JP4259695B2 - Seamless belt manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seamless belt used in an electrophotographic copying machine, a laser printer, and the like, and more particularly, to a method of manufacturing a seamless belt for intermediate transfer, paper conveyance, development, or fixing. .
[0002]
[Prior art]
Conventionally, when manufacturing a seamless belt, although not shown, a cylindrical mold is rotated at a low speed, and a relatively large amount of a polymer material solution in which a polymer material is dissolved in an organic solvent is supplied to the mold. Leveling is performed, and the organic solvent is volatilized and removed, and the polymer material layer, that is, the seamless belt is centrifugally formed. Thereafter, the dried seamless belt is removed from the mold, and both end portions thereof are cut and removed to obtain a cylindrical and flexible seamless belt.
[0003]
As a related prior art documents of this type, JP-A-3-34817 Publication and the like.
[0004]
[Problems to be solved by the invention]
The conventional seamless belt manufacturing method simply supplies a large amount of the polymer material solution at a time as described above, and thus has a large problem that the volatilization rate of the organic solvent is very slow and the drying is delayed. . Moreover, since the difference in drying speed between the inner and outer surfaces of the seamless belt is large, the smoothness of the inner surface cannot be expected.
[0005]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a seamless belt manufacturing method capable of shortening the drying time and improving the smoothness of the inner surface.
[0006]
[Means for Solving the Problems]
In the present invention, in order to solve the above-mentioned problems, a high-viscosity polymer material solution composed of a polymer material and an organic solvent is supplied into a cylindrical mold at a predetermined temperature, and this mold is rotated and the surroundings are In the manufacturing method, the organic solvent in the polymer material solution is removed by heating from the mold, and the flexible seamless belt is centrifugally molded. Then, the seamless belt is removed from the mold and both ends thereof are removed. There,
The same polymer material solution supply and organic solvent removal are repeated multiple times, and the mold rotation speed when removing the organic solvent is set lower than the maximum speed when supplying the polymer material solution. A belt is formed by laminating substantially the same polymer material, and a skin is interposed between a plurality of polymer materials.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, a seamless belt 1 according to the present embodiment includes a plurality of substantially identical materials (in this embodiment, The three polymer material layers 2 are laminated by centrifugal molding to be formed into a cylindrical shape, and the polymer material layers 2 are laminated via the skin 3.
[0009]
The substantially homogeneous material means that main components such as a polymer material and a conductive filler are homogeneous. Therefore, the difference in the blending ratio within ± 10%, the addition of an additive that is not a main component, or the difference in the molecular weight distribution of the polymer material is substantially the same. The skin 3 is formed by the formation of a film at the interface in contact with air when the polymer material solution 4 supplied into the mold 10 described later is solidified with rotation.
[0010]
Next, the manufacturing method of the seamless belt 1 in the present embodiment will be described. As shown in FIG. 3 and the like, the polymer material solution 4 is supplied from the supply device 5 into the mold 10 of the molding device 9, and this mold is used. 10 is a manufacturing method in which the organic solvent is volatilized and removed while the supply of the same polymer material solution 4 and the removal of the organic solvent are repeated a plurality of times, and the mold 10 is rotated during the removal of the organic solvent. The speed is set to be lower than the maximum speed when the polymer material solution is supplied.
[0011]
The polymer material solution 4 is a solution in which a polymer material such as PES or PET is dissolved in various organic solvents such as NMP and carbon is blended. In addition to these, the polymer materials include polyester resins such as PBT and PEN, polyimide resins, polyamideimide resins, polyamide resins, fluororesins, polysulfones, polyethersulfones, polycarbonates, aramid resins, or Examples thereof include polyether ether ketone, and among these, PES having excellent creep resistance is preferable. The polymer material may be either thermoplastic or thermosetting, and an appropriate material can be selected depending on the production method to be performed.
[0012]
As shown in FIG. 3, the supply device 5 includes a pump 7 provided with a long and narrow discharge nozzle 6 horizontally, and a hopper 8 that supplies the polymer material solution 4 to the pump 7. Then, based on the driving of a gear mechanism and a belt mechanism (not shown), the inner periphery of the mold 10 moves forward and backward with respect to the axial direction of the mold 10 as indicated by an arrow and is 20 to 30 mm away from the tip of the discharge nozzle 6. A liquid polymer material solution 4 having a high viscosity (1 poise or more and 100 poise or less at room temperature) is supplied to the surface while hanging down on the streaks.
[0013]
As shown in FIGS. 4 and 5, the molding device 9 includes a mold 10 for centrifugally molding the polymer material layer 2, that is, the seamless belt 1, a drive device 11 for rotating the mold 10, and the drive device 11. It is comprised from the follower 12 which can contact / separate with respect to. The mold 10 is formed in a horizontally long cylindrical shape using various metals, and the inner peripheral surface is subjected to smooth mirror surface processing, fluorine processing, or silicone resin processing so that the seamless belt 1 can be easily removed from the mold. At the same time, matte black (not shown) is applied to the outer peripheral surface, and this black efficiently absorbs heat from the external heater. A ring-shaped lid 13 for preventing leakage of the polymer material solution 4 is detachably fitted to both ends of the mold 10, and a supply hole for the polymer material solution 4 is formed at the center of the lid 13. Has been.
[0014]
The drive device 11 covers various motors 14, a drive shaft 15 that rotates by driving the motor 14, a plurality of drive wheels 16 that are fitted to the drive shaft 15, and an outer peripheral surface of each drive wheel 16. In addition, it is composed of a cylindrical elastic elastomer 17 having a heat resistance and durability that exerts a damping function by contacting and supporting the lower part of the outer peripheral surface of the lid 13. The elastic elastomer 17 is made of, for example, silicone rubber, chloroprene rubber, or fluororubber having excellent oil resistance, organic solvent resistance, chemical resistance, weather resistance, heat resistance, and the like, and is 90 ° Hs or less, preferably 30 ° Hs to It has a hardness of 90 ° Hs. This is because if it is less than 30 ° Hs, the compression set characteristics deteriorate, and if it exceeds 90 ° Hs, the vibration damping property becomes poor.
[0015]
As shown in FIG. 4, the driven device 12 includes a free driven shaft 18 that slides horizontally and horizontally with respect to the drive shaft 15, a plurality of driven wheels 19 that are fitted to the driven shaft 18, and each driven wheel. 19 is composed of a cylindrical elastic elastomer 17A having a heat resistance and durability, which is covered with an outer peripheral surface of 19 and supports the lower portion of the outer peripheral surface of the lid 13 so as to exhibit a damping function. Since the elastic elastomer 17A is the same as the elastic elastomer 17 of the drive device 11, the description thereof is omitted.
[0016]
Next, a specific method for manufacturing the seamless belt 1 will be described. First, the driving device 11 is driven to apply a centrifugal force of 50 G or more to the horizontal mold 10 (for example, the inner diameter of the mold is 200 mm). In this case, the mold 10 is rotated at a predetermined temperature (although there is no particular limitation, about 70 ° C. to 100 ° C.), and the supply device 5 is appropriately advanced and retracted with respect to the axial direction of the mold 10. The polymer material solution 4 is supplied and applied while hanging on the inner peripheral surface of the mold 10 that is moved and rotated, and the polymer material solution 4 is uniformly leveled on the inner peripheral surface of the mold 10. When the polymer material solution 4 is completely leveled in this way, the rotational speed of the mold 10 is changed from the maximum speed to a low speed at which a centrifugal force of 2 to 20 G acts (for example, when the inner diameter of the mold is 200 mm, 134 rpm or more, 134 to 423 rpm). ), The organic solvent is released from the centrifugal force, and the mold 10 is heated from the outside with an external heater to promote the reduction of the viscosity of the polymer material solution 4 and the evaporation of the organic solvent.
[0017]
The reason why the centrifugal force of 2G to 20G is applied is that the speed is lower than 2G because the leveled polymer material solution 4 may sag. Conversely, if it exceeds 20 G, the organic solvent will not be sufficiently released from the centrifugal force, and it will be difficult to shorten the removal time of the organic solvent.
[0018]
Next, the mold 10 is rotated again at the maximum speed, and the supply device 5 is moved back and forth with respect to the axial direction of the mold 10 so that the same height is applied on the polymer material layer 2 attached to the inner peripheral surface of the mold 10. The molecular material solution 4 is supplied and applied while hanging down through the skin 3, and the polymer material solution 4 is uniformly leveled on the skin 3. When the polymer material solution 4 is leveled, the rotational speed of the mold 10 is changed from the highest speed to the lower speed again, and the mold 10 is heated from the outside with an external heater to reduce the viscosity of the polymer material solution 4 and evaporate the organic solvent. Facilitate.
[0019]
Next, the mold 10 is rotated again at the maximum speed, and the supply device 5 is moved back and forth with respect to the axial direction of the mold 10 to form the same polymer material on the second polymer material layer 2 of the mold 10. The solution 4 is supplied and applied while dripping through the skin 3, and the polymer material solution 4 is uniformly leveled on the skin 3. When the polymer material solution 4 is leveled, the rotational speed of the mold 10 is changed from the highest speed to the lower speed again, and the mold 10 is heated from the outside with an external heater to reduce the viscosity of the polymer material solution 4 and evaporate the organic solvent. The multi-layer polymer material layer 2, in other words, the seamless belt 1 having the outer skin 3 on the peripheral surface is centrifugally molded. During these operations, if the organic solvent is rapidly evaporated and dried by simply heating with an external heater, the state of the peripheral surface of the seamless belt 1 deteriorates, so that the temperature of the mold 10 is 120 ° C. higher than the boiling point of the organic solvent. It heats so that it may become about -50 degreeC low, A heating temperature is raised after the dry touch state is obtained, and a drying operation is complete | finished.
[0020]
Next, the mold 10 is removed from the molding apparatus 9, the mold 10 is set in a dryer to evaporate and dry the residual organic solvent, and the mold 10 is removed from the dryer and air-cooled at room temperature. Then, the seamless belt 1 naturally peels from the inner peripheral surface of the mold 10 due to a difference in thermal expansion between the mold 10 and the seamless belt 1. In the case where the mold 10 and the seamless belt 1 are not in close contact with each other, the seamless belt 1 can be removed from the mold 10 by gradually peeling off the end of the seamless belt 1. After that, if both ends of the seamless belt 1 are cut at a predetermined length, a flexible cylindrical and thick seamless belt 1 can be obtained.
[0021]
According to the above method, since the polymer material solution 4 is supplied to the mold 10 a plurality of times, the amount of charge per time can be reduced, thereby significantly speeding up the volatilization of the organic solvent and promoting the formation of the skin 3. Thus, productivity can be improved. For example, when the charge amount per one time of the polymer material solution 4 is 1/3, the total drying speed can be tripled. Further, since the thickness variation of the first time can be corrected after the second time by supplying the polymer material solution 4 a plurality of times, the difference in the drying speed between the inner and outer surfaces of the seamless belt 1 is reduced, and the seamless belt 1 The smoothness of the inner surface and the accuracy of the seamless belt 1 can be greatly improved.
[0022]
Further, since the polymer material solution 4 is supplied not to the mold 10 rotating at a low speed but to the mold 10 rotating at the maximum speed, quick leveling becomes very easy. In addition, since the organic solvent is released from the centrifugal force by rotating the mold 10 rotating at the maximum speed at a low speed when removing the organic solvent or drying, the drying time can be shortened by more than half and the seamless belt. It is possible to prevent the thickness of one end portion from becoming non-uniform very effectively. In addition, since the high-viscosity polymer material solution 4 is discharged and applied from the discharge nozzle 6 instead of flying the low-viscosity polymer material solution 4 to the mold 10 at a high pressure, 4 does not scatter and the thickness of the seamless belt 1 does not become uneven. Therefore, the highly accurate seamless belt 1 having a thickness of about 50 μm to 80 μm and 1 mm or less and having a precision of about ± 3 μm or less can be manufactured in a short time.
[0023]
In addition, since the mold 10 is mounted by the driving device 11 and the driven device 12, not only a small diameter but also a large-diameter seamless belt 1 of 200 μm or more can be easily centrifugally formed. Further, since the mold 10 is rotated only by the driving wheel 16 of the driving device 11 and the driven wheel 19 is rotated, there is no speed difference between the driving wheel 16 and the driven wheel 19, and it is simple. With such a configuration, it is possible to prevent the mold 10 from moving up and down and minute slips very effectively. Furthermore, since the driven device 12 approaches or separates from the drive device 11, it can be expected to facilitate the maintenance and replacement of the mold 10 or easily deal with the mold 10 used differently. Furthermore, since the elastic elastomers 17 and 17A are excellent in heat resistance, long-term continuous use can be greatly expected even when the mold 10 is heated.
[0024]
In the above embodiment, the polymer material solution 4 is supplied to the mold 10 three times. However, the polymer material solution 4 can be supplied twice or four times or more as needed. . In addition, the mold 10 is rotated at the maximum speed from the beginning, and the polymer material solution 4 is supplied and applied while hanging down on the inner peripheral surface of the mold 10, but the mold 10 is supplied and applied with at least the polymer material solution 4. You only need to rotate at the maximum speed later. Therefore, initially, the mold 10 may be rotated at a speed lower than the maximum speed, and the polymer material solution 4 may be supplied and applied to the inner peripheral surface of the mold 10 and then rotated at a maximum speed of 50 G or more. In the above embodiment, the driving device 11 and the driven device 12 are used. However, the driven device 12 may be omitted and a pair of driving devices 11 may be used.
[0025]
Further, although the driven device 12 can be contacted and separated with respect to the drive device 11, the drive device 11 can be contacted and separated with respect to the driven device 12, and the drive device 11 and the driven device 12 can be contacted and separated from each other. Also good. Furthermore, the elastic elastomers 17 and 17A of the driving wheel 16 and the driven wheel 19 are brought into contact with the lower part of the outer peripheral surface of the lid 13, but the elastic elastomers 17 and 17A of the driving wheel 16 and the driven wheel 19 are attached to the lower part of the outer peripheral surface of the mold 10. You may make it contact.
[0026]
【Example】
Hereinafter, the Example of the manufacturing method of the seamless belt 1 which concerns on this invention, a comparative example, and evaluation are demonstrated sequentially.
Example First, the driving device 11 is driven to rotate a horizontal mold (inner diameter 200 mm, outer diameter 220 mm, length 400 mm) 10 at a maximum speed of 1,000 rpm, and the temperature of the mold 10 is set to 75 ° C. Then, the supply device 5 is moved forward and backward with respect to the axial direction of the mold 10 to supply and apply 101 g of the polymer material solution 4 to the inner peripheral surface of the mold 10, and the polymer is applied to the inner peripheral surface of the mold 10. The material solution 4 was leveled uniformly. The polymer material solution 4 was prepared by dissolving polyamideimide in NMP and blending 5-20 wt% of carbon in this material (solid content 15%). When the polymer material solution 4 was leveled in this way, the rotational speed of the mold 10 was changed from the highest speed to a low speed of 200 rpm, and the mold 10 was heated from the surroundings to 120 ° C. with an external heater and dried for 20 minutes.
[0027]
Next, the mold 10 is rotated again at the maximum speed of 1,000 rpm, and the supply device 5 is moved back and forth with respect to the axial direction of the mold 10 so that the polymer material layer 2 attached to the inner peripheral surface of the mold 10 is removed. 100 g of the same polymer material solution 4 was applied to the skin 3 while being dropped, and the polymer material solution 4 was uniformly leveled on the skin 3. When the polymer material solution 4 is leveled, the rotational speed of the mold 10 is changed from the maximum speed to a low speed of 200 rpm, the mold 10 is heated to 120 ° C. from the surroundings with an external heater and dried for 25 minutes, and the seamless belt 1 is centrifugally molded. did. The centrifugal molding time of the seamless belt 1 was 60 minutes including the supply time and the temperature raising time.
[0028]
Next, the mold 10 is removed from the molding apparatus 9, the mold 10 is set in a dryer at 250 ° C., the residual organic solvent is evaporated and dried, and after 1 hour, the mold 10 is removed from the dryer at room temperature. Cooled down. Then, the seamless belt 1 is demolded using the difference in thermal expansion between the mold 10 and the seamless belt 1, and both ends of the seamless belt 1 are cut to a predetermined length to obtain a seamless belt 1 having a thickness of about 100 μm. Obtained.
[0029]
The same driving device 11 as in the comparative example is driven to rotate the same mold 10 at a low speed of 200 rpm, the temperature of the mold 10 is set to 75 ° C., and the supply device 5 is moved in the axial direction of the mold 10. In contrast, 201 g of the polymer material solution 4 was supplied and applied while hanging down on the inner peripheral surface of the mold 10, and the polymer material solution 4 similar to the example was uniformly leveled on the inner peripheral surface of the mold 10. . When the polymer material solution 4 was leveled, the rotating mold 10 was heated to 120 ° C. from the surroundings with an external heater and dried for 20 minutes, and the seamless belt 1 was centrifugally molded. The centrifugal molding time of the seamless belt 1 in this case was 90 minutes.
[0030]
Next, the mold 10 is removed from the molding apparatus 9, the mold 10 is set in a dryer at 250 ° C., the residual organic solvent is evaporated and dried, and after 1 hour, the mold 10 is removed from the dryer at room temperature. Cooled down. Then, the seamless belt 1 is removed from the mold 10 and the seamless belt 1 by using the difference in thermal expansion, and then both ends of the seamless belt 1 are cut to a predetermined length to obtain a seamless belt having a thickness of about 100 μm. 1 was obtained.
[0031]
When the thickness of the peripheral wall of the seamless belt 1 obtained in the evaluation examples was measured every 10 mm in length and width, the average value was 100.1 μm, and the variation (maximum-minimum) could be suppressed within 6 μm. On the other hand, when the thickness of the peripheral wall of the seamless belt 1 obtained in the comparative example was measured, a variation of 11 μm was confirmed. Furthermore, unlike the examples, fine undulations were observed on the inner surface (surface) of the seamless belt 1.
[0032]
【The invention's effect】
As described above, according to the present invention, the drying time of the seamless belt can be shortened, and the smoothness of the inner surface of the seamless belt can be improved.
Specifically, since the polymer material solution is supplied to the mold a plurality of times, the amount of charge at one time can be reduced, which accelerates the volatilization of the organic solvent and promotes the formation of the epidermis. Improvements can be made. In addition, since the thickness variation of the first time can be corrected after the second time by supplying the polymer material solution multiple times, the difference in the drying speed between the inner and outer surfaces of the seamless belt is reduced, and the inner surface of the seamless belt is smoothed. And the accuracy of the seamless belt can be improved.
Further, since the polymer material solution is supplied not to the mold rotating at a low speed but to the mold rotating at the maximum speed, quick leveling is facilitated. In addition, since the organic solvent is released from the centrifugal force by discharging the mold rotating at the maximum speed at a low speed when removing the organic solvent or drying, the drying time can be shortened and the end of the seamless belt It is possible to effectively prevent the thickness of the film from becoming uneven. In addition, a high-viscosity polymer material solution is not applied to the mold at high pressure, but a high-viscosity polymer material solution is applied to the mold. Thickness does not become uneven.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective explanatory view showing an embodiment of a seamless belt according to the present invention.
FIG. 2 is an enlarged explanatory view of a part II in FIG. 1;
FIG. 3 is an explanatory view showing an embodiment of a method for producing a seamless belt according to the present invention.
FIG. 4 is a front view showing a molding apparatus in an embodiment of a seamless belt manufacturing method according to the present invention.
FIG. 5 is a side view of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Seamless belt 2 Polymer material layer 3 Skin 4 Polymer material solution 5 Supply apparatus 9 Molding apparatus 10 Mold

Claims (1)

A high-viscosity polymer material solution composed of a polymer material and an organic solvent is supplied into a cylindrical mold at a predetermined temperature, and this mold is rotated and heated from the surroundings to obtain a solution in the polymer material solution. A seamless belt is produced by centrifugally forming a flexible seamless belt by removing the organic solvent, and then removing the seamless belt from the mold and removing both ends thereof.
  The same polymer material solution supply and organic solvent removal are repeated multiple times, and the mold rotation speed when removing the organic solvent is set lower than the maximum speed when supplying the polymer material solution. A method for producing a seamless belt, comprising: forming a belt by laminating substantially the same polymer material; and interposing a skin between the plurality of polymer materials.

Images