Composition for silicone rubber foam, manufacturing method of silicone rubber foam, and silicone rubber foam

Abstract

There are provided a composition for silicone rubber foam, a manufacturing method of a silicone rubber foam, and a silicone rubber foam in which it is possible to control the foaming states. The composition for silicone rubber foam contains: (A) 100 parts by mass of polyorganosiloxane having a degree of polymerization of 4,000 to 10,000 and having two or more alkenyl groups at a content of 0.001 mmol / g or more and less than 0.3 mmol / g; an amount of polyorganohydrogensiloxane having an average of two or more Si-atom-bonded hydrogen atoms so that a molar ratio of the hydrogen atoms to the alkenyl groups in the (A) component is 0.001 to 5; 0.1 to 10 parts by mass of an organic foaming agent with a decomposition temperature of 50 to 250 DEG C.; 5 to 200 parts by mass of silica powder; and a catalyst amount of a platinum-based metal catalyst activated with ultraviolet rays.

Description

technical field [0001] The present invention relates to a composition for a silicone rubber foam, a method for producing a silicone rubber foam, and a silicone rubber foam. Background technique [0002] Silicone rubber foam is widely known as a material excellent in weather resistance, electrical characteristics, compression set, and the like. The silicone rubber foam can basically be obtained by mixing azobisisobutyronitrile (AIBN), azodicarbonamide (ADCA), dinitrosopentamethylene Organic foaming agents and curing agents such as tetramine (DPT) are obtained by heating to make them foam and cure. Here, in order to obtain a silicone rubber foam having good properties, it is necessary to balance the foaming speed (decomposition speed) of the organic foaming agent and the curing speed of the silicone rubber composition. [0003] That is, if the decomposition rate of the organic foaming agent is slower than the curing rate of the silicone rubber composition, although the cells...

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Problems solved by technology

[0005] In the crosslinking based on peroxide, the crosslinking speed can be adjusted to some extent by the selection or compounding amount of the organic oxide, but it is difficult to strictly adjust the crosslinking density at the moment when the organic blowing agent decomposes. Disadvantages of excess organic blowing agent, or the need to strictly manage process conditions

[0006] Addition-type heat-curable silicone rubber using a platinum catalyst (see Patent Document 1), or combining it with the above-mentioned peroxide crosslinking (see Patent Document 2), it is relatively easy to adjust the crosslinking density at the time of blowing agent decomposition , but at normal production speeds, when the crosslinking density when the blowing agent is decomposed is optimized, the storage stability is poor. When the storage stability is prioritized, it takes a long time to form a predetermined crosslinking state, which has the disadvantage of poor productivity.

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