may not be stable and may form into silica.

[Problem that the invention seeks to solve]

The present invention is based on a novel combination of a hydrazone compound and an inder resin, which can fully exhibit the aforementioned characteristics such as sensitivity and stability of bright area potential upon repeated charging exposure. This was made to provide a photographic photoreceptor.

[Means for solving problems]

That is, according to the present invention, at least one hydrazone compound represented by the following general formula CD and the following structural formula (II)
An electrophotographic photoreceptor is provided, which has a photosensitive layer containing a licargenate resin represented by:

〔Record〕

General formula (1) In the formula, R1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group @R2 and R3 each represent an optionally substituted alkyl group, an aralkyl group, or an aryl group. represents a group. As an alkyl group,
Examples include methyl, ethyl, propyl, butyl, hexyl, etc.Aralkyl groups include benzyl, 7enethyl, naphthylmethyl, and aryl groups. ,
Examples include phenyl group and naphthyl group.

Examples of atoms or groups that may be substituted with the groups represented by R2 and R3 include alkyl groups such as methyl, ethyl, propyl, and methyl; methoxy, ethoxy, propoxy, and butoxy groups; Examples include alkoxy groups, halodane atoms such as chlorine atoms, bromine atoms, and iodine atoms, and dialkylamino groups such as dimethylamino groups, diethylamino groups, dialkylamino groups, and diptylamino groups.

R4 is hydrogen, chlorine, bromine, alkyl group, alkoxy group,
Indicates a dialkylamino group or a nitro group.

Examples of alkyl groups include methyl group, ethyl group, propyl group, butyl group, etc.; examples of alkoxy groups include ethoxy group, ethoxy group, propoxy group, butoxy group, etc.
Examples of the dialkylamino group include a dimethylamino group, a diethylamino group, a dialkylamino group, and a dibutylamino group.

Structural formula (U) (In the formula, n indicates the average degree of polymerization and ranges from 50 to 5000.) [Detailed description of the invention and examples] Specific examples of hydrazone compounds represented by the general formula CI) is shown by the compound formula and structural formula below.

Compound structure formula CH3 CH.

α and H3 CH.

α◆ CM.

(To) CH3 CH.

(Foundation) CH3 (To) 0H.

(stomach) CH.

(To) CH.

CH.

(to) CH5 (To) CH.

CH3 (to) 2H5 (to) 21I5 2H5 0 and 2H5 2H5 2H5 2H5 C2H5 ■ 2H5 2H5 2H5 2H5 2H5 συ 2H5 σri 2H40H 2H40H ff→ 2H40H (c) 2H40H 2H40H ση 2H 40H 2H40H (Foundation) C2H4Ct 2H4Ct 2H4Ct ( ■ 2H4Ct 翰2H4Ct C2H4Ct (To) 2H4Ct Polycarbinate resins generally have (1) good transparency, (2) good compatibility with hydrazone compounds, and hydrazone compounds are difficult to separate. ) It has the following characteristics: (4) it has high electrical insulation and withstand voltage; (4) it is dangerous because it interferes with the charge mobility of hydrazone compounds; (5) it has high surface hardness and excellent mechanical durability. However, polycarbonate A resin, which is a typical polycarbanate resin, i.e., bisphenol A type polycarnate resin represented by the general formula, has a high polymer crystallinity, so when dissolved in a solvent, it becomes difficult to dissolve. There is no stability. Therefore, after dissolution, 1 to 2
Within days, the solution turned dull or white, making it unusable.

However, the polycarnate 2 resin represented by the structural formula (If), ie, the bisphenol 2 type polycarnate resin, has very good solution stability] and also has good solution storage stability. Since the solution in which the precargonate resin and hydrazone compound are dissolved can be used for a long time, it greatly contributes to improving the productivity and stabilizing the quality of electrophotographic photoreceptors.

Examples of the form of the photosensitive layer containing the hydrazone compound represented by the general formula CI) and the polycarbonate resin represented by the structural formula [I] according to the present invention include a, the hydrazone compound represented by the general formula [''I], and K.

Charge-transfer complexes formed by combining other electron-donating compounds as necessary with electron-accepting substances such as trinitrofluorenone, tetranitrofluorenone, cyanofluorenone, tetracyanoethylene, and nitroanthracene; b. Sensitized by adding a dye; C. Charge-generating pigment dispersed; d. Functionally separated into a charge-generating layer and a charge-transporting layer.

etc. Among them, the function-separated photoreceptor d is excellent, and the layer containing the hydrazone compound represented by the general formula [1] and the polycarbonate resin represented by the structural formula [] is applied to the charge transport layer. is preferred.

The electrophotographic photoreceptor of type d will be explained in more detail below.

As the charge generation material used in the charge generation layer, any material can be used as long as it absorbs light and generates charge carriers with extremely high efficiency. Preferred materials include selenium and selenium tekka. , - kL/7, inorganic substances such as cadmium arsenic sulfide, amorphous silicon, pyrillicum dyes, thiobyrillicum dyes, triarylmethane dyes, thiazine dyes, shea giant dyes, azulenium dyes, phthalocyanine pigments, - Examples include organic substances such as e-rylene pigments, indica pigments, thioindi pigments, quinacridone pigments, squaric acid pigments, azo pigments, and polycyclic quinone pigments. The thickness of the charge generation layer is preferably 5 microns or less, preferably 0.05 to 3 microns.

Depending on the type of charge-generating material used, the charge-generating layer may be provided by means such as vacuum evaporation, sputtering, glow discharge, or coating, or may be provided as a uniform solution of a binder and charge-generating material.

When the charge generation layer is formed by applying a resin dispersion or solution of the charge generation material, the ratio of the binder in the charge generation layer is 80% or less, preferably 40%, because if the amount of binder used is large, it will affect the sensitivity. The following are desirable. As the binder and resin used in the charge generation layer, various conventionally used resins such as polyvinyl butyral can be used.

The charge transport layer may be either above or below the charge generation layer. In order to exhibit the characteristics of the nate z resin, it is better to place it on the charge generation layer.

The thickness of the charge transport layer is 5 to 30μ, preferably 8 to 20μ.
It is. Other electron-donating compounds and polymeric substances such as polyvinylcarbazole and polyvinylanthracene may be mixed in the charge transport layer.

The photosensitive layer consisting of the charge generation layer and the charge transport layer is provided on a substrate provided with a subbing layer, if necessary.

The base material can be metal such as aluminum or stainless steel.
A cylindrical cylinder or film of plastic or the like is used.

The undercoat layer is formed to improve adhesion of the photosensitive layer, improve coating properties, protect the substrate, cover defects on the substrate, improve charge injection from the substrate, protect the photosensitive layer from electrical breakdown, etc. . Materials for the undercoat layer include polyvinyl alcohol, polyvinyl alcohol, and polyvinyl alcohol.
J, N-vinylimidaso A/, /IJ;
c tyrene oxide, ethyl cellulose, methyl cellulose, ethylene a/! j# Acid: TI remer, casein,
4-lyamide, copolymerized nylon, glue, gelatin, etc. are known.

In addition to these structures, the electrophotographic photoreceptor of the present invention may have a non-photosensitive intermediate layer, a protective layer, etc., as is known in the photosensitive industry.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 19: An aluminum cylinder of 60φ x 260m was prepared as a base.

Next, 4 parts of copolymerized nylon (trade name: 0M8000, manufactured by Toshi ■) and 4 parts of type 8 nylon (trade name: 2 Tsukamite 5003, manufactured by Dainippon Ink ■) were mixed with 5 parts of methanol.
The solution was dissolved in 50 parts of n-butanol and dip coated on the conductive layer to form a 0.6μ thick /IJ amide undercoat layer.

Next, add 10 parts of bisazo pigment of the following structural formula and polyvinyl petral resin (product name: S-LEC BM2.Sekisui Chemical ■
) was mixed with 120 parts of cyclohexanone in a sand mill for 10 hours.

Dispersed. 30 parts of methyl ethyl ketone was added to the dispersion and coated on the undercoat layer to form a charge generation layer with a thickness of 0.15 μm.

Next, 10 parts of Polycarbonate Z resin (manufactured by Mitsubishi Gas Chemical Co., Ltd.) with a weight average molecular weight of 120,000 were prepared, and 10 parts of each of the hydrazone compounds selected from the above-mentioned exemplified compounds were prepared.
1 part was dissolved in 80 parts of monochlorobenzene. This was applied onto the charge generation layer to form a charge transport layer with a thickness of 16μ.

Photoreceptors 1 to 19 manufactured in this way were heated to -5,6k
V corona charging, image exposure, dry toner development.

Toner transfer to plain paper, urethane is mug grade (hardness 7)
0', pressure 5 gw/cm, angle to photoreceptor 200
) to evaluate the electrophotographic properties.

When the potential was measured, the dark potential (VD) was 700V.9.
The potential (VL) when exposed to light of 0 lux·sec is
The results are shown in Table 1.

Comparative Examples 1 to 3 In place of the hydrazone compounds of Examples 1 to 19, the following A-
A photoreceptor was produced using the hydrazone compound C and in the same manner as above. The measurement results of the characteristics are also shown in Table 1.

Table 1 also shows the measurement results of vL after 11,000 repetitions of the compound.

As shown in Table 1, it was found that the Example had a lower vL and higher sensitivity than the Comparative Example.

Comparative Example 4 In the example, when forming the charge transport layer, the polycar was replaced with Neto Z resin, and the polycar was replaced with Neto A resin (trade name:
When using L-1250 (manufactured by Teijin Kasei), the characteristics as a photoreceptor are:

The change in vL was about 0 to 10 V], which was the extent of experimental error), and there was no significant difference. However, in the case of a solution of a hydrazone compound and a resin, there was no change in the viscosity even after 24 hours when the polycar was Nato Z resin, whereas in the case of Polycar R Na) A resin, the viscosity did not change after 24 hours. The amount increased 3 to 4 times, and after 48 hours, it became dull and lost its fluidity. As described above, there was a large difference between the two in terms of solution stability.

Example 20 For the substrate used in Example 1.

Using a 120φ x 330m aluminum cylinder,
A photoreceptor was manufactured in the same manner as in Example 1 except for the following.

On the other hand, a photoreceptor was manufactured in the same manner as in Example 20, except that the following resin was used in place of the polycargonate resin when forming the charge transport layer.

Comparative Example 5 Acrylic resin (product name: BR80, manufactured by Mitsubishi Rayon) 116yJe restyrene resin (product name Nistyron 47)
0. 7 Phenoxy resin (product name: YP40゜Tobu Kasei) #8 Polyester resin (product name: Pylon 300,
(Toyo Ali) These photoreceptors were evaluated using an electronic copying machine having the same process as in Example 1. Evaluation is early VD
, vL, and VD after 10,000 rotations, vL. Furthermore, an unused photoreceptor was humidified at 30° C. and 85% RH, and VD and V were measured in that environment and compared.

The results are shown in Table 2.

Table 2 As mentioned above, in terms of durability after 10,000 rotations.

In particular, the examples of the present invention using polycargonate resin were excellent.

〔Effect of the invention〕

According to the present invention, specific hydrazone compounds and polycarbons? N) The photosensitive layer containing the Z resin has high sensitivity and low residual potential, and is stable without an increase in bright area potential when charging exposure is repeated. In addition, the surface has high hardness and excellent lubricity, so it resists scratches and has good mechanical durability.

On the other hand, since the coating stability is good, productivity during coating is improved and quality is stabilized.

Claims (1)

[Scope of Claims] An electrophotographic photosensitive material comprising a photosensitive layer containing at least one hydrazone compound represented by the following general formula [I] and a polycarbonate resin represented by the following structural formula [II] body. [Note] General formula [I] ▲ Numerical formula, chemical formula, table, etc.▼ (In the formula, R_1 represents a methyl group, ethyl group, 2-hydroxyethyl group, or 2-chloroethyl group. R_2 and R_3 are respectively, Represents an optionally substituted alkyl group, aralkyl group or aryl group.R
_4 represents a hydrogen atom, a chlorine atom, a bromine atom, an alkyl group, an alkoxy group, a dialkylamino group, or a nitro group. ) Structural formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, n indicates the average degree of polymerization and is in the range of 50 to 5000.)