JP2002235734A - Rubber roller and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber roller easily released from a form block having superior manufacturing workability, and a provide its manufacturing method. SOLUTION: This rubber roller is provided with a roller shaft and a roller body formed by injecting and molding liquid rubber into the form block formed concentrically to the outer circumference of the roller shaft. The form block is provided with a film concentrically disposed about the roller shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rubber roller and a method of manufacturing the same, and more particularly to a rubber roller suitable for an oil application roller and an image fixing roller in office equipment such as a copying machine and a method of manufacturing the same.

[0002]

2. Description of the Related Art In an image forming process of an electrophotographic system such as a copying machine or a facsimile, rubber rollers such as an image fixing roller and an oil applying roller for preventing offset are often used. In these rubber rollers, heat-resistant rubber such as silicone rubber, fluorine rubber, or fluorinated silicone rubber is used for the entire roller or the surface layer of the roller. In addition, since there is no need to reduce the size of the apparatus and to prevent contamination due to oil leakage, an oil-containing rubber roller in which the rubber roller itself holds a certain amount of oil is used as the oil application roller.

FIG. 5 shows a conventional method of manufacturing a rubber roller.
This will be described with reference to FIG. 5 (a) to 5 (c) are manufacturing process diagrams of the rubber roller. First, a cylindrical mold 4, a disk-shaped mold 5 and a mold 6 for sealing the top and bottom of the cylindrical mold 4 are provided.
And a molding die having a cavity 8 having a vertical cylindrical shape is prepared. The roller shaft 2 made of metal or the like is vertically arranged at the center of the cylindrical shaft of the cavity 8 (FIG. 5).
(A)). A mold release agent is applied to the inner wall surface 4a of the cylindrical mold 4, and the mold 5 is provided with an injection port 5a. Thereafter, the liquid rubber 9 is injected into the cavity 8 in which the roller shaft 2 is arranged, and is heated and cured (FIG. 5B). A rubber roller in which the roller shaft 2 and the roller body 3 are integrally formed is obtained by applying an extruding force A from the molding die after the heat curing or by pulling out with a drawing force B (FIG. 5).
(C)).

[0004]

However, the roller body 3 is soft, unlike the resin material, even after the liquid rubber 9 is cured, and even if the release agent is applied, The friction with 4a is large. In addition, since the rubber material has a large Poisson's ratio of about 0.5, when the rubber material is to be extruded from the cylindrical mold 4, a deformation stress component in the extrusion direction acts on the inner wall surface of the mold to further increase the friction. If you try to pull out
Due to the frictional force with the inner wall surface of the mold, there is a problem that the rubber is cut unless it is pulled very slowly with a small force.

If the mold 4 is divided into two parts, it is easy to take out the rubber roller, but it is difficult to process the shape of the rubber roller with high accuracy, and the number of processing steps is increased and the cost must be increased. There is.

SUMMARY OF THE INVENTION The present invention has been made to address such a problem, and it is an object of the present invention to provide a rubber roller having excellent dimensional accuracy of a roller body, easy removal from a molding die, and excellent manufacturing workability, and a method of manufacturing the same. Aim.

[0007]

SUMMARY OF THE INVENTION The present invention provides a roller shaft,
A roller body formed by injecting liquid rubber into a molding die formed concentrically on the outer periphery of the roller shaft; and a roller body comprising the molding die disposed concentrically on the roller shaft. It is characterized by comprising a film. Further, the liquid rubber is an oil-containing liquid rubber. The JIS hardness after rubber roller molding is 3 ~
70 degrees, the ratio of the axial length L of the molded product to the outer diameter D (L /
D) is 2 to 20.

[0008] By using a molding die in which a film is arranged in a concentric cylindrical shape, the rubber roller can be easily separated from the molding die, and a rubber roller having high dimensional accuracy can be obtained. Further, since no stress such as compression or elongation is applied when the rubber roller is taken out from the mold, peeling or cracking of the rubber roller surface does not occur.

In the method of manufacturing a rubber roller according to the present invention, a step of arranging a roller shaft around the center of a cylindrical shaft of a molding die for forming a cylindrical cavity, and a step of injecting liquid rubber into the cavity in which the roller shaft is arranged. And, a manufacturing method comprising a step of curing the liquid rubber under predetermined conditions,
A molding die for forming the cavity includes a film disposed concentrically on the roller shaft. Further, the molding die is characterized in that a film is mounted on an inner surface of a molding die. Further, the film has a heat resistance higher than the curing temperature of the liquid rubber. Further, the film is a plastic film. The film is characterized in that a fluororesin coating is formed on the inner surface side of the cavity.

[0010] Since the molding die for forming the cylindrical cavity is provided with the film concentrically arranged on the roller shaft and is extruded or pulled out from the molding die together with the film, the cured liquid rubber is molded. It can be easily removed from the mold without applying stress such as compression or elongation.
In particular, by mounting a film on the inner surface of a molding die, heating and curing the liquid rubber, and taking it out together with the film, the rubber roller made of a soft rubber material is excellent in dimensional accuracy even with a simple device, and the manufacturing process. Is simplified.

[0011]

FIG. 1 shows an example of a rubber roller according to the present invention. FIG. 1 is a perspective view of a rubber roller. The rubber roller 1 includes a roller shaft 2 and a roller body 3 formed by condensing liquid rubber on the outer periphery of the roller shaft 2 to form a concentric cylinder.
It is composed of A non-woven fabric or the like is wound around the roller shaft 2 as needed to improve the adhesion between the roller shaft 2 and the roller body 3. The roller body 3 is preferably an oil-containing liquid rubber described later. The JIS hardness of the roller body 3 is 3 to 70 degrees, and the ratio of the axial length L to the outer diameter D (L /
D) is 2 to 20. In the present invention, in the manufacturing process, the rubber roller having the roller main body is easily obtained because the film is provided with the film concentrically arranged on the roller shaft.

The liquid rubber which can be used in the present invention may be any liquid rubber which can be poured into a mold forming a cylindrical cavity and which exhibits rubber elasticity by a curing reaction such as a crosslinking or vulcanization reaction. , Fluorine rubber, fluorine silicone rubber and the like. Among these, liquid silicone rubber is particularly preferable because it can be made into an oil-containing silicone rubber by blending silicone oil, fluorine-modified silicone oil, fluorine-based oil and the like. The liquid silicone rubber becomes a rubber elastic body by injecting and curing a paste-like or fluid liquid material with a polyorganosiloxane having a crosslinkable group.

As the liquid silicone rubber, either an addition type liquid silicone rubber or a condensation type liquid silicone rubber can be used. In the present invention, an addition-type liquid silicone rubber in which the curing reaction proceeds uniformly from the surface to the inside without generating by-products is preferable.

The addition-type liquid silicone rubber is prepared by combining a polyorganosiloxane base having a vinyl group at a terminal or a side chain and a compound containing -SiH groups having three or more -SiH groups at a molecular terminal in the presence of a platinum-based catalyst. It is a rubber that is crosslinked by a hydrosilylation reaction that is an addition reaction. The polyorganosiloxane base is a polyorganosiloxane in which a methyl group is bonded to a silicon atom in a main chain, and a phenyl group, a trifluoropropyl group and the like are bonded as required. The -SiH group-containing compound as a cross-linking agent is a polymer having a relatively low molecular weight, and is used in an amount of 1 to 3 molar equivalents of the -SiH group per 1 molar equivalent of the polyorganosiloxane-based vinyl group.

Commercially available addition type liquid silicone rubbers include, for example, KE1603 and KE16 manufactured by Shin-Etsu Chemical Co., Ltd.
00, KE1310T, KE1310S, KE1310
ST, KE1300 and the like can be exemplified.

The oil to be blended with the silicone rubber is preferably a silicone oil, a fluorine-modified silicone oil or a fluorine-based oil which has a difference in solubility parameter with the silicone rubber within 3 and has excellent compatibility. Particularly preferred oils are silicone oils that are most compatible with silicone rubber.

As the silicone oil that can be used in the present invention, any of so-called straight silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and so-called modified silicone oils such as alkyl-modified silicone oil and aralkyl-modified silicone oil can be used. Among these, silicone oils whose side chains are non-reactive are preferred because they easily achieve a balance between oil retention and oil releasability. Specifically, dimethyl silicone oil and methylphenyl having a methylsiloxane unit, which is a non-reactive straight silicone oil, are preferred. Silicone oils are preferred. The silicone oil has a kinematic viscosity at 40 ° C. of 1200 cst or less, preferably 10 to 500 cst, because evaporation at a high temperature is small.

When a rubber roll is used for an oil application roller or the like of a copying machine, a filler can be blended with the liquid rubber in order to maintain appropriate hardness and strength. Specific examples of the filler include fine powders such as silica, mica, aluminum oxide, iron oxide, magnesium oxide, titanium oxide, boron nitride, and aluminum nitride. Among these, silica fine powder is most preferable, and aluminum oxide fine powder, titanium oxide fine powder and the like are also preferable because they improve oil retention. Further, an oil retaining agent such as talc can be blended.

In the rubber roller of the present invention, the JIS hardness of the roller body after molding is 3 to 70 degrees, and the ratio of the axial length to the outer diameter is 2 to 20. If the JIS hardness exceeds 70 degrees, it is not necessary to use a mold provided with a film arranged concentrically on the roller shaft, and the JIS hardness is 3 degrees.
If it is less than the degree, it is very soft and deforms greatly when a force is applied. When the ratio of the axial length (L) of the roller body to the outer diameter (D), L / D is less than 2, friction with the wall surface of the mold becomes small. There is no need to use and manufacture. Also, the L / D does not exceed 20 as judged from the practical size of the paper and the size of the copying machine.

A method of manufacturing a rubber roller having the above characteristics will be described with reference to FIG. 2 (a) to FIG.
(E) is a manufacturing process diagram of a rubber roller. First, a cylindrical mold 4, a disk-shaped mold 5 for sealing the top and bottom of the cylindrical mold 4.
8 that assembles the mold and the mold 6 into a vertical cylindrical shape
Is prepared. The roller shaft 2 made of metal or the like is vertically arranged at the center of the cylindrical shaft of the cavity 8. Further, a film 7 is arranged in contact with the inner wall surface of the cylindrical mold 4 so as to be concentric with the roller shaft 2. The mold 5 is provided with an injection port 5a (FIG. 2A).
In the present invention, since the film 7 is disposed, the cylindrical mold 4 may be a split mold.

As shown in FIG. 3, the film 7 is formed by winding one rectangular film in contact with the inner wall surface of the cylindrical mold 4. FIG. 3 is an example of a cross-sectional view taken along the line CC in FIG. The winding of the film 7 is abutted (FIG. 3A),
Lap winding (Fig. 3 (b)), multiple lap winding (Fig. 3 (c))
And can be. It is preferable to form at least 1.5 to 2.0 multiple lap windings since the expansion and contraction during the crosslinking reaction of the liquid rubber can be absorbed. Further, the wound film 7 can be heat-treated to be in close contact with the inner wall surface of the cylindrical mold 4.

As long as the film 7 has a mechanical strength capable of being wound in contact with the inner wall surface of the cylindrical mold 4, it is a film having a thickness of 100 μm or less and having heat resistance higher than the curing temperature of the liquid rubber described later. If you can use it. If the thickness exceeds 100 μm, a step is formed in the lap winding portion, and the surface of the rubber roller may not be uniform. Further, the heat resistance higher than the curing temperature of the liquid rubber means that, even when the liquid rubber generates heat due to a vulcanization reaction or the like, it can maintain the shape of the film wound on the inner wall surface of the cylindrical mold 4. It means having heat resistance to maintain strength.

Examples of the material of the film 7 include a metal film and a plastic film. Particularly, a plastic film is preferable because it easily contacts the inner wall surface of the cylindrical mold 4 and is easy to handle in the manufacturing process. Examples of the type of the plastic film include polyester films such as polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polyester ether, polyamide films, polyamide imide films, polyimide films, and fluororesin films.

It is preferable that the plastics film has a coating film having excellent releasability formed on the inner surface side of the cavity. Examples of the coating film having excellent releasability include a fluororesin coating film.

In the above example, the film 7 is disposed in contact with the inner wall surface of the mold 4. However, in the case of a film having excellent heat resistance and mechanical strength, the wound film itself is used instead of the mold 4. it can. An example is shown in FIG. FIG. 4 is a sectional view of a molding die. The film 7 is wound in contact with the outer periphery of the disk-shaped molds 5 and 6. Film fixing member 1
The mold 7 having the cavity 8 having a vertical cylindrical shape is obtained by fixing the film 7 with the use of 0. The roller shaft 2 made of metal or the like is vertically arranged at the center of the cylindrical shaft of the cavity 8. The mold 5 is provided with an injection port 5a.

A liquid rubber 9 such as liquid silicone rubber or oil-containing liquid silicone rubber is injected into the molding die or the cavity 8 of the molding die through the injection port 5a (FIG. 2).
(B)). For example, liquid silicone rubber component, oil component,
If necessary, the mixture of the fillers is mixed at room temperature so as to be homogeneous, and the mixture is injected after defoaming.

The liquid rubber is cured under predetermined conditions. Curing conditions are determined by the type of liquid rubber, oil content, and the like. In the case of the present invention, it is preferable to cure by combining primary vulcanization in the mold and secondary vulcanization after being removed from the mold. Since the primary vulcanization temperature can be lowered by the two-stage vulcanization, the types of plastic film materials that can be used increase. Further, the secondary vulcanization suppresses the deformation amount when the rubber roller is actually used. For this reason, the primary vulcanization temperature is
40-110 ° C, the secondary vulcanization temperature is a temperature close to the temperature at the time of actual use, for example, in the case of oil-containing liquid silicone rubber, 150-220
° C.

After the heat curing, the roller body 3 integrally formed with the roller shaft 2 is taken out of the mold 4 together with the film 7 by an extruding force A or a drawing force B (FIG. 2).
(C) and (d)). Since the film 7 is wound, the roller body 3 in which the liquid rubber has hardened can be easily taken out of the mold 4. When the mold 4 is a split mold, the rubber roller 1 wound around the film 7 can be taken out without extruding. Finally, the rubber roller 1 is obtained by peeling the film 7 (FIG. 2E).

[0029]

EXAMPLES The materials used in the respective examples and comparative examples are shown below. In addition, [] shows the symbol in Table 1. 1) Silicone rubber component Addition type liquid silicone rubber [silicone rubber]: KE1603A and KE1603B (manufactured by Shin-Etsu Chemical Co., Ltd.), and the rubber component is KE1603A (kinematic viscosity 7).
50cst (40 ° C)) and KE1603B (Kinematic viscosity 500cst (40
Is a rubber component that is compounded and cured at a weight ratio of 1/1. 2) Offset prevention liquid Dimethyl siloxane type silicone oil [silicone oil]: KF96SS (Kinematic viscosity 1 manufactured by Shin-Etsu Chemical Co., Ltd.)
00cst (40 ° C)) 3) Non-woven fabric: Bencott (made by Asahi Kasei Corporation)

Examples 1 to 3 As shown in FIG. 2, a stainless steel roller shaft having an outer diameter of 6 mm and a length of 259 mm was assembled, and a fluororesin-coated polyester film was placed on the cavity side of the fluororesin coating surface. And mounted twice inside the mold 4. As the polyester film, a 100 μm thick polyethylene terephthalate film having a 10 μm thick polytetrafluoroethylene coating layer was used. After the liquid rubber having the compounding ratio shown in Table 1 was injected into the mold, it was placed in a thermostat at 60 ° C. for 1 hour to perform primary vulcanization. Thereafter, the film was removed from the mold, the film was removed, and the film was further kept in a thermostat at 150 ° C. for 1 hour to perform secondary vulcanization to obtain a rubber roller having a roller body length of 230 mm and a roller outer diameter of 18 mm. Easy removal from mold,
The surface state of the rubber roller after removing the film and the hardness of the rubber portion of the rubber roller were evaluated. Table 1 shows the results
Shown in Regarding the removability from the mold, the case where the rubber roller could be taken out from the mold by extrusion or drawing was indicated by ○, and the case where the rubber roller could not be taken out was indicated by ×. The surface condition of the rubber roller was indicated by x when peeling or cracking occurred on the surface, and by ○ when it did not occur. The hardness of the rubber part was measured according to JIS S6050.

Example 4 A rubber roller was obtained under the same conditions and method as in Example 1 except that a non-woven bencot was wound around a stainless steel roller shaft and liquid rubber having a compounding ratio shown in Table 1 was used. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

Example 5 Example 1 was repeated except that the film mounted inside the mold 4 was a polyethylene terephthalate film having a thickness of 100 μm.
A rubber roller was obtained under the same conditions and method as described above. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

Example 6 Example 1 was repeated except that the film mounted inside the mold 4 was a polytetrafluoroethylene film having a thickness of 100 μm.
A rubber roller was obtained under the same conditions and method as described above. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

Comparative Examples 1 to 4 A rubber roller was obtained under the same conditions and method as in Example 1 except that the film was not mounted inside the mold 4 and that the liquid rubber having the compounding ratio shown in Table 1 was used. Was. Table 1 shows the results of the evaluation performed in the same manner as in Example 1.

[0035]

[Table 1]

As shown in Table 1, each of the examples was excellent in the removability from the mold, and the surface condition of the rubber roller was also good. On the other hand, in each of the comparative examples, even when the rubber hardness was almost the same as in each of the examples, the removability from the mold was poor, and peeling and cracking occurred on the surface of the rubber roller.

[0037]

The rubber roller according to the present invention comprises a roller shaft, and a roller main body formed by injecting liquid rubber into a molding die formed concentrically on the outer periphery of the roller shaft,
Since the above-mentioned forming die is provided with a film arranged concentrically on the roller shaft, it can be easily separated from the forming die and has excellent dimensional accuracy. Further, since no stress such as compression or elongation is applied when the rubber roller is taken out from the mold, peeling or cracking of the rubber roller surface does not occur. In particular, since the oil-containing liquid rubber and / or the JIS hardness and the roller shape have a predetermined hardness and shape, the above characteristics are more exhibited.

In the method of manufacturing a rubber roller according to the present invention, since the molding die for forming the cavity is provided with a film concentrically arranged on the roller shaft, the cured liquid rubber is subjected to stress such as compression or elongation from the molding die. It can be easily taken out without applying. In particular, by mounting a film on the inner surface of a molding die, heating and curing the liquid rubber, and taking it out together with the film, the rubber roller made of a soft rubber material is excellent in dimensional accuracy even with a simple device, and the manufacturing process. Is simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view of a rubber roller.

FIG. 2 is a manufacturing process diagram of a rubber roller.

FIG. 3 is an example of a cross-sectional view taken along the line CC in FIG.

FIG. 4 is a sectional view of a molding die.

FIG. 5 is a manufacturing process diagram of a conventional rubber roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rubber roller 2 Roller shaft 3 Roller body 4 Cylindrical mold 5, 6 Disc-shaped mold 7 Film 8 Cavity 9 Liquid rubber 10 Film fixing member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 105: 20 B29K 105: 20 B29L 31:32 B29L 31:32 F term (Reference) 3J103 AA02 AA13 AA23 AA32 EA02 FA15 GA02 GA57 GA66 GA73 HA03 HA05 HA12 HA15 HA33 HA41 HA53 4F204 AA33 AA45 AH04 EA03 EB12 EF01 EF05 EK07 EK24

Claims (8)

[Claims] 1. A rubber roller comprising: a roller shaft; and a roller main body formed by injecting liquid rubber into a molding die formed concentrically on the outer periphery of the roller shaft. A rubber roller comprising a film disposed concentrically on a roller shaft. 2. The rubber roller according to claim 1, wherein the liquid rubber is an oil-containing liquid rubber. 3. The roller body has a JIS hardness of 3 to 70 degrees,
3. The rubber roller according to claim 1, wherein a ratio (L / D) of the axial length L to the outer diameter D is 2 to 20. 4. A step of arranging a roller shaft around the center of a cylindrical axis of a molding die for forming a cylindrical cavity, a step of injecting liquid rubber into the cavity in which the roller shaft is arranged, and Curing the liquid rubber. A method of manufacturing a rubber roller, wherein the mold for forming the cavity includes a film concentrically disposed on the roller shaft. . 5. The method for manufacturing a rubber roller according to claim 4, wherein the molding die is formed by mounting the film on an inner surface of a molding die. 6. The method according to claim 4, wherein the film has heat resistance higher than a curing temperature of the liquid rubber. 7. The method according to claim 6, wherein the film is a plastic film. 8. The film according to claim 4, wherein a fluororesin coating is formed on the inner surface of the cavity of the film.
A method for manufacturing a rubber roller according to claim 7.