JPH0735500B2 - Adhesive composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an adhesive composition. More specifically, it relates to an adhesive composition used for adhering a metal and hydrogenated NBR.

[Conventional technology]

Hydrogenated NBR is generally an acrylonitrile content of 30 to 50 wt% acrylonitrile-hydrogenated butadiene double bond in the butadiene copolymer rubber, showing a chemical stability at a hydrogenation rate of about 80% or more, In particular, it has excellent heat resistance and chemical resistance, and also has the property of high rubber strength. In terms of heat resistance, the higher the hydrogenation rate, the better the heat resistance. Therefore, it is preferable to use the one with a hydrogenation rate of 100%, but from the viewpoint of required heat resistance, cost, etc. Hydrogenation with low hydrogenation rate
NBR (hydrogenation rate of about 90 to 100%) is also often used practically.

Utilizing these favorable properties of hydrogenated NBR and adhering it to metal, it has been used for various oil seals, packings, valves, gasket materials, etc. There was no suitable adhesive for hydrogenated NBR formulations with high oxide content.

For example, with the conventional phenol resin alone adhesive, air is generated during the molding of hydrogenated NBR, which causes a decrease in the adhesive strength. Further, the chlorinated rubber adhesive has low heat resistance, which means that the desirable heat resistance of hydrogenated NBR cannot be effectively exhibited.

[Problems to be solved by the invention]

The inventors of the present invention, when adhering hydrogenated NBR to a metal, variously seek an adhesive that can ensure sufficient adhesiveness without substantially lowering the preferable heat resistance of hydrogenated NBR. As a result, it was found here that an adhesive composition capable of co-crosslinking both hydrogenated NBR and a novolac type phenolic resin can sufficiently satisfy such requirements.

[Means for solving problems]

Therefore, the present invention relates to an adhesive composition for bonding metal and hydrogenated NBR, wherein the adhesive composition contains a hydrogenated NBR composition containing an organic peroxide crosslinking agent and other compounding agents and a curing agent. The above novolac type phenol resin composition is dissolved in a solvent consisting of a ketone, an aromatic hydrocarbon or a mixture thereof.

As the hydrogenated NBR, those mentioned above are used.
An organic peroxide cross-linking agent and other compounding agents are compounded in the composition. Examples of the organic peroxide crosslinking agent include dicumyl peroxide, 2,5-dimethyl-2,5-di (tertiary butylperoxy) hexane and 2,5-dimethyl-2,5-
Di (tertiary butylperoxy) hexyne-3, 1,3-bis (tertiary butylperoxyisopropyl) benzane, etc. are used by blending in a ratio of about 0.1 to 15 parts by weight per 100 parts by weight of hydrogenated NBR. As other compounding agents, various compounding agents that are usually used are used, but fillers such as carbon black, white carbon, talc, clay, wollastonite, and celite are preferably compounded. Agents, antioxidants, cross-linking accelerators, etc. are also added as needed.

Further, the novolac type phenol resin used together with the hydrogenated NBR is represented by the following general formula.

Thus, the novolak type phenolic resin is obtained as a pine or pine-like substance soluble in an organic solvent such as alcohol or ketone by reacting phenol or an alkyl-substituted phenol with formaldehyde under an acid catalyst,
An insoluble and infusible phenol resin is formed by adding a curing agent such as an amine compound or a phosphorus compound to this and heating it. In the present invention, a fast-curing resin is preferably used because it has a high ortho bond and a free phenol content of 3%.
Those having a melting point of about 90 to 120 ° C. or less are generally used.

As the curing agent for the novolac type phenol resin, an amine compound or a phosphorus compound is generally used.

As the amine compound, those represented by the following general formula are used.

_{(A) H 2 N (CnH} 2 nNH) mCnH 2 nNH 2 m: 0 or up to about 25 positive integer n: a positive integer _{(b) H 2 N-R} 3 -NH 2 R 3: (C) Heterocyclic amine compound hexamethylenetetramine, etc. (d) Ammonium salt, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrapropylammonium chloride, etc. Further, examples of the phosphorus compound include phosphines such as triphenylphosphine, benzyltrine and the like. Phosphonium salts such as phenylphosphonium chloride are used.

Of these curing agents, hexamethylenetetramine is preferably used, and the mixing ratio thereof is about 10 to 15 parts by weight per 100 parts by weight of the novolac type phenol resin.

The novolac type phenol resin is used in a ratio of about 10 to 200 parts by weight per 100 parts by weight of hydrogenated NBR, and is used in a ratio of about 50 to 150 parts by weight from the viewpoint of workability, fluidity and adhesiveness.

Hydrogenated NBR and novolac type epoxy resin are blended with other compounding agents on a roll or the like, and are mixed in a solvent consisting of a ketone, an aromatic hydrocarbon or a mixture thereof in an amount of about 5 to 15% by weight. The adhesive composition is formed by dissolving it at a concentration of. Methyl ethyl ketone or the like is used as the ketone, and toluene, benzene or the like is used as the aromatic hydrocarbon, and both are preferably used as a mixture in which they account for about 30 to 70% by weight from the viewpoint of sprayability.

In the adhesion using the adhesive solution thus prepared, the metal is first undercoated with a phenolic resin solution as a primer. As the metal, mild steel, stainless steel, aluminum, aluminum die cast, brass, zinc and the like are used, and a phenolic resin which has been conventionally used for adhesion with hydrogenated NBR is applied as a primer solution.

After that, the adhesive solution is applied, and solvent drying is performed for about 5 to 30 minutes, and then the vulcanization mold is used to bring it into contact with the hydrogenated NBR, which is also generally used in the form of a blend, to about 140 to
Vulcanization adhesion of metal and hydrogenated NBR is performed by heating under pressure at 180 ° C. for about 3 to 30 minutes.

〔The invention's effect〕

The adhesive composition according to the present invention can be applied to adhesion of metal and hydrogenated NBR, acrylic rubber, fluororubber, etc., but since its main component is hydrogenated NBR, heat resistance and the like are taken into consideration. , Generally used for adhesion of hydrogenated NBR and metal.

In the case of hydrogenated NBR, the peroxide crosslinking method is usually used, and hydrogenated NB with a high organic peroxide content is used.
The phenomenon such as the decrease in adhesive strength due to the inclusion of air, which is often observed when R compound is vulcanized and molded, uses hydrogenated NBR for both the adhesive composition and the adherend. It is no longer visible because and co-crosslink and bond.

Moreover, while sufficient adhesiveness is secured between the metal and the hydrogenated NBR in this manner, the preferable heat resistance of the hydrogenated NBR is not substantially impaired, so that it can be used in various applications as described above. It can be used effectively.

〔Example〕

 Next, the present invention will be described with reference to examples.

Example 1 Hydrogenated NBR (Nippon Zeon Product Zetpol 1020) 100 parts SRF carbon black 40 Zinc white 10 Stearic acid 1 Anti-aging agent [Poly (2,2,4-trimethylene-1,2-dihydroquinoline)] 1 Crosslinking Agent (dicumyl peroxide) 8 Curing agent (hexamethylenetetramine) 15 Novolac-type phenol resin 75 The above components are kneaded with an open roll, and 10 parts by weight of the resulting mixture and 90 parts by weight of a mixture of methyl ethyl ketone-toluene, etc. The parts were stirred with an agitator stirrer to prepare an adhesive composition.

Apply a phenol resin primer (Anchor Chemical's product type line BN) on a mild steel plate that has been surface-roughened by solvent degreasing and shot blasting at 120 ° C.
After 10 minutes of drying, the above-mentioned adhesive composition was applied onto the primer layer and left at room temperature for 1 hour to evaporate the solvent.

Next, in the above composition, a novolac type phenolic resin and a curing agent thereof were not compounded, and an adhesive rubber composition in which the amount of the crosslinking agent was halved was used, and JIS K-6301 8.3 paragraph 90 ° peel test method (autograph, Vulcanization adhesion to the adhesive-coated mild steel sheet at 180 ° C., 60 kg / cm ² , 4
It was carried out under the condition of minute.

Example 2 In Example 1, the amount of the novolac type phenolic resin was changed to 125 parts by weight when preparing the adhesive composition.

Comparative Example 1 In Example 1, a commercially available phenol adhesive was applied instead of the adhesive composition, and baking was performed at 100 ° C. for 30 minutes.

Comparative Example 2 In Example 1, a commercially available chlorinated rubber adhesive was used instead of the adhesive composition.

The results of the peeling test for the adhesives obtained in the above Examples and Comparative Examples are shown in Table 1 below.

For the adhesives of Example 1 and Comparative Example 2 above, 150 ° C
Heat treatment was performed for a predetermined time in the above atmosphere, and the heat treatment product was subjected to the same peel test. The results obtained are shown in Table 2 below.

Claims (1)

[Claims] 1. A hydrogenated NBR compound containing an organic peroxide cross-linking agent and other compounding agents and a novolac type phenolic resin compound containing a curing agent are used, and 10 to 10 novolak type phenolic resins per 100 parts by weight of hydrogenated NBR. Used in a proportion of 200 parts by weight, each of these blends was dissolved in a solvent consisting of a ketone, an aromatic hydrocarbon or a mixture thereof,
An adhesive composition for bonding metal and hydrogenated NBR.