Siloxane copolymers containing alkenyl groups, process for preparing the same and their use

Claim 1

A siloxane copolymer having alkenyl groups and contains (a) siloxane units of the formula ##STR13## in which R is selected from the group consisting of hydrocarbon radicals having from 1 to 18 carbon atom(s) per radical and halogenated hydrocarbon radicals having from 1 to 18 carbon atom(s) per radical, R 1 is an alkyl radical having from 1 to 4 carbon atom(s) per radical which can be substituted by an ether oxygen atom; a is 0, 1, 2 or 3; b is 0, 1, or 3; and the sum of a+b is not greater than 3; (b) at least one siloxane unit per molecule of the formula ##STR14## in which R is the same as above, c is 0, 1 or 2, G is a radical of the formula --CH.sub.2 CHR.sup.2 CHR.sup.2 OY(OCHR.sup.2 CR.sup.2 ═CH.sub.2).sub.x-1 in which R 2 is selected from the group consisting of a hydrogen atom and a methyl radical; Y is a trivalent, tetravalent, pentavalent or hexavalent hydrocarbon radical which has from 2 to 20 carbon atoms per radical which can be substituted by groups of the formula --OH; --OCR 3 ; --OSiR 4 3 ; ##STR15## or --X; or can be interrupted by at least one oxygen atom or sulfur atom or one carbonyl group, or Y represents a trivalent radical of the formula .tbd.P, .tbd.P═O or SiR.sup.5, in which R 3 is an alkyl radical having from 1 to 6 carbon atom(s) per radical, R 4 is selected from the group consisting of a methyl, ethyl, isopropyl, tert-butyl and phenyl radical, X is a halogen atom and R 5 is a monovalent hydrocarbon radical having from 1 to 8 carbon atoms(s) per radical, or Y represents a tetravalent element selected from the group consisting of ##STR16## and x is 3, 4, 5 or 6, and optionally (c) at least one unit per molecule selected from the group consisting of units of the formulas ##STR17## in which R and c are the same as above, G 1 is a radical of the formula ##STR18## in which R 2 , Y and x are the same as above.