Abstract: Spherical polysilsesquioxane particles in which, in a first step, trialkoxysilane of formula (I) RSi(OR1)3 ??(I), in which R represents a C1-16 hydrocarbon radical whose carbon chain may be interrupted by nonadjacent —O— groups, and Rl represents a C1-4 alkyl radical, is reacted with acidified water having a pH of not more than 6 with commixing to afford a hydrolyzate, in a second step the hydrolyzate is mixed with a solution of a base in water or C1-4 alkanol, in a third step the mixture is stored for 30 minutes to 6 hours, in a fourth step the mixture is mixed with a further solution of a base in water or C1-4 alkanol, in a fifth step the mixture is agitated for at least 5 minutes, and in a sixth step the polysilsesquioxane particles are isolated.

Abstract: Spherical organopolysiloxane resin particles with improved flow properties can be reproducibly obtained employing trialkoxysilanes having different hydrolysable chlorine contents by regulating pH in a first, acid hydrolysis step, and then adjusting pH in a second step to a desired value between 1 and 6. Particles are allowed to grow without agitation in a subsequent basic condensation step.

Abstract: Spherical polysilsesquioxane particles are prepared by reacting trialkoxysilanes of formula, (I) RSi(OR1)3??(I), where R represents a C1-16 hydrocarbon radical whose carbon chain may be interrupted by nonadjacent —O— groups, R1 represents a C1-4 alkyl radical, with acidified water having a pH?6 with stirring to produce a hydrolysate, in a second step mixing the hydrolysate with a solution of NaOH and/or KOH, and in a third step storing the mixture is stored for at least 8 h before isolating polysilsesquioxane particles thus formed.

Abstract: Spherical organopolysiloxane resin particles with improved flow properties can be reproducibly obtained employing trialkoxysilanes having different hydrolysable chlorine contents by regulating pH in a first, acid hydrolysis step, and then adjusting pH in a second step to a desired value between 1 and 6. Particles are allowed to grow without agitation in a subsequent basic condensation step.

Abstract: Spherical polysilsesquioxane particles are prepared by reacting trialkoxysilanes of formula, (I) RSi(OR1)3 ??(I), where R represents a C1-16 hydrocarbon radical whose carbon chain may be interrupted by nonadjacent —O— groups, R1 represents a C1-4 alkyl radical, with acidified water having a pH?6 with stirring to produce a hydrolysate, in a second step mixing the hydrolysate with a solution of NaOH and/or KOH, and in a third step storing the mixture is stored for at least 8 h before isolating polysilsesquioxane particles thus formed.