| 摘要 |
PROBLEM TO BE SOLVED: To obtain a hydrosilylation platinum catalyst which shortens hardening time and reduces the amount (ppm) of platinum required. SOLUTION: A mixture of an alkenylpolysiloxane and a cycloalkylpolysiloxane is equilibrated in the presence of a halogenoplatinic acid and the resulting equilibrated product is treated with a base to produce the objective platinum hydrosilylation catalyst. Before the equilibration of the mixture, sufficient moles of the alkenylpolysiloxane to give at least 1 mole alkenylsiloxy unit per atom of platinum and sufficient moles of the cycloalkylpolysiloxane to give about 0.3-20 mole cycloalkylpolysiloxane per mole of the alkenylpolysiloxane are used per mole of the halogenoplatinic acid. An increased hardening rate and a lowered ppm level of platinum required to carry out hydrosilylation are attained.
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