JPS63178241A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body having high sensitivity, decreased electrical fatigue during repetitive use and excellent light resistance by using a specific hydrazone compd. as an electric charge transfer layer. CONSTITUTION:The hydrazone compd. expressed by the formula is incorporated as an electric charge carrier transfer agent into a photosensitive layer formed on a conductive base. A soln. prepd. by dissolving the hydrazone compd. together with a suitable binder in an org. solvent is coated on said layer and is dried to form the charge transfer layer. An acrylic resin, polycarbonate resin, polyester resin, polysulfone resin, etc., are usable as a binder. The hydrazone compd. and the binder are usable in a range of 2-0.5pts.wt. binder with 1pt.wt. hydrazone. The photosensitive body having not only the excellent initial performance and performance after repetitive use but the excellent sensitivity and repetitive use resisting characteristic as well is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an electrophotographic photoreceptor, and more specifically,
The present invention relates to an electrophotographic photoreceptor comprising a photoconductive layer formed on a conductive substrate and containing a specific hydrazone compound as a charge carrier transfer agent.

(Prior Art) Conventionally, photoconductive materials for photoreceptors used in electrophotography include inorganic materials such as selenium, cadmium sulfide, and zinc oxide. The "electrophotographic method" referred to here is a general method in which a positive or negative charge is generated in a dark place by corona discharge, etc., and then the charge in the exposed area is selectively erased by image exposure. A so-called electrostatic latent image is obtained, and this latent image portion K is formed.

Positive iL resists the adhesion of negatively charged colored fine particles.

This is an image forming method that develops and visualizes images.

The characteristics required of the photoreceptor used in such electrophotography are (sufficient potential &
C2) the charged potential can be maintained for a sufficient period of time in a dark place; and (3) the charge must disappear quickly when exposed to light.

In recent years, in order to compensate for these drawbacks, organic electrophotographic photoreceptors using various organic substances have been proposed. The organic electrophotographic photoreceptor has the following characteristics: (1) It is lightweight; (ii)
The selection of 010 material has good processability and can be processed into films, sheets, and domes.

(IV) Non-toxic substances can be used.

They have features such as the ability for users to handle and dispose of them themselves, and are promising for the future, with many of them already in practical use.

For example, BoIJ-N-vinylcarbazole and 2.4.
A photoreceptor made of 7-dolinitrofluorene-9-ontka (Japanese Patent Publication No. 5O-10496), a photoreceptor made of poly-N-vinylcarbazole sensitized with biryllium salt (
U.S. Pat. No. 3,141,770).

Photoreceptors made of a eutectic complex of thiapyrylium salt and triphenylmethane (% 10735, 1973) are known, and recently, charge generation and charge transfer have been separated into separate functions, and multilayer photoreceptors have been developed. Developments regarding organic photoreceptors with different structures are being actively carried out.

The advantage of the functionally separated type is that the performance of the photoreceptor can be varied by selecting the charge generation layer and the charge transfer layer separately. for example.

By selecting the charge generation layer, it is possible to achieve high resistance and panchromaticity, and by selecting the charge transfer layer, it is possible to provide durability and flexibility. Based on this idea, it has already entered the practical stage.

One in which dimethylperylimide is used as a charge generation layer and Okijo diazole is used as a charge transfer layer [J, Appl, Photo.

Eng., 4118 (1978)], squarylium, chlorodian blue, etc. as a charge generation layer and pyrazoline as a charge transfer layer (JP-A-49-105536,
Japanese Patent Publication No. 49-105557. ) etc. are known. All of them have excellent characteristics as photoreceptors for electrophotography, but electrophotography was first applied to copying machines and then to laser printers.

As its applications expand into a wide range of applications, including LED printers, LCD printers, and other types of printers, and color printing, the characteristics required of photoreceptors are also changing slightly. For this reason, there are still many charge generating agents available today.

Charge transfer agents have been developed.

(Problems to be Solved by the Invention) Although the inorganic material Fi as described above has many characteristics that are adapted to the critically required characteristics described above, it is also true that it also has various drawbacks. It is.

For example, selenium, which is currently widely used, is difficult to manufacture, expensive, inflexible, difficult to process into belts, and is susceptible to heat and moisture. Because the characteristics deteriorate.

Sufficient care must be taken when handling it. and.

A major drawback of selenium is its toxicity, and when handling photoreceptors, it is necessary to be very careful about the toxicity of ;f:. For this reason, general users cannot dispose of used photoconductors by discarding them or incinerating them.

This is a major obstacle to the widespread use of copiers and printers that utilize electrophotography. In addition to selenium, cadmium sulfide and zinc oxide can also be dispersed in a binder as an inorganic substance and used as a photoreceptor.

However, these materials have many mechanical drawbacks such as hardness, friction resistance, and tensile strength, and for long-term repeated use, it is necessary to use properties that remain unsolved or have many problems.

(Friendly Means for Solving Problems) The present invention aims to obtain a charge transfer layer with high sensitivity and high durability. It was found that the present invention 8
I have completed A.

Many examples of functionally separated photoreceptors using hydrazone additives as a charge transfer layer have already been used. for example,
Japanese Patent Publication No. 55-42380 has a charge transfer layer of p-sialgylaminobenzaldehyde-diphenylhydrazone, and Japanese Patent Publication No. 5757-2O4549 has a p-dialkylaminobenzaldehyde phenylna 7-tyl hydrazone t' frame charge transfer layer. An example, JP-A-54-1501
No. 28 discloses an example in which aN-alkylcarbazole-3-carbaldehyde diphenylhydrazone is used as a charge transfer layer, and JP-A-55-46760 discloses N-alkylcarbazole-3-carbaldehyde phenylalkylhydrazone t.
- An example of using it as a charge transport layer is shown. However, the reality is that these charge transfer layers require further improvement in terms of sensitivity, repeated use characteristics, and light resistance.

The inventors of the present invention have conducted intensive research in view of the above circumstances, and have found that
It has been discovered that by using a specified hydrazone compound represented by the following general formula (I) in the charge transfer layer, a photoreceptor can be obtained which is significantly improved compared to the hydrazone compounds known so far. .

(However, R represents a C3-C2 alkyl group.) The specified hydrazone compound used in the present invention is R
When is a methyl group, it can be obtained from 4(4-ethoxyphenoxy)benzaldehyde and diphenylhydrazine hydrochloride by a known method.

That is, the following.

4(4-Ethoxyphenoxy)benzaldehyde-(diphenylhydrazone) 4(4-n-propoxyphenoxy)penzalteside(diphenylhydrazine) 4(4-isopropoxyphenoxy)benzaldehyde-(diphenylhydrazine) a(4-n-7 "Toxyphenoxy)benzaldehyde-(diphenylhydrazone) 4(4-methoxyphenoxy)benzaldehyde-(diphenylhydrazone)" Here, 1. The hydrazone compound used in the present invention can be used in the same manner as conventionally used as a charge transfer agent. A sensitizing dye, a sensitizing pigment, or a charge generating agent is dispersed therein, along with a binder, adjacent to a photoreceptor or a charge generating layer.

It can be laminated with a binder to form a photosensitive member.

In the present invention, when the above-mentioned hydrazone compound is used as a charge transfer layer of a functionally separated photoreceptor, it is possible to obtain a friend photoreceptor that has particularly high lacrimal sensitivity, less electrical fatigue during repeated use, and excellent light resistance. .

As for the layer structure of the functionally separated photoreceptor, a conductive layer, a charge generation layer, and a charge transfer layer are essential, and a barrier layer and a protective layer can be provided as necessary.

The conductive layer, charge generation layer, and charge transfer layer may be stacked in any order, but the charge generation layer and charge transfer layer must be adjacent to each other.

As the conductive layer, Fi, a conventionally used conductive material 1, for example, a full minicum plate, an aluminum vapor-deposited plastic, a metal plate coated with a conductive paint, a plastic material, etc. can be used.

As a charge generation material used in the charge generation layer.

Any material that absorbs light and generates charge carriers with high efficiency can be used.

Preferred materials include selenium and selenium tellurium.

Inorganic materials such as cadmium sulfide, biryllium salts.

Organic materials such as squarylium salts, azo pigments, cyanine pigments, quinone pigments, and 7-thalocyanine pigments can be used. These materials are formed into a charge generating layer by vapor deposition or coating from a dispersion.

The thickness of this charge generation layer can range from 0.01 to 5 microns.

A charge transfer layer is provided on the specific charge generation layer provided by any of the above methods.1 The hydrazone compound of the present invention is dissolved in an organic solvent together with a suitable binder, coated with a specific solution for 1 m, and dried to form the charge transfer layer. shall be.

As the binder, acrylic resin, polycarbonate resin, polyester resin, polysulfone resin, etc. can be used. The ratio of the hydrazone compound of the present invention to the binder can be in the range of 2 parts by weight to 0.5 mftt part of the binder per 1 mi part of crack 2 fufu.

The thickness of the charge transfer layer may range from 5 to 30 microns.

(Action of invention) The electrophotographic photoreceptor obtained in this manner is as follows.

It can be applied to many fields such as electrophotographic copying machines, laser printers, LED printers, LCD printers, electrophotographic master plates, and electrophotographic microfilms.

The photosensitive properties of the obtained photoreceptor were 5P-428 manufactured by Kawaguchi Denki.
It is evaluated in the following manner using a mold testing machine.

First, the photoreceptor was charged with a corona discharge of -5.6 KV and left in a dark place until a constant voltage was reached.

Subsequently, the photoreceptor surface was irradiated with light such that the surface potential was 20 lux using a tungsten lamp, and the surface potential became 1/1 of that before irradiation.
Measure the time until it becomes 2, and multiply it with the illuminance: Looks 1
Sensitivity is expressed in seconds. Also.

Spectral sensitivity is the product of the energy intensity μW/d of the photoreceptor surface of the force-sensed light and the time until the surface potential reaches 172.The half-decreased exposure energy μJule/dfI: is calculated, and the reciprocal of this is the spectral sensitivity. to be called.

The fatigue characteristics during repeated use were similarly measured using Kawaguchi Electric's 5P-428 type testing machine, and the surface of the photoreceptor was subjected to a corona discharge of -5,6 KV at a corona linear velocity of 20 m/Inn. Then, leave it for 0.5 seconds and measure the charged potential vo at that time. Subsequently, light with a surface illuminance of 500 lux is applied to the surface of the photoreceptor for seconds. This operation is all 2.
Repeat for 5 seconds/cycle.

By repeating this operation, the charging capacity (V
Observe changes in o) and changes in residual potential (vR).

Evaluate fatigue characteristics as cyclic characteristics.

It has been found that the electrophotographic photoreceptor according to the present invention has superior sensitivity and repeatability characteristics compared to conventional photoreceptors.

(Example) The present invention will be described in detail below using Examples S and Comparative Examples. In these Examples and Comparative Examples, 1 part represents M and % by weight.

Synthesis Example 1 Synthesis of hydrazone compound Place 60-ml ethanol in a 100-ml round bottom flask,
5.5f of N,N-diphenylhydrazine hydrochloride is dissolved in this. Further, 4.67 ml of 4-(4-methoxyphenoxy)benzaldehyde is added little by little while stirring and dissolved. After addition, the contents are heated to 60-70C.
and stir for about 1 hour. After the completion of the reaction, the reaction solution was cooled and the crystals formed were separated to obtain a 'R-colored solid product in a yield of 83 mmol. Dissolve the solids in hot toluene and reconsolidate. The structure of the obtained crystal is confirmed by NMR analysis.

Peak position 5.82 (S), 6.86-7.63 (M
) @ Elemental analysis value carbon, hydrogen, m, acid, calculated value 79.19 5,58 7,11 8.12
Measured value 79,21 5,54 7,15 8.16
Synthesis Examples 2 to 4 Hydrazone compounds are synthesized using the same reaction procedure as in Synthesis Example 1. It is synthesized by reacting a first-order aldehyde ratio compound.

Synthesis Example 2 Human. Addition amount: 4.8 f, yield: 80.2 mol Synthesis Example S Rudehyde. Added ff15. IP, yield 81.0 mol Synthesis Example 4 Rudehyde. Table 1 shows the structure and analysis results of a hydrazone compound obtained using an aldehyde compound with an addition amount of 5.4 f and a yield of 67.3 molti or more.

Example 1 Creation of charge generation in the production of a functionally separated photoreceptor A 1% methanol solution of Tone's soluble polyamide (0M4001) was applied and dried on a 100μ thick aluminum plate.
A single barrier layer with a thickness of 0.05μ was provided.

A charge generation layer as described below was provided on this barrier layer.

One hour of chlordian blue represented by the above formula was added to tetra'chloroethane, and then 0.5% of butyral resin was added and dispersed in a ball mill. This dispersion was applied and dried on the aluminum plate on which the barrier layer had been provided, forming a charge generation layer with a thickness of 0.2 μm.

Created.

(b) Squarylium 1' having the following structure? 30
- in tetrahydrofuran and dispersed in Paul Millet to create a dispersion. In the same way as in (a), a layer of barrier layer is applied (C) on the aluminum substrate. :, 1000X, and a charge generation node was created.

(d) On the aluminum plate with a single layer of /
It was deposited to give oX. This vapor deposited film.

! immersed in toluene 507 containing 500M and kept at room temperature'C.
It was left to stand for 30 minutes, and a 1-part load generation W' was created.

(e) 1 part of copper phthalocyanine (Lionol GS, manufactured by Toyo Ink Co., Ltd.) and 0.5 part of acrylic resin (Acridic A-801, manufactured by Dainippon Ink Co., Ltd.) in 1.2-2 chloroethane to give a concentration of 5 parts. In addition, thoroughly disperse in a ball mill. Dilute the solid dispersion with 11,2-dichloroethane to give a solid dispersion of 0,75 (4).This dispersion was dried and glazed on an aluminum plate with a barrier layer to a thickness of 100X. Created a charge generation no.

Example 2 Preparation of Coating Liquid for Charge Transfer Layer The hydrazone prepared in Synthesis Examples 1 to 4 was combined with primary baingu in a ratio of 1 part to 1 part, and mixed, respectively.
- dissolved in 10 parts of dichloroethane.

Charge transfer! I! Create a special solution for the first layer and then proceed.

(1) Methyl methacrylate f111 resin (Asahi Kasei Delvet) (ID polycarbonate resin (Mitsubishi Gas Chemical Kneepilon E-2000) 41 polished styrene acrylic resin (Nippon Steel Chemical MS-600) Examples 3 to 62 Example 1 (a) to ( Coating solution 7 prepared in Example 2 was applied at 70C onto the Kyuden caustic layer prepared in step e).

After removing the solvent and pre-drying, it is further dried on aoC for 60 minutes. A photoreceptor having a film thickness of 15 μm was prepared under these conditions. Examples of photoreceptor preparation are shown in the table below.

Table 2 Photoreceptor of Synthesis Example 1 Synthesis Example 1 Synthesis Example 2 Photoreceptor of Synthesis Example 2 Below, the same ratio Examples 1 to 5 As a comparative example, a hydrazone compound (Formula ■) having the following structure was used, and Example A coating liquid was prepared in the same manner as in 2. Photoreceptors prepared by combining this coating liquid and the charge generation layer of Example 1 are referred to as Comparative Examples 1 to 5.

Hydrazone compound (comparative example) Coating liquid: 1 part of hydrazone compound, 1 part of polycarbonate (Kneepilon, E-2000 manufactured by Mitsubishi Gas Chemical)? : Dissolved in 10 parts of 1,2-dicumylethane.

Performance of Examples and Comparative Examples The performance of each photoreceptor of Examples and Comparative Examples was measured by the ratio measurement 44 described above (measurement using white light).

The results are shown in the WIs table.

Table 3: Ratios measured for each photoreceptor of Examples and Comparative Examples using a 790 nm spectral light source. The results are shown in Table 4.

Table 4 (Effects of the Invention) The hydrazone compound represented by the general formula (1) of the present invention is:
This is a novel and unprecedented photoreceptor, and as specifically shown in the examples, its performance is not only excellent both in initial performance and performance after repeated use, but also in sensitivity and repeated durability characteristics. It turns out that it is a photoconductor.

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor comprising a hydrazone compound represented by the following general formula (I) as a charge carrier transfer agent in a photosensitive layer formed on a conductive support. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R represents an alkyl group of C_1 to C_4.)