JPH0689043A - Electrophotographic sensitive body, and electrophotographic apparatus and facsimile having the same - Google Patents

Abstract

PURPOSE:To obtain the electrophotographic sensitive body superior in durability even in the case of a toner containing an external additive high in hardness and abrasive power. CONSTITUTION:The electrophotographic sensitive body provided on a conductive substrate with at least one photosensitive layer is uniformly electrically charged, exposed to form a latent image, developed with a dry toner containing fine particles high in hardness as an external additive, and transferred to a transfer paper or the like, and the outermost layer of the electrophotographic sensitive body contains a polymer or a copolymer of a monomer or monomers selected from vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, and perfluoroalkyl vinyl ether, or fine particles of carbon fluoride represented by (CF)n or (CF2)n in an amount of >=10 weight %, and the electrophotographic apparatus and facsimile are manufactured by using it, thus permitting the obtained electrophotographic sensitive body to be superior in durability, and freed of image trailing and dropout of transfer and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, an electrophotographic apparatus using the same and a facsimile.

[0002]

2. Description of the Related Art An electrophotographic process usually consists of uniform charging of the surface of a photosensitive member, formation of a latent image by exposure, formation of a developed image by toner, and transfer onto a transfer material such as paper.

To the toner used here, various resin fine particles and ceramic fine particles are often added as external additives in order to improve the fluidity of the toner, prevent aggregation, and remove stains on the photoconductor.

On the other hand, as an electrophotographic photoreceptor, an organic photoreceptor has come to be used instead of an inorganic photoreceptor. When an ordinary organic photoreceptor is used in an apparatus using a toner containing the above-mentioned external additive, the surface of the photoreceptor may be scraped off and thinned due to the polishing effect of fine particles, and the desired electrophotographic characteristics may not be achieved. Therefore, it has been proposed to form a protective layer with high hardness as the outermost layer in order to enhance abrasion resistance, but image deletion and transfer omission do not occur in all environments, and transfer residual toner is mechanically removed. It was difficult to satisfy the cleaning property.

[0005]

When a high-hardness crosslinkable resin such as a conventional acrylic resin and some silicone resins is used, the abrasion resistance is excellent, but the releasability is poor and the transfer is poor. The efficiency is low, a large amount of transfer residual toner is generated, and image blurring due to moisture absorption occurs under high humidity.

On the other hand, the fluorine-based straight-chain polymer material has a drawback that it is inferior in transparency and has a low hardness, so that it is easily scratched.

In any case, it was impossible to satisfy the characteristics required for the surface layer of the photoreceptor.

[0008]

That is, the present invention is directed to uniform charging on an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, latent image formation by exposure, and high hardness fine particles as an external additive. In an electrophotographic photosensitive member used in an electrophotographic apparatus for forming an image by developing with a dry toner containing, and transferring onto a transfer target material, the outermost layer of the photosensitive member is vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene. 10% by weight or more of a polymer or copolymer of a compound selected from tetrafluoroethylene, hexafluoropropylene, and perfluoroalkyl vinyl ether, or fluorocarbon fine particles represented by (CF) _n and (C ₂ F) _n. It is an electrophotographic photosensitive member characterized by containing.

According to the present invention, the amount of wear on the surface can be reduced even in an electrophotographic apparatus using a toner containing a high hardness resin or ceramic fine particles such as CeO ₂ , TiO ₂ , and SiO ₂ as an external additive. In addition to extending the life of the photoconductor, the cleaning property, image quality, and transfer efficiency are also improved.

When the electrophotographic photoreceptor of the present invention is manufactured,
As the conductive support, a metal such as aluminum or stainless steel, a cylindrical cylinder such as paper or plastic, or a film is used. An undercoat layer (adhesive layer) having a barrier function and an undercoat function can be provided on these supports.

The subbing layer improves the adhesion of the photosensitive layer, the coating property, the protection of the support, the coating of defects on the support, the improvement of the charge injection from the support, the protection of the photosensitive layer against electrical coating, etc. Formed for. Known materials for the subbing layer include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, copolymerized nylon, glue and gelatin. These are dissolved in a suitable solvent and coated on a support. The film thickness is about 0.2 to 2 μm. Specific examples of the photosensitive layer include a photosensitive layer having a laminated structure of a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance, a single layer containing a charge generating substance and a charge transporting substance. There is a photosensitive layer composed of. Examples of the charge generating substance include pyrylium, thiopyrylium dye, phthalocyanine-based pigment anthanthrone pigment, dibenzpyrenequinone pigment, pyrantrone pigment, trisazo pigment, disazo pigment, azo pigment, indigo pigment, quinacridone pigment, asymmetric quinocyanine, and quinocyanine. Can be used. Examples of the charge transport material include pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-N-phenylhydrazino-3-methylidene-9-ethylcarbazole, N, N-diphenylhydrazino-3-methylidene-9. -Ethylcarbazole, N, N-diphenylhydrazino-3-methylidene-
10-ethylphenothiazine, N, N-diphenylhydrazino-3-methylidene-10-ethylphenoxazine, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehino-2-methylphenyl) -phenylmethane Triarylmethane compounds such as 1,1-bis (4-N, N-)
Diethylamino-2-methylphenyl) heptane, 1,
Polyarylalkanes such as 1,2,2-tetrakis (4-N, N-dimethylamino-2-methylphenyl) ethane and triarylamines can be used.

For example, in the case of a function-separated type photoreceptor in which a charge transport layer is laminated on the side farther from the support than the charge generation layer, the electrophotographic photoreceptor can be prepared as follows.

A homogenizer, an ultrasonic wave, and the above charge generating substance together with a binder resin and a solvent in an amount of 0.3 to 10 times.
Disperse well by methods such as ball mill, vibration ball mill, sand mill, attritor, and roll mill. This dispersion is applied onto the support coated with the undercoat layer and dried to form 0.1
A coating film of about 1 μm is formed. The charge transport layer is formed by dissolving the charge transport material and the binder resin in a solvent and coating the charge transport layer. The mixing ratio of the charge transport material and the binder resin is about 2: 1 to 1: 2. As the solvent, aromatic hydrocarbons such as toluene and xylene, chlorine-based hydrocarbons such as dichloromethane, chlorobenzene, chloroform and carbon tetrachloride are used. When applying this solution, for example, a coating method such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method or a curtain coating method can be used, and drying is performed at 10 ° C to 200 ° C. It can be carried out at a temperature in the range of 20 ° C. to 150 ° C. for 5 minutes to 5 hours, preferably 10 minutes to 2 hours under blast drying or static drying.
The thickness of the generated charge transport layer is about 5 to 50 μm.

Next, a protective layer is formed on the photoreceptor. As the constituent material of the protective layer, any of a room temperature dry type, a thermosetting type, a UV curing type, an electron beam curing type, etc. may be used.
The contact angle with water after film formation may be 100 ° or more. Examples include, but are not limited to, fluorine-substituted compounds such as polyester resins, silicone resins, polycarbonate resins, polyacrylate resins, polyimide resins, polyamide resins, and epoxy resins. Further, a high molecular compound which is hardly soluble or insoluble in a general organic solvent can be used after being pulverized into a small particle size (3 μm or less) and dispersed in an appropriate binder resin. As the solvent-insoluble resin particles, fluorine-substituted compounds of the above resins can also be used, but if desired, a fluorine selected from vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene, tetrachloroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether. It is a fluorine-based resin particle made of a polymer or copolymer of a olefin compound, and can increase the catalyst angle with pure water. The binder resin may be any polymer compound capable of forming a film, but polyacrylate, polycarbonate, polyester, epoxy resin and the like are excellent. Further, a dispersant can be added if necessary. Further, conductive fine powder or a photoconductive substance can be added as appropriate. When the resin is dispersed, a homogenizer, ultrasonic waves, a ball mill, a vibrating ball mill, a sand mill or the like can be used as the method. Examples of the coating method include a dipping method, a blade coating method, a spray method and a curtain coating method. Drying depends on the solvent used, but 50 ° C to 200
C., preferably 80 to 150.degree. C. for 10 to 120 minutes. The film thickness is about 0.1 to 20 μm, preferably 0.5 to 10 μm. It is also effective to expose the dispersed particles to the surface by polishing the surface.

FIG. 1 shows a schematic structural 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 photosensitive member 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 photosensitive member 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 out and converted into a signal, and scanning of the laser beam or 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 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 during recording by the printer 19.

The image is 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.

[0028]

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

Example 1 After 10 parts by weight of methoxymethylated nylon and 150 parts by weight of isopropanol were mixed and dissolved, an outer diameter of 80 mm,
An aluminum cylinder having a length of 358 mm was applied by dipping, and an undercoat layer of 1 μm was provided. Next, 10 parts by weight of the following bisazo pigment,

[0030]

[Chemical 1] Polycarbonate resin (bisphenol A, molecular weight 30
000) 5 parts by weight and 700 parts by weight of cyclohexanone were dispersed in a sand mill, and this dispersion was dip-coated on the undercoat layer to obtain a charge generation layer of 0.05 μm.

Next, 10 parts by weight of the following triphenylamine,

[0032]

[Chemical 2] Polycarbonate resin (bisphenol A, molecular weight 25
000) 10 parts by weight was dissolved in a mixed solvent of chlorobenzene and dichloromethane 1: 1 and applied on the charge generation layer by dipping and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm.

Then, 70 parts by weight of chlorobenzene was added to 10 parts by weight of polytetrachloroethylene particles having an average primary particle size of 0.3 μm and 20 parts by weight of a polycarbonate (bisphenol A, molecular weight 80,000), and dissolved and dispersed by a hole mill to obtain a product. 10 parts by weight of the charge-transporting substance was added to the dispersion, and diluted with dichloromethane to obtain a dispersion having a solid content of 3% by weight. The dispersion was spray-coated on the charge-transporting layer and dried at 110 ° C. for 30 minutes to form a film having a thickness of 6 A protective layer having a thickness of 0.5 μm was formed, and the surface was polished with a # 2000 polishing tape to a surface roughness Rz of about 0.6 μm.

A comparative sample 1 was prepared in the same manner with 2 parts by weight of polytetrochloroethylene. Further, Comparative Sample 2 was one without a protective layer.

Example 2 A photoconductor was prepared by using polyvinylidene fluoride powder in place of polytetrachloroethylene in Example 1. Polishing was carried out in the same manner as in Example 1 to expose the polyvinylidene fluoride particles on the surface to obtain Sample 2.

Example 3 A photoconductor was similarly prepared by using 10 parts by weight of carbon fluoride ((CF) _n ) in place of the polytetrachloroethylene in Example 1 to prepare Sample 3. The obtained photoreceptor sample was mounted on a commercially available negative charging type copying machine and a continuous image forming test was conducted. SiO ₂ as an external additive was about 0.
5% is added. The results are shown in Table 1.

[0037]

[0038]

As described above, according to the present invention, an electrophotographic photosensitive member having high durability can be obtained even in an electrophotographic apparatus using a toner containing a high hardness and an external additive having a high polishing power.

[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

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location G03G 9/08 375 (72) Inventor Tatsuya Ikesue 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Co., Ltd. (72) Inventor Issei Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shoji Amamiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. A uniform charge on an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, latent image formation by exposure, development with a dry toner containing high hardness fine particles as an external additive, and transfer. In an electrophotographic photosensitive member used in an electrophotographic apparatus for forming an image by transfer to a material, the outermost layer of the photosensitive member is vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoroethylene. An electrophotographic photosensitive material comprising a polymer or copolymer of a compound selected from fluoroalkyl vinyl ethers, or 10% by weight or more of fine particles of carbon fluoride represented by (CF) _n and (C ₂ F) _n. body. 2. The electrophotographic photosensitive member according to claim 1, wherein the high hardness fine particles are resin fine particles or ceramic fine particles. 3. An electrophotographic photosensitive member comprising the electrophotographic photosensitive member according to claim 1. 4. An electrophotographic photosensitive member according to claim 1,
A facsimile characterized by having a receiving means for receiving image information from a remote terminal.