| abstract |
This invention relates to a method of surface treating particulate inorganic fillers with a surfacetreating agent which is an equilibrated reaction mixture consisting essentially of R<sub>2</sub>SiO<sub>2/2</sub> units, RSiO<sub>3/2</sub> units and CH<sub>3</sub>O<sub>½</sub> radicals wherein the mixture contains A moles of R<sub>2</sub>SiO<sub>2/2</sub> units per mole of RSiO<sub>3/2</sub> units and B moles of CH3O<sub>½</sub> radicals, A having an average value of from 0.5 to 10 and B having an average value of from 3 to 6, the value of B being related to A such that when A = 0.5, B = 6 and when A <sup>=</sup> 10, B = 3, and R being a hydrocarbon radical of from 1 to 10 inclusive carbon atoms or a haloalkyl radical of from 1 to 10 inclusive carbon atoms. Reinforcing silica fillers, surface-treated with such equilibrated reaction mixtures can be compounded with polydiorganosiloxanes curable to elastomers and cured to obtain silicone elastomers possessing high optical clarity and physical properties which make the cured elastomer uniquely suitable for use as prosthetic devices for use on or within the body. |