JPH01284858A - Photosensitive body - Google Patents

Abstract

PURPOSE:To enhance the sensitivity of the photosensitive body and to lessen the fatigue and deterioration by repetitive use by incorporating a specific styryl compd. into said body. CONSTITUTION:A photoconductive layer 6 contg. a photoconductive material 3 such as, for example, bisazo pigment and a charge transfer layer 5 contg. a charge transfer material 2 are laminated on a conductive base 1 and the styryl compd. expressed by the formula I is used for the material 2. In the formula, Ar1 denotes alkyl, aryl, etc.; Ar2, Ar5 denote aryl, an arom. polycyclic group, etc.; Ar3 denotes arylene, heterocyclic group; Ar4 denotes H, alkyl, etc.; n denotes 1, 2; the specific example of the compd. expressed by the formula includes the compd. expressed by the formula II, etc. Lamination of the layers 6, 5 in reverse order is possible as well. The formation of the photosensitive layer into single-layer constitution is also possible.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a photoreceptor, and more particularly to a photoreceptor having a photosensitive layer containing a styryl compound as a main component.

Conventional technologies and issues As photoreceptors, there are two types: a functionally separated type, in which a charge generation layer and a charge transport layer are laminated on a conductive support, and a photoconductive layer, in which photoconductive particles are dispersed in a resin, on a support. The dispersed type formed by the following methods is widely known.

In the functionally separated type, the basic functions of a photoreceptor, such as generation and transport of charge carriers, are assigned to separate substances, resulting in high surface potential, large charge retention, high photosensitivity, and stable repeatability. A photosensitive layer can be obtained. It is known that a large number of compounds are effective for both functionally separated charge generation materials for charge generation and charge transport materials for charge transport. For example, many I-type materials have been proposed using low-molecular light-absorbing conductors as charge transport layers. However, the method using 2,5-bis(p-diethylaminophenyl)-1,3,4-oxadiazole described in U.S. Patent No. 3,189,447 has compatibility with the binder. is low, and crystals tend to precipitate. In addition, although the diaryl alkane derivative described in U.S. Patent No. 3820.989 has good compatibility with binders, there are still problems such as changes in sensitivity when used repeatedly. There are significant points that need to be improved in terms of initial sensitivity and residual potential characteristics, changes in sensitivity after repeated use, and durability. Also, JP-A-60
-98437 publication has the following formula [wherein, RI-R,,A
r<+> to A<r>2 have the meanings given in the number in the above publication] A photoconductive material represented by the following is disclosed, but it is different from the compound that the present application intends to disclose.

Means for Solving the Problems It is an object of the present invention to overcome the above-mentioned conventional drawbacks and to provide a photoreceptor that has high photosensitivity and stable electrophotographic characteristics even after repeated use.

That is, the gist of the present invention is a photoreceptor characterized by containing a styryl compound represented by the following general formula [11]: [wherein Ar1 is an alkyl group, an aralkyl group, or each has a substituent, and Yoshi\Ar1 Nor group or heterocyclic group; A r 4 is hydrogen, an alkyl group, and aralkyl is an aryl group that may have a substituent; Ar2 and A r s
171 is an aryl group which may each have a substituent or an aromatic polycyclic group (or a heterocyclic group; Ar3 is an arylene group or a divalent heterocyclic group which may each have a substituent) Cyclic group; n represents a number of 1 or 2, and Ar, and Ar2, and Ar4 and Ar5 may be combined to form a ring.1 In the present invention, the styryl group represented by the general formula [11] By using the compound as a photoconductive substance in a photoreceptor, or by utilizing only the excellent charge transport ability of the styryl compound of the present invention and using it in the charge transport layer of a functionally separated photoreceptor, the physical properties of the film can be improved. It is possible to produce a photoreceptor that has excellent electrophotographic properties such as charge retention ability, sensitivity, and residual potential, and exhibits stable properties with little fatigue deterioration even when subjected to repeated use.

In the general formula [I], Ar is an alkyl group, an aralkyl group,
Alternatively, each represents an aryl group or a heterocyclic group which may have a substituent.

Alkyl groups include methyl, ethyl, propyl, etc. Aralkyl groups include benzyl, phenethyl, methylbesidyl, etc. Aryl groups which may have substituents include alkylphenyl, alkoxyphenyl, disubstituted aminophenyl, Halogenated phenyl, diphenyl, naphthyl, alkoxynaphthyl, etc.: Heterocyclic groups that may have substituents include; The following can be exemplified.

Preferred Arl is an alkyl group, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent.

Arl is hydrogen, an alkyl group, an aralkyl group, or an aryl group that may have a substituent; examples of the alkyl group include methyl, propyl, etc.; examples of the aralkyl group include benzyl, methylbenzyl, and the like; Aryl groups that may have include: fynyl,
Examples include alkylphenyl, alkoxyphenyl, disubstituted aminophenyl, halogenated phenyl, diphenyl, naphthyl, and alkoxynaphthyl.

Preferred Ar is hydrogen or an aryl group which may have a substituent.

Ar2 and Ars are each an aryl group, an aromatic polycyclic group, or a heterocyclic group that may have a substituent; examples of the aryl group that may have a substituent include: phenyl,
Alkylphenyl, alkoxyphenyl, disubstituted aminophenyl, halogenated phenyl, diphenyl, naphthyl, alkoxynaphthyl, etc.: Aromatic polycyclics that may have substituents include: anthracene, pyrene, phenanthrene, fluorene, etc.: Substituents Examples of the heterocyclic group which may have the following include residues such as dioxindane, carbazole, phenothiazine, tetrahydroquinoline, julolidine, phenoxanthin, indoline, pyridine, furan, and thiophene.

Preferred Ar2 is an aryl group or a heterocyclic group, each of which may have a substituent.

Preferred Ars are an aryl group, a heterocyclic group, or an aromatic polycyclic group, each of which may have a substituent.

Ar represents an arylene group or a divalent heterocyclic group, each of which may have a substituent; n represents a number of 1 or 2, and Ara and Ar2, and Ara and Ar5 together form a ring. For example, a divalent ring such as a fluorene ring, an indene ring, a hydroxynaphthalene ring, a xanthine ring, a thioxanthin ring, or a hydroquinanthracene ring may be formed. Preferably, it is a divalent ring such as a fluorene ring or a xanthine ring.

More preferred specific examples of the styryl compound represented by the general formula [1] of the present invention include, for example, those having the following structural formula, but are not limited thereto.

[lO] [11] [121 [■3] [141 [15] [161 [17] [18] [19] [201 [21] [22] [231 [24] [25] [261 [27] [ 28] [29] [30] [31] [32] [33] [34] [351 [36] [37] [39] [40] The compound represented by the general formula [I] of the present invention is, for example, The following general formula [R1; [wherein Ar3, Ar4, and Ars have the same meanings as [1] R2 represents an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group that forms a phosphonium salt. ] The phosphorus compound represented by the following general formula [■] ; [wherein,
Ar, Ar, has the same meaning as [I], and m represents a number of 0 or l. ] It can be easily obtained by condensation with an acrolein compound represented by the following.

R and R2 of the phosphorus compound represented by the general formula [II] are particularly preferably a cyclohexyl group, a benzyl group, a phenyl group, or a lower alkyl group.

Examples of the reaction solvent in the above method include hydrocarbons,
Good for alcohols and ethers, methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, dioxane, tetrahydro7
Ran, toluene, xylene dimethyl sulfoxide, N,
N-dimethylformamide, N-methylpyrrolidone, l
, 3-dimethyl-2-imidazolidinone, and the like. 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 strium methylate and potassium ter-butoxide 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 80°C.

Further, the compound [U] used in the present invention may be prepared by using a corresponding quaternary phosphonium salt, such as a triphenylphosphonium salt, instead of the phosphorus compound, and
It can be obtained by condensing with an aldehyde compound [III] through a phosphorylene step according to the method of (Tig). These styryl compounds may be used alone or in combination.

A first example of the structure of a photoreceptor using the styryl compound of the present invention is shown below.
It is schematically shown in FIG. Figure 1 shows the base (1)
This is a photoreceptor on which a photosensitive layer (4) containing a photoconductive material (3) and a charge transporting material (2) as a binder is formed, and the styryl compound of the present invention is used as the charge transporting material. There is.

FIG. 2 shows a functionally separated photoreceptor having a charge generation layer (6) and a charge transport layer (5) as photosensitive layers.
A charge transport layer (5) is formed on the surface of 6). 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 surface of the charge transport layer (5) is A charge generation layer is formed.

FIG. 4 shows an additional surface protective layer (
7), and the photosensitive layer (4) is provided with a charge generation layer (
6) and a charge transport layer (5), it may be of a functionally separated type.

FIG. 5 shows an intermediate layer (8) between the substrate (1) and the photosensitive layer (4).
), and the middle N (8) is for improving adhesion,
It can be provided to improve coating properties, protect the substrate, and improve charge injection from the substrate to the photoconductive layer. As the intermediate layer, polyimide resin, polyester resin, polyvinyl butyral resin, casein, etc. may be used. The photoreceptor of this embodiment may also have a photosensitive layer of a functionally separated type.

The photoreceptor of the present invention can be prepared by dissolving or dispersing a styryl compound represented by the general formula [11] together with a binder in a suitable solvent, and optionally adding a photoconductive material and an electron-withdrawing compound.
Alternatively, a coating solution obtained by adding a sensitizing dye or other pigments is applied onto a conductive substrate and dried, usually to a thickness of 5 to 30 μm.
1. It can be manufactured by forming a photosensitive layer preferably having a thickness of 6 to 20 μm.

Suitable solvents for use in this case include carbon tetrachloride, dichloromethane, dichloroethane, chloroform, halogenated aliphatic hydrocarbons such as lydichloroethane, ketones such as cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone, dioxane, and telorahydrofuran. , dioxolane, 4-methyldioxolane, dimethyldioxane, or a mixed solvent thereof.

The styryl compound of the present invention has excellent solubility in the above-mentioned solvents and gives good results in coating properties and photosensitivity.

Furthermore, the styryl compound of the present invention has good compatibility with the binder resin, which results in good photosensitivity.

Specifically, a functionally separated photoreceptor has a structure similar to that of the photoreceptor shown in FIG. The charge generating material is vacuum deposited on the surface, or a coating solution prepared by dispersing the charge generating material in a suitable solvent or, if necessary, a solution containing a binder resin, is applied and dried to form a charge generating layer. A charge transporting layer is obtained by applying a solution of a styryl compound and a binder resin dissolved in a suitable solvent as a charge transporting material and drying the film to form a charge transporting layer. For example, metal-free phthalocyanine, titanyl phthalocyanine,
Phthalocyanines such as alumincrophthalocyanine are used. Further, in the case of dispersing, for example, a disazo pigment or the like is used. The thickness of the charge generation layer at this time is 4 .mu.m or less, preferably 2 .mu.m or less, and the charge transport layer has a thickness of 3 to 30 .mu.m, preferably 5 to 20 .mu.m. The proportion of the styryl compound in the charge transport layer is 0.02 to 2 parts by weight, preferably 0.02 to 2 parts by weight, per 1 part by weight of the binder resin.
．． The amount is preferably 0.03 to 1.3 parts by weight. Further, other charge transport materials may be used in combination. In the case of polymeric charge transport materials that can themselves be used as binders, no other binder may be used. The structure of the photoreceptor may be similar to the photoreceptor shown in FIG. 3 described above, in which a charge transport layer is formed on a conductive support, and a charge generation layer is laminated thereon.

A dispersion type photoreceptor, which is composed of a photoconductive layer formed on a conductive support and has a structure similar to that of the photoreceptor shown in FIG. It is obtained by dispersing it in a solution, coating it on a conductive support, and drying it to form a photoconductive layer. The thickness of the photoconductive layer at this time is 3 to 30 μm, preferably 5 to 20 μm.
μm is good.

If too little photoconductive material is used, the sensitivity will be poor;
If the amount is too large, the charging property will deteriorate and the strength of the photoconductive layer will become weak.The amount of photoconductive material in the photoconductive layer is preferably 0.01 to 2 parts by weight per 1 part by weight of the resin. is 0.
05 to 1 part by weight is good, and the proportion of the styryl compound is 1 part by weight of the resin.
0.01 to 2 parts by weight, preferably 0.0 parts by weight
2 to 1.2 parts by weight is preferred. It may also be used in combination with a polyvinylcarbasyl nanopolymer photoconductor which itself can be used as a binder. It may also be combined with other charge transport materials, such as hydrazone compounds.

The charge-generating materials used in the functionally separated type photoreceptor of the present invention and the photoconductive materials used in the dispersed type include bisazo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthine dyes, and cyanine dyes. , styryl dyes, pyrylium dyes, azo pigments,
Quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments,
Organic substances such as induthrone pigments, squarylium pigments, phthalocyanine pigments, selenium, selenium/tellurium,
Examples include inorganic substances such as selenium, arsenic, cadmium sulfide, and amorphous silicon. In addition to this, any material can be used as long as it absorbs light and generates charge carriers with extremely high efficiency.

Moreover, the binder that can be used is electrically insulating, and all known thermoplastic resins, thermosetting resins, photocurable resins, and photoconductive resins can also be used. Examples of suitable binder resins include, but are not limited to, saturated polyester resins, polyamide resins, acrylic resins, ethylene-vinyl acetate copolymers,
Ionically crosslinked olefin copolymer (ionomer), styrene-butadiene block copolymer, polyarylate,
Polycarbonate, vinyl chloride-vinyl acetate copolymer,
Thermoplastic binders such as cellulose ester, polyimide, and styrene resins; Thermosetting binders such as epoxy resins, urethane resins, silicone resins, phenol resins, melamine resins, xylene resins, alkyd resins, and thermosetting acrylic resins; light Curable resin: photoconductive resin such as poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, etc. These can be used alone or in combination. It is desirable that these electrically insulating resins have a volume resistivity of 1 xio'' Ω·cm or more when measured alone. More preferred are polyester resin, polycarbonate, and acrylic resin.

In addition to the binder, the photoreceptor of the present invention contains a plasticizer such as halogenated paraffin, polychlorinated biphenyl, dimethylnaphthalene, dibutyl phthalate, and 0-terphenyl.
Chloranil, tetracyanoethylene, 2,4.7-1-
Electron-withdrawing sensitizers such as Rinitro-9-fluorenone, 5,6-dicyazbenzoquinone, tetracyanoquinodimethane, tetrachlorophthalic anhydride, 3,5-dinitrobenzoic acid, methyl violet, rhodamine B1 cyanine dye, pyrylium salt , thiapyrylium salts and the like may be used.

The photoreceptor formed in this manner may have an adhesive layer, an intermediate layer, and a surface protection layer as required, as shown in FIGS. 4 and 5 described above.

Materials used for the intermediate layer include polymers such as polyimide, polyamide, nitrocellulose, polyvinyl butyral, and 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. , a vapor deposited film of silicon oxide, etc. is 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 can be prepared with oxygen, nitrogen,
It may contain halogen, atoms of Group 1 and Group V of the periodic table.

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

As described above, the styryl compound of the present invention can be easily produced, and a photoreceptor containing it can be used as a functionally separated type or a dispersed type, and can be combined with various charge-generating materials and binder resins. , and optionally other charge transport materials can be added. Therefore, the photoreceptor containing the styryl compound of the present invention is extremely easy to manufacture and has a wide range of uses, and the styryl compound effectively prevents optical fatigue, resulting in excellent repeatability, improved sensitivity, and reduced surface potential changes. It becomes less.

The present invention will be explained in more detail below using examples.

Synthesis Example (Compound [5]) 3.30s of a phosphonate represented by the following formula and 3.50g of an acrolein compound represented by the following formula were dissolved in 30 bottles of dimethylformamide, and while cooling to 5°C, dimethyl A suspension containing 5 g of potassium ter-butokind was added dropwise to 70 mQ of formamide.

Thereafter, the mixture was stirred at room temperature for 8 hours and then left in the apparatus overnight.

The obtained mixture was added to ice water 900TnQ, 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 4.3 g of yellow-orange needle crystals. (
Yield: 82%) Elemental analysis is as follows.

Example 1 0.45 parts of a disazo compound represented by the following general formula (A) and 0.45 parts of a polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) were dispersed together with 50 parts of cyclohexanone using a sand grinder.

The obtained disazo compound dispersion was applied onto a 100 μm thick aluminized mylar using a film applicator.
The coating was applied to a dry film thickness of 0.3 g/m2 and then dried. 70 parts of styryl compound [2] and polycarbonate resin (K
A solution prepared by dissolving 70 parts of 1300 (manufactured by Teijin Kasei Ltd.) in 400 parts of 1,4-dioxane was applied to a dry film thickness of 16 μm to form a charge transport layer. In this way, a photoreceptor having a two-layer photoreceptor layer was obtained.

Using a commercially available electrophotographic copying machine (EP-4702 manufactured by Minolta Camera Co., Ltd.), the photoreceptor thus obtained was
The initial surface potential VO (V) and the exposure amount E1/2 (lux-
ssc), and the decay rate DDR, (%) of the initial potential was measured after being left in the dark for 1 second.

Examples 2 to 4 Same structure as in Example 1, except that styryl compounds [5], [7], and [1O] were used in place of styryl compound [2] used in Example 1. A photoreceptor was produced.

V was applied to the thus obtained photoreceptor in the same manner as in Example 1. , E1/2, and DDR.

Example 5 0.45 parts of disazo compound (B) represented by the following general formula (B), polystyrene resin (molecular weight 40,000) 0
．． 45 parts were dispersed with 50 parts of cyclohexanone in a sand grinder. The resulting dispersion of the disazo compound was applied onto a 100 μm thick aluminized Mylar using a film applicator to give a dry film thickness of 0.3 g/m.
It was applied and dried. 70 parts of styryl compound [11] and polyarylate resin (U-100, Unitika Co., Ltd.) were placed on the charge generation layer thus obtained.
A charge transport layer was formed by dissolving 70 parts of 1.4-dioxane in 400 parts of 1.4-dioxane and applying the solution to a dry film thickness of 16 μm. In this manner, a photoreceptor having a two-layer photoreceptor layer was produced.

Examples 6 to 8 Photoreceptors having the same structure and using the same method as Example 5, except that styryl compounds [131, [14], and [151] were used in place of styryl compound [11] used in Example 5. was created.

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

Example 9 50 parts of copper phthalocyanine and 0.2 parts of tetranitro copper phthalocyanine were dissolved in 500 parts of 98% concentrated sulfuric acid with sufficient stirring, and this was poured into 5000 parts of water to obtain a photoconductive material composition of copper phthalocyanine and tetranitro copper phthalocyanine. 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 was added to a thermosetting acrylic resin (Acridik A405; Dainippon Ink Co., Ltd.).
(manufactured by) 22. ! 5 parts, 7.5 parts of melamine resin (Super Beckamine J820; manufactured by Dainippon Ink Co., Ltd.), and 15 parts of the above-mentioned styryl compound [13] were ball-milled together with 100 parts of a mixed solvent prepared by mixing equal amounts of methyl ethyl ketone and quintylene. A photosensitive coating liquid was prepared by dispersing the mixture in a pot for 48 hours, and this coating liquid was applied onto an aluminum substrate and dried to form a photosensitive layer with a thickness of about 15 μm, thereby producing a photoreceptor.

The photoreceptor thus obtained was corona charged in the same manner as in Example 1, except that the voltage was +6 KV. ,E1/
2. DDR was measured.

Examples 1O to 12 Photoreceptors having the same structure and using the same method as Example 9, except that styryl compounds [181, [19], and [211] were used in place of the styryl compound [13] used in Example 9. was created.

Regarding the photoreceptor thus obtained, Vo, E1/2, and DDR were measured in the same manner as in Example 9.

Comparative Examples 1 to 4 Same structure as in Example 9, except that the following compounds (C), (D), (E), (F) were used in place of the styryl compound [13] used in Example 9. ) A photoreceptor was prepared in exactly the same manner as in Example 9 except that each of the following was used.

Regarding the photoreceptor thus obtained, Vo, E1/2, and D D Rr were measured in the same manner as in Example 9.

Comparative Examples 5 to 8 Same method and same structure as Example 9, except that the following styryl compounds (G), (H), (I), (J ) A photoreceptor was produced in exactly the same manner as in Example 9 except that each of the following was used.

Regarding the photoreceptor thus obtained, vo, E1/2, and DDR were measured in the same manner as in Example 9.

vo of photoreceptors obtained in Examples 1 to 12 and Comparative Examples 1 to 8
, E1/2, DDR+(7) measurement results are summarized in Table 1.

In Comparative Examples 1.2.5.7, crystals precipitated during the production of the photoreceptor due to poor solubility in solvents and resins.

(Hereinafter, blank space) Table 1 As can be seen from Table 1, the photoreceptor of the present invention has sufficient charge retention ability whether it is a laminated type or a single layer type, and the dark decay rate is also at a level that can be used as a photoreceptor. It is clear from the data that it is small in size and has excellent sensitivity.

In addition, a commercially available electrophotographic copying machine (Minolta Camera Co., Ltd.)
A repeated live-photographing test was conducted on the photoconductor of Example 9 during positive charging using the product manufactured by EP-3502), and even after 1,000 copies were made, the gradation was excellent in the initial and final images, and there was no change in sensitivity. It can be seen that clear images are obtained and the photoreceptor of the present invention has stable repeatability.

Effects of the Invention The photoreceptor of the present invention contains the above-mentioned styryl compound, has excellent charge transport properties, has a stable initial surface potential, has a sufficiently small dark decay rate, and has good charging properties. have It also has fewer carrier traps and is highly sensitive.
Less light fatigue.

The photoreceptor obtained using the compound of the present invention effectively suppresses optical fatigue, exhibits little decrease in surface potential, increase in residual potential, and little change in sensitivity when used repeatedly, and has stable electrophotographic properties. Since it is highly sensitive, it is possible to obtain clear images.

Furthermore, styryl compounds are particularly effective as charge transport materials for functionally separated photoreceptors.

[Brief explanation of the drawing]

1 to 5 are schematic diagrams of photoreceptors according to the present invention, and FIGS. 1, 4, and 5 show dispersion type photoreceptors in which a photosensitive layer is laminated on a conductive support. Figures 2 and 3 show the structure of
The figure 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. ■... Conductive support 2... Charge transport material 3.
...Photoconductive material 4...Photosensitive layer 5...Charge transport layer 6...Photoconductive layer 7...Surface protection layer
8... Middle class patent applicant Minolta Camera Co., Ltd. agent Patent attorney 1 person Figure 1 Figure 2 ff 13 Figure 4

Claims (1)

[Claims] 1. A photoreceptor characterized by containing a styryl compound represented by the following general formula [I]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, Ar_1 is alkyl group, an aralkyl group, or an aryl group or a heterocyclic group each optionally having a substituent; Ar_4 is hydrogen, an alkyl group, an aralkyl group, or an aryl group optionally having a substituent; Ar_2 and Ar_5 are Aryl group, aromatic polycyclic group or heterocyclic group, each of which may have a substituent; Ar_3 is an arylene group or divalent heterocyclic group, each of which may have a substituent; n is Represents the number 1 or 2, Ar_1 and Ar_2, and Ar_4 and Ar_
5 may be integrated to form a ring. ]