Block copolymer and compositions

摘要

A block copolymer composed of polyphenylene sulfide segments and aromatic sulfide sulfone polymer segments and having a logarithmic viscosity [ xi ], determined at 206 DEG C. for its solution in alpha-chloronaphthalene in a polymer concentration of 0.4 g/100 ml of solution and calculated in accordance with the equation [ xi ]=ln (relative viscosity)/polymer concentration, of 0.03 to 1.0. A resin composition comprising the block copolymer and polyphenylene sulfide and/or an aromatic sulfide sulfone polymer and optionally a filler. The block copolymer and the resin composition have improved mechanical strength and are suitable, for example, for encapsulation of electronic component parts.