JPH0572929B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention is a composite material that can be interposed between cloth or metal, particularly between steel plates, or between metal parts and metal bodies, to create a strong composite without the need for adhesives. This relates to rubber compositions for materials, mainly for producing highly elastic and high-strength composite materials by adhering rubber and cloth, and for obtaining vibration-damping steel plates for noise countermeasures from various machines, various structures, etc. It was developed for this purpose. <Prior Art> Attempts are being made to interpose rubber or synthetic resin having rubber elasticity between metals, mainly for the purpose of damping vibrations. The most familiar example of this can be seen in the development of composite vibration damping materials in which elastic polymeric substances are sandwiched between steel plates for the purpose of noise prevention in automobiles. The structure that has been proposed for this purpose is one in which a heat-adhesive film is pasted on both sides of rubber and sandwiched between two steel plates in the shape of a sandwich (Japanese Patent Application Laid-Open No. 59-73945, No. 59 -146837), those using polyvinyl acetal resin as the viscoelastic polymer material (No. 59-124847), and those using crosslinked polyolefin sheets (No. 59-124847).
59-152847) etc. <Problems to be solved by the invention> In these conventional products, the polymeric materials with rubber elasticity used are limited to special ones, and they lack versatility or have limited temperature range with thermal stability. It has disadvantages such as being narrow, having weak interlayer adhesion, being expensive, and containing only a small amount of filler. <Means for Solving the Problems> Therefore, the present inventor selected rubbers that are generally used, depending on the purpose of use, to find oil-resistant, heat-resistant,
We have investigated rubber compositions for composite materials that can be freely selected from those with vibration damping properties, and have now completed our research. The characteristics of the present invention are that (a) 1 to 40 parts of a diene polymer are added to 100 parts of the rubber raw material, and (b) 0.1 to 0.1 to 40 parts of a polyfunctional monomer are added to a general-purpose rubber composition consisting of a rubber raw material, a filler, a crosslinking agent, etc. It is made by mixing 30 parts. Here, in the diene polymer (a), the terminal functional group of polybutadiene or butadiene copolymer (NBR, SBR, etc.) is a hydroxyl group due to etherification, a carboxylated group due to esterification, an epoxy group due to epoxy modification, an amino group, It has one or more of carboxylic acid anhydride groups formed by maleic anhydride, mercapto groups, halogen atoms, and vinyl groups formed by acrylic modification. In addition, the polyfunctional monomer (b) has a plurality of functional groups such as a carboxyl group, or a monomer having a single functional group and a plurality of unsaturated bonds,
Polyhydric alcohol methacrylate, polyhydric alcohol acrylate, triallyl trimellitate, N,
It is one type or a mixture of two or more types of N'-methylenebisacrylamide. The raw rubbers that can be used are SBR, BR, IIR,
General-purpose rubbers such as EPM, EPDM, IR, NBR, and CR, as well as special rubbers such as epichlorohydrin rubber, acrylic rubber, and propylene rubber, can be freely selected depending on the purpose. As for the compounding agents added to these, crosslinking agents (vulcanization accelerators) and anti-aging agents suitable for each raw material rubber can be freely selected and used. Further, suitable amounts of fillers such as calcium carbonate, magnesium carbonate, carbon, etc. can be freely added. If necessary, calcium oxide may be used as a dehydrating agent to suppress foaming, and an appropriate oil or plasticizer may be used to soften the material. <Function> The rubber composition for composite materials as described above may be interpenetrating (IPN) by interposing it between cloth or metal layers and applying appropriate heat and pressure.
Polymer Network: A network of interpenetrating polymers that can be bonded to cloth, metal, plastic, etc. without adhesive. A metal composite material formed by interposing this composite rubber composition between metal plates has sound absorption and vibration damping effects. The present invention will be explained in detail below with reference to Examples. <Example 1> In a small Banbury mixer with a capacity of 1.6, 100 parts of IIR (brominated butyl rubber), 100 parts of calcium carbonate, and 5 parts of liquid xylene resin (softening agent) were placed and kneaded for 6 minutes in the usual manner. (In the examples and the following text, parts are parts by weight). Next, the kneaded material was transferred to a roll, and on top of it, 5 parts of zinc white (vulcanizing agent), 10 parts of CaO (dehydrating agent), and 10 parts by weight of liquid polybutadiene rubber with terminal hydroxyl groups as a diene polymer, and as a polyfunctional monomer. 5 parts by weight of triallyl trimellitate was added and kneaded to form a sheet with a thickness of about 5 mm (hereinafter referred to as a sheet rubber composition for composite materials). Next, for the adhesion test with metal, a 6.0 mm thick, 100 mm long sheet rubber composition for composite materials was prepared.
The strip was shaped into a strip with a length of 60 mm, a width of 25 mm, and a thickness of 2.0 mm and was pressure-bonded at 160°C for 30 minutes. The adhesion test was conducted using a peel tester based on JIS-K-6301. The results are shown in Table 1. Furthermore, drawing workability was tested when this rubber composition for composite material was used as a metal composite material as a vibration-damping steel plate. The test method for this was based on the Erichsen test (JIS-Z-2247).
mm square, and the sheet rubber composition for composite material was adhered thereto to a thickness of 1.0 mm. Adhesion is done by heating at 160°C for 30 minutes in a heat press. After cutting a cut line diagonally into the rubber surface of such a composite material of rubber and steel plate with a cutter, push it with a metal protrusion from the back of the steel plate to make it bulge out to the side where the rubber is attached, causing cracks in the steel plate. The degree of stress peeling of the adhesive surface was measured by pressing the adhesive until it reached 100. The results are also shown in Table 1. <Examples 2 to 13> As shown in Table 1, rubber raw materials, fillers,
Examples 2 to 13 of rubber compositions for composite materials were prepared in the same manner as in Example 1 by changing the additive compositions of the vulcanizing agent, dehydrating agent, diene polymer, and polyfunctional monomer.
Further, as Comparative Examples 1 and 2, cases were also prepared in which no diene polymer or polyfunctional monomer was added.

【table】

[Table] These Examples were tested for adhesion to metal and drawing workability in the same manner as in Example 1, and the results are shown in the lower column of Table 1. Next, the composite of the rubber composition for composite material shown in Example 2 and the steel plate was subjected to a heat aging test. The test method for adhesive strength change and hardness change is the JIS-K- mentioned above.
Pursuant to Law 6301. Figure 1 shows the hardness and adhesive strength between the steel plate and the steel plate at a constant temperature (100°C). As seen in these results, the adhesive strength increases over time, and after about 100 hours, the rubber breaks, and the adhesive strength reaches an equilibrium state, and in contrast to general deterioration over time, the adhesive strength decreases. Good results have been obtained in which no damage is caused. Figure 2 shows the hardness and adhesion strength between the composite rubber composition and the steel plate under constant heating conditions (70 hours) and the adhesive strength between the composite material and the steel plate. As is clear from these results, the gradual increase in hardness and
It is characterized by a rapid increase in adhesive strength up to the point of rubber failure R, which is in contrast to such composite materials, where the adhesive strength generally decreases as the temperature increases. As can be derived from the above results, there is no deterioration over time or decrease in adhesive strength at high temperatures, so
A damping steel plate formed by laminating the rubber composition for composite materials of the present invention between steel plates in a sandwich-like manner exhibits a soundproofing effect for a long period of time at high temperatures. The situation is shown in Figure 3. Figure 3 shows Example 2
This figure shows the change over time in the loss coefficient η at 500 Hz at 100°C for a composite steel plate in which the rubber composition for composite materials shown in Figure 2 is made into a sandwich shape with a 0.2 mm steel plate.
The comparative example is a composite steel plate for vibration damping, in which oriolefin sheets (0.5 mm) are bonded together, and both sides are sandwiched with 0.2 mm steel plates. As seen in these results, the loss coefficient of conventional products decreases at high temperatures, but the damping steel plate using the composite rubber composition of the present invention maintains a consistently high loss coefficient over a long period of time. be able to. Therefore, it is suitable for vibration-damping steel plates used in places exposed to high temperatures, such as automobile oil pans and engine covers. <Example 14> To one side of the 6 mm thick sheet of the rubber composition of Example 1
(A) polyester cloth (15 count single thread 43 x 40), (B) cotton cloth (16 count double thread 42 x 42), (C) phenolic resin plate, heated at 160°C. After being bonded under pressure and heat for 30 minutes, it was subjected to an adhesion test according to JIS-K-6301. As a result, the average peel strength was (A) 11.9Kg/in (25.4mm) (B) 12.0Kg/in (25.4mm) (C) 14.5Kg/in (25.4mm). On the other hand, when using only general-purpose butyl rubber, it peeled off easily, as is well known. As is clear from the test results shown in Table 1 and the results of Example 14, when forming a composite material using a general-purpose rubber, the rubber composition for composite materials of the present invention is superior to conventional rubber compositions. It has now become possible to form strong bonds with metals, fibers, plastics, and even other woods, ceramics, etc. (not shown in the examples), which were difficult to bond with. <Effects of the Invention> The rubber composition for composite materials of the present invention having the structure detailed above has the following advantages. Unvulcanized fabric has a long pot life. That is, it has high storage stability. Sufficient adhesion is obtained without the need for an adhesive or an adhesive layer film during the manufacture of the composite. When made into a metal composite material, it can be drawn and can also exhibit performance as a vibration damping material. Raw rubber can be freely selected and blended according to the purpose of heat resistance, oil resistance, sound insulation, vibration damping, etc. Since it has become possible to bond rubber to materials that were previously impossible, it is possible to develop composite materials with special functions.

[Brief explanation of drawings]

FIG. 1 is a graph showing hardness and adhesive strength when the temperature is constant, and FIG. 2 is a graph showing changes in hardness and adhesive strength when the temperature is changed. FIG. 3 is a graph showing the change in loss coefficient over time.

Claims (1)

[Claims] 1 A general-purpose rubber composition consisting of a rubber raw material, a filler, a crosslinking agent, etc. has a polybutadiene or butadiene copolymer whose terminal or intramolecular functional group is a hydroxyl group, carboxyl group, epoxy group, amino group, carboxylic anhydride group, or mercapto group. , halogen atom, diene polymer having one or more vinyl groups, polyhydric alcohol methacrylate, polyhydric alcohol acrylate, triallyl trimellitate, N,
A polyfunctional monomer consisting of one type or a mixture of two or more types of N'-methylenebisacrylamide is added, and 1 to 40 parts of the diene polymer and 0.1 to 30 parts of the polyfunctional monomer are mixed per 100 parts of the rubber raw material. A rubber composition for composite materials.