| 摘要 |
The invention concerns a method for preparing a precipitated silica suspension in a silicone oil, said suspension being useable for producing silicones crosslinkable by polyaddition, polycondensation or condensation by dehydrogenation (elastomers). The invention aims at solving the problem of finding a compromise between cost, rheology and mechanical properties of the final elastomers. Therefor, the invention provides a method for preparing a precipitated silica suspension treated with trimethylchlorosilane, in the presence of hexamethyldisiloxane, in a crosslinkable silicone oil. HCl can be used. Grafting of hydrophobic units on the silica and incorporation of the polyorganosiloxane silicone material are carried out during one single processing sequence, without passing through the powder form for the silica. Sodium silicate promoting MQ resin can be incorporated in the reaction medium. One of the characteristics of the inventive method is that it does not at all comprise a step involving dried hydrophobic silica. The invention also concerns the preparation of a crosslinkable silicone elastomer composition from said suspension, and the resulting composition. |
