above in the case of the radical r 2 particularly preferred radicals r 13 are the methyl ethyl vinyl and phenyl radicals particularly preferred radicals r 15 are methyl ethyl propyl and butyl radicals examples of radicals r 14 are the epoxyethyl 2 3 epoxypropyl 3 4 epoxybutyl 5 6 epoxyhexyl 9 10 epoxydecyl glycidyloxy 3 glycidyloxypropyl glycidyloxyisobutyl 2 methylglycidyloxypropyl 3 phenylglycidyloxypropyl glycidyloxyphenylnonyl glycidyloxybenzylethyl 3 4 epoxycyclohexyl 2 3 4 epoxycyclohexyl ethyl 3 3 4 epoxycyclohexyl propyl 1 4 epoxycyclohexyl and 2 1 4 epoxycyclohexyl ethyl radicals preferred radicals r 14 are the 3 4 epoxycyclohexyl 3 3 4 epoxycyclohexyl propyl and glycidoxypropyl radicals the radical r 14 preferably has from 2 to 10 carbon atoms the radical r 14 is preferably an alkyl radical the particularly preferred radical r 14 is the glycidoxypropyl radical as alkoxysilane e having an epoxide group particular preference is given to glycidyloxypropyltrimethoxysilane glymo the content of alkoxysilane e having an epoxy group is preferably selected so that the silicone mixture has a content of compound e of 0 01 5 by weight preferably 0 1 2 by weight in particular 0 2 1 by weight the silicone mixture can also contain filler f examples of nonreinforcing fillers f are fillers having a bet surface area of up to 50 m 2 g e g quartz diatomaceous earth calcium silicate zirconium silicate zeolites metal oxide powders such.