JP2008250164A - Method for manufacturing rubber roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the manufacturing process of a rubber roller to be used for an electrophotographic device or the like. <P>SOLUTION: The peripheral surface of a core 1 into which a heating means 18 is inserted is internally heated by the heating means 18. The core 1 as heated is rotated, and a liquid rubber material is discharged from a nozzle 7B while the nozzle 7B is moved in the axial direction of the core so as to pour and apply the liquid rubber material to the peripheral surface of the core 1. The rubber material is heated and cured to form a rubber layer G. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a rubber roller mainly used for an electrophotographic apparatus, a fixing roller of a printer, and the like.

  Conventionally, as a method of manufacturing this type of rubber roller, a core metal is inserted into a shaft core portion of a cylindrical mold, a liquid rubber raw material is injected into the mold, and the liquid rubber raw material is cured by heating. A method of forming a rubber layer around the mandrel by caulking is employed (see, for example, cited documents 1, 2, 3, and 4).

JP 2003-39452 A JP-A-5-192934 JP 2006-65171 A JP-A-9-85756

In the above conventional manufacturing method, since a mold is used, assembling of the mold → setting of the tetrafluoroethylene perfluoroalkyl vinyl ether copolymer tube (release tube) into the mold → core into the mold Eight steps were required: insertion of gold (core) → injection of liquid rubber raw material into the mold → heat curing → cooling → decomposition and demolding of the mold. Furthermore, the mold in which the liquid rubber material is injected is introduced into the heating chamber and heated from the outside. However, such a heating method is inefficient in heat, requires a long time for heat curing of the liquid rubber material, and saves energy. From the point of view, it is not desirable.
Furthermore, since this type of rubber roller presses the paper surface with uniform pressure, the diameter of the central part in the axial direction is increased, the crown shape that reduces the diameter of the end part, or the diameter of the central part in the axial direction is reduced. In many cases, a reverse crown shape is used to increase the diameter of the steel, but this shape becomes an undercut part during mold removal, and the diameter difference is such that it can be removed from the mold by rubber deformation. Only small crown shapes or reverse crown shapes can be applied.

As a means for solving the above problems, the inventor inserts a heating means into a pipe-shaped core, heats the core from the inside by the heating means, and rotates the core around an axis. The liquid rubber material coating layer is formed on the outer periphery of the core by pouring a liquid rubber material from a nozzle that moves along the axial direction, and then the liquid rubber coating layer is cured by heating to form a rubber layer. To do.
More specifically, a nozzle that inserts heating means into the pipe-shaped core, heats the core from the inside by the heating means, rotates the core around the axis, and moves along the axial direction above the core. The core primer is applied to the outer periphery of the core by pouring it from the core and dried, and then the liquid rubber material is applied from the nozzle that moves along the axial direction above the core to which the core primer has been applied. The liquid rubber material coating layer is formed on the outer periphery of the core, and then the liquid rubber coating layer is pre-cured by heating to form a pre-cured rubber layer. Modified tetrafluoroethylene perfluoroalkyl vinyl ether copolymer plastic introduced with a functional group from a nozzle moving along A modified tetrafluoroethylene perfluoroalkyl vinyl ether copolymer primer layer is formed on the outer periphery of the rubber layer by pouring a mer dispersion, and further, tetrafluoroethylene perfluoro is fed from a nozzle that moves along the axial direction above the core. A tetrafluoroalkyl vinyl ether copolymer release layer is formed on the outer periphery of the silicone rubber layer through the modified tetrafluoroethylene perfluoroalkyl vinyl ether copolymer primer layer by pouring an alkyl vinyl ether copolymer dispersion, A method for producing a rubber roller, comprising heating the tetrafluoroalkyl vinyl ether release layer together with the precured rubber layer to fuse the release layer to the rubber layer and completely curing the precured rubber layer to form a rubber layer. It is intended to provide.

[Action]
The heating means 18 is inserted into the pipe-shaped core 1, and the core 1 is heated from the inside by the heating means 18. The heated core 1 is rotated about the axis, and liquid rubber is poured over the peripheral surface of the core 1 from a nozzle 7B that moves along the axial direction above the core 1. Since the core 1 is heated from the inside by the heating means 18 as described above, the liquid rubber flowed over the peripheral surface of the core 1 is heated by the core 1, and the viscosity is lowered to easily spread. It can be applied uniformly. Further, the liquid rubber coating layer is heated and baked by the core 1 and cured to become a rubber layer G. Thus, a rubber roller is manufactured by forming the rubber layer G having a predetermined thickness on the peripheral surface of the core 1.
Dispersion of modified tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA) primer whose adhesion to the core 1 is improved by further rotating the core 1 and introducing functional groups after the rubber layer G is formed. Then, the dispersion coating layer is heated by the core 1 to form the PFA primer layer P2, and then the PFA dispersion is further applied to the surface of the PFA primer layer P2. By forming the PFA release layer R by heating the coating layer, a rubber roller whose surface is rich in release properties is manufactured.

〔effect〕
Therefore, in the method of the present invention, since a molding die is not used, the steps of assembling the conventional molding die, inserting a core metal (core) into the molding die, and disassembling and removing the molding die are unnecessary.
Further, in the method of the present invention, the heating energy is heated from the inside of the core, so that heat energy required for heat curing of the liquid rubber material coating layer formed around the core, heat drying fusion of the PFA dispersion coating layer, and the like. The efficiency is greatly improved.
Further, as described above, in the method of the present invention, since no mold is used, the problem of undercut at the time of demolding is eliminated, and a rubber roller having a large diameter difference or a reverse crown can be manufactured.

The present invention is described in detail below.
As shown in FIG. 1, both ends of the core 1 are supported by tip cone-shaped chucks 2A and 2B. The core 1 is made of a metal such as steel, stainless steel, or aluminum, and the diameter of the core 1 is usually 20 to 30 mm. The core 1 is previously cleaned with a cleaning solution and dried. The chucks 2A and 2B are rotatably supported by support frames 3A and 3B via ball bearings 4A and 4B, and one chuck 2A is slidably supported by the support frame 3A, and further air (not shown). A pressing means such as a cylinder, a hydraulic cylinder, or a spring is pressed in the direction indicated by the arrow A in FIG. 1 (the direction of the chuck 2B), and the shaft 5 of the chuck 2A is further rotated at a rotational speed by a driving means such as a motor (not shown).

  In this way, the core 1 is supported by the pair of chucks 2A and 2B so as to be rotatable at a rotational speed while being pressed.

  A nozzle 7A (for primer) is disposed immediately above the core 1. The interval between the tip of the nozzle 7A and the peripheral surface of the core 1 is usually set in the range of 0.1 mm to 2.0 mm.

  The nozzle 7A is attached to the upper end of the movable frame 8 through an elevating frame 9 and a sliding frame 10 so as to be movable up and down as indicated by an arrow B and slidable back and forth as indicated by an arrow C. The vertical position can be adjusted, and the front / rear position can be adjusted by the dial 12. In addition, although raising / lowering and sliding mechanism of this raising / lowering frame 9 and the sliding frame 10 are not illustrated, well-known mechanisms, such as the combination of a screw rod and a female screw, the combination of a rack and a pinion, are applied.

  The movable frame 8 is erected on a moving table 14 that moves on the base 13 along the axial direction of the core. The screw hole 15 of the movable frame 8 is variable in rotation speed by a drive source such as a motor (not shown). A screw 16 that is rotated forward and backward is screwed in, and the moving table 14 is rotated at a predetermined speed along the axial direction of the core 1 by rotating the screw 16 at a predetermined number of rotations by a drive source. Can be moved forward and backward. The moving table 14 is guided by a rail 17 of the base 13.

  Further, a blade 20 is fed out from the sliding table 19 on the moving table 14 toward the core 1, and the sliding table 19 can be slid back and forth by operating a dial 21.

  In the coating apparatus in which the core 1 is set, the dials 11, 12, and 21 are operated to move the nozzle 7 </ b> A up and down position (distance between the nozzle 7 </ b> A tip and the core 1 circumferential surface) and the blade 20 front and back position (blade 20 tip). -Adjust the distance between the core circumferences.

  During the rubber roller manufacturing process, the heating means 18 is inserted into the core 1 in advance. As the heating means 18, for example, a known heating means of an electric heating type, an electromagnetic wave heating method, or a far infrared radiation method is applied.

  In the first step, a primer layer P1 is formed by applying a primer to the peripheral surface of the core 1.

  The primer is supplied to the nozzle 7A from a primer tank (not shown) via a tube 22A by a metering pump. The nozzle 7A is moved over the core 1 along the axial direction from one end to the other end. The nozzle 7A is applied by spraying from the nozzle 7A to the peripheral surface of the core 1, and the thickness of the nozzle 7A is adjusted by the blade 20 while flowing uniformly. Be expanded.

  As the primer, a solution, dispersion, emulsion, silane coupling agent, etc. of a resin having adhesion to a rubber layer formed on the core peripheral surface such as acrylic resin, vinyl acetate resin, epoxy resin, urea resin, melamine resin, etc. Is used.

  In the first step, the core 1 set in the coating apparatus is usually rotated at a rotational speed of 100 rpm to 600 rpm, and the moving speed of the nozzle 7A is normally set to 300 mm / min to 2000 mm / min. The distance from the tip of 7A to the peripheral surface of the core is set to 0.1 mm to 2.0 mm, and the primer discharge amount from the nozzle 7A is usually set to 0.5 ml / min to 5.0 ml / min.

  After applying the primer, if necessary, air-dry at room temperature for 30 minutes to 90 minutes, then set the core 1 peripheral surface temperature to usually 100 ° C. to 150 ° C. by the heating means 18 and heat for 30 minutes to 60 minutes. The primer layer P1 is formed on the peripheral surface of the core 1 by baking. The thickness of the primer layer P1 is usually set to 0.5 μm to 100 μm.

  The core 1 in which the primer layer P1 is formed in advance on the peripheral surface of the core 1 may be set in the coating apparatus. In this case, the primer is applied to the peripheral surface of the core by a well-known application means such as flow coating, spraying, brushing, etc., and after application, it is introduced into a heating furnace and the same as described above at 100 to 150 ° C. for 30 to 60 minutes. Bake with heat.

  In the second step, after the primer layer P1 is formed, the nozzle 7A is replaced with a rubber nozzle 7B. The nozzle 7B is supplied with a liquid rubber material from a rubber tank (not shown) via a tube 22B by a metering pump. While the core 1 is cooled or not cooled, the nozzle 7B is moved over the core 1 along the axial direction from one end to the other while the liquid rubber material is passed from the nozzle 7B to the circumference of the core 1 It is poured over the surface, the thickness is adjusted by the blade 20, and the flow is spread and smoothed uniformly. Normally, the rotation speed of the core 1 is set to 150 rpm to 800 rpm, preferably 200 rpm to 400 rpm, the preheating temperature of the core 1 is 50 to 100 ° C., preferably 60 to 80 ° C., and the nozzle 7B has a diameter of about 1 mm. The moving speed is usually set to 200 to 1000 mm / min, preferably 300 to 600 mm / min, and the discharge amount of the liquid rubber material from the nozzle 7B is usually 25 to 40 g / min, preferably 30 to 30 mm / min. Set to 35 g / min.

  Examples of the liquid rubber material include urethane rubber, prepolymer, silicon resin prepolymer, epoxy resin prepolymer, and unvulcanized rubber. In the case of a prepolymer, generally a curing agent is mixed before coating. . If the prepolymer itself is liquid, it is not necessary to dilute with a solvent, but if it is a solid or a high-viscosity liquid, it is diluted with a solvent to a predetermined viscosity. Usually, the viscosity of the liquid rubber material is 500 to 200,000 centipoise (CP) at 25 ° C. As the solvent, general organic solvents such as ethyl acetate, n-butyl acetate, toluene, xylol, methyl ethyl ketone, methyl isobutyl ketone, cellosolve acetate, n-hexane, cyclohexane, n-hebutane, ethanol, isopropanol and the like are usually used in combination. The

  In the step of pouring and applying the liquid rubber material to the peripheral surface of the core, if the temperature of the peripheral surface of the core is less than 50 ° C., it is difficult for the liquid rubber material to decrease in viscosity, and the liquid surface is uniformly applied to the peripheral surface of the core. It becomes difficult to apply the rubber material, and when the temperature exceeds 100 ° C., the liquid rubber material is cured, and uniform application becomes difficult. There is a risk of dripping down from the peripheral surface of the core.

  The liquid rubber material applied by being applied to the circumferential surface of the core 1 is adjusted in thickness by the blade 20 and is uniformly spread and smoothed.

  After application of the liquid rubber material, pre-curing is usually performed by heating for about 1 minute at a temperature of the core 1 peripheral surface temperature of about 100 ° C. After preliminary curing, cool to room temperature.

  In the third step, a modified tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (modified PFA) aqueous dispersion (PFA primer) having a functional group introduced as a primer is applied to the surface of the precured rubber material coating layer. Examples of the functional group introduced into the modified PFA include an epoxy group, a carboxyl group, an amino group, and an amide group. By introducing the functional group, the modified PFA is combined with the precured rubber material in the fourth step. Good adhesion to both of the PFA release layers to be formed. As the solvent for the aqueous dispersion, water or a mixed solvent of water and a water-soluble organic solvent such as methanol, ethanol, isopropanol or acetone is used. Used, some amount of surfactant is added as a dispersion stabilizer.

  Also in the third step, the nozzle 7C dedicated to the PFA primer is used, and the PFA primer is supplied to the nozzle 7C from a PFA primer tank (not shown) via the tube 22C. It moves from one end to the other end along the axial direction of the core, and the PFA primer is applied to the surface of the precured rubber material coating layer.

  After the application of the PFA primer, pre-drying is usually performed at a core 1 peripheral surface temperature of 50 ° C. to 70 ° C. for about 1 minute to 2 minutes while maintaining the rotation of the core 1. The thickness of the PFA primer layer is set to about 20 μm or less.

  In the fourth step, a PFA aqueous dispersion is applied after the PFA primer coating layer is pre-dried. The aqueous PFA dispersion is obtained by dispersing unmodified PFA in the same solvent as the PFA primer.

  Also in the fourth step, a nozzle 7D dedicated to PFA aqueous dispersion is used as the nozzle, and PFA aqueous dispersion is supplied to the nozzle 7D from a PFA dispersion tank (not shown), and the nozzle 7D has the core at a predetermined speed. It moves from one end to the other end along the uniaxial direction, and the PFA aqueous dispersion is applied to the surface of the PFA primer coating layer.

  After applying the PFA aqueous dispersion, the temperature of the peripheral surface of the core is usually raised to 300 ° C. to 400 ° C. and baked for about 5 minutes.

  In the fifth step, the core 1 having the rubber layer G having the PFA release layer R formed on the surface in this manner is removed from the coating apparatus and introduced into a heating furnace, and usually 150 ° C. to 250 ° C. for 3 hours. Heat treatment for ˜5 hours.

  In the heat treatment, the rubber layer G is completely cured, and the thickness of the PFA release layer R is usually set to 5 μm to 50 μm.

  In this way, as shown in FIG. 3, the rubber layer G is formed on the peripheral surface of the core 1 via the primer layer P1, and the surface of the rubber layer G is exposed to the PFA release layer R via the PFA primer layer P2. The rubber roller 30 in which is formed is manufactured. The thickness of the rubber layer G is usually set to 1 mm or less.

  The above process is a process for producing the rubber roller 30 in which the PFA release layer R is formed on the surface of the rubber layer G. However, in the present invention, the PFA release layer R is not essential. When omitting the PFA release layer R, after pre-curing the liquid rubber material coating layer in the second step, the core 1 on which the pre-cured rubber material coating layer is formed is removed from the coating apparatus and placed in a heating furnace. Introduced and baked in the same manner as described above. In the present invention, the blade was used to spread and smooth the sprinkled primer, liquid rubber material, etc. You may do it.

  If desired, the rubber roller may be coated with a PFA tube as a release layer and heated and melted.

  Further, when manufacturing a rubber roller having a crown shape or an inverted crown shape as described above, the moving speed of the nozzle 7B in the second step is changed to adjust the coating amount of the liquid rubber material. That is, in the case of the crown shape, the moving speed of the nozzle 7B is gradually decreased from one end to the center, and gradually increased from the center to the other end. In the case of the reverse crown shape, the moving speed of the nozzle 7B is increased from one end to the center. The speed gradually increases from the center to the other end.

  In addition to adjusting the moving speed of the nozzle 7B, the amount of liquid rubber discharged from the nozzle 7B may be adjusted.

  FIG. 4 is a graph showing the moving speed (mm / min) of the nozzle 7B and the liquid rubber material discharge amount (g / 10 seconds). Referring to FIG. 4, it can be seen that the discharge rate decreases as the nozzle movement speed increases. In this embodiment, when the relationship between the discharge amount of the liquid rubber material from the nozzle and the film thickness is obtained, y = −500x + 700 (x = film thickness (mm), y = moving speed (mm / min).

  In the nozzle movement mode shown in FIG. 4, a reverse crown rubber roller 30 as shown in FIG. 4 is manufactured. In this case, the maximum diameter−minimum diameter = 30 μm.

  In the present invention, since a molding die is not used for manufacturing the rubber roller, the manufacturing process of the rubber roller is shortened, and an undercut crown-shaped or inverted crown-shaped rubber roller can be easily manufactured.

1 to 4 show an embodiment of the present invention.
Side view of coating device in core set state Description of coating device in core set state Partial side sectional view of rubber roller Graph showing relationship between nozzle movement speed and liquid rubber material discharge amount − ● −: Discharge amount, −Δ−: Nozzle movement speed Reverse crown rubber roller side view

Explanation of symbols

1 Core 2A, 2B Chuck 7A, 7B, 7C, 7D Nozzle 30 Rubber roller P1 Primer G Rubber layer P2 PFA primer layer R PFA release layer

Claims (6)

  A heating means is inserted into the pipe-shaped core, the core is heated from the inside by the heating means, the core is rotated around the axis, and the liquid rubber material is discharged from a nozzle that moves along the axial direction above the core. A method for producing a rubber roller, wherein the liquid rubber material coating layer is formed on the outer periphery of the core by pouring, and then the liquid rubber coating layer is cured by heating to form a rubber layer. A heating means is inserted into the pipe-shaped core, the core is heated from the inside by the heating means, the core is rotated about the axis, and a core primer is applied from a nozzle that moves along the axial direction above the core. The core primer is applied to the outer periphery of the core by flowing and dried,
Next, the liquid rubber material coating layer is formed on the outer periphery of the core by pouring the liquid rubber material from a nozzle that moves along the axial direction above the core with the core primer coated on the outer periphery. Pre-cured by heating the layer to a pre-cured rubber layer,
Further, the outer periphery of the rubber layer is formed by flowing a modified tetrafluoroethylene perfluoroalkyl vinyl ether copolymer primer dispersion into which a functional group is introduced from a nozzle that moves along the axial direction above the core on which the precured rubber layer is formed. To form a modified tetrafluoroethylene perfluoroalkyl vinyl ether copolymer primer layer,
Further, the modified tetrafluoroethylene perfluoroalkyl vinyl ether copolymer is placed on the outer periphery of the silicon rubber layer by pouring a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer dispersion from a nozzle that moves along the axial direction above the core. Form a tetrafluoroalkyl vinyl ether copolymer release layer through the primer layer,
Thereafter, the tetrafluoroalkyl vinyl ether release layer is heated together with the precured rubber layer to fuse the release layer to the rubber layer, and the precured rubber layer is completely cured to form a rubber layer. Manufacturing method of rubber roller.   3. The method for producing a rubber roller according to claim 1, wherein the moving speed of the nozzle is gradually increased from one end toward the center and gradually decreased from the center toward the other to form an inverted crown-shaped rubber layer.   The method for producing a rubber roller according to claim 1 or 2, wherein the moving speed of the nozzle is gradually decreased from one end toward the center and gradually increased from the center toward the other to form a crown-shaped rubber layer.   The method for producing a rubber roller according to claim 1 or 2, wherein the discharge amount of the liquid rubber material from the nozzle is gradually increased from one end toward the center and gradually decreased from the center toward the other to form a crown-shaped rubber layer. The method for producing a rubber roller according to claim 1 or 2, wherein the discharge amount of the liquid rubber material from the nozzle is gradually decreased from one end toward the center, and is gradually increased from the center toward the other to form a reverse crown-shaped rubber layer. .