JPS58118650A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To provide spectral sensitivity from visible to IR regions and to improve durability by providing an electric charge generating layer and an electric charge transport layer on a conductive substrate and using the electric charge generating layer as a photosensitive layer contg. a specific cyanine dye. CONSTITUTION:An aq. ammonia soln. of casein is coated on a conductive substrate of an aluminum plate or the like and is dried, whereby an undercoating layer is provided. Then, a resin soln. wherein 1 kind of the cyanine dyes expressed by the formulas (I) and (II) is dispersed in an ethanol soln. of a butyral resin is obtained. The resin soln. contg. the cyanine dye is coated on the undercoating layer and is dried to form an electric charge generating layer. Further a soln. prepd. by dispersing a hydrazone compd. in a polycarbonate resin soln. is coated on the charge generating layer and is dried to form an electric charge transport layer, whereby an electrophotographic receptor is obtained. This receptor has spectral sensitivity from visible to IR regions and provides the electrophotographic receptor having high durability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved electrophotographic photoreceptor,
In particular, this book concerns an electrophotographic photoreceptor having a laminated structure in which a layer for generating charges and a layer for transporting TA charges are separated in function.

Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been used as photoconductive materials for photoreceptors.
L-characteristic materials are known. These photoconductive materials have many advantages: they can be charged to an appropriate potential in the dark, they have little charge dissipation in the dark, and they quickly dissipate charge when exposed to light. Although it has advantages such as being able to do so, it also has various disadvantages. For example, with a selenium-based photoreceptor, the IhK value may change due to factors such as temperature, humidity, dust, and pressure.
Crystallization progresses, and particularly when the ambient temperature exceeds 40° C., crystallization becomes significant, resulting in disadvantages such as a decrease in charging performance and the appearance of white spots on images. Furthermore, selenium-based photoreceptors and cadmium sulfide-based photoreceptors have the disadvantage that stable durability cannot be obtained when used over time under high humidity.

One drawback of these sensitizing dyes is that they cannot provide stable images over a long period of time because they cause charge deterioration due to corona charging and photobleaching due to exposure light.

On the other hand, various organic photoconductive polymers including polyvinylcarbazole have been proposed, but these polymers lack film-forming properties and light weight compared to the aforementioned inorganic photoconductive materials. Despite the superiority of K, its practical application to this day is f! This was because they were inferior to inorganic photoconductive materials in terms of sensitivity, durability, and stability against environmental changes.

For these reasons, proposals have recently been made to form a laminated structure in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer. For example, the following electrophotographic photoreceptors are known which have this laminated structure as a photosensitive layer.

(1) The charge generation layer is composed of a layer containing a squaric acid methine dye, and the charge transport layer is composed of a layer containing a triarylpyrazoline compound (Japanese Patent Application Laid-Open No. 105536/1983).

(2) The charge generation layer is composed of a layer containing Diane Blue, and the charge transport layer is a layer containing 2,5-bis-(p-diethylamide/phenyl)-1,3,4-oxadiazole. (Japanese Unexamined Patent Publication No. 48-6.
6444).

(The 31111N generation layer was composed of a vapor-deposited layer of Perrin thread pigment, and the IIE transport layer was composed of a layer containing 2,5-his-(P-diethylamine/phenyl)-1,3,4-oxadiazole. Things (Unexamined Fi49-4833
Publication No. 4).

A (4) I
However, few of these conventionally known electrophotographic photoreceptors still provide sufficient sensitivity, and the surface may deteriorate when repeatedly charged and exposed. Fluctuations in potential, especially during edge-reverse exposure and charging, can cause an increase in bright area potential and a decrease in dark area potential, and changes in the environment, especially humidity fluctuations, can cause changes in the sensitivity of the photoreceptor. It has the disadvantage that the image quality changes.

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel electrophotographic photoreceptor that can overcome the above-mentioned drawbacks and mechanical disadvantages.

Another object of the present invention is to provide a highly sensitive electrophotographic photoreceptor. Another object of the present invention is to provide an electrophotographic photoreceptor having spectral sensitivity from the visible region to the infrared region.

Another object of the present invention is to provide a highly durable electrophotographic photoreceptor.

Another object of the present invention is to provide an electrophotographic photoreceptor that exhibits stable characteristics against fluctuations in humidity. Probably.

This object of the present invention is achieved by a photoreceptor for an electronic harp having a charge generation layer containing a cyanine dye represented by the following general formulas (1) and ω).

In the general formula, RI and R1 represent an alkyl group (e.g., methyl group, ethyl group, n-propyl group, 160-propyl group,
n-butyl group, 1.0-butyl group, 18゜butyl group,
t-butyl group, amyl group, 1-amyl group, n-hexyl group, n-octyl group, t-octyl group, etc.), substituted alkyl groups (e.g. 2-hydroxyethyl group, 3-hydroxypropyl group) \4-Hydroxybutyl group, 2-acetoxyethyl group, carboxymethyl group, 2-carboxyethyl group, 3-carboxypropyl group, 2-sulfoethyl group, 3-sulfopropyl group, 4-sulfobutyl group, 3
-sulfate brobyl group, 4-sulfate butyl group, M-(methylsulfonyl)-lupamylmethyl iE,
3-(acetylsulfamyl)propyl group, 4-(acetylsulfamyl)butyl group, etc.), cyclic alkyl group (for example, cyclohexyl group, etc.), allyl group (on!
=on -OH,-), aralkyl group (e.g., benzyl group, phenethyl group, α-su7tyl methyl group, β-
(7-tylmethyl group, etc.), substituted aralkyl group (e.g.,
carboxybenzyl group, sulfobenzyl group, hydroxybenzyl group, etc.), ary A/ group (e.g., phenyl group, etc.) or #'i-substituted aryl group (e.g., carboxyphenyl group, sulfophenyl group, hydroxyphenyl group, etc.) . Particularly in the present invention, among these organic residues, hydrophobic ones are preferred.

zl and 2. is a substituted or unsubstituted heterocycle, for example, a thiazole series nucleus (e.g. thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5 -dimethylthiazole, 4 (2-
chenyl)-thiazole, etc.), benzothiazole series nuclei (e.g. h-benzothiazole, 5-chlorobenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5,6-dimethylbenzothiazole, 5
-bromobenzothiazole, 5-phenylbenzothiazole, 5-methoxybenzothiazole, 6-methoxybenzothiazole, 5,6-simethoxybenzothiazole, 5,6-dijxymethylenebenzothiazole, 5- and dioxybenzo thiazole, 6-hydroxybenzothiazole, 4°5.6.7-teF-rahydropenzothiazole, etc.), naphthothiazole series nuclei (e.g. naphtho(
2,1-a) thiazole, na7) (1,2-d) thiazole, 5-methoxynaphtho (1,2-(1) thiazole, 5-ethoxynaphtho(1,2-d) Thiazole, 8-methoxynaphtho(2,1-11)thiazole, 7
-Medoxina 7) (2,1-4) thiazole, etc.), thionaphthene (7,6-(L) thiazole series Cedar (e.g. 7-medoxythionaphthene (7,6-a) thiazole), oxazole series Nuclei (e.g. 4-methyloxazole, 5-methyloxazole, 4-phenyloxazole, 4.5'-dimethyloxazole, 4-ethyloxazole, 4; 5-dimethyloxazole, 5
-phenyloxazole), benzoxazole series nuclei (e.g. benzoxazole, 5-chlorobenzoxazole, 5-methylbenzoxazole, δ-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylpenzoxazole, 5-methoxybenzoxazole, 6-methoxybenzoxazole, 5-and-droxybenzoxazole, 6-hydroxybenzoxazole, etc.), nandoxazole series nuclei (e.g. naph) (2,1-a,) oxazole,
(7) (1,2-d)oxazole, etc.), selenazole series nuclei (e.g. 4-methyloxazole, 4-phenylselenazole, etc.), benzoselenazole series cedar (e.g. ttl'benzoselenazole, 5- Chlorobenzoselenazole, 5-methylbenzoselenazole, 5.6
-Simethylbenzoselenazole, 5-methoxybenzoselenazole, 5-methyl-6-methoxybenzoselenazole, 5,6-cyoxymethylenebenzoselenazole,
5-hydroxybenzoselenazole, 4,5,6.7-
trihydrobenzo-selenazole, etc.), naphthoselenazole series nuclei (e.g., s7to(2+ 1-a) selenazole, natto(1,2-a) selenazole) 1, thiazoline series nuclei (e.g. thiazoline, 4- methylthiazoline, 4-hydroxymethyl-4-methylthiazoline, 4.4-bis-hydroxymethylthiazoline, etc.),
Oxazoline series nuclei (e.g. oxazoline), selenazoline series nuclei (e.g. selenazoline), 2-quinoline series nuclei (e.g. quinoline, 6-methylquinoline, 6-
4-quinoline series (e.g. quinoline, 6-medoxyquinoline, two-methylquinoline, 8-methylquinoline), l-isoquinoline series nuclei (e.g. isoquinoline, 3°4-dihydroisoquinoline), 3-ink/phosphorus series nuclei (e.g. isoquinoline), 3,3-dialkylindolenine series nuclei (e.g. 3,3-dimethylindolenine, 3. 5-dimethyl-5-chloroisodorenine, 3,3,5-)dimethylindolenine, 3,3,7-)limethylindolenine, pyridine series nuclei (e.g. pyridine, 5-methylpyridine), benzimidazole series nucleus (e.g. 1-ethyl-5,6-dichlorobenzimidazole, 1-hydroxyethyl/%'-5,6-dichlorobenzimidazole, 1-ethyl-5-chlorobenzimidazole, 1-
Ethyl-5,6-dibromobenzimidazole, l-ethyl-5-7dynylpenzimidazole, 1-ethyl-
5-fluorobenzimidazole, l-ethyl-5-cya/benzimidazole, l-(β-acetoxyethyl)-5-cyanobenzimidazole, 1-ethyl A/-
5-chloro-6-cya/benzimidazole, l-ethyl-5-fluoro-6-cya/benzimidazole, l
-ethyl-5-acetylbenzimidazole, l-ethyl-5-carboxybenzimidazole, 1-ethyl-
5-Ethoxysulfonylbenzimidazole, 1-ethyl-5-sulfamylbenzimidazole, 1-ethyl-5-N-ethylsulfamylbenzimidazole, l
-ethyl-5,6-difluoropenzimidazole, l
-ethyl-5,6-dicyatupenzimidazole, l-
Ethyl-5-ethylsulfonylbenzimidazole, l
-ethyl-5-methylsulfonylbenzimidazole,
1-ethyl-5-trifluoromethylbenzimidazole, 1-ethyl-5-trifluoromethylsulfonylbenzimidazole, 1-ethyl-5-trifluoromethylsulfinylbenzimidazole, etc.). represent t is chloride ion, bromide ion, miranide ion, perchlorate ion, benzenesulfonate ion, P-toluenesulfonate ion, methyl sulfate ion, ethyl sulfate ion, propyl sulfate ion. represents an anion such as ion, xC)F
lR, and/or R1 itself is an anionic group, such as -so, θ, oso, <q-0000・SξNH-1-
It does not exist when it contains 8O, -M-00-1-8O7-so-8O□-. --1 represents a cation such as a hydrogen cation, sodium cation, ammonium cation, potassium cation, or pyridium cation.

Next, representative examples of cyanine dyes used in the present invention are listed below, and for convenience, they are represented by a betaine structure.

However, in the preparation of these dyes, mixtures of dyes in betaine or salt form are obtained and are therefore used as mixtures.

These cyanine dyes can be used alone or in combination of two or more.

In addition, these cyanine dyes are
As described in Publication No. 1, for example, the combination of croconic acid or its derivatives (e.g. mono- and dialkyl esters) with 2-methyl-cycloammonium quaternary salts or the corresponding 2-methylene bases known in the field of cyanine dye chemistry. Can be prepared by condensation.

The cyanine-dyed fP4 used in the present invention can be dispersed in a binder to form a charge generation layer.

Examples of the binder used in this case include polyester, polycarbonate, polyvinyl butyral, polymethyl methacrylate, polyvinyl chloride, polyamide, chlorinated rubber, polyvinylidene chloride, polystyrene, polyvinylpyridine, styrene-maleic anhydride copolymer, and the like.

As the solvent for these binders, it is preferable to use, for example, benzene, toluene, xylene, mesitylene, monochlorobenzene, hetetrahydrolane, tyrene, or the like.

The proportion of the binder in the charge generation layer is 80% by weight or less, preferably 50% by weight or less of the total weight of the charge generation layer.
Particularly suitable is a weight of 40 kg or less.

As a method for dispersing the cyanine dye in the binder, a ball mill dispersion method, an attritor dispersion method, a sand mill dispersion method, etc. can be used.
It is effective to set the particle size to preferably 2 microns or less, and the optimum Ktf051 to 4 microns or less.

The thickness of the charge generation layer used in the present invention is generally about 0.1 to 2 microns, particularly about 0.5 microns. Also,
The charge generation layer is formed by applying the above-mentioned binder composition in which the cyanine dye is dispersed onto a suitable support by a double blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method. It can be obtained by using a coating method such as a coating method.

When dispersing the aforementioned cyanine dye in the binder,
A suitable surfactant, especially a nonionic surfactant, can be used in combination. Suitable nonionic surfactants include, for example, saponin, polyethylene glycol monostearate, polyethylene glycol monolaurate, polyethylene glycol distearate, polyethylene glycol dilaurate, nrubitan monolaurate, sorbitan monopalmitate, nrubitan. Monostearate, sorbitan sesquiolate, sorbitan triolate, glycerol monostearate, diethylene glycol monostearate, glycolamide stearate, myristic acid jetanolamide, coconut fatty acid jetanolamide,
Polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monolaurate, etc. can be used.

Further, the charge generation layer of the present invention can be a film of the above-mentioned cyanine dye formed by a vacuum deposition method.

In the electrophotographic photoreceptor of the present invention, a charge transport layer can be provided on the charge generation layer described above. This charge transport layer is formed by containing a charge transport material in a suitable binder. Although it can be a charge transport material, hole transport materials such as hydrazone compounds or pyrazoline compounds are particularly suitable in the present invention.

The above-mentioned hydrazone compound is particularly preferably a compound represented by the following general formula 11 (2) or (vl).

General formula % formula % () In the formula, Mu, U phenyl group, naphthyl group, aralkyl group,
Aryl groups such as pyrenyl groups, or pazole rings,
Represents a monovalent heterocyclic group derived from a heterocycle such as a 7-ran ring, a thiophene ring, a pyridine ring, a phenothiazine ring, a phenoxazine ring, a benzimidazole ring, a benzothiazole ring, a benzoxazole ring, and these aryl groups are , dimethylamino group, 7 diethylamide groups, 7 dipropylamino groups, dibutylamino group, 7 dibenzylamide groups,
7 diethyl amide groups, 7 diphenyl amine groups, 7 ditolyl amine groups
group, a di-substituted amino group such as a di-substituted amino group, a cyclic amide group such as a pyrrolidino group, a piperidino group, a morphorif group, etc.
groups, acol*oxy groups such as methoxy, ethoxy, propoxy, and butoxy groups, alkyl groups such as methyl, ethyl, propyl, butyl, and amyl groups, chlorine atoms, bromine atoms,
It may be substituted by a halogen atom such as an iodine atom.
. A! and alkyl groups such as mu, ke, methyl, ethyl, propyl, butyl, and amyl groups, phenyl groups,
It represents an aralkyl group such as a naphthyl group, a benzyl group, a 7enehthyl group, or a naphthylmethyl group.

These are substituted with alkyl-substituted amino groups such as methoxy, ethoxy, propoxy, and butoxy groups, di-alkyl-substituted amino groups such as dimethylamino, diethylamide 7, dipropylamino, and dibutylamino groups, and hydroxy groups. Furthermore, the aryl group and aralkyl group may be substituted with an alkyl group such as a methyl group, ethyl group, propyl group, butyl group.

A4Fi, phenyl group having as a substituent a di-substituted amino group such as di-substituted amino group, diethylamino group, dipropylamino group, seven diethylamino groups, dibenzylamino group, ditolylamino group, etc. 1 carbazole ring, pyridine ring, 7-ran ring, thiophene represents a monovalent heterocyclic group derived from a bicyclic ring such as a ring, an indole ring, a benzimidazole ring, a benzimidazole ring, or a benzothiazole ring, and can be substituted with an appropriate atom or organic residue. is a phenyl group, which can be substituted with a suitable atom or organic residue.

Preferred substituents include methoxy group, ethoxy group,
These include alkoxy groups such as propoxy group and butoxy group, dimethylamino group, diethylamino group, di-substituted amino group, dibutylamino group, dibenzylamino group, diphenylamino group, and diphenylamino group.

is carbazole ring, oxazole ring 1 benzoxazole ring, naphthoxazole ring, thiazole ring, benzothiazole ring, naphthothiazole ring, indole ring, imidazole ring, benzimidazole ring, benzoselenazole ring, naphthoselenazole ring, quinoline l derived from ring, phenoxazine ring, phenothiazine ring, etc.
ftJ (D@represents a bare ring group, which may be substituted with an appropriate atom or organic residue. M? represents a substituted or unsubstituted alkyl group (e.g., methyl group, ethyl group, propyl group, 1sO -Propyl group, butyl group, t-butyl group, amyl group, t-amyl group, octyl crystal, 2-ethylhexyl group, 2-hydroxyethyl group, 2-methoxyethyl group, 2-chloroethyl 1.3-hydroxyethyl group , 3-methoxypropyl group, 4-methoxybutyl group, 3-sulfopropyl group), substituted or unsubstituted aralkyl group (for example, benzyl group, 7ene-thyl group,
α-su7tylmethyl group, chlorobenzyl group, dichlorobenzyl group, trichlorobenzyl group, ethylbenzyl group,
methoxybenzyl group, cyanobenzyl group, etc.) or substituted or unsubstituted aryl group (e.g., phenyl group,
Tolyl group, xylyl group, biphenyl group, ethylphenyl group, methoxyphenyl group, dimethoxyphenyl group, 44 phenyl group, dichlorophenyl group, trichlorotetraphenyl group, cyanophenyl M, brw-di-methylaminophenyl group, M, M-diethylamino 7-ethyl group, MeM
-di-propylaminophenyl group, M, M-dibenzylaminophenyl group, morpholinophenyl group, piperazinophenyl group, virolidi/phenyl l&etc.).

2 is a heterocyclic ring (e.g., thiazoline ring, thiazole ring, benzothiazole ring, naphthothiazole ring, oxazole ring, oxazoline ring, benzoxazole ring, naphthoxazole ring, imidazole ring, benzimidazole ring, natimidazole ring) , benzoselenazole ring, naphthoselenazole ring, indoline ring, 2-quinoline ring, 4-quinoline ring, 2-pyridine ring, 4-pyridine ring, triazole ring, thiadiazole ring, inbenzimidazole amount, inbenzoxazole ring, etc. ) is shown below. These complex ratios are halogen atoms (e.g. chlorine atom, bromine atom, iodine atom, etc.),
Alkyl groups (e.g., methyl, ethyl, propyl, butyl, amyl, octyl, etc.), alkoxy groups (e.g., methoxy, ethoxy, propoxy,
butoxy group), aryl group (e.g. phenyl group,
tolyl group, xylyl group, lysylophenyl group, bromophenyl group, etc.), nitro group, cyano group, hydroxy group, amine 7 group, alkylamino 7 group (for example, N-methylamino group, N-ethylamino group, N - You can also be.

Also, nriO'g! or 1.

Hydra (32) suitable for use in the charge transport layer of the present invention In addition, the above-mentioned pyrazoline compound is particularly suitable for the following general formula (ν
Preferably, the compound represented by ρ is ψ.

General formula (Vj J:?4 J1 In the formula, D□ (ri represents a monovalent hetero ll group derived from an aryl group such as a phenyl group, or a heterocyclic ring such as a pyridine ring, a quinoline ring, or a benzothiazole ring; A phenyl group or a ring group, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, or an alkoxy group such as an oxy group, an ethoxy group, a propoxy group, a butoxy group, etc. Moyo-Ikuma and Ri represent a monovalent heterocyclic group derived from an aryl group such as a phenyl group, or a heterocycle such as a furan ring, a thiophene ring, a pyridine ring, or a carbazole ring.This heterocyclic group may be substituted with a suitable atom or organic residue.

In particular, di-substituted amino groups as described above are used. i
)4 and RI are hydrogen atoms, alkyl groups, (for example,
methyl group, ethyl group, propyl group, butyl group, amyl group, etc.), aralkyl group (el, ttf benzyl group, 7enethyl group, naphthylmethyl group, etc.) or aryl group (
For example, phenyl group, tolyl group, 1,000 silyl group, etc.), and the alkyl group, aralkyl group and aryl group may be substituted with a suitable atom or organic residue. m#″lt.

0 or /Ii1.

Representative examples of these pyrazoline compounds are shown below.

These hydrazone compounds or pyrazoline compounds are
It can be used alone or in combination of two or more, and it can also be used in combination with a hydrazone compound and a pyrazoline compound. -ethylcarbazole,
N-isopropylcarnoxole, 2,5-bis(p-
diethylaminophenyl)-1,3,4-oxadiazole, triphenylamine, poly-N-vinylcarbazole, helogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinyanthracene, polyvinyl acridine, poly-9-vinyl 7-ethyl El anthracene,
Pyrene-formaldehyde resin, ethyl carbazole formaldehyde resin, etc. can also be used as charge transport materials.

The charge transport layer used in the present invention is preferably formed by applying a solution prepared by dissolving the above-mentioned charge transport substance and binder in a suitable solvent and drying the solution. Binders used here include polysulfone, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin, polycarbonate, polyurethane, or repeats of these resins. Examples include copolymer resins containing two or more of the units, with polyester resins and polycarbonates being particularly preferred. Photoconductive polymers which themselves have heavy transport capabilities, such as poly-N-vinylcarbazole, can also be used as binders.

The blending ratio of the binder and the charge transport compound is 1
It is preferable that the amount of the charge transport compound is 10 to 5001jL per 00 parts by weight. The thickness of this charge transport layer is 2~
100 microns, preferably 5-30 microns.

In addition, the coating method used when providing the charge transport layer is the usual method such as blade coating method, Mayer-Per coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method, etc. can be used.

Further, the solvent used in forming the charge transport layer of the present invention includes many useful organic solvents. Typical examples include aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, and chlorobenzene, ketones such as acetone and 2-butanone, and halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, and ethylene chloride. Examples include hydrocarbons, cyclic or linear ethers such as tetrahydro7rane, ethyl ether, and mixed solvents thereof.

The charge transport layer of the present invention can contain various additives. Such additives include diphenyl, diphenyl chloride, 0-terphenyl, p-terphenyl, dibutyl heptatarate, dimethyl glycol hetatalate, dioctyl heptatarate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, dimethyl laurylthiopropionate, 3,5-dinitrosalicylic acid,
Various fluorocarbons, silicone oil, silicone rubber (diptylated hydroxydoluene, 2゜2'-
Methylene-bis-(6-t-butyl-4-methylphenol, α-toph7erol, 2-t-octyl-5-
Examples include phenolic compounds such as chlorohydroquinone and 2,5-di-t-octylhydroquinone.

The electrophotographic photoreceptor of the present invention has the general formula CI) or if
A vapor-deposited layer or a coating layer of the cyanine dye shown in (11) is provided on a suitable support to form a charge generation layer, and a coating layer containing the above-mentioned charge transport substance is laminated on top of this charge generation layer. It can be prepared by In this type of electrophotographic photoreceptor, a suitable intermediate layer may be provided on a support, the above-mentioned charge generation layer may be provided through this, and the above-mentioned Kajiir$11 transport layer may be formed thereon. ψ. This intermediate layer prevents the injection of free charges from the conductive support to the photosensitive layer when the photosensitive layer made of laminated Sakaki structure is charged, and also allows the photosensitive layer to be integrally adhered and held to the conductive support. It acts as an adhesive layer. This intermediate layer is made of aluminum oxide, indium oxide, tin oxide, indium oxide-tin oxide mixture, polyethylene, polypropylene, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenolic resin, epoxy resin, polyester resin. , alkyd resin, polycarbonate, polyurethane, polyimide resin, vinylidene chloride resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol, water-soluble polyethylene, nitrocellulose, casein, gelatin, etc. can be used. The thickness of this intermediate layer or adhesive layer is suitably between 5 and 5 microns, preferably between 5 and 3 microns.

Further, the electrophotographic photoreceptor of the present invention may have a woven resin layer structure in which a charge generation layer is provided on a charge transport layer. At this time, polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin 1 epoxy resin, polyester resin, alkyd resin, polycarbonate, polyurethane, polyimide resin, vinylidene chloride resin are used on the charge generation layer. It is also possible to provide a protective layer made of vinyl chloride-vinyl acetate copolymer or the like.

In addition, in the electrophotographic photoreceptor of the present invention, in order to uniformly inject carriers into the charge transport layer above the charge generation layer, the surface of the charge generation layer may be polished to a mirror finish, if necessary. can. As the mirror finishing method, for example, the method disclosed in Japanese Patent Application Laid-Open No. 155356/1984 can be used.

The support used in the electrophotographic photoreceptor of the present invention may be any support as long as it is endowed with conductivity, and any type of conductive layer conventionally used may be used. Specifically, metal sheets such as aluminum, vanadium, molybdenum, lime, cadmium, titanium, nickel, copper, zinc, palladium, indium, tin, platinum, gold, stainless steel, brass, etc. - Examples include laminated plastic sheets. Further, its shape may be sheet-like, cylindrical, or other shapes.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in a wide range of electrophotographic applications such as laser printers, CRT printers, and electrophotographic plate making systems.

According to the present invention, the sensitivity is significantly higher than that of conventional electrophotographic photoreceptors, and even when repeatedly charged and exposed to light of 10ρ00tgI or more, the bright area potential increases and the dark area potential decreases. do not have. In addition, there is no change in sensitivity due to changes in humidity, and it has excellent environmental stability.

The present invention will be explained below according to examples.

Example 1 Ammonia aqueous solution of casein (casein 1
1.2 g, 28% ammonia water, 11% water, 222 aJ) was applied with a Mayer bar and dried, coating amount: 1.2g. An adhesive layer of Og/Wl was formed.

Next, among the cyanine dyes exemplified above, 5 g of cyanine dye A (5+) was added to butyral resin (butyralized g
The mixture was added to a solution consisting of 2 g of t63 mol %) and 95% of ethanol, and dispersed in a ball mill for 40 hours. The thus obtained dispersion was applied onto the adhesive layer using a Mayer bar so that the coating amount after drying was 0.2 J/d to form a charge generation layer.

Then, among the hydrazone compounds exemplified above,! (
5 g of the hydrazone compound of 1) was added to a solution consisting of 5 g of poly-4°4'-dioxydiphenyl-2,2'-propane carbonate (molecular weight: 30,000) and 701 of tetrahydrofuran and dissolved therein. This solution was applied onto the previously obtained charge generation layer using a Mayer bar so that the coating amount after drying was 1 Og/Wt to form a charge transport layer.

In this way, an electrophotographic photoreceptor having a charge generation layer and a charge transport layer was prepared, and the electrophotographic photoreceptor was heated at a temperature of 20°C and a relative humidity of 6°C.
After conditioning the humidity at 5%, use Seikan Copying Paper Test System @ manufactured by Kawaguchi Heavy Industries ■.
[moa·l SF-428J was used to statically apply corona charging to −5 volts, and after holding in a dark place for 10 seconds, the charging characteristics were examined when exposed to light at an illuminance of 5 lux. At this time, the initial voltage is VO (-volt), the potential retention rate for 10 seconds in the dark is Vk (%), and the charging voltage is the initial voltage 1'.

The charging characteristics were measured by setting the required exposure amount to 1/2 of E1 (with look on, seconds). The results are shown in Table 1.

Table 1 Vo' -580 volts vk: 88% 11i1/2: 4.3 Lux·sec Example 2 In place of the cyanine dye layer (5) used in Example 1, a cyanine dye from among the cyanine dyes described above was used. An electrophotographic photoreceptor was prepared in exactly the same manner as in Example 1 except that an Aa sickle was used, and then its charging characteristics were measured. This result is the second
Shown in the table.

Table 2 Vo: -550 Volts VK: 87% Town/2: 4.8 Lux・sec Example 3 Aluminum drum with a diameter of 120φ T casein water% g
and water 22211/) and coated on this Alce drum with a coating amount of 1. A casein adhesive layer of Og/sr was formed.

Next, 1. Of the cyanine dyes exemplified above, 5 g of AQG cyanine dye was added to butytail resin (butyralization degree 63).
This was added to a solution consisting of 2 g (mol%) and 95 w of ethanol, and this was dispersed in a ball mill for 40 hours. The thus obtained dispersion was applied onto the adhesive layer by dip coating so that the coating weight after drying was 0.2 g/111 to form a charge generation layer.

Then, among the hydrazone compounds exemplified above, mu(
5gt bis7 enol of the hydrazone compound of 1) was copolymerized with terephthalic-iso7tal alcohol and dissolved.

This solution was applied onto the previously obtained charge generation layer by a dip coating method so that the coating amount after drying was Log/G to form a charge transport layer.

The characteristics of band 11 of the electrophotographic photoreceptor thus prepared were measured in the same manner as in Example 1. The results are shown in Table 3.

Table 3 yo: -600 volts yk: 89% ``I/!: 4.5/l/tux・sec implementation f
I14-14 An electrophotographic photoreceptor was prepared in the same manner as in Example 3, except that the cyanine dye A (LQ) used in Example 3 was replaced with the cyanine dye listed in Table 4 below. The electrification characteristics were measured using Example 1 and Ichikawa's method.These results are also listed in Table 4. instead”
Cs Using the hydrazones listed in Table 5 above, an electrophotographic photoreceptor was prepared in exactly the same manner as in Example 1, and its charging characteristics were determined in the same manner as in Example 1. It was measured with

These results are also listed in Table 5.

Table 5 Example 22 In place of the hydrazone compound used in Example 1, the following
Example 1 shows how the pyrazoline compounds listed in the table were used.
An electrophotographic photoreceptor was prepared in exactly the same manner as in Example 1, and its charging characteristics were measured in the same manner as in Example 1. These results are shown in Table 6.

Table 6 Patent applicant Canon Co., Ltd.

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor having a charge generation layer and a charge transport layer, wherein the charge generation layer contains at least one cyanine dye represented by the following general formulas (1) and [1). Characteristic electrophotographic photoreceptor. General formula (wherein R1 and R1 represent a substituted or unsubstituted alkyl group, a cyclic alkyl group, an allyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.2. and Z, H1 represents the nonmetallic atomic group necessary to complete the substituted or unsubstituted heterocycle.
The cation is shown and the 9th digit is the anion. )