JP2990310B2 - Polystyryl compound and electrophotographic photoreceptor using the compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photosensitive member, and more particularly, to an electrophotographic photosensitive member having a photosensitive layer containing a carrier generating substance and a carrier transporting substance.

[0002]

2. Description of the Related Art Heretofore, as an electrophotographic photosensitive member, a photosensitive member having a photosensitive layer containing an inorganic photoconductor such as selenium, zinc oxide, cadmium sulfide, or silicon as a main component has been widely known. However, these are not always satisfactory in characteristics such as thermal stability and durability, and also have problems in production and handling.

On the other hand, a photoreceptor having a photosensitive layer containing an organic photoconductive compound as a main component is relatively easy to manufacture, inexpensive, easy to handle, and generally used as a selenium photoreceptor. It has many advantages, such as better thermal stability, and as such an organic photoconductive compound, poly-N-vinylcarbazole is the most well-known, and this is 2,4,7- A photoreceptor having a photosensitive layer mainly composed of a charge transfer complex formed with a Lewis acid such as trinitro-9-fluorenone has already been put to practical use.

On the other hand, there is known a photoconductor having a function-separating type photosensitive layer of a laminated type or a single layer type in which a carrier generating function and a carrier transporting function of the photoconductor are respectively assigned to different substances. A photoreceptor having a photosensitive layer including a carrier generating layer composed of a thin amorphous selenium layer and a carrier transporting layer containing poly-N-vinylcarbazole as a main component has already been put to practical use.

[0005] However, poly-N-vinylcarbazole is
Lack of flexibility, the film is hard and brittle, and easily cracks and peeling. The photoreceptor using this is inferior in durability. In this case, the residual potential is increased, and the residual potential is accumulated with repeated use, so that the fog gradually increases and the copy image quality is deteriorated.

[0006] Since low molecular organic photoconductive compounds generally do not have a film-forming ability, they are used in combination with an appropriate binder, and the physical properties or photosensitive properties of the film are determined by selecting the type and composition of the binder. However, the types of organic photoconductive compounds having high compatibility with the binder are limited. Actually, there are few types of binders that can be used for forming a photosensitive layer, particularly a photosensitive layer of an electrophotographic photosensitive member.

For example, US Pat. No. 3,189,447 describes 2,5
-Bis (p-diethylaminophenyl) -1,3,4-oxadiazole has low compatibility with binders commonly used as materials for the photosensitive layer of the electrophotographic photoreceptor, such as polyester and polycarbonate, and has poor electrophotographic properties. When the photosensitive layer is formed by mixing at a ratio required for conditioning, crystals of oxadiazole come to be precipitated at a temperature of 50 ° C. or more, and have a disadvantage that electrophotographic properties such as charge holding power and sensitivity are reduced. .

On the other hand, the diarylalkane derivative described in US Pat. No. 3,820,989 has little compatibility problem with a binder, but has low stability to light, and is used for repetitive transfer type electrophotography in which charging and exposure are repeated. When used in the photosensitive layer of the photoreceptor, there is a disadvantage that the sensitivity of the photosensitive layer gradually decreases.

US Patent No. 3,274,000, JP-B-47-3642
No. 8 describes different types of phenothiazine derivatives, but all have the disadvantages of low photosensitivity and low stability upon repeated use.

The stilbene compounds described in JP-A-58-65440 and JP-A-58-190953 have relatively good charge holding power and sensitivity, but are not satisfactory in durability when used repeatedly. Absent.

As a matter of fact, a carrier transporting material having practically satisfactory characteristics for producing an electrophotographic photosensitive member has not been found yet.

[0012]

An object of the present invention is to provide a novel polystyryl compound. Another object of the present invention is to provide a zone containing a novel polystyryl compound as a carrier transporting substance.
An object of the present invention is to provide an electrophotographic photosensitive member having excellent electrical properties and sensitivity . Another object of the present invention is to provide an electrophotographic photoreceptor containing a compound capable of forming a film using only a carrier transporting substance.

[0013]

Means for Solving the Problems As a result of intensive studies for the above objects, an electrophotographic photoreceptor containing at least one compound represented by the following general formula [I] has excellent utility. I found that.

[0014]

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In the formula, Ar ¹ is a biphenylene group, and Ar ^{2 to} Ar ³ are
The following two groups which may have an alkyl or alkoxy group: an arylene group and a divalent heterocyclic group. R ¹ , R ² ,
R ³ represents the following two groups which may have a hydrogen atom, a halogen atom, an alkyl group and an alkoxy group; an aryl group and a heterocyclic group . n represents a numerical value of 2 or more.

As the aryl group, phenyl, naphthyl,
Biphenylyl and heterocyclic groups include furyl, thienyl, pyridyl, quinolyl and the like. Ar ^{1 to} Ar ³ , R ¹ to
R ³ may have a substituent, and examples thereof include an alkyl group such as methyl, ethyl, propyl and butyl; an alkoxy group such as methoxy, ethoxy and propoxy; and a halogen atom such as fluorine, chlorine and bromine.

Hereinafter, specific compounds of the formula [I] will be exemplified.

[0018]

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[0019]

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[0020]

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Synthesis Example (Exemplified Compound 3)

[0022]

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Synthesis of intermediate [2]: N, N-dimethylformamide (4 mol ratio) and phosphorus oxychloride (3 mol ratio) were added to triphenylamine [1] (1 mol ratio), and the mixture was heated at 70 to 90 ° C. so
Reaction for 24 hours, 4,4'-diformyl-
Triphenylamine was obtained with a yield of 68%.

Intermediate

Synthesis of [9]: Bromobenzene [3] (3 mole ratio), benzoyl chloride [4] (1 mole ratio), and AlCl ₃ (1.5 mole ratio) were reacted at 80 ° C. for 5 hours and purified to obtain [5]. Obtained in 39.8% yield.

[5] (0.33 mol), NiBr ₂ [PEt ₃ ] ₂ (9.
8 × 10 ^-4 mol), Zn (0.49 mol), KI (0.39 mol) and N-
After reacting with 500 ml of methylpyrrolidine under nitrogen at 70 ° C. for 3 hours, the mixture was allowed to cool, then post-treated with 1N HCl and water, and precipitated with toluene to obtain [6] in a yield of 75.8%.

[6] (0.121 mol), THF 300 ml, water 30 m
l, NaBH ₄ (0.218 mol) was reacted to quantitatively obtain [7].

[7] (0.106 mol), 250 ml of benzene and acetyl chloride were refluxed for 2 hours to obtain [8] in a yield of 95%.

[8] (0.101 mol) and triethyl phosphite (0.24 mol) are refluxed for 6 hours and post-treated.

[9] in a yield of 71.8
%.

[0029]

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3.0 g of t-BuOK, [2] (0.0064 mol),

[9] (0.0063 mol), 50 ml of DMF are added, and the mixture is reacted at about 50 ° C. for 3 hours. Then, diethyl phenyl-p-tolylmethylphosphonate (0.001 mol) is added and reacted for 1 hour. When the reaction solution was drained, it was purified by reprecipitation with toluene / methanol to obtain Exemplified Compound 3. The molecular weight was 0.2969 × 10 ⁴ .

FIG. 1 shows the infrared spectral absorption spectrum of Exemplified Compound 3.

Although various structures are known for the structure of the electrophotographic photosensitive member, the electrophotographic photosensitive member of the present invention can take any of these forms.

Usually, the configuration is as shown in FIGS. 2 (a) to 2 (f). 2A and 2B, a carrier generating layer 2 mainly composed of a carrier generating substance is provided on a conductive support 1.
And a photosensitive layer 4 composed of a laminate of a carrier transport layer 3 containing a carrier transport material as a main component.

As shown in FIGS. 3C and 3D, the photosensitive layer 4 may be provided via an intermediate layer 5 provided on a conductive support. Thus, when the photosensitive layer 4 has a two-layer structure, a photosensitive member having the best electrophotographic characteristics can be obtained.
Further, in the present invention, as shown in FIGS. 4E and 4F, the photosensitive layer 4 formed by dispersing the carrier generating substance 7 in a layer 6 containing a carrier transporting substance as a main component is used as a conductive support 1. It may be provided directly on or via the intermediate layer 5. In the present invention, a protective layer 8 may be provided as the outermost layer as shown in FIG. 2A to 2F, a carrier transport layer made of a carrier transport material alone may be formed.

The following are examples of the carrier generating substance used in the carrier generating layer of the photosensitive layer according to the present invention.

(1) Azo dyes such as monoazo dyes, disazo dyes and trisazo dyes; (2) perylene dyes such as perylene anhydride and perylene imide; and (3) indigo dyes such as indigo and thioindigo. Polycyclic quinones such as quinone, pyrenequinone and flavanthrone (5) quinacridone dye (6) bisbenzimidazole dye (7) indathrone dye (8) squarylium dye (9) cyanine dye (10) Azurenium-based dyes (11) Triphenylmethane-based dyes (12) Amorphous silicon (13) Phthalocyanine-based pigments such as metal phthalocyanine and metal-free phthalocyanine (14) Selenium, selenium-tellurium, selenium-arsenic (15) CdS, CdSe (16 ) Pyrylium salt dyes and thiapyrylium salt dyes It itself has a coating forming ability and can form a photosensitive layer alone. Further, the compound of the present invention has excellent compatibility with various binders,
The photosensitive layer can be formed by combining various binders.

Although any binder can be used here, it is hydrophobic and has a high dielectric constant.
It is preferable to use an electrically insulating film-forming polymer. Examples of such a high-molecular polymer include the following, but are not limited thereto.

(P-1) Polycarbonate (P-2) Polyester (P-3) Methacrylic resin (P-4) Acrylic resin (P-5) Polyvinyl chloride (P-6) Polyvinylidene chloride (P-7) Polystyrene (P-8) Polyvinyl acetate (P-9) Styrene-butadiene copolymer (P-10) Vinylidene chloride-acrylonitrile copolymer (P-11) Vinyl chloride-vinyl acetate copolymer (P-12) Chloride Vinyl-vinyl acetate-maleic anhydride copolymer (P-13) Silicone resin (P-14) Silicone-alkyd resin (P-15) Phenol formaldehyde resin (P-16) Styrene-alkyd resin (P-17) Poly -N-vinylcarbazole (P-18) polyvinyl butyral (P-19) polyvinyl formal These binder resins may be used alone or in combination of two or more. It can be used as a compound.

As the solvent for forming the carrier generating layer and the transport layer according to the present invention, N, N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, 1,
2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol,
Examples include isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve, and the like, and they can be used in combination.

Although the photoreceptor of the present invention is a function-separated laminated photoreceptor, the carrier-generating layer may contain the carrier-transporting substance of the present invention. It is preferred to use 1 to 50 parts by weight of the substance. The thickness of the carrier generation layer formed as described above is preferably 0.01 to 10 μm, particularly preferably 0.1 to 5 μm.
μm.

On the other hand, the proportion of the binder in the carrier transporting layer is preferably 2 to 20 parts by weight, particularly preferably 3 to 15 parts by weight, per 10 parts by weight of the carrier transporting substance. The thickness of the carrier transport layer is preferably 5 to 50 μm, particularly preferably 5 to 30 μm.

Examples of the conductive support used in the electrophotographic photoreceptor of the present invention include a metal plate, a metal drum or a conductive polymer containing an alloy, a conductive compound such as indium oxide, and aluminum, palladium containing an alloy. Paper, plastic film, etc., which are made conductive by applying, depositing or laminating a thin metal layer such as gold.

As the binder used for the intermediate layer, the protective layer, etc., those mentioned above for the carrier generating layer and the carrier transporting layer can be used. In addition, polyamide resin, nylon resin, ethylene-vinyl acetate, etc. Polymers, ethylene resins such as ethylene-vinyl acetate-maleic anhydride copolymer, ethylene-vinyl acetate-methacrylic acid copolymer, polyvinyl alcohol, cellulose derivatives and the like are effective.

Organic amines can be added to the photosensitive layer of the present invention for the purpose of improving the carrier generating function of the carrier generating substance. Among the organic amines, it is particularly preferable to add a secondary amine.

The photosensitive layer may contain a deterioration inhibitor such as an antioxidant or a light stabilizer for the purpose of improving the storage stability, durability and environmental resistance. Compounds used for such purposes include, for example, chromanol derivatives such as tocopherol and etherified or esterified compounds thereof, polyarylalkane compounds,
Hydroquinone derivatives and their mono- and dietherified compounds, benzophenone derivatives, benzotriazole derivatives, thioether compounds, phosphonate esters, phosphite esters, phenylenediamine derivatives, phenol compounds, hindered phenol compounds, linear amine compounds,
Cyclic amine compounds, hindered amine compounds, and the like are effective. Specific examples of particularly effective compounds include “IRGAN
OX 1010 "," IRGANOX 565 "(manufactured by Ciba-Geigy),
Hindered phenol compounds such as "Sumilyzer BHT" and "Sumilyzer MDP" (manufactured by Sumitomo Chemical Co., Ltd.), and hindered amine compounds such as "Sanol LS-2626" and "Sanol LS-622LD" (manufactured by Sankyo).

In the present invention, one or two or more electron accepting substances can be contained in the carrier generating layer for the purpose of improving sensitivity, reducing residual potential or reducing fatigue during repeated use.

Examples of the electron-accepting substance which can be used here include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, and 3-nitrophthalic anhydride. Acid, 4-nitrophthalic anhydride, pyromellitic anhydride,
Merritic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, paranitrobenzonitrile, piclink chloride, quinone chlorimide, chloranil, bulmanyl, di Chlordicyanoparabenzoquinone, anthraquinone, dinitroanthraquinone, 2,7-dinitrofluorenone, 2,4,7-trinitrofluorenone,
2,4,5,7-tetranitrofluorenone, 9-fluorenylidenemalonodinitrile, polynitro-9-fluorenylidene-
Malonodinitrile, picric acid, o-nitrobenzoic acid, p-
Examples thereof include nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, melitic acid, and other compounds having a high electron affinity.

The amount of the electron accepting substance to be added is, in terms of weight ratio, carrier generating substance: electron accepting substance = 100: 0.01 to 200, preferably 100: 0.1 to 100.

The electron accepting substance may be added to the carrier transport layer. The amount of the electron-accepting substance added to the layer is carrier transporting substance: electron-accepting substance = 100: 0.01 to 1 by weight ratio.
00, preferably 100: 0.1 to 50.

The photoreceptor of the present invention may further contain, if necessary, an ultraviolet absorber for the purpose of protecting the photosensitive layer, and may contain a dye for correcting color sensitivity.

The electrophotographic photoreceptor of the present invention has the above-mentioned structure and, as will be apparent from the examples described later, has excellent charging characteristics, sensitivity characteristics and image forming characteristics, especially when used repeatedly. Also, it has little fatigue deterioration and excellent durability.

Further, the electrophotographic photosensitive member of the present invention can be widely used in application fields such as a photosensitive member of a printer using a laser, a cathode ray tube (CRT), and a light emitting diode (LED) as a light source, in addition to an electrophotographic copying machine. .

[0053]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but it should not be construed that the present invention is limited thereto.

Example 1 A thickness of 0.08 of a vinyl chloride-vinyl acetate-maleic anhydride copolymer “ESREC MF-10” (manufactured by Sekisui Chemical Co., Ltd.) was formed on a conductive support obtained by evaporating aluminum on a polyester film. An intermediate layer of μm is provided thereon, and dibromoanthranthrone “Monolite Red 2Y” (CI No. 59300
1 g of ICI) was added to 30 ml of 1,2-dichloroethane and dispersed in a ball mill, and 1.5 g of polycarbonate “PANLITE L-1250” (manufactured by Teijin Chemicals) was dissolved in a dispersion obtained and coated well. The liquid was applied so that the film thickness after drying was 2 μm to form a carrier generation layer.

On top of this, 7 g of the exemplified compound (3), 10 g of polycarbonate "Z-200" (Mitsubishi Gas Chemical) and 2% of an anti-deterioration agent "IRGANOX 1010" were added to the carrier transporting material, and 80 ml of 1,2-dichloroethane was added. A carrier transporting layer was formed by applying a solution dissolved in the above solution so that the film thickness after drying became 20 μm, thereby preparing a photoreceptor of the present invention.

The photoreceptor thus obtained was evaluated for the following characteristics using EPA-8100 manufactured by Kawaguchi Electric Co., Ltd. After charging 5 seconds electrification voltage -6 KV, illuminance at 5 seconds dark standing then the photosensitive member surface was irradiated with a halogen lamp light so as to 2Lux, the initial surface potential V _A, the half decay exposure E1 / 2 determined Was. The results were as shown in Table 1.

Examples 2 to 10 In place of Exemplified Compound 2, the same preparations and measurements were made using the exemplified compounds shown in Table 1. Example 11 Polyamide resin "A-70" (manufactured by Toray Industries, Inc.) on a conductive support obtained by evaporating aluminum on a polyester film.
An intermediate layer having a thickness of 0.1 μm was formed.

[0058]

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2 g of the bisazo pigment having the above structure and 2 g of the polycarbonate resin “PANLITE L-1250” were mixed with 1,2-
The mixture was mixed with 100 ml of dichloroethane and dispersed with a sand grinder for 8 hours. This dispersion was applied on the intermediate layer so that the thickness after drying was 0.2 μm.

Illustrative compound (3) as a carrier transporting substance
A photoreceptor was prepared in the same manner as in Example 1 by adding 2 wt% of the deterioration inhibitor "IRGANOX 1010" to the carrier transporting substance. The same measurement as in Example 1 was performed on this photoreceptor, and the results in Table 1 were obtained.

Examples 12 to 20 Photoconductors were prepared and measured in the same manner as in Example 11, except that the exemplified compounds shown in Table 1 below were used instead of the exemplified compound (3).

Example 21 A polyamide resin "CM8000" (manufactured by Toray Industries, Ltd.) was placed on a conductive support obtained by evaporating aluminum on a polyester film.
An intermediate layer having a thickness of 0.2 μm was provided.

3 g of titanyl phthalocyanine having an X-ray diffraction spectrum shown in FIG. 3 and a silicone resin “KR-5240, 1”
Of 5% xylene-butanol solution ”(Shin-Etsu Chemical Co., Ltd.)
Was dispersed in 100 ml of isopropyl alcohol using a sand mill, and the dispersion was dried on an intermediate layer to a thickness of 0.
It was applied to a thickness of 2 μm. Next, 7 g of the exemplary compound (3) as a carrier transporting substance and 10 g of polycarbonate "Z-200" were dissolved in 80 ml of 1,2-dichloroethane. This solution was applied so that the film thickness after drying was 20 μm, to form a carrier transport layer.

The measurement of this photoreceptor was performed in the same manner as in Example 1, and the results shown in Table 1 were obtained.

Example 22 A 0.2 μm intermediate layer made of ethylene-vinyl acetate-methacrylic acid copolymer resin “ELVAX 4260” (manufactured by Mitsui DuPont Chemical Co., Ltd.) was formed on an aluminum drum. 1 g of the exemplified compound (3) and 1.5 g of a polyester resin “Vylon 200” (manufactured by Toyobo Co., Ltd.)
A solution dissolved in 10 ml of 2-dichloroethane was applied on the intermediate layer, and dried to form a carrier transporting layer having a thickness of 15 μm. On the other hand, 1 g of titanyl phthalocyanine having an X-ray diffraction spectrum shown in FIG. 3 as a carrier-generating substance, and polycarbonate "Panlite L-1250" as a binder resin
After dispersing 3 g (manufactured by Teijin Chemicals), 15 ml of monochlorobenzene as a dispersion medium and 35 ml of 1,2-dichloroethane using a ball mill, the compound (3) was further added as a carrier transporting substance at 75 wt% to the binder resin. Was added so that The dispersion thus obtained is applied on the carrier transport layer by a spray coating method to form a film having a thickness of 2 μm.
m carrier generation layer was formed.

The photoreceptor thus obtained was evaluated in the same manner as in Example 1 except that the charging polarity was changed to a positive polarity.

Example 23 An intermediate layer and a carrier generating layer were applied in the same manner as in Example 11, and then a solution in which 1.0 g of the exemplified compound (3) was dissolved in 1.0 g of 1,2-dichloroethane was dried to a film thickness of 20 μm. Thus, a photoconductor was prepared. This photoreceptor was measured in the same manner as in Example 1, and the results shown in Table 1 were obtained.

-Table 1-Examples Exemplified compounds- _VA (v) E1 _{/ 2} (lux.sec) 13 1632 3.68 22 1520 3.20 37 1586 3.88 4 10 1602 3.51 511 1498 3.44 6 12 1423 3.57 7 13 1575 3.69 8 15 1473 3.36 9 16 1665 3.38 10 20 1543 3.77 11 3 1542 2.98 12 2 1487 2.38 13 7 1395 2.37 14 10 1431 3.04 15 11 1422 2.96 16 12 1386 2.56 17 13 1493 2.41 18 15 1508 2.88 19 16 1486 2.70 20 20 1534 2.65 21 3 1381 0.4 22 3 -1235 0.74 23 3 720 0.82

[0069]

The electrophotographic photoreceptor of the present invention has excellent chargeability, high sensitivity, surface potential even when used repeatedly,
Stable performance is obtained with little degradation of sensitivity.

[Brief description of the drawings]

FIG. 1 is an infrared spectrum diagram of Exemplified Compound 2.

FIGS. 2A to 2F are cross-sectional views of an example of a photoconductor of the present invention.

FIG. 3 shows the X of titanyl phthalocyanine used in the examples.
Line diffraction spectrum diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support 2 Carrier generation layer 3 Carrier transport layer 4 Photosensitive layer 5 Intermediate layer 6 Layer containing carrier transport material as a main component 7 Carrier generator material 8 Protective layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification code FI G03G 5/06 313 G03G 5/06 313 (58) Investigated field (Int.Cl. ⁶ , DB name) C07C 211/54 CAPLUS ( STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A polystyryl compound having a structure represented by the general formula [I]. Embedded image (Wherein, Ar ¹ is a biphenylene group, Ar ^{2 to} Ar ³ are alkyl or
Represents the following two groups which may have an alkoxy group; an arylene group and a divalent heterocyclic group. R ¹ , R ² and R ³ represent the following two groups which may have a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group; an aryl group and a heterocyclic group . n
Represents a numerical value of 2 or more. ] 2. An electrophotographic photoreceptor comprising at least one of the compounds represented by the general formula [I].