JP2013041028A - Lubricant molding, manufacturing method thereof, lubricant application device, image carrier cleaning unit, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that uniformly supplies lubricant in a width direction of an image carrier from immediately after the start of use and forms favorable images in both central and end sections simultaneously.SOLUTION: The lubricant molding is used in a lubricant application device including the long lubricant molding, and a brush roller that rotates and rubs a friction surface of the lubricant molding whose longitudinal direction is parallel to an axis and whose both ends are axially retained, to supply the lubricant to an image carrier. The lubricant molding has a convex curved friction surface.

Description

  The present invention relates to a lubricant molded article for applying a lubricant to the surface of an electrophotographic image carrier, a manufacturing apparatus therefor, a lubricant applying apparatus, and a method for manufacturing a lubricant molded article used in the lubricant applying apparatus. The present invention relates to an image carrier cleaning unit provided with the lubricant application device, and an image forming apparatus provided with the image carrier cleaning unit.

  An image forming apparatus using an electrophotographic system is provided with an image carrier, and is charged by charging the surface of the image carrier, and the surface of the charged image carrier is exposed to form 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, after fixing the visible image transferred on the surface of the transfer paper, the transfer paper is discharged out of the apparatus.

  In such an image forming apparatus, deposits containing untransferred toner or the like remain on the surface of the image carrier after transferring the visible image, so that these deposits do not adversely affect image formation. The surface of the image carrier is cleaned by an image carrier cleaning unit to prepare for the next image forming process.

  As such an image carrier cleaning unit, 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 attach untransferred toner or the like. What removes a kimono is generally used, and among these, a cleaning unit that uses a cleaning blade is widely used because it is advantageous in terms of stability of cleaning performance and cost.

  However, these cleaning blades have a problem in that if they are continuously rubbed against the image carrier, they are worn over time to cause chipping or deformation, and at that time, the cleaning performance deteriorates. Further, since not only the cleaning blade but also the surface of the image carrier is 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 is an increasing demand for higher image quality. For this reason, in order to realize the formation of a high-definition color image, the toner particles have been reduced in diameter and spheroidized. When the toner particles are reduced in size, the dot reproducibility is improved, and when the toner particles are made spherical, an effect of improving developability and transferability is obtained.

  However, the toner cleaning properties are further reduced by reducing the diameter and spheroidization of the toner particles.

  Therefore, in recent image carrier cleaning units, a lubricant is applied to the surface of the image carrier to reduce the frictional resistance acting between the image carrier and the cleaning member, so that the cleaning member and the image carrier The occurrence of defects due to wear has been eliminated.

  Further, when the lubricant is applied to the surface of the image carrier in this way, 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 to the toner are cleaned. It is possible to prevent the problem of fixing to the surface of the image carrier with the contact pressure with the member (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.

  Here, examples of means for applying the lubricant to the surface of the image carrier include the following devices. That is, a solid lubricant obtained by compression-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. . The solid lubricant is attached to the compression member and pressed against the brush roller with a constant pressure.

  In this application means, when the brush roller is driven to rotate, the solid lubricant is scraped by the friction of the brush roller and becomes powder and adheres to the fibers of the brush roller. A lubricant is applied to the surface of the image carrier (Japanese Patent Laid-Open No. 2009-186738, Patent Document 1).

  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 coating. At this time, the lubricant is sufficiently applied. In the unexposed portion, defective cleaning or uneven wear of the image carrier may occur. 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 lubricant will reach the surface of the charging roller close to the surface of the image carrier, contaminating the charging roller, or unevenness in the amount of coating on the image carrier. As a result, unevenness occurs in an image such as a halftone portion.

  Further, in an environment of high temperature and high humidity, the lubricant applied excessively on the surface of the image carrier absorbs moisture, so that an electrostatic latent image formed on the surface of the image carrier flows and causes image blur.

  In order to prevent such an obstacle, it is important to stably apply an appropriate amount of lubricant to the surface of the image carrier.

  For this reason, various studies have been made, but it is particularly difficult to apply the lubricant uniformly in the width direction of the image carrier, and it is difficult to obtain a good image at the center and both ends at the same time. Met.

  The present invention has been made in view of the above background, and it is possible to supply the lubricant uniformly in the width direction of the image carrier immediately after the start of use, which is good at the center and both ends at the same time. An object is to provide an image forming apparatus capable of obtaining an image.

  In order to solve the above problems, the present inventors made various studies and found the following.

  That is, in the currently used lubricant application apparatus, the brush roller that rubs the solid lubricant is supported by both ends thereof, and the brush roller bends even if both ends are firmly supported. Therefore, there is a difference in the surface pressure between the lubricant and the brush roller between the center and the end, the amount of the lubricant rubbed varies depending on the position, and the amount of lubricant applied to the image carrier is wide. It has been found that there is a problem of changing depending on the position of the direction, and the present invention has been achieved.

  That is, the lubricant molded product of the present invention has a long lubricant molded product, and the longitudinal direction of the lubricant molded product is parallel to the length of the lubricant molded product and is fixed at both ends. And a brush roller for rotating and rubbing the rubbing surface of the lubricant molding to supply the lubricant to the image bearing member. A lubricant molded product characterized by a curved surface.

  The method for producing a lubricant molded product according to the present invention is the method for producing a lubricant molded product according to claim 2, wherein a long bottomed box-shaped mold is provided in the longitudinal direction of the mold. Lubricant filling step of filling the lubricant so that the filling amount of the lubricant per unit length decreases with increasing distance from the central portion, and laminating an elastic body layer made of an elastic body on the lubricant layer made of the lubricant Production of a lubricant molded product comprising: an elastic body layer laminating step, and a lubricant molded product molding step for forming a lubricant molded product by pressurizing the lubricant layer through the elastic layer. Is the method.

  According to a third aspect of the present invention, there is provided a lubricant application device comprising the lubricant molded product according to the first aspect.

Further, as described in claim 4, the lubricant application device of the present invention is the lubricant application device according to claim 3, wherein a portion facing the axis of the rubbing surface of the lubricant molded product is The distance from the equidistant point corresponding portion corresponding to the equidistant point from the two fixed positions of the shaft is retracted from the equidistant point corresponding portion with respect to the brush roller as it moves away from the brush roller shaft in parallel. The shaft of the brush roller is a round bar having a diameter R (mm) and is made of a material having a Young's modulus E (N / mm ² ). The lubricant molded product is applied to the brush roller with a load w (N). L is a distance between two portions of the shaft that are fixed to the shaft, and
When the ^{I = πR 4/64 (mm} 2), as from the equidistant points corresponding portion corresponding parallel distance x (mm) away to the shaft of the brush roller to the equidistant points, the following equation (1) in represented by σ _x (mm), characterized in that it recedes from the equidistant points corresponding parts.

  According to a fifth aspect of the present invention, there is provided an image carrier cleaning unit comprising the lubricant application device according to the third or fourth aspect.

  According to a sixth aspect of the present invention, there is provided an image forming apparatus comprising the image carrier cleaning unit according to the fifth aspect.

  According to the lubricant molded product of the present invention, since the rubbing surface is a convex curved surface, the difference in the amount of lubricant supplied to the image carrier at the center and the end from the beginning of use is reduced and uniform. Since the problem such as partial excessive supply and partial insufficient supply of the lubricant is solved, good image formation is possible.

  According to the method for producing a lubricant molded article of the present invention, filling the lubricant per unit length into a long bottomed box-shaped mold as the distance from the central portion in the longitudinal direction of the mold increases. A lubricant filling step of filling the lubricant so as to reduce the amount, an elastic layer laminating step of laminating an elastic body layer made of an elastic body on the lubricant layer made of the lubricant, and via the elastic body layer In order to have a lubricant molded product molding step for forming a lubricant molded product by pressurizing the lubricant layer in sequence, a lubricant molded product having various rubbing surfaces without a large number of special molds, It can be produced at low cost.

  Since the lubricant application device of the present invention has the lubricant molded product according to claim 1, the difference in the amount of lubricant supplied to the image carrier at the center and the end is reduced from the beginning of use. Thus, it is possible to apply uniformly, and problems such as partial excessive supply and partial undersupply of the lubricant are solved, so that favorable image formation is possible.

  Further, in the lubricant application device of the present invention, since the portion facing the axis of the rubbing surface of the lubricant molded product is a curved surface represented by the formula (1), The difference in the amount of lubricant supplied to the image carrier at the edge can be reduced, making it possible to apply evenly, eliminating problems such as partial and excessive supply of lubricant. Therefore, very good image formation is possible.

  Since the image carrier cleaning unit of the present invention has the above-described lubricant application device, the difference in the amount of lubricant supplied to the image carrier at the center portion and the end portion from the beginning of use is reduced, and uniform application is performed. As a result, problems such as partial oversupply and partial undersupply of the lubricant are solved, so that favorable image formation is possible.

  Since the image forming apparatus of the present invention has the above image carrier cleaning unit, the difference in the amount of lubricant supplied to the image carrier at the center and the end is reduced from the beginning of use, and the coating is uniformly applied. As a result, problems such as partial oversupply and partial undersupply of the lubricant can be solved, so that favorable image formation is possible.

FIG. 1 is a diagram schematically illustrating an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing an outline of a lubricant application device according to an embodiment of the present invention. FIG. 3 is a model diagram showing a lubricant molded product according to the present invention used in the lubricant application apparatus of the present invention. FIG. 4 is a model diagram showing the deformation of the brush roller when the lubricant molding is energized. FIG. 5 is a model side view showing the lubricant molded product of the present invention. FIG. 6 is a model diagram showing a method for producing a lubricant molded product of the present invention. FIG. 7 is a view showing a state in which the air circulation grooves 17d are provided along the vertical direction on the respective side surfaces of the elastic body layer 14 and the punch 15 in the method for manufacturing a lubricant molded product of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a model diagram showing an outline of an image forming apparatus according to an embodiment of the present invention.

  Around the image carrier 1, there are a charging device 2 as a charging means for charging the image carrier 1, and an exposure device 3 as a latent image forming means for forming an electrostatic latent image on the charged image carrier 1. And a developing device 4 as developing means for visualizing the electrostatic latent image on the image carrier 1 as a toner image, and a transfer for transferring the toner image on the image carrier 1 to a recording material made of a sheet-like medium A transfer device 5 as a means and a cleaning device 7 as a cleaning means for removing unnecessary toner adhering to the surface of the image carrier 1 are arranged.

As a lubricant application device 6 for applying a lubricant to the image carrier 1, a lubricant molded product 6b, a brush roller 6c, and a compression member for pressing (urging) the lubricant molded product 6b against the brush roller (this) In the example, an elastic member (a metal spring) 6 a is combined and arranged in the rotational direction of the image carrier 1 and upstream of the cleaning device 7.
Here, in this example, the cleaning unit includes the lubricant application device 6 and the cleaning device 7.

  The charging device 2 uniformly charges the surface of the image carrier 1, and preferably includes a charging roller 2a and a charging cleaning roller 2b.

  The charging device 2 makes the charging member contact the surface of the image carrier 1 or arranges the surface of the image carrier 1 with a small gap, and applies a charging bias to the surface to make the surface of the image carrier 1 Charge uniformly to desired polarity and desired potential. As such a charging member, for example, a charging roller 2a made of an elastic body, a scorotron charger using a wire electrode and a grid electrode, or the like can be used.

  The exposure device 3 forms an electrostatic latent image corresponding to image data on the surface of the image carrier 1 charged by the charging device 2. The exposure apparatus 3 uses, for example, an LD (Laser Diode) or LED (Light Emitting Diode) as a light emitting element, and irradiates light based on image data onto the surface of the uniformly charged image carrier 1. As a result, an electrostatic latent image is formed on the surface of the image carrier 1. The exposure apparatus 3 is not limited to such a configuration, and a widely known apparatus can be used.

  The developing device 4 performs development by attaching toner to the electrostatic latent image formed on the surface of the image carrier 1, and preferably includes a developing sleeve 4a, a screw 4b, and a doctor blade 4c. .

  The developing device 4 includes a developing sleeve 4a as a developer carrying member having a magnet roller as a magnetic field generating means arranged in a fixed manner, and the developing sleeve 4a rotates while carrying the developer on the surface. As a result, the developer is transported to the developing area facing the image carrier 1.

  In this embodiment, a two-component developer consisting of a toner and a carrier is used as a developer, and a magnetic brush development method is used in which the carrier is sprinkled in the development region by the magnetic force of the magnet roller and developed in a brush shape. Yes. However, as the developer, a one-component developer composed only of toner may be used without using a carrier like the two-component developer.

  A developing bias is applied to the developing sleeve 4a from a developing bias power source. By applying this voltage, a potential difference is generated between the surface potential of the developing sleeve 4a and the potential of the electrostatic latent image portion on the surface of the image bearing member 1 in the developing region constituted by the opposing region between the image bearing member 1 and the developing sleeve 4a. In response to the development electric field formed by this potential difference, the toner in the developer adheres to the electrostatic latent image, and the electrostatic latent image on the image carrier 1 becomes a toner image. The developing device 4 in the present invention is not limited to such a configuration, and a widely known device can be used.

  The transfer device 5 transfers the toner image on the image carrier 1 onto a recording material, and preferably includes a transfer roller 5a and an intermediate transfer belt 5b.

  In the transfer device 5, the intermediate transfer belt 5b is brought into contact with the surface of the image carrier 1 with a predetermined pressing force by the transfer roller 5a, and the toner image on the surface of the image carrier 1 is placed on the recording material on the intermediate transfer belt 5b. Transfer to The toner image on the surface of the image carrier 1 is transferred onto the recording material via the intermediate transfer belt 5b. A fixing device (not shown) serving as a fixing unit for fixing the toner image on the recording material is disposed on the downstream side in the recording material conveyance direction in which the recording material such as paper is conveyed by the transfer device 5.

  The lubricant application device 6 whose model is shown in FIG. 2 is for applying a lubricant to the surface of the image carrier 1 and for supplying the lubricant to the entire surface of the image carrier 1. 1 is composed of a long lubricant molding 6b substantially equal to one roll width, a brush roller 6c substantially equal to the length of the lubricant molding 6b, and a compression member (biasing means) 6a.

  The brush roller 6c is installed so that the longitudinal direction of the lubricant molded product 6b is parallel to the longitudinal axis of the lubricant molded product 6b and is fixed at both ends so that the brush roller 6c rotates so as to come into contact with the lubricant molded product 6b. The lubricant molded product 6b is scraped off (rubbed). At this time, the lubricant, which is powdered by rubbing the rubbing surface 6b3 with the brush, is adhered and held on the surface of the brush fiber constituting the brush roller 6c, and the surface of the image carrier 1 is rotated by the rotation of the brush roller 6c. To be applied and applied.

In order to eliminate uneven contact between the brush roller 6c and the lubricant molded product 6b on the side opposite to the brush facing surface of the lubricant molded product 6b, a compression member (a metal spring as an urging means) 6a is disposed. 6b is pressed against (biased) the brush roller 6c with a load of about 3 to 50N. Since the brush is supported by the both ends of the roller 6c, the central portion of the core bar bends due to the load pressing the lubricant molding against the brush roller.
This amount of deflection can be calculated by the equation of beam deflection (material mechanics), which is a double-end supported and uniformly distributed load.

  In the present invention, the portion facing the brush roller shaft of the rubbing surface of the lubricant molded article is from the equidistant point corresponding portion corresponding to the equidistant point from the two locations where the shaft of the brush roller shaft is fixed. The rubbing surface of the lubricant molded product is formed in advance so as to be a curved surface (convex surface) retreating from the equidistant point corresponding portion with respect to the brush roller as it moves away in parallel with the axis of the brush roller. For this reason, even a lubricant application device having a new lubricant molded product can supply the lubricant uniformly in the width direction (the width direction of the image carrier roller).

Furthermore, the portion of the rubbing surface of the lubricant molded article facing the brush roller shaft is a round bar having a diameter of R (mm) and the Young's modulus E (N / mm ² ). When the distance between the two locations where the shaft of the brush roller is fixed is L (mm), the lubricant molded product is biased toward the brush roller with a load w (N) In addition, as schematically shown in FIG. 4, the central portion in the length direction of the brush roller is projected toward an image carrier (not shown), and the shaft of the brush roller is deformed in an arc shape. Sliding Kosumen this time lubricant molded body is, I = πR ^4/64 is taken as (mm ^2), parallel to the distance to the axis of the brush roller from the equidistant points corresponding portion corresponding to the equidistant points As the distance x (mm) increases, σ _x (mm) represented by the following formula (1) is retreated from the equidistant point corresponding portion (see FIG. 5). It is possible to supply a completely uniform lubricant over the entire area.

  The brush roller 6c is made of resin fibers such as nylon, rayon, acrylic, vinylon, polyester, vinyl chloride, etc., and uses conductive fibers composed of the aforementioned resin mixed with a conductive agent such as carbon as necessary. May be.

  The brush roller 6c usually has a metal core having a thickness of 5 to 10 (mm) and a brush hair having a length of 0.2 to 20 (mm), preferably 0.5 to 10 (mm). A brush planted on the base fabric is wound in a spiral shape.

  The cleaning device 7 removes untransferred toner remaining on the surface of the image carrier 1 without being transferred from the surface of the image carrier 1.

  As the cleaning device 7, a cleaning blade 7 a member for scraping and removing the transfer residual toner on the surface of the image carrier 1 is used.

  The cleaning blade 7a member uses a polyurethane blade member affixed to a metal support, and the contact method with the image carrier 1 is to contact the arrow indicating the rotation direction of the image carrier 1 in the counter direction. Yes.

  As for the cleaning blade 7a member, not only toner removal from the image carrier 1, but also impurities such as discharge products and additives added to the toner when the image carrier 1 is charged by discharge by the charging device 2 are imaged. It also has a function of removing from the carrier 1.

  Having at least the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the lubricant application device 6, and the cleaning device 7, a lubricant film formed on the surface of the image carrier 1. A reduction in film loss due to charging hazards, and commercial flow systems that can achieve high image quality, and a highly durable image carrier that does not deteriorate cleaning performance even when spherical toner is used. Can be obtained.

  The process cartridge 9 includes an image carrier 1, a cartridge case 8 that rotatably holds the image carrier 1, and the lubricant application device 6 according to claim 3 held in the cartridge case 8. Have.

  As described above, the image carrier 1, the cartridge case 8 that rotatably holds the image carrier 1, and the lubricant application device 6 according to claim 3 that is held by the cartridge case 8 are provided. The parts can be easily replaced, so that the part replacement time can be shortened.

  The process cartridge 9 includes a cleaning device 7 and the lubricant application device 6 on the upstream side of the cleaning device 7 in the moving direction of the image carrier 1. As described above, when the process cartridge 9 includes the cleaning device 7 and includes the lubricant application device 6 on the upstream side of the cleaning device 7 in the moving direction of the image carrier 1, Lubricant can be applied to the surface of the image carrier 1 to form a lubricant coating curtain, and then the surface of the lubricant coating film can be brought into sliding contact with cleaning to form a lubricant film. Therefore, it is possible to provide a process cartridge 9 that can obtain a good cleaning property and a charging hazard property, and thus can maintain the cleaning performance of the surface of the image carrier 1 for a long period of time and obtain a higher quality image.

FIG. 6 shows the manufacturing process of the lubricant molded product 6b.
First, a lubricant (powder) is weighed and filled into a long bottomed box-shaped compression molding die 11 (consisting of a bottom surface portion and four side surface portions) (FIG. 6A). ). In this example, as shown in FIG. 6A, the mold is filled with the lubricant powder in 5 to 10 divisions.

  Specific examples of the lubricant powder include boron nitride, polytetrafluoroethylene, and melamine cyanurate as solid lubricants, and zinc stearate as a fatty acid metal salt that is excellent in film formation. It is possible to mix and use at the formulation ratio. Of course, any other lubricating material that meets the object of the present invention can be used.

  In filling, the lubricant is filled so that the amount of the lubricant filled per unit length decreases as the distance from the central portion in the longitudinal direction of the compression mold 11 increases (lubricant filling step, FIG. 6 (b). )). Then, the filling amount of each fraction is distributed so as to satisfy Expression (1).

  Next, an elastic body layer 14 made of an elastic body is laminated on a lubricant layer (lubricant powder layer) 12 made of a lubricant (elastic body layer lamination step, FIG. 6C).

  In this example, the elastic body layer 14 is made of hard rubber, and a buffer made of metal (pre-hardened 40FRC) is provided between the elastic body layer 14 and the lubricant layer 12 for the purpose of improving releasability from the surface of the friction surface. The layer 13 (for example, 0.5 mm thick) is sandwiched. In the figure, reference numeral 15 denotes a molding punch (made of iron).

  Next, a lubricant molding step for molding the lubricant molding 6b by pressurizing the lubricant layer 12 through the elastic body layer 14 by the molding punch 15 using a hydraulic cylinder (not shown) (FIG. 6D). Is performed (FIG. 6E). In the molding, for example, molding is performed with an applied pressure of about 140 kN to 170 kN using an actuator.

  At this time, since the mold used in this example is composed of the bottom surface part and the four side surface parts as described above, the mold is clamped at the time of molding to prevent the movement of each member constituting the mold. By doing so, stable molding can be performed. That is, positioning and mold clamping are performed using hydraulic cylinders or the like from the respective directions of the four wall surfaces of the mold. The mold clamping force at this time is increased or decreased in accordance with the applied pressure, but is usually preferably 100 to 300N.

  Specifically, when the applied pressure is 150 kN, it is preferable that the clamping force on both short sides of the mold is about 9.8 kN, and the clamping force on both long sides of the mold is about 315 kN.

  In the molding process, air exists between the powders. In order to release the air, one or a plurality of air flow grooves are provided along the vertical direction on the side surfaces of the elastic body layer 14 and the molding punch 15. Thus, the lubricant molded product 6b having no voids (voids) can be obtained.

  Here, FIG. 7 shows an example of a molding punch provided with such air circulation grooves (an elastic layer and a buffer layer are integrated). 7A is a top view of the model, and FIG. 7B is a cross-sectional view of the model. In the figure, reference numeral 15 denotes a punch body, 14 denotes an elastic body layer (in this example, made of hard rubber, thickness: 30 mm), air flow grooves 17a are provided on these side surfaces, and metal (made from pre-hardened 40FRC). The air flow holes 17b are respectively provided in the portions corresponding to the air flow grooves 17a of the buffer layer 13 having a thickness of 0.5 mm), and the air in the mold 11 and the lubricant layer 12 can be released to the outside. It is like that.

  After completion of molding, pressurization by the actuator to the punch for taking out the punch from the compression mold 11 containing the lubricant molded product 6b is completed, and at the same time, the mold clamping by the hydraulic cylinder is released. At this time, the surface where the buffer layer and the lubricant molding are in contact with each other is in a vacuum, and when the punch is raised in this state, the stress due to the punch rise acts on the lubricant molding and the lubricant molding may be broken. is there. For this purpose, it is preferable to release the vacuum between the buffer layer and the lubricant molding by introducing air from the air circulation groove 17a of FIG. The air pressure at this time is preferably in the range of 0.1 to 0.3 Mpa so as not to scatter the material.

  Next, the lubricant molding is removed from the mold. In this demolding step, the compression molding die 11 is disassembled, and the compression molded lubricant molded product 6b is taken out.

  In the above-mentioned forming method, the number of divisions at the time of powder filling described above is examined in advance (the productivity is lowered if the number is too large, and a sufficiently smooth rubbing surface is obtained if the number is too small. The material (elasticity), thickness, molding pressure, etc. of the elastic layer are determined so that a lubricant molded product having a desired shape of the friction surface can be obtained.

  According to such a method, it is possible to obtain a lubricant molded product having a friction surface with various curvatures only by changing the filling distribution amount at the time of powder filling.

Example 1
Add powdered lubricant (zinc stearate; the same shall apply hereinafter) to the compression mold so that the amount of lubricant filled per unit length decreases as the distance from the central portion in the longitudinal direction of the mold increases. 77.54 g was filled, and the molding punch shown in FIG. 7 was molded at a pressure of 140 kN. The density was 1.168 g / cm ³ , the size was 21 mm × 10 mm × 322.01 mm, and the rubbing surfaces were at both ends. A long (bar-shaped) lubricant molded product having a convex surface with a retraction amount of 0.32 mm with respect to the central portion of the was obtained.

(Comparative example)
77.10 g of powdery lubricant is uniformly filled in a compression mold, and the density is 1.168 g / cm ³ , 21 mm × 10 mm × 322.1 mm, using a molding punch (made of all metal). A long-sized lubricant molded product was obtained.

Each of the long lubricant moldings of Example 1 and Comparative Example is a brush roller (shaft) having a metal core made of a round bar made of stainless steel (SUS430, Young's modulus E: 203944 N / mm ² ) with a diameter of 8 mm. 1 is mounted on a lubricant application device having a distance L between the two locations of the fixed shaft of 32 mm and biased against the brush roller with a load w: 13 (N). Images were formed with the device (unused).

  Under the conditions at this time, the rubbing surface of the lubricant molded product of Example 1 satisfies the condition of the formula (1).

  Of the images obtained above, the first to 1000th images from the start of image formation were evaluated in detail. For the one using the lubricant molded product according to Example 1, the occurrence of image unevenness was observed. However, in the case where the lubricant molded product according to the comparative example was used, unevenness in the peripheral halftone image portion due to uneven application of the lubricant on the image carrier was observed.

Further, in the same manner as in Example 1, however, there was no unevenness in the image formation test similar to the above using a lubricant molded product prepared so that σ _x in formula (1) was always 0.9 k or 1.1 k. However, in the lubricant molded product prepared such that σ _x in the formula (1) is always 0.8 k or 1.2 k, the density unevenness occurred in the image.

(Example 2)
A total of 260.23 g of the powdered lubricant is filled in the compression mold so that the amount of the lubricant per unit length decreases as the distance from the central portion in the longitudinal direction of the mold increases. In the molding punch shown in FIG. 1, the pressure is adjusted in the range of 100 to 180 kN, the density is 1.167 g / cm ³ , the size is 90.149 mm × 10.0 mm × 440 mm, and the rubbing surfaces are at both ends. A long (bar-shaped) lubricant molded product having a convex surface with a retraction amount of 69.149 mm with respect to the center of the part was obtained.

Each of the long lubricant moldings of Example 2 is a brush roller having a metal core made of a round bar having a diameter of 5 mm made of wood (Young's modulus E: 13000 N / mm ² ). The image forming apparatus shown in FIG. 1 (unused) is mounted on a lubricant application device having a distance L between two locations (440 mm) and urged against a brush roller with a load w: 30 (N). Formed.

  Under these conditions, the rubbing surface of the lubricant molded product of Example 2 satisfies the condition of the formula (1).

  Among the images obtained above, the first to 1000th images from the start of image formation were evaluated in detail, and no image unevenness occurred.

Here, in the same manner as in Example 2, however, unevenness occurs in an image formation test similar to the above using a lubricant molded product prepared so that σ _x in formula (1) is always 0.9 k or 1.1 k. However, in the lubricant molded product prepared so that σ _x in the formula (1) always becomes 0.8 k or 1.2 k, the density unevenness occurred in the image.

(Example 3)
A total of 77.109 g of powdery lubricant is packed into a compression mold so that the amount of lubricant per unit length decreases as the distance from the central portion in the longitudinal direction of the mold increases. By adjusting the pressure with the same molding punch, the density is 1.167 g / cm ³ , the size is 21.004 mm × 10.0 mm × 322.1 mm, and the sliding surface has a retraction amount with respect to the center portion of both ends. A long (rod-shaped) lubricant molded product having a convex surface of 0.004 mm was obtained.

Each of the long lubricant moldings of Example 2 is a brush roller having a core bar made of a 15 mm diameter round bar made of stainless steel (SUS430, Young's modulus E: 203944 N / mm ² ). The image forming apparatus shown in FIG. 1 (unused) is mounted on a lubricant application device having a distance L between two locations of 322.1 mm and urged against a brush roller with a load w: 5 (N). ) To form an image.

  Under the conditions at this time, the rubbing surface of the lubricant molded product of Example 3 satisfies the condition of the formula (1).

  Among the images obtained above, the first to 1000th images from the start of image formation were evaluated in detail, and no image unevenness occurred.

DESCRIPTION OF SYMBOLS 1 Image carrier 2 Charging device 2a Charging roller 2b Charging cleaning roller 3 Exposure device 4 Developing device 4a Developing sleeve 4b Screw 4c Doctor blade 5 Transfer device 5a Transfer roller 5b Intermediate transfer belt 6 Lubricant coating device 6a Compression member 6b Lubricant molding Object 6b3 Rub surface 6c Brush roller 7 Cleaning device 7a Cleaning blade 7b Support member 7c Toner recovery coil 7d Spring 8 Cartridge case 9 Process cartridge 10 Image forming device 11 Mold for compression molding 12 Lubricant layer 13 Buffer layer 14 Elastic body layer 15 Molding punch 17a Air circulation groove 17b Air circulation hole

JP 2009-186738 A

Claims (6)

A long lubricant molded article, and the length direction and axis of the lubricant molded article are parallel to each other and fixed at both ends to rotate and slide on the rubbing surface of the lubricant molded article. In a lubricant molded product used in a lubricant application device having a brush roller to be supplied to an image carrier,
The lubricant molded product, wherein the rubbing surface is a convex curved surface. In the method for producing the lubricant molding,
Lubricant filling in which a lubricant is filled in a long bottomed box-shaped mold so that the amount of the lubricant filled per unit length decreases as the distance from the longitudinal central portion of the mold increases. Process,
An elastic body layer laminating step of laminating an elastic body layer made of an elastic body on the lubricant layer made of the lubricant, and
A method for producing a lubricant molded article, comprising sequentially forming a lubricant molded article by molding the lubricant molded article by pressurizing the lubricant layer through the elastic body layer.   A lubricant application device comprising the lubricant molded product according to claim 1. The portion of the lubricant molding that faces the shaft of the rubbing surface is parallel to the shaft of the brush roller from the equidistant point corresponding portion corresponding to the equidistant point from the two locations where the shaft is fixed. As you move away, the brush roller is retracted from the equidistant point corresponding part,
The brush roller shaft is a round bar having a diameter R (mm) and is made of a material having a Young's modulus E (N / mm ² ),
The lubricant molding is biased toward the brush roller with a load w (N);
L (mm) is the distance between the two locations where the shaft is fixed, and
When the ^{I = πR 4/64 (mm} 2),
As the distance x (mm) moves away from the equidistant point corresponding portion corresponding to the equidistant point in parallel to the axis of the brush roller, σ _x (mm) represented by the following formula (1) corresponds to the equidistant point The lubricant application device according to claim 3, wherein the lubricant application device is retracted from the portion.

  An image carrier cleaning unit comprising the lubricant application device according to claim 3.   An image forming apparatus comprising the image carrier cleaning unit according to claim 5.

Images