JP2626096B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic photosensitive member.

[Conventional technology]

Conventionally, phthalocyanines and metal phthalocyanines have been
It is known to exhibit excellent photoconductivity, and some are used for electrophotographic photoreceptors. In recent years, with the development of non-impact printer technology, electrophotographic optical printers using laser light or LED as a light source and capable of high image quality and high speed are becoming widespread, and photoconductors that meet those demands are being actively developed. It is.

In particular, when a laser is used as a light source, semiconductor lasers are often used because of their small size, low cost, and simplicity. However, the oscillation wavelengths of semiconductor lasers currently used in these lasers are limited to relatively long wavelengths in the near infrared region. Have been. Therefore, it is inappropriate to use a photoreceptor having sensitivity in the visible region, which has been conventionally used in an electrophotographic copying machine, for a semiconductor laser, and a photoreceptor having photosensitivity up to the near infrared region is required. Is coming.

Methine squaric acid dyes, indoline dyes, cyanine dyes pyrylium dyes, polyazo dyes, phthalocyanine dyes, naphthoquinone dyes and the like are conventionally known as organic materials satisfying this requirement. Dyes, indoline dyes, and cyanine dyes pyrylium dyes can be extended in wavelength, but lack practical safety (repeating properties), and polyazo dyes are difficult to increase in wavelength and are disadvantageous in production. At present, naphthoquinone dyes have difficulty in sensitivity.

In contrast, phthalocyanine dyes have a peak in spectral sensitivity in the long wavelength region of 600 nm or more, and have high sensitivity, and the spectral sensitivity changes depending on the central metal and the type of crystal form. It is considered to be suitable, and R & D is being conducted vigorously.

Among the phthalocyanine compounds studied so far,
Examples of compounds exhibiting high sensitivity in a long wavelength region of 780 nm or more include x-type metal-free phthalocyanine, ε-type copper phthalocyanine, vanadyl phthalocyanine, and the like.

On the other hand, in order to increase the sensitivity, a stacked photoreceptor using a phthalocyanine deposited film as a charge generation layer has been studied.
Some phthalocyanines having a group Ia or group IV metal as a central metal having relatively high sensitivity have been obtained. References relating to such metal phthalocyanines include, for example, JP-A-57-211149, JP-A-57-148745 and JP-A-57-148745.
-36254, 59-44054, 59-30541, 59-319
Nos. 65 and 59-166959. However,
The preparation of the deposited film requires a high vacuum evacuation device, and the equipment cost is high. Therefore, the organic photoreceptor as described above must be expensive.

On the other hand, using phthalocyanine not as a vapor deposition film but as a resin dispersion layer and using this as a charge generation layer,
A composite photoreceptor having a charge transfer layer applied thereon has also been studied.

As a charge transfer material, as disclosed in JP-A-54-59143, a hydrazone compound having high sensitivity, low residual potential, low light fatigue even when repeatedly used according to an electrophotographic process, and excellent in durability is used. Is being developed.

Metal-free phthalocyanine (Japanese Patent Application Sho
57-66963) and indium phthalocyanine (Japanese Patent Application No. 59-2)
No. 20493), which are relatively high-sensitivity photoreceptors, but the former has the disadvantage that the sensitivity is rapidly reduced in the long wavelength region of 800 nm or more, and the latter has a charge. When the generating layer is formed of a resin dispersion system, it has disadvantages such as insufficient sensitivity for practical use.

[Problems to be solved by the invention]

In recent years, in particular, those using titanyl phthalocyanine having electrophotographic characteristics having relatively high sensitivity have been studied (JP-A-59-49544, JP-A-61-23928, and JP-A-61-23928).
It is known that there are differences in characteristics depending on various crystal forms. In order to produce these various crystal forms, special purification and special solvent treatment are required. The treatment solvent is different from that used when forming the dispersion coating film. This is because various crystals obtained easily grow in a growth processing solvent, and when this solvent is used as a coating solvent, it is difficult to control the crystal form and particle size, there is no stability of the paint, and as a crystal, This is because the electrical characteristics are deteriorated and are not suitable for practical use. For this reason, a chlorine-based solvent such as chloroform, which does not easily promote the crystal growth, is usually used when forming a coating material. However, these solvents do not always have good dispersibility in titanyl phthalocyanine, and are problematic in terms of the dispersion stability of the paint.

In addition, titanyl phthalocyanine generally has a large ionization potential, and when used with a hydrazone compound having a small ionization potential, the difference in ionization potential is large, so that injection of holes from the titanyl phthalocyanine to the hydrazone compound easily occurs. Significant decrease in surface potential due to repeated use and light fatigue. Even in the case of using a photoreceptor of a dispersion system containing a charge generation material and a charge transfer material in a single layer, there is a problem that it is difficult to include a large amount of the charge generation material for improving the sensitivity while maintaining the chargeability. . On the other hand, a material containing a butadiene compound as a main component has light resistance to light fatigue, but has a drawback in electrical characteristics.

An object of the present invention is to use a titanyl phthalocyanine composition having high crystal stability, good dispersibility and excellent photosensitivity as a charge generation material in combination with an organic photoconductive material in a solvent used at the time of forming a coating material. It is an object of the present invention to provide a stable electrophotographic photoreceptor that satisfies the above-mentioned various characteristics by improving characteristics such as fatigue and reduction in surface potential due to repeated use.

[Means for solving the problem]

In order to achieve the above object, an electrophotographic photoreceptor according to the present invention is an electrophotographic photoreceptor including a charge generation material and a charge transfer material, wherein (a) the charge generation material is selected from phthalocyanine and naphthalocyanine A crystalline phthalocyanine-based compound in which at least one kind is combined with titanyl phthalocyanine as a crystal nucleus; at least one of phthalocyanine and naphthalocyanine is contained in a range of 50 parts by weight to 1 part by weight; The titanyl phthalocyanine is contained in 100 parts by weight, and the charge generation material has an absorption wave number (cm ^-1 ) of 1490 ± 2,1415 ± 2,1332 ± 2,1119 ± 2,1072 ± 2,
It has a characteristic strong absorption at 1060 ± 2,961 ± 2,893 ± 2,780 ± 2,751 ± 2,730 ± 2, a black angle (2θ ± 0.2 degrees) in the X-ray diffraction spectrum, a maximum diffraction peak at 27.3 degrees, and a peak of 9.7%. Degrees, showing a strong diffraction peak at 24.1 degrees, or showing a maximum diffraction peak at 27.3 degrees, and 7.4 degrees, 22.3 degrees.
Phthalocyanine crystal showing strong diffraction peaks at 24.1, 25.3, and 28.5 degrees as an active ingredient. (B) The hydrazone compound represented by the general formula [I] is used as the charge transfer material. (In the formula (I), R ₁ represents a substituted amino group, R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxyl group, and R ₃ and R ₄ represent a hydrogen atom, a substituted or unsubstituted alkyl group. , A substituted or unsubstituted aryl group, or a ring such as a pyridyl group, a pyrrhodino group, a carbazono group, etc.) and a compound represented by the general formula [II]: (In the formula (II), R _{6 to} R ₈ are alkyl groups which may be the same or different.) A butadiene compound is used as an active ingredient.

The hydrazone compound is a hydrazone selected from the group consisting of P-diethylaminobenzaldehyde- (diphenylhydrazone), P-diphenylaminobenzaldehyde- (diphenylhydrazone), and O-methyl-P-dibenzylaminobenzaldehyde- (diphenylhydrazone). Compound.

The butadiene compound is 1,1-bis (P-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene.

[Operation] Hereinafter, the present invention will be described in detail.

The phthalocyanine compound and naphthalocyanine compound used in the present invention can be obtained by known methods such as Moser and Thomas's "phthalocyanine compound" (Reinhold 1963) and "phthalocyanine" (CRC Publishing 1983) and other suitable methods. Use things.

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 titanium oxyphthalocyanines,
It can be easily synthesized according to the reaction formula shown in the following (1) or (2).

Examples of the organic solvent include nitrobenzene, quinoline, α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenyl ether,
A high boiling organic solvent which is inert to the reaction of diphenylmethane, diphenylethane, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, etc. is preferred, and the reaction temperature is usually 150 ° C to 300 ° C, particularly 200 ° C inner circumference 250 ° C. Is preferred.

In the present invention, the crude titanyl phthalocyanine compound thus obtained is treated with tetrahydrofuran after the non-crystallization treatment. At that time, the organic solvent used for the condensation reaction is removed in advance using a suitable organic solvent, for example, an alcohol such as methanol, ethanol, or isopropyl alcohol, or an ether such as tetrahydrofuran or 1,4-dioxane. Water treatment is preferred. In particular, it is preferable to wash until the washing liquid pH after the hot water treatment becomes about 5 to 7.

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

Examples of the phthalocyanine nitrogen isotope include various porphines, for example, tetrapyridinoporphyrazine in which one or more benzene nuclei of phthalocyanine are replaced with a quinoline nucleus, and metal phthalocyanines include
Examples include various materials such as copper, nickel, cobalt, zinc, tin, aluminum, and titanium.

Examples of the substituents of phthalocyanines and naphthalocyanines include an amino group, a nitro group, an alkyl group, an alkoxy group, a cyano group, a mercapto group, and a halogen atom, and a sulfonic acid group, a carboxylic acid group, or a metal salt thereof. ,
Ammonium salts and amine salts can be exemplified as relatively simple ones. Further, various substituents can be introduced into the benzene nucleus via an alkylene group, a sulfonyl group, a carbanyl group, an imino group, etc., and these are conventionally known in the technical field of phthalocyanine pigments as agglomeration inhibitors or crystal transformation inhibitors. (Eg US Patent No.
3973981 and 4088507), or others.

In the present invention, the composition ratio of titanyl phthalocyanine and a phthalocyanine nitrogen isotope or a metal-free and metal phthalocyanine which may have a substituent in a benzene nucleus, and a metal-free and metal naphthalocyanine which may have a substituent in a naphthyl nucleus is The ratio may be 100/50 (weight ratio) or more, but is desirably 100/20 to 0.1 (weight ratio). Above this ratio, the crystals will contain many single crystals in addition to the mixed crystal composition, and it will be difficult to identify the novel material of the present invention in the infrared absorption spectrum or X-ray diffraction spectrum (hereinafter, these mixed compositions Is referred to as a titanyl phthalocyanine composition.)

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

For example, non-crystalline particles can be obtained by weakening agglomeration between particles by a method such as an acid pasting method or an acid slurry method and then grinding by a mechanical treatment method. The equipment used during milling includes kneaders, Banbury mixers, attritors, edge runner mills, roll mills, ball mills, sand mills, SPEX mills,
Examples include, but are not limited to, homomixers, dispersers, agitators, jaw crushers, stample mills, cutter mills, micronizers, and the like. The acid pasting method, which is well-known as a chemical treatment method, is a method in which a pigment is dissolved in 95% or more sulfuric acid or a sulfate is poured into water or ice water to reprecipitate. By maintaining the water at preferably 5 ° C. or lower and slowly injecting sulfuric acid into the water with high-speed stirring, amorphous particles can be obtained with better conditions.

In addition, there are a method of directly grinding the crystalline particles by mechanical treatment for an extremely long time, a method of treating the particles obtained by the acid pasting method with the above-mentioned solvent and the like, and then grinding.

Amorphous particles can also be obtained by sublimation. For example,
Raw materials obtained by various methods under vacuum 500 ° C ~ 6
It can be obtained by sublimation by heating to 00 ° C. and rapid co-evaporation deposition on the substrate.

The amorphous titanyl phthalocyanine composition obtained as described above is treated in tetrahydrofuran,
Obtain new stable crystals. As a method for treating tetrahydrofuran, 5-300 parts by weight of tetrahydrofuran is added to 1 part by weight of the amorphous titanyl phthalocyanine composition and stirred in various stirring tanks. The temperature can be either heating or cooling, but heating will accelerate the crystal growth,
Slow at low temperatures. As the stirring tank, in addition to a normal stirrer, an ultrasonic ball mill, a sand mill, a homomixer, a disperser, an agitator, a micronizer, etc., which are used for dispersion, and a mixer such as a concal blender V-type mixer are appropriately used. But not limited to these. After these stirring steps, filtration, washing and drying are usually performed to obtain stabilized titanyl phthalocyanine crystals. At this time, a resin or the like can be added to the dispersion as needed without filtering and drying to form a coating. When used as a coating film of an electrophotographic photoreceptor or the like, the process is omitted and is extremely effective.

FIG. 1 shows the infrared absorption spectrum of the titanyl phthalocyanine composition of the present invention thus obtained. This titanyl phthalocyanine has an absorption wave number (cm ⁻¹ , including an error of ± 2) of 1490,1415,1332,1119,107.
It shows a characteristic strong peak at points 2,1060,961,893,780,751,730.

Also. FIG. 2 shows an X-ray diffraction pattern using CuKa rays. The titanyl phthalocyanine composition showed a maximum diffraction peak at 27.3 degrees in black angle (2θ (including an error range of ± 0.2 degrees)) in the X-ray diffraction diagram, and 9.
Some show strong peaks at 7 degrees and 24.1 degrees, others show strongest peaks at 27.3 degrees and show strong peaks at 7.4 degrees, 22.3 degrees, 24.1 degrees, 25.3 degrees, and 28.5 degrees. These differences are generally considered to be due to the fact that the intensity of the diffraction line is substantially proportional to the size of each crystal face, and therefore the degree of growth of each crystal face of the same structure crystal is different.

The titanyl phthalocyanine of the present invention does not show a large change in the infrared absorption spectrum even when the crystal growth is promoted by further heating and stirring in tetrahydrofuran, and is a very stable and good crystal.

By coating a titanyl-based phthalocyanine compound with an appropriate binder as the charge generation layer of the present invention, a charge generation layer having extremely good dispersibility and extremely high photoelectric conversion efficiency can be obtained.

Coating is performed using a spin coater, an applicator, a spray coater, a bar coater, a dipping coater, a doctor blade, a roller coater, a curtain coater, a bead coater, and drying is preferably performed by heating at 40 to 200 ° C. for 10 minutes. It is performed under static or blowing conditions for a period of up to 6 hours. After drying, the coating is applied to a thickness of 0.01 to 5 microns, preferably 0.1 to 1 micron.

The resin that can be used when forming the charge generation layer by coating can be selected from a wide range of insulating resins.
-It can be selected from organic photoconductive polymers such as vinyl carbazole, polyvinyl anthracene and polyvinyl pyrene. Preferably, polyvinyl butyral, polyarylate (such as a condensation polymer of bisphenol A and phthalic acid), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin,
Polyamide, polyvinyl pyridine, cellulosic resin,
Insulating resin such as urethane resin, epoxy resin, silicon resin, polystyrene, polyketone, polyvinyl chloride, polyvinyl chloride copolymer, polyvinyl acetal, polyacrylonitrile, phenol resin, melamine resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone Can be mentioned. The resin contained in the charge generation layer is 100
Suitably less than 40% by weight, preferably less than 40% by weight. These resins may be used alone or in combination of two or more. The solvent for dissolving these resins differs depending on the type of the resin, and it is preferable to select a charge transfer layer or an undercoat layer, which will be described later, from those that do not affect the coating. Specifically, aromatic hydrocarbons such as benzene, xylene, ligroin, monochlorobenzene and dichlorobenzene, ketones such as acetone, methyl ethyl ketone and cyclohexanone, alcohols such as methanol, ethanol and isopropanol, ethyl acetate and methyl cellosolve Esters, carbon tetrachloride, aliphatic halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, 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.

One of the electric field transfer agents used in the present invention is a hydrazone compound represented by the general formula [I], Preferred specific examples are as follows.

[P-dimethylaminobenzaldehyde- (diphenylhydrazone)] [P-diethylaminobenzaldehyde- (diphenylhydrazone)] [P-diphenylaminobenzaldehyde- (diphenylhydrazone)] [P-dibenzylaminobenzaldehyde- (diphenylhydrazone)] [P-dibenzyl-methoxyphenyl) aminobenzaldehyde- (diphenylhydrazone)] [O-methyl-P-diethylaminobenzaldehyde-
(Diphenylhydrazone)] [O-methyl-P-dibenzylaminobenzaldehyde- (diphenylhydrazone)] [O-methoxy-P-diethylaminobenzaldehyde- (diphenylhydrazone)] [O-benzyloxy-P-diethylaminobenzaldehyde- (diphenylhydrazone)] [P-diethylaminobenzaldehyde- (methyl-phenylhydrazone)] [O-methyl-P-dibenzylaminobenzaldehyde- (methyl-phenylhydrazone)] [O-methyl-P-dibenzylaminobenzaldehyde- (benzyl-phenylhydrazone)] The other is a butadiene compound represented by the general formula [II], Preferred specific examples are [1,1-bis (P-dimethylaminophenyl) -4,4-diphenyl-1,3-butadiene] [1,1-bis (P-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene].

These hydrazone compounds and butadiene compounds are known prior to the present application, and each is produced by a conventional method.

The electrophotographic photoreceptor of the present invention dissolves the hydrazone compound of the general formula [I] and the butadiene compound of the general formula [II] together with a resin (binder) in a suitable solvent, and absorbs light as necessary. Photoconductive substance that generates electric charge by
A coating liquid obtained by adding various additives such as an electron-absorbing material, a deterioration preventing substance or a plasticizer is applied to a conductive substrate,
After drying, a photosensitive layer having a thickness of usually 5 to 30 μm can be formed.
The mixing ratio of the hydrazone compound and the butadiene compound to the resin is 30 to 300 parts by weight, preferably 50 to 200 parts by weight, per 100 parts by weight of the resin. Furthermore, the mixing ratio of the hydrazone compound and the butadiene compound is
The butadiene compound is used in an amount of 10 to 2,000 parts by weight, preferably 50 to 1000 parts by weight, based on parts by weight. Resins used for this electric field transfer layer include silicone resin, ketone resin, polymethyl methacrylate, polyvinyl chloride, acrylic resin polyarylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, and polyvinyl. Insulating resin such as formal, polysulfone, polyacrylamide, polyamide, chlorinated rubber,
Insulating resin such as poly-N-vinyl carbazole, poly-N-vinyl carbazole, polyvinyl anthracene,
Polyvinyl pyrene or the like is used.

These resins may be used alone or in combination of two or more. The coating method is performed using a spin coater, an applicator, a spray coater, a bar coater, a dipping coater, a doctor blade, a roller coater, a curtain coater, a bead coater, and the like.
It is preferred that the coating be applied to 50 microns, preferably 10 to 30 microns.

In addition to these layers, an undercoat layer having a barrier function and an adhesive function can be provided between the conductive substrate and the photosensitive layer.

As an undercoat layer, alcohol-soluble polyamides such as nylon 6, nylon 66, nylon 11, nylon 610, copolymerized nylon, alkoxymethylated nylon, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, gelatin, polyurethane, polyvinyl Metal oxides such as butyral and aluminum oxide are used. It is also effective to include conductive particles such as metal oxide and carbon black in the resin.

The thickness of the undercoat layer is 0.05 to 10 μm, preferably
About 0.1 to 1 μm is appropriate.

Further, the electrophotographic photoreceptor of the present invention, on a conductive substrate,
An undercoat layer, a charge generation tank, and a charge transfer layer are preferably stacked in this order. However, an undercoat layer, a charge transfer layer, and a charge generation layer are stacked in this order. The charge transfer material may be dispersedly coated with a suitable resin. Further, these undercoat layers can be omitted as necessary.

The electrophotographic photoreceptor of the present invention has an absorption peak at a wavelength near 800 nm as shown in the spectral sensitivity characteristic diagram of FIG. 4, and is used not only as an electrophotographic photoreceptor in copying machines and printers but also in solar cells. It is also suitable as a photoelectric conversion element and an absorbing material for optical disks.

Hereinafter, the present invention will be described specifically, but the present invention is not limited to the following examples unless it exceeds the gist.

〔Example〕

An embodiment of the present invention will be described. In the examples, the division is
Indicates parts by weight.

(1) Production of novel titanyl phthalocyanine (Synthesis Example 1) After heating and reacting 20.4 parts of o-phthalodinitrile and 7.6 parts of titanium tetrachloride in 50 parts of quinoline at 200 ° C for 2 hours, the solvent was removed by steam distillation. The product was purified with a 2% aqueous hydrochloric acid solution and subsequently with a 2% aqueous sodium hydroxide solution, washed with methanol, N, N-dimethylformamide, and dried to obtain 21.3 parts of titanyl phthalocyanine (TiOPc).

(Synthesis Example 2) 14.5 parts of aminoiminoisoindolenine was heated in 50 parts of quinoline at 200 ° C for 2 hours. After the reaction, the solvent was removed by steam distillation, followed by a 2% aqueous hydrochloric acid solution, followed by a 2% aqueous sodium hydroxide solution. And then sufficiently washed with methanol and N, N-dimethylformamide, followed by drying to obtain 8.8 parts of metal-free phthalocyanine (yield 70%).

(Synthesis Example 3) 20 parts of o-naphthalodinitrile was added to 50 parts of quinoline in 200 parts
After heating at 4 ° C. for 4 hours, the reaction mixture was purified with a 2% aqueous hydrochloric acid solution, washed with methanol, N, N-dimethylformamide, and dried to obtain 15 parts of a metal-free naphthalocyanine.

(Example 1) 1 part of titanyl phthalocyanine obtained in Synthesis Example 1 and 0.05 part of metal-free phthalocyanine obtained in Synthesis Example 2 were dissolved little by little in 30 parts of 98% sulfuric acid at 5 ° C, and the mixture was dissolved in about 1 part. time,
Stir while keeping the temperature below 5 ° C. Subsequently, the sulfuric acid solution was slowly poured into 500 parts of ice water with high-speed stirring,
The precipitated crystals are filtered. The crystals are washed with distilled water until no acid remains, to obtain a wet cake. The cake (processed with 1 part of phthalocyanine contained) was stirred in 100 parts of tetrahydrofuran for about 1 hour, filtered and washed with tetrahydrofuran to obtain a tetrahydrofuran dispersion of a titanyl phthalocyanine composition having a pigment content of 0.95 parts. Obtained. Partly dried, infrared absorption spectrum and X
The line diffraction image was examined. As a result, the infrared absorption spectrum was new as shown in FIG. 1, and the X-ray diffraction pattern was as shown in FIG.

Next, 1.5 parts by dry weight of this composition, 1 part of butyral resin (BX-5, manufactured by Sekisui Chemical), and tetrahydrofuran (TH
F) The paint was prepared using an ultrasonic disperser so as to be 80 parts. This dispersion is applied to a polyamide resin (CM-8000 manufactured by Toray)
Has a dry film thickness of 0.3 on an aluminum plate coated with 0.5 μm
It was coated to a thickness of μm to obtain a charge generation layer. As a result of examining the infrared absorption spectrum and the X-ray diffraction image at this time, the results were as shown in FIG. 1 and FIG. Further, [o- of the hydrazone compound (7) of the general formula [I] is used as a charge transfer material.
30 parts of methyl-P-dibenzylaminobenzaldehyde- (diphenylhydrazone) and [1,1-bis- (P-diethylaminophenyl) -4,4-diphenyl-1 of the butadiene compound (14) of the general formula [II] , 3-butadiene) 70
Part, polycarbonate resin (Mitsubishi Gas Chemical Z-200) 100
Part, [2,4-bis- (n-octylthio) -6- (4-
(Hydroxy-3,5-di-t-butylanilino) -1,3,5-
Triazine] and a solution dissolved in 5 parts of toluene and 500 parts of a mixed solution of toluene / THF (1/1) were applied to a dry film thickness of 15 μm to form a charge transfer layer.

Thus, an electrophotographic photosensitive member having a laminated photosensitive layer was obtained. The half-life exposure amount (E1 / 2) of the photoreceptor was measured by an electrostatic copying paper tester (EPA-8100 manufactured by Kawaguchi Electric Works). That is, it was charged by a corona discharge of -5.5 KV in a dark place, and then exposed to white light having an illuminance of 51 ux, and an exposure amount E1 / 2 (1 ux.sec) required to attenuate to half the surface potential was obtained.

(Example 2) A method similar to that of Example 1 was used except that the hydrazone compound (7) used in Example 1 was replaced with [P-diethylaminobenzaldehyde- (diphenylhydrazone)] of the hydrazone compound (2). A photoreceptor was made.

(Example 3) A method similar to that of Example 1 was used except that [P-diphenylaminobenzaldehyde- (diphenylhydrazone)] of the hydrazone compound (3) was used instead of the hydrazone compound (7) used in Example 1. A photoreceptor was made.

Example 4 Example 1 was repeated except that 0.08 part of the metal-free phthalocyanine obtained in Synthesis Example 3 was used instead of the metal-free phthalocyanine of Example 1.
A sample was prepared in the same manner as described above, and it was confirmed that the infrared absorption spectrum was the same as that in FIG. On the charge generation layer using the same, 60 parts of [o-methyl-P-diethylaminobenzaldehyde- (diphenylhydrazone)] of the hydrazone compound (6) and [1,1-bis ( [P-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene] 40 parts, polycarbonate resin 80 parts, [2,4-bis- (n-octylthio) -6-
(4-hydroxy-3,5-di-t-butylanilino)-
1,3,5-triazine 3 parts, [2-hydroxy-4-methoxybenzophenone] 3 parts and toluene / THE (1/1)
A photoconductor was prepared in the same manner as in Example 1, except that a solution dissolved in 500 parts of the mixed solution was used.

(Comparative Example 1) 100 parts of a hydrazone compound (2), 100 parts of a polycarbonate resin, and toluene were formed on the charge generation layer used in Example 1.
A photoreceptor coated with a solution consisting of 500 parts of a / THF (1/1) mixture was prepared and measured.

(Comparative Example 2) In Comparative Example 1, a photoreceptor was prepared using the hydrazone compound (7) instead of the hydrazone compound (2).

Comparative Example 3 A photoconductor was prepared using the butadiene compound (14) instead of the hydrazone compound (2) in Comparative Example 1.

Table 1 shows the results of evaluating various characteristics of the electrophotographic photosensitive members prepared in Examples 1 to 4 and Comparative Examples 1 to 3 described above.

Vo: Surface potential (-5.5KV) E1 / 2: Half exposure DDR1: Dark decay rate (initial) DDR2: Dark decay rate (after 1000 cycles) Vo1: Initial charging potential Vo2: Charging potential after 1000 cycles VR1: Initial Residual potential VR2: Residual potential after 1000 cycles [Effects of the Invention] As is clear from Table 1, when a hydrazone compound or a butadiene compound is used alone (Comparative Examples 1 to 4)
3) Deterioration of dark decay rate (DDR2) due to repeated use, large decrease in surface potential (Vo2), large increase in residual potential (VR2), etc. appear, making it unsuitable for photoreceptors. It is shown that. By using a combination of the two components of the hydrazone compound and the butadiene compound of the present invention, a stable electrophotographic photoreceptor having little variation in dark decay rate, surface potential, and the like even when used repeatedly can be obtained. Further, the charge generation material of the present invention is a novel stable result,
Since it is stable to solvents, it is easy to select a solvent when forming a coating, and a coating with good dispersion and a long life can be obtained. Therefore, uniform film formation, which is important in photoconductor production, is facilitated. The obtained electrophotographic photosensitive member has high photosensitivity to a laser wavelength range, and is particularly effective as a high-speed, high-quality photosensitive member for a printer.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of the titanyl phthalocyanine composition according to the present invention, FIG. 2 is an X-ray diffraction diagram of the same, FIG. 3 is an X-ray diffraction diagram in a coated state, and FIG. FIG. 3 is a spectral sensitivity characteristic diagram of the electrophotographic photoreceptor of the present invention.

Claims (3)

(57) [Claims] 1. An electrophotographic photoreceptor containing a charge generating material and a charge transfer material, wherein (a) the charge generating material comprises at least one of phthalocyanine and naphthalocyanine and titanyl phthalocyanine as a crystal nucleus. A charge-generating material comprising a crystalline phthalocyanine-based compound bonded thereto, wherein at least one of phthalocyanine and naphthalocyanine is contained in a range of 50 to 1 part by weight, and titanyl phthalocyanine is contained in 100 parts by weight. Indicates that the absorption wave number (cm ^-1 ) of the infrared absorption spectrum is 1490 ± 2,1415 ± 2,1332 ± 2,1119 ± 2,1072 ± 2,
It has a characteristic strong absorption at 1060 ± 2,961 ± 2,893 ± 2,780 ± 2,751 ± 2,730 ± 2, a black angle (2θ ± 0.2 degrees) in the X-ray diffraction spectrum, a maximum diffraction peak at 27.3 degrees, and a peak of 9.7%. Degrees, showing a strong diffraction peak at 24.1 degrees, or showing a maximum diffraction peak at 27.3 degrees, and 7.4 degrees, 22.3 degrees.
Phthalocyanine crystal showing strong diffraction peaks at 24.1, 25.3, and 28.5 degrees as an active ingredient. (B) The hydrazone compound represented by the general formula [I] is used as the charge transfer material. (In the formula (I), R ₁ represents a substituted amino group, R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group or an alkoxyl group, and R ₃ and R ₄ represent a hydrogen atom, a substituted or unsubstituted alkyl group. , A substituted or unsubstituted aryl group, or a ring such as a pyridyl group, a pyrrhodino group, a carbazono group, etc.) and a compound represented by the general formula [II]: ([II] wherein R _{6 to} R ₈ are alkyl groups which may be the same or different) An electrophotographic photoreceptor comprising a butadiene compound as an active ingredient. 2. The hydrazone compound is P-diethylaminobenzaldehyde- (diphenylhydrazone), P-
The electron according to claim 1, wherein the hydrazone compound is selected from the group consisting of diphenylaminobenzaldehyde- (diphenylhydrazone) and O-methyl-P-dibenzylaminobenzaldehyde- (diphenylhydrazone). Photoreceptor. 3. The butadiene compound is 1,1-bis (P
-Diethylaminophenyl) -4,4-diphenyl-1,3-
The electrophotographic photoreceptor according to claim 1, wherein the electrophotographic photoreceptor is butadiene.