JPH0688380B2 - Ethylene / propylene rubber composite and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a EP rubber composite that is easily attachable and is formed by adhering an adhesive on one or both sides of an EP rubber molded article having excellent weather resistance. Regarding the manufacturing method, the EP rubber composite can be widely used as a cushioning material, a vibration-proof material, a sound-proof material, etc. in the field of electrical products and the like.

[Conventional technology]

For electrical equipment such as radios, stereos, personal computers, and other measurement equipment that requires high-accuracy measurement, cushioning materials, vibration-proof materials, and sound-proof materials are installed at the required locations in order to protect these equipment from vibration and shock. ing. As such a cushioning material or the like, a molded product made of natural rubber or synthetic rubber has been conventionally used, and the cushioning material is provided with a recess on the bottom surface of the above-mentioned equipment and fitted into the recess, or one side of these cushioning material sheets. It is attached by adhering an adhesive material with release paper to. Further, a device such as a calculator or a blood pressure monitor is provided with a soundproofing / vibrating material for the purpose of preventing slippage and shock of a collision, and its application form is almost the same as the above.

[Problems to be Solved by the Invention]

By the way, natural rubber and most synthetic rubbers that have been conventionally used as cushioning materials have a problem in weather resistance,
If left in the air, cracks may occur on the surface, or the hardness may increase and the flexibility may be lost. On the other hand, among synthetic rubbers, EP rubber is exceptionally excellent in weather resistance, and in that sense, it can withstand long-term use as a cushioning material. However, while EP rubber has good weather resistance, it has poor adhesion compared to other rubber materials, and even if an adhesive material with release paper is attempted to adhere to the EP rubber molded product, it can be sufficiently adhered. There was a problem that it could not be done.
In other words, in the case of EP-based rubber cushioning materials, it is difficult to manufacture cushioning materials and vibration-proof materials that have an adhesive material with release paper that can be easily attached, and this hinders the application of EP-based rubber molded products with excellent weather resistance. Had become a factor to.

The present invention has been made in view of these circumstances, and aims to utilize the advantages of EP rubber by overcoming the poor adhesion of EP rubber (with release paper).
It is intended to provide an EP-based rubber composite (a cushioning material, a vibration-proof material or a sound-proof material) in which an adhesive material is firmly adhered and which can be easily attached.

[Means for Solving the Problems]

The EP-based rubber composite of the present invention which has achieved the above-mentioned object has a gist in that the heat-activatable adhesive layer is unwound on at least one surface of the EP-based rubber molded article to bond an adhesive material, Further, the method of the present invention for obtaining the above EP rubber composite has a gist in that a heat-activatable adhesive is interposed between an EP rubber molded article and an adhesive material and heat-pressed to integrally bond them. To do.

[Action]

In the present invention, EP rubbers include EPM (Ethylene Propylene Rubber), EPDM
(Ethylene Propylene Diene Rubber
Lene Diene Rubber) and the like, which are generally added with a vulcanizing agent and thermally crosslinked, and the EP rubber in the present invention is limited to vulcanized rubber. Although these EP rubbers have excellent weather resistance as described above, they have a problem in that they have poor adhesiveness, particularly adhesiveness with a pressure-sensitive adhesive.

The present invention has been completed as a result of various studies in order to firmly bond the EP rubber and the pressure-sensitive adhesive via the adhesive layer in order to eliminate the drawbacks of the EP rubber.

That is, the adhesive in the present invention is a composition whose main component is a compound having a molecular structure similar to both the EP rubber and the pressure-sensitive adhesive, and the adhesive adheres to the EP rubber due to its molecular structure. Since it has an affinity for both agents, it penetrates well even into minute voids on the surface and exerts an anchoring effect, and exhibits excellent adhesiveness. In particular, it works effectively against EP rubber that is difficult to adhere to and overcomes its drawbacks, and it is possible to firmly integrate the EP rubber and the adhesive material.

A preferable example of such an adhesive is an ethylene vinyl acetate copolymer (Ethyle) containing ethylene in the main chain.
n vinyl acetate copolymer: hereafter referred to as EVA),
Methyl methacrylate (Ethyl methacrylate: Below, EMA
Notated), ethylene ethyl acrylate (Ethylen
Copolymers such as ethyl acrylate: hereinafter referred to as EEA) and ethylene acrylic acid (hereinafter referred to as EAA) and organic acid-grafted EVA (hereinafter referred to as
Polyolefins containing acid graft copolymers such as acid graft EVA), organic acid graft polyethylene (hereinafter referred to as acid graft PE), organic acid graft polypropylene (hereinafter referred to as acid graft PP), etc. Examples of the system copolymer composition include: The copolymers that make up these main components have strong polar groups in their side chains and in the acid moieties that have been graft-polymerized, so these polar groups are chemically resistant to EP rubber and adhesives. It is considered to exhibit affinity, good penetrability, bondability, and adhesiveness.

The polyolefin-based copolymer (main component) is preferably selected and used according to the type of the adhesive material. For example, an acrylic resin-based adhesive material such as polyacrylic acid, polybutyl acrylate, poly (2-ethylhexyl acrylate), etc. In contrast, EVA, EMA, EEA, EAA, adhesive composition containing a copolymer containing ethylene in the main chain as a main component shows a stronger affinity,
For rubber-based adhesives such as polyisoprene, SB rubber, butyl rubber, and polyisobutylene, the adhesive composition containing acid-grafted EVA, acid-grafted PE, acid-grafted PP, etc. as a main component shows high affinity. In the above-mentioned adhesive composition, other compounding ingredients such as rosin, coumarone indene, tackifier such as phenol resin, phthalate ester, phosphate ester, plasticizer such as paraffin chloride, butyltin system, octyltin system, etc. It is possible to add stabilizers and the like.

Further, the adhesive in the present invention is a heat-activatable adhesive, which is solid at 50 ° C. or lower and does not have adhesiveness, and is melted by heating at 80 to 150 ° C. It will become effective, and after adhesion,
By cooling it to 50 ° C or lower again, it solidifies in the adhesive state and returns to the original solid state. Therefore, by interposing between the pressure-sensitive adhesive layer and the EP-based rubber sheet as described later and heating and pressing preferably at 80 to 150 ° C., the function as an adhesive can be fully exerted.

The EP-based rubber composite according to the present invention is formed by adhering an EP-based rubber molded article and a pressure-sensitive adhesive through such an adhesive layer,
In producing the EP rubber composite, for example, the adhesive is applied to a sheet-like pressure-sensitive adhesive or laminated in the form of a film, and then an EP rubber sheet is laminated thereon and heated and compressed by a heat roll. The method of integration may be adopted, but the order of stacking is not limited to the above, and first,
It is also possible to stack the adhesive layer on the EP rubber sheet and then laminate the adhesive sheet, or to laminate the EP rubber sheet, adhesive layer and adhesive sheet at the same time by using a heat roll or the like. You may integrate.

It is desirable that a release paper be adhered to the adhesive sheet for the purpose of protecting the adhesive surface before use.

〔Example〕

Example 1 A rubber material having the composition shown in Table 1 was kneaded with a rubber roll and uniformly dispersed to prepare an EP rubber unvulcanized rubber. However, in Table 1, FEF Black is Fast Extrusion Furnace
Black, SRF Black is Semi Rein-forcing Furnace Bla
ck and MT black are short for Medium Thermal Black. Axel M, Axel TMTD, and Axel PZ are trade names of Kawaguchi Chemical Industry Co., Ltd., where Axel M is 2-Mercaptobenzothiazole and Axel TMTD is Tetra.
methyl Tiuram Disulfide, Accel PZ is Zinc Dimethyl
Dithiocarbamate. The unvulcanized rubber was charged into a die for making a 1.0 mm rubber plate, and the flat plate heat press heated to 170 ° C
It was pressed for a minute to prepare an EP vulcanized rubber sheet of 240 × 240 × 1.0 mm. The surface of this rubber sheet was wiped with a waste cloth containing toluene for degreasing. Heat activated film adhesive 1
(For example, CLEARITE SA01, thickness 30 μm, manufactured by Sekisui Chemical Co., Ltd.) and acrylic resin adhesive 2 with release paper 3
(For example, Knit-No. 500, manufactured by Nitto Denko Co., Ltd.) is pre-bonded by pressing with a roll 4 as shown in FIG.

Next, the pre-bonded adhesive layer with a heat-bonding material and the degreased EP vulcanized rubber sheet 3 were bonded together, and pressed by a flat plate heat press heated to 120 ° C. for 30 seconds to be integrated. After depressurization, it was cooled at room temperature, cut into a 10 mm square by a cutting machine (see FIGS. 2 and 3), and used as a cushioning material. Table 2 shows the difference in adhesive strength from the conventional product.

Example 2 A method for manufacturing a long product is shown in FIG.

Adhesive material 11 with release paper (for example, Knit-No.500, manufactured by Nitto Denko Corporation) and heat-activatable film adhesive 12 (for example, Cleartite SB-01, thickness 100 μm-Sekisui Chemical Co., Ltd.)
(Made) is pressed with a roll press 21 and is temporarily bonded by adhering while removing air, while a long EP vulcanized rubber sheet 14 (e.g. EPTW-160, thickness 0.3 mm) formed by a calender roll is used. Kameido Rubber Co., Ltd. is preheated in a heating furnace 22 at 100 ° C. while being bonded to the adhesive side, and is moved at a speed of 30 cm / min while being pressed with a heating roll press 23 heated to 120 ° C. An adhesive material with a pattern paper and an EP vulcanized rubber sheet are joined and integrated. This was once wound into a roll. In the next step, this sheet was half-cut to a predetermined size and shape by a cutting machine up to the front of the release paper and used as a vibration isolator.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The present invention is configured as described above, and an adhesive material can be firmly bonded and integrated to an EP rubber molded product, which has excellent weather resistance and can be easily attached to an EP rubber composite ( Cushioning material, vibration damping material or sound insulating material).

Further, since the heat-activatable film adhesive is used as the adhesive, the laminating work is very easy and the variation of the adhesive strength is reduced, and the continuous laminating of long products becomes possible.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a bonding state of a pressure-sensitive adhesive material with release paper and an adhesive, FIGS. 2 and 3 are perspective explanatory views showing a shape of a cushioning material, and FIG. 4 shows a method for manufacturing a long product. It is a schematic explanatory drawing. 1 …… Film adhesive 2,11 …… Adhesive material 3 …… Release paper 4,21 …… Roll 14 …… Rubber sheet 22 …… Heating furnace 23 …… Heating roll press

Claims (5)

[Claims] 1. An EP-based rubber composite comprising an ethylene / propylene (hereinafter referred to as EP) -based rubber molded article and an adhesive material bonded to at least one surface of the molded article via a heat-activatable adhesive layer. . 2. A heat-activatable adhesive is a polyolefin-based copolymer composition containing ethylene compounds such as ethylene-vinyl acetate copolymer containing ethylene, ethyl methacrylate, ethylene ethyl acrylate and ethylene acrylic acid as a main component. The EP rubber composite according to item (1). 3. A polyolefin-based copolymer composition containing an acid-modified ethylene compound such as an organic acid-grafted ethylene vinyl acetate copolymer, an organic acid-grafted polyethylene, or an organic acid-grafted polypropylene as a main component, in which the heat-activatable adhesive contains ethylene. The EP rubber composite according to claim 1, which is a product. 4. The EP rubber composite according to claim 1, wherein the adhesive is an acrylic resin adhesive or a synthetic rubber adhesive. 5. A method for producing an EP-based rubber composite, characterized in that a heat-activatable adhesive is interposed between an EP-based rubber molded article and an adhesive material, and heat-pressed to bond and integrate them.