JPS6243186B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an apparatus for lubricating and polishing the surface of an image carrier that is used repeatedly, and a lubricating and polishing member thereof. Electrostatic or toner images are formed by various electrophotographic processes. Image holding members on which electrostatic images or toner images are formed include electrophotographic photoreceptors and other image holding members. Electrophotographic photoreceptors have various configurations in order to obtain predetermined characteristics or depending on the type of electrophotographic process to which they are applied. As typical electrophotographic photoreceptors, there are photoreceptors having a photoconductive layer formed on a support and photoreceptors having an insulating layer on the surface, which are widely used. The photoreceptor, consisting of a support and a photoconductive layer, is prepared by the most common electrophotographic processes: charging, image exposure and development.
Furthermore, it is used for image formation by transfer, if necessary. In addition, for photoreceptors equipped with an insulating layer, this insulating layer is used for purposes such as protecting the photoconductive layer, improving the mechanical strength of the photoreceptor, improving dark decay characteristics, or being applied to certain electrophotographic processes. It is established for the purpose of Typical examples of electrophotographic processes using such a photoreceptor having an insulating layer or a photoreceptor having an insulating layer include, for example, U.S. Pat. 15446 Publication, Special Publication No. 46-3713, Publication No. 23910-1972, Publication No. 24748-1974,
It is described in Japanese Patent Publication No. 42-19747, Japanese Patent Publication No. 4121-1974, etc. A predetermined electrophotographic process is applied to the electrophotographic photoreceptor to form an electrostatic image, and this electrostatic image is developed and visualized. Some representative image bearing members will be described next. (1) For example, Japanese Patent Publication No. 32-7115, Japanese Patent Publication No. 32-7115,
As described in Japanese Patent Publication No. 8204 and Japanese Patent Publication No. 43-1559, an electrostatic image formed on an electrophotographic photoreceptor is transferred to another image holding member for the purpose of improving the repeatability of the electrophotographic photoreceptor. After transfer and development, the toner image is transferred to a recording medium. In addition to the case of "other image holding members" used in such an electrophotographic process, in addition to the above process, (2) the electrostatic image formed on the electrophotographic photoreceptor is As other electrophotographic processes for forming electrophotographic images, for example, as described in Japanese Patent Publication No. 45-30320, Japanese Patent Publication No. 48-5063, and Japanese Patent Application Laid-Open No. 51-341, By forming an electrostatic image on a screen-shaped electrophotographic photoreceptor having large openings by a predetermined electrophotographic process, and performing corona charging treatment on other image holding members via this electrostatic image, corona can be charged. Examples include a process in which an electrostatic image is formed on another image holding member by modulating an ion flow, and this is developed with toner and transferred to a recording medium to form a final image. It may also be "another image holding member" used in such an electrophotographic process. According to yet another electrophotographic process, (3)
A toner image formed on an electrophotographic photoreceptor or other image holding member is not directly transferred to a recording medium, but is further transferred to another image holding member, and then the toner image is transferred from this image holding member to the recording medium and fixed. do. It may also be "another image holding member" used in such an electrophotographic process. This process is particularly useful for forming color images or for high speed copying. Recording media are usually made of highly flexible materials such as paper or film, so it is better to transfer a three-color image onto a recording material while accurately aligning it, which causes almost no deformation. A more accurately aligned color image is formed by transferring a three-color image to an image-bearing member that can be formed from a material and then transferring it to a recording medium at once. Furthermore, it is effective for speeding up copying that the toner image is transferred to the recording medium via the image holding member. (4) Also,
An electrostatic image corresponding to the electric signal can be formed on the surface of an image holding member such as a web-like insulator by applying an electric signal to the multi-needle electrode, and this can be developed to form an image.
In the case of "image holding members" (1) to (4) used in such electrophotographic processes or electrostatic recording processes, the image holding members do not necessarily include a photoconductive layer. As described above, as image holding members on which electrostatic images or toner images are formed, various members, including electrophotographic photoreceptors, are generally used whose surfaces are temporarily or permanently insulating. The image holding member is required not only to have electrical properties according to the electrophotographic process to which it is applied, but also to have important properties such as durability and cleanability. Durability is a property required when the image holding member is used repeatedly, and cleanability is a property that determines the ease with which toner remaining on the surface of the image holding member can be removed. These characteristics significantly affect the formation of clear images and furthermore the prevention of damage to the cleaning means. Adding a protective layer to the surface of the image holding member in order to improve its durability and cleanability, or forming an insulating layer with excellent durability, or providing lubricity to the surface, or , and removing substances attached to the surface. Generally, there are two causes for reducing the durability of an image holding member. One is residual toner,
The other one is charging treatment. The toner image formed on the image holding member is transferred to a recording medium such as paper and fixed to form a final image.
The image bearing member surface is then typically reused over and over again. At this time, a new toner image is formed on the surface of the image carrier every toner image forming cycle. For this reason, once a desired image forming cycle is completed, that is, after the toner image has been transferred, it is necessary to completely remove and clean the toner remaining on the surface of the image holding member. Methods for removing toner include wiping or scraping the surface of the image holding member with a cleaning blade, rubbing and wiping with a web, wiping with a fur brush, etc. However, even if these methods are used to remove the toner remaining on the surface of the image carrier, the cleaning effect decreases as the number of repeated uses increases, and the cleaning process using the above methods gradually becomes less effective. Even if you do this, toner will remain on the surface. The reason for this is not clear, but since cleaning by the above method involves mechanical dynamic contact between the surface of the image carrier and the cleaning means, toner remaining on the surface of the image carrier may adhere or adhere during the cleaning process. It is thought that it causes welding and adheres to the surface of the photoreceptor. If toner remains on the surface of the image holding member, streaks may appear in the newly formed toner image, or even ghost images may appear. In even more severe cases, the surface of the image holding member is damaged, making it impossible to use the image holding member repeatedly. Furthermore, before an electrostatic image or a developed image is formed on the image holding member, charging treatment by corona discharge is performed.
Corona discharge may also occur during transfer, and the image holding member is exposed to a corona ion atmosphere. These corona ions cause deterioration of the electrical characteristics of the surface of the image holding member. This is because corona ions directly collide with the surface of the image holding member, and the material molecules that make up the surface of the image holding member are cut, oxidized, and degraded by this energy, and furthermore, due to corona discharge. The resulting ionized substances, such as oxygen, nitrogen, carbon dioxide, water, ammonia, and silicon, adhere to the surface and absorb moisture, reducing the electrical resistance of the image carrier surface and making it difficult to retain static charge. becomes. Therefore, in order to reuse an image holding member to which residual toner has adhered or whose electrical characteristics have deteriorated, the surface must be polished to expose a new surface and restore the initial surface condition. I need to do it. As mentioned above, in order to improve the durability of the image holding member, it is necessary to increase its hardness to prevent surface damage, abrasion, and deterioration. As a general characteristic of highly hardened materials such as mold insulating materials, they have very poor lubricity, so cleaning blades made of polyurethane rubber, etc., used to remove residual toner on image holding members have extremely poor lubricity, making them difficult to put into practical use. difficult to do. Furthermore, even when cleaning is performed with a fur brush or the like, toner is not easily separated from the surface of the image holding member, resulting in insufficient cleaning and residual toner. Therefore, it is necessary to provide lubricity to the surface of the image holding member, and lubricants such as Teflon, fatty acid metal salts, talc silicone oil, molybdenum disulfide, and graphite are used. When the surface deteriorates due to corona discharge, the lubricant covers the surface and the surface is not regenerated into a new surface, resulting in accumulation of degraded materials, lowering the surface electrical resistance and making it impossible to retain static charge. , it becomes unusable as an image holding member. Therefore, in order to provide lubricity to the surface of the image holding member and at the same time to reuse an image holding member whose electrical properties have deteriorated, it is necessary to polish the surface to expose a new surface and restore the initial surface condition. be. However, it has traditionally been difficult to provide lubrication and polishing to the surface of the image holding member at the same time, so it has been difficult to mix lubricant and abrasive and impregnate the web onto the surface of the image holding member, or use an auxiliary blade installed after the cleaning blade. A method of applying the abrasive by placing it on top of the abrasive was proposed, but the effect of the abrasive was not sufficiently apparent and it was not practical. The main object of the present invention is to provide a lubrication/polishing device and its member effective for lubricating and polishing the surface of an image holding member in order to solve the above-mentioned drawbacks. The details of the present invention will be explained below using specific examples and drawings. FIG. 1 shows a lubricating abrasive member according to the present invention.
1 , an abrasive layer 3 and a lubricant layer 4 are provided on both sides of a web-like substrate 2. The lubricant layer 4 provides lubricity, and the abrasive layer 3 on the opposite side performs polishing. FIG. 2 shows a device for applying this lubricating and abrasive member to an image holder. A lubricating and abrasive member web 1 is fed out from a shaft 5 wound into a roll, and an image is held by a rubber pressure roller 6. It is pressed against the member 11 and provides lubricity to the surface of the image holding member. The surface of the image holding member 11 is then pressed against the image holding member 11 by the rubber pressure roller 7, and is polished by the cleaning blade 10 to remove deposits on the surface of the image holding member. It is wound up by a take-up roll 9. In other words, both sides of the lubricating and abrasive member are used in one feeding process,
It can perform the functions of lubrication and polishing. The abrasive layer of the present invention is formed by mixing and dispersing an abrasive in a resin and coating it on one side of a web-shaped support member, and the lubricant layer is formed by mixing and dispersing a lubricant in a resin and coating the abrasive layer. It is formed by coating on the opposite side. As the dispersing resin, water-soluble resins such as polyvinyl alcohol, polyvinyl butyral, and carboxymethyl cellulose, and organic solvent-soluble resins such as thermoplastic polyester, polycarbonate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and polystyrene are used. As the abrasive, a conventionally used abrasive is used. Examples include calcium carbonate, cerium oxide, magnesium oxide, silicon oxide, magnesium silicate, calcium silicate, aluminum sulfate, calcium sulfate, barium sulfate, magnesium sulfate, and boron nitride. Among these, cerium oxide, silicon oxide, calcium carbonate, and barium sulfate are effective, and cerium oxide is particularly suitable. The particle size of the abrasive is usually 0.01~20μ, especially 0.1
It is preferable to set it to ~10μ. Also, the ratio (weight ratio) of abrasive to resin is
The degree of polishing effect can be controlled by changing the ratio in the range of 100:1 to 100:50. FIG. 3 shows the change in polishing force depending on the abrasive and resin ratio. The smaller the ratio of resin, the lower the polishing force, and the larger the ratio, the higher the polishing force.It is determined by the balance with the hardness of the image holding member, and generally 100:10 to 100:30 is suitable. Typical lubricants include polyethylene,
Polytetrafluoroethylene, polyethylene terephthalate, polyvinylidene fluoride, polyvinyl chloride, metal stearate, paraffin wax,
Examples include those that are substantially insoluble in common solvents, such as talc. The lubricant particle size is approximately 20μ in primary particle size.
The following are preferred. In addition, the ratio (weight ratio) of lubricant to binder resin is in the range of 100:1 to 100:50, and the ratio is 100:5 to 100:5, which does not cause lubricant scattering and does not impair the lubrication effect.
A ratio of 100:20 is preferred. Materials for the web substrate 2 include plain paper, art paper, nonwoven fabric, thin metal plate, cloth, and artificial paper, depending on the surface quality.
It is used as appropriate considering the tensile strength. When the image holding member is an electrophotographic photoreceptor, the most typical structure is a laminate of a photoconductive layer and a support. The support is formed from any material such as a metal plate such as stainless steel, copper, aluminum, or tin, paper, sheet, or resin film. The support may be omitted if necessary. The photoconductive layer is S, Se, PbO, and S, Se, Te,
It is formed by vacuum deposition of an inorganic photoconductive material such as an alloy or intermetallic compound containing As, Sb, etc. In addition, when using the sputtering method, ZnO, CdS,
A high melting point photoconductive material such as CdSe or TiO ₂ can also be attached to the support to form the photoconductive layer. In addition, when a photoconductive layer is formed by coating, organic photoconductive materials such as polyvinylcarbazole, anthracene, phthalocyanine, dye-sensitized or Lewis acid-sensitized materials, and mixtures of these with insulating binders are used. Can be used. Also, ZnO, CdS,
Mixtures of inorganic photoconductors such as TiO ₂ , Pbo, etc. with insulating binders are also suitable. Note that various resins are used as the insulating binder. Although the thickness of the photoconductive layer depends on the type and characteristics of the photoconductive material used, it is generally preferred to have a thickness of about 5 to 100 microns, particularly about 10 to 50 microns. In addition, when an insulating layer is attached with the main purpose of protecting the image holding member, improving durability, dark decay characteristics, etc., the insulating layer is set to be relatively thin, and when the image holding member is used in a specific electrophotographic process, the insulating layer is set to be relatively thin. The insulating layer provided on the insulating layer is set to be relatively thick. usually,
The thickness of the insulating layer is set between 0.1 and 100μ, particularly between 0.1 and 50μ. The resins used to form the surface insulating layer include:
Various ordinary resins can be used as appropriate.
Examples include polyethylene, polyester, polypropylene, polystyrene, polyvinyl chloride, polyvinyl acetate, acrylic resin, urethane resin, polycarbonate, silicone resin, fluororesin, epoxy resin, and the like. Examples are shown below in order to better understand the present invention. Example: Cerium oxide with an average particle size of 4μ was used as an abrasive.
100 parts by weight polyvinyl alcohol (product name B-
17, manufactured by Denki Kagaku Kogyo) in 200 parts of water, stir thoroughly with a homogenizer at 3000 rpm for 10 minutes, and leave until bubbles disappear. It was then coated with a bottom-feed reverse coater on 80 g/m ² double-sided art paper in an amount of 20 g/m ² as solids.
A web-like abrasive member coated with an abrasive layer on one side was obtained by passing it through a 20 m drying oven at 80°C to 100°C. As a lubricant, 100 parts by weight of low molecular weight tetrafluoroethylene with an average particle size of 0.3μ (trade name: Lublon L-2 manufactured by Daikin Industries), 10 parts by weight of thermoplastic polyester (trade name: Vylon 200 manufactured by Toyobo), and a surfactant. (trade name: Florado FC431 Sumitomo 3M) was mixed and dispersed and dissolved in 200 parts by weight of methyl ethyl ketone. Next, a bottom-feed reverse coater is used to apply the abrasive layer to the opposite side of the web, at a solid content of 20 g/m ² , and then passed through a 20 m drying oven at 60°C to 80°C to coat one side. A lubricated abrasive member was obtained in which an abrasive layer was applied on one side and a lubricant layer was applied on the opposite side. Since the surface on which the abrasive layer is applied is important in determining the polishing ability, it is necessary to carefully select coating conditions. A photoreceptor was used which had a 35 μm thick photoconductive layer formed by dispersing 88 parts of cadmium sulfide in 12 parts of vinyl chloride-vinyl acetate copolymer resin on the surface of an Al cylinder, and a 30 μm thick insulating layer on the photoconductive layer. Note that the insulating layer of the photoreceptor is formed from a cured silicone resin (trade name: X-12-917, manufactured by Shin-Etsu Chemical). This photoreceptor is charged with a primary charge of +7KV corona charge and a secondary charge of AC7.5KV corona charge at the same time as 3.0lux・sec.
The image is irradiated, and the entire surface is exposed at 200 lux/sec to form an electrostatic image, which is then dry developed with toner to form a toner image, which is transferred to transfer paper.
Next, the surface of the photoreceptor was cleaned using the urethane blade 10, and then lubricated and polished using the second apparatus shown in the figure. That is, the lubricating abrasive member 5 installed as shown in FIG.
The surface of the abrasive layer is pressed by a rubber pressure roller 7 having a hardness of 60° at a pressure of 100 g/cm to polish and renew the surface of the photoreceptor. Next, the photoconductor rotates, and the lubricant layer of the lubricating abrasive member 5 is applied to a rubber pressure roller 6 having a hardness of 60°.
The photoreceptor is brought into contact with a pressure of 100 g/cm, applying lubricant to the surface of the photoreceptor and generating lubricity. The above-mentioned lubricating abrasive member 5 is applied to the surface of the photoreceptor at a rate of 0.1 per rotation of the photoreceptor.
The above electrophotographic process was repeated 200,000 times with the setting set to feed by mm. This result is shown as data A in Table 1. In place of the lubricating abrasive member 5, a lubricating member prepared by applying only a lubricant layer in the same manner was used, and the same process as described above was repeated 200,000 times. This result is the first
It is shown as data B in the table. In place of the lubricating abrasive member 5, an abrasive member prepared by similarly applying only the abrasive layer was used, and the above process was repeated. The results are shown as Data C in Table 1.

[Table] As shown in Table 1 above, when using the lubricating and abrasive member of the present invention that uses both a lubricant layer and an abrasive layer, even after repeating the above process for 200,000 sheets, toner still adheres to the surface of the photoreceptor. No decrease in surface electrical resistance was observed, and the copied images maintained their original image quality and were clear.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the structure of a lubricating/abrasive member according to the present invention. FIG. 2 is an explanatory diagram showing the configuration of a specific example lubrication/polishing device based on the present invention. FIG. 3 is an explanatory diagram showing the correlation between the abrasive/resin ratio and the abrasive force of the lubricating/abrasive member according to the present invention. In the figure, 1; lubricating abrasive member; 2; web-like substrate;
3; abrasive layer, 4; lubricant layer, 5; shaft, 6, 7;
Pressure roller, 9; take-up roll.

Claims (1)

[Scope of Claims] 1. In a device that performs a lubricating action and an abrasive action on the surface of an image carrier that is used repeatedly, one surface is a lubricating surface containing a substance that performs a lubricating action, and the other surface is a polishing surface that has a substance that performs an abrasive action. a web-like member that is a surface; a feeding device that sequentially sends out the web-like member; a winding device that sequentially winds up the web-like member; and a lubricating surface pressing device that presses the lubricated surface against the surface of the image carrier. A lubricating polishing device comprising: a polishing surface pressing means for pressing the polishing surface against the surface of an image carrier. 2. A lubricating/abrasive member that is web-shaped and has a lubricating substance on one side and an abrasive substance on the other side. 3 In the invention described in claim 2, the lubricating substance provided on one surface of the web-like member has a mixing (weight) ratio of lubricant and resin of 100:1.
Lubrication characterized by being in the range of ~100:50
Abrasive parts. 4 In the invention described in claim 2, the substance that performs the abrasive action provided on one surface of the web-like member has a mixing (weight) ratio of abrasive and resin of 100:1.
Lubrication characterized by being in the range of ~100:50
Abrasive parts.