Bonding primer composition

Claim 1

A primer composition for bonding a silicone rubber composition to a substrate, said composition comprising A. 100 parts by weight of a silane of the formula R.sub.n Si[OCC(CH.sub.3).sub.3 ].sub.4-n where R represents alkyl containing from one to four carbon atoms, aryl, substituted alkyl where the alkyl portion contains from one to four carbon atoms, or substituted aryl where the substituent is halogen and n is 1, 2 or 3; B. from 5 to 500 parts by weight of an organosilicon compound containing at least two alkoxy groups per molecule and at least one unit corresponding to the average formula R.sup.1.sub.a R.sup.2.sub.b (OR.sup.3).sub.c SiO.sub.(4-a-b-c)/2 where R l is methyl, ethyl, aryl, substituted methyl, substituted ethyl or substituted aryl where the substituent is a halogen or a cyano group R 2 represents a monovalent radical containing a functional group selected from the group consisting of vinyl, allyl, epoxy, methacryloxy, mercapto, amino and N-aminoalkyl), where said functional group is bonded to silicon directly or by means of a divalent hydrocarbon radical; R 3 is methyl, ethyl, propyl, phenyl, 2-methoxyethyl or 2ethoxyethyl, the value of a is from 0 to 3, inclusive, the value of b is from 0 to 3, inclusive, the value of c is greater than 0 and no greater than 4 and the sum of a+b+c is greater than 0 and no greater than 4; C. from 0.1 to 50 parts by weight of an organotitanate ester; and D. an organic liquid in an amount sufficient to solubilize said primer composition.