JPH1090919A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoreceptor excellent in durability in which electric characteristic such as charged potential, sensitivity or residual potential is never changed even by repeated use, image characteristic such as image fogging is stabilized, and no filming is observed by containing a specified compound. SOLUTION: In an electrophotographic photoreceptor having a photosensitive layer containing a carrier generating material and a carrier transport material on a conductive support body, the eletrophotographic photoreceptor contains a compound represented by the formula. This compound is contained in the surface layer constituting the photoreceptor. In the formula Rf represents n- valent fluorine-contained hydrocarbon residue having 2-10 carbon atoms, R represents alkyl group, alkenyl group, aralkyl group, or acyl group. (n) represented 1 or 2. As the fluorine-contained hydrocarbon residue of Rf, aliphatic or aromatic ones are preferably used, and concrete example thereof include perfluoroalkyl group such as pentafluoroethyl, tridecafluorohexyl, heptadecafluorooctyl and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photosensitive member for forming an electrostatic latent image. More specifically, the present invention relates to an electrophotographic photosensitive member having excellent resistance to ozone and NOx.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic photosensitive member, an inorganic photosensitive member having a photosensitive layer mainly composed of an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide, and silicon has been widely used. However, these are not always satisfactory in sensitivity, thermal stability, moisture resistance, durability, and the like. In addition, some inorganic photoreceptors contain substances that are harmful to the human body in the photoreceptor, and thus pose a problem in disposal. There is.

In order to overcome the disadvantages of these inorganic photoconductors, research and development of organic photoconductors having a photosensitive layer containing various organic photoconductive compounds as main components have been actively conducted in recent years. In particular, a function-separated type photoconductor in which the carrier generation function and the carrier transport function are assigned to different substances, respectively,
Since various materials can be selected from a wide range, and a photoreceptor having an arbitrary performance can be relatively easily produced, much research has been made, and some of them have been put to practical use.

The surface layer of such an organic photoreceptor is subjected to electrical and mechanical external forces such as corona charging, toner development, transfer to paper, and cleaning, so that it is required to have durability against these. In particular, as factors related to the deterioration of the photoconductor, 1) deterioration caused by discharge products such as ozone and nitrogen oxide (NOx) generated during corona charging, and 2) toner or its constituent components and paper powder are exposed to light. Degradation caused by adhesion to the body surface (filming) is considered. In actual images of copiers and printers, these are intertwined in a complicated manner, causing fat characters, blurred images, missing images, black spots, etc. Appears as an image abnormality.

The mechanism for such photoreceptor deterioration has been studied from various aspects, and for example, the following technical measures have been proposed. For example, a method of adding a specific hindered amine or a hindered phenol compound to a photoreceptor as an antioxidant is disclosed in JP-A-63-18355 and JP-A-63-7.
No. 3255. A combination of a specific antioxidant and a fluorine-containing polycarbonate resin binder is described in JP-A-2-132450.

However, these additives reduce the influence of ozone, NOx, etc., but may deteriorate the sensitivity and residual potential. The need for mounting on high-duty copiers and printers has increased, and miniaturization of copiers and printers has made it difficult to remove discharge products from around photoconductors. Conventional photoconductors have insufficient durability.

[0007]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to keep the electrical characteristics such as charging potential, sensitivity and residual potential unchanged even after repeated use, and to stabilize image characteristics such as image blur. An object of the present invention is to provide an electrophotographic photoreceptor which has excellent film durability without filming.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, a compound represented by the general formula (A) has been found to be an excellent active ingredient for an electrophotographic photoreceptor. They have found that they can work and have completed the present invention. That is, the object of the present invention is to provide an electrophotographic photosensitive member in which a photosensitive layer containing at least a carrier generating substance and a carrier transporting substance is provided on a conductive support, wherein the electrophotographic photosensitive member is represented by the following general formula (A): An electrophotographic photoreceptor, characterized by containing the compound represented by
The compound represented by the general formula (A) is achieved by the above-mentioned electrophotographic photosensitive member contained in a surface layer constituting the photosensitive member.

[0009]

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In the general formula (A), Rf is an n-valent carbon number of 2 to 2.
Represents a fluorine-containing hydrocarbon residue of 10, R is an alkyl group,
Represents an alkenyl group, an aralkyl group or an acyl group. N represents 1 or 2.

The fluorine-containing hydrocarbon residue for Rf is preferably an aliphatic or aromatic one, and specific examples thereof include perfluoro such as pentafluoroethyl, tridecafluorohexyl, heptadecafluorooctyl, and hexafluoropropylene. Examples thereof include an alkyl group, and a fluorine-substituted phenyl group such as hexafluorophenyl, tetrafluorophenylene, and bis (trifluoromethyl) phenyl. Examples of the alkyl group and aralkyl group of R include a methyl group, an ethyl group, a butyl group and a benzyl group, and examples of the alkenyl group include an alkenyl group having 2 to 10 carbon atoms such as a propenyl group. Examples of the acyl group include an acetyl group, a benzoyl group and a crotonyl group.

Next, specific examples of the compound of the present invention represented by the general formula (A) will be described, but the compound of the present invention is not limited thereto.

[0013]

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[0014]

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[0015]

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[0016]

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[0017]

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[0018]

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The compound of the present invention can be easily synthesized by the following method. Synthesis Example 1 (Synthesis of Exemplified Compound No. 15) N- (2′-propenyl) -2,2,6,6-tetramethyl-4-piperidinol (9.9 g; 0.05 mol)
Was dissolved in pyridine (100 ml) and stirred at room temperature.
Pentafluorobenzoic acid chloride (11.5 g;
(0.5 mol). After reacting at the same temperature for 3 hours,
The reaction product is poured into a 1% aqueous sodium carbonate solution (400 ml), and organic substances are extracted with toluene. After washing the toluene layer with water, it is dried with sodium sulfate. After removing the toluene, the residue was purified by a silica gel column (eluent hexane: ethyl acetate = 19: 1) to give Exemplified Compound No. Fifteen
Get. (15.8 g; 81% yield)

Synthesis Example 2 (Synthesis of Exemplified Compound No. 17) 4-Pentafluorobenzoyloxy-2,2,6,6
-Tetramethylpiperidine (7.0 g; 0.02 mol)
Is added to acetic anhydride (30 ml) and reacted under heating and reflux for 2 hours. After the reaction, the reaction is poured into ice water (150 ml) and stirred. The precipitated crystals were collected by filtration, washed with water and dried, and then recrystallized from a mixed solvent of ethanol and water. 17 is obtained. (5.5 g; yield 70%)

The compound of the present invention may be contained in any of the layers constituting the electrophotographic photoreceptor, the carrier transporting layer, the carrier generating layer and the like. Preferably, the surface layer of the constituting layers, ie, the conductive support In the layer furthest away from
The surface layer may be a protective layer or a carrier transporting layer constituting the surface layer.

The electrophotographic photoreceptor to which the compound of the present invention is added has excellent electrophotographic properties, controls the effects of discharge products generated by corona charging, and reduces filming of toner, paper powder, and the like. Thus, a highly durable photosensitive member that provides stable potential characteristics and images even when used repeatedly.

The layer structure of the photoreceptor according to the present invention may be a single layer structure in which a carrier generating substance and a carrier transporting substance are dispersed in a binder resin, or may include a carrier generating layer containing a carrier generating substance and a carrier transporting substance. A configuration in which a carrier transport layer is stacked may be employed. In the case of this laminated structure, any layer may be on the outermost layer side. If necessary, an intermediate layer may be provided between the conductive support and the photosensitive layer, and a protective layer may be provided on the photosensitive layer. The compound of the present invention is preferably added to the outermost surface layer of the photosensitive layer because the deterioration proceeds from the surface and the filming property is effective for the physical properties of the photosensitive layer. When a protective layer is provided, it is preferably added to these layers.

The amount of the compound of the present invention may be determined in the layer (the photosensitive layer in the case of a single layer, or the outermost surface layer in the case of a laminated photosensitive layer).
0.1 to 20% by weight, more preferably 1 to 20% by weight
10% by weight is added.

As the carrier-generating substance used in the photoreceptor of the present invention, any known substances can be used. For example, various phthalocyanine compounds, azo compounds,
Pyrylium compounds, perylene compounds, cyanine compounds, squarium compounds, and polycyclic quinone compounds can be used.

As the carrier transporting substance used in the photoreceptor according to the present invention, any known carrier transporting substance can be used. For example, a triarylamine compound, a triarylamine thrill compound, a hydrazone compound and a pyrazoline compound can be used.

The binder resin used in the photoreceptor according to the present invention includes, for example, polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, silicone-modified butyral resin, epoxy resin, polyurethane resin, Phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin and
Copolymer resins containing two or more of these resin repeating units are exemplified. In addition to these insulating resins,
A high molecular organic semiconductor such as poly-N-vinyl carbazole is exemplified.

The photosensitive layer of the present invention comprises a dispersion of the compound of the present invention dissolved or dispersed in a suitable solvent together with a binder resin and, if necessary, a carrier transporting substance and / or a carrier generating substance, as an applicator, bar coater or dip coater. It can be formed by coating and drying using the method described above.
Examples of the solvent used for preparing the dispersion include hydrocarbons such as toluene and xylene; methylene chloride,
Halogenated hydrocarbons such as 1,2-dichloroethane; ketones such as methyl ethyl ketone and cyclohexane; esters such as ethyl acetate and butyl acetate; methanol, ethanol, propanol, butanol, methyl cellosolve,
Alcohols such as ethyl cellosolve and derivatives thereof; ethers such as tetrahydrofuran and 1,4-dioxane; amines such as pyridine and diethylamine; N, N-
Nitrogen compounds such as amides such as dimethylformamide; other fatty acids and phenols; one or more of sulfur and phosphorus compounds such as carbon dioxide and triethyl phosphate can be used.

Next, as a conductive support for supporting the photosensitive layer, a metal plate or a metal drum of aluminum, nickel, or the like, a plastic film on which aluminum, tin oxide, indium oxide, or the like is deposited, or a conductive material is applied. Paper, plastic films, drums, etc. can be used.

The photoreceptor according to the present invention may further contain, if necessary, an ultraviolet absorber or a dye for correcting color sensitivity for the purpose of protecting the photosensitive layer. In addition to the compound of the present invention, another antioxidant may be used in combination.

[0031]

EXAMPLES Examples will be given below. Incidentally, “parts” means “parts by weight” unless otherwise specified. Example 1 A polyamide resin “CM8” was placed on a cylindrical aluminum substrate.
000 "(manufactured by Toray Industries, Inc.) in 100 parts of a mixed solvent of methanol: n-butanol = 9: 1 was applied by dip coating to form an intermediate layer having a thickness of 0.5 μm.

Further, as a carrier generating substance, a Bragg angle 2θ of 9.5 °, 24.1 °, 2
Titanyl phthalocyanine 10 having a peak at 7.2 °
Part, 5 parts of silicone-modified butyral resin, and 500 parts of t-butyl acetate: methoxymethylpentanone = 9: 1 dispersed with a sand grinder by dip coating.
A charge generation layer having a thickness of 0.3 μm was formed.

Next, the carrier transporting substance (P-1) 75
Part, Exemplified Compound (No. 8) of the present invention, 5 parts, and 100 parts of a polycarbonate resin "Iupilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Ltd.) dissolved in 1500 parts of THF were dip-coated on the carrier generating layer. A 25 μm-thick carrier transporting layer was formed to prepare Example Photoconductor 1.

Example 2 Compound No. 1 in Example 1 was used. 8 as No. 8. Except for changing the sample No. 13, the example photoconductor 2 was manufactured in the same manner as the example 1.

Example 3 The exemplified compound No. 1 in Example 1 was used. 8 as No. 8. A photoconductor 3 of Example 1 was prepared in the same manner as Example 1, except that the photoconductor 3 was changed to 15.

Example 4 Compound No. 1 of Example 1 8 as No. 8. A photoconductor 4 of Example 1 was made in the same manner as Example 1 except that the number was changed to 17.

Example 5 Compound No. 1 in Example 1 was used. 8 as No. 8. A photoconductor 5 of Example 1 was made in the same manner as Example 1 except that the photoconductor 5 was changed to 25.

Comparative Example 1 Compound No. 1 of Example 1 Comparative Example Photoconductor 1 was prepared in the same manner as in Example 1 except that No. 8 was removed.

Comparative Example 2 Exemplified Compound No. in Example 1 8 as Comparative Compound AO
A photosensitive member 2 of Comparative Example was prepared in the same manner as in Example 1 except that the value was changed to -1.

Comparative Example 3 Exemplified Compound No. in Example 1 8 as Comparative Compound AO
Comparative Example Photoconductor 3 was prepared in the same manner as in Example 1, except that the composition was changed to -2.

Comparative Example 4 Exemplified Compound No. in Example 1 8 as Comparative Compound AO
Comparative Example Photoconductor 4 was prepared in the same manner as in Example 1, except for changing to -3.

[0042]

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Evaluation The photoconductors obtained in the respective Examples and Comparative Examples were mounted on a digital copy “Konica 7050” manufactured by Konica Corporation.
In a high-temperature, high-humidity environment (33 ° C .; 80% RH), 5,000 actual shooting tests were performed, and the black potential V at the initial stage and after 5,000 iterations
b, gray potential Vg and residual potential Vr were measured. Further, the image characteristics (blurring) of the copied image after 5,000 times actual shooting and the surface of the photoreceptor after 5,000 times actual shooting were visually and microscopically observed.

[0044] Of the three-step method, Was evaluated by a three-step method. Table 1 shows the results.

[0045]

[Table 1]

In the photoreceptors of Comparative Examples 1 and 2, filming was observed on the photoreceptor surface after actual photographing 5,000 times, whereas the photoreceptors of Examples 1 to 5 were particularly applied to the photoreceptor surface. No kimono was found.

[0047]

As described above, the electrophotographic photoreceptor using the compound of the present invention exhibits stable electric characteristics and image characteristics even when used repeatedly, and is excellent in durability.

Claims (2)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer containing at least a carrier-generating substance and a carrier-transporting substance on a conductive support, wherein the electrophotographic photosensitive member is a compound represented by the following general formula (A): An electrophotographic photoreceptor comprising: Embedded image (In the formula, Rf represents an n-valent fluorine-containing hydrocarbon residue having 2 to 10 carbon atoms, R represents an alkyl group, an alkenyl group, an aralkyl group, or an acyl group, and n represents 1 or 2.) 2. The electrophotographic photoconductor according to claim 1, wherein the compound represented by the general formula (A) is contained in a surface layer constituting the photoconductor.