JPS6120951A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body superior in triboelectrification retentivity, sensitivity, durability, etc., by forming on a conductive substrate a photosensitive layer consisting essentially of a specified semicarbazone compd. as a photoconductor, a specified sensitizer, and a specified polymer binder. CONSTITUTION:The superior electrophotographic sensitive body triboelectrifiable to a positive polarity can be obtained by laminating on the conductive substrate a photosensitive layer contg. at least one kind of sensitizer from phthalocyanine type, bisazo type, indigo type, and triphenyl type sensitizers, and a polymer binder, and an org. photoconductor represented by the formula shown here in which A is alkyl, aralkyl, aryl, or heterocyclic; X is O or S; Y is -NR<1>R<2>, -N= CR<1>R<2>, -N=CH-(CH=CH)m-B, -NHR<3>R<4>, -NH=CR<3>R<4>, -NHN=CH-(CH= CH)m-B, and R<1> and R<2>, R<3> and R<4> may form a fing, respectively, and this ring may be composed of only carbons or a combination of C and one or more selected from O, N, and S, and when they form no ring with each other, each is H, alkyl, aralkyl, aryl, or heterocyclic; B is same as A; and m is 1 or 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photoreceptor for electrophotography. More specifically, the present invention relates to an electrophotographic photoreceptor having a photosensitive layer comprising an effective organic photoconductor and a polymeric binder.

[Conventional technology]

Organic photoconductors are generally lighter, more flexible, and have better transparency than inorganic photoconductors. Easy to combine with other materials. Conventionally, derivatives of polyvinylcarbazole, oxadiazole, and pyrazoline have been known.

What are the basic characteristics required for electrophotographic photoreceptors?

It has good electrostatic charge acceptance and charge retention in the dark, good sensitivity, low residual potential, and wide spectral sensitivity in the visible region. Good light resistance and durability.

It is harmless. Manufacturing processability (film formability, transparency, flexibility,
Good mass productivity, etc.). It is difficult to find a single material for organic photoconductors and inorganic photoconductors that has been proposed so far that satisfies all of the various basic properties required for electrophotographic photoreceptors, and there are some drawbacks. The reality is that one has no choice but to use one.

Under these circumstances, functionally separated electrophotographic photoreceptors have recently been proposed. By separating the respective functions into a charge transfer material that absorbs light and generates a charge and a charge transfer material that transfers the generated charge, the range of material selection can be expanded and It is an attempt to satisfy some or all of the various basic characteristics required of a photoreceptor. Although many proposals have been made regarding such functionally separated electrophotographic photoreceptors, only a few of them have been put into practical use, and even then, it is inevitable to use products with obvious drawbacks. The reality is that we don't get anything.

Moreover, the combination of charge-generating materials and charge-transferring materials has not been dealt with theoretically to date, and the reality is that various combinations have been studied through trial and error.

However, in general, positive polarity is preferable compared to negative polarity because it generates less ozone during corona discharge, causes less deterioration of electrophotographic photoreceptors, and causes less environmental pollution. Since there are few known electrophotographic photoreceptors made of organic photoconductors that are effective in positive polarity, the reality is that they are unavoidably used in negative polarity. The positive polarity and effective method (No. 4?87226/1983) also has problems such as difficult preparation conditions.

In view of these circumstances, the present inventors.

It is an organic photoconductor that is effective as a photoconductor in itself and is also an excellent charge transfer material.

Sulfonylhydrazone compounds, semicarbazone compounds,
We discovered carbohydranone compounds and filed an application earlier (
JP 58-205158).

After that, as a result of further intensive research, they discovered an electrophotographic photoreceptor containing an even better organic photoconductor and a polymeric binder, and completed the present invention.

[Problem that the invention seeks to solve]

An object of the present invention is to provide an electrophotographic photoreceptor that has good static charge retention and charge retention in the dark, high sensitivity, and excellent durability.

Another object of the present invention is to provide an electrophotographic photoreceptor that is effective in positive polarity.

Still another object of the present invention is to provide a photosensitive layer comprising a polymeric binder and an organic photoconductor that has good compatibility or dispersibility with the polymeric binder.

[Failure to solve the problem]

The present invention has the following configuration to achieve the above object.

That is, in an electrophotographic photoreceptor comprising a photosensitive layer laminated on a conductive substrate, the photosensitive layer comprises (A) an organic photoconductor comprising at least one compound represented by the following general formula (I), and (B) phthalocyanine. The present invention is characterized by an electrophotographic photoreceptor containing at least one compound (C) polymer binder selected from a bisazo compound, a bisazo compound, an indigo compound, and a triphenylmethane compound.

General formula (1) A+’CHmiOH+CH=NNHCY During the ceremony A: Alkyl group, aralkyl group, aryl group.

Heterocyclic residue.

X: oxygen atom, sulfur atom.

n: 1 or 2 Y: -NR'R", -NeCR'R", -NcrocodileC
H+CH=CH÷B-NHNR"R', -NHN=
CR”R’.

-NHN-cH+CH=CH-)-s Rl and R1, R1 and R4: When they belong to the same ring system.

m Carbon atoms, or (2) belong to the same ring system or the same ring system containing a combination of carbon atoms and at least one selected from the group consisting of oxygen atoms, nitrogen atoms, and sulfur atoms as ring bone core atoms. If not, hydrogen atom, alkyl group, aralkyl group, aryl group, heterocyclic residue B: alkyl group, aralkyl group, aryl group.

heterocyclic residue mHl or 2 Each is selected from

(A) General formula (1) which is an essential component of the photosensitive layer of the present invention
), (B) a phthalocyanine compound, a bisazo compound, an indigo compound.

The triphenylmethane compound and (C) the polymeric binder will be explained in detail.The organic photoconductor represented by the above general formula (1) is more specifically shown as compounds (1) to (2). ). As compound (1), +21.

(1) A semicarbazone compound represented by the following general formula (a), (b) 4 or (C) (hereinafter abbreviated as compound (1)).

A +CH-CH-)-CH-NNHCNR'R"
(a) A(-CHmoCH-3-CHμ
NNHCNhi CR'R friend (b) A war H-
C Gin C1 Snow NNHCN Waterfall CM ÷ OR Snow CB 10B
(c) In the formula, A and B are each an alkyl group, and if they do not belong to an aralkyl group, they are a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic residue.

X is an oxygen atom or a sulfur atom.

n and m are 1 or 2 Each is selected from

Combined hydrazone compound (hereinafter abbreviated as compound (2))
.

(I A (-, CH=CH+CH, 1INNHCNHNR'
R4(d) A+CH=CH→-CH=NN11(JiH
N=CR'R' (e)A (-CH
1=CH+CH=NNHCNHN=CH-gH=CHSB (f) In the formula, A and B are each an alkyl group, an aralkyl group, an aryl group, or a heterocyclic residue.

When R'' and R'' belong to the same ring system, when they do not belong to two systems, they are a hydrogen atom or an alkyl group.

Aralkyl group, aryl group, heterocyclic residue.

X is an oxygen atom or a sulfur atom.

n, +n is 1 or 2 Each is selected from

In the above compounds (1) to (2), A, B and R1
~R'' may have a substituent, and the argyl group has 1 to 12 carbon atoms, the aralkyl group has 7 to 14 carbon atoms, and the aryl group has carbon, and
3-30 membered compounds, such as virol, pyrazole, pyrazoline, imidazole, triazole, pyridine, and pyrimidine.

Pyrazine. Triazines, indoles, quinolines.

Quinazoline, Phthalazine, Carbazole, Acridine,
Tzenazino. Furan, biran, benzofuran, thiophene, benzothiophene, oxazole, benzoxazole, oxadiazole. Thiazole, benzothiazole, thiazine, thiadiazole, imidasilone, imidazothione, carbostyril and the like are preferred. Substituents include alkyl groups such as methyl, ethyl, and propyl, alkoxy groups such as methoxy, fluorine, chlorine, and bromine.

Halogen groups such as iodine, amino, methylamino.

ethylamino, propylamine, dimethylamino.

Amine groups such as diethylamino and benzylamino.

Hydroxyl group, acyl group such as acyl group, thiol group.

Examples include alkylthio groups such as methylamino and ethylthio.

The details of each compound will be explained below.

In compound (1), preferred semicarbazone compounds having the general formula (a), (b) or (C) include:

For example, the 9th order can be cited.

H C,H.

-N(CH,L (1-27)
(1 so 28) -N(CH,), (1-!1
0) Furthermore, those having two or more semicarbazone groups are also effective. Of course, it is not limited to these. These semicarbazide compounds may be used alone or in combination of two or more.

The above compound (1) can be produced by a known method. Specifically, for example, a semicarbazide compound of equal molecular weight and an a,β-unsaturated aldehyde metal are mixed in an organic solvent with an acid (for example, as required).

It is obtained by polycondensation by heating in the presence of acetic acid, hydrochloric acid, etc.).

Next, in compound (2), general formula (d), (
Preferred carbohydrazone compounds having (e) and (f) include the following compounds.

” Q$1 H, NNHCNHN, =CH-CH, (2-18
)H9NNHCNHN=CH-CH-6H<”)I
(2-19)0oNHNCNHN to CH-CH=C
HON(CH,), (2-20)((CH,), N
0CH,=CH-CkN,NH+C(2-22)((C
, H, ), N()CH=CH-CH=N, NH÷C(2
-23) -N(C,H),
(2-25)=N(C,H,),
Those having two or more carbohydrazone groups like (2-26) are also effective. Of course, it is not limited to these. These carbohydrazone compounds may be used alone or in combination of two or more.

It is obtained by condensing a bohydrazide compound and an α,β-unsaturated aldehyde compound by heating in an organic solvent in the presence of an acid (eg, acetic acid, hydrochloric acid, etc.) as necessary.

Next, the following phthalocyanine compounds, bisazo compounds, indigo compounds, and triphenylmethane compounds are used. Particularly preferably used phthalocyanine compounds include, but are not limited to, metal-free phthalocyanine or metal phthalocyanine represented by the following general formula (2) or (1).

General formula (1) In the formula, Hs, H4, Hl, and R1 are hydrogen atoms or halogen atoms.

No is 0, 1, 2, 3.4 each selected from These may be used alone or in combination of two or more.

These phthalocyanine compounds are electron acceptor compounds that can be used with commonly known electron acceptor compounds and sensitizing additives for the purpose of improving sensitivity, reflux characteristics, etc.

For example, phthalic anhydride, chlorophthalic anhydride, S
-1 lycyanobenzene, vicryl chloride, 2゜4-dinitrochlorobenzene, 2,4-dinitrobromobenzene,
4-nitrobiphenyl, 4,4'-dinitrobiphenyl. 2,4.6-) IJ=)072/-le, 1-1)
Chlorotrinitrobenzene, trinitro-〇-toluene, 4,6-dichloro-1,6-cinitrobenzene, 4
．． 6-”'Nia'Romo1.3-Dinitrobenzene*P-Dinitrobenzene, Chloranil.

Bromoanil, 2,4,7-dolinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone.

Non, trinitroanthracene, dinitroacrylic, zine, tetracyanopyrene, dinitroanthraquinone and the like are preferably used, but are not limited thereto. The sensitizing additive is a metal-free or metal phthalocyanine having a substituent on one or more of the four benzene nuclei. For example, simple substituents include an amine group, a nitro group, an alkyl group, an alkoxy group. , cyano group, carboxylic acid group, thiol group.

Examples include an alkylthio group, and derivatives having a benzene nucleus and a divalent bonding group, such as a methylene group, a carbonyl group, a sulfonyl group, and an imino group, are also preferably used.

As such a sensitizing additive.

CuPc (-CHI-NCI>), ,
(3-3)Cubc+CH,C00C,H,9)P(
3-7) Cu P c + COCH, N HCs H1
7) p (''-8) in the formula, CuP
c is a copper phthalocyanine residue.

p is 1, 2, 5.4 shows.

Examples include, but are not limited to.

In the present invention, the weight ratio of phthalocyanine compound/electron acceptor compound/sensitizing additive is 110 to 0.5.
It is appropriately selected within the range of 70 to 0.5.

Preferably used bisazo compounds are, for example, those represented by the following general formula (IV).

In the formula, (c) is a group selected from 0q, /, 4j is H, CH,...
OCR,.

A group selected from Go, H, OH, C1 and Br.

R, R, R, R are hydrogen, alkyl or alkyl derivatives having 1 to 15 carbon atoms, aryl or aryl derivatives having 1 to 15 carbon atoms, aralkyl or aralkyl derivatives having 7 to 15 carbon atoms, amino or amino derivatives,
A group selected from nitro, halogen, hydroxyl, alkoxy and acyl, with 0,1 or 2 (k
, 20 o'clock R2R, R, and R may not be the same).

Specific example QCH2 is an example of a bisazo pigment useful in the present invention. Not limited to these.

These bisazo compounds may be used alone or in combination of two or more.

Preferred indigo compounds include the following.

These may be used alone or in combination of two or more.

CI OCl C1OC1 C10 Examples of triphenylmethane compounds include 1.

Malachite Green, Seven Glaucine, Brilliant Green, Guinea Green B, Brilliant Milling Green B, Erioglaucine, Rose Magenta (Baratuxin), Methyl Violet B.

Methyl violet, ethyl violet, gristal violet, formyl violet 84B, :/IJ
Kneeple Blue, Eriochrome Azurol B, Eriochrome Cyanine R, Victoria Blue B, Naphthalene Green V, Wool Green S.

Victoria Pure Blue B, Brilliant Indocyanine, Brome Cresol Green, From Fenoble,
Tetrabromophenol blue and the like are preferably used, but are not limited thereto.

These triphenylmethane compounds may be used alone or in combination of two or more.

In the present invention, in the organic photoconductor comprising at least one compound represented by the general formula (1), there is one compound that is poorly soluble or insoluble in ordinary solvents and is not compatible with polymeric binders and is in a dispersed state. There is something that exists in In this case, these organic photoconductors exhibit good dispersibility when the particle size is reduced.

The preferred particle size is 1 μm or less, more preferably 0.1 μm or less.

Furthermore, since the 7-sigma cyanine compounds, bisazo compounds, and indigo compounds of the present invention are insoluble in ordinary solvents, they exhibit good dispersibility by reducing their particle sizes. The particle size of these compounds is preferably 1 μm or less, more preferably 0.1 μm or less.

As the polymer binder, commonly known polymer binders are used.

Preferably used ones include, for example, the following.

Polyamide, polyurethane, polyester, polyester amide, polyether, polycarbonate, polyamideimide, polyacrylic acid ester and its copolymer, polymethacrylic acid ester and its copolymer, polystyrene and its copolymer, polyvinyl acetate and its copolymer. copolymers, polyvinyl chloride and its copolymers, polyvinyl acetals,
Polychlorinated olefins and their copolymers, alkyd resins.

Examples include, but are not limited to, silicone resin, ketone resin, xylene resin, and epoxy resin.

These polymer binders may be used alone or in a mixed system of two or more, or may be used as a copolymer.

Further, crosslinking may be carried out by adding a suitable crosslinking agent.

The organic photoconductor represented by the general formula (1) used in the electrophotographic photoreceptor of the present invention is effective as a photoconductor in itself and is also excellent as a charge transfer material. When a photosensitive layer is formed by combining at least one compound selected from bisazo compounds, indigo compounds, and triphenylmethane compounds with a polymer binder, an electrophotographic photoreceptor with excellent positive polarity can be obtained. Of course, it is also excellent in negative polarity. The electrophotographic photoreceptor may have a conventionally known form, for example.

(a) Conductive substrate/photoconductive layer (b) Conductive substrate/charge generation layer/charge transfer layer (C)
Any form of conductive substrate/charge transfer layer/charge generation layer can be used. Among them, considering the above characteristics, when used with positive polarity, organic photoconductors represented by general formula (1) and phthalocyanine compounds, bisazo compounds, indigo compounds, and triphenylmethane compounds are selected. A form (-) in which at least one compound and a polymeric binder are contained in a single photoconductive layer is particularly preferably used.

In addition, in forms (b) and (C), the general formula (' I
) and a polymer binder to form a charge transfer layer, and at least one compound selected from phthalocyanine compounds, bisazo compounds, indigo compounds, and triphenylmethane compounds and a polymer binder. A charge generating layer is formed from a molecular binder.

The photosensitive layer of the present invention is laminated on the conductive substrate.

This is a general term for a photoconductive layer, a charge generation layer/charge transfer layer, and a charge transfer layer/charge generation layer.

In the above form (-), the photoconductive layer has the general formula (1)
Organic photoconductor and phthalocyanin compound,
At least one compound selected from bisazo compounds, indico compounds, and triphenylmethane compounds, a polymeric binder, and, if necessary, known sensitizers and charge-generating materials described below may be mixed. The proportions of the sensitizing dye and the charge generating material to 1 part by weight of the organic photoconductor represented by the general formula (1) are 0 to 0.2 parts by weight, and θ to 0.5 parts by weight, respectively.
It is appropriately selected within the range of parts by weight.

The above photoconductive layer, charge transfer layer, and charge generation layer.

It may be a stack of two or more layers each having a different composition. For example, the charge generation layer may be a stack of charge generation layers made of charge generation materials having different wavelength sensitivities.

Furthermore, in these forms, a conductive substrate and a photoconductive layer,
Intermediate layers between charge transport layers or charge generation layers may also be provided. Here, the intermediate layer is an adhesive layer or a barrier layer, and preferably has a thickness of 20 μm or less, particularly 5 μm or less.

In the present invention, a protective layer may be provided on the surface of the electrophotographic photoreceptor as necessary (for example, in the case of the above form (-), conductive substrate/photoconductive layer/protective layer). It is Noh.

The electrophotographic photoreceptor of the present invention can be used for slide films, microfilms, OHP films, etc. when a transparent photoreceptor is provided on a transparent conductive substrate. Further, when the transparent electrophotographic photoreceptor is applied to an electrophotographic method in which light is exposed from the side of a transparent conductive substrate, a white dielectric layer can be provided on the photosensitive layer as necessary.

The electrophotographic photoreceptor is useful because, for example, when a toner image formed on a white dielectric layer is directly fixed, a clear image can be obtained, especially in the case of a color image.

The photosensitive layer in the present invention can be formed by a commonly known method. For example, in the above embodiment (a), the photoconductive layer is selected from an organic photoconductor made of at least one compound represented by the general formula (1), a phthalocyanine compound, a bisazo compound, an indigo compound, and a triphenylmethane compound. A solution prepared by dissolving at least one compound and a polymeric binder in a solvent, or if not dissolved, a dispersion obtained by mixing and dispersing fine particles in a dispersion medium using a ball mill, homomixer, etc. is applied. . It can be formed by a method such as.

In the present invention, a photoconductive layer, a charge generation layer, a charge transfer layer,
Furthermore, methods for adding the intermediate layer include film attachment, brush coating, dip coating, knife coating, roll coating,
Spray painting, pour painting.

An appropriate coating method can be selected from commonly used coating methods such as rotary coating (spinner, whaler, etc.).

In the electrophotographic photoreceptor of the present invention, among the organic photoconductors represented by the general formula (1), the compound [2] is preferred in terms of positive polarity, and more preferably the compound [2] is represented by the general formula (g) of the compound (2). The represented compounds are preferred, particularly symmetrical carbohydrazone compounds.

Furthermore, among at least one compound selected from phthalocyanine compounds, bisazo compounds, indigo compounds, and triphenylmethane compounds, phthalocyanine compounds and bisazo compounds are preferred in terms of positive polarity.

In the present invention, an organic photoconductor consisting of at least one compound represented by general formula (1)/at least one compound selected from phthalocyanine compounds, bisazo compounds, indigo compounds, and triphenylmethane compounds/polymer The weight ratio of the binder is 1'10.0001~
It is selected as appropriate within the range of 110.5 to 30.

Various additives can be added to the photoconductive layer, charge generation layer, and charge transfer layer used in the electrophotographic photoreceptor of the present invention. For example, when forming these layers by coating, It is also possible to use plasticizers to improve the gloss and smoothness of the coating during application, and if necessary, additives such as adhesion promoters, stabilizers, antioxidants, UV absorbers, and lubricants. Furthermore, conventionally known organic photoconductors and charge-generating materials can be used as necessary, within the range that does not impair the properties of the electrophotographic photoreceptor that is the object of the present invention. material, charge transfer material may be added.

In the embodiment (a), the composition of the photoconductive layer is represented by the general formula (I
) Organic photoconductor consisting of at least one compound represented by: phthalocyanine compound, bisazo compound,
At least one compound selected from indigo compounds and triphenylmethane compounds/polymer binder/sensitizer/charge generating material/other additives in a weight ratio of 170-
0001~110.5~3010~0210~0.5
/ is preferably 0 to 1, and form (b), form (
In c), the composition of the charge transfer layer is:

It is preferable that the weight ratio of the organic photoconductor/polymer binder/other additives consisting of at least one compound represented by the general formula (I) is 110.5 to 3010 to 1.

The composition of the charge generation layer is a phthalocyanine compound.

The weight ratio of at least one compound selected from bisazo compounds, indigo compounds, and triphenylmethane compounds and charge generating agents/polymer binders/other additives is 170.2 to 570 to 5 It is preferable that Here, other additives are a general term for electron acceptor compounds when the above-mentioned phthalocyanine compounds are used, sensitizing additives, and various additives added during coating.

Examples of sensitizing dyes include rhodamines, xanthine dyes, thiazine dyes, acridine dyes, quinoline dyes, quinone dyes, ketone dyes, cyanine dyes,
Examples include, but are not limited to, polymethine dyes, azo dyes, azomethine dyes, and carbonyl dyes.

Examples of charge-generating materials include inorganic photoconductors such as selenium, selenium alloys, and cadmium sulfide.

Examples include, but are not limited to, organic photoconductors such as perylene pigments, anthraquinone pigments, cyanine pigments, quinacridone pigments, and perinone pigments.

In the above embodiment (,), the thickness of the photoconductive layer is 2μ-50
μ, the thickness of the charge generation layer is 0 in forms (b) and (C)
．． The thickness of the charge transfer layer is preferably 6 to 60 μ, respectively. Note that the conductive substrate is not particularly limited as long as it is commonly known. That is, paper, plastic film, etc. made conductive by adding a conductive compound, a metal foil layer, etc., a metal plate, etc. are used.

〔Effect of the invention〕

The electrophotographic photoreceptor of the present invention includes, on a conductive substrate, an organic photoconductor comprising at least one compound represented by the general formula (1), a phthalocyanine compound, a bisazo compound, an indigo compound, Since it has a photosensitive layer containing at least one compound selected from triphenylmethane compounds and a polymer binder, it has good electrostatic charge acceptance and charge retention in the dark, and is highly sensitive and durable. It has excellent properties.

In addition, an effective electrophotographic photoreceptor with positive polarity can be obtained.

Furthermore, an organic photoconductor comprising at least one compound represented by the general formula (1) of the present invention, and at least one compound selected from phthalocyanine compounds, bisazo compounds, in silico compounds, and triphenylmethane compounds Since it has good compatibility or dispersibility with polymer binders, there is a wide range of polymer binders to choose from. For this reason, in the electrophotographic photoreceptor of the present invention, not only two-component toners but also -component toners can be used in the developing process, and the range of toner selection is wide.

[Method of measuring characteristics]

Kawaguchi, newly manufactured by Denki Seisaku, electrostatic copying paper testing equipment (EPA-8
P-428), apply voltage: ±6 kV for 6 seconds to determine the acceptance potential. 9. Then dark decay for 5 seconds to determine the amount of dark decay. 0. Next, use tungsten light with a color temperature of 2854° as the light source. , 300, /71ux for 15 seconds to determine the half-life exposure.

The acceptance potential determined in this manner indicates electrostatic charge acceptance in the dark, the amount of dark decay indicates charge retention, and the half-exposure indicates sensitivity.

〔Example〕

The present invention will be described below with reference to Examples, but the present invention is not limited thereto.

Example 1 Prepare two types of compounds represented by the compounds (2-22) and (1-12) of the present invention. The particle size of (2-22) is 0.1μ or less). ε-type copper phthalocyanine: polyester resin: tetrahydrofuran, = 10: 2: 10: '180 was fractionated in a ball mill for 6 hours to obtain a dispersion (dispersion (1) and 9 dispersions (respectively). 2)).

On the other hand, Al
Two conductive films were prepared by vacuum-depositing 0.1μ of the following.

on the A/deposition side of these two conductive films.

The thickness of the above dispersion (1) after drying 1 dispersion (2) is 1
A photoreceptor for electrophotography having two types of photoconductive layers was obtained by coating each layer so as to have a thickness of 2μ.
1), photoreceptor (2)).

Acceptance potential of two types of electrophotographic photoreceptors.

The dark attenuation amount and half-reduction exposure amount were measured and shown in Table 1.

Comparative Example 1 At vapor deposition of the conductive film obtained in Example 1 using a dispersion obtained by dispersing compound (2-22): polyester resin: tetrahydrofuran in the same manner as in Example 1 in a ratio of 10:10:180. It is clear that when coated on a surface to a thickness of 12 μm after drying, it exhibits superior electrophotographic properties in positive polarity compared to the electronic thickness of Comparative Example 1.

Example 2 A photosensitive layer having the composition shown in Table 2 was formed on the conductive film obtained in Example 1 in the same manner as in Example 1 to obtain electrophotographic photoreceptors (3) to (8) of the present invention. ) was obtained. The measurement results with positive polarity are shown in Table 2.

Compared to electrophotographic photoreceptor (1) of Comparative Example 1, all of the electrophotographic photoreceptors in Table 2 have improved sensitivity at positive polarity, and are excellent electrophotographic photoreceptors in terms of positive polarity. It is the body.

Claims (2)

[Claims] (1) In an electrophotographic photoreceptor comprising a photosensitive layer laminated on a conductive substrate, the photosensitive layer is (A) an organic photoconductor comprising at least one compound represented by the following general formula (I); (B) an electrophotographic photoreceptor containing at least one compound selected from phthalocyanine compounds, bisazo compounds, indigo compounds, and triphenylmethane compounds; (C) a polymer binder; . General formula (I) ▲There are numerical formulas, chemical formulas, tables, etc.▼ In the formula A: alkyl group, aralkyl group, aryl group, heterocyclic residue X: oxygen atom, sulfur atom n: 1 or 2 Y: -NR^1R ^2, -N=CR^1R^2, -N=
CH■CH=CH■B-NHNR^2R^4, -NHN
=CR^3R^4, -NHN=CH■CH=CH■_m
BR^1 and R^2, R^3 and R^4: If they belong to the same ring system, (1) carbon atom, or (2) If they do not belong to the same ring system or the same ring system that contains a combination of carbon atoms and at least one selected from the group consisting of oxygen atoms, nitrogen atoms, and sulfur atoms as ring bone atoms, hydrogen Atom, alkyl group, aralkyl group, aryl group, heterocyclic residue, B: alkyl group, aralkyl group, aryl group, heterocyclic residue, m: selected from 1 or 2, respectively.