WO2010024223A1 - Method for producing rubber member - Google Patents

Abstract

Disclosed is a method for producing a self-lubricating rubber member in which exuding of a lubricant can be remarkably accelerated.  The method for producing a rubber member comprises a step of maintaining a rubber member at a temperature of 50-70°C for 8 or more hours, after a step of vulcanization-molding the rubber member.

Description

Manufacturing method of rubber member

The present invention relates to a method for producing a rubber member formed by vulcanizing and forming a rubber member having self-lubricating properties by precipitating a lubricant contained therein, and in particular, depositing the lubricant on the surface. It relates to what can be done early.

As a rubber member having self-lubricating properties, a stabilizer bush will be described below as an example. As shown in a perspective view in FIG. 1, the stabilizer bush 20 includes an inner hole 21 that holds a stabilizer bar, and an outer peripheral surface 22 that holds a stay for attachment to a vehicle body or a suspension. In order to allow relative displacement in a plurality of directions between the stabilizer bush 20 and the stabilizer bar, and between the stabilizer bush 20 and the stay, the stabilizer is configured to slide. The bush 20 has a self-lubricating property and is configured such that the lubricant contained therein is deposited on the surfaces of the inner hole 21 and the outer peripheral surface 22.

As a process for producing such a self-lubricating rubber member, as shown in the process diagram of FIG. 2, vulcanization is performed by vulcanizing an unvulcanized rubber material blended with a lubricant in a mold. It comprises a molding step 1, an inspection step 2 for inspecting the vulcanized stabilizer bush 20 taken out from the mold, a subsequent packaging step 3, and a shipping step 4.

Japanese Unexamined Patent Publication No. 63-184512

However, it is difficult to deposit a sufficient amount of lubricant on the surface of the stabilizer bush immediately after going through the above-mentioned steps. Therefore, it is necessary to keep the lubricant in a warehouse or the like until it is shipped, for example, for several months until the lubricant comes to the surface.

The present invention has been made in view of such problems, and an object thereof is to provide a method for producing a self-lubricating rubber member capable of remarkably promoting the precipitation of a lubricant on the surface.

<1> is a method of manufacturing a rubber member formed by vulcanizing and forming a rubber member having self-lubricating properties by precipitating a lubricant contained therein on the surface,
A method for producing a rubber member comprising a step of keeping the rubber member at a temperature of 50 to 70 ° C. for 8 hours or more after the step of vulcanization molding.

<2> is the method for producing a rubber member according to <1>, wherein the heat retention of the rubber member in the heat retention step is started within one hour after the vulcanization molding step.

<3> is a method for producing a rubber member according to <1> or <2>, further comprising a step of forcibly cooling the rubber member after the heat retaining step.

<4> is a method for producing a rubber member in which the lubricant is a fatty acid amide in any one of <1> to <3>.

According to <1>, after the step of vulcanizing and molding, the step of keeping the rubber member at a temperature of 50 to 70 ° C. for 8 hours or more is provided. Can be accelerated.

<2> According to <2>, since the heat retention of the rubber member is started within one hour after the vulcanization molding step, the effect of early precipitation of the lubricant can be further enhanced.

<3> According to <3>, since the step of forcibly cooling the rubber member is provided after the heat retaining step, the effect of early precipitation of the lubricant can be further enhanced.

According to <4>, since the lubricant is a fatty acid amide, the lubrication between the rubber member and the member in contact with the rubber member can be ensured.

It is a perspective view which shows a stabilizer bush as an example of a rubber member. It is process drawing which shows the manufacturing method of the conventional rubber member. It is process drawing which shows the manufacturing method of the rubber member which concerns on this invention. It is a perspective view which shows the example of the rubber member which this invention makes object. It is a perspective view which shows the other example of the rubber member which this invention makes object.

A method for manufacturing a rubber member according to an embodiment of the present invention will be described by taking a stabilizer bush as an example. As shown in the process diagram of FIG. 3, the rubber member manufacturing method includes a vulcanization molding process 1 in which an unvulcanized rubber material blended with a lubricant is vulcanized in a mold, and is taken out from the mold. In addition to the inspection process 2 for inspecting the vulcanized stabilizer bush 20, the packaging process 3, and the shipping process 4, a heat retention process 10 is provided between the vulcanization molding process 1 and the inspection process 2. This can be performed, for example, by leaving the rubber member taken out of the mold in a chamber kept at a temperature higher than normal temperature for a predetermined time.

Here, it is essential to keep the temperature at 50 to 70 ° C when the temperature is kept. If this temperature is less than 50 ° C or exceeds 70 ° C, the surface of the lubricant will be brought to the surface early. The precipitation effect is not sufficient. In particular, when the temperature is kept at a temperature higher than 80 ° C., the amount of precipitation is lower than when nothing is kept warm.

And it is necessary to keep warm for more than 8 hours. Moreover, it is preferable that the heat retention of the rubber member in the heat retention step 10 is started within one hour immediately after the vulcanization molding step, that is, immediately after the rubber member is taken out of the mold.

In addition, after the heat retaining step 10, for example, a forced cooling step 11 for forcibly cooling the rubber member maintained at a temperature higher than the normal temperature by forcibly cooling with water, wind or the like having a temperature equal to or lower than the normal temperature. 3), which can further increase the amount of lubricant deposited on the surface per hour, and can be distributed over a sufficient surface of the lubricant from the beginning of use. However, this forced cooling process 11 is not necessarily required. Actually, there are lubricants that move from the inside to the surface and those that move from the surface to the inside, and due to this difference, the amount of precipitation on the surface of the lubricant per hour, that is, the precipitation rate. However, the cooling step described above has an effect of suppressing movement from the surface to the inside, and as a result, the deposition rate can be increased.

The rubber component of the target rubber composition is not particularly limited, but natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), isoprene isobutylene rubber (IIR), ethylene Propylene rubber (EPM, EPDM), chloroprene rubber (CR) and the like can be included.

In addition, it is preferable to use a fatty acid amide as the lubricant, and as the fatty acid amide, an unsaturated fatty acid amide such as oleic acid amide or erucic acid amide may be used. The blending amount is 2 to 50% by weight, particularly 20 to 25% by weight, based on the rubber 100.

The stabilizer bush manufactured by the manufacturing method provided with the heat retaining process (however, there is no forced cooling process) shown in FIG. 3 is taken as an example, and for comparison with this, the manufacturing method without the heat retaining process shown in FIG. Using the manufactured stabilizer bush as a conventional example, the amount of lubricant deposited on the surface of the rubber member was measured to evaluate the early precipitation effect of the lubricant. The evaluation results are shown in Table 2 and Table 3.

Table 1 shows the composition of the rubber members used in Examples and Conventional Examples.

The amount of lubricant deposited on the surface of the rubber member was measured after the completion of molding, or when the temperature was kept after that, the lubricant was deposited when the temperature of the rubber member dropped to room temperature after the completion of heat insulation. The surface was wiped with an organic solvent such as toluene or IPA, and the change in weight before and after wiping was measured to determine the amount of precipitation. Table 2 summarizes the dependence of the amount of precipitation on the standing time (h), the temperature (° C.), and the temperature (h) until the start of heat retention. Conventional example, comparative example, and implementation The amount of precipitation in each of Examples 1 to 9 was expressed as an index with the conventional example being 100. A larger value means a larger amount of precipitation. In all of the examples in Table 2, the amount of lubricant was measured after being left for several minutes after the heat insulation.
Table 3 summarizes the measurement results of the precipitation amount for three examples, with a pair of examples that differ only in the presence or absence of rapid cooling in the water after heat retention. The precipitation amount of each example Is an index with an example of 100 that does not quench rapidly for each group.

According to Table 2, there is a clear increase in the amount of lubricant deposited in all of Examples 1 to 9 as compared with the conventional example. Accordingly, by providing a step of keeping the rubber member at a temperature of 50 to 70 ° C. for 8 hours or more after the step of vulcanization molding, the precipitation of the lubricant on the surface can be accelerated.
Comparing Examples 2, 7 to 9 and Comparative Examples in which only the heat insulation temperature is different from the heat insulation conditions, the amount of lubricant deposited is highest when the heat insulation temperature is 65 ° C. Even if it is not kept warm, it will be low. This is considered to be because when the temperature becomes too high, the speed of the lubricant from the surface to the inside is superior to the speed of the lubricant from the inside to the surface.

Further, comparing Examples 1 and 2 in which only the heat retention time is different from each other as the heat retention condition, it is obvious that the longer the heat retention time, the faster the precipitation of the lubricant on the surface.
Furthermore, when Examples 2 to 6 in which only the standing time until the start of the heat retention after the vulcanization is different from each other as the heat retaining conditions are compared, the effect of accelerating the precipitation of the lubricant on the surface when the standing time until the start of the heat retaining is 1 hour. However, it turns out that the effect disappears when this is over 2 hours.

Further, according to Table 3, in comparison with Examples 10 and 11 which differ only in the presence or absence of rapid cooling in the water after the heat retention, the amount of lubricant precipitated is larger when the water is rapidly cooled after the heat retention. Comparison with Examples 14 and 15 also shows that the amount of lubricant precipitated is greater when the material is cooled rapidly after the temperature is kept. From this, when the rubber member is kept warm and then cooled, It can be seen that the deposition on the surface of the agent is further accelerated.

Examples of the rubber member manufactured by the above manufacturing method include the bush shown in FIG. 4 and the stopper shown in FIG. 5 in addition to the stabilizer bush 20, and the cylindrical bush rubber 24 used for the bush is: As shown in FIG. 4, the inner cylinder 25 is disposed radially inward and the outer cylinder 26 is disposed radially outward, and between the bush rubber 24 and the inner cylinder 25 and between the bush rubber 24 and the outer cylinder. 26 is configured to slide mutually through a lubricant. Then, a currant 27 is provided on a part of the bush rubber 24. In the case where the currant 27 is present, there is a possibility that abnormal noise is generated due to the rubber or rubber hitting or rubbing, and this can be prevented.

On the other hand, as shown in FIG. 5, the stopper rubber 32 used for the stopper is bonded to the base 33 via an adhesive, and this is also provided with a curl 34, and the rubber and the rubber hit or rub against each other. Noise can be prevented. In addition, interlinks, interleafs, and the like may be embedded in these.

DESCRIPTION OF SYMBOLS 1 Vulcanization molding process 2 Inspection process 3 Packing process 4 Shipment process 10 Heat retention process 11 Forced cooling process 20 Stabilizer bush 21 Stabilizer bush inner hole 22 Stabilizer bush outer peripheral surface 24 Bush rubber 25 Inner cylinder 26 Outer cylinder 27 Currant 32 Stopper rubber 33 Base 34 Currant

Claims (4)

In the method of manufacturing a rubber member formed by vulcanizing and forming a rubber member having self-lubricating properties by precipitating a lubricant contained therein on the surface,
A method for producing a rubber member comprising a step of keeping the rubber member at a temperature of 50 to 70 ° C. for 8 hours or more after the step of vulcanization molding. The method for producing a rubber member according to claim 1, wherein the heat insulation of the rubber member in the heat insulation step is started within one hour after the vulcanization molding step. The method for producing a rubber member according to claim 1 or 2, further comprising a step of forcibly cooling the rubber member after the heat retaining step. The method for producing a rubber member according to any one of claims 1 to 3, wherein the lubricant is a fatty acid amide.

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