JP2893189B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a photoconductor for electrophotography.

[Conventional technology]

2. Description of the Related Art In recent years, as a photoconductor used in an electrophotographic copying machine, a photoconductor using an organic photosensitive material having advantages such as low cost, productivity, and no pollution has begun to spread.

Organic electrophotographic photoreceptors include photoconductive resins such as polyvinyl carbazole (PVK) and PVK-TNF (2,4,7
-Trinitrofluorenone), a pigment-dispersed type represented by a phthalocyanine-binder, a function-separated type photoreceptor using a combination of a charge generating substance and a charge transporting substance, and the like. In particular, a function-separated type photoconductor has attracted attention.

When such a function-separated type high-sensitivity photoreceptor is applied to the Carlson process, the chargeability is low, the charge retention characteristics are poor (dark decay is large), and these characteristics are greatly deteriorated due to repeated use. In addition, there is a disadvantage that density unevenness, fog, and background development occur in the case of reversal development.

In general, the charge sensitivity of a high-sensitivity photoreceptor decreases due to fatigue due to pre-exposure. Since the pre-exposure fatigue is mainly caused by light absorbed by the charge raw material, the longer the charge generated by light absorption remains in the photoreceptor in a movable state, the larger the number of the charge It is considered that the lower the chargeability due to the pre-exposure fatigue becomes, the more the more. That is, even if the charging operation is performed in a state where the charge generated by light absorption remains, the surface charge is neutralized by the movement of the remaining carrier, so that the surface potential increases until the residual charge is consumed. No, the rise of the surface potential is delayed by the pre-exposure fatigue, and the apparent charging potential is reduced.

For the above-mentioned disadvantages, for example, JP-A-47-6341, 48-
Nos. 3544 and 48-12034 have cellulose nitrate-based resin interlayers as disclosed in JP-A-48-47344, 52-25638, 58-30757, and 58-6.
Nos. 3945, 58-95351, 58-98739 and 60-66258 disclose a nylon-based resin intermediate layer and JP-A-49-69332 and JP-A-49-69332.
No. 38 discloses a maleic acid resin intermediate layer, and
No. 105155 discloses a polyvinyl alcohol resin intermediate layer. Further, an intermediate layer in which various conductive additives are contained in a resin in order to control the electric resistance of the intermediate layer has been proposed. For example, JP-A-51-65942 discloses an intermediate layer in which a carbon or chalcogen-based substance is dispersed in a curable resin, and JP-A-52-82238 discloses the use of an isocyanate-based curing agent by adding a quaternary ammonium salt. JP-A-51-1180451 discloses a resin intermediate layer to which a resistance modifier is added, and JP-A-58-58556 discloses a resin intermediate layer in which aluminum or tin oxide is dispersed. JP-A-58-93
JP-A-58-93063, 60-97363 and 60-111255 disclose a resin intermediate layer in which conductive particles are dispersed, and JP-A-59-8425 discloses a resin intermediate layer containing an organometallic compound.
7, 59-93453 and 60-32054 disclose a resin intermediate layer in which TiO ₂ and SnO ₂ powder are dispersed.

However, the deterioration of the chargeability due to repeated use, particularly the delay in the rise of each charge, is still insufficient, and further improvement has been desired.

JP-A-54-8528 discloses a photoreceptor having a layer in which a charge generating substance coated with an electron-donating substance and / or an electron-accepting substance is dispersed in a resin.
Japanese Patent Application Laid-Open No. 63-281167 discloses a laminated photoconductor in which a charge transporting material is contained in a charge generation layer, but none of them satisfy the above requirements. Was.

[Problems to be solved by the invention]

An object of the present invention is to provide an electrophotographic photoreceptor which has high sensitivity and has a remarkably small decrease in chargeability due to pre-exposure fatigue, and has no delay in rising of a charging potential even after repetition of charging and exposure. I do.

[Means for solving the problem]

According to the present invention, in an electrophotographic photoreceptor in which at least a charge generation layer and a charge transport layer are sequentially laminated on a conductive support, the following general formula (I) is used in the charge generation layer. An electrophotographic photosensitive member comprising at least one compound represented by the formula:

(Wherein R ¹ , R ³ and R ⁴ are a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom or a substituted or unsubstituted R ² represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or a halogen, provided that R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms. k, l, m and n are integers of ¹ , ² , 3 or 4, and when each is an integer of 2, 3 or 4, said R ¹ , R ² , R ³ and R ⁴ may be the same or different. May be.) (Wherein, R ⁵ represents a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group, a dialkylamino group, a diarylamino group, or a halogen atom, and R ⁶ and R ⁷ represent a substituted or unsubstituted alkyl group, As for the substituted aryl group, p represents an integer of 1 or 2.) As described above, the high-sensitivity laminated organic electrophotographic photoreceptor causes a delay in the rise of charging due to repeated use. The present inventors have found that the charge generation layer of the layered organic electrophotographic photoreceptor contains at least one compound represented by the general formula (I) or the general formula (II), The inventor has found that an electrophotographic photosensitive member having no delay in the rise of the charged position after repeated use can be obtained, and the present invention has been completed.

 Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing a configuration example of the electrophotographic photoreceptor of the present invention, in which a charge generation layer 15 and then a charge transport layer 17 are provided on a conductive support 11.

FIG. 2 is a sectional view showing another configuration example of the present invention;
An undercoat layer 13 is provided between the conductive support 11 and the charge generation layer 15.

FIGS. 3 and 4 are cross-sectional views showing still another configuration example. FIG. 3 shows a structure in which a protective layer 19 is provided on a charge transport layer 17, and FIG. The protective layer is provided at the same time.

Examples of the conductive support 11 include those exhibiting conductivity of 10 ¹⁰ Ωcm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, and platinum; and metals such as tin oxide and indium oxide. Oxide coated on film or cylindrical plastic, paper, etc. by vapor deposition or sputtering, or aluminum, aluminum alloy, nickel, stainless steel, etc. and DI, II, extrusion, drawing, etc. After the raw material is formed, a pipe or the like whose surface is treated by cutting, superfinishing, polishing, or the like can be used.

 Next, the charge generation layer 15 will be described.

The charge generation layer 15 is a layer containing a charge generation substance and at least one compound represented by the general formula (I) or the general formula (II) as main components, and a binder resin may be used as necessary.

As the binder resin, polyamide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, polyacrylamide and the like are used.

In the present invention, the aminobiphenyl compound represented by the general formula (I) contained in the charge generation layer may be, for example, a compound represented by the general formula (A) (Wherein R ¹ , R ² , k and l are the same as above, and X represents halogen.) And a general formula (B) (Wherein, R ³ , R ⁴ , m and n are the same as those described above).

The aminobiphenyl compound represented by the general formula (I) obtained by the above synthesis method is exemplified below.

In the invention, the amino compound represented by the general formula (II) to be contained in the charge generation layer is, for example, a compound represented by the general formula (C) (Wherein, R ⁵ , R ⁶ , R ⁷ , Ar, and p are the same as those described above).

Examples of the amino compound represented by the general formula (II) obtained by the above synthesis method are shown below.

As the charge generating substance, known materials can be used, and in particular, the following disazo or trisazo pigments are preferably used.

(However, Cp is a coupler residue, and so on) (However, R represents a hydrogen atom, a substituted or unsubstituted alkyl group.) (However, R represents a hydrogen atom, an alkyl group, or a halogen atom.) (However, A represents -NH-, -0-, -S-.) (However, n represents an integer between 1 and 5.) Examples of these coupler residues Cp include compounds having a phenolic hydroxyl group such as phenols and naphthols, aromatic amino compounds having an amino group or aminonaphthols having an amino group and a phenolic hydroxyl group, aliphatic and aromatic compounds. Compounds having an enol ketone group (compounds having an active methylene group) are preferably used, and are preferably those represented by the following general formulas (1) to (11).

[In the above formulas (1), (2), (3) and (4), X,
Y ₁ , Z, m and n each represent the following.

(R ₁ and R ₂ represent hydrogen or a substituted or unsubstituted alkyl group, and R ₃ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.) Y ₁ : hydrogen, halogen, substituted or An unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a carboxy group, a sulfone group, a substituted or unsubstituted sulfamoyl group or (R ₄ represents hydrogen, an alkyl group or a substituted product thereof, a phenyl group or a substituted product thereof, Y ₂ represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or (Provided that R ₅ represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or a styryl group or a substituted product thereof, R ₆ represents a hydrogen atom, an alkyl group, a phenyl group or a substituted product thereof, or ₅ and R ₆ may form a ring together with the carbon atom to which they are attached.) Z: a hydrocarbon ring or a substituent thereof or a heterocycle or a substituent thereof n: an integer of 1 or 2 m: an integer of 1 or 2] [In the formulas (5) and (6), R ₇ represents a substituted or unsubstituted hydrocarbon group, and A represents a divalent group of an aromatic hydrocarbon or a divalent group of a heterocyclic ring containing a nitrogen atom in the ring. (These rings may be substituted). X is the same as above. ] [Wherein, R ₈ represents an alkyl group, a carbamoyl group, a carboxy group or an ester thereof, Ar ₁ represents a hydrocarbon ring group or a substituted product thereof, and X is the same as described above. ] [In the above formulas (8) and (9), R ₉ represents hydrogen or a substituted or unsubstituted hydrocarbon group, and Ar ₂ represents a hydrocarbon ring group or a substituted product thereof. ] Z of the general formula (1), (2), (3) or (4)
Examples of the hydrocarbon ring include a benzene ring and a naphthalene ring, and examples of the heterocyclic ring (which may be substituted) include an indole ring, a carbazole ring, a benzolan ring, and a dibenzofuran ring. Examples of the substituent in the ring of Z include a halogen atom such as a chlorine atom and a bromine atom.

Examples of the hydrocarbon ring group for Y ₂ or R ₅ include a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group and the like, and examples of the heterocyclic group include a pyridyl group, a cyenyl group, a furyl group, an indolyl group, a benzofuranyl group, and a carbazolyl group. Group, a dibenzofuranyl group, and the like. Examples of the ring formed by combining R ₅ and R ₆ include a fluorene ring.

Y ₂ or R ₅ hydrocarbon ring group or heterocyclic group or R ₅
And a substituent in the ring formed by R ₆ is a methyl group, an ethyl group, a propyl group, an alkyl group such as a butyl group, a methoxy group, an ethoxy group, a propoxy group,
Alkoxy groups such as butoxy group, chlorine atom, halogen atom such as bromine atom, dimethylamino group, dialkylamino group such as diethylamino group, halomethyl group such as trifluoromethyl group, nitro group, cyano group, carboxyl group or ester thereof, Examples include a hydroxyl group and a sulfonate group such as —SO ₃ Na.

Examples of the substituent of the phenyl group for R ₄ include a halogen atom such as a chlorine atom or a bromine atom.

Representative examples of the hydrocarbon group for R ₇ or R ₉ include an alkyl group such as a methyl group, an ethyl group, a propyl group, and a butyl group, an aryl group such as a phenyl group, and a substituted product thereof.

Examples of the substituent in the hydrocarbon group of R ₇ or R ₉ include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a methoxy group, an ethoxy group, a propoxy group, an alkoxy group such as a butoxy group, a chlorine atom, Examples thereof include a halogen atom such as a bromine atom, a hydroxyl group, and a nitro group.

Examples of the hydrocarbon ring group in Ar ₁ or Ar ₂ include a phenyl group and a naphthyl group, and the substituents in these groups include a methyl group, an ethyl group,
Propyl group, alkyl group such as butyl group, methoxy group,
Examples thereof include alkoxy groups such as ethoxy group, propoxy group and butoxy group, halogen atoms such as nitro group, chlorine atom and bromine atom, and dialkylamino groups such as cyano group, dimethylamino group and diethylamino group.

 Among X, a hydroxyl group is particularly suitable.

Among the above-mentioned coupler residues, the above-mentioned general formulas (2), (5), (6), (7), (8) and (9)
Wherein X in the general formula is a hydroxyl group. The general formula (1
0) (Y ₁ and Z are the same as described above.). (Z, Y ₂ and R ₂ are the same as described above.)

Furthermore, among the above preferred coupler residues, general formula (12) or (13) (Z, R ₂ , R ₅ and R ₆ are the same as described above, and R ₁₀ is exemplified by the substituents of Y ₂ described above.)

The compound represented by the general formula (I) or the general formula (II) and the charge generating substance described above are used alone or in combination of two or more.

The compound represented by formula (I) or (II) is suitably used in an amount of 0.01 part by weight or more, preferably 0.05 part by weight or more, more preferably 0.1 part by weight, based on 1 part by weight of the charge generating substance. That is all.

Although the binder resin may not be used, the use of the binder resin can further enhance the effect of the present invention. The amount of the binder resin used at that time is preferably 0.02 to 3 parts by weight, more preferably 0.1 to 3 parts by weight, based on 1 part by weight of the charge generating substance.
It is 2 to 2 parts by weight.

The charge generation layer is ball milled using a solvent such as tetrahydrofuran, cyclohexanone, dioxane or dichloroethane together with at least one compound represented by the general formula (I) or (II) and a binder if necessary. , An attritor, a sand mill, or the like, and the dispersion is appropriately diluted and applied. The coating can be performed by a dip coating method, a spray coating method, a bead coating method, or the like.

The thickness of the charge generation layer is about 0.01 to 5 μm, and preferably 0.1 to 2 μm.

The charge transport layer 17 can be formed by dissolving or dispersing a charge transport substance and a binder resin in a suitable solvent, and applying and drying the same.

The charge transport materials include a hole transport material and an electron transport material.

Examples of the electron transporting material include chloranil, bromanil, tetracyanoethylene, tetracyanoquinonedimethane, 2,4,7-trinitro-9-fluorenone,
2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-
Tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b]
Electron accepting substances such as thiophen-4-one and 1,3,7-trinitrodibenzothiophenone-5,5-dioxide.

Examples of the hole transporting substance include an electron donating substance represented by the following general formula, and are preferably used.

(Wherein R ₁ , R ₂ , R ₃ and R ₄ represent a hydrogen atom, a substituted or unsubstituted aryl group, Ar ₁ represents a substituted or unsubstituted aryl group, and Ar ₁ and R ₁ are commonly used A ring may be formed, and n is an integer of 0 or 1.) (However, R ₁ represents a lower alkyl group, a lower alkoxy group or a halogen atom, n represents an integer of 0 to 4, R ₂ ,
R ₃ may be the same or different and represents a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom. ) (Wherein, R ₁ represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group or a heterocyclic residue; R ₂ and R ₃ may be the same or different; Represents an alkyl group, a C _{1 to} C ₄ hydroxyalkyl group, a C _{1 to} C ₄ chloroalkyl group, or a substituted or unsubstituted aralkyl group, and R ₂ and R ₃ together form a nitrogen-containing heterocyclic ring R ₄ and R ₅ may be the same or different and each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom.) (In the formula, R ₁ represents a hydrogen atom or a halogen atom, and R ₂ represents a substituted or unsubstituted aromatic residue or a heterocyclic residue (provided that the substituent is halogen, cyano, di-lower alkylamino, substituted or unsubstituted Selected from the group consisting of substituted diaralkylamino groups, lower alkyl groups, lower alkoxy groups, and nitro groups.) (Wherein R ₁ and R ₃ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, or a di-lower alkylamino group;
R ₂ represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom or a nitro group, and n represents 0 or 1. ) (Wherein R is a carbazolyl group, a pyridyl group, a thienyl group, an indolyl group or a furyl group, or a substituted or unsubstituted phenyl group, a styryl group, a naphthyl group or an anthryl group, respectively, provided that the substituent is a di-lower alkylamino group , A lower alkyl group, a lower alkoxy group, a halogen atom, an aralkylamino group or an amino group). (In the formula, R ₁ , R ₂ , and R ₃ may be the same or different and represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a phenyl group, a phenoxy group, or a halogen atom.) (Wherein, R ₁ represents a hydrogen atom, a halogen atom, a cyano group, a lower alkyl group, and Ar is (However, R ₂ , R ₃ and R ₆ represent a hydrogen atom, a substituted or unsubstituted lower alkyl group or a substituted or unsubstituted benzyl group, and R ₄ and R ₅ represent a hydrogen atom, a halogen atom, a lower alkyl group or Represents a lower alkoxy group or a di-lower alkylamino group). ) (Wherein R ₁ , R ₂ , R ₃ , R ₄ and R ₆ represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a substituted or unsubstituted di-lower alkylamino group or a dibenzylamino group. , R ₅ represents a lower alkyl group or a benzyl group.) (In the formula, Ar represents a naphthalene ring, an anthracene ring, a styryl group or a substituted product thereof, or a pyridine ring, a furan ring, or a thiophene ring, and R represents a lower alkyl group or a benzyl group.) (Wherein, R ₁ represents a lower alkyl group, a 2-hydroxyethyl group or a 2-chloroethyl group, R ₂ represents a lower alkyl group, a benzyl group or a phenyl group, and R ₃ represents a hydrogen atom, a halogen atom, a lower alkyl group. Group, lower alkoxy group, di-lower alkylamino group or nitro group.) (Wherein, R ₁ represents a hydrogen atom, a lower alkyl group, a chloroethyl group or a hydroxyethyl group, R ₂ represents a hydrogen atom or a halogen atom, and R ₃ represents a lower alkyl group, a di-lower alkylamino group, a diarylamino group. Substituted or unsubstituted styryl group, substituted or unsubstituted aromatic ring residue (aromatic ring or benzene ring, naphthalene ring, anthracene ring, etc.), substituted or unsubstituted heterocyclic residue (heterocycle is pyridine ring, quinoxaline Ring, carbazole ring, etc.). (Wherein, R ₁ represents a lower alkyl group, R ₂ represents a lower alkyl group, a di-lower alkylamino group, a diarylamino group,
Substituted or unsubstituted styryl group, substituted or unsubstituted aromatic ring residue (aromatic ring is benzene ring, naphthalene ring, anthracene ring, etc.), substituted or unsubstituted heterocyclic residue (heterocycle is pyridine ring, quinoxaline ring Carbazole ring). ) (Wherein R ₁ and R ₂ may be the same or different and each represents a hydrogen atom, a lower alkyl group, a hydroxy lower alkyl group, a chloro lower alkyl group, an alkyl acyl group having 1 to 2 carbon atoms, an alkyl carbon Represents a cycloalkyl group of the formulas 5 to 6, or a substituted or unsubstituted aralkyl group.) (Wherein R ¹ , R ³ and R ⁴ are a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom, or a substituted or unsubstituted Wherein R ² represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or a halogen, provided that R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms. k, l, m and n are
R ¹ , R ² , R ³ and R ⁴ may be the same or different when each is an integer of 2, 3 or 4;

A—CH ₂ CH ₂ —Ar ¹ —CH ₂ CH ₂ —A (wherein, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group or a heterocyclic group, and A represents a substituted or unsubstituted N
A substituted carbazolyl group or (However, Ar ² is a substituted or unsubstituted aromatic hydrocarbon group or heterocyclic group, and R ¹ and R ² are a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.) Express. These charge transport materials are used alone or in combination of two or more.

Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene, -butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, and poly (vinyl acetate). Vinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene,
Thermoplastic or thermosetting resins such as poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin.

As the solvent, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride and the like are used.

The thickness of the charge transport layer 17 is suitably about 5 to 100 μm. In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer 17. As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are,
The amount used is suitably about 0 to 30% by weight based on the binder resin. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil are used, and the amount of the silicone oil is suitably about 0 to 1% by weight based on the binder resin.

Undercoat layer 13 provided between support 11 and charge generation layer 15
Is provided for the purpose of further improving the effect of the present invention and improving the adhesiveness, and the material is SiO, Al ₂ O ₃ ,
Inorganic materials such as silane coupling agents, titanium coupling agents, and chromium coupling agents, polyamide resins, alcohol-soluble polyamide resins, water-soluble polyvinyl butyral, polyvinyl butyral, and binder resins having good adhesive properties such as PVA are used. In addition, a resin in which ZnO, TiO ₂ , ZnS or the like is dispersed in the above-mentioned resin having good adhesiveness can also be used.
As a method for forming the undercoat layer, a method such as sputtering or vapor deposition is used when an inorganic material is used alone, and a usual coating method is used when an organic material is used. The thickness of the undercoat layer is 5 μm
The following are appropriate:

The protective layer 19 is provided for the purpose of protecting the surface of the photoconductor, and as a material used for the protective layer 19, ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide , Polyamide imide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene,
Examples include resins such as AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. Other protective layers include fluororesins such as polytetrafluoroethylene, silicone resins, and those obtained by dispersing inorganic materials such as titanium oxide, tin oxide, and potassium titanate in these resins for the purpose of improving abrasion resistance. Can be added. As a method for forming the protective layer, a normal coating method is employed. The thickness of the protective layer is 0.5
About 10 μm is appropriate.

Further, in the present invention, another intermediate layer (not shown) can be provided between the charge transport layer 17 and the protective layer 19.

〔Example〕

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

All parts used in the examples are parts by weight.

Example 1 On a polyethylene terephthalate film on which aluminum was vapor-deposited, a coating liquid for a charge generation layer having the following composition and a coating liquid for a charge transport layer were sequentially applied and dried to form a charge generation layer having a thickness of 0.2 μm and a charge having a thickness of 22 μm. A transport layer was formed to prepare an electrophotographic photoreceptor of the present invention.

(Charge transport layer coating solution)

8 parts of charge transport material of the following structural formula Polycarbonate (manufactured by Teijin Chemicals Ltd., Panlite L-1250) 10 parts Tetrahydrofuran 70 parts Example 2 On the same support as in Example 1, an undercoat layer coating solution, a charge generation layer coating solution and a charge of the following composition Transport layer coating solution
It was coated and dried to form a 0.3 μm undercoat layer, a 0.2 μm charge generation layer and a 20 μm charge transport layer, respectively, to prepare an electrophotographic photoreceptor of the present invention.

(Undercoat coating solution)

Water-soluble polyvinyl butyral 50 parts 25% aqueous solution (Esrec W-201 manufactured by Sekisui Chemical Co., Ltd.) Water 150 parts Methanol 200 parts [Charge generating layer coating liquid] 1 part of a charge generating substance of the following structural formula 1.5 parts of a compound of general formula (I) having the following structural formula Cyclohexanone 40 parts 2-butanone 20 parts [Coating solution for charge transport layer] 9 parts of charge transport material having the following structural formula Polycarbonate (Panlite K- manufactured by Teijin Chemicals Ltd.)
1300) 10 parts Tetrahydrofuran 80 parts Example 3 On a polyethylene terephthalate film provided with a Hastelloy conductive layer, an undercoat layer coating solution, a charge generation layer coating solution and a charge transport layer coating solution having the following compositions were sequentially applied. After drying, a 2 μm undercoat layer, a 0.3 μm charge generation layer and 1
An 8 μm charge transport layer was formed to prepare an electrophotographic photosensitive member of the present invention.

(Undercoat coating solution)

Titanium dioxide 10 parts Polyester 1 part (Toyobo Co., Ltd. Byron 200) Toluylene-2,4-diisocyanate 0.2 parts 2-butanone 100 parts 4-methyl-2-pentanone 70 parts [Coating solution for charge generation layer] The following structural formula Charge generation material 3 parts 0.2 part of the compound of general formula (I) having the following structural formula Polyvinyl butyral 0.3 part (UCC manufacture XYHL) Cyclohexanone 100 parts Tetrahydrofuran 60 parts [Coating solution for charge transport layer] 7 parts of charge transport material of the following structural formula Polyarylate 9 parts (U-100 manufactured by Unitika Ltd.) Tetrahydrofuran 80 parts Example 4 A charge generation layer coating solution and a charge transport layer coating solution having the following compositions are sequentially applied on a 0.2 mm thick aluminum plate. The resultant was dried to form a 0.2 μm charge generation layer and a 17 μm charge transport layer, respectively, to prepare an electrophotographic photoreceptor of the present invention.

(Charge generation layer coating solution)

1 part of charge generating substance of the following structural formula 0.2 part of the compound of general formula (I) having the following structural formula Polyester 1 part (Toyobo Co., Ltd. Byron 300) Tetrahydrofuran 100 parts [Charge transport layer coating solution] Charge transport material of the following structural formula 10 parts Polycarbonate 10 parts (Lexan-141 manufactured by GE) Methylene chloride 100 parts Example 5 An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer were formed on an electroformed nickel plate having a thickness of 0.1 mm. The coating liquid and the protective layer coating liquid were sequentially applied and dried to form a 0.3 μm undercoat layer, a 0.2 μm charge generation layer, an 18 μm charge transport layer, and a 3 μm protection layer, respectively. A photoreceptor was prepared.

(Undercoat coating solution)

Polyvinyl alcohol 2 parts (Denka Povar H-20 manufactured by Denki Kagaku Kogyo KK) Water 100 parts Methanol 100 parts [Coating liquid for charge generating layer] Charge generating material of the following structural formula 3 parts 2.5 parts of a compound of general formula (I) having the following structural formula Polysulfone (P-1700 manufactured by Nissan Chemical Industries, Ltd.) 0.8 parts Cyclohexanone 100 parts Tetrahydrofuran 90 parts [Coating solution for charge transport layer] 9 parts of charge transport material having the following structural formula Polycarbonate 11 parts (Panelite K-1300 manufactured by Teijin Chemicals Co., Ltd.) 80 parts of methylene chloride [coating solution for protective layer] 80 parts of styrene-methyl methacrylate 80 parts of 3-methacryloxypropyltrimethoxysilane copolymer 80 parts of tin oxide toluene 170 parts 2-butanone 100 parts Example 6 On the same support as in Example 4, an undercoat layer coating solution, a charge generation layer coating solution and a charge transport layer coating solution having the following compositions were sequentially added.
Coating and drying were performed to form an undercoat layer of 2 μm, a charge generation layer of 0.4 μm, and a charge transport layer of 22 μm, respectively, to thereby prepare an electrophotographic photoreceptor of the present invention.

(Undercoat coating solution)

Titanium dioxide 8 parts Polyvinyl butyral 10 parts (S-LEC BL-1 manufactured by Sekisui Chemical Co., Ltd.) 2-butanone 60 parts Ethyl acetate 40 parts [Charge generating layer coating liquid] 2 parts of a charge generating material having the following structural formula 0.6 parts of a compound of the following general formula (I) Polyester 2 parts (Vylon 200, manufactured by Toyobo Co., Ltd.) Tolylen-2,4-diisocyanate 0.1 part Tetrahydrofuran 50 parts 4-methyl-2-pentanone 100 parts [Coating solution for charge transport layer] Charge transport material having the following structural formula 10 Department Polycarbonate 10 parts (Mitsubishi Gas Chemical Co., Ltd., polycarbonate Z) 50 parts Methylene chloride 50 parts 1,2-dichloroethane 25 parts Example 7 On a 60 mm-diameter Al cylindrical support, a charge generation layer coating solution having the following composition, charge transport The layer coating solution and the protective layer coating solution are sequentially applied and dried to form a 0.2 μm charge generation layer, 20 μm each.
An electrophotographic photoreceptor of the present invention was prepared by forming a charge transport layer of m and a protective layer of 5 μm.

(Charge generation layer coating solution)

3 parts of charge generating substance of the following structural formula 2 parts of a compound of general formula (I) having the following structural formula 100 parts of cyclohexanone 150 parts of 4-methyl-2-pentanone [Coating solution for charge transport layer] 9 parts of charge transport material having the following structural formula Polycarbonate 10 parts (Panelite C-1400 manufactured by Teijin Chemicals Limited) 70 parts methylene chloride [Protective layer coating liquid] Styrene-methyl methacrylate-2-hydroxyethyl methacrylate-trifluoroethyl methacrylate copolymer 70 Part Conductive titanium oxide 90 parts Toluene 220 parts n-butanol 60 parts Example 8 A charge generation layer coating solution, a charge transport layer coating solution, and a protective layer coating of the following composition were formed on an 80 mm-diameter Al cylindrical support. The liquid was sequentially applied and dried to form a 0.2 μm charge generation layer and 19 μm each.
A μm charge transport layer was formed to prepare an electrophotographic photoreceptor of the present invention.

(Charge generation layer coating solution)

2 parts of charge generating material of the following structural formula 0.2 part of the compound of general formula (I) having the following structural formula Polyvinyl butyral 1 part (S-LEC BM-S manufactured by Sekisui Chemical Co., Ltd.) Tolylene-2,4-diisocyanate 0.1 part Cyclohexanone 70 parts 2-butanone 50 parts [Charge transport layer coating liquid] Charge transport material of the following structural formula 8 Department Polyester 10 parts (Toyobo Co., Ltd. Byron 200) Tetrahydrofuran 70 parts Comparative Examples 1 to 8 In the photoconductors of Examples 1 to 8 prepared as described above,
Photoconductors were formed in the same manner as in Examples 1 to 8 except that the compound of the general formula (I) was not contained in each of the charge generation layers, thereby obtaining photoconductors of Comparative Examples 1 to 8.

The characteristics of each photoreceptor described above were measured using an electrostatic copying paper test apparatus (SP-428, manufactured by Kawaguchi Electric Works) (Examples 1 to 6, Comparative Examples 1 to 6).
6) and the measuring devices disclosed in JP-A-60-100167 (Examples 7 to 8 and Comparative Examples 7 to 8) were evaluated as follows.

First, corona discharge was performed for 15 seconds at a discharge pressure of -5.5 KV, and then dark-decayed for 10 seconds, and then 4.5 lux tungsten light was irradiated.

At this time, the surface potential V ₁ (V) for 1 second and 15 seconds after the start of charging,
V ₁₅ (V) and the surface potential V ₂₅ (V) after dark decay 10 seconds were measured, and the exposure amount E1 / 2 (lux · sec) required to reduce V ₂₅ to half the potential. Was measured. The dark decay rate (DD) is defined by the following equation.

DD = V ₂₅ / V ₁₅ Further, after charging and exposure under the above conditions were simultaneously performed for 30 minutes to fatigue, the same measurement as above was performed again. Table 1 shows the evaluation results.

Example 9 On a polyethylene terephthalate film on which aluminum was deposited, a coating liquid for a charge generation layer having the following composition and a coating liquid for a charge transport layer were sequentially applied and dried to form a charge generation layer having a thickness of 0.2 μm and a charge having a thickness of 22 μm. A transport layer was formed to prepare an electrophotographic photoreceptor of the present invention.

(Charge generation layer coating solution)

2 parts of charge generating material of the following structural formula 2 parts of a compound of general formula (II) having the following structural formula Polyvinyl butyral resin 0.2 parts (Denka Butyral # 4000-1 manufactured by Denki Kagaku Kogyo Co., Ltd.) 100 parts of cyclohexanone 50 parts of 2-butanone [Coating solution for charge transport layer] 9 parts of charge transport material having the following structural formula Polycarbonate (Panlite L-1250 manufactured by Teijin Chemicals Limited) 10 parts Tetrahydrofuran 81 parts Example 10 On the same support as in Example 9, an undercoat layer coating solution, a charge generation layer coating solution and a charge were formed as shown below. Transport layer coating solution
It was coated and dried to form a 0.3 μm undercoat layer, a 0.2 μm charge generation layer and a 20 μm charge transport layer, respectively, to prepare an electrophotographic photoreceptor of the present invention.

(Undercoat coating solution)

Water-soluble polyvinyl butyral 50 parts 25% aqueous solution (Esrec W-201 manufactured by Sekisui Chemical Co., Ltd.) Water 150 parts Methanol 200 parts [Charge generating layer coating liquid] 1 part of a charge generating substance of the following structural formula 1.3 parts of a compound of general formula (II) having the following structural formula 40 parts of cyclohexanone 40 parts of 2-butanone [Coating solution for charge transport layer] 10 parts of charge transport material having the following structural formula Polycarbonate (Panlite K-1300 manufactured by Teijin Chemicals Ltd.) 10 parts Tetrahydrofuran 75 parts Example 11 A coating liquid for an undercoat layer and a coating liquid for a charge generation layer having the following composition on a polyethylene terephthalate film provided with a Hastelloy conductive layer. And the coating solution for the charge transport layer were sequentially applied and dried to form an undercoat layer of 2 μm, a charge generation layer of 0.3 μm, and 1
An 8 μm charge transport layer was formed to prepare an electrophotographic photosensitive member of the present invention.

(Undercoat coating solution)

Titanium dioxide 10 parts Polyester 1 part (Toyobo Co., Ltd. Byron 200) Toluylene-2,4-diisocyanate 0.2 part 2-butanone 100 parts 4-metal-2-pentanone 70 parts [Coating solution for charge generation layer] The following structural formula Charge generation material 3 parts 0.3 part of a compound of the following general formula (II) Polyvinyl butyral 0.6 part (XYHL manufactured by UCC) Cyclohexanone 180 parts Tetrahydrofuran 70 parts [Coating solution for charge transport layer] 8 parts of charge transport material of the following structural formula Polyarylate 10 parts (U-100 manufactured by Unitika Ltd.) Tetrahydrofuran 82 parts Example 12 A coating liquid for a charge generation layer and a coating liquid for a charge transport layer having the following compositions were sequentially applied on an aluminum plate having a thickness of 0.2 mm. The resultant was dried to form a 0.2 μm charge generation layer and a 17 μm charge transport layer, respectively, to prepare an electrophotographic photoreceptor of the present invention.

(Charge generation layer coating solution)

1 part of charge generating substance of the following structural formula 0.4 part of a compound represented by the following general formula (II) Polyester 0.6 parts (Toyobo Co., Ltd. Byron 300) Tetrahydrofuran 80 parts [Coating solution for charge transport layer] Charge transport material of the following structural formula 10 parts Polycarbonate 10 parts (Lexan-141 manufactured by GE) Methylene chloride 100 parts Example 13 An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer on an electroformed nickel plate having a thickness of 0.1 mm were formed as follows. The coating liquid and the protective layer coating liquid were sequentially applied and dried to form a 0.3 μm undercoat layer, a 0.2 μm charge generation layer, an 18 μm charge transport layer, and a 3 μm protection layer, respectively. A photoreceptor was prepared.

(Undercoat coating solution)

Polyvinyl alcohol 2 parts (Tenkapovar H-20 manufactured by Denki Kagaku Kogyo KK) Water 100 parts Methanol 100 parts [Coating liquid for charge generating layer] Charge generating material of the following structural formula 3 parts 4.5 parts of a compound of the following general formula (II) Polysulfone (P-1700 manufactured by Nissan Chemical Co., Ltd.) 1.5 parts Cyclohexanone 400 parts Tetrahydrofuran 100 parts [Coating solution for charge transport layer] 9 parts of charge transport material having the following structural formula Polycarbonate 10 parts (Panelite K-1300 manufactured by Teijin Chemicals Co., Ltd.) 80 parts of methylene chloride [Protective layer coating liquid] 80 parts of styrene-methyl methacrylate 80 parts of 3-methacryloxypropyltrimethoxysilane copolymer 80 parts of tin oxide toluene 170 parts 2-butanone 100 parts Example 14 On the same support as in Example 12, an undercoat layer coating solution, a charge generation layer coating solution and a charge transport layer coating solution having the following compositions were sequentially applied:
Coating and drying were performed to form an undercoat layer of 2 μm, a charge generation layer of 0.4 μm, and a charge transport layer of 22 μm, respectively, to thereby prepare an electrophotographic photoreceptor of the present invention.

(Undercoat coating solution)

Titanium dioxide 6 parts Polyvinyl butyral 10 parts (S-LEC BL-1 manufactured by Sekisui Chemical Co., Ltd.) 2-butanone 50 parts Ethyl acetate 50 parts [Charge generating layer coating liquid] 2 parts of a charge generating material having the following structural formula 0.7 part of the compound of the general formula (II) having the following structural formula Polyester 2.3 parts (Byron 200, manufactured by Toyobo Co., Ltd.) Toluylene-2,4-diisocyanate 0.1 part Tetrahydrofuran 100 parts 4-methyl-2-pentanone 60 parts [Coating solution for charge transport layer] Charge transport material having the following structural formula 10 Department Polycarbonate 12 parts (Mitsubishi Gas Chemical Co., Ltd., polycarbonate Z) 70 parts Methylene chloride 70 parts 1,2-dichloroethane 30 parts Example 15 On a 60 mm-diameter Al cylindrical support, a coating liquid for a charge generation layer having the following composition, charge transport The layer coating solution and the protective layer coating solution are sequentially applied and dried to form a 0.2 μm charge generation layer, 20 μm each.
An electrophotographic photoreceptor of the present invention was prepared by forming a charge transport layer of m and a protective layer of 5 μm.

(Charge generation layer coating solution)

3 parts of charge generating substance of the following structural formula 2.5 parts of a compound represented by the following general formula (II) 120 parts of cyclohexanone 80 parts of 4-methyl-2-pentanone [Coating solution for charge transport layer] 7 parts of charge transport material having the following structural formula Polycarbonate 10 parts (Panelite C-1400 manufactured by Teijin Chemicals Limited) 80 parts methylene chloride [Protective layer coating liquid] Styrene-methyl methacrylate-70 parts 2-hydroxyethyl methacrylate-trifluoroethyl methacrylate Combined conductive titanium oxide 90 parts Toluene 220 parts n-butanol 60 parts Example 16 A charge generating layer coating solution, a charge transport layer coating solution, and a protective layer coating of the following composition on an Al cylindrical support having a diameter of 80 mm. The liquid was sequentially applied and dried to form a 0.2 μm charge generation layer and 19 μm each.
A μm charge transport layer was formed to prepare an electrophotographic photoreceptor of the present invention.

(Charge generation layer coating solution)

5 parts of charge generating substance of the following structural formula 2 parts of a compound of general formula (II) having the following structural formula Polyvinyl butyral 2 parts (S-LEC BM-S manufactured by Sekisui Chemical Co., Ltd.) Toluylene-2,4-diisocyanate 0.1 part Cyclohexanone 150 parts 2-butanone 100 parts [Coating solution for charge transport layer] Charge transport material of the following structural formula 10 Department Polyester 10 parts (Toyobo Co., Ltd. Byron 200) Tetrahydrofuran 80 parts Comparative Examples 9-16 In the photoconductors of Examples 9-16 prepared as described above,
Photoconductors were formed in the same manner as in Examples 9 to 16 except that the compounds of the general formula (II) were not contained in the respective charge generation layers, thereby obtaining photoconductors of Comparative Examples 9 to 16.

The characteristics of each photoreceptor described above were measured using an electrostatic copying paper test apparatus (SP-428, manufactured by Kawaguchi Electric Works) (Examples 9 to 14, Comparative Examples 9 to 1).
4) and the measuring devices disclosed in JP-A-60-100167 (Examples 15 to 16, Comparative Examples 15 to 16) were evaluated as follows.

First, a corona discharge was performed for 20 seconds at a discharge pressure of −5.8 KV, and then a 6 lux tungsten light beam was irradiated when the surface potential became −800 V after dark attenuation.

At this time, the surface potential V ₁ (−
V), V ₂₀ (-V) and the surface potential during light irradiation is -400V
Exposure amount E ₄₀₀ (lux · sec) required to obtain was measured.

Further, the photoreceptor was irradiated with 10,000 lux · sec of tungsten light having a color temperature of 2856 ° K to cause photo fatigue, and V ₁ , V ₂₀ and E ₄₀₀ were measured in the same manner as described above. Table 2 shows the evaluation results.

[Effect of the Invention] The layered organic electrophotographic photoreceptor having high sensitivity of the present invention can prevent a delay in rising of a charging potential after repeated use.

Therefore, according to the present invention, it is possible to obtain a good image without background contamination when the image density is reduced, the image density is uneven, the fogging or the inverted image occurs in a copying machine, a printer, or the like.

[Brief description of the drawings]

1 to 4 are schematic cross-sectional views of the electrophotographic photosensitive member according to the present invention.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-210943 (JP, A) JP-A-1-118147 (JP, A) JP-A-63-50848 (JP, A) JP-A-60-1985 254045 (JP, A) JP-A-58-123542 (JP, A) JP-A-2-82253 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 5 / 00-5 / 16

Claims (1)

(57) [Claims] 1. An electrophotographic photoreceptor comprising a conductive support on which at least a charge generation layer and a charge transport layer are sequentially laminated, wherein the charge generation layer contains the following formula (I) or (I)
An electrophotographic photoreceptor comprising at least one of the compounds represented by I). (Wherein R ¹ , R ³ and R ⁴ are a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom or a substituted or unsubstituted R ² represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or a halogen, provided that R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms. k, l, m and n are integers of ¹ , ² , 3 or 4, and when each is an integer of 2, 3 or 4, said R ¹ , R ² , R ³ and R ⁴ may be the same or different. May be.) (Wherein, R ⁵ represents a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group, a dialkylamino group, a diarylamino group, or a halogen atom, and R ⁶ and R ⁷ represent a substituted or unsubstituted alkyl group, A substituted aryl group, and p represents an integer of 1 or 2.)