| 摘要 |
A polyamide comprising from 60 to 100 % by mole of divalent terephthaloylalkylenediamine constituent units (a), from 0 to 40 % by mole of divalent diacyloylalkylenediamine constituent units (b) and from 0.1 to 5 % by mole of trivalent diacyloylalkylenediamine units (c), said constituent units (a), (b) and (c) being arranged at random to provide a branched linear structure, said polyamide being free from a gel-forming cross-linked structure and soluble in concentrated sulfuric acid and having: an intrinsic viscosity ¢?! of from 0.5 to 3 dl/g, as measured in concentrated sulfuric acid at a temperature of 30.degree.C., a melting point of from 280.degree.C to 370.degree.C. and a glass transition temperature of from 100.degree.C to 160.degree.C., as measured by means of a differential scanning calorimeter at a heating rate of 10.degree.C/min., and a crystallinity of from 10 to 30 X, as measured by X-ray diffractometry. The polyamide has an excellent gas-barrier property, and thus, it is useful in applications where a gas-barrier property is particularly required, alone or in blend or lamination with other melt-moldable polymers. |
