JP3064594B2 - Electrophotographic photoreceptor, electrophotographic apparatus provided with the electrophotographic photoreceptor, and facsimile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, an electrophotographic apparatus provided with the electrophotographic photosensitive member, and a facsimile, and more particularly, to an electrophotographic photosensitive member having a photosensitive layer containing an azo pigment having a specific structure. And an electrophotographic apparatus and a facsimile provided with the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art Conventionally, an electrophotographic photoreceptor using an inorganic photoconductor such as selenium, cadmium sulfide, or zinc oxide as a photosensitive component has been known. On the other hand, a number of organic photoconductors have been developed since the discovery that specific organic compounds exhibit photoconductivity. For example, organic photoconductive polymers such as poly-N-vinyl carbazole and polyvinyl anthracene, carbazole, anthracene, pyrazolines,
Low molecular organic photoconductors such as oxadiazols, hydrazones, arylalkanes, and phthalocyanine pigments;
Organic pigments and dyes such as azo pigments, cyanine pigments, polycyclic quinone pigments, perylene pigments, indigo pigments, thioindigo pigments, and squaric acid methine dyes are known. In particular, organic pigments and dyes having photoconductivity are easier to synthesize than inorganic materials, and the variety in which compounds exhibiting photoconductivity in an appropriate wavelength range can be selected has been expanded. Photoconductive organic pigments and dyes have been proposed. For example, U.S. Pat. Nos. 4,123,270, 4,247,614 and 4,251,613.
No. 4,251,614, No. 4,256
No. 821, No. 4,260,672, No. 42
Azo pigments exhibiting photoconductivity as a charge generating substance in a photosensitive layer functionally separated into a charge generating layer and a charge transporting layer as disclosed in JP-A-68596, JP-A-4278747 and JP-A-4293628. An electrophotographic photoreceptor using the same is known. Also, U.S. Pat.
No. 9981, No. 4,352,876, No. 4,356,243, No. 4,390,611, No. 4,418,133, No. 4,436,800, No. 4,439,506, No. 44475.
No. 13, No. 4471040, No. 44
No. 95264, No. 4,551,404, No. 4,571,369, No. 4,587,271, No. 4,599,287, No. 4,600,674, and the like. Known as charge generating substances.

An electrophotographic photoreceptor using such an organic photoconductor can be produced by coating by appropriately selecting a binder, so that an extremely high productivity and inexpensive photoreceptor can be provided. It has the advantage that the photosensitive wavelength range can be freely controlled by selecting a pigment, and thus has been rapidly commercialized in recent years. However, such a conventional electrophotographic photoreceptor cannot be said to be sufficient in terms of sensitivity and potential stability upon repeated use, and only very few materials have been put to practical use.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel photoconductive material, and to provide an electrophotographic photoreceptor having practical high sensitivity characteristics and stable potential characteristics in repeated use. An object of the present invention is to provide an electrophotographic apparatus and a facsimile provided with an electrophotographic photosensitive member.

[0005]

According to the present invention, there is provided an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer comprises an organic residue represented by the following general formula (1): And an azo pigment having a structure bonded to an aromatic hydrocarbon ring or an aromatic heterocyclic ring which may be substituted and which may have a substituent. General formula (1)

Embedded image (In the formula, X ₁ is required to be condensed with a benzene ring in the formula to form an optionally substituted anthracene ring, carbazole ring, benzocarbazole ring, dibenzofuran ring and fluorene ring. R ₁ and R ₂ are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group, an aryl group, a heterocyclic group, and a bond between R ₁ and R ₂ A cyclic amino group containing a nitrogen atom in the ring in the formula thus formed, and Z represents an oxygen atom or a sulfur atom.)

More specific examples of the organic residue represented by the general formula (1) include those represented by the following formula.

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image In the above formula, R ₁ , R ₂ and Z have the same meanings as in the general formula (1), and R ₃ represents a substituent at X ₁ in the general formula (1).

Examples of the substituent represented by R ₃ include an alkyl group such as methyl and ethyl, an alkoxy group such as methoxy and ethoxy, a halogen atom such as a fluorine atom, a bromine atom and an iodine atom, a halomethyl group such as trifluoromethyl and a nitro group. And a cyano group.

R ₁ and R ₂ are a hydrogen atom, an optionally substituted alkyl group such as methyl, ethyl, propyl and butyl, an aralkyl group such as benzyl, phenethyl and naphthylmethyl, phenyl, diphenyl, naphthyl and anthryl An aryl group such as pyridine, thienyl, furyl, thiazolyl, carbazolyl, dibenzofuryl, benzimidazolyl, benzothiazolyl or a heterocyclic group formed by bonding R ₁ and R ₂ to a nitrogen atom in the formula. And the substituents of the alkyl group include halogen atoms such as a fluorine atom, a bromine atom and an iodine atom, a nitro group, a cyano group, and the like, and include an aralkyl group, an aryl group, and a heterocyclic group. Examples of the substituents on the ring group include alkyl groups such as methyl, ethyl and propyl, and methoxy. , An alkoxy group such as ethoxy, a halogen atom such as a fluorine atom, a bromine atom and an iodine atom, an alkylamino group such as dimethylamino and diethylamino, a phenylcarbamoyl group, a nitro group, a cyano group, and a halomethyl group such as trifluoromethyl. Can be

As the cyclic amino group containing a nitrogen atom in the ring, pyrrol, pyrroline, pyrrolidine, pyrrolidone, indoline, isoindole, carbazole, benzoindole, imidazole, pyrazole, pyrazoline, Cyclic amino groups derived from oxazine, phenoxazine, benzocarbazole and the like are mentioned. Examples of the substituent include alkyl groups such as methyl, ethyl and propyl, alkoxy groups such as methoxy and ethoxy, fluorine atom, bromine atom and iodine. Examples include a halogen atom such as an atom, a nitro group, a cyano group, and a halomethyl group such as trifluoromethyl.

It is preferable that one of R ₁ and R ₂ is a hydrogen atom. When R ₁ is a hydrogen atom, R ₂ is an alkyl group, an aralkyl group or an aryl group which may have a substituent. And an aryl group which may have a substituent, particularly a phenyl group which may have a substituent is most preferable in terms of sensitivity and durability.

The aromatic hydrocarbon ring or aromatic heterocyclic ring to which the organic residue represented by the general formula (1) is bonded, which may be bonded via a bonding group, and which may have a substituent, is Benzene, naphthalene, fluorene, phenanthrene,
Anthracene, pyrene, furan, thiophene, pyridine, indole, benzothiazole, carbazole, acridone, dibenzothiophene, benzoxazole,
Benzotriazole, oxadiazol, thiazole and the like. Further, when the above aromatic ring is bonded directly or by an aromatic group or a non-aromatic group, triphenylamine, diphenylamine, N-methyldiphenylamine , Biphenyl, terphenyl, binaphthyl,
Fluorenone, phenanthrenequinone, anthraquinone, benzanthrone, diphenyloxadiazol,
Examples include phenylbenzoxazole, diphenylmethane, diphenylsulfone, diphenylether, benzophenone, stilbene, distyrylbenzene, tetraphenyl-p-phenylenediamine, and tetraphenylbenzidine. Examples of the substituent which the aromatic hydrocarbon ring or the aromatic hetero ring which may be bonded through the above-mentioned bonding group may have include an alkyl group such as methyl, ethyl and propyl, an alkoxy group such as methoxy and ethoxy, and a fluorine atom. Atom, bromine atom, halogen atom such as iodine atom, dialkylamino group such as diethylamino, hydroxy group, nitro group, cyano group, halomethyl group and the general formula (2) -N = N-Cp (where Cp is pheno- A azo group having a OH group).

In formula (2), examples of the coupler residue represented by Cp include those having the following structures. General formula (4)

Embedded image General formula (5)

Embedded image General formula (6)

Embedded image General formula (7)

Embedded image General formula (8)

Embedded image General formula (9)

Embedded image General formula (10)

Embedded image General formula (11)

Embedded image General formula (12)

Embedded image General formula (13)

Embedded image General formula (14)

Embedded image General formula (15)

Embedded image General formula (16)

Embedded image

In the above formula, X ₂ is condensed with a benzene ring,
Naphthalene ring which may have a substituent, anthracene ring,
It represents a residue necessary for forming an aromatic hydrocarbon ring such as a carbazole ring, a benzocarbazole ring, a dibenzofuran ring, a benzonaphthofuran ring and a fluorene ring or an aromatic heterocyclic ring.

R ₄ and R ₅ are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group, an aryl group, a heterocyclic group, or a group wherein R ₄ and R ₅ are bonded. A cyclic amino group having a nitrogen atom in the ring formed therein, wherein R ₆ and R ₇ are the same or different and are a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group, R ₈ represents an alkyl group which may have a substituent, an aralkyl group, an aryl group or a heterocyclic group.

Y ₁ represents a divalent hydrocarbon group or a heterocyclic group which may have a substituent, including Y ₁

Embedded image as,

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image And Y ₂ represents a divalent aromatic hydrocarbon ring group which may have a substituent, and a group such as o-phenylene, o-naphthylene, 1,2-anthrylene, 9,10-phenanthrylene and the like. Y ₃ represents a divalent aromatic hydrocarbon ring group which may have a substituent or a divalent heterocyclic group containing a nitrogen atom in the ring, and o-phenylene, o-naphthylene, , 2-Anthrylene, 9,10-phenanthrylene, 3,4-pyrazoldiyl, 2,3-pyridinediyl, 4,5-pyrimidinediyl, 6,7-indazo-
Rudiyl, 5,6-benzimidazol-diyl, 6,7
-Quinolinediyl and the like.

B represents an oxygen atom, a sulfur atom, an N-substituted or unsubstituted imino group (an N-substituent includes an optionally substituted alkyl group, an aralkyl group, and an aryl group; ).

Examples of the alkyl group in the above expression include groups such as methyl, ethyl, propyl and butyl, examples of the aralkyl group include groups such as benzyl, phenethyl and naphthylmethyl, and examples of the aryl group include phenyl and diphenyl. , Naphthyl, anthryl, and the like, and examples of the heterocyclic group include pyridyl, thienyl, furyl, thiazolyl, carbazolyl, dibenzofuryl, benzimidazolyl, and benzothiazolyl. Is pyrrol, pyrroline, pyrrolidine, pyrrolidone, indole, indoline, isoindole, carbazole, benzoindo-
, Imidazole, pyrazole, pyrazoline, oxazine, phenoxazine, benzocarbazole and the like; and as a substituent, an alkyl group such as methyl, ethyl and propyl; and an alkoxy group such as methoxy and ethoxy. Groups, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; an alkylamino group such as dimethylamino and diethylamino; a halomethyl group such as a phenylcarbamoyl group, a nitro group, a cyano group, and trifluoromethyl.

Tables 1 to 8 show typical examples of the azo pigment used in the present invention. For the purpose of description, the following azo pigment types are classified by the number n as basic type 1 (general formula (3)), and -N = N in a portion corresponding to an organic residue represented by general formula (1).
The portion excluding-is represented by A. In the azo pigment type shown below, a portion excluding -N = N- in the portion corresponding to the organic residue represented by the general formula (1) in the following azo pigment type is A ₁ , and the general formula (2)
In in the portion corresponding to the organic residue represented, representing a portion corresponding to Cp in A _2. Basic type 1 (general formula (3))

Embedded image (Wherein, Ar represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring which may be bonded via a bonding group and may have a substituent, and n is an integer of 1, 2, 3 or 4) And R ₁ , R
₂ , X ₁ and Z are as defined above) Basic type 2

Embedded image (Wherein, Ar, R ₁ , R ₂ , X ₁ and Z are as defined above)

[0019]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8]

The azo pigment used in the present invention has the following general formula (17)

Embedded image (Wherein X ₁ , R ₁ , R ₂ , and Z have the same meanings as in the general formula (1)) and a compound having a diazonium salt structure and a compound having a diazonium salt structure.

The coupler component is represented by the following general formula (1)
8)

Embedded image (Wherein X ₁ is as defined above) and a carboxylic acid compound represented by the following general formula (19) (Wherein R ₁ and R ₂ are as defined above) in an aromatic solvent such as benzene, toluene, xylene, chlorobenzene and o-dichlorobenzene in the presence of phosphorus trichloride at 80 to 200 ° C. Or heat-condensed with the following general formula (20)

Embedded image (Wherein X ₁ has the same meaning as described above), and the acid chloride compound and the amine compound can be synthesized by heating in an aromatic solvent.

Using the above coupler component, the following general formula (2)
1) An amino compound represented by Ar- (NH ₂ ) _n (where Ar and n are as defined above) is diazotized by an ordinary method and is subjected to aqueous coupling in the presence of an alkali, or the amino compound (general formula ( 2
The salt obtained by once isolating the diazonium salt of 1)) in the form of a salt such as a borofluoride salt or a zinc chloride double salt, and a suitable solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl The desired azo pigment can be produced by coupling with an organic solvent in an organic solvent such as sulfoxide in the presence of a base such as soda acetate, pyridine, trimethylamine and triethylamine.

The azo pigment used in the present invention may have at least one organic residue represented by the general formula (1) in the same molecule, and may be an amino compound represented by the following general formula (22). Wherein Ar is as defined above, is diazotized by a conventional method,
The resulting diazonium salt is coupled with a coupler component represented by the above general formula (17) in the presence of an alkali, and then hydrolyzed with a mineral acid such as hydrochloric acid.
Reaction product corresponding to 3)

Embedded image (Wherein Ar, R ₁ , R ₂ , X ₁ , and Z have the same meanings as described above), and the product is again diazotized by a conventional method, and then another coupler component having a phenolic OH group is obtained. It may be synthesized by a sequential coupling reaction. On the other hand, the diazonium salt of an amino compound represented by the general formula (21) obtained by a conventional method contains at least one coupler component represented by the general formula (17). It may be added to a mixed coupler solution and subjected to a coupling reaction in the presence of an alkali for synthesis. Alternatively, after primary coupling with one kind of the coupler component represented by the general formula (17) in the presence of an alkali, It can also be synthesized by a method in which a different kind of coupler component in the presence of an alkali is successively added to complete the coupling reaction.

The electrophotographic photoreceptor of the present invention has a photosensitive layer containing an azo pigment having the above specific structure on a conductive support. The form of the photosensitive layer may be any known form, but a function-separated type photosensitive layer in which a layer containing the azo pigment is used as a charge generation layer, and a charge transport layer containing a charge transport substance is laminated thereon. Layers are particularly preferred.

The charge generation layer can be formed by applying a coating solution obtained by dispersing the azo pigment in a suitable solvent together with a binder resin onto a conductive support by a known method. Is preferably 5 μm or less, preferably 0.1 to 1 μm.

The binder resin used at this time is selected from a wide range of insulating resins or organic photoconductive polymers, but may be selected from polyvinyl butyral and polyvinyl benzer.
, Polyarylates, polycarbonates, polyesters, phenoxy resins, cellulose resins, acrylic resins, polyurethanes, and the like are preferable, and the amount of use is 80% by weight or less in terms of the content in the charge generation layer, preferably It is at most 40% by weight.

The solvent to be used is preferably selected from those which dissolve the resin and do not dissolve the charge transport layer and the undercoat layer described below. Specifically, ethers such as tetrahydrofuran and 1,4-dioxane, ketones such as cyclohexane and methyl ethyl ketone, amides such as N, N-dimethylformamide, esters such as methyl acetate and ethyl acetate, toluene, Aromatics such as xylene and chlorobenzene, methanol, ethanol, 2
Alcohols such as -propanol; and aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene.

The charge transport layer is stacked on or below the charge generation layer, and has a function of receiving charge carriers from the charge generation layer in the presence of an electric field and transporting the carriers. The charge transporting layer is formed by dissolving a charge transporting material in a solvent together with a suitable binder resin as required and coating the solution. The film thickness is generally 5 to 40 μm, but is 15 to 30 μm.
m is preferred.

As the charge transporting substance, there are an electron transporting substance and a hole transporting substance.
Electron-withdrawing substances such as 4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, chloranil, and tetracyanoquinodimethane, and those obtained by polymerizing these electron-withdrawing substances; Polycyclic aromatic compounds such as pyrene and anthracene as hole transporting substances,
Carbazole-based, indole-based, imidazole-based, oxazole-based, thiazol-based, oxadiazol-based, pyrazol-based, pyrazoline-based, thiadiazol-based, triazole-based compounds, etc. A heterocyclic compound, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone,
N, N-diphenylhydrazino-3-methylidene-9-
Hydrazone compounds such as ethyl carbazole, α-phenyl-4′-N, N-diphenylaminostilbene,
5- [4- (di-p-tolylamino) benzylidene]-
Styryl-based compounds such as 5H-dibenzo [a, d] cycloheptene, benzidine-based compounds, triarylmethane-based compounds, triphenylamine, or polymers having a group consisting of these compounds in the main chain or side chain (for example, —N-vinylcarbazole, polyvinylanthracene, etc.). In addition to these organic charge transport materials, selenium, selenium-tellurium, amorphous silicon,
An inorganic material such as cadmium sulfide can also be used. These charge transport materials can be used alone or in combination of two or more.

When the charge transport material does not have a film forming property, an appropriate binder can be used. Specifically, acrylic resin, polyarylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, polyacrylamide, polyamide,
Examples thereof include insulating resins such as chlorinated rubber and organic photoconductive polymers such as poly-N-vinyl carbazole and polyvinyl anthracene.

As the conductive support on which the photosensitive layer is formed, for example, aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold and platinum are used. In addition, plastics (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) formed by coating such metals or alloys by vacuum evaporation, and conductive particles (for example, carbon black, silver particles, etc.) ) To a suitable binder
A support coated on a plastic or metal substrate together with a resin, a support in which conductive particles are impregnated in plastic or paper, or the like can be used.

An undercoat layer having a barrier function and an adhesive function can be provided between the conductive support and the photosensitive layer. The undercoat layer can be formed of casein, polyvinyl alcohol, nitrocellulose, polyamide (nylon 6, nylon 66, nylon 610, copolymer nylon, alkoxymethylated nylon, etc.), polyurethane, aluminum oxide, or the like. The thickness of the undercoat layer is 5 μm or less, preferably 0.1 to 3 μm.

Another specific example of the present invention is an electrophotographic photoreceptor in which the above-mentioned azo pigment and a charge transporting substance are contained in the same layer. In this case, a charge transfer complex compound composed of poly-N-vinylcarbazole and trinitrofluorenone can be used as the charge transport material. The electrophotographic photoreceptor of this example can be formed by applying and drying a liquid in which the azo pigment and the charge transfer complex are dispersed in an appropriate resin solution. In any electrophotographic photoreceptor,
The crystal form of the azo pigment may be amorphous or crystalline, and if necessary, two or more of the azo pigments may be combined or used in combination with a known charge generating substance. It is.

The electrophotographic photoreceptor of the present invention is used not only for electrophotographic copying machines but also for digital electrophotographic copying machines, laser beam printers, CRT printers, LED printers, liquid crystal printers, laser printers, and the like. -It can be widely used in many electrophotographic application fields of digital recording systems using near infrared rays such as plate making and facsimile.

Further, the present invention comprises an electrophotographic apparatus provided with the electrophotographic photoreceptor of the present invention.

Further, the present invention comprises an electrophotographic apparatus having the electrophotographic photoreceptor of the present invention and a facsimile having means for receiving image information from a remote terminal.

Next, an electrophotographic apparatus provided with the electrophotographic photosensitive member of the present invention and a facsimile will be described. FIG.
FIG. 1 shows a schematic configuration of a general transfer type electrophotographic apparatus using the drum type photoreceptor of the present invention.

In FIG. 1, reference numeral 1 denotes a drum type photosensitive member as an image bearing member, which is driven to rotate around an axis 1a in a direction of an arrow at a predetermined peripheral speed. The photoreceptor 1 is uniformly charged at a predetermined positive or negative potential on its peripheral surface by a charging means 2 during the rotation process, and then, in an exposure section 3, a light image exposure L (slit exposure, (Laser beam scanning exposure, etc.). As a result, an electrostatic latent image corresponding to the exposure image is sequentially formed on the peripheral surface of the photoconductor.

The electrostatic latent image is then toner-developed by the developing means 4, and the toner-developed image is transferred between the photosensitive member 1 and the transfer means 5 from a paper feeding unit (not shown) by the transfer means 5. 1
Are sequentially transferred onto the surface of the transferred transfer material P fed in synchronization with the rotation of.

The transfer material P having undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8, and printed out of the machine as a copy (copy) which undergoes image fixing. The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by the cleaning unit 6 to remove the transfer residual toner, and is subjected to a static elimination process by the pre-exposure unit 7 to be repeatedly used for image formation.

As the uniform charging means 2 for the photosensitive member 1, a corona charging device is generally widely used. Also, the corona transfer means is generally widely used for the transfer device 5.

As an electrophotographic apparatus, a plurality of components such as the above-described photosensitive member, developing means, and cleaning means are integrally connected as an apparatus unit, and this unit is attached to the apparatus body. It may be configured to be detachable. For example, the photoreceptor 1 and the cleaning means 6 may be integrated into one apparatus unit, and may be configured to be detachable using guide means such as rails of the apparatus body. At this time, the above-described device unit may be provided with a charging unit and / or a developing unit.

When the electrophotographic apparatus is used as a copier printer, the light image exposure L uses reflected light or transmitted light from the original, or reads the original and converts it into a signal. This is performed by scanning the beam, driving a light emitting diode array, or driving a liquid crystal shutter array. When used as a facsimile printer, the optical image exposure L is an exposure for printing received data.

FIG. 2 is a block diagram showing an example of this case. The controller 10 controls the image reading section 9 and the printer 18. The entire controller 10 is controlled by the CPU 16.

The read data from the image reading section is transmitted to the partner station through the transmission circuit 12. Data received from the partner station is sent to the printer 18 through the receiving circuit 11. Predetermined image data is stored in the image memory. The printer controller 17 controls the printer 18. 13 is a telephone.

The image received from the line 14 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 11, and then the CPU 16 performs signal processing of the image information and sequentially stores the image in the image memory. 15 is stored. When at least one page of images is stored in the memory 15,
The image of the page is stored. The CPU 16 is a memory 1
5 to read out one page of image information and send the signalized one page of image information to the printer controller 17.

The printer controller 17 includes a CPU 16
When one page of image information is received from the printer, the printer 18 is controlled to record the image information of the page. The CPU 16 is receiving the next page during recording by the printer 18. As described above, image reception and recording are performed.

[0048]

EXAMPLES 1 to 7 5 g of methoxymethylated nylon (weight average molecular weight 32,000) and 10 g of alcohol-soluble copolymerized nylon (weight average molecular weight 29,000) on an aluminum support were treated with methanol. 95
The solution dissolved in g was applied with a Myr bar to form an undercoat layer having a thickness of 1 μm after drying.

Next, 5 g of Pigment Example 2-4 was added to a solution prepared by dissolving 2 g of polyvinyl benzal (a degree of benzalization of 75% or more) in 95 g of cyclohexanone, and dispersed in a sand mill for 20 hours. This dispersion was applied on a previously formed undercoat layer with a Myr bar so as to have a thickness of 0.2 μm after drying, and dried to form a charge generation layer.

Next, a styryl compound represented by the following structural formula

Embedded image 5 g of polymethyl methacrylate (weight average molecular weight 10
5 g was dissolved in 40 g of chlorobenzene, and this was coated on the charge generating layer with a Myer bar so that the film thickness after drying was 20 μm, and dried to form a charge transport layer. Was prepared.

Electrophotographic photoreceptors corresponding to Examples 2 to 7 were prepared in exactly the same manner except that pigments of other pigment examples were used instead of pigment examples 2-4.

The produced electrophotographic photoreceptor was used by Kawaguchi Electric Co., Ltd.
Was negatively charged by a corona discharge of -5 KV using an electrostatic copying paper tester Model SP-428, and was held for 1 second in a dark place, and then exposed at an illuminance of 10 lux using a halogen lamp to evaluate charging characteristics. . As the charging characteristics, the surface potential (V ₀ ) and the exposure amount (E1 / 2) required for the surface potential after leaving in a dark place to attenuate to １ ／ were measured. The results are shown. Example 1 pigment Example _{2-4 V 0: -730V, E1 /} 2: 3.1
Looks seconds Example 2 pigment Example _{2-5 V 0: -700V, E1 /} 2: 2.9
Looks seconds Example 3 pigment Example _{2-6 V 0: -700V, E1 /} 2: 3.8
Looks seconds Example 4 pigment Example _{2-12 V 0: -700V, E1 /} 2: 2.5
Looks seconds Example 5 Pigment example _{3-2 V 0: -690V, E1 /} 2: 2.6
Looks / second Example 6 Pigment example 3-5 V0: -710 V, E1 / 2: 4.3
Looks seconds Example 7 pigment Example _{4-1 V 0: -720V, E1 /} 2: 3.8
Looks Second

Comparative Examples 1 to 4 The pigment used in the above Examples was Comparative Pigment 1 represented by the following structural formula.
An electrophotographic photoreceptor was prepared in exactly the same manner as in this example, except that the charge was changed to 4, and the charging characteristics were evaluated in the same manner. Comparative pigment 1

Embedded image Comparative pigment 2

Embedded image Comparative pigment 3

Embedded image Comparative pigment 4

Embedded image Comparative Example 1 Comparative pigment _{1 V 0: -680V, E1 /} 2: 4.2 lux · sec Comparative Example 2 Comparative pigment _{2 V 0: -710V, E1 /} 2: 4.8 lux · sec Comparative Example 3 Comparative pigment 3 _{V 0: -720V, E1 / 2} : 6.9 lux-seconds comparative example 4 comparative pigment _{4 V 0: -710V, E1 /} 2: 3.7 lux-seconds

From these results, it can be seen that the electrophotographic photosensitive member of the present invention has a sufficient charging ability and excellent sensitivity.

[0055]

According to the electrophotographic photoreceptor of the present invention, by using an azo pigment having a specific structure in the photosensitive layer, one or both of the efficiency of charge carrier generation and / or the injection efficiency in the photosensitive layer is improved, and the sensitivity is improved. In addition, a remarkable effect that characteristics excellent in potential stability upon repeated use can be obtained is obtained, and the same remarkable effect is also obtained in an electrophotographic apparatus and a facsimile provided with the electrophotographic photosensitive member.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a general transfer type electrophotographic apparatus.

FIG. 2 is a block diagram of a facsimile using the electrophotographic apparatus as a printer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Drum type photoreceptor as an image carrier (electrophotographic photoreceptor of the present invention) 2 Corona charging device 3 Exposure unit 4 Developing unit 5 Transfer unit 6 Cleaning unit 7 Pre-exposure unit 8 Image fixing unit L Light image exposure P Transfer material after image transfer 9 Image reading unit 10 Controller 11 Receiving circuit 12 Transmitting circuit 13 Telephone 14 Line 15 Image memory 16 CPU 17 Printer controller 18 Printer

────────────────────────────────────────────────── ─── of the front page continued (51) Int.Cl. ⁷ identification mark FI G03G 5/06 354 G03G 5/06 354A 354Z 360 360C 365 365D 367 367 C09B 29/20 C09B 29/20 B 31/068 31/068 35/033 35/033 35/035 35/035 35/06 35/06 35/24 35/24 35/378 35/378 35/64 35/64 56/04 56/04 56/16 56/16 H04N 1 / 29 H04N 1/29 D (56) Reference JP-A-57-188042 (JP, A) JP-A-3-37668 (JP, A) JP-A-61-16653 (JP, A) JP-A-62-267 192747 (JP, A) JP-A-4-118661 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 5/06 340-369 CA (STN) REGISTRY (STN)

Claims (6)

(57) [Claims] 1. An electrophotographic apparatus having a photosensitive layer on a conductive support.
In true photoreceptor shown of the photosensitive layer by the following general formula (1)
Wherein the organic residue may be attached to through a linking group, to contain azo pigment having a structure bonded with an aromatic hydrocarbon ring or aromatic heterocyclic ring which may have a substituent Electrophotographic photoreceptor. General formula (1) ( Wherein X ₁ is condensed with a benzene ring in the formula to form an optionally substituted anthracene ring, carbazole ring,
R ₁ and R ₂ are the same or different and represent a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group, a carbazole ring, a dibenzofuran ring and a fluorene ring. Ali - group, nitrogen <br/> atom in formulas heterocyclic group and R ₁ and R ₂ is formed by combining the indicated cyclic amino group containing in the ring, Z is an oxygen atom or a sulfur atom Is shown. ) 2. A organic residue shown by the formula (1), R ₁ is hydrogen atom, an alkyl group R ₂ is substituted, aralkyl group and ants - Le group The electrophotographic photosensitive member according to claim 1. Wherein the azo pigment, by the general formula (1) an organic residue organic residue selected from organic residues are the selected at least one and represented by the different following general formula (2) azo pigments and at least one organic residue represented has a may be bonded by through a linking group, bound to an aromatic hydrocarbon ring or aromatic heterocyclic ring which may have a substituent structure The electrophotographic photoreceptor according to claim 1 or 2, wherein Formula ( 2 ) -N = N-Cp (where Cp is a coupler having a phenolic OH group)
Indicates the residue. ) Wherein the azo pigment is shown by the following general formula (3)
The electrophotographic photosensitive member according to claim 3, which is an azo pigment. General formula (3) ( Wherein X ₁ is condensed with a benzene ring in the formula to form an optionally substituted anthracene ring, carbazole ring,
R ₁ and R ₂ are the same or different and represent a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group, a carbazole ring, a dibenzofuran ring and a fluorene ring. Ali - group, nitrogen <br/> atom in formulas heterocyclic group and R ₁ and R ₂ is formed by combining the indicated cyclic amino group containing in the ring, Z is an oxygen atom or a sulfur atom are shown, Ar may be bonded by through a bonding group, an aromatic may have a substituent represents a hydrocarbon ring or aromatic heterocyclic ring, n represents an integer of 1, 2, 3 or 4 Show. ) 5. The electrophotographic photoreceptor according to claim 1, a charging unit, a developing unit, a transfer unit, and a toner.
- an electrophotographic apparatus comprising the training means. 6. The method of claim 1 to 4 or an electrophotographic apparatus and comprising an electrophotographic photosensitive member according to remote - <br/>, characterized in that it comprises means for receiving image information from a preparative terminal facsimile.