Patent ID: 6391944
Filing Date: 2002-05-21
Classification: C08G,C08K,C08L

Abstract:
A process for preparing a suspension of a particulate filler in a material, wherein said material is prepared from a silicone oil comprising:polyorganosiloxanes (POS fluids) of type (I) which carry Si-alkenyl functional groups capable of reacting with the Siâ€”H crosslinking functional groups of a POS fluid of type II, optionally, POS fluids of type (II) which carry Siâ€”H crosslinking functional groups capable of reacting with the Si-alkenyl functional groups of the POS fluids (I), and/or, optionally, POS fluids of type (III) which differ from the POS fluids (I) and (II), said suspension being able to be used for producing silicone compositions that can be cured by polyaddition, and wherein said particulate filler is treated with a compatibilizer; said process comprising, forming a preparation mixture of the particulate filler and the silicone oil, and introducing compatibilizer into the preparation mixture either: before and/or simultaneously with the contacting of at least part of the silicone oil employed with at least part of the particulate filler used, this introduction of compatibilizer taking place in one or more steps or, after the contacting of at least part of the silicone oil employed with at least part of the particulate filler used; and wherein: all or some of the silicone oil, water and all or some of the particulate filler are mixed with a first compatibilizer fraction of between 1 and 3% by dry weight with respect to the filler, a second compatibilizer fraction, representing between 10 and 15% by dry weight of filler, is incorporated into the mixture, optionally, the rest of the silicone oil and the rest of the are added, the mixture is allowed to react, the mixture is devolatilized, optionally, the devolatilized mixture is allowed to cool, and optionally, the suspension is completed with the rest of the silicone oil.