<p>Cohesive bonding between silicone rubber compositions and plastics is achieved using primer compositions comprising a solution of at least one member of a specified class of organotitanate esters in an organic liquid. Cohesive bonding of silicone rubber compositions to both plastic and metals is achieved by including at least one member from either of two specified classes of organosilicon compounds in the primer composition together with the organotitanate ester.</p>
