JPH05287093A - Rubber packing and production of the same - Google Patents

Abstract

PURPOSE:To obtain a rubber packing which is not required to be pretreated with a solvent or the like before a double-face adhesive tape is stuck to the surface of the rubber packing, but can secure a good self-adhesion of the double- face adhesive tape to the rubber packing, by subjecting a thin plate of a rubber to a specific treatment to activate the skin thereof. CONSTITUTION:The skin of a thin plate of a rubber (e.g. CR rubber) is activated by corona discharge treatment which is carried out pref. under conditions involving a space of 1 to 6mm between the treatment roll of a treatment machine and the rubber sheet, a discharge voltage of 25 to 50kV and a rate of treatment of 1 to 5m/min. It is further pref. to activate the surface of the thin plate of the vulcanized rubber by the corona discharge treatment and then punch the plate into a desired pattern.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber packing for interposing between machine parts and a method for manufacturing the same.

[0002]

2. Description of the Related Art When a mechanical part is fixed to a base with bolts or the like, a rubber packing may be interposed between the mechanical part and the base. The rubber packing used for such a purpose is a natural rubber packing. It is made by molding rubber and synthetic rubber such as SBR and NBR into a sheet by an extruder or a calender, vulcanizing the sheet, and punching it into a desired shape.

When the above-mentioned rubber packing is attached to a predetermined position such as a frame or a base of a mechanical device, and the attachment point is directed upward, the rubber packing and the attachment parts are simply placed on top of each other. Good.
However, it is necessary to prevent the rubber packing from falling down to improve workability when the installation location is facing downwards such as the bottom of a car chassis or ceiling, or when facing sideways such as a wall. Conventionally, the surface of the rubber packing is activated by treating it with a solvent such as MEK or toluene, or a halogen-based chemical or an acid, and a piece of double-sided adhesive tape is attached to this activated surface. Was temporarily fixed to the lower surface of the chassis or the like by pressure bonding.

[0004]

However, when the surface of the rubber packing is treated with a solvent or the like in order to increase the adhesiveness of the rubber packing to the adhesive tape, the working environment is contaminated, and waste liquid treatment becomes necessary. In addition, there were problems such as high costs.

According to the present invention, when a double-sided adhesive tape is attached to the surface of a rubber packing, it can be directly attached with a strong adhesive force without pretreatment with a solvent or the like, and there is no pollution of the working environment, and the waste liquid is treated. The present invention provides a rubber packing that can reduce the cost without the need for.

[0006]

A first aspect of the present invention is a rubber packing which is made of a thin rubber plate and whose surface layer is activated by corona discharge treatment. A second invention relates to the method for producing the rubber packing according to the first invention, characterized in that the surface of the vulcanized rubber thin plate is activated by corona discharge treatment and then punched into a desired shape. .

The thin rubber plate is formed by molding a rubber compound such as natural rubber, SBR, NBR, CR or EPDM into a sheet having a thickness of 0.5 to 6 mm by an extruder or a calendar as in the conventional case. Made from sulfur. After vulcanization, the surface is subjected to corona discharge treatment. The conditions for this corona discharge treatment are preferably a gap of 1 to 6 mm between the treatment roll of the treatment machine and the rubber sheet, a discharge voltage of 25 to 50 KV, and a treatment speed of 1 to 5 m / min.

[0008]

By applying the corona discharge treatment to the surface of the rubber sheet, the treated surface is activated and the wetting property is improved. Therefore, a rubber packing having good adhesiveness to the double-sided adhesive tape can be obtained, the double-sided adhesive tape is attached to the discharge-treated surface of the rubber packing, and the attachment surface of the adhesive tape is pressure-bonded to a part for mounting a component such as a machine base. The rubber packing is easily temporarily fixed, does not fall off by its own weight, and the mechanical parts can be easily attached.

However, when the gap between the treatment roll and the rubber sheet is less than 1 mm or the discharge voltage exceeds 50 KV, the treatment surface is apt to be destroyed due to excessive treatment, and conversely the above gap is generated. Exceeding 6mm, discharge voltage is 2
If it is less than 5 KV, the treatment is insufficient and the desired adhesive strength cannot be obtained. Further, if the processing speed is less than 1 m / min, the treated surface of the rubber sheet is easily broken,
On the other hand, if it exceeds 5 m / min, the desired adhesive force cannot be obtained.

[0010]

【Example】

Example 1 A rubber sheet having a thickness of 1 mm was molded using a CR type rubber,
After vulcanization, a discharge voltage of 45 KV, a gap between the processing roll and the rubber sheet of 2.5 mm, and a discharge rate of 3 m / min were applied to discharge treatment, and the rubber was cut into a width of 25 mm and a length of 200 mm to obtain the rubber of Example 1. Manufactured packing. On the other hand, the rubber packing of Comparative Example 1 was manufactured by omitting the above discharge treatment. Further, the rubber packing of Comparative Example 1 was treated with a solvent (toluene) to manufacture a rubber packing of Comparative Example 2.
The experimental results comparing the adhesive strength and the wetting property of the above-mentioned Example 1, Comparative Example 1 and Comparative Example 2 are shown in Table 1 below.

However, as for the adhesive force, the treated surface of the rubber packing is attached to the surface of the metal roll by a double-sided adhesive tape, and a supporting tool for rotatably supporting the metal roll is attached to one clip of the tensile tester and the metal roll. One end of the rubber packing peeled from the above double-sided adhesive tape was fixed to the other clip, and the rubber packing was pulled at a speed of 300 mm / min for measurement. Moreover, the wetting property is JIS K6768-1.
977 Measured according to the wetting test method for polyethylene and polypropylene films.

Table 1 Example 1 Comparative Example 1 Comparative Example 2 Adhesive force (gf / 25 mm) 1300 740 850 Wetting property (dyn / cm) 40 or more 30 or less 35 or more

Example 2 NBR rubber was used, and the discharge voltage of Example 1 was 35 KV.
A rubber packing of Example 2 was manufactured in the same manner as in Example 1 except that the rubber packing was changed to. Also, the rubber packing of Comparative Example 3 was manufactured by omitting the discharge treatment of Example 2 above. Further, the rubber packing of Comparative Example 3 was treated with toluene to manufacture the rubber packing of Comparative Example 4. These Example 2,
The measurement results of the adhesive strength and the wetting property of Comparative Example 3 and Comparative Example 4 are shown in Table 2 below.

Table 2 Example 2 Comparative Example 3 Comparative Example 4 Adhesive force (gf / 25 mm) 1650 1325 1950 Wetting property (dyn / cm) 35 or more 30 or less 35 or more

Example 3 Using EPDM rubber, the gap between the processing roll and the rubber sheet in Example 1 was set to 2.0 mm, and the processing speed was 2 m.
Example 3 is the same as Example 1 except that it is changed to / minute.
Manufactured rubber packing. Also, the rubber packing of Comparative Example 5 was manufactured by omitting the discharge treatment of Example 3 above. Further, the rubber packing of Comparative Example 5 was treated with toluene to produce a rubber packing of Comparative Example 6. Table 3 below shows the results of measuring the adhesive strength and the wettability of Example 3, Comparative Example 5 and Comparative Example 6.

Table 3 Example 3 Comparative Example 5 Comparative Example 6 Adhesive force (gf / 25 mm) 1100 550 650 Wetting property (dyn / cm) 35 or more 30 or less 30 or less

As is clear from Tables 1 to 3 above, Examples 1 to 3 which were subjected to the corona discharge treatment were superior in adhesive strength and wetting property to Comparative Examples 1 to 3 which were not treated. Comparative example 2 which was significantly improved and was treated with a conventional solvent,
It has the performance comparable to 4 and 6.

[0018]

As described above, according to the first aspect of the present invention, since the surface layer is the rubber packing activated by the corona discharge treatment, when the double-sided adhesive tape is attached to the surface of the rubber packing. The above double-sided pressure-sensitive adhesive tape can be directly applied to the, without pretreatment with a solvent etc.
Therefore, the workability when attaching mechanical parts to the lower surface of the chassis via rubber packing is better than that without corona discharge treatment, and the work environment is not polluted like when treated with a solvent. In addition, there is no need for waste liquid treatment, which enables cost reduction. Then, according to the invention described in claim 2, the rubber packing described in claim 1 is manufactured.

Claims (2)

[Claims] 1. A rubber packing comprising a thin rubber plate, the surface layer of which is activated by corona discharge treatment. 2. A method for producing rubber packing, characterized in that the surface of a vulcanized rubber thin plate is activated by corona discharge treatment and then punched into a desired shape.