A process for producing polypropylene, which comprises preliminarily polymerizing 3-methylbutene-1 in the presence of a catalyst system formed from
[A] a solid titanium catalyst component containing magnesium, titanium, halogen and polycarboxylic acid esters as essential components,
[B] an organoaluminum compound, and
[C] an organosilicon compound represented by the general formula RnSi(OR′)4-n wherein R and R′ represent a hydrocarbon group, and 0
一种生产聚
丙烯的工艺,其中包括在以下物质组成的催化剂体系存在下初步聚合 3-甲基
丁烯-1: 1.
[A] 一种固体
钛催化剂组分,其基本成分包括
镁、
钛、卤素和聚
羧酸酯、
[B] 一种
有机铝化合物,以及
[C] 由通式 RnSi(OR′)4-n 表示的
有机硅化合物,其中 R 和 R′代表烃基,0
丙烯沿至少一个方向拉伸,该薄膜具有优异的透视性,且透明度或刚性损失很小。