FORFARANDE FOR FRAMSTELLNING AV MODIFIERADE ORGANOPOLYSILOXANER SAMT ANVENDNING DERAV FOR VID RUMSTEMPERATUR TILL ELASTER HERDBARA MASSOR

1487495 Production of grafted organopolysiloxanes CONSORTIUM FUR ELEKTROCHEMISCHE INDUSTRIE GmbH 6 Feb 1975 [7 Feb 1974] 5103/75 Heading C3G A modified organopolysiloxane is produced by grafting an olefinically unsaturated monomer on to an organopolysiloxane by means of a free radical initiator in the presence of 2 to 20% by weight, relative to the weight of the polymerization components, of a liquid that is a non-solvent under the polymerization conditions for both the initial and modified organopolysiloxanes, that is inert toward the polymerization components and that has a boiling point of not more than 100‹ C. at 760 mm. Hg. The inert liquid may be water, methanol or a saturated aliphatic halogenohydrocarbon. Examples are given in which a hydroxyl-terminated dimethylpolysiloxane is grafted with styrene and n-butyl acrylate in the presence of water. The product is cured using ethyl polysilicate and a dibutyl tin derivative of cyclic C 9 to C 11 -carboxylic acids.