JPH0672220B2 - Vulcanized adhesive composition and bonding method using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vulcanized adhesive composition and an adhesion method using the same. More specifically, it relates to a vulcanized adhesive composition that is effectively used for adhering a metal and a silicone rubber, and an adhering method using the same.

[Prior Art] and [Problems to be Solved by the Invention] For the adhesion between metal and silicon rubber, an organic silane-based adhesive has been conventionally used, but when this adhesive is used, The surface of the metal, especially the surface of the steel plate, rusted due to the outside air environment, which was the cause of the peeling of the adhesive.

The present inventors have investigated variously in order to find a vulcanized adhesive composition for this kind of application which suppresses rusting which causes such adhesive peeling and has excellent peeling force, and as a result of various investigations, a novolak-type phenol resin and hexamethylenetetramine. It has been found that the above problem can be effectively solved by adding a specific organic silane compound to the curing agent.

[Means for Solving Problems] and [Operation] Accordingly, the present invention relates to a vulcanizing adhesive composition used for bonding a metal and a silicone rubber, and the vulcanizing adhesive composition is a novolak type. At least one of vinyltrialkoxysilane and γ-aminopropyltrialkoxysilane is added to a phenol resin and hexamethylenetetramine curing agent.

The present invention also relates to a method for adhering a metal and a silicone rubber using such a vulcanizing adhesive composition, in which the metal and the silicone rubber are adhered by applying the vulcanizing adhesive composition on a metal,
After performing a baking treatment, the unvulcanized compound of silicon rubber is bonded thereto, and pressure vulcanization is performed at the vulcanization temperature of the silicon rubber.

The novolak type phenol resin is a soluble and fusible phenol-formaldehyde resin obtained by condensing phenol and formaldehyde using an acid as a catalyst, and in the present invention, its melting point (softening temperature) is about 100 ° C. Generally, a two-step method phenol resin having a molecular weight of several hundreds to several thousands is used. Since novolak molecules do not have a reactive group (methylol group), condensation between molecules does not occur simply by heating, and thermoplasticity is maintained permanently, but formaldehyde is used as a methylene group supply source for curing. Alternatively, when hexamethylenetetramine is added and heated, it becomes insoluble and infusible.

The vulcanized adhesive composition according to the present invention comprises 100 parts by weight of a novolak type phenol resin and about 5 to 20 parts by weight of a hexamethylenetetramine curing agent, and a vinyltrialkoxysilane generally used at a ratio of about 0.5 to 4 parts by weight. It is prepared by adding at least one γ-aminopropyltrialkoxysilane. In these organosilane compounds, the alkoxy group is preferably an ethoxy group.

A mixture comprising the above-mentioned respective components is generally prepared and used in the form of an organic solvent solution. As the organic solvent, any solvent can be used as long as it can dissolve each of these compounding components, but methanol, ethanol and the like are particularly preferably used. And the organic solvent solution is about 0.5 ~ 15
%, Preferably about 3 to 7%, so that the solid content concentration is within the range.

When the vulcanized adhesive composition solution prepared in this way is used for bonding metal and silicone rubber, this solution is applied onto a metal, for example, mild steel plate and the like.
After heating and drying to about 50-60 ℃, generally about 180-210 ℃
And heat it for about 5 to 30 minutes to bake it, join the unvulcanized compound of silicone rubber to it, and heat it to about 160 to 200 ° C, which is the vulcanization temperature of silicone rubber, using a mold. Bonding is performed by pressure vulcanization.

The unvulcanized compound of the silicone rubber to be joined is generally prepared by adding a filler and a vulcanizing agent to the organopolysiloxane raw rubber, and as the filler, a reinforcing silica-based filler or the like is used. An organic peroxide is generally used as

〔The invention's effect〕

The vulcanized adhesive composition according to the present invention, when it is used for adhesion between a metal and a silicone rubber, shows no rust on the metal surface in the outside air environment, and therefore adhesion peeling based on rusting. The above phenomenon is not observed, and an effect that a stable adhesive effect is always obtained can be obtained.

The vulcanized adhesive composition of the present invention showing such effects is effectively applied as an adhesive between metal and silicon rubber, for example, as an engine seal, a cylinder-head gasket, an oil seal in a high temperature atmosphere, or the like. Can be used.

〔Example〕

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

Example 1 Novolac-type phenol resin (melting point 100 ° C.) 100 parts by weight hexamethylenetetramine 10 vinyltriethoxysilane 1 γ-aminopropyltriethoxysilane 1 methanol 2240 It was applied to a mild steel plate whose surface was roughened to about 10 to 15 μm by a shot blast treatment. Then, it was dried at 50 ° C. for 10 minutes and then baked at 200 ° C. for 10 minutes, and the baked metal plate was left in an atmosphere of 30 ° C. and 85% relative humidity for 1 day or 3 days.

On this metal plate, 100 parts of organopolysiloxane raw rubber,
An unvulcanized silicone rubber compound having a weight composition of 50 parts of a reinforcing silica-based filler and 2 parts of di-tert-butylperoxyhexane was joined according to JIS K-6301, 90 ° peel test method, The mold was subjected to pressure vulcanization at 180 ° C. for 4 minutes, and then the vulcanized adhesive was heat-treated at 175 ° C. for 5 hours.

Example 2 In Example 1, a solution vulcanized adhesive formulation was prepared using 2 parts by weight of vinyltriethoxysilane without using γ-aminopropyltriethoxysilane.

Example 3 In Example 1, a solution vulcanized adhesive formulation was prepared using 2 parts by weight of γ-aminopropyltriethoxysilane without using vinyltriethoxysilane.

Comparative Example Commercially available organosilane-containing adhesive (Nippon Unica-AP13
Using 3), coating and vulcanization adhesion to mild steel sheets were performed in the same manner as in Example 1.

Obtained in each of the above Examples and Comparative Examples, for the vulcanized adhesive of the adhesive-coated metal plate and silicon rubber,
The peeling force was measured by the peeling test method and the area ratio of the remaining portion of the rubber after peeling was measured, and the rusting state was also observed. The results obtained are shown in the following table.

Claims (4)

[Claims] 1. To 100 parts by weight of a novolac type phenolic resin and 5 to 20 parts by weight of a hexamethylenetetramine curing agent,
A vulcanized adhesive composition for use in adhering a metal and a silicone rubber, which is obtained by adding at least one of vinyltrialkoxysilane and γ-aminopropyltrialkoxysilane in an amount of 0.5 to 4 parts by weight. 2. A vulcanized adhesive formulation according to claim 1 prepared in the form of an organic solvent solution. 3. 100 parts by weight of a novolac type phenolic resin and 5 to 20 parts by weight of a hexamethylenetetramine curing agent,
A vulcanized adhesive composition containing 0.5 to 4 parts by weight of at least one of vinyltrialkoxysilane and γ-aminopropyltrialkoxysilane is applied onto a metal, and after baking treatment, a silicone rubber A method for adhering to a metal silicon rubber, which comprises bonding an unvulcanized compound and vulcanizing under pressure at a vulcanizing temperature of the silicon rubber. 4. A method according to claim 3 in which the vulcanized adhesive formulation is used in the form of an organic solvent solution.