JPH03166547A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance electrophotographic characteristics, such as resistance to light fatigue and resistance to change of surface potential due to repeated uses by forming a photosensitive layer containing a specified hydrazone derivative, a specified butadiene derivative, and a specified oxadiazole derivative. CONSTITUTION:The photosensitive layer contains the hydrazone derivative represented by formula I, the butadiene derivative represented by formula II, and the oxadiazole derivative represented by formula III, and in formulae I-III, each of R<1>-R<4> is H, alkyl, or the like; each of R<5>-R<8> is alkyl, optionally same or different; and each of R<9> and R<10> is H, alkyl, acyl, or cycloalkyl, optionally same or different, thus permitting the obtained electrophotographic sensitive body to be stabilized in dark decay factor and surface potential and superior in characteristics against repeated uses.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrophotographic photoreceptor, and particularly to an electrophotographic photoreceptor using an organic photoconductive material.

[Prior Art and its Problems] With the recent development of non-impact printing technology, research and development of electrophotographic printers using lasers as light sources have been actively conducted.

In this laser beam printer, high speed, high sensitivity, long life, and low cost are currently desired.

Photoconductive materials for electrophotographic photoreceptors generally contain selenium (Se).
a, cadmium sulfide (CdS), zinc oxide (ZnO)
Although inorganic materials such as , amorphous silicon <a-s + >, etc. have been used, they do not necessarily satisfy the characteristics required of electrophotographic photoreceptors. For example, selenium (
Although Se) has sufficiently satisfactory charging characteristics, it has drawbacks such as being difficult to process into a film and being sensitive to heat and mechanical shock, requiring care in handling. Furthermore, amorphous silicon (a-S i ) has the disadvantage that manufacturing conditions are difficult and manufacturing costs are high.

In recent years, various photoreceptors using organic materials such as hydrazone compounds, butadiene compounds, oxadiazole compounds, etc. that eliminate the above-mentioned drawbacks have been proposed, and some of them have been put into practical use.

However, although those containing hydrazone compounds as a main component have excellent electrical properties such as high sensitivity and low residual potential, they are susceptible to optical fatigue due to repeated use and have poor durability. In addition, although compounds containing butadiene compounds as the main component are effective for suppressing photofatigue, they have drawbacks in electrical properties, and furthermore, hydrazone compounds and butadiene compounds have high crystallinity, causing problems in film formation. be. Further, although those containing an oxadiazole compound as a main component have excellent electrical properties, they have a problem with optical fatigue.

On the other hand, when adjusting the roughness with the charge-generating material, in the case of a printer, since an LED or a semiconductor laser is used as a light source, a material having sensitivity to relatively long wavelengths in the near-infrared region is required. Phthalocyanine dyes are organic materials that meet this requirement, and are being actively researched and developed.

In addition, in order to increase the sensitivity, a laminated photoreceptor using a vapor-deposited film of phthalocyanine as a charge generation layer was studied.
Among the phthalocyanines having group a and group IV metals as their central metals, some have been obtained that have relatively high sensitivity. Documents related to such metal phthalocyanines include, for example, JP-A-57-211149, JP-A-57-148745, JP-A-59-36254, JP-A-59-44054, and JP-A-59-30541.
Publication No. 59-31965, Publication No. 59-166
There are publications such as Publication No. 959. However, the preparation of the vapor deposited film requires a high vacuum evacuation device, which increases the equipment cost, so the above-mentioned organic photoreceptor inevitably becomes expensive.

In contrast, phthalocyanine is not deposited as a film, but
A multi-unit type photoreceptor has also been considered, in which a resin dispersion layer is used as a charge generation layer, and a charge transport layer is applied thereon. There are photoreceptors that use indium phthalocyanine (Japanese Patent Application No. 57-66963) and indium phthalocyanine (Japanese Patent Application No. 59-220493), and these are relatively highly sensitive photoreceptors, but the former rapidly degrades in the long wavelength region of 800 nm or more. This method has disadvantages such as decreased sensitivity, and the latter has disadvantages such as insufficient sensitivity for practical use when the charge generation layer is prepared from a resin dispersion system.

In addition, particularly in recent years, studies have been conducted on using titanyl phthalocyanine, which has relatively high sensitivity electrophotographic properties (Japanese Patent Application Laid-Open No. 59-49544 @ Publication No. 61-
It is known that there are differences in properties depending on the crystal form. In order to produce these various crystal forms, special purification and special solvent treatments are required. The processing solvent is different from that sometimes used in break-through coatings. This means that the various crystals obtained are
Crystals tend to grow in long-term processing solvents, and when the same solvents are used as coating solvents, it is difficult to control the crystal shape and particle size, resulting in poor paint stability and poor electrostatic properties, making it difficult to put into practical use. This is because it is inappropriate. For this reason, chlorinated solvents such as chloroform, which do not easily promote crystal growth, are usually used when making paints, but these solvents do not necessarily have good dispersibility for titanyl phthalocyanine and may affect the dispersion stability of paints. This is a problem.

Furthermore, titanyl phthalocyanine generally has a high ionization potential, and when used together with a hydrazone compound that has a low ionization potential, the large difference in ionization potential easily causes holes to be injected from the titanyl phthalocyanine into the hydrazone compound, resulting in even worse charging properties. However, there was a drawback that the durability was poor.

The present invention was made in view of the above-mentioned drawbacks, and combines organic photoconductive materials to improve properties such as optical fatigue, reduction in surface potential due to repeated use, and increased sensitivity, and to form a film by crystallization. The object of the present invention is to provide a stable electrophotographic photoreceptor that satisfies various characteristics such as eliminating the adverse effects of.

[Means for Solving the Problems] The present invention provides a hydrazone compound represented by the following general formula [I], a butadiene compound represented by the following general formula [II], and a hydrazone compound represented by the following general formula [III]. An electrophotographic photoreceptor comprising a photosensitive layer containing an oxadiazole compound.

(In the formula, R1 is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a halogen atom, a substituted or unsubstituted amino group, a morphorno group, a biperidino group, or a phenyl group to form a carbazono group. R2 may represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted 7ralkyloxy group, and R
3, R4 may be in the form of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, or a ring such as a pyridyl group, a pyrrolodino group, or a carbazono group. . ) (In the formula, R5 to Re represent an alkyl group, and may be the same or different.) (In the formula, R9 and R10 represent a hydrogen atom, an alkyl group, an acyl group, or a cycloalkyl group, and each They may be the same or different.> Further, the present invention provides an electrophotographic photoreceptor comprising a charge generating material and a charge transporting material, in which (a) the charge generating material is a non-metallic phthalocyanine nitrogen isomer or a metal phthalocyanine nitrogen isomer. , metal-free phthalocyanine, metal phthalocyanine, metal-free naphthalocyanine or metal naphthalocyanine (however, metal-free phthalocyanine nitrogen isoform, metal phthalocyanine nitrogen isoform, metal-free phthalocyanine and metal phthalocyanine may have a substituent on the benzene nucleus) , metal-free naphthalocyanine and metal naphthalocyanine may have a substituent on the naphthyl nucleus).
The active ingredient is a titanyl phthalocyanine composition crystal containing parts by weight, and the composition crystal has an infrared absorption spectrum of 1490±2Cm'-1 and 1415±2cIIt-'
, 1332±2CIR-', 1119±2CIlt-'
, 1072±2Cm", 1060±2 cat-'
961±2C '1, 893±2that-' 780
±2 cm-' 751±2 cm-' and 730±
2a! has a characteristic strong absorption at t-1, and (b) the charge transfer material is a hydrazone compound represented by the above general formula [I], a butadiene compound represented by the above general formula [II], and the above general formula This is an electrophotographic photoreceptor characterized by containing an oxadiazole compound represented by formula [III] as an active ingredient.

According to the present invention, as a charge transfer material, the general formula [I]
By using a hydrazone compound represented by the above, a butadiene compound represented by the above general formula [II], and an oxadiazole compound represented by the above general formula [III] in combination, a hydrazone compound, a butadiene compound The drawbacks of oxadiazole compounds and oxadiazole compounds as charge transfer materials are mutually complementary.

Add other phthalocyanines or naphthalocyanine compounds as described below to titanyl phthalocyanine, and treat the resulting amorphous composition with tetrahydrofuran to form a new infrared absorbing compound that is not crystallized. By combining it with a titanyl phthalocyanine composition that exhibits excellent photoconductivity and exhibits excellent photoconductivity, the difference in ionization potential can be resolved, resulting in high sensitivity, excellent charging properties, little optical fatigue even after repeated use, and excellent durability. An excellent electrophotographic photoreceptor can be obtained.

The present invention will be explained in detail below.

Preferred specific examples of the hydrazone compound of general formula [I], the butadiene compound of general formula [II], and the oxadiazole compound of general formula [II1] are as follows.

(Hereinafter, blank spaces) Examples of the hydrazone compound of general formula [I] include the following compounds.

[p-dimethylaminobenzaldehyde (diphenylhydrazone)] [p-diethylaminobenzaldehyde (diphenylhydrazone)] [D-diphenylaminobenzaldehyde (diphenylhydrazone)] [p-dibenzylaminobenzaldehyde (diphenylhydrazone)] hydrazone)] [p-(benzylmethoxyphenyl>aminobenzaldehyde-(diphenylhydrazone)] [0-methyl-p-diethylaminobenzaldehyde-
(diphenylhydrazone) ] [0-Methyl-p-dibenzylaminobenzaldehyde-{diphenylhydrazone}] [O-methoxy p-diethylaminobenzaldehyde (diphenylhydrazone) ] [0-penzyloxy-p-diethylaminobenzaldehyde (diphenylhydrazone)] [p-diethylaminobenzaldehyde-(methyl-phenylhydrazone)] [O-methyl-p-dibenzylaminobenzaldehyde-(methyl-phenylhydrazone)] [0-methyl-p
-Dibenzylaminobenzaldehyde-(pendyluphenylhydrazone)] Next, examples of the butadiene compound of general formula [II] include the following compounds.

CH3 CH3 [III,1-bis-(p-dimethylaminophenyl)
-4,4-diphenyl-1,3-butadiene C2H
5 [III. 1-bis-(p-diethylaminophenyl)
-4.4-diphenyl-1,3-butadiene] Further, examples of the oxadiazole compound of the general formula [III11] include the following compounds.

[2,5-bis(4-dimethylaminophenyl)-1
．． 3.4-oxadiazole] [2,5-bis-(4-diethylaminophenyl)-1
．． 3.4-oxadiazole] [2,5-bis-(4-n-propylaminophenyl)
-1, 3.4-oxadiazole] [2.5-bis-{4-isoisoarylaminophenyl}-
1,3,4-oxadiazole] ...(19) [2,5-bis-(4-cyclobentylaminophenyl)-1.3.4-oxadiazole] ...(20) [ 2,5-bis-{4-cyclohexylacunophenyl}-1.3.4-oxadiazole 1 [2.5-bis(<4-di-n-probyl>-aminophenyl)-1.3 .4-oxadiazoleco[2,5
-bis=(4-acetylaminophenyl)-1.3.4
-Oxadiazole] [2,5-bis(4-ethylaminophenyl)-1.
3.4-oxadiazole] [2.5-bis-(4-N-ethyl-N-n-propyluaminophenyl)-1.3.4-oxadiazole]
[2.5-bis-(4-<N-ethyl-N-acetyl>
-Ami. nophenyl) 1,3,4-oxadiazole]
0 [2-(4-diethylaminophenyl)-5-(4゜-dimethyl-aminophenyl)-1.3.4-oxadiazole] N - N υ [2-(4-mono1〇 -proby-aminophenyl)-
5-(4゜-dimethyl-aminophenyl)-1.3.4
-oxadiazole] υ [2-(4-mono101propyluaminophenyl)-
5-(4゜-monoethyl-7minophenyl)-1.3
．． 4-Oxadiazole] Among these compounds, particularly desirable hydrazone compounds include p-diethylaminobenzaldehyde (diphenylhydrazone). It is p-diphenylaminobenzaldehyde (diphenylhydrazone) or O-methyl-p-dibenzylaminobenzaldehyde- (diphenylhydrazone), and in the butadiene compound it is 1,1-
It is bis-(p-diethylaminophenyl)-4,4-diphenyl-1,3-butadiene, and the oxadiazole compound is 2,5-bis-(4-diethylaminophenyl)-1.3.4-oxa. It is a diazole.

Furthermore, these hydrazone compounds, butadiene compounds, and oxadiazole compounds are known prior to the filing of this application, and can be manufactured by conventional methods.

Next, the phthalocyanine compounds and naphthalocyanine compounds used as charge generating materials in the present invention are "Phthalocyanine Compounds" by Moser and Thomas (Reinhold Co., Ltd. 1963), "Phthalocyanine J (CRC)
Publication 1983) and other suitable methods are used.

For example, titanyl phthalocyanine can be easily synthesized from 1,2-dicyanobenzene (O-phthalodinitrile) or a derivative thereof and a metal or metal compound according to a known method.

For example, in the case of titanyl phthalocyanines, the following (1)
Alternatively, they can be easily combined according to the reaction formula shown in (2).

PcT=O (where Pc represents a phthalocyanine residue) Examples of organic solvents include nitrobenzene, quinoline, α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene,
A high boiling point organic solvent inert to the reaction of methoxynaphthalene, diphenyl ether, diphenylmethane, diphenylethane, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, etc. is preferable, and the reaction temperature is usually 150 to 300°C, particularly 200 to 250°C. °C is preferred.

In the present invention, the thus obtained crude titanyl phthalocyanine compound is used as it is or after being purified by the method described below. In the case of purification, treatment is performed with tetrahydrofuran after the amorphization treatment. At that time, after removing the organic solvent used in the condensation reaction using an appropriate organic solvent, for example, alcohols such as methanol, ethanol, and isopropyl alcohol, and ethers such as tetrahydrofuran and 1,4-dioxane. , preferably hydrothermal treatment. In particular, it is preferable to wash until the p value of the washing liquid after hot water treatment reaches about 5 to 7.

Subsequent treatment with an electron-donating solvent such as 2-ethoxyethanol, diglyme, dioxane, tetrahydrofuran, N,N-dimethylformamide, N-methylpyrrolidone, pyridine, and morpholine is more preferred.

Next, as phthalocyanine nitrogen congeners, there are various borfins, such as tetraviridinoborufirazine, in which one or more of the benzene nuclei of phthalocyanine is replaced with a quinoline nucleus, and as metal phthalocyanines, copper,
Various materials such as nickel, cobalt, zinc, tin, aluminum, and titanium can be mentioned.

In addition, substituents for phthalocyanines and naphthalocyanines include amino groups, nitro groups, alkyl groups, alkoxy groups, cyano groups, mercapto groups, halogen atoms, and sulfonic acid groups, carboxylic acid groups, or metal salts thereof. , ammonium salts, amine salts, etc. can be exemplified as relatively simple examples. Furthermore, an alkylene group is added to the benzene nucleus,
Various substituents can be introduced via sulfonyl groups, carbonyl groups, imino groups, etc., and these are known as anti-aggregation agents or crystal conversion inhibitors in the technical field of phthalocyanine pigments (for example, U.S. Patent No. 39
No. 73981 and No. 4088507).

In the present invention, titanyl phthalocyanine and metal-free and metal phthalocyanine nitrogen isoconstructs that may have a substituent on the benzene nucleus, metal-free and metal phthalocyanines, or metal-free and metal naphthalocyanines that may have a substituent on the naphthyl nucleus. It is sufficient that the ratio of the combination with the
．． 1 (weight ratio). 100/0.I On JX, the crystals contain many single crystals in addition to the mixed crystal composition, and the new material of the present invention in the infrared absorption spectrum and X-ray diffraction spectrum (hereinafter, these mixed compositions will be referred to as titanyl phthalocyanine compositions).

The titanyl phthalocyanine composition of the present invention can be produced by mixing titanyl phthalocyanine and other phthalocyanines, and treating the amorphous composition of the mixture with tetrahydrofuran to crystallize it. .

In this method, the amorphous titanyl phthalocyanine composition can be obtained by a single chemical method or mechanical method,
More preferably, it can be obtained by a combination of various methods.

For example, amorphous particles can be obtained by weakening agglomeration between particles using a method such as an acid pasting method or an acid slurry method, and then grinding using a mechanical processing method. Equipment used during grinding includes seconder, Banbury mixer, attritor, edge runner mill, roll mill, ball mill, sand mill, SPEX mill, homo mixer, disperser, agitator, jaw crusher, stamp mill, cutter minor, Examples include, but are not limited to, micronizers.

In addition, the acid basing method, which is well known as a chemical treatment method, is a method in which a pigment is dissolved or made into a sulfate in 95% or more sulfuric acid and then poured into water or ice water to re-precipitate. Amorphous particles can be obtained under even better conditions by keeping the temperature preferably at 5° C. or lower and slowly injecting sulfuric acid into water that is stirred at high speed.

Other methods include a method in which crystalline particles are directly ground for a very long time using a mechanical processing device, and a method in which particles obtained by an acid basing method are processed with the above-mentioned solvent and then ground.

Amorphous particles can also be obtained by sublimation. For example, each raw material obtained by various methods under vacuum is
It can be obtained by heating to 600° C. to sublimate it and immediately co-evaporating it onto a substrate.

The amorphous titanyl phthalocyanine composition obtained as described above is treated in tetrahydrofuran to obtain new stable crystals. As a method for treating tetrahydrofuran, 5 to 300 parts by weight of tetrahydrofuran are put into various stirring tanks per 1 part by weight of the amorphous titanyl phthalocyanine composition, and the mixture is stirred. Both heating and cooling are possible, but heating will speed up the crystal growth.
It also slows down at low temperatures. As the stirring tank, in addition to a normal stirrer, a mixer used for dispersion such as an ultrasonic ball mill, a sand mill, a homomixer, a disperser, an agitator, a micronizer, etc., or a concal blender V-type mixer, etc. can be used as appropriate. However, it is not limited to these.

After these stirring steps, filtration, washing, and drying are usually performed to obtain stabilized crystals of titanyl phthalocyanine complex. At this time, without filtration or drying, it is possible to add a resin or the like to the separated liquid as necessary to make it into a paint, which is extremely effective as it saves a number of steps when used as a coating film for electrophotographic photoreceptors and the like.

The infrared absorption spectrum of the titanyl phthalocyanine composition of the present invention thus obtained is shown in FIG. This titanyl phthalocyanine complex has an absorption wave number<cm-',
However, it shall include an error of ±2> is 1490, 14
15, 1332, 1119, 1072, 1060,96
It shows characteristic strong peaks at points 1, 893, 780, 751, and 730.

Further, an X-ray diffraction diagram using CuKcx rays is shown in FIG.

In the X-ray diffraction diagram, this titanyl phthalocyanine composition shows a maximum diffraction peak at a Bragg angle 2θ (with an error range of ±0.2 degrees) of 27.3 degrees, 9.7 degrees, 24. Those showing a strong peak at once, and those showing a strong peak at two times.
There are cases where the maximum peak is shown at 7.3 degrees, and strong peaks are shown at 7.4 degrees, 22.3 degrees, 24.1 degrees, 25.3 degrees, and 28.5 degrees. These differences are thought to be due to the difference in the length of each crystal plane in crystals with the same structure, since the intensity of a diffraction line is generally approximately proportional to the size of each crystal plane.

The titanyl phthalocyanine composition of the present invention shows no major change in the infrared absorption spectrum even when heated and stirred in tetrahydrofuran to promote crystal growth, and is an extremely stable and good crystal.

The electrophotographic photoreceptor of the present invention preferably has an undercoat layer, a charge generation layer, and a charge transfer layer laminated in this order on a conductive substrate. It may be a layered structure or a structure in which a charge generation material and a charge transfer material are dispersed and coated on an undercoat layer with a suitable resin. Furthermore, these undercoat layers can be omitted if necessary.

The charge transfer layer of the electrophotographic photoreceptor of the present invention has the general formula [
I], the butadiene compound of the general formula [II], and the oxadiazole compound of the general formula [II1] are dissolved together with a resin (binder) in a suitable solvent, and if necessary, A coating liquid obtained by adding various additives such as a photoconductive substance that absorbs light and generates a charge, a sensitizing agent, an electron-absorbing material, a functional deterioration inhibitor, and a plasticizer is applied onto a conductive substrate. It can be produced by drying and forming a photosensitive layer (charge transfer layer) having a thickness of usually 5 to 30 μs.

Resins used for the charge transfer layer include silicone resin, ketone resin, polymethyl methacrylate, polyvinyl chloride, acrylic resin polyarylate, poduester, polycarbonate, polystyrene, acrylonitrile-butadiene copolymer, acrylonitrile-butadiene copolymer,
Insulating resins such as polyvinylbutyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, chlorinated rubber, polyN-vinyl rubber, polyvinyl anthracene, polyvinyl pyrene, etc. are used.

The amount of the mixture of the hydrazone compound of general formula [I], the butadiene compound of general formula [I], and the oxadiazole compound of general formula [II1] added is 20 to 500 parts by weight per 100 parts by weight of the resin. , preferably 50 to 300 parts by weight. Generally speaking, the mixing ratio of the hydrazone compound, butadiene compound and oxadiazole compound is 10 to 2000 parts by weight of the butadiene compound and 10 to 500 parts by weight of the oxadiazole compound, but preferably, to 100 parts by weight of the hydrazone compound. The butadiene compound is 50 to iooo parts by weight, and the oxadiazole compound is 30 to 400 parts by weight.

The coating method is performed using equipment such as a spin coater, applicator spray coater, bar coater, dip coater, doctor blade, roller coater, curtain coater, bead coater, etc., and the film thickness after drying is 5 to 50 JJM.
It is preferable to apply the coating to a thickness of 1, preferably 10 to 20 coats.

Furthermore, by using the titanyl-based phthalocyanine composition according to the present invention as a charge generating agent and dissolving it in a suitable solvent together with a suitable resin, a charge generating layer having extremely good dispersibility and extremely high photoelectric conversion efficiency can be obtained. be able to.

The resin that can be used to form the charge generation layer by coating can be selected from a wide range of insulating resins, and poly-N
- Can be selected from organic photoconductive polymers such as vinyl rubber rubazole, polyvinylanthracene and polyvinylpyrene. Preferably, polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin,
polyamide, polyvinylpyridine, cellulose resin,
Insulating properties of urethane resin, epoxy resin, silicone resin, polystyrene, polyketone, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, polyvinyl acetal, polyacrylonitrile, phenol resin, melamine resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, etc. Examples include resins. The resin contained in the charge generation layer is 10
A suitable content is 0% by weight or less, preferably 40% by weight or less.

Further, these resins may be used alone or in combination of two or more.

The solvent for dissolving these resins varies depending on the type of resin, and is preferably selected from those that do not affect the charge transfer layer described above or the undercoat layer described below during coating. Specifically, aromatic hydrocarbons such as benzene, xylene, ligroin, monochlorobenzene, dichlorobenzene, ketones such as acetone, methyl ethyl ketone, cyclohexanone, alcohols such as methanol, ethanol, isoprobanol, ethyl acetate, methyl cellosolve, etc. esters of carbon tetrachloride, chloroform, dichloromethane, dichloroethane, aliphatic halogenated hydrocarbons such as trichloroethylene, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, N,N-dimethylformamide, N, N
-Amides such as dimethylacetamide and sulfoxides such as dimethylsulfoxide are used.

Coating is performed using a spin coater, applicator, spray coater, bar coater, dip coater doctor blade, roller coater, curtain coater, bead coater, and drying is preferably done by heating for 40 minutes.
The test is carried out at ~200°C for 10 minutes to 6 hours under stationary or ventilation conditions.

The film thickness after drying is 0. 01-5 legs, preferably 0.1-1
It is painted so that it becomes clear.

Further, as the charge generating material, in addition to the above-mentioned titanyl phthalocyanine composition, known photoconductive materials such as 3e, 3e-4e alloy, Se-AS alloy, CdS, Zn
Inorganic materials such as O, Cu, Af! ,In,Ti,
Phthalocyanines containing gold a such as Pb and V, as well as metal-free phthalocyanines, chlorodianes, azo pigments,
It is also useful to use organic materials such as bisazo pigments or cyanine pigments alone or in combination of two or more.

In addition to these layers, an undercoat layer can be provided on the conductive substrate for the purpose of preventing a decrease in chargeability and improving adhesion. As the undercoat layer, nylon 6, nylon 66, nylon 11, nylon 610, copolymerized nylon, alcohol-soluble polyamide such as alkoxymethylated nylon, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, gelatin, polyurethane, Metal oxides such as polyvinyl butyral and aluminum oxide are used. It is also effective to incorporate conductive particles such as metal oxides and carbon black into the resin.

The appropriate thickness of the undercoat layer is about 0.05 to 10tJJn, preferably about 0.2 to 3IjII1.

The electrophotographic photoreceptor of the present invention has an absorption peak at a wavelength of around 800 nm, as shown in the spectral sensitivity characteristic diagram in FIG. It is also suitable as an absorbing material for batteries, photoelectric conversion elements, and optical discs.

[Examples] Examples of the present invention will be described below, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In addition, parts in the examples indicate parts by weight.

Preparation of phthalocyanines (1) Synthesis Example 1 20.4 parts of 0-phthalodinitrile, 7.6 parts of titanium tetrachloride
After reacting by heating in 50 parts of quinoline at 200°C for 2 hours, the solvent was removed by steam distillation, and 2% aqueous hydrochloric acid solution was added.
% sodium hydroxide aqueous solution, methanol, N
, N-dimethylformamide, dried, and 1 q of 21.3 parts of titanyl phthalocyanine (TiOPc) was added thereto.

Example 2: 14.5 parts of aminoiminoisoindolenine and 5 parts of quinoline
After the reaction, the solvent was removed by steam distillation, purified with a 2% aqueous hydrochloric acid solution, then a 2% aqueous sodium hydroxide solution, and then purified with methanol and M,N-dimethylformamide. After sufficient washing and drying, 8.8 parts of metal-free phthalocyanine (yield 70%) was obtained.

Example 3: 20 parts of 0-naphthalene dinitrile in 50 parts of quinoline
After a heating reaction at 00° C. for 4 hours, the product was purified with a 2% aqueous hydrochloric acid solution, washed with methanol and N,N-dimethylformamide, and dried to obtain 15 parts of metal-free naphthalocyanine.

Example 1 Synthesis of electrosensitive material: Combination with 1 part of titanyl phthalocyanine obtained in Example 1 and Example 2
0.05 part of the metal-free phthalocyanine obtained in
% sulfuric acid, and the mixture is dissolved in approx.
Stir for an hour while maintaining the temperature below 5°C. Subsequently, the sulfuric acid solution was slowly poured into 500 parts of ice water that was stirred at high speed, and the precipitated homogeneous composition was filtered. This is washed with distilled water until no acid remains, to obtain a wet cake. The cake (assuming the amount of phthalocyanine contained is 1 part)
The mixture was stirred for about 1 hour in 100 parts of tetrahydrofuran, filtered, and washed with tetrahydrofuran to obtain a tetrahydrofuran separated solution of titanyl phthalocyanine composition crystals containing 0.95 parts of pigment. It was partially dried and examined for infrared absorption spectrum and X-ray diffraction image. As a result, the infrared absorption spectrum was similar to that shown in FIG. 1, and the X-ray diffraction pattern was as shown in FIG. 2.

Next, 1.5 parts by dry weight of this assembly, 1 part of butyral resin (BX-5 manufactured by Sekisui Chemical Co., Ltd.), and tetrahydrofuran (T
A coating material was prepared using an ultrasonic disperser so that the amount of F>80 parts. This dispersion liquid is made of polyamide resin (Toray! i!
CM-8000) was coated on an aluminum plate coated with 0.5 NI so that the dry film thickness was 0.2.lffl to obtain a charge generation layer. The results of examining the infrared absorption spectrum and X-ray diffraction at this time were as shown in FIGS. 1 and 3.

Further, as a charge transfer material, 20 parts of p-diethylaminobenzaldehyde (diphenylhydrazone), which is the hydrazone compound (2) of the general formula [I], and 1, which is the butadiene compound (14) of the general formula [II]. ,1
-bis-(p-diethylaminophenyl)-4,4-diphenyl-1,3-butadiene and 60 parts of general formula [II
2,5-bis-(4-diethylaminophenyl)-1.3.4- which is the oxadiazole compound (16) of
20 parts of oxadiazole and 100 parts of polycarbonate resin (Z-200 manufactured by Mitsubishi Gas Chemical Co., Ltd.) were mixed with toluene/
A solution prepared by dissolving 500 parts of the T/F (1/1) mixed solution was applied so that the dry film thickness was 15 feet to form a charge transfer layer.

In this way, an electrophotographic photoreceptor having a laminated photosensitive layer was obtained. The half-decreased exposure (E1/2) of this photoreceptor was measured using an electrostatic copying paper testing device (Kawaguchi Electric Seisakusho EPA4100).That is, it was charged by corona discharge of -5.5 kV in a dark place, and then white with an illuminance of 51 ux. exposed to light,
Exposure amount El/2 required to attenuate the surface potential to half
(lux *sec) was calculated.

Example 2 A photoreceptor was prepared in the same manner as in Example 1, except that hydrazone compound (3), p-diphenylaminobenzaldehyde (diphenylhydrazone), was used in place of hydrazone compound (2) used in Example 1. was created.

Example 3 The same method as in Example 1 except that hydrazone compound (7) O-methyl-p-dibenzylaminobenzaldehyde (diphenylhydrazone) was used in place of hydrazone compound (2) used in Example 1. A photoreceptor was prepared.

Example 4 Oxadiazole compound (17) 2.5-bis-(4-n-propylaminophenyl)-1.3.4 was used in place of oxadiazole compound (16) used in Example 3. −
A photoreceptor was produced in the same manner as in Example 3 except that oxadiazole was used.

Example 5 In place of the oxadiazole compound (16) used in Example 3, 2.5-bis-(4-acetylaminophenyl)-1.3.4-oxa of the oxadiazole compound (22) was used. A photoreceptor was produced in the same manner as in Example 3 except that diazole was used.

Example 6 The same procedure as Example 1 was carried out except that 0.8 part of the metal-free naphthalocyanine obtained in Example 3 was used in place of the metal-free phthalocyanine obtained in Example 2. A tetrahydrofuran dispersion of titanyl phthalocyanine compound was obtained.

The partially dried product showed an infrared absorption spectrum similar to that shown in FIG.

O-methyl-p-dibenzylaminobenzaldehyde, which is the hydrazone compound (7) of general formula [I], was added as a charge transport layer on the charge generation layer prepared in the same manner as in Example 1 using the titanyl phthalocyanine composition. -(diphenylhydrazone) and 60 parts of 1,1-bis(p-diethylaminophenyl)-4.4-diphenyl-1,3-butadiene, which is the butadiene compound (14) of general formula [II], 2,5-bis-(4-dimethylaminophenyl)-1.3.4-oxadiazole 30, which is the oxadiazole compound (15) of general formula [II1]
parts, 100 parts of polycarbonate resin, 2,4-bis-(
n-octylthio)-6-(4-hydroxy-3,5-
di-t-butylanilino)-1.3.5-triazine 5
A photoreceptor was prepared in the same manner as in Example 1, except that a solution prepared by dissolving 1 part and 4 parts of 2-hydroxy-4-methoxybenzophenone in 500 parts of dichloromethane was used.

Comparative Example 1 A hydrazone compound (
2) A photoreceptor was prepared by coating a solution consisting of 100 parts of a polycarbonate resin and 500 parts of a toluene/T}-IF (1/1) mixed solution.

Comparative Example 2 In Comparative Example 1, a photoreceptor was produced using a butadiene compound (14) in place of the hydrazone compound (2).

Comparative Example 3 In Comparative Example 1, a photoreceptor was produced using an oxadiazole compound (16) in place of the hydrazone compound (2).

Comparative Example 4 On the charge generation layer used in Example 1, and Drazone compound (
2) 50 parts, butadiene compound (14) 50 parts, polycarbonate resin 100 parts and toluene/THE
(1/1) A photoreceptor was prepared by applying a solution consisting of 500 parts of the mixed solution.

Comparative Example 5 In Comparative Example 4, a photoreceptor was produced using 40 parts of the oxadiazole compound (16) in place of the butadiene compound (14).

Table 1 shows the results of evaluating various characteristics of the electrophotographic photoreceptors produced in Examples 1 to 6 and Comparative Examples 1 to 5 as described in Example 1.

(Left below) ■o: Surface potential (-5.5 kV) E: Half-decreased exposure dose 1/2 DDRI: Dark decay rate (initial period) DDR2: /l (after 1000 cycles) ■o
1: Initial charging potential Vo2: Charging potential after 1000 cycles VRI: Initial residual potential VR2: Residual potential after 1000 cycles As is clear from Table 1 above, Comparative Examples 1 to 3 have drawbacks of each material. appears, indicating that it is not suitable for use as a photoreceptor when used alone. Furthermore, characteristic deterioration due to repeated use is also observed in Comparative Examples 4 and 5, and the degree of improvement is low. By combining the hydrazone compound of the present invention with a butadiene compound and an oxadiazole compound, an excellent electrophotographic photoreceptor can be obtained in which the surface charging potential and dark decay rate are stabilized and the increase in residual potential is small.

Furthermore, by using a titanyl phthalocyanine compound as a material for the charge generation layer in combination with the charge transfer material described above, an electrophotographic photoreceptor with high sensitivity and excellent electrophotographic properties can be obtained, and it can also be used as a paint (dispersion solution). Since a long-life coating with good separation and a stable crystal type can be obtained, it is easy to form a homogeneous film, which is useful in the production of electrophotographic photoreceptors.

[Effect of the Invention 1] As explained above, the electrophotographic photoreceptor of the present invention has stable dark decay rate and surface potential, and has good repeatability. Further, the electrophotographic photoreceptor of the present invention has high photosensitivity in the laser wavelength range, and is particularly effective as a photoreceptor for high-speed, high-quality printers.

[Brief explanation of the drawing]

Figure 1 is an infrared absorption spectrum diagram of the titanyl phthalocyanine composition used as the charge generating material of the present invention, Figure 2
The figure shows the X-ray diffraction diagram, and Figure 3 shows the X-ray diffraction diagram in the coating state.
The line diffraction diagram, FIG. 4, is a spectral sensitivity characteristic diagram of an electrophotographic photoreceptor obtained according to an embodiment of the present invention. Wave number (cm-”) Fig. 1 Plug angle (20) Fig. 2 Plug angle (2θ) Fig. 3

Claims (2)

[Claims] (1) A hydrazone compound represented by the following general formula [I], a butadiene compound represented by the following general formula [II],
An electrophotographic photoreceptor comprising a photosensitive layer containing an oxadiazole compound represented by the following general formula [III]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] (In the formula, R^1 is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a halogen atom, a substituted or unsubstituted may form a carbazono group together with an amino group, a morphorno group, a piperidino group, or a phenyl group, and R^2 is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted An aralkyloxy group, R^3 and R^4 are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, or a pyridyl group, a pyrrolodino group, or a carbazono group. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [II] (In the formula, R^5 to R^8 represent alkyl groups, and they may be the same or different.) ) ▲Mathematical formulas, chemical formulas, tables, etc.▼...[III] (In the formula, R^9 and R^1^0 represent a hydrogen atom, an alkyl group, an acyl group, or a cycloalkyl group. , may be the same or different from each other.) (2) In an electrophotographic photoreceptor containing a charge-generating material and a charge-transfer material, (a) the charge-generating material is a metal-free phthalocyanine nitrogen isoform, a metal-phthalocyanine nitrogen isoform, a metal-free phthalocyanine, a metal phthalocyanine, a metal-free naphthalocyanine; or metal naphthalocyanine (however, metal-free phthalocyanine nitrogen isoform, metal phthalocyanine nitrogen isoform, metal-free phthalocyanine and metal phthalocyanine may have a substituent on the benzene nucleus, and metal-free naphthalocyanine and metal naphthalocyanine (which may have a substituent on the naphthyl nucleus) in a total of 50 parts by weight or less, and 100 parts by weight of titanyl phthalocyanine.
The active ingredient is a titanyl phthalocyanine composition crystal containing parts by weight, and the composition crystal has an infrared absorption spectrum of 1490 ± 2 cm^-^1 and 1415 ± 2 cm^-^
1, 1332±2cm^-^1, 1119±2cm^-
^1, 1072±2cm^-^1, 1060±2cm^
-^1, 961±2cm^-^1, 893±2cm^-
^1, 780±2cm^-^1, 751±2cm^-^
(b) The charge transfer material is a hydrazone compound represented by the following general formula [I] and a hydrazone compound represented by the following general formula [II]. An electrophotographic photoreceptor comprising a butadiene compound represented by the following general formula [III] and an oxadiazole compound represented by the following general formula [III] as active ingredients. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] (In the formula, R^1 is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a halogen atom, a substituted or unsubstituted may form a carbazono group together with an amino group, a morphorno group, a piperidino group, or a phenyl group, and R^2 is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted An aralkyloxy group, R^3 and R^4 are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, or a pyridyl group, a pyrrolodino group, or a carbazono group. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [II] (In the formula, R^5 to R^8 represent alkyl groups, and may be the same or different. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [III] (In the formula, R^9 and R^1^0 represent a hydrogen atom, an alkyl group, an acyl group, or a cycloalkyl group, They may be the same or different.)