Patent ID: 8535478

Claim:
A silicone elastomer composition, which is adhesive and crosskinkable under heat, intended in particular to bond a silicone substrate, this composition comprising: the components (a-1) corresponding to at least one polyorganosiloxane gum (I), optionally having per molecule at least two alkenyl groups, preferably C 2 -C 6 , bound to a silicon atom, which crosslinks by the action of a catalyst based on at least one organic peroxide, a reinforcing mineral filler (III), an effective quantity of cross-linking catalyst comprising at least one organic peroxide (IV), an adhesion promoter of polyorganohydrogensiloxane type comprising Si—H groups (VI), optionally at least one additional adhesion promoter (VII) optionally at least one additional filler (VIII), optionally at least one cross-linking inhibitor (IX), optionally at least one polyorganosiloxane resin (X), and optionally one or more functional additives for conferring specific properties wherein the nature and the quantity of said adhesion promoter of polyorganohydrogensiloxane type (VI) are chosen so that the amount of Si—H groups is such that, after the reaction for cross-linking the composition, the potential surface density of Si— covalent bonds with the silicone substrate to be bonded is of at least one Si— covalent bond per 60 nm 2 , preferably at least one Si— covalent bond per 40 nm 2 , and wherein said adhesion promotor of polyorganohydrogensiloxane type comprising Si—H groups (VI) is selected from the group consisting of the copolymers with (dimethyl)-(hydrogenmethyl)-polysiloxane units with trimethylsilyl ends or with hydrogendimethylsilyl ends, the hydrogenmethylpolysiloxanes with trimethylsilyl ends or with hydrogendimethylsilyl ends, the cyclic hydrogenmethylpolysiloxanes, and wherein the adhesion promoter of polyorganohydrogensiloxane type (VI) is a polymethylhydrogensiloxane having between 10 and 45% by weight Si—H or a methylhydrogensiloxane and dimethylsiloxane copolymer, having between 10 and 48% by weight Si—H.