Patent ID: 7153914
Filing Date: 2006-12-26
Classification: C08G,C08L,G02B

Abstract:
1. An addition-crosslinking silicone resin composition comprising (1) 100 parts by weight of a polyorganosiloxane of the formula in which R 1 is a monovalent, aromatic, optionally substituted C 6-16 hydrocarbon radical, R 2 is a monovalent C 2-10 alkenyl radical, R 3 is a monovalent radical selected from the group consisting of C 1 –C 18 -alkyl radicals, C 1 –C 6 -alkoxy radicals, and hydroxyl radicals, a, b and c, per siloxane unit, are 0, 1, 2 or 3, with the proviso that the sum of a+b+c is ≦3, and a, b and c, based on the average empirical formula (I), are on average 0.3≦a≦1.0, 0.1≦b<0.3, 0.5≦c≦1.5, the sum a+c being on average 1.0≦a+c<2.0, with the further proviso that at least two alkenyl radicals R 2 , at least one aromatic radical R 1 , and at least one unit of the formula RSiO 3/2 in which R is a radical R 1 , R 2 or R 3 , or SiO 2 , are contained per molecule, (2) from 50 to 200 parts by weight of a polyorganosiloxane of the formula in which d, e and f, per siloxane unit, are 0, 1, 2 and 3, with the proviso that the sum d+e+f is ≦3, and d, e and f, based on the average empirical formula (II), are on average 0.3≦d≦1.0, 0.1≦e<0.4, 0.5≦f≦1.5, the sum d+f being on average 1.0≦d+f≦2.0, with the further proviso that at least two Si-bonded hydrogen atoms and at least one aromatic radical R 1 are contained per molecule, or, instead of the components (1) and (2), (3) 200 parts by weight of a polyorganosiloxane of the general formula in which g, h, i and k, per siloxane unit, are 0, 1, 2 and 3, with the proviso that the sum g+h+i+k is ≦3, and g, h, i and k, based on the average empirical formula (III), are on average 0.3≦g≦1.0, 0.1≦h<0.3, 0.5≦i≦1.5, 0.1≦k<0.4, the sum of g+i being on average 1.0≦g+i≦2.0, and the ratio of h to k is on average 0.7≦h/k≦1.3, with the proviso that at least two alkenyl radicals R 2 , at least two Si-bonded hydrogen atoms, at least one aromatic radical R 1 and at least one unit of the formula RSiO 3/2 in which R is a radical R 1 , R 2 or R 3 , or SiO 2 , are contained per molecule, (4) from 1 to 100 parts by weight of an alkenyl-rich polyorganosiloxane of the formula in which l, m and n, per siloxane unit, are 0, 1, 2 and 3, with the proviso that the sum l+m+n is ≦3, and l, m and n, based on the average empirical formula (IV), are on average 0≦l≦0.5, 0.6≦m≦1.0, 0.5≦n≦2, the sum l+m+n being on average 1.0≦l+m+n≦2.5, with the further proviso that at least two alkenyl radicals R 2 are contained per molecule, and, additionally or instead of component (4), (5) from 1 to 100 parts by weight of a hydrogen-rich polyorganosiloxane of the formula in which o, p and q, per siloxane unit, are 0, 1, 2 and 3, with the proviso that the sum o+p+q is ≦3, and o, p and q, based on the average empirical formula (V), are on average 0≦o≦0.5, 0.6≦p≦1.0, 0.5≦q≦2, the sum o+p+q being on average 1.0≦o+p+q≦2.5, with the further proviso that at least two Si-bonded hydrogen atoms are contained per molecule, and (6) a catalyst which promotes the addition of Si-bonded hydrogen to aliphatic double bonds.