JPH03122652A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To prevent deterioration of surface potential due to light fatigue and repeated uses and to enhance sensitivity by incorporating a specified butadiene compound and an oxazole compound in a photosensitive layer. CONSTITUTION:The photosensitive layer contains the butadiene compound represented by formula I and the oxazole compound represented by formula II. In formulae I and II, each of R<1> - R<4> is alkyl, optionally same or different from each other; and each of R<5> and R<6> is H, alkyl, acryl, or cycloalkyl, optionally same or different from each other. A combination of the compounds I and II is used as an electric charge transfer material, thus permitting the defects of both as the charge transfer material to be complemented by each other and deterioration of surface potential to be prevented and sensitivity to be enhance.

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 Problems Therewith] With the recent development of non-impact printing technology, research and development efforts have been made to develop electrophotographic printers using lasers as light sources.

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).
), cadmium sulfide (CdS), zinc oxide (ZnO)
, amorphous silicon (a-3l), etc., but these do not necessarily satisfy the characteristics required for 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-3i) has the disadvantage that manufacturing conditions are difficult and manufacturing costs are high.

Incidentally, in recent years, various photoreceptors using organic materials such as butadiene compounds and ochinasiazole compounds, which eliminate the above-mentioned drawbacks, have been proposed, and some of them have been put into practical use. However, although those containing butadiene compounds are effective in suppressing photofatigue, they have drawbacks in electrical properties, and those containing oxadiazole compounds as a main component have excellent electrical properties but do not produce light. I have a fatigue problem.

On the other hand, in combination with a charge-generating material, since printers use LEDs or semiconductor lasers as light sources, materials that are sensitive to relatively long wavelengths in the near-infrared region are 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, and
Among the phthalocyanines having Group and 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;
-148745M, No. 59-36254, No. 59-44054N, No. 5930541, No. 59-31965, No. 59-166959, and the like. However, the preparation of the vapor deposited film requires a high vacuum evacuation device, which increases the cost of equipment, so the organic photoreceptor as described above has to be expensive and weigh less than 1 tsubo.

In contrast, phthalocyanine is not deposited as a film, but
A composite 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. 5766963M> and indium phthalocyanine (Japanese Patent Application No. 59-220493), these are photoreceptors with relatively high sensitivity, but the former has problems such as rapidly decreasing sensitivity in the long wavelength region of 800 nm or more. Furthermore, the latter has drawbacks 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, methods using titanyl phthalocyanine, which has relatively high sensitivity electrophotographic properties, have been studied (Japanese Patent Application Laid-open Nos. 59-49544 and 61-2).
Publication No. 3928, Publication No. 61-109056 @ Publication No. 62
-275272), and it is known that there are differences in properties depending on various crystal forms. Creating these various crystal forms requires special purification and special solvent treatments. The processing solvent is different from that used when forming the dispersion coating film. This is because the various crystals obtained tend to grow easily in the growth treatment solvent, and when the same solvent is used as a coating solvent, it is difficult to control the crystal shape and particle size, the coating is unstable, and as a result, it becomes static. This is because the electrical properties deteriorate and it is unsuitable for practical use. 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, which may affect the dispersion stability of the paint. That's the problem.

In general, titanyl phthalocyanine generally has a large ionization potential, and when used together with a butadiene compound that has a small ionization potential, the large difference in ionization potential easily causes holes to be injected from the titanyl phthalocyanine into the butadiene 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 it satisfies the above-mentioned characteristics by combining organic photoconductive materials and improving characteristics such as optical fatigue, reduction in surface potential due to repeated use, and increased sensitivity. The object of the present invention is to provide a stable electrophotographic photoreceptor that is

[Means for Solving the Problems] The present invention includes a photosensitive layer containing a butadiene compound represented by the following general formula [I] and an oxadiazole compound represented by the following general formula [II]. This is an electrophotographic photoreceptor characterized by the following.

1 R3・[1] (In the formula, R1-R4 represent an alkyl group and may be the same or different from each other.) (In the formula, R5 and R6 represent a hydrogen atom, an alkyl group, an acyl group, or a cycloalkyl group. The present invention also 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, a metal phthalocyanine Nitrogen isoform, 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 have a substituent on the benzene nucleus) (Also, 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 ± 2 Cm" and 1415 ± 2 cm-1,133
2±2Cm-', 1119±2Cm-', 1072±2
Cm", 1060±2 cm - 961 words
±2Cm-', 893±2cm-1780±2
cm-'751±2Cm-' and? 30±20-
(b) The charge transfer material effectively transfers the butadiene compound represented by the above general formula [E] and the oxadiazole compound represented by the above general formula [N]. This is an electrophotographic photoreceptor characterized by comprising:

According to the present invention, as a charge transfer material, the general formula [I]
By using the compounds represented by and [I[] in combination, the drawbacks of the butadiene compound and the oxadiazole compound as charge transfer materials are mutually complemented. In general, other phthalocyanines or naphthalocyanine compounds as described below are added to titanyl phthalocyanine, and the amorphous composition of the same mixture is crystallized by treatment with tetrahydrofuran, which shows a new infrared absorption spectrum. By combining titanyl phthalocyanine composition crystals, which also have excellent photoconductivity, the difference in ionization potential is resolved, resulting in high sensitivity, excellent chargeability, little optical fatigue even after repeated use, and excellent durability. An electrophotographic photoreceptor is obtained.

The present invention will be explained in detail below.

Preferred specific examples of the butadiene compound of general formula [I] and the oxadiazole compound of general formula [■] are as follows.

As the butadiene compound of general formula [I], R1-R4
It is preferable that each of them is a methyl group or an ethyl group, especially H3[1,1-bis-(dimethylaminophenyl)-4
,4-diphenyl-1,3-butadiene], c2)15 [1,1-bis-(p-diethylaminophenyl)-4
, 4-diphenyl-1,3-butadiene] is preferred.

Further, as the oxadiazole compound represented by the general formula [I[], both R5 and R6 are hydrogen atoms, alkyl groups,
Preferably, one or up to three compounds are selected from the group of acyl groups and cycloalkyl groups. For example, [2,5-bis-(4-n-propylaminophenyl)
-1゜3.4-oxadiazole], [2,5-bis-(4-dimethylaminophenyl)-1
,3,4-oxadiazole], [2,5-bis-(4-yneamylaminophenyl)-
13,4-oxadiazole], [2,5-bis-(4-diethylaminophenyl)-1
,3,4-oxadiazole], ... (g) [2,5-bis-(4-cyclopentylaminophenyl)-1,3,4-oxadiazole], (hereinafter referred to as the margin) ... ( h) [2,5-bis-(4-cyclohexylaminophenyl)-1,3,4-oxadiazole], [2,5-bis-(4-acetylamino-2-lyolophenyl)- 1,3,4-oxadiazole][2,5-
Bis-(4-<n-propylamino>-2-chloro[2
,5-disu(<4-di-n-propyl>-aminophenyl)-1,3,4-oxadiazoleconol)-
1,3,4-oxadiazoleco[2,5-bis-(4
-acetylaminophenyl)-1,3,4-[2,5-
Bis-(4-ethylaminophenyl)-1,3,4-oxadiazole], Oxadiazole] -N -dimethyl-aminophenyl)-5-
(4°-Amiphenyl)-1,3,4-oxadiazolecono-3-chlorophenyl)-1,3,4-oxadiazoleco[2,5-bis-(4-<N-ethyl-N-acetyl) 〉
-aminophenyl)-1,3,4-oxadiazole]
[2-(4-mono-n-propyl-aminophenyl)-
5-(4°-dimethyl-aminophenyl)-1,3,4-oxadiazole] υ (2-(4-diethyl-aminophenyl)-5-(4°
-dimethyl-aminophenyl) -1,3,4-oxadiazole] [2-(4-mono-pro-aminophenyl)-
5-(4゛-mono-ethyl-aminophenyl)-1,3
, 4-oxadiazole].

Among the above substances, butadiene compounds are particularly 1,1
-bis-(diethylaminophenyl)-4,4-diphenyl-1,3-butadiene is preferred, and the oxadiazole compound is particularly 2,5-bis-(4-diethylaminophenyl)-1,3,4-oxadiene. Diazoles are preferred. These butadiene compounds and oxadiazole compounds are known prior to the filing of this application, and are each produced by conventional methods.

Next, the phthalocyanine compounds and naphthalocyanine compounds used in the present invention are referred to as "phthalocyanine compounds" by Moser and Thomas (Reinhold Co., 1966).
3), “Phthalocyanine J (CRC Publishing 1983)
) and other suitable methods are used.

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

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

PCT i=.

(However, 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, especially 200'C. ~250°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, the grains are treated with amorphous grains and then treated with hydrofuran. At that time, a suitable organic solvent such as methanol,
After removing the organic solvent used in the condensation reaction using alcohols such as ethanol and isopropyl alcohol, and ethers such as tetrahydrofuran and 1,4-dioxane,
Hydrothermal treatment is preferred. Especially the p of the washing liquid after hot water treatment.
It is preferred to wash until H is about 5-7.

It is more preferable to subsequently treat with an electron-donating solvent such as 2-ethoxyethanol, diglyme, dioxane, tetrahydrofuran, N,N-dimethylformamide, N-methylpyrrolidone, pyridine, or morpholine.

Next, as phthalocyanine nitrogen isoconstructs, there are various porphines, such as tetrapyridinoporphyrazine 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 amine groups, nitro groups, alkyl groups, alkoxy groups, cyan groups, mercapto groups, halogen atoms, and sulfonic acid groups, carboxyl 1F2 groups, or metal salts thereof. , ammonium salts, amine salts, etc. can be exemplified as relatively simple examples. Furthermore, various substituents can be introduced to the benzene nucleus via an alkylene group, a sulfonyl group, a carbonyl group, an imino group, etc., and these are known as anti-aggregation agents or crystal conversion inhibitors in the technical field of conventional phthalocyanine pigments. (for example, see US Pat. Nos. 3,973,981 and 4,088,507), or unknown ones. Known methods for introducing each substituent are omitted. In addition, those that are not known are described as synthesis examples in the Examples.

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. The composition ratio between the
．． 1 (weight ratio). 10010.1 or higher, the crystals contain many single crystals in addition to the mixed crystal composition, which may make it difficult to identify the new material of the present invention in infrared absorption spectra and X-ray diffraction spectra (hereinafter referred to as , these mixed compositions are referred to as titanyl phthalocyanine compositions (7Sζ).

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.

The amorphous titanyl phthalocyanine composition can be obtained by a single chemical or mechanical method, but more preferably by a combination of various methods.

For example, by weakening the agglomeration between particles using a method such as an acid pasting method or an acid slurry method, and then grinding using a mechanical treatment method, amorphous particles can be (q). The equipment used is a kneader,
Banbury mixer attritor, edge runner mill, roll mill.

Examples include, but are not limited to, a ball mill, a sand mill, a 5PEX mill, a homomixer, a disperser, an agitator, a show crusher, a stamp mill, a cutter mill, and a micronizer. In addition, the acid pasting method, which is well known as a chemical treatment method,
The method involves dissolving the pigment in 95% or more sulfuric acid or making it into a sulfate salt, and then pouring it into water or ice water to re-precipitate it.
By keeping sulfuric acid and water desirably at 5° C. or lower and slowly injecting sulfuric acid into water that is stirred at high speed, amorphous particles can be obtained under fairly good conditions.

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

Amorphous particles are also reduced by 1q by sublimation. for example,
500 each of raw materials obtained by various methods under vacuum
It can be obtained by heating to ~600[deg.] 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 placed in 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 speeds up crystal growth.
It also slows down at low temperatures. As a stirring tank, in addition to a normal starter, mixers used for dispersion such as an ultrasonic ball mill, sand mill, homomixer, disperser, agitator, micronizer, etc., and a concal blender-V type mixer are suitable. However, it is not limited to these.

After these stirring steps, filtration, washing, and drying are usually performed to obtain stabilized crystals of the titanyl phthalocyanine composition. At this time, it is possible to add a resin or the like to the dispersion liquid as necessary without performing filtration or drying to form a coating. When used as a coating film for electrophotographic photoreceptors, etc., the process is saved and is extremely effective.

The infrared absorption spectrum of the titanyl phthalocyanine composition of the present invention obtained in this way is shown in FIG.
, however, it includes an error of ±2) is 1490.14
15.1332.1119.1072.1060°96
It shows a characteristic strong peak at the point 1.893.780.751.730.

Furthermore, an X-ray diffraction diagram using CuKa radiation is shown in FIG. This titanyl phthalocyanine composition exhibits a maximum diffraction peak at a Bragg angle 2θ (including an error range of ±0.2 degrees) of 27.3 degrees in an X-ray diffraction diagram,
Those showing strong peaks at 9.7 degrees and 24.1 degrees, and those showing strong peaks at 27 degrees.
The maximum peak was at 3 degrees, 7.4 degrees, 22.3 degrees,
Some exhibit strong peaks at 24.1 degrees, 25.3 degrees, and 28.5 degrees. These differences are thought to be due to the difference in the growth rate of each crystal plane of a crystal 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 significant 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] butadiene compound (hereinafter referred to as butadiene)
and an oxadiazole compound of general formula [II] (hereinafter,
Oxadiazole) is dissolved in a suitable solvent together with a resin (binder), and if necessary, a photoconductive substance that absorbs light and generates an electric charge, a sensitizing dye, an electron-absorbing material, or a plasticizer. It can be produced by applying a coating solution obtained by adding various additives such as the like onto a conductive substrate and drying it to form a photosensitive layer (charge transfer layer) having a thickness of usually 5 to 30 μm.

The resin used for the charge transfer layer is silicone resin.

Ketone resin, polymethyl methacrylate, polyvinyl chloride, acrylic resin polyarylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal,
Polysulfone.

Insulating resins such as polyacrylamide, polyamide, chlorinated rubber, poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, etc. are used.

The amount of the mixture of butadiene of general formula [I] and oxadiazole of general formula [II] to be added is in a range of 20 to 300 parts by weight, preferably 50 to 200 parts by weight, based on 100 parts by weight of the resin. . Furthermore, the ratio (mixing ratio) of butadiene and oxadiazole is 10 to 2,000 parts by weight, preferably 50 to 1,000 parts by weight, per 100 parts by weight of butadiene. Further, these resins may be used alone or in combination of two or more.

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 5011.
It is preferable to apply the coating so that the number of In1 is desirably 10 to 20.

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

Coating is performed using a spin coater, applicator, spray coater, bar coater, dip coater doctor blade, roller coater, curtain coater, or bead coater, and drying is preferably done by heating for 40 minutes.
The test is carried out at 0 to 200°C for 10 minutes to 6 hours under stationary or ventilation conditions. The film thickness after drying is 0.01 to 5N11, preferably 0.1 to 11I! It is coated so that it becomes n.

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 vinylcarbazole, 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 resins such as 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, polyvinylpyrrolidone, etc. can be mentioned. The resin contained in the charge generation layer is 10
A content of 0% by weight or less, preferably 40% by weight or less is suitable.

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 generation layer or the undercoat layer during coating. Specifically benzene and xylene.

Aromatic hydrocarbons such as ligroin, monochlorobenzene and dichlorobenzene, ketones such as acetone, methyl ethyl ketone and cyclohexanone, alcohols such as methanol, ethanol and isopropanol, esters such as ethyl acetate and methyl cellosolve, carbon tetrachloride , aliphatic halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, trichloroethylene, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and sulfoxides such as dimethyl sulfoxide.

In addition, charge-generating materials include not only the titanyl phthalocyanine composition crystals described above, but also known photoconductive materials, such as 3e, 3e-Te alloy, 3e-AS alloy, CdS, and Zn.
Inorganic materials such as O, Cu, Al2. In, Ti,
Phthalocyanines containing metals such as Pb and V, metal-free phthalocyanine, 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. Alcohol-soluble polyamides such as copolymerized nylon and alkoxymethylated nylon, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymers, gelatin, polyurethane, polyvinyl butyral, and metal oxides such as aluminum oxide are used. It is also effective to incorporate conductive particles such as metal oxides and carbon black into the resin.

The thickness of the undercoat layer is 0.1 to 5 thick, preferably 0.
．． Approximately 4 to 31 m is appropriate.

In addition, 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 disks.

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

Production synthesis example of phthalocyanines 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.
% aqueous sodium hydroxide solution, methanol, N,
After washing with N-dimethylformamide and drying, 21.3 parts of titanyl phthalocyanine (Ti0Pc) was obtained.

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

Synthesis Example 3 20 parts of 0-naphthalodinitrile in 50 parts of quinoline
After DO thermal 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.

Production Example 1 of Electrophotographic Photoreceptor 1 part of titanyl phthalocyanine obtained in Synthesis Example 1 and Synthesis Example 2
0.05 part of the metal-free phthalocyanine obtained in
It is dissolved little by little in 30 parts of 8% sulfuric acid and the mixture is stirred for about 1 hour while maintaining the temperature below 5°C. Subsequently, the sulfuric acid solution was slowly poured into 500 parts of ice water 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) was stirred in 100 parts of tetrahydrofuran for about 1 hour, filtered, and washed with tetrahydrofuran, and the titanyl phthalocyanine composition crystals containing 0.95 parts of pigment were obtained. 1 q of tetrahydrofuran dispersion was prepared. 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 composition, butyral resin (Tsukusui Kagaku BX-5>1 part, tetrahydrofuran (T
A coating material was prepared using an ultrasonic dispersion machine so as to have a total weight of 80 parts (HF). This dispersion was mixed with polyamide resin (CM-
8000) was coated on an aluminum plate coated with 0.5 C to give a dry film thickness of 0.21 JJn 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 agent, 70 parts of 1,1-bis-(p-diethylaminophenyl)-4,4-diphenyl-1,3-butadiene, which is the butadiene compound (b) of the general formula [I], 30 parts of 2,5-bis-(4-diethylaminophenyl)-1,3,4-oxadiazole which is the oxadiazole compound (d) of formula [II], polycarbonate resin (Z-200 manufactured by Mitsubishi Gas Chemical Co., Ltd.) )
100 parts and 2,4-bis-(n-octylthio)
-10 parts of -6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine in toluene/T
A charge transfer layer was formed by applying a solution dissolved in 500 parts of HF (1/1) mixture to a dry film thickness of 15 mm.

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 tester (Kawaguchi Electric Seisakusho EP^-8100). That is, it is charged by -5.5 kV corona discharge in a dark place, then exposed to white light with an illuminance of 51 ux, and the exposure amount [g:
(lux · sec) was calculated at 72.

Example 2 On the charge generation layer used in Example 1, 1, which is the butadiene compound (b) of the general formula [I], was added as a charge transport layer.
, 1-bis-(p-diethylaminophenyl)-4,4
-diphenyl-1,3-butadiene 90 parts, general formula [I
2,5-bis-(4-isoamylaminophenyl)-1,3,,i, which is the oxadiazole compound (f) of [I]
-10 parts of oxadiazole, 80 parts of polycarbonate resin
An electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that a solution of 30 parts of dichloromethane and 30 parts of 2-hydroxy-4-methoxybenzophenone was dissolved in 500 parts of dichloromethane.
It was measured.

Example 3 Oxadiazole compound (f) used in Example 2 above
oxadiazole compound (i) in place of 2,5-
Bis-(<4-di-n-propyl>-aminophenyl)
Example 2 except that -1,3,4-oxadiazole was used
A photoreceptor was prepared in the same manner as described above.

Example 4 Oxadiazole compound (f) used in Example 2 above
2,5- which is an oxadiazole compound (j) in place of
Bis-(4-acetylaminophenyl)-1,3,4-
A photoreceptor was produced in the same manner as in Example 2 except that oxadiazole was used.

Example 5 On the charge generation layer used in Example 1, 1,1- which is a butadiene compound (a) of general formula [I] was added as a charge transport layer.
75 parts of bis-(p-dimethylaminophenyl)-4,4-diphenyl-1,3-butadiene, 2,5-bis-(
<4-di-n-propyl>-aminophenyl)-1,3
A photoreceptor was prepared in the same manner as in Example 1, except that a solution of 25 parts of 4-oxadiazole and 90 parts of polycarbonate resin dissolved in 600 parts of dichloromethane was used.

Example 6 Oxadiazole compound (i) used in Example 5 above
2,5- which is an oxadiazole compound (m) in place of
A photoreceptor was produced in the same manner as in Example 5 except that bis-(4-ethylaminophenyl)-1,3,4-oxadiazole was used.

Example 7 Oxadiazole compound (0), 2,5-bis-(4-<N-ethyl-N-acetyl>-aminophenyl), was used in place of oxadiazole compound (i) used in Example 5. A photoreceptor was produced in the same manner as in Example 5 except that -1,3,4-oxadiazole was used.

Example 8 In place of 0.05 part of metal-free phthalocyanine in Example 1,
A sample was prepared in the same manner as in Example 1, except that 0.05 part of the metal-free naphthalocyanine obtained in Synthesis Example 3 was used, and it was confirmed that the infrared absorption spectrum was the same as that shown in FIG.

Next, 1,1-bis-(p-diethylaminophenyl)-, which is the butadiene compound (b) of general formula [I], was added as a charge transport layer on the charge generation layer formed using the same in the same manner as in Example 1. 70 parts of 4,4-diphenyl-1,3-butadiene, an oxadiazole compound of general formula [II] (
m), 30 parts of 2,5-bis-(4-ethylaminophenyl)-1,3,4-oxadiazole, 100 parts of polycarbonate resin, 2,4-bis-(n-octylthio)-6-( 10 parts of 4-hydroxy-3,5-di-t-butylanilino-1,3,5-triazine and 2
A photoreceptor was prepared and measured in the same manner as in Example 1, except that a solution in which 5 parts of -hydroxy-4-methoxybenzophenone was dissolved in 500 parts of a toluene/THF (1/1) mixed solution was used.

Comparative Example 1 A butadiene compound (b
) ioo part, polycarbonate resin (Z-200) 1
00 parts and toluene/THF (1/1) mixed solution 500 parts
A photoreceptor was prepared and measured with a solution consisting of:

Comparative Example 2 A photoreceptor was produced in the same manner as in Comparative Example 1, except that the oxadiazole compound (d) was used in place of the butadiene compound (b).

Comparative Example 3 A butadiene compound (b
) A photoreceptor was prepared by coating a solution consisting of io part, 90 parts of a hydrazone compound dimethylaminobenzaldehyde (diphenylhydrazone), 100 parts of polycarbonate resin (Z-200), and 500 parts of dichloromethane.

Comparative Example 4 A photoreceptor was produced in the same manner as in Comparative Example 3, except that the oxadiazole compound (d) was used in place of the butadiene compound (b).

Table 1 shows the results of evaluating various characteristics of the electrophotographic photoreceptors produced in Examples 1 to 8 and Comparative Examples 1 to 4 as described in Example 1.

(Left below) Vo: Surface potential (-5,5kV) E1/2: Half-decreased exposure DDRl: Dark decay rate (initial) DDR2: ! / (After 1000 cycles) Vo
l: initial charging potential y. 2: Charging potential after 1,000 cycles VR1: Initial residual potential VR2: Residual potential after 1,000 cycles As is clear from the above-mentioned Example 1, in Comparative Example 1, the dark decay rate (DDR2> varied greatly due to repeated use, and the surface There is a drawback that the potential (Vo2>) decreases significantly.Also, although the photoreceptor of Comparative Example 2 has little variation in dark decay rate, the residual potential (VR2>) increases significantly due to repeated use. It is also shown that when each of the oxadiazole compounds is used alone, it is not suitable for the photoreceptor.The photoreceptors of Comparative Examples 3 and 4 also show characteristic deterioration due to repeated use.

The photoreceptors of Examples 1 to 8 using the two components of the butadiene compound and oxadiazole compound of the present invention all have stable dark decay rate and surface potential, small increase in residual potential, etc.
It can be seen that the repeatability is good. Furthermore, by using titanyl phthalocyanine composition crystals as the material for the charge generation layer and combining them with the charge transfer material described above, a long-life coating with good dispersion and stable crystal type can be obtained, making it easy to form a homogeneous film. This is useful for manufacturing photoreceptors.

[Effects of the Invention] As explained above, the electrophotographic photoreceptor of the present invention has stable dark decay rate and surface potential, and has good repeatability. Therefore, 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 drawings]

FIG. 1 is an infrared absorption spectrum diagram of a titanyl phthalocyanine composition crystal used as a charge generating material of the present invention;
FIG. 2 is an X-ray diffraction diagram thereof, FIG. 3 is an X-ray diffraction diagram thereof in a coated state, and FIG. 4 is a spectral sensitivity characteristic diagram of an electrophotographic photoreceptor obtained according to an embodiment of the present invention. agent

Claims (2)

[Claims] (1) An electrophotographic photoreceptor comprising a photosensitive layer containing a butadiene compound represented by the following general formula [I] and an oxadiazole compound represented by the following general formula [II]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・［
I] (In the formula, R^1 to R^4 represent alkyl groups and may be the same or different.) ▲There are numerical formulas, chemical formulas, tables, etc.▼... [II] (In the formula, R^5 and R^6 are hydrogen atoms, alkyl groups,
(Indicates an acyl group or cycloalkyl group, which may be the same or different) (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 butadiene compound represented by the following general formula [I] and a butadiene compound represented by the following general formula [II]. An electrophotographic photoreceptor comprising an oxadiazole compound as an active ingredient. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] (In the formula, R^1 to R^4 represent alkyl groups, and may be the same or different.) ▲Mathical formulas, chemical formulas, tables, etc. etc. ▼...[II] (In the formula, R^5 and R^6 are hydrogen atoms, alkyl groups,
(Indicates an acyl group or cycloalkyl group, which may be the same or different)