| 主权项 |
1. A manufacturing method of a silicone rubber foam, comprising:
a step (1) of irradiating a composition for silicone rubber foam including, (A) 100 parts by mass of alkenyl group-containing polyorganosiloxane expressed by a following general formula (A1), having a mass average degree of polymerization of 4,000 to 10,000 and having two or more R2s in the following general formula (A1) as a content per mass in a molecule at a rate of 0.001 mmol/g or more and less than 0.3 mmol/g,where R1 represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, R2 represents an alkenyl group, R3 represents a monovalent group indicating each independent R1 or R2, n and m represent the total numbers of each recurring unit obtained by random polymerization or block polymerization, and n+m+2 obtained by adding 2 that is the number of terminal groups to n and m represents amass average degree of polymerization,
(B) an amount of polyorganohydrogensiloxane having an average of two or more hydrogen atoms bonded to a silicon atom in a molecule so that a molar ratio of the silicon-atom-bonded hydrogen atoms to the alkenyl groups in the (A) component (the number of moles of hydrogen atoms bonded to the silicon atoms in the (B) component/the number of moles of the alkenyl groups in the component) is 0.001 to 5, (C) 0.1 to 10 parts by mass of an organic foaming agent with a decomposition temperature of 50 to 250° C., (D) 5 to 200 parts by mass of silica powder, and (E) a catalyst amount of a platinum-based metal compound catalyst activated with ultraviolet rays, with ultraviolet rays at a temperature lower than the decomposition temperature of the (C) organic foaming agent to obtain a cross-linked body; and a step (2) of heat-treating the cross-linked body at a temperature equal to or higher than the decomposition temperature of the (C) organic foaming agent to obtain a silicone rubber foam. |
