Polyfunctional polysiloxanes with (meth) acrylic acid ester groups bonded via SiOC groups and an unmodified polysiloxane block, process for their preparation and their use as radiation-curable abhesive coating

摘要

Organopolysiloxanes having (meth) acrylic acid ester groups bonded via SiOC groups and having an unmodified polysiloxane block are obtained by addition of SiH-containing organopolysiloxanes of the general formula Iworin R 1 are identical or different aliphatic or aromatic hydrocarbon radicals having 1 to 20 C atoms, R 2 R 1 or H, with the proviso that at least three radicals R 2 are H, a 5 to 500, b 1 to 50, c 0 to 5, of vinylsiloxanes of the general formula II, d 60 to 1,000 in the presence of platinum or rhodium catalysts below with the proviso that the organopolysiloxanes of the general formula I in at least 6-fold molar excess, based on the vinylsiloxane of the general formula II, and subsequent teiweiser or complete reaction of remaining after the above reaction SiH groups in the presence of a suitable catalyst having at least one Alcohol that is selected from the group of single or multiple Ach (meth) acrylated monoalcohols or polyalcohols.