JPH0990651A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high sensitivity and a low residual potential. SOLUTION: In this electrophotographic photoreceptor with a photosensitive layer on the electrically conductive substrate, a styryl compd. represented by formula I is contained in the photosensitive layer. In the formula I, R<1> is an alkyl or aryl, R<2> is an alkyl, alkoxy, etc., each of R<3> -R<6> is H, an alkyl, etc., and each of A and B is a group represented by formula II or III. In the formulae II, III, each of R<7> -R<9> and R<12> -R<14> is H, an alkyl, etc., each of R<10> and R<11> is H or an aryl, R<10> and R<11> may be condensed, each of R<15> and R<16> is an alkyl or aryl, R<15> and R<16> may be condensed and each of (m) and (n) is 0 or an integer of >=1.

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 sensitive and high performance electrophotographic photosensitive member having a photosensitive layer containing an organic photoconductive substance.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive substances such as selenium, cadmium sulfide, and zinc oxide have been widely used for a photosensitive layer of an electrophotographic photosensitive member. However, selenium and cadmium sulfide need to be recovered as poisons, selenium is crystallized by heat and therefore has poor heat resistance, cadmium sulfide and zinc oxide have poor moisture resistance, and zinc oxide has no printing durability Therefore, efforts have been made to develop new photoconductors. Recently, researches using organic photoconductive materials for the photosensitive layers of electrophotographic photoreceptors have progressed, and some of them have been put to practical use. Organic photoconductive materials are lighter in weight than inorganic ones, film formation is easy, photoconductors are easy to manufacture, transparent photoconductors can be manufactured depending on the type, and materials are harmless It has advantages such as

Recently, a so-called function-separated type photoconductor in which charge generation and transfer functions are shared by different compounds is effective in increasing the sensitivity, and has become the mainstream of development. The organic photoconductor is also put into practical use. As the charge carrier transfer medium, there are a case where a high molecular weight photoconductive compound such as polyvinylcarbazole 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 mechanically selected because a polymer having excellent film-forming property, flexibility and adhesiveness as a binder can be selected. A photoreceptor having excellent characteristics can be obtained (for example, JP-A-62-264058, JP-A-3-48254, JP-A-64-13553, JP-A-4-292662, and JP-A-3262). -136
057, etc.). However, it has been difficult to find a compound suitable for producing a highly sensitive photoreceptor.

[0005]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies on organic low-molecular photoconductive compounds which can satisfy these objects, and have found that a specific styryl compound is suitable. Invented. That is, the gist of the present invention is an electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the photosensitive layer contains a styryl compound represented by the following general formula [I]. It exists in the electrophotographic photoreceptor.

[0006]

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(In the general formula [I], R ¹ represents an alkyl group which may have a substituent or an aryl group which may have a substituent; R ² represents a substituent. Optionally alkyl group, optionally substituted alkoxy group, optionally substituted aryl group, optionally substituted aryloxy group, optionally substituted Represents a good aralkyl group or an aralkyloxy group which may have a substituent; R ³ , R ⁴ , R ⁵ and R ⁶ are each a hydrogen atom, an alkyl group which may have a substituent or a substituent Represents an aryl group which may have a group,
These may be the same or different from each other; A and B each represent a group represented by the following general formula [II] or [III], and these may be the same or different from each other;

[0008]

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[In the general formulas [II] and [III], R ⁷ ,
R ⁸ , R ⁹ , R ¹² , R ¹³ and R ¹⁴ each represent a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent, and these are mutually R ¹⁰ and R ¹¹ each represent a hydrogen atom or an aryl group which may have a substituent, which may be the same or different, and R ¹⁰ and R ¹¹ may be the same or different. May be condensed with each other, provided that R
¹⁰ and R ¹¹ are not hydrogen atoms at the same time; R ¹⁵ and R ¹⁶ each represent an alkyl group which may have a substituent or an aryl group which may have a substituent; May be the same or different from each other, and R ¹⁵
And R ¹⁶ may be condensed with each other; m and n each represent 0 or an integer of 1 or more, which may be the same or different from each other. ]

X represents an alkylene group which may have a substituent; Ar ¹ , Ar ² and Ar ³ are each
Represents an aromatic hydrocarbon group which may have a substituent or a condensed polycyclic group which may have a substituent, which may be the same or different from each other; j is 0 or 1 to 4; Represents an integer; l represents 0 or an integer of 1 or more; k represents 0
Or represents 1. )

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The electrophotographic photosensitive member of the present invention contains the styryl compound represented by the general formula [I] in the photosensitive layer. In the general formula [I], R ¹ represents an alkyl group such as a methyl group, an ethyl group or a propyl group; or an aryl group such as a phenyl group or a naphthyl group, and an aryl group is particularly preferable. These alkyl group and aryl group may have a substituent, and examples of the substituent include an alkyl group such as a methyl group, an ethyl group and a propyl group; an alkoxy group such as a methoxy group, an ethoxy group and a butoxy group; chlorine. Examples thereof include an atom, a halogen atom such as a bromine atom and an iodine atom; an aryl group such as a phenyl group and a naphthyl group.

R ² is an alkyl group such as a methyl group, an ethyl group and a propyl group; an alkoxy group such as a methoxy group and an ethoxy group; an aryl group such as a phenyl group and a naphthyl group; an aryloxy group such as a phenoxy group and a naphthoxy group. An aralkyl group such as a benzyl group or a phenethyl group; or an aralkyloxy group such as a benzyloxy group or a phenethyloxy group. These alkyl group, alkoxy group, aryl group, aryloxy group, aralkyl group and aralkyloxy group may have a substituent, and the substituent is an alkyl group such as a methyl group, an ethyl group and a propyl group; Examples thereof include alkoxy groups such as methoxy group and ethoxy group; halogen atoms such as chlorine atom, bromine atom and iodine atom.

R ³ , R ⁴ , R ⁵ and R ⁶ each represent a hydrogen atom; an alkyl group such as a methyl group, an ethyl group or a propyl group; or an aryl group such as a phenyl group or a naphthyl group, which may be the same as each other. It may be different. These alkyl group and aryl group may have a substituent, and examples of the substituent include an alkyl group such as a methyl group, an ethyl group and a propyl group; an alkoxy group such as a methoxy group, an ethoxy group and a butoxy group; chlorine. Examples thereof include an atom, a halogen atom such as a bromine atom and an iodine atom; an aryl group such as a phenyl group and a naphthyl group.

A and B each represent a group represented by the above general formula [II] or [III], which may be the same or different. R ⁷ , R ⁸ , R ⁹ , R ¹² , R
¹³ and R ¹⁴ are each a hydrogen atom; an alkyl group such as a methyl group, an ethyl group, a propyl group; or a phenyl group,
It represents an aryl group such as a naphthyl group and these may be the same or different from each other. These alkyl group and aryl group may have a substituent, and examples of the substituent include an alkyl group such as a methyl group, an ethyl group and a propyl group; an alkoxy group such as a methoxy group, an ethoxy group and a butoxy group; chlorine. Examples thereof include an atom, a halogen atom such as a bromine atom and an iodine atom; an aryl group such as a phenyl group and a naphthyl group.

R^TenAnd R¹¹Are hydrogen atoms respectively;
Represents an aryl group such as a phenyl group and a naphthyl group.
They may be the same or different from each other. Where R^Ten
And R ¹¹Are not hydrogen atoms at the same time. Also, R^Ten
And R¹¹May be condensed with each other. The aryl group is
It may have a substituent, as the substituent, a methyl group,
Alkyl groups such as ethyl and propyl; methoxy and
Alkoxy groups such as toxy group and butoxy group; chlorine atom, odor
Halogen atom such as elementary atom and iodine atom; dimethylamino
Group, dialkyl-substituted amino group such as diethylamino group; di
Diphenyl such as phenylamino group and phenylnaphthylamino group
Examples thereof include reel-substituted amino groups.

R ¹⁵ and R ¹⁶ each represent an alkyl group such as a methyl group, an ethyl group and a propyl group; or an aryl group such as a phenyl group and a naphthyl group. Particularly, an aryl group is preferable, and these are the same or different. May be. R ¹⁵ and R ¹⁶ may be condensed with each other. These alkyl group and aryl group may have a substituent, and as the substituent, an alkyl group such as a methyl group, an ethyl group and a propyl group; an alkoxy group such as a methoxy group and an ethoxy group; a chlorine atom, a bromine atom And halogen atoms such as iodine atom; dialkyl-substituted amino groups such as dimethylamino group and diethylamino group; and diaryl-substituted amino groups such as diphenylamino group and phenylnaphthylamino group.

M and n each represent an integer of 0 or 1 or more, which may be the same or different, and 0, 1 or 2 is particularly preferable. X represents an alkylene group such as a methylene group, an ethylene group and a propylene group, and may have a substituent, and the substituent includes an alkyl group such as a methyl group, an ethyl group and a propyl group; a methoxy group and an ethoxy group. An alkoxy group such as a butoxy group; a halogen atom such as a chlorine atom, a bromine atom and an iodine atom; an aryl group such as a phenyl group and a naphthyl group.

Ar ¹ , Ar ² and Ar ³ each represent an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a phenylene group or a naphthylene group; or a condensed polycyclic group such as a fluorenyl group or an acenaphthyl group. They may be the same or different from each other. These aromatic hydrocarbon groups and condensed polycyclic groups may have a substituent, and examples of the substituent include an alkyl group such as a methyl group, an ethyl group and a propyl group;
Alkoxy group such as methoxy group, ethoxy group, propyl group; aryl group such as phenyl group, naphthyl group; halogen atom such as chlorine atom, bromine atom, iodine atom; dialkylamino group such as dimethylamino group, diethylamino group;
Examples thereof include diaryl-substituted amino groups such as diphenylamino group and phenylnaphthylamino group.

J represents 0 or an integer of 1 to 4, particularly 0
Or 1 is preferred. l represents 0 or an integer of 1 or more, and 0, 1 or 2 is particularly preferable. k represents 0 or 1. The styryl compound represented by the general formula [I] is particularly preferably the styryl compound represented by the following general formula [IV].

[0020]

[Chemical 6]

In the general formula [IV], R ³ , R ⁴ , R ⁵ ,
R ⁶ , X, A, B, l and k have the same meanings as in formula [I]. ) Representative examples of the styryl-based compound represented by the general formula [I] are shown below. However, these representative examples are shown for the purpose of illustration, and the styryl-based compound used in the present invention is represented by these representative examples. It is not limited to.

[0022]

[Chemical 7]

[0023]

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[0024]

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[0025]

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[0026]

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[0027]

[Chemical 12]

[0028]

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[0029]

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[0030]

[Chemical 15]

[0031]

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The styryl compound represented by the above general formula [I] can be produced by a known method. Speaking of a preferred production method, for example, after performing a carbonyl introduction reaction to a known styryl compound, reduction, bromination,
It is reacted with a trialkyl phosphite to give a phosphonic acid dialkyl ester derivative, which is combined with a known carbonyl compound and Wittig-Hornor-Emmon.
s reaction, then W after the introduction of the carbonyl group
In this method, the target compound is obtained by carrying out the ittig-Hornor-Emmons reaction or the hydrazone-forming reaction a desired number of times. To explain this method in detail,

[0033]

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When R ³ = H: General formula [V] (in the general formulas [V] and [VI], R ¹ , R
² , R ³ , X and j have the same definition as in general formula [I]. ) In the presence of phosphorus oxychloride, a styryl compound represented by the formula: N, N-dimethylformamide, N-
When reacted with a formylating agent such as methylformanilide, an aldehyde derivative represented by the general formula [VI] is obtained. The formylating agent can be used in a large excess and can also serve as a reaction solvent, but a solvent inert to the reaction such as o-dichlorobenzene or benzene can also be used.

When R ³ ≠ H, the styryl compound represented by the general formula [V] is treated with a Lewis acid catalyst such as aluminum chloride, iron chloride or zinc chloride in a solvent such as nitrobenzene, dichloromethane or carbon tetrachloride, by reaction with an acid chloride of the formula Cl-CO-R ^3, carbonyl compound represented by the general formula [VI] is obtained. [Carbonyl introduction reaction]

Then, the general formula [V
The carbonyl compound represented by the formula [I] is reduced with a reducing agent such as sodium borohydride and lithium aluminum hydride to give a compound represented by the general formula [VII] (in the general formula [VII], R ¹ ,
R ² , R ³ , X and j have the same definition as in general formula [I]. ) Is obtained.

[0037]

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Then, the alcohol compound represented by the general formula [VII] is brominated with a brominating agent such as phosphorus tribromide,

[0039]

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General formula [VIII] (in the general formula [VIII],
R ¹ , R ² , R ³ , X and j have the same definition as in general formula [I]. ) Is obtained.
Then, the bromine compound represented by the general formula [VIII] is converted to the general formula P
By reacting with a trialkyl phosphite represented by (OR ¹⁷ ) ₃ (R ¹⁷ represents an alkyl group such as a methyl group and an ethyl group), the compound represented by the general formula [IX] (the general formula [IX]
Wherein R ¹ , R ² , R ³ , X and j have the same definition as in general formula [I]. ) The phosphonic acid dialkyl ester derivative represented by

[0041]

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Next, in the general formula [X] (in the general formula [X],
R^Four, R^Five, R⁶, Ar¹, Ar², Ar^ThreeAnd l is
It has the same definition as in general formula [I]. )
Carbonyl compound and phospho represented by general formula [IX]
Acid dialkyl ester derivative
N, N, N-dimethylformamide, 1,2-dimethoxide
In a solvent such as ciethane, potassium-t-butoxide, sodium
For reacting in the presence of a base such as indium hydride
From the general formula [XI] (in the general formula [XI], R¹, R ², R
^Three, R^Four, R^Five, R⁶, X, Ar¹, Ar², Ar^ThreeOh
And l have the same definition as in general formula [I]
You. ) The styryl compound represented by this is obtained. [Wit
tig-Hornor-Emmons reaction]

[0043]

[Chemical 21]

When A is a group represented by the general formula [II] A carbonyl group is introduced into the styryl compound represented by the general formula [XI] to form the general formula [XII] (general formulas R ¹ , R ² , R ^2
3 , R ⁴ , R ⁵ , R ⁶ , X, Ar ¹ , Ar ² , Ar ³ ,
j, 1, R ⁷ , R ⁸ , R ⁹ and m have the same definition as in general formula [I]. ) Is obtained.

[0045]

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A) When m = 0 The styryl compound represented by the general formula [XI] has the above-mentioned cal
By carrying out a bonyl introduction reaction, it can be represented by the general formula [XII].
A carbonyl compound is obtained. B) In the case of m ≧ 1 In the styryl compound represented by the general formula [XI],
By carrying out a bonyl introduction reaction, the compound of the general formula [XIII] (
R in general formula [XIII]¹, R², R^Three, R^Four, R ^Five,
R⁶, X, Ar¹, Ar², Ar^Three, J, l, R⁷And
And R⁸Has the same definition as in general formula [I]
You. ) Is obtained.

[0047]

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Then, a carbonyl compound represented by the general formula [XIII] and a general formula [R ⁸ —CH ₂ PPh ₃ ] ⁺ W
^- (W represents a halogen atom such as a chlorine atom, a bromine atom or an iodine atom, and Ph represents a phenyl group), and a phosphonium salt represented by sodium methoxide or sodium hydride in the presence of a base, N, N-dimethylformamide,
By reacting in a solvent inert to the reaction such as dioxane, toluene, benzene, etc., the compound represented by the general formula [XIV] (in the general formula [XIV], R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ ,
X, Ar ¹ , Ar ² , Ar ³ , j, l, R ⁷ and R ⁸
Has the same definition as in general formula [I]. ) The styryl compound represented by this is obtained. [Wittig reaction]

[0049]

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When m ≧ 2, the styryl compound represented by the general formula [XIV] is subjected to the Wittig reaction described above after the carbonyl introduction reaction described above (m
-1) general formula [XV] (general formula [XV]
Medium, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , X, A
r ¹ , Ar ² , Ar ³ , R ⁷ , R ⁸ and m have the same definition as in general formula [I]. ) The styryl compound represented by this is obtained.

[0051]

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Next, the styryl compound represented by the general formula [XV] is subjected to the above-mentioned carbonyl introduction reaction to obtain the carbonyl compound represented by the general formula [XII].

[0053]

[Chemical formula 26]

Then, a carbonyl compound represented by the general formula [XII] and a general formula R ¹⁰ R ¹¹ CP (O) (OR ¹⁸ ) (R ¹⁸
Represents an alkyl group such as a methyl group and an ethyl group. ) The phosphonic acid dialkyl ester derivative represented by
The general formula [XVI] (in general formula [XVI], R ¹ ,
R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , X, Ar ¹ , Ar ² ,
Ar ³ , j, l, R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and m have the same definitions as in formula [I]. ) The styryl type compound represented by this is obtained.

[0055]

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When A is a group represented by the general formula [III] A carbonyl group is introduced into the styryl compound represented by the general formula [XI] in the same manner as in the case where A is a group represented by the general formula [II]. , In the general formula [XVII], R ¹ , R ² , R ³ ,
R ⁴ , R ⁵ , R ⁶ , X, Ar ¹ , Ar ² , Ar ³ , j,
l, R ¹² , R ¹³ , R ¹⁴ and n have the same definitions as in the general formula [I]. ) Is obtained.

[0057]

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Next, a carbon dioxide represented by the general formula [XVII]
Compound having the general formula H₂N-NR^FifteenR ¹⁶Hydra represented by
General formula [XVIII] by dehydration condensation with gin
(R in the general formula [XVIII]¹, R², R^Three, R^Four,
R^Five, R⁶, X, Ar¹, Ar², Ar^Three, J, l, R
¹², R¹³, R¹⁴, R^Fifteen, R¹⁶And n are in the general formula [I]
Has the same definition as ) Styryl system
The compound is obtained.

[0059]

[Chemical 29]

The dehydration condensation reaction may be carried out at a temperature of 50 ° C. to 1 if necessary.
Under heating at 50 ° C., in a solvent inert to the reaction such as methanol, ethanol, tetrahydrofuran, N, N-dimethylformamide, etc., if desired, hydrochloric acid as a reaction accelerator,
You may use auxiliary agents, such as paratoluenesulfonic acid and sodium acetate. [Hydrazone reaction]

When k = 1, a carbonyl group is introduced in the same manner as described above with respect to the styryl compound represented by the general formula [XVI] or the general formula [XVIII].
Then, the aforementioned Wittig-Hornor-Emm
The general formula [XIX] (in the general formula [XIX], R ¹ , R ² , R
³ , R ⁴ , R ⁵ , R ⁶ , X, Ar ¹ , Ar ² , Ar ³ ,
A, B, j, and l have the same definition as in general formula [I]. ) The styryl type compound represented by this is obtained.

[0062]

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In these reactions, in some cases,
After each step, or after all steps, recrystallization purification,
A highly purified product can be obtained by a known purification means such as column purification. The electrophotographic photosensitive member of the present invention contains one or two styryl compounds represented by the general formula [I].
It has a photosensitive layer containing at least one species. The styryl compound represented by the general formula [I] exhibits extremely excellent performance as an organic photoconductor. In particular, when used as a charge transport material, it provides a photoreceptor having high sensitivity and excellent durability.

Various forms of the photosensitive layer of the electrophotographic photosensitive member are known, and any of them may be used as the photosensitive layer of the electrophotographic photosensitive member of the present invention. For example, a photosensitive layer containing a styryl compound and optionally a sensitizer dye or an electron-withdrawing compound in a binder, photoconductive particles that generate charge carriers with extremely high efficiency when absorbing light (charge generating substance Particles) together with a photosensitive layer in which a styryl compound is added as a charge transport substance in a binder, a charge transport layer consisting of a styryl compound and a binder, and a charge generation substance that generates charge carriers with extremely high efficiency when absorbing light. And a photosensitive layer in which particles of the substance or particles of the substance and a charge generation layer of a binder are laminated.

In these photosensitive layers, along with the styryl-based compound represented by the general formula [I], other known arylamine-based compounds, hydrazone-based compounds and styryl-based compounds having excellent performance as organic photoconductors are contained. You may mix a compound etc. In the present invention, when the styryl compound represented by the general formula [I] is used in the charge transport layer of the photosensitive layer composed of two layers of the charge generation layer and the charge transport layer, the sensitivity is particularly high and the residual potential is small. Further, when repeatedly used, it is possible to obtain a photoreceptor having excellent durability with little fluctuation in surface potential, decrease in sensitivity, accumulation of residual potential and the like.

In the electrophotographic photoreceptor of the present invention, a styryl compound represented by the above general formula [I] is dissolved in a suitable solvent together with a binder in a suitable solvent according to a conventional method, and light is absorbed if necessary, resulting in an extremely high charge efficiency. A charge generating substance that generates a carrier, a sensitizing dye, an electron-withdrawing compound, or a coating liquid obtained by adding a plasticizer, a pigment and other additives is coated on a conductive support, dried, It can be produced by forming a photosensitive layer having a film thickness of micron to several tens of microns, preferably 10 to 40 microns. In the case of a photosensitive layer consisting of two layers, a charge generation layer and a charge transport layer, the above-mentioned coating layer is applied on the charge generation layer, or the charge generation layer is formed on the charge transport layer obtained by applying the above coating solution. Can be produced.

As the solvent for preparing the coating solution, ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as methyl ethyl ketone and cyclohexane; aromatic hydrocarbons such as toluene and xylene; N, N-dimethylformamide and acetonitrile , N-methylpyrrolidone,
Aprotic polar solvents such as dimethyl sulfoxide; esters such as ethyl acetate, methyl formate and methyl cellosolve acetate; and solvents which dissolve styryl compounds such as chlorinated hydrocarbons such as dichloroethane and chloroform. Of course, it is necessary to select one that dissolves the binder from these. Also, as a binder,
Polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester and butadiene, polyvinyl acetal, polycarbonate, polyester, polystyrene, polyphenylene oxide, polyurethane, cellulose ester, cellulose ether, phenoxy Various polymers compatible with styryl compounds such as resins, silicon resins, and epoxy resins can be mentioned. The amount of the binder used is usually 0.5 to 30 times by weight, preferably 0.7 to 10 times by weight that of the styryl compound.

Well-known materials can be used as the charge-generating substance, dye pigment, and electron-withdrawing compound added to the photosensitive layer. Selenium, selenium-as the charge generating substance
Inorganic photoconductive particles such as tellurium alloy, selenium-arsenic alloy, cadmium sulfide, and amorphous silicon; metal-containing phthalocyanine, perylene pigment, thioindigo, quinacridone, perylene pigment, anthraquinone pigment, azo pigment, bisazo pigment, trisazo Examples include organic photoconductive particles such as pigments, tetrakis azo pigments, and cyanine pigments. In particular, when combined with a metal-containing phthalocyanine, the sensitivity to laser light is improved and an excellent photoreceptor having a small residual potential can be obtained.

Examples of the dyes include triphenylmethane dyes such as methyl violet, brilliant green and crystal violet, thiazine dyes such as methylene blue, quinone dyes such as quinizarine, cyanine dyes, pyrylium salts, thiabilylium salts and benzopyrylium salts. Can be mentioned.

Further, as the electron-withdrawing compound forming a charge transfer complex with a styryl compound, for example, chloranil,
Quinones such as 2,3-dichloro-1,4-naphthoquinone, 1-nitroanthraquinone, 1-chloro-5-nitroanthraquinone, 2-chloroanthraquinone and phenanthrenequinone; aldehydes such as 4-nitrobenzaldehyde; 9-benzoyl Ketones such as anthracene, indandione, 3,5-dihydrobenzophenone, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, 3,3 ', 5,5'-tetranitrobenzophenone Acids such as phthalic anhydride and 4-chloronaphthalic anhydride; tetracyanoethylene,
Terephthalmalononitrile, 9-anthrylmethylidene malononitrile, 4-nitrobenzalmalononitrile,
Cyano compounds such as 4- (p-nitrobenzoyloxy) benzalmalononitrile; 3-benzalphthalide, 3-
(Α-cyano-p-nitrobenzal) phthalide, 3-
(Α-Cyano-p-nitrobenzal) -4,5,6,7
-Electron withdrawing compounds such as phthalides such as 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. Therefore, examples of the plasticizer to be added to the coating solution include phthalic acid esters, phosphoric acid esters, epoxy compounds, chlorinated paraffins, chlorinated fatty acid esters, and aromatic compounds such as methylnaphthalene. When the styryl compound is used as the charge transporting material in the charge transporting layer, the coating solution may have the above composition, but the charge generating material, dye pigment, electron withdrawing compound, etc. may be removed or added in a small amount. The charge generation layer in this case is a thin layer obtained by coating and drying a coating liquid obtained by dissolving or dispersing the above charge generation substance and, if necessary, a solvent such as a binder polymer, an organic charge generation substance, a dye pigment, and an electron-withdrawing compound. Alternatively, a layer formed by depositing the charge generating substance by means such as vapor deposition may be used.

Further, the photosensitive layer of the electrophotographic photosensitive member of the present invention may contain well-known additives in order to improve the electrical characteristics or the durability against repeated use. For this purpose, the additives to be added to the coating solution include phenol compounds, organic phosphorus compounds, organic sulfur compounds and the like. It goes without saying that the photoreceptor thus formed may also have an adhesive layer, an intermediate layer, a transparent insulating layer, etc., if necessary. As the conductive support on which the photosensitive layer is formed, any of those known in electrophotographic photoreceptors can be used. Specifically, for example, a metal drum made of aluminum, stainless steel, copper, or the like,
Examples include a sheet, a laminate of these metal foils, and a vapor deposition product. Further, there may be mentioned plastic films, plastic drums, papers, paper tubes, etc. which have been subjected to a conductive treatment by coating a conductive material such as metal powder, carbon black, copper iodide, or a polymer electrolyte with a suitable binder. In addition, examples include conductive plastic sheets and drums containing conductive materials such as metal powder, carbon black, and carbon fibers.

[0073]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following production examples and examples as long as the gist thereof is not exceeded. In the following, “parts” indicates “parts by weight”.

(Production Example 1) 25.0 g of 1-phenyl-3,4-dihydronaphthalene was dissolved in 70 ml of N, N-dimethylformamide, 60 ml of phosphorus oxychloride was added dropwise, and the mixture was reacted at 60 ° C. for 4 hours. After cooling, the reaction solution was discharged into 200 ml of ice water, hydrolyzed with sodium hydroxide, 150 ml of toluene was added, and the toluene layer was extracted, purified and concentrated by a conventional method to obtain 26.7 g of an aldehyde derivative shown below. It was

[0075]

[Chemical 31]

Next, 25.0 g of the obtained aldehyde compound was mixed with 60 ml of tetrahydrofuran and ethyl alcohol 3
It was dissolved in 0 ml of a mixed solvent, 5.4 g of sodium borohydride was added, and the mixture was reacted at 60 ° C. for 1 hour. After allowing to cool, 150 ml of toluene and 150 ml of water were added, and the toluene layer was extracted, purified and concentrated by a conventional method to obtain 23.7 g of the alcohol compound shown below.

[0077]

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Next, 23.0 g of the obtained alcohol compound was dissolved in 150 ml of tetrahydrofuran, 9.4 g of phosphorus tribromide was added dropwise at 5 to 10 ° C, and the reaction was carried out at 5 to 10 ° C for 2 hours. Toluene (200 ml) and water (200 ml) were added, and the toluene layer was extracted, purified and concentrated by a conventional method to obtain 27.1 g of a bromine product shown below.

[0079]

[Chemical 33]

Then, 10.4 g of triethyl phosphite was added to 27.0 g of the obtained bromine product, and the mixture was reacted at 130 to 140 ° C. for 1 hour and then purified by a conventional method to give a phosphonic acid diethyl ester derivative shown below. 31.3 g was obtained.

[0081]

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Next, 24.0 g of the obtained phosphonic acid diethyl ester derivative and 15.3 g of the aldehyde compound shown below.

[0083]

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Was dissolved in 130 ml of tetrahydrofuran and potassium tert-butoxide 8.6 was added at 15 to 20 ° C.
After the reaction was carried out for 2 hours at room temperature, the reaction product was discharged into a mixed solution of 480 ml of methyl alcohol and 48 ml of water, and the precipitated solid was collected by filtration and purified by a conventional method to give styryl shown below. 15.9 g of compound was obtained.

[0085]

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Then, the obtained styryl compound 15.8
g was suspended in 190 ml of N, N-dimethylformamide, 8.5 ml of phosphorus oxychloride was added dropwise, and the temperature was 65 to 70 ° C.
And reacted for 5 hours. After allowing to cool, the reaction solution is cooled to 200 ml with ice water.
To 200 ml of toluene, 200 ml of toluene was added, and the toluene layer was extracted, purified, and concentrated by a conventional method to give the aldehyde derivative 15.
4 g was obtained.

[0087]

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Then, 6.0 g of the obtained aldehyde derivative and 4.0 of the phosphonic acid diethyl ester derivative shown below were obtained.
g

[0089]

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After dissolving in 20 ml of tetrahydrofuran and adding 2.4 g of potassium-t-butoxide at 15 to 20 ° C. and reacting at room temperature for 1 hour, the reaction product was discharged into 200 ml of methyl alcohol, and the precipitated solid was filtered. It was taken and purified by a conventional method to obtain 5.2 g of a yellow powder (melting point 180 to 181 ° C.). This compound was found to be a styryl compound (Exemplified Compound No. 1) shown below from the elemental analysis values and the infrared absorption spectrum (FIG. 1).

[0091]

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[0092]

Table 1 Elemental analysis value C ₅₀ H ₃₉ N C (%) H (%) N (%) Calculated value 91.85 6.01 2.14 Measured value 91.84 5.99 2.12

(Production Example 2) 3.0 g of the following aldehyde obtained in the middle of Production Example 1

[0094]

[Chemical 40]

1.6 g of 1,1-diphenylhydrazine
Was reacted at 60 ° C. for 2 hours in a mixed solvent of 10 ml of tetrahydrofuran and 10 ml of methyl alcohol under an acetic acid catalyst. The reaction solution was discharged into 100 ml of methyl alcohol, and the precipitated solid was collected by filtration and purified by a conventional method to give 2.4 g of a yellow powder (melting point 194 to 195.5).
° C). This compound was found to be a styryl compound (No. 25) shown below from the elemental analysis values and the infrared absorption spectrum (FIG. 2).

[0096]

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[0097]

Table 2 Elemental analysis value C ₄₉ H ₃₉ N ₃ C (%) H (%) N (%) Calculated value 87.86 5.87 6.27 Measured value 87.85 5.84 6.23

(Production Example 3) 2.0 g of the styryl compound (Exemplified Compound No. 1) obtained in Production Example 1 was dissolved in 20 ml of N, N-dimethylformamide, and 1.4 ml of phosphorus oxychloride was added dropwise. The reaction was carried out at 60 to 65 ° C for 5 hours. After cooling, the reaction product was discharged into 80 ml of ice water, hydrolyzed with sodium hydroxide, and added with 50 ml of toluene.
The toluene layer was extracted, purified and concentrated by a conventional method to obtain 1.9 g of an aldehyde derivative shown below.

[0099]

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Next, 1.8 g of the obtained aldehyde compound and 0.9 g of the phosphonic acid diethyl ester derivative shown below were added.

[0101]

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It was dissolved in 5 ml of tetrahydrofuran, 0.5 g of potassium-t-butoxide was added at 15 to 20 ° C., and the mixture was reacted at room temperature for 1 hour. The reaction solution was discharged into 500 ml of methyl alcohol, and the precipitated solid was collected by filtration and purified by a conventional method to obtain 2.0 g of a styryl compound (Exemplified Compound No. 32) shown below.

[0103]

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(Production Example 4) Triphenylphosphine 2.
4 g was dissolved in 6 ml of N, N-dimethylformamide,
After 1.9 g of methyl iodide was added dropwise at 20 to 30 ° C., the following aldehyde derivative 3.0 obtained in the middle of Production Example 1 was obtained.
g to N, N-dimethylformamide

[0105]

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It was dissolved in 5 ml and added, and 3.3 g of 28% methyl alcohol solution of sodium methoxide was added dropwise to 50
The reaction was performed at 0 ° C for 2 hours. After cooling, the reaction product was discharged into 30 ml of ice water, 20 ml of toluene was added, and the toluene layer was extracted, purified and concentrated by a conventional method to obtain 2.8 g of a styryl derivative shown below.

[0107]

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2.8 g of the obtained styryl derivative was dissolved in 30 ml of N, N-dimethylformamide, 0.8 ml of phosphorus oxychloride was added dropwise, and the mixture was reacted at 60 to 65 ° C. for 3 hours. After cooling, the reaction product was discharged into 50 ml of ice water, hydrolyzed with sodium hydroxide, 40 ml of toluene was added, and the toluene layer was extracted, purified, and concentrated by a conventional method to give 2.3 g of an aldehyde derivative shown below. Obtained.

[0109]

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Next, 2.3 g of the obtained aldehyde and 1.3 g of 1,1-diphenylhydrazine were treated with an acetic acid catalyst,
Tetrahydrofuran 10 ml and methyl alcohol 1
The reaction was carried out in 0 ml of a mixed solvent at 60 ° C. for 2 hours. After allowing to cool, the reaction product was extracted with 30 ml of toluene, and purified and concentrated by a conventional method to obtain 1.9 g of a styryl compound (Exemplified Compound No. 28) shown below.

[0111]

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(Example 1) 1.0 part of a naphthalic acid-based bisazo pigment represented by the following structural formula was used.

[0113]

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In addition to 14 parts of dimethoxyethane, a dispersion treatment was carried out with a sand grinder.
Parts and 4-methoxy-4-methylpentan-2-one 14
And diluted with polyvinyl butyral (produced by Denki Kagaku Kogyo Co., Ltd., trade name Denka Butyral # 600).
0-C) and phenoxy resin (manufactured by Union Carbide Co., trade name UCAR (registered trademark) PKH)
H) 0.5 parts of dimethoxyethane 6 parts, 4-methoxy-
4-Methylpentan-2-one was mixed with a liquid dissolved in a mixed solvent of 6 parts to obtain a dispersion liquid. This dispersion is dried on an aluminum vapor-deposited layer vapor-deposited on a polyester film having a thickness of 75 μm and the weight after drying is 0.4 g / m ² (about 0.4 μm).
And then dried to form a charge generating layer. Polycarbonate resin having 90 parts of the styryl compound produced in Production Example 1 and the structure shown below

[0115]

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A coating liquid prepared by dissolving 100 parts in a mixed solvent of 585 parts of tetrahydrofuran and 315 parts of dioxane was applied and dried to form a charge transport layer having a thickness of 20 μm.
When the sensitivity, that is, the half-exposure amount was measured with the electrophotographic photosensitive member having the photosensitive layer composed of two layers thus obtained, it was 0.50 lux · sec. The half-exposure amount is as follows. First, the photoconductor is negatively charged by a corona current of 50 μA in the dark, and then exposed with white light of 1 lux, and the surface potential is −.
It was determined by measuring the exposure amount required to attenuate from 450V to -225V. Furthermore, the exposure time is 9.9.
When the surface potential in seconds was measured as the residual potential, it was -5V. This operation was repeated 2000 times, but no increase in residual potential was observed.

Example 2 Instead of the naphthalic acid bisazo pigment used in Example 1, the following structural formula was used.

[0118]

[Chemical 51]

A photoreceptor prepared in the same manner as in Example 1 except that the naphthalic acid-based bisazo pigment represented was used was exposed to white light, and the half-exposure amount was measured to be 0.61 lu.
It was x · sec. The residual potential was -6V.

Example 3 In place of the naphthalic acid-based bisazo pigment used in Example 1, an X-ray diffraction spectrum using Cu-Kα radiation was used to measure the Bragg angle (2θ ± 0.2).
°) 9.3 °, 10.6 °, 13.2 °, 15.1 °,
15.7 °, 16.1 °, 20.8 °, 23.3 °, 2
Prepared in the same manner as in Example 1 except that a titanium oxyphthalocyanine pigment showing a strong diffraction peak at 7.1 ° was used, 70 parts instead of 90 parts of the styryl compound was used, and a charge transport layer having a film thickness of 17 μm was formed. 780
When exposed to light having a wavelength of 500 nm (light amount: 500 nW) and the half-exposure amount was measured, it was 0.48 μJ / cm ² . The residual potential was -5V.

(Example 4) In place of the titanium oxyphthalocyanine pigment used in Example 3, an X-ray diffraction spectrum using Cu-Kα rays was used to determine the Bragg angle (2θ).
(± 0.2 °) A photoreceptor prepared in the same manner as in Example 3 except that a titanium oxyphthalocyanine pigment showing strong diffraction peaks at 9.5 °, 27.1 °, and 27.3 ° was used, was exposed to light of 780 nm. When exposed and measured the half exposure,
It was 0.20 μJ / cm ² . The residual potential was -7V.

(Examples 5 to 10) Instead of the styryl compound used in Example 1, a styryl compound shown in Table 1 below, which was synthesized in the same manner as in Production Examples 1 to 4, was used. Table 3 shows the sensitivity and residual potential of the electrophotographic photosensitive member prepared in the same manner as in.

[0123]

Table 3 Table 1 Example Example compound No. Sensitivity (lux · sec) Residual potential (V) 5 11 0.48 -5 6 13 0.52 -4 7 19 0.54 -4 8 25 25 0.51 -6 9 28 0.56 -5 10 36 0. 47 -3

Examples 11 to 16 Example 3 was repeated except that the styryl compounds used in Example 1 were replaced by the styryl compounds shown in Table 2 below, which were synthesized in the same manner as in Production Examples 1 to 4. Table 2 shows the sensitivity and residual potential of the electrophotographic photosensitive member prepared in the same manner as in.

[0125]

Table 4 Example 2 Exemplified Compound No. Sensitivity (μJ / cm ² ) Residual potential (V) 11 11 0.47 -5 12 13 0.45 -3 13 19 0.45 -3 14 25 0.43 -3 15 15 28 0.42 -3 16 360 .46-5

(Comparative Examples 1 to 3) The sensitivity and residual potential of the electrophotographic photosensitive member prepared in the same manner as in Example 1 except that the following comparative compound was used in place of the styryl compound used in Example 1 It is shown in Table 3.

[0127]

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[0128]

[Table 5] Table 3 Comparative Examples Comparative Compounds Sensitivity (lux · sec) Residual potential (V) 1 Comparative Compound 1 0.58-11 2 Comparative Compound 2 0.63-10 3 Comparative Compound 3 0.60-8

[0129]

The electrophotographic photosensitive member of the present invention has a very high sensitivity and a small residual potential that causes fogging. Further, since light fatigue is small, accumulation of residual potential due to repeated use and strong exposure and A printer such as a laser printer, a liquid crystal shutter printer, an LED printer, etc., which has a small change in surface potential and sensitivity and is excellent in durability and is not only suitable for PPC but also required to have stable performance and reliability. It is also a photoconductor that is also suitable as a photoconductor.

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum diagram of a styryl compound produced in Production Example 1.

FIG. 2 is an infrared absorption spectrum diagram of a styryl compound produced in Production Example 2.

Claims (4)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the photosensitive layer has the following general formula [I]:
An electrophotographic photoreceptor containing a styryl compound represented by: Embedded image (In the general formula [I], R ¹ represents an alkyl group which may have a substituent or an aryl group which may have a substituent; R ² represents an alkyl which may have a substituent. Group, an alkoxy group which may have a substituent, an aryl group which may have a substituent, an aryloxy group which may have a substituent, an aralkyl group which may have a substituent Or represents an aralkyloxy group which may have a substituent; R ³ , R ⁴ , R ⁵ and R ⁶ each have a hydrogen atom, an alkyl group which may have a substituent or a substituent. And A and B each represent a group represented by the following general formula [II] or [III], which may be the same or different from each other. They may be different; [In the general formulas [II] and [III], R ⁷ , R ⁸ , R ⁹ , R ¹² , R ¹³ and R ¹⁴ are each a hydrogen atom, an alkyl group which may have a substituent or a substituent Represents an optionally substituted aryl group, which may be the same or different from each other; R ¹⁰ and R
¹¹ each represent a hydrogen atom or an optionally substituted aryl group, these may be the same or different from each other, R ¹⁰ and R ¹¹ may be fused together, provided that R ¹⁰ And R ¹¹ are not hydrogen atoms at the same time; R ¹⁵ and R ¹⁶ each represent an alkyl group which may have a substituent or an aryl group which may have a substituent. They may be the same or different from each other, and R ¹⁵ and R ¹⁶ may be condensed with each other; m and n each represent an integer of 0 or 1 or more, and these may be the same or different from each other. In the general formula [I], X represents an alkylene group which may have a substituent; Ar ¹ , Ar ² and Ar ³ are
Each represents an aromatic hydrocarbon group which may have a substituent or a condensed polycyclic group which may have a substituent, and these may be the same or different from each other; j is 0 or 1 to 1 Represents an integer of 4; l represents an integer of 0 or 1 or more; k represents 0 or 1. ) 2. The electrophotographic photosensitive member according to claim 1, wherein the styryl compound represented by the general formula [I] is represented by the following general formula [IV]. Embedded image [In the general formula [IV], R ³ , R ⁴ , R ⁵ , R ⁶ , X, A,
B, l and k have the same meanings as in formula [I]. ) 3. The photosensitive layer contains a charge generating substance and a charge transporting substance, and the styryl compound represented by the general formula [I] according to claim 1 is used as the charge transporting substance. Item 1. The electrophotographic photosensitive member according to item 1. 4. The photosensitive layer according to claim 1, wherein the photosensitive layer has at least a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance and a binder resin. The styryl compound represented by the general formula [I] is used, and the electrophotographic photosensitive member according to claim 1 or 3.