Self-adhesive addition-crosslinking silicon compositions

An addition-crosslinking silicone composition comprising

• (A) at least one diorganopolysiloxane of the formula (1)
• R1aR2bSiO(4−a−b)/2 (1),
• in which
• R1 is a hydroxyl radical or a monovalent, optionally halogen-substituted C1-20 hydrocarbon radical optionally containing O, N, S or P atoms, and being free of aliphatically unsaturated groups,
• R2 is a monovalent, aliphatically unsaturated, optionally halogen-substituted C1-10 hydrocarbon radical optionally containing O, N, S or P atoms,
• a has a value from 1.0 to 2.0,
• b is from 0.0003 to 2, with the proviso that 1.5<(a+b)<3.0, that on average at least two aliphatically unsaturated radicals R2 are present per molecule, and that the viscosity of the diorganopolysiloxane(s) (A) is 1 mPa·s to 40,000 Pa·s, determined at 25° C.,
• (B) organohydropolysiloxanes of the general formula (2)
• R3cR4dR5eHfSiO(4−c−d−2e−f)/2 (2),
• in which
• R3 is a monovalent aliphatically saturated C1-20 hydrocarbon radical,
• R4 is (a) an optionally halogen-substituted monovalent C6-15 hydrocarbon radical which contains at least one aromatic C6 ring, or (b) a halogen-substituted, saturated monovalent C2-20 hydrocarbon radical optionally containing O, N, S or P atoms,
• R5 is a bivalent, optionally halogen-substituted C6-20 hydrocarbon radical Si-bonded at both ends, optionally containing O, N, S or P atoms,
• c, d, e and f are independently zero or a non-zero number, with the proviso that the organohydropolysiloxane (B) contains on average at least 3 SiH groups per molecule, that the relationship:
• 0.05<100 (d+e)/(c+d+e+f) is fulfilled, and that the viscosity of the organohydropolysiloxane (B) is 1 mPa·s to 100 Pa·s determined at 25° C.,
• (C) adhesion promoters
• in which each R12 independently is a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl, alkenyl, alkoxy, alkenyloxy or aryl group, or a monovalent organic group containing an alkenyl, alkoxy, glycidyl, carbonyl, carbonyloxy, silyloxy or alkoxysilyl group, at least one of the radicals R12 being an alkenyl group or a monovalent organic group containing an alkenyl group,
• and X is selected from the following groups:
• —(R13—)C(—R13)—, —(O═)S(═O)—, —(O═)S—, —C(═O)—, —O—(CH3—)Si(—CH3)—O—, —(CH2)s— or —O—
• in which R13 is a hydrogen atom, a halogen atom or a substituted or unsubstituted alkyl, aryl, alkenyl or alkynyl group and s is a positive number of at least 2, and r is 0 or 1, and
• (D) a hydrosilylation catalyst.