JP2000047405A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-sensitivity and high-durability electrophotographic photoreceptor by providing a photosensitive layer containing a specific aryl amine compound on a conductive base. SOLUTION: This electrophotographic photoreceptor is provided with a photosensitive layer containing an aryl amine compound expressed by the formula I on a conductive base, where A-F indicate the benzene ring which may have the substitutional group, Y indicates the bivalent aromatic hydrocarbon residue or the like which may have the substitutional group, R1-R4 indicate each hydrogen atom, cyano group, nitro group, halogen atom or the like, n1 and n2 indicate integers of 1-4 respectively. X1 and X2 indicate each the groups expressed by the formula II and formula III. In the formula II and formula III, n3 and n4 indicate integers of 0-4, and R5-R14 indicate each hydrogen atom, cyano group, nitro group, alkyl group which may have the substitutional group, aryl group which may have the substitutional group, or heterocyclic group which may have the substitutional group respectively.

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, and selenium crystallizes due to heat and therefore has poor heat resistance, cadmium sulfide and zinc oxide have poor moisture resistance, and zinc oxide has no printing durability. It has drawbacks and efforts to develop new photoreceptors are ongoing. 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, easier to form films, easier to produce photoconductors, can produce transparent photoconductors depending on the type, and have no material compared to inorganic ones. It has advantages such as pollution.

[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 they can be easily used in mechanical applications. A photosensitive member having excellent characteristics can be obtained (for example, JP-A-60-196767, JP-A-60-218652, and JP-A-60-2331).
No. 56, JP-A-63-48552, JP-A-1
-267552, JP-B-3-39306,
JP-A-3-113459, JP-A-3-12335
8, JP-A-3-149560 and JP-A-6-149.
273950, JP-A-62-36674,
JP-A-7-036203, JP-A-6-1185
4, 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, a semiconductor laser has been actively applied as a light source in the field of printers. In this case, the wavelength of the light source is about 800 nm, so that 8
There is a strong demand for the development of a photoreceptor having high sensitivity to long wavelength light of about 00 nm. Materials suitable for this purpose are described in JP-A-59-49544, JP-A-59-214034, and JP-A-61-109056.
JP, JP-A-61-171771, JP-A-61-171771
JP-A-217050, JP-A-61-239248, JP-A-62-67094, JP-A-62-13
No. 4651, JP-A-62-275272, JP-A-63-198067, JP-A-63-1980
No. 68, JP-A-63-210942, JP-A-63-218768, and the like. Oxytitanium phthalocyanines each having a crystal type suitable as a material for an electrophotographic photoreceptor are exemplified. Various 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. The third objective is 800 nm
High sensitivity and chargeability, dark decay,
An object of the present invention is to provide an electrophotographic photoreceptor having a well-balanced residual potential and the like. The fourth purpose is good responsiveness,
An object of the present invention is to provide a photoconductor having a high carrier mobility.

[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 arylamine-based compound is suitable. This has led to the present invention. That is, the gist of the present invention resides in an electrophotographic photosensitive member having a photosensitive layer containing an arylamine compound represented by the following general formula [1] on a conductive support.

[0009]

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(In the above general formula [1], A, B, C, D,
E and F represent an optionally substituted benzene ring.
And they may combine with each other to form a heterocyclic ring;
Y is a divalent aromatic hydrocarbon residue which may have a substituent
Or a divalent heterocyclic compound residue which may have a substituent
Represents; R¹ , R^Two , R^Three And R^Four Are each water
Element atom, cyano group, nitro group, halogen atom,
Alkyl group which may have, aryl which may have a substituent
A heterocyclic group which may have a substituent or a substituent.
They may be the same or different from each other; n₁ and
n_Two Represents an integer of 1 to 4;
May be the same or different from each other; X ¹ And X^Two 
Are represented by the following general formulas [2] and [3], respectively.
These are the same or different groups.
May be. )

[0011]

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(In the above general formulas [2] and [3], n ₃
Represents an integer of 0 to 4; n ₄ represents an integer of 1 to 4; R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ ,
R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each a hydrogen atom,
A cyano group, a nitro group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent; And a pair consisting of R ⁸ and R ⁹ and R ¹³
And a pair consisting of R ¹⁴ may be condensed to form a carbocyclic group or a heterocyclic group, and when one of R in these pairs is a hydrogen atom, the other is an aryl group or It is a heterocyclic group. )

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The electrophotographic photoreceptor of the present invention contains the arylamine-based compound represented by the general formula [1] in the photosensitive layer.

In the general formula [1], R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom; a cyano group; a nitro group; 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 group or an isopropyl group; an aryl group such as a phenyl group, a naphthyl group and a pyrenyl group; a heterocyclic group such as a pyridyl group and a thienyl group; And a hydrogen atom, a methyl group, and a phenyl group are particularly preferable. In the formula [1], n ₁ and n ₂ each represent an integer of 1 to 4, which may be the same or different.

These alkyl groups, aryl groups, heterocycles
The group may have a substituent, and the substituent may be hydroxyl
Groups such as fluorine, chlorine, bromine and iodine;
Rogen atom; methyl group, ethyl group, propyl group, butyl
An alkyl group such as a benzyl group, a hexyl group, or an isopropyl group;
Alkoxy such as xy, ethoxy and propyloxy
Groups; alkenyl such as allyl, vinyl, and butenyl
Groups such as benzyl, naphthylmethyl, phenethyl, etc.
Aralkyl group; aryl such as phenoxy group and toloxy group
Roxy group; benzyloxy group, phenethyloxy group, etc.
Arylalkoxy groups such as phenyl and naphthyl
Aryl group; aryl such as styryl group and naphthylvinyl group
Acyl group such as acetyl group and benzoyl group;
Dialkylamino such as dimethylamino and diethylamino
Amino group, diphenylamino group, dinaphthylamino group, etc.
Diarylamino group, dibenzylamino group, diphenetici
Diaralkylamino groups such as
, A diheterocyclic amino group such as a dithienylamino group, a dia
A di-substituted amino group such as a lylamino group,
Substitute one of the substituents of the substituted amino group with another
Di-substituted amino group or mono-substituted amino group
And a substituted amino group. Alkyl group, aryl
The above-mentioned various substituents of the group or heterocyclic group may be singular or plural.
The substituents may be interchangeable.
The same R ¹ , R^Two , R^Three Or R^Four Inside
Or different R¹ , R^Two Between or different R ^Three , R
^Four Single bond, methylene group, ethylene group, carbonyl
Group, vinylidene group, ethylenylene group, etc.
Oxygen atom, sulfur atom, nitrogen atom, if desired.
A heterocyclic ring containing an element atom or the like may be formed.

In the general formula [1], A, B, C, D, E
And F each represent a benzene ring, which are bonded to each other to form a single bond or methylene group between any two of A, B and C or between any two of D, E and F; May form a heterocyclic ring containing a nitrogen atom via an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group, etc., and if desired, further form a heterocyclic ring containing an oxygen atom, a sulfur atom, a nitrogen atom, etc. May be.

These benzene rings may have a substituent, such as a hydroxyl group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; a methyl group;
Alkyl groups such as ethyl group, propyl group, butyl group, hexyl group and isopropyl group; alkoxy groups such as methoxy group, ethoxy group and propyloxy group; alkenyl groups such as allyl group, vinyl group and butenyl group; benzyl group and naphthyl Aralkyl groups such as methyl group and phenethyl group; aryloxy groups such as phenoxy group and toloxy group; arylalkoxy groups such as benzyloxy group and phenethyloxy group; aryl groups such as phenyl group and naphthyl group; acetyl group and benzoyl group Acyl groups; dialkylamino groups such as dimethylamino group and diethylamino group, diarylamino groups such as diphenylamino group and dinaphthylamino group;
Dibenzylamino group, diaralkylamino group such as diphenethylamino group, dipyridylamino group, diheterocyclic amino group such as dithienylamino group, disubstituted amino group such as diallylamino group, or these disubstituted amino groups And a substituted amino group such as a di-substituted amino group or a mono-substituted amino group in which one of the substituents is replaced with another substituent or a hydrogen atom. The substituents on each benzene ring may be singular or plural, and in the case of plural, they may be the same or different from each other.Moreover, these substituents are condensed with each other to form on each benzene ring Single bond, methylene group, ethylene group, carbonyl group,
A carbon ring may be formed via a vinylidene group, an ethylenylene group or the like, and if desired, a heterocyclic group containing an oxygen atom, a sulfur atom, a nitrogen atom or the like may be formed.

In the general formula [1], Y is phenylene,
A divalent aromatic hydrocarbon residue such as naphthylene or biphenylene; a divalent heterocyclic compound residue such as thienylene,
It is preferably phenylene or biphenylene, and the heterocyclic compound residue is particularly preferably a heterocyclic compound residue having aromaticity, for example, thienylene.

These divalent residues may have a substituent on the carbon ring or the heterocyclic ring, and the substituent may be singular or plural, and when plural, the same or different. And the substituents may be fused together to form a carbocyclic or heterocyclic ring between different positions on each ring or with another ring. Further, those condensed rings may have a substituent. Examples of the substituents on the divalent residue or the ring formed by condensation include a methyl group, an ethyl group, a propyl group,
Alkyl groups such as butyl group, hexyl group and isopropyl group; aryl groups such as phenyl group and naphthyl group; cyano group; alkoxycarbonyl group; aryloxycarbonyl group; nitro group: fluorine atom, chlorine atom, bromine atom and iodine atom And the like.

In the general formula [1], X ¹ represents a group represented by the following general formula [2], and X ² represents a group represented by the following general formula [3]. But they may be different.

[0021]

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In the general formulas [2] and [3], n ₃ is 0
And n ₄ represents an integer of 1 to 4. n ₃ is preferably 0 to 2 from the viewpoint of solubility.

R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R
¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each represent a hydrogen atom; a cyano group; a nitro group; an alkyl group such as a methyl group, an ethyl group, a propyl group or an isopropyl group; a phenyl group, a naphthyl group, a pyrenyl group and the like. And a heterocyclic group such as a pyridyl group and a thienyl group, which may be the same or different, and particularly preferably a hydrogen atom, a methyl group or a phenyl group.

These alkyl groups, aryl groups, heterocycles
The group may have a substituent, and the substituent may be hydroxyl
Groups such as fluorine, chlorine, bromine and iodine;
Rogen atom; methyl group, ethyl group, propyl group, butyl
An alkyl group such as a benzyl group, a hexyl group, or an isopropyl group;
Alkoxy such as xy, ethoxy and propyloxy
Groups; alkenyl such as allyl, vinyl, and butenyl
Groups such as benzyl, naphthylmethyl, phenethyl, etc.
Aralkyl group; aryl such as phenoxy group and toloxy group
Roxy group; benzyloxy group, phenethyloxy group, etc.
Arylalkoxy groups such as phenyl and naphthyl
Aryl group; aryl such as styryl group and naphthylvinyl group
Acyl group such as acetyl group and benzoyl group;
Dialkylamino such as dimethylamino and diethylamino
Amino group, diphenylamino group, dinaphthylamino group, etc.
Diarylamino group, dibenzylamino group, diphenetici
Diaralkylamino groups such as
, A diheterocyclic amino group such as a dithienylamino group, a dia
A di-substituted amino group such as a lylamino group,
Substitute one of the substituents of the substituted amino group with another
Di-substituted amino group or mono-substituted amino group
And a substituted amino group. Alkyl group, aryl
The above-mentioned various substituents of the group or heterocyclic group may be singular or plural.
The substituents may be interchangeable.
The same R ^Five , R⁶ , R⁷ , R⁸ , R⁹ ,
R^Ten, R¹¹, R¹², R¹³Or R¹⁴Within a different R
^Five , R⁶ In between, different R^Ten, R¹¹In between, R⁷ And R^Five , R
⁶ Between or R ¹²And R^Ten, R¹¹And a single bond,
Methylene group, ethylene group, carbonyl group, vinylidene
May form a carbocycle via a group, an ethylenylene group, etc.
If desired, contain oxygen, sulfur, nitrogen, etc.
Alternatively, a heterocyclic ring may be formed. Where R⁸ And R⁹ From
A pair and R¹³And R¹⁴A pair consisting of
May form a group or a heterocyclic group.
When one of R of the pair is a hydrogen atom, the other is
Is an aryl group or a heterocyclic group.

Hereinafter, typical examples of the arylamine-based compound represented by the general formula [1] will be listed for illustrative purposes. Of course, the arylamine-based compound used in the present invention is not limited to only these representative examples. In the following examples, the structural formula of the compound and the substituents X1 and X2 are separately displayed according to the general formula [1]. Represents only the substituents X1 and X2.

[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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[0042]

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[0043]

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The arylamine compound represented by the general formula [1] can be produced by a known method. For example, using a known arylamine-based compound as a raw material, a known carbonyl introduction reaction is performed, and then Wit
In this method, a target compound is obtained by performing a tig reaction. To explain this method in detail, first, the carbonyl introduction reaction is represented by the following reaction formula.

[0045]

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In the above-mentioned reaction formula showing the carbonyl introduction reaction and the reaction formula showing the Wittig reaction described below, the rings A, B, C, D, E and F, the groups R ¹ , R ² , R ³ , R
^{4, R 5, R 6,} R 7, R 9, R 10, R 11, R 12,
R ¹³ , R ¹⁴ , Y, X ¹ and X ² and the subscripts n ₁ ,
n ₂ , n ₃ and n ₄ Is the aforementioned general formula [1],
It has the same meaning as in [2] and [3].

1) When R ⁵ = R ¹⁰ = H: General formula [4]
Is reacted with a formylating agent such as N, N-dimethylformamide, N-methylformanilide in the presence of phosphorus oxychloride,
An aldehyde compound represented by the general formula [5] is obtained. At this time, a large excess of the formylating agent can be used as a reaction solvent, but a solvent inert to the reaction such as O-dichlorobenzene or benzene can also be used.

2) When R ⁵ and R ¹⁰ ≠ H: The arylamine compound represented by the general formula [4] is
Aluminum chloride, iron chloride, the presence of a Lewis acid and zinc chloride, nitrobenzene, dichloromethane, four in a solvent such as carbon tetrachloride, formula Cl-CO-R acid chloride represented by ⁵ and the formula Cl-CO-R ¹⁰ By reacting with an acid chloride represented by the formula, a ketone compound represented by the general formula [5] is obtained.

Next, the carbonyl was obtained by the carbonyl introduction reaction.
In a known organic solvent inert to the reaction of the aldehyde compound or ketone compound represented by the general formula [5] with N, N-dimethylformamide, N, N-dimethylacetamide, tetrahydrofuran, dioxane, benzene, toluene or the like, General formulas [6] and [6 '] (wherein Q is a chlorine atom,
Shows a halogen atom such as a bromine atom. And a Wittig reagent obtained by reacting a triphenylphosphine or trialkoxy phosphorus compound (R ¹⁵ O) ₃ P (R ¹⁵ represents an alkyl group such as a methyl group or an ethyl group) with the halogen compound represented by By reacting at a temperature of 10 to 200 ° C., preferably 20 to 100 ° C. in the presence of a known basic catalyst such as butyllithium, phenyllithium, sodium methoxide, sodium ethoxide, potassium t-butoxide, the general formula An arylamine compound represented by [1] is obtained. This Wittig
The reaction is represented by the following reaction formula.

[0050]

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At this time, as the arylamine-based compound represented by the general formula [1], any one of a cis-form, a trans-form, and a mixture of the cis-form and the trans-form is obtained.
In these reactions, in some cases, after completion of each step or after completion of all the steps, it is possible to obtain a high-purity substance by a known purification means such as recrystallization purification, reprecipitation purification, sublimation purification, and column purification. .

In the electrophotographic photoreceptor of the present invention, a photosensitive layer (photoconductive layer) containing one or more arylamine compounds represented by the above general formula [1] is provided on a conductive support. Have. Thus, the arylamine-based compound 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 is provided.

In the electrophotographic photoreceptor of the present invention, the photosensitive layer can take any form as long as it contains the arylamine compound represented by the above general formula [1]. That is, the photosensitive layer comprises a charge generation layer containing a charge generation material that generates charge carriers with extremely high efficiency when absorbing light, and a charge transport layer containing a charge transport material that transports charge carriers. A so-called lamination type in which layers are sequentially formed, or a so-called dispersion type in which a layer in which particles of a charge generation material are dispersed in a dispersion medium containing a charge transport material may be formed.

In the present invention, when the arylamine-based compound represented by the general formula [1] is used in a charge transport layer of a laminated photosensitive layer composed of two layers, a charge generation layer and a charge transport layer. , Especially high sensitivity, small residual potential,
In addition, when used repeatedly, a photosensitive member excellent in durability can be obtained with little change in surface potential, decrease in sensitivity, accumulation of residual potential, and the like.

The charge generation material used in the electrophotographic photoreceptor of the present invention is not particularly limited, and inorganic photoconductive particles such as selenium, selenium-tellurium alloy, selenium-arsenic alloy, cadmium sulfide, and amorphous silicon; Organic photoconductive particles such as metal phthalocyanine, metal-containing phthalocyanine, perinone pigments, thioindigo, quinacridone, perylene pigments, anthraquinone pigments, monoazo pigments, bisazo pigments, trisazo pigments, polyazo pigments, cyanine pigments, etc. No. Further, various organic dyes such as polycyclic quinone, pyrylium salt, thiopyrylium salt, indigo, anthantrone and pyranthrone can be used.

Among these charge generating materials, metal-free phthalocyanine; copper, indium chloride, gallium chloride,
Metals such as tin, oxytitanium, zinc and vanadium or oxides thereof, and metal-containing phthalocyanines coordinated with chlorides; azo pigments such as monoazo, bisazo, trisazo and polyazo are preferred.

Among them, the metal-containing phthalocyanine and the metal-free phthalocyanine are preferable when combined with the arylamine-based compound represented by the general formula [1], since a photoconductor having improved sensitivity to laser light can be obtained.
In particular, a) the Bragg angle (2θ) of the X-ray diffraction spectrum
± 0.2 °) oxytitanium phthalocyanine showing diffraction peaks at 9.7 °, 14.2 ° and 27.3 °,
b) Bragg angle (2θ ± 0.2) of X-ray diffraction spectrum
°) 9.3 °, 13.2 °, 26.2 ° and 27.1.
Oxytitanium phthalocyanine showing a diffraction peak in ° or c) X-ray diffraction Bragg angle (2θ ±
0.3 °) 9.2 °, 14.1 °, 15.3 °, 19.
An electrophotographic photoreceptor containing a dihydroxysilicon phthalocyanine compound having diffraction peaks at 7 ° and 27.1 ° has high sensitivity, low residual potential, high chargeability, and small fluctuation due to repetition. Is good, and can be used as a highly durable photoreceptor. 750-850 nm
Is particularly suitable for a photoreceptor for a semiconductor laser printer.

The method for producing the oxytitanium phthalocyanine of the above a) is not particularly limited, but is produced, for example, by the following method. 1 A method for producing a type II crystal 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
Directly or in an organic acid solvent, sulfuric acid or formula R-SO ₃ H
(Wherein, R represents an aliphatic or aromatic residue which may have a substituent), or heat-treated with a sulfonate represented by the formula With a mixed solvent of 3. If desired, after previously dissolving in concentrated sulfuric acid and releasing it into ice water, or making it 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-treating with the above sulfonated product. And heat treatment with a mixed solvent of water-insoluble organic solvent and water. 4. In the case of treatment with the above-mentioned sulfonated product, a mechanical grinding method such as a paint shaker, a ball mill, and a sand grind mill is used in place of the heat treatment.

In the present invention, two or more phthalocyanine compounds can be used in combination as the charge generating material. For example, the Bragg angles (2θ ± 0.2 °) of the aforementioned X-ray diffraction spectrum are 9.7 °, 14.2 ° and 27.
Oxytitanium phthalocyanine showing a diffraction peak at 3 ° and the Bragg angle (2θ ± 0.2
°) 9.3 °, 13.2 °, 26.2 ° and 27.1.
In combination with oxytitanium phthalocyanine showing a diffraction peak at °, or diffraction peaks at 9.7 °, 14.2 ° and 27.3 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum. Angle of oxytitanium phthalocyanine showing X-ray diffraction spectrum (2θ
± 0.2 °) 8.5 °, 12.2 °, 13.8 °, 1
It is preferable in combination with dichlorotin phthalocyanine which shows diffraction peaks at 6.9 °, 22.4 °, 28.4 ° and 30.1 ° in terms of sensitivity.

The electrophotographic photoreceptor of the present invention can be manufactured according to a conventional method. That is, the above-mentioned charge generating material and / or charge transporting material are dissolved in a suitable solvent together with a binder, and if necessary, a known sensitizing dye, an electron-withdrawing compound, a plasticizer and other known additives are added. The coating solution obtained in this manner is applied onto a conductive support, dried, and formed into a photosensitive layer having a predetermined thickness. In the case of a laminated photosensitive layer composed of two layers, a charge generating layer and a charge transporting layer, it is necessary to prepare the charge generating material and the charge transporting material as separate coating solutions and apply them sequentially. In this case, it is only necessary to apply a coating solution containing both materials. Needless to say, the charge generation layer of the laminated photosensitive layer can be formed not by coating but by vapor deposition.

Examples of the binder resin used for the charge generation layer in the laminated photosensitive layer include polyester resin, polyvinyl acetate, polyester polycarbonate, polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, phenoxy resin, epoxy resin, urethane resin, Examples include cellulose esters and cellulose ethers. There is no limitation as long as it can form a dispersion layer in which fine particles such as a charge generation material are bound with various binder resins. Besides these, binder resins such as polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylates, methacrylates, vinyl alcohol, and ethyl vinyl ether, polyamides, and silicon resins can also be used. . In this case, the charge generating material is used in an amount of usually 20 to 2,000 parts by weight, preferably 30 to 500 parts by weight, more preferably 3 to 100 parts by weight of the binder resin.
It is selected from the range of 3 to 500 parts by weight.

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, Polymers and copolymers of vinyl compounds such as butadiene, polyvinyl acetal, polycarbonate, polyester,
Polyester carbonate, polysulfone, polyimide, polyphenylene oxide, polyurethane, cellulose ester, cellulose ether, phenoxy resin,
Various polymers such as a silicon resin and an epoxy resin may be mentioned, and a partially cross-linked cured product thereof may also be used. The amount of the binder used is 0.5 to 30 with respect to the charge transporting material.
It is in the range of 0.7 times to 10 times by weight.

Solvents for preparing a coating solution include ethers such as tetrahydrofuran, 1,4-dioxane and dimethoxyethane, methyl ethyl ketone, and 4-methoxy-4-
Ketones such as methylpentanone-2 and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; N, N-
Aprotic polar solvents such as dimethylformamide, acetonitrile, N-methylpyrrolidone and dimethylsulfoxide; esters such as ethyl acetate, methyl formate and methyl cellosolve acetate; chlorinated hydrocarbons such as dichloroethane and chloroform. Of course, it is necessary to select one that dissolves the binder from these.
Further, in the case of a photosensitive layer containing a charge transporting material such as an arylamine-based compound, it is necessary to select a solvent in which these are dissolved.

Next, in the present invention, dyes which 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 cyanine dyes, and billyllium salts, thiabilillium salts, and benzobrillium salts.

Examples of the electron-withdrawing compound which forms a charge transfer complex with the arylamine compound include chloranil, 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, , 4,
Ketones such as 7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, 3,3 ', 5,5'-tetranitrobenzophenone; acid anhydrides such as phthalic anhydride and 4-chloronaphthalic anhydride A cyano compound such as tetracyanoethylene, terephthalalmalononitrile, 9-anthrylmethylidenemalononitrile, 4-nitrobenzalmalonitrile, 4- (p-nitrobenzoyloxy) benzalmalonitrile; 3-benzalphthalide; 3- (α-cyano-p-nitrobenzal) phthalide, 3- (α-cyano-p-nitrobenzal) -4,
Electron-withdrawing compounds such as phthalides such as 5,6,7-tetrachlorophthalide.

Further, the photosensitive layer of the electrophotographic photosensitive member of the present invention may contain a well-known plasticizer in order to improve film forming property, flexibility and mechanical strength. In particular,
Phthalates, phosphates, epoxy compounds,
Examples include chlorinated paraffins, chlorinated fatty acid esters, and aromatic compounds such as methylnaphthalene.

In addition to the various additives described above, the charge generation layer in the case of the laminated photosensitive layer may be added, if necessary, with various additives such as a leveling agent for improving coating properties, an antioxidant, and a sensitizer. It may contain an agent. Furthermore, the charge generation layer may be a deposited film of the above-described charge generation material. The thickness of the charge generation layer is usually 0.05 to 5 μm, preferably 0.1 to 2 μm.
m, more preferably 0.15 to 0.8 μm.

The charge transport layer in the case of the laminated photosensitive layer has, if necessary, excellent performance as various additives such as an antioxidant and a sensitizer and other charge transport materials, for example, an organic photoconductor. It may contain other known arylamine compounds, hydrazone compounds, and stilbene compounds. In addition to the above, various additives for improving the mechanical strength and durability of the coating film can be used in the charge transport layer. Examples of such additives include various stabilizers, flowability-imparting agents, cross-linking agents and the like in addition to the above-mentioned plasticizers. The thickness of the charge transport layer is usually 10 to 60 μm, preferably 10 to 45 μm,
More preferably, the thickness is 27 to 40 μm.

In the case of the dispersion type photosensitive layer, in addition to the above-mentioned plasticizer for improving film formability, flexibility, mechanical strength, etc., an additive for suppressing a residual potential, and an improvement in dispersion stability. , A leveling agent for improving applicability, and a surfactant, for example, silicone oil, fluorine-based oil, and other additives may be added. The thickness of the dispersion type photosensitive layer is usually 5 to 50 μm, preferably 10 to 50 μm.
45 μm is preferred.

In the case of the dispersion type photosensitive layer, the particle size of the charge generating material 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
Although it is in the range of 50% by weight, if the amount is too small, sufficient sensitivity cannot be obtained, and if it is too large, there are adverse effects such as a decrease in chargeability and a decrease in sensitivity. You.

In the present invention, examples of a coating method for forming a predetermined 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 Considering the degree of adhesion, adhesion efficiency, etc., in the case of a rotary atomization type electrostatic spray, the conveying method disclosed in Japanese Patent Laid-Open Publication No. 1-805198, that is, a cylindrical work is rotated and spaced apart in the axial direction. By transporting continuously without
An electrophotographic photoreceptor excellent in uniformity of film thickness with high overall deposition efficiency can be obtained.

The spiral coating method is disclosed in
Japanese Patent Application Laid-Open No. H11-231966 discloses a method using a liquid injection coating machine or a curtain coating machine disclosed in Japanese Patent Application Publication No. 119651.
There is a method disclosed in Japanese Patent Application Laid-Open Publication No. H10-193, in which the coating material is continuously flew from the minute opening in a streak shape, and a method using a multi-nozzle body disclosed in Japanese Patent Application Laid-Open No. 3-193161.

In the dip coating method, a coating solution prepared for dipping in advance is used. That is, the coating liquid is adjusted so that the total solid concentration of the photoreceptor and the binder resin is 25% or more, more preferably 40% or less, and the viscosity is usually 50 to 300 centipoise, preferably 100 to 200 centipoise. To adjust. Here, the viscosity of the coating solution is substantially determined by the type of the binder resin and its molecular weight. However, if the molecular weight is too low, the mechanical strength of the resin itself is reduced. Preferably, a resin is used.

Thereafter, the coating film is dried, and the drying temperature and time may be adjusted so that necessary and sufficient drying is performed. The drying temperature is usually 100 to 250 ° C., preferably 110 to 250 ° C.
The temperature is 170 ° C, more preferably 120-140 ° C. As a drying method, a hot air dryer, a steam dryer, an infrared dryer, a far infrared dryer, or the like can be used.

The photoreceptor thus formed may be provided with a barrier layer, an adhesive layer, a blocking layer, etc., if necessary, between the photosensitive layers or between the photosensitive layer and the support in order to improve the electrical and mechanical properties. Needless to say, the photosensitive layer may have a surface layer such as a protective layer on the surface of the photosensitive layer.

Examples of the intermediate layer include an anodized aluminum film, an inorganic layer such as aluminum oxide and aluminum hydroxide, polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, polyamide and the like. Organic layers are used. Further, as the surface layer, for example, a protective layer such as an ultraviolet curable resin is used.

As the conductive support on which the photosensitive layer is formed, any of those used for electrophotographic photosensitive members can be used. Specifically, aluminum, stainless steel,
A drum or sheet made of a metal material such as copper or nickel, or a laminate of these metal foils; a polyester film having a surface provided with a conductive layer such as aluminum, copper, palladium, tin oxide, or indium oxide by evaporation or the like;
Insulating support such as paper; plastic film, plastic drum, paper, paper tube, etc., which has been subjected to conductive treatment by applying a conductive substance such as metal powder, carbon black, copper iodide, and polymer electrolyte together with an appropriate binder; Conductive plastic sheets and drums containing conductive materials such as powder, carbon black, and carbon fiber; tin oxide;
Plastic films and belts subjected to conductive treatment with a conductive metal oxide such as indium oxide may be used. Above all,
A metal drum such as aluminum is a preferred support.

Hereinafter, the present invention will be described in more detail with reference to Examples. (Production Example) Carbonyl introduction reaction Arylamine compound represented by the following formula

[0079]

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[0080] 12.9 g was dissolved in 100 mL of DMF. The temperature was raised to 60 ° C., and 9.5 g of phosphorus oxychloride was added dropwise (65 ° C. ± 5 ° C.). The reaction was allowed to proceed at 65 ° C. ± 5 ° C. for 2 hours. After confirming the completion of the reaction by TLC, the reaction solution was allowed to cool and discharged into an aqueous potassium hydroxide solution (21 g of KOH / 1 L of water). After standing all day and night, the precipitated solid was separated by filtration and 1 L
And washed twice with water (confirmed that the filtrate was neutral).
Dried under reduced pressure at 60 ° C. for 30 hours, and 100 ml of DMF
Was dissolved. The solid was discharged into 1 L of water, and the precipitated solid was separated by filtration and dried under reduced pressure at 60 ° C. for 30 hours to obtain 13 g of a formyl compound represented by the following formula and a dark yellow solid.

[0081]

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Wittig Reaction 6.7 g of the above formyl compound and Wit represented by the following formula
tig reagent

[0083]

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Dissolve 9.4 g in 100 mL of THF,
7.7 g of a 28% solution of sodium methoxide in methanol
Was added in small portions (20 ° C. ± 5 ° C.). Stir for 1 hour,
The reaction product was discharged into 500 mL of methanol, and the precipitated solid was separated by filtration. The solid was dried at 60 ° C. under reduced pressure and purified by a column to obtain 5.6 g of a compound represented by the structural formula first mentioned as a representative example and having the third substituents X1 and X2. The infrared spectrum is shown in FIG.

Example 1 Formation of Charge Generation Layer In the X-ray diffraction spectrum, the Bragg angle (2θ ± 0.
2 °) 9.3 °, 10.6 °, 13.2 °, 15.1
°, 15.7 °, 16.1 °, 20.8 °, 23.3
°, 26.2 °, and 27.1 °, 1.0 part of a titanium oxyphthalocyanine pigment exhibiting strong diffraction peaks was added to 14 parts of dimethoxyethane, and after dispersion treatment with a sand grinder, 14 parts of dimethoxyethane and 4-part Methoxy-
4-Methylpentanone-2 (manufactured by Mitsubishi Chemical Corporation) 14
And then diluted with polyvinyl butyral (Denka Butyral # 600, manufactured by Denki Kagaku Kogyo KK)
0-C) and phenoxy resin (trade name: UCAR (registered trademark) PKH, manufactured by Union Carbide Co., Ltd.)
H) 0.5 part of dimethoxyethane 6 parts, 4-methoxy-
It was mixed with a solution of 4-methylpentanone-26 in a mixed solvent to obtain a dispersion. This dispersion was applied on a 70 μm-thick polyester 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 generate charge. A layer was formed.

Formation of Charge Transport Layer On the charge generation layer thus formed, the arylamine-based compound synthesized in the above-mentioned Production Example (the compound represented by the structural formula shown first as a typical example described above and having a 3 70 parts of a compound having the first substituents X1 and X2) and a polycarbonate resin represented by the following formula:

[0087]

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A coating solution prepared by dissolving 100 parts in 900 parts of a mixed solvent mainly composed of tetrahydrofuran is applied and dried.
A charge transporting layer having a thickness of 20 μm was formed, and a so-called laminated type electrophotographic photoreceptor having two photosensitive layers was obtained.

Evaluation of Photoreceptor The following electrical characteristics were measured for the electrophotographic photoreceptor thus obtained. (1) Sensitivity, ie, half-exposure amount: The half-exposure amount is first negatively charged by a corona current of 50 μA in a dark place.
Then, 780 nm light (exposure energy 10 μW / c) obtained by passing white light of 20 lux through an interference filter
m ² ) and the surface potential is from −550 V to −275 V
It was determined by measuring the amount of exposure required to decay to. The measured value was 0.53 μJ / cm ² . (2) Residual potential: Further, when the surface potential when the exposure time was set to 9.9 seconds was measured as a residual potential, it was 13 V. This operation was repeated 2000 times, but no increase in the residual potential was observed. (3) Hole mobility: When the hole mobility of the charge transport layer of this photoreceptor was examined by the TOF method, the result shown in FIG. 2 was obtained. In the figure, the horizontal axis indicates the square root of the electric field strength,
The vertical axis indicates the mobility.

Comparative Example 1 Comparative compound 1 represented by the following formula was used instead of the arylamine compound used in Example 1.

[0091]

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An electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that the polymer was dissolved in a polymer solution and applied. When the solvent was dried, a solid precipitated on the coated surface, and the Properties could not be measured.

Comparative Example 2 In place of the arylamine compound used in Example 1, Comparative Compound 2 represented by the following formula

[0094]

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An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the above was used. However, an attempt was made to dissolve it in a polymer solution, but it was not completely dissolved, and the electrical characteristics could not be measured. .

Comparative Example 3 In place of the arylamine compound used in Example 1, Comparative Compound 3 represented by the following formula

[0097]

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[0098] Except for using
After dissolving in the polymer solution, the solution was applied. During drying of the solvent, some solid precipitated on the applied surface, and the applied surface was whitened. Since the measurement of the electric characteristics was possible, the sensitivity, the residual potential and the mobility were measured in the same manner as in Example 1. The sensitivity and residual potential are shown in the following table in comparison with the measurement results for the photoconductor of Example 1. Example 1 Comparative Example 3 Sensitivity (μJ / cm ² ) 0.53 0.53 Residual potential (V) 1349

Therefore, the arylamine-based compound of Example 1 is clearly superior in solubility in the polymer solution as compared with the charge transport compounds of Comparative Examples 1, 2, and 3. Also in the electrical characteristics, both the sensitivity and the residual potential are excellent, and it can be seen that the electric potential is particularly excellent in comparison with Comparative Example 3. Further, it can be seen that the mobility is also superior to the compound of Comparative Example 3.

[0100]

The electrophotographic photoreceptor of the present invention has a high compatibility with a polymer, a small residual potential causing fogging, and a small light fatigue. It has a feature that the fluctuation of the surface potential and the sensitivity is small and the durability is excellent.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a hole mobility of a charge transport layer in the photoconductors of Example 1 and Comparative Example 3.

Claims (3)

[Claims] 1. An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer containing an arylamine compound represented by the following general formula [1]. Embedded image (In the above general formula [1], A, B, C, D, E and F
Represents an optionally substituted benzene ring, which may combine with each other to form a heterocyclic ring; Y represents an optionally substituted divalent aromatic hydrocarbon residue Or a divalent heterocyclic compound residue which may have a substituent;
¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, a cyano group, a nitro group, a halogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent or a substituent Which may be the same or different from each other; n ₁ and n ₂ each represent an integer of 1 to 4, which may be the same or different from each other X ¹ and X ² each represent a group represented by the following formulas [2] and [3], which may be the same or different. ) (In the above general formulas [2] and [3], n ₃ represents an integer of 0 to 4; n ₄ represents an integer of 1 to 4; R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ^9, R ^10, R ^11,
R ¹² , R ¹³ and R ¹⁴ each have a hydrogen atom, a cyano group, a nitro group, an alkyl group optionally having a substituent, an aryl group optionally having a substituent or a substituent And a pair of R ⁸ and R ⁹ and a pair of R ¹³ and R ¹⁴ are fused to form a carbocyclic or heterocyclic group. And when one of R of these pairs is a hydrogen atom, the other is an aryl group or a heterocyclic group. ) 2. A method according to claim 1, wherein the charge transporting material is formed on a conductive support.
It contains an arylamine-based compound represented by the general formula [1], and as a charge generation material, a metal-free phthalocyanine;
The electrophotographic photosensitive member according to claim 1, further comprising a photosensitive layer containing a metal phthalocyanine or a bisazo pigment. 3. The electrophotographic photoreceptor according to claim 2, wherein the charge generation material is at least one metal phthalocyanine compound selected from the group consisting of the following a) to c). a) Bragg angle (2θ ± 0.2) of X-ray diffraction spectrum
°) Oxytitanium phthalocyanine showing diffraction peaks at 9.7 °, 14.2 ° and 27.3 ° b) Bragg angle of X-ray diffraction spectrum (2θ ± 0.2
°) 9.3 °, 13.2 °, 26.2 ° and 27.1.
C) Bragg angle (2θ ± 0.3) of X-ray diffraction spectrum showing oxytitanium phthalocyanine showing a diffraction peak at °
゜) Dihydroxysilicon phthalocyanine compound having diffraction peaks at 9.2 °, 14.1 °, 15.3 °, 19.7 ° and 27.1 °