Patent ID: 8158707
Filing Date: 2012-04-17
Classification: C08G,C08L

Abstract:
1. A process for the production of base compositions with a viscosity <400,000 mPas measured at 25° C. using a shear rate of 1 s −1 , by a) in a first stage, homogeneously mixing and kneading with one another: at least one organopolysiloxane (A) containing, on average, per molecule, on average, at least 1.5 radicals having aliphatically unsaturated carbon-carbon multiple bonds, or hydroxy groups or hydrogen atoms, or a combination thereof and at least one prehydrophobized oxidic reinforcing filler (B) having at least 0.5% by weight carbon content gained via a hydrophobizing process, in a kneading cascade with at least two kneading chambers arranged alongside one another in series, each comprising, parallel to the axis, two kneading units driven so as to corotate or counterrotate, and connected to other kneading chamber(s) via passage apertures running perpendicularly with respect to the axes of the kneading units, where at least the first kneading chamber has a supply aperture and the last kneading chamber has a discharge aperture, to form a kneaded product b) in a second downstream stage of the process, subjecting the kneaded product to aftertreatment in a mixing apparatus, which has a supply aperture, by way of which kneaded product is introduced at a volume flow rate X, subjected to shear force and devolatilized with constant renewal of the surface, with use of rotating mixing units, dispersing units, scrapers, or a combination thereof, and discharging a base composition from the second stage by way of a discharge aperture at a volume flow rate Y.