Patent ID: 6974853

Claim:
An initiator system for free-radical polymerizations, comprised of a combination of compounds of the formulae in which R′, R″, R′″, R″″ are chosen independently of one another and represent a) branched and unbranched C 1 to C 18 alkyl radicals; C 3 to C 18 alkenyl radicals; C 3 to C 18 alkynyl radicals; b) C 3 to C 18 alkynyl radicals; C 3 to C 18 alkenyl radicals; C 1 to C 18 alkyl radicals substituted by at least one OH group or halogen atom or a silyl ether; c) C 2 -C 18 hetero alkyl radicals having at least one oxygen atom and/or an NR group in the carbon chain; R being chosen from one of groups a), b), and d) to g), d) C 3 -C 18 alkynyl radicals, C 3 -C 18 alkenyl radicals, C 1 -C 18 alkyl radicals substituted by at least one ester group, amine group, carbonate group and/or epoxide group and/or by sulfur and/or by sulfur compounds, especially thioethers or dithio compounds; e) C 3 -C 12 cycloalkyl radicals; f) C 6 -C 10 aryl radicals; g) hydrogen; X represents a group with at least one carbon atom wherein the free radical X• derived from X has the ability to initiate a polymerization of ethylenically unsaturated monomers and further comprising thermally decomposing radical-forming azo and/or peroxo initiators, wherein the compounds of formula (I) are present in a proportion of from 1 mol. % up to 10 mol. %, based on amount of the compounds of the formula (II), and/or the azo and/or peroxo initiators are present in a proportion from 1 to 10 mol. %, based on the amount of compound of the formula (II).