The present invention relates to a curable resin composition comprising a curable resin mixture and at least one C2-C3-alkenyl-substituted compound of formula (I) wherein m is 1, 2 or 3; Rm1, Rm2, Rm3 and Rm4 are hydrogen or C6-C14-aryloxy, which is substituted by one or more radicals selected from C1-C24-alkyl and C6-C14-aryl-C1-C10-alkylene; R5, R6, are hydrogen or optionally substituted C6-C14-aryl, or R5 and R6 together are a diradical of the formula A; A is a diradical of the formulae A.1 or A.2 wherein R7 is C2-C3-alkenyl; R8, n are as defined in the claims and in the description. The present invention also relates to a polymer comprising in copolymerized form at least one compound of formula (I) and an organopolysiloxane and to novel compounds of formula (I).