Silicone elastomer compositions

A curable silicone elastomer composition that can achieve adhesion on plastic/thermoplastic/resin material substrates, the curable silicone elastomer composition comprising:

• (A) one or more organopolysiloxanes containing at least 2 alkenyl and/or alkynyl groups per molecule and having a viscosity in a range of 1,000 to 500,000 mPa·s at 25° C.;
• (B) a curing agent comprising
• (B)(i) an organic peroxide radical initiator;
• or
• (B)(ii) a hydrosilylation cure catalyst package comprising a hydrosilylation catalyst and
• an organosilicon compound having at least 2, optionally at least 3 Si—H groups per molecule;
• (C) at least one reinforcing filler and optionally one or more non-reinforcing fillers;
• and
• (D) an organopolysiloxane based additive which comprises at least one, optionally at least two Si—H groups per molecule and which comprises at least one, optionally at least two epoxide functional groups per molecule.