Polyfunctional vinyl aromatic copolymer, process for producing the same, and resin composition

Abstract

An end-modified soluble polyfunctional vinyl aromatic copolymer, which is improved in heat resistance, thermal stability, solvent solubility, and compatibility with acrylate compounds, and a curable resin composition using the same are disclosed. The end-modified soluble polyfunctional vinyl aromatic copolymer is obtained by allowing a divinyl aromatic compound (a), a monovinyl aromatic compound (b), and an aromatic ether compound (c) to react with each other, and has, at an end, an end group derived from the aromatic ether compound and having an acrylate bond. The copolymer has a number average molecular weight Mn of 500 to 100,000, an introduction amount (c1) of the end group derived from the aromatic ether compound satisfies (c1)≧1.0 (group/molecule), a molar fraction a' of a structural unit derived from the divinyl aromatic compound and a molar fraction b′ of a structural unit derived from the monovinyl aromatic compound in the copolymer satisfy 0.05≦a′/(a′+b′)≦0.95. Besides, the curable resin composition includes the copolymer and an unsaturated acrylate monomer.