JP2009001649A - Molded lubricant, lubricant applicator, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a molded lubricant stably supplying a lubricant onto an image carrier over a long period of time. <P>SOLUTION: In the molded lubricant 6b containing the lubricant 31 to be applied on the surface of the image carrier carrying a latent image in a fine powder state as a principal component, gallium 31 is incorporated. The lubricant 31 is composed of preferably one kind of lubricating substance selected from melamine cyanurate, polytetrafluoroethylene and boron nitride or one kind of wax selected from paraffin and polyethylene. The molded lubricant is preferably molded by compression in a rod shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lubricant molding to be applied to the surface of an electrophotographic image carrier, a lubricant coating device for applying the lubricant molding to the surface of an electrophotographic image carrier, and a lubricant coating device thereof. The present invention relates to a process cartridge provided and an image forming apparatus provided with the lubricant application device.

  An image forming apparatus using an electrophotographic system includes an image carrier, and charges the surface of the image carrier by applying a charge, and then exposes the surface of the charged image carrier to expose an electrostatic latent image. The toner is supplied to the electrostatic latent image formed on the surface of the image carrier to form a visible image, and the visible image formed on the surface of the image carrier is transferred to the surface of the transfer paper. Then, the visible image transferred on the surface of the transfer paper is fixed and discharged. In such an image forming apparatus, deposits containing untransferred toner or the like remain on the surface of the image carrier after the transfer of the visible image. In order not to adversely affect the formation, it is cleaned by a cleaning device and prepared for the next image forming process. As such a cleaning device, a cleaning brush formed of an elastic material such as rubber or a fiber made of synthetic resin is rubbed against the surface of the image carrier to remove deposits such as untransferred toner. It is generally known to remove. In particular, cleaning devices using cleaning blades are widely used in terms of stability of cleaning performance and cost.

  However, these cleaning blades have a problem that the cleaning performance is deteriorated because they are worn over time to cause chipping or deformation when sliding with the image carrier continues. Further, since the surface of the image carrier is also worn, there is a problem that the life of the image carrier is shortened.

  In recent years, in the field of image forming apparatuses, there has been a growing demand for higher image quality. In particular, in order to realize the formation of a high-definition color image, the toner has been reduced in particle size and spheroidized. When the toner particle size is reduced, the dot reproducibility is improved, and when the toner is made spherical, the developability and transferability can be improved. However, due to the reduction in the particle size and spheroidization of the toner, toner cleaning properties are becoming more difficult. Further, since the surface of the image carrier is worn by the rubbing between the cleaning member (cleaning blade) and the image carrier, the life of the image carrier is shortened. Therefore, by applying a lubricant to the surface of the image carrier and reducing the frictional resistance acting between the image carrier and the cleaning member, problems due to wear between the cleaning member and the image carrier are eliminated. Yes. Further, when a lubricant is applied to the surface of the image carrier, the coefficient of friction of the surface of the image carrier is reduced. Therefore, additives such as a fluidity imparting agent and a charge control agent added externally to the toner can It is possible to prevent the problem of fixing to the surface of the image carrier with the contact pressure (so-called filming problem). Furthermore, since the adhesion force of the toner on the surface of the image carrier is reduced, the transferability of the toner image formed on the image carrier is improved.

  As means for applying the lubricant to the surface of the image carrier, for example, there are the following apparatuses. That is, a solid lubricant obtained by molding a lubricant such as a fatty acid metal salt into a rod shape is installed, and a brush roller (lubricant supply member) is provided so as to contact both the solid lubricant and the image carrier. According to this application means, when the brush roller is driven to rotate, the solid lubricant is scraped by the friction of the brush roller to become powder and adheres to the fibers of the brush roller, and the powder adhered to the brush roller. A lubricant is applied to the surface of the image carrier.

  If the amount of the lubricant applied to the surface of the image carrier is too small, there will be a portion where the lubricant is sufficiently applied and a portion where the lubricant is not applied, resulting in uneven application or sufficient application of the lubricant. Inadequate cleaning or uneven wear of the image carrier may occur in the unexposed area. In addition, there is a problem that the above-mentioned filming occurs on the image carrier and the toner is not developed in that portion. On the other hand, if the amount of lubricant applied is too large, the surface of the charging roller adjacent to the surface of the image carrier may be contaminated, or unevenness in the amount of coating on the image carrier may be noticeable. The image is uneven. Further, when the lubricant absorbs moisture in a high-temperature and high-humidity environment, an electrostatic latent image formed on the surface of the image carrier flows and causes image blurring. Therefore, it is important to apply an appropriate amount of lubricant to the surface of the image carrier.

  As a material for the lubricant, a fatty acid metal salt, particularly zinc stearate, is generally known. When an appropriate amount of this zinc stearate is applied as described above, deterioration of the image carrier due to AC charging hazard can be prevented, and wear of the image carrier due to friction with the cleaning blade can be reduced. For this reason, the life of the image carrier can be improved, but on the other hand, the wear of the cleaning blade is accelerated and contamination due to zinc stearate adhering to the charging roller causes the image to run before the life of the image carrier. The above problems often occur.

In order to solve the problems peculiar to fatty acid metal salts, materials such as polytetrafluoroethylene and wax generally contained in toners have been proposed as materials that can be used as lubricants (Patent Document 1). , 2). However, the lubricating substance and wax typified by polytetrafluoroethylene are expected to have an effect of suppressing the abrasion of the cleaning blade and the contamination of the charging roller, but when applied as a molded body molded by the molding means, There is a problem that the coating amount on the surface of the image carrier is not stable. Specifically, the amount of lubricant supplied onto the image carrier by a lubricant supply means such as a brush roller is used. Each time it drops, there was a problem that the supply was eventually stopped.
JP-A-4-264482 Japanese Patent No. 35495942

  The present invention aims to solve this problem.

  That is, the first object of the present invention is to provide a lubricant molded article that stably supplies a lubricant on an image carrier over a long period of time at a low cost. A second object of the present invention is to provide, at low cost, a lubricant application device that is applied to the surface, a process cartridge that includes the lubricant application device, and an image forming apparatus that includes the lubricant application device.

  In order to achieve the above object, the invention described in claim 1 is a lubricant molded product containing, as a main component, a lubricant that is applied in the form of fine powder on the surface of an image carrier that carries a latent image. A lubricant molded product containing gallium.

  The invention described in claim 2 is the invention described in claim 1, wherein the lubricant is one type of lubricating substance selected from melamine cyanurate, polytetrafluoroethylene, and boron nitride, or paraffin. And one kind of wax selected from polyethylene.

  The invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the lubricant molded product is compression-molded into a rod shape.

  According to a fourth aspect of the present invention, the fine powder formed by scraping the lubricant molded product in contact with the tip of the lubricant molded product and the image bearing member while rotating is formed on the image bearing member. In the lubricant application device having at least a brush roller supplied to the surface, the lubricant molded product has the lubricant molded product according to any one of claims 1 to 3. This is a lubricant application device.

  The invention described in claim 5 includes at least an image carrier, a lubricant application device that applies a lubricant to the surface of the image carrier, and a cleaning unit that cleans the surface of the image carrier. 5. A process cartridge that is integrally supported and is detachably fixed to an image forming apparatus, wherein the lubricant application device includes the lubricant application device according to claim 4. .

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the lubricant application device is disposed upstream of the cleaning unit with respect to the moving direction of the image carrier. It is a feature.

  The invention described in claim 7 is the invention described in claim 5 or 6, wherein the cleaning means is a cleaning blade formed of an elastic member.

  The invention described in claim 8 is characterized in that, in the invention described in claim 7, the cleaning blade is supported in a counter direction with respect to a moving direction of the image carrier. .

  The invention described in claim 9 is the invention described in any one of claims 5 to 8, wherein the process cartridge includes a charging device that uniformly charges the surface of the image carrier. It is characterized by.

  The invention described in claim 10 forms an electrostatic latent image by exposing an image carrier that carries a latent image, a charging device that uniformly charges the image carrier, and a surface of the image carrier. An exposure device, a developing device that develops the electrostatic latent image with a developer containing toner to form a visible image, a transfer device that transfers the visible image to a recording medium, and a lubricant for the image carrier 5. The lubricant application device according to claim 4, wherein the lubricant application device includes at least a lubricant application device that applies a toner and a cleaning unit that removes toner remaining on the surface of the image carrier. An image forming apparatus having the apparatus.

  The invention described in claim 11 is the invention described in claim 10, wherein the lubricant application device is located downstream of the transfer device in the moving direction of the image carrier, and It is arranged at a position upstream of the charging device in the moving direction of the image carrier.

  The invention described in claim 12 is characterized in that, in the invention described in claim 10, the cleaning means used in the cleaning device is a cleaning blade formed of an elastic member.

  The invention described in claim 13 is the invention described in claim 12, wherein the cleaning blade is supported in a counter direction with respect to a rotation direction of the image carrier. .

  According to a fourteenth aspect of the present invention, there is provided an image forming apparatus comprising the process cartridge according to any one of the fifth to ninth aspects.

  According to the first aspect of the present invention, in the lubricant molded product containing, as a main component, the lubricant applied in the form of fine powder on the surface of the image carrier that carries the latent image, gallium is contained. Therefore, when the surface temperature of the lubricant molding reaches the vicinity of the melting point (29.8 ° C.) of gallium, the gallium inside or on the surface of the lubricant molding gradually melts. It is possible to provide a lubricant molded article that stably supplies the lubricant onto the image bearing member over a long period of time at a low cost. it can.

  According to the invention described in claim 2, the lubricant is one kind selected from melamine cyanurate, polytetrafluoroethylene and boron nitride, or one kind selected from paraffin and polyethylene. Therefore, it is possible to suppress the abrasion of the cleaning blade that contacts the image carrier and the adhesion to the charging roller. For this reason, the inclusion of gallium increases the strength of the lubricant molding during molding. It is possible to provide a lubricant molded product having a formulation in which the shaving property of the lubricant molded product is improved while being maintained, so that the lubricant can be stably supplied onto the image carrier for a longer period of time.

  According to the invention described in claim 3, since the lubricant molded product is compression-molded into a rod shape, it melts into a small gap generated between the lubricants constituting the lubricant molded product. Gallium penetrates, and therefore, the shaving property of the lubricant molded product can be improved efficiently. In addition, since the lubricant molded product is compression-molded into a rod shape, the installation space for the lubricant molded product can be reduced, and therefore, the operation of incorporating the lubricant molded product into the apparatus is facilitated.

  According to the fourth aspect of the present invention, the fine powder formed by scraping the lubricant molded product in contact with the tip of the lubricant molded product and the image carrier while rotating is obtained. In the lubricant application device having at least a brush roller supplied to the surface of the body, the lubricant molded product according to any one of claims 1 to 3 is included as the lubricant molded product. Further, it is possible to provide a lubricant application device that stably and uniformly applies fine powder of lubricant to the surface of an image carrier over a long period of time.

  According to the invention described in claim 5, at least an image carrier, a lubricant application device for applying a lubricant to the surface of the image carrier, and a cleaning means for cleaning the surface of the image carrier. A process cartridge that is integrally supported and is detachably fixed to the image forming apparatus includes the lubricant application device according to claim 4 as the lubricant application device. The lubricity between the surface of the carrier and the member in contact with the image carrier can be improved over a long period of time, and therefore a process cartridge that can form a high-quality image for a long period of time can be provided.

  According to the sixth aspect of the present invention, since the lubricant application device is disposed upstream of the cleaning unit with respect to the moving direction of the image carrier, Therefore, it is possible to provide a process cartridge in which fine powder of a lubricant is stably and uniformly applied to the surface of an image carrier for a longer period of time.

  According to the seventh aspect of the present invention, since the cleaning device is made of an elastic member and has a cleaning blade, the fine powder of the lubricant supplied to the surface of the image carrier is easily applied uniformly. In addition, a process cartridge that can minimize the cost of the cleaning member can be provided.

  According to the invention described in claim 8, since the cleaning blade is supported in the counter direction with respect to the moving direction of the image carrier, untransferred toner even when a small particle size and spherical toner is used. It is possible to provide a process cartridge with improved cleaning performance.

  According to the invention described in claim 9, in the invention described in any one of claims 5-8, the process cartridge includes a charging device that uniformly charges the surface of the image carrier. Therefore, the image forming apparatus can be simplified and downsized.

  According to the invention described in claim 10, an image carrier that carries a latent image, a charging device that uniformly charges the image carrier, and a surface of the image carrier that is exposed to form an electrostatic latent image. An exposure device for forming, a developing device for developing the electrostatic latent image with a developer containing toner to form a visible image, a transfer device for transferring the visible image to a recording medium, and the image carrier. 5. The lubrication device according to claim 4, wherein the lubricant application device includes at least a lubricant application device that applies a lubricant and a cleaning unit that removes toner remaining on the surface of the image carrier. Since the lubricant application device is provided, the lubricant can improve the lubricity between the surface of the image carrier and the member in contact with the image carrier over a long period of time, and therefore, a high quality image can be lengthened. To provide an image forming apparatus capable of forming a period Kill.

  According to an eleventh aspect of the present invention, the lubricant application device is located at a position downstream of the transfer device in the moving direction of the image carrier and the image carrier is more than the charging device. Therefore, the lubricant can be applied without being influenced by other processes. For this reason, the fine powder of the lubricant is applied to the surface of the image carrier for a longer period of time. Therefore, it is possible to provide an image forming apparatus that can form a high-quality image for a longer period of time.

  According to the invention described in claim 12, since the cleaning means used in the cleaning device is a cleaning blade formed of an elastic member, the fine powder of the lubricant supplied to the surface of the image carrier is uniform. Thus, it is possible to provide an image forming apparatus that can be easily applied to the film and that can minimize the cost of the cleaning member.

  According to the invention described in claim 13, since the cleaning blade is supported in the counter direction with respect to the moving direction of the image carrier, untransferred toner even when a small particle size and spherical toner is used. It is possible to provide an image forming apparatus with improved cleaning performance.

  According to the invention described in claim 14, since the process cartridge according to any one of claims 5 to 9 is provided, parts maintenance and replacement work and the like are facilitated. An image forming apparatus with a minimum cost can be provided.

  FIG. 1 is a schematic cross-sectional explanatory view of a lubricant molded product showing an embodiment of the present invention. FIG. 2 is a schematic explanatory view showing a method for producing a lubricant molded product according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional explanatory view of a lubricant molded product showing another embodiment of the present invention. FIG. 4 is a schematic explanatory view of an image forming apparatus showing an embodiment of the present invention. FIG. 5 is an explanatory diagram for explaining a counter method which is a contact condition of the cleaning blade. FIG. 6 is an explanatory diagram for explaining a trailing method that is a contact condition of the cleaning blade.

  Since gallium is a metal having a melting point of 29.96 ° C., it changes from a normal temperature state to a liquid state by slightly applying heat. The lubricant molded product 6b of the present invention is created by making use of the physical characteristics of such gallium. That is, as shown in FIGS. 1, 3, and 4, a lubricant molded product 6b containing, as a main component, lubricants 31 and 41 applied in the form of fine powder on the surface of the image carrier 1 carrying a latent image. Contains gallium 32 and 42. The gallium 32 and 42 is contained, for example, in the lubricant molded product 6b or in the surface portion.

  As described above, the lubricant molded product 6b containing the lubricants 31 and 41 applied as fine powders on the surface of the image carrier 1 carrying the latent image as a main component contains gallium 32 and 42. When the surface temperature of the lubricant molded product 6b reaches around the melting point (29.8 ° C.) of the gallium 32, 42, for example, the gallium 32, 42 inside or on the surface of the lubricant molded product 6b gradually melts. For this reason, the bonding force between the lubricants 31 and 41 is weakened, and the shaving property of the lubricant molded product 6b is improved. Therefore, the lubricants 31 and 41 are long on the image carrier 1. The lubricant molded product 6b that is stably supplied over a period can be provided at a low cost.

  In the present invention, the content of the gallium 32, 42 in the lubricant molded product 6b is preferably 0.1 to 20% by weight with respect to the lubricant 31, 41 in the lubricant molded product 6b. More preferably, it is 0.5 to 10% by weight. Thus, when the content of the gallium 32 and 42 in the lubricant molded product 6b is 0.1 to 20% by weight with respect to the lubricant 31 and 41 in the lubricant molded product 6b, image evaluation is performed. Even when the temperature in the apparatus rises abnormally, it can have the necessary strength. Further, when the content of the gallium 32, 42 in the lubricant molded product 6b is 0.5 to 10% by weight with respect to the lubricant 31, 41 in the lubricant molded product 6b, the material cost is suppressed. The best prescription.

  The lubricants 31 and 41 are preferably composed of one type of lubricating substance selected from melamine cyanurate, polytetrafluoroethylene, and boron nitride, or one type of wax selected from paraffin and polyethylene. ing. As described above, the lubricants 31 and 41 are composed of one type of lubricating material selected from melamine cyanurate, polytetrafluoroethylene, and boron nitride, or one type of wax selected from paraffin and polyethylene. Therefore, the progress of wear of the cleaning blade 7a contacting the image carrier 1 and the adhesion to the charging roller 2a can be suppressed. For this reason, the inclusion of the gallium 32, 42 makes it possible to prevent the lubricant molded product 6b from being molded. Provided is a lubricant molded product 6b having a formulation that improves the shaving property of the lubricant molded product 6b while maintaining the strength, and thus can supply the lubricants 31 and 41 onto the image carrier 1 for a longer period of time. can do.

  The lubricant molded product 6b is preferably compression molded into a rod shape. That is, as shown in FIG. 2, the lubricant molded product 6b is compression-molded by mixing a given amount of lubricant 31 and gallium 32 with a super mixer at a predetermined press pressure using a general-purpose press. Is done. At the time of compression molding or after compression molding, the compression molded product (the lubricant molded product 6b) can be heated to increase its strength, but the compression molded product (the lubricant described above) can be used even in cold compression without heat treatment. A molding 6b) can be produced. The lubricant molded product 6b manufactured by this cold compression is shown in FIG. In this lubricant molded product 6b, gallium 32 is uniformly dispersed and contained. As another manufacturing method, as shown in FIG. 2, only the lubricant 41 is compression-molded to form a lubricant molded product 6b, and then the surface is coated with gallium powder using a brush or the like. It can also be produced by applying a proper amount. This lubricant molded product 6b is contained in a state where the surface portion is coated with gallium 32. The above-mentioned method of mixing before compression molding is more suitable for mass production and is cheaper to manufacture. Further, as shown in FIG. 1, gallium 32 is dispersed in the lubricant molded product 6b. This is preferable in that the shaving amount of the molded product 6b is easily stabilized.

  Further, the surface shape of the lubricant molded product 6b manufactured by the compression molding described above can be transferred from the shapes of the upper punch 21 and the lower punch 22 in FIG. The shape can be made easily. For example, the surface with which the brush roller 6c abuts can be formed into a concavo-convex shape to intentionally increase the scraping amount of the initial lubricant formation 6b.

  Therefore, when the lubricant molded product 6b is compression-molded into a rod shape, the gallium 32 and 42 dissolved into a slight gap generated between the lubricants 31 and 41 constituting the lubricant molded product 6b are formed. Therefore, it is possible to efficiently improve the shaving property of the lubricant molded product 6b. Further, since the lubricant molded product 6b is compression-molded into a rod shape, the installation space for the lubricant molded product 6b can be reduced, and therefore, the operation of incorporating the lubricant molded product 6b into the apparatus is easy. Become.

  The lubricant application device 6 of the present invention is in contact with the tip of the lubricant molded product 6b and the image carrier 1 while rotating, and scrapes the lubricant molded product 6b to form fine powder. At least a brush roller 6c supplied to the surface of the carrier 1 is provided. And the lubricant application apparatus 6 of this invention has the lubricant molding of any one of Claims 1-3 as the said lubricant molding 6b. The lubricant molded product 6b is preferably compressed by the compression member 6a. The compression member 6a is, for example, a spring such as a compression spring or a leaf spring, and a compression spring is preferably used. Further, the lubricant molded product 6b is scraped off and consumed by the brush roller 6c, and its thickness decreases with time, but since it is pressurized by the compression member 6a, it is always in contact with the brush roller 6c. . The brush roller 6c applies the lubricant scraped off to the image carrier 1 while rotating.

  Thus, when the lubricant molded product according to any one of claims 1 to 3 is used as the lubricant molded product 6b, fine powder of the lubricants 31 and 41 is formed on the surface of the image carrier 1. It is possible to provide the lubricant application device 6 that stably and uniformly coats a long period of time.

  The brush roller 6 c is rotatably provided in the lubricant application device 6. Although the rotation direction of the brush roller 6c is not particularly defined, for example, when it is desired to supply a large amount of lubricant onto the image carrier 1, the rotation direction of the brush roller 6c with respect to the rotation direction of the image carrier 1 is It is appropriately selected such as reverse rotation. In the brush roller 6c, a pile made by implanting a chemical fiber in a raw cloth is wound around a metal core spirally, or the chemical fiber is directly implanted in a metal core whose surface is covered with an adhesive. There is something. The chemical fiber is preferably a thermoplastic resin fiber such as polypropylene, polyester, nylon, and acrylic. In particular, polyester and nylon fibers capable of supplying the lubricants 31 and 41 to the surface of the image carrier 1 without damaging the image carrier 1 are preferable.

  The process cartridge 9 of the present invention includes an image carrier 1, a lubricant application device 6 that applies lubricants 31 and 41 to the surface of the image carrier 1, and a cleaning device 7 that cleans the surface of the image carrier 1. And are integrally supported, and are detachably fixed to the image forming apparatus 10. The process cartridge 9 includes the lubricant application device according to claim 4 as the lubricant application device 6. The leaning means 7 includes, for example, a cleaning blade 7a, a support member 7b, a toner recovery coil 7c, and a spring 7d. In FIG. 4, 8 is a cartridge case for rotatably holding the image carrier 1.

  As described above, at least the image carrier 1, the lubricant applying device 6 for applying the lubricants 31 and 41 to the surface of the image carrier 1, and the cleaning device 7 for cleaning the surface of the image carrier 1 are provided. In addition, the process cartridge 9 that is integrally supported and is detachably fixed to the image forming apparatus 10 includes the lubricant application device according to claim 4 as the lubricant application device 6. 31 and 41 can improve the lubricity between the surface of the image carrier 1 and the member in contact with the image carrier 1 over a long period of time. Can be provided.

  In the process cartridge 9, the lubricant application device 6 is disposed upstream of the cleaning device 7 with respect to the moving direction of the image carrier 1. As described above, when the lubricant application device 6 is arranged upstream of the cleaning device 7 in the moving direction of the image carrier 1, the application of the lubricants 31 and 41 affects other processes. Therefore, it is possible to provide a process cartridge 9 for applying fine powders of the lubricants 31 and 41 to the surface of the image carrier 1 stably and uniformly over a long period of time.

  In the process cartridge 9, the cleaning device 7 has a cleaning blade 7a. The cleaning blade 7a is formed by forming an elastic body such as urethane elastomer, silicone elastomer, fluorine elastomer or the like into a plate shape, the edge of which is in contact with the surface of the image carrier 1, and the image carrier remaining after transfer. Toner and paper dust on the body 1 are removed. In particular, urethane elastomers are superior in terms of wear resistance and high mechanical strength. Although not shown, the cleaning blade 7 a is attached to and supported by a support member 7 b made of metal, plastic, ceramic, or the like, and is installed at a predetermined angle with respect to the image carrier 1. Further, the cleaning blade 7a is brought into contact with the surface of the image carrier 1 with a predetermined contact pressure and a biting amount by being pressed by a spring 7d or being fixed to the process cartridge case 8.

  Thus, when the cleaning device 7 has the cleaning blade 7a, the fine powders of the lubricants 31 and 41 supplied to the surface of the image carrier 1 are easily applied uniformly, and the cleaning device 7 A process cartridge 9 can be provided that minimizes costs.

  The cleaning blade 7a is in contact with an image carrier (photosensitive member) by a counter method (see FIG. 5) or a trailing method (see FIG. 4). In the present specification, the counter method is referred to as a counter method when β is the contact angle of the cleaning blade 7a with respect to the image carrier 1 and β = 0 ° to 90 °, and β = 90 ° to The case of 180 ° is called a trailing method.

  In the process cartridge 9, the cleaning blade 7 a is preferably supported in a counter direction (see FIG. 5) with respect to the moving direction of the image carrier 1. As described above, when the cleaning blade 7a is supported in the counter direction with respect to the moving direction of the image carrier 1, the cleanability of untransferred toner is improved even when a small particle size and spherical toner is used. A process cartridge 9 can be provided.

  Further, in the process cartridge 9, in the invention described in any one of claims 5 to 8, a charging device (charging device) 2 in which the process cartridge 9 charges the surface of the image carrier 1 uniformly. It has. The charging device 2 is preferably composed of a charging roller 2a and a charging cleaning roller 2b. As described above, in the invention described in any one of claims 5 to 8, when the process cartridge 9 includes the charging device 2 that uniformly charges the surface of the image carrier 1, image formation is performed. Simplification and downsizing of the device 10 are possible.

  An image forming apparatus 10 according to the present invention includes an image carrier 1 that carries a latent image, a charging device 2 that uniformly charges the image carrier 1, and a surface of the image carrier 1 by exposing the surface of the image carrier 1. An exposure device 3 that forms a visible image by developing the electrostatic latent image with a developer containing toner, a transfer device 5 that transfers the visible image to a recording medium, The apparatus includes at least a lubricant applying device 6 that applies lubricants 31 and 41 to the image carrier 1 and a cleaning device 7 that removes toner remaining on the surface of the image carrier 1. The lubricant application device 6 includes the lubricant application device according to claim 4.

  As described above, the image carrier 1 that carries a latent image, the charging device 2 that uniformly charges the image carrier 1, and the exposure device that exposes the surface of the image carrier 1 to form an electrostatic latent image. 3, a developing device 4 that develops the electrostatic latent image with a developer containing toner to form a visible image, a transfer device 5 that transfers the visible image to a recording medium, and the image carrier 1. In the image forming apparatus 10 having at least the lubricant applying device 6 for applying the lubricants 31 and 41 and the cleaning device 7 for removing the toner remaining on the surface of the image carrier 1, the lubricant applying device 6 is used. When the lubricant application device according to claim 4 is provided, the lubricants 31 and 41 improve the lubricity between the surface of the image carrier 1 and the member in contact with the image carrier 1 over a long period of time. Therefore, images that can form high-quality images for a long time It is possible to provide the forming apparatus 10.

  Further, in the image forming apparatus 10 of the present invention, the lubricant applying device 6 is located downstream of the transfer device in the moving direction of the image carrier 1 and more than the charging device 2. The image carrier 1 is arranged at an upstream position in the moving direction. As described above, the lubricant application device 6 is located downstream of the transfer device 2 in the movement direction of the image carrier 1 and the movement direction of the image carrier 1 relative to the charging device 2. The lubricant 31, 41 can be applied without being affected by other processes, and for this reason, the fine powder of the lubricant 31, 41 is applied to the surface of the image carrier 1. Can be stably and uniformly applied over a long period of time, and thus the image forming apparatus 10 capable of forming a high-quality image for a long period of time can be provided.

  In the image forming apparatus 10 of the present invention, the cleaning device 7 has a cleaning blade 7a. Thus, when the cleaning device 7 has the cleaning blade 7a, the fine powders of the lubricants 31 and 41 supplied to the surface of the image carrier 1 are easily applied uniformly, and the cost of the cleaning member is increased. It is possible to provide the image forming apparatus 10 that minimizes the above.

  In the image forming apparatus 10 of the present invention, the cleaning blade 7a is supported in the counter direction (see FIG. 5) with respect to the moving direction of the image carrier 1. As described above, when the cleaning blade 7a is supported in the counter direction with respect to the moving direction of the image carrier 1, the cleanability of untransferred toner is improved even when a small particle size and spherical toner is used. The image forming apparatus 10 can be provided.

  Further, the image forming apparatus 10 of the present invention has the process cartridge 9 according to any one of claims 5 to 9. As described above, when the process cartridge 9 according to any one of claims 5 to 9 is provided, it is easy to perform maintenance and replacement work of parts, and therefore, the running cost is minimized. The image forming apparatus 10 can be provided.

  Next, the image carrier 1, the charging device (charging device) 2, the exposure device 3, the developing device (developing device) 4, and the transfer device (transfer device) 5 in the image forming apparatus 10 of the present invention will be described. In the image forming apparatus 10 of the present invention, the image carrier (photosensitive member) 1 is rotatably supported and rotated in the direction of the arrow. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, a lubricant application device 6, and a cleaning device 7 are arranged on the outer periphery of the image carrier 1 based on an electrophotographic system. Although there are four image carriers 1 (not shown), the image forming parts provided around are the same, and the color of the color material (toner) handled by the developing device 4 is different. Part of the image carrier 1 is in contact with the intermediate transfer belt 5 b of the transfer device 5. In FIG. 4, 5a is a transfer roller.

  The image carrier 1 is obtained by providing a photosensitive layer, which is a photoconductive substance, on the surface of a conductive support having a diameter of about 30 to 100 mm. The conductive support can be a conductive metal such as aluminum, aluminum alloy, nickel, stainless steel. In the present invention, an image carrier 1 having an amorphous silicon surface layer can also be employed. In the image forming apparatus of the present invention shown in FIG. 1, the drum-shaped image carrier 1 is used, but a belt-like image carrier may also be used.

  Further, the photosensitive layer in the image carrier 1 has a single layer type in which the functions of the charge generation material and the charge transport material are integrally formed, and a two-layer configuration of the charge generation layer and the charge transport layer. It is possible to adopt a function separation type. In a general function-separated type image carrier 1, a charge generation layer is provided directly on a conductive support or via an undercoat layer (intermediate layer), and a charge generation layer is formed on the charge generation layer. A resin layer (charge transport layer) containing a transport material is provided. In particular, the use of a function-separated type laminated image carrier increases the degree of freedom in sensitivity design. Therefore, the image carrier 1 is preferably a function-separated type laminated image carrier. The developing means 4 is preferably composed of a developing sleeve 4a, a screw 4b, and a doctor blade 4c, and the transfer means 5 is preferably composed of a transfer roller 5a and an intermediate transfer belt 5b. .

  The charging device 2 according to the present invention is an illustration for bringing a charging roller 2a or a charging roller 2a configured by covering a conductive core bar with a medium resistance elastic layer as a charging member to abut the image carrier 1. It has a spring that does not. The charging roller 2a is connected to a power source (not shown) and is applied with a predetermined voltage. In addition, the charging roller 2a can be arranged by providing spacer members at both ends so that the spacer contacts the image carrier 1 and has a certain gap from the image carrier 1. Around the charging roller 2a, there is provided a charging cleaning roller 2b which is a charging cleaning member that contacts the charging roller 2a and the image carrier 1 and cleans foreign matter adhering to the surface of the charging roller 2a. Thereby, the life extension of the charging roller 2a can be realized.

  The exposure means 3 according to the present invention is based on a known laser system, and irradiates the surface of the image carrier 1 uniformly charged with light information corresponding to color image formation as a latent image. As the exposure means 3 in the present invention, an exposure apparatus comprising an LED array and an image forming means can be employed.

  In the present invention, the developing means 4 is provided with a developing sleeve 4 a provided with a magnetic field generating means inside at a position facing the image carrier 1. Below the developing sleeve 4a, there are provided two screws 4b for mixing toner introduced from a toner bottle (not shown) with the developer and pumping it up to the developing sleeve 4a while stirring. The developer composed of toner and magnetic carrier pumped up by the developing sleeve 4a is regulated to a predetermined developer layer thickness by the doctor blade 4c and is carried on the developing sleeve 4a. The developing sleeve 4 a carries and conveys the developer while moving in the direction of the arrow at a position facing the image carrier 1, and supplies toner to the latent image surface of the image carrier 1.

  In the present invention, the transfer means 5 includes a transfer roller 5a configured by covering a conductive cored bar with an intermediate resistance elastic layer as a transfer member, a resin film having a base thickness of 20 to 600 μm, or rubber. The intermediate transfer belt 5b has a heat resistance and resistance value that enables electrostatic transfer of toner to the substrate, and the intermediate transfer belt 5b is movable in the direction of the arrow. It is supported and stretched using a tension roller or the like. In addition, a transfer roller 5 a is provided in the vicinity of the image carrier 1 inside the belt loop. Here, the transfer roller 5a is a roller type that applies a high voltage, but a charger that discharges from an electrode can also be adopted.

  In the image forming apparatus 10 of the present invention, the process cartridge 9 is located downstream of the transfer device (transfer means) 5 and downstream of the exposure device (exposure means) 3 with respect to the moving direction of the image carrier 1. Has been placed. As described above, when the process cartridge 9 is disposed downstream of the transfer device (transfer means) 5 in the movement direction of the image carrier 1 and upstream of the exposure device (exposure means) 3, The cleanability of untransferred toner is improved, and a high-quality image can be obtained.

  In the image forming apparatus 10 of the present invention, when a toner having a small particle diameter is used in the developing unit 4, the toner can be densely attached to the latent image. However, when the volume average particle size is less than 3 μm, when used as a two-component developer, the toner fuses to the surface of the magnetic carrier during long-term stirring in the developing means 4, so that the charging ability of the magnetic carrier is high. When used as a one-component developer, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur. Conversely, if the volume average particle size of the toner exceeds 8 μm, it becomes difficult to obtain a high-resolution and high-quality image, and the toner particle size varies when the balance of the toner in the developer is performed. growing. Further, by narrowing the particle size distribution, the toner charge amount distribution becomes uniform, a high-quality image can be obtained, and the transfer rate can be increased. However, it is not preferable that Dv / Dn exceeds 1.40 because the charge amount distribution becomes wide and the resolution is lowered.

  Therefore, in the image forming apparatus 10 of the present invention, the volume average particle size of the toner used in the developing unit 4 is preferably 3 to 8 μm, and the volume average particle size of the toner used in the developing unit is The ratio (Dv / Dn) between (Dv) and the number average particle diameter (Dn) is preferably 1.00 to 1.40. Thus, the volume average particle size of the toner used in the developing unit 4 is 3 to 8 μm, and the volume average particle size (Dv) and the number average particle size (Dn) of the toner used in the developing unit 4 are set. ) (Dv / Dn) is 1.00 to 1.40, the toner can be densely attached to the latent image, and the toner charge amount distribution becomes uniform and the transfer rate is uniform. As a result, higher quality images can be obtained.

  In the image forming apparatus 10 of the present invention, the toner preferably has a circularity of 0.93 or more. Circularity SR = (peripheral length of a circle having the same area as the particle projection area / perimeter length of the particle projection image) × 100%. The closer the toner is to a true sphere, the closer to 100%. In the conventional image forming apparatus, when such toner is used, there is a case where the cleaning member such as a cleaning blade cannot sufficiently scrape off. This is because the toner easily rolls on the image carrier. In this case, as a countermeasure, it is conceivable that the cleaning blade is brought into contact with the image carrier with a stronger force, but it affects the rotation or movement accuracy of the image carrier and causes banding. In contrast, by applying a lubricant to the surface of the image carrier and reducing the coefficient of friction on the surface of the image carrier, the burden of cleaning by the cleaning blade is reduced, and no banding occurs even when the cleaning blade comes into contact with a strong force. It becomes possible to perform cleaning.

  Therefore, in the image forming apparatus 10 of the present invention, the average circularity of the toner used in the developing unit 4 is preferably 0.93 to 1.00. As described above, when the average circularity of the toner used in the developing unit 4 is 0.93 to 1.00, fine packing is possible, and thus a higher quality image can be obtained.

Example 1
A powder mixture in which the content of gallium particles with respect to melamine cyanurate particles is mixed to 0.5% by weight is uniformly filled in a press mold shown in FIG. A cuboid-shaped lubricated molded product having a length of 324 mm, a width of 8.2 mm, a height of 6 mm, and a weight of 40 g was obtained.

(Example 2)
A lubricated molded product was obtained in the same manner as in Example 1, except that the powder mixture was mixed so that the content of gallium particles with respect to the melamine cyanurate particles was 10.0% by weight.

(Example 3)
A lubricated molded product was obtained in the same manner as in Example 1 except that the powder mixture was mixed so that the content of gallium particles with respect to the melamine cyanurate particles was 20.0% by weight.

Example 4
After uniformly filling the press mold shown in FIG. 2 with a powder mixture in which the content of gallium particles with respect to polytetrafluoroethylene particles is 0.5% by weight, this is compression molded at a press pressure of 150 MPa for 30 sec. A cuboid-shaped lubricated molded product having a length of 324 mm, a width of 8.2 mm, a height of 6 mm, and a weight of 40 g was obtained.

(Example 5)
A lubricated molded product was obtained in the same manner as in Example 4 except that the powder mixture was mixed so that the content of gallium particles relative to the polytetrafluoroethylene particles was 10.0% by weight.

(Example 6)
A powder mixture in which the content of gallium particles with respect to boron nitride particles is mixed to 0.5% by weight is uniformly filled in a press mold shown in FIG. A rectangular parallelepiped-shaped lubricating molded product having a length of 324 mm, a width of 8.2 mm, a height of 6 mm, and a weight of 40 g was obtained.

(Example 7)
A lubricated molded product was obtained in the same manner as in Example 6 except that the powder mixture was mixed so that the content of gallium particles with respect to boron nitride particles was 10.0% by weight.

(Example 8)
A powder mixture in which the content of gallium particles with respect to paraffin wax is mixed to 0.5% by weight is uniformly filled in a press mold shown in FIG. : 324 mm, width: 8.2 mm, height: 6 mm, weight: 40 g of a rectangular parallelepiped-shaped lubricating molded product was obtained.

Example 9
A lubricated molded product was obtained in the same manner as in Example 8 except that the powder mixture was mixed so that the content of gallium particles with respect to paraffin wax was 10.0% by weight.

(Example 10)
A powder mixture in which the content of gallium particles with respect to polyethylene wax is mixed to 0.5% by weight is uniformly filled in a press mold shown in FIG. : 324 mm, width: 8.2 mm, height: 6 mm, weight: 40 g of a rectangular parallelepiped-shaped lubricating molded product was obtained.

Example 11
A lubricated molded product was obtained in the same manner as in Example 10 except that the powder mixture was mixed so that the content of gallium particles with respect to polyethylene wax was 10.0% by weight.

(Comparative Example 1)
A powder mixture consisting only of melamine cyanurate particles is uniformly filled in a press mold shown in FIG. 2 and then compression-molded at a press pressure of 150 sec for 30 sec. A cuboid lubricating molded product having a weight of 40 g was obtained.

(Comparative Example 2)
A lubricated molded product was obtained in the same manner as in Comparative Example 1 except that the powder mixture was composed only of polytetrafluoroethylene particles.

(Comparative Example 3)
A powder mixture consisting only of polyethylene wax is uniformly filled in the press mold shown in FIG. 2 and then compression-molded at a press pressure of 150 sec for 30 sec. Length: 324 mm, width: 8.2 mm, height: 6 mm, weight : 40 g of a rectangular parallelepiped lubricating molded product was obtained.

  A pile of straight polyester fibers and a fiber density of 30 k fibers / inch2 was wound around a metal core so as to have a diameter of 12 mm and a brush length of 311 mm to obtain a brush roller. And it was set as the lubricant application device which made the lubrication molding obtained in Examples 1-11 and Comparative Examples 1-3 contact | abut to the said brush roller with the load of 6.0N. Next, the lubricant application device is incorporated into a process cartridge in a digital copying machine (image MP MP4500, manufactured by Ricoh) to produce a process cartridge holding an image carrier, and then the process cartridge is connected to the digital copying machine (image MP). C4500, manufactured by Ricoh Co., Ltd.) to obtain an image forming apparatus. Subsequently, 80,000 sheets of prescribed images having an image area ratio of 5% with respect to A4 size paper were passed through this image forming apparatus, and the following items were evaluated. At that time, a polymerized toner (manufactured by Ricoh Co., Ltd.) having a toner average circularity of 0.972, a volume average particle diameter of 5.0 μm, and a thermal softening point of the binder resin of 70 ° C. was used.

(Evaluation items and methods)
Lubricant consumption linearity: Using the above-mentioned image forming apparatus, the lubricant consumption was measured from the change in weight of the lubricant molded product when 20, 50, and 80K sheets were passed. Then, a correlation coefficient R is calculated from the number of sheets passed and the amount of lubricant consumed, and linearity is obtained by a value R ^{2 obtained} by squaring them, that is, a stable supply of a lubricant molded product and a lubricant application device using them (Application) Performance was evaluated. In addition, it can be considered that the closer the correlation coefficient is to 1, the more stable supply of the lubricating substance is.

(Evaluation criteria)
The case where R ² is 0.95 or more and there is no problem in practical use is marked with ◯, and the case where R ² is less than 0.95, the lubrication substance is supplied excessively or insufficiently supplied. Since it was judged that the chemical substance could not be stably supplied at the time of durability, it was evaluated as x. The evaluation results are shown in the following Table 1.

It is a section schematic explanatory view of a lubricant molding showing one embodiment of the present invention. It is a schematic explanatory drawing which shows the manufacturing method of the lubricant molding which shows one embodiment of this invention. It is a cross-sectional schematic explanatory drawing of the lubricant molding which shows other one Embodiment of this invention. 1 is a schematic explanatory diagram of an image forming apparatus showing an embodiment of the present invention. It is explanatory drawing explaining the counter system which is the contact conditions of a cleaning blade. It is explanatory drawing explaining the trailing system which is the contact conditions of a cleaning blade.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image carrier 2 Charging device (charging means)
2a Charging roller 2b Charging cleaning roller 3 Exposure device (exposure means)
4 Developing device (Developing means)
4a Development sleeve 4b Screw 4c Doctor blade 5 Transfer device (transfer means)
5a transfer roller 5b intermediate transfer belt 6 lubricant application device 6a compression member 6b lubricant molded product 6c brush roller 7 cleaning device 7a cleaning blade (cleaning means)
7b Support member 7c Toner recovery coil 7d Spring 8 Cartridge case 9 Process cartridge 10 Image forming apparatus 21 Upper punch 22 Lower punch 31, 41 Lubricant or wax 32, 42 Gallium

Claims (14)

  A lubricant molded article containing, as a main component, a lubricant applied as a fine powder to the surface of an image carrier that carries a latent image, wherein the lubricant molded article contains gallium.   The lubricant is composed of one kind of lubricating substance selected from melamine cyanurate, polytetrafluoroethylene, and boron nitride, or one kind of wax selected from paraffin and polyethylene. The lubricant molded product according to claim 1.   The lubricant molded product according to claim 1 or 2, wherein the lubricant molded product is compression-molded into a rod shape.   A brush roller configured to supply the fine powder formed by scraping the lubricant molded product to the surface of the image bearing member while rotating and contacting the tip of the lubricant molded product and the image bearing member; At least a lubricant coating device having the lubricant molding according to any one of claims 1 to 3 as the lubricant molding.   An image carrier, a lubricant coating device that applies a lubricant to the surface of the image carrier, and a cleaning device that cleans the surface of the image carrier are integrally supported and attached to and detached from the image forming apparatus. 5. A process cartridge that is freely fixed, wherein the lubricant application device includes the lubricant application device according to claim 4.   6. The process cartridge according to claim 5, wherein the lubricant application device is disposed upstream of the cleaning device with respect to the moving direction of the image carrier.   The process cartridge according to claim 5, wherein the cleaning device includes a cleaning blade.   The process cartridge according to claim 7, wherein the cleaning blade is supported in a counter direction with respect to a moving direction of the image carrier.   9. The process cartridge according to claim 5, further comprising a charging device that uniformly charges the surface of the image carrier.   An image carrier that carries a latent image, a charging device that uniformly charges the image carrier, an exposure device that exposes the surface of the image carrier to form an electrostatic latent image, and the electrostatic latent image A developing device that develops a visible image by developing with a developer containing toner, a transfer device that transfers the visible image to a recording medium, a lubricant application device that applies a lubricant to the image carrier, and An image forming apparatus having at least a cleaning unit that removes toner remaining on the surface of the image carrier, wherein the lubricant application device includes the lubricant application device according to claim 4. Image forming apparatus.   The lubricant application device is disposed downstream of the transfer device in the moving direction of the image carrier and upstream of the charging device in the moving direction of the image carrier. The image forming apparatus according to claim 10.   The image forming apparatus according to claim 10, wherein the cleaning unit used in the cleaning device is a cleaning blade made of an elastic member.   The image forming apparatus according to claim 12, wherein the cleaning blade is supported in a counter direction with respect to a rotation direction of the image carrier.   An image forming apparatus comprising the process cartridge according to claim 5.

Images