Patent ID: 7960030

Claim:
A free-standing film comprising a cured organopolysiloxane resin, wherein the glass transition temperature of the cured organopolysiloxane resin is equal to or greater than 100° C. and the coefficient of thermal expansion at 100° C. is equal to or below 200 ppm/K, obtained by conducting a cross-linking reaction between (A) an organopolysiloxane resin represented by the following average siloxane unit formula: [R 1 a R 2 3-a SiO 1/2 ] v [R 3 SiO 3/2 ] w (1) or [R 1 a R 2 3-a SiO 1/2 ] x [R 3 SiO 3/2 ] y [SiO 4/2 ] z (2) where R 1 designates univalent hydrocarbon groups of one or more than one type selected from alkyl groups having 1 to 4 carbon atoms and univalent aromatic hydrocarbon groups having 6 to 8 carbon atoms; R 2 designates alkenyl groups having 2 to 6 carbon atoms; R 3 designates univalent hydrocarbon groups of one or more than one type selected from alkyl groups with 1 to 4 carbon atoms and univalent aromatic hydrocarbon groups having 6 to 8 carbon atoms; at least 50 mole % of R 3 groups being phenyl groups; “a” is 0, 1, or 2; 0.82≦w<1.0 and v+w=1; 0<x<0.4, 0.5<y<1, 0<z<0.4, and x+y+z=1; and (B) an organosilicon compound that contains in one molecule two or more silicon-bonded hydrogen atoms, in which not less than 5 mole % of all silicon-bonded univalent groups are univalent aromatic hydrocarbon groups, in the presence of (C) a hydrosilylation catalyst.