JPH0689034A - Electrophotographic sensitive body and electrophotographic device and facsimile using the same - Google Patents

Abstract

PURPOSE:To obtain excellent electrophotographic characteristics even for repeated use and to obtain a stable picture image of good picture quality without causing fog or toner deposition. CONSTITUTION:This electrophotographic sensitive body has a photosensitive layer and a protective layer on a conductive supporting body. The photosensitive layer contains <=5000ppm residual solvent concn. The electrophotographic device and the facsimile use this electrophotographic sensitive body. Thereby, the obtd. electrophotographic sensitive body has excellent electrophotographic characteristic even for repeated use and gives stable picture images of good picture quality without causing fog or toner deposition, and the electrophotographic device and the facsimile using that can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a surface protective layer.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member is required to have required sensitivity, electrical characteristics and optical characteristics according to an electrophotographic process to be used. For example, the surface layer of the photoreceptor, that is, the layer that is most isolated from the support is directly applied with external electric and mechanical force such as corona charging, toner development, transfer to paper and cleaning treatment. 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 corona charging. On the other hand, there is a problem that the toner adheres to the surface layer due to repeated development and cleaning of the toner, and it is required to improve the cleaning property of the surface layer.

In order to satisfy the characteristics required for the surface layer as described above, an attempt has been made to provide a surface protective layer containing a resin as a main component, as proposed in, for example, JP-A-63-313356. However, the conventionally used methods have problems such as deterioration of electrophotographic characteristics due to repeated charging and deterioration of cleaning performance due to adhesion of toner to the surface of the photoconductor.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to provide an electrophotographic photosensitive member which meets the above-mentioned requirements.
That is, an object of the present invention is to provide an electrophotographic photosensitive member which is excellent in slipperiness and has durability against abrasion of the surface due to rubbing and generation of scratches. Another object of the present invention is to provide an electrophotographic photoconductor that exhibits stable electrophotographic characteristics without accumulation of residual potential and deterioration of sensitivity in repeated electrophotographic processes. Another object of the present invention is to provide an electrophotographic photosensitive member which can maintain high quality image quality without toner adhesion to the photosensitive drum during repeated durability.

[0005]

As a result of intensive studies made by the present inventors in accordance with the above-mentioned object, in an electrophotographic photosensitive member having a photosensitive layer and a protective layer on a conductive support, the residual in the photosensitive member. By setting the solvent concentration to 5000 ppm or less, it was possible to provide an electrophotographic photosensitive member that meets the above-mentioned requirements.

The residual solvent contained in the photoreceptor is 5000 p
If it exceeds pm, the residual potential rises due to the durability, the background stain of the image due to the rise of V _L (light portion potential), the image stain due to the filming due to the adhesion of the toner to the photosensitive drum and the cleaning failure, and the object of the present invention. Can not be achieved.

Therefore, in the present invention, the present invention has been completed by drying the protective layer under specific drying conditions in order to reduce the residual solvent in the photoconductor to 5000 ppm or less.

The contents of the present invention will be described in detail below.

The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having a photosensitive layer and a protective layer on a conductive support.

The photosensitive layer in the present invention is a single-layer type photoconductor in which a charge-generating material and a charge-transporting material whose functions are separated are mixed, or a charge-generating layer containing the charge-generating material, and a charge-transporting material containing the charge-transporting material. It takes the form of a laminated photoreceptor in which layers are laminated.

As the charge generating material, organic dyes such as pyrylium, thiopyrylium dyes, phthalocyanine pigments, anthanthrone pigments, perylene pigments, dibenzpyrenequinone pigments, pyranthrone pigments, azo pigments, incigo pigments and quinacryton pigments, Selenium, selenium-
Inorganic materials such as tellurium and amorphous silicon zinc oxide are used.

As the charge transport material, compounds of pyrazoline type, hydrazone type, stilbene type, triphenylamine type, benzidine type, oxazole type, indole type and carbazole type are used.

In the case of a single-layer photoreceptor, the above-mentioned charge generating material and charge transport material are dispersed and dissolved in a suitable binder resin, and a photosensitive layer is formed on the conductive support by coating. On the other hand, as the laminated type, (1) a charge generation layer and a charge transport layer are laminated in this order on a conductive support, or (2) a charge transport layer,
In some cases, the charge generation layers are laminated in this order. As a method of forming the charge generation layer, a charge generation material is dispersed in a binder resin and a solvent,
There are methods of melting and applying, methods of vapor deposition, sputtering, and the like. The charge transport layer is formed by dissolving the above charge transport material in a binder resin and laminating it on the charge generation layer. On the other hand, when the charge generation layer is laminated on the charge transport layer, both layers are formed by applying the above-mentioned organic material together with the binder resin. At this time, it is preferable to include a charge transport material also in the charge generation layer. The photosensitive layer of the present invention may further contain known additives such as an antioxidant, an ultraviolet absorber and a plasticizer for improving flexibility.

The surface protective layer used in the present invention includes thermoplastic resins such as polyester, polycarbonate, polyarylate, polystyrene, acrylic copolymers and polyether resins, polyurethane, epoxy resin, thermosetting acrylic resin, phenol. Resins, melamine resins, alkyd resins, thermosetting resins such as silicone resins and unsaturated polyesters, epoxy resins, urethane resins, and photocurable resins such as photocurable acrylic resins can be used. Charge generating materials or charge transporting materials, conductive materials such as metals and their oxides, nitrides, salts, alloys and carbons, and insulating high hardness materials such as fluorine resin powders and ceramic particles, and if necessary. The protective layer may contain additives such as an antioxidant, an ultraviolet absorber and a smoothing material. Specific examples of the fluorine-based resin powders include polymers such as tetrafluoroethylene, hexafluoropropylene, trifluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride and perfluoroalkyl vinyl ether, and their copolymers. Coalescence is used. The particle size of fluororesin powder is 0.0
It can be used in the range of 1 to 5 μm, and its molecular weight is 30.
It can be used in the range of 0 to 5,000,000, and the content of fluorine atoms in the fluororesin powder is preferably 30% by weight or more and 90% by weight or less. The thickness of the protective layer is 0.
The thickness is 01 to 20 μm, preferably 0.5 to 10 μm.

The conductive support used in the electrophotographic photosensitive member of the present invention is a metal or alloy such as iron, copper, nickel, aluminum, titanium, tin, antimony, indium, lead, zinc, gold and silver, or those. It is possible to use the oxides, carbons, conductive resins and the like. The shape is cylindrical,
There are belts and sheets. The conductive material may be molded and processed, but may be applied as a paint or vapor-deposited.

An undercoat layer may be provided between the conductive support and the photosensitive layer. The undercoat layer is mainly composed of a binder resin, but may contain the above-mentioned conductive material or acceptor.
As the binder resin forming the undercoat layer, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetal, nylon, phenol resin, acrylic resin , Silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, butyral resin, and the like. As a method for producing the electrophotographic photosensitive member of the present invention, methods such as vapor deposition and coating are used. A bar coater, knife coater, roll coater, attritor, spray, dip coating, electrostatic coating, powder coating, or the like is used for coating.

FIG. 1 shows a schematic constitutional example of a general transfer type electrophotographic apparatus using the electrophotographic photosensitive member of the present invention.

In the figure, reference numeral 1 denotes a drum type photosensitive member of the present invention as an image bearing member, which is rotationally driven around a shaft 1a in a direction of an arrow at a predetermined peripheral speed. 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 between the photoconductor 1 and the transfer means 5 from a paper feeding portion (not shown). The images are sequentially transferred onto the surface of the transfer material P that is synchronously taken out and fed.

The transfer material P which 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 the image fixing and printed out as a copy.

After the image transfer, the surface of the photosensitive member 1 is cleaned by the cleaning means 6 to remove residual toner after transfer, and is further discharged by the pre-exposure means 7 to be repeatedly used for image formation.

As the uniform charging means 2 for the photoconductor 1, a corona charging device is generally widely used. In addition, the transfer device 5
Corona transfer means are also widely used. The electrophotographic apparatus is configured by integrally combining a plurality of constituent elements such as the photoconductor, the developing unit, and the cleaning unit described above as an apparatus unit, and the unit is configured to be detachable from the apparatus body. May be. For example, the photoconductor 1
Alternatively, the cleaning unit 6 and the cleaning unit 6 may be integrated into one unit, and may be detachably configured by using a guide unit such as a rail of the apparatus main body. At this time, the above device unit may be provided with a charging unit and / or a developing unit.

When the electrophotographic apparatus is used as a copying machine or a printer, the light image exposure L is reflected light or transmitted light from a document or a document is read and converted into a signal, and scanning of a laser beam or an LED array is performed by this signal. Drive or liquid crystal shutter array drive.

When used as a printer for a facsimile, the optical image exposure L becomes an exposure for printing the received data. FIG. 2 is a block diagram showing an example of this case.

The controller 11 controls the image reading section 10 and the printer 19. The entire controller 11 is CP
It is controlled by U17. The read data from the image reading unit 10 is transmitted to the partner station through the transmission circuit 13. The data received from the partner station is sent to the printer 19 through the receiving circuit 12. The image memory 16 stores predetermined image data. The printer controller 18 controls the printer 19. 14 is a telephone.

The image information received from the line 15 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 12, then decoded by the CPU 17, and sequentially stored in the image memory 16. Is stored. When the image information of at least one page is stored in the memory 16, the image recording of that page is performed. The CPU 17 reads out one page of image information from the memory 16 and sends the decoded one page of image information to the printer controller 18. Upon receiving the image information of one page from the CPU 17, the printer controller 18 controls the printer 19 to record the image information of the page.

The CPU 17 is receiving the next page while the printer 19 is recording.

Images are received and recorded as described above.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in laser beam printers, C
RT printer, LED printer, liquid crystal printer,
It can be widely used in electrophotographic application fields such as laser plate making.

[0030]

EXAMPLES The present invention will be described in more detail with reference to specific examples. The middle part of an Example shows a weight part.

Example 1 An alcohol-soluble polyamide resin (Amilan CM-800) was placed on an aluminum cylinder (φ80 mm × 360 mm).
0, Toray Co., Ltd. 10 parts, methoxymethylated 6 nylon resin (Toresin EF-30T, Teikoku Kagaku Co., Ltd.) 3
A preparation liquid obtained by dissolving 0 part in a mixed solvent of 150 parts of methanol and 150 parts of butanol was applied by dip coating and dried at 90 ° C. for 10 minutes to form an undercoat layer having a film thickness of 1 μm.

Next, the azo pigment 4 represented by the following structural formula
Department,

[0033]

[Chemical 1] Butyral resin (S-REC BL-S, Sekisui Chemical Co., Ltd.)
2 parts) and 100 parts of cyclohexanone were dispersed in a sand mill for 48 hours, and then tetrahydrofuran 10
0 part was added to prepare a dispersion liquid for the charge generation layer. This dispersion was dip-coated on the undercoat layer and dried at 80 ° C. for 15 minutes to form a charge generation layer having a thickness of 0.15 μm.

Next, the following structural formula

[0035]

[Chemical 2] Of styryl compound and polyarylate resin (U
Polymer U-100, manufactured by Unitika Ltd. (10 parts) is dissolved in a mixed solvent of dichloromethane (20 parts) and monochlorobenzene (60 parts), and this solution is dip-coated on the charge generation layer and dried at 120 ° C. for 60 minutes. Then, a charge transport layer having a film thickness of 18 μm was formed.

Next, 1 part of the styryl compound (1) and 4 parts of polyarylate resin (U Polymer U-100, manufactured by Unitika Ltd.) were dissolved in a mixed solvent of 20 parts of dichloromethane and 60 parts of monochlorobenzene, This solution was applied onto the charge transport layer by spray coating to form a protective layer having a thickness of 5 μm on the charge transport layer and then dried under the conditions as shown in Table 1 to remove different residual solvents from each other. A photoconductor contained therein was obtained. The residual solvent in the photoconductor was measured by Hitachi 263-70 type gas chromatograph.

[0037]

[Table 1]

The electrophotographic photosensitive member thus prepared was attached to a copying machine in which the process of charging-exposure-developing-transfer-cleaning was repeated in a cycle of 1.5 seconds, evaluation of electrophotographic characteristics, and repeated image development durability. Was performed 5000 times. As a result, the residual solvent in the photoconductor is 5000 pp
The electrophotographic characteristics of the photoconductors 1 to 3 having a length of m or less did not change due to durability. On the other hand, the residual solvent is 5000p
The electrophotographic characteristics of the comparative photoconductors 4 to 5 exceeding pm deteriorated due to durability. The results are shown in Table 2.
V _O is the surface potential of the photoconductor when discharged at a corona discharge voltage of +5 kV, and E ₅₀₀ is a surface potential of 700 V to 2 V.
Shown as the amount of exposure required to attenuate to 00V.
_r represents the residual potential after image exposure.

[0039]

[Table 2]

Example 2 By the same procedure as in Example 1, the charge transport layer was prepared.

Next, 1 part of polytetrafluoroethylene resin fine powder (Lubron L-2, manufactured by Daikin Industries, Ltd.),
6 parts of polyarylate resin (U Polymer U-100, manufactured by Unitika Ltd.), 120 parts of monochlorobenzene, and 80 parts of dichloromethane were dispersed in a sand mill for 8 hours, and then 3 parts of the styryl compound (1) was added and mixed. After dissolution, a 3 μm protective layer was coated on the charge transport layer by spray coating and then dried under the conditions as shown in Table 3 to obtain photoconductors containing different residual solvents in the protective layer. .

These photoreceptors were evaluated in the same manner as in Example 1, and the results are shown in Tables 3 and 4.

[0043]

[Table 3]

[0044]

[Table 4]

Example 3 The photoreceptors 1 and 5 produced in Example 1 and the photoreceptors 6 and 10 produced in Example 2 were further subjected to 50,000 cycles of durability, and then images were evaluated. As a result, in the photoconductors 1 and 6 of the present invention, the image was good even after the durability test was performed 50,000 times, whereas in the photoconductors 6 and 10 of the comparison, the image fogging occurred and Body 1
At 0, toner adhesion was found on the photoconductor.

[0046]

INDUSTRIAL APPLICABILITY The electrophotographic photosensitive member of the present invention has a residual solvent concentration of 5000 in the photosensitive member having a protective layer.
Since the content is less than or equal to ppm, it is possible to provide a stable image having excellent electrophotographic characteristics even in repeated durability and good image quality without image fogging or toner adhesion.

[Brief description of drawings]

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

FIG. 2 is a block diagram of a facsimile using the electrophotographic apparatus as a printer.

[Explanation of symbols]

 1 Photoreceptor 2 Charging Means 3 Exposure Part 4 Developing Means 5 Transfer Means 6 Cleaning Means 7 Pre-Exposure Means 8 Image Fixing Means

Claims (7)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer and a protective layer on a conductive support, wherein the residual solvent concentration in the photosensitive layer is 5000 ppm or less. 2. The electrophotographic photosensitive member according to claim 1, wherein the protective layer contains a polyarylate resin. 3. The electrophotographic photosensitive member according to claim 1, wherein the protective layer contains a charge transport material. 4. The electrophotographic photosensitive member according to claim 1, wherein the protective layer contains a fluorine-substituted resin powder. 5. The electrophotographic photoreceptor according to claim 4, wherein the fluorine content of the fluorine-substituted resin powder is 30% by weight or more and 90% by weight or less. 6. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1. 7. A facsimile comprising the electrophotographic photosensitive member according to claim 1 and a receiving means for receiving image information from a remote terminal.