JP3398765B2 - Electrophotographic photoreceptor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to a high-sensitivity electrophotographic photoreceptor having a charge transport layer made of a polymer charge transport material.

[0002]

2. Description of the Related Art The Carlson process and its various deformation processes are known as electrophotographic methods, and 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. Polyvinyl carbazole (PV
Photoconductive resin typified by K), PVK-TNF (2,
4,7-trinitrofluorenone), a charge transfer complex type, a phthalocyanine-binder type, a pigment dispersion type, and a function-separated type photoconductor in which a charge generating substance and a charge transporting substance are used in combination are known. In particular, a 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. By the way, most 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 composed of a low molecular weight charge transport material and an inactive polymer is generally soft and is likely to cause film abrasion due to repeated use 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. This is because the content of the low molecular weight charge transport material is usually 50% by weight or less. That is, the charge mobility can certainly be increased by increasing the content of the low molecular weight charge transport material, but at the same time, the film forming property is deteriorated.

On the other hand, polymer type charge transport materials are disclosed, for example, in JP-A-50-82056 and JP-A-51-73.
888, JP-A-54-8527, JP-A-5
4-11737, JP-A-56-150749, JP-A-57-78402, and JP-A-63-28
5552, JP 1-1728, JP 1
-19049 and Japanese Patent Laid-Open No. 3-50555. However, the photosensitivity of the photoconductor in which the charge transport layer composed of the polymer charge transport material and the charge generation layer are combined is significantly inferior to the case where the above-mentioned low molecular charge transport material is used. Was strongly desired.

As described above, when the charge transport layer of the function-separated layered photoconductor is composed of a low-molecular charge transport material and an inert polymer, the charge mobility, that is, the response speed is limited, and the charge due to repeated use is reduced. There is a problem in that the transport layer is scraped. On the other hand, when a polymer charge transport material is used for the charge transport layer, there is a fatal defect that the sensitivity of the photoreceptor is low.

[0007]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a high-sensitivity laminated photoreceptor using a polymer charge transport material. A second object of the present invention is to provide an electrophotographic photosensitive member having a high-speed photoresponse characteristic. A third object of the present invention is to provide a photoconductor having excellent wear resistance when repeatedly used.

[0008]

The generation of photocarriers in a function-separated layered photoconductor has heretofore been considered to be caused by photoexcitation of a charge-generating material in a charge-generating layer, and this has been verified. There were very few cases where I did it. The present inventors have conducted studies on the generation of photocarriers in a laminated photoreceptor that uses a fluorenone bisazo material for the charge generation layer, and as a result, have found that the photoabsorbed charge generation layer bulk has excitons.
on), the excitons are dissociated into free carriers at the interface between the charge generation layer and the charge transport layer, and it is found that photocarriers are generated.
Applied Physics, Vol. 29, No. 12, 2746
~ 2750.

Further, the inventors of the present invention conducted further experiments and obtained the following findings. Generation of carriers at the charge generation layer-charge transport layer interface is recognized in many materials, but is particularly remarkable in the azo pigment system. The amount of carriers generated should be larger as the degree of contact and mixing between the charge generation material and the low molecular weight charge transport material increases. When the charge-transporting layer is composed of a low-molecular-weight charge-transporting material and an inert polymer, a laminated photoreceptor is produced by a usual cast coating method. The contact amount between the charge-generating material and the charge-transporting material is sufficient to cause carrier generation. It is assumed that the quantity is secured. Based on such a new finding, the present inventors have actively studied a technique for increasing the sensitivity of a laminated photoconductor using the above-mentioned polymer charge transfer material, and have completed the present invention.

That is, according to the present invention, the following inventions are provided.
Provided . (1) In an electrophotographic photoreceptor in which a charge generation layer and a charge transport layer made of a polymer charge transport material are laminated on a conductive substrate, arylamine is used as the polymer charge transport material in the main chain or side chain. An electrophotographic photoreceptor comprising the above polymer and containing a hole transporting low molecular weight charge transporting material in the charge generating layer. (2) In an electrophotographic photoreceptor in which a charge generation layer and a charge transport layer made of a polymer charge transport material are laminated on a conductive substrate, arylamine is contained in the main chain or side chain as the polymer charge transport material. An electrophotographic photosensitive member comprising a polymer having the above, and a layer which is in contact with the charge generating layer and has a hole transporting low molecular weight charge transporting material as a main component. (3) The electrophotographic photoreceptor according to (1) or (2) above, wherein the charge generating material used in the charge generating layer is an azo pigment.

The electrophotographic photosensitive member according to the present invention has high sensitivity,
It has excellent high-speed responsiveness and excellent resistance to film abrasion during repeated use. The reason for this is not clear at this time, but it is believed that it is due to the following circumstances.

That is, since the polymer charge transporting material is a polymer, its steric degree of freedom is limited, and when it is used in the charge transporting layer, the contact with the charge generating material is not sufficiently ensured, and the carrier is not easily generated. Although the number of generation sites is insufficient, on the other hand, in the electrophotographic photosensitive member having the above structure, the low-molecular charge transport material has three-dimensional freedom when the photosensitive member is made, and therefore, sufficient contact with the charge generation material is maintained. Therefore, since the number of carrier generation sites is sufficient, high sensitivity can be achieved.

Further, in the photoreceptor of the present invention, since the charge transport layer is composed of the polymer charge transport material, it is possible to exhibit high charge mobility based on the densification of charge transport sites, and therefore low molecular charge transport. The material has a high-speed photoresponse which could not be realized by the material-inert polymer system.

Further, the photoconductor of the present invention can realize a high hardness photoconductor since the charge transport material is a polymer, and exhibits excellent characteristics of film abrasion resistance during repeated use.

Next, the structure of the electrophotographic photosensitive member of the present invention will be described with reference to the drawings. 1 and 2 are cross-sectional views showing an electrophotographic photoreceptor of the present invention, in which a charge generation layer 13 and a charge transport layer 15 containing a polymer charge transport material as a main component are laminated on a conductive substrate 11. It has a composition. Fig.3 (a)-
(D) is a cross-sectional view showing another configuration example of the present invention, in which a layer 17 (hereinafter referred to as a contact layer 17) which is in contact with the charge generation layer 13 and contains a low-molecular charge transport material as a main component is provided. Has been.

The conductive substrate 11 has a volume resistance of 10 10
Those exhibiting conductivity of Ωcm or less, for example, a metal such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, or a metal oxide such as tin oxide or indium oxide, which is formed into a film or by vapor deposition or sputtering. Cylindrical plastic, paper coated, or plates made of aluminum, aluminum, nickel, stainless steel, etc. I. , I. I. It is possible to use a tube or the like which is made into a raw tube by a method such as extrusion or drawing and then surface-treated by cutting, superfinishing, polishing or the like.

The charge generating layer 13 is a layer containing a charge generating substance as a main component, and a binder resin can be used together if necessary. As the binder resin, polyimide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinylyl formal,
Polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, polyacrylamide and the like are used.

Examples of the charge generating substance include phthalocyanine pigments, naphthalocyanine pigments, perylene pigments, perinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squaric acid dyes, azurenium dyes and azo pigments. Used. Among these, perylene pigments, perinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squalic oxygen dyes, azurenium dyes, and azo pigments can be used favorably, but particularly good when azo pigments are used. It is possible to obtain various results. However, the azo pigments mentioned here refer to all known materials. The charge generating substances may be used alone or in combination of two or more. The binder resin is appropriately 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.

In the invention of claim 1, the charge generating layer contains a low molecular weight charge transporting material, and the content thereof is 10 parts by weight or more, preferably 15 parts by weight or more with respect to 100 parts by weight of the charge generating substance. Is desirable.

Examples of the electron transport substance include chloranil, bromanil, tetracyanoethylene, tetracyanoquinone dimethane, 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-
Examples thereof include electron-accepting substances such as trinitro-4H-indeno [1,2-b] thiophen-4-one and 1,3,7-trinitrodibenzothiophene-5,5-dioxide.

As the hole-transporting substance, an oxazole derivative, an oxadiazole derivative, an imidazole derivative, a monoarylamine derivative, a diarylamine derivative, a triarylamine derivative, a triarylmethane derivative,
9-styrylanthracene derivative, pyrazoline derivative,
Other known materials such as divinylbenzene derivative, hydrazone derivative, indene derivative and butadiene derivative can be used.

The charge generating layer 13 contains a charge generating substance, if necessary, together with a binder resin and a low molecular weight charge transporting material.
It can be formed by dispersing with a ball mill, attritor, sand mill or the like using a solvent such as tetrahydrofuran, cyclohexane, dioxane, dichloroethane, etc., and appropriately diluting the dispersion. The coating can be performed by using a dip coating method, a spray coating method, a bead coating method, or the like. Further, a sublimable charge generating material can be provided by a vacuum thin film forming method such as a vacuum vapor deposition method and can be preferably used.

For the charge transport layer 15, a polymer charge transport material alone or, if necessary, a binder resin is used at the same time. The charge transport layer 15 can be formed by dissolving or dispersing these materials in a suitable solvent, applying the material on the charge generating layer, and drying. If necessary, a plasticizer, a leveling agent, etc. may be added.

Examples of the polymer charge transport material include the following, but in the present invention, of these,
It is characterized by using (d). (A) Polymers having a carbazole ring in the side chain, for example, poly-N-vinylcarbazole, compounds described in JP-A No. 50-82056, "54-9632", "〃", "54-11737", and "〃". To be (B) Polymer having a hydrazone structure in the side chain For example, compounds described in JP-A-57-78402, JP-A-3-50555 〃〃〃, etc. are exemplified. (C) Polysilylene polymer For example, the compounds described in JP-A-63-285552 are exemplified. (D) A polymer having an arylamine in the main chain or side chain, for example, poly-p-vinyltriphenylamine, compounds described in JP-A No. 1-1728, 〃 1-105260〃〃〃〃2-167335〃〃〃 Are exemplified. (E) Other polymers, for example, formaldehyde condensation polymer of nitropyrene, compounds described in JP-A-51-73888, "56-150749" and the like are exemplified.

As the binder resin used in combination as required, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-acetic acid. Vinyl copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal rule, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone Examples thereof include thermoplastic or thermosetting resins such as resins, epoxy resins, melamine resins, urethane resins, phenol resins and alkyd resins. Among these binder resins, polycarbonate containing bisphenol A, bisphenol C or bisphenol Z as a bisphenol component can be preferably used.

The amount of the binder resin used is appropriately 0 to 100 parts by weight based on 100 parts by weight of the polymer charge transport material.

Tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride and the like are used as the solvent. A suitable thickness of the charge transport layer 15 is about 5 to 50 μm.

In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer 15. 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 thereof is 0 to 30 relative to the polymer component.
About wt% is appropriate. 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 the polymer component. 1% by weight
Is appropriate.

Further, in the second aspect of the present invention, the contact layer 17 containing a low molecular charge transport material as a main component is provided.
The low-molecular-weight charge transport material is the above-mentioned hole transport material.
A charge transport material is used as the material. In the contact layer 17,
It is also possible to use a binder resin together. As the binder resin, the resin that can be used in the charge generation layer and the resin that can be used in the charge transport layer can be used. The amount of the binder resin used in the contact layer 17 is 100 parts by weight of the low molecular weight charge transport material.
0 to 200 parts by weight is suitable. The contact layer 17 can be formed by dispersing / dissolving the above materials in an appropriate solvent, coating / drying the film, or by a vacuum thin film forming method.

In the electrophotographic photosensitive member of the present invention, an undercoat layer can be provided between the conductive support 11 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, it is desirable that the resin has high solvent resistance to an organic solvent. . 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,
Examples include phenolic resins, alkyd-melamine resins, epoxy resins, and other curable resins that form a three-dimensional network structure. Further, in order to prevent moire and reduce the residual potential, a fine powder pigment of a metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide, etc. may be added to the undercoat layer. These undercoat layers can be formed 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, etc. can be used as the undercoat layer of the present invention. In addition to the above, the undercoat layer of the present invention is provided with Al2O3 by electrolytic electrode oxidation, organic substances such as polyparaxylylene (parylene), SiO, S
An inorganic substance such as nO ₂ , TiO ₂ , ITO or CeO 2 provided by a vacuum thin film forming method can also be favorably used. The thickness of the undercoat layer is suitably 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, poly. Butylene terephthalate, polycarbonate, polyether sulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polychloride Examples of the resin include vinylidene and epoxy resin. The protective layer may also be 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. Can be added.

As a method for 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, it is possible to provide another intermediate layer 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 of forming the intermediate layer, the usual coating method is adopted as described above. The thickness of the intermediate layer is 0.05 to 2 μm.
The degree is appropriate.

Further, in the electrophotographic photosensitive member of the present invention, an antioxidant can be added for the purpose of improving the environmental resistance, particularly 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. Known materials can be used as the antioxidant that can be used in the present invention, and commercially available products such as rubber, plastics, oils and fats can be used.

[0034]

EXAMPLES Examples will be shown below, but the examples explain the present invention in detail, and the present invention is not limited to the examples. All parts in the examples are parts by weight.

Comparative Example 1 On a polyethylene terephthalate film on which aluminum was vapor-deposited, a charge generation layer coating solution having the following composition and a charge transport layer coating solution were sequentially applied and dried to form a charge generation layer having a thickness of 0.2 μm and a charge generation layer respectively. A 22 μm thick charge transport layer was formed to prepare an electrophotographic photoreceptor of Comparative Example 1. [Charge generation layer coating liquid] 3 parts of the charge generation substance having the following structural formula

[Chemical 1] Polyvinyl butyral resin 1 part (Denka Butyral # 4000-1 manufactured by Denki Kagaku Kogyo Co., Ltd.) Cyclohexanone 100 parts 2-Butanone 80 parts [Charge Transport Layer Coating Liquid] 10 parts of the charge transport material having the following structural formula

[Chemical 2] 50 parts of tetrahydrofuran

[0036]Comparative example 2 The charge generation layer coating liquid of Comparative Example 1 was prepared using a low molecular charge of the following structural formula.
Similar to Comparative Example 1 except that 1 part of the transport material was added.
Comparative example 2An electrophotographic photoconductor of was prepared.

[Chemical 3]

[0037]Comparative Example 3 The charge transport layer coating liquid of Comparative Example 1 was prepared using the following low molecular charge
Same as Comparative Example 1 except that 3 parts of transport material was added.
Comparative Example 3An electrophotographic photoconductor of was prepared.

[Chemical 4]

[0038]Comparative Example 4 Between the charge generation layer and the charge transport layer of the photoreceptor of Comparative Example 1,
A contact layer having a thickness of 0.3 μm using the contact layer coating liquid having the above composition
In the same manner as in Comparative Example 1 except thatComparative Example 4Electronic
A photographic photoreceptor was created. [Contact layer coating liquid]     3 parts charge transport material with the following structural formula

[Chemical 5] 15 parts of toluene

Comparative Example5 Polyethylene terephthalate with Hastelloy conductive layer
A charge generation layer coating solution of the following composition and charge on the film
The transport layer coating solution is applied and dried sequentially to a thickness of 0.3 μm.
Forming a charge generation layer and a charge transport layer having a thickness of 18 μm,
Comparative example5An electrophotographic photoconductor of was prepared. [Charge generation layer coating liquid]     4 parts of charge generation material with the following structural formula

[Chemical 6] Polyvinyl butyral (XYHL, XYHL) 2 parts Cyclohexanone 100 parts Tetrahydrofuran 100 parts [Charge Transport Layer Coating Liquid] 10 parts charge transport material of the following structural formula

[Chemical 7] 50 parts of tetrahydrofuran

Comparative example6 Comparative example5The charge generation layer coating liquid of
Comparative example except that 3 parts of transportation material was added6The feeling of electrophotography
Created a light body.

[Chemical 8]

Comparative example7 Comparative example5The charge transport layer coating liquid of
Comparative example except that 4 parts of transportation material was added5As well as
Comparative example7An electrophotographic photoconductor of was prepared.

[Chemical 9]

Comparative Example8 Comparative example5Between the charge generation layer and the conductive substrate of the
A contact layer having a thickness of 0.5 μm using a contact layer coating solution having the above composition
Comparative example, except that5Comparative example similar to8Electronic
A photographic photoreceptor was created. [Contact layer coating liquid]     4 parts of charge transport material with the following structural formula

[Chemical 10] Polycarbonate (A2200 manufactured by Idemitsu Petrochemical) 4 parts Methylene chloride 35 parts

Comparative Example9 Undercoating of the following composition on a 0.2 mm thick aluminum plate
Layer coating liquid, charge generation layer coating liquid and charge transport layer coating liquid
Sequential coating and drying are performed to form a charge generation layer with a thickness of 0.3 μm.
And a charge transport layer having a thickness of 20 μm are formed, and a comparative example9Electronic
A photographic photoreceptor was created. [Undercoat layer coating liquid]     Water-soluble polyvinyl butyral 25% aqueous solution 50 parts     (S-REC W-201, manufactured by Sekisui Chemical Co., Ltd.)     150 parts of water     200 parts of methanol [Charge generation layer coating liquid]     3 parts of charge generation material with the following structural formula

[Chemical 11] Cyclohexanone 90 parts 2-Butanone 80 parts [Charge Transport Layer Coating Liquid] 10 parts of charge transport material having the following structural formula

[Chemical 12] Polycarbonate 3 parts (Teijin Kasei Co., Ltd. Panlite K-1300) Methylene chloride 70 parts

Example1 Comparative example9The charge generation layer coating liquid of
Comparative example except that 2 parts of transportation material was added9As well as
Example1An electrophotographic photoconductor of was prepared.

[Chemical 13]

Comparative example10 Comparative example9The charge transport layer coating liquid of
Comparative example except that 2.5 parts of transportation material was added9alike
Then working example10An electrophotographic photoconductor of was prepared.

[Chemical 14]

ExampleTwo Comparative example9Between the charge generation layer and the undercoat layer of the photoconductor of
A contact layer with a thickness of 0.2 μm is prepared using the contact layer coating solution
Comparative example except for digits9Example similar toTwoElectronic photo of
A photoconductor was created. [Contact layer coating liquid]     5 parts charge transport material with the following structural formula

[Chemical 15] Polyester (Byron 200, Toyobo) 2 parts Tetrahydrofuran 35 parts

Comparative example11 Charge of the following composition on an aluminum plate with a thickness of 0.2 mm
Apply the coating solution for the transport layer and the coating solution for the charge generation layer in sequence and dry.
When dried, each has a charge transport layer of 17 μm and a thickness of 0.5 μm.
Comparative example with charge generation layer formed11Made of electrophotographic photoreceptor
I made it. [Charge transport layer coating liquid]     10 parts of charge transport material having the following structural formula

[Chemical 16] Tetrahydrofuran 50 parts [charge generation layer coating liquid] 3 parts of charge generation substance having the following structural formula

[Chemical 17] Polyvinyl butyral 2 parts (Sekisui Chemical Co., Ltd. S-REC BM-S) Toluylene-2,5-diisocyanate 1.0 part Cyclohexanone 100 parts 2-Butanone 100 parts

Comparative Example12 Comparative example11The charge generation layer coating solution of
Comparative example except that 3 parts of cargo transportation material was added11alike
And a comparative example12An electrophotographic photoconductor of was prepared.

[Chemical 18]

Comparative ExampleThirteen Comparative example11The charge transport layer coating liquid of
Comparative example except that 2 parts of cargo transportation material were added11alike
And a comparative exampleThirteenAn electrophotographic photoconductor of was prepared.

[Chemical 19]

Comparative Example14 Comparative example11Between the charge generation layer and the charge transport layer of the photoreceptor of
The thickness of the low-molecular transport material with the structure shown below is determined by vacuum deposition.
Comparative example except that a contact layer of 0.1 μm was provided11same as
And comparison example14An electrophotographic photoconductor of was prepared.

[Chemical 20]

Comparative Example 15 On a 0.2 mm thick nichrome plate, a charge transport layer coating solution, a charge generating layer coating solution and a protective layer coating solution having the following compositions were sequentially applied and dried to form 19 μm each. Charge transport layer, 0.3
A charge generating layer having a thickness of 2 μm and a protective layer having a thickness of 2 μm were formed to prepare an electrophotographic photosensitive member of Comparative Example 15 . [Charge transport layer coating liquid] 10 parts of the charge transport substance having the following structural formula

[Chemical 21] Polycarbonate 6 parts (Polycarbonate Z manufactured by Mitsubishi Gas Chemical Co., Inc.) Methylene chloride 60 parts 1,2-Dichloroethane 10 parts [Charge generating layer coating liquid] 4 parts of charge generating substance having the following structural formula

[Chemical formula 22] Polyester 1 part (Toyobo Co., Ltd. Byron 200) Tetrahydrofuran 210 parts [Protection 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

Comparative Example16 Comparative example15The charge generation layer coating solution of
Comparative example except that 2 parts of cargo transportation material were added15alike
And a comparative example16An electrophotographic photoconductor of was prepared.

[Chemical formula 23]

Comparative example17 Comparative example15The charge transport layer coating liquid of
Comparative example except that 6 parts of cargo transportation material was added15alike
And a comparative example17An electrophotographic photoconductor of was prepared.

[Chemical formula 24]

Comparative example18 Comparative example15Between the charge generation layer and the protective layer of the photoreceptor of
A contact layer having a composition of 0.5 μm is used to form a contact layer coating solution.
Comparative example except that it was provided15Comparative example similar to18Electric power
A child photoconductor was created. [Contact layer coating liquid]     3 parts charge transport material with the following structural formula

[Chemical 25] Polyvinyl phthalic resin 2 parts (Sekisui Chemical Co., Ltd. S-REC BL-1) 2-butanone 30 parts

The characteristics of each of the above photoconductors were evaluated as follows by using an electrostatic copying paper test apparatus (Kawaguchi Denki Seisakusho SP-428 type). First, -5.2KV (or + 5.6K
Corona charging is performed for 15 seconds at a discharge voltage of (KV),
Then, dark decay was performed, and after 10 seconds of dark decay, 6 lux of tungsten light was irradiated. At this time, the surface potential 15 seconds after the start of charging is V15 (V), and the surface potential 10 seconds after dark decay is V
25 (V) was measured. Also, the amount of exposure E1 / 2 (lux · sec) required to attenuate V25 to half the potential is measured, and the surface potential 20 seconds after light irradiation is Vr (V).
Also measured.

[0056]

[Table 1]

[0057]

EFFECTS OF THE INVENTION According to the present invention, it is possible to overcome the drawback of low sensitivity which is common to the function-separated layered electrophotographic photoconductors in which a polymer charge transport material is used for the charge transport layer. And an electrophotographic photoreceptor having high durability can be provided.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a typical laminated electrophotographic photosensitive member of the present invention.

FIG. 2 is a schematic cross-sectional view of another representative laminated type electrophotographic photosensitive member of the present invention.

3 (a) to 3 (d) are schematic cross-sectional views of still another laminated electrophotographic photosensitive member of the present invention.

[Explanation of symbols] 11 Conductive substrate 13 Charge generation layer 15 Charge transport layer 17 Contact layer

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-1-134457 (JP, A) JP-A-54-66842 (JP, A) JP-A-56-33653 (JP, A) JP-A-2- 151605 (JP, A) JP 61-20953 (JP, A) JP 3-180852 (JP, A) JP 2-82253 (JP, A) JP 2-82254 (JP, A) JP-A-4-163462 (JP, A) JP-A-4-128846 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 5/00-5/16

Claims (3)

(57) [Claims] 1. An electrophotographic photosensitive member comprising a conductive substrate, and a charge generation layer and a charge transport layer made of a polymer charge transport layer laminated on the conductive substrate, wherein the polymer charge transport material has an aryl group in a main chain or a side chain. An electrophotographic photosensitive member comprising a polymer having an amine and containing a hole transporting low molecular weight charge transporting material in the charge generating layer. 2. An electrophotographic photosensitive member comprising a conductive substrate and a charge generation layer and a charge transport layer made of a polymer charge transport material laminated on a conductive substrate, wherein the polymer charge transport material has an aryl group in a main chain or a side chain. An electrophotographic photosensitive member comprising a polymer having an amine, which is provided with a layer which is in contact with the charge generation layer and has a hole transporting low molecular weight charge transporting material as a main component. 3. The electrophotographic photoreceptor according to claim 1, wherein the charge generating material used in the charge generating layer is an azo pigment.