Patent ID: 6762242
Filing Date: 2004-07-13
Classification: A61K,C08K

Abstract:
Silicone material which comprises the following constituents:I. a POS composition crosslinkable by polyaddition reactions comprising: (1) at least one POS(1) composition carrying Si-alkenyl functional groups which are capable of reacting by addition reactions with the Siâ€”H crosslinking functional groups of a POS(2) composition, (2) at least one POS(2) composition carrying Siâ€”H functional groups which are capable of reacting with the Si-alkenyl functional groups of the POS(1) composition, (3) optionally, at least one unreactive POS(3) composition, differing from the POS(1) and POS(2) compositions, (4) a catalyst for catalyzing the polyaddition reactions, and (5) a particulate reinforcing mineral filler treated with a compatibilizing agent (CA); II. a wetting agent comprising one or more surfactants allowing the surface of the silicone material to be given a hydrophilic character; wherein the filler constituent (5) is employed, during preparation of the POS composition, in the form of a suspension obtained by the following steps: bringing the reinforcing mineral filler into contact with the compatibilizing agent (CA) and with a silicone oil comprising some or all of the POS(1) composition(s) and optionally with water; this contacting operation comprising (a) introducing a first portion of the CA either before or approximately simultaneously with the incorporation of the particulate reinforcing mineral filler into at least part of the silicone oil employed and into the water optionally present, wherein the first portion of CA is less than or equal to 8% by weight with respect to the particulate reinforcing filler; and (b) after incorporation of the reinforcing filler, adding the second portion of CA into the at least part of the silicone oil and the water optionally present.