JPH0446352A - Photosensitive body - Google Patents

Abstract

PURPOSE:To enhance the characteristics of the photosensitive body, such as sensitivity, electric charge transfer performance, initial surface potential, and dark decay, and to reduce light fatigue even at the time of repeated uses by incorporating a specified styryl compound in a photosensitive layer formed on a conductive substrate. CONSTITUTION:The photosensitive layer formed on the conductive substrate contains the styryl compound represented by formula I in which R1 is optionally substituted alkyl, aralkyl, or aryl; R2 is H, alkyl, aralkyl, or optionally substituted aryl; Ar is an optionally substituted aryl or heterocyclic group; X is an O, S, or optionally substituted N atom; Z is residue combined with X and N atom and is optionally substituted; and R2 may combine with Ar to form a ring, thus permitting the photosensitive body to be superior in sensitivity and potential acceptance, small in fatigue deterioration at the time of repeated uses and stable in electrophotographic characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a photoreceptor having a photosensitive layer containing a novel styryl compound.

BACKGROUND TECHNOLOGY AND PROBLEMS Generally, in electrophotography, the surface of the photosensitive layer of a photoreceptor is charged,
A direct method involves exposing to light to form an electrostatic latent image, developing it with a developer to make it visible, and directly fixing the visible image on the photoreceptor to obtain a copy image. A powder image transfer method in which a visual image is transferred onto a transfer material such as paper and the transferred image is fixed to obtain a copy image, or an electrostatic latent image on a photoreceptor is transferred onto a transfer paper, and the electrostatic latent image on the transfer paper is transferred. Electrostatic transfer methods and the like for developing and fixing images are known.

Inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been known as materials constituting the photosensitive layer of a photoreceptor used in this type of electrophotography.

Although these photoconductive materials have many advantages, such as less charge dissipation in the dark or the ability to quickly dissipate charge by light irradiation,
It has various drawbacks.

For example, the manufacturing conditions for selenium-based photoreceptors are difficult;
It is expensive to manufacture and must be handled with care as it is susceptible to heat and mechanical shock. Cadmium sulfide photoreceptors and zinc oxide photoreceptors do not provide stable sensitivity in humid environments, and the dyes added as sensitizers cause charging deterioration due to corona charging and photobleaching due to exposure, so they cannot be used for long periods of time. It has the disadvantage that it cannot provide stable characteristics over a long period of time.

On the other hand, various organic photoconductive polymers such as polyvinylcarbazole have been proposed, but these polymers are superior to the above-mentioned inorganic photoconductive materials in terms of film formability and light weight. However, they are still inferior to inorganic photoconductive materials in terms of sufficient sensitivity, durability, and stability against environmental changes.

In addition, low molecular weight organic photoconductive compounds are preferable in that the physical properties or electrophotographic properties of the film can be controlled by selecting the type and composition ratio of the binder used in combination; Since it is used in combination with materials, high compatibility with the binder is required.

Photoreceptors in which these high-molecular-weight and low-molecular-weight organic photoconductive compounds are dispersed in a binder resin have drawbacks such as high residual potential and low sensitivity due to a large number of carrier traps. Therefore, it has been proposed to incorporate a charge transporting material into a photoconductive compound to solve the above-mentioned drawbacks.

Further, a functionally separated photoreceptor has been proposed in which the charge generation function and the charge transport function of the photoconductive function are assigned to separate substances. In such functionally separated type photoreceptors, many organic compounds have been mentioned as charge transport materials used in the charge transport layer, but in practice they have various problems.

For example, 2,5-bis(P-diethylaminophenyl,
3,4-year-old xadia/-ol has low compatibility with binders and tends to precipitate crystals. U.S. Patent No. 3,820.9
Although the diarylalkane derivatives described in Japanese Patent No. 89 have good compatibility with binders, sensitivity changes occur when used repeatedly. Also, JP-A-54-591
The hizolazone compound described in Publication No. 43 has relatively good residual potential characteristics, but has the drawbacks of poor charging ability and repeatability. The reality is that there are almost no low-molecular-weight organic compounds that have practically desirable properties for producing photoreceptors.

JP-A-55-6424 discloses a styryl compound represented by the following general formula % (wherein, X1n and Ar are those described in Part 2 of the above-mentioned report), and is designated as X.

JP-A-60-164752 discloses a styryl compound represented by the following general formula: (wherein R1-R1 are as described in the above publication).

JP-A No. 60-98437 shows the following general formula: (wherein, YSR is as described in the above publication) (wherein Ar, -Ar2, R, -R,, n are as described in the above publication) Disclosed are styryl compounds represented by:

However, both compounds have different structures from the compounds of the present invention.

Problems to be Solved by the Invention The present invention has been made in view of the above facts, and contains a styryl compound as a photoconductive substance that has excellent compatibility with binders and charge transport ability, and has excellent sensitivity and charging ability. Excellent in
An object of the present invention is to provide a photoreceptor that exhibits little fatigue deterioration when used repeatedly and has stable electrophotographic characteristics.

Means for Solving the Problems The present invention provides a photoreceptor having a photosensitive layer containing a styryl compound represented by the following general formula [I] on a conductive support.

[In the formula, R1 is an alkyl group, an aralkyl group, or an aryl group that may each have a substituent; R2 is a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group that may have a substituent; are each an aryl group or a heterocyclic group which may have a substituent; X is an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent; 2 is a residue bonded to X and the nitrogen atom may have a substituent; R2
and Ar may be combined to form a ring.

In the general formula [I], RI represents an alkyl group such as a methyl group or an ethyl group, an aralkyl group such as a benzyl group or a phenethyl group, or an aryl group such as a phenyl group. These groups may have a substituent, for example an alkyl group such as a methyl group or an ethyl group, or an alkoxy group such as a methoxy group or an ethoxy group.

R2 represents a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, an aralkyl group such as a benzyl group or a phenethyl group, or an aryl group such as a phenyl group. When R4 is an aryl group, a substituent such as an alkyl group such as a methyl group or an ethyl group or a methoxy group,
It may have an alkoxy group such as an ethoxy group.

Ar represents a heterocyclic group such as an aryl group, for example a phenyl group. Ar represents a substituent, such as an alkyl group (such as a methyl group or an ethyl group), an alkoxy group (such as a methquine group or an ethoxy group), an aryl group (such as a phenyl group),
It may have a hydroxy group or a substituted amino group (diethylamino group, diphenylamino group, etc.).

Ar may be bonded to R2 directly or via a carbon atom, an oxygen atom, etc., and may form a ring together with Ar8 and the carbon atom to which R2 is bonded.

X represents an oxygen atom, a sulfur atom or a nitrogen atom. X
When is a nitrogen atom, it may have a substituent, for example the same as R1.

2 is a residue bonded to the nitrogen to which X and R are bonded, such as -CH, -CH, CH, - or -CH=
etc. Z may have a substituent, for example, an alkyl group (such as a methyl group or an ethyl group) or an aryl group (such as a phenyl group).

Examples of the styryl compound of the present invention represented by the general formula [I] include, but are not limited to, these.

C2H.

OCR.

CH.

As a preferable specific example of
.

[291 OCH3 [303 CJ(j "27] [28] The compound represented by the general formula [I] of the present invention can be easily synthesized by a conventional method.

For example, an aldehyde compound represented by the following general formula [■]: [wherein R1, Z and X have the same meanings as [1]] and the following general formula [II[]Ar
R4 [wherein R2 and Ar have the same meanings as [1], R3 and R4 are
represents an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group.

R3 and R6 of the phosphorus compound represented by the general formula [II[]
In particular, cyclohexyl group, benzyl group, phenyl group,
Alkyl groups are preferred.

As the reaction solvent in the above method, for example, hydrocarbons,
Good for alcohols and ethers, methanol, ethanol, indalobanol, butanol, 2-methoxyethane, 1,2-dimethoxyethane, his(2)
-methoxyethyl)ether/L=, dioxane, tetrahydro7rane, toluene, xylene, dimethylsulfokide, N,N-dimethylformamide, N-methylpyrrolidone, 1°3-dimethyl-2-imidazolidinone, etc. . Among them, polar solvents such as N,N-dimethylformamide and dimethylsulfoxide are preferred.

As the condensing agent, caustic soda, caustic potash, sodium amide, sodium hydroxide, and alcoholades such as sodium methylate, sodium ethylate, potassium methylate, potassium ethylate, potassium tre-butoxide, and n-butyllithium are used.

The reaction temperature can be selected over a wide range from about 100°C to about 100°C. Preferably it is 10°C to about 80°C.

In addition, the compound [I[[] used in the present invention can be converted into an aldehyde by using a corresponding quaternary phosphonium salt, such as a triphenylphosphonium salt, in place of the phosphorus compound, and passing through the phosphorylene stage according to the method of Wittig. Styryl compound [II may be synthesized by condensation with compound [■].

The photoreceptor of the present invention has a photosensitive layer containing one or more styryl compounds represented by the general formula [II].

Good electrophotographic properties can also be obtained by combining it with other charge transport materials, such as hydrazone compounds and other styryl compounds.

Various forms of photoreceptors are known, and the photoreceptor of the present invention may be any of them.

For example, a single-layer photoreceptor in which a charge-generating material and a photosensitive layer made of a styryl compound dispersed in a resin binder is provided on a support, or a charge-generating layer containing a charge-generating material as a main component on a support, There is a so-called laminated photoreceptor having a charge transport layer thereon. Although the styryl compound of the present invention is a photoconductive substance, it acts as a charge transport material and can transport charge carriers generated by absorbing light very efficiently.

In order to produce a single-layer type photoreceptor, fine particles of a charge generating material may be dispersed in a resin solution or a solution containing a charge transporting material and a resin, and this may be applied onto a conductive support and dried. The thickness of the photosensitive layer at this time is preferably 3 to 30 μm, preferably 5 to 20 μm. If the amount of the charge generating material used is too small, the sensitivity will be poor, and if it is too large, the charging property will be poor and the mechanical strength of the photosensitive layer will be weakened. te 0.01~3
Parts by weight, preferably in the range of 0.2 to 2 parts by weight.

To produce a laminated photoreceptor, a charge-generating material is vacuum-deposited on a conductive support, or it is dissolved in a solvent such as amine and coated, or a pigment is coated with a suitable solvent or if necessary. - Obtained by coating and drying a coating solution prepared by dispersing the inder resin in a solution, and then coating and drying a solution containing a charge transport material and a binder thereon.

For example, metal-free phthalocyanine,
Phthalocyanines such as titanyl phthalonanine and aluminum chlorophthalocyanine are used. In addition, in the case of dispersing, for example, bisazo pigments are used.

At this time, the thickness of the charge generation layer is preferably 4 μm or less, preferably 2 μm or less, and the charge transport layer has a thickness of 3 to 30 μm.
Preferably 5 to 20 μm ◇The ratio of the charge transport material in the charge transport layer is 0.2 to 1 part by weight of the binder resin.
~2 parts by weight, preferably 0.3 to 13 parts by weight.

In addition to the binder resin, the photoreceptor of the present invention contains plasticizers such as halogenated paraffin, polychlorinated biphenyl, dimethylnaphthalene, dibutyl phthalate, and 〇-terphenyl, as well as chloranil, tetracyanoethylene, 2,4,7-dolinitrofluorenone, 5 Electron-withdrawing sensitizers such as 6-cycyanobenzoquinone, tetracyanoquinodimethane, tetrachlorophthalic anhydride, 3,5-dinitrobenzoic acid,
Sensitizers such as methyl violet, rhodamine B1 cyanine dye, biryllium salts, thiapyrylium salts, etc. may be used.

Further, antioxidants, ultraviolet absorbers, dispersion aids, anti-settling agents, etc. may also be used as appropriate.

As the electrically insulating binder resin used in the present invention, electrically insulating binders such as thermoplastic resins, thermosetting resins, photocuring resins, and photoconductive resins that are known per se can be used. .

Examples of suitable binder resins include, but are not limited to, saturated polyester resins, polyamide resins, acrylic resins, ethylene-vinyl acetate resins, ionically crosslinked olefin copolymers (ionomers), styrene-butadiene. Block copolymer, polycarbonate, vinyl chloride-vinyl acetate copolymer, cellulose ester, polyimide,
Thermoplastic resins such as styrene resin - thermosetting resins such as dipoquin resin, urethane resin, nicole resin, phenolic resin, melamine resin, xylene resin, alkyd resin, thermosetting acrylic resin: photocurable resin: holvinyl-rubazole, Photoconductive resins such as polyvinylpyrene, polyvinylanthracene, and polyvinylpyrrole.

These can be used alone or in combination.

These electrically insulating resins have a resistance of 1×1012 when measured alone.
It is desirable to have a volume resistivity of Ω·cm or more.

Charge-generating materials include bisazo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthine dyes, cyanine dyes, styryl dyes, biryllium dyes, azo pigments, quinacridone pigments, and indigo dyes. Organic substances such as pigments, perylene pigments, polycyclic bovine pigments, bisbenzimidazole pigments, induthrone pigments, squalium base pigments, azulene pigments, phthalocyanine pigments, selenium, selenium/tellurium, selenium, etc. Examples include inorganic substances such as selenium alloys such as arsenic, cadmium sulfide, cadmium selenide, zinc oxide, and amorphous silicon. In addition to these materials, any material can be used as long as it absorbs light and generates charge carriers with an extremely high probability.

As the conductive support used in the photoreceptor of the present invention, a sheet or drum-shaped foil or plate of metal or alloy such as copper, aluminum, silver, iron, zinc, or nickel is used. A metal is vacuum-deposited or electrolessly plated on a plastic film, etc., or a layer of a conductive compound such as a conductive polymer indium oxide or tin oxide is coated or vapor-deposited on a support such as paper or a plastic film. The one given is used.

Examples of the structure of a photoreceptor using the styryl compound of the present invention are schematically shown in FIGS.

Figure 1 shows a photoreceptor in which a photosensitive layer (4) containing a photoconductive material (3) and a charge transporting material (2) as a binder is formed on a substrate (1). The styryl compound of the present invention is used.

Figure 2 shows a functionally separated photoreceptor that has a charge generation layer (6) and a charge transport layer (5) as photosensitive layers, and the charge transport layer (5) is formed on the surface of the charge generation layer (6). ing.

The styryl compound of the present invention is blended into the charge transport layer (5).

Figure 3 shows a functionally separated photoreceptor having a charge generation layer (6) and a charge transport layer (5) as in Figure 2, but contrary to Figure 2, the charge transport layer (5) is A charge generation layer (6) is formed on the surface.

FIG. 4 shows an additional surface protective layer (
7), and the photosensitive layer (4) is provided with a charge generation layer (
6) and a functionally separated photoreceptor having a charge transport layer (5).

FIG. 5 shows an intermediate layer (8) between the substrate (1) and the photosensitive layer (4).
), and the intermediate layer (8) has improved adhesion,
It can be provided to improve coating properties, protect the substrate, and improve charge injection from the substrate to the photosensitive layer.

Materials used for the intermediate layer include polymers such as polyimide, polyamide, nitrocellulose, and polyvinyl butyrano-polyvinyl alcohol, either as they are, or in which low-resistance compounds such as tin oxide or indium oxide are dispersed, aluminum oxide, and zinc oxide. , silicon oxide, etc. are suitable.

Further, the thickness of the intermediate layer is preferably 1 μm or less.

Materials used for the surface protective layer include acrylic resin,
Suitable materials include polymers such as polyaryl resins, polycarbonate resins, and urethane resins as they are, or those in which low-resistance compounds such as tin oxide and indium oxide are dispersed.

Additionally, organic plasma polymerized films can also be used. The organic plasma polymerized film may contain oxygen, nitrogen, halogen,
It may contain atoms of Group 3 or Group 5 of the periodic table.

Further, the thickness of the surface protective layer is desirably 5 μm or less.

The present invention will be explained below with reference to Examples. In addition, in the examples, "parts" means "parts by weight" unless otherwise specified.
shall be hail.

Natsume Encounter (Compound Example [Synthesis of 31) Phosphonate 3.049 represented by the following formula and 2.39 g of an aldehyde compound represented by the following formula were dissolved in dimethylformamide 3QmQ, and while cooling to 5°C or less, A suspension containing 2 g of potassium ter-butoxide in 50 i of dimethylformamide was added dropwise. Thereafter, the mixture was stirred at room temperature for 8 hours and then left in the apparatus overnight. The returned mixture was added to 900 g of ice water, neutralized with dilute hydrochloric acid, and after about 30 minutes, the precipitated crystals were filtered. The filtered product was washed with water and further purified by recrystallization using acetonitrile to obtain 2.8 g of yellow needle crystals.

(yield 72%) Elemental analysis is as follows.

*C! aH23NO Example 1 0.45 parts of a bisazo compound represented by the following general formula [A], polyester resin (Vylon 200; manufactured by Toyobo Co., Ltd.)
0.45 part was dispersed with 50 parts of cyclohexanone using a sand glider.

The resulting bisazo compound dispersion was applied onto a 100 μm thick aluminized mylar using a film applicator.
Dry film thickness is 0.3g/m! It was applied and dried. 70 parts of styryl compound [3] and polycarbonate resin (K
-1300 (manufactured by Kijin Kasei Co., Ltd.) dissolved in 400 parts of 1,4-dioxane was applied to form a charge transport layer so as to have a dry film thickness of 16 μm. In this way, an electrophotographic photoreceptor having a two-layer photosensitive layer was obtained.

The photoreceptor thus obtained is used in a commercially available electrophotographic copying machine (EP).
-4702, manufactured by Minolta Camera Co., Ltd.), and corona charging at -6 KV, initial surface potential VO (V), and exposure amount E required to reduce the initial potential to 1/2.

/2 (lux-sec), and the decay rate D D Rl (%) of the initial potential when left in the dark for 1 second was measured.

Examples 2 to 4 Photosensitization using the same method and the same structure as Example 1, except that styryl compounds [41, [5], and [7] were used in place of styryl compound [3] used in Example 1. The body was created.

Regarding the photoreceptor thus obtained, vo, E, /2, and DDR were measured in the same manner as in Example 1.

Example 5 0.45 parts of a hisazo compound represented by the following general formula [B] and 0.45 parts of polystyrene resin (molecular weight 40,000) were dispersed together with 50 parts of cyclohexanone using a sand grinder. The resulting bisazo compound dispersion was applied onto a 1100p thick aluminized Mylar using a film applicator so that the dry film thickness was 0.39/II+2, and then dried. A solution prepared by dissolving 70 parts of styryl compound [10] and 70 parts of polyarylate resin (U-100, manufactured by Unitika Co., Ltd.) in 400 parts of 1°4-dioxane was applied onto the charge generation layer thus obtained as a dry film. The coating was applied to a thickness of 16 μm to form a charge transport layer. In this manner, an electrophotographic photoreceptor having a two-layer photosensitive layer was produced.

Examples 6 to 8 Same structure as in Example 5, except that styryl compounds [11], [12], and [13] were used in place of styryl compound [10] used in Example 5. A photoreceptor was produced.

V was applied to the thus obtained photoreceptor in the same manner as in Example 1. :E1/:, DDR, was measured.

Example 9 0.45 part of polycyclic quinone type face represented by 1 in the following general formula, polycarbonate resin (Panlite -13000:
(manufactured by Ryotai Kasei Co., Ltd.) was dispersed in a sand mill with 50 parts of dichloroethane.

The resulting polycyclic quinone pigment dispersion was applied onto a 100 μm thick aluminized Mylar using a film applicator to a dry film thickness of 0.49 parts m 2 and then dried. A styryl compound [2H2O part and a polyarylate resin (U
A solution prepared by dissolving 50 parts of A-100 (manufactured by Unitika) in 400 parts of 1,4-dioxane was applied to a dry film thickness of 18 μm and dried to form a charge transport layer.

In this way, an electrophotographic photoreceptor having a two-layer photosensitive layer was produced. The vo, E18, and DDR of the thus obtained photoreceptor were measured in the same manner as in Example 1.

Examples 1O-11 iJ! A photoreceptor having the same structure as in Example 9 was prepared, except that styryl compounds [211 and [251] were used in place of styryl compound [20] used in Example 9.

V was applied to the thus obtained photoreceptor in the same manner as in Example 1. ,E,/2,DDR, was measured.

Example 12 0.45 parts of perylene pigment represented by the following general formula [D], 0.45 parts of butyral resin (SX-t: manufactured by Tanezu Kagaku Kogyo Co., Ltd.).
45 parts were dispersed in a sand mill with 50 parts of cycloethane.

The obtained perylene pigment dispersion was applied to a 100 μm thick aluminized mylar using a film applicator to give a dry film thickness of 0.4 mm. /m2.
: Post-dried. 1.50 parts of styryl compound [26] and 50 parts of polycarbonate resin (PC-Z, manufactured by Mitsubishi Gas Chemical Co., Ltd.) were placed on the charge generation layer thus obtained.
A solution prepared by dissolving 400 parts of 4-dioxane was applied to give a dry film thickness of 18 μm to form a charge transport layer.

In this way, an electrophotographic photoreceptor having a two-layer photosensitive layer was produced. V was applied to the thus obtained photoreceptor in the same manner as in Example 1. ,E l/'! , DDR, was measured.

Examples 13 to 14 Photoreceptors having the same structure as in Example 12 were prepared using the same method, except that styryl compounds [24] and [28] were used in place of the styryl compound [261] used in Example 12. .

Regarding the photoreceptor thus obtained, Vo, E1/2, and DDR were measured in the same manner as in Example 1.

Example 15 0.45 parts of titanyl phthalocyanine, butyral resin (
0.45 parts of BX-1 (manufactured by Tanemizu Kagaku Kogyo Co., Ltd.) were dispersed together with 50 parts of dichloroethane using a sand mill.

The obtained dispersion of phthalonanine pigment was made to a thickness of 100 μm.
Using a film applicator, the film was applied onto aluminized Mylar to a dry film thickness of 0.39 m2, and then dried. A solution of 50 parts of styryl compound [7] and 50 parts of polycarbonate resin (pC-Z: manufactured by Mitsubishi Gas Chemical Co., Ltd.) dissolved in 400 parts of 1,4-dioxane was dried on the charge generation layer thus obtained. Film thickness is 18μm
A charge transport layer was formed.

In this way, an electrophotographic photoreceptor having a two-layer photosensitive layer was produced, and in the same manner as in Example 1, Vo, E1/
2. DDR was measured.

Examples 16 to 17 Photoreceptors having the same structure as in Example 15 were produced using the same method, except that styryl compounds [13] and [18] were used in place of styryl compound [7] used in Example 15. did.

Regarding the photoreceptor thus obtained, vo, E1/3, and DDR were measured in the same manner as in Example 1.

Example 18 50 parts of copper phthalocyanine and 0.2 parts of tetranitrocopper phthalonanine were dissolved in 500 parts of 98% concentrated sulfuric acid with sufficient stirring, and this was poured into 5000 parts of water to prepare a photoconductive material composition of copper phthalocyanine and tetranitrocopper phthalonanine. After precipitating the product, it was filtered, washed with water, and dried at 120°C under reduced pressure.

10 parts of the photoconductive composition thus obtained were mixed with 22.5 parts of a thermosetting acrylic resin (Acridic A405, manufactured by Dainippon Ink Co., Ltd.), and 22.5 parts of a melamine resin (Super Beckamine J82).
7.5 parts (manufactured by Inu Nippon Ink Co., Ltd.) and 15 parts of the styryl compound [3] mentioned above were placed in a ball mill bottle with 100 parts of a mixed solvent containing equal amounts of methyl ethyl ketone and xylene, and dispersed for 48 hours to make the photosensitive. Prepare a coating liquid, apply this coating liquid onto an aluminum substrate, and dry it to a thickness of about 1.
A photoreceptor was prepared by forming a 5 μmO')q optical layer.

The thus obtained photoreceptor was charged in the same manner as in Example 1, except that corona charging was performed at +6 Kv to give Vo, E, /
', ,DDR, was measured.

Examples 19-21 Same structure as in Example 18, except that styryl compounds [20], [33], and [38] were used in place of styryl compound [3] used in Example 18, respectively. A photoreceptor was produced.

With respect to the thus obtained photoreceptor, V was treated in the same manner as in Example 18. , E+/:, DDR, were measured.

Comparative Examples 1 to 4 Same method and same structure as Example 18, except that the following compound [E
], [F1, [Gco, and [H] were respectively used, but a photoconductor was prepared in exactly the same manner as in Example 18.

Regarding the photoreceptor thus obtained, vo, E1/2, and DDR were measured in the same manner as in Example 18.

Comparative Examples 5 to 8 Same method and same structure as Example 18, except that the styryl compound [6] used in Example 18 was replaced with the following styryl compounds [■], [J], [K], [ A photoreceptor was produced in exactly the same manner as in Example 18, except that each of the photoreceptors was used.

Stop and show.

As can be seen from Table 1, the photoreceptor of the present invention has sufficient charge retention ability whether it is a multilayer type or a single layer type, the dark decay rate is small enough to be used as a photoreceptor, and it also has excellent sensitivity. It is clear from the data that

Furthermore, a commercially available electrophotographic copying machine (manufactured by Minolta Camera Co., Ltd.: E
P-3502) was conducted on the photoreceptor of Example 18 during positive charging, and even after 1000 copies, the gradation was excellent in the initial and final images, there was no change in sensitivity, and the image was clear. It can be seen that the photoreceptor of the present invention has stable repeatability characteristics.

(Hereafter, blank space) Regarding the thus obtained photoreceptor, Vo, E, /, and DDR were measured in the same manner as in Example 18.

Examples 1-21. t obtained in Comparative Examples 1 to 8; V of photoreceptor
Table 1 shows the results of measurement of o, E1/2, and DDR.Table 1 (Continued) Effects of the Invention The present invention provides a photoconductive compound useful for photoreceptors.

The photoconductive compounds of the present invention are styryl compounds and are particularly useful as charge transport materials.

A photoreceptor containing the styryl compound of the present invention has excellent photoreceptor properties such as sensitivity, charge transportability, initial surface potential, and dark decay rate, and has little optical fatigue due to repeated use.

[Brief explanation of drawings]

Figures 1 to 5 are schematic diagrams of photoreceptors according to the present invention, and Figures 11, 4, and 5 are diagrams of dispersion type photoreceptors in which a photosensitive layer is laminated on a conductive support. The structure is shown in Figure 2, W
Figure c3 shows the structure of a functionally separated photoreceptor in which a charge generation layer and a charge transport layer are laminated on a conductive support. 1... Conductive support 2... Charge transport material 3...
- Photoconductive material 4... Photosensitive layer 5... Charge transport layer 6... Charge generation layer 7... Surface protective layer 8
...Middle layer patent applicant Minolta Camera Co., Ltd. Agent Patent attorney Haka Aoyama 1 person Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A photoreceptor having a photosensitive layer containing a styryl compound represented by the following general formula [I] on a conductive support: ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] [ In the formula, R_1 is an alkyl group, an aralkyl group, or an aryl group that may each have a substituent; R_2 is a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group that may have a substituent; Ar is Aryl group or heterocyclic group that may have a substituent; X is an oxygen atom, a sulfur atom, or a nitrogen atom that may have a substituent; Z is substituted with a residue bonding to It may have a group;
R_2 and Ar may be combined to form a ring].