Heat curable organopolysiloxane compositions containing adhesion additives

Claim 1

A heat curable organopolysiloxane composition which consists of (1) 100 parts by weight of an organopolysiloxane having the general formula R.sub.a SiO.sub.4.sub.-a/2 wherein R is a hydroxy group, an alkoxy radical containing 1-4 carbon atoms or a substituted or unsubstituted hydrocarbon radical containing 1-8 carbon atoms, a is 1-3 and at least 25 mol percent of the R groups are monovalent unsubstituted hydrocarbon groups, (2) 0-400 parts by weight of particulate or fibrous filler, (3) 0.01-10 parts by weight of an organic peroxide catalyst and, (4) 0.01-20 parts by weight of an organosilicon compound having (i) at least one A(R'O) 2 Si-- group attached thereto wherein A is a monovalent hydrocarbon group containing at least one ##STR13## R' is a low molecular weight alkyl group, and (ii) at least one alkyl group containing 1-4 carbon atoms or (iii) at least one low molecular weight alkenyl group or hydrogen atom bound to silicon.