Curable organopolysiloxane composition

Claim 1

A curable organopolysiloxane composition which comprises: (A) 100 parts by weight of an organopolysiloxane having at least two vinyl groups each joined to silicon atoms in one molecule and having a viscosity not lower than 50 centipoises at 25° C.; (B) from 0.5 to 20 parts by weight of an organohydrogenpolysiloxane of the following general formula (R.sup.1.sub.2 R.sup.2 SiO.sub.1/2).sub.1 (R.sup.1 HSiO.sub.2/2).sub.m (R.sup.1.sub.2 SiO.sub.2/2).sub.n (R.sup.1 SiO.sub.3/2).sub.k wherein R 1 's may be the same or different and represent an unsubstituted or substituted monovalent hydrocarbon group other than aliphatic unsaturated hydrocarbon groups, R 2 represents a hydrogen atom or a monovalent hydrocarbon group represented by R 1 , and l, m, n and k are such that l+m+n+k is a value which permits the organopolysiloxane to have a viscosity at 25° C. of from 5 to 1,000 centipoises and that m≧2, k≧1, 0.5≦l/k≦3 and 0≦n/m≦1; and (C) a catalytic amount of a platinum group catalyst.