Method for preparation of aqueous emulsion of long-chain alkyl-modified silicone

摘要

The invention discloses an efficient and convenient method for the preparation of an aqueous emulsion of an organopolysiloxane having long-chain alkyl groups bonded to the silicon atoms. Instead of dispersing and emulsifying an organopolysiloxane modified in advance with long-chain alkyl groups in an aqueous medium, as is the case in the prior art method, an organohydrogenpolysiloxane having silicon-bonded hydrogen atoms and a long-chain alpha-olefin compound are co-emulsified in an aqueous medium containing a surface active agent and this aqueous emulsion is heated under agitation with addition of a catalytic platinum compound so as to effect the in situ hydrosilation reaction between the silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane and the ethylenically unsaturated bonds in the alpha-olefin compound. The aqueous emulsion prepared by the inventive method exhibits excellent stability against long-term storage, dilution with water and mechanical shearing force.