The propylene polymer of the invention is transparent and has good low-temperature heat-sealability and scratch resistance, and is favorable to wrapping and packaging films. (1) The polymer has a melting point, Tm (°C), measured through differential scanning calorimetry, of 110 ≤ Tm ≤ 140; (2) its heat of fusion △H (J/g) and melting point Tm (°C) satisfy ΔH ≥ 0.45 × Tm + 22; (3) the half-value width Th (°C) of the peak top of its elution curve obtained in programmed-temperature fractionation is Th ≤ 5; and (4) its intrinsic viscosity [η] (dl/g) measured in a solvent of tetralin at 135°C falls between 0.5 and 5.
本发明的
丙烯聚合物是透明的,具有良好的低温热封性和抗划伤性,有利于包装和包裹薄膜。(1) 通过差示扫描量热法测量,该聚合物的熔点 Tm (℃)为 110 ≤ Tm ≤ 140;(2) 其熔化热 △H (J/g) 和熔点 Tm (℃)满足 △H ≥ 0.45 × Tm + 22;(3) 在程序温度分馏中得到的其洗脱曲线峰顶的半值宽度 Th(℃)为 Th ≤ 5;(4) 在 135℃的四
萘溶剂中测得的其固有粘度[η](dl/g)介于 0.5 和 5 之间。