Image Number 5 for United States Patent #8133955.
An aromatic polyester resin composition, comprising: a melt-kneaded product of 99-70 weight parts of an aromatic polyester resin and 1-30 wt. parts (providing a total of 100 wt. parts together with the aromatic polyester resin) of a polyglycolic acid resin, wherein the composition is characterized by a transesterification rate C.sub.TE (%) of 20-60% determined by formula (1) below based on a peak integration ratio of methylene group in polyglycolic acid appearing at .sigma.4.87 ppm with reference to tetramethylsilane according to .sup.1H-NMR measurement: C.sub.TE (%)=(1-I(B)/I(A)).times.100 (1), wherein I (A): a peak integration ratio of the methylene group of the polyglycolic acid main chain with respect to the alkylene group of the aromatic polyester main chain calculated from the components weight ratio; and I (B): a peak integration ratio of the methylene group of polyglycolic acid main chain to the alkylene group of the aromatic polyester main chain in the resin composition. As a result, the aromatic polyester resin composition obtained by adding a relatively small amount of polyglycolic acid resin is provided with a good harmony of gas-barrier property and transparency.