JPH0887125A - Electrophotographic photoreceptor and electrophotographic device equipped with heat electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE: To obtain a photoreceptor having durability against surface wear or scratches due to rubbing by incorporating a fluorocarbon resin powder and a binder resin in the most distant layer from a conductive supporting body. CONSTITUTION: This electrophotographic photoreceptor has a photosensitive layer on a conductive supporting body. The conductive supporting body consists of aluminum having the surface subjected to anodic oxidation. The most distant layer from the conductive supporting body contains a fluorocarbon resin powder and a binder resin. In a function-separated photoreceptor having a photosensitive layer consisting of a laminated structure of comprising a charge producing layer and a charge transfer layer, the most distant layer from the conductive supporting body consists of the charge transfer layer when the charge transfer layer is formed on the charge producing layer, and when the charge producing layer is formed on the charge transfer layer, the most distant layer consists of the charge producing layer, or further, when a protective layer is formed on the surface, the protective layer constitutes the most distant layer. Therefore, by subjecting the supporting body to anodic oxidation, variation in the potential or deterioration in images due to the powder or the powder and a dispersion assistant can be prevented against environmental changes or repetition of use.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member and an electrophotographic apparatus using the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member is required to have predetermined sensitivity, electrical characteristics and optical characteristics according to an electrophotographic process to be applied, but the electrophotographic photosensitive member is repeatedly used. In that case, the surface layer, that is, the layer most distant from the conductive support, is directly subjected to an external electric or mechanical force such as charging, toner development, transfer to paper, cleaning treatment, etc. Durability is required.

Specifically, it is required to have durability against abrasion and scratches on the surface due to rubbing, and deterioration of the surface due to ozone generated during charging.

On the other hand, there is a problem that toner is adhered to the surface layer due to repeated toner development and cleaning, and it is required to improve the cleaning property of the surface layer.

Various methods have been studied in order to satisfy the characteristics required for the surface layer as described above, and among them, the method of providing the surface layer in which the fluorine-containing resin powder is dispersed is particularly effective. That is, if the surface layer in which the fluorine-containing resin powder is dispersed is provided, the durability against scratches, cleaning properties, abrasion, etc. is improved, and the water repellency and releasability of the surface of the photoconductor are improved. It is also effective for preventing surface deterioration due to adhered substances.

Further, when the surface layer is provided as a protective layer, the charge transport material and the charge generating material which are easily deteriorated by ozone are separated from the surface, and the durability can be further improved. However, when the surface layer in which the fluororesin powder is dispersed is used for the photoreceptor, the electrophotographic characteristics may be deteriorated due to the environment or repeated use due to the fluororesin powder or the dispersion aid.

On the other hand, by using anodized aluminum surface as a conductive support,
It was possible to produce an electrophotographic photosensitive member having high durability without deterioration of the electrophotographic characteristics as described above.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member which has durability against surface abrasion and scratches caused by rubbing, and which solves the above-mentioned drawbacks, and an electrophotographic photosensitive member. It is to provide an electrophotographic apparatus used.

[0009]

The present invention relates to an electrophotographic photoreceptor having a photosensitive layer on a conductive support, the conductive support comprising aluminum having an anodized surface, and The electrophotographic photosensitive member is characterized in that the layer most distant from the conductive support contains a fluorine-containing resin powder and a binder resin.

In the electrophotographic photoreceptor of the present invention, the layer farthest from the conductive support is the charge-generating layer in the case of a function-separated photoreceptor having a structure in which the photosensitive layer has a charge-generating layer and a charge-transporting layer laminated. A photosensitive layer having a charge transport layer provided thereon corresponds to a charge transport layer, and a photosensitive layer having a charge generation layer provided on a charge transport layer corresponds to the charge generation layer. The layers correspond.

The present invention will be described in detail below by taking a function-separated electrophotographic photosensitive member having a charge transport layer laminated on a charge generation layer as an example.

When producing the electrophotographic photosensitive member of the present invention,
As the conductive support, an anodized surface of aluminum is used. In addition, a plastic having a layer obtained by anodizing the surface of an aluminum coating formed by a vacuum deposition method (for example, polyethylene, polypropylene, polychlorinated) is used. Vinyl, polyethylene terephthalate,
Acrylic resin, polyfluorinated ethylene, etc.) can be used. The conductive support is before anodizing treatment,
Acid, alkali, organic solvent, surfactant, emulsion,
Degreasing treatment is preferably performed by various degreasing methods such as electrolysis.

The anodic oxide film is usually formed by anodizing treatment in an acidic bath of sulfuric acid, chromic acid, oxalic acid, boric acid, sulfonic acid, etc. The treatment gives the best results. In the case of anodizing in sulfuric acid or sulfonic acid, the concentration is 5
-30%, dissolved aluminum concentration is 2 to 15 g / 1, liquid temperature is 15 to 45 ° C, electrolysis voltage is 5 to 80 V, and current density is preferably 0.5 to 3 A / dm ^2. . The average film thickness of the anodized film is usually 0.01-
3.0 μm, particularly 0.1 to 0.4 μm is preferable.

The anodic oxide coating thus formed may be subjected to a sealing treatment by immersing it in an aqueous solution containing nickel fluoride, nickel acetate or the like as a main component in order to enhance the stability of the coating. The concentration of the aqueous solution used can be appropriately selected, but it is preferably within the range of 3 to 20 g / 1. The liquid temperature should be 25 to 100 ° C, preferably 35 to 95 ° C. In addition, in order to further improve the physical properties of the film, additives such as cobalt fluoride, nickel sulfate, and a surfactant may be added to the aqueous solution. As the sealing agent for the sealing treatment, an aqueous solution of a metal salt such as cobalt acetate, lead acetate, barium nitrate or hot water containing no metal salt can be used. Then, it is washed with water and dried to complete the sealing treatment.

The fluorine-containing resin powder used in the present invention is a polymer of ethylene tetrafluoride, ethylene trifluoride chloride, hexafluoroethylene propylene, vinyl fluoride, vinylidene fluoride or ethylene difluoride dichloride. Alternatively, a powder of a copolymer thereof or a copolymer resin with vinyl chloride is appropriately used, but a powder of tetrafluoroethylene or vinylidene fluoride resin is particularly preferable. At that time, the molecular weight of the resin is suitably from 1,000 to 30,000, and particularly from 3,000 to 3,000.
10000 is preferable. The particle size of the powder is 0.05 ~
2.0 μm is suitable, and 0.1 to 0.5 μm is particularly preferable.

In order to further enhance the dispersion effect, a small amount of various additives such as various surfactants, coupling agents, silicone oils and leveling agents may be added as dispersion aids.

The content of the fluorine-containing resin powder to be dispersed is appropriately 1 to 50% by weight based on the total solid content of the dispersion, and particularly 3
-40% by weight is preferred.

The photosensitive layer containing the compound used in the present invention is mixed by adding the compound used in the present invention to a solution prepared by dissolving or dispersing an organic photoconductive substance and a binder resin described below in a suitable solvent. Alternatively, it can be formed by coating and drying a coating solution obtained by simultaneously mixing these to dissolve or disperse them.

The charge generating substance may be any substance as long as it has a charge generating ability, and examples thereof include the following substances. (1) Azo-based pigments such as monoazo, disazo and trisazo (2) Phthalocyanine-based pigments such as metal phthalocyanine and non-metal phthalocyanine (3) Indigo-based pigments such as indigo and thioindigo (4) Perylene anhydride and perylene imide (5) Polycyclic quinone pigments such as anthraquinone and pyrenequinone (6) Squarium dyes (7) Pyrylium salts and thiapyrylium salts (8) Triphenylmethane dyes (9) Selenium and amorphous silicon Inorganic substance These charge generating substances may be used alone or in combination of two or more kinds.

Examples of the charge transport material include hydrazone compounds, stilbene compounds, carbazole compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, thiarylmethane compounds and polyarylalkanes. May be used alone or in combination of two or more.

In order to produce a function-separated type electrophotographic photosensitive member, first, the charge generating substance as described above is dispersed in a suitable binder resin, and this is coated on a conductive support to form a charge generating layer. Can be formed. It can also be formed by forming a thin film on the conductive support by a dry method such as vapor deposition, sputtering or CVD.

The binder resin is a wide range of binders.
The resin can be selected from, for example, polycarbonate, polyester, polyarylate, butyral resin, polystyrene, polyvinyl acetal, diallyl phthalate resin,
Acrylic resin, methacrylic resin, vinyl acetate resin, phenol resin, silicone resin, polysulfone, styrene-
Butadiene copolymer, alkyd resin, epoxy resin,
Examples thereof include urea resins and vinyl chloride-vinyl acetate copolymers, but are not limited thereto. These binder resins may be used alone or as a copolymer of each component or as a mixture of two or more kinds of binder resins.

The resin contained in the charge generation layer is preferably 80% by weight or less, more preferably 40% by weight or less, based on the total weight of the layer.

The charge generation layer has a film thickness of 5 μm or less, and particularly 0.
01 to 2 μm is preferable.

Further, various sensitizers may be added to the charge generation layer.

The charge-transporting layer is prepared by dissolving the above-mentioned charge-transporting substance in a suitable binder resin using a suitable solvent.
After the fluorine-containing resin powder is dispersed, the solution is applied onto the charge generation layer and dried to form the layer.

Examples of the binder resin include photoconductive polymers such as polyvinylcarbazole and polyvinylanthracene, in addition to those used for forming the charge generation layer.

The compounding ratio of the binder resin and the charge transport material is preferably 10 to 500 parts by weight of the charge transport material per 100 parts by weight of the binder resin.

The thickness of the charge transport layer is 5 to 40 μm, especially 1
0 to 30 μm is preferable.

The above-mentioned various layers are formed by using an appropriate organic solvent by a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Mayer bar coating method. It can be formed on the conductive support by a coating method such as a coating method or a blade coating method.

As described above, the electrophotographic photoreceptor of the present invention is
Although the function-separated electrophotographic photoreceptor in which the charge transport layer is laminated on the charge generation layer has been described as an example, the present invention is not limited to this. For example, as described above, even if the function-separated electrophotographic photoreceptor provided with the charge transport layer under the charge generation layer and the surface resin layer in which the fluorine-containing resin powder is dispersed are the photoreceptor protective layers. Good.

The present invention also comprises an electrophotographic apparatus provided with the electrophotographic photosensitive member of the present invention.

FIG. 1 shows a schematic structure of a general transfer type electrophotographic apparatus using the drum type photoreceptor of the present invention. In the figure, reference numeral 1 denotes a drum type photosensitive member as an image bearing member, and a shaft 1
It is rotationally driven around a at a predetermined peripheral speed in the arrow direction.
The photosensitive member 1 is uniformly charged at its peripheral surface by a charging unit 2 at a predetermined positive or negative potential in the course of its rotation, and then at an exposure unit 3 an optical image exposure L (slit exposure Laser beam scanning exposure). As a result, electrostatic latent images corresponding to the exposed image are sequentially formed on the peripheral surface of the photoconductor. The electrostatic latent image is then toner-developed by the developing means 4, and the toner-developed image is rotated by the transfer means 5 from a paper feeding portion (not shown) between the photosensitive body 1 and the transfer means 5. Then, the images are sequentially transferred onto the surface of the transfer material 9 that is fed in synchronization with the above. The transfer material 9 that has received the image transfer is separated from the surface of the photoconductor and is introduced into the image fixing means 8 where it is subjected to image fixing and printed out as a copy (copy). After the image transfer, the surface of the photoconductor 1 is cleaned by the cleaning means 6 to remove the residual toner after transfer, and is discharged by the pre-exposure means 7 to be repeatedly used for image formation. As a uniform charging means 2 for the photoconductor 1, a corona charging device is generally widely used. Also, as the transfer device 5, corona transfer means is generally widely used. As an electrophotographic apparatus, a plurality of constituent elements such as the above-mentioned photoconductor, developing means, and cleaning means are integrally combined and configured as an apparatus unit, and this unit is detachably attached to the apparatus main body. You may comprise. For example, the photosensitive member 1 and the cleaning means 6 may be integrated into one device unit, and the device body may be detachable by using a guide means such as a rail. At this time, the above-mentioned apparatus unit may be configured with a charging means and / or a developing means. When the electrophotographic apparatus is used as a copying machine or a printer, the light image exposure L uses reflected light or transmitted light from an original, or the original is read and converted into a signal by a laser. -Beam scanning,
This is performed by driving the light emitting diode array or the liquid crystal shutter array.

[0034]

【Example】

Example 1 An aluminum cylinder having a diameter of 30 mm and a length of 346 mm was used as a conductive support, and this was first degreased and washed with an aqueous solution of a surfactant and then washed with water. 1.5 A / dm ^{2 in} 15% sulfuric acid electrolyte (dissolved aluminum concentration 6 g / 1)
Anodization was performed at a current density of 1 to form an anodized film having an average film thickness of 0.3 μm.

Then, after washing with water, an aqueous solution of nickel fluoride (1
0 g / 1) was immersed at 55 ° C. for 5 minutes for sealing treatment.
Then, it was thoroughly washed with pure water and dried.

Next, as a charge generating substance, 10 parts by weight of a disazo pigment having the following structural formula (weight part, the same applies hereinafter),

Embedded image 6 parts of polyvinyl butyral (trade name S-REC BL-S, manufactured by Sekisui Chemical Co., Ltd.) and 50 parts of cyclohexanone were dispersed in a sand mill using a glass bead. To this dispersion, 100 parts of methyl ethyl ketone was added and coated on the cylinder to form a charge generation layer having a thickness of 0.2 μm.

Next, a polycarbonate (trade name: Z-20
0, Mitsubishi Gas Chemical Co., Ltd., 10 parts, polytetrafluoroethylene powder (molecular weight 4,000,000 to 5) as fluorine-containing resin powder
2 parts, 0.5 parts of dispersion aid (trade name Aron GF300, manufactured by Toagosei Co., Ltd.), 10 parts of dichloromethane, and 50 parts of chlorobenzene were dispersed in a stainless steel ball mill, and the obtained dispersion liquid was obtained. As a charge transport material, 10 parts of a stilbene compound having the following structural formula was dissolved to prepare a charge transport layer coating solution.

Embedded image This coating solution was applied on the charge generation layer to form a 20 μm thick charge transport layer.

Example 2 Example 2 was repeated except that polytrifluoroethylene chloride (molecular weight of 3 to 4,000,000) was used as the fluorine-containing resin powder instead of polytetrafluoroethylene powder. 1
An electrophotographic photoreceptor was prepared in the same manner as in.

Example 3 In Example 1, the polyfluorotetrafluoroethylene powder was used as the fluorine-containing resin powder instead of vinylidene fluoride (molecular weight 3
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that 1,000,000) was used.

COMPARATIVE EXAMPLE 1 In Example 1, a powder made of titanium oxide fine particles having a coating layer of antimony-containing tin oxide without anodizing treatment on an aluminum cylinder (trade name: ECTT-
1. Titanium Industry Co., Ltd. 150 parts, Resole-type phenol resin (trade name Prio-Fen J325, Dainippon Ink and Chemicals Co., Ltd.) 75 parts, methyl cellosolve 60 parts and methanol 15 parts. Apply the coating solution dispersed by a sand mill using glass beads onto an aluminum cylinder.
A μm thick intermediate layer was formed.

Next, copolymerized nylon (trade name Amilan C
A solution in which 10 parts of M8000, manufactured by Toray Industries, Inc. was dissolved in a mixed solution of 60 parts of methanol and 40 parts of butanol was applied onto the intermediate layer to form a barrier layer. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except for these intermediate layer and barrier layer.

Comparative Example 2 An electrophotographic photosensitive member was prepared in the same manner as in Comparative Example 1 except that the intermediate layer was not provided on the aluminum cylinder in Comparative Example 1.

Each of the electrophotographic photoconductors produced in Example 1, Comparative Example 1 and Comparative Example 2 was mounted in a positive development electrophotographic copying machine, and the dark potential (V _D ) of the photoconductor was set to -70.
The latent image conditions were set so that the light potential ( _VL ) was 0 V and -200 V, and the process of charging-exposure-developing-transfer-cleaning was repeated in a 0.8 second cycle.

For these photoconductors, low temperature and low humidity (15
℃, 15% RH) and high temperature and high humidity (30 ℃, 85% RH)
In this environment, ΔV _D and ΔV _L of the potential change of the photoconductor after repeating 10,000 copies and the potential change (ΔV _SL ) immediately after the pre-exposure were measured. The results are shown in Tables 1 and 2.

[Table 1]

[Table 2]

In the electrophotographic photosensitive member of Example 1, the potential change was small and the image was good in any environment.
However, the electrophotographic photosensitive members of Comparative Examples 1 and 2 showed a large change in electric potential, and white spots, density unevenness, and the like were noticeable.

Example 4 As an electrically conductive support, an aluminum cylinder having a diameter of 30 mm and a length of 346 mm was used and treated in the same manner as in Example 1.

Next, a polycarbonate (trade name: Z-20
0, Mitsubishi Gas Chemical Co., Ltd.) and 10 parts of the stilbene compound as a charge transport material in dichloromethane 10 parts.
Parts and 50 parts of chlorobenzene to prepare a charge transport layer coating solution. This coating solution was applied to form a charge transport layer having a thickness of 15 μm.

Next, in the same manner as in Example 1, a charge generation layer having a thickness of 0.2 μm was formed.

Next, an acrylic monomer 6 having the following structural formula
0 copies,

[Chemical 3] 60 parts of tin oxide fine particles having an average particle size of 400 angstrom before dispersion, 50 parts of the above polytetrafluoroethylene, 20 parts of 2-methylthioxanthone as a photoinitiator, and methano
400 parts were dispersed in a sand mill for 48 hours. Using this dispersion, a film was formed on the above charge generation layer by a beam coating method and dried, and then a high pressure mercury lamp was used.
Photocured for 20 seconds at a light intensity of mW / cm ² and 4 μm
An electrophotographic photosensitive member was prepared by providing a thick surface layer.

Example 5 Example 5 was repeated except that polytrifluoroethylene chloride (molecular weight 3 to 4,000,000) was used as the fluorine-containing resin powder instead of polytetrafluoroethylene powder. Four
An electrophotographic photoreceptor was prepared in the same manner as in.

Example 6 In Example 4, as the fluorine-containing resin powder, polytetrafluoroethylene powder was used instead of vinylidene fluoride (molecular weight 3
An electrophotographic photosensitive member was prepared in the same manner as in Example 4 except that (1,000,000) was used.

Comparative Example 3 An electrophotographic photosensitive member was prepared in the same manner as in Example 4 except that the aluminum cylinder in Example 4 was not subjected to anodizing treatment and the intermediate layer and the barrier layer were provided in the same manner as in Comparative Example 1. Created the body.

Comparative Example 4 An electrophotographic photosensitive member was prepared in the same manner as in Comparative Example 3 except that the intermediate layer was not provided on the aluminum cylinder in Comparative Example 3.

Examples 4, 5 and 6, Comparative Example 3 and Comparative Example 4
Each of the electrophotographic photoconductors manufactured in 1. is mounted on a positive development electrophotographic copying machine, and the dark portion potential (V
_D) the -700V, the light portion potential _{(V L)} -200V
The latent image conditions were set so that the following conditions were satisfied, and the charging-exposure-developing-transfer-cleaning process was repeated in a 0.8 second cycle.

For these photoconductors, low temperature and low humidity (15
℃, 15% RH) and high temperature and high humidity (30 ℃, 85% RH)
Under the above environment, the changes ΔV _D and ΔV _{L in} the potential of the photoconductor after repeating 10,000 copies and the change in the potential immediately after pre-exposure (ΔV _SL ) were measured. The results are shown in Tables 3 and 4.

[Table 3]

[Table 4]

[0056]

INDUSTRIAL APPLICABILITY The electrophotographic photosensitive member of the present invention was subjected to anodizing treatment when producing an electrophotographic photosensitive member having a surface layer containing a fluororesin powder or the powder and a dispersion aid. The use of the conductive support has a remarkable effect of preventing potential fluctuations and image deterioration caused by the powder or the powder and the dispersion aid even when the environment is changed or repeated use.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a general transfer type electrophotographic apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Drum type photoconductor as an image carrier (electrophotographic photoconductor of the present invention) 1a axis 2 corona charging device 3 exposure unit 4 developing unit 5 transfer unit 6 cleaning unit 7 pre-exposure unit 8 image fixing unit 9 image transfer unit Transfer material received L light image exposure

Claims (6)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the conductive support is made of aluminum having an anodized surface and is most separated from the conductive support. An electrophotographic photosensitive member, wherein the layer containing the fluorine-containing resin powder and a binder resin. 2. The fluororesin powder is a polymer of tetrafluoroethylene, ethylene trifluoride chloride, hexafluoroethylene propylene, vinyl fluoride, vinylidene fluoride, ethylene difluoride dichloride, or a polymer thereof. The electrophotographic photosensitive member according to claim 1, which is selected from the group consisting of copolymers. 3. The electrophotographic photosensitive member according to claim 1, wherein the content of the fluorine-containing resin powder is 1 to 50% by weight based on the total solid content of the surface layer. 4. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer. 5. The electrophotographic photosensitive member according to claim 1, wherein the surface resin layer in which the fluorine-containing resin powder is dispersed is a protective layer. 6. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1. [0001]