JPH1170594A - Manufacture of rubber roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a rubber roll for developing a method for applying a thermoplastic releaser on a core bar, applying the releaser at the normal temperature, releasing easily a rubber layer together with the releaser from the core bar without tearing off the rubber layer in the middle or making the releaser remain on the core bar and eliminating the necessity of cleaning after the release. SOLUTION: In a manufacturing method for a rubber roll, first a thermosetting releaser is applied on a rubber layer non-forming section of a core body 1 to form a releaser layer 2. Then the core bar 1 with the releaser layer 2 is fed into an extruder 3, and the core bar 1 and an unvulcanized rubber material 4 are coextruded to form an unvulcanized rubber layer 5 on the periphery of the core bar 1. The unvulcanized layer 5 is vulcanized and cured. Only the vulcanized rubber layer 7 on the release layer 2 is released together with the releaser 2 off the core bar 1. As the releaser 2, preferably a thermosetting type fluorine releaser is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rubber roll useful as a paper feed roll, a developing roll, a charging roll, a transfer roll, a platen roll, and the like used in a copying machine, an LBP (laser beam printer), a facsimile, and the like. .

[0002]

2. Description of the Related Art Conventionally, rubber rolls used for the above-mentioned applications have been obtained by removing a core metal without providing a rubber layer partially even at both ends of a rubber roll set on a bearing portion of a device body and also at an intermediate portion. Some have a portion that is not. As a method for producing these rubber rolls, an extrusion molding method is mainly employed. As an example of this manufacturing method, the present inventor has previously proposed the method shown in FIGS. That is, plastic caps b are attached to both ends of the cored bar a (see FIG. 2A), and these are continuously supplied to an extruder die c (see FIG. 2B). A rubber material is supplied to a die c (not shown). Next, the core metal a, the cap b and the unvulcanized rubber material d are co-extruded from the extruder die c, and the unvulcanized rubber material d covered with the unvulcanized rubber material d is co-extruded around the core metal a and the cap b. A vulcanized rubber layer e was provided (see FIG. 2 (c)), and the rubber roll on which the unvulcanized rubber layer e was formed was separated one by one (see FIG. 2 (d)), and the cap b was covered. Only the unvulcanized rubber layer e is peeled off (see FIG. 2 (e)), the caps b are removed from both ends of the rubber roll (see FIG. 2 (f)), and then the unvulcanized rubber roll is cured in a drying furnace f. (Figure 2
(See (g)).

In the above-mentioned manufacturing method, the cap made of plastic resin attached to both ends of the metal core has a concave portion or a through hole which matches the shape of the rubber layer non-formed portion such as the thickness and length of the metal core. Therefore, if the shape, thickness, length, position, etc. of the cored bar are different, it is necessary to separately prepare a cap having a shape corresponding to the shape. Also,
If there is a gap between the cored bar and the cap, the unvulcanized rubber material wraps around this gap, and the rubber material adheres to the portion where the rubber layer is not desired, that is, the rubber layer non-formed portion, and the attached rubber material is After vulcanization and curing, burrs are formed, and deburring is difficult and time-consuming, which has been a factor in increasing costs. As a countermeasure, a method has been devised in which a thermoplastic release agent that has been heated and melted is applied in advance to a portion of the core metal where the rubber layer is not formed (Japanese Patent Application Laid-Open No. 08-294952). According to this method, it is no longer necessary to prepare caps of various sizes according to the shape of the rubber layer non-formed portion.

[0004]

The method of applying a thermoplastic release agent to a portion of the core metal where the rubber layer is not formed is based on the fact that the release agent used is solid at room temperature and is a heat-melting type. In order to provide it, it was necessary to keep it warm and liquid. In addition, since only wax-based materials can be practically adopted due to the property of being used after heating, the contact angle, which is an index of releasability, does not always have a high level value. Furthermore, because the strength of the film after application is low,
Even if you try to peel only the rubber layer of the rubber layer non-formed part, to prevent the rubber from being broken in the middle or the release agent remaining on the core metal because it cannot be removed, it will not interfere with the normal rotation of the rubber roll. In some cases, cleaning is required.

According to the present invention, a method of applying a thermoplastic release agent to a core metal is developed, and the release agent can be applied at room temperature, and when only the rubber layer adhered to the rubber layer non-formed portion is peeled off. A method of manufacturing a rubber roll that can easily peel off a rubber layer from a core metal together with a release agent without the rubber layer being torn in the middle or leaving the release agent on the core metal, and requiring no cleaning after peeling. I will provide a.

[0006]

A method of manufacturing a rubber roll according to the present invention comprises a step of forming a release agent layer by applying a thermosetting release agent to a portion of a core metal where a rubber layer is not formed; Supplying the cored bar with the layer to an extruder die, co-extruding the cored bar and the unvulcanized rubber material to form an unvulcanized rubber layer around the cored bar, The method includes a step of vulcanizing and curing the layer, and a step of peeling only the vulcanized rubber layer on the release agent layer together with the release agent layer from the core metal. The curing of the thermosetting release agent can be performed before the core metal is supplied to the extruder or when the unvulcanized rubber layer is vulcanized and cured. Further, as the thermosetting release agent, a heat-curable fluorine-based release agent is preferably used.

In the present invention, the portion of the core metal where the rubber layer is not formed,
Mainly the two ends of the rubber roll set on the bearing part of the equipment main body, but in the case of a paper feed roll, etc., a single cored bar with rubber layers separated from each other and provided at multiple locations In this case, between the rubber layers is a non-rubber layer-formed portion.

As the core metal for the rubber roll, metals such as aluminum, stainless steel, plated steel and steel alloy are used. The thermosetting release agent used in the present invention is a heat-curable type in which a solid film is formed by heating, and in particular, it is preferable to use a fluorine-based heat-curable coating agent having high releasability. desirable. The fluorine-based heat-curable coating agent has good releasability from the core metal and also adheres well to the unvulcanized rubber material, thereby making the separation between the core metal and the rubber layer more complete.

[0009] The application of the thermosetting release agent to the rubber roll core may be performed, for example, by first chucking both ends of the core and rotating the rubber around the axis of the rubber roll while applying a silicone rubber sponge impregnated with the release agent. This is performed while pressing an acrylic rubber sponge, a urethane rubber sponge, or the like against a predetermined portion of the core metal, that is, a portion where the rubber layer is not formed. At this time, the rotation speed of the core metal is
50 rpm or more is preferred. After the release agent is applied, it is left as it is, or is placed in a drying furnace and cured by heating to form a film of the release agent, and the process proceeds to the next step.

As the releasing agent, a low molecular weight fluororesin is used.
Phenol resin, urea resin containing 0.05% by weight or more,
Thermosetting resins such as melamine resin, polyester resin, epoxy resin, epoxy acrylate resin, urethane resin, silicon resin, diallyl phthalate resin, or coatings in which these thermosetting resins are dissolved in organic solvents or low molecular weight monomers Agents and the like. Furthermore, heat of natural rubber, styrene butadiene rubber, isoprene rubber, acrylonitrile butadiene rubber, butyl rubber, chloroprene rubber, epichlorohydrin rubber, fluorine rubber, ethylene propylene rubber, acrylic rubber, silicone rubber, urethane rubber, etc. A curable rubber containing a fluorine resin may be used. Further, there may be mentioned those obtained by modifying the above-mentioned thermosetting resin or thermosetting rubber with fluorine.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in more detail with reference to FIG. First, a thermosetting release agent is applied to a portion of the rubber roll core bar 1 where a rubber layer is not desired to be formed, and a release agent layer 2 is formed (see FIG. 1A). . The core 1 provided with the release agent layer 2 is supplied to the extruder die 3, preferably a plurality of cores are brought into contact with each other and supplied sequentially (see FIG. 1 (b)). The rubber material 4 is co-extruded from the extruder die 3, and the periphery of the core is covered with the unvulcanized rubber material 4 to provide an unvulcanized rubber layer 5 (see FIG. 1 (c)). Further, the rubber roll precursor on which the release agent layer 2 and the unvulcanized rubber layer 5 are formed is separated one by one (see FIG. 1 (d)), and then the rubber roll precursor is heated in a drying furnace 6, The vulcanized rubber layer 5 is vulcanized and cured to form a vulcanized rubber layer 7 (see FIG. 1E). The release agent layer 2 may be vulcanized and cured before being supplied to the extruder die 3, or may be vulcanized and cured together with the unvulcanized rubber layer 5 after the unvulcanized rubber layer 5 is formed. Thereafter, only the vulcanized rubber layer 7 'on the release agent layer 2 is peeled off from the core 1 together with the release agent layer 2 to produce a desired rubber roll (FIG. 1).
(F)).

[0012]

EXAMPLES Specific embodiments of the present invention will be described below in more detail with reference to Examples and Comparative Examples. Example 1 Outer diameter 6 mm, length 250 mm as core metal for rubber roll
Was subjected to electroless nickel plating. A fluorine-based heat-curable release agent is applied to both ends of each 20 mm of this core metal:
X70-029B (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) was coated with a release agent obtained by mixing FR thinner (as above) and DF-29 (as above), and a drying furnace maintained at 300 ° C. For 3 minutes. Next, the cored bar is supplied to an extruder die, co-extruded with the unvulcanized silicone rubber, the periphery of the cored bar is coated with the unvulcanized silicone rubber, and further heated in a drying oven at 250 ° C. for 15 minutes. Thus, the provided unvulcanized silicone rubber layer was vulcanized and cured. Next, the vulcanized silicone rubber layer together with the release agent layer was peeled off from the core metal at the rubber layer non-formed portions at both ends of the core bar provided with the release agent layer. At this time, the release agent layer is firmly attached to the vulcanized silicone rubber layer, so that the vulcanized silicone rubber layer and the release agent layer do not generate burrs,
It was able to be peeled off neatly integrally.

Example 2 An outer diameter of 6 mm and a length of 250 mm were used as a core metal for a rubber roll.
Was subjected to electroless nickel plating. A fluorine-based heat-curable release agent is applied to both ends of each 20 mm of this core metal:
X70-029B (same as above), FR thinner (same as above), DF-2
A release agent obtained by mixing 9 (as described above) was applied. next,
The core metal is supplied to the extruder die, co-extruded with the unvulcanized silicone rubber, the periphery of the core metal is coated with the unvulcanized silicone rubber, and further heated in a drying oven at 250 ° C. for 15 minutes. The obtained unvulcanized silicone rubber layer and release agent layer were vulcanized and cured. Next, the vulcanized silicone rubber layer together with the release agent layer was peeled off from the core metal at the rubber layer non-formed portions at both ends of the core bar provided with the release agent layer. At this time, the release agent layer is firmly attached to the vulcanized silicone rubber layer, and the vulcanized silicone rubber layer and the release agent layer do not generate burrs,
It was able to be peeled off neatly integrally.

Comparative Example 1 A heat-melting type paraffin wax (melting point: 58 ° C.) was used as a releasing agent instead of a heat-curing type releasing agent.
A mold release agent was applied to each of the 20 mm ends of the core used in Step 2 by immersing it in a 100 ° C. melt of the paraffin wax. Thereafter, a vulcanized silicone rubber layer was provided in the same manner as in Examples 1 and 2. When the vulcanized silicone rubber layer in the rubber layer non-formed portion was peeled off from the core metal, the vulcanized silicone rubber layer was torn off in the middle or toward the core metal. The release agent remained and could not be peeled cleanly. The peeling force measured at this time was 1.5 kgf for the conventional paraffin wax and 1.1 kgf for the fluorine-based heat-curable type.

[0015]

The method for producing a rubber roll according to the present invention does not require the production of caps of various sizes conventionally used for the portion of the core metal where the rubber layer is not formed. With the agent, there was a peeling failure when peeling off from the core metal, or a release agent remained on the core metal, but instead of these, the heat-curable release agent was vulcanized without generating burrs It can be easily and completely removed together with the rubber layer. For this reason, the wiping operation and the cleaning operation after the processing of the cored bar become unnecessary, and this is an extremely excellent production method capable of producing a desired rubber roll at lower cost than before.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of the present invention in the order of steps.

FIG. 2 is a schematic cross-sectional view showing a conventional method of manufacturing a rubber roll in the order of steps.

[Explanation of symbols]

 1, a core metal, release agent layer 3, c extruder die 4, d Unvulcanized rubber material, 5, e ... unvulcanized rubber layer, 6, f ... drying oven, 7, 7 '... vulcanized rubber layer, b ... ·······cap.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 15/16 103 G03G 15/16 103

Claims (3)

[Claims] A step of applying a thermosetting release agent to a portion of the core metal where the rubber layer is not formed to form a release agent layer, and supplying the core having the release agent layer to an extruder die. A step of co-extruding the core metal and the unvulcanized rubber material to form an unvulcanized rubber layer around the core metal, a step of vulcanizing and curing the unvulcanized rubber layer, and a release agent Separating the vulcanized rubber layer only on the release agent layer together with the layer from the core metal. 2. The method for producing a rubber roll according to claim 1, wherein the curing of the thermosetting release agent is performed before the core metal is supplied to the extruder or when the unvulcanized rubber layer is vulcanized and cured. 3. The method for producing a rubber roll according to claim 1, wherein a heat-curable fluorine-based release agent is used as the thermosetting release agent.