| 摘要 |
FIELD: chemistry.SUBSTANCE: invention relates to a catalyst system, production and use of high-purity heterophase propylene copolymers which contain (A) a matrix of a propylene homo- or copolymer whose weight ratio ranges from 73 to 98%, with ISO 1133 MFRindex ?45 g/10 min and (B) an elastomeric copolymer whose weight ratio ranges from 2 to 27%, wherein the weight ratio of propylene is at least 50% of component (B) and weight ratio of ethylene and/or any other C-Calpha-olefin is at least 50% of component (B). Propylene copolymers are obtained during multi-step polymerisation in the presence of the catalyst system, including (i) a Ziegler-Natta procatalyst which contains a product of transesterificatin of a lower alcohol and a phthalic ester of complex acids, and (ii) possibly an organometallic cocatalyst, and (iii) an external donor of formula (I) Si(OCHCH)(NRR), where elements Rand Rcan be the same or different hydrocarbon groups, each containing 1-12 carbon atoms. The copolymers are used to produce moulded articles.EFFECT: obtained polymers have high MFR index, low content of oligomers, high purity and low misting.16 cl, 1 tbl, 8 ex |
