JPH0457055A - Photosensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body having superior sensitivity and electrostatic chargeability, hardly undergoing deterioration due to fatigue even after repeated use and maintaining stable electrophotographic characteristics by forming a photosensitive layer contg. a specified compd. on an electrically conductive substrate. CONSTITUTION:A photosensitive layer 4 contg. a photoconductive material 3 and an electric charge transferring material 2 blended with a binder is formed on a substrate 1. A styryl compd. represented by the formula [where each of Ar1 and Ar5 is aryl, each of Ar2-Ar4 is arylene, each of R1 and R2 is alkyl, aralkyl, aryl or a heterocyclic group, R3 is H, alkyl or aryl and X is -O-, -S-, -(R4)C(R5)- or -N(R6)- (where each of R4 and R5 is H, alkyl or aryl and R6 is alkyl, aralkyl or aryl)] is used as the electric charge transferring material.

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.

Conventional Technologies and Issues In general, in electrophotography, the surface of the photosensitive layer of a photoreceptor is charged and exposed to form an electrostatic latent image, which is developed with a developer to make it visible, and the visible image is directly printed as is. A direct method that obtains a copy image by fixing it on a photoreceptor, a powder image transfer method or a photosensitive method that transfers the visible image on the photoreceptor onto a transfer material such as paper and fixes the transferred image to obtain a copy image. The electrostatic latent image on the body is transferred onto transfer paper, and the electrostatic latent image on the transfer paper is developed.
Electrostatic transfer methods for fixing 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. With cadmium sulfide photoreceptors and zinc oxide photoreceptors, stable sensitivity cannot be obtained in humid environments, and the dye added as a sensitizer causes charge deterioration due to corona charging and photobleaching due to exposure. 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, 2,5-his(P~diethylaminophenyl, 3,4-oxadiazole), which is still underdeveloped due to its sufficient sensitivity, durability and environmental changes, is
It has low compatibility with binders, and crystals tend to precipitate. Although the diarylalkane derivatives described in US Pat. No. 3,820,989 have good compatibility with binders, sensitivity changes occur when used repeatedly.

Further, the hizolazone compound described in JP-A-54-59143 has relatively good residual potential characteristics, but has the disadvantage 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 X and nXAr are as described in the above publication).

JP-A No. 60-164752 describes the following general formula: In terms of quality, it is inferior to inorganic photoconductive materials.

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 of binder used together, the lubricant ratio, etc. Since it is used in combination with a binder, 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 a functionally separated photoreceptor, many organic compounds have been proposed as charge transport materials used in the charge transport layer, but in practice they have various problems.

For example, US Pat. No. 3,189,447 discloses a styryl compound represented by the formula (wherein R□ to R1 are those described in the above publication).

JP-A-60-98437 discloses a styryl compound represented by the following general formula: (wherein Ar, -Ar2, R1 to R4, and n are as described in the above publication).

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 binding H and charge transport ability, and has high sensitivity and chargeability. 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: Ar5/R,R2 [wherein Ar, and Ars independently represent an aryl group which may have a substituent; Ar2, Ar3 and Ars independently represent an arylene group which may have a substituent; R3 is a hydrogen atom, Represents an alkyl group or an aryl group that may have a substituent: R1 and R2 independently represent an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, and each group has a substituent. may be; X is o--3--(R4)C(R6)--N
(R6) (wherein R1 and R6 independently represent a hydrogen atom, an alkyl group, or an aryl group; Ra represents an alkyl group, an aralkyl group, or an aryl group);

In the above general formula [1], Ar and At2 are independently an aryl group, such as a phenyl group, a tolyl group, a naphthyl group; or a heterocyclic group, such as a dioxaingen group;
Represents a furyl group, thienyl group, carbazole group, virol group, etc. These groups may have substituents, such as alkyl groups such as methyl, ethyl and propyl groups, or alkoxy groups such as methoxy, ethoxy and propoxy groups.

Ar2, Ars and Ar4 independently represent an arylene group, such as a phenylene group, a naphthalene group, etc. These groups may have substituents, such as alkyl groups such as methyl, ethyl and propyl groups, or alkoxy groups such as methoxy, nidoxy and propoxy groups.

R1 and R2 are independently an alkyl group, such as a methyl group, an ethyl group, a propyl group; an aralkyl group, such as a benzyl group, a phenethyl group, a methylbenzyl group; an aryl group, such as a phenyl group, a tolyl group, a naphthyl group; etc;
Represents a heterocyclic group such as thiophene, virol, furan, pyridine, carbazole, etc. These groups may have substituents, such as alkyl groups such as methyl, ethyl and propyl; heterocyclic groups such as thiophene, pyrrole, pyridine, furan and carbazole.

X is OS (R4) C(R6)N(Ra)
-, in which R4 and R6 independently represent a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group, etc., or an aryl group such as a phenyl group,
Represents tolyl group, naphthyl group, etc. R6 represents an alkyl group, such as a methyl group, an ethyl group, a propyl group, an aralkyl group, such as a benzyl group, a phenethyl group, a methylbenzyl group, etc., or an aryl group, such as a phenyl group, a tolyl group, a naphthyl group, etc.

Preferred specific examples of the styryl compound represented by the general formula [I] of the present invention include those having the following structural formula, but these examples are not intended to limit the scope of the present invention. isn't it.

[3] [4 pieces [5J [6] [7] [14] [15] H3 1■ CI(.

[8] [9] [10] [11] H3 [19] [20] [31] Shi113 [35] [40] Shif13 The compound represented by the general formula [I] of the present invention can be prepared by a conventional method. Can be easily synthesized.

For example, the following general formula [■1: [wherein, R11R2, Ar, , Ar, Ar, and X
is the same meaning as above II] and the following general formula [I [[] The condensing agent is caustic soda, caustic potash, sodium amide, sodium hydroxide, sodium methylate, sodium ethylate, potassium methylate, potassium ethylate. Alcolades such as potassium tert-butoxide, n-butyllithium, and the like are used.

The reaction temperature can be selected over a wide range from about 0°C to about 100°C. Preferably it is 10°C to about 8000°C.

Further, the compound [I11] used in the present invention can be converted into an aldehyde compound [I11] by using a corresponding quaternary phosphonium salt, such as triphenylphosphonium salt, in place of the phosphorus compound, and passing through the phosphorylene stage according to Wittig's method. ff] may be used to synthesize the styryl compound [I].

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

It can also be used in combination with other charge transport materials, such as hydrazone compounds and other styryl compounds [where Ars, R3 are [
Same meaning as 11, R,,R.

represents an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group] It can be synthesized by condensation reaction with a phosphorus compound represented by the following.

R and R5 of the phosphorus compound represented by the general formula [I[] are particularly preferably a cyclohexyl group, a benzyl group, a phenyl group, or an 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, tetrahydrofuran, toluene, xylene, dimethyl sulfoxide , N
, N-dimethylformamide, N-methylpyrrolidone,
l.

Examples include 3-dimethyl-2-imidazolidinone. Among them, polar solvents such as N,N-dimethylformamide and dimethylsulfoxide are preferred.

It is also possible to obtain good electrophotographic properties by using

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 provided thereon. The styryl compound of the present invention, which is a photoconductive substance, 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~
The amount is preferably 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 an amine and applied, or the pigment is coated with a suitable solvent or a binder if necessary. It is obtained by coating and drying a coating liquid prepared by dispersing a 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 7-thalocyanine 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 it is 5 to 20 μm.

The proportion of the charge transport material in the charge transport layer is different from that of the binder, but includes saturated polyester resins, polyamide resins, acrylic resins, ethylene-vinyl acetate resins, ionically crosslinked olefin copolymers (ionomers), and styrene-butadiene block copolymers. coalescence, polycarbonate, vinyl chloride-vinyl acetate copolymer, cellulose ester, polyimide,
Thermoplastic resins such as styrene resins; Thermosetting resins such as epoxy resins, urethane resins, silicone resins, phenolic resins, melamine resins, xylene resins, alkyd resins, thermosetting acrylic resins; Photocurable resins; polyvinyl carbazole, polyvinylpyrene , polyhinyl anthracene, polyvinylpyrrole, and the like.

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.

The charge generating material may be used in an amount of 0.2 to 2 parts by weight, preferably 0.3 to 1.0 parts by weight, per 1 part by weight of bisazo pigment, triarylmethane dye, thiazine dye, or oxa-resin.
It is 3 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-taphenyl, as well as chloranil, tetracyanoethylene, 2,4.7-1-
Electron-withdrawing sensitizers such as linitrofluorenone, 5.6-dicyazbenzoquinone, tetracyanoquinodimethane, tetrachlorophthalic anhydride, 3.5 dinitrobenzoic acid, methyl violet, rhodamine B1 cyanine dye, pyrylium salt, thiapyrylium Sensitizers such as salts may also 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, gin-based dyes, xanthine-based dyes, cyanine-based dyes, styryl-based dyes, biryllium-based dyes, azo-based pigments, quinacridone-based pigments, indigo-based pigments, and perylene-based pigments. Organic substances such as pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indathrone pigments, squalium base pigments, azulene pigments, and phthalocyanine pigments; selenium alloys such as selenium, selenium/tellurium, and selenium/arsenic; Examples include inorganic substances such as 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 previous one is used.

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 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 having 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.

In FIG. 4, it is appropriate to use the photoreceptor shown in FIG. 1 with surface matter further dispersed on its surface.

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.

Synthesis of Compound Example [2] 3.04 g of a phosphonate represented by the following formula and 5.32 g of an aldehyde compound represented by the following formula were dissolved in 30 mα of dimethylformamide, and a protective layer (7 ), and the photosensitive layer (4) may be a functionally separated photoreceptor having a charge generation layer (6) and 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, polyvinyl butyral, and polyvinyl alcohol as they are, or in which low-resistance compounds such as tin oxide and indium oxide are dispersed, aluminum oxide, zinc oxide, A vapor deposited film of silicon oxide or the like 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,
While cooling polymers such as polyaryl resins, polycarbonate resins, and urethane resins as they were, or into low-resistance compounds such as tin oxide and indium oxide, a suspension containing 2 g of potassium-ter-butoxide was dropped into dimethylformamide 50+++ff. . Thereafter, the mixture was stirred at room temperature for 8 hours and then left in the apparatus overnight. The resulting mixture was added to 900 rAf2 of ice water, neutralized with dilute hydrochloric acid, and the precipitated crystals were filtered after about 30 minutes. Wash the filtered product with water,
Further chromatographic purification using toluene/hexane was performed to obtain 4.4 g of yellowish white crystals (yield 64.5%).

Incidentally, the melting point Cmp of the obtained crystal was 67 to 70°C.

Elemental analysis is as follows.

*C6゜H3,N,0 Example 1 0.45 parts of a bisazo compound represented by the following general formula [A], 0.45 parts of a polyester resin (Vylon 20C!; manufactured by Toyobo Co., Ltd.), and 50 parts of cyclohexanone. It was also dispersed using a sand glider.

The resulting bisazo 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 [1] and polycarbonate resin (K
-1300; manufactured by Ondai Kasei Co., Ltd.) dissolved 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,
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 was corona charged at 6 KV, and the initial surface potential was V. (V), initial potential is 1
Exposure amount E1/2 (lux-se
c), the decay rate D of the initial potential when left in the dark for 1 second
DR+ (%) was measured.

70 parts of styryl compound [7] and 70 parts of polyarylate resin (U-100: manufactured by Unitika) were added to 1. .

A solution dissolved in 400 parts of 4-dioxane has a dry film thickness of 1
It was applied to a thickness of 6 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 Photosensitization using the same method and the same structure as Example 5, but using styryl compounds [9], [IO], and [111] instead of styryl compound [7] used in Example 5. The body was created.

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

Example 9 Polycyclic quinone pigment represented by the following general formula [C] Example 2
~4 A photoreceptor with the same structure as in Example 1, but using styryl compounds [2], [4], and [6] instead of styryl compound [1] used in Example 1 was used. Created.

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

Example 5 0.45 parts of a bisazo 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 obtained bisazo compound dispersion was applied onto a 100 μm thick aluminized Mylar using a film applicator so that the dry film thickness was 0.3 g/m, and then dried. 0.45 parts of the charge generating layer (Upper-13000: manufactured by Ondai Kasei Co., Ltd.) was decomposed in a sand mill together with 50 parts of dichloroethane.

The obtained polycyclic quinone pigment dispersion was applied onto a 100 μm thick aluminized Mylar using a film applicator so that the dry film thickness was 0.4 g/m 2 and then dried. 60 parts of styryl compound [12] and polyarylate resin (
A solution prepared by dissolving 50 parts of U-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.

VOSE+/2, D D R1 in the same manner as in Example 1
was measured.

Examples 1O to 11 Photoreceptors having the same configuration as in Example 9 were prepared using styryl compounds [15] and [16] instead of styryl compound [12] used in Example 9. did.

V was applied to the thus obtained photoreceptor in the same manner as in Example 1. , , El/2, and DDRI were measured.

Example 12 0.45 parts of perylene pigment represented by the following general formula [D], 0.45 parts of butyral resin (BX-1: manufactured by Tanezu Kagaku Kogyo Co., Ltd.).
45 parts to 50 m of dichloroethane,! : Both were dispersed using a sand mill.

The obtained perylene pigment dispersion was applied onto a 100 μm thick aluminized roller using a film applicator.
The coating was applied to a dry film thickness of 0.4 g/m2 and then dried. 50 parts of styryl compound [17] and polycarbonate resin (
A solution prepared by dissolving 50 parts of PC-Z (manufactured by Mitsubishi Gas Chemical Co., Ltd.) in 400 parts of 1,4-dioxane was coated to a dry film thickness of 18 μm to form a charge transport layer.

A solution prepared by dissolving 21,150 parts of a styryl compound [21,150 parts] and 50 parts of polycarbonate resin (PC-Z: manufactured by Mitsubishi Gas Chemical Co., Ltd.) in 400 parts of 1,4-dioxane was applied to the charge generation layer to give a dry film thickness of 18 μm. A charge transport layer was formed.

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

Examples 16 to 17 Photoreceptors having the same configuration as in Example 15 were produced using the same method as in Example 15, except that styryl compounds [23] and [25] were used in place of the styryl compound [21] used in Example 15. did.

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

Example 18 50 parts of copper phthalocyanine and 0.2 parts of copper tetranitro phthalocyanine were dissolved in 50 parts of 98% concentrated sulfuric acid with sufficient stirring, and this was poured into 5000 parts of water, and the copper phthalocyanine and copper tetranitro phthalo were dissolved in this manner. An electrophotographic photoreceptor having a two-layer photosensitive layer was produced.

V in the same manner as in Example 1. , E-engineering/2, DDR.

was measured.

Examples 13 to 14 Photoreceptors having the same structure as in Example 12 were produced using the same method, except that styryl compounds [18] and [19] were used in place of the styryl compound [17] used in Example 12. did.

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

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 phthalocyanine pigment dispersion was made into a 100 μm thick dispersion.
The cyanine photoconductive material composition thus obtained was deposited using a film applicator on aluminized Mylar to a dry film thickness of 0.3 i+/m''. After that, it was filtered, washed with water, and dried under reduced pressure for 120 minutes.
Dry at °C.

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 melamine resin (Super Beckamine J).
820 (manufactured by Dainippon Ink Co., Ltd.) and 15 parts of the styryl compound [2] described above were placed in a ball mill pot with 100 parts of a mixed solvent prepared by mixing equal amounts of methyl ethyl ketone and xylene, and dispersed for 48 hours to make it photosensitive. A coating liquid was prepared, and this coating liquid was applied onto an aluminum substrate and dried to form a photosensitive layer having 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 at +6 Kv. ,E,/
2. DDR was measured.

Examples 19 to 21 Same structure as in Example 18, except that styryl compounds [7], [26], and [28] were used in place of styryl compound [2] 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. , E1/2, and DDRo were measured.

Comparative Examples I to 4 Same method and same structure as Example 18, except that the following compound [E
], [F], [G], and [H] were used, but a photoreceptor was produced in exactly the same manner as in Example 18, except for using each of [F], [G], and [H].

Regarding the photoreceptor thus obtained, Example 183! ) 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 laminated 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), the photoreceptor of Example 18 was subjected to a repeated live-photograph test when positively charged, and even after 1,000 copies, the initial and final images had excellent gradation, no sensitivity change, and were clear. An image was obtained, and it can be seen that the photoreceptor of the present invention has stable repeatability.

(Hereafter, margin) Vo, E1/2, and DDR were measured in the same manner as above.

Comparative Examples 5 to 7 Same structure as in Example 18, except that the following styryl compounds [I], [Moon, and [K] were used in place of the styryl compound [2] used in Example 18, respectively. A photoreceptor was produced in the same manner as in Example 18 except for this.

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

■ of the photoreceptors obtained in Examples 1 to 21 and Comparative Examples 1 to 7. ,
The measurement results for E, 8, and DDRI are shown in Table 1 - Table 1 above (Continued) Effects of the Invention The present invention suppresses photoconductive compounds useful for photoreceptors.

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

The 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]

FIGS. 1 to 5 are schematic diagrams of photoreceptors according to the present invention, and FIGS. 1, 4, and 5 are dispersion type photoreceptors in which a photosensitive layer is laminated on a conductive support. FIG. 2 and FIG. 3 show the structure of a functionally separated photoreceptor in which a charge generation layer and a charge transport layer are laminated on a conductive support.

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, Ar_1 and Ar_5 independently represent an aryl group which may have a substituent: Ar_2, Ar_3
and Ar_4 independently represent an arylene group which may have a substituent; R_3 represents a hydrogen atom, an alkyl group, or an aryl group which may have a substituent; R_1 and R_2 independently, It represents an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group, and each group may have a substituent;
_4) C(R_5)-, -N(R_6)-(in the formula, R_
4 and R_5 independently represent a hydrogen atom, an alkyl group, or an aryl group; R_6 represents an alkyl group, an aralkyl group, or an aryl group].