Patent ID: 8617529

Claim:
A method of preparing an organomodified siloxane block copolymer, said method comprising: A) incorporating at least one organopolysiloxane of general formula I in which R 1 are identical or different aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms, R 2 is R 1 or H, with the proviso that at least three radicals R 2 are H, a is 5 to 500, b is 1 to 50, c is 0 to 5, onto a siloxane of general formula II containing double bonds where d is 10 to 1000 and R 3 , independently of one another, are identical or different hydrocarbon radicals having 2 to 12 carbon atoms and containing at least one double bond, wherein said incorporating includes an addition reaction of said at least one organopolysiloxane of general formula I onto said siloxane of general formula II in the presence of a platinum catalyst or a rhodium catalyst, with the proviso that at least one organopolysiloxane of the general formula I is present in at least a 6-fold molar excess, based on the siloxane of the general formula II containing double bonds, to give a reaction product having Siâ€”H groups; and reacting the reaction product in at least one of the stages of: B) a transition-metal-catalysed partial or complete addition of the SiH groups onto alkenyl and/or alkynyl compounds, or C) a partial or complete reaction of the Siâ€”H groups remaining after the above reaction(s) in the presence of a catalyst with at least one alcohol selected from the group of linear or branched, saturated, mono- or polyunsaturated, aromatic, aliphatic-aromatic, optionally halogen-atom-containing monoalcohols, polyether monoalcohols, polyester monoalcohols, and amino alcohols.