| 摘要 |
PURPOSE:To produce fine spherical silicone particles having a narrow particle size distribution by using a hydrocarbon-substd. organopolysiloxane which is an inexpensive starting material. CONSTITUTION:An organopolysiloxane comprising constituent units of [R<1>SiO3/2] or constituent units of [R<1>SiO3/2] and [R<2>2SiO] and/or [SiO2], and represented by the average compositional formula: R<1>jR<2>kSiOI (wherein R<1> and R<2> each stand for a group selected from the group consisting of 1-4C alkyl groups, 2-4C alkenyl groups, and a phenyl group; j and k are respective no. of 0 to 1.4, provided that j +k=0.6 to 1.4; and l is a no. of 1.3 to 1.7, provided that 2l+j+k=4) is dissolved in an aq.soln. of an alkali hydroxide, followed by removal of cations by an ion exchange method. The soln. thus obtained is subjected to gelation at 50 deg.C or above and a pH of 10 or above to obtain the fine spherical silicone particles having an average particle size of 0.1 to 20mum. |
