JPH0627690A - Production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve sensitivity and durability by forming a charge generating layer by a vapor deposition method, then bringing a solvent which dissolves a charge transfer layer into contact therewith from above. CONSTITUTION:This photosensitive body is constituted by providing the charge transfer layer CTL 2 on a conductive base 1 and further, depositing the charge generating layer CGL 3 by evaporation thereon in Fig. (1). An org. photosensitive layer 4 is constituted of the CTL 2 and CGL 3 which are respectively independent in this embodiment. Fig. (2) is the case where the photosensitive body is constituted by adding an intermediate layer 5 between the CTL 2 and the conductive base 1. Fig. (3) is the case where the photosensitive body is constituted by providing the org. photosensitive layer 4 consisting of a single layer on the conductive base 1 by codeposition of the CTL and the CGL by evaporation. Fig. (4) is the case where the photosensitive body is constituted by adding the intermediate layer 5 between the org. photosensitive layer 4 and the conductive base 1. Fig. (5) is the constitution provided with a surface protective layer and Fig. (6) is the constitution further added with the intermediate layer 5.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
The present invention relates to a layer forming method of an electrostatic image carrying layer (photosensitive layer).

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic photosensitive member, an inorganic photosensitive member having a photosensitive layer containing an inorganic photoconductive substance such as selenium, zinc oxide, cadmium sulfide as a main component is widely used.

On the other hand, the utilization of various organic photoconductive substances as materials for the photosensitive layer of an electrophotographic photoreceptor has been actively developed and studied in recent years.

For example, Japanese Patent Publication No. 50-10496 discloses an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-trinitro-9-fluorenone. However, this photoreceptor is not always satisfactory in sensitivity and durability.

In order to improve such drawbacks, an attempt is made to develop an organic photoreceptor having high sensitivity and high durability by separately sharing a charge generation function and a charge transport function in a photosensitive layer. Has been done. In such a function-separated type electrophotographic photoconductor, since substances exhibiting each function can be selected from a wide range of substances, it is relatively easy to produce an electrophotographic photoconductor having arbitrary characteristics. Is possible. According to such an organic electrophotographic photoreceptor, since the photosensitive layer can be formed by coating, the manufacturing cost is low, pollution and environmental pollution can be prevented, and it can be easily processed into various shapes (sheet shape, etc.).

However, the organic electrophotographic photoreceptor has the following drawbacks, and there is a strong demand for solving these drawbacks.

(A) For example, since a layer is formed by binding a low molecular weight organic compound with a high molecular weight organic resin (binder), the mechanical strength is not always sufficient, and when the photoreceptor is repeatedly used, The surface of the photoconductor is scratched or worn due to rubbing of the developing blade.

(B) The photoconductor is mainly used for negative charging. As described in JP-A-60-247647, a thin charge generating layer is provided on a support, and a relatively thick charge transport layer is provided thereon. A structure in which layers are provided is adopted.

The reason for this is that when negatively charged, a hole transporting material can be used, which is advantageous in terms of high sensitivity and the like, while an electron transporting material has excellent characteristics. It is because it is extremely small, has toxicity or carcinogenicity, and cannot be used.

However, when the photoreceptor having the hole-transporting material is used in negative charging, a large amount of ozone is generated during charging, which deteriorates the environmental conditions. Further, the ozone and other ionic substances are adsorbed on the surface of the photoconductor to deteriorate the quality of the material, and the potential is lowered, the residual potential is increased, the sensitivity is lowered and the image quality is lowered by repeated use, and the life of the photoconductor is shortened.

Therefore, research and development have been carried out on a positive charging photoreceptor having a charge transporting layer containing a hole transporting charge transporting substance on a support and a charge generating layer as a surface layer thereon. . According to the positive charging photoreceptor, ozone is hardly generated at the time of charging, which is advantageous in environmental hygiene (Japanese Patent Laid-Open Publication No. Sho.
62-92962 etc.).

However, the positive charging photoreceptor is inferior to the negative charging photoreceptor in terms of sensitivity and durability, and a satisfactory one is not obtained at present.

[0013]

OBJECTS OF THE INVENTION It is an object of the present invention to provide a positive charging type organic photoreceptor having a sensitivity equal to or higher than that of a negative charging type organic photoreceptor, and yet another object is to be used for repetitive image formation. Even if the accumulation of residual potential is increased and the sensitivity is not deteriorated due to wear of the film, a positively charged organic photoreceptor is provided.

[0014]

The constitution, action and effect of the present invention are as follows: In an electrophotographic photosensitive member comprising at least a charge transport layer and a charge generation layer laminated in this order on a support, the charge generation layer is formed by a vapor deposition method, and then a solvent that dissolves the charge transport layer is applied from above. 1. a method for producing an electrophotographic photosensitive member, which comprises a step of contacting; In an electrophotographic photosensitive member comprising at least a charge transport layer and a charge generation layer laminated in this order on a support, the charge generation layer is formed by a vapor deposition method, and then a solution containing a charge transport substance is applied from above. 2. A method for producing an electrophotographic photosensitive member, which comprises a step of contacting. An electrophotographic photoreceptor comprising a support, and at least a charge transport layer and a charge generation layer laminated in this order, wherein the charge generation layer is formed by co-evaporating the charge transport material and the charge generation material. 3. A method for producing an electrophotographic photosensitive member, In an electrophotographic photosensitive member comprising a support, on which at least a charge transport layer, a charge generation layer, and a surface protective layer are laminated in this order, the charge generation layer is formed by a vapor deposition method, and then a solvent that dissolves the charge transport substance is used. A method for producing an electrophotographic photosensitive member, which comprises forming a surface protective layer using a solution containing
Achieved by

The operation of the present invention will be described below.

Conventionally, an organic photoconductor (OPC) is often prepared by coating from the viewpoint of productivity. That is,
After applying a charge generation layer of about 0.1 to 0.5 μm on the substrate,
The mainstream was a negatively charged organic photoreceptor on which a charge transport layer having a thickness of 10 to 30 μm was laminated and coated.

On the other hand, when the charge generating layer is formed by vapor deposition instead of coating, it is known that the charge generating substance can be formed more densely, which is advantageous in improving electrophotographic characteristics such as sensitivity. ing.

On the other hand, the negatively charged OPC described above requires a positively charged OPC because a large amount of ozone is generated during corona discharge.

The present inventors formed a conventional coating type charge generation layer (CGL) by vapor deposition in positively charged OPC,
We considered improving electrophotographic performance. However, contrary to the intention, it was found that the sensitivity was hardly exhibited in the positively charged OPC in which CGL was vapor-deposited on the charge transport layer (CTL), and the purpose was not achieved by that alone.

As a result of diligent study on this, CT
It has been found that the OPC in which CGL is vapor-deposited on L does not exhibit sensitivity as compared with the conventional coating type because the charge transport material (CTM) does not exist in the immediate vicinity of the charge generation material (CGM).

That is, in the coating type, when the CGL is coated on the CTL, the CGL coating liquid dissolves the CTL to dissolve the CGL.
This is because the CTM melts into the CGM and enters into the immediate vicinity of the CGM, whereas the above-mentioned melt-through cannot be expected when the CGM is vapor-deposited on the CTL.

On the other hand, in the structure of the present invention, even in the OPC in which the CGL is vapor-deposited on the CTL, the CTM can be present in the immediate vicinity of the CGM, and the CGL is a dense film formed by vapor deposition. Therefore, high sensitivity can be obtained.

Next, a specific structural example of the electrophotographic photosensitive member according to the present invention will be described with reference to the drawings.

FIG. 1 (1) shows a CT on a conductive support 1.
In this example, L2 is provided, and CGL3 is vapor-deposited on the L2 to form an electrophotographic photosensitive member. In this example, the organic photosensitive layer 4 is composed of CTL2 and CGL3 which are independent of each other.

FIG. 2 (2) shows the CT in the example of (1).
This is a configuration in which the intermediate layer 5 is added between the L2 and the conductive support 1. The intermediate layer 5 functions as, for example, an adhesive layer or a barrier layer.

FIG. 3C shows a structure in which the organic photosensitive layer 4 composed of a single layer formed by co-evaporating CTL and CGL is provided on the conductive support 1.

FIG. 4 (4) shows a structure in which an intermediate layer 5 is added between the organic photosensitive layer 4 and the conductive support 1 in the example of (3).

FIG. 5 (5) shows a structure in which the surface protective layer 6 is provided in the example of (1), and (6) shows a structure in which the intermediate layer 5 is further added.

As the CGM used in the CGL of the photosensitive layer according to the present invention, either an inorganic pigment or an organic dye can be used as long as it absorbs light and generates a free charge. An organic pigment as shown by is preferably used.

(1) Azo pigments such as monoazo pigments, polyazo pigments, metal complex salt azo pigments, pyrazolone azo pigments, stilbene azo and azo azo pigments (2) Perylene pigments such as perylene anhydride and perylene imide ( 3) Anthraquinone-based or polycyclic quinone-based pigments such as anthraquinone derivatives, anthanthrone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives, violanthrone derivatives and isobiolanthrone derivatives (4) Indigooid pigments such as indigo derivatives and thioindigo derivatives (4) 5) Phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine (6) Carbonium pigments such as diphenylmethane pigment, triphenylmethane pigment, xanthene pigment and acridine pigment (7) Azine pigment, oxazine pigment and thiazine pigment Quinoneimine pigments such as gin pigments (8) Methine pigments such as cyanine pigments and azomethine pigments (9) Quinoline pigments (10) Nitro pigments (11) Nitroso pigments (12) Benzoquinone and naphthoquinone pigments (13) Na pigments Phthalimide pigments (14) Perinone pigments such as bisbenzimidazole derivatives.

From the viewpoint of ozone resistance, polycyclic quinone pigments and perylene pigments are most preferable. The details are unclear, but probably because polycyclic quinones are inert to ozone.

Examples of phthalocyanine pigments include the following, which can be preferably used in combination with the substrate according to the present invention.

(IV-1) X-type metal-free phthalocyanine (IV-2) τ-type metal-free phthalocyanine (IV-3) Chloroaluminum phthalocyanine (IV-4) Titanyl phthalocyanine (IV-5) Vanadyl phthalocyanine (IV-6) ε-type copper phthalocyanine (IV-7) chloroindium phthalocyanine Next, the CTM usable in the present invention is not particularly limited, and examples thereof include an oxazole derivative, an oxadiazole derivative, a thiazole derivative, a thiazole derivative, a triazole derivative, and imidazole. Derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, pyrazoline derivatives, oxazolone derivatives, benzthiazole derivatives,
Benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative,
It may be one or more selected from aminostilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene and the like. CGL
It is also possible to use different CTMs for CTL and CTL.

Further, as the solvent capable of dissolving the CTM according to the present invention, N, N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, monochlorobenzene, toluene, xylene, chloroform,
1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol , Ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve and the like can be mentioned, and they can be used in combination.

On the other hand, when the photosensitive layer of the present invention has a single layer structure,
The weight ratio of CTM to CGM is preferably 0 to 5 parts by weight when CGM is 1 part by weight, and the thickness of the photosensitive layer formed is preferably 5 to 50 μm, particularly preferably 10 parts by weight.
~ 30 μm.

Intermediate layer, surface protective layer or CT if necessary
As the binder used for L, any binder can be used, but it is preferable to use an electrically insulating film-forming polymer which is hydrophobic and has a high dielectric constant. Examples of such high molecular weight polymers include, but are not limited to, the followings.

(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 are used alone. It can be used as a mixture of two or more kinds.

In addition, polyamide resin, nylon resin,
Ethylene resins such as ethylene-vinyl acetate copolymers, ethylene-vinyl acetate-maleic anhydride copolymers, ethylene-vinyl acetate-methacrylic acid copolymers, polyvinyl alcohol, cellulose derivatives and the like are effective.

Further, in the above-mentioned photosensitive layer, storability, durability,
For the purpose of improving the environmental resistance, a deterioration inhibitor such as an antioxidant or a light stabilizer may be contained. Examples of the compound used for such a purpose include biphenyl, terphenyl, diphenyl ether, diphenyl carbonate, phenyl benzoate, diphenyl phthalate, chromanol derivatives such as tocopherol and etherified or esterified compounds thereof, polyarylalkane compounds, Hydroquinone derivatives and mono- and dietherified compounds thereof, benzophenone derivatives, benzotriazole derivatives, thioether compounds, phosphonic acid esters, phosphorous acid esters, phenylenediamine derivatives, phenol compounds, hindered phenol compounds, linear amine compounds,
Cyclic amine compounds and hindered amine compounds are effective. Specific examples of particularly effective compounds include "IRGANO
"X1010", "IRGANOX565" (made by Ciba Geigy),
Examples thereof include 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 Co.). The weight ratio of these compounds to CTM is 0.001 to 0.1: 1, preferably 0.05 to 0.1: 1.

In the present invention, CGL may contain one or more electron-accepting substances for the purpose of improving sensitivity, reducing residual potential or reducing fatigue during repeated use.

Examples of the electron accepting substance that 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 dianhydride,
Mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, paranitrobenzonitrile, picrin chloride, quinone chlorimide, chloranil, bulmannyl, di Chlordicyanoparabenzoquinone, anthraquinone, dinitroanthraquinone, 2,7-dinitrofluorenone, 2,4,7-trinitrofluorenone,
2,4,5,7-Tetranitrofluorenone, 9-fluorenylidene malonodinitrile, polynitro-9-fluorenylidene-
Malonodinitrile, picric acid, o-nitrobenzoic acid, p-
Nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, meritic acid, etc.
Nos. 2-214866, 2-135362, and U.S. Pat. No. 455,659 can be mentioned as compounds having a high electron affinity.

The amount of the electron-accepting substance added is CG by weight.
M: electron acceptor = 100: 0.01-200, preferably 10
0: 0.1 to 100.

The electron accepting substance may be added to the CTL. The amount of the electron-accepting substance added to the layer is C by weight.
TM: electron acceptor = 100: 0.01-100, preferably 10
0: 0.1 to 50.

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

As the conductive support, (1) a plate-shaped or drum-shaped conductive support made of a metal such as aluminum or stainless steel, or (2) aluminum or palladium on a support such as paper or a plastic film. , A conductive support having a thin layer made of metal such as gold provided by lamination or vapor deposition, (3) conductive polymer, indium oxide, on a support such as paper or plastic film,
Examples thereof include a conductive support having a structure in which a layer of a conductive compound such as tin oxide is provided by coating or vapor deposition.

[0046]

EXAMPLES The present invention will be described in detail with reference to examples.

Example 1 A coating liquid consisting of polycarbonate (Teijin Kasei Panlite L-1250) 200 g, compound (A) * 300 g dichloroethane 1000 ml * on the aluminum pipe having an outer diameter of φ80 mm and a length of 355.5 mm. 30μ after dried by dip coating
m CTLs were formed.

Subsequently, the compound (B) described in "Chemical Formula 1" was used thereon by vacuum deposition to form CGL having a thickness of 0.5 μm.
Was formed.

Further, CGL was sprayed with 1,1,2-trichloroethane using a spray gun. Finally at 100 ℃ 1
Heat dried for an hour.

Thus, the photoreceptor 1 of the present invention was prepared.

Comparative Example (1) A comparative photoconductor (1) was formed in the same manner as in Example 1, except that 1,1,2-trichloroethane was not sprayed by a spray gun.

Example 2 A photoreceptor 2 of the present invention was prepared in the same manner as in Example 1 except that the compound (C) described in "Chemical formula 1" was used.

Example 3 A photoreceptor 3 of the present invention was prepared in the same manner as in Example 1, except that the following liquid was sprayed instead of spraying 1,1,2-trichloroethane with a spray gun.

Monochlorobenzene 100 ml Compound (A) 20 g Example 4 In Example 1, the photosensitive layer was compounded with compound (C) and compound (A).
A photoreceptor 4 of the present invention was prepared in the same manner except that was formed by co-evaporation.

Example 5 The same procedure as in Example 1 was carried out except that a surface protection layer having a thickness of 1 μm was formed by a circular slide hopper using the following liquid instead of spraying 1,1,2-trichloroethane with a spray gun. The photoreceptor 5 of the present invention was prepared.

Comparative Example (2) In Example 1, CGL was formed by a circular slide hopper using a dispersion liquid having the following composition and sprayed with a spray gun.
Comparative comparative photoconductor (2) was prepared in the same manner except that 1,2-trichloroethane was not sprayed.

Compound (B) 20 g 1,2-dichloroethane 1000 ml

[0058]

[Chemical 1]

Characteristic Evaluation: The obtained photoconductor was used as an electrostatic charging test apparatus EPA manufactured by Kawaguchi Electric Co., Ltd.
It was evaluated by -8100. The results are shown in Table 1.

Evaluation was made by charging for 5 seconds, dark decay for 5 seconds, and light decay for 10 seconds.
Seconds were measured, and the charging potential, dark decay rate, and photosensitivity were used.
As the light source, a 2850K tungsten lamp was used, and long wavelength light of 610 nm or longer was cut by a filter.

[0061]

[Table 1]

As is apparent from Table 1, the photoconductor of the present invention has very excellent sensitivity.

[0063]

EFFECTS OF THE INVENTION A high-sensitivity positively chargeable organic photoreceptor having good chargeability and film properties can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of an example of a positive charging type photoreceptor according to the present invention.

[Explanation of symbols]

 1 Conductive Support 2 Charge Transport Layer 3 Charge Generation Layer 4 Photosensitive Layer 5 Intermediate Layer 6 Surface Protective Layer

Claims (4)

[Claims] 1. In an electrophotographic photosensitive member comprising a support, and at least a charge transport layer and a charge generation layer laminated in this order, the charge generation layer is formed by a vapor deposition method, and then the charge transport layer is dissolved. A method for producing an electrophotographic photosensitive member, comprising the step of bringing a solvent into contact therewith. 2. An electrophotographic photosensitive member comprising a support and at least a charge transport layer and a charge generation layer laminated in this order, the charge generation layer being formed by a vapor deposition method, and thereafter containing a charge transport substance. A method for producing an electrophotographic photosensitive member, comprising the step of bringing a solution into contact therewith. 3. An electrophotographic photoreceptor comprising a support, and at least a charge transport layer and a charge generation layer laminated in this order, wherein the charge generation layer is formed by co-evaporating the charge transport material and the charge generation material. A method of manufacturing an electrophotographic photosensitive member, comprising: 4. An electrophotographic photoreceptor comprising a support, and at least a charge transport layer, a charge generation layer, and a surface protective layer laminated in this order, the charge generation layer being formed by a vapor deposition method, and then the charge transport material. A method for producing an electrophotographic photosensitive member, which comprises forming a surface protective layer using a solution containing a solvent which dissolves.