| 摘要 |
Propylene polymers having a content of isotactic pentads (mmmm) higher than 97%, molecular weight distribution, expressed by the formula (a) ratio, equal to or higher than 6 and a value of formula (b) ratio equal to or lower than 5.5. The said polymers are prepared in the presence of a particular combination of Ziegler-Natta solid catalyst components and highly stereoregulating electron-donor compounds. Laminated articles, in particular bi-axially oriented films and sheets, can be prepared with the said polymers. <?in-line-formulae description="In-line Formulae" end="lead"?>{overscore (M<SUB>w</SUB>/{overscore (M<SUB>n </SUB> (a) <?in-line-formulae description="In-line Formulae" end="tail"?> <?in-line-formulae description="In-line Formulae" end="lead"?>{overscore (M<SUB>z</SUB>/{overscore (M<SUB>w </SUB> (b) <?in-line-formulae description="In-line Formulae" end="tail"?>
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