| abstract |
An object of the present invention is to provide a curable resin composition for forming a cured product having excellent heat resistance, light resistance, flexibility and toughness. The present invention provides a curable resin composition comprising the following components in a specific amount. (A): average unit formula: [R 1 is alkyl, aryl, alkenyl, etc., the ratio of alkyl to the total amount of R 1 is 30 to 98 mol%, the proportion of aryl is 1 to 50 mol%, and the proportion of alkenyl is 1 to 20 mol%. the polyorganosiloxane represented by a1> 0, a2> 0, a3≥0, a4> 0, 0.01≤a1 / a2≤10, a1 + a2 + a3 + a4 = (B): a polyorganosiloxane having 20 to 60 mol% of alkenyl groups based on the total amount (100 mol%) of organic groups bonded to silicon atoms and having 10 or less silicon atoms (C): The following average unit formula: Wherein R x is alkyl, aryl, alkenyl, etc., the ratio of aryl to the total amount of R x is 1 to 50 mol%. At least two of the total R x are alkenyl. R A is a divalent hydrocarbon group. The organopolysiloxane represented by the formula: 0.05? X1? 0, x2 + x3> 0, x4> 0 and x1 + x2 + x3 + x4 = (D): The following average composition formula: [R 2 is alkyl, aryl, And at least two hydrogen atoms bonded to silicon atoms. 0.7? M? 2.1, 0.001? N? 1, 0.8? M + n? 3] (E): hydrosilylation catalyst |