Abstract: The invention concerns the preparation of a silica suspension in a silicon fluid, said suspension being used to produce silicon vulcanisable by polyaddition (RTV elastomers). The problem which the invention aims to solve is that of finding a technical compromise between the rheological and mechanical properties of the final RTV. The invention solves the problem by providing a method for preparing a silica suspension treated with hexamethyldisilazane (HMDZ) in a silicon fluid with siloxyl Si-Vinyl function, characterised in that it consists essentially in introducing HMDZ in the preparation medium, before and/or substantially while bringing at least part of the silicon fluid prepared with at least part of the particulate filler used, said introduction being carried out once or several times for a HMDZ fraction corresponding to a proportion not more than 8% by dry weight with respect to the total silica charge and after bringing together the POS and the filler.

Abstract: The aqueous polyorganosiloxane emulsion, in particular for the coating of textiles or similar materials, which comprises an organopolysiloxane formula which is a precursor of the elastomer comprising a polydiorganosiloxane, preferably an inorganic filler, a catalyst and optionally a crosslinking agent, in the absence of surfactant in this formula, is characterized in that the organopolysiloxane formula is in emulsion in an aqueous protective hydrocolloid solution and in that this emulsion is obtained by direct emulsification of the complete organopolysiloxane formula in the aqueous protective hydrocolloid solution. The protective hydrocolloid is preferably a poly(vinyl alcohol) (PVA) or a PVA mixture.Preparation method relating thereto, coating process using these emulsions and products thus coated.