JP2010190915A - Lubricant applying brush roller, lubricant applying device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant applying brush roller which is the one for applying lubricant to an image carrier provided in an image forming apparatus such as a copying machine, a facsimile and a printer and capable of suppressing or preventing the enlargement of the height difference of the irregularities of a lubricant surface and to provide a lubricant applying device having the lubricant applying brush roller and an image forming apparatus having the lubricant applying device. <P>SOLUTION: The lubricant applying brush roller 47Y is provided with brush fibers 89Y scraping the lubricant and applying the scraped lubricant to the image carrier. The brush fibers 89Y have the irregularities for scraping the lubricant in the longitudinal direction of the brush fibers 89Y in the side surfaces of the brush fibers 89Y. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a lubricant application brush roller for applying a lubricant to an image carrier provided in an image forming apparatus such as a copying machine, a facsimile machine, or a printer, a lubricant application apparatus having the same, and an image forming apparatus having the same.

  In recent years, in image forming apparatuses such as copying machines, facsimiles, printers, etc., by applying a lubricant to the surface of an image carrier such as a photoconductor, the coefficient of friction with respect to the toner on the surface of the image carrier is reduced, thereby reducing the image carrier. In order to obtain the advantages such as suppressing the occurrence of transfer failure when transferring the toner image formed on the body surface to a transfer material such as paper and improving the image quality of the transferred toner image, a lubricant is applied to the surface of the image carrier. There has been proposed an image forming apparatus including a lubricant application device for application (see, for example, [Patent Document 1] to [Patent Document 5]). Such an image forming apparatus is particularly advantageous in that it is possible to improve the image quality by suppressing the occurrence of a character part dropout phenomenon in which a part of the character image lacks a worm-eating shape. The application of the lubricant to the image carrier also has the advantage of preventing the toner filming on the surface of the image carrier due to charging hazard and contributing to the long life of the image carrier by suppressing the abrasion of the surface layer. As described above, the lubricant is applied to the image carrier for the purpose of reducing the coefficient of friction on the surface of the image carrier and maintaining the surface properties such as protecting the surface of the image carrier.

  As such a lubricant application device, one having a brush roller provided with brush fibers for scraping off the lubricant and applying the scraped lubricant to the image carrier is known (for example, [Patent Document 1] to [Patent Document 1]. 5]). In such a lubricant application device, the lubricant is shaved into powder by brush fibers by the rotation of the brush roller, and the shaved lubricant is transferred to the image carrier. As such a lubricant application device, a device provided with a blade that extends the lubricant transferred to the image carrier onto the surface of the image carrier is known.

  The shape of the brush fiber is generally uniform in cross section perpendicular to the longitudinal direction, and the cross-sectional shape is generally a round shape. However, such a cross-sectional shape may be an irregular shape such as a polygon. It has been proposed (for example, see [Patent Document 1]).

  As described above, the brush roller scrapes off the lubricant by the brush fibers by rotation, and in this process, unevenness may occur on the surface of the lubricant. Then, the brush fiber enters the concave portion on the surface of the lubricant due to the contact pressure against the lubricant, and the tip of the brush scrapes the lubricant at the bottom portion of the concave portion, so that the depth of the concave portion is further increased, and the height difference of the concave and convex portions. Works to expand. When such a height difference is enlarged, the convex portion becomes so brittle that it can be broken even by a light impact. When the convex portion breaks, the lubricant moves as a lump from the brush roller to the image carrier, but the lump of lubricant has a problem that the above-described function cannot be performed sufficiently. In the worst case, the configuration including the blade described above has a problem that a lump is sandwiched between the blade and the image carrier, which may cause toner to slip through and may deteriorate image quality. .

  In order to suppress or prevent such a problem, it is preferable to suppress or prevent the expansion of the height difference. However, as described above, when the cross-section perpendicular to the longitudinal direction of the brush fiber is substantially uniform and the cross-sectional shape is round, the scraping of the lubricant is performed at the tip, It cannot be expected to suppress or prevent such an increase in height difference. In addition, as described above, when the cross-section perpendicular to the longitudinal direction is substantially uniform and the cross-sectional shape is irregular, the shape of the brush fiber facilitates the expansion of the height difference. It can be. This is because, in the case of a shape in which the brush fiber is applied, the contact pressure against the lubricant is concentrated on the convex portion on the side surface of the brush fiber, and this convex portion mainly covers the bottom portion of the concave portion of the lubricant. This is because it acts so as to cut, so that scraping of the bottom portion of the concave portion of the lubricant by the tip portion of the brush fiber is promoted.

  The present invention relates to a lubricant application brush roller for applying a lubricant to an image carrier provided in an image forming apparatus such as a copying machine, a facsimile machine, a printer, and the like, which suppresses or prevents an increase in level difference of unevenness on the surface of the lubricant. It is an object of the present invention to provide a lubricant roller for applying a lubricant, a lubricant applying device having the same, and an image forming apparatus having the same.

  In order to achieve the above object, the invention according to claim 1 is a brush roller for applying lubricant, which is provided with brush fibers for scraping off the lubricant and applying the scraped lubricant to the image carrier. The lubricant application brush roller has irregularities for scraping off the lubricant on its side surface along the longitudinal direction.

  According to a second aspect of the present invention, in the brush roller for applying a lubricant according to the first aspect, the brush fiber has a lubricant scraping ability equivalent to the tip of the brush fiber.

  A third aspect of the present invention is the brush roller for lubricant application according to the first or second aspect, wherein the brush fiber has a surface roughness Rz measured in parallel to the longitudinal direction of 20 μm ≦ Rz ≦ 100 μm. It has in the said side.

  According to a fourth aspect of the present invention, in the brush roller for applying a lubricant according to any one of the first to third aspects, the amount of biting into the image carrier is larger than the amount of biting into the lubricant.

  According to a fifth aspect of the present invention, there is provided a lubricant application device having the lubricant application brush roller according to any one of the first to fourth aspects.

  According to a sixth aspect of the present invention, there is provided an image forming apparatus comprising the lubricant application device according to the fifth aspect and an image carrier on which the lubricant is applied by the lubricant application device.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect, the image carrier is a photosensitive member and / or an intermediate transfer member and / or a recording medium conveying member.

  The present invention is a brush roller for lubricant application provided with brush fibers for scraping off the lubricant and applying the scraped lubricant to the image carrier, the brush fiber on its side surface along its longitudinal direction, Since the lubricant application brush roller has unevenness for scraping off the lubricant, it can be suppressed or prevented from expanding the level difference of unevenness on the surface of the lubricant. Thus, it is possible to provide a lubricant application brush roller that can contribute to good image formation by suppressing or preventing the application to the image carrier.

  The brush fiber, if the side surface is provided with a scraping ability of the lubricant equivalent to the tip of the brush fiber, it is possible to better suppress or prevent the expansion of the unevenness of the unevenness of the lubricant surface, To provide a brush roller for applying a lubricant that can contribute to good image formation by suppressing or preventing the lubricant from being scraped off by a brush roller for applying a lubricant in a lump state and applied to an image carrier. Can do.

  If the brush fiber has a portion on the side surface where the surface roughness Rz measured in parallel to the longitudinal direction is 20 μm ≦ Rz ≦ 100 μm, the unevenness of the unevenness on the surface of the lubricant can be further improved. By being able to suppress or prevent, it is possible to suppress or prevent the lubricant from being scraped off by the brush roller for applying the lubricant in a lump state and applied to the image carrier, and to apply a lubricant having an appropriate particle size to the lubricant. By scraping with a brush roller and applying it to the image carrier, a lubricant application brush roller that can contribute to good image formation can be provided.

  If the amount of biting into the image carrier is larger than the amount of biting into the lubricant, it is possible to suppress or prevent the level difference of the unevenness of the lubricant surface from being increased or decreased. Can be prevented or prevented from being applied to the image carrier and contributes to good image formation by more reliably applying the lubricant scraped off by the lubricant application brush roller to the image carrier. A brush roller for applying lubricant can be provided.

  Since the present invention is in a lubricant application apparatus having such a lubricant application brush roller, the lubricant application brush roller can suppress or prevent expansion of the level difference of the unevenness of the lubricant surface, so that the lubricant is in a lump state. A lubricant application device that can contribute to good image formation can be provided by suppressing or preventing the application brush roller from being scraped off and applied to the image carrier.

  The present invention resides in an image forming apparatus having such a lubricant application device and an image carrier to which the lubricant is applied by this lubricant application device, so that the spread of unevenness on the surface of the lubricant is suppressed by the lubricant application brush roller. By being able to prevent or prevent the lubricant from being scraped off with a lubricant application brush roller in a lump state and applied to the image carrier by the lubricant application device, good image formation can be performed. An image forming apparatus can be provided.

  If the image carrier is a photosensitive member and / or an intermediate transfer member and / or a recording medium conveying member, it is possible to suppress or prevent an increase in the level difference of the unevenness of the lubricant surface by the lubricant application brush roller. An image forming apparatus capable of performing good image formation by suppressing or preventing the lubricant from being scraped off by a brush roller for applying lubricant in a lump state and being applied to various image carriers by the lubricant applying apparatus. Can be provided.

1 is a schematic front view of an image forming apparatus to which the present invention is applied. FIG. 2 is a schematic front view showing a configuration around a plurality of image carriers and intermediate transfer members provided in the image forming apparatus shown in FIG. 1. FIG. 2 is a schematic sectional view of an intermediate transfer member provided in the image forming apparatus shown in FIG. 1. FIG. 1 is a schematic view showing a configuration around one image carrier among a plurality of image carriers provided in the image forming apparatus shown in FIG. 1, and including a lubricant application brush roller and a lubricant application device to which the present invention is applied. It is a front view. It is a schematic front view which shows the structure and arrangement position of the brush roller for lubricant application | coating shown in FIG. (A) is the schematic which looked at the front-end | tip of the brush application | coating brush roller from the rotation direction of the same brush fiber state that the brush fiber with which the lubricant application brush roller shown in FIG. (B) is the schematic which looked at the brush fiber with which the brush brush with which the conventional lubricant application brush was equipped scraped off the lubricant when the tip of the brush fiber was seen from the rotation direction upstream side of the lubricant application brush roller. FIG. 2 is a perspective view showing a part of toner recycling means disposed in a process cartridge provided in the image forming apparatus shown in FIG. 1. FIG. 2 is a perspective view showing a part of a process cartridge provided in the image forming apparatus shown in FIG. 1 and a part of a toner recycling unit disposed in the process cartridge. FIG. 2 is a cross-sectional view illustrating various configuration examples of a plurality of image carriers provided in the image forming apparatus illustrated in FIG. 1. It is the schematic which showed the mode of the unevenness | corrugation which may arise on the surface of the lubricant with which the lubricant application apparatus shown in FIG. 4 was equipped. FIG. 10 is a schematic front view illustrating a part of another configuration example of the image forming apparatus to which the present invention is applicable.

  FIG. 1 shows an outline of an image forming apparatus to which the present invention is applied. The image forming apparatus 100 is a multifunction peripheral of a copying machine, a printer, and a facsimile machine, and can perform full-color image formation. Other image forming apparatuses, that is, a monochrome machine, a copying machine, a printer, It may be a single facsimile, or another multifunction device such as a multifunction device of a copying machine and a printer. When used as a printer, the image forming apparatus 100 performs an image forming process based on an image signal corresponding to image information received from the outside. This is the same when the image forming apparatus 100 is used as a facsimile.

  The image forming apparatus 100 can form an image on a sheet-like recording medium using not only plain paper generally used for copying, but also OHP sheets, cardboard, cardboard, cardboard, and envelopes. It is. The image forming apparatus 100 is also a double-sided image forming apparatus capable of forming an image on both sides of a transfer sheet as a recording medium as a recording medium.

  The image forming apparatus 100 includes a main body 101 that occupies a central position in the vertical direction and functions as a printer unit, a reading device 21 that is positioned above the main body 101 and that reads a document, and a document on which a document is stacked and loaded. An automatic document feeder 22 which is an automatic document feeder called ADF which is sent out toward 21, and the photosensitive drums 20 </ b> Y, 20 </ b> M, 20 </ b> C, 20 </ b> BK located below the main body 101 and the transfer belt 11. A sheet feeding device 23 serving as a paper feeding device serving as a paper feeding table on which the transfer paper to be conveyed is stacked.

  The image forming apparatus 100 includes a plurality of photosensitive drums 20Y, 20M, 20C, and 20BK that can form images as images corresponding to colors separated into yellow, magenta, cyan, and black, respectively. 1 is a tandem type image forming apparatus that employs a tandem structure in which the two are arranged side by side. The photosensitive drums 20Y, 20M, 20C, and 20BK have the same diameter, and are transfer belts as intermediate transfer belts that are intermediate transfer members that are endless belts disposed almost at the center inside the main body 101 of the image forming apparatus 100. 11 are arranged at equal intervals on the outer peripheral surface side, that is, on the image forming surface side.

  The transfer belt 11 is movable in the arrow A1 direction, which is the clockwise direction in the figure, while facing the respective photosensitive drums 20Y, 20M, 20C, and 20BK. The visible image, that is, the toner image formed on each of the photoconductive drums 20Y, 20M, 20C, and 20BK is superimposed and transferred onto the transfer belt 11 that moves in the direction of the arrow A1, and is then collectively transferred onto the transfer paper. It has become. As described above, the image forming apparatus 100 employs the indirect transfer method. Accordingly, the image forming apparatus 100 is a tandem indirect transfer type electrophotographic apparatus.

  In the superimposing transfer to the transfer belt 11, the toner images formed on the photosensitive drums 20Y, 20M, 20C, and 20BK are transferred to the same position on the transfer belt 11 while the transfer belt 11 moves in the A1 direction. As described above, a primary transfer device as a transfer charger that is disposed at a position facing each of the photosensitive drums 20Y, 20M, 20C, and 20BK across the transfer belt 11 and that is in contact with the inner peripheral surface of the transfer belt 11. As a result of voltage application by the primary transfer rollers 12Y, 12M, 12C, and 12BK, the timing is shifted from the upstream side toward the downstream side in the A1 direction, and the positions immediately below the photosensitive drums 20Y, 20M, 20C, and 20BK, that is, 1 It is performed at the transfer position which is the next transfer position.

  The photosensitive drums 20Y, 20M, 20C, and 20BK are arranged in this order from the upstream side in the A1 direction. The photosensitive drums 20Y, 20M, 20C, and 20BK are provided in image stations 60Y, 60M, 60C, and 60BK, respectively, for forming yellow, magenta, cyan, and black images.

  The image forming apparatus 100 includes an image forming unit 60 which is an image forming unit as an image forming unit configured by four image stations 60Y, 60M, 60C, and 60BK, and below the photosensitive drums 20Y, 20M, 20C, and 20BK. The transfer belt unit 10 is an intermediate transfer unit provided with the transfer belt 11, and faces the transfer belt 11 on the side opposite to the image forming unit 60 with the transfer belt 11 in between. And a secondary transfer belt 5 which is a paper conveying belt as a transfer member which is in contact with the transfer belt 11 and rotates in the same direction as the transfer belt 11 and moves endlessly at the contact position with the transfer belt 11. A secondary transfer unit 76 as a secondary transfer device that transfers and conveys the toner image on the transfer belt 11 onto transfer paper is provided.

  The image forming apparatus 100 also includes an optical scanning device 8 serving as an exposure device serving as an optical writing unit serving as an optical writing device serving as an optical writing device disposed above the image stations 60Y, 60M, 60C, and 60BK, and a sheet. The transfer sheet conveyed from the feeding device 23 is transferred between the transfer belt 11 and the secondary transfer belt 5 at a predetermined timing in accordance with the toner image formation timing by the image stations 60Y, 60M, 60C, and 60BK. A registration roller pair 13 that is fed out toward the printing section, and a sensor (not shown) that detects that the leading edge of the transfer paper has reached the registration roller pair 13.

  The image forming apparatus 100 also serves as a belt-fixing type fixing unit for transferring the toner image on the transfer belt 11 transferred by the secondary transfer unit 76 and fixing the toner image on the transfer paper. A fixing unit 6, a paper discharge unit that discharges the fixed transfer paper to the outside of the main body 101, and a reverse path that transports the transfer paper toward the registration roller pair 13 again. 79, the secondary transfer unit 76, and the fixing device 6 are arranged in parallel with the image forming unit 60. The paper discharge unit 79 forms an image on one side so as to record images on both sides of the transfer paper. When the transferred transfer paper is conveyed to the reversing path, the transfer paper is switched back, reversed, and transported toward the registration roller pair 13 again. And a duplex unit 96.

  The image forming apparatus 100 also includes a paper discharge tray 75 as a stack unit that is disposed outside the main body 101 and stacks transfer sheets on which image formation has been performed, and a manual sheet feeding device disposed on the right side surface of the main body 101 in FIG. 33, an operation panel (not shown) that operates the image forming apparatus 100, and a control unit (not shown) as a control unit that controls the operation of the entire image forming apparatus 100.

  In addition to the transfer belt 11, the transfer belt unit 10 includes primary transfer rollers 12Y, 12M, 12C, and 12BK as primary transfer means, and first to third support rollers around which the transfer belt 11 is wound and wound. The transfer belt 11 is sandwiched between the tension roller 72, the transfer inlet roller 73, and a drive roller 74 that is a tension roller as a rotation drive roller that rotationally drives the transfer belt 11, and the drive roller 74. The intermediate transfer belt cleaning device 14 for cleaning the toner, the three conductive rollers 37 shown in FIG. 2 as the leakage preventing members that contact the transfer belt 11 from the inside, and the drive roller 72 are driven to rotate so that the transfer belt 11 is A1. Belt drive motor (not shown) that moves endlessly in the direction, and image formation is performed with multicolor images of two or more colors And a transfer belt unit driving means (not shown) for displacing the transfer belt 11 or the like according to either performed in a single color image or monochrome image of Luke black only. The rotation driving roller may be constituted by the tension roller 72 or the transfer entrance roller 73. In this case, the other rollers are driven to rotate.

  As an intermediate transfer belt such as the transfer belt 11, a fluorine-based resin, a polycarbonate resin, a polyimide resin, or the like has been conventionally used. However, in recent years, an elastic member in which the entire belt layer or a part of the belt is used as an elastic member. Belts have been used. As shown in FIG. 3, the transfer belt 11 according to this embodiment includes a base layer 11a as a base layer made of a material that hardly stretches, such as a fluorine resin having a small elongation or a rubber material having a large elongation, and a fluorine-based rubber or acrylonitrile- Medium resistance elastic layer 11b formed of butadiene copolymer rubber or the like and formed on the surface of base layer 11a, and coating as a smooth surface layer made of a fluororesin and covering the surface of elastic layer 11b with a coating Layer 11c.

This is because a color image transfer using a resin belt has the following problems.
Since a color image is usually formed with four color toners, one to four toner layers are formed on one color image. The toner layer receives pressure through the primary transfer from each of the photoconductive drums 20Y, 20M, 20C, and 20BK to the transfer belt 11 and the secondary transfer from the transfer belt 11 to the transfer paper, and the cohesive force between the toners is increased. Get higher. When the cohesive force between the toners increases, the phenomenon of missing characters in the characters and missing edges in the solid portion image tends to occur. Since the resin belt has a high hardness and does not deform according to the toner layer, the toner layer is easily compressed, and the character dropout phenomenon is likely to occur.
Recently, there is an increasing demand for forming full-color images on various transfer papers, for example, Japanese paper or intentionally uneven paper. However, transfer paper with poor smoothness tends to generate toner and voids at the time of transfer, and transfer loss tends to occur. When the transfer pressure at the secondary transfer portion is increased to improve the adhesion, the condensing power of the toner layer is increased, and the above-described character void is generated.

The elastic belt is used for the following purposes.
Since the elastic belt has a lower hardness than the resin belt, the elastic belt is deformed at the transfer portion corresponding to the toner layer and transfer with poor smoothness. In other words, since the elastic belt deforms following local unevenness, good adhesion can be obtained without excessively increasing the transfer pressure on the toner layer, and even on transfer paper with poor flatness, A transfer image with excellent uniformity and no missing characters is obtained.

  The elastic belt resin is polycarbonate, fluororesin (ETFE, PVDF), polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer. Styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate) Copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylate copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-phenyl methacrylate copolymer). Etc.), Styrene-α-Chloracryl Styrene resins (monopolymers or copolymers containing styrene or styrene-substituted products) such as methyl acid copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, methyl methacrylate resin, butyl methacrylate resin, acrylic acid Ethyl resin, butyl acrylate resin, modified acrylic resin (silicone-modified acrylic resin, vinyl chloride resin-modified acrylic resin, acrylic / urethane resin, etc.), vinyl chloride resin, styrene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer Coalesce, rosin modified maleic acid resin, phenol resin, epoxy resin, polyester resin, polyester polyurethane resin, polyethylene, polypropylene, polybutadiene, polyvinylidene chloride, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene Down - ethyl acrylate copolymer, xylene resin and polyvinyl butyral resin, polyamide resin, one kind or two kinds or more selected from the group consisting of modified polyphenylene oxide resin or the like can be used. However, it is not limited to the said material.

  Elastic rubbers and elastomers include butyl rubber, fluorine rubber, acrylic rubber, EPDM, NBR, acrylonitrile-butadiene-styrene rubber natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, ethylene-propylene rubber, ethylene-propylene ter Polymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, ricone rubber, fluororubber, polysulfide rubber, polynorbornene rubber, hydrogenated nitrile rubber , Selected from the group consisting of thermoplastic elastomers (for example, polystyrene, polyolefin, polyvinyl chloride, polyurethane, polyamide, polyurea, polyester, fluororesin) One or two or more types that are available. However, it is not limited to the said material.

  There are no particular restrictions on the conductive agent for adjusting the resistance value. For example, carbon black, graphite, metal powder such as aluminum and nickel, tin oxide, titanium oxide, antimony oxide, indium oxide, potassium titanate, antimony oxide-tin oxide composite Conductive metal oxides such as oxides (ATO) and indium oxide-tin oxide composite oxides (ITO), and conductive metal oxides are coated with insulating fine particles such as barium sulfate, magnesium silicate and calcium carbonate But you can. However, it is not limited to the said electrically conductive agent.

  There are no restrictions on the surface layer material, but it is preferable to use a material that reduces the adhesive force of the toner to the surface of the transfer belt 11 and increases the secondary transfer property. For example, one or more of polyurethane, polyester, epoxy resin, etc. are used. Materials that reduce surface energy and improve lubricity, such as fluororesins, fluorine compounds, fluorocarbons, titanium dioxide, silicon carbide, etc., one type or two or more types or particles with different particle sizes It can be used in a distributed manner. Further, it is possible to use a material having a surface energy reduced by forming a fluorine-rich layer on the surface by performing a heat treatment, such as a fluorine-based rubber material.

  The method of manufacturing the transfer belt 11 is not limited. For example, a centrifugal molding method in which a material is poured into a rotating cylindrical mold to form a belt, a spray coating method to form a thin film on the surface layer, and a cylindrical mold. Examples include a dipping method in which the material is soaked in a solution, a casting method in which it is poured into an inner mold and an outer mold, a method in which a compound is wound around a cylindrical mold, and vulcanization polishing is performed. It is also possible to manufacture a belt by combining the above.

A method for manufacturing the transfer belt 11 of this embodiment will be described.
PVDF 100 parts by weight Carbon black 18 parts by weight Dispersant 3 parts by weight Toluene 400 parts by weight is uniformly dispersed in a cylindrical mold, gently lifted at 10 mm / sec, dried at room temperature, and dried at 75 μm. A uniform film of PVDF is formed. A mold on which a 75 μm film is formed is repeatedly immersed in a cylindrical mold in the solution under the above conditions, gently lifted at 10 mm / sec, and dried at room temperature to form a 150 μm PVDF belt. The 150 μm PVDF is formed in a dispersion in which 100 parts by weight of a polyurethane prepolymer, 3 parts by weight of a curing agent (isocyanate), 20 parts by weight of carbon black, 3 parts by weight of a dispersant, and 500 parts by weight of MEK are uniformly dispersed. Immerse the cylindrical mold and pull it up at 30 mm / sec to dry naturally. It repeats after drying and forms the target 150-micrometer urethane polymer layer.

  Further, 100 parts by weight of polyurethane prepolymer, 3 parts by weight of curing agent (isocyanate), 50 parts by weight of PTFE fine powder powder, 4 parts by weight of dispersant and 500 parts by weight of MEK are uniformly dispersed for the surface layer.

  The cylindrical mold on which the 150 μm urethane prepolymer is formed is dipped and pulled up at 30 mm / sec and air-dried. After drying, the process is repeated to form a urethane polymer surface layer in which 5 μm of PTFE is uniformly dispersed. After drying at room temperature, crosslinking was carried out at 130 ° C. for 2 hours to obtain a three-layer transfer belt having a resin layer: 150 μm, an elastic layer: 150 μm, a surface layer: 5 μm.

  As a method for preventing the elastic belt from stretching, there are a method of forming a rubber layer in the core resin layer having a small elongation as in the above examples, a method of adding a material for preventing the elongation to the core layer, etc. It is not related to.

  Examples of the material constituting the core layer for preventing elongation include natural fibers such as cotton and silk, polyester fibers, nylon fibers, acrylic fibers, polyolefin fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, and polyvinylidene chloride fibers. 1 type selected from the group consisting of synthetic fibers such as polyurethane fiber, polyacetal fiber, polyfluoroethylene fiber and phenol fiber, inorganic fibers such as carbon fiber, glass fiber and boron fiber, and metal fibers such as iron fiber and copper fiber, or A woven or thread-like material using two or more kinds is used. Of course, the material is not limited to the above.

The yarn may be twisted in any manner, such as a twist of one or a plurality of fillers, a single twisted yarn, various twisted yarns, a double yarn and the like. Further, for example, fibers of a material selected from the above material group may be blended. Of course, it is also possible to use the yarn after applying an appropriate conductive treatment.
On the other hand, the woven fabric can be any woven fabric, such as knitted weave, and of course, a woven fabric that has been woven can also be used, and naturally it can be subjected to a conductive treatment.

  The production method for providing the core layer is not particularly limited, for example, a method of providing a woven fabric woven in a cylindrical shape on a mold and the like, and providing a coating layer thereon, the woven fabric woven in a cylindrical shape is a liquid rubber For example, a method of providing a coating layer on one or both sides of the core layer by immersing the core body layer, a method of winding a thread around a die or the like at an arbitrary pitch, and providing a coating layer thereon.

  The thickness of the elastic layer depends on the hardness of the elastic layer, but if it is too thick, the surface expands and contracts and cracks are likely to occur in the surface layer. In addition, it is not preferable to be too thick because the expansion / contraction amount is large and the expansion / contraction of the image is large.

  An appropriate range of the hardness of the elastic layer is 10 ≦ HS ≦ 65 ° (JIS-A). The optimum hardness needs to be adjusted according to the belt layer thickness. Those having a hardness of less than 10 ° (JIS-A) are very difficult to mold with high dimensional accuracy. This is due to the fact that it is susceptible to shrinkage and expansion during molding. In order to make it softer, it is a general method to contain an oil component in the base material, but there is a problem that the oil component starts to ooze out when continuously operated in a pressurized state. As a result, it has been found that the photosensitive member in contact with the surface of the intermediate transfer member is contaminated to cause horizontal band-like unevenness. In general, a surface layer is provided to improve releasability, but in order to completely prevent bleeding, the surface layer has high required quality such as durability, and selection of materials, securing of properties, etc. It becomes difficult. On the other hand, those having a hardness of 65 ° (JIS-A) or higher can be molded with high accuracy, and the oil content can be suppressed or reduced, so that the contamination of the photoreceptor can be prevented. However, the effect of improving transferability, such as character dropout, cannot be obtained, and it is difficult to stretch the roller.

  When the image formation is performed with two or more multi-color images, the transfer belt unit driving means places the transfer belt 11 in a state where the transfer belt 11 is stretched substantially horizontally as shown in FIG. When contact is made with 20Y, 20M, 20C, and 20BK and image formation is performed in a monochrome image, the transfer belt 11 is moved away from the photosensitive drums 20Y, 20M, and 20C so that the left side of the figure is displaced downward. It is assumed that the belt 11 is in contact with only each photosensitive drum 20BK. When the image formation is performed with a monochrome image, the operations of the image stations 60Y, 60M, and 60C are stopped, including the rotation of the photosensitive drums 20Y, 20M, and 20C. In such a configuration, the four image stations 60Y, 60M, 60C, and 60BK are arranged side by side in the order of the image stations 60C, 60M, 60Y, and 60BK from the upstream in the A1 direction, and development as described below is performed. In any case, the image forming unit 60 is disposed on the transfer belt 11 stretched between the tension roller 72 and the driving roller 74. As described above, the order of colors for forming an image varies depending on the aim and characteristics of the image forming apparatus 100 and is not limited.

  As shown in FIG. 2, the intermediate transfer belt cleaning device 14 has two fur brushes 14a and 14b as cleaning members, metal rollers 14c and 14d that are in contact with the fur brushes 14a and 14b, and metal rollers 14c and 14d, respectively. Connected power supplies 14e and 14f, blades 14g and 14h whose tips are pressed against the metal rollers 14c and 14d, and power supplies (not shown) that apply biases of different polarities to the fur brushes 14a and 14b, respectively. It has a tank of illustration.

The fur brushes 14a and 14b have a diameter of 20 mm, acrylic carbon, 6.25 D / F, 100,000 / inch ² , E + 7Ω, and are provided so as to contact the transfer belt 11 and rotate in the counter direction. It has been.
The metal rollers 14c and 14d are provided so as to contact the fur brushes 14a and 14b and rotate in the forward direction with respect to the fur brushes 14a and 14b. The metal rollers 14c and 14d may be provided so as to rotate in the opposite direction with respect to the fur brushes 14a and 14b.
The power supply 14e applies a (−) voltage, specifically −700 V, to the metal roller 14c, and the power supply 14f applies a (+) voltage to the metal roller 14d.

  The intermediate transfer belt cleaning device 14 having such a configuration cleans the surface of the transfer belt 11 by applying a bias (−) using the fur brush 14a as the transfer belt 11 rotates in the A1 direction. When a voltage of −700 V is applied to the metal roller 14 c by the power supply 14 e, the fur brush 14 a becomes −400 V, and the (+) toner on the transfer belt 11 is transferred to the fur brush 14 a side. The removed toner is further transferred from the fur brush 14a to the metal roller 14c by a potential difference and scraped off by the blade 14g.

  Even if the toner on the transfer belt 11 is removed by the fur brush 14 a in this way, a large amount of toner may still remain on the transfer belt 11. These toners are charged (−) by a (−) bias applied to the fur brush 14a. This is considered to be charged by charge injection or discharge.

Then, next, the toner is removed by performing cleaning by applying a bias of (+) using the fur brush 14b. The removed toner is transferred from the fur brush 14b to the metal roller 14d due to the potential difference and scraped off by the blade 14h.
The toner scraped off by the blades 14g and 14h is collected in a tank.

  The transfer belt 11 after being cleaned with the fur brush 14b in this way is in a state in which most of the toner is removed, but there is a possibility that a small amount of toner still remains on the transfer belt 11. .

  These toners are charged to (+) by the (+) bias applied to the fur brush 14b. The toner charged to (+) is transferred to the photosensitive drum 20Y side by a transfer electric field applied at the primary transfer position, and is collected by a cleaning device 70Y described later. In the first primary transfer portion, the toner is transferred to the most photosensitive drum 20Y side.

  The conductive roller 37 is in contact with the base layer 11a of the transfer belt 11 between the primary transfer rollers 12Y, 12M, 12C, and 12BK, and bias applied by the primary transfer rollers 12Y, 12M, 12C, and 12BK during transfer. Is provided to prevent the medium resistance elastic layer 11b from flowing into the adjacent primary transfer position.

  In addition to the secondary transfer belt 5, the secondary transfer unit 76 is a tension roller around which the secondary transfer belt 5 is wound. A transfer entrance roller 73 that is a backup roller as a counter roller that is provided and pressed via the transfer belt 11 and a power supply (not shown) that applies a secondary transfer bias having a polarity opposite to that of the toner to the driving roller 15 are provided. .

  The driving roller 15 and the transfer entrance roller 73 sandwich the transfer belt 11 and the secondary transfer belt 5 between them, and the secondary transfer belt 11 and the secondary transfer belt 5 come into contact with each other by the sandwiching. A nip is formed. In the secondary transfer nip, by applying a secondary transfer bias, a four-color toner image carried on the transfer belt 11 is electrostatically moved from the transfer belt 11 side to the drive roller 15 side as described later. A secondary transfer electric field is formed. The four-color toner image is transferred to the transfer paper conveyed between the transfer belt 11 and the secondary transfer roller 5 by the registration roller 13 by a secondary transfer electric field and nip pressure as will be described later.

  The secondary transfer unit 76 also has a sheet conveyance function for conveying the transfer paper onto which the toner image has been transferred from the transfer belt 11 to the fixing device 6. The secondary transfer unit 76 includes a transfer roller or a non-contact type. A configuration employing a charger may be used. In this case, another member for transporting the transfer paper toward the fixing device 6 is required.

  The optical scanning device 8 shown in FIG. 1 scans and exposes scanning surfaces formed by the surfaces of the photosensitive drums 20Y, 20M, 20C, and 20BK, and forms image signals for forming an electrostatic latent image. A light source (not shown) that emits the laser light L shown in FIG. 4 as a laser beam based on the above, a polygon mirror (not shown) that scans the laser light emitted by the light source by its rotation, and a polygon motor (not shown) that drives the polygon mirror to rotate The laser beam scanned by the polygon mirror forms an image on the photosensitive drums 20Y, 20M, 20C, and 20B, and has a number of optical elements (not shown) such as an f-θ lens (not shown) and a reflecting mirror. . An LED may be used as the light source.

  The registration roller pair 13 is used while being grounded. This is because, in an image forming apparatus that employs an intermediate transfer method, such as the image forming apparatus 100 of the present embodiment, it is generally difficult for paper dust to move to the photosensitive member, so there is little need to consider paper dust transfer. It is. However, it is also possible to apply a bias to the registration roller pair 13 in order to remove paper dust from the transfer paper. For example, each roller of the registration roller pair 13 is a conductive rubber roller, and a bias is applied. Specifically, the diameter of each roller is 18 and the surface is made of conductive NBR rubber having a thickness of 1 mm. The electrical resistance is about 10E9 Ωcm in terms of the volume resistance of the rubber material. As the applied voltage, a voltage of about −800 V is applied to the front side, which is the toner transfer side, and a voltage of about +200 V is applied to the back side of the paper. A DC bias may be applied as the applied voltage, but an AC voltage having a DC offset component may be used in order to more uniformly charge the transfer paper. The surface of the transfer paper after passing through the resist roller pair 13 to which a bias is applied is slightly charged on the minus side. Therefore, it may be necessary to change the transfer condition from the intermediate transfer body 11 to the transfer paper as compared to the case where no voltage is applied to the registration roller pair 13.

  The fixing device 6 includes a heating roller 62 having a heat source therein, a fixing belt 64 wound around the heating roller 62, a fixing roller 65 wound around the fixing belt 64 together with the heating roller 62, and the fixing roller 65. And a pressure roller 63 that presses against the fixing belt 64 and forms a fixing nip as a fixing portion that is a pressing portion. The heating roller 62, the fixing belt 64, and the fixing roller 65 constitute a belt unit in which the fixing belt 64 moves endlessly. The fixing device 6 passes the transfer paper carrying the toner image through the fixing nip, thereby fixing the carried toner image on the surface of the transfer paper by the action of heat and pressure.

  A paper discharge unit 79 transports the fixed transfer paper transported from the fixing device 6 toward the duplex unit 96, a paper discharge roller 98 that discharges the paper to the outside of the main body 101, and a fixed transfer. There is provided a switching claw 94 for switching whether the paper is guided to the paper discharge path with the conveying roller 97 and discharged out of the main body 101 or the paper is guided to the reverse path with the paper discharge roller 98 to enter the duplex unit 96.

  The duplex unit 96 is a tray 92 on which transfer paper having an image formed on one side, which has been conveyed from the paper discharge unit 79, is temporarily stacked, a reverse roller 93 that switches back the transfer paper on the tray 92, and a reverse roller. The sheet feeding roller 95 and the like for feeding the transfer sheet switched back by 93 to the registration roller 13 are provided.

  The sheet feeding device 23 includes a paper bank 26 in which a plurality of sheet feeding cassettes 25 that can store a plurality of transfer sheets in a bundle of sheets are arranged in a vertical direction, and a plurality of transfer sheets stacked on the sheet feeding cassette 25. Among them, a feeding roller 24 as a sheet feeding roller that contacts the upper surface of the uppermost transfer sheet, a separation roller 27 that separates the transfer sheets fed by the feeding roller 24 one by one, a sheet feeding roller 24 and a separation roller And a paper feed path 29 through which the transfer paper fed by the roller 27 passes.

  The paper feed path 29 includes a transport roller 28 that transports the transfer paper fed by the paper feed roller 24 and the separation roller 27 toward the registration roller pair 13 and a registration roller 13 that is positioned at the downstream end in the transport direction of the transfer paper. The transfer paper sheet feeding device 23 transported by the transport roller 28 is provided so as to continue into the main body 101, and the transport roller 28 is also disposed in the paper feed path 29 in the main body 101.

  In the sheet feeding device 23, the feeding roller 24 is rotated in the counterclockwise direction in the drawing, and the separation roller 27 acts to guide the uppermost transfer paper into the paper feeding path 29, so that the conveying roller 28 The sheet is fed toward the registration roller pair 13 by rotation, and the transferred transfer paper is abutted against the registration roller pair 13 and stopped.

  The manual paper feed device 33 includes a manual feed tray 34 on which transfer paper is stacked, a feed roller 35 as a paper feed roller that contacts the upper surface of the uppermost transfer paper among the transfer papers stacked on the manual feed tray 34, It has a separation roller 36 for separating the transfer paper fed by the feed roller 35 one by one, and a paper sensor for detecting that the transfer paper is placed on the manual feed tray 34.

  In the manual sheet feeding device 33, the feeding roller 35 is driven to rotate in the clockwise direction in the drawing, and the separation roller 36 acts to guide the uppermost transfer sheet into the sheet feeding path 29 on the main body 101 side and to register the sheet. The transfer paper fed to the roller pair 13 is transported against the registration roller pair 13 and stopped.

  The reading device 21 includes a contact glass 21a on which a document is placed, a light source (not shown) that irradiates light on the document placed on the contact glass 21a, and a first light source (not shown) that reflects light reflected from the light source. A first traveling body 21b that includes a reflector and travels in the left-right direction in FIG. 1; a second traveling body 21c that includes a second reflector (not shown) that reflects light reflected by the reflector of the first traveling body 21b; An image forming lens 21d for forming an image of light from the second traveling body 21c, a reading sensor 21e for receiving the light passing through the image forming lens 21d and reading the contents of the document are provided.

  The automatic document feeder 22 has a document table 22a on which a document is placed. The automatic document feeder 22 is rotatable with respect to the reading device 21, and the contact glass 21a is exposed when the automatic document feeder 22 is rotated upward.

The operation panel is an operation display unit having a liquid crystal display, a start button that functions as a copy start switch for starting copying, and various key buttons such as a numeric keypad for inputting the number of copies. On the operation panel, it is possible to specify whether image formation is performed with a multicolor image or a monochrome image, and it is possible to set a single-sided print mode, which is a mode for forming an image only on one side of a transfer sheet. Yes. The single-sided print mode includes a direct discharge mode, a reverse discharge mode, and a reverse decal discharge mode, and one of these is selected.
The control means includes a CPU, a memory as a storage means, and the like.

  Regarding the image stations 60Y, 60C, 60M, and 60BK, the configuration will be described as a representative of the configuration of the image station 60Y including the photosensitive drum 20Y. Since the configuration of other image stations is substantially the same, in the following description, for the sake of convenience, reference numerals corresponding to the reference numerals assigned to the configuration of the image station including the photosensitive drum 20Y are used for other image stations. A detailed description will be omitted as appropriate for the station configuration, and those with Y, C, M, and K at the end of the reference numerals are used to form yellow, cyan, magenta, and black images, respectively. It is assumed that this is the configuration.

  As shown in FIG. 4, the image station 60Y provided with the photosensitive drum 20Y has a primary transfer roller 12Y and a cleaning member around the photosensitive drum 20Y along the rotation direction B1 that is counterclockwise in the drawing. A cleaning device 70Y as a primary transfer cleaning device as a photosensitive member cleaning device as a means, a neutralizing device 90Y as a neutralizing means, a charging device 30Y as a charging unit as a charging means, and a developing unit as a developing means. The developing device 80Y has a cartridge case 59Y in which these are integrated.

  The image station 60Y also includes a toner recycling device 50Y as a toner recycling unit that returns the toner collected by the cleaning device 70Y to the developing device 80Y for reuse in the developing device 80Y.

  The photosensitive drum 20Y, the cleaning device 70Y, the charge eliminating device 90Y, the charging device 30Y, the developing device 80Y, and the toner recycling device 50Y are integrated by a cartridge case 59Y, and an image station 60Y as a process cartridge is integrated. It is composed. The image station 60Y as a process cartridge can draw out the cartridge case 59Y from the main body 101 along a guide rail (not shown) fixed to the main body 101, and can push the cartridge case 59Y into the main body 101. Is detachably installed.

  When pushed into the main body 101, the image station 60Y as a process cartridge is loaded and positioned at a predetermined position suitable for image formation. Making a process cartridge in this way is very preferable because it can be handled as a replacement part, so that the maintainability is remarkably improved. In addition, since the life of each part, which is an element of the process cartridge, is equal, unnecessary replacement is prevented and suppressed, and the structure is further preferable.

  The image station 60Y as a process cartridge includes a photosensitive drum 20Y, a cleaning device 70Y, a charge removal device 90Y, a charging device 30Y, a developing device 80Y, and a toner recycling device 50Y. The unit 70 </ b> Y is a unit that is configured by being integrated and is detachably installed on the main body 101.

  A primary transfer nip formed by the primary transfer roller 12Y pressing the transfer belt 11 toward the photosensitive drum 20Y is a contact position between the transfer belt 11 and the photosensitive drum 20Y. Constitutes a transfer position NP at which the toner image is transferred to the transfer belt 11. The primary transfer device is not limited to the roller shape as in the present embodiment, but may be configured by a conductive brush shape, a non-contact corona charger, or the like.

The photosensitive drum 20Y has a linear velocity of 200 mm / s, a diameter of 50 mm, and a thickness of 30 μm.
Details of the photosensitive drum 20Y will be described later.

  The static eliminator 90Y includes a static elimination lamp (not shown) disposed in the vicinity of the surface of the photoconductor drum 20Y, and the surface of the photoconductor drum 20Y is neutralized by making it electrically clean. Is initialized.

  The charging device 30Y includes a charging roller 31Y that rotates in contact with the surface of the photosensitive drum 20Y, and a cleaning roller 32Y as a charging cleaning member that rotates in contact with the charging roller 31Y.

  The charging roller 31Y is connected to a voltage applying means (not shown) for applying a bias of an alternating current component to a direct current, and in the charging region facing the photosensitive drum 20Y, the charging drum 31Y is charged by the discharging device 90Y. The surface is uniformly charged to a predetermined polarity. The charging potential of the photosensitive drum 20Y by the charging roller 31Y, that is, the pre-exposure potential V0 is −700V.

The cleaning roller 32Y is driven to rotate by the charging roller 31Y to clean the charging roller 31Y.
As described above, in this embodiment, a charging system using a contact roller is adopted. However, the charging system may use a proximity roller or a non-contact scorotron charger. There may be.

  The optical scanning device 8 shown in FIG. 1 applies the laser light L modulated and deflected to a region between a charging region where the charging device 30Y faces the photosensitive drum 20Y and a developing region where the developing device 80Y faces. Image information that is irradiated while scanning and the surface to be scanned on the surface of the photosensitive drum 20Y after being charged by the charging device 30Y is exposed by spot irradiation and visualized as a yellow toner image by the developing device 80Y. An electrostatic latent image corresponding to the is written. The beam spot diameter on the surface of the photosensitive drum 20Y by the optical scanning device 8 is 50 × 60 μm, and the light quantity is 0.47 mW. The charged potential of the photosensitive drum 20Y after the exposure by the optical scanning device 8, that is, the post-exposure potential VL is −120V.

  As shown in FIG. 4, the developing device 80Y includes a developing roller 81Y carrying a two-component developer (hereinafter referred to as developer) including toner and a carrier disposed in close proximity to the photosensitive drum 20Y, and a developing roller 81Y. A doctor blade 82Y that regulates the developer on the roller 81Y to a certain height, and a first conveying screw that is arranged in parallel with each other and agitates the developer and supplies the developer to the developing roller 81Y. 83Y and the second transport screw 84Y, a partition wall 87Y that is a partition plate provided between the first transport screw 83Y and the second transport screw 84Y, and a part of the cartridge case 59Y that houses them. And a developing case 85Y.

  The developing device 80Y also develops a toner concentration sensor 86Y as a toner concentration detecting unit attached to the developing case 85Y below the first conveying screw 83Y, a toner bottle 88Y containing yellow toner, and a developing bias of a DC component. A bias applying unit (not shown) for applying to the roller 81Y and a developing driving unit as a driving unit (not shown) for driving the developing roller 81Y, the first conveying screw 83Y, the second conveying screw 84Y, and the like are included.

The first conveying screw 83Y, the second conveying screw 84Y, and the partition wall 87Y constitute an agitating unit 38Y that conveys the developer while stirring and supplies the developer to the developing roller 81Y.
The developing roller 81Y and the doctor blade 82Y occupy a position higher than the agitating unit 38Y, and constitute a developing unit 39Y that transfers the toner of the developer attached to the developing roller 81Y to the photosensitive drum 20Y.

  The developing roller 81Y has a developing sleeve (not shown) that is a developer carrying member that carries the developer on the surface thereof, and a plurality of magnets (not shown) fixed inside the developing sleeve.

  The developing sleeve has a non-magnetic rotatable sleeve shape with a diameter of 18 mm. The surface of the developing sleeve is formed such that Rz falls within a range of 10 to 30 μm by performing sandblasting or forming a plurality of grooves having a depth of 1 to several mm. The linear velocity of the developing sleeve is 240 mm / s. The smaller the developing gap Gp, which is the gap between the developing sleeve and the photosensitive drum 20Y, is more advantageous for improving the developing efficiency. In this embodiment, the developing gap Gp can be set in the range of 0.4 to 0.8 mm.

  The magnet has five magnetic poles of N1, S1, N2, S2, and S3 in the rotation direction of the developing sleeve from a position facing the doctor blade 82Y. These magnetic poles and magnets are fixed, and a magnetic force is applied when the developer passes through a predetermined place so as to be carried as a magnetic brush on the developing sleeve. The magnetic pole of S1 of the magnet faces the photosensitive drum 20Y, and a magnetic brush that rubs the surface of the photosensitive drum 20Y is carried on the developing sleeve in a region facing the photosensitive drum 20Y.

  The doctor blade 82Y is disposed so that the tip thereof is close to the developing sleeve. The distance between the distal end of the doctor blade 82Y and the developing sleeve is 500 μm.

  The bias applying means applies a developing bias having an appropriate size between the exposed portion and the non-exposed portion of the photosensitive drum 20Y to the developing sleeve. Specifically, the development bias voltage is −470V, and development is performed with a development potential of 350V.

  In the developing device 80Y, a partition wall 87Y forms a first supply unit that accommodates the developing roller 81Y and the first conveyance screw 83Y and a second supply unit that accommodates the second conveyance screw 84Y. Has been.

  The first transport screw 83Y is rotationally driven by the driving means, and supplies the developer in the first supply section to the developing roller 81Y while transporting the developer from the back side to the front side in FIG. The developer conveyed to the vicinity of the end in the first supply unit by the first conveyance screw 83Y enters the second supply unit through an opening (not shown) formed in the partition wall 87Y.

  In the second supply unit, the second transport screw 84Y transports the developer sent from the first supply unit in the direction opposite to that of the first transport screw 83Y by being rotationally driven by the driving unit. The developer transported to the vicinity of the end of the second supply unit by the second transport screw 84Y returns to the first supply unit through another opening (not shown) provided in the partition wall 87Y.

  The toner charge amount is preferably in the range of −10 to −30 μC / g on the developing sleeve, and the first conveying screw 83Y and the second conveying screw 84Y stir the developer so as to satisfy this.

  The developer in the developing case 85Y is a two-component developer including a magnetic carrier and a yellow toner that is a negatively charged color toner. The developer is supplied with yellow toner from a toner bottle 88Y. The supplied yellow toner and developer are agitated and mixed while being agitated and conveyed by the first conveying screw 83Y and the second conveying screw 84Y, frictionally charged, supplied to the developing roller 81Y, and pumped up by the magnet roller. Is held by the developing sleeve, and is carried in such a manner that a magnetic brush is formed on the developing sleeve.

  In the developing roller 81Y, the developer carrying amount is regulated by the doctor blade 82Y by the rotation of the developing sleeve, the layer thickness is regulated, the magnetic brush is trimmed to an appropriate amount, and the developer that has been cut off enters the stirring unit 38Y. Returned. The developing roller 81Y also carries an appropriate amount of developer by the doctor blade 82Y to the developing area between the developing roller 81Y and the photosensitive drum 20Y by the rotation and the developing bias by the bias applying means. The yellow toner is electrostatically transferred to an electrostatic latent image formed on the surface of the photosensitive drum 20Y, and the electrostatic latent image is made visible as a yellow toner image and visualized as an image. Yes.

The developer that has consumed the yellow toner by the development leaves the developing sleeve at the position where the magnetic force of the magnet roller has decreased with the rotation of the developing roller 81Y, and returns to the stirring unit 38Y.
By repeating this, the toner concentration in the agitating unit 38Y becomes low, and when this is detected by the toner concentration sensor 86Y, the toner concentration sensor 86Y detects that the toner concentration has reached a predetermined concentration from the toner bottle 88Y. Toner is replenished and supplied.

In this embodiment, the DC component developing bias is applied by the bias applying means. However, the developing bias may be an AC component, or an AC component superimposed on the DC component.
Details of the developer will be described later.

  The cleaning device 70Y includes a cleaning case 71Y configured by a part of the cartridge case 59Y that forms a housing thereof, and is housed in the cleaning case 71Y. The tip of the cleaning device 70Y comes into contact with the photosensitive drum 20Y and is on the photosensitive drum 20Y. A cleaning blade 78Y as a cleaning member that scrapes off, collects, and removes foreign matters such as transfer residual toner, carrier, paper dust, and the like, and a blade support 73Y that supports the cleaning blade 78Y with respect to the cleaning case 71Y. The support shaft 69Y that rotatably supports the blade support 73Y on the cleaning case 71Y, and the cleaning blade 78Y are pressed against the photosensitive drum 20Y with a predetermined elastic force so that the edge thereof is pressed against the photosensitive drum 20Y. With spring 79Y There.

  The cleaning device 70Y is also rotatably supported by the cleaning case 71Y, and the cleaning blade 78Y scrapes off the transfer residual toner and the like from the photosensitive drum 20Y, and also removes unnecessary items such as waste toner generated by the removal. 4 is brought to one side on the front side of the paper surface in FIG. 4 and discharged screw 67Y, which is a collection screw as a waste toner conveying screw that conveys to toner recycling device 50Y, and protective agent 42Y as a lubricant that is a lubricant that protects photosensitive drum 20Y. And a protective film forming device 40Y as a lubricant coating device which is a lubricant coating device which is a protective film forming means for coating the photosensitive drum 20Y.

  The cleaning device 70Y is also rotatably supported by the cleaning case 71Y, and the electric field roller 77Y engaged with the protective film forming device 40Y, the scraper 91Y in contact with the electric field roller 77Y, the electric field roller 77Y, and a brush roller described later. And a voltage applying means (not shown) for forming a bias with 47Y.

  The protective film forming apparatus 40Y includes an image carrier protecting agent which is a solid lubricant formed in a bar shape, a protective agent 42Y as an image carrier protecting agent, and a direction opposite to the rotation direction B1 of the photosensitive drum 20Y, that is, Lubricant application member as a scraping member that rotates in the counter direction D1 and scrapes off the protective agent 42Y to supply the photosensitive drum 20Y and apply it to protect the photosensitive drum 20Y. A brush roller 47Y as a lubricant application brush roller, which is a fur brush application brush as a lubricant application brush.

  The protective film forming apparatus 40Y also holds the protective agent 42Y and supports it with respect to the cleaning case 71Y, and supports 49Y as a lubricant holding member that supports the protective agent 42Y in the direction of contacting and separating from the brush roller 47Y. It has a spring 48Y as a spring member as a lubricant pressurizing spring, which is a pressurizing spring as an elastic member as a pressing means for pressing the protective agent 42Y against the brush roller 47Y via the support 49Y.

  The protective film forming apparatus 40Y also includes a cleaning blade 78Y, an electric field roller 77Y, a scraper 91Y, a voltage applying unit, and a development driving unit, and serves as a driving unit for rotationally driving the brush roller 47Y and the electric field roller 77Y. And a lubricant application driving means.

  The protective agent 42Y is made of, for example, a dry solid hydrophobic lubricant. Representative examples of this lubricant include zinc stearate, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, stearic acid. Magnesium, zinc oleate, manganese oleate, iron oleate, cobalt oleate, lead oleate, magnesium oleate, copper oleate, palmitic acid, zinc cobalt palmitate, copper palmitate, magnesium palmitate, aluminum palmitate, Examples include relatively higher fatty acids such as calcium palmitate, lead caprylate, lead caproate, zinc linolenate, cobalt linolenate, calcium linolenate, and cadmium ricolinolenate. That. Natural wax such as carnauba wax may also be used.

  As shown in FIGS. 5 and 6, the brush roller 47Y includes a shaft member 47aY extending in the width direction of the photosensitive drum 20Y that is perpendicular to the paper surface of FIGS. 1 and 5, and an outer peripheral surface of the shaft member 47aY. And a plurality of brush fibers 89Y as raised hairs. The brush roller 47Y is formed by winding and fixing a base cloth (not shown) in which a plurality of brush fibers 89Y are implanted around the shaft member 47aY.

  The length of the brush roller 47Y in the width direction is adjusted so that the brush fibers 89Y are in contact with at least the entire width direction of the photosensitive drum 20Y. The brush fiber 89Y, the base fabric, the shaft member 47aY, and the like are conductive, and the brush roller 47Y is conductive.

In order to uniformly apply the protective agent 42Y to the surface of the photoconductor drum 20Y, the density of the brush fibers 89Y that are the raised portions of the brush roller 47Y is 20,000 / 645.16 [mm ² ] or higher. Is preferred. If the coating amount of the protective agent 42Y on the photosensitive drum 20Y is non-uniform, the amount of toner that forms the toner image formed on the surface of the photosensitive drum 20Y becomes non-uniform due to the non-uniform coating. This is because density unevenness occurs and the formed image quality may deteriorate. Specifically, the toner adhesion amount is small in the portion where the coating amount of the protective agent 42Y is large, and conversely, a large amount of toner adheres to the portion where the coating amount of the protection agent 42Y is small, thereby causing uneven density in the toner image. Will occur. In particular, uneven density tends to occur in a low-density toner image.

  As shown in FIG. 4, the brush roller 47Y contacts the photosensitive drum 20Y at a position TP downstream of the transfer position NP and upstream of a cleaning position CP described later in the B1 direction. 42Y can be applied to the photosensitive drum 20Y. This position TP is a lubricant application position.

  The brush roller 47Y rotates in the D1 direction by transmission of the rotational driving force from the lubricant application driving means to the shaft member 47aY. By this rotation, the protective agent 42Y is scraped off and attached to the brush fibers 89Y, and then applied to the surface of the photosensitive drum 20Y at the lubricant application position TP in a state where the brush roller 47Y is in contact with the photosensitive drum 20Y. The

  As shown in FIG. 5, the brush roller 47Y is disposed such that the amount of biting x1 into the photosensitive drum 20Y is larger than the amount of biting x2 into the lubricant 42Y. As a result, the shaved lubricant 42Y is more reliably transferred to the photosensitive drum 20Y.

  The cleaning blade 78Y is made of polyurethane rubber, and is in contact with the photosensitive drum 20Y at an angle similar to a so-called counter type, that is, a reading type. The cleaning position CP is a position where the cleaning blade 78Y contacts the photosensitive drum 20Y and unnecessary materials such as transfer residual toner on the photosensitive drum 20Y are cleaned.

  At the cleaning position CP, the cleaning blade 78Y applies a protective agent 42Y applied or supplied to the photosensitive drum 20Y at the lubricant application position TP by the brush roller 47Y on the photosensitive drum 20Y, and forms a film on the surface of the photosensitive drum 20Y. It functions as a coating blade for forming a protective film as a protective layer. The cleaning blade 78Y leveles the protective agent 42Y on the photosensitive drum 20Y so as to eliminate even a slight distribution unevenness in the protective agent 42Y on the photosensitive drum 20Y.

  Thus, when the brush roller 47Y is rotationally driven, the cleaning device 70Y is driven as the protective film forming device 40Y. The rotation direction of the brush roller 47Y may be the forward direction instead of the reverse direction to the B1 direction.

  The film formed on the surface of the photoconductive drum 20Y by the protective agent 42Y has a function of preventing the surface of the photoconductive drum 20Y from being deteriorated due to proximity discharge, and the protective film forming apparatus 40Y functions as a discharge deterioration preventing means. It is. The deterioration here refers to both wear of the photosensitive drum 20Y due to discharge, acceleration of the wear, and activation of the surface of the photosensitive drum 20Y.

In addition, the coating prevents deterioration such as wear caused by friction between the photosensitive drum 20Y and the cleaning blade 78Y, and the protective film forming apparatus 40Y functions as a friction deterioration preventing unit.
As described above, the protective film forming apparatus 40Y suppresses the deterioration by applying the protective agent 42Y to the surface of the photosensitive drum 20Y.

Further, the protective film forming apparatus 40Y is a contact brush in which the brush roller 47Y is in contact with the photosensitive drum 20Y, and cleans unnecessary materials such as transfer residual toner on the photosensitive drum 20Y, like the cleaning blade 78. It functions as a cleaning brush as a cleaning member.
In addition, the configuration of the protective film forming apparatus 40Y will be described later.

  The electric field roller 77Y is in contact with the brush roller 47Y, and is rotationally driven in a direction opposite to the brush roller 47Y, that is, in a counter direction at a position facing the brush roller 47Y by the lubricant application driving means. The electric field roller 77Y is driven to rotate in this way, and a bias is applied by the voltage application unit, thereby cleaning unnecessary materials such as transfer residual toner on the brush roller 47Y.

  The scraper 91Y cleans unnecessary materials such as transfer residual toner on the rotating electric field roller 77Y. The unwanted matter removed from the electric field roller 77Y by the scraper 91Y is conveyed to the toner recycling device 50Y by the discharge screw 67Y together with the unwanted matter removed from the photosensitive drum 20Y by the cleaning blade 78Y.

  As shown in FIGS. 7 and 8, the toner recycling device 50Y includes a roller 51Y disposed at the front end of the discharge screw 67Y in FIG. 4, and a belt-like collected toner wound around the roller 51Y. A conveying belt 52Y as a conveying member, a roller portion 53Y that is arranged separately from the first conveying screw 83Y on the front side of the first conveying screw 83Y in FIG. A conveyance path case 54Y configured by a part of the cartridge case 59Y is housed.

The roller portion 51Y has a pin 55Y protruding from the peripheral surface thereof.
The conveyor belt 52Y has an endless belt-like belt main body 56Y, wings 57Y projecting from the outer peripheral surface of the belt main body 56Y at regular intervals, and long holes 58Y into which pins 55Y are inserted.
The roller unit 53Y is rotatably supported by the conveyance path case 54Y, and a conveyance belt 52Y is stretched together with the roller unit 51Y.

  In the toner recycling apparatus 50Y having such a configuration, the roller 51Y is rotationally driven by the rotation of the discharge screw 67Y to rotationally drive the conveying belt 52Y. The toner and the like collected from the photosensitive drum 20Y conveyed by the discharge screw 67Y by the rotation of the conveyance belt 52Y is guided to the arrangement position of the second conveyance screw 84Y in the developing device 80Y through the conveyance path case 54Y. By rotation of the second stirring screw 84Y and the first stirring screw 83Y, it is conveyed and circulated while being stirred together with the developer already in the developing device 80Y, and used for developing the photosensitive drum 20Y.

The photoreceptor drum 20Y can employ various configurations as shown in FIG.
In FIG. 6A, the photosensitive drum 20Y includes a conductive support 131, and a single-layer photosensitive layer 133 provided on the conductive support 131 and mainly composed of a charge generation material and a charge transport material. The structure which has is shown. In this case, at least the surface of the single-layer photosensitive layer 133 contains a filler.
FIG. 6B shows that the photosensitive drum 20Y is formed on a conductive support 131, a charge generation layer 135 mainly composed of a charge generation material provided on the conductive support 131, and a charge generation layer 135. A structure having a stacked charge transport layer 137 mainly composed of a charge transport material is shown. In this case, at least the surface of the charge transport layer 137 contains a filler.
FIG. 4C shows a photosensitive drum 20Y having a conductive support 131, a single-layer photosensitive layer 133 having charge generating materials and charge transport materials as main components provided on the conductive support 131, The structure which has the filler reinforcement | strengthening charge transport layer 139 containing the filler provided in the single-layer photosensitive layer 133 surface is shown.
FIG. 4D shows that the photosensitive drum 20Y is formed on a conductive support 131, a charge generation layer 135 mainly composed of a charge generation material provided on the conductive support 131, and a charge generation layer 135. A configuration is shown that includes a stacked charge transport layer 137 mainly composed of a charge transport material and a filler-reinforced charge transport layer 139 containing a filler provided on the charge transport layer 137.

Examples of the conductive support 131 include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, and other metals, tin oxide, indium oxide, and the like. The metal oxide of the above is coated with film or cylindrical plastic or paper by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel or the like and extruded by drawing or drawing. After pipe formation, surface-treated pipes such as cutting, superfinishing, and polishing can be used. Further, an endless nickel belt or an endless stainless steel belt disclosed in Japanese Patent Application Laid-Open No. 52-36016 can be used as the conductive support 131.

  In addition to this, the conductive support 131 can also be obtained by applying conductive powder dispersed in an appropriate binder resin on the conductive support 131 described above. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, or metal oxide powder such as conductive tin oxide. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, toluene and the like.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support 131.

The photosensitive layer may be a single layer type in which a charge generation material is dispersed in a charge transport layer, or a laminate type in which a charge generation layer and a charge transport layer are sequentially stacked.
A stacked photoreceptor in which the charge generation layer 135 and the charge transport layer 137 are sequentially stacked will be described.

  The charge generation layer 135 is a layer mainly composed of a charge generation material, and a binder resin may be used as necessary. As the charge generation material, inorganic materials and organic materials can be used.

  Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. As amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms or phosphorous atoms are preferably used.

  On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and non-metal phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzo An azo pigment having a thiophene skeleton, an azo pigment having a fluorenone skeleton, an azo pigment having an oxadiazol skeleton, an azo pigment having a bis-stilbene skeleton, an azo pigment having a distyryl oxadiazol skeleton, a distyrylcarbazole skeleton Azo pigments, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Njigoido pigments, bisbenzimidazo - such as Le based pigments. These charge generation materials can be used alone or as a mixture of two or more.

  The binder resin used as necessary for the charge generation layer 135 is polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, polyarylate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N. -Vinylcarbazole, polyacrylamide, etc. are used. These binder resins can be used alone or as a mixture of two or more. In addition, a polymer charge transport material can be used as the binder resin of the charge generation layer. Furthermore, you may add a low molecular charge transport material as needed.

  Charge transport materials that can be used together with the charge generation layer 135 include an electron transport material and a hole transport material, and these include a low molecular charge transport material and a high molecular charge transport material. In the following description, the polymer type charge transport material is referred to as a polymer charge transport material.

  Examples of the electron transporting material include chloroanil, bromanyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron accepting substances such as nitrodibenzothiophene-5,5-dioxide. These electron transport materials can be used alone or as a mixture of two or more.

  Examples of the hole transporting material include the electron donating materials shown below and are used favorably. For example, oxazole derivatives, oxadiazol derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene , Styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazol derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, and the like. These hole transport materials can be used alone or as a mixture of two or more.

  In addition, it is possible to use a polymer charge transport material represented below. For example, a polymer having a carbazole ring such as poly-N-vinylcarbazole, a polymer having a hydrazone structure exemplified in JP-A-57-78402, and JP-A-63-285552 are exemplified. Examples thereof include polysilylene polymers and polymers having a triarylamine structure exemplified in JP-A-7-325409. These polymer charge transport materials can be used alone or as a mixture of two or more.

  The charge generation layer 135 includes a charge generation material, a solvent, and a binder resin as main components, and includes any additive such as a sensitizer, a dispersant, a surfactant, and silicone oil. Also good.

  Methods for forming the charge generation layer 135 include a vacuum thin film manufacturing method and a casting method from a solution dispersion system. For the former method, vacuum deposition method, glow discharge decomposition method, ion plating method, sputtering method, reactive sputtering method, CVD method, etc. are used, and the above-mentioned inorganic materials and organic materials can be satisfactorily formed. It is. Further, in order to provide a charge generation layer by a casting method, a ball mill, an attritor, or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone together with a binder resin, if necessary, the inorganic or organic charge generation material described above. It is formed by dispersing with a sand mill or the like and applying the solution after diluting the dispersion appropriately. The coating can be performed using a dip coating method, a spray coating method, a bead coating method, or the like.

  The film thickness of the charge generation layer 135 provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

The charge transport layer 137 will be described.
The charge transport layer 137 can be formed by dissolving or dispersing a mixture or copolymer mainly composed of a charge transport component and a binder component in an appropriate solvent, and applying and drying the mixture. The film thickness of the charge transport layer 137 is appropriately about 10 to 100 μm, and about 10 to 30 μm is appropriate when resolution is required.

  Examples of the polymer compound that can be used as the binder component include polystyrene, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, styrene / maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride / Vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, silicone resin, fluorine resin, epoxy resin, melamine resin And thermoplastic or thermosetting resins such as urethane resin, phenol resin, and alkyd resin, but are not limited thereto. These polymer compounds can be used singly or as a mixture of two or more kinds, or copolymerized with a charge transport material.

  Examples of the material that can be used as the charge transport material include the above-described low molecular weight electron transport materials, hole transport materials, and polymer charge transport materials. When a low molecular charge transport material is used, the amount used is 20 to 200 parts by weight, preferably about 50 to 100 parts by weight per 100 parts by weight of the polymer compound. When a polymer charge transport material is used, a material in which the resin component is copolymerized at a ratio of about 0 to 500 parts by weight with respect to 100 parts by weight of the charge transport component is preferable.

  Examples of the dispersion solvent that can be used in preparing the charge transport layer coating solution include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone, ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve, toluene, xylene, and the like. Aromatics, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate.

  When the charge transport layer 137 is not provided with a filler-reinforced charge transport layer 139 described later, it is necessary to add a filler material to at least the surface portion for the purpose of improving wear resistance. Examples of the organic filler material include fluororesin powder such as polytetrafluoroethylene, silicone resin powder, a-carbon powder, etc., and inorganic filler material includes metal powder such as copper, tin, aluminum, indium, Metal oxides such as silica, tin oxide, zinc oxide, titanium oxide, alumina, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony-doped tin oxide, tin-doped indium oxide, tin fluoride, fluoride Examples thereof include metal fluorides such as calcium and aluminum fluoride, and inorganic materials such as potassium titanate and boron nitride. Among these fillers, it is advantageous to use an inorganic material from the viewpoint of the hardness of the filler to improve the wear resistance. In particular, silica, titanium oxide, and alumina can be used effectively. Moreover, these filler materials are used individually or in mixture of 2 or more types. These fillers may be subjected to modification of the filler surface with a surface treatment agent for the purpose of improving dispersibility in the coating liquid and coating film.

  These filler materials can be dispersed by using an appropriate disperser together with a charge transport material, a binder resin, a solvent, and the like. The average primary particle size of the filler is preferably 0.01 to 0.8 μm from the viewpoint of the transmittance and wear resistance of the charge transport layer.

  Further, these fillers can be contained in the entire charge transport layer 137, but since the exposed portion potential may be increased, the outermost surface side of the charge transport layer 137 has the highest filler concentration, and is electrically conductive. The structure is such that a filler concentration gradient is provided so as to lower the support 131 side, or a plurality of charge transport layers 137 are provided so that the filler concentration is sequentially increased from the conductive support 131 side to the surface side. It is preferable. The thickness of the inorganic filler layer contained on the surface side of the charge transport layer 137, that is, the depth from the surface is preferably 0.5 μm or more, more preferably 2 μm or more.

  When the filler-reinforced charge transport layer 139 is provided, the charge transport layer 137 is obtained by dissolving or dispersing a mixture or copolymer mainly composed of the charge transport component and the binder component in an appropriate solvent, and applying and drying the mixture. It can be formed. The thickness of the charge transport layer is suitably about 10 to 100 μm, and about 10 to 30 μm is appropriate when resolution is required.

Examples of the binder component that can be used for the charge transport layer 137 in this case include the above-described thermoplastic or thermosetting resin. These polymer compounds can be used singly or as a mixture of two or more kinds, or copolymerized with a charge transport material.
Examples of the material that can be used as the charge transport material include the above-described low molecular weight electron transport materials, hole transport materials, and polymer charge transport materials.

  If necessary, a low molecular weight compound such as an appropriate antioxidant, plasticizer, lubricant, ultraviolet absorber, low molecular charge transport material, and leveling agent may be added. These compounds can be used alone or as a mixture of two or more. The amount of the low molecular compound used is 0.1 to 200 parts by weight, preferably 0.1 to 30 parts by weight based on 100 parts by weight of the polymer compound, and the amount of the leveling agent used is 100 parts by weight of the polymer compound. On the other hand, about 0.001 to 5 parts by weight is appropriate.

The filler reinforced charge transport layer 139 will be described.
The filler-reinforced charge transport layer 139 refers to a functional layer that includes at least a charge transport component, a binder resin component, and a filler and has both charge transport properties and mechanical resistance. The filler-reinforced charge transport layer 139 has a characteristic of exhibiting high charge mobility comparable to a conventional charge transport layer, which is distinguished from the surface protective layer. The filler-reinforced charge transport layer 139 is used as a surface layer obtained by functionally separating the charge transport layer 137 in the multilayer photoconductor into two or more layers. That is, this layer is used in a laminate with the charge transport layer 137 containing no filler and is not used alone. For this reason, it is distinguished from the single layer of the charge transport layer 137 when the filler is dispersed in the charge transport layer 137 as an additive.

As the filler material used for the filler-reinforced charge transport layer 139, as mentioned in the description of the charge transport layer 137, inorganic materials, particularly silica, titanium oxide, and alumina can be used effectively. Moreover, these filler materials are used individually or in mixture of 2 or more types.
For the purpose of improving dispersibility in the coating liquid and coating film, these fillers may be subjected to modification of the filler surface with a surface treatment agent as described above.

  These filler materials can be dispersed by using an appropriate disperser together with a charge transport material, a binder resin, a solvent, and the like. The average primary particle size of the filler is preferably 0.01 to 0.8 μm from the viewpoint of the transmittance and wear resistance of the charge transport layer.

As the coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.
The film thickness of the filler-reinforced charge transport layer 139 is preferably 0.5 μm or more, more preferably 2 μm or more.

Next, the case where the photosensitive layer has a single layer structure will be described.
The single-layer photosensitive layer 133 can be formed by dissolving or dispersing a charge generation material, a charge transport material, and a binder resin in a suitable solvent, and applying and drying the solution. Further, if necessary, a plasticizer, a leveling agent, an antioxidant or the like can be added.

  As the binder resin, in addition to the binder resin previously described in the description of the charge transport layer 137, the binder resin described in the description of the charge generation layer 135 may be mixed and used. Of course, the polymer charge transport materials mentioned above can also be used favorably. The amount of the charge generating material with respect to 100 parts by weight of the binder resin is preferably 5 to 40 parts by weight, and the amount of the charge transporting material is preferably 0 to 190 parts by weight, and more preferably 50 to 150 parts by weight. The single-layer photosensitive layer 133 is formed by dip coating or spray coating with a coating solution in which a charge generation material and a binder resin are dispersed together with a charge transport material using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane. It can be formed by coating with a bead coat or the like. The film thickness of the single photosensitive layer is suitably about 5 to 25 μm.

  In a configuration in which the photosensitive layer is the outermost surface layer, it is necessary to contain a filler at least on the surface of the photosensitive layer. In the case of the single-layer photosensitive layer 133 as well, as in the case of the charge transport layer 137, the entire photosensitive layer can contain a filler. However, a filler concentration gradient is provided or a configuration of a plurality of photosensitive layers is adopted. It is an effective means to sequentially change the filler concentration.

  An undercoat layer can be provided between the conductive support 131 and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, the resin may be a resin having high solvent resistance with respect to a general organic solvent. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. In addition, a fine powder pigment of metal oxide which can be exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide, etc. may be added to the undercoat layer in order to prevent moire and reduce residual potential. .

These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. Further, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer. In addition, the undercoat layer is formed by anodizing Al ₂ O ₃ , organic materials such as polyparaxylylene (parylene), and inorganic materials such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, and CeO _2. Can also be used satisfactorily. In addition to this, it is possible to use known ones. The thickness of the undercoat layer is suitably from 0 to 20 μm, preferably from 1 to 10 μm.

  In order to improve environmental resistance, an antioxidant is added to each layer such as the charge generation layer 135, the charge transport layer 137, the undercoat layer, the protective layer, and the intermediate layer, in particular, for the purpose of preventing a decrease in sensitivity and an increase in residual potential. It is possible to add plasticizers, lubricants, UV absorbers, low molecular charge transport materials and leveling agents. Representative materials of these compounds are described below.

Examples of the antioxidant that can be added to each layer include, but are not limited to, the following.
(A) Phenolic compounds 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, n-octadecyl-3- (4′- Hydroxy-3 ', 5'-di-t-butylphenol), 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-ethyl- 6-t-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1,3 -Tris- (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxy Benzyl) benzene, tetraki -[Methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis (4'-hydroxy-3'-t- Butylphenyl) butyric acid] cricol ester, tocopherols and the like.
(B) Paraphenylenediamines N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylene Diamine, N, N′-di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.
(C) Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2 -(2-octadecenyl) -5-methylhydroquinone and the like.
(D) Organic sulfur compounds Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.
(E) Organic phosphorus compounds Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine and the like.

Examples of the plasticizer that can be added to each layer include, but are not limited to, the following.
(A) Phosphate ester plasticizer Triphenyl phosphate, tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, trichloroethyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, Triphenyl phosphate etc.
(B) Phthalate ester plasticizers Dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, phthalate Dinonyl acid, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate, butyl lauryl phthalate, methyl oleyl phthalate, octyl decyl phthalate, dibutyl fumarate, dioctyl fumarate Such.
(C) Aromatic carboxylic acid ester plasticizers Trioctyl trimellitic acid, tri-n-octyl trimellitic acid, octyl oxybenzoate and the like.
(D) Aliphatic dibasic ester plasticizer dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, di-n-octyl adipate, adipic acid n-octyl-n-decyl , Diisodecyl adipate, dicapryl adipate, di-2-ethylhexyl azelate, dimethyl sebacate, diethyl sebacate, dibutyl sebacate, di-n-octyl sebacate, di-2-ethylhexyl sebacate, di-2 sebacate -Ethoxyethyl, dioctyl succinate, diisodecyl succinate, dioctyl tetrahydrophthalate, di-n-octyl tetrahydrophthalate and the like.
(E) Fatty acid ester derivatives butyl oleate, glycerin monooleate, methyl acetylricinoleate, pentaerythritol ester, dipentaerythritol hexaester, triacetin, tributyrin and the like.
(F) Oxyacid ester plasticizers Methyl acetyl ricinoleate, butyl acetyl ricinoleate, butyl phthalyl butyl glycolate, tributyl acetyl citrate and the like.
(G) Epoxy plasticizer Epoxidized soybean oil, epoxidized linseed oil, epoxy butyl stearate, decyl epoxy stearate, octyl epoxy stearate, benzyl epoxy stearate, dioctyl epoxy hexahydrophthalate, didecyl epoxy hexahydrophthalate, etc. .
(H) Dihydric alcohol ester plasticizers such as diethylene glycol dibenzoate and triethylene glycol di-2-ethylbutyrate.
(I) Chlorine-containing plasticizer Chlorinated paraffin, chlorinated diphenyl, chlorinated fatty acid methyl, methoxychlorinated fatty acid methyl and the like.
(J) Polyester plasticizer Polypropylene adipate, polypropylene sebacate, polyester, acetylated polyester and the like.
(K) Sulfonic acid derivative
p-toluenesulfonamide, o-toluenesulfonamide, p-toluenesulfoneethylamide, o-toluenesulfoneethylamide, toluenesulfone-N-ethylamide, p-toluenesulfone-N-cyclohexylamide and the like.
(L) Citric acid derivatives Triethyl citrate, triethyl acetyl citrate, tributyl citrate, tributyl acetyl citrate, tri-2-ethylhexyl acetyl citrate, n-octyl decyl acetyl citrate and the like.
(M) Others Terphenyl, partially hydrogenated terphenyl, camphor, 2-nitrodiphenyl, dinonylnaphthalene, methyl abietate and the like.

Examples of the lubricant that can be added to each layer include, but are not limited to, the following.
(A) Hydrocarbon compound Liquid paraffin, paraffin wax, microwax, low-polymerized polyethylene and the like.
(B) Fatty acid compounds Lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and the like.
(C) Fatty acid amide compounds Stearylamide, palmitylamide, oleinamide, methylenebisstearamide, ethylenebisstearamide and the like.
(D) Lower alcohol esters of ester compound fatty acids, polyhydric alcohol esters of fatty acids, fatty acid polyglycol esters, and the like.
(E) Alcohol compounds Cetyl alcohol, stearyl alcohol, ethylene glycol, polyethylene glycol, polyglycerol and the like.
(F) Metal soap Lead stearate, cadmium stearate, barium stearate, calcium stearate, zinc stearate, magnesium stearate and the like.
(G) Natural wax Carnauba wax, candelilla wax, beeswax, whale wax, ivotaro, montan wax and the like.
(H) Others Silicone compounds, fluorine compounds, etc.

Examples of ultraviolet absorbers that can be added to each layer include, but are not limited to, the following.
(A) Benzophenone series 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ', 4-trihydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4- Such as methoxybenzophenone.
(B) Salsylate type Phenyl salsylate, 2,4 di-t-butylphenyl 3,5-di-t-butyl 4-hydroxybenzoate, and the like.
(C) Benzotriazole series (2′-hydroxyphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy3) '-Tertiarybutyl 5'-methylphenyl) 5-chlorobenzotriazole (d) cyanoacrylate series ethyl-2-cyano-3,3-diphenyl acrylate, methyl 2-carbomethoxy 3 (paramethoxy) acrylate, and the like.
(E) Quencher (metal complex)
Nickel (2,2′thiobis (4-t-octyl) phenolate) normal butylamine, nickel dibutyldithiocarbamate, nickel dibutyldithiocarbamate, cobalt dicyclohexyldithiophosphate and the like.
(F) HALS (hindered amine)
Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6 6-tetramethylpyridine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy- 2,2,6,6-tetramethylpiperidine and the like.

Production Example of Photosensitive Drum 20Y An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition were sequentially applied and dried on a φ30 mm aluminum drum. An undercoat layer of 5 μm, a charge generation layer 135 of 0.2 μm, and a charge transport layer 137 of 28 μm were formed. On top of that, the following inorganic filler coating solution was pulverized (blocked) for 2 hours with a paint shaker using zirconia beads to obtain a coating solution. This liquid was applied by spraying to provide a 1.5 μm filler-reinforced charge transport layer 139 to obtain a photoreceptor drum 20Y.

[Coating liquid for undercoat layer]
Alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals): 6 parts by weight Melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink and Chemicals): 4 parts by weight Titanium oxide (CR-EL Ishihara Sangyo Co., Ltd.): 40 parts by weight Methyl ethyl ketone: 200 parts by weight

[Coating liquid for charge generation layer]
Oxotitanium phthalocyanine pigment: 2 parts by weight Polyvinyl butyral (UCC: XYHL): 0.2 part by weight Tetrahydrofuran: 50 parts by weight

[Coating liquid for charge transport layer]
Polycarbonate resin (Z polycarbonate, viscosity average molecular weight; 50,000, manufactured by Teijin Chemicals Ltd.): 12 parts by weight Low molecular charge transport material having the following structure: 10 parts by weight

Tetrahydrofuran: 100 parts by weight 1% silicone oil (KF50-100CS manufactured by Shin-Etsu Chemical Co., Ltd.) Tetrahydrofuran solution: 1 part by weight

[Filler-reinforced charge transport layer coating solution]
Polycarbonate resin (Z polycarbonate, viscosity average molecular weight: 50,000, manufactured by Teijin Chemicals Ltd.): 4 parts by weight Low molecular charge transport material having the following structure: 3 parts by weight

α-alumina (Sumicorundum AA-03, manufactured by Sumitomo Chemical Co., Ltd.): 0.7 parts by weight Cyclohexanone: 280 parts by weight Tetrahydrofuran: 80 parts by weight

  The developer will be described.

・ Toner Toner, external additives are added to base particles containing a binder resin with a colorant and, if necessary, other materials such as a charge control agent and a release agent. Yes.

  As the binder resin used for the toner, conventionally known resins can be used. For example, polystyrene, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-acrylate copolymer, styrene -Methacrylate copolymer, acrylic resin, polyester resin, epoxy resin, polyol resin, rosin-modified maleic acid resin, phenol resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin, polyurethane resin, ketone resin, ethylene-ethyl An acrylate copolymer, a polybutyral, a silicone resin, etc. are mentioned, These can be used individually or in combination of 2 or more types, Especially a polyester resin and a polyol resin are preferable.

Here, various types of polyester resins can be used,
At least one selected from 1.2-valent carboxylic acids and lower alkyl esters and acid anhydrides thereof;
2. Diol component represented by the following general formula (I)

(In the formula, R1 and R2 may be the same or different and each is an alkylene group having 2 to 4 carbon atoms, and x and y are the number of repeating units, each being 1 or more, and x + y = 2. ~ 16.)
3. A polyester resin obtained by reacting at least one selected from the group consisting of a trivalent or higher polyvalent carboxylic acid and its lower alkyl ester and acid anhydride, and a trivalent or higher polyhydric alcohol. It is preferable.

  Here, 1. Examples of the divalent carboxylic acids and their lower alkyl esters and anhydrides include terephthalic acid, isophthalic acid, sebacic acid, isodecyl succinic acid, maleic acid, fumaric acid and their monomethyl, monoethyl, dimethyl and diethyl esters, And phthalic anhydride, maleic anhydride and the like, and terephthalic acid, isophthalic acid and dimethyl esters thereof are particularly preferred in terms of blocking resistance and cost. These divalent carboxylic acids and their lower alkyl esters and acid anhydrides greatly affect the fixing properties and blocking resistance of the toner. That is, although depending on the degree of condensation, if a large amount of aromatic terephthalic acid, isophthalic acid or the like is used, the blocking resistance is improved, but the fixing property is lowered. Conversely, if a large amount of sebacic acid, isodecyl succinic acid, maleic acid, fumaric acid or the like is used, the fixing property is improved, but the blocking resistance is lowered. Accordingly, these divalent carboxylic acids are appropriately selected according to other monomer composition, ratio and degree of condensation, and used alone or in combination.

  2. Examples of the diol component represented by the general formula (I) include polyoxypropylene- (n) -polyoxyethylene- (n ′)-2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene -(N) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (n) -2,2-bis (4-hydroxyphenyl) propane, etc. Polyoxypropylene- (n) -2,2-bis (4-hydroxyphenyl) propane where n ≦ 2.5 and polyoxyethylene- (n) -2,2 where 2.0 ≦ n ≦ 2.5 -Bis (4-hydroxyphenyl) propane is preferred. Such a diol component has the advantage of improving the glass transition temperature and making it easier to control the reaction.

  In addition, it is also possible to use aliphatic diols such as ethylene glycol, diethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, propylene glycol as the diol component. is there.

  3. Examples of trivalent or higher polyvalent carboxylic acids and lower alkyl esters and acid anhydrides thereof include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,3,5-benzenetricarboxylic acid, 2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthylenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexatricarboxylic acid, 1 , 3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxy) methane, 1,2,7,8-octanetetracarboxylic acid, empole trimer acids and their monomethyl, monoethyl, dimethyl and A diethyl ester etc. are mentioned.

  3. Examples of trihydric or higher polyhydric alcohols include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2 , 4-butanetriol, 1,2,5-pentatriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3 , 5-trihydroxymethylbenzene and the like.

  Here, the blending ratio of the trivalent or higher polyvalent monomer is suitably about 1 to 30 mol% of the whole monomer composition. When it is 1 mol% or less, the offset resistance of the toner is lowered, and the durability is likely to deteriorate. On the other hand, when the amount is 30 mol% or more, toner fixability tends to deteriorate.

  Of these trivalent or higher polyvalent monomers, benzenetricarboxylic acids such as benzenetricarboxylic acid and anhydrides or esters of these acids are particularly preferable. That is, by using benzenetricarboxylic acids, it is possible to achieve both fixability and offset resistance.

  As the polyol resin, various types can be used. An epoxy resin; b. An alkylene oxide adduct of dihydric phenol or a glycidyl ether thereof; c. A compound having one active hydrogen in the molecule that reacts with an epoxy group, d. It is preferable to use a polyol resin obtained by reacting a compound having two or more active hydrogens in the molecule that react with an epoxy group.

  Where: a. The epoxy resin is preferably obtained by binding bisphenol such as bisphenol A or bisphenol F and epichlorohydrin. In particular, the epoxy resin is at least two or more bisphenol A type epoxy resins having different number average molecular weights in order to obtain stable fixing characteristics and gloss, and the number average molecular weight of the low molecular weight component is 360 to 2000, and the high molecular weight component The number average molecular weight is preferably 3000 to 10,000. Further, the low molecular weight component is preferably 20 to 50% by weight, and the high molecular weight component is preferably 5 to 40% by weight. When there are too many low molecular weight components, or when the molecular weight is lower than 360, there is a possibility that the gloss will be too high or the storage stability may be deteriorated. Further, when the amount of the high molecular weight component is too large, or when the molecular weight is higher than 10,000, the gloss may be insufficient or the fixability may be deteriorated.

  B. Examples of the dihydric phenol alkylene oxide adduct as the above compound are as follows. That is, reaction products of ethylene oxide, propylene oxide, butylene oxide and mixtures thereof with bisphenols such as bisphenol A and bisphenol F can be mentioned. The resulting adduct may be used after glycidylation with epichlorohydrin, β-methylepichlorohydrin, or the like. In particular, diglycidyl ether of an alkylene oxide adduct of bisphenol A represented by the following formula (II) is preferable.

(In the formula, R is —CH 2 —CH 2 —, —CH 2 —CH (CH 3) — or —CH 2 —CH 2 —CH 2 —, and n and m are the number of repeating units, each of which is 1 or more, N + m = 2 to 6.)

  Moreover, it is preferable that 10 to 40 weight% of the alkylene oxide adduct of dihydric phenol or its glycidyl ether is contained with respect to polyol resin. If the amount is small, problems such as an increase in curl occur, and if n + m is 7 or more, or if the amount is too large, there is a possibility of excessive glossiness and deterioration of storage stability.

  C. Examples of the compound having one active hydrogen that reacts with the epoxy group in the molecule include monohydric phenols, secondary amines, and carboxylic acids. The following are illustrated as monohydric phenols. That is, phenol, cresol, isopropylphenol, aminophenol, nonylphenol, dodecylphenol, xylenol, p-cumylphenol and the like can be mentioned. Secondary amines include diethylamine, dipropylamine, dibutylamine, N-methyl (ethyl) piperazine, piperidine and the like. Examples of carboxylic acids include propionic acid and caproic acid.

  D. Examples of the compound having two or more active hydrogens that react with the epoxy group in the molecule include dihydric phenols, polyhydric phenols, and polycarboxylic acids. Bivalent phenols include bisphenols such as bisphenol A and bisphenol F. Examples of polyhydric phenols include orthocresol novolaks, phenol novolacs, tris (4-hydroxyphenyl) methane, and 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] benzene. Examples of the polyvalent carboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, terephthalic acid, trimellitic acid, and trimellitic anhydride.

  Further, these polyester resins and polyol resins are preferably non-crosslinked or weakly crosslinked (THF insoluble content is 5% or less) because it is difficult to obtain transparency and gloss when having a high crosslinking density. It is preferable.

  Moreover, the manufacturing method of these binder resin is not specifically limited, Any of block polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc. can be used.

Next, conventionally known dyes and pigments can be used as the colorant used in the toner.
Examples of the yellow colorant include naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow, (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Examples thereof include benzimidazolone yellow and isoindolinone yellow.

  Examples of red colorants include bengara, red lead, lead vermilion, cadmium red, cadmium mercurial red, antimony vermilion, permanent red 4R, para red, fire red, parachloro ortho nitroaniline red, and risol fast scarlet. G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red (F5R, FBB), Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bonmaru Nlite, Bonmaroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Examples include orange and oil orange.

  Examples of blue colorants include cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC), indigo , Ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridiane, emerald green, pigment green B, naphthol green B, Examples include green gold, acid green lake, malachite green lake, phthalocyanine green, and anthraquinone green.

  Examples of black colorants include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and complex metal oxides. .

  Examples of other colorants include titania, zinc white, litbon, nigrosine dye, and iron black.

  These colorants can be used alone or in combination of two or more kinds, and the content is usually 1 to 30 parts by weight, preferably 3 to 20 parts by weight with respect to 100 parts by weight of the binder resin. .

In addition, other materials such as a charge control agent and a release agent can be added to the toner as necessary.
Here, as the charge control agent, conventionally known ones can be used, and examples thereof include nigrosine dyes, chromium-containing complexes, quaternary ammonium salts, and the like, which are properly used depending on the polarity of the toner particles. In particular, in the case of a color toner, a colorless or light-colored toner that does not affect the color tone of the toner is preferable, and examples thereof include a salicylic acid metal salt or a metal salt of a salicylic acid derivative (Bontron E84, manufactured by Orient).

  These charge control agents can be used alone or in combination of two or more kinds, and the content is usually 0.5 to 8 parts by weight, preferably 1 to 5 parts by weight with respect to 100 parts by weight of the binder resin. Part.

Further, in order to improve the releasability of the toner from the fixing member at the time of fixing and to improve the fixability of the toner, it is possible to contain a release agent in the toner.
Here, as the release agent, conventionally known ones can be used. For example, low molecular weight polyethylene wax such as low molecular weight polyethylene and low molecular weight polypropylene, synthetic hydrocarbon wax such as Fischer-Tropsch wax, dense wax, Natural waxes such as carnauba wax, candelilla wax, rice wax and montan wax, petroleum waxes such as paraffin wax and microcrystalline wax, higher fatty acids such as stearic acid, palmitic acid and myristic acid, and metal salts of higher fatty acids, Examples thereof include higher fatty acid amides and various modified waxes thereof.

  These release agents can be used singly or in combination of two or more, but it is possible to obtain good release properties, particularly by using carnauba wax.

  Further, the content of the release agent is usually 1 to 15 parts by weight, preferably 2 to 10 parts by weight with respect to 100 parts by weight of the binder resin. If it is 1 part by weight or less, the effect of preventing offset is insufficient, and if it is 15 parts by weight or more, transferability, durability, etc. are lowered.

The toner may contain a magnetic material and be used as a magnetic toner.
Specific magnetic materials include iron oxides such as magnetite, hematite and ferrite, metals such as cobalt and nickel, or these metals and aluminum, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, Examples thereof include alloys with metals such as calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof.

  These magnetic materials preferably have an average particle size of about 0.1 to 2 μm, and the content is usually 20 to 200 parts by weight, preferably 40 to 150 parts by weight, with respect to 100 parts by weight of the binder resin. .

An example of toner production will be described below.
1. The above-described binder resin, colorant, or, if necessary, a charge control agent, a release agent, a magnetic material, etc. are sufficiently mixed by a mixer such as a Henschel mixer.
2. Batch type twin rolls, Banbury mixer and continuous twin screw extruder, for example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by KCK, Using Ikekai Tekko's PCM type twin screw extruder, Kurimoto Iron Works' KEX type twin screw extruder, and continuous type single screw kneader, for example, heat kneaders such as Bush's co-kneader. Mix thoroughly.
3. After cooling the kneaded product, it is coarsely pulverized using a hammer mill or the like, and further pulverized by a fine pulverizer or mechanical pulverizer using a jet stream, and a classifier using a swirling air stream or a classifier using the Coanda effect To obtain a base particle.

  As other production methods, a polymerization method, a capsule method, or the like can be used. An outline of these production methods is described below.

(Polymerization method)
1. A polymerizable monomer and, if necessary, a polymerization initiator, a colorant and the like are granulated in an aqueous dispersion medium.
2. The granulated monomer composition particles are classified to an appropriate particle size.
3. The monomer composition particles having a prescribed inner particle diameter obtained by the classification are polymerized.
4). Appropriate treatment is performed to remove the dispersant, and then the polymerization product obtained above is filtered, washed with water, and dried to obtain base particles.

(Capsule method)
1. A resin and, if necessary, a colorant are kneaded with a kneader or the like to obtain a molten toner core material.
2. The toner core material is put in water and stirred vigorously to form a fine particle core material.
3. The above-mentioned core material fine particles are put in a shell material solution, and a poor solvent is dropped while stirring and encapsulated by covering the surface of the core material with a shell material.
4). The capsule obtained above is filtered and dried to obtain base particles.
Next, the base particles and additives are sufficiently mixed by a mixer such as a Henschel mixer (made by Mitsui Miike), a mechano-fusion system (made by Hosokawa Micron), a mechano mill (made by Okada Seiko Co., Ltd.), and if necessary, 150 μm. Pass through a sieve with an opening of less than about, and remove aggregates and coarse particles.

  As the additive, conventionally known additives can be used. For example, Si, Ti, Al, Mg, Ca, Sr, Ba, In, Ga, Ni, Mn, W, Fe, Co, Zn, Cr, Mo , Cu, Ag, V, Zr, and the like, and oxides such as Si, Ti, and Al, silica, titania, and alumina are preferably used.

The addition amount of the additive is preferably 0.6 to 4.0 parts by weight, particularly preferably 1.0 to 3.6 parts by weight with respect to 100 parts by weight of the base particles.
If the additive amount is less than 0.6 parts by weight, the fluidity of the toner is lowered, so that sufficient chargeability cannot be obtained, and transferability and heat-resistant storage stability are insufficient. It is easy to cause dirt and toner scattering.
On the other hand, if the amount exceeds 4.0 parts by weight, the fluidity is improved, but the cleaning of the photoconductor such as chatter and blade turning, and the filming on the photoconductor due to the additive released from the toner are likely to occur. And durability of the photosensitive member and the like are lowered, and the fixing property is also deteriorated.

Although there are various methods for measuring the content of the additive, it is generally determined by fluorescent X-ray analysis. That is, it is possible to prepare a calibration curve by fluorescent X-ray analysis for a toner with a known additive content, and to determine the additive content using this calibration curve.
Furthermore, it is preferable that the additive is subjected to a surface treatment for the purpose of hydrophobizing, improving fluidity, controlling chargeability, and the like, if necessary.

  The treating agent used for the surface treatment is preferably an organic silane compound, for example, alkylchlorosilanes such as methyltrichlorosilane, octyltrichlorosilane, and dimethyldichlorosilane, and alkylmethoxysilanes such as dimethyldimethoxysilane and octyltrimethoxysilane. , Hexamethyldisilazane, silicone oil and the like.

  In addition, the treatment method includes a method of immersing an additive in a solution containing an organosilane compound and drying, a method of spraying and drying a solution containing an organosilane compound as an additive, and the like in the present invention. Any method can be suitably used.

Furthermore, the particle diameter of the additive added to the base particles is preferably 0.002 to 0.2 μm in average primary particle diameter, particularly preferably 0.005 to 0 in terms of imparting fluidity. .05 μm.
Additives having an average primary particle size of less than 0.002 μm are likely to be embedded in the surface of the base particles, so that aggregation is likely to occur and sufficient fluidity cannot be obtained. Furthermore, filming on the photoconductor and the like is likely to occur, and these tendencies are particularly remarkable under high temperature and high humidity. In addition, if the average primary particle size is smaller than 0.002 μm, the additives tend to aggregate each other, and this also makes it difficult to obtain sufficient fluidity.
Additives with an average primary particle size greater than 0.2 μm reduce the fluidity of the toner, so that sufficient chargeability cannot be obtained, which tends to cause scumming or toner scattering. Additives having an average primary particle size larger than 0.1 μm are liable to damage the surface of the photoconductor and also cause filming.
The particle size of the additive can be determined by measuring with a transmission electron microscope.

It is also possible to add other additives to the toner in addition to the above-mentioned additives.
Examples of such additives include Teflon (registered trademark), zinc stearate, and polyvinylidene fluoride as a lubricant, and cerium oxide, silicon carbide, strontium titanate, and the like as an abrasive. Zinc oxide, antimony oxide, tin oxide and the like can be mentioned respectively.

The particle diameter of the toner is preferably 4 to 9 μm, particularly preferably 5 to 8 μm, in terms of weight average diameter.
When the particle diameter is smaller than 4 μm, background stains or toner scattering may occur during development, or fluidity may be deteriorated and toner replenishment or cleaning performance may be hindered. Further, when the particle diameter is larger than 8 μm, dust in the image, deterioration of resolution, or the like may be a problem. Particularly, in the case of a color image, the influence is large.

  Such a toner can be applied to both a one-component developer and a two-component developer. In the case of a two-component developer, toner is mixed with a carrier and used.

-Carrier As the carrier, conventionally known ones can be used, and examples thereof include magnetic powders such as iron powder, ferrite powder, nickel powder, and glass beads. It is preferable to coat with etc.

Examples of the resin used include polyfluorinated carbon, polyvinyl chloride, polyvinylidene chloride, phenol resin, polyvinyl acetal, acrylic resin, and silicone resin.
As a method for forming this resin layer, a resin may be applied to the surface of the carrier by means of a spraying method, a dipping method or the like, as in the past.
As a usage-amount of resin, 1-10 weight part is preferable normally with respect to 100 weight part of carriers.
The resin film thickness is preferably 0.02 to 2 [mu] m, particularly preferably 0.05 to 1 [mu] m, more preferably 0.1 to 0.6 [mu] m. However, when the film thickness is thin, it tends to be easily affected by film scraping over time.

The average particle diameter of this carrier is usually 10 to 100 μm, preferably 30 to 60 μm.
The mixing ratio of the toner and the carrier is generally about 0.5 to 7.0 parts by weight with respect to 100 parts by weight of the carrier.

-Examples of Developer Examples of the developer will be specifically described below. The part in an Example represents a weight part.

<Example of toner production>

Binder resin Polyester resin (terephthalic acid, fumaric acid, polyoxypropylene- (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyester resin synthesized from trimellitic acid, Tg: 62 ° C., (Softening point: 106 ° C.): 100 parts

Colorant Yellow pigment (disazo yellow pigment: CI Pigment Yellow 17): 7.0 parts Magenta toner pigment (quinacridone magenta pigment: CI Pigment Red 122): 7.0 parts For cyan toner Pigment (copper phthalocyanine blue pigment: CI Pigment Blue 15: 3): 3.5 parts Black toner pigment (carbon black: CI Pigment Black 7): 6.0 parts

Charge control agent Salicylic acid derivative zinc salt: 2.5 parts Release agent: Carnauba wax (melting point: 85 ° C.): 5 parts

  The raw materials were mixed with a Henschel mixer and then melt-kneaded with a biaxial kneader set at 110 ° C. The kneaded product was cooled with water, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and mother particles were obtained using an air classifier.

Further, the above base particles: 100 parts Additive silica (hexamethyldisilazane surface-treated product, average primary particle size: 0.01 μm): 0.8 parts titania (isobutyltrimethoxysilane surface-treated product, average primary particle size: 0) .015 μm): 1.0 part was mixed with a Henschel mixer, and then air-screened with a sieve having an opening of 100 μm to obtain a toner (weight average diameter: 6.8 μm) of Production Example.

  The particle size distribution of the toner can be measured by various methods. In this example, the particle size distribution was performed using a Coulter Multisizer. That is, Coulter Multisizer IIe type (manufactured by Coulter Inc.) is used as a measuring device, and an interface (manufactured by Nikkiki Co., Ltd.) for outputting the number distribution and volume distribution is connected to a personal computer. A 1% NaCl aqueous solution was prepared.

  As a measurement method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. A dispersion treatment of ˜3 minutes was performed. Further, 100 to 200 ml of the electrolytic aqueous solution was put into another beaker, and the sample dispersion was added to a predetermined concentration, and 50,000 pieces were used as the aperture by the Coulter Multisizer IIe type. This was done by measuring the average of the particles.

<Example of carrier production>

Core material Cu—Zn ferrite particles (weight average diameter: 45 μm): 5000 parts

Coating material Toluene: 450 parts Silicone resin SR2400 (made by Toray Dow Corning Silicone, nonvolatile content 50%): 450 parts Aminosilane SH6020 (made by Toray Dow Corning Silicone): 10 parts Carbon black: 10 parts

  The coating material is dispersed with a stirrer for 10 minutes to prepare a coating solution, and the coating solution and the core material are coated in a fluidized bed while forming a swirling flow with a rotating bottom plate disk and stirring blades. The coating solution was applied on the core material.

  The obtained carrier was baked in an electric furnace at 250 ° C. for 2 hours to obtain a carrier (film thickness: 0.5 μm) of a production example.

<Examples of developer production>
5 parts of the toner of the above production example and 95 parts of the carrier of the above production example were mixed with a tumbler mixer to obtain a developer.

  In the image station 60Y configured as described above, the surface of the photosensitive drum 20Y is uniformly charged by the charging device 30Y along with the rotation in the B1 direction during image formation. By the exposure scanning of the modulated and deflected laser beam L, the potential of the photosensitive drum 20Y in the exposure portion, that is, the irradiation portion is attenuated to form an electrostatic latent image corresponding to yellow, and this electrostatic latent image is developed. The yellow toner image developed by the apparatus 80Y is developed with the yellow toner, and the yellow toner image obtained by the development is primary transferred to the transfer belt 11 that moves in the A1 direction by the primary transfer electric field and nip pressure formed by the primary transfer roller 12Y. Unnecessary materials including toner remaining after the transfer are removed by the cleaning device 70Y, and the neutralizing device 90Y and the charging device 30Y are used. Neutralization of is subjected to charging.

At this time, the protective film forming apparatus 40Y scrapes the lubricant 42Y into powder by the brush fibers 89Y by the rotation of the brush roller 47Y, moves the shaved lubricant 42Y to the photosensitive drum 20Y, and transfers it to the photosensitive drum 20Y. The coated lubricant 42Y is extended onto the photosensitive drum 20Y by the cleaning blade 78Y, whereby a film is formed on the surface of the photosensitive drum 20Y by the protective agent 42Y, and the proximity discharge and the photosensitive drum 20Y and the cleaning blade 78Y are mutually connected. Deterioration of the surface of the photoconductor drum 20Y caused by friction is prevented, and as a result, transfer performance is maintained over time, and toner filming is suppressed or prevented, thereby forming a good image. Is planned.
In this way, in the protective film forming apparatus 40Y, the lubricant 42Y is scraped and consumed by the brush fibers 89Y by the rotation of the brush roller 47Y.

  However, in this process, unevenness may occur on the surface of the lubricant 42Y as shown in FIG. In this case, as shown in FIG. 6, the brush fiber 89Y enters the recess on the surface of the lubricant 42Y by the contact pressure against the lubricant 42Y, and the tip of the brush fiber 89Y scrapes the lubricant 42Y at the bottom of the recess. Thus, the depth of the concave portion can be further increased, and the height difference of the unevenness can be increased. When the height difference increases, the convex portion becomes so brittle that it can be broken even with a light impact. When the convex portion is broken, the lubricant 42Y adheres to the brush roller 47Y in a lump state rather than in powder form, and the photosensitive drum 20Y. However, there is a possibility that the lubricant 42Y cannot sufficiently perform the above-described function in a lump state. In the worst case, the lump-like lubricant 42Y may be sandwiched between the cleaning blade 78Y and the photosensitive drum 20Y, which may cause toner to slip through and reduce image quality.

  In order to suppress or prevent such problems, it is preferable to suppress or prevent such an increase in height difference. However, the shape of the brush fiber 89Y is, as shown in FIG. 6 (b), a cylindrical shape, substantially uniform in the cross section perpendicular to the longitudinal direction, and the cross-sectional shape is round. Since the scraping of the agent 42Y is performed at the tip thereof, the lubricant 42Y can be mainly scraped at the bottom of the concave portion on the surface of the lubricant 42Y as shown by the alternate long and short dash line in FIG. Therefore, it is difficult to expect to suppress or prevent such an increase in height difference. Although not shown, when the shape of the brush fiber 89Y is substantially uniform in the cross section perpendicular to the longitudinal direction, and the cross-sectional shape is irregular, the expansion of the height difference is promoted. It might be. When the brush fiber 89Y has such a shape, the contact pressure against the lubricant 42Y is concentrated on the convex portion on the side surface of the brush fiber 89Y, and this convex portion is the concave portion of the lubricant 42Y. This is because it mainly acts to cut the bottom portion, so that the scraping of the bottom portion of the concave portion of the lubricant 42Y by the tip portion of the brush fiber 89Y is promoted.

  Under such circumstances, the inventors have intensively studied, and as shown in FIG. 6 (a), the shape of the brush fiber 89Y is different from the conventional one, thereby preventing such inconvenience. It was found to be suppressed. Specifically, the shape of the brush fiber 89Y shown in FIG. 6A is formed on the side surface thereof from the fiber direction which is the longitudinal direction thereof, in other words, from the base end on the shaft member 47aY side to the lubricant 42Y opposite to this. Concavities and convexities for scraping off the lubricant 42Y are provided along the direction toward the tip, which is the abutting side. Such irregularities can have various shapes, such that the brush fiber 89Y has a crimped shape, the brush fiber 89Y has a spiral shape, and a spiral on the side of the brush fiber 89Y. In which a plurality of ring-shaped grooves independent in the longitudinal direction are formed on the side surface of the brush fiber 89Y.

  The shape of the brush fiber 89Y is thus provided with roughness on the side surface in the longitudinal direction of the brush fiber 89Y, so that the brush fiber 89Y has the surface of the lubricant 42Y as shown by a one-dot chain line in FIG. In addition to cutting the bottom part of the concave part, the side part of the concave part and even the projecting part are also cut, so that the level difference of the unevenness on the surface of the lubricant 42Y is suppressed or eliminated, or such unevenness is originally Can be less likely to occur.

  Also in the brush fiber 89Y having such a shape, the side surface of the brush fiber 89Y is pressed against the surface of the lubricant 42Y by the waist of the brush fiber 89Y, in other words, the force by which the tip of the brush fiber 89Y is pressed against the surface of the lubricant 42Y. This tip is considered to be smaller than the applied force, but the tip cuts the lubricant 42Y almost at one point, whereas the side faces linearly contact the lubricant 42Y due to the elastic deformation of the brush fiber 89Y. Therefore, by adjusting the shape of the brush fiber 89Y and other elasticity, the side surface can have the scraping ability of the lubricant 42Y equivalent to the tip of the lubricant 42Y. The shape and other elasticity of the brush fiber 89Y are adjusted so as to have such ability. Therefore, the above-mentioned function by the brush fiber 89Y is exhibited well.

  Here, the evaluation result about the surface roughness Rz of the brush fiber 89Y is shown in Table 1. The surface roughness Rz is the ten-point average roughness of the side surface of the brush fiber 89Y measured in parallel with the longitudinal direction of the brush fiber 89Y, and indicates the state of the unevenness on the side surface. The thickness was 500 μm.

  In the table, “the depth of the unevenness” means whether the unevenness of the lubricant 42Y becomes large, and “large lubrication particle size” means whether the particle size of the scraped lubricant 42Y is large. Means. The evaluation was made with “good”, “good”, “good”, and “poor” for both “the depth of the unevenness” and “the large lubricating particle diameter”. From the table, it was found that the surface roughness Rz is preferably 20 μm ≦ Rz ≦ 100 μm. This value also satisfies the condition that the side surface of the brush fiber 89Y has the scraping ability of the lubricant 42Y equivalent to the tip of the brush fiber 89Y.

  In the image forming apparatus 100 having such a configuration, when copying is performed, a document is set on the document table 22a of the automatic document feeder 22 or the automatic document feeder 22 is rotated upward to be on the contact glass 21a. After the document is placed on the automatic document feeder 22, the automatic document feeder 22 is rotated downward to close the document and press the document, and then the start button on the operation panel is pressed. The document set on the automatic document feeder 22 is, for example, a bundle-shaped sheet document, and the document set on the contact glass 21a is, for example, a single-bound document that is bound in a main shape. When the image forming apparatus 100 is used as a printer, an image forming start operation is performed after image data to be formed is selected and input by an external input device such as a PC connected to the image forming apparatus 100.

  When copying is performed and the document is set on the document table 22a, the document is read by the reading device 21 after the set document is sent onto the contact glass 21a. When the document is placed on 21a, the reading device 21 reads the document when the start button is pressed, and image data is generated.

  Based on the generated image data or the input image data, the image stations 60Y, 60M, 60C, and 60BK having the above-described configuration operate. In parallel with the document reading operation, the devices in the image stations 60Y, 60M, 60C, and 60BK, which are the process cartridges, the transfer belt unit 10, the secondary transfer unit 76, the fixing device 6 and the like are driven. Start.

  In the image station 60Y, as described above, the surface of the photosensitive drum 20Y is uniformly charged by the charging device 30Y along with the rotation in the B1 direction, and an electrostatic latent image is formed by the optical scanning device 8, The electrostatic latent image is developed with yellow toner by the developing device 80Y, the yellow toner image is primarily transferred to the transfer belt 11 by the primary transfer roller 12Y, and unnecessary materials including toner remaining after the transfer are cleaned. It is removed by the device 70Y and used for the next charge removal and charging by the charge removal device 90Y and the charging device 30Y. At this time, the lubricant 42Y is applied to the photosensitive drum 20Y with a suitable particle diameter while suppressing or preventing the unevenness of the surface thereof, and the state of the photosensitive drum 20Y is kept good. A toner image is satisfactorily formed.

  In the other photoconductor drums 20C, 20M, and 20BK, the toner images of the respective colors are similarly formed while maintaining the good state. The formed toner images of the respective colors are the primary transfer rollers 12C, 12M, By 12BK, primary transfer is sequentially performed at the same position on the transfer belt 11 moving in the A1 direction. A four-color superimposed toner image constituted by toner images superimposed on the transfer belt 11, that is, a four-color toner image, is a position facing the secondary transfer roller 5 as the transfer belt 11 rotates in the A1 direction. It moves to the next transfer nip, is secondarily transferred to the transfer paper, and a full color image is carried on the transfer paper.

  As for the transfer paper conveyed between the transfer belt 11 and the secondary transfer roller 5, one feed roller 24 of the sheet feeding device 23 is selected by pressing the start button, and the corresponding paper feed cassette is rotated by this rotation. 25, fed from the manual feed tray 33 by the rotation of the feed roller 35 of the manual paper feed device 33, or fed from the duplex unit 96. The toner image on the transfer belt 11 is transferred to the secondary transfer belt by the registration roller pair 13 based on the detection signal from the sensor. 5 is sent out at a timing facing 5. Such a feed operation is started substantially simultaneously with the document reading operation described above.

  When the toner image of all colors is transferred and carried on the transfer paper, it enters the fixing device 6 and passes through the fixing portion between the fixing belt 64 and the pressure roller 63 due to the action of heat and pressure. The carried toner image is fixed, and a good color image is formed on the transfer paper. The fixed transfer paper that has passed through the fixing device 6 is stacked on the paper discharge tray 75 via the paper discharge roller 98 or on the duplex unit 96 via the conveyance roller 97 according to the position of the switching claw 94. Enter to prepare for double-sided image formation. On the other hand, the transfer belt 11 that has finished the secondary transfer is cleaned by removing residual toner and the like remaining on the intermediate transfer belt cleaning device 14 to prepare for the next image formation.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and the present invention described in the claims is not specifically limited by the above description. Various modifications and changes are possible within the scope of the above.

  For example, even if the image forming apparatus is a tandem type, the direct transfer system can be adopted as shown in FIG. 11 instead of the indirect transfer system described above. FIG. 11 shows a part of an image forming apparatus of a tandem type direct transfer system, and the same reference numerals are given to the same configurations as those in the above embodiment. This image forming apparatus has a sheet conveying belt 11 ′, which is a recording medium conveying member as an image carrier, instead of the above-described transfer belt 11, and the transfer paper in the process of being conveyed by the sheet conveying belt 11 ′. In addition, the toner images of the respective colors formed by the image stations 60BK, 60C, 60M, and 60Y are sequentially superimposed and transferred.

  Comparing the direct transfer method and the indirect transfer method, the former arranges a paper feeding device (not shown) on the upstream side of the image stations 60BK, 60C, 60M, and 60Y and a fixing device 6 on the downstream side in the transfer paper conveyance direction. In contrast, the latter tends to increase in size in the conveying direction, whereas the latter can set the secondary transfer position relatively freely. Therefore, the sheet feeding device and the fixing device 6 are connected to the image station 60BK, It is possible to overlap with 60C, 60M, and 60Y, and there is an advantage that downsizing is possible. In the former case, the fixing device 6 is disposed close to the sheet conveyance belt 11 ′ in order to suppress an increase in size in the transfer sheet conveyance direction. For this reason, it is difficult to arrange the fixing device 6 with a sufficient margin for the transfer paper to bend, the impact when the leading edge of the transfer paper enters the fixing device 6 (particularly noticeable with thick transfer paper), and the fixing device 6. The fixing device 6 tends to affect upstream image formation due to the speed difference between the transfer speed of the transfer paper when passing through and the transfer speed of the transfer paper by the sheet transport belt 11 ′, whereas the latter The fixing device 6 can be disposed with a sufficient margin for the transfer paper to bend, and the fixing device 6 can hardly affect the image formation. In these respects, in recent years, the indirect transfer method has attracted attention in the tandem type.

  The image forming apparatus is not a so-called tandem type image forming apparatus, but a so-called one-drum type image forming apparatus that sequentially forms toner images of respective colors on a single photosensitive drum and sequentially superimposes the color toner images to obtain a color image. The present invention can be similarly applied to an image forming apparatus.

  Comparing the one-drum type and the tandem type, the former has one photosensitive drum, so that it can be made relatively small and can be reduced in cost. Since full-color images are formed by repeating image formation multiple times (usually 4 times), it is difficult to increase the image formation speed. On the other hand, the latter can be increased in size and cost, but the image formation speed is high. There is an advantage that it is easy to make. In recent years, the tandem type has been attracting attention because the demand for full-color monochrome speeds is desired.

In addition, in recent years, in accordance with demands from the market, color image forming apparatuses, such as color copiers and color printers, have increased in number, but image forming apparatuses can only form monocolor images. It may be.
The developer used in such an image forming apparatus is not limited to a two-component developer but may be a one-component developer.

  The lubricant application apparatus including the brush roller for applying lubricant to which the present invention is applied is not only provided for the photosensitive member, but also an intermediate transfer body such as the transfer belt 11 and a recording medium transport body such as the sheet transport belt 11 ′. May be provided.

  The image forming apparatus may not be a copier, a printer, and a facsimile machine, but may be a single unit thereof, or may be a multi-function machine of another combination such as a copier and printer. .

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

DESCRIPTION OF SYMBOLS 11 Intermediate transfer body 11 'Recording medium conveyance body 20Y, 20M, 20C, 20BK Photosensitive body 20Y, 20M, 20C, 20BK, 11, 11' Image carrier 40Y Lubricant coating apparatus 42Y Lubricant 47Y Lubricant application brush roller 89Y Brush fiber 100 Image forming apparatus x1 Amount of biting into the image carrier of the brush roller for applying lubricant x2 Amount of biting into the lubricant of the brush roller for applying lubricant

JP 2008-096948 A JP 2007-292866 A Japanese Patent Laid-Open No. 2007-079468 JP 2003-057996 A Japanese Patent Laid-Open No. 2007-079247

Claims (7)

A lubricant application brush roller comprising brush fibers for scraping off the lubricant and applying the scraped lubricant to the image carrier,
The brush fiber is a brush roller for lubricant application having unevenness on its side surface along the longitudinal direction for scraping off the lubricant. The lubricant application brush roller according to claim 1,
The brush fiber for applying a lubricant, wherein the side surface of the brush fiber has a scraping ability of a lubricant equivalent to the tip of the brush fiber. The brush roller for lubricant application according to claim 1 or 2,
The brush fiber for lubricant application, wherein the brush fiber has a portion on the side surface where a surface roughness Rz measured in parallel with the longitudinal direction is 20 μm ≦ Rz ≦ 100 μm. The lubricant application brush roller according to any one of claims 1 to 3,
A brush roller for applying lubricant, wherein the amount of biting into the image carrier is larger than the amount of biting into the lubricant.   A lubricant application device comprising the lubricant application brush roller according to any one of claims 1 to 4.   An image forming apparatus comprising: the lubricant application device according to claim 5; and an image carrier on which the lubricant is applied by the lubricant application device. The image forming apparatus according to claim 6.
An image forming apparatus, wherein the image carrier is a photosensitive member and / or an intermediate transfer member and / or a recording medium conveying member.

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