Patent ID: 7476706

Claim:
A method for producing polyorganosiloxane particles, which comprises the step (A) of hydrolyzing and condensing a silicon compound of the general formula (I), R 1 n Si(OR 2 ) 4-n (I) wherein R 1 , which is a non-hydrolyzable group, is an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and having a (meth)acryloyloxy group or epoxy group, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, R 2 is an alkyl group having 1 to 6 carbon atoms and n is an integer of 1 to 3, provided that when a plurality of R 1 s are present, each of R 1 s may be identical to, or different from, other or every other one, and that when a plurality of OR 2 are present, each of OR 2 s may be identical to, or different from, other or every other one, in the presence of a catalyst, to form seed particles of polyorganosiloxane particles and thereby obtaining a seed-particles-containing solution, and the step (B) of mixing said seed-particles-containing solution with a particle-diameter-growing aqueous solution containing a silicon compound of said general formula (I) or a hydrolyzate thereof, to grow said seed particles, the method comprising the step (A) of obtaining the seed-particles-containing solution in which, when said silicon compound is dissolved in an aqueous medium, 0.7 to 6.5 mass ppm of a basic catalyst is added to said aqueous medium to cause the silicon compound to undergo preliminary hydrolysis and condensation, and a basic catalyst is added thereto in an amount necessary for forming the seed particles formed of polyorganosiloxane, to form said seed particles.