| 摘要 |
<p>PURPOSE:The titled pipe having excellent rigidity, creeping resistance, and impact strength and a high rate of transition of crystal, comprising a poly-1-butene resin of specified properties. CONSTITUTION:A pipe formed from a poly-1-butene having an intrinsic viscosity (eta) of 1.5-4.0dl/g, a weight-average MW (Mw) to number-average MW (Mn) ratio <=6, and an isotacticity index >=95%. When the eta is smaller than 1.5dl/g, the resin has lowered creeping resistance and impact strength, while when it is larger than 4.0dl/g, the resin has reduced moldability and a smaller rate of transition of crystal. When the Mw to Mn ratio exceeds 6, the resin has lowered impact strength, while when the isotacticity index is below 95%, the resin has lowered rigidity and a smaller rate of transition of crystal. The poly-1-butene resin pipe having the above properties can show improved rigidity, creeping resistance, and impact strength and a higher rate of transition of crystal, which is of great advantage in handling a fresh molded product.</p> |
