JP2593347B2 - Photoconductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photoreceptor, for example, an electrophotographic photoreceptor.

B. 2. Description of the Related Art As an electrophotographic photoreceptor, not only electrophotographic characteristics such as good charging characteristics and sensitivity but also low dark decay are required, but in addition, printing durability, abrasion resistance, moisture resistance, etc. in repeated use. Good physical properties, resistance to ozone generated during corona discharge, resistance to ultraviolet light during exposure, etc. (environmental resistance) are also required.

In recent years, the use of various organic photoconductive substances as materials for photosensitive layers of electrophotographic photosensitive members has been actively developed and studied in recent years. According to such an organic electrophotographic photoreceptor,
Since the photosensitive layer can be formed by coating, the manufacturing cost is low,
Pollution and environmental pollution can be prevented, and it can be easily processed into various shapes (such as sheets).

However, the organic electrophotographic photoreceptor has the following drawbacks, and there is a strong demand for solving these drawbacks.

(A) For example, when a layer is formed by binding a low-molecular organic compound with a high-molecular organic resin (binder), the mechanical strength is not always sufficient, and when the photoreceptor is repeatedly used, the developing blade is rubbed. For example, the surface of the photoreceptor is scratched or the surface is worn.

(B) The photoreceptor is mainly used for negative charging. A thin carrier generation layer is provided on a support as described in JP-A-60-247647, and a relatively thick carrier transport layer is provided thereon. A configuration is provided.

The reason for this is that, in the case of negative charging, the hole mobility of the carrier is large, so that a hole transporting material can be used, which is advantageous in terms of photosensitivity and the like, whereas the electron transporting property is advantageous. This is because few of the materials have excellent properties, or they cannot be used because they have carcinogenicity and teratogenicity.

However, at the time of negative corona discharge or at the time of negative charging by the charger, the amount of ozone generated in the atmosphere is large, resulting in deterioration of environmental conditions. For this reason, the adsorption of the ionic substance to the photoreceptor surface and the deterioration of the material of the photoreceptor surface cause the potential to drop when repeatedly used, causing a rise in the residual potential, a decrease in sensitivity, and a deterioration in image quality. Decreases the life of the photoconductor.

(C) Since equipment such as an electrophotographic copying machine is used under various conditions for a long period of time, it is often placed under conditions of high temperature and high humidity. Therefore, a practical photoreceptor having high environmental resistance is demanded.

C. Object of the Invention The object of the present invention is high mechanical strength, charging potential characteristics,
An object of the present invention is to provide a photoreceptor having excellent sensitivity characteristics, residual potential characteristics, and excellent environmental resistance.

D. The present invention relates to a photoreceptor obtained by sequentially laminating a carrier generating layer and a carrier transporting layer on a conductive support, wherein the structural unit represented by the following general formula [I] A resin having at least one of the structural units represented by Formula (II) as a repeating unit is contained in at least a surface region on a surface side on which the carrier transport layer is provided, and the carrier transport layer is a lower layer on the conductive support side. And an upper layer on the surface region side, and the lower layer has a thickness of 5 to 30 μm,
The thickness of the upper layer is 0.1 to 10 μm, and the content ratio (weight ratio, carrier transport material / binder resin) of the carrier transport material in the lower layer to the binder resin is based on the binder resin of the carrier transport material in the upper layer. Content ratio (weight ratio, carrier transport material / binder resin)
The photoreceptor is 10% by weight or more.

General formula [I] (R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ are each a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group, a substituted or unsubstituted Represents a substituted carbocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted alkoxy group, and further R ⁹ and R ¹⁰ are jointly substituted or unsubstituted carbocyclic or substituted or unsubstituted It may be an atom group or atoms necessary for constituting a heterocyclic ring. Where R ¹ ,
At least one of R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ represents a fluorine atom or a substituent having a fluorine atom. General formula [II] (R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰
Each hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted aromatic group, or a substituted or represents unsubstituted alkoxy group, further the R ¹⁹ R ²⁰ may be a group or atoms necessary to form a substituted or unsubstituted carbon ring or a substituted or unsubstituted heterocyclic ring. Where R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R
^At least one of ²⁰ represents a fluorine atom or a substituent having a fluorine atom. The “surface region on the surface side on which the carrier transport layer is provided” means a region on the surface side of the photoreceptor (opposite the conductive substrate).

The photoreceptor of the invention has a remarkable feature in that the carrier transport layer is divided into two constituent layers, and the respective carrier transport substance concentrations are changed.

That is, the “constituent layer of the carrier transport layer” on the conductive support side
Since the concentration of the carrier transporting material is made higher in the above, the photocarriers generated in the carrier generating layer are efficiently injected into the carrier transporting layer.

Further, since the concentration of the carrier transporting substance in the “constituent layer of the carrier transporting layer” on the photoconductor surface area side is lower, the lower the concentration of the low molecular weight carrier transporting substance,
The mechanical strength of the carrier transport layer can be increased.

Further, it is important that at least the surface region on the carrier transport layer side of the photoreceptor contains a resin having a structural unit represented by the above general formula [I] or [II] as a repeating unit.

That is, these resins are excellent in mechanical strength, scratch resistance, abrasion resistance, printing durability, and charging performance. In particular, it has a feature that the surface is hard and has an appropriate slip property, and has good transparency and insulating properties, and also has excellent compatibility with a carrier transporting substance.

Moreover, these resins are difficult for ozone to penetrate,
The carrier transporting material is less likely to deteriorate. In conjunction with this, the concentration of the carrier transporting material in the “constituent layer of the carrier transporting layer” on the photoconductor surface region side is further reduced, so that the degree of deterioration of the carrier transporting material is further reduced.

Next, the general constitution of the photoreceptor of the present invention is illustrated in FIGS.

The photoreceptor shown in FIG. 1 has a carrier generation layer 2 provided on a conductive support 1, and a carrier transport layer 3 composed of constituent layers 3A and 3B provided on the carrier generation layer 2. 2, the conductive support 1 is formed by providing a conductive layer 1B on a flexible base 1A. In the photoconductor of FIG. 4, an intermediate layer or an undercoat layer 6 is provided between the carrier generation layer 2 and the conductive support 1 in the photoconductor of FIG.

The content ratio (weight ratio, carrier transporting material / carrier transporting material / binder ratio) of the carrier transporting material to the binder material in the carrier transporting layer constituting layer (constituting layer 3B in the examples of FIGS. 1 to 4) on the uppermost layer side.
The binder material is preferably 70% by weight or less, more preferably 5 to 70% by weight. Thereby, the film forming strength can be increased, and the carrier transport ability is not hindered.

The content ratio of the carrier transporting substance to the binder substance in the carrier transporting layer constituting layer on the lowermost side (constituting layer 3A in the example of FIGS. 1 to 4) is 30% by weight or more, and more preferably 30 to 30% by weight.
Preferably it is 300% by weight. Thereby, the ability to inject light carriers from the carrier generation layer can be increased. It should be noted that the content ratio of the carrier transporting substance is set to, for example, 30.
This can be made as large as 0% by weight, which is made possible by increasing the film forming strength of the carrier transport layer constituting layer on the photosensitive member surface region side.

The content ratio of the carrier transporting substance to the binder substance in the carrier transporting layer constituting layer on the uppermost layer side (carrier transporting substance / binder substance, weight ratio), and the ratio of the carrier transporting substance to the binder substance in the carrier transporting layer constituting layer on the lowermost layer side It is preferable that there is a difference of 10% by weight or more from the content ratio.

The thickness of the lower constituent layer 3A is preferably 5 to 50 μm,
More preferably, it is 30 μm. The thickness of the upper layer 3B is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.

The thickness of the carrier generation layer is preferably 0.01 to 10 μm, more preferably 0.1 to 5 μm.

The binder of each constituent layer of the carrier transport layer may be a resin having a structural unit represented by the general formulas [I] and [II]. Thereby, the film forming strength is further increased.

 Next, the materials and prescriptions constituting the photoreceptor will be described.

First, a resin having at least one of the structural unit represented by the general formula [I] and the structural unit represented by the general formula [II] as a main repeating unit will be described.

The resin used in the photoreceptor of the present invention is obtained by introducing fluorine into the structure of a so-called polycarbonate or polyarylate.

This resin has a structural unit represented by the general formula [I] and / or [II] as a main repeating unit. Here, among the various structural units represented by the general formulas [I] and [II], only one kind may be co-condensed, or many kinds may be co-condensed. Furthermore, structural units having no fluorine atom in any of R ^{1 to} R ¹⁰ and R ^{11 to} R ^{20 in} the general formulas [I] and [II] (for example, all of R ^{1 to} R ⁸ are hydrogen atoms And a structural unit in which R ⁹ and R ¹⁰ are methyl groups) and structural units represented by formulas [I] and [II]. In this case, the general formula [I],
The proportion of the fluorine-containing structural unit represented by [II] is preferably at least 20 mol%, more preferably at least 50 mol%.

Further, if necessary, for the purpose of further improving the physical, chemical and electrical properties, etc., structural units other than the structural units represented by the general formulas (I) and (II) may be contained, and co-condensation may be performed. May be.

Further, a homopolymer comprising only the structural units represented by the general formulas [I] and [II] is preferable.

Next, the contents of the structural units represented by the general formulas [I] and [II] will be described.

In the general formulas (I) and (II), `` as the aliphatic group,
Examples of a methyl group, an ethyl group, a propyl group and the like, examples of the `` carbocyclic group '' include a cyclohexyl group and the like, examples of the `` aromatic group '' include a phenyl group and a naphthyl group, and examples of the `` alkoxy group '' Is, for example, a methoxy group. Examples of the “substituted aliphatic group” include a perfluoroalkyl group, a chlorofluoroalkyl group, an ethoxycarbonyl group, a butoxycarbonyl group, and the like. Examples of the substituent of the “carbocyclic group” include a chloro atom.
Examples of the substituent of the “aromatic group” include an alkyl group, a perfluoromethyl group, a fluorine atom, and a perfluoropropyl group. Examples of the “substituted alkoxy group” include a perfluoromethoxy group.

When R ⁹ and R ¹⁰ (or R ¹⁹ and R ²⁰ ) form a carbocyclic ring,
Examples of the carbocycle include a cycloalkyl ring such as a cyclopentane ring and a cyclohexane ring, and a bicycloalkyl ring. Examples of the “substituted carbocycle” include a perfluorocycloalkyl ring and an acetylcycloalkyl ring.
Examples of the “heterocycle” include those composed of a carbon atom, an oxygen atom and the like.

In the general formulas [I] and [II], R ⁹ , R ¹⁰ (R ¹⁹ ,
At least one of R ²⁰ ) can be a bulky group. Such a bulky group preferably has 3 or more carbon atoms and has a steric hindrance such as hindering the molecular chain arrangement.

R ^9, one (one or R ^19, R ²⁰⁾ of R ¹⁰ when Gakasa a high group and the other is a hydrogen atom, a fluorine atom, an alkyl group such as a methyl group, may be a perfluoromethyl group R ⁹ and (de and or R ¹⁹ and R ²⁰⁾ and R ¹⁰ in the case of forming the ring, preferably a carbon ring or a 5- or 6-membered heterocyclic ring.

When a bulky group is used for at least one of R ⁹ and R ¹⁰ (or R ¹⁹ , R ²⁰ ) or a cyclic structure is formed, it is effective to arrange fat molecular chains in a specific direction. It is thought that it can be prevented. Therefore, it is considered that the crystallinity of the resin can be reduced.

The above resin has excellent mechanical strength, scratch resistance, abrasion resistance, printing durability, and good charging performance. In particular, it has a feature that the surface is hard and has an appropriate slip property, and has good transparency, insulating property, cleaning property, and excellent compatibility with CTM.

In particular, it has been found that a fluorine atom is contained, but transparency is not lost by polymerization, and even if the above-mentioned resin is contained in the surface region of the photoreceptor, there is an effect that light transmission is not blocked. Further, there is an effect of increasing the sensitivity. Although the reason for this is not clear, it is considered that it is due to the strong electron-withdrawing property of the fluorine atom.

Hereinafter, the structural units represented by the general formulas [I] and [II] will be exemplified, but the present invention is not limited thereto.

In order to obtain a polycarbonate having a structural unit represented by the general formula [I], at least one of bisphenols represented by the following general formula (I) is used, and a general polycarbonate synthesis method such as a phosgene method is applied. Good.

In order to obtain a polyarylate having a structural unit represented by the general formula [II], a general polyarylate synthesis method such as a terephthalic acid method is used by using one or more of bisphenols represented by the following general formula (2). Just apply.

Further, the following modified polycarbonates (3),
What consists of copolymerization of (4) is preferable.

R ²¹ , R ²² , R ²³ and R ²⁴ each represent a hydrogen atom, an alkyl group (preferably having 1 to 3 carbon atoms) or a halogen atom.

R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ each represent a hydrogen atom, an alkyl group (preferably having 1 to 3 carbon atoms) or a halogen atom. R ²⁹ and R ³⁰ each represent a hydrogen atom, an alkyl group, (preferably having 1 to 3 carbon atoms) or a phenyl group.

Viscosity average molecular weight of this modified polycarbonate 10,000 ~
100,000 is preferred, and 15,000 to 50,000 is more preferred.

This modified polycarbonate has the following general formula (5):
It can be synthesized according to a conventional method using the bisphenol compound of (6).

The usage ratio of (5) and (6) is [(5):
(6)] = (95: 5) to (1:99), preferably (70:30)
To (5:95) are more preferred.

Specific examples of the above (5) include 1,1,1,3,3,3-hexafluoro-2,2-bis (4-hydroxyphenyl) propane, 1,1,1,3,3,3- Hexafluoro-2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1,1,3,3,
3-hexafluoro-2,2-bis (4-hydroxy-3,5
-Dimethylphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (4-hydroxy-3-chloro-
5-methylphenyl) propane and 1,1,1,3,3,3-hexafluoro-2,2-bis [4-hydroxy-3- (2-propyl) phenyl] -propane.

Specific examples of the above (6) include 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, and 2,2-bis (4-hydroxy-3-methylphenyl) propane. Bis (4-hydroxy-3-chloro-5-methylphenyl) propane, 2,2-bis [4-hydroxy-3- (2-propyl) phenyl] propane, 1,1, bis (4-hydroxy-3- Methylphenyl) ethane, 1,
1-bis (4-hydroxy-3,5-dimethylphenyl) ethane, bis (4-hydroxyphenyl) methane, 1,1-
Bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4
-Hydroxyphenyl) butane, 1-phenyl-2,2-
Bis (4-hydroxyphenyl) ethane and the like can be mentioned.

The modified polycarbonate specifically, methylene chloride, in the presence of an inert solvent such as 1,2-dichloroethane,
An alkaline aqueous solution or pyridine is added as an acid acceptor to the bisphenol-based compound, and the mixture is reacted while introducing phosgene.

When an aqueous alkaline solution is used as the acid acceptor, the reaction rate increases when a tertiary amine such as trimethylamine or triethylamine or a quaternary ammonium compound such as tetrabutylammonium chloride or benzyltributylammonium bromide is used as a catalyst. If necessary, a monohydric phenol such as phenol or p-tert-butylphenol may be present as a molecular weight regulator. The catalyst may be added from the beginning, or may be added after synthesizing the oligomer to increase the molecular weight.

This modified polycarbonate has excellent solubility in organic solvents and is well soluble in non-halogen solvents such as ethyl acetate, THF, and 1,4-dioxane.

The following method can be used to copolymerize two or more bisphenols.

(A) A method in which one is first reacted with phosgene, and after a certain degree of reaction, the other is added and polymerized. (B) An oligomer is produced by separately reacting with phosgene.
(C) Method of simultaneously reacting two or more bisphenol compounds with phosgene for copolymerization Next, the carrier transporting material contained in the carrier transporting layer will be described.

Preferred examples of the carrier transporting substance include the following general formulas.

General formula [III]: (Wherein, in this general formula, R ^{23 is a} substituted or unsubstituted aryl group, R ^{24 is a} hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, an amino group, a hydroxyl group, a substituted amino group, R ²⁵ : Represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group.) General formula [IV]: (Wherein, in this general formula, R ²⁶ and R ²⁷ each represent a hydrogen atom or a halogen atom; R ²⁸ and R ²⁹ each represent a substituted or unsubstituted aryl group; Ar ³ represents a substituted or unsubstituted arylene group; .) General formula [V]: (Wherein, in this general formula, R ³⁰ : a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, R ³¹ : a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group , Q: a hydrogen atom, a halogen atom, an alkyl group, a substituted amino group, an alkoxy group or a cyano group, p: 0 represents an integer of 1 or 1.) General formula [VI]: (Wherein, in this general formula, R ³² : substituted or unsubstituted aryl or substituted or unsubstituted heterocyclic group, R ³³ : hydrogen atom, substituted or unsubstituted alkyl group or substituted or unsubstituted aryl group, Q : A hydrogen atom, a halogen atom, an alkyl group, a substituted amino group, an alkoxy group or a cyano group, and represents an integer of q: 0 or 1.) General formula [VII] (However, in this general formula, l: 0 or the integer ^{1, R 34, R 35, R} 36: a substituted or unsubstituted aryl group, R ^37, R ^38: a hydrogen atom, an alkyl of 1 to 4 carbon atoms Group,
Or a substituted or unsubstituted aryl group or aralkyl group (provided that R ²⁷ and R ²⁸ are not both hydrogen atoms, and when 1 is 0, R ²⁷ is not a hydrogen atom). General formula [VIII]: (In the formula, R ³⁹ and R ⁴⁰ represent a substituted or unsubstituted alkyl group or phenyl group, and an alkyl group, an alkoxy group, or a phenyl group is used as the substituent.

R ⁴¹ : a substituted or unsubstituted phenyl group, naphthyl group,
Represents an anthryl group, a fluorenyl group or a heterocyclic group, and an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, or a phenyl group is used as a substituent.

R ^{41 represents a} hydrogen atom, a substituted or unsubstituted alkyl group, or a phenyl group.

R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ : represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or an alkylamino group. ) General formula [IX]: (However, in this general formula, Ar ⁴ and Ar ⁵ represent a substituted or unsubstituted phenyl group,
As the substituent, a halogen atom, an alkyl group, a mitro group,
Use an alkoxy group.

Ar ⁶ : a substituted or unsubstituted phenyl group, naphthyl group,
Represents an anthryl group, a fluorenyl group, or a heterocyclic group, and the substituent is an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an aryloxy group, an aryl group, an amino group, a nitro group, a piperidino group, a morpholino group, a naphthyl group, anthryl Groups and substituted amino groups are used. However, an acyl group, an alkyl group, an aryl group, or an aralkyl group is used as a substituent of the substituted amino group. ) General formula [X] (D represents a substituted or unsubstituted phenyl group or a substituted or unsubstituted carbazolyl group.

In particular, Is mentioned.

R ⁴⁶ and R ⁴⁷ represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group, examples of the aralkyl group include a benzyl group and a phenethyl group, and examples of the aryl group include a phenyl group, an α-naphthyl group, and a β-naphthyl. And the like. Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, a substituted amino group (dimethylamino group,
Diethylamino group, dipropylamino group, dibenzylamino group) and the like.

R ⁴⁸ , R ⁴⁹ and R ⁵⁵ represent the same as R ⁴⁶ and R ⁴⁷ . R ⁵⁰ ,
R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ and R ⁵⁶ represent an alkyl group, an alkoxy group, a halogen atom or the like. These CTMs are specifically exemplified in Japanese Patent Application No. 59-28309. Carrier-generating substances that can be used in the carrier-generating layer are described, for example, in Japanese Patent Application No. 63-211536,
This is exemplified in the specification of 9-28309.

 The following are also preferable as the carrier generating substance.

General formula [XI]: General formula [X II]: General formula [XIII]: (In the above formulas, X represents a halogen atom, a nitro group, a cyano group, an acyl group or a carboxyl group;
An integer of 4 and m represents an integer of 0 to 6. General formula [XVI]: [X ¹ and X ² each represent a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a nitro group, a cyano group, a hydroxy group or a substituted or unsubstituted amino group, X ¹ And at least one of X ² is a halogen atom.

p and q each represent an integer of 0, 1 or 2, p and q are not simultaneously 0, and when p is 2, X ¹ may be the same or different group; Is 2
In this case, X ² may be the same or different groups.

 A represents a group represented by the following general formula [XVII].

General formula (X VII) (Wherein, Ar ¹⁰ represents an aromatic carbocyclic group or an aromatic heterocyclic group having at least a fluorinated hydrocarbon group. Z is a substituted or unsubstituted aromatic carbocyclic ring or a substituted or unsubstituted aromatic heterocyclic ring Represents a group of non-metallic atoms necessary to form a.) M and n each represent an integer of 0, 1 or 2. However, m and n do not become 0 at the same time. Examples of the halogen atom represented by X ¹ and X ^{2 in the} general formula [XVI] include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. Of X ¹ and X ^2, at least one is a halogen atom.

The alkyl group represented by X ¹ and X ² has 1 carbon atom
And 4 or more substituted or unsubstituted alkyl groups are preferred. Examples of such alkyl groups include, for example, methyl, ethyl, β-cyanoethyl, iso-propyl, trifluoromethyl, t-butyl and the like. And the like.

The alkoxy group represented by X ¹ and X ² is preferably a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms. Examples of such an alkoxy group include a methoxy group, an ethoxy group and a β- Chlorethoxy group, sec-
Butoxy group and the like.

Further, as the substituted or unsubstituted amino group represented by X ¹ and X ² , for example, those substituted with an alkyl group, an aryl group (preferably a phenyl group) and the like, for example, an N-methylamino group, an N-ethylamino group Group, N, N-dimethylamino group, N, N-diethylamino group, N-phenylamino group, N, N-diphenylamino group and acetylamino group further substituted with acyl group, p-chlorobenzoylamino group And the like.

In the general formula [XVI], p and q are
Represents 0, 1 or 2, wherein p and q are not simultaneously 0, and preferably p = 1, q = 0 or p = 1, q =
This is the case of 1.

Furthermore, when p or q is 2, X ¹ or X ² may each be the same or different.

In the general formula [XVI], A is represented by the following general formula [XVII].

General formula (X VII) In the formula, Ar ¹⁰ represents an aromatic carbocyclic group or an aromatic heterocyclic group having at least one fluorinated hydrocarbon group, wherein the fluorinated hydrocarbon group has 1 to 4 carbon atoms. Are preferable, and examples thereof include a trifluoromethyl group, a pentafluoroethyl group, a tetrafluoroethyl group, and a heptafluoropropyl group. Among these, a more preferred fluorinated hydrocarbon group is a trifluoromethyl group. Examples of the aromatic carbocyclic group include a phenyl group, a naphthyl group and an anthryl group,
Preferably it is a phenyl group. Further, examples of the aromatic heterocyclic group include a carbazolyl group and a dibenzofuryl group. Furthermore, as the substituent other than the fluorinated hydrocarbon group in the aromatic carbocyclic group and the aromatic heterocyclic group, for example, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, for example, a methyl group, Ethyl group, isopropyl group, t-butyl group, trifluoromethyl group and the like; substituted and unsubstituted aralkyl groups such as benzyl group and phenethyl group; halogen atom such as chlorine atom, bromine atom, fluorine atom and iodine atom; 1 atom
4 substituted or unsubstituted alkoxy groups such as methoxy group, ethoxy group, isopropoxy group, t-butoxy group, 2-chloroethoxy group and the like; hydroxy group; substituted or unsubstituted aryloxy group such as p-chloro group Phenoxy group, 1-naphthoxy group and the like; acyloxy group such as acetyloxy group, p-cyanobenzoyloxy group and the like; carboxyl group and its ester group such as ethoxycarbonyl group and m-bromophenoxycarbonyl group; carbomoyl group such as aminocarbonyl Acyl group such as acetyl group, o-nitrobenzoyl group; sulfo group, sulfamoyl group such as aminosulfonyl group, t-butylaminosulfonyl group, p-tolyl Aminosulfonyl group, etc .; Group, an acylamino group, such as an acetylamino group, a benzoylamino group or the like; sulfonamido group, for example, methanesulfonamido group, p- toluenesulfonamide group or the like; a cyano group; a nitro group and the like. Among these substituents, preferred are those having 1 carbon atom.
4 to 4 substituted or unsubstituted alkyl groups such as methyl group, ethyl group, isopropyl group, t-butyl group, trifluoromethyl group and the like; halogen atoms such as chlorine atom, bromine atom, fluorine atom and iodine atom; 1 to 4 atoms
Substituted / unsubstituted alkoxy groups such as methoxy group,
Ethoxy, t-butoxy, 2-chloroethoxy and the like; nitro; cyano and the like.

In the general formula (XVII), Z is a group of atoms necessary to form a substituted / unsubstituted aromatic carbocyclic ring or a substituted / unsubstituted aromatic heterocyclic ring. Unsubstituted benzene ring, substituted / unsubstituted naphthalene ring,
It represents a group of atoms necessary to form a substituted / unsubstituted indole ring, a substituted / unsubstituted carbazole ring and the like.

Examples of the substituent of the group of atoms necessary to form these rings include a series of substituents exemplified as the substituent of Ar ¹⁰ , but a halogen atom (a chlorine atom, a bromine atom, A fluorine atom, an iodine atom), a sulfo group, and a sulfamoyl group (for example, an aminosulfonyl group, a p-tolylaminosulfonyl group, etc.).

The bisazo compound represented by the general formula (XVI) is preferably the following general formulas (XVIII), (XIX), (XX),
[XXI].

General formula (XVIII) General formula (X IX) General formula (XX) General formula (XXI) In the formula, X ^1a , X ^1b , X ^2a and X ^2b each represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group,
Represents a substituted or unsubstituted alkoxy group, nitro group, cyano group, hydroxy group or substituted or unsubstituted amino group, and represents at least one of X ^1a , X ^1b , X ^2a and X ^2b
One is a halogen atom. X ^1a and X ^1b , and X ^2a and X ^2b may be the same or different groups, respectively.

Y has the same meaning as the substituent of Z in the general formula [XVI].

The bisazo compound represented by the general formula [XVI] can be easily synthesized by a known method.

Synthesis Example (Synthesis of Compound X VI-71) 2.89 g of 2,7-diamino-4-bromo-9-fluorenone
(0.01 mol) was dispersed in 10 ml of hydrochloric acid and 20 ml of water, and a solution of 1.40 g (0.02 mol) of sodium nitrite dissolved in 5 ml of water was added dropwise while keeping the temperature at 5 ° C. or lower. After further stirring at the same temperature for 1 hour, insolubles were removed by filtration, and a solution of 4.6 g of ammonium hexafluorophosphate dissolved in 50 ml of water was added to the filtrate. The precipitated tetrazonium salt was collected by filtration and dissolved in 100 ml of N, N-dimethylformamide (DMF). While keeping the temperature below 5 ° C,
A solution of 6.62 g (0.02 mol) of 2-hydroxy-3-naphthoic acid-3-trifluoromethylanilide dissolved in 200 ml of DMF was added dropwise.

Then, a solution prepared by dissolving 6 g (0.04 mol) of triethanolamine in 30 ml of DMF was added dropwise while maintaining the temperature at 5 ° C. or less.
The mixture was stirred at 5 ° C or lower for 1 hour and at room temperature for 4 hours. After the reaction, the precipitated crystals were collected by filtration, washed with DMF, washed with water and dried to obtain 8.71 g of the desired product.

Theoretical value C = 60.5%, H = 2.77%, N = 8.63% Observed value C = 60.1%, H = 2.95%, N = 8.72% Other compounds were prepared using the corresponding amino compounds in the same manner as in the above Synthesis Examples. Make a diazonium salt, then 2-
It can be prepared by reacting with hydroxy-3-naphthoic acid-substituted anilide or 2-hydroxy-3- (substituted phenylcarbamoyl) benzo [a] -substituted / unsubstituted carbazole.

As a material of the conductive support, for example, aluminum,
Nickel, copper, zinc, palladium, silver, indium,
Metal sheets such as tin, platinum, gold, stainless steel, and brass can be used.

Alternatively, a conductive layer can be provided on an insulating substrate to form a conductive support. In this case, as the insulating substrate, a substrate having flexibility, such as paper or a plastic sheet, and having sufficient strength against stresses such as bending and tension is suitable. Also, the conductive layer can be provided by laminating a metal sheet or vacuum depositing metal, or by other methods.

The carrier generation layer may be made of a carrier generation material (CGM) alone, or a material obtained by adding an appropriate binder resin thereto, or a material having a high mobility for a carrier having a specific or non-specific polarity (ie, a carrier transport material). It can be formed by the addition.

As a specific forming method, a method in which CGM is vacuum-deposited on the support, a method in which CGM is dissolved or dispersed in an appropriate solvent alone or together with an appropriate binder resin is applied (or dipped) and dried. There is a method that can be used.

In this latter method, a binder resin or a carrier transporting substance may be added, and in that case, the ratio of the carrier generating substance: the binder resin: the carrier transporting substance is 1: (0 to 100) :( weight ratio). 0-500),
In particular, 1: (0 to 10): (0 to 50) is preferable.

In addition, each constituent layer of the carrier transport layer is coated with a solution or dispersion obtained by dissolving and dispersing a carrier transport material and a binder resin in a solvent, on a carrier generation layer or another carrier transport layer constituent layer, and drying. Can be formed.

1 to 4, constituent layers of the carrier transport layer 3
3A, 3B may be formed of the same binder resin,
It may be formed of mutually different binder resins. For example, when the upper constituent layer 3B is formed of a resin having a structural unit represented by the general formulas (I) and (II), and the lower constituent layer 3A is formed of bisphenol A type polycarbonate,
It is preferable from the viewpoint of improving light sensitivity.

The binder resin for coating and forming the lower constituent layer 3A may be hardly soluble (low in solubility) in the solvent for forming and forming the upper constituent layer 3B. In this case, diffusion of the carrier transporting substance into the lower constituent layer 3A,
The swelling of the lower constituent layer 3A can be prevented.

Further, the method of applying and forming the upper constituent layer 3B and the lower constituent layer 3A can be made different. For example, if the constituent layer 3A is formed by dip coating and the constituent layer 3B is formed by spray coating, dissolution and swelling of the lower constituent layer 3A can be prevented.

Each layer of the photoreceptor can be formed by various coating methods such as dip coating, spray coating, blade coating, roll coating, spiral coating, and slide hopper coating. For example, when the constituent layer 3B is formed by dip coating, gas such as ozone is more difficult to permeate from the constituent layer 3B, which is more advantageous in preventing deterioration of the carrier transport material.

The intermediate layer or the undercoat layer can be formed by applying and drying a solution obtained by dissolving a binder resin in a solvent.

Examples of the solvent or dispersion medium used in the above method include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, monoethanolamine,
Triethanolamine, triethylenediamine, N, N-
Dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol,
Ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide and others can be used.

As the binder resin, in addition to the resin having a structural unit represented by the general formula (I) or (II) as a main repeating unit, for example, other than the above, polycarbonate, polyester, methacrylic resin, acrylic resin, polyvinyl chloride,
Polyvinylidene chloride, polystyrene, polyvinyl acetate, melamine resin, polyurethane, styrene-acrylic copolymer, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate -One or more resins selected from a maleic anhydride copolymer, a silicone resin, a silicone-alkyd resin, a phenol resin, a styrene-alkyd resin, poly-N-vinylcarbazole, polyvinyl butyral, and the like, or a mixture thereof can be used.

Binder resin used for the intermediate layer or the undercoat layer, as materials, metal oxides such as aluminum oxide and indium oxide, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenolic resin, polyester Polymer materials such as resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, vinyl chloride-vinyl acetate copolymer resin, and vinyl chloride-vinyl acetate-maleic anhydride copolymer resin can be used.

A high molecular organic semiconductor may be contained in the photosensitive layer. Among these high-molecular organic semiconductors, poly-N-vinylcarbazole or a derivative thereof has a large curing property and is preferably used. Such a poly-N-vinyl carbazole derivative is one in which all or a part of the carbazole ring in the repeating unit is substituted with various substituents, for example, an alkyl group, a nitro group, an amino group, a hydroxy group or a halogen atom. .

In addition, at least one kind of electron accepting substance can be contained in the photosensitive layer for the purpose of improving sensitivity, reducing residual potential, or reducing fatigue during repeated use. Specific examples thereof are described in Japanese Patent Application No. 63-211536.

Further, a silicone oil or a fluorine-based surfactant may be present as a surface modifier. Further, an ammonium compound may be contained as a durability improver.

Further, an ultraviolet absorber may be used. As preferred ultraviolet absorbers, nitrogen-containing compounds such as benzoic acid, stilbene compounds and derivatives thereof, triazole compounds, imidazole compounds, triazine compounds, coumarin compounds, oxadiazole compounds, thiazole compounds and derivatives thereof are used.

An antioxidant can be contained in the carrier transport layer, the carrier generation layer, and the photosensitive layer. As a result, the influence of ozone generated by discharge can be suppressed, and an increase in the residual potential and a decrease in the charged potential during repeated use can be prevented.

Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, organic phosphorus compounds and the like.

Specific examples of these compounds include Japanese Patent Application No. 61-162866.
No., No. 61-188975, No. 61-195878, No. 61-157644,
No. 61-195879, No. 61-162867, No. 61-204469, No. 61-
Nos. 217493, 61-217492 and 61-221541.

The photoreceptor of the present invention can be used in electrophotographic copying machines, laser beam printers, CRT printers, electrophotographic plate making systems, and the like.

At this time, various light sources such as a He-Ne laser, a semiconductor laser (780 nm, 680 nm, etc.), an LED, and a halogen lamp can be used as the light source.

E. EXAMPLES Hereinafter, examples of the present invention will be described, but embodiments of the present invention are not limited thereto.

<Production of Resin> First, each resin used in the examples was produced as follows.

First, a fluorine atom-containing polycarbonate (homopolymer) was produced as follows.

0.15 mol of bisphenols, 0.353 g of phenol, 16.8 g of NaOH, 238 ml of water in a 500 ml separable flask with a stirrer
Was added and dissolved by heating at 50 ° C., then cooled to 25 ° C., and 147 ml of methylene chloride was added.

Next, 19.1 g of phosgene was introduced over 60 minutes while stirring at 25 ° C.

Then, trimethylbenzyl ammonium chloride
After adding 0.0342 g, 4.5 g of NaOH and 30 ml of water, polymerization was carried out for 4.5 hours while stirring at 25 ° C.

After completion of the polymerization, the mixture was diluted by adding 360 ml of methylene chloride, washed with hydrochloric acid to be weakly acidic, and further washed with water 5 times. The polymer solution is poured into methanol for coagulation, separated and 100
The polymer was dried at 1 mmHg for 15 hours to obtain a white polymer.

As described above, (I-2), (I-14), (I-35)
Each polycarbonate (homopolymer) which consists of a structural unit represented by these was obtained. The following symbols are assigned to each homopolymer.

Structural Units IA (I-2) IB (I-14) IC (I-35) Next, each modified polycarbonate (I-35) (Copolymer).

(A) Production of polycarbonate oligomer 1,1,1,3,3,3-hexafluoro-2,2-bis (4-hydroxyphenyl) -propane 100 parts sodium hydroxide 50 parts water 870 Part methylene chloride 530 parts p-tert-butylphenol 2 parts The above mixture was charged into a reactor equipped with a stirrer, and stirred at 800 rpm. 70 parts of phosgene was blown into this for 2 hours.
Interfacial polymerization was performed. After completion of the reaction, only the methylene chloride solution containing the polycarbonate oligomer was collected. The analysis results of the methylene chloride solution of the obtained oligomer were as follows.

Oligomer concentration 24.0% by weight Terminal chloroformate group concentration 0.56N Terminal phenolic hydroxyl group concentration 0.13N The oligomer solution obtained by the above method shall be the oligomer solution A.

(B) Production of polycarbonate oligomer 16.6% aqueous solution of bisphenol A sodium salt prepared by dissolving bisphenol A in aqueous sodium hydroxide solution 100 parts p-tert-butylphenol 0.23 parts Methylene chloride 40 parts Phosgene 7 parts The mixture having the above composition was quantitatively supplied to a pipe reactor to perform interfacial polymerization.

The reaction mixture was separated, and only the methylene chloride solution containing the polycarbonate oligomer was collected.

The analysis results of the methylene chloride solution of the obtained oligomer were as follows.

Oligomer concentration 24.5% by weight Terminal chloroformate group concentration 1.3N Terminal phenolic hydroxyl group concentration 0.3N The oligomer solution obtained by the above method is referred to as Oligomer solution B.

(C) Production of copolymerized polycarbonate Oligomer solution-A 80 parts Oligomer solution-O 180 parts Methylene chloride 100 parts p-tert-butylphenol 0.3 part was charged into a reactor equipped with a stirrer and stirred at 550 rpm. Further, an aqueous solution having the following composition was charged and interfacial polymerization was performed for 5 hours.

Sodium hydroxide 14 parts Triethylamine 0.07 parts Water 80 parts Subsequently, the reaction mixture was separated, and the methylene chloride solution containing the polycarbonate resin was washed with water, an aqueous hydrochloric acid solution and water, and finally the methylene chloride was evaporated to remove the resin. I took it out.

The average molecular weight ^* of this resin was 24,900. Also NMR
As a result of the analysis, the amount of bisphenol A copolymerized was 71% by weight.

This resin is designated ID. Similarly, resins IE and IF shown in the following table were obtained.

Next, a fluorine atom-containing polycarbonate (homopolymer) was produced as follows.

Specifically, a solution in which 1.0 mol of bisphenols was dissolved in a 1 mol aqueous solution of sodium hydroxide, a surfactant was added, and a vigorously stirred solution of 1.0 mol of terephthalic acid chloride in chloroform was added. After stirring was continued, the obtained emulsion was poured into acetone to precipitate a polymer, which was sufficiently washed with water, filtered, and dried by heating to obtain a white polymer.

As described above, (II-2), (II-14), (II-35)
Each polycarbonate (homopolymer) which consists of a structural unit represented by these was obtained. The following symbols are assigned to each homopolymer.

Structural unit II-A (II-2) II-B (II-14) II-C (II-35) <Preparation of electrophotographic photoreceptor> Example 1A 80 mmφ On a drum-shaped aluminum conductive substrate (aluminum cylinder), an intermediate layer of vinyl chloride-vinyl acetate-maleic acid copolymer "ESLEC MF-10" (manufactured by Sekisui Chemical Co., Ltd.) having a thickness of about 0.1 μm was formed. Provided. Next, 4 g of a polycyclic quinone pigment represented by the following structural formula (XI-3) was pulverized with a ball mill for 24 hours, and this was mixed with bisphenol A-type polycarbonate “Panlite L-1250” (manufactured by Teijin Chemicals Limited) 20
g was dissolved in 1300 ml of 1,2-dichloroethane, and the mixture was further dispersed for 24 hours.The resulting dispersion was applied onto the intermediate layer by dip coating and dried sufficiently to form a CGL having a thickness of about 0.5 μm. did.

Next, 80 g of a styryl compound (carrier transporting substance) represented by the following structural formula VIII-35 and polycarbonate “PANLITE L
A solution obtained by dissolving 100 g of -1250 '' in 1,000 ml of 1,2-dichloroethane was applied onto the carrier generating layer by dip coating, and the temperature was 80
After drying at 1 ° C. for 1 hour, a lower constituent layer having a thickness of 18 μm was formed. Here, the content ratio (weight ratio, carrier transport material / binder resin) of the carrier transport material to the binder resin is 80%.

Next, 60 g of a styryl compound represented by the structural formula VIII-35
And 100 g of the resin I-A of the above synthesis example, and 1,2-dichloroethane
The resulting solution was dissolved in 1,000 ml, and the resulting solution was spray-coated on the lower component layer to obtain a 4 μm-thick upper component layer. In this layer, the content ratio of the carrier transporting material to the binder material is 60%.

Examples 1B to 1H and Comparative Examples 1B and 1C In Example 1A, the binder resin and the CTM content and the film thickness of the lower constituent layer and the upper constituent layer were set as shown in FIG. 5, respectively. Other than that, each electrophotographic photoreceptor was prepared in the same manner as in Example 1A.

However, in Example 1G, the following structural formula (V-2) was used as the carrier transport material for the upper constituent layer and the lower constituent layer.
In 1H, (VII-22) was used as a carrier transport material.

Comparative Example 1A An intermediate layer and a carrier generation layer were formed in the same manner as in Example 1.

Next, a solution obtained by dissolving 80 g of the carrier transporting material represented by Structural Formula VIII-35 and 100 g of polycarbonate `` Panlite L-1250 '' in 1,000 ml of 1,2-dichloroethane was dip-coated on the carrier generating layer, and Carrier transport layer (film thickness 22μ)
m) was formed to obtain a photoconductor for comparison.

Example 2A The carrier generating substance was changed to a fluorenone compound represented by the following structural formula XVI-71, and the carrier transporting substance was replaced by the following structural formula VI.
An intermediate layer and a carrier generation layer were formed in the same manner as in Example 1 except that the substituted styryl compound represented by II-38 was used.

Next, 10 g of the polyarylate of the above synthesis example (II-A) and 100 g of a carrier transporting substance (structural formula VIII-38) were dissolved in 1000 ml of monochlorobenzene, and this solution was applied on the above-mentioned carrier generating layer to form a film. A lower constituent layer having a thickness of 15 μm was formed.

Next, in the solution for the lower constituent layer, the content of the carrier transporting substance was set to 70 g, and the other conditions were the same as above to prepare a solution for the upper constituent layer. This solution was spray-coated on the lower constituent layer to form an upper constituent layer having a thickness of 5 μm.

Examples 2B and 2C, Comparative Example 2B In Example 2A, the binder resin and the CTM content and the film thickness of the upper constituent layer and the lower constituent layer were set as shown in FIG. Otherwise, each electrophotographic photosensitive member was prepared in the same manner as in Example 2A.

Comparative Example 2A An intermediate layer and a carrier generation layer were formed in the same manner as in Example 2A.

Next, the solution for the lower layer constituting the carrier transporting layer (the carrier transporting substance content: 100 g) in Example 2A was dip-coated on the carrier generating layer to form a single 20 μm-thick carrier transporting layer. It was a photoreceptor.

Example 3A An intermediate layer was formed in the same manner as in Example 1A.

Next, in Example 1A, the carrier-generating substance was changed to a bisazo compound having the following structural formula XIV-5, and the binder resin was a polyester resin “Vylon-200” (manufactured by Toyobo Co., Ltd.).
The carrier generation layer was formed in the same manner as in Example 1A except for the above.

Next, 10 g of a carrier transporting substance of the following structural formula X-2 and poly-N-vinylcarbazole “Rubican M-170” (BASF
Was dissolved in 1000 ml of tetrahydrofuran (THF), and this solution was applied onto the carrier generating layer by dip coating to form a lower constituent layer having a thickness of 18 μm.

Next, 60 g of the carrier transporting substance of the structural formula X-2 and 100 g of the polyarylate of Synthesis Example (II-A) were dissolved in 1,000 ml of 1,2-dichloroethane, and this solution was applied on the lower constituent layer. Then, an upper component layer having a thickness of 4 μm was formed.

Examples 3B and 3C, Comparative Example 3A In Example 3A, the contents of the binder resin and CTM in the upper constituent layer and the lower constituent layer and the film thickness were changed as shown in FIG. Further, the upper component layer of the carrier transport layer, Example 3B
Was formed by dip coating, and in Example 3C, coating was performed using a circular slide hopper. Others were the same as in Example 3A to prepare each electrophotographic photosensitive member.

Comparative Example 3B An intermediate layer and a carrier generation layer were formed in the same manner as in Example 3A.

Next, a coating solution similar to the solution for the lower component layer in the carrier transporting layer in Example 3A was prepared, and the coating solution was dip-coated on the carrier generating layer to form a single carrier transporting layer ( Film thickness 22 μm).

Structural formula <Evaluation of Photoconductor Characteristics> The electrophotographic photoconductor sample obtained as described above was manufactured by Konica Corporation.
Attached to U-Bix1550MR, performs Stock test 50,000 times copying, black paper potential V _b, the blank potential V _w was measured. Also 5
The amount of thickness loss and the occurrence of image flaws after 10,000 copies were examined. However, V _b and V _w are shown in the figure (initial value and after copying 50,000 times)
And the variation amounts ΔV _b and ΔV _w after 50,000 copies.

Note that the black paper potential here refers to the surface potential of the photoconductor when the above-described copying cycle is performed on a black paper original having a reflection density of 1.3, and the blank potential indicates the potential of the photoconductor when a white paper is used as the original. Represents the surface potential. The measurement results are shown in FIG.

However, in FIG. 5, “actual-” indicates an example, and “ratio-” indicates a comparative example.

From the results shown in FIG. 5, the electrophotographic photoreceptors of the examples are excellent in abrasion resistance and scratch resistance, show good values in both black paper potential and white paper potential, and can be continuously copied on many sheets. It is understood that a stable copy image can be obtained with little change in the black paper potential and the white paper potential.

[Brief description of the drawings]

1, 2 and 3 are partial cross-sectional views each showing an example of the electrophotographic photosensitive member of the embodiment. FIG. 4 is a table showing the electrophotographic characteristics of each photoconductor. In addition, in the code | symbol shown in drawing, 1 ... conductive support 2 ... Carrier generation layer 3 ... Carrier transport layer 3A ... Lower constituent layer 3B ... Upper constituent layer 6 ... Intermediate layer.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Matsuura 2970 Ishikawacho, Hachioji-shi, Tokyo Inside Konica Corporation (56) References JP-A-1-285950 (JP, A)

Claims (1)

(57) [Claims] 1. A photoreceptor comprising a carrier generating layer and a carrier transporting layer sequentially laminated on a conductive support, comprising: a structural unit represented by the following general formula [I];
A resin having at least one of the structural units represented by I) as a repeating unit is contained in at least a surface region on a surface side on which the carrier transport layer is provided, and the carrier transport layer includes a lower layer and a conductive support side. It is composed of two constituent layers, an upper layer on the surface region side, and the lower layer has a thickness of 5 to 30 μm.
Wherein the thickness of the upper layer is 0.1 to 10 μm, and the content ratio of the carrier transporting substance in the lower layer to the binder resin (weight ratio, carrier transporting substance / binder resin) is the ratio of the carrier transporting substance in the upper layer. A photoreceptor characterized in that the content ratio is greater than the content ratio (weight ratio, carrier transport material / binder resin) to the binder resin by 10% by weight or more. General formula [I] (R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group, a substituted or unsubstituted Represents a substituted carbocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted alkoxy group, and further R ⁹ and R ¹⁰ are jointly substituted or unsubstituted carbocyclic or substituted or unsubstituted It may be an atom group or atoms necessary for constituting a heterocyclic ring. Where R ¹ , R ² , R ³ , R ⁴ ,
At least one of R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ represents a fluorine atom or a substituent having a fluorine atom. General formula [II] (R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and R ²⁰ are each a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group, a substituted or unsubstituted Represents a substituted carbocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted alkoxy group, and furthermore, R ¹⁹ and R ²⁰ are jointly substituted or unsubstituted carbocyclic or substituted or unsubstituted It may be an atom group or atoms necessary for constituting a heterocyclic ring. Where R ¹¹ , R
^12, R ^13, at least one of ^{R 14, R 15, R 16} , R 17, R 18, R 19, R 20 denote the substituent having a fluorine atom or a fluorine atom. ]