Curable two-part silicone rubber compositions with improved adhesion properties

Claim 1

A curable composition of matter which consists essentially of a mixture of (a) an organopolysiloxane containing at least two hydrogen atoms bonded to silicon atoms and having the general formula R.sub.a SiO.sub.4-a/2 wherein a has an average value of 1-3 and R is hydrogen, hydroxy radicals or unsubstituted or substituted monovalent hydrocarbon radicals which do not contain aliphatic unsaturation, (b) an organopolysiloxane containing at least one A(R'O) 2 Si- group and at least two lower alkenyl radicals bonded to silicon atoms, in each molecule, wherein A is a monovalent hydrocarbon radical containing a ##STR15## radical, R' is a lower alkyl radical containing 1-6 carbon atoms, the sum of the number of hydrogen atoms bonded to silicon atoms in component (a) and the number of lower alkenyl radicals bonded to silicon atoms in component (b) is five or greater wherein there is present 0.1-10 mols of lower alkenyl groups bonded to silicon in (b) for every mol of hydrogen atoms bonded to silicon atoms in (a), and (c) 0.1-40 parts by weight per one million parts by weight of components (a) and (b) of an addition reaction catalyst for the addition reaction of the hydrogen atoms bonded to silicon atoms with the lower alkenyl groups bonded to silicon atoms.