JPH10111576A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrophotographic photoreceptor having high electrification ability and high sensitivity, undergoing no change of various characteristics even after repeated use and capable of exhibiting stable performance by using phthalocyanine as an electric charge generating material and a specified stilbene compd. as an electric charge transferring material. SOLUTION: This electrophotographic photoreceptor contains phthalocyanine as an electric charge generating material and a stilbene compd. represented by the formula as an electric charge transferring material. In the formula, each of R1 -R4 is H or alkyl, R5 is aryl or a heterocyclic group, R6 is H, alkyl, aryl, aralkyl or a heterocyclic group, R7 is H, alkyl, alkoxy or halogen, R8 is H, alkyl or aryl, A is alkenyl, each of (p) and (q) is 0 or 1, (n) is 1 or 2, (m) is 0 or 1 and n+m=2.

Description

DETAILED DESCRIPTION OF THE INVENTION

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BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member using an organic photoconductive material, and more particularly to an electrophotographic photosensitive member containing a specific organic photoconductive material.

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2. Description of the Related Art In recent years, the use of the electrophotographic method has spread not only in the field of copying machines but also in fields in which photographic technology has been conventionally used, such as printing plate materials, slide films, and microfilms. Application to a high-speed printer using a light source is also being studied. Recently, the use of a photoconductive material other than an electrophotographic photosensitive member, for example, an application to an electrostatic recording element, a sensor material, an EL element, and the like has begun to be studied. Accordingly, demands for photoconductive materials and electrophotographic photoreceptors using the same are becoming higher and wider.
Heretofore, inorganic photoconductive materials such as selenium, cadmium sulfide, zinc oxide, and silicon have been known as electrophotographic photosensitive members, and have been widely studied and put to practical use. While these inorganic materials have many advantages, they also have various disadvantages. For example, selenium has drawbacks in that the production conditions are difficult and it is easy to crystallize due to heat and mechanical shock, and cadmium sulfide and zinc oxide have poor moisture resistance and durability. It has been pointed out that silicon is insufficient in chargeability and difficult to manufacture. In addition, selenium and cadmium sulfide have toxicity problems.

On the other hand, organic photoconductive materials have good film-forming properties, excellent flexibility, are lightweight, have good transparency, and are sensitive to a wide wavelength range by an appropriate sensitization method. Due to its advantages such as easy design of the body, its practical use has attracted attention.

Incidentally, the photoreceptor used in the electrophotographic technology is generally required to have the following basic properties. That is, (1) high chargeability against corona discharge in a dark place, (2) little leakage (dark decay) of the obtained charge in a dark place, and (3) charge charge by light irradiation. (4) The residual charge after light irradiation is small.

However, many studies have been made on photoconductive polymers such as polyvinyl carbazole as organic photoconductive substances to date, but these have not always had sufficient film-forming properties, flexibility and adhesiveness. Also, it is difficult to say that the above-mentioned basic properties of the photoreceptor are sufficiently provided.

On the other hand, as for the organic low-molecular-weight photoconductive compound, by selecting a binder or the like used for forming the photoreceptor, the photoreceptor having excellent mechanical strength such as film property, adhesiveness and flexibility can be obtained. Can be obtained, but it is difficult to find a compound suitable for maintaining high-sensitivity properties.

In order to improve such a point, an organic photoreceptor having a higher sensitivity characteristic has been developed in which the charge generation function and the charge transport function are shared by different substances. The feature of such a photoreceptor, which is called a function-separated type, is that a material suitable for each function can be selected from a wide range, and a photoreceptor having an arbitrary performance can be easily manufactured. Has been advanced.

Among them, various substances such as phthalocyanine pigments, squarium dyes, azo pigments and perylene pigments have been studied as substances in charge of the charge generation function. Among them, azo pigments can have various molecular structures. Also, since high charge generation efficiency can be expected, it has been widely studied, and its practical use has been advanced. However, in this azo pigment, the relationship between the molecular structure and the charge generation efficiency has not been clarified yet. The fact is that we are searching for the optimal structure through extensive synthesis research, but it fully satisfies the basic properties and high durability demands of the photoconductors listed above. Things have not yet been obtained.

In recent years, laser beam printers and the like, which use laser light as a light source instead of conventional white light and have the advantages of high speed, high image quality and non-impact, have become widespread in conjunction with the progress of information processing systems. At the same time, there is a demand for the development of a material that can withstand the demand. In particular, among laser beams, in recent years, applications to compact disks, optical disks, and the like have increased, and semiconductor lasers, which have undergone remarkable technological advances, have been actively applied in the field of printers as compact and highly reliable light source materials. In this case, since the wavelength of the light source is around 780 nm, there is a strong demand for the development of a photoreceptor having high sensitivity to long wavelength light around 780 nm. Among them, the development of photoreceptors using phthalocyanine, which has light absorption particularly in the near infrared region, has been actively conducted. However, nothing has yet been achieved.

On the other hand, the substances in charge of the charge transport function include a hole transport substance and an electron transport substance. Various kinds of substances such as hydrazone compounds and stilbene compounds have been studied as hole transport substances, and 2,4,7-trinitro-9-fluorenone and diphenoquinone derivatives have been studied as electron transport substances.
Practical application is also progressing, but the fact is that we are also pursuing a huge amount of synthetic research to search for the optimal structure. In fact, many improvements have been made so far, but none of the above-mentioned photoconductors sufficiently satisfy the requirements such as the basic properties and high durability required for the photoconductors.

As described above, various improvements have been made in the production of an electrophotographic photosensitive member, but the basic characteristics and high durability required for the above-described photosensitive member have not been sufficiently satisfied. At present, there is no satisfactory product yet.

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SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor having a high charging potential, high sensitivity, and exhibiting stable performance without changing various characteristics even when used repeatedly. .

[0013]

Means for Solving the Problems The present inventors have conducted research to achieve the above object, and as a result, have found that an organic photoconductive material having a specific structure is effective, and reached the present invention. The organic photoconductive material having a specific structure as described above means that a phthalocyanine is used as a charge generating substance and a stilbene compound represented by the following general formula (1) is used as a charge transporting substance.

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In the general formula (1), R ₁ , R ₂ , R ₃ ,
R ₄ represents a hydrogen atom or an alkyl group which may have a substituent, and R ₅ represents an aryl group or a heterocyclic group which may have a substituent. R ₆ represents a hydrogen atom, an optionally substituted alkyl group, an aryl group, an aralkyl group, or a heterocyclic group; R ₇ represents a hydrogen atom, an optionally substituted alkyl group, an alkoxy group; Represents a group or a halogen atom. R ₈ represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group, and A represents an alkenyl group which may have a substituent. p and q each represent an integer of 0 or 1. N is 1 or 2, m is 0 or 1, and n and m satisfy n + m = 2.

In the general formula (1), R ₁ , R ₂ , R ₃ ,
Specific examples of R ₄ include a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, a pentyl group, a hexyl group, and a trifluoromethyl group. .

Specific examples of R ₅ include aryl groups such as phenyl group, naphthyl group, anthryl group and pyrenyl group, and heterocyclic groups such as pyridyl group, thienyl group and furyl group. Specific examples of R ₆ include a hydrogen atom, an alkyl group such as a methyl group and an ethyl group, an aryl group such as a phenyl group, a naphthyl group, an anthryl group and a pyrenyl group, a benzyl group, an α-naphthylmethyl group, and a β-naphthylmethyl group. And heterocyclic groups such as an aralkyl group such as a group, a pyridyl group, a thienyl group, and a furyl group.

Specific examples of R ₇ include a hydrogen atom,
Examples include an alkyl group such as a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, and a halogen atom such as a fluorine atom, a chlorine atom, and a bromine atom. Specific examples of R ₈ include a hydrogen atom, an alkyl group such as a methyl group and an ethyl group, and an aryl group such as a phenyl group, a naphthyl group, an anthryl group, and a pyrenyl group.

Specific examples of A include alkenyl groups such as vinyl, allyl, 1-propenyl, 1-butenyl, 2-butenyl and 2-methylallyl.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Specific examples of the stilbene compound represented by the general formula (1) according to the present invention include, for example, those having the following structural formulas, but are not limited thereto.

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The phthalocyanines used in the present invention include, for example, metal-free phthalocyanines, titanyloxyphthalocyanines, copper phthalocyanines, aluminum phthalocyanines, germanium phthalocyanines, chlorogallium phthalocyanines, bromogallium phthalocyanines, and chloroindium. Phthalocyanines, bromoindium phthalocyanines, iodoindium phthalocyanines, magnesium phthalocyanines, chloroaluminum phthalocyanines, bromoaluminum phthalocyanines, tin phthalocyanines, dichlorotin phthalocyanines, vanadyloxyphthalocyanines, gallium phthalocyanines, zinc phthalocyanines, cobalt Phthalocyanines, nickel phthalocyanines, hydroxy Lium phthalocyanines, dihydroxygermanium phthalocyanines, barium phthalocyanines, beryllium phthalocyanines, cadmium phthalocyanines, chlorocobalt phthalocyanines, dichlorotitanyl phthalocyanines, iron phthalocyanines, silicon phthalocyanines, lead phthalocyanines, platinum phthalocyanines, diphenoxygermanium Phthalocyanines, metal-free naphthalocyanines, aluminum naphthalocyanines, titanyloxynaphthalocyanines, among which metal-free phthalocyanines, titanyloxyphthalocyanines, copper phthalocyanines, aluminum phthalocyanines, germanium phthalocyanines, chlorogallium phthalocyanines , Chloroindium phthalocyanines, magne Um phthalocyanines, chloroaluminum phthalocyanines, tin phthalocyanines, vanadyloxyphthalocyanines, gallium phthalocyanines, zinc phthalocyanines, cobalt phthalocyanines, nickel phthalocyanines, hydroxygallium phthalocyanines, dichlorotitanyl phthalocyanines, diphenoxygermanium phthalocyanines, Metal-free naphthalocyanines, aluminum naphthalocyanines, and titanyloxynaphthalocyanines are preferably used.

More preferably, the following Bragg angle (2θ ± 0.2) with respect to X-rays of CuKα1.541 angstroms.
°) is used.

Metal-free phthalocyanines: 7.6 °, 9.
2 °, 16.8 °, 17.4 °, 20.4 °, 20.9
Metal-free phthalocyanine (τ-type metal-free phthalocyanine) having an X-ray diffraction spectrum showing a main peak at °
7.5 °, 9.1 °, 16.8 °, 17.3 °, 20.
Metal-free phthalocyanine (τ′-type metal-free phthalocyanine) having an X-ray diffraction spectrum showing major peaks at 3 °, 20.8 °, 21.4 ° and 27.4 °, 7.5 °,
Metal-free phthalocyanine (X-type metal-free phthalocyanine) having an X-ray diffraction spectrum showing major peaks at 9.1 °, 16.7 °, 17.3 °, 22.3 °, 7.6 °,
9.2 °, 16.8 °, 17.4 °, 28.5 ° or 7.6 °, 9.2 °, 16.8 °, 17.4 °, 2
Metal-free phthalocyanine having an X-ray diffraction spectrum showing a main peak at 1.5 ° (η-type metal-free phthalocyanine), 7.5 °, 9.1 °, 16.8 °, 17.3 °,
20.3 °, 20.8 °, 21.4 °, 27.4 ° or 7.5 °, 9.1 °, 16.8 °, 17.3 °, 2
0.3 °, 20.8 °, 21.4 °, 22.1 °, 2
Metal-free phthalocyanine having an X-ray diffraction spectrum showing main peaks at 7.4 ° and 28.5 ° (η′-type metal-free phthalocyanine).

Titanyloxyphthalocyanines: 7.5
°, 12.3 °, 16.3 °, 25.3 °, 28.7 °
Titanyloxyphthalocyanine (α-type titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 9.3 °, 10.6 °, 13.2 °, 1
5.1 °, 15.7 °, 16.1 °, 20.8 °, 2
Titanyloxyphthalocyanine (β-type titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 3.3 °, 26.3 ° and 27.1 °, 7.0
°, 15.6 °, 23.4 °, 25.5 °, titanyloxyphthalocyanine having an X-ray diffraction spectrum showing main peaks (C-type titanyloxyphthalocyanine),
Titanyloxyphthalocyanine (m-type titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 6.9 °, 15.5 ° and 23.4 °, 9.5
°, 9.7 °, 11.7 °, 15.0 °, 23.5 °,
Titanyloxyphthalocyanine (Y) having an X-ray diffraction spectrum showing major peaks at 24.1 ° and 27.3 °
Type titanyloxyphthalocyanine), 7.3 °, 17.
Titanyloxyphthalocyanine (γ-type titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 7 °, 24.0 °, 27.2 °, 28.6 °, 9.0 °, 14.2 °, 23.9 °, 27.1 °
Titanyloxyphthalocyanine (type I titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 7.4 °, 11.0 °, 17.9 °, 2
Titanyloxyphthalocyanine (E-form titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing main peaks at 0.1 °, 26.5 °, and 29.0 °, amorphous titanyl having no clear peak Oxyphthalocyanine.

Copper phthalocyanines: ε-type copper phthalocyanine and β-type copper phthalocyanine.

Chloroaluminum phthalocyanines:
Chloroaluminum phthalocyanine having an X-ray diffraction spectrum showing major peaks at 6.7 °, 11.2 °, 16.7 ° and 25.6 °, and an X-ray diffraction spectrum showing major peaks at 25.5 ° Chloroaluminum phthalocyanine, 6.5 °, 11.1 °, 13.7 °, 1
7.0 °, 22.0 °, 23.0 °, 24.1 °, 2
Chloroaluminum phthalocyanine having an X-ray diffraction spectrum showing a major peak at 5.7 °.

Chloroindium phthalocyanines: 7.
X showing major peaks at 4 °, 16.7 ° and 27.8 °
Chloroindium phthalocyanine having a line diffraction spectrum.

Vanadyloxyphthalocyanines: 9.3
°, 10.7 °, 13.1 °, 15.1 °, 15.7
°, 16.1 °, 20.7 °, 23.3 °, 26.2
°, vanadyloxyphthalocyanine having an X-ray diffraction spectrum showing a major peak at 27.1 °, 7.5 °,
Vanadyloxyphthalocyanine having an X-ray diffraction spectrum showing major peaks at 24.2 °, 27.7 °, 28.6 °, 14.3 °, 18.0 °, 24.1 °, 2
Vanadyloxyphthalocyanine having an X-ray diffraction spectrum showing a main peak at 7.3 °, and amorphous vanadyloxyphthalocyanine having no clear peak.

Chlorogallium phthalocyanines: 7.4
Chlorogallium phthalocyanine having an X-ray diffraction spectrum showing major peaks at °, 16.6 °, 25.5 ° and 28.3 °.

Hydroxygallium phthalocyanines:
7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.
X showing major peaks at 6 °, 25.1 °, 28.3 °
Hydroxygallium phthalocyanine with line diffraction spectrum, 7.7 °, 16.5 °, 25.1 °, 26.6
Hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing a major peak at °, 7.9 °, 16.5
Hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing major peaks at °, 24.4 °, 27.6 °, 7.0 °, 7.5 °, 10.5 °, 11.7 °,
12.7 °, 17.3 °, 18.1 °, 24.5 °, 2
Hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing major peaks at 6.2 ° and 27.1 °,
Hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing major peaks at 6.8 °, 12.8 °, 15.8 °, 26.0 °, or 7.4 °, 9.9
A hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing major peaks at °, 25.0 °, 26.2 °, and 28.2 °.

In general, phthalocyanine is produced by a phthalodinitrile method in which phthalodinitrile and a metal chloride or an alkoxy metal are melted by heating or heated in the presence of an organic solvent, and phthalic anhydride is converted into urea and a metal chloride. And the Wiler method of heating and melting or heating in the presence of an organic solvent,
A method of reacting cyanobenzamide with a metal salt at a high temperature, a method of reacting dilithium phthalocyanine with a metal salt, and the like are not limited thereto. Examples of the organic solvent used for the reaction include α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenylnaphthalene, ethylene glycol, dialkyl ether, quinoline, sulfolane, dichlorobenzene, and N-methyl-2- Reaction-inactive, high-boiling solvents such as pyrrolidone and dichlorotoluene are preferred.

The phthalocyanine compound obtained by the above-mentioned method is converted into an acid, an alkali, acetone, methanol, ethanol, methyl ethyl ketone, tetrahydrofuran, pyridine, quinoline, sulfolane, α-chloronaphthalene,
By purifying with toluene, xylene, dioxane, chloroform, dichloroethane, N, N-dimethylformamide, N-methyl-2-pyrrolidone, etc., a high-purity phthalocyanine compound which can be used for electrophotography is obtained. Examples of the purification method include a washing method, a recrystallization method, an extraction method such as Soxhlet, a hot suspension method, and a sublimation method. The purification method is not limited to these, and any method may be used as long as it removes unreacted substances and reaction by-products.

Next, synthesis examples of the compound used in the present invention will be described, but the present invention is not limited thereto.

Synthesis Example 1 Synthesis of titanyloxyphthalocyanine (β-type) 25.5 g of 1,3-diiminoisoindoline, titanium
15.0 g of tetra-n-butoxide was dissolved in 180 ml of 1-chloronaphthalene, and the mixture was heated and stirred at 180 ° C. on an oil bath. Five hours later, the precipitated crystals were collected by filtration, washed with toluene and acetone in that order, and dried to obtain 21.4 g of titanyloxyphthalocyanine crystals. FIG. 1 shows an X-ray diffraction spectrum and FIG. 2 shows an IR spectrum of this compound.

Synthesis Example 2 Synthesis of titanyloxyphthalocyanine (amorphous) 3.0 g of titanyloxyphthalocyanine obtained in Synthesis Example 1
Was slowly added to and dissolved in 150 ml of concentrated sulfuric acid cooled to about 0 ° C. The solution was slowly poured into 1.2 l of cooled ice water to precipitate crystals. The crystals were collected by filtration, washed with water until neutral, and dried to obtain 2.6 g of amorphous titanyloxyphthalocyanine. The IR spectrum of this compound shows the same peak as in FIG. 2, and the X-ray diffraction spectrum is shown in FIG. From these, it was confirmed that only the crystal form was converted without decomposing the compound by this operation.

Synthesis Example 3 Synthesis of titanyloxyphthalocyanine (Y type) 2.0 g of the amorphous titanyloxyphthalocyanine obtained in Synthesis Example 2, 28.0 g of water, and 6.0 of chlorobenzene
g was heated and stirred at 50 ° C. After 1 hour, the mixture was cooled to room temperature, and the crystals were collected by filtration and washed with methanol. Dry and Y
1.7 g of type titanyloxyphthalocyanine was obtained. FIG. 4 shows the X-ray diffraction spectrum of this compound.

Hereinafter, phthalocyanines synthesized by the same method and their X-ray diffraction spectra are shown. X-type metal-free phthalocyanine (FIG. 5), τ-type metal-free phthalocyanine (FIG. 6), m-type titanyloxyphthalocyanine, (FIG. 7),
Diphenoxygermanium phthalocyanine (FIG. 8).

Synthesis Example 4 Synthesis of Exemplified Compound (2)

[0081]

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Diethylbenzhydryl phosphonate7.
6 g and 3.5 g of the above-mentioned dialdehyde compound (171) were dissolved in 25 ml of dimethoxyethane, and 4.2 g of potassium t-butoxide was added with stirring at room temperature. After 2 hours, the precipitate was separated by filtration, the filtrate was poured into water, and extracted with ethyl acetate.
After drying over sodium sulfate, the solvent was distilled off to obtain a red oily substance. The obtained oil was purified by silica gel column chromatography to give oily Exemplified Compound (2) at 2.36.
g was obtained.

Synthesis Example 5 Synthesis of Exemplified Compound (17)

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Diethylbenzhydrylphosphonate 1
0.9 g, 4.0 g of the dialdehyde compound (172)
Was dissolved in 50 ml of methyl cellosolve, and stirred at room temperature,
5.0 g of potassium t-butoxide were added. After 4 hours, the reaction mixture was poured into water and neutralized with dilute hydrochloric acid to precipitate a red oily substance. After removing the supernatant, the oil was dissolved in ethyl acetate and dried over sodium sulfate, and then the solvent was distilled off to obtain a red oil. The obtained oil was purified by silica gel column chromatography to obtain 4.21 g of oily exemplary compound (17).

Various forms of the photosensitive member are known, and any of them can be used. For example, there is one in which a photosensitive layer comprising a charge generating substance, a charge transporting substance, and a film-forming binder resin is provided on a conductive support. Further, a laminated photoreceptor in which a charge generation layer composed of a charge generation substance and a binder resin and a charge transport layer composed of a charge transport substance and a binder resin are provided on a conductive support is also known. . Either of the charge generation layer and the charge transport layer may be an upper layer. In addition, if necessary, an undercoat layer is provided between the conductive support and the photosensitive layer, an overcoat layer is provided on the surface of the photosensitive member, and in the case of a laminated photosensitive member, an intermediate layer is provided between the charge generation layer and the charge transport layer. Can also be provided. As a support for producing a photoreceptor using the compound of the present invention, a metal drum,
A metal plate, a paper subjected to conductive processing, a plastic film sheet, a drum-shaped or belt-shaped support, and the like are used.

As the film-forming binder resin used for forming the photosensitive layer on the support, there are various resins depending on the field of use. For example, for photoreceptors for copying, polystyrene resin, polyvinyl acetal resin, polysulfone resin, polycarbonate resin, vinyl acetate
Crotonic acid copolymer resin, polyester resin, polyphenylene oxide resin, polyarylate resin, alkyd resin, acrylic resin, methacrylic resin, phenoxy resin and the like. Among these, polystyrene resin, polyvinyl acetal resin, polycarbonate resin, polyester resin, polyarylate resin, and the like are excellent in potential characteristics as a photoconductor. Also, these resins are
One type or a mixture of two or more types may be used alone or as a copolymer. The amount of these binder resins added to the photoconductive compound is preferably from 10 to 1000% by weight, more preferably from 50 to 500% by weight.

In the case of a laminate type photoreceptor, these resins contained in the charge generation layer are 10 to 50 with respect to the charge generation substance.
0% by weight is preferable, and 50 to 150% by weight is more preferable. If the ratio of the resin is too high, the charge generation efficiency is lowered, and if the ratio of the resin is too low, there is a problem in film formability. Further, the content of these resins contained in the charge transport layer is preferably from 20 to 1,000% by weight, more preferably from 50 to 500% by weight, based on the charge transport material. If the ratio of the resin is too high, the sensitivity is lowered, and if the ratio of the resin is too low, the repetition characteristics may be deteriorated or the coating film may be damaged.

Among these resins, tension, bending,
Some have weak mechanical strength such as compression. To improve this property, substances which impart plasticity can be added. Specifically, phthalic acid esters (eg, DOP, DOP
BP, etc.), phosphate esters (eg, TCP, TOP
Etc.), sebacic esters, adipic esters, nitrile rubbers, chlorinated hydrocarbons and the like. If these substances are added unnecessarily, they adversely affect the electrophotographic properties. Therefore, the ratio is preferably 20% or less based on the binder resin.

In addition, as an additive to the photoreceptor, a leveling agent or the like for improving coating properties, such as an antioxidant or an anti-curl agent, can be added as needed.

The compound represented by the general formula (1) can be used in combination with another charge transporting substance. The charge transport materials include a hole transport material and an electron transport material. Examples of the former include oxadiazoles disclosed in JP-B-34-5466 and JP-B-45-555.
JP, JP-B-52-4188, etc., pyrazolines, etc .;
Examples thereof include hydrazones disclosed in JP-B-55-42380, oxadiazoles disclosed in JP-A-56-123544 and the like. On the other hand, examples of electron transporting substances include chloranil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,4
7-trinitro-9-fluorenone, 2,4,5,7-
Tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 1,3,7-trinitrodibenzothiophene, 1,3,7-trinitrodibenzothiophene- 5,
5-dioxide and the like. These charge transport materials can be used alone or in combination of two or more.

The photoreceptor of the present invention may contain a certain kind of electron-withdrawing compound as a sensitizer for further enhancing the sensitizing effect. Examples of the electron withdrawing compound include 2,3-dichloro-1,4-naphthoquinone,
Quinones such as -nitroanthraquinone, 1-chloro-5-nitroanthraquinone, 2-chloroanthraquinone and phenanthrenequinone, aldehydes such as 4-nitrobenzaldehyde, 9-benzoylanthracene, indandione, 3,5-dinitrobenzophenone and 3 ,
Ketones such as 3 ', 5,5'-tetranitrobenzophenone, acid anhydrides such as phthalic anhydride and 4-chloronaphthalic anhydride, terephthalmalononitrile, 9-anthrylmethylidenemalononitrile, 4-nitrobenzal Cyano compounds such as malononitrile, 4- (p-nitrobenzoyloxy) benzalmalononitrile, 3-benzalphthalide, 3- (α-cyano-p-nitrobenzal) phthalide, 3- (α-cyano-p-nitrobenzal)- 4,
Phthalides such as 5,6,7-tetrachlorophthalide and the like can be mentioned.

The organic photoconductive material of the present invention is dissolved or dispersed in an appropriate solvent together with the above-mentioned various additives depending on the form of the photoreceptor, and the coating solution is coated on the above-mentioned conductive support. And dried to produce a photoreceptor.

Examples of the coating solvent include halogenated hydrocarbons such as chloroform, dichloroethane, dichloromethane, trichloroethane, trichloroethylene, chlorobenzene and dichlorobenzene, aromatic hydrocarbons such as benzene, toluene and xylene, dioxane, tetrahydrofuran, methyl cellosolve, ethyl cellosolve, and the like. Ether solvents such as ethylene glycol dimethyl ether, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, methyl isopropyl ketone and cyclohexanone, ester solvents such as ethyl acetate, methyl formate, methyl cellosolve acetate, N, N-dimethylformamide, acetonitrile; Non-protonic polar solvents such as N-methylpyrrolidone and dimethyl sulfoxide and alcohol solvents can be exemplified. These solvents can be used alone or as a mixed solvent of two or more kinds.

[0095]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 1 part by weight of X-type metal-free phthalocyanine and 1 part by weight of a polyester resin (Vylon 220 manufactured by Toyobo) were mixed with 1 part by weight of dioxane.
And mixed with glass beads in a paint conditioner for 3 hours. The dispersion thus obtained was applied on an aluminum-evaporated polyester using an applicator and dried to form a charge generation layer having a thickness of about 0.2 μm. Next, a stilbene compound (exemplary compound (2)) is
Polyarylate resin (U-polymer manufactured by Unitika) and 1:
1 by weight, and 10 parts by weight of dichloroethane as a solvent.
% Solution was prepared and applied on the above-mentioned charge generation layer with an applicator to form a charge transport layer having a thickness of about 20 μm.

The electrophotographic characteristics of the laminated photoreceptor thus manufactured were evaluated using an electrostatic recording tester (SP-428, manufactured by Kawaguchi Electric Co., Ltd.). Measurement conditions: applied voltage −6 kV, static No. 3 (turntable rotation speed mode: 10 m / min). As a result, the charging potential (Vo) was -760 V, and the half-exposure amount (E1 / 2)
Showed a high sensitivity value of 1.0 lux / sec.

Further, the same apparatus was used to evaluate characteristics for repeated use in which charge-discharge (discharge light: white light, 400 lux × 1 second irradiation) was performed in one cycle. 5000
The change in the charged potential due to the repetition of
The 5000th charging potential (Vo) was -740V, compared to the charging potential (Vo) of -760V at the time of charging, and showed stable characteristics without a decrease in potential due to repetition. The first half-exposure dose (E1 / 2) was 1.0 lux / sec, whereas the 5000th half-exposure dose (E1 / 2).
Showed excellent characteristics without change, which was 1.1 lux / sec.

Examples 2 to 18 In place of the exemplified compound (2) of Example 1, each of Table 1 was used.
A photoreceptor was prepared in the same manner as in Example 1 except that the stilbene compound shown in (1) was used, and its characteristics were evaluated. Table 1 shows the results.

[0100]

[Table 1]

Examples 19 to 36 The procedure of Example 1 was repeated, except that the phthalocyanines and stilbene compounds shown in Table 2 were used instead of the X-type metal-free phthalocyanine of Example 1 and Exemplified Compound (2). A body was prepared and its properties were evaluated. Table 2 shows the results
Shown in However, the crystal forms of the phthalocyanines used in Examples 32 to 36 are as shown in Table 3.

[0102]

[Table 2]

[0103]

[Table 3]

Example 37 One part by weight of X-type metal-free phthalocyanine and 40 parts by weight of tetrahydrofuran were dispersed together with glass beads for 4 hours by a paint conditioner. To the dispersion thus obtained, 2.5 parts of a stilbene compound (exemplary compound (2)) was added.
Parts by weight, 10 parts by weight of a polycarbonate resin (PCZ-200; manufactured by Mitsubishi Gas Chemical) and 60 parts by weight of tetrahydrofuran were added, and after a further 30 minutes of dispersing treatment with a paint conditioner, the mixture was applied on an aluminum-evaporated polyester with an applicator. Thus, a photoreceptor having a thickness of about 15 μm was formed. The electrophotographic characteristics of this photoreceptor were evaluated in the same manner as in Example 1. However, only the applied voltage was changed to +5 kV. As a result, the first charging potential (Vo) 300
V, half-exposure (E1 / 2) 1.1 lux / sec, 50
The charge potential (Vo) after repeated 00 times and the half-decrease exposure amount (E1 / 2) were 1.1 lux / sec, showing excellent characteristics with high sensitivity and little change.

Examples 38 to 54 A photoconductor was prepared in the same manner as in Example 37 except that the stilbene compounds shown in Table 4 were used instead of the compound (2) of Example 37, and the characteristics were evaluated. did. Table 4 shows the results.

[0106]

[Table 4]

Examples 55 to 72 In the same manner as in Example 37, except that the phthalocyanines and stilbene compounds shown in Table 5 were used instead of the X-type metal-free phthalocyanine and Exemplified Compound (2) in Example 37, respectively. A body was prepared and its properties were evaluated. Table 5 shows the results. However, the crystal forms of the phthalocyanines used in Examples 68 to 72 are as shown in Table 6.

[0108]

[Table 5]

[0109]

[Table 6]

Comparative Example 1 A photoconductor was prepared in the same manner as in Example 1 except that the following comparative compound (173) was used instead of the exemplary compound (2) as the charge transporting substance, and the characteristics were evaluated. As a result, the first charging potential (Vo) was -780 V, and the half-exposure amount (E1
/ 2) has a low sensitivity of 3.2 lux-seconds and is 500
The 0th charging potential (Vo) was -425 V, the half-life exposure amount (E1 / 2) was 3.0 lux / sec, and a significant decrease in potential due to repetition was observed.

Comparative Example 2 A photoconductor was prepared and the characteristics were evaluated in the same manner as in Example 1, except that the following comparative compound (174) was used instead of the exemplary compound (2) as the charge transporting substance. As a result, the first charging potential (Vo) was -750 V, and the half-exposure amount (E1 /
2) was a relatively good result of 1.9 lux seconds, but the 5000th charging potential (Vo) was −210 V, and the half-life exposure amount (E1 / 2) was 2.0 lux seconds. A significant decrease in potential due to repetition was observed.

Comparative Example 3 A photoconductor was prepared and the characteristics were evaluated in the same manner as in Example 1, except that the following comparative compound (175) was used instead of the X-type metal-free phthalocyanine as the charge generating substance. As a result, the charging potential (Vo) is -740 V, and the half-exposure amount (E1
/ 2) was 3.0 lux · sec, which was insufficient sensitivity.

Comparative Example 4 A photoreceptor was prepared and evaluated in the same manner as in Example 1, except that the following comparative compound (176) was used in place of the X-type metal-free phthalocyanine as the charge generating substance. As a result, the first charging potential (Vo) was -790 V and the half-life exposure amount (E1 / 2) was 1.8 lux / sec, which were relatively good results. -2
At 20 V, the half-life exposure amount (E1 / 2) was 1.9 lux / sec, and a significant decrease in potential due to repetition was observed.

Comparative Example 5 A photoconductor was prepared and the characteristics were evaluated in the same manner as in Example 37, except that the following comparative compound (173) was used instead of the exemplary compound (2) as the charge transporting substance. As a result, the first charging potential (Vo) was 300 V, and the half-exposure amount (E1 /
2) has a low sensitivity of 4.1 lux-seconds and 5000
The second charging potential (Vo) was 125 V, and the half-exposure amount (E1
/ 2) was 4.1 lux · sec, and a significant decrease in potential due to repetition was observed.

Comparative Example 6 A photoconductor was prepared and the characteristics were evaluated in the same manner as in Example 37, except that the following comparative compound (174) was used instead of the exemplary compound (2) as the charge transporting substance. As a result, the first charging potential (Vo) was 250 V, and the half-exposure amount (E1 /
2) was a relatively good result of 2.0 lux seconds, but the 5000th charging potential (Vo) was 110 V, the half-life exposure amount (E1 / 2) was 4.2 lux seconds, and the repetition was repeated. Caused a significant decrease in potential and a decrease in sensitivity.

Comparative Example 7 Example 37 was repeated except that the following comparative compound (175) was used in place of the X-type metal-free phthalocyanine as the charge generating substance.
A photoreceptor was prepared in the same manner as described above, and its characteristics were evaluated. As a result, the charging potential (Vo) was 200 V, and the half-exposure amount (E1
/ 2) was 5.7 lux / sec, which was insufficient sensitivity.

Comparative Example 8 Example 37 was repeated except that the following comparative compound (176) was used instead of the X-type metal-free phthalocyanine as the charge generating substance.
A photoreceptor was prepared in the same manner as described above, and its characteristics were evaluated. As a result, the charging potential (Vo) was 200 V, and the half-exposure amount (E1
/ 2) was 5.2 lux-seconds, which was insufficient sensitivity.

[0118]

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[0119]

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[0120]

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[0121]

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[0122]

As is clear from the above, according to the present invention, high sensitivity can be obtained by using a phthalocyanine as a charge generating substance as an organic photoconductive material and a stilbene compound represented by the general formula (1) as a charge transporting substance. Thus, an electrophotographic photosensitive member having high durability can be provided.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction spectrum of titanyloxyphthalocyanine (β type) obtained in Synthesis Example 1.

FIG. 2 is an IR spectrum diagram of titanyloxyphthalocyanine (β type) obtained in Synthesis Example 1.

FIG. 3 is an X-ray diffraction spectrum of titanyloxyphthalocyanine (amorphous) obtained in Synthesis Example 2.

FIG. 4 is an X-ray diffraction spectrum of titanyloxyphthalocyanine (Y type) obtained in Synthesis Example 3.

FIG. 5 is an X-ray diffraction spectrum of X-type metal-free phthalocyanine.

FIG. 6 is an X-ray diffraction spectrum of τ-type titanyloxyphthalocyanine.

FIG. 7 is an X-ray diffraction spectrum of m-type titanyloxyphthalocyanine.

FIG. 8 is an X-ray diffraction spectrum of diphenoxyphthalocyanine.

Claims (10)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer containing a charge-generating substance and a charge-transporting substance as constituents on a conductive support, wherein a phthalocyanine is used as the charge-generating substance and An electrophotographic photosensitive member comprising a stilbene compound represented by the formula: Embedded image (In the general formula (1), R ₁ , R ₂ , R ₃ , and R ₄ each represent a hydrogen atom or an alkyl group which may have a substituent, and R ₅ may have a substituent. R ₆ represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group, an aralkyl group or a heterocyclic group, and R ₇ represents a hydrogen atom or a substituent. And R ₈ represents a hydrogen atom, an alkyl group or an aryl group which may have a substituent, and A has a substituent. And p and q each represent an integer of 0 or 1. Also, n is 1 or 2, m is 0 or 1, and n and m satisfy n + m = 2.) 2. The phthalocyanines according to claim 1, wherein the phthalocyanines are metal-free phthalocyanines, titanyloxy phthalocyanines, copper phthalocyanines, aluminum phthalocyanines, germanium phthalocyanines, chlorogallium phthalocyanines, chloroindium phthalocyanines,
Magnesium phthalocyanines, chloroaluminum phthalocyanines, tin phthalocyanines, vanadyl oxyphthalocyanines, gallium phthalocyanines, zinc phthalocyanines, cobalt phthalocyanines, nickel phthalocyanines, hydroxygallium phthalocyanines, dichlorotitanyl phthalocyanines, diphenoxygermanium phthalocyanines, An electrophotographic photosensitive member comprising at least one selected from metal-free naphthalocyanines, aluminum naphthalocyanines, and titanyloxynaphthalocyanines. 3. The phthalocyanine according to claim 2, wherein the metal-free phthalocyanine has a Bragg angle (2θ ± 0.2 °) with respect to X-rays of CuKα1.541 angstroms of 7.6 °, 9.2 °, 1
Metal-free phthalocyanine (τ-type metal-free phthalocyanine) having an X-ray diffraction spectrum showing major peaks at 6.8 °, 17.4 °, 20.4 °, 20.9 °, 7.5 °,
9.1 °, 16.8 °, 17.3 °, 20.3 °, 2
Metal-free phthalocyanine (τ′-type metal-free phthalocyanine) having an X-ray diffraction spectrum showing main peaks at 0.8 °, 21.4 °, and 27.4 °, 7.5 °, 9.1
Metal-free phthalocyanine (X-type metal-free phthalocyanine) having an X-ray diffraction spectrum showing main peaks at °, 16.7 °, 17.3 °, and 22.3 °, 7.6 °, 9.2
°, 16.8 °, 17.4 °, 28.5 ° or 7.
6 °, 9.2 °, 16.8 °, 17.4 °, 21.5 °
Metal-free phthalocyanine (η-type metal-free phthalocyanine) having an X-ray diffraction spectrum showing major peaks at 7.5 °, 9.1 °, 16.8 °, 17.3 °, 2
0.3 °, 20.8 °, 21.4 °, 27.4 ° or 7.5 °, 9.1 °, 16.8 °, 17.3 °, 2
0.3 °, 20.8 °, 21.4 °, 22.1 °, 2
An electrophotographic photosensitive member, which is a metal-free phthalocyanine (η'-type metal-free phthalocyanine) having an X-ray diffraction spectrum showing main peaks at 7.4 ° and 28.5 °. 4. The phthalocyanine in claim 2 is a titanyloxyphthalocyanine, and the titanyloxyphthalocyanine has a Bragg angle (2θ ± 0.2 °) with respect to X-ray of CuKα1.541 angstroms of 7.5.
°, 12.3 °, 16.3 °, 25.3 °, 28.7 °
Titanyloxyphthalocyanine (α-type titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 9.3 °, 10.6 °, 13.2 °, 1
5.1 °, 15.7 °, 16.1 °, 20.8 °, 2
Titanyloxyphthalocyanine (β-type titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 3.3 °, 26.3 ° and 27.1 °, 7.0
°, 15.6 °, 23.4 °, 25.5 °, titanyloxyphthalocyanine having an X-ray diffraction spectrum showing main peaks (C-type titanyloxyphthalocyanine),
Titanyloxyphthalocyanine (m-type titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 6.9 °, 15.5 ° and 23.4 °, 9.5
°, 9.7 °, 11.7 °, 15.0 °, 23.5 °,
Titanyloxyphthalocyanine (Y) having an X-ray diffraction spectrum showing major peaks at 24.1 ° and 27.3 °
Type titanyloxyphthalocyanine), 7.3 °, 17.
Titanyloxyphthalocyanine (γ-type titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 7 °, 24.0 °, 27.2 °, 28.6 °, 9.0 °, 14.2 °, 23.9 °, 27.1 °
Titanyloxyphthalocyanine (type I titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing major peaks at 7.4 °, 11.0 °, 17.9 °, 2
Titanyloxyphthalocyanine (E-form titanyloxyphthalocyanine) having an X-ray diffraction spectrum showing main peaks at 0.1 °, 26.5 °, and 29.0 °, or an amorphous type having no distinct peak. An electrophotographic photoreceptor, which is titanyloxyphthalocyanine. 5. The electrophotographic photoreceptor according to claim 2, wherein the phthalocyanines are copper phthalocyanines, and the copper phthalocyanines are ε-type copper phthalocyanines or β-type copper phthalocyanines. 6. The phthalocyanine according to claim 2, which is a chloroaluminum phthalocyanine, and the chloroaluminum phthalocyanine has a Bragg angle (2θ ± 0.2 °) with respect to X-rays of CuKα1.541 angstroms.
Is a chloroaluminum phthalocyanine having an X-ray diffraction spectrum showing major peaks at 6.7 °, 11.2 °, 16.7 ° and 25.6 °, an X-ray diffraction showing major peak at 25.5 ° Chloroaluminum phthalocyanine having a spectrum, or 6.5 °, 11.1 °, 1
3.7 °, 17.0 °, 22.0 °, 23.0 °, 2
An electrophotographic photoreceptor comprising chloroaluminum phthalocyanine having an X-ray diffraction spectrum showing main peaks at 4.1 ° and 25.7 °. 7. The phthalocyanine of claim 2 is a chloroindium phthalocyanine, and the chloroindium phthalocyanine has a Bragg angle (2θ ± 0.2 °) with respect to X-rays of CuKα1.541 angstroms.
X showing major peaks at 4 °, 16.7 ° and 27.8 °
An electrophotographic photoreceptor comprising chloroindium phthalocyanine having a line diffraction spectrum. 8. The phthalocyanine according to claim 2, wherein the vanadyloxyphthalocyanine has a Bragg angle (2θ ± 0.2 °) with respect to X-rays of CuKα1.541 angstroms of the vanadyloxyphthalocyanine, which is 9.3.
°, 10.7 °, 13.1 °, 15.1 °, 15.7
°, 16.1 °, 20.7 °, 23.3 °, 26.2
°, vanadyloxyphthalocyanine having an X-ray diffraction spectrum showing a major peak at 27.1 °, 7.5 °,
Vanadyloxyphthalocyanine having an X-ray diffraction spectrum showing major peaks at 24.2 °, 27.7 °, 28.6 °, 14.3 °, 18.0 °, 24.1 °, 2
An electrophotographic photosensitive member comprising vanadyloxyphthalocyanine having an X-ray diffraction spectrum showing a main peak at 7.3 ° or amorphous vanadyloxyphthalocyanine having no clear peak. 9. The phthalocyanine according to claim 2, which is a chlorogallium phthalocyanine, wherein the chlorogallium phthalocyanine has a Bragg angle (2θ ± 0.2 °) of X-ray of CuKα1.541 angstroms of 7.4.
An electrophotographic photoreceptor comprising chlorogallium phthalocyanine having an X-ray diffraction spectrum showing main peaks at °, 16.6 °, 25.5 °, and 28.3 °. 10. The phthalocyanine according to claim 2, wherein the gallium phthalocyanine is a hydroxygallium phthalocyanine, and the hydroxygallium phthalocyanine has a Bragg angle (2θ ± 0.2 °) with respect to X-rays of CuKα1.541 angstroms.
Are 7.5 °, 9.9 °, 12.5 °, 16.3 °, 1
Hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing major peaks at 8.6 °, 25.1 °, 28.3 °, 7.7 °, 16.5 °, 25.1 °, 2
Hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing a major peak at 6.6 °, 7.9 °, 1
Hydroxygallium phthalocyanine with X-ray diffraction spectra showing major peaks at 6.5 °, 24.4 °, 27.6 °, 7.0 °, 7.5 °, 10.5 °, 11.
7 °, 12.7 °, 17.3 °, 18.1 °, 24.5
Hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing major peaks at °, 26.2 °, 27.1 °, 6.8 °, 12.8 °, 15.8 °, 26.0 °
Hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing a major peak at 7.4 °, 9.
An electrophotographic photosensitive member comprising hydroxygallium phthalocyanine having an X-ray diffraction spectrum showing main peaks at 9 °, 25.0 °, 26.2 °, and 28.2 °.