JPH0553339A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide the photosensitive body which has a charge transfer layer having excellent film formability and allows high-speed photoresponseness by forming a charge transfer material of triaryl amine or its deriv. and specifying the content thereof to prescribed weight %. CONSTITUTION:The charge transfer material constituting the charge transfer layer 3 of the electrophotographic sensitive body constituted by laminating a charge generating layer 2 and the charge transfer layer 3 on a conductive base body 1 is the triaryl amine or its deriv. and the content of the charge transfer material in the charge transfer layer 3 is >=54wt.%. The sufficient film formability is thereby obtd. In addition, the high-speed photoresponse characteristics equiv. to the high-speed photoresponse characteristics of polysilane which are heretofore not attaniable with this material can be exhibited. The higher sensitivity is obtd. with the photosensitive body formed to >=20mum, more preferably >=25mum and further preferably >=30mum film thickness of the charge transfer layer. The fluctuation in the sensitivity occurring in the film chipping by repetitive use is simultaneously minimized. Further, the film chipping is ameliorated by providing a surface protective layer on the uppermost layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, and more particularly to an electrophotographic photosensitive member having remarkably improved light attenuation response characteristics (response time).

[0002]

2. Description of the Related Art As the electrophotographic method, the Carlson process and various deformation processes thereof are known, and they are widely used in copying machines and printers. Among the photoconductors used in such an electrophotographic method, those using an organic photosensitive material have recently begun to be used because of advantages such as low cost, mass productivity, and pollution-free property.

For organic electrophotographic photoreceptors, a photoconductive resin represented by polyvinylcarbazole (PVK), P
Charge transfer complex type typified by VK-TNF (2,4,7 trinitrofluorenone), pigment dispersion type typified by phthalocyanine-binder, and function separation type photosensitivity using a combination of a charge generating substance and a charge transporting substance. The body and the like are known, and in particular, the function-separated type photoconductor is drawing attention.

It is known that the function-separated type photoreceptor is used in combination with a charge-transporting substance having an absorption mainly in the ultraviolet region and a charge-generating substance having an absorption mainly in the visible region to the near-infrared region. , And useful.

Many charge transport materials have been developed as low molecular weight compounds, but since low molecular weight compounds alone have no film-forming property, they are usually used by being dispersed and mixed in an inert polymer.

However, the charge transport layer comprising a low molecular charge transport material made of an inert polymer is generally soft, and film abrasion due to repeated use tends to occur in the Carlson process. Further, the charge transport layer having this structure has a limit in charge mobility, which has been an obstacle to speeding up or downsizing the Carlson process, which has a strong tendency in recent years.

That is, the journal of the Electrophotographic Society, Vol. 25, 83-8
The electrophotographic photosensitive member described on page 9 surely exhibits a faster photoresponse characteristic than the conventional one, but it is not satisfactory from the viewpoint of the above-mentioned Carlson process, and further improvement in this respect is strong. Was wanted.

On the other hand, Japanese Patent Laid-Open No. 58-211760 discloses a function-separated type photoreceptor comprising a support, a charge generation layer, a charge transport layer and a protective layer, wherein the protective layer is made of polyparaxylylene resin, and Disclosed is a technique for improving the ozone resistance of an electrophotographic photoreceptor, which is characterized in that the ratio of the dye to the binder in the charge transport layer is in the range of 10/10 to 30/10. In addition, Japanese Patent Laid-Open No. Sho 61
No. 123848 discloses an organic light-emitting device in which a charge transporting layer containing a charge transporting material and a binder and a charge generating layer containing a charge generating material and a binder are laminated in this order on a conductive support. In the conductor, the weight ratio of the charge transport material in the charge transport layer to the binder is 12/10 or more, and the charge generation layer contains the charge transport material. A technique having high sensitivity and capable of reducing potential fluctuation is disclosed, and JP-A-61-61
JP-A-278855 discloses a conductive substrate, a charge generating layer containing a charge generating substance provided on one surface of the conductive substrate, a charge transporting layer containing a charge transporting substance, the charge generating layer and the charge. An electrophotographic photoreceptor characterized by comprising an intermediate layer which is interposed between a transport layer and contains the charge-transporting substance in a concentration lower than that of the charge-transporting layer, and is more adhesive than a conventional intermediate layer, Although a technique of excellent fatigue property and improving charging ability has been disclosed, the electrophotographic photoreceptor of the present invention is completely different from those of the present invention in all of constitution, purpose and effect.

Recently, with the trend toward higher speed or smaller size of the Carlson process, it is strongly expected that the organic photoconductor will have a further high speed photoresponse. Among them, for example, the polysilane compound disclosed in Japanese Patent Laid-Open No. 63-285552 has a high hole drift mobility of ^{-10 -4} cm ² / V · sec, and has a charge transporting property for a high-speed photoconductor. Expectations are high as a material. However, it is known that this polysilane is decomposed by ultraviolet light, and it is inevitable at least to avoid absorption of ultraviolet light that accompanies corona charging.

On the other hand, the charge transport layer comprising a low molecular weight charge transport material and a binder resin has usually been used with a content of the charge transport material of 50% by weight or less from the viewpoint of film-forming property and abrasion resistance.

[0011]

SUMMARY OF THE INVENTION The first object of the present invention is to form a charge-transporting layer in a function-separated type laminated photoreceptor by a low-molecular-weight transport material and a binder resin.
An object of the present invention is to provide an electrophotographic photosensitive member which is excellent in film-forming property and exhibits higher photo-responsiveness than conventional organic photosensitive members. A second object of the present invention is to provide a technique for increasing the sensitivity of the above high-speed photoresponsive photoreceptor.

A third object of the present invention is to provide a wear resistance technique by repeatedly using the above high-speed photoresponsive photoreceptor.

[0013]

SUMMARY OF THE INVENTION The inventors of the present invention have formed a charge transport layer by forming a charge transport layer using a conventionally known low-molecular charge transport material and a binder polymer while achieving high-speed photoresponse. As a result of studying with emphasis on the property, in an electrophotographic photoreceptor comprising a charge generating layer and a charge transporting layer laminated on a conductive substrate, the charge transporting material constituting the charge transporting layer is triarylamine or its An electrophotographic photoreceptor characterized in that it is a derivative, and the content of the charge transport material in the charge transport layer is 54% by weight or more, has sufficient film-forming ability and It was found that high-speed photoresponse characteristics comparable to those of polysilane that could not be reached could be expressed,
The invention of claim 1 of the present invention has been completed.

However, in the invention having such a structure, the sensitivity is not improved, and the current state is only maintained. However, the sensitivity referred to here is the amount of attenuation of the surface potential caused by a constant exposure amount, and is an amount irrelevant to the photoresponse characteristic (time). However, what has improved this point is a photoconductor in which the thickness of the charge transport layer is 20 μm or more, preferably 25 μm or more, more preferably 30 μm or more,
While achieving high sensitivity, it is possible to minimize sensitivity fluctuations due to film abrasion due to repeated use.

However, as the content of the low-molecular weight charge transport material increases, the amount of film abrasion due to repeated use increases, which can be improved by providing the surface protective layer. That is, the effect of the protective layer in the present invention is significantly larger than the role of the protective layer in the conventionally known photoreceptor.

Next, the structure of the electrophotographic photosensitive member of the present invention will be described with reference to the drawings. 1 and 2 are basic layer structure diagrams showing an electrophotographic photosensitive member of the present invention, which has a structure in which a charge generation layer 2 and a charge transport layer 3 are laminated on a conductive substrate 1.

The conductive substrate 1 has a volume resistance of 10 ¹⁰ Ω.
Films or cylinders with conductivity of cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold and platinum, metal oxides such as tin oxide and indium oxide by vapor deposition or sputtering. -Shaped plastics, paper coated with aluminum, aluminum, aluminum alloy, nickel, stainless steel plates, etc. I. , I. I. A tube or the like which has been surface-treated by cutting, superfinishing, polishing or the like can be used after being made into a raw tube by a method such as extrusion or drawing.

The charge generating layer 2 is a layer containing a charge generating substance as a main component, and a binder resin may be used if necessary.

As the charge generating substance, an inorganic material and an organic material can be used. Examples of inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. As amorphous silicon, dangling bonds terminated with hydrogen atoms or halogen atoms or doped with boron atoms, phosphorus atoms or the like are preferably used.

On the other hand, organic materials include phthalocyanine pigments, naphthalocyanine pigments, perylene pigments, perinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squalic acid dyes, azurenium salt dyes, and monoazo pigments. , Disazo pigments, trisazo pigments and the like can be used.

Among these charge generating substances, disazo or trisazo pigments are preferably used.

These charge generating substances may be used alone or in combination of two or more.

As the binder resin used as necessary, 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.

The binder resin is suitably used in an amount of 0 to 100 parts by weight, preferably 0 to 50 parts by weight, based on 100 parts by weight of the charge generating substance.

As a method for forming the charge generation layer 2, a vacuum thin film forming method and a casting method from a solution dispersion system can be largely cited.

As the former method, a vacuum vapor deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used. As the charge generation layer 17, the above-mentioned inorganic materials and organic materials are used. The system material layer can be formed well.

In order to provide the charge generating layer by the latter casting method, the above-mentioned inorganic or organic charge generating substance is used together with a binder resin, if necessary, in a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone. Ball mill,
It can be formed by dispersing with an attritor, a sand mill or the like, and diluting the dispersion appropriately and applying. The coating can be performed by using a dip coating method, a spray coating method, a bead coating method, or the like.

The film thickness of the charge generation layer provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

The charge-transporting layer 3 is composed of a charge-transporting material and a binder resin. Triarylamine or its derivative is used as the charge-transporting material of the present invention. In particular, the material represented by the following general formula is preferably used. To be done.

[0030]

[Chemical 1]

(In the formula, R ₁ , R ₂ and R ₃ may be the same or different and each represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a phenyl group, a phenoxy group or a halogen atom.)

[0032]

[Chemical 2]

(In the formula, R ¹ , R ³ and R ⁴ are hydrogen atom, amino group, alkoxy group, thioalkoxy group, aryloxy group, methylenedioxy group, substituted or unsubstituted alkyl group, halogen atom or substituted Or an unsubstituted aryl group, R ² represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or halogen, provided that all of R ¹ , R ² , R ³ and R ⁴ are hydrogen atoms. Further, k, l, m and n are integers of 1, 2, 3 or 4, and when each is an integer of 2, 3 or 4, R ¹ ,
R ² , R ³ and R ⁴ may be the same or different.

[0034]

[Chemical 3]

(Wherein R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted lower alkyl group or a substituted or unsubstituted aryl group, and Ar ₁ , Ar ₃ and Ar ₄ are substituted or unsubstituted aryl). Represents a group, Ar ₂ represents a substituted or unsubstituted arylene group, Ar ₁ and R ₁ may together form a ring, and n is an integer of 0 or 1.)

[0036]

[Chemical 4]

(Wherein 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 and R ₃ may be the same or different, and a hydrogen atom or a lower alkyl group). group, a lower alkoxy group or a halogen _{atom.) a-CH 2 CH 2} -Ar 2 -CH 2 CH 2 -A { in the formula, Ar ² is a substituted or unsubstituted aromatic hydrocarbon group or heterocyclic group Where A is

[0038]

[Chemical 5]

(Wherein Ar ² is a substituted or unsubstituted aromatic hydrocarbon group or a heterocyclic group, and R ¹ and R ² are substituted or unsubstituted aryl groups)}

[0040]

[Chemical 6]

(Wherein R ¹ is a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group, a dialkylamino group,
A diarylamino group or a halogen atom, R ² and R ³ represent a substituted or unsubstituted aryl group, Ar represents an aromatic hydrocarbon group or a heterocyclic group, and n represents an integer of 1 or 2. )

[0042]

[Chemical 7]

(Wherein R ¹ and R ² are a hydrogen atom, an amino group, a substituted or unsubstituted dialkylamino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a substituted or unsubstituted alkyl group, a halogen atom, A substituted or unsubstituted aryl group, R ³ and R ⁴ represent a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or a halogen atom, Ar is a substituted or unsubstituted monocyclic aromatic hydrocarbon group, a substituted Or, represents an unsubstituted non-condensed polycyclic aromatic hydrocarbon group or a substituted or unsubstituted heterocyclic group.)

[0044]

[Chemical 8]

(In the above formula, Ar is an aromatic hydrocarbon group or a heterocyclic group, R ¹ and R ² are substituted or unsubstituted aryl groups), R is an alkyl group, an alkoxy group or a halogen atom. Any one, n is an integer of 0-4,
When n ≧ 2, R may be the same or different. }

[0046]

[Chemical 9]

{Where A is

[0048]

[Chemical 10]

Wherein Ar represents a substituted or unsubstituted arylene group, R ¹ and R ² represent a substituted or unsubstituted aryl group, and R is a hydrogen atom, a substituted or unsubstituted alkyl group. Represents a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group. m represents an integer of 2-8. n represents an integer of 0 or 1. }

[0050]

[Chemical 11]

{Where A is

[0052]

[Chemical formula 12]

(Wherein Ar represents a substituted or unsubstituted arylene group, R ¹ and R ² represent a substituted or unsubstituted aryl group), and R is a hydrogen atom, a substituted or unsubstituted alkyl group. Represents a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group. n represents an integer of 0-8. }

[0054]

[Chemical 13]

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and these may be the same or different.)

[0056]

[Chemical 14]

(In the formula, R ₁ and R ₂ represent a substituted or unsubstituted aryl group.)

[0058]

[Chemical 15]

(In the formula, R ¹ and R ² represent a substituted or unsubstituted aryl group, and R ¹ and R ² may be the same or different. R ³ and R ⁴ are a hydrogen atom, an alkyl group or an alkoxy group. Represents a group or a halogen atom, m is 1, 2, 3 and n is an integer of 1, 2, 3, 4, and when m and n are respectively plural, R ³ and R ⁴ are the same or different. You may.)

[0060]

[Chemical 16]

(Where m is an integer of 0 or 1 and m =
When 1, X is an oxygen atom, a sulfur atom,

[0062]

[Chemical 17]

--CH _2- , --CH ₂ CH _2-, or --CH
═CH—, and R ¹ and R ² represent a carbocyclic aromatic group or a heterocyclic group. R ³ and R ⁴ represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom.
Ar represents a carbocyclic aromatic group or a heterocyclic group. n is an integer of 0 or 1. R ³ may form a benzene ring together with X. ) Other known triarylamines or their derivatives.

These charge transport materials may be used alone or in admixture of two or more.

As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate , Polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate,
Cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin,
Examples thereof include thermoplastic or thermosetting resins such as silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin.

Among these binder resins, polycarbonate containing bisphenol A, bisphenol C or bisphenol Z as a bisphenol component can be preferably used.

As the solvent, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride or the like is used.

The thickness of the charge transport layer 3 is suitably about 20 to 100 μm, preferably 25 to 90 μm, more preferably 30 to 90 μm.

In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer 3. As the plasticizer, those used as a plasticizer for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount of the plasticizer used is preferably 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, and polymers or oligomers having a perfluoroalkyl group in the side chain are used, and the amount thereof is 0 to 1 weight with respect to the binder resin. % Is appropriate.

In the present invention, when the content of the charge transport material in the charge transport layer is 54% by weight or more, preferably 57% by weight or more, more preferably 60% by weight or more, the effects of the present invention can be exhibited well. ..

In the electrophotographic photosensitive member of the present invention, an undercoat layer can be provided between the conductive support 1 and the photosensitive layer. The undercoat layer generally contains a resin as a main component, but considering that the photosensitive layer is coated on the resin with a solvent, the resin may be a resin having high solvent resistance to a general organic solvent. desirable. Examples of such resins include polyvinyl alcohol, casein, water-soluble resins such as sodium polyacrylate, copolymer nylon, alcohol-soluble resins such as methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, epoxy. Examples of the resin include curable resins that form a three-dimensional network structure such as resins.

To the undercoat layer, fine powder pigments of metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide and indium oxide may be added to prevent moire and reduce residual potential. Good.

These undercoat layers can be formed by using an appropriate solvent and coating method as in the above-mentioned photosensitive layer.

Further, a silane coupling agent, a titanium coupling agent, a chromium coupling agent or the like can be used as the undercoat layer of the present invention.

In addition to the above, the undercoat layer of the present invention is formed by anodizing Al ₂ O ₃ , an organic substance such as polyparaxylylene (parylene), SiO, SnO ₂ , TiO ₂ , and IT.
An inorganic substance such as O or CeO ₂ provided by a vacuum thin film forming method can also be favorably used.

The thickness of the undercoat layer is preferably 0 to 5 μm.

In the electrophotographic photoreceptor of the present invention, a protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer.

Materials used for this are ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide,
Polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate,
Polyether sulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide,
Polysulfone, polystyrene, AS resin, butadiene-
Examples thereof include resins such as styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. The protective layer may be made of a fluororesin such as polytetrafluoroethylene, a silicone resin, or a dispersion of an inorganic material such as titanium oxide, tin oxide or potassium titanate in these resins for the purpose of improving wear resistance. It can be added.

As a method of forming the protective layer, a usual coating method is adopted. The thickness of the protective layer is preferably about 0.5 to 10 μm.

In addition to the above, known materials such as i-C and a-SiC formed by the vacuum thin film forming method can also be used as the protective layer.

In the present invention, another intermediate layer may be provided between the photosensitive layer and the protective layer.

A binder resin is generally used as a main component in the intermediate layer. Examples of these resins include polyamide, alcohol-soluble nylon resin, water-soluble polyvinyl butyral resin, polyvinyl butyral, and polyvinyl alcohol.

As a method for forming the intermediate layer, a usual coating method is employed as described above. The thickness of the intermediate layer is 0.05-
About 2 μm is suitable.

Further, in the electrophotographic photosensitive member of the present invention, an antioxidant can be added for the purpose of improving the environmental resistance, especially for the purpose of preventing the sensitivity from decreasing and the residual potential from increasing due to the oxidizing environment. .. The antioxidant may be added to any layer containing an organic substance, but good results can be obtained by adding it to the layer containing a charge transporting substance.

As the antioxidant that can be used in the present invention, known materials can be used, and among others, commercially available products such as rubber, plastics and fats and oils can be used.

[0086]

EXAMPLES Examples will be shown below, but the examples are for explaining the present invention in detail, and the present invention is not limited by the examples.

All parts in the examples are parts by weight.

Examples 1 to 4 and Comparative Examples 1 to 3 On a polyethylene terephthalate film on which aluminum was vapor-deposited, a charge generation layer coating solution and a charge transport layer coating solution having the following compositions were sequentially applied and dried, respectively. An electrophotographic photosensitive member was prepared by forming a charge generation layer having a thickness of 0.2 μm and a charge transport layer having a thickness of 25 μm.

<Coating Liquid for Charge Generation Layer> 3 parts of the charge generation substance having the following structural formula

[0090]

[Chemical 18]

Polyvinyl butyral (Sekisui Chemical Co., Ltd. S-REC BL-1) 1 part THF 130 parts Ethyl cellosolve 110 parts <Charge transport layer coating liquid> Charge transport substance of the following structural formula

[0092]

[Chemical 19]

Polycarbonate (Panlite K-1300 manufactured by Teijin Chemicals Ltd.) Amount described in Table 1 Tetrahydrofuran 80 parts

[0094]

[Table 1]

Each of the photoconductors prepared as described above was subjected to -5.2 k by an electrostatic copying paper test apparatus (SP-428 manufactured by Kawaguchi Electric Co., Ltd.).
At a discharge voltage of V, it is charged to -800 V or more, then darkly attenuated to -800 V, and when it reaches -800 V, 6 lux of tungsten light is irradiated, and the exposure amount E _1/5 (lux. sec) was measured.

Next, the measurement of the optical response characteristic is performed by Proceedi.
ng of THE FITH INTERNATIONAL CONGRESS ON
ADVANCES IN NON-IMPACT P
RINTING TECHNOLOGIES (1989
November) Published by The Soc
yety for Imaging Science a
The response time Tr was measured by the method described in nd Technology 60-71. Results are shown in FIG.

Comparative Example 4 A compound having the following structure as a charge transport material

[0098]

[Chemical 20]

A photoconductor of Comparative Example 4 was prepared in the same manner as in Example 3 except that the above was used. The photoreceptor of Comparative Example 4 was left unattended overnight, and crystals of the charge transport material were deposited in the charge transport layer, and the photoreceptor became unusable. On the other hand, the photoreceptor of Example 3 did not show any change even after being left for one month.

Comparative Example 5 A compound having the following structure as a charge transport material

[0101]

[Chemical 21]

A photoconductor of Comparative Example 5 was prepared in the same manner as in Example 2 except that was used. When E _1/5 and Tr of this photosensitive member were measured in the same manner as in Example 2, E _1/5 =
It was 1.31 lux · sec and Tr = 87 msec.

Next, the photoconductors of Example 2 and Comparative Example 5 were belt-bonded and coated with a conductive layer to form a photoconductor for mounting, which was mounted on Myricopy M-5 manufactured by Ricoh Co., Ltd. The photoconductor of Example 2 gave a clear image even after 2,000 copies, but the photoconductor of Comparative Example 5 became unusable for practical use due to cracking of the charge transport layer after 100 copies.

Examples 5 to 8 and Comparative Examples 6 and 7 A charge transport layer coating liquid, a charge generating layer coating liquid and a protective layer coating liquid having the following compositions were sequentially applied on an aluminum plate having a thickness of 0.2 mm. Then, it was dried to form a charge transport layer, a charge generation layer having a thickness of 0.3 μm and a protective layer having a thickness of 2 μm to prepare an electrophotographic photoreceptor of the present invention.

<Coating Liquid for Charge Transport Layer> 14 parts of a charge transport material having the following structural formula

[0106]

[Chemical formula 22]

Polycarbonate (Mitsubishi Gas Chemical's Iupilon Z-200) 10 parts Toluene 45 parts THF 45 parts <Charge generating layer coating liquid> 3 parts of charge generating substance having the following structural formula

[0108]

[Chemical formula 23]

Polyvinyl butyral (S-REC BM-S manufactured by Sekisui Chemical Co., Ltd.) 2 parts Toluylene-2,4-diisocyanate 0.3 part Cyclohexanone 100 parts 2-butanone 160 parts <Protective layer coating liquid> Styrene-methyl methacrylate -2-Hydroxyethyl methacrylate-trifluoroethyl methacrylate copolymer 70 parts Conductive titanium oxide 90 parts Toluene 220 parts n-Butanol 60 parts Example 5; CTL film thickness 22 μm 〃 6; 〃 26 μm 〃 7; 〃 32 μm 〃 8: 〃 50 μm Comparative Example 6; 〃 11 μm 〃 7; 〃 17 μm The light attenuation characteristics of each photoconductor prepared as described above were measured for E _1/5 and Tr according to the above method. However, the corona discharge voltage was set to +5.6 kV. The results are shown in Fig. 4.

Comparative Example 8 A compound having the following structural formula as a charge transport material

[0111]

[Chemical formula 24]

A photoconductor of Comparative Example 8 was prepared in the same manner as in Example 6 except that the above was used. Example 6
When E _1/5 and Tr were measured in the same manner as, E _1/5 =
It was 1.06lux · sec and Tr = 130msec.

Comparative Example 9 A compound having the following structure as a charge transport material

[0114]

[Chemical 25]

A photoconductor of Comparative Example 9 was prepared in the same manner as in Example 5, except that the above-mentioned was used. The photoreceptor of Comparative Example 9 was left to stand overnight, and crystals of the charge transporting material were deposited in the charge transporting layer, which made it unusable. On the other hand, the photoreceptor of Example 5 did not show any change even after being left for one month.

Example 9 and Comparative Example 10 An aluminum cylinder having a diameter of 80 mm was coated with each coating solution having the following composition and dried to form an undercoat layer having a thickness of 1.5 μm.
A charge generation layer and a charge transport layer having a thickness of 0.3 μm were sequentially provided.

(1) Undercoat layer coating liquid TiO ₂ powder (Ishihara Sangyo Co., Ltd., Taipaque R-670) 15 parts by weight Alcohol-soluble nylon (Tresin manufactured by Teikoku Chemical Industry) 7 parts by weight Ethanol 150 parts by weight (2 ) Charge generation layer coating liquid 8 parts by weight of disazo pigment having the following structure 140 parts by weight of cyclohexanone

[0118]

[Chemical formula 26]

(3) Charge Transport Layer Coating Solution 13 parts of the charge transport material having the following structure

[0120]

[Chemical 27]

Polycarbonate (A2700 manufactured by Idemitsu Petrochemical) 10 parts Methylene chloride 80 parts Example 9; Charge transport layer film thickness 25 μm Comparative example 10; Charge transport layer film thickness 18 μm Examples 10 and 11 Examples 9 and 10 A protective layer having a thickness of 2 μm was formed on the same photoreceptor by the following coating solution for protective layer, and each of Example 1 was used.
The photoreceptors of 0 and 11 were used.

<Protective Layer Coating Liquid> Styrene-methyl methacrylate-2-hydroxyethyl methacrylate copolymer 80 parts Tin oxide 90 parts Toluene 250 parts 2-butanone 70 parts Examples 9 to 11 prepared as above and Comparative Example 10
Each of the photoconductors was mounted on a copying machine FT6550 manufactured by Ricoh Co., Ltd., and 10,000 sheets were continuously copied. Each of these photoreceptors was measured before and after continuous copying with the evaluation device disclosed in JP-A-60-100167 as follows. -5.2k
It is charged to -800V or more at a discharge voltage of V, then dark-decayed, and when it reaches -800V, it is irradiated with 6lux of tungsten light, and the exposure charge E _1/5 (luc. sec) was measured.

In addition to this, Tr was measured before continuous copying in the same manner as in Example 1, and the film thickness of the photosensitive layer after continuous copying was measured by an eddy current type film thickness meter.

The results are shown in Table 2.

[0125]

[Table 2]

It is clear that the background stain on the image after continuous copying in Comparative Example 10 is due to the decrease in sensitivity due to the abrasion of the photoconductor film.

[0127]

According to claim 1 of the present invention, since it is possible to provide an electrophotographic photosensitive member having a charge transport layer having excellent film-forming properties and having a high-speed photoresponsiveness that could not be realized conventionally. The Carlson process can be speeded up and downsized.

According to claim 2 or 3 of the present invention, high sensitivity and / or high durability, which could not be realized in claim 1, can be realized at the same time.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a basic layer structure of the present invention.

FIG. 2 is an explanatory diagram of another basic layer structure of the present invention.

FIG. 3 is a graph showing the photoresponsiveness of the present invention.

FIG. 4 is a graph showing optical attenuation characteristics of the present invention.

[Explanation of symbols]

 1 Conductive Substrate 2 Charge Generation Layer 3 Charge Transport Layer

Claims (3)

[Claims] 1. An electrophotographic photoreceptor comprising a charge generation layer and a charge transport layer laminated on a conductive substrate, wherein the charge transport material constituting the charge transport layer is triarylamine or a derivative thereof, and An electrophotographic photoreceptor, wherein the content of the charge transport material in the charge transport layer is 54% by weight or more. 2. The electrophotographic photosensitive member according to claim 1, wherein the thickness of the charge transport layer is 20 μm or more. 3. The electrophotographic photosensitive member according to claim 1, which has a protective layer as the uppermost layer.