Patent ID: 8575239

Claim:
A curing composition comprising a polyarylate having epoxy group and a cyanate ester resin, wherein the polyarylate having epoxy group has a repeating unit that is represented by the following Formula 2, wherein the polyarylate having epoxy group has a weight average molecular weight of 32,000 to 100,000, wherein the cyanate ester resin is contained in an amount of 50 to 200 parts by weight, based on 100 parts by weight of the polyarylate having epoxy group, wherein a cyanurate structure is formed by curing the cyanate ester group of the cyanate ester resin, and an isocyanurate structure is formed by reacting the cyanurate structure with the epoxy group in the polyarylate, and wherein the polyarylate is incorporated into the network structure of the cyanate ester resin, leading to graft formation: wherein x and y are a molar ratio satisfying x+y=1, x≧0, and y>0, a and b are an integer of 1 to 4, R 1 and R 2 are the same as or different from each other, each independently selected from the group consisting of hydrogen atom, halogen atom, alkyl, arylalkyl, alkenyl, arylalkenyl, aryl, alkylaryl, alkenylaryl, nitrile and alkoxy, W 1 and W 2 are each independently selected from the group consisting of direct bond, oxygen, sulfur, alkylene, cycloalkylene, fluorene, sulfonyl, sulfinyl, and carbonyl, and Ar is selected from the group consisting of phenylene, naphthylene and biphenylene.