JPH031155A - 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 photosen sitive layer contg. specific compds. CONSTITUTION:The photosensitive layer contg. the dibenzoperylene 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> denotes a halogen atom, alkoxy group; R<2> to R<6> denote a hydrogen atom, alkyl group; R<7> to R<11> denote an alkyl group, alkoxy group, etc. The photosensitive body which is excellent not only in electrophotographic characteristics, such as electrostatic charge characteristic, sensitivity and residual 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, in order to move electrons and holes within a single 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.

In view of the above problems, an electrophotographic photoreceptor (Japanese Patent Application No. 63-223651) has been proposed in which dibromoanthrone and a diamine derivative are combined.

(Problems to be Solved by the Invention) However, the above-mentioned photoreceptor has not yet been able to obtain sufficient electrophotographic properties, has excellent electrophotographic properties such as charging properties, sensitivity, and residual potential. However, it is desired to develop a photoreceptor with better surface potential stability.

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 problem) Therefore, in the present invention, the following formula (1) is used as a charge generating material in the binder resin. A phenylenediamine compound (wherein R1 represents a halogen atom or an alkoxy group, and n
represents an integer of O to 4), and a charge transporting material of the following general formula (II) (wherein R2 represents a hydrogen atom or an alkyl group (in the formula,
R3, R', R' and R6 represent a hydrogen atom or an alkyl group. The fluororesin represented (in the formula,
R', R'', R'', and R''% R'' represent an alkyl group, an alkoxy group, or a halogen atom, each of which may not be substituted with a phenyl group or may be substituted with any number of phenyl groups as long as it can be substituted, Further, a photosensitive layer containing at least one selected from the group consisting of (all substituents may be the same or different from each other) is formed on a conductive substrate to constitute an electrophotographic photoreceptor. As a result, the above objectives were achieved.

As a result of intensive research, the present inventors have found that a dibenzopyrene compound represented by the general formula (1) as a charge-generating material and a diamine derivative represented by the general formula (Il) as a charge-transporting material are mixed in a binder resin. In the photoreceptor having a single-layer type photosensitive layer containing the above-mentioned formula (III), a fluorene-based compound represented by the above-mentioned formula (IV), a fluorene-based compound represented by the above-mentioned formula (IV), ) 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 dibenzopyrene compound as the charge generating material used in the present invention is represented by the formula CI), and R1 in the formula
Among these, examples of halogen atoms include fluorine, bromine, and iodine. Among the above halogen atoms, chlorine or bromine is preferred.

In addition, alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy,
Examples include alkoxy groups having 1 to 6 carbon atoms such as tert-butoxy, pentyloxy, and hexyloxy groups.

Specifically, dibenzo(def, mno) cene-6,12-dione, 2,8-dichloro-dibenzo(
def, mno) chrysene-6,12-dione, 4.1
0-dichloro-dibenzo (def.

mno) Chrysene-6,12-dione, 2,4°8.1
0-tetrachloro-dibenzo (def, mno) chrysene-6,12-dione, 2,8-dibromo-dibenzo (
def, mno) chrysene-6,12-dione, 4.1
0-dibromodibenzo(def, mno)chrysene-6,12-dione, 2,4,8.10-tetrabromodibenzo(def, mno)chrysene-6,12-dione, 28-dichloro-4 ,10-dibromo-dibenzo(def, mno)chrysene-6,12-dione, 2,
8-dimethoxydibenzo(def,mno)chrysene-6,12-dione, 4.10-dimethoxy-dibenzo[def,mno]chrysene-6,12-dione, 2
, 8-diethoxydibenzo (def, mno) chrysene-6,12-dione, 4,10-diethoxy-dibenzo (def, mno: l chrysene-6,12-dione,
2゜4.8.10-tetramethoxy-dibenzo (def
, mno) chrysene-6,12-dione, 2°4.8.
10-tetraethoxy-dibenzo(der,mno)chrysene-6,12-dione, 2°8-dimethoxy-41
0-Jethoxy-dibenzo [def, mno) chrysene-6,12-dione, 4,10-dipropoxy-dibenzo (def.

mno) chrysene-6,12-dione, 4,10-diisopropoxy-dibenzo(def, mnO]chrysene-
6,12-dione, 4,10-dibutoxydibenzo[
def, mno] chrysene-6,12-dione, 4,1
0-diisobutoxy-dibenzo (def, mno) chrysene-6,12-dione, 4,10-di-tert, -
butoxydibenzo(def,mno)chrysene-6,1
2-dione, 4,10-dipentyloxydibenzo (
def, mno) chrysene-6,12-dione, 4,1
Examples include 0-dihexyloxydibenzo (def, mno) chrysene-6,12-dione. Among the above dibenzopyrene compounds, 4,10-dibromo-
Dibenzo (def, mnol chrysene-6,12-dione is preferred).

Note that the halides and alkoxides of the dibenzopyrene compounds described above are difficult to isolate and purify, and the positions of the substituents may not be specified in some cases.

The dibenzopyrene compounds represented by formula (r) above may be used alone or in combination of two or more.

The diamine derivative as a charge transport material used in the present invention is 3,3° - expressed by the above formula [■].
Dimethyl-N, N, N., N.-tetrakis-4
-methylphenyl(1,t'-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, Olefin polymers such as polypropylene and ionomers, polyvinyl chloride, vinyl chloride vinyl acetate copolymers, polyesters, alkyd resins, polyamides, polyurethanes, epoxy resins, polycarbonates, polyarylates, polysulfones, diallyl tucrate, silicone resins, )y -1-one resin, polyvinyl butyral resin, polyether resin,
Various polymers can be used, such as phenolic resins and photocurable resins such as epoxy acrylate. Poly (4,
4--cyclohexylidene diphenyl) carbonate is preferred. When using the above-mentioned poly(4,4'-cyclohexylidene diphenyl) carbonate, unlike bisphenol A type polycarbonate, for which conventionally only chlorinated solvents such as dichloromethane and monochlorobenzene could be used from the viewpoint of solution stability, tetrahydrofuran,
A filler such as methyl ethyl ketone can also be used, which is preferable from the viewpoint of safety and hygiene, and is easy to handle. Furthermore, among the above-mentioned poly(4,4"-cyclohexylidene diphenyl) carbonates, those with molecules 115,000 to 25
000, and those having a glass transition point of about 58°C are preferred.

The proportions of the dibenzopyrene compound, diamine derivative, and binder resin to be used are not particularly limited, and can be appropriately selected depending on the desired characteristics of the electrophotographic photoreceptor. 2 to 20 parts by weight, preferably 3 to 15 parts by weight of the dibenzopyrene compound,
40 to 200 parts by weight of diamine derivative, preferably 50 parts by weight
~100 parts by weight are used. If the dibenzopyrene compound and diamine BM conductor are used in less than the above amounts,
Not only is the sensitivity of the photoreceptor insufficient, but the residual potential becomes large. Further, if the amount exceeds the above range, the abrasion resistance of the photoreceptor will not be sufficient.

Further 2. A single layer type photoreceptor containing the above-mentioned dibenzopyrene compound and diamine derivative in a binder resin is coated with the above-mentioned hydrazone-based compound represented by I [I], and the above-mentioned hydrazone-based compound represented by fluorene compound, the above-
Select and mix one type of m-phenylenediamine compound represented by Ritual (V), or mix it with the above-mentioned - Ritual [■
] to the fluorene compound represented by the formula [■], or the m-phenylenediamine compound represented by the formula (V) above. By selecting and mixing the seeds, it is possible to prevent a decrease in surface potential during repeated copying processes and maintain a stable surface potential.

The alkyl group in the above-mentioned formula (I [I), (IV), (V) is a group having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl group, etc. An example is an alkyl group. In addition, the alkoxy group in the above-mentioned formula (V) includes methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy,
Examples include pentyloxy and hexyloxy groups. In addition, as the halogen atom in the above-mentioned ritual (V),
Mention may be made of fluorine, chlorine, bromine and iodine atoms.

The hydrazone compounds represented by the above-mentioned formula (]]1) include 3-carbazolylaltehyde I'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-butyl-3-carbazolyl aldehyde N, N-diphenylhydrazone, N-pentyl-3-carbazolyl aldehyde N, N-diphenylhydrazone, N-hexyl-3-carbazolyl aldehyde N
, N-diphenylhydrazone, etc., among which N-ethyl-3-carbazolyl aldehyde N,N-diphenylhydrazone is preferred.

Examples of the fluorene compounds represented by the formula (TV) include 9-carbazolyliminofluorene, 9-(3-
medylcarbazolylimino)fluorene, 9-(3,6
-dimethylcarbazolylimino)fluorene, 9-(3
, 6-ethylcarbazolylimino)fluorene, 9-
(3-ethyl6-methylcarbazolylimino)fluorene, 9-(3,6-dipropylcarbazolylimino)fluorene, 9-(3,6-diitupropylcarbazolylimino)fluorene, 9-( 3,6-dibutylcarbazolylimino)fluorene, 9-(3゜6-dibutylcarbazolylimino)fluorene, 9-(3,6-diterm-methylcarbazolylimino)fluorene, 9
-(3,6-dibentylcarbazolylimino)fluorene, 9-(3,6-dihexylcarbazolylimino)fluorene, 9-(3,6-dimethylcarpazolylimino)-3-methylfluorene , 9-(3,6-dimethylcarbazolylimino)-3,6-dimethylfluorene, 9
-(3,6-dimethylcarbazolylimino)-3,6-
Examples include ethylfluorene, 9-(3,6-dimethylcarbazolylimino)-3-ethylfluorene, and among them, 9-carbazolyliminofluorene is preferred.

The m-phenylenediamine compounds represented by the formula [V] include N, N, N', N'-tedraphenyl-1,3-phenylenediamine, N.

N N', N'-tetrakis(3-tolyl)-1゜3
-phenylenediamine, N,N,N',N'-tetraphenyl-3,5-)lylenediamine, N.

N,N',N'-tetrakis(3-tolyl)-3゜5-
Tolylene diamine, N, N, N', N" -tetrakis(4-tolyl)-1,3-phenylene diamine, N, N
, N', N''-tetrakis(4-tolyl)-3,5-)
Lylene diamine, N, N, N'.

No-tetrakis(3-ethylphenyl)-1゜3-phenylenediamine, N, N, N', N' -tetrakis(4-propylphenyl)-1,3-phenylenediamine, N, N, N', N “-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-
tolyl)-N,N-bis(3-tolyl)-1,3-
Phenylenediamine, N, N-bis(4-tolyl)-
N, N=-bis(3-1-lyl)-3,5-1-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
,6-4lymethylphenyl)-1,3-phenylenediamine, N,N,N',N'-teI.rakis(2,4,
6-doramethylphenyl)-3゜5-tolylenediamine, N, N, No 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''Nl-tetrakis(3-chlorophenyl)-1, 3-phenylenediamine, N, N, N'
, N'-tetrakis(3-bromophenyl)-1,3-
Phenylenediamine, N,N,N" N I-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. R7 and R11 in the above-mentioned ritual (V)
, RIQ, a compound in which R is substituted at the meta position relative to the nitrogen atom, or a group in which R7 and R11 are substituted at the para position relative to the nitrogen atom, and R11 and R1++ are substituted at the meta position relative to the nitrogen atom Compounds with 7 are preferred. Specifically, N, N, N', N'-tetrakis(3-tolyl)-1
,3-phenylenediamine, N,N.-bis(4-tolyl)-N,No-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, but when using a hydrazone compound among the above compounds, a diamine compound as a charge transport material and a hydrazone compound are used. The compound is preferably 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:
It is preferably contained in the photosensitive layer in a weight ratio of 25 to 25:75, particularly 70:30 to 50:50.

In other words, if the photosensitive layer contains each of the above compounds in a proportion smaller than the above weight ratio, the repeatability will not be sufficient, whereas if the photosensitive layer contains each of the above compounds in a proportion exceeding the above weight ratio, the repeatability will be high but the repeatability will be poor. etc. will no longer be sufficient.

In addition, since the dibenzopyrene compound has no spectral sensitivity on the long wavelength side, it becomes more dangerous when the single-layer electrophotographic photoreceptor of the present invention is combined with a halogen lamp that has a large red spectral energy. It is preferable to use phthalocyanine compounds such as metal-free phthalocyanine and oxotitanyl phthalocyanine that have spectral sensitivity on the long wavelength side.

The metal-free phthalocyanine has a Blang angle (2θ±0.2') of 7.5", 9°1° 16.
X-type materials showing strong diffraction peaks at 7°, 17.3° and 22.3° are preferred. When 1.25 to 3.75 parts by weight of the above-mentioned X-type metal-free phthalocyanine is added to 100 parts by weight of the dibenzopyrene compound, the spectral sensitivity region shifts to the longer wavelength side, and the sensitivity of the photoreceptor becomes higher. . However, 1.2 parts by weight of X-type metal-free phthalocyanine per 100 parts by weight of the dibenzopyrene compound
Addition of 5 parts by weight or less does not produce a sensitizing effect toward longer wavelengths. In addition, 3.75 parts by weight of X-type metal-free phthalocyanine was added to 100 parts by weight of the dibenzopyrene compound.
If more than one part by weight is added, the spectral sensitivity on the long wavelength side will conversely increase, resulting in poor reproducibility of red originals.

Examples of the oxotitanylphthalocyanine include:
The following formula (VI) having various crystal forms such as α type, β type, γ type, δ type and ε type (wherein, X represents a halogen atom, and m represents O or an integer of 1 or more) Among them, the halogen atom in the -ritual (', JT) is bromine or chlorine, m is O, and the Bragg angle in the X-ray diffraction spectrum (2θ±0 .2°) but 6.9.9
゜6'15.6'!7.6', 21°9°
, 23.6', 24.7° and 28.0'', and α-type oxotitanyl phthalocyanine is preferred, which exhibits the characteristic that the diffraction peak at 6.9° among the Bragg angles is the largest.

Since the dibenzopyrene compound does not have spectral sensitivity on the long wavelength side, the oxotitanyl phthalocyanine is added at 0.62 parts by weight per 100 parts by weight of the dibenzopyrene compound.
By adding 1.88 parts by weight, the spectral sensitivity region shifts to the long wavelength side, and when combined with a halogen lamp with large red spectral energy, the sensitivity of the photoreceptor becomes higher. However, simply adding 0.62 parts by weight or less of oxotitanylphthalocyanine to 100 parts by weight of the dibenzopyrene compound does not produce an exacerbating effect on the long wavelength side. Further, 1.0% of oxotitanylphthalocyanine was added to 100 parts by weight of the dibenzopyrene compound.
If 88 parts by weight or more is added, 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 antioxidants mentioned above include 2,6-di-ter-butyl-p-cresol, triethylene glycol-bis(
3-(3-tert-butyl-5-methyl-4-
hydroxyphenyl)propionate], 1,6-hexanethiol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], pentaerythrityl-tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate),
ert--)'f-4-hydroxyphenyl)propionate), 2,2-thio-diethylenebis[3-(3
, 5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-thiobis(4-methyl-
6-tert-butylphenol), N,N-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 1. ．． Examples include phenolic antioxidants such as 3,5-trimethyl-24,6-1-lis(3,5-di-butyl-4-hydroxybenzyl)benzene, among others, 2,6-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., and the resulting dispersion is applied. In this case, conventional coating methods such as dip coating, spray coating, spin coating, roller coating, blade coating, curtain coating, bar coating, etc. 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 1 100 parts by weight of poly-(4,4'-cyclohexylidene diphenyl) carbonate (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name Polycarbonate Z), 4.10-dibromo-dibenzo (def, mno) chrysene-6, 12--dione 8
Parts by weight, X-type metal-free phthalocyanine (manufactured by Dainippon Ink Co., Ltd.) 0.2 parts by weight, 3.3゛-dimethyl-N,
N, N=, N=tetrakis-4-methylphenyl(1,1″-biphenyl)-4,4=-diamine 95 parts by weight, N-ethyl-3-carbazolyl aldehyde N,N-diphenylhydrazone 5 parts by weight part, antioxidant (
5 parts by weight of ANTAGE BHT (manufactured by Kawaguchi Chemical Co., Ltd., trade name), 0.01 part by weight of polydimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.), and a predetermined amount of tetrahydrofuran were mixed and dispersed using an ultrasonic disperser to obtain a dispersion for a single-layer photosensitive layer. An electrophotographic photoreceptor was prepared by adjusting the solution and coating it on an alumite-treated aluminum tube to form a photosensitive layer with a thickness of about 23 μm, followed by heat treatment at about 100°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 (1,1
・-biphenyl)-4,4°-diamine 30 parts by weight was used instead of 95 parts by weight, and N-ethyl-3-carbazolylaldehyde N, N-diphenylhydrazone was replaced with 5 parts by weight of N, N, N. , N.-tetrakis(3-tolyl)-
A single-layer electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that 70 parts by weight of 1,3-phenylenediamine was used.

Example 4 N, N, N., N.-tetrakis(3-)lyl)-1,3-phenylenediamine used in Example 3 was replaced with N,N.-bis(4-tolyl)-N.

A single-layer electrophotographic photoreceptor was prepared in the same manner as in Example 3 except that 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 process was carried out in the same manner as in Example 1, except that 0.1 part by weight of α-type oxotitanylphthalocyanine was used in place of 0.2 parts by weight of X-type metal-free phthalocyanine in Example 1. created a body.

Comparative Example 1 N-ethyl-3-carbazolyl aldehyde used in Example 1, without adding N,N-diphenylhydrazone, 3.3
・ -dimethyl-N, N, N・,N.

-Tetrakis-4-methylphenyl(1,tobiphenyl)-4,4--Diamine A single-layer electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that 100 parts by weight of diamine was used instead of 95 parts by weight. It was created.

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

N′N= -tetrakis-4-methylphenyl (1,
Example, except that 100 parts by weight of N-ethyl-3-carbazolyl aldehyde N,N-diphenylhydrazone was used instead of 5 parts by weight with the addition of 1°-biphenyl)-4,4°-diamine. A single-layer electrophotographic photoreceptor was prepared in the same manner as in Example 1.

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 is V s, P, (
In addition to measuring v), the surface of the electrophotographic photoreceptor is exposed using a tungsten lamp with an illuminance of 10 lux, and the time required for the surface potentials V S, P to become 1/2 is determined, and the half-reduction exposure ftE 1 /2 (u J/am2) was calculated. Further, the surface potential after 0.15 seconds after exposure was defined as residual potential V, , , (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 O. .

Furthermore, after copying a gray original with the same brightness as red and measuring the reflection density of the obtained copy using a reflection densitometer, red reproducibility was investigated by calculating . Those with red color reproducibility of 70% or less were evaluated as x, those in the range of 70 to 100% were evaluated as Δ, and those in the range of 100% or more were evaluated as O.

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

Table 1 The electrophotographic photoreceptor of Example 2 had low sensitivity and high residual potential.

(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. In addition, since it is a single-layer photoreceptor, it not only has excellent positive chargeability (
, it has the unique effects of being easily manufactured with good yield and being inexpensive.

As is clear from Table 1, the electrophotographic photoreceptors of Examples 1 to 6 all have excellent charging characteristics, high sensitivity,
It was found that the residual potential was small, and the repeatability and red color reproducibility were good.

On the other hand, the electrophotographic photoreceptors of Comparative Examples 1 and 2 both have excellent red reproducibility, but have insufficient repeatability, and furthermore, the comparative patent applicant: Sanda Kogyo Co., Ltd. Industrial 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 represents a halogen atom or an alkoxy group,
n is an integer from 0 to 4), and a diamine derivative represented by the following general formula [II] ▲ Numerical formula, chemical formula, table, etc. are available▼ [II] as a charge transport material , Furthermore, a group consisting of hydrazone compounds represented by the following general formula [III], fluorene compounds represented by the following general formula [IV], and m-phenylenediamine compounds represented by the following general formula [V]. An electrophotographic photoreceptor comprising: a photosensitive layer containing at least one selected from the following, formed on a conductive substrate. ▲There are mathematical formulas, chemical formulas, tables, etc.▼[III] (In the formula, R^2 represents a hydrogen atom or an alkyl group) ▲There are mathematical formulas, chemical formulas, tables, etc.▼[IV] (In the formula, R^3, R^4, R^5 and R^6 represent a hydrogen atom or an alkyl group) ▲There are mathematical formulas, chemical formulas, tables, etc.▼[V] (In the formula, R^7, R^8, R^9, R^1^0, R^1
^1 represents an alkyl group, an alkoxy group, or a halogen atom, each of which may not be substituted with a phenyl group, or may be substituted with as many numbers as possible, and all substituents may be the same or different from each other. ). (2) The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer contains metal-free phthalocyanine or oxotitanylphthalocyanine. (3) The electrophotographic photoreceptor according to claim 1 or 2, wherein the photosensitive layer contains an antioxidant. (4) The electrophotographic photoreceptor according to claim 1, wherein the dibenzopyrene compound is 4,10-dibromo-dibenzo[def, mno]chrysene-6,12-dione.