JPH02165154A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve sensitivity and to enhance environment resistance and durability by incorporating a resol type phenol resin as a binder in an electric charge generating layer. CONSTITUTION:The photosensitive body is formed by laminating on a conductive substrate at least the charge generating layer containing the resol type phenol resin to restrain deterioration of chargeability due to repeated uses and an electric charge transfer layer, preferably, containing a trisazo pigment as a charge transfer material to enhance the effect, thus permitting the characteristics of the photosensitive body, such as chargeability, not to deteriorate, even at the time of repeated uses, and durability and storage stability to be enhanced.

Description

[Detailed description of the invention] [Industrial field] The present invention relates to an electrophotographic photoreceptor.

More specifically, the present invention relates to an electrophotographic photoreceptor that exhibits good sensitivity, excellent environmental resistance, and excellent durability.

[Conventional technology]

Inorganic materials such as selenium, cadmium sulfide, and zinc oxide have been conventionally known as photoconductive materials for electrophotographic photoreceptors.6However, these inorganic materials lack the photosensitivity and thermal stability required for electrophotographic photoreceptors. For example, selenium tends to crystallize due to heat, dirt, etc. and its properties tend to deteriorate, and there are also problems in handling such as manufacturing cost, impact resistance, toxicity, etc. There are drawbacks such as the need for caution.

Photoreceptors using cadmium sulfide have poor moisture resistance and durability, and are also susceptible to toxicity. Zinc oxide also has the disadvantage of poor moisture resistance and durability.

For electrophotographic photoreceptors using these inorganic photoconductive materials,
Photoreceptors using organic photoconductive materials are being actively researched and developed due to their light weight, ease of film formation, manufacturing cost, and wide variation as organic compounds1. Photoreceptor containing polyvinylcarbazole and 2,4,7-dolinitro-9-fluorenone described in Japanese Patent Publication No. 50-10496, Japanese Patent Publication No. 1987-10496, 4g
A photoreceptor in which polyvinyl carbazole is sensitized with a biryllium base dye as described in Japanese Patent No. 25658, or a photoreceptor having a eutectic complex as a main component has been proposed. However, these photoreceptors do not have sufficient sensitivity and durability.

Therefore, in recent years, a functionally separated type photoreceptor in which a charge generation layer and a charge transport layer are separated has been proposed, and
A photoreceptor comprising a combination of chlordiane blue and a hydrazone compound described in No. 1, and a bisazo compound as the charge generating substance, described in JP-A-53-133445, JP-A-54-21728, JP-A-4-22834.
As described in the publication, the charge transport material is JP-A-58-198.
043 JP-A-58-199352 and the like are known.

However, these function-separated type photoreceptors are still unsatisfactory, especially in terms of durability.

In recent years, as demands for durability have increased, ensuring charging stability has become an issue that cannot be ignored. In other words, if the charging property decreases, it will cause a decrease in the image density of copies in copying machines, and in the case of laser printers that use a reversal development method, it will cause deterioration in image quality such as background stains. To solve this problem, it has been proposed to provide an intermediate layer between the conductive substrate and the photosensitive layer. However, if a high-resistance material with high barrier properties is used for the intermediate layer in order to stabilize the charging property, although the charging property will improve, the photosensitivity will decrease.
The disadvantage is that the residual potential increases. Furthermore, if a material with relatively low resistance that does not increase the residual potential is used, charging stability will be insufficient.

- On the other hand, the charge generation layer basically consists of an organic pigment as a charge generation substance and a binder as a binder. Examples of such binders include polyvinyl butyral (Japanese Unexamined Patent Publication No. 58-105154), fatty acid cellulose ester (Japanese Unexamined Patent Publication No. 58-166353), and acrylic resins with a Tg of 70°C or less and an acid value of 10 to 40 (Japanese Unexamined Patent Publication No. 58-166353). Kaisho 58-19
No. 2040), Tg is 70 or less and Tg is 75
A mixture of resins with a temperature of ℃ or above
No. 9), which is redispersed by adding a less compatible resin-solvent system to the charge-generating substance-resin-solvent system (Japanese Patent Laid-Open No. 56
-12646), polyvinylpyrrolidone (Unexamined Japanese Patent Publication No. 12646), polyvinylpyrrolidone
-113140), polyvinyl formal (Unexamined Japanese Patent Publication No. 6
Examples include those using resins such as Nos. 1 to 235844). However, the conventional view of the binder in the charge generation layer is that it is a binder for the charge generation substance and is monodisperse.
In most cases, it provides dispersion stability and adhesion to other layers. For this reason, the conventional functionally separated type electron beam photoreceptor is not sufficient in terms of potential characteristics such as residual potential and potential fluctuation.

[Problem to be solved by the invention]

The present invention has been made in view of the above-mentioned state of the prior art, and its purpose is to provide an electrophotographic photoreceptor that exhibits good sensitivity, excellent environmental resistance, and high durability. .

Furthermore, another object of the present invention is to provide a photoreceptor for a semiconductor laser printer, and also to provide a functionally separated photoreceptor that is easy to manufacture.

[Means to solve the problem]

According to the present invention, in a functionally separated electrophotographic photoreceptor comprising at least a charge generation layer and a charge transport layer laminated on a conductive support, the charge generation layer contains a resol type phenolic resin as a binder. An electrophotographic photoreceptor is provided.

Since the electrophotographic photoreceptor of the present invention contains a resol type phenolic resin as a binder in the charge generation layer, deterioration in charging property due to repeated use is suppressed, resulting in long life, high reliability, and high sensitivity. It is something.

Further, in the present invention, when a trisazo pigment represented by the following general formula (1) is used as the charge generating substance, the above effects can be further enhanced.

(In the formula, A represents a coupler residue having a phenolic OR group.) In the present invention, as described above, a resol type phenolic resin is used as a binder for the charge generation layer. Any conventionally known resol type phenolic resin can be used.

As a specific example, for example, Bryofen TD-
Commercial products such as 447 and Bryophen J-325 (manufactured by Dainippon Ink Chemical Co., Ltd.) can be mentioned.

Although such resol type phenolic resin can be used alone as a binder, it can also be used in combination with a resin such as polyvinyl butyral resin, alkyd resin, epoxy resin, melamine resin, urethane resin, or urea resin to bind the charge generation layer. It may also be used as an adhesive.

In the present invention, a trisazo pigment represented by the general formula (1) above is preferably used with * as a charge-generating substance, but it is preferable to use a pigment in which the coupler residue (A) is the following group.

[Example of coupler residue]

l-'x-' 7・Y! , /'Y! S'-zノ'z-' (wherein, X is a naphthalene ring fused with a benzene ring,
Represents a residue necessary to form a polycyclic aromatic ring or heterocycle selected from anthracene ring, carbazole ring, benzcarbazole ring, dibenzofuran ring and diphenylene sulfide ring, R6 and R6 are hydrogen atoms, substituted or unsubstituted represents a group selected from alkyl, aralkyl, aryl, and heterocyclic groups, and R,, R, may form a cyclic amino group together with the nitrogen atom to which they are bonded * RvJs represents a substituted or unsubstituted furkyl group, an aralkyl group and aryl group, Y' is a divalent aromatic hydrocarbon group or a heterocyclic divalent group containing a nitrogen atom in the ring, R1°,
. JII and RI yo represent a hydrogen atom, a substituted or unsubstituted alkyl group, an aralkyl group, an aryl group, and a heterocyclic group, and LxtRia may form a 5- or 6-membered ring; In this case, the 5-membered ring and the 6-membered ring may have a fused aromatic ring.

2 is necessary to form a polycyclic aromatic ring or heterocycle selected from naphthalene ring, anthracene ring, carbazole ring, benzcarbazole ring, dibenzofuran ring, benzonaphthofuran ring and diphenylene sulfide ring condensed with a benzene ring. Indicates a residue, Ar means aromatic rings such as benzene ring and naphthalene ring, and substituted products thereof;
(nza-R14 represents hydrogen, a lower alkyl group, a carboxyl group, or an ester thereof) Specific examples of the trisazo pigment represented by the general formula (1) that can be used in the present invention are shown below.

Further, as another charge generating substance that can be used in the present invention, an azo pigment having a carbazole bone core (Japanese Patent Application Laid-Open No.
3-95033), an azo pigment having a distyrylbenzene core (described in JP-A-53-133445), an azo pigment having a triphenylamine core (described in JP-A-53-133445),
(described in JP-A No. 53-132347), azo pigments having dibenzothiophene bone cores (described in JP-A No. 54-217)
28 fi), an azo pigment having an oxadiazole bone core (described in JP-A-54-12742), an azo pigment having a fluorenone bone core (described in JP-A-54-228)
34), an azo pigment having a bisstilbene bone core (described in JP-A-54-17733), an azo pigment having a distyryloxadiazole bone core (described in JP-A-54-17733),
There are azo pigments such as ff) an azo pigment having a distyrylcarbazole bone core (described in JP-A-54-14967).

Further, in the present invention, a charge transporting material is used together with a charge generating material, and the charge transporting material includes a hole transporting material and an electron transporting material. Examples of the hole transport substance include compounds represented by the following general formulas (1) to (12).

[In the formula, R1 represents a methyl group, ethyl group, 2-hydroxyethyl group, or 2-chloroethyl group, R2 represents a methyl group, ethyl group, benzyl group, or phenyl group, and R
3 represents hydrogen, chlorine, bromine, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, a dialkylamino group, or a nitro group. and substituted products thereof, or pyridines, furans, and thiophenes, and R represents an alkyl group or a benzyl group.] [In the formula, R8 represents an alkyl group, a benzyl group, a phenyl group,
represents a naphthyl group, R2 represents hydrogen, an alkyl group having 1 to 3 carbon atoms, an alkoxyl group having 1 to 3 carbon atoms, a dialkylamino group, a dialkylamino group, or a diarylamino group; n represents an integer of 1 to 4; , when n is 2 or more, R2 may be the same or different; R3 represents hydrogen or a methoxy group; [In the formula, R8 is an alkyl group having 1 to 11 carbon atoms, substituted or unsubstituted phenyl] represents a group or a heterocyclic group, R1,
R5 each may be the same or different and represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a chloroalkyl group, a substituted or unsubstituted aralkyl group,
Further, R and R3 may be bonded to each other to form a nitrogen-containing heterocycle, and R4 may be the same or different and represents hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or a halogen. [In the formula, R represents hydrogen or a halogen atom, and Ar represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group, or carbazolyl group. ] [In the formula, R represents hydrogen, halogen, a cyano group, an alkoxy group having 1 to 4 carbon atoms, or an alkyl group having 1 to 4 carbon atoms, and R1 represents an alkyl group having 1 to 4 carbon atoms; R,,R3
represents hydrogen, halogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a dialkylamino group, and n is 1 or 2, and when n is 2, R1 is the same or different. R4 and R1 each represent hydrogen, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted benzyl group. [In the formula, H is a carbazolyl group, a pyridine group, a thienyl group, an indolyl group,
a furyl group or a substituted or unsubstituted phenyl group, styryl group, naphthyl group or anthryl group, in which these substituents are a dialkylamino group, an alkyl group, an alkyl group, a carboxy group or an ester thereof, a halogen atom, Cyano group, aralkylamino group, N-alkyl-
Represents a group selected from the group consisting of an N-aralkyl amino group, an amino group, a 21-st group, and an acetylamino group,
] (R) [In the formula, R1 represents a lower alkyl group, a benzyl group, or a substituted or unsubstituted aryl group, and R2 represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a 21-ro group, an amino or an amino group substituted with a lower alkyl group or a benzyl group, and n represents an integer of 1 or 2.] [In the formula, R1 represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, and R
7 and R3 represent an alkyl group, a substituted or unsubstituted 7ralkyl group, or a substituted or unsubstituted aryl group,
R represents a water atom or a substituted or unsubstituted phenyl group, and Ar represents a phenyl group or a naphthyl group. ] [In the formula, n is O or an integer of 1, R,, R,, R3 is water 14)) "X child, alkyl group, or substituted or unsubstituted phenyl group, A is 9-anthryl group or substituted or represents an unsubstituted N-alkylcarbazolyl group, where R4 is a hydrogen atom,
Alkyl group, alkoxy group, halogen (represents an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted allyl group, R7 and the base may form a ring) , the vote is an integer of 0, 1.2 or 3, and when m is 2 or more, R4 may be the same or different.] [In the formula, R1, R, and R1 are hydrogen, a lower alkyl group, represents a lower alkoxy group, dialkylamino group, or a halogen atom; n represents 0 or 1; [wherein, R1 represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom; For example, 9-ethylcarbazole-3-aldehyde-1-methyl-1-
Phenylhydrazone, 9-ethylhydrazone(sol-3-
aldehyde-1-benzyl-1-phenylhydrazone,
9-ethylcarbazole-3-aldehyde-1,1-diphenylhydrazone and the like.

The compound represented by the general formula (2) includes, for example, 4-diethylaminostyrene-β-aldehyde-1-methyl-
1-phenylhydrazone, 4-methoxynaphthalene-1
-Aldehyde-1-benzyl-1-phenylhydrazone and the like.

Examples of the compound represented by the general formula (3) include 4-methoxybenzaldehyde-1-methyl-1-phenylhydrazone, 2,4-dimethoxybenzaldebido l-
Benzyl-1-phenylhydrazone, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone,
4-methoxybenzaldehyde-1-benzyl-1-(
Examples include 4-methoxy)phenylhydrazone, 4-diphenylaminobenzaldehyde-1-benzyl-1-phenylhydrazone, and 4-dibenzylaminobenzaldehyde-1,1-diphenylhydrazone.

The compound represented by general formula (4) includes, for example, 1.1
-bis(4-dibenzylaminophenyl)propane, tris(4-diethylaminophenyl)methane, 1.1
-bis(4-dibenzylaminophenyl)propane, 2
．． 2'-dimethyl-4,4'-bis(diethylamino)
- Triphenylmethane, etc.

The compound represented by general formula (5) includes, for example, 9-(
Examples include 4-diethylaminostyryl)anthracene, 9-promo-1O-(4-diethylaminostyryl)anthracene, and the like.

The compound represented by general formula (6) includes, for example, 9-(
4-dimethylaminobenzylidene) fluorene, 3-(
Examples include 9-fluorenylidene)-9-ethylcarbazole.

The compound represented by general formula (7) includes, for example, 1.2
-bis(4-diethylaminostyryl)benzene, 1.
2-bis(2,4-dimethoxystyryl)benzene.

Examples of the compound represented by the general formula (8) include 3-styryl-9-ethylcarbazole and 3-(4-methoxystyryl)-9-ethylcarbazole.

Examples of the compound represented by the general formula (9) include 4-diphenylaminostilbene, 4-dibenzylaminostilbene, and 4-ditolyllaminostilbene.

1-(4-diphenylaminostyryl)naphthalene, 1
-(4-diethylaminostyryl)naphthylene, etc.

The compound represented by the general formula (10) includes, for example, 4'
-diphenylamino-α-phenylstilbene, 4'-
Examples include methylphenylamino-α-phenylstilbene.

The compound represented by the general formula (11) includes, for example, l-
Phenyl-3-(4-diethylaminostyryl)-5-
(4-diethylaminophenyl)pyrazoline, 1-phenyl-3-(4-dimethylaminostyryl)-5-(4
-dimethylaminophenyl)pyrazoline, etc.

The compound represented by general formula (12) includes N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(
1,,1'-bisphenyl)-4,4'-diamine, N
, N'diphenyl-N,N'-bis(chlorophenyl)
-(1,1'-biphenyl]-4,4'-diamine, 3
, 3'-dimethylbenzidine, etc.

Other hole transport substances include, for example, 2,5-bis(4-diethylaminophenyl)-1,3,4-oxadiazole, 2,5-bis(4-(4-diethylaminostyryl)phenyl)- 1,3,4-oxydiazole, 2-(9-ethylcarbazolyl-3-)-5-(4
oxadiazole compounds such as -diethylaminophenyl)-1,3,4-oxadiazole, 2-vinyl-4
There are low molecular weight compounds such as oxazole compounds such as -(2-chlorophenyl)-5-(4-diethylaminophenyl)oxazole and 2-(4-diethylaminophenyl)-4-phenyloxazole. Further, polymer compounds such as poly-N-ruvinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, pyrene formaldehyde resin, and ethylcarbazole formaldehyde resin can also be used.

Examples of the electron transport substance include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinone dimethane, 2,4,7-dolinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone,
2,4,5.7-titranitroxanthone, 2,4°8
-trinidrothioxanthone, 2,6.8-trinitro-4H-indeno(1,2-b)thiophen-4-one, 1,3.7-trinitrodibenzothiophene-5,
Examples include 5-dioxide.

The photosensitive layer of the electrophotographic photoreceptor of the present invention can be of a normally charged type or a negatively charged functionally separated type by combining a charge generation layer and a charge transport layer.

In the case of a negative charge type, a charge generation layer containing a charge generation substance and a binder is formed on the substrate, and a charge transport layer containing a charge transport substance and a binder is formed thereon; In this case, the charge generation layer and the charge transport layer are stacked in reverse order.

Note that a charge transporting substance may be contained in the charge generation layer, and particularly in the case of a positively charged structure, the sensitivity is improved.

In addition, an intermediate layer may be provided between the photosensitive layer and the substrate to improve adhesion and charge blocking properties, and a protective layer may be provided on the photosensitive layer to improve mechanical durability such as abrasion resistance. Layers may be provided. Binders used in the charge transport layer include polycarbonate (bisphenol A type, bisphenol A type), polyester, methacrylic resin, acrylic resin, polyethylene, vinyl chloride, and vinyl acetate.

Polystyrene, phenolic resin, epoxy resin, polyurethane, vinylidene chloride, alkyd resin.

Silicone resin, polyvinyl carbazole, polyvinyl butyral, polyvinyl formal, polyarylate, polyacrylamide, polyamide, phenoxy resin, etc. are used. These binders can be used alone or as a mixture of two or more.

When creating a photoreceptor using the above layer structure and materials, there is a preferable range for the film thickness and the ratio of materials.
In this case, in the charge generation layer, the ratio of the charge generation substance to the binder is 20 to 500% by weight, and the film thickness is 0.1 to 57% by weight.
In the case of charge transport material, the ratio of the charge transport substance to the binder is preferably 20 to 200% by weight, and the film thickness is 5% by weight.
It is preferable to set the number to 50 units.

Positive charging type (substrate/charge transport M/f!1 charge generation layer stack)
In this case, in the charge transport layer, the ratio of the charge transport substance to the binder is 20 to 200% by weight, and the film thickness is 5 to 50% by weight.
The charge generation layer preferably contains a charge generation substance in an amount of 10 to 100% by weight based on the binder. Furthermore, it is preferable that the charge generation layer contains a charge transport substance. It is preferable that the charge transport substance is contained in an amount of 20 to 200% by weight based on the binder, which has the effect of suppressing residual potential and improving sensitivity.

The intermediate layer provided as needed is generally made of a resin as a main component, considering that a photosensitive layer is coated on top of these resins with a solvent.

It is desirable that the resin has high solvent resistance to common organic solvents. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, copolymerized nylon, and methoxymethylated nylon. alcohol-soluble resin, polyurethane, melamine resin,
Examples include curable resins that form a three-dimensional network structure, such as phenol resins and epoxy resins.

In addition, the intermediate layer contains titanium oxide, silica, alumina, zirconium oxide, etc. to prevent moiré and have a low residual potential.
Finely powdered pigments of metal oxides such as tin oxide and indium oxide may also be added.

Examples of the solvent or dispersion medium used in forming the charge generation layer and the charge transport layer include N,N'-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, and 1,2-dichloroethane.

Examples include dichloromethane, monochlorobenzene, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, and the like.

The photosensitive layer can be formed by immersing the substrate in a coating solution for the charge generation layer or charge transport layer, or by spraying the coating solution onto the substrate.

Substrates used in the electrophotographic photoreceptor of the present invention include metal drums and sheets made of aluminum, brass, stainless steel, nickel, etc., materials such as polyethylene terephthalate, polypropylene, nylon, paper, etc., on which metals such as aluminum and nickel are vapor-deposited. , or titanium oxide,
Examples include sheet-like or cylindrical substrates such as plastics and paper that are coated with a conductive substance such as tin oxide or carbon black together with a suitable binder to conductivity treatment.

〔Effect of the invention〕

Since the electrophotographic photoreceptor of the present invention has the above-mentioned structure, the photoreceptor properties such as charging properties do not deteriorate even after repeated use over a long period of time, and it has high durability and good storage stability, so it has extremely practical value. It's expensive.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 was dissolved in 50 parts by weight of methyl ethyl ketone, and titanium oxide powder [Tie Bake CR-IEL (Shiji 114
Work! II) 390 parts were added and dispersed in a ball mill for 12 hours to prepare a coating solution for an intermediate layer. This is 80m in diameter
m, applied on a 360 m long aluminum drum, 1
It was dried at 40° C. for 20 minutes to form a 2-thick intermediate layer.

Next, resol type phenolic resin (Bleiofen T
6.7 parts by weight of O-447 (manufactured by Dainippon Ink & Chemicals) was dissolved in 147.3 parts by weight of cyclohexanone.

To this was added 10 parts by weight of the trisazo pigment of Exemplified Compound &42 and dispersed in a ball mill for 48 hours, and further 210 parts by weight of cyclohexanone was added and dispersed for 3 hours. This was taken out into a container and diluted with cyclohexanone so that the solid content was 1.5% by weight. The charge generation layer coating solution thus obtained was coated on the intermediate layer at 130°C by dip coating.
This was dried for 20 minutes to form a charge generation layer having a thickness of 0.27711 mm.

Further, 8 parts by weight of a charge transport substance represented by the following structural formula (U), 10 parts by weight of polycarbonate resin [Panlite-1300 (Teijin Kasei! 11)], silicone oil (KF-
50 (Shin-Etsu Chemical Co., Ltd. 111)) was dissolved in 85 parts by weight of methylene chloride to prepare an IT charge transfer N coating solution. Applying this to the charge generation layer using a dip coating method,
It was dried at 110° C. for 20 minutes to form a charge transport layer with a thickness of 20 μm.

In this manner, the electrophotographic photoreceptor of the present invention was produced.

Example 2 In Example 1, a resol type phenolic resin (Bryophen TO-447: manufactured by Dainippon Ink and Chemicals Co., Ltd.) was used.
6.7 parts by weight of resol type phenolic resin (Pryophen TO-447: Dainippon Ink & Chemicals Co., Ltd. fa) 5
．． 3! m1 (f[ was replaced with parts and polyvinyl butyral [S-LEC 0L-1 (Building Chemical Industry Il!)] 00.8 parts by weight, and 147.3 parts by weight of cyclohexanone was replaced with 147.9 parts by weight of cyclohexanone. An electrophotographic photoreceptor was produced in the same manner as in Example 1 except for this.

Example 3 In Example 1, 6.7 parts of the resol type phenolic resin (Bliophen TD-447) was replaced with 6.7 parts of the resol type phenolic resin (Bliofen TD-447: 1-
j Hon Ink Kagaku Kogyo Co., Ltd.) 5.3 parts by 11 parts and alkyd resin (M-6404-5 parts by Dai Nippon Ink Kagaku Kogyo Co., Ltd.) 1.6 parts, and cyclohexanone 147 parts.
, except that 3 parts by weight was replaced by 147.1 parts by weight of cyclohexanone.

An electrophotographic photoreceptor was produced in the same manner as in Example 1.

Comparative Example 1 In Example 1, a resol type phenolic resin (Bryophen TD-447: manufactured by Dainippon Ink and Chemicals) was used.
6.7 The heavy base is alkylphenol resin (Super Beccacy h 1oool; manufactured by Honink Kagaku Kogyo Co., Ltd.) 4
In place of parts by weight, cyclohexanone 147. :(An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the weight part was changed to 150 parts by weight of cyclohexanone.

Comparative Example 2 In Example 1, 6.7 parts by weight of 1 nozole type phenolic resin (Bryophen TD-447: manufactured by Dainippon Ink and Chemicals) was mixed with vinyl chloride-vinyl acetate-anhydride matrix.
In place of the main acid resin (S-LEC MF-10; manufactured by Sekisui Chemical Co., Ltd.) 4, cyclohexanone 147°3
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that cyclohexanone 150 was used instead of cyclohexanone 150.

Comparative Example 3 In Example 1, a resol-type phenolic resin (Bryophen TO-447: manufactured by Dainippon Ink and Chemicals Co., Ltd.) was used.
6゜7 parts by weight of polycarbonate 1-(Panrai!-1,
1250; manufactured by Dennyi Kasei Co., Ltd.), and 147.3 parts by weight of cyclohexanone was replaced with 50 parts by weight of cyclohexanone and 100 parts by weight of tetrahydrofuran. Created a body.

The obtained photoreceptor was used as Imagi No. 320 (manufactured by Ricoh).
30,000 copies were made, and the surface potential at the initial stage and after 30,000 copies was evaluated. The results are shown in Table-1.

The surface potential was evaluated by attaching a surface potential meter to the development position and measuring the surface potential of the exposed area (VL) and the non-exposed area (Vo).

Table 1 As is clear from the results in Table 1, the electrophotographic photoreceptor of the present invention exhibits high durability with small potential fluctuations between exposed and non-exposed areas even after repeated charging and exposure. .

Patent applicant Rico Co., Ltd.

Claims (1)

[Claims] (1) In a functionally separated electrophotographic photoreceptor in which at least a charge generation layer and a charge transport layer are laminated on a conductive support, a resol type phenolic resin is contained as a binder in the charge generation layer. Characteristic electrophotographic photoreceptor.