JPH01279252A - Photosensitive body - Google Patents

Abstract

PURPOSE:To improve photosensitivity and the coatability of a layer contg. a carrier generating material by adding a vinyl acetate resin to a resin exclusive of the vinyl acetate resin as a binder resin of the layer contg. the carrier generating material and making combination use of both. CONSTITUTION:The photosensitive layer 4A of the laminated constitution consisting of the carrier generating layer 2 contg. the carrier generating material and a binder resin as a lower layer and the carrier transfer layer 3 contg. the carrier transfer material and a binder resin at need as an upper layer is provided on a base 1. The vinyl acetate resin is also added to the binder resin of the layer contg. the carrier generating material, i.e., the resin exclusive of the vinyl acetate resin. The vinyl acetate resin is confined to >=50wt.% ratio of vinyl acetate which is the monomer of both resins in case of a copolymer resin. The photosensitivity of the photosensitive body is thereby improved and the coatability of the layer contg. the carrier generating material is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a photoreceptor, for example, an electrophotographic photoreceptor.

B6 Prior Art In the electrophotographic copying method of the Carlson method, after the surface of a photoreceptor is charged, an electrostatic latent image is formed by exposure, and the electrostatic latent image is developed with toner, and then the visible image is formed. Transfer and fix onto paper, etc. At the same time, the photoreceptor is subjected to removal of adhered toner, neutralization of static electricity, and surface cleaning, and is used repeatedly over a long period of time.

Therefore, as an electrophotographic photoreceptor, it not only has electrophotographic properties such as good charging characteristics, good sensitivity, and low dark decay, but also physical properties such as stiffness resistance, abrasion resistance, and moisture resistance after repeated use. It is also required to have good properties and resistance to ozone generated during corona discharge, ultraviolet rays during exposure, etc. (environmental resistance).

Conventionally, as electrophotographic photoreceptors, inorganic photoreceptors having a photosensitive layer mainly composed of an inorganic photoconductive substance such as selenium, zinc oxide, or cadmium sulfide have been widely used.

On the other hand, the use of various organic photoconductive substances as materials for photosensitive layers of electrophotographic photoreceptors has been actively developed and researched in recent years.

For example, in Japanese Patent Publication No. 50-10496, poly-N-
Vinyl carbazole and 2.4. '1-1-Rinitro 9
- An organic photoreceptor having a photosensitive layer containing fluorenone is described. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability. In order to improve these shortcomings, attempts have been made to develop photoreceptors with high sensitivity and durability by assigning the carrier generation function and carrier transport function to different substances in the photosensitive layer. being done. In such so-called function-separated type electrophotographic photoreceptors, substances that exhibit each function can be selected from a wide range of materials, so it is relatively easy to produce electrophotographic photoreceptors with arbitrary characteristics. Is possible. Therefore,! It is expected that organic photoreceptors with high density and durability will be obtained.

In the photosensitive layer of such an electrophotographic photoreceptor, efforts are being made to obtain an electrophotographic photoreceptor having excellent electrophotographic properties and film strength by using a carrier-generating substance and a polymer binder in combination.

At this time, the carrier-generating substance is dissolved, dispersed, etc. in the polymer binder, and the generated photocarriers are transported through the layer. Therefore, the light carrier transport ability in the layer is greatly influenced by the type of polymer binder. Therefore, the selection of a polymeric binder is one of the most important factors governing the photosensitivity of a photoreceptor. However, there is no general rule for uniform selection of binders, and the actual situation is that binders are selected based on repeated experiments, taking into account the type of carrier-generating substance, etc.

On the other hand, even if a polymeric binder is used to provide an electrophotographic photoreceptor with excellent electrical properties, the physical properties and stability of the coating liquid used to form a photosensitive layer may not be sufficient, especially when forming a deep layer. During coating, the uniformity of the coating layer was microscopically insufficient, and the electrophotographic properties of the resulting electrophotographic photoreceptor were sometimes uneven.

C1. Purpose of the Invention The purpose of the present invention is to provide a photoreceptor that has excellent photosensitivity, has a layer containing a carrier-generating substance, has good coating properties, and is capable of producing uniform and high-quality images. be.

21 Structure of the Invention and Its Effects The present invention relates to a carrier generating substance and a vinyl acetate resin (however, in the case of a copolymer resin, a monomer of the same resin).

The present invention has a remarkable feature in the binder resin of the layer containing the carrier-generating substance.

That is, it is important that "vinyl acetate resin" is added to "resin other than vinyl acetate resin" as the binder resin, and both are used in combination.

As mentioned above, various studies have been made regarding the binder resin itself of the layer containing the carrier-generating substance.

In contrast, in the present invention, the binder resin (resin other than vinyl acetate resin) of the "layer containing a carrier-generating substance"
In addition, vinyl acetate resin is also added. As a result, the photosensitivity of the photoreceptor has been significantly improved, and the coatability of the "layer containing a carrier-generating substance" has also been improved, resulting in uniform and fine image defects (non-uniform fogging, blackening of solid black areas, etc.). This resulted in a high-quality image with suppressed effects such as chromatography, deterioration, etc.).

The reason for the increased sensitivity is thought to be an improvement in the range probability of photocarriers, for example, by controlling the junction state at the interface, controlling the electric field effect and transport sites, and reducing the number of trap sites.

Moreover, the reason for the improvement in image quality is presumed to be the uniformity of the coating film due to changes in coating liquid physical properties (viscosity, flow characteristics, etc.) due to binder interaction, CGM-binder interaction, etc.

However, these causes are not necessarily clear.

Furthermore, as will be described later, it has been confirmed that simply adding a small amount of vinyl acetate resin significantly improves the photosensitivity and the coating properties of the layer containing the carrier-generating substance.
This can be said to be extremely noteworthy.

The photoreceptor of the present invention has a support 1 as shown in FIG.
(a conductive layer is provided on a conductive support or sheet), a carrier generation N2 (hereinafter sometimes referred to as CGL) containing a carrier generation material i (CGM) and a binder resin is placed as a lower layer to transport carriers. A photosensitive Jii 4A having a laminated structure with a carrier transport layer 3 (hereinafter sometimes referred to as CTL) as an upper layer containing a substance (CTM) and a binder resin as needed, a support as shown in FIG. A photosensitive layer 4B having a laminated structure with CTL3 as a lower layer and CGL2 as an upper layer is provided on support 1, and as shown in FIG. A photosensitive IJ4B with a layered structure and a photosensitive IJ4B with a layered structure as shown in FIG.
(see FIG. 2) on which a protective layer 5 is provided.

Further, CGL may contain both CGM and CTM, a protective layer (OCL) may be provided on the photosensitive layers 4A and 4D, and an intermediate layer or undercoat layer may be provided between the support and the photosensitive layer. It may be provided.

The "layer containing a carrier-generating substance" corresponds to the carrier-generating layer 2 and the photosensitive layer 4D in the examples shown in FIGS. 1 to 4.

In the "layer containing a carrier-generating substance", when the content of CGM is 100 parts by weight, the content of "resin other than vinyl acetate resin" is preferably 10 to 500 parts by weight, and 20 parts by weight. More preferably, the amount is 300 parts by weight.

In addition, the content of "vinyl acetate resin" is 0.1 to 250
The amount is preferably 0.2 to 150 parts by weight, and more preferably 0.2 to 150 parts by weight. Similarly, the content of CTM is 0 to 5
The amount is preferably 0.00 parts by weight, and more preferably 0 to 300 parts by weight.

Furthermore, when the content of "resin other than vinyl acetate resin" in the "layer containing a carrier-generating substance" is 100 parts by weight, the content of "vinyl acetate resin" is 0.02 to 100 parts by weight.
The amount is preferably 50 parts by weight, more preferably 0.1 to 40 parts by weight, and even more preferably 0.2 to 30 parts by weight.

The "vinyl acetate resin" includes vinyl acetate resins produced by polymerizing vinyl acetate monomers, as well as vinyl acetate copolymer resins.

Other copolymerizable monomers that can be copolymerized as necessary include known polymerizable monomers, such as vinyl alcohol, various vinyl esters such as vinyl propionate, vinyl chloride, vinylidene chloride, acrylonitrile, and methacrylate. nitrile, styrene, various acrylic acids,
Methacrylic acid, acrylic ester, methacrylic ester, hydroxyacrylic acrylate, ethylene, propylene, isobutyne, butadiene, isoprene, vinyl ether, ether, ester, acrylamide, methacrylamide, maleic ester, diethyl maleic acid, etc. is exemplified.

Also included are partially hydrolyzed vinyl acetate copolymers.

Particularly preferred are vinyl acetate-vinyl chloride, vinyl acetate-maleic acid, and vinyl acetate-maleic anhydride copolymers. At this time, the content of vinyl chloride and/or maleic acid and/or maleic anhydride component (if both are included, the total amount) is 0 to 50% by weight.

The polymerization degree of vinyl acetate resin is effective over a wide range, and can be determined by balancing solubility and additive concentration.The allowable range varies depending on the (co)polymer and solvent used, but for example, about 50 to 2000 is used. easy.

However, this is not the case.

The above-mentioned vinyl acetate copolymer is polymerized by a polymerization method such as emulsion polymerization, solution polymerization, suspension polymerization, or bulk polymerization. In either method, known techniques such as divisional addition or continuous addition of a molecule M regulator, a polymerization initiator, and a monomer can be applied as necessary.

Examples of "resins other than vinyl acetate resins" include polyethylene, polypropylene, acrylic resins, methacrylic resins, epoxy resins, polyurethane resins, polyester resins, alkyd resins, polycarbonate resins, silicone resins, melamine resins, methacrylic resins, acrylic resins, Addition polymer resins such as polyvinylidene chloride and polystyrene, polyaddition resins, polycondensation resins, copolymer resins containing two or more of these repeating units, styrene-butadiene copolymer resins, vinylidene chloride Examples include acrylonitrile copolymer resins and polymer organic semiconductors such as N-vinylcarbazole.

Among these, polyester resins, polycarbonate resins, acrylic resins, epoxy resins, styrene-acrylic resins, polyvinyl acecool (for example, polyvinyl butyral), phenolic resins, silicone resins, etc. are preferred.

As the carrier generator '37 (CGM), any inorganic pigment or organic pigment can be used as long as it absorbs electromagnetic waves and generates free carriers. CGM
The following are examples.

(1) Amorphous selenium, trigonal selenium, selenium-arsenic alloy, selenium-tellurium alloy, cadmium sulfide, cadmium selenide, cadmium selenide sulfide, mercury sulfide, lead sulfide,
Inorganic pigments such as zinc oxide and amorphous silicon (2) Azo pigments such as monoazo pigments, polyazo pigments, metal complex azo pigments, pyrazolone azo pigments, stilbene azo and thiazole azo pigments, (3) anthraquinone derivatives, anthraquinone derivatives, dibenzpyrenequinone derivatives, pyrantrone derivatives,
Anthraquinone or polycyclic quinone pigments such as violanthrone derivatives and isoviolanthrone derivatives (4) Indigoid pigments such as indigo derivatives and thioindigo derivatives (5) Diphenylmethane pigments, triphenylmethane pigments, xanthine pigments, acridine pigments, etc. Carbonium pigments (6) Quinoneimine pigments such as azine pigments, oxazine pigments and thiazine pigments (7) Methine pigments such as cyanine pigments and azomethine pigments (8) Quinoline pigments (9) Nitro pigments (10) Nitroso pigments (11) Benzoquinone and naphthoquinone pigments (12)
Naphthalimide pigments (13) Perylene pigments such as bisbenzimidazole i-form (14) Fluorenone pigments (15) Squarylium pigments (16) Azulenium compounds (17) Perylene pigments such as perylenic anhydride and perylenic acid imide (18) Metal-free phthalocyanine pigments such as alpha-type, beta-type, Particularly preferred are pigments, azo pigments, and phthalocyanine pigments.

Preferred azo pigments and polycyclic quinone pigments are illustrated below.

(Space below) Exemplary compound group [I]: Exemplary compound group [■]: Bottom margin) Exemplary compound group [■]: Exemplary compound group [■]: Also, the exemplary compound group consisting of the following polycyclic quinone pigments ( Vl
) to [■] can also be used as carrier-generating substances.

Exemplary compound group [■]: fjj bedded gold compound group]: Exemplary compound group [■]: In the photoreceptor as shown in FIG. 1, the thickness of the carrier generation layer is preferably 0.1 to 5 μm; The thickness of the carrier transport layer is preferably 5 to 50 μm. In the photoreceptor shown in Figure 2, the carrier generation layer has a thickness of 1 to 10
The thickness of the carrier transport layer is preferably 1 to 30 μm. +
The length is preferably 1 m.

In the photoreceptor shown in FIG. 3, the thickness of the photosensitive layer is preferably 5 to 30 μm.

The thickness of the subbing layer or intermediate layer provided between the photosensitive layer and the conductive substrate as needed is preferably 0.01 to 5 μm.

The thickness of the surface protective layer provided as necessary is 0.1 to 5.
μm is preferred.

The content of the carrier transport substance in the carrier transport layer is preferably 10 to 200 parts by weight per 100 parts by weight of the binder resin.

In the layer containing the carrier-generating substance, the particulate carrier-generating substance is bound in the binder resin (which may contain a carrier transporting substance if necessary), and is dispersed in the layer in the form of a dye or pigment. Preferably.

When a photosensitive layer is formed by dispersing a granular carrier-generating substance, the carrier-generating substance is in the form of powder with an average particle size of 2 μm or less, preferably 1 μm or less, and more preferably 0.5 μm or less. is preferred.

Further, in the carrier transport layer, the carrier transport substance preferably has excellent compatibility with the binder substance. This allows for a very wide mixing ratio with the binder material, making the carrier transport layer uniform and stable.
As a result, sensitivity and charging characteristics become better. Furthermore, it is possible to use a photoreceptor that can form clear images with high sensitivity, and it is possible to achieve the effect that fatigue deterioration is less likely to occur especially during repeated use.

The "layer containing a carrier-generating substance" can be provided by the following method.

(a) A method in which a binder and a solvent are added to a carrier-generating substance and a mixed solution is applied.

(b) Use a ball mill, homomixer, or
A method of applying a dispersion obtained by forming fine particles in a dispersion medium with or with a binder using a sand mill, ultrasonic dispersion machine, attritor, etc., and mixing and dispersing with a binder if necessary.

When the particles are dispersed by the action of ultrasonic waves in these methods, uniform dispersion becomes possible.

At this time, if the "vinyl acetate resin" is insoluble in the solvent that should dissolve the "resin other than vinyl acetate resin,"
What is necessary is to dissolve the "vinyl acetate resin" in another solvent and then mix the solutions of each resin. Further, the same effect can be obtained by mixing before or after dispersion.

When a carrier transporting substance is contained in a layer containing a carrier generating substance, a method of dissolving or dispersing the carrier transporting substance in the solution (a) or the dispersion liquid of (b) above, that is, in the carrier generating layer. There is a method of adding a carrier transport substance. Further, in the type shown in FIG. 1, there is a method in which a solution containing a carrier transport substance is applied onto the carrier generation layer, and the carrier generation layer is swollen or partially dissolved to diffuse the carrier transport substance into the carrier generation layer. When this method is adopted, it is not necessary to add a carrier transporting substance to the carrier generation layer as described above, but the above-mentioned Niga method may be carried out at the same time.

Further, the carrier transport layer can be formed by coating and drying the above-mentioned carrier transport substance alone or by dissolving and dispersing it together with the above-mentioned binder resin.

Examples of solvents used for forming the photosensitive layer include hydrocarbons such as hexane, benzene, toluene, and xylene, methylene chloride, 1,2-dichloroethane, and
111+ -tetrachloroethane, cis-1,2--
dichloroethylene, 1,1,2-trichloroethane, 1
．． 1.1-Halogenated hydrocarbons such as trichloroethane, chloroform, bromoform, and chlorobenzene, ketones such as acetone, methyl ethyl ketone, and chlorohexanone, esters such as ethyl acetate and butyl acetate, methanol, ethanol, propatool, butanol, cyclo Alcohols such as hexanol, methanol, ethylene glycol, methyl cellosolve, ethyl cellosolve, acetic acid cellosolve and derivatives thereof.

Ethers such as tetrahydrofuran, 1,4-dioxane, furan and ralfural, acetals, nitrogen compounds such as pyridine, amines and amides, fatty acids and phenols, sulfur and phosphorus compounds such as carbon disulfide and triethyl phosphate, etc. Any of these solvents may be used as a single solvent, or various mixed solvents containing these solvents as main components may be used.

Furthermore, any of the above-mentioned solvents can be used as the solvent for the "vinyl acetate resin", but especially alcohols (methanol, ethanol, isopropanol, etc.),
Ketones (acetone, methyl ethyl ketone, isobutyl ketone, cyclohexanone, etc.), esters (methyl acetate, ethyl acetate, isobutyl acetate, etc.), aromatics (benzene, toluene, xylene, chlorobenzene, etc.), halogen hydrocarbons (methylene chloride, 1,2-dichloroethane, trichloroethane, etc.) or a mixture thereof is preferable.

The photosensitive layer (layer containing a carrier-generating substance, carrier transport layer), undercoat layer, intermediate layer, protective layer, etc. can be formed by, for example, blade coating, dip coating, spray coating, roll coating, etc.
It can be provided by spiral coating or the like.

The carrier transport substances used in the present invention include carbazole derivatives, oxazole derivatives, oxadiazole derivatives,
Thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidasilone derivatives,
imidazolidine derivatives, bisimidazolidine m8 bodies, styryl compounds, hydrazone compounds, pyrazoline derivatives,
Oxacilone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline W'h'4 bodies, benzofuran derivatives, acridine derivatives, phenazine derivatives,
Aminostilbene ff1lI, triarylamide 7t
A conductor, phenylenediamine derivative, steel/L/pen f
It may be one or more selected from ig form, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, and the like.

Specific examples of such carrier transport substances are disclosed in Japanese Patent Application No. 1983.
-298013, etc. The general formula is given below.

The following general formula (IX) or (X
) styryl compounds can be used.

- Formula [■]: (However, in this general formula, R1, RZ represents a substituted or unsubstituted alkyl group, aryl group, and substituents include an alkyl group, an alkoxy group, a substituted amino group, a hydroxyl group, a halogen atom, Use an aryol group.

Ar', Ar'': Represents a substituted or unsubstituted aryl group, and the substituent used is an alkyl group, an alkoxy group, a substituted amino group, a hydroxyl group, a halogen atom, or an aryl group.

R3, R4 represent a substituted or unsubstituted oryl group, a hydrogen atom, and the substituents include an alkyl group, an alkoxy group, a substituted amino group, a hydroxyl group, a halogen atom, and an aryl group #) General formula [X] : (However, in this general formula, R5, substituted or unsubstituted aryl group, R6 diatomic atom, halogen atom, substituted or unsubstituted alkyl group,
Alkoxy group, amino group, substituted amino group, hydroxyl group, R7: represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group. ) In addition, the following general formula (XI), (
Xn), (Xlla), (X 11 b] or (XI[
[) Hydrazone compounds can also be used.

General formula (XI): (In this formula, R8 and R9: each a hydrogen atom or an A sedan atom, RIO and R1+, each a substituted or unsubstituted aryl group, Ar': a substituted or unsubstituted arylene group) represent.

) General formula (XII): (In this formula, RIS: represents a substituted or unsubstituted oryl group, a substituted or unsubstituted carbazolyl group, or a substituted or unsubstituted heterocyclic group, RI3, R" and RIS: represent a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aralkyl group.) R" (However, in this formula, RI: methyl group, ethyl group, 2-hydroxyethyl group or 2-chloroethyl group, R'': methyl group, ethyl group, benzyl group or phenyl group, R'': methyl group, ethyl group, benzyl group or phenyl group.

General formula (Xnb): (In this formula, RI9 is a substituted or unsubstituted naphthyl group; R20 is a substituted or unsubstituted alkyl group,
Aralkyl group or aryl group; R21 is a hydrogen atom, an alkyl group or an alkoxy group; R'' and R'' are the same or different groups consisting of a substituted or unsubstituted alkyl group, aralkyl group or aryl group; ) General formula (XI[I): (However, in this formula, R24: substituted or unsubstituted aryl group or substituted or unsubstituted heterocyclic group ・R'': hydrogen atom, substituted or unsubstituted Alkyl group or substituted or device-substituted teryl group, Q: hydrogen atom, halogen atom, alkyl group, substituted amino group, alkoxy group or cyano group, represents an integer of s20 or 1) Also, carrier transport As a substance, the following general formula (XIV)
pyrazoline compounds can also be used.

- Formula (XIV): [However, in this formula, l: 0 or 1, R'' and R1?: substituted or unsubstituted aryl group, R
21l: substituted or unsubstituted aryl group or heterocyclic group, R29 and R30: hydrogen atom, alkyl group having 1 to 4 carbon atoms, or substituted or unsubstituted aryl group or aralkyl group (however, RlQ and R30 are both (RlQ is not a hydrogen atom, and when l is O, RlQ is not a hydrogen atom.) Furthermore, an amine derivative of the following general formula (XV) can also be used as a carrier transport substance.

General formula [XV): Ar', Ar5: represents a substituted or unsubstituted phenyl group, and a halogen atom, an alkyl group, a nitro group, or an alkoxy group is used as a substituent.

Ar6: represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group, fluorenyl group, or heterocyclic group, and substituents include an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an aryloxy group, an aryl group, an amino group, A nitro group, a piperidino group, a morpholino group, a naphthyl group, an anthryl group and a substituted amino group are used. However, an acyl group, an alkyl group, an aryl group, or an aralkyl group is used as a substituent for the substituted amino group. ) Furthermore, a compound of the following general formula (XVT) can also be used as a carrier transport substance.

General formula (XVI): (However, in this formula, Ar): represents a substituted or unsubstituted arylene group, R3fold, R3t, R3go and R34: substituted or unsubstituted alkyl group, substituted or unsubstituted represents an aryl group or a substituted or unsubstituted aralkyl group) Furthermore, a compound of the following general formula [X■] can also be used as a carrier transport substance.

General formula [X■]: [However, in this formula, R", Roll, R" and R" each represent a hydrogen atom, a substituted or unsubstituted alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, a benzyl group, group or aralkyl group, Ral? and R40 are each a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 40 carbon atoms, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group or an aralkyl group (however, R "and R" may jointly form a saturated or unsaturated hydrocarbon ring having 3 to 10 carbon atoms) R"% R", R" and Ro are a hydrogen atom and a halogen atom, respectively , a hydroxyl group, a substituted or unsubstituted alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, an amino group, an alkylamino group, or an arylamino group. ] An antioxidant can be contained in the carrier transport layer, carrier generation layer, and photosensitive layer. This makes it possible to suppress the influence of ozone generated during discharge, and prevent an increase in residual potential during repeated use.

Examples of the antioxidant include hindered phenol, hindered amine, paraphenylene diamine, aryl alkane, hydroquinone, spirochroman, spiroindanone and derivatives thereof, organic sulfur compounds, organic phosphorus compounds, and the like.

These specific compounds are disclosed in Japanese Patent Application No. 61-1628.
No. 66, No. 61-188975, No. 61-19587
No. 8, No. 61-157644, No. 61-195879
No. 61-162867, No. 61104469,
It is described in No. 61-217493, No. 61-217492, and No. 61-221541.

A polymeric organic semiconductor can also be included in the photosensitive layer. Among these polymeric organic semiconductors, BoIJ-N-vinylcarbazole or its derivatives are highly effective and are preferably used. Such poly-N-vinylcarbazole derivatives are those in which all or part of the carbazole ring in the repeating unit is substituted with various substituents, such as an alkyl group, a nitro group, an amino group, a hydroxy group, or a halogen atom. .

Furthermore, at least one type of electron-accepting substance can be contained in the photosensitive layer for the purpose of improving sensitivity, reducing residual potential or fatigue during repeated use, and the like.

Electron-accepting substances that can be used in the photoreceptor of the present invention include:
For example, succinic anhydride, maleic anhydride, dibromaleic anhydride, acid, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, pyromellitic anhydride, Merit anhydride. Acid, tetracyanoethylene, tetracyanoquinodimethane, 0-dinitrobenzene, m-dinitrobenzene, 1.3.5-) dinitrobenzene, varanitrobenzonitrile, vicryl chloride, quinone chlorimide, chloranil, brumanil, 2 - methylnaphthoquinone,
dichlorodicyanobara benzoquinone, anthraquinone,
Dinitroanthraquinone, trinitrofluorenone, 9
-Fluorenylidene [dicyanomethylene malonodinitrile], polynitro-9-fluorenylidene [dicyanomethylene malonodinitrile], picric acid, 0-nitroben, dizoic acid, p-nitrobenzoic acid, 3, Examples include one or more of 5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3.5-dinitrosalicylic acid, phthalic acid, mellitic acid, and other compounds with high electron affinity. Among these, fluorenone series, quinone series, and benzene derivatives having electron-withdrawing substituents such as C1, CN, NO, etc. are particularly preferred.

Furthermore, a silicone oil or a fluorosurfactant may be present as a surface modifier, and an ammonium compound may be contained as a durability improver.

Further, an ultraviolet absorber may be used. Preferred ultraviolet absorbers include benzoic acid, stilbene compounds, etc. and derivatives thereof, triazole compounds, imidazole compounds, triazine compounds, coumarin compounds, oxadiazole compounds, thiazole compounds and derivatives thereof. The following nitrogen-containing compounds are used.

The various binder resins described above can be used in the carrier transport layer.

In addition, for the subbing layer or intermediate layer provided as necessary,
In addition to the above binder resins, for example, polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, casein, N-alkoxymethylated nylon, starch, etc. can be used.

As a binder for the protective layer provided as necessary,
Volume resistance 108Ω・1 or more, preferably 1010Ω・1
As mentioned above, a transparent resin having a value of 10'2 Ω or more is more preferably used. Further, the binder may be a resin that is cured by light or heat, and examples of the resin that is cured by light or heat include thermosetting acrylic resin, silicone resin, epoxy resin, urethane resin, urea resin, polyester resin, Examples include alkyd resins, melamine resins, photocurable cinnamic acid resins, and copolymerized or condensed resins thereof, as well as all other photocurable or thermosetting resins used in electrophotographic materials. If necessary, the protective layer may contain less than 50% by weight of a thermoplastic resin for the purpose of improving processability and physical properties (preventing cracks, imparting flexibility, etc.). Such thermoplastic resins include, for example, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polycarbonate resin, silicone resin, or copolymer resins thereof, such as vinyl chloride-vinyl acetate-maleic anhydride. Acid copolymer resins, polymeric organic semiconductors such as poly-N-vinylcarbazole, and other thermoplastic resins used in electrophotographic materials can all be used.

The conductive substrate is a metal plate, a metal drum or a conductive polymer,
Applying a conductive thin layer made of a conductive compound such as indium oxide or a metal such as aluminum, palladium, or gold,
Those provided on a substrate such as paper or plastic film by means such as vapor deposition or lamination are used.

E. Examples The present invention will be described in detail below, but the embodiments of the present invention are not limited thereby.

[Experiment■]

Vinyl chloride-vinyl acetate-maleic acid copolymer [S-LEC M
Made of F-104 (manufactured by Block Chemical Industry Co., Ltd.), thickness approximately 0.1
An intermediate layer of .mu.m was provided.

Next, 100 parts by weight of CC,M (1) shown in FIG. 5 was ground in a ball mill for 24 hours, and a predetermined "binder resin other than vinyl acetate resin" shown in FIG. 5 was added to it!
A solution dissolved in 4170 parts by weight of 1,2-dichloroethane was added and further dispersed in a ball mill for 24 hours. A solution of "vinyl acetate resin" shown in Figure 5 dissolved in a prescribed solvent was added to the obtained dispersion, and the resulting liquid was mixed with a prescribed amount of vinyl acetate resin as a solid component. It was applied by dip coating onto the intermediate layer and sufficiently dried to form a CGL having a thickness of 1 μm.

Next, 75 parts by weight of the following CTM (I) and polycarbonate "Nipiron/Z-200J (manufactured by Mitsubishi Gas Chemical Industries, Ltd.)
100 parts by weight of 1,2-dichloroethane was dissolved in 625 parts by weight of 1,2-dichloroethane, and the resulting solution was applied by dip coating onto the carrier generation layer, and dried at a temperature of 80°C for 1 hour to form a carbon film with a thickness of 20 μm.
TL was formed.

"Resin other than vinyl acetate resin" Polycarbonate resin': "Panlite L-1250
J (manufactured by Kijin Kasei Co., Ltd.) Polyester resin: "Byron 200" (manufactured by Toyobo Co., Ltd.) Acrylic resin = "Acrivet #001 J (manufactured by Mitsubishi Rayon Co., Ltd.) Polyvinyl butyral resin: "S-Lefta BL-3J (manufactured by Mitsubishi Rayon Co., Ltd.)
(Manufactured by Tanesui Kagaku Co., Ltd.) Epoxy resin: "Epicote 100IJ (manufactured by Yuka Shell Epoxy Co., Ltd.) "Vinyl acetate resin" Vinyl acetate resin; "Denka Rank #41M J (manufactured by Kikagaku Kogyo Co., Ltd.)
Vinyl acetate component: 55% by weight Vinyl chloride component: 45% by weight CGM (1) 4.10-Dibromoanthanthrone CTM (I) Example photoreceptor! -A-1-G and comparative example photoreceptor l-3-
-Ig was created.

Using an electrostatic charge testing device rEPA-8100J (Kawaguchi Electric Seisakusho), a voltage of +6 KV was applied to the charging electrode to charge the photosensitive layer by corona discharge for 5 seconds. Thereafter, it was left for 5 seconds (the potential at this time is referred to as the initial potential).

), and then irradiated with light from a halogen lamp with a light intensity of 21 ux on the surface of the photosensitive layer to bring the initial potential to 16
Exposure amount E1° required to attenuate from 00V to -100V. (lux-see) was measured.

Further, Sλ was measured at a wavelength λ”” of 540 nm using a spectrometer MC-2OL (manufactured by Ritsuichi Applied Optics Co., Ltd.). However, for S input, light of a specific wavelength λ is 0.5μ-/c11! This is the amount of potential attenuation per unit energy during the attenuation from V6=800V to V=-100V when irradiated with . In FIG. 5, the values are expressed as relative values when the value of S) for the photoreceptors of each comparative example is set to 1.00. That is, for photoreceptors I-A and 1-B, photoreceptor I-
Relative value when the value of aO3 is set to 1.00, photoconductor 1
-D is a relative value when the 3x value of photoconductor ■-d is set to 1.00, and photoconductor I-E is a relative value when photoconductor I-e is
Relative value when the S input value of is 1.00, photoconductor I-
For F, the value is relative when the value of Sλ of photoreceptor weight -f is set to 1.00, and for photoreceptor iG, the nominal Ω value of photoreceptor 1-g is 1.00. Each is expressed as a relative value when OO.

Furthermore, for each electrophotographic photoreceptor, U-Bix155
Installed on 0MR (manufactured by Konica) modified machine, black paper potential V1,
The initial values of the blank paper potential ■8 and the residual potential Vr and the respective fluctuation amounts Δ■1, ΔV, Δ■7 after 10,000 copies were measured. That is, Δv,=lv.

After 10,000 copies, the initial value of 1-IVb is 1, and the same holds true for the others.

The black paper potential here refers to the surface potential of the photoreceptor when the above-mentioned copying cycle is performed using a black paper original with a reflection density of 1.3, and the white paper potential refers to the surface potential of the photoreceptor when a blank paper is used as the original. Represents the surface potential of the body.

The results of these measurements are shown in FIG.

[Experiment■]

An intermediate layer was formed in the same manner as in Experiment I.

Next, a predetermined amount of 1,2-dichloroethane 1 of the predetermined "binder resin other than vinyl acetate resin" shown in FIG.
0,500 parts by weight of the CGM shown in FIG.
(n) Add 100 parts by weight and use a sand grinder to
Spread out time. Into this dispersion, a solution of "vinyl acetate resin" shown in Figure 6 dissolved in a specified solvent is mixed, and a predetermined amount of vinyl acetate resin (solid component) is mixed into the resulting liquid. was dip-coated onto the intermediate layer to form a CGL with a thickness of 0.4 μm.

Next, in Experiment I, CTM (1) was converted to the following CTM (
CT with a thickness of 20 μm in the same manner except for
L was formed.

In this way, photoreceptors II-A to II-II of Examples and photoreceptor U-a of Comparative Example were prepared.

For each of these electrophotographic photoreceptors, measurements similar to those in Experiment (2) were performed. However, for 3 people, the value of ■-a is 1.0
It is expressed as a relative value when it is set to 0. The results are shown in FIG.

(Margin below) CGM (II) CTM (II) [Experiment■] An intermediate layer was formed in the same manner as in Experiment (2).

Next, a solution prepared by dissolving a predetermined amount of the binder resin shown in FIG. 6 in 6200 parts by weight of methyl ethyl ketone was added to 100 parts by weight of CGM (I[I) shown in FIG.
Dispersion was performed using a sand grinder for 5 hours. A solution obtained by dissolving the "vinyl acetate resin" shown in Fig. 6 in a predetermined solvent is mixed into the obtained dispersion liquid, and a predetermined amount of vinyl acetate resin is mixed as a solid component. was applied onto the intermediate layer by dip coating and sufficiently dried to form a CGL having a thickness of 0.4 μm.

Next, in experiment ①, CTM (I) was changed to the following CTM
(III), except that the thickness was 20 μm.
CTLs were formed.

Electrophotographic photoreceptor m-A of the example thus produced
, III-B, and Comparative Example Photoreceptors ■-a and [[-b were subjected to the same measurements as in Experiment ■. The results are shown in FIG. However, regarding S input, for photoconductor m-A, the value is shown assuming that the S input value of photoconductor m-a is 1.00, and for photoconductor I[[-B, the value is shown when the S input value of photoconductor m-a is The values are shown when the value of Sλ of body 1-S is set to 1.00.

CGM (I[[) τ-type metal-free phthalocyanine CTM (III) [Experiment■] An intermediate layer was formed in the same manner as in Experiment I.

Next, a carrier generation layer and a carrier transport layer were sequentially coated and formed on the intermediate layer in the same manner as in Experiment 2 except that CGM (III) in Experiment 2 was replaced with CGM (N).

Electrophotographic photoreceptor IV- of the example thus produced
The same measurements as in Experiment I were carried out on Photoreceptors A, IV-B, and Comparative Example Photoreceptors IV-a and IV-b. The results are shown in FIG. However, for S input, photoconductor 1f-A
is expressed as a relative value when the S input value of photoconductor IV-a is set to 1.00, and for photoconductor ■-B, it is expressed as a relative value when the S input value of photoconductor IV-a is
It is expressed as a relative value when the value of S% of V-b is set to 1600.

CGM (IV) x-form metal phthalocyanine [Experiment■] An intermediate layer similar to Experiment ① was provided.

Next, 75 parts by weight of the CTM (If) and 100 parts by weight of polycarbonate "Panrye 1-1300J (manufactured by Mitsubishi Chemical Industries, Ltd.) were mixed with 76 parts by weight of 1,2-dichloroethane.
The resulting solution was applied onto the intermediate layer by dip coating, and dried at a temperature of 80'C for 1 hour to form a CTL with a thickness of 20 μm.

Next, 50 parts by weight of CGM (1) shown in FIG. 7 was ground in a ball mill for 24 hours, and a predetermined [binder resin other than vinyl acetate resin] shown in FIG.
- A solution dissolved in 1750 parts by weight of dichloroethane was added and further dispersed in a ball mill for 24 hours. To this dispersion, 75 parts by weight of CTM (II) was added, further 750 parts by weight of monochlorobenzene, and a solution of "vinyl acetate resin" shown in FIG. ) was added to prepare a coating liquid. This coating liquid was spray coated onto the carrier transport layer to obtain a carrier generation layer having a thickness of 5 μm.

Electrophotographic photoreceptor V-A of the example thus produced
, Experiments were conducted on the photoreceptor V-a of the comparative example in 1. It is expressed as a relative value when OO. The results are shown in FIG.

[Experiment■]

First, an intermediate layer similar to Experiment I was formed.

Next, 50 parts by weight of CGM (II) shown in FIG.
A solution prepared by dissolving a predetermined amount of the binder resin shown in the figure in 1750 parts by weight of 1°2-dichloroethane was added and dispersed for 8 hours using a sand grinder.

To this dispersion, 75 parts by weight of the following CTM (m) was added, and a solution (containing a predetermined amount of vinyl acetate resin as a solid component) in which "vinyl acetate resin" shown in Fig. 7 was dissolved in a predetermined solvent was added. ) was added to prepare a coating solution.

This coating solution was dip coated onto the intermediate layer to a thickness of 15 mm.
A photosensitive layer of μm was obtained.

Electrophotographic photoreceptor Vl- of the example thus produced
A. Regarding the photoreceptor Vl-a of Comparative Example, the same measurements as in Experiment ① were carried out. However, regarding the S value of photoreceptor Vl-A in the example, the value of eight people for photoreceptor VI-a was 1.00.
It is expressed as a relative value when The results are shown in FIG.

Note that the resins shown in FIGS. 6 and 7 are the same as each resin shown in FIG. 5.

As is clear from the above experimental results, the photoreceptor of the example has good photosensitivity and is particularly excellent in white paper potential (L).

[Experiment■]

The following experiment was conducted using the photoreceptor formulation described in Experiment (2).

That is, in the same manner as described in the experimental summer, 50 parts by weight of polycarbonate resin, vinyl acetate resins ■, ■, ■, and CG
An electrophotographic photoreceptor having a carrier generation layer containing 100 parts by weight of M (1) was prepared.

The value calculated based on 100 parts by weight of fat was varied.

was measured. However, the S value was a relative value with the S content being 1.00 when the vinyl acetate resin content ratio was 0 parts by weight.

The results are shown in FIG.

Although the resin used in the intermediate layer was a vinyl chloride/acetic acid/bimaleic acid copolymer, the same results were obtained regardless of the presence or absence of the resin.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are sectional views of each photoreceptor. Figures 5, 6, and 7 are graphs showing the electrophotographic sensitivity. Figure 8 is a graph showing the relationship between the amount of potential attenuation per unit energy during light irradiation and the amount of vinyl chloride resin added in the xeria generation layer. be. In addition, in the reference numerals shown in the drawings, 1---------1--Conductive support 2---Charge generation l (CGL)3 ・--
11---Charge transport layer (CTL) 4A, 4B, 4D
------1 Photosensitive layer 5-1 -1 Surface (protective) layer (
OCL). Agent Patent Attorney Hiroshi Aisaka＾11'n ＋

Claims (1)

[Claims] 1. A carrier generating substance and a vinyl acetate resin (however, in the case of a copolymer resin, the proportion of vinyl acetate, which is a monomer of the resin, is 50% by weight or more) and a resin other than the vinyl acetate resin. A photoreceptor having a layer containing.