JP2014164130A - Polishing roll and fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing roll and fixing device capable of preventing transfer of a scar or striation produced on a surface of a fixing member to an image, without lowering polishing performance even if it the surface of the fixing member is continuously polished.SOLUTION: A polishing roll 1 which polishes a fixing member used for a fixing part of a fixing device includes a core body 10 and polishing layer 11 provided in a surrounding of the core body 10. The polishing layer 11 contains silicon carbide 12 of polygonal shape and at least one kind of binder selected from resin and rubber.

Description

  The present invention relates to a polishing roll for polishing a surface of a fixing member used in a fixing unit of a fixing device and a fixing device provided with the same, and is suitable for reducing the unevenness of scars and streaks generated on the fixing member. is there.

  Image forming apparatuses such as copying machines, facsimile machines, and laser beam printers are provided with a fixing device. The fixing device includes a fixing member such as an endless fixing belt, and a pressure roll disposed to face the fixing member. In the fixing device, the toner is fixed by heat and pressure when the recording paper passes through a nip formed by a fixing member and a pressure roll. When a recording sheet of the same size or a thick recording sheet passes continuously through the nip portion, a scar or a streak is formed on the portion of the fixing member that contacts the end of the recording sheet. Since scars and streaks remain as irregularities on the surface of the fixing belt, there is a problem that when these are transferred to an image, an image defect is caused.

  As a technique for preventing such image defects, a method of adjusting and recovering the surface shape of the fixing member by rotating a roll containing alumina particles on the surface while contacting the fixing member has been proposed (for example, Patent Documents). 1, see Patent Document 2).

  However, the rolls described in Patent Documents 1 and 2 have problems that the alumina particles are worn by long-term use, and shavings resulting from the fixing member adhere to the roll surface and become clogged.

JP 2010-230825 A JP 2008-40364 A

  In view of such circumstances, the present invention is a polishing roll capable of preventing the scarring and streak generated on the surface of the fixing member from being transferred to the image without reducing the polishing performance even if the surface of the fixing member is continuously polished. And a fixing device.

  An aspect of the present invention that solves the above problem is a polishing roll that polishes the surface of a fixing member used in a fixing portion of a fixing device, and includes a core body and a polishing layer provided around the core body. The polishing layer is a polishing roll containing polygonal silicon carbide and at least one binder selected from resin and rubber.

  According to this invention, even if the surface of the fixing member is continuously polished, the polishing performance is not deteriorated, the difference in the unevenness of the scar and the trace generated on the fixing member can be reduced, and the scar and the trace can be repaired. . As a result, it is possible to prevent the scars and streaks of the fixing member from being transferred to the image.

  Here, the content of the silicon carbide in the polishing layer is preferably in the range of 45 mass% to 70 mass%.

  According to this, it is possible to further reduce the unevenness of the scars and traces generated on the fixing member, and to satisfactorily repair such scars and traces.

  Here, the average particle diameter of the silicon carbide is preferably 8 μm to 10 μm.

  According to this, the convex part of a polishing layer can be arrange | positioned in a predetermined range, and the unevenness | corrugation difference of the whole surface including the scar of a fixing member, and a trace can be further reduced.

  Here, the binder is preferably a fluororesin.

  According to this, silicon carbide can be stably held, and the convex portion of the polishing layer can be formed uniformly. In recent years, it has been desired to suppress the generation of ultra fine particles (UFP) due to the growing awareness of environmental problems. Generation of UFP can be reduced by using a fluororesin.

  Another aspect of the present invention is a fixing device comprising the polishing roll according to any one of the above and the fixing member.

  According to this invention, even if the surface of the fixing member is continuously polished, the polishing roll that does not deteriorate the polishing performance is provided, so that scars and streaks generated on the fixing member can be prevented from being transferred to the image. . Thereby, a highly reliable fixing device can be realized.

  According to the present invention, even if the surface of the fixing member is continuously polished, the polishing performance is not deteriorated, the unevenness difference between the scar and the trace generated on the fixing member can be reduced, and the scar and the trace can be repaired. As a result, it is possible to realize a polishing roll and a fixing device that can prevent scars and streaks of the fixing member from being transferred to the image.

FIG. 3 is a side view, a transverse cross-sectional view, and a main part enlarged cross-sectional view of the polishing roll according to Embodiment 1. FIG. 3 is a cross-sectional view illustrating a state where the surface of the fixing belt is polished using the polishing roll according to the first embodiment. 1 is a cross-sectional view of a fixing device including a polishing roll according to Embodiment 1. FIG. It is a graph which shows the relationship between the difference of ten-point average roughness, and content of an abrasive grain.

  Hereinafter, the present invention will be described in detail based on embodiments.

(Embodiment 1)
The polishing roll according to the present invention polishes the surface of the fixing member used in the fixing unit of the fixing device, and repairs scars and streaks generated on the surface of the fixing member. In Embodiment 1, an endless fixing belt is exemplified as the fixing member, and a polishing roll for polishing the surface of the fixing belt will be described.

  FIG. 1A shows a side view of the polishing roll according to the present embodiment, FIG. 1B shows a cross-sectional view of the polishing roll, and FIG. 1C shows an enlarged cross-sectional view of the main part of the polishing roll.

  The polishing roll 1 has a cylindrical shape. The polishing roll 1 has a length (longitudinal dimension) substantially equal to that of the fixing belt and a width (short dimension) for forming a polishing surface obtained by press-contacting the fixing belt surface.

  As shown in FIGS. 1A and 1B, the polishing roll 1 includes a core body 10 and a polishing layer 11 provided around the core body 10, and the core body 10 and the polishing layer are provided from the inside. 11 are stacked. The polishing layer 11 for polishing the surface of the fixing belt is composed of polygonal silicon carbide 12 and a binder. Polygonal silicon carbide 12 is contained as abrasive grains for polishing the surface of fixing belt 20.

  As shown in FIG. 1C, the polygonal silicon carbide 12 protrudes from the surface of the polishing layer 11, and the surface has a number of convex portions. When the polishing roll 1 having such a configuration is rotated while being pressed against the fixing belt 20, the surface of the fixing belt 20 is pressed by a large number of convex portions. Differences can be reduced and scars and streaks can be repaired.

  The core body 10 constituting the polishing roll 1 is made of a metal or a resin material. The metal or resin material is not particularly limited as long as it can hold silicon carbide via a binder. Further, the thickness and shape of the core body 10 are not particularly limited.

  The binder contained in the polishing layer 11 is used for bonding the core body 10 and the silicon carbide 12. The binder preferably contains at least one selected from resin and rubber. Examples of the resin include a fluororesin, an epoxy resin, a phenol resin, a melamine resin, an acrylic resin, a polyurethane resin, a polyimide resin, a polyamideimide resin, and a polyetheretherketone resin. Particularly, it has heat resistance and wear resistance. A fluororesin is preferred.

  Examples of the fluororesin include perfluoroalkoxy fluororesin (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene / ethylene copolymer (ETFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), Polyvinylidene fluoride (PVDF), chlorotrifluoroethylene / ethylene copolymer (ECTFE) and the like can be mentioned, and PFA and PTFE are particularly preferable. In this embodiment, PFA is used as a binder.

  Examples of rubber include fluorine rubber and urethane rubber.

  The silicon carbide 12 contained in the polishing layer 11 has a polygonal shape as described above. Due to the polygonal shape, the surface of the polishing layer 11 becomes a sharp convex portion, and the entire surface including scars and streaks of the fixing belt can be pressed uniformly.

  The content of silicon carbide in the polishing layer is preferably 45 mass% to 70 mass%, more preferably 50 mass% to 65 mass%. When the content is less than 45% by mass, the amount of silicon carbide as abrasive grains is small, and the polishing performance cannot be sufficiently exhibited. Moreover, it is because silicon carbide becomes easy to peel from a grinding | polishing layer with content more than 70 mass%.

  Moreover, it is preferable that the average particle diameter of a silicon carbide is 8 micrometers-10 micrometers. When the average particle diameter of silicon carbide is less than 8 μm, the convex portions formed on the surface of the polishing layer 11 become small, and the unevenness difference between scars and streaks cannot be reduced uniformly. On the other hand, if the average particle size of silicon carbide is larger than 10 μm, the convex portion formed on the surface of the polishing layer becomes large, and there is a risk of scratching the fixing belt. The average particle size of silicon carbide can be calculated from the particle size distribution measured by laser analysis / scattering method or Coulter counter method. In the present embodiment, values measured by a laser analysis / scattering method are used.

  Here, unlike the alumina abrasive grains conventionally used as the abrasive grains, the polygonal silicon carbide 12 contained in the polishing layer 11 does not deteriorate the polishing performance even if the surface of the fixing belt 20 is continuously polished. Abrasive grain. This is because the hardness of the silicon carbide 12 is higher than that of alumina, and the surface of the polishing layer 11 has a polygonal shape, that is, has a sharp convex portion. Since the silicon carbide 12 is very hard and has a property of not easily deforming, even if it is rotated while being pressed against the fixing belt, the sharp convex portion can be maintained in a certain shape. Further, even if the silicon carbide 12 is crushed during polishing, the polygonal silicon carbide 12, that is, the hard and sharp convex portion is regenerated. For this reason, it becomes possible to use the polishing roll 1 for a long period of time by using the polygonal silicon carbide 12 as an abrasive grain.

  In addition, the thickness of the polishing layer 11 is, for example, 10 μm to 60 μm, and preferably 20 μm to 40 μm. This is a thickness that allows the resin constituting the polishing layer 11 to stably hold the silicon carbide 12. The polishing layer 11 may be added with a curing agent, a pigment, an additive, or the like together with the resin and the silicon carbide 12.

  According to the polishing roll 1 according to the present embodiment, even if the surface of the fixing belt 20 is continuously polished, the polishing performance is not deteriorated, and the difference in unevenness between the scars and the streaks generated on the surface of the fixing belt is reduced. The traces can be repaired. As a result, it is possible to prevent the flaws and traces of the fixing belt from being transferred to the image.

  Next, a method for polishing the fixing belt 20 will be described. FIG. 2 is a cross-sectional view showing a state in which the surface of the fixing belt is polished using a polishing roll.

  As shown in FIG. 2, the fixing belt 20 is polished by rotating the fixing belt 20 and the polishing roll 1 in the directions indicated by the arrows, that is, in the opposite directions at different linear velocities while being pressed against each other with a predetermined pressure. Is preferred. In this way, by pressing and rotating the fixing belt and the polishing roll at different linear velocities, the convex portions of the silicon carbide 12 of the polishing roll 1 can be surely pressed over the entire surface of the fixing belt 20. It is possible to further reduce the unevenness of the scars and streaks. The rotation of the fixing belt and the polishing roll may be in the same direction, and the linear velocity may be constant.

  Next, the fixing device of this embodiment will be described.

  The fixing device 2 according to the present embodiment includes the polishing roll 1 described above.

  FIG. 3 is a cross-sectional view of the fixing device showing a state in which the surface of the fixing belt is polished using the polishing roll according to the first embodiment. As shown in FIG. 3, the fixing device 2 is provided inside the fixing roll 20, the polishing roll 1 according to the first embodiment, the fixing belt 20, a pressure roll 22 disposed to face the fixing belt 20, and the fixing belt 20. And a pressing member 21 that presses the pressure roll 22 via the fixing belt 20 to form a predetermined nip portion.

  The fixing device 2 according to the present embodiment further fixes a fixing unit based on a count unit 25 that counts the number of sheets passing through a nip formed by the fixing belt 20 and the pressure roll 22 and a signal from the counting unit 25. And a control means 26 for stopping the operation and carrying out the polishing operation by the polishing roll 1.

  The fixing belt 20 preferably uses a resin belt such as polyimide or an electroformed belt. In particular, an electroformed belt is preferably applied because an electroformed belt is unlikely to break due to stress concentration.

  The pressing member 21 is made of, for example, an elastic body such as rubber, resin, metal, or the like. A layer made of a fluororesin or the like may be formed on the surface as needed, or a sliding sheet, a groove, or the like may be provided.

  The pressure roll 22 includes a metal core 23 made of, for example, metal, and an elastic layer 24 made of rubber or the like formed around the metal core 23. Further, a release layer made of a fluororesin or the like may be provided around the elastic layer 24.

  Although not shown, a heating unit for heating the fixing belt 20 is provided inside or outside the fixing belt 20. Examples of the heating means include a halogen heater, a heating wire heater, an infrared heater, and electromagnetic induction heat generation by an exciting coil (heat source).

  The fixing belt 20 is polished by the count unit 25 and the control unit 26. First, the count unit 25 transmits the count number of the number of sheets to be passed to the control unit 26 when the total number of sheets passed for each paper type, such as normal recording paper or thick recording paper, reaches a predetermined number. To do. As shown in FIG. 3, the control means 26 temporarily stops the fixing operation when the received count number exceeds a predetermined number, and the polishing roll 1 disposed away from the fixing belt 20 is disposed as shown in FIG. 3. The fixing belt 20 is disposed in contact with the fixing belt 20. Then, the polishing operation is performed by rotating the fixing belt 20 while pressing the fixing belt 20 with a predetermined pressure. The polishing operation may be performed manually.

  According to the fixing device of this embodiment, when the number of sheets to be passed increases or a flaw or a trace of the fixing belt may occur, the fixing operation in the fixing unit is temporarily stopped to polish the surface of the fixing belt. Can be implemented. Further, the fixing device 2 of the present embodiment includes a polishing roll that does not deteriorate the polishing performance even if the surface of the fixing belt is continuously polished. As a result, a highly reliable fixing device can be realized without transferring scars or streaks of the fixing belt to the image.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited.

Example 1
The polishing roll 1 was manufactured by the following procedure. 50 mass parts of PFA paint (Mitsui DuPont Fluorochemical Co., Ltd .: EM-500CL) as a fluororesin solid content and 50 mass parts of polygonal silicon carbide abrasive grains (manufactured by Baikowski Japan Co., Ltd .: average particle diameter of 8 μm to 10 μm) Partially mixed to prepare a coating solution. The prepared coating solution was uniformly applied to the surface of the cylindrical core body by spraying to produce a polishing layer having a thickness of 30 μm. As the core, a SUS core metal having a diameter of 13.95 mm was used. Then, it baked for about 1 hour in a 350 degreeC-400 degreeC thermostat, and obtained the grinding | polishing roll 1 of outer diameter (phi) 14mm provided with the core 10 and the grinding | polishing layer 11 containing the silicon carbide 12. FIG.

(Example 2)
In Example 2, a coating solution was prepared by mixing PFA paint as a fluororesin solid content with 40 parts by mass and 60 parts by mass of polygonal silicon carbide abrasive grains. Except this, the polishing roll 1 was produced in the same process as in Example 1.

(Example 3)
In Example 3, a coating solution was prepared by mixing 30 parts by mass of PFA paint as a fluororesin solid content and 70 parts by mass of polygonal silicon carbide abrasive grains. Except this, the polishing roll 1 was produced in the same process as in Example 1.

(Comparative Example 1)
In Comparative Example 1, a coating solution was prepared by mixing PFA paint as a fluororesin solid content with 60 parts by mass and 40 parts by mass of polygonal silicon carbide abrasive grains. Except this, the polishing roll 1 was produced in the same process as in Example 1.

(Comparative Example 2)
In Comparative Example 2, a coating solution was prepared by mixing PFA paint as a fluororesin solid content in 60 parts by mass and 40 parts by mass of polygonal alumina abrasive grains. Except this, the polishing roll 1 was produced in the same process as in Example 1.

(Comparative Example 3)
In Comparative Example 3, a coating solution was prepared by mixing 30 parts by mass of PFA paint with fluororesin solids and 70 parts by mass of polygonal alumina abrasive grains. Except this, the polishing roll 1 was produced in the same process as in Example 1.

(Comparative Example 4)
In Comparative Example 4, a coating solution was prepared by mixing 30 parts by mass of PFA paint as a fluororesin solid and 70 parts by mass of spherical alumina abrasive grains. Except this, the polishing roll 1 was produced in the same process as in Example 1.

(Test Example 1)
About the polishing roll produced in Examples 1-3 and Comparative Examples 1-4, polishing performance was evaluated in the following procedures using the fixing device shown in FIG. In Table 1, the ten-point average roughness calculated by the type, shape, and content of the abrasive grains contained in the polishing layer on the surface of the polishing roll prepared in Examples 1 to 3 and Comparative Examples 1 to 4, and the following formula 1. The difference value is shown.

  First, the fixing belt was heated to 150 ° C., and the polishing roll was pressed against the fixing belt with a constant load. Next, the polishing roll and the fixing belt were rotated for 3 hours with a difference in linear velocity, and the surface of the polishing roll was clogged. Next, the fixing belt was replaced with a fixing belt having traces, a linear speed difference was provided, the polishing roll and the fixing belt were rotated, and the surface of the fixing belt was polished for 3 minutes. The surface roughness (ten-point average roughness Rz) of the polished fixing belt was measured, and the polishing performance of the polishing roll was evaluated.

The evaluation of the polishing performance is carried out using the following formula 1 and the difference between the ten-point average roughness Rz ₁ of the trace portion of the fixing belt and the ten-point average roughness Rz ₂ of the normal portion (hereinafter referred to as “ten-point average roughness” This was done by quantifying the degree of polishing of the traces. When the 10-point average roughness difference was 0.3 or less, it was evaluated that the traces were polished, that is, the polishing performance was good.

[Formula 1]
Rz ₁ of the trace portion of the fixing belt −Rz ₂ of the normal portion of the fixing belt | ≦ 0.3

  The ten-point average roughness Rz was measured using a non-contact type roughness meter (laser microscope: VK-X100 manufactured by Keyence Corporation) at a measurement magnification of 1000 times.

  Here, the “ten-point average roughness” is a value defined by the JIS standard (B0601-1994). Specifically, the reference length is extracted from the cross-sectional curve, and the average value of the absolute value of the highest part from the highest part to the fifth part with respect to the average line of the extracted part and the lowest value from the lowest part to the fifth part The sum of the absolute values of the heights of the portions is expressed in micrometers (μm).

  Hereinafter, the evaluation results of the polishing performance will be described. FIG. 4 shows the relationship between the ten-point average roughness difference and the abrasive content (mass%).

  When polishing performance was evaluated using a polishing roll having a polygonal silicon carbide content of 50 mass% to 70 mass% (Examples 1 to 3), the difference in ten-point average roughness was 0.3. It became less than. On the other hand, when the content of silicon carbide was reduced to 40% by mass (Comparative Example 1), the difference in ten-point average roughness was larger than 0.3. Accordingly, the difference in ten-point average roughness can be reduced to 0.3 or less by setting the silicon carbide content to 50% by mass or more, and according to FIG. It was found that the performance can be improved. Further, when alumina was used as the abrasive grains (Comparative Examples 2 to 4), the difference in ten-point average roughness was greater than 0.3 in both cases where the abrasive grains were polygonal or spherical. Moreover, even if the content of alumina was increased to 70% by mass from Comparative Examples 3 and 4, the difference in ten-point average roughness was greater than 0.3.

  From the above results, it was found that the polishing performance can be improved by containing 45 mass% or more of polygonal silicon carbide as abrasive grains in the polishing layer of the polishing roll. This is because silicon carbide has a polygonal shape and high hardness. Polygonal silicon carbide is considered to maintain its polishing performance for a long period of time without being degraded, because even if pulverized during polishing, hard and sharp protrusions are regenerated.

  According to the polishing roll of the present invention, even if the surface of the fixing belt is continuously polished, the polishing performance does not deteriorate, and scars and streaks generated on the fixing belt can be repaired. The fixing device having such a polishing roll is highly reliable because image defects due to transfer of scars and streaks on the fixing belt to the image are unlikely to occur.

DESCRIPTION OF SYMBOLS 1 Polishing roll 2 Fixing apparatus 10 Core body 11 Polishing layer 12 Silicon carbide 20 Fixing belt 21 Pressing member 22 Pressing roll 23 Core metal 24 Elastic layer 25 Counting means 26 Control means

Claims (5)

A polishing roll for polishing a surface of a fixing member used in a fixing unit of a fixing device,
Comprising a core and a polishing layer provided around the core;
The polishing layer contains a polygonal silicon carbide and at least one binder selected from resins and rubbers. In the polishing roll according to claim 1,
Content of the said silicon carbide in the said grinding | polishing layer exists in the range of 45 mass%-70 mass%, The polishing roll characterized by the above-mentioned. In the polishing roll according to claim 1 or 2,
The polishing roll, wherein the silicon carbide has an average particle size of 8 μm to 10 μm. In the polishing roll as described in any one of Claims 1-3,
A polishing roll, wherein the binder is a fluororesin.   A fixing device comprising: the polishing roll according to claim 1; and the fixing member.