| 摘要 |
<p>A continuous process for preparation of propylene-ethylene block copolymer suitable for moldings with high rigidity and high impact resistance are provided, which process is a continuous process for preparation of highly rigid propylene-ethylene block copolymers, wherein propylene and ethylene are polymerized in the specified 2 steps with use of a catalyst system comprising (A) a solid catalyst component containing Ti, Mg, halogen and polyvalent carboxylic ester, (B) an organic aluminium compound, as well as (C) an organic silicon compound expressed by the general formula R<4>xR<5>ySi(OR<6>)z (wherein, x+y+z=4), and wherein the ratio between the maximum value and the minimum value of MFR(1)) is <MATH> and the ratio between the average MFR(i) and MFR(ii) in the subsequent polymerization procedure (II) containing ethylene in a relatively large amount which is carried out by adding the glycol type compound is <MATH> The product having less fish eye and high impact resistant value was obtained from the copolymer according to the invention. <IMAGE></p> |
