JP2000066419A - 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 arylamine compd. on an electrically conductive substrate. SOLUTION: The electrophotographic photoreceptor has a photosensitive layer contg. an arylamine compd. of the formula on the electrically conductive substrate. In the formula, each of A to F is a benzene ring which may have substituents at least one of which is alkyl, Y is a divalent residue of an arom. hydrocarbon which may have a substituent or a divalent residue of a heterocyclic compd. which may have a substituent, each of R1-R4 is H, cyano, nitro, halogen, alkyl which may have a substituent, aryl which may have a substituent or a heterocyclic group which may have a substituent, R1-R4 may be the same or different, each of n1 and n2 is an integer of 1-4 and each of X1 and X2 is a specified 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, 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, at least one of which has an alkyl group,
They may also combine with each other to form a heterocycle;
Y represents a divalent aromatic hydrocarbon residue which may have a substituent or a divalent heterocyclic compound residue which may have a substituent; R ¹ , R ² , R ³ and R ⁴ is 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 heterocyclic group which may have a substituent, respectively. And these 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
Represents a group represented by the following general formulas [2] and [3], which may be the same or different. )

[0011]

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(In the above general formulas [2] and [3], R
⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ 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; The pair consisting of R ⁶ and R ⁷ and the pair consisting of R ⁹ and R ¹⁰ may be condensed to form a carbocyclic or heterocyclic group.
When either one is a hydrogen atom, the other is an aryl group or 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. A methyl group,
An alkyl group such as an ethyl group, a propyl group or an isopropyl group;
Aryl groups such as phenyl, naphthyl and pyrenyl;
Represents a heterocyclic group such as a pyridyl group or a thienyl group, which may be the same or different, and particularly preferably a hydrogen atom, a methyl group or a phenyl group. 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 a hydroxyl group; a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or the like.
A halogen atom; methyl, ethyl, propyl, butyl
Alkyl groups such as tyl, hexyl, and isopropyl;
Alcohols such as methoxy, ethoxy, propyloxy, etc.
Xy group; alkenyl such as allyl group, vinyl group and butenyl group
Benzyl group, naphthylmethyl group, phenethyl group, etc.
Aralkyl groups; ants such as phenoxy and toloxy groups
Oxy group; benzyloxy group, phenethyloxy group
Arylalkoxy groups such as phenyl group, naphthyl group, etc.
Aryl groups; styryl groups, naphthylvinyl groups and other ants
Vinyl group; acyl such as acetyl group and benzoyl group
Groups: dimethylamino, diethylamino, etc.
Ruamino group, diphenylamino group, dinaphthylamino group
Diarylamino, dibenzylamino, dife
Diaralkylamino group such as netylamino group, dipyridyl
An amino group, a diheterocyclic amino group such as a dithienylamino group,
A disubstituted amino group such as a diallylamino group, or
One of the disubstituted amino group substituents is replaced with another substituent or water
Di-substituted amino group or mono-substituted amino group converted to an elemental atom
And the like. Alkyl group, ally
Group, the various substituents of the heterocyclic group may be singular
More than one may be used, and in the case of more than one,
Condensed together to form the same R ¹ , R^Two , R^Three Or R^Four 
Within or different R¹ , R^Two Between or different R ^Three ,
R^Four Single bond, methylene group, ethylene group, carbonyl
Carbocycle via a benzyl group, vinylidene group, ethylenylene group
And, if desired, an oxygen atom, a sulfur atom,
A heterocyclic ring containing a nitrogen 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.

At least one of these benzene rings has, as a substituent, a methyl group, an ethyl group, a propyl group,
It has an alkyl group such as a butyl group, a hexyl group, and an isopropyl group. 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 May form a carbon ring via a single bond, a methylene group, an ethylene group, a carbonyl group, a vinylidene group, an ethylenylene group, or the like.

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;
A cyano group; an alkoxycarbonyl group; an aryloxycarbonyl group; a nitro group; and a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

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], R ⁵ and R
⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each 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 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; 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; aralkyl groups such as benzyl group, naphthylmethyl group and phenethyl group; aryloxy groups such as phenoxy group and toloxy group An arylalkoxy group such as a benzyloxy group or a phenethyloxy group; an aryl group such as a phenyl group or a naphthyl group; an arylvinyl group such as a styryl group or a naphthylvinyl group; an acyl group such as an acetyl group or a benzoyl group; , A dialkylamino group such as a diethylamino group, a diarylamino group such as a diphenylamino group, a dinaphthylamino group, a diaralkylamino group such as a dibenzylamino group, a diphenethylamino group, a dipyridylamino group, a dithienylamino group or the like. Heterocyclic amino group,
A disubstituted amino group such as a diallylamino group, or a substituted amino group such as a disubstituted amino group or a monosubstituted amino group in which one of the substituents of these disubstituted amino groups is replaced with another substituent or a hydrogen atom No.

Having an alkyl group, an aryl group and a heterocyclic group
The above-mentioned various substituents may be singular or plural, and
In the case of a plurality, these substituents are condensed with each other to form R
^Five , R ⁶ , R⁷ , R⁸ , R⁹ Or R^TenWithin R^Five When
R⁶ , R⁷ Between or R⁸And R⁹ , R^TenBetween
Single bond, methylene group, ethylene group, carbonyl group, vinyl
Forming a carbocycle via a redene group, an ethylenylene group, etc.
If desired, oxygen, sulfur, nitrogen, etc.
And may form a heterocyclic ring. Where R⁶ And R⁷ 
A pair consisting of and R⁹ And R^TenOne of the pairs of R consisting of
When one is a hydrogen atom, the other is an aryl group or
It is a heterocyclic group. Also, R ⁶ And R⁷ A pair consisting of and R
⁹ And R^TenIs a fused or carbocyclic group or a heterocyclic ring
A carbocyclic group which may be further formed
Or a heterocyclic group is a methyl group, an ethyl group, a propyl group,
Alkyl such as butyl, hexyl and isopropyl
Groups; aryl groups such as phenyl and naphthyl; alkoxy
Cycarbonyl group, aryloxycarbonyl group, cyano
Group, nitro group; fluorine atom, chlorine atom, bromine atom, iodine
It may have a substituent such as a halogen atom such as an element atom.

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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The arylamine compound represented by the general formula [1] can be produced by a known method. For example, it is a method of obtaining a target compound by performing a known carbonyl introduction reaction and a Wittig reaction using a known arylamine-based compound as a raw material. To explain this method in detail, first, these reactions are represented by the following reaction formulas.

[0042]

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The above carbonyl introduction reaction and Witt
In a reaction formula showing an ig reaction, rings A, B, C, D, and E
And F, groups R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R
⁷ , R ⁸ , R ⁹ , R ¹⁰ , Y, X ¹ and X ² and the subscripts n ₁ and n ₂ are the same as those of the above-mentioned general formulas [1], [2],
It has the same meaning as in [3].

1) When R ⁵ = R ⁸ = H: The arylamine compound represented by the general formula [4] or [6] is converted into N, N-dimethylformamide, N- By reacting with a formylating agent such as methylformanilide, an aldehyde compound represented by the general formula [5] or [7] 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 ⁸ ≠ H: The arylamine compound represented by the general formula [4] or [6] is converted to nitrobenzene, dichloromethane or dichloromethane in the presence of a Lewis acid such as aluminum chloride, iron chloride or zinc chloride. , four in a solvent such as carbon tetrachloride, and acid chlorides of the general formula Cl-CO-R acid chloride represented by ⁵ and the formula Cl-CO-R ^8, formula by reacting [5] or The ketone represented by [7] is obtained.

Then, the carbonyl was obtained by the carbonyl introduction reaction.
An aldehyde or ketone represented by the general formula [5] or [7] and N, N-dimethylformamide, N,
In a known organic solvent which is inert to the reaction of N-dimethylacetamide, tetrahydrofuran, dioxane, benzene, toluene or the like, a compound represented by the general formula R ⁶ R ⁷ CHQ or R ⁹ R ¹⁰ C
HQ (wherein Q represents a halogen atom such as a chlorine atom or a bromine atom), a triphenylphosphine or trialkoxy phosphorus compound (R
¹⁵ W) ₃ P (R ¹⁵ represents an alkyl group such as a methyl group or an ethyl group) and a Wittig reagent obtained by the reaction with butyllithium at a temperature of 10 to 200 ° C, preferably 20 to 100 ° C. And phenyllithium, sodium methoxide, sodium ethoxide, potassium t-butoxide, and the like, to obtain an arylamine-based compound represented by the general formula [1] or [6]. .

At this time, as the arylamine-based compound represented by the general formula [1], any 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-based compound represented by the 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 laminate type photosensitive layer comprising 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 generating 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 pigment, thioindigo, quinacridone, perylene pigment, anthraquinone pigment, monoazo pigment, bisazo pigment, trisazo pigment, polyazo pigment, cyanine pigment, etc. No. Further, various organic dyes such as polycyclic quinone, pyrylium salt, thiopyrylium salt, indigo, anthantrone and pyranthrone can be used.

Among these charge generation materials, metal-free phthalocyanines; 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 oxytitanium phthalocyanine of the above a) is not particularly limited, but for example, it is produced 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 photosensitive member 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, and the like. 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 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 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, for example, 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 properties 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 needs to 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 liquid that has been adjusted 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 are preferably 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

[0075]

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6.4 g was dissolved in 100 mL of DMF. The temperature was raised to 60 ° C., and 4.6 g of phosphorus oxychloride was added dropwise (65 ° C. ± 5 ° C.). The reaction was carried out at 65 ° C. ± 5 ° C. for 2 hours.
Released into aqueous potassium hydroxide solution (10 g KOH / 500 g water). After standing overnight, the precipitated solid is filtered off,
The suspension was washed twice with 0.5 L of water (confirmed that the filtrate was neutral). Dried under reduced pressure at 60 ° C. for 30 hours.
Dissolved in 00 ml. The solid was discharged into 0.5 L of water, and the deposited solid was separated by filtration and dried under reduced pressure at 60 ° C. for 30 hours to obtain 6 g of a formyl compound represented by the following formula and a dark yellow solid.

[0077]

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Wittig Reaction 3.5 g of the above formyl compound and Wit represented by the following formula
tig reagent

[0079]

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3.7 g was dissolved in 50 mL of THF, and t
1.6 g of BuOK was added little by little (20 ° C. ± 5
° C). After stirring for 1 hour, the reaction product was discharged into 200 mL of methanol, and the precipitated solid was separated by filtration. 60 ° C under reduced pressure
, And purified by a column. The first substituent X represented by the structural formula given at the outset as the representative example described above.
2.0 g of a compound having 1, X2 was obtained. The infrared absorption 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 Production Example (1 represented by the structural formula first mentioned as the representative example above) 70 parts of a compound having the first substituents X1 and X2) and a polycarbonate resin represented by the following formula:

[0083]

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100 parts of a coating solution prepared by dissolving 100 parts of a mixed solvent mainly composed of tetrahydrofuran was 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 0.43 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 -9 V. This operation was repeated 2000 times, but no increase in the residual potential was observed.

(Example 2) Instead of the arylamine compound used in Example 1, the first substituents X1 and X2 represented by the structural formulas listed as the second representative examples above are used.
An electrophotographic photoreceptor was obtained in the same manner as in Example 1, except that a compound having the following formula was used. The sensitivity and residual potential of the electrophotographic photoreceptor thus obtained were measured. The measurement results are shown in Table 1 below.

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

[0088]

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Except for using the same procedures as in Example 1,
An electrophotographic photosensitive member was obtained. The results of measuring the sensitivity and the residual potential are shown in Table 1 below.

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

[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 3 In place of the arylamine compound used in Example 1, Comparative Compound 3 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. .

Table 1 Example 1 Example 1 Comparative Example 1 Sensitivity (μJ / cm ² ) 0.43 0.41 0.43 Residual potential (V) 9 9 34

Accordingly, it can be seen that the arylamine compounds of Examples 1 and 2 are particularly superior in the residual potential and the sensitivity as compared with the charge transport compound of Comparative Example 1. Further, it can be seen that, compared to the compounds of Comparative Examples 2 and 3, the solubility of the coating solution and the compatibility with the polycarbonate are excellent.

[0098]

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.

Claims (4)

[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, at least one of which has an alkyl group, and these may be bonded to each other to form a heterocyclic ring; A divalent aromatic hydrocarbon residue which may be substituted or a divalent heterocyclic compound residue which may be substituted;
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], R ⁵ , R ⁶ , R
⁷ , R ⁸ , R ⁹ and R ¹⁰ are each a hydrogen atom, a cyano group, a nitro group, an alkyl group which may have a substituent,
Have an aryl group or a substituted group may have a substituent represents also heterocyclic group, they may be the same or different, R ⁶ and consisting of R ⁷ pair, and R ⁹ R
^The pair consisting of ¹⁰ may be condensed to form a carbocyclic group or a heterocyclic group, and when one of R of these pairs is a hydrogen atom, the other is an aryl group or a heterocyclic group. 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 ° 4. The electrophotographic photosensitive member according to claim 1, wherein n ₁ and n ₂ are 1.