申请人:CHISSO CORPORATION
公开号:EP0790262A1
公开(公告)日:1997-08-20
A propylene-ethylene copolymer composition is obtained which has a good moldability and is excellent in the balance of rigidity, toughness, and impact-strength.
A propylene-ethylene copolymer composition having a melt flow rate of 10 to 300 g/10 minutes and obtained by
producing 60 to 95 % by weight, based on the weight of whole polymer, of a propylene polymer having a melt flow rate (ASTM D-1238) in the range of 100 to 1,000 g/10 minutes and having a ratio (Cf) of integrated values of the propylene polymer dissolved in o-dichlorobenzene at a temperature of lower than 112°C, and a temperature of 112°C or higher, respectively, which is an index of the stereoregurality in molecules and molecular weight distribution, when the amounts of the propylene polymer dissolved therein at each of the temperatures were determined by raising the temperature of the o-dichlorobenzene continuously or stepwise, of 0.5 or less, by carrying out polymerization of propylene in the presence of a highly stereoregular catalyst and hydrogen in a polymerization step (I), and then
producing 5 to 40 % by weight, based on the weight of whole polymer, of an ethylene-propylene copolymer by feeding ethylene and propylene to the propylene polymer produced in the polymerization step (I) to react so that the content of ethylene becomes 30 to 80 % by weight, in a polymerization step (II); and a propylene-ethylene copolymer composition comprising the composition mentioned above and a α-crystal and/or β-crystal nucleator added therewith.
一种丙烯-乙烯共聚物组合物具有良好的成型性,并且在刚性、韧性和冲击强度的平衡方面表现优异。
一种熔体流动速率为 10 至 300 克/10 分钟的丙烯-乙烯共聚物组合物,通过以下方法获得
以整个聚合物的重量为基准,生产 60% 至 95% 重量百分比的丙烯聚合物,其熔体流动速率(ASTM D-1238)在 100 至 1,000 克/10 分钟范围内,在温度低于 112°C、和 112°C 或更高温度下溶解在邻二氯苯中的丙烯聚合物的综合值之比 (Cf),这分别是分子立体性和分子量分布的指标,当通过连续或逐步提高邻二氯苯的温度 0.5 或更低,在聚合步骤 (I) 中,在高度立体配位催化剂和氢的存在下进行丙烯聚合,然后
在聚合步骤(II)中,通过向聚合步骤(I)中生成的丙烯聚合物中加入乙烯和丙烯进行反应,使乙烯的含量达到 30% 至 80%(以整个聚合物的重量计),生成 5% 至 40%(以重量计)的乙烯-丙烯共聚物;以及丙烯-乙烯共聚物组合物,该组合物包括上述组合物和加入其中的 α 结晶和/或 β 结晶成核剂。