| 摘要 |
<p>A silicone composition crosslinkable into an adhesive gel by hydrosilylation consisting of three specified (optionally four) polyorganosiloxanes and hydrosilylation catalyst. The first polyorganosiloxane (POS) comprises terminal silyl units of type M ((R) 2(H)SiO 1 / 2, R : optionally substituted 1-6C alkyl or aryl ) and siloxyl units of type D ((R 1>) p(H) qSiO 2 / 2, R 1>R; p : 1-2; q : 0,1; p+q : 2 ). It comprises at least two SiH radicals per molecule. The second POS comprises terminal siloxyl units of type M ((X) s(R 2>) tSiO 1 / 2, R 2>R; X : 2-6C alkenyl and preferably vinyl; s : 0-1; t : 2-3; s+t : 3 ) and siloxyl units of type D ((X) u(R 3>) vZiO 2 / 2, R 3>R,u = 0,1; v : 1-3; u+v : 2 ). It comprises at least two radicals X per molecule. The third POS is monofunctional and essentially linear with less than 2% by moles (mol.%), more preferably less than 1.5 mol.% and most preferably less than 1 mol.% of siloxyl units of type T (RSiO 3 / 2). It comprises an alkenyl group X, preferably vinyl, directly bonded to silicon and comprises terminal siloxyl groups of type M ((X) w(R 4>) xSiO 1 / 2, R 4>R; w : 0-1; x : 2, 3; w+x : 3 ) and at least one siloxyl unit of type D ((X) y(R 5>) zSiO 2 / 2, R 5>R; y : 0,1; z : 1, 2; y+z : 2 ). The optional POS is not functionalized. It comprises terminal groups of type M ((R 6>) 3SiO 1 / 2, R 6>R ) and siloxyl units of type D ((R 7>) 2SiO 2 / 2, R 7>R ). The amount of the constituents is so chosen that the molar ratio (r) of hydrogen atoms bonded to silicon to alkenyl radicals X bonded to silicon is 0.1:1 to 1.5:1. Independent claims are included for a two component system comprising POS 1-3 and optionally 4 and the catalyst separately and for a crosslinked gel adhesive obtainable by crosslinking of the composition or the component system.</p> |
