Soluble terminally modified imide oligomer using 2-phenyl-4, 4'-diaminodiphenyl ether, varnish, cured product thereof, imide prepreg thereof, and fiber-reinforced laminate having excellent heat resistance

Abstract

A novel terminally modified imide oligomer having excellent solubility in organic solvents, excellent solution storage stability, and excellent molding properties such as low melt viscosity. Also, a varnish obtained by dissolving the terminally modified imide oligomer in an organic solvent; a cure product obtained by using the terminally modified imide oligomer and having excellent thermal and mechanical characteristics such as heat resistance, elastic modulus, tensile strength at break and tensile elongation at break; a prepreg; and a fiber-reinforced laminate. The soluble terminally modified imide oligomer is represented by general formula (1). In the formula, Rand Reach represents a divalent aromatic diamine residue; Rand Reach represents a tetravalent aromatic tetracarboxylic acid residue; Rand Reach represents a hydrogen atom or a phenyl group, with Ror Rbeing a phenyl group; m and n satisfy the following relations: m≧1, n≧0, 1≦m+n≦20 and 0.05≦m/(m+n)≦1; and the repeating units may be arranged in blocks or randomly.