Flowability improver for engineering plastics, thermoplastic resin compositions containing the same and molded articles of the compositions

摘要

A flowability improver for engineering plastics which comprises a polymer (A) comprising of 50 to 99.5% by mass of aromatic vinyl monomer units (a1), 0.5 to 50% by mass of (meth)acrylate monomer units (a2) having an ester group of phenyl or substituted phenyl group, and 0 to 40% by mass of other monomer units (a3) (with the proviso that the total of the units (a1) to (a3) is 100% by mass) and having a weight average molecular weight of 5000 to 150000. The flowability improver can improve engineering plastics in melt-flow characteristics (processability in molding) and chemical resistance without impairing the plastics in heat resistance, exfoliation resistance, and transparency.