JPH10123733A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrophotographic photoreceptor having high sensitivity and high durability by forming a photosensitive layer contg. a specified metallocene deriv. on an electrically conductive substrate. SOLUTION: A photosensitive layer contg. a metallocene deriv. represented by formula I is formed on an electrically conductive substrate. In the formula I, each of R1a -R1d and R2a -R2d is H, a halogen, etc., M is a metallic atom and each of X1 and X2 is a group represented by formula II or H but X1 and X2 are not simultaneously H. In the formula II, (i) is an integer of 0-4, each of R3 -R7 is H, an alkyl which may have a substituent, etc., R6 and R7 may form a carbocyclic or heterocyclic group by condensation, and when one of R6 and R7 is H or an alkyl, the other is an aryl which may have a substituent or a heterocyclic group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member. More specifically, the present invention relates to a very high-sensitivity and high-performance electrophotographic photosensitive member having a photosensitive layer containing an organic photoconductive substance.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive substances such as selenium, cadmium sulfide, and zinc oxide have been widely used for a photosensitive layer of an electrophotographic photosensitive member. However, selenium and cadmium sulfide need to be recovered as poisons, selenium has poor heat resistance for crystallization by heat, cadmium sulfide and zinc oxide have poor moisture resistance, and zinc oxide has no printing durability. Therefore, efforts have been made to develop new photoconductors. Recently, studies have been made on the use of organic photoconductive materials for the photosensitive layer of an electrophotographic photoreceptor, and some of them have been put to practical use. Organic photoconductive materials are lighter in weight, easier to form films, easier to manufacture photoconductors, and less polluting than materials that can produce transparent photoconductors, compared to inorganic ones. And so on.

[0003] Recently, a so-called function-separated type photoreceptor in which the functions of generating and transferring charge carriers are shared by different compounds, which is effective for increasing the sensitivity, has become the mainstream of development. Has been put into practical use. As the charge carrier transport medium, there are a case where a polymer photoconductive compound such as polyvinyl carbazole is used and a case where a low molecular weight photoconductive compound is dispersed and dissolved in a binder polymer.

[0004]

In particular, organic low-molecular-weight photoconductive compounds can be easily selected from polymers having excellent film properties, flexibility, adhesiveness, etc. as binders, so that mechanical properties can be easily obtained. (JP-A-60-196767, JP-A-60-196767)
JP-A-218652, JP-A-60-233156, JP-A-63-48552, JP-A-1-267
552, Japanese Patent Publication No. 3-39306,
JP-A-1113459, JP-A-3-123358, JP-A-3-149560, JP-A-6-273
950, JP-A-62-36674, JP-A-7-036363, JP-A-6-11854, and JP-A-63-48553. However,
It has been difficult to find a compound suitable for producing a highly sensitive photoreceptor.

[0005] Furthermore, in the constant demand for higher sensitivity,
In terms of electrical characteristics, there are various problems such as insufficient residual potential, poor photo-responsibility, deterioration of charging property when used repeatedly, and accumulation of residual potential. A technique of using a combination of hydrazone compounds to prevent a rise in residual potential without significantly impairing other characteristics of the photoreceptor (Japanese Patent Application Laid-Open No. 61-134767) has been reported. However, the balance of the characteristics is not always sufficient, and a technique for improving the characteristics of the entire photoreceptor in a well-balanced manner has been demanded. Further, semiconductor lasers have been actively applied as light sources in the field of printers. In this case, since the wavelength of the light source is around 800 nm, a photosensitive material having high sensitivity to long wavelength light around 800 nm is used. Development of the body is strongly desired.

A material meeting this purpose is disclosed in
-49544, JP-A-59-214034, JP-A-61-109056, JP-A-61-1
No. 71771, JP-A-61-217050,
JP-A-61-239248, JP-A-62-670
No. 94, JP-A-62-134651, JP-A-62-275272, JP-A-63-198067
JP-A-63-198068, JP-A-63-198068
JP-A-210942, JP-A-63-218768 and the like, and various oxytitanium phthalocyanines each having a crystal type suitable as a material for an electrophotographic photosensitive member are known. However, there has been a demand for an electrophotographic photoreceptor having high sensitivity to long-wavelength light and excellent other electrical characteristics.

The present invention has been made to solve the above-mentioned problems, and a first object of the present invention is to provide an electrophotographic photosensitive member having high sensitivity and high durability. The second object is an electrophotographic photoreceptor having high sensitivity, a sufficiently low residual potential even when the film thickness is increased, a small variation in characteristics even when used repeatedly, and an extremely excellent durability. Is to provide. A third object of the present invention is to provide a balanced electrophotographic photoreceptor that has high sensitivity even at a long wavelength of about 800 nm and has good chargeability, dark decay, and residual potential.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies on organic low-molecular-weight photoconductive compounds that can satisfy these objects, and have found that a specific metallocene derivative is suitable. I have reached. That is, the gist of the present invention is that the following general formula [1]

[0009]

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(In the general formula [1], R _1a , R _1b , R _1c , R
_1d , R _2a , R _2b , R _2c and R _2d each have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, and a substituent A silyl group, a phosphino group optionally having a substituent, an aryl group optionally having a substituent, and a heterocyclic group optionally having a substituent, which may be the same or different from each other. M often represents a metal atom, and in the general formula [1], X ₁ and X ₂
Is the following general formula [2]

[0011]

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(In the general formula [2], i represents an integer of 0 to 4, and R ₃ , R ₄ , R ₅ , R ₆ and R ₇ each represent
A hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, a cyano group, an aryl group which may have a substituent, or a hetero group which may have a substituent Represents a cyclic group, which may be the same or different, or a pair consisting of R ₆ and R ₇ may be fused to form a carbocyclic group or a heterocyclic group, provided that R ₆ and R _{In the} pair consisting of ₇ , when either one is a hydrogen atom or an alkyl group, the other is an aryl group which may have a substituent or a heterocyclic group which may have a substituent. ) Or a hydrogen atom, and X ₁ , X
₂ may be the same or different. Where X
₁ and X ₂ are not simultaneously hydrogen atoms. The present invention relates to an electrophotographic photoreceptor having a photoreceptor containing a metallocene derivative represented by the formula (1).

Hereinafter, the present invention will be described in detail. The electrophotographic photoreceptor of the present invention contains a metallocene derivative represented by the general formula [1] in a photosensitive layer. The general formula [1]
In the formula, M represents a metal atom. It is preferably an iron atom or a ruthenium atom, and more preferably an iron atom. In the general formula [1], R _1a , R _1b , R _1c , R _1d , R _2a , R _2b ,
R _2c and R _2d are each a hydrogen atom; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; an alkyl group such as a methyl group, an ethyl group, a propyl and an isopropyl group; a methoxy group and an ethoxy group. An alkoxy group; an aryl group such as a phenyl group, a naphthyl group and a pyrenyl group; a heterocyclic group such as a furyl group and a thienyl group; a trialkylsilyl group such as a trimethylsilyl group; and a diarylphosphino group such as a diphenylphosphino group. May be the same or different from each other; particularly, a hydrogen atom, a methyl group and a phenyl group are preferable.

These alkyl group, alkoxy group, aryl group and heterocyclic group may have a substituent, such as a hydroxyl group; a fluorine atom, a chlorine atom, a bromine atom,
A halogen atom such as an iodine atom; a methyl group, an ethyl group,
Alkyl groups such as propyl group, butyl group, hexyl group, and isopropyl group; alkoxy groups such as methoxy group, ethoxy group, and propyloxy group: aralkyl groups such as allyl group, benzyl group, naphthylmethyl group, and phenethyl group; Aryloxy groups such as toloxy groups; arylalkoxy groups such as benzyloxy groups and phenethyloxy groups; aryl groups such as phenyl groups and naphthyl groups; arylvinyl groups such as styryl groups and naphthylvinyl groups; acetyl groups and benzoyl groups Acyl group; dialkylamino group such as dimethylamino group and diethylamino group; diarylamino group such as diphenylamino group and dinaphthylamino group;
A diaralkylamino group such as a dibenzylamino group or a diphenethylamino group, a diheterocyclic amino group such as a dipyridylamino group or a dithienylamino group; a diallylamino group, or a disubstitution obtained by combining the above-mentioned amino group substituents A substituted amino group such as an amino group; these substituents are condensed with each other to form a carbon ring group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group, etc .; an oxygen atom And a heterocyclic group containing a sulfur atom, a nitrogen atom and the like.

In the general formula [1], X ₁ and X ₂ each represent the following general formula [2]

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Or a hydrogen atom, X ₁ ,
X ₂ may be the same or different. However, X ₁ and X ₂ are not simultaneously hydrogen atoms. I in the general formula [2] represents an integer of 0 to 4, and R ₃ , R ₄ , R ₅ , R
₆ and R ₇ are each a hydrogen atom; a cyano group; an alkyl group such as a methyl group, an ethyl group and a propyl group; an alkoxy group such as a methoxy group, an ethoxy group and a propyloxy group;
Aryl groups such as phenyl group, naphthyl group, anthracenyl group and pyrenyl group; and heterocyclic groups such as pyrrolyl group, thienyl group, furyl group, carbazolyl group and the like.
They may be the same or different. The heterocyclic group is particularly preferably a heterocyclic group having aromaticity.

These alkyl group, aryl group and heterocyclic group may have a substituent. Examples of the substituent include a hydroxyl group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; Alkyl groups such as groups, ethyl groups, propyl groups, butyl groups, hexyl groups, and isopropyl groups;
Alkoxy groups such as methoxy group, ethoxy group and propyloxy group: aralkyl groups such as allyl group, benzyl group, naphthylmethyl group and phenethyl group; aryloxy groups such as phenoxy group and toloxy group; benzyloxy group and phenethyloxy group An arylalkoxy group; a phenyl group,
Aryl groups such as naphthyl group; arylvinyl groups such as styryl group and naphthylvinyl group; acyl groups such as acetyl group and benzoyl group; dialkylamino groups such as dimethylamino group and diethylamino group; diphenylamino group and dinaphthylamino group A diarylamino group; a diaralkylamino group such as a dibenzylamino group or a diphenethylamino group;
Diheterocyclic amino groups such as dipyridylamino group and dithienylamino group; substituted amino groups such as diallylamino group, and disubstituted amino group obtained by combining the above-mentioned amino group substituents; Are fused to each other to form a carbon ring group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group, etc .; an oxygen atom,
A heterocyclic group containing a sulfur atom, a nitrogen atom and the like may be formed.

When i is 2 or more, R ₃ and R ₄ may be the same or different, or R ₆ and R 4
_The pair consisting of ₇ is a condensed carbon ring group via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group, etc .; a heterocyclic group containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. May be further formed, and those rings may have a substituent.As the substituent, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group,
Alkyl groups such as isopropyl group; aryl groups such as phenyl group and naphthyl group; cyano group, alkoxycarbonyl group, aryloxycarbonyl group and nitro group; halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom. can give. However, when one of the pair consisting of R ₆ and R ₇ is a hydrogen atom or an alkyl group, the other is an aryl group or a heterocyclic group. In the following, representative examples of the metallocene derivatives represented by the general formula [1] are shown in Table 1, but these representative examples are given for illustrative purposes only, and the metallocene derivatives used in the present invention are representative of these. It is not limited to the example.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

[0023]

[Table 5]

[0024]

[Table 6]

[0025]

[Table 7]

The metallocene derivative represented by the general formula [1] can be produced by a known method. For example, this is a method in which a known carbonyl introduction reaction is performed using a known metallocene derivative as a raw material, and then a Wittig reaction is performed to obtain a target compound. To elaborate on this method, first,

[0027]

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1) When R ₃ = H In general formulas [3] (in general formulas [3] and [4], M and R
_1a , R _1b , R _1c , R _1d , R _2a , R _2b , R _2c , R _2d , R ₃
Has the same meaning as in general formula [1]. ) Is reacted with a formylating agent such as N, N-dimethylformaldehyde or N-methylformanilide in the presence of phosphorus oxychloride to give an aldehyde represented by the general formula [4]. . A large excess of the formylating agent can be used as a reaction solvent, but an inert solvent such as O-dichlorobenzene and benzene can also be used.

2) R_ThreeIn the case of ≠ H, the metallocene derivative represented by the general formula [3] is converted to aluminum chloride.
Nitrogen in the presence of Lewis acids such as ammonium, iron chloride and zinc chloride
In a solvent such as benzene, dichloromethane, carbon tetrachloride, etc.
General formula Cl-CO-R_ThreeReact with the acid chloride represented by
As a result, a ketone body represented by the general formula [4] is obtained.
You. Next, the obtained aldehyde which is represented by the general formula [4] is obtained.
And N, N-dimethylformamide,
N, N-dimethylacetamide, tetrahydrofuran,
Inactive in the reaction of dioxane, benzene, toluene, etc.
In a known organic solvent, general formula [5] (in general formula [5],
R_Three, R_Four, R_Five, R₆, And R₇Is the general formula [2]
Q has the same meaning as in
Shows halogen atoms such as elemental atoms. Halogen represented by)
Of triphenylphosphine
Or the above halogen compound and trialkoxy phosphorus compound
(R₈O) _ThreeP (R₈Is an alkyl such as a methyl group or a methyl group
Represents a group. ) And Wittig obtained
Reagent and 10 to 200 °, preferably 20 to 100 °
Butyllithium, phenyllithium, sodium
Um methoxide, sodium ethoxide, potassium t-
The reaction is carried out in the presence of a known basic catalyst such as butoxide.
By this, a compound represented by the general formula [6] is obtained.

At this time, any one of a cis-form, a trans-form and a mixture of the cis-form and the trans-form is obtained. (In the following formulas, the general formulas [1] and [6] represent any one of a cis-form, a trans-form and a mixture of a cis-form and a trans-form.) In the case of X ₂ ≠ H, the above formula is further added to [6]. Thus, the target compound [1] can be obtained by performing a carbonyl introduction reaction to synthesize the general formula [7] and then performing a Wittig reaction as described below. In some cases in these reactions, after completion of each step or after completion of all steps, recrystallization purification, reprecipitation purification, sublimation purification, column purification,
It is also possible to obtain a highly purified product by a known purification means such as an adsorbent treatment.

[0031]

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[0032]

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The electrophotographic photoreceptor of the present invention comprises one metallocene derivative represented by the above general formula [1], or
It has a photosensitive layer containing two or more types. The metallocene derivative represented by the general formula [1] exhibits extremely excellent performance as an organic photoconductor. In particular, when used as a charge transport medium, a photosensitive member having high sensitivity and excellent durability can be obtained. Although various forms are known as the form of the photosensitive layer of the electrophotographic photosensitive member, any of the photosensitive layers of the electrophotographic photosensitive member of the present invention may be used.

The photosensitive layer (photoconductive layer) is formed by laminating a charge generating layer and a charge transporting layer in this order, or by laminating the charge generating layer and the charge transporting layer in reverse order. Any configuration such as a so-called dispersion type in which particles of the (generating substance) are dispersed can be used. For example, a photosensitive layer in which a metallocene derivative and, if necessary, a dye or an electron-withdrawing compound serving as a sensitizer are added to a binder, a charge-generating material (photoconductive particles) that generates charge carriers with extremely high efficiency when absorbing light. A photosensitive layer in which a metallocene derivative is added to a binder, a charge transport layer composed of a metallocene derivative and a binder, and a charge generation layer composed of a charge generation material that generates charge carriers with extremely high efficiency when absorbing light or a charge generation layer composed of this and a binder And the like.

These photosensitive layers may be mixed with a metallocene derivative represented by the general formula [1] and other known arylamine compounds, hydrazone compounds, and stilbene compounds having excellent performance as organic photoconductors. Good. In the present invention, when the metallocene derivative represented by the general formula [1] is used in a charge transport layer of a photosensitive layer composed of a charge generation layer and a charge transport layer (charge transfer layer), the sensitivity is particularly high. Thus, a photoreceptor having high durability, a small residual potential, and little variation in surface potential, lowering of sensitivity, accumulation of residual potential, and the like when used repeatedly, and having excellent durability can be obtained.

Specifically, usually, a charge generation material is directly deposited or coated as a dispersion with a binder to form a charge generation layer, on which an organic solvent solution containing the metallocene derivative is cast, or A layered photosensitive material comprising a charge transport layer containing a charge transport material containing the metallocene derivative represented by the general formula [1] by dissolving the metallocene derivative together with a binder or the like and applying a dispersion thereof. The charge generation layer and the charge transport layer may be stacked in reverse order. Further, the charge generating material and the charge transporting material may be a single layer type photoreceptor in which the charge generating material and the charge transporting material are applied to a conductive support in a state of being dispersed and dissolved in a binder.

As the charge generating material, selenium, selenium-
Inorganic photoconductive particles such as tellurium alloy, selenium-arsenic alloy, cadmium sulfide, and amorphous silicon; metal-free phthalocyanine, metal-containing phthalocyanine, perinone-based pigment, thioindigo, quinacridone, perylene-based pigment, anthraquinone-based pigment, and azo-based pigment And organic photoconductive particles such as bisazo pigments, trisazo pigments, tetrakis azo pigments, and cyanine pigments. Further, various organic pigments and dyes such as polycyclic quinone, pyrylium salt, thiopyrylium salt, indigo, anthantrone and pyranthrone can be used. Among them, metals such as metal-free phthalocyanine, copper, indium chloride, gallium chloride, tin, oxytitanium, zinc, and vanadium, or oxides thereof, phthalocyanines coordinated with chloride, monoazo, bisazo, trisazo, and azo such as polyazos Pigments are preferred.

Among them, when a metal-containing and metal-free phthalocyanine is combined with a metallocene derivative represented by the above general formula [1], a photoreceptor having improved sensitivity to laser light can be obtained. In an electrophotographic photoreceptor having at least a photosensitive layer containing a charge generating material and a charge transporting material, the charge generating material may be a black angle (2θ ± 0.2 °) of 27.3 X-ray diffraction spectrum of 27.3.
An electrophotographic photoreceptor containing oxytitanium phthalocyanine showing a main peak at an angle of ° and containing, as the charge transporting material, an arylamine compound represented by the above general formula [1] is preferable. The electrophotographic photoreceptor thus obtained has high sensitivity, low residual potential, high chargeability, and small variation due to repetition, and in particular, good charge stability affecting image density, It can be used as a highly durable photoreceptor. Also, since the sensitivity is high in the range of 750 to 850 nm, it is particularly suitable for a photoreceptor for a semiconductor laser printer.

The oxytitanium phthalocyanine used as the charge generating material has a main peak at 27.3 ° at a black angle (2θ ± 0.2 °) in its X-ray diffraction spectrum. The above-mentioned "main recovery peak" refers to the peak having the highest (highest) intensity in the X-ray recovery spectrum. X-ray powder spectrum of oxytitanium phthalocyanine used, black angle (2θ
The main peak is the rejection peak at 27.3 °. The peak other than the main peak varies depending on detailed conditions. Is less than 50%, from the standpoint of chargeability, sensitivity and the like, as an electrophotographic photoreceptor.

The method for producing the oxytitanium phthalocyanine is not particularly limited, but is produced, for example, by the following method. 1. A method for producing type [II] crystals described in Production Example 1 of JP-A-62-67094. That is, orthophthalodinitrile and a halide of titanium are heated and reacted in an inert organic solvent, and then hydrolyzed. 2 Various types of oxytitanium phthalocyanine were directly converted to sulfuric acid or a compound of the formula R-SO ₃ H (R
Represents an aliphatic or aromatic residue which may have a substituent. Or heat treatment with a mixed solvent of an insoluble organic solvent and water. 3 If desired, previously dissolved in concentrated sulfuric acid and then released into ice water or made amorphous by a known method such as a mechanical grinding method such as a paint shaker, ball mill, sand grind mill, etc., and then heat-treated with the above sulfonated product. Heat treatment is performed with a mixed solvent of an insoluble organic solvent and water. 4. In the case of treatment with the above-mentioned sulfonated product, it can also be produced by using a mechanical grinding method such as a paint shaker, a ball mill, and a sand grind mill instead of the heat treatment.

The oxytitanium phthalocyanine particles exhibiting a main peak at 27.3 ° in the black angle (2θ ± 0.2 °) of the X-ray diffraction spectrum are composed of a binder polymer and other organic photoconductive compounds if necessary. , A dye, an electron-withdrawing compound, and the like are dissolved or dispersed in a solvent, and the thus obtained coating solution is applied and dried to obtain a charge generation layer. For example, the oxytitanium phthalocyanine which shows a main peak at 27.3 ° in the black angle (2θ ± 0.2 °) of the X-ray diffraction spectrum and the black angle (2θ ± 0.2 °) in the X-ray diffraction spectrum 9.3 °, 13.2
Using oxytitanium phthalocyanine, which shows major peaks at 0 °, 26.2 ° and 27.1 °,
Alternatively, the black angle (2θ ±
0.2 °) Oxytitanium phthalocyanine showing a main peak at 27.3 ° and the black angle (2θ ± 0.2 °) of the X-ray diffraction spectrum 8.5 °, 12.2 °, 1
It is preferred to use dichlorotin phthalocyanine which shows major peaks at 3.8 °, 16.9 °, 22.4 °, 28.4 ° and 30.1 °.

Next, in the present invention, dyes that are optionally added include, for example, triphenylmethane dyes such as methyl violet, brilliant green, and crystal violet; thiazine dyes such as methylene blue;
Examples thereof include quinone dyes such as quinizarin, and dianine dyes, and beryllium salts, thiavirylium salts, and benzobrillium salts. Examples of the electron-withdrawing compound which forms a charge transfer complex with the arylamine-based compound include, for example, chloranil, 2,3-dichloro-1,4-naphthoquinone, 1-nitroanthraquinone, 1-chloro-5-nitroanthraquinone, Quinones such as chloroanthraquinone and phenanthrenequinone; aldehydes such as 4-nitrobenzaldehyde; 9-benzoylanthracene, indandione, 3,5-dinitrobenzophenone and 2,4,7-
Ketones such as trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, 3,3 ', 5,5'-tetranitrobenzophenone; acid anhydrides such as phthalic anhydride and 4-chloronaphthalic anhydride; Sinoa compounds such as tetracyanoethylene, terephthalalmalononitrile, 9-anthrylmethylidenemalononitrile, 4-nitrobenzalmalonenitrile, 4- (p-nitrobenzoyloxy) benzalmalononitrile; 3-benzalphthalide, 3- Electron-withdrawing compounds such as phthalides such as (α-cyano-p-nitrobenzal) phthalide.

The charge generation layer in the laminated type photosensitive layer is made of fine particles of these substances, for example, polyester resin, polyvinyl acetate, polyester, polycarbonate, polyvinyl acetoacetal, polyvinyl propional,
It may be used in a dispersion layer of a form bound with various binder resins such as polyvinyl butyral, phenoxy resin, epoxy resin, urethane resin, cellulose ester, cellulose ether and the like. Further, examples of the binder resin include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinyl alcohol, and ethyl vinyl ether, polyamide, and silicon resin. In this case, the charge generating material (charge generating substance) is used in an amount of usually 20 to 2,000 parts by weight, preferably 30 to 500 parts by weight, more preferably 33 to 500 parts by weight, based on 100 parts by weight of the binder resin. The thickness of the charge generation layer is usually 0.05 to 5 μm, preferably 0.1 μm.
To 2 μm, more preferably 0.15 μm to 0.8 μm
m is preferred. Further, the charge generation layer may contain various additives such as a leveling agent, an antioxidant, and a sensitizer for improving applicability, if necessary. Furthermore, the charge generation layer may be a deposited film of the above-described charge generation material.

The particle size of the charge generating material in the case of the dispersion type photosensitive layer must be sufficiently small, and is preferably 1 μm or less, more preferably 0.5 μm or less. The amount of the charge generating material dispersed in the photosensitive layer is, for example, 0.5 to 5
Although it is in the range of 0% by weight, if the amount is too small, sufficient sensitivity cannot be obtained. If the amount is too large, there are adverse effects such as a decrease in chargeability and a decrease in sensitivity. More preferably, the amount is used in the range of 1 to 20% by weight. . The thickness of the dispersion type photosensitive layer is usually 5 to 50 μm, more preferably 10 to 45 μm. Also in this case, a known plasticizer for improving film formability, flexibility, mechanical strength, etc., an additive for suppressing residual potential, a dispersion aid for improving dispersion stability, and a coating property. Leveling agents and surfactants for improvement, for example, silicone oil, fluorinated oil and other additives may be added.

Further, the photosensitive layer of the electrophotographic photoreceptor of the present invention may contain a well-known plasticizer in order to improve film formability, flexibility and mechanical strength. Therefore, examples of the plasticizer to be added to the coating solution include phthalic acid esters, phosphate esters, epoxy compounds, chlorinated paraffins, chlorinated fatty acid esters, and aromatic compounds such as methylnaphthalene. When the arylamine-based compound is used as the charge transporting material in the charge transporting layer, the coating liquid may have the above-described composition, but the photoconductive particles, the dye, and the electron withdrawing compound may be removed or a small amount may be added. . As the charge generation layer in this case, the above-mentioned photoconductive particles and, if necessary, a binder polymer and other organic photoconductive substances, a dye,
Examples thereof include a thin layer formed by applying and drying a coating solution obtained by dissolving or dispersing in a solvent such as an electron-withdrawing compound, or a layer in which the photoconductive particles are formed into a film by means such as vapor deposition.

The photoreceptor thus formed may have, if necessary, improved electrical and mechanical properties such as a barrier layer, an adhesive layer, an intermediate layer such as a blocking layer, a transparent insulating layer or a protective layer. Needless to say, a layer for the above may be provided. As the conductive support on which the photosensitive layer is formed, any of those used for known electrophotographic photosensitive members can be used. Specifically, for example, aluminum,
Drums and sheets made of metal materials such as stainless steel, copper, nickel, etc., laminates of these metal foils, deposited materials, or aluminum, copper, palladium,
Examples include an insulating support such as a polyester film or paper provided with a conductive layer such as tin oxide or indium oxide. Further, a plastic film, a plastic drum, paper, a paper tube, and the like, which are subjected to a conductive treatment by applying a conductive substance such as metal powder, carbon black, copper iodide, and a polymer electrolyte together with an appropriate binder, may be mentioned. Further, a plastic sheet or drum containing a conductive substance such as a metal powder, carbon black, or carbon fiber to become conductive may be used. Further, plastic films and belts which have been subjected to conductive treatment with a conductive metal oxide such as tin oxide or indium oxide may be used. Among them, an endless pipe made of metal such as aluminum is a preferable support. As the barrier layer and the intermediate layer, for example, aluminum anodized film, aluminum oxide, inorganic materials such as aluminum hydroxide, polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, polyamide, etc. Organic layers are used.

The electrophotographic photoreceptor of the present invention is prepared by dissolving the metallocene derivative represented by the above general formula [1] together with a binder in a suitable solvent according to a conventional method, and, if necessary, using a suitable charge generating material, sensitizing infection. Material, an electron-withdrawing compound, another charge transport material, or a coating solution obtained by adding a known additive such as a plasticizer or a pigment onto a conductive support, followed by drying. ~ Several tens of μ, preferably 10 to 45 μ
m, particularly preferably 27 μm or more. In the case of a photosensitive layer comprising a charge generation layer and a charge transport layer, the above-mentioned coating solution is applied on the charge generation layer, or the charge generation layer is placed on the charge transport layer obtained by applying the above coating solution. Can be produced.

Solvents for preparing the coating solution include ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as methylethylkent and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; N, N-dimethylformamide; Acetonitrile, N-methylpyrrolidone,
Aprotic polar solvents such as dimethyl sulfoxide; esters such as ethyl acetate, methyl formate, and methyl cellosolve acetate; solvents that dissolve arylamine compounds such as chlorinated hydrocarbons such as dichloroethane and chloroform. Of course, it is necessary to select a material that dissolves the binder from these.

The binder resin used for the charge transport layer in the case of the laminated photosensitive layer or the binder resin used as the matrix in the case of the dispersed photosensitive layer includes:
Polymers that have good compatibility with the charge transport material and that do not crystallize or charge-separate the charge transport material after forming the coating film, such as styrene, vinyl acetate, vinyl chloride, acrylate, methacrylate, Various polymers such as polymers and copolymers of vinyl compounds such as butadiene, polyvinyl acetal, polycarbonate, polyester carbonate, polysulfone, polyimide, polyphenylene oxide, polyurethane, cellulose ester, cellulose ether, phenoxy resin, silicon resin, and epoxy resin. And partially cured crosslinked products thereof. The amount of the binder used is usually 0.5 to 30 times by weight based on the arylamine-based compound,
It is preferably in the range of 0.7 to 10 times by weight.

The charge transport layer in the case of the laminated type photosensitive layer may contain various additives such as an antioxidant and a sensitizer, and other charge transport materials, if necessary. The thickness of the charge transport layer is usually 10 to 60 μm, preferably 10 to 45 μm.
m, more preferably 27 to 40 μm. As the outermost surface layer, a conventionally known overcoat layer mainly composed of, for example, a thermoplastic or thermosetting polymer may be provided. Usually, the charge transfer layer is formed on the charge generation layer, but the reverse is also possible. As a forming method of each layer, a known method such as sequentially applying a coating solution obtained by dissolving or dispersing a substance to be contained in a layer in a solvent can be applied. In addition to the mechanical strength of the coating,
Various additives for improving durability can be used.

Examples of such additives include well-known plasticizers, various stabilizers, fluidity-imparting agents, and cross-linking agents. Examples of the method for coating the photosensitive layer include a spray coating method, a spiral coating method, a ring coating method, and a dip coating method. Spray coating methods include air spray, airless spray, electrostatic air spray, electrostatic airless spray, rotary atomizing electrostatic spray, hot spray, hot airless spray, etc., but fine particles to obtain a uniform film thickness Degree,
Considering the adhesion efficiency and the like, in a rotary atomizing electrostatic spray, the transfer method disclosed in Japanese Patent Laid-Open Publication No. 1-805198, that is, continuous rotation of a cylindrical work without rotating an axial direction while rotating the work. By conveying the photosensitive member, it is possible to obtain an electrophotographic photosensitive member having high overall deposition efficiency and excellent film thickness uniformity. Examples of the spiral coating method include a method using a liquid injection coating machine or a curtain coating machine disclosed in Japanese Patent Application Laid-Open No. 52-119651, and a method of coating a coating material through a fine opening disclosed in Japanese Patent Application Laid-Open No. 1-231966. Method for continuously flying in a streak shape
No. 193161 discloses a method using a multi-nozzle body.

Hereinafter, the dip coating method will be described. Using the metallocene derivative represented by the aforementioned general formula [1], a binder, a solvent and the like, a suitable total solid content concentration is 25% or more, more preferably 40% or less, and a viscosity is usually 50 centipoise to 300 centipoise. Hereinafter, a coating liquid for forming a charge transport layer having a thickness of preferably 100 to 200 centipoise cheese is prepared. Here, the viscosity of the coating liquid is substantially determined by the type and molecular weight of the binder polymer. However, if the molecular weight is too low, the mechanical strength of the polymer itself is reduced, so the binder polymer has a molecular weight that does not impair the mechanical strength. It is preferred to use The charge transport layer is formed by a dip coating method using the coating solution thus adjusted. Thereafter, the coating film is dried, and the drying temperature and time are preferably adjusted so that necessary and sufficient drying is performed. Drying temperature is usually 100 to 250
° C, preferably 110 to 170 ° C, more preferably 1 to 170 ° C.
It is in the range of 20 to 140C. As a drying method, a hot air dryer, a steam dryer, an infrared dryer, a far infrared dryer, or the like can be used.

[0053]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to the following Production Examples and Examples as long as the gist of the present invention is not exceeded. In the examples, “parts” means “parts by weight”.

[0054]

Embedded image

Ferrocene carboxaldehyde 2.1 g
(10 mmol) and 3.65 g (12 mmol) of diethyl 1,1-diphenylmethylphosphonate in THF 20m
1 g of t-BuOK (15 m
mol) was added in small portions. After stirring for 1 hour, 20 ml of toluene was added and liquid separation was performed. After drying the organic layer and evaporating the solvent under reduced pressure, using silica gel chromatography,
(Developing solvent: toluene: hexane = 1: 1) Purification was performed to obtain 3.1 g (8.5 mmol) of a red solid. Yield: 85% This compound was identified as Compound No. 1 by the following elemental analysis values and infrared absorption spectrum (FIG. 1). It turned out that it is a compound represented by the structural formula of 2.

(Elemental analysis value) (Results of Mass Spectrometry) As C ₂₄ H ₂₀ Fe Mw = 364 Mw ⁺ = 364

(Example 1) In the X-ray diffraction spectrum, the black angle (2θ ± 0.2 °) 9.3 °, 10.6
°, 13.2 °, 15.1 °, 15.7 °, 16.1
°, 20.8 °, 23.3 °, 27.1 ° titanium oxyphthalocyanine pigment showing strong peaks at 1.0 °
Was added to 14 parts of dimethoxyethane, and the mixture was dispersed with a sand grinder.
14 parts of methoxy-4-methyl-2-pentanone (manufactured by Mitsubishi Chemical Corporation) was added to dilute the mixture, and then polyvinyl butyral (trade name: Denkabutyral # 6000-C, manufactured by Denki Kagaku Kogyo Co., Ltd.) was added. 5 parts and 0.5 part of a phenoxy resin (trade name: UCAR (registered trademark) PKHH, manufactured by Union Carbide Co., Ltd.), 6 parts of dimethoxyethane,
It was mixed with a solution of 6 parts of 4-methoxy-4-methyl-2-pentanone dissolved in a mixed solvent to obtain a dispersion. This dispersion was applied on a 75 μm-thick amino film deposited on a polyester film with a wire bar so that the weight after drying was 0.4 g / m ² , and then dried to form a charge generation layer. Formed. On this, 70 parts of the ferrocene derivative produced in Production Example 1 and the polycarbonate resin shown below

[0058]

Embedded image

A coating solution prepared by dissolving 100 parts in a mixed solvent of 585 parts of tetrahydrofuran and 315 parts of dioxane was applied and dried to form a 17 μm-thick charge transport layer, thereby obtaining an electrophotographic photosensitive member. (Example 2) Instead of the titanium oxyphthalocyanine pigment used in Example 1, in the X-ray diffraction spectrum, the black angle (2θ ± 0.2 °) 9.5 °, 27.1
An electrophotographic photoreceptor was obtained in the same manner as in Example 1, except that a titanium oxyphthalocyanine pigment exhibiting strong peaks at 0 ° and 27.3 ° was used. Comparative Example 1 Example 1 was repeated except that the following comparative compound 1 was used in place of the ferrocene compound used in Example 1.
An electrophotographic photoreceptor was obtained in the same manner as described above.

[0060]

Embedded image

Comparative Example 2 An electrophotographic photoreceptor was obtained in the same manner as in Example 1 except that Comparative Compound 2 shown below was used instead of the ferrocene-based compound used in Example 1.

[0062]

Embedded image

Comparative Example 3 An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that Comparative Compound 3 shown below was used instead of the ferrocene compound used in Example 1.

[0064]

Embedded image

Comparative Example 4 An electrophotographic photoreceptor was obtained in the same manner as in Example 1 except that Comparative Compound 4 shown below was used instead of the ferrocene-based compound used in Example 1.

[0066]

Embedded image

The photoreceptors prepared in Examples 1 and 2 and Comparative Examples 1 to 4 were negatively charged by a corona discharge of 50 μA in a dark place, and then 20 lux white light was obtained through a interference filter at 780 nm ( Exposure energy 10μW
/ Cm ² ) was measured as the residual potential when exposed for 9.9 seconds. Table 2 shows the results.

[0068]

[Table 8]

From the results, it can be seen that the photoreceptor of Example 1 has a very excellent value of the residual potential as compared with the photoreceptors of Comparative Examples 1 to 4. Further, for the photoconductor of Example 1,
This operation was repeated 2000 times, but no increase in the residual potential was observed.

[0070]

The photoreceptor for electrophotography of the present invention has a small residual potential which causes fogging, and in particular, has a small amount of light fatigue, so that the residual potential is accumulated due to repeated use, and the fluctuation of the surface potential and sensitivity is small and the durability is small. It has the feature of being excellent in properties.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of a ferrocene derivative obtained in Production Example 1.

Claims (8)

[Claims] 1. A conductive support having the following general formula [1] embedded image (In general formula [1], R _1a , R _1b , R _1c , R _1d , R _2a , R
_2b , R _2c and R _2d each represent a hydrogen atom, a halogen atom,
An alkyl group which may have a substituent, an alkoxy group which may have a substituent, a silyl group which may have a substituent, a phosphino group which may have a substituent, Represents an aryl group or a heterocyclic group which may have a substituent, which may be the same or different, M represents a metal atom, and in the general formula [1], X ₁ and X ₂ represent , Each of the following general formula [2]: (In the general formula [2], i represents an integer of 0 to 4,
R ₃ , R ₄ , R ₅ , R ₆ and R ₇ each have a hydrogen atom, an alkyl group optionally having a substituent, an alkoxy group optionally having a substituent, a cyano group, and a substituent. Represents an aryl group which may be substituted, or a heterocyclic group which may have a substituent, and these may be the same or different from each other, or a pair consisting of R ₆ and R ₇ is fused to form a carbocyclic group or ,
May form a heterocyclic group, provided that, when one of R ₆ and R ₇ is a hydrogen atom or an alkyl group, the other is an aryl group which may have a substituent,
Alternatively, it is a heterocyclic group which may have a substituent. ) Or a hydrogen atom, and X ₁ and X ₂ may be the same or different. However, X ₁ and X ₂ are not simultaneously hydrogen atoms. An electrophotographic photoreceptor comprising a photoreceptor containing a metallocene derivative represented by the following formula: 2. The electrophotographic photosensitive member according to claim 1, wherein M in the general formula [1] represents an iron atom or a ruthenium atom. 3. A conductive support comprising a photosensitive layer containing the above general formula [1] as a charge transporting material and oxytitanium phthalocyanine or a non-metallic phthalocyanine as a charge generating material. The electrophotographic photosensitive member according to claim 1. 4. A conductive support containing the above general formula [1] as a charge transporting material and a black angle (2θ ± 0.2 °) of X-ray diffraction spectrum 27.3 as a charge generating material.
Oxytitanium phthalocyanine showing a main peak at °°, or (2θ ± 0.2 °) 9.3 °, 13.
2. The electrophotographic photoreceptor according to claim 1, further comprising a photosensitive layer containing oxytitanium phthalocyanine showing main peaks at 2 °, 26.2 ° and 27.1 °. 5. The photosensitive layer contains a charge transport material (hereinafter abbreviated as CTM) and a charge generation material (hereinafter abbreviated as CGM).
2. The electrophotographic photoreceptor according to claim 1, wherein M includes the above [1]. 6. A charge generation layer containing CGM (hereinafter abbreviated as CGL) and a charge transport layer containing CTM (hereinafter abbreviated as CTL), wherein the CTL contains the above [1]. Item 2. The electrophotographic photosensitive member according to Item 1. 7. The electrophotographic photoreceptor according to claim 1, wherein the CTL contains the [1] and a binder, and the CGL contains a CGM and a binder. 8. In the photosensitive layer, the CT represented by the above [1] is used.
M and a general formula [X] or [X '] as a coupler
The electrophotographic photosensitive member according to claim 1, comprising a CGM having a substituent represented by the following formula: Embedded image (Wherein, B represents a divalent group of a heterocyclic ring which may have a substituent containing nitrogen, or a divalent group of an aromatic hydrocarbon which may have a substituent, and A contains nitrogen Represents a heterocyclic ring which may have a substituent, or an aromatic hydrocarbon which may have a substituent, and D is condensed with a benzene ring to form an aromatic hydrocarbon ring or a heterocyclic ring. Represents the required divalent group)