High-strength silicone rubber particulate

Method for the preparation of a high-strength silicone rubber particulate wherein said method

• I mixes
• (A) 100 weight parts diorganopolysiloxane having silicon-bonded hydroxyl or alkenyl at the molecular chain terminals.
• (B) organohydrogenpolysiloxane having at least 3 silicon-bonded hydrogen atoms in each molecule, in a quantity sufficient to cure component (A).
• (C) 3 to 50 weight parts hydrophobic silica prepared by a hydrophobicization which is carried out by mixing and heating
• (a) 100 weight parts wet-method silica and
• (b) 1 to 100 weight parts organopolysiloxane represented by the following average unit formula
• R.sup.1.sub.a R.sup.2.sub.b SiO.sub.(4-a-b)/2
• wherein R.sup.1 is a monovalent hydrocarbon group, R.sup.2 is the hydrogen atom, a is from 1 to 3 inclusive, and b is from zero to 1 inclusive, with the provisos that a+b is from 1.90 to 2.10 inclusive and b/(a+b) is from zero to 0.45 inclusive, and having a viscosity of from 5 to 1000 centipoise (0.005 to 1 Pa.s)
• and
• (D) a catalytic quantity of a curing catalyst;
• II then disperses the aforesaid liquid silicone rubber composition in surfactant-containing water to give a water-based emulsion in which the aforesaid composition is dispersed as the discontinuous phase in the water;
• and
• III subsequently contacts the aforesaid emulsion with a gas which resides at a temperature higher than the temperature of the water therein in order to bring about a complete cure of the aforesaid silicone rubber composition while simultaneously evaporating the water.