JPH01246558A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To make it difficult to cause defects in coating at the time of manufacture by incorporating at least one of bisazo type compounds or phthalocyanine type compounds and at least one of polycyclic quinone type compounds in an electric charge generating layer and specifying its thickness. CONSTITUTION:The charge generating layer contains at least one of the bisazo type compounds or phthalocyanine type compounds and at least one of the polycyclic quinone type compounds, and the layer has film thickness of 0.5-5mum, preferably, 0.5-3mum, thus permitting the best electrophotographic characteristics to be obtained, and coating defects to be made difficult to occur at the time of manufacture because a comparatively thick film can be made. In addition, a preferable weight ratio of the charge generating material to a binder resin is 100:0-100:500.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrophotographic photoreceptor using two types of charge generating substances.

[Background of the Invention] With the recent increase in speed and miniaturization of electrophotographic copying machines, there is an increasing demand for higher sensitivity of the electrophotographic photoreceptors used in these machines.From this perspective, so-called functionally separated type Electrophotographic photoreceptors are becoming mainstream.

Azo pigments, especially bisazo pigments (
For example, JP-A-47-3754, JP-A-53-133445
No. 58-70232, No. 58-140745, etc.) have good sensitivity on the long wavelength side of 570 rv or more, and have relatively high sensitivity as a whole. However, when such an azo pigment is used as a charge generating substance, its charge transport ability is low, and in order to take advantage of the long wavelength sensitivity, the thickness of the charge generating layer must be approximately 0.1 to 0.3 μl. need to be formed. If the film thickness is increased, the charging ability and sensitivity will be insufficient, and the repeatability will also deteriorate. When such a thin film is applied using the dip coating method, which is a common manufacturing method, uneven coating, liquid dripping,
Coating defects such as agglomeration are likely to occur, leading to lower coating yields, lower productivity, and higher costs.

In addition, phthalocyanine pigments are also known as charge-generating substances (Japanese Patent Publication No. 49-4338, JP-A No. 58-1
No. 82639, No. 60-19154, etc.), which have the same problems as the above-mentioned azo pigments.

On the other hand, polycyclic quinone pigments are known as pigments with good copy image reproducibility (see JP-A-57-67933).
. Polycyclic quinone pigments generally have a higher charge transport ability than bisazo pigments, and when used in a relatively thick charge generation layer, usually about 0.5 to 3 μm, a photoreceptor with good electrophotographic properties can be obtained. Therefore, since a relatively thick film can be formed, coating defects are less likely to occur during manufacturing. However, when this polycyclic quinone pigment is used, the sensitivity decreases greatly in the region of 570n1 or more, and there is almost no sensitivity in the region of 580 to f32Orv, so high-speed copying that requires high sensitivity The sensitivity is insufficient for use in printers and small copying machines.

[Object of the invention] The present invention has been made in view of the above-mentioned conventional problems,
Firstly, to provide an electrophotographic photoreceptor that has sufficient sensitivity even when used in high-speed copying machines and small-sized copying machines, and is resistant to coating defects during manufacturing and has excellent productivity.Secondly, it has excellent repeatability. The purpose is to provide an electrophotographic photoreceptor with excellent high sensitivity.

[Structure of the Invention] The above object of the present invention is to provide an electrophotographic photoreceptor having at least a charge generation layer and a charge transport layer on a conductive support, in which the charge generation layer is selected from bisazo compounds and phthalocyanine compounds. This is achieved by an electrophotographic photoreceptor containing at least one type of compound and at least one type of polycyclic quinone compound, and wherein the charge generation layer has a thickness of 0.5 μIll to 5 μI.

The bisazo compound used in the present invention is represented by, for example, -Monka8-+N-N-A)2.

Here, A represents a coupler, and B represents a divalent i group in which carbon atoms to which an azo group is bonded form a conjugated double bond system. Specifically, for example, the compounds represented by the following - Monana [I] to [VI] are representative.

General formula [I] K+ R2R3K4 In the formula, A "1, Ar2 and Ar s l;
IF represents a substituted or unsubstituted aromatic carbocyclic residue or a substituted or unsubstituted aromatic heterocyclic residue. R1, R2,
R3 and R4 each do not represent a hydrogen atom or an electron-withdrawing group. However, at least one of R1 to R4 is an electron-withdrawing group.

A1 is -NHS O2-Ra (here t' Rs and R7
each represents a hydrogen atom or a substituted or unsubstituted alkyl group, and R8 represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. ). Yl represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, a carboxyl group, or a sulfo group.

zl does not represent an atomic group necessary to constitute a substituted or unsubstituted carbocyclic aromatic ring or a substituted or unsubstituted heterocyclic aromatic ring. R5 is a hydrogen atom, a substituted or unsubstituted argyl group, a substituted or unsubstituted amim LI? Represents a substituted or unsubstituted carbamoyl group, carboxyl group, or an ester group thereof.

A' does not represent a substituted or unsubstituted aryl group.

n represents an integer of 1, 2 or 3; 1 represents an integer of 0.1 or 2;

In general formula [I], when the residue represented by Ar1, Ar2 or Ars has a substituent on its ring, examples of the substituent include a halogen atom, an alkyl group and the like.

Examples of the electron-withdrawing group represented by R1, R2, R3 or R4 include a halogen atom (a single atom, a bromine atom, etc.), a cyano group, a 21-ro group, and the like.

-Momona tI] Typical examples of the compound shown below are shown below, but the invention is not limited thereto.

The following gold layer”・-′”3・ No, A.

No, A.

No, A.

No, RI Rz R3R4, AtNo, 1
-17 No, l-18 No, l-19 No, l-2O NC), l-21 No, A.

- Monna [n] Here, Ar1 represents an aromatic rii group or a heterocyclic group. Ars and Ars each have aroma 1! X represents a ring group. R9 and [11 each represent a hydrogen atom, an alkyl group, or an aryl group'! 1', R10 is an alkyl group,
Represents a carboxyl group or its ester group.

Z2 represents an atomic group necessary to form an aromatic ring or a heterocycle.

The aromatic ring group represented by Ars, Ar5 or Ars is, for example, a phenyl group, a naphthyl group, etc., and the heterocyclic group represented by Ars is, for example, a dibenzofuran ring, a carbazole ring, an indole ring, etc.

The alkyl group represented by Rs, Rho or Rat is, for example, a lower alkyl group such as a methyl group or an ethyl group, and R9
Alternatively, the aryl group represented by R++ is, for example, a phenyl group. Specific examples of the aromatic ring or heterocycle formed by Z2 include those similar to the above specific examples of Ar+ to Ars.

The polygroup represented by Ar4 to Ar6, R9 to R11 and z2 may have a substituent, and examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, a nitro group,
These include substituted amino groups, acylamino groups, cyano groups, carboxyl groups, sulfonic acid groups, and sulfamoyl groups.

Typical specific examples of the compound represented by the general formula [II] are shown below, but the invention is not limited thereto.

Here it is! and 101 Menu No., Ar< R*
No, Ar4 Rs No, Ar4 R* General formula C1 [I] ○ In the formula, A2 has the same meaning as A2 in the above general formula [TI].

Typical specific examples of the compound represented by the general formula [I[[] are shown below, but the invention is not limited to these.No, Ar<R-
N o , A r <
Rs('-1 No, Ar4R* General formula []V] In the formula, R+2 and R?3 each represent a hydrogen atom, a halogen atom, or an alkyl group, and X2 is 10- or -N-
(RI4 represents a hydrogen atom, an alkyl group, or an aryl group. R15 represents an alkyl group or an aryl group; T and Rts represent a hydrogen atom, an alkyl group, or an aryl group; Ar7 represents an aryl group.

Y2 represents an atomic group necessary to form an aromatic carbocycle or a heterocycle.

Examples of the alkyl group represented by R+2 to R+s include a methyl group and an ethyl group, and Rn to R+s, Ar
Examples of the aryl group represented by 7 include phenyl group,
Examples include naphthyl group, and these groups may have a substituent.

It is particularly preferable that x2 is -0-.

Examples of the arylene group represented by Z3 include a phenylene group and a naphthylene group, and these groups may have a substituent. Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, a nitro group, and a hydroxyl group. Z3 is particularly preferably a substituted or unsubstituted phenylene group.

The aromatic carbocycle or heterocycle formed by Y2 is, for example, a benzene ring, a naphthalene ring, a triazole ring, etc.

Typical specific examples of compounds represented by general formula [IV].

No, R+z R,,R,
.

■-7HH-CH5 TV-8HH-C,H.

IV-9HH-C2H, OCH.

IV-10HH-C,H,○C2H.

N-u HH-C,H,0HN-12-C
H, (3rd position) -CH, (3rd position) -CH.

■-13-CH, 43rd place) -CH, (3rd place)
-C28%■-14-CH, (3rd position) -CH, (3
position) -C, H, OCH.

IV-15-CH, (3rd position) -CH, (3rd position)
C3H-OC2H5IV-18-CH5 (3rd position)
-CH, (3rd position) -C2H,○HNo,
TV-17 No, Rlz R13R1! Art No.
, R12R1ffR+i Ar.

The following is a blank general formula [V] In the formula, Ara and Ars each represent a substituted or unsubstituted aromatic carbocyclic residue or a substituted or unsubstituted aromatic heterocyclic residue. R17 and R+a each represent a hydrogen atom or an electron-withdrawing group.

However, at least one of R17 and R+a is an electron-withdrawing group.

A4 represents -NH8O2-R22 (where R20 and R2+ each represent a hydrogen atom or a substituted or unsubstituted alkyl group, and R22 represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group). .

Y3 represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, a carboxyl or a sulfo group. Z4 represents an atomic group necessary to constitute a substituted or unsubstituted carbocyclic aromatic ring or a substituted or unsubstituted heterocyclic aromatic ring. R+9 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted carbamoyl group, a carboxyl group, or an ester group thereof. A"
represents a substituted or unsubstituted aryl group. n is 1,
It represents an integer of 2 or 3, and m represents an integer of 0, 1 or 2.

In general formula [V], the residue represented by Ara or Ars includes, for example, when the ring has a substituent, 8 1@M includes, for example, a halogen atom, an alkyl group, an alkoxy group, a cyan group, etc. .

As the electron-withdrawing group represented by R+7 or R+a,
Examples include halogen atoms (chlorine atoms, bromine atoms, etc.), cyano groups, nitro groups, and the like.

- Typical specific examples of the compound represented by Monna [V] are shown below, but the compound is not limited thereto.

1+H-, JJN O, R+yRl*
A+No. R. tR,,
A.

No, R, t · R,, A4-Monken [Vl] In the formula, A5 and R24 each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or a hydroxyl group. R25
does not represent an argyl group or an alkoxycarbonyl group. n
does not represent 1, 2 or 3.

- J3 in the hole [Vr] and the halogen atom represented by R23 or R24 is, for example, i! Examples of the alkyl group include a methyl group and an ethyl group; examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the alkyl group represented by R25 include a methyl group and an ethyl group, and examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

- Monana [Representative examples of the compound represented by Vtl are shown below, but the invention is not limited thereto.

Below is the margin ゛1 □-. - No, R2) R24n■
-1-OCH,H1 ■-2-CH,HI VI-3-CI HIVl-4-C1
-OCH, (6th position) IVI-5-C1-CIC4
2■-6-C1-C1 (6th place)
1'v1-7 -C1-C1 (5th place)
IV (-8-C1-C1 (4th position) 1'l/l
-9Br H1■-10-OHHI Vl-11-C1-CH, (3rd position, 5th position) 2N O
, R23Rz -n V[-12-C1-CH, (2nd position) IVI-13
-C1-CH5 (2nd, 4th) 2jH4) general formula [VI] X.

In the formula, x1 represents a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group.

86 represents. Here, R26 represents a substituted or unsubstituted carbamoyl group, and 'a Zs represents an atomic group necessary to form a carbocyclic aromatic ring or a heterocyclic aromatic ring.

R27 represents an alkyl group or an aryl group.

- In the pattern [VI], examples of the halogen atom represented by ×1 include jn elementary atom, bromine atom, etc.
Examples of the argyl group include a methyl group and an ethyl group, and examples of the alkyl group include a methoxy group and an ethoxy group.

Examples of the substituted carbamoyl group represented by R26 include N-phenylcarbamoyl W, N-ethylcarbamoyl group, N-naphthylcarbamoyl N-phenyl-N-ethylcarbamoyl group, and N.

Examples include N-diphenylcarbamoyl group, and these groups may optionally have a substituent.

It will be done.

The carbocyclic or heteroaromatic ring formed by z5 is, for example, a benzene ring, a naphthalene ring, a carbazole ring, etc. 1 1! If! It would be good if it had W.

Examples of the alkyl group represented by R27 include a methyl group and an ethyl group, and examples of the aryl group include a phenyl group, and these groups may have a substituent.

Typical specific examples of the compound represented by the general formula [■] are shown below, but the invention is not limited thereto.

Y.

No, A.I.
X4No, As
X4No, As
X4CH.

Above, representative examples of compounds represented by -Momona [I] to [■] have been given, but as other specific examples, -Momona [I]
For example, JP-A-58-70232 and JP-A-58-70232.
140745, - Mon'ana [II], for example, JP-A-53-133445, - Mon'ana [I [I], for example, JP-A-54-22834, - Mon'ana [rV], for example, JP-A-54-22834. No. 59-229564, - Monana [V
Regarding this, for example, JP-A No. 57-182747,
No. 8-115447, No. 56-116040, - Monana [VI], for example, JP-A-47-37543,
- Regarding the pattern hole [■], for example, JP-A-56-11603
Compounds described in No. 9 can be mentioned.

Further, the above-mentioned bisazo compounds can be easily synthesized by the methods described in the above-mentioned publications.

The phthalocyanine compounds used in the present invention can be either gold-free pan-phthalocyanine compounds or metal phthalocyanine compounds, such as α, β, γ, τ, τ′, η, η′
, an X-type metal-free phthalocyanine compound, and an ε-type copper phthalocyanine compound. Among these, metal-free phthalocyanine compounds are characterized by excellent sensitivity and charging stability. Among these, some characteristic values of metal-free phthalocyanine compounds are as follows.

In addition, these metal-free phthalocyanine compounds are
Publication No. 9-4338, Japanese Unexamined Patent Publication No. 1988-19154,
It is described in detail in Japanese Unexamined Patent Publication No. 182639/1983.

Further, ε-type copper phthalocyanine is described in Japanese Patent Publication No. 40-2780.

The polycyclic quinone compounds used in the present invention are as follows-
Anthoanthrone pigment indicated by pattern hole [A], below-
At least one selected from the dibenzpyrenequinone pigment represented by Monana [B] and the vilanthrone pigment represented by the following - Monana [C] can be mentioned, but in particular -
The hole [A] is 1″5°゛°, -几.

The following is a blank matrix - Mon'ana [A] - Mon'an [B] - Mon'an [CJ In the formula, m represents an integer of 0 to 6. Specific compounds of the anthoanthrone pigment represented by 1°-pattern [A] are as follows.

[Al1 [A2] [A
3] [A4] [A5]
[A6] [A7]
[A8] [A9] [A10] [A11] Specific compound examples of the dibenzpyrenequinone pigment represented by the general formula [B] are as follows.

[B11 [B21 [B11 [B4] [B51 [B11 [B11] [B11 [B11] Vilantrone pigment composition represented by the general formula [C] [C1] [C2] [C3] [C4] [C5] EC6 [C7] [C8] [C9] The polycyclic quinone compounds described above can be synthesized by known methods, but they can also be obtained as commercial products.

Various configurations of electrophotographic photoreceptors are known, but
The electrophotographic photoreceptor of the present invention can take any of these forms.

Usually, the configuration is as shown in FIGS. 1 to 4. Figures 1 and 2
In the figure, at least one compound selected from the above-mentioned bisazo compounds and phthalocyanine compounds is placed on the III-based support 1.
A photosensitive material consisting of a laminate of a charge generation layer 2 with a thickness of 0.5 μIl to 5 μm containing at least one species and a polycyclic quinone compound, and a charge transport layer 3 containing a charge transport substance described below as a main component. A layer 4 is provided, and the stacking order of the charge generation layer 2 and the charge transport layer 3 is different between FIG. 1 and FIG. As shown in FIGS. 3 and 4, this photosensitive layer 4 may be provided on a conductive support with an intermediate layer 5 such as an adhesive layer or a barrier layer interposed therebetween. When the photosensitive layer 4 has a two-layer structure in this manner, a photoreceptor having the most excellent electrophotographic properties can be obtained.

Further, in the present invention, a protective layer may be provided as the outermost layer.

The charge generation layer 2 constituting the photosensitive N4 having a two-layer structure can be applied directly on the conductive support 1 or the charge transport layer 3, or on an intermediate layer 5 such as an adhesive layer or a barrier layer if necessary, for example. It can be formed by the following method.

M-1) A solution in which at least one selected from bisazo compounds and 7' talocyanine compounds and at least one polycyclic quinone compound are dissolved together or separately in an appropriate solvent, or if necessary, a binder. A method of applying a solution in which resin is added and mixed and dissolved.

M-2) At least one selected from bisazo compounds and phthalocyanine compounds and at least one polycyclic quinone compound are mixed together or separately into fine particles (preferably particle size 5.
μIIl or less, more preferably 1 μm or less), and if necessary, a binder resin is added and mixed and dispersed, and a dispersion is applied.

Examples of the solvent or dispersion medium used for forming the charge generation layer include lobethylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N,N-dimethylformamide, acetone, methylethylketone, cyclohexanone, benzene, Toluene, xylene, chloroform, 1
．． 2-dichloroethane, 1,2-dichloropropane, 1
゜1.2-trichloroethane, 1,1.1-trichloroethane, trichloroethylene, tetrachloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate,
Examples include butyl acetate, dimethyl sulfoxide, methyl cellosolve, and the like.

Further, the charge transport layer can be formed in the same manner as the charge generation layer described above.

Any binder resin can be used to form the charge generation layer or the charge transport layer, but it is preferable to use a film-forming polymer that is hydrophobic, has a high dielectric constant, and is electrically insulating. preferable. Examples of such high molecular weight polymers include, but are not limited to, the following.

P-1) Polycarbonate P-2) Polyester P-3) Methacrylic acid P-4) Acrylic resin P-5) Polyvinyl chloride P-6) Polyvinylidene chloride P-7) Polystyrene P-8) Polyvinyl acetate P-9 ) Styrene-butadiene copolymer p-10) Vinylidene chloride-acryloni-1-lyl copolymer p-11) Vinyl chloride-vinyl acetate copolymer p-12)
Vinyl chloride-vinyl acetate-maleic anhydride copolymer p-13) Silicone resin p-14) Silicone-alkyd resin p-15) Phenol formaldehyde resin p-1
6) Styrene-alkyd resin p-17) Poly-N-
Vinyl carbazole P-18) Polyvinyl butyral P-19) Polyvinyl formal These binder resins can be used alone or as a mixture of two or more.

The thickness of the charge generation layer formed as described above was set to 0.5
The best electrophotographic properties can be obtained by setting the thickness to 5 μm to 11 μm, preferably 0.5 to 3 μm. Furthermore, since a relatively thick film can be formed, coating defects are less likely to occur during manufacturing.

Further, in the charge generation layer formed as described above, the weight ratio of the charge generation substance consisting of at least one selected from bisazo compounds and phthalocyanine compounds and at least one polycyclic quinone compound and the binder is Preferably it is 100:0 to 100:500. If the content of the charge generating substance is less than this, the photosensitivity will be low and the residual potential will increase, and if it is more than this, the dark decay and acceptance potential will decrease.

Further, the combined ratio of at least one polycyclic quinone compound and at least one selected from bisazo compounds and phthalocyanine compounds is 100:1 to 100:1 by weight.
It is preferably 30, and if the proportion of at least one selected from bisazo compounds and phthalocyanine compounds is greater than this, electrophotographic properties will deteriorate.

Further, in the charge transport layer formed as described above, the charge transport material is the binder resin 100 in the charge transport layer.
It is preferably 20 to 200 parts by weight, particularly preferably 30 to 150 parts by weight.

Further, the thickness of the charge transport layer to be formed is preferably 5 to 5.
The thickness is preferably 5 to 30 μm.

The charge transporting substance used in the present invention is not particularly limited, but includes, for example, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidasilone derivatives, imidazolidine derivatives, and imidazole derivatives. Lysine derivatives, styryl compounds, hydrazone compounds, pyrazoline derivatives, amine derivatives, oxacilone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline g 1, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole , poly-1-vinylpyrene, poly-9-nylanthracene, and the like.

The charge transport material used in the present invention has an excellent ability to transport holes generated during light irradiation to the support side, and is also suitable for combination with the polycyclic quinone compounds, bisazo compounds, phthalocyanine compounds, etc. Preferred charge transport materials include those represented by the following symbols (A), (B) and (C).

General formula (A> However, Ar+, Ar2, Ar+ each represent a substituted or unsubstituted aryl group, Ar3 represents a substituted or unsubstituted arylene group, R1 is a hydrogen atom, a substituted or unsubstituted alkyl group , or represents a substituted or unsubstituted aryl group.

Specific examples of such compounds are given in JP-A-58-65440, pages 3-4 and JP-A-58-1980/13, pages 3-6.
It is described in detail on the page.

General formula (B) R. However, R1 is a substituted or unsubstituted aryl group, or a substituted.

It is an unsubstituted heterocyclic group, and R2 is a hydrogen atom and is substituted.

It represents an unsubstituted alkyl group, a substituted or unsubstituted aryl group, and in detail, it is described in JP-A-58-134642 and JP-A-58-134642.
It is described in the publication No. 166354.

- Monna (C) However, R1 is a substituted or unsubstituted 7-aryl group, and R2 is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group,
Substituted, unsubstituted alkoxy group, substituted.

unsubstituted amino group, hydroxy group, R3 is substituted,
Represents an unsubstituted aryl group, substituted or unsubstituted heterocyclic group. Synthesis methods and examples of these compounds are given in Japanese Patent Publication No. 57-
It is described in detail in Japanese Patent No. 148750, and can be incorporated into the present invention.

Other preferred charge transport materials of the present invention include JP-A-57-67940, JP-A-59-15252, and JP-A-57.
Examples include hydrazone compounds described in JP-101844.

The conductive support used in the electrophotographic photoreceptor of the present invention is a metal plate including an alloy, a metal drum or a conductive polymer, a conductive compound such as indium oxide, aluminum including an alloy, palladium, gold, etc. Apply a thin layer of total bending,
Examples include paper and plastic films made conductive by vapor deposition or lamination. As an intermediate layer such as an adhesive layer or a barrier layer, in addition to the polymer used as the binder resin, organic polymer substances such as polyvinyl alcohol, ethyl cellulose, and carboxymethyl cellulose, or aluminum oxide are used.

Specific amines may be added to the photosensitive layer of the present invention for the purpose of improving the charge generation function of the charge generation substance, and in particular, amines may be added to the photosensitive layer of the present invention.
Preferably, a grade amine is added.

Examples of such secondary amines include dimethylamine, diethylamine, di-n-amylamine, di-isopropylamine, di-n-butylamine, di-isobutylamine,
Di-n amylamine, di-isoamylamine, di-n hexylamine, di-isohexylamine, di-n pentylamine, di-isopentylamine, di-n octylamine, di-isooctylamine, di-n nonylamine ,
Examples include di-isononylamine, di-n-decylamine, di-isodecylamine, di-n-monodecylamine, di-isomonodecylamine, di-n-dodecylamine, and di-isododecylamine.

The amount of organic amines to be added is preferably 1 times or less, preferably 0.2 to 0.005 times the amount of the charge generating substance.

Further, an antioxidant can be added to the photosensitive layer of the present invention for the purpose of preventing ozone deterioration.

Typical examples of such antioxidants are shown below, but the invention is not limited thereto.

Group (I): Hindered phenols dibutylhydroxytoluene, 2.21-methylenebis(6-t-butyl-4-methylphenol), 4.4'
-butylidenebis(6-t-butyl-3-methylphenol), 4.4' ~thiobis(6-t-butyl-3-
methylphenol), 2,2'-butylidene bis(6-
[-butyl-4-methylphenol), α-tocopherol, β-tocopherol, 2,2,4-trimethyl-
6-Hydroxy7-t-butylchroman, pentaerythyltetrakis [3-(3,5-di-t-butyl-4
-hydroxyphenyl)propionate], 2.2'
-thiodiethylenebis[3-(3°5-di-t-butyl-4-hydroxyphenyl)propionate], 1.6
-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], butylhydroxyanisole, dibutylhydroxyanisole, 1-[2-((3,5-di-tert-butyl-4-
-hydroxyphenyl)propionyloxy)ethyl]
-4-[3-(3,5-di-tert-butyl-4-
hydroxyphenyl)propionyloxy]-2,2,
6,6-tetramethylbiveridyl, etc.

Group (n): Paraphenylenediamines N-phenyl-N'-isopropyl-〇-phenylenediamine, N,N'-di-5ec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p −
phenylene diamine, N.

N'-diisopropyl-p-phenylenediamine, N,
N'-dimethyl-N, N'-di-t-butyl-p-phenylenediamine, etc.

(Iff) group: Hydroquinones 2.5-di-octylhydroquinone, 2゜6-sidodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-[-
Octyl-5-methylhydroquinone, 2-(2-octadecenyl)-5-methylhydroquinone, etc.

(rV) group: organic sulfur compounds dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate, etc.

(Group V1: Organophosphorus compounds triphenylphosphine, tri(nonylphenyl)phosphine, tri(dinonylphenyl)bosphine, tricresylphosphine, tri(2,4-dibutylphenoxy)phosphine, etc.

These compounds are known as antioxidants for rubber, plastics, oils and fats, and are easily available commercially.

These antioxidants may be added to any of the charge generation layer, charge transport layer, or protective layer, but are preferably added to the charge transport layer. In this case, the amount of the antioxidant added is 0.1 to 100 parts by weight, preferably 1 to 50 parts by weight, particularly preferably 1 to 50 parts by weight, based on 1001 parts of the charge transport material.
It is 25 parts by weight.

In the present invention, the charge generation layer may contain one or more electron-accepting substances for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use.

Examples of electron-accepting substances that can be used here include succinic anhydride, maleic anhydride, dibromaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride,
Tetrabromo phthalic anhydride, 3-nitro phthalic anhydride,
4-nitrophthalic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, 0-dinitrobenzene, l-dinitrobenzene, 1.3.5-trinitrobenzene, paranitrobenzonitrile, Picryl chloride, quinone chlorimide,
Chloranil, brumanil, dichlorodicyanobarabenzoquinone, anthraquinone, dinitroanthraquinone, 2
．． 7-sinitrofluorenone, 2,4.7-trinitrofluorenone, 2゜4.5.7-tetranitrofluorenone, 9-fluorenylidene [dicyanomethylenemalonodinitrile], polynitro-9-fluorenylidene-[
dicyanomethylenemalonodinitrile], picric acid, 0
-Nitrobenzoic acid, p-nitrobenzoic acid, 3.5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3.5-dinitrosalicylic acid, phthalic acid, mellitic acid, and other compounds with high electron affinity. can be mentioned.

The addition m of the electron-accepting substance is such that the ratio of charge-generating substance to electron-accepting substance is 100:0.01 to 200, preferably IOQ: 0.1 to 100.

An electron-accepting substance may be added to the charge transport layer.

The amount of electron-accepting substance added to this layer is ff1ffi ratio: charge-transporting substance:electron-accepting substance=100:0.
01-100, preferably 100: 0.1-50
It is.

In addition, the photoreceptor of the present invention may also contain, if necessary, an ultraviolet absorber or the like for the purpose of protecting the photosensitive layer, and may also contain a dye for color sensitivity correction.

The electrophotographic photoreceptor of the present invention has the above structure,
As is clear from the examples described later, it has high sensitivity, and in particular has sufficient sensitivity even when used in high-speed copying machines and small-sized copying machines. Further, the electrophotographic photoreceptor of the present invention has stable characteristics even when used repeatedly.

Furthermore, the electrophotographic photoreceptor of the present invention has good characteristics as a photoreceptor by forming a relatively thick charge generation layer, and therefore has excellent productivity with fewer coating defects during manufacturing as described above. It is something that

[Examples] Hereinafter, the present invention will be specifically explained using Examples, but the embodiments of the present invention are not limited thereby.

Example-1 Polycarbonate resin (Panlite L -1250° manufactured by Konjin Kasei) 5 (+1,2-dichloroethane 2001
After dissolving in 12, 10 o of the exemplified polycyclic bovine non-based compound [A3] was mixed as a charge generating substance CGM2, and dispersed with a sand grinder for 10 hours. This is called liquid A.

Next, after dissolving 1 g of the above polycarbonate resin in 120 iN of 1,2-dichloroethane, the charge generating material CGM1 was dissolved.
The exemplified suazo compounds No. I-22 and 29 were mixed and dispersed with a sand grinder for 10 hours. This is called liquid B.

The above liquids A and B may be used alone or both may be stirred and mixed to form a coating liquid for forming a charge generation layer. Using this coating liquid, the coating liquid is coated on an aluminum drum by a dip coating method to form a charge generation layer. was formed. At this time, the film thickness was varied by changing the rate of pulling up from the coating solution.

Next, a charge transport layer having a thickness of 20 μm after drying was laminated on the above charge generation layer by the same dip coating method using a coating solution for forming a charge transport layer having the following composition to obtain a photoreceptor.

1.2-Dichloroethane 15 g of 100112 polycarbonate resin (same as above) Characteristic evaluation tests of the photoreceptor samples thus obtained were conducted as follows.

[Sensitivity test] Electrostatic charging test device EPA-8100 (Kawaguchi Electric)
(manufactured in
Exposure m E 1/2 (
1-ux·sea> was measured.

[Repetitive characteristic test] Using the above electrostatic charging test device EPA-8100, charging → exposure → static elimination was repeated 100 times, and the test was conducted between the first and 10th time.
0th change in band T3 potential ΔVaO → 100 (v)
was measured.

From the results in Table 1, it is clear that the photoreceptor of the present invention exhibits superior performance in all respects of sensitivity, repeatability, and productivity compared to the comparative photoreceptor.

Example 2 The combination of charge generating substances used was changed as shown in Table 2, and the polycarbonate resin used in the coating liquid for forming the charge transport layer was replaced with Kneepilon 2-200 (manufactured by Mitsubishi Gas Chemical vA). A sample was prepared in the same manner as in Example-1, and a characteristic evaluation test was conducted in the same manner as in Example-1. The obtained results are shown in the table below. The results show that the photoreceptor of the present invention exhibits excellent performance in all aspects of sensitivity, repeatability, and productivity.

Example-3 The combination of charge-generating substances used was changed as shown in Table-3, and the polycarbonate resin used in the coating liquid for forming the charge-transporting layer was replaced with Nipiron Z-200 (mentioned above). A sample was prepared in the same manner as in Example-1 except that .
The test was conducted and the results obtained are shown in Table 3.

From the results in Table 3, it can be seen that the photoreceptor of the present invention exhibits excellent performance in all aspects of sensitivity, repeatability, and productivity. .

Example 4 The combination of charge generating substances used was changed as shown in Table 4, and the polycarbonate resin used in the coating liquid for forming the charge transport layer was roughly replaced with Nipiron 2-200 (mentioned above). A sample was prepared in the same manner as the actual IMLfA-1 except that the transport substance was replaced with 1, and the characteristics evaluation trial training was conducted in the same manner as in Example 1. The obtained results are shown in Table 4.

The following margins: ',, -T--j From the results in Table 4, it can be seen that the photoreceptor of the present invention exhibits excellent performance in all aspects of sensitivity, repeatability, and productivity.

[Brief explanation of the drawing]

FIGS. 1 to 4 are cross-sectional views showing structural examples of the photoreceptor of the present invention, respectively. 1... Conductive support 2... Charge generation layer 3... Charge transport layer 4... Photosensitive layer 5... Intermediate layer

Claims (1)

[Claims] In an electrophotographic photoreceptor having at least a charge generation layer and a charge transport layer on a conductive support, the charge generation layer contains at least one selected from bisazo compounds and phthalocyanine compounds and at least one polycyclic quinone compound. The charge generation layer contains seeds and has a thickness of 0.5 μm.
An electrophotographic photoreceptor having a diameter of m to 5 μm.