JPH031153A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To maintain a stable surface potential even after repetition of copying processes by mixing at least one kind of a hydrazone compd., fluorene compd. and m-phenylene diamine compd. which are respectively specific into a photosensitive layer contg. specific compds. CONSTITUTION:The photosensitive layer contg. the perylene compd. expressed by formula I as a charge generating material and the diamine deriv. expressed by formula II, as a charge transfer material, and further at least one kind of the hydrazone compd., fluorene compd. and m-phenylene diamine compd. respectively expressed by formulas III to V in a binder resin is formed. In the formulas I to V, R<1> to R<4> denote an alkyl group; R<5> to R<9> denote a hydrogen atom, alkyl group, R<10> to R<14> denote an alkyl group, alkoxyl group, etc. The photosensitive body which is excellent not only in electrophotographic characteristics, such as electrostatic charge characteristic, sensitivity and resid ual potential but in the repetitive stability as well is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic photoreceptor suitably used in an image forming apparatus such as a copying machine.

(Prior art) In recent years, organic photoreceptors have been used as photoreceptors for electrophotography, in which a photosensitive layer is formed on a conductive substrate, as they are easy to process and are advantageous in terms of manufacturing costs, as well as offering greater freedom in functional design. has been done. The above-mentioned organic photoreceptor has a photosensitive layer in which the charge generation function and the charge transport function are separated by a charge generation material that generates a charge upon light irradiation and a charge transport material that transports the generated charge, thereby achieving high sensitivity. A functionally separated type electrophotographic photoreceptor is known. The photosensitive layer of the functionally separated electrophotographic photoreceptor is a laminated photoreceptor in which at least a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material and a binder resin are laminated. A variety of single-layer photoreceptors have been proposed in which a charge-generating material and a charge-transporting material are dispersed in a binder resin.

The laminated photoreceptor has various functions separated by a charge generation layer and a charge transport layer, and therefore, unlike the single-layer photoreceptor, it has the advantage of high sensitivity and a wide selection of photosensitive materials.

By the way, many charge transport materials are of the positive charge transport type, and in order to provide durability on the surface, a laminated photosensitive material for negative charging, in which a charge generation layer is provided on a conductive substrate and a charge transport layer is further provided on top of the charge generation layer, is used. It is common to take the structure of the body. However, with such a laminated photoconductor for negative charging, ozone is generated in the atmosphere when negatively charged, causing deterioration of the photoconductor and contamination of the copying environment, and in addition, positively charging toner, which is difficult to manufacture, is required for development. There are problems such as.

On the other hand, the single-layer type photoreceptor described above can not only be positively charged, but also use a negatively charged toner as a toner for developing an electrostatic latent image on the photoreceptor. This is advantageous in that it is generally easy to obtain toner that is negatively charged, so there is a wide range of toner materials to choose from, and a variety of toner materials can be used.

However, - to move electrons and holes in the layer,
Either one becomes a trap and the residual potential tends to increase. Moreover, there is a problem in that electrophotographic properties such as charging characteristics, sensitivity, and residual potential are greatly influenced by the combination of the charge-generating material and the charge-transporting material.

Therefore, in view of the above problems, by combining a diamine derivative whose drift mobility has low dependence on electric field strength and a perylene compound, a positively chargeable monolayer with excellent electrophotographic properties such as chargeability, sensitivity, and residual potential can be created. A type electrophotographic photoreceptor (Japanese Patent Application No. 62-277158) was previously proposed.

(Problems to be solved by the invention) However, the previously proposed patent application No. 62-277158
Although the photoreceptor disclosed in the publication has excellent electrophotographic properties such as charging characteristics, sensitivity, and residual potential, the inventors of the present invention aimed to provide a photoreceptor with excellent surface potential stability even during repeated copying processes. As a result of intensive research, the photoreceptor of the present invention was completed.

Accordingly, an object of the present invention is to provide a positively chargeable single-layer electrophotographic photoreceptor that is excellent not only in electrophotographic properties such as charging characteristics, sensitivity, and residual potential, but also in repeated stability.

(Means and effects for solving the problems) Therefore, in the present invention, a fluorene compound represented by the following -Formation (1) type compound and the following -Formation (IV) type compound is used as a charge generating material in the binder resin. , a m-phenylenediamine compound represented by the following -formation [v] (wherein R5 represents a hydrogen atom or an alkyl group (in the formula,
R', R", R', and R4 represent an alkyl group)
A perylene compound represented by: and a diamine derivative represented by the following formula [■] (wherein R'', R', R' and R' represent a hydrogen atom or an alkyl group) as a charge transport material. And, furthermore, the hydrazone represented by the following - formation [■] (in the formula,
RIO1R, R"5R13, R+4 is an alkyl group,
an alkoxyl group or a halogen atom, each of which does not need to be substituted with a phenyl group, or may be substituted with any number of phenyl groups as long as it can be substituted, and all substituents may be the same or different from each other) The above object was achieved by forming an electrophotographic photoreceptor by forming a photosensitive layer containing at least one selected from the group on a conductive substrate.

As a result of intensive research, the present inventors have found that a perylene compound represented by the general formula (1) as a charge-generating material and a diamine derivative represented by the general formula (If) as a charge-transporting material are mixed into a binder resin. In a photoreceptor having a single-layer type photosensitive layer containing the above-mentioned -formation (II[), a hydrazone-based compound represented by the above-mentioned -formation (II[)], a fluorene-based compound represented by the above-mentioned -formation (IV), the above-mentioned -formation (V) ) It has been found that a stable surface potential can be maintained even when the copying process is repeated by selecting and mixing at least one type from the group consisting of m-phenylenediamine compounds represented by the following.

(Preferred Embodiment of the Invention) The perylene compound as a charge generating material used in the present invention is represented by the above-mentioned formula (1), and R1, R1 in the formula
, R3, R4, the alkyl group includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t
1 carbon number such as ert-butyl, pentyl, hexyl group, etc.
-6 alkyl groups are exemplified.

Specifically, N, N-di(3,5-dimethylphenyl)perylene-3,4,9,10-tetracarboxydiimide, N, N=-di(3-methyl-5-ethylphenyl)perylene -3,4,9゜10-tetracarboxydiimide, N, N゛ -di(3,5-diethylphenyl)perylene-3,4゜9.10-tetracarboxydiimide, N, N=-di(3, 5-dipropylphenyl)perylene-3,4,9,' 10-tetracarboxydiimide, N, N=-di(3,5-diisopropylphenyl)perylene-3,4,9,10-tetracarboxydiimide , N, N-di(3-methyl-
5=isopropylphenyl)perylene-3,4,9゜1
0-Tetracarboxydiimide, N, N-di(3
,5-dibutylphenyl)perylene-3,4゜9.10
-tetracarboxydiimide, N, N・-di(3,
5-di-tert-butylphenyl)perylene-3,4
,9,10-tetracarboxydiimide, N, N・-
Di(3,5-dibutylphenyl)perylene-3,4,9
, 10-tetracarboxydiimide, N, N--di(
3,5-dibutylphenyl)perylene-3,4,9,1
Examples include 0-tetracarboxydiimide, among which N,N.-di(3,5-dimethylphenyl)perylene-3,4,9,10-tetracarboxydiimide is preferred.

The diamine derivative as a charge transport material used in the present invention is 3,3°-
Dimethyl-N, N, N., No-tetrakis-
4-methylphenyl(1,1”-biphenyl)-4,
4-diamine is used.

Various binder resins can be used in the present invention, such as styrene polymers, acrylic polymers, styrene-acrylic polymers, polyethylene, ethylene-vinyl acetate copolymers, chlorinated polyethylene, and polypropylene. ,
Olefin polymers such as ionomers, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, polyesters, alkyd resins, polyamides, polyurethanes, epoxy resins, polycarbonates, polyarylates, polysulfones, diallyl phthalate, silicone resins, ketone resins,
Various polymers can be used, such as polyvinyl butyral resin, polyether resin, phenol resin, and photocurable resins such as epoxy acrylate.
Poly(4,4°
-cyclohexylidene diphenyl)carbonate is preferred. When using the above poly(4,4=-cyclohexylidene diphenyl) carbonate, unlike bisphenol A polycarbonate, for which conventionally only chlorinated solvents such as dichloromethane and monochlorobenzene could be used from the viewpoint of solution stability, tetrahydrofuran Since solvents such as , methyl ethyl ketone, etc. can also be used, they are preferable from the viewpoint of safety and hygiene, and are easy to handle. In addition, among the above poly(4,4''-cyclohexylidene diphenyl) carbonates, those having a molecular weight of 15,000 to 25,000;
It is preferable that the glass transition point is about 58°C.

The ratio of the perylene compound, diamine derivative, and binder resin to be used is not particularly limited and can be appropriately selected depending on the desired characteristics of the electrophotographic photoreceptor, etc. , perylene compounds 2-2
0 parts by weight, preferably 3 to 15 parts by weight, and 40 to 200 parts by weight, preferably 50 to 100 parts by weight of the diamine derivative. If the amount of perylene compounds and diamine derivatives used is less than the above range, not only the sensitivity of the photoreceptor will not be sufficient, but the residual potential will become large.If the amount exceeds the above range, the abrasion resistance of the photoreceptor will not be sufficient. .

Furthermore, the -formation (
hydrazone compound represented by III), the -formation (
IV) Fluorene compound represented by -formation [V
] is selected from the m-phenylenediamine compounds represented by the formula (IV), or the -formation (I[
A combination of hydrazone compounds represented by I) or
Alternatively, by selecting and mixing two combinations of m-phenylenediamine compounds represented by -formation (V) above, a decrease in surface potential during repeated copying processes is prevented and a stable surface potential is maintained. be able to.

The alkyl group in the above-mentioned -formation (III), (IV), and (V) includes an alkyl group having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, and hexyl group. is exemplified. Further, examples of the alkoxyl group in the general 2 (V) include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, terL-butoxy, pentyloxy, and hexyloxy groups.

Further, examples of the halogen atom in the above-mentioned -formation [V] include fluorine, chlorine, bromine and iodine atoms.

The hydrazone compounds represented by -formation (II[) include 3-carbazolylaldehyde N, N-diphenylhydrazone, N-methyl-3-carbazolylaldehyde N, N-diphenylhydrazone, N-ethyl -3-
Carbazolyl aldehyde N.

N-diphenylhydrazone, N-propyl-3-carbazolyl aldehyde N, N-diphenylhydrazone, N-
Isopropyl-3-carbazolylaldehyde N, N-diphenylhydrazone, N-butyl-3-carbazolylaldehyde N, N-diphenylhydrazone, N-isobutyl-3-carbazolylaldehyde N, N-diphenylhydrazone, N -tert-7'' thyl-3-carbazolyl aldehyde N, N-diphenylhydrazone, N-pentyl-3-carbazolyl aldehyde N, N-diphenylhydrazone, N-hexyl-3-carbazolyl aldehyde N, Examples include N-diphenylhydrazone, among others, N-ethyl-3-carbazolyl aldehyde N,N-
Diphenylhydrazone is preferred.

The fluorene compounds represented by the above-mentioned -formation (IV) include 9-carbazolyliminofluorene, 9-(3-
Methylcarbazolylimino)fluorene, 9-(3,6
-dimethylcarbazolylimino)fluorene, 9-(3
, 6-dinithylcarbazolylimino)fluorene, 9-
(3-ethyl-6-methylcarbazolylimino)fluorene, 9-(3,6-dipropylcarbazolylimino)
Fluorene, 9-(3,6-diitubrobylcarbazolylimino)fluorene, 9-(3,6-sibutylcarbazolylimino)fluorene, 9-(3゜6-diitubutylcarbazolylimino) ) Fluorene, 9-(3,6
-tert-butylcarbazolylimino)fluorene, 9-(3,6-dibentylcarbazolylimino)fluorene, 9-(3,6-dihexylcarbazolylimino)fluorene, 9-(3,6-dibentylcarbazolylimino)fluorene, -dimethylcarbazolylimino)-3-methylfluorene, 9-(3,6-dimethylcarbazolylimino)-3,6-dimethylfluorene, 9-(3,6-dimethylcarbazolylimino) )−
Examples include 3,6-dinitylfluorene, 9-(3,6-dimethylcarbazolylimino)-3-ethylfluorene, and among them, 9-carbazolyliminofluorene is preferable.

Examples of the m-phenylenediamine compound represented by -formation (V) include N, N, N', N'-tetraphenyl-1,3-phenylenediamine, N.

N,N',N'-tetrakis(3-tolyl)-1°3-phenylenediamine, N,N,N',N'-tetraphenyl-3,5-tolylenediamine, N.

N, N', N'-tetrakis(3-tolyl)-3゜5-tolylene diamine, N, N, N', N'
-tetrakis(4-tolyl)-1,3-phenylenediamine, N,N,N',N"-tetrakis(4-tolyl)-3,5-lylenediamine, N,N,N'.

No-tetrakis(3-ethylphenyl)-1゜3-phenylenediamine, N,N,N'' Nl-tetrakis(4-propylphenyl)-1,3-phenylenediamine, N,N,N',No- Tetraphenyl-5-methoxy-1,3-phenylenediamine, N,N~bis(3
-tolyl)-N', N'diphenyl-1,3-phenylenediamine N.

No-bis(4-tolyl)-N,N'-diphenyl-
1,3-phenylenediamine, N, N-bis(4
-1-lyl)-N,N--bis(3-tolyl)-1,3
-Phenylenediamine, N, Nobis(4-tolyl)-
N, No -bis(3-tolyl)-3,5-)lylenediamine, N, N--bis(4-ethylphenyl)-
N, N=-bis(3-ethylphenyl)-1,3-phenylenediamine, N, N.-bis(4-ethylphenyl)-N.

No-bis(3-ethylphenyl)-3,5-tolylenediamine, N,N,N',N'-tetrakis(2,4
,6-drimethylphenyl)-1,3-phenylenediamine, N,N,N',N'-tetrakis(2,4,6
-1-limethylphenyl)-3゜5-tolylenediamine, N,N,N',N' -tetrakis(3,5-dimethyl)-1,3-phenylenediamine, N,N,N',
N'-tetrakis(3<5-dimethyl)-3,5-tolylenediamine, N.

N,N',N''-tetrakis(3,5-diethyl)1.
3-phenylenediamine, N, N, N'.

N''-tetrakis(3,5-dimethyl)-3,5-tolylenediamine, N,N,N',N'-tetrakis(3
-chlorophenyl)-1,3-phenylenediamine, N
, N, N', N'-tetrakis(3-bromophenyl)
-1,3-phenylenediamine, N, N, N', N'-
Tetrakis(3-iodophenyl)-1,3-phenylenediamine N.

N,N',N'-tetrakis(3-fluorophenyl)
Examples include -1,3-phenylenediamine, but among them, the interaction between molecules is small due to poor molecular symmetry, and conversely, the interaction with the resin is large, so it is extremely crystalline. RIO, R1 in the above-formation [V] is
1, RI:1. , a group in which R14 is substituted in the meta position relative to the nitrogen atom, and a compound, or a group in which Rto, R14 is substituted in the rose position relative to the nitrogen atom, and RI +, R1ff is substituted in the meta position relative to the nitrogen atom. Compounds that have the following properties are preferred. Specifically, N, N, N', N'-tetrakis (3
-tolyl)-1,3-phenylenediamine, N, N
= -His(4-tolyl)-N, N= -bis(3
-tolyl)-1,3-phenylenediamine.

Each of the above compounds can be used in an appropriate amount depending on the characteristics of the photoreceptor, etc. However, when using a hydrazone compound among the above compounds, a diamine compound and a hydrazone compound as a charge transport material are used. It is preferable that these are contained in the photosensitive layer in a weight ratio of 95:5 to 90:10.

Furthermore, when a fluorene compound is used among the above compounds, it is preferable that the diamine compound as a charge transport material and the fluorene compound are contained in the photosensitive layer in a weight ratio of 90:10 to 80:20. .

In addition, when using an m-phenylenediamine compound among the above-mentioned compounds, the diamine compound as a charge transport material and the m-phenylenediamine compound are 75:
Weight ratio of 25 to 25 near 5, especially 70:30 to 50
:50 in the photosensitive layer.

That is, if each of the above compounds is contained in the photosensitive layer in a proportion smaller than the above weight ratio, the repeatability characteristics will not be sufficient, whereas if the above compounds are contained in a proportion exceeding the above weight ratio, the repeatability characteristics will be high, but the sensitivity etc. will be insufficient. Dena (becomes)

In addition, since the perylene-based compound has no spectral sensitivity on the long wavelength side, in order to increase the sensitivity when the single-layer electrophotographic photoreceptor of the present invention is combined with a halogen lamp having a large red spectral energy, It is preferable to use an X-type metal-free phthalocyanine that has spectral sensitivity on the long wavelength side.

The above X-type metal-free phthalocyanine has a Bragg angle (2θ±0.2°) of 7.5', 9°1@, 16
．． It is preferable that the X-type metal-free phthalocyanine exhibits strong diffraction peaks at 7'17.3" and 22.3".
When 25 to 3.75 parts by weight is added, the spectral sensitivity region shifts to the longer wavelength side, and the sensitivity of the photoreceptor becomes higher. However, simply adding 1.25 parts by weight or less of the X-type metal-free phthalocyanine to 100 parts by weight of the perylene compound does not produce a sensitizing effect on the long wavelength side. Furthermore, if 3.75 parts by weight or more of X-type metal-free phthalocyanine is added to 100 parts by weight of the perylene compound, the spectral sensitivity on the long wavelength side will conversely increase, resulting in poor reproducibility of red originals. .

Further, when an antioxidant is used in combination, it is possible to suitably prevent deterioration due to oxidation of charge transport materials, etc., which have a structure that is not easily affected by oxidation.

The above antioxidants include 2,6-tert-butyl-p-cresol, triethylene glycol-bis(
3-(3-tert-butyl-5methyl-4-hydroxyphenyl)propione-)L 1,6-hexanediolubis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) ) propionate], pentaerythrityl-tetrakis (3-(3,5-di-t)
ertbutyl-4-hydroxyphenyl)propione
)), 2,2-thio-diethylenebis[3-(3,5-
di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-thiobis(4-methyl-6-L)
ert-butylphenol), N, N=-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 1,3.5-)dimethyl-
Examples include phenolic antioxidants such as 2゜4.6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, among which 2,6-
C-tert-butyl-p-cresol is preferred.

The photoreceptor of the present invention can be obtained by preparing a coating solution containing the above-mentioned components, coating the coating solution on a conductive substrate, and drying the coating solution.

The conductive substrate may be in the form of a conductive sheet or a drum, and may be made of various conductive materials,
For example, surface-anodized or untreated aluminum, aluminum alloys, copper, tin, platinum, gold,
Single metals such as silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, brass, etc., and plastic materials with layers of the above metals, indium oxide, tin oxide, etc. formed by means such as vapor deposition. Examples include aluminum and glass, among which aluminum which has been anodized by a sulfuric acid alumite method and sealed with nickel acetate is preferred.

Further, the conductive substrate may be surface-treated with a surface treatment agent such as a silane coupling agent or a titanium coupling agent to improve adhesion to the photosensitive layer, if necessary.

In addition, when preparing the above-mentioned coating liquid, an appropriate organic solvent is used depending on the type of binder resin used, and examples of the organic solvent include methanol, ethanol, propatool, isopropateol, and butanol. Alcohols such as n-hexane, octane, cyclohexane, etc., aromatic hydrocarbons such as benzene, toluene, xylene, etc., halogenated hydrocarbons such as dichloromethane, dichloroethane, carbon tetrachloride, chlorobenzene, tetrahydrofuran, Examples include various solvents such as ethers such as ethylene glycol dimethyl ether and ethylene glycol diethyl ether, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and esters such as ethyl acetate and methyl acetate, which may be used singly or in combination of two or more. . In addition, when preparing each of the above coating liquids, in order to improve dispersibility, coating properties, etc., silicone oil such as polydimethylsiloxane, leveling agents such as surfactants, etc.
Alternatively, various additives such as conventionally known sensitizers such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination.

Each of the above-mentioned coating liquids can be prepared using a conventional mixing and dispersing method, such as a paint shaker mixer, ball mill, sand mill, attritor, ultrasonic disperser, etc. When applying the obtained dispersion liquid, etc. Conventional coating methods such as dip coating, spray coating, spin coating, roller coating, blade coating, curtain coating, and bar coating methods are employed.

The single-layer type photosensitive layer of the electrophotographic photoreceptor in the present invention may have an appropriate thickness, but is 15 to 30 μm, particularly 18 to 30 μm.
A thickness of 27 μm is preferred.

(Examples) The present invention will be described in more detail below based on Examples.

Example 1 Poly-(4,4'-cyclohexylidene diphenyl) carbonate (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name Polycarbonate Z) 100 parts, N,N-di(3,5-dimethylphenyl)perylene-3゜4,9.10-Tetracarpoxydiimide 8 parts by weight, X-type metal-free phthalocyanine (manufactured by Dainippon Ink Co., Ltd.) 062 parts by weight, 3,3" -
Dimethyl-N, N, No, N= -tetrakis-4-methylphenyl(1,1゛-biphenyl)-4,
95 parts by weight of 4°-diamine, N-ethyl-3-carbazolylaldehyde N, 5 parts by weight of N-diphenylhydrazone, antioxidant (manufactured by Kawaguchi Chemical Co., Ltd., trade name: ANTAGE BH)
T) Mix and disperse 5 parts by weight of polydimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.01 part by weight of polydimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.), and a predetermined amount of tetrahydrofuran to prepare a dispersion liquid for a single-layer photosensitive layer, and alumite treatment. A photosensitive layer with a thickness of about 23 μm was formed, and a photosensitive layer of about 10
An electrophotographic photoreceptor was prepared by heat treatment at 0°C.

Example 2 A single-layer electrophotographic photoreceptor was produced in the same manner as in Example 1, except that 10 parts by weight of 9-carbazolyliminofluorene was added.

Example 3 3,3゛-dimethyl-N, N used in Example 1.

N=, N-tetrakis-4-methylphenyl (1,
Using 30 parts by weight instead of 95 parts by weight of 1=-biphenyl)-4,4'-diamine, and using N, N, No in place of 5 parts by weight of N-ethyl-3-carbazolyl aldehyde A single-layer electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that 70 parts by weight of N''-tetrakis(3-tolyl)-1,3-phenylenediamine was used.

Example 4 3,3°-dimethyl-N, N used in Example 1.

No, N= -tetrakis-4-methylphenyl (
701 parts by weight of 1,1'-biphenyl)-4,4-diamine was used in place of 95 parts by weight, and N, N was used in place of 5 parts by weight of N-ethyl-3-carbazolyl aldehyde N, N-diphenylhydrazone.・-bis(4-tolyl)-N,
A single-layer electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that 30 parts by weight of N.-bis(3-tolyl)-1,3-phenylenediamine was used.

Example 5 A single-layer electrophotographic photoreceptor was produced in the same manner as in Example 3, except that 10 parts by weight of 9-carbazolyliminofluorene was added.

Example 6 A single-layer electrophotographic photoreceptor was produced in the same manner as in Example 4, except that 10 parts by weight of 9-carbazolyliminofluorene was added.

Comparative Example 1 N-Ethyl-3-carbazolylaldehyde used in Example 1 Without adding N,N-diphenylhydrazone, 3,3
・-Dimethyl-N, N, N., N.

Tetrakis-4-methylphenyl (1,l=biphenyl)-4,4=-diamine 95 10 in place of fJ part
A single-layer electrophotographic photoreceptor was produced in the same manner as in Example 1 except that 0 parts by weight was used.

Comparative example 2 3,3゛-dimethyl-N, N used in Example 1.

N=, N= -Tetrakis-4-methylphenyl(1,i'-biphenyl)-4,4--diamine not added, N-ethyl-3-carbazolylaldehyde N
A single-layer electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that 100 parts by weight of N-diphenylhydrazone was used instead of 5 parts by weight.

Comparative Example 3 Example 1 except that N,N-diethylaminobenzaldehyde-N,N-diphenylhydrazone was used in place of N-ethyl-3-carbazolylaldehyde N,N-diphenylhydrazone used in Example 1. A single-layer electrophotographic photoreceptor was prepared in the same manner as above.

In order to investigate the charging characteristics and photosensitive characteristics of each electrophotographic photoreceptor obtained in the above Examples and Comparative Examples, an electrostatic copying tester (manufactured by Dientic Co., Ltd., Dientic Cynthia 3) was used.
Each of the electrophotographic photoreceptors was positively charged using 0M).

Note that the surface potential of each electrophotographic photoreceptor V s, p, (
At the same time, the surface of the electrophotographic photoreceptor is exposed to light using a tungsten lamp with an illuminance of 10 lux, and the time required for the surface potentials V S and P to become 1/2 is determined, and the half-decreased exposure amount is determined. El/2 (μJ/cm") was calculated. Also, the surface potential 0.15 seconds after exposure was defined as residual potential -,p, (v).

In addition, it was also investigated whether the surface potential would decrease after repeated use 1000 times. In addition, due to repeated use of the photoreceptor, those whose surface potential decreased by 100 V or more were evaluated as ×, those whose surface potential decreased within the range of 50 to 100 V were evaluated as Δ, and those whose surface potential decreased by only 50 V or less were evaluated as ○. .

Furthermore, after copying a gray original with the same brightness as red and measuring the reflection density of the resulting copy using a reflection densitometer, those with a reproducibility of 70% or less are classified as ×, and those within the range of 70-100% was evaluated as Δ, and those of 100% or more were evaluated as ○.

Table 1 shows the charging characteristics, photosensitive characteristics, etc. of each electrophotographic photoreceptor obtained in the above Examples and Comparative Examples.

Red color reproducibility was investigated by calculating . As is clear from the above Red Table 1, the electrophotographic photoreceptors of Examples 1 to 6 all have excellent charging characteristics, high sensitivity, low residual potential, and good repeatability and red color reproducibility. It turns out that there is something.

On the other hand, although the electrophotographic photoreceptors of Comparative Examples 1 to 3 are all excellent in red reproducibility, the electrophotographic photoreceptors of Comparative Examples 2 and 3 have low sensitivity and low residual potential. Moreover, the electrophotographic photoreceptors of Comparative Examples 1 to 3 had insufficient repeatability.

(Effects of the Invention) As described above, the electrophotographic photoreceptor of the present invention has excellent charging characteristics, high sensitivity, and low residual potential, as well as excellent repeatability and red color reproducibility. Also,
Since it is a single-layer type photoreceptor, it not only has excellent positive chargeability, but also has the unique effects of being easily manufactured with good yield and being inexpensive.

Patent applicant: Mita Kogyo Co., Ltd. Japan Distilling Industry Co., Ltd. Nippon Shokubai Chemical Co., Ltd.

Claims (4)

[Claims] (1) In the binder resin, as a charge generating material, the following general formula [
I ] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [ I ] (In the formula, R^1, R^2, R^3, and R^4 represent an alkyl group) , diamine derivatives represented by the following general formula [II] ▲Mathematical formulas, chemical formulas, tables, etc.▼[II] as charge transport materials, and hydrazone compounds represented by the following general formula [III], the following general A photosensitive layer containing at least one selected from the group consisting of a fluorene compound represented by the formula [IV] and an m-phenylenediamine compound represented by the following general formula [V] is provided on a conductive substrate. An electrophotographic photoreceptor characterized by being formed into. ▲There are mathematical formulas, chemical formulas, tables, etc.▼[III] (In the formula, R^5 represents a hydrogen atom or an alkyl group) ▲There are mathematical formulas, chemical formulas, tables, etc.▼[IV] (In the formula, R^6, R^7, R^8 and R^9 represent a hydrogen atom or an alkyl group) ▲There are mathematical formulas, chemical formulas, tables, etc.▼[V] (In the formula, R^1^0, R^1^1, R^1^2, R^1
^3 and R^1^4 represent an alkyl group, an alkoxyl group, or a halogen atom, and each may be substituted with any number of phenyl groups as long as it can be substituted, and all substituents are (can be the same or different from each other). (2) The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer contains an X-type metal-free phthalocyanine. (3) The electrophotographic photoreceptor according to claim 1 or 2, wherein the photosensitive layer contains an antioxidant. (4) The perylene compound is N,N'-bis(3,5-
2. The electrophotographic photoreceptor according to claim 1, which is dimethylphenyl)perylene-3,4,9,10-tetracarboxydiimide.