| 摘要 |
FIELD: chemistry of polymers. ^ SUBSTANCE: invention relates to polyolefin compositions comprising a component of crystalline propylene polymer chosen from homopolymers of propylene and statistic copolymers of propylene-ethylene and/or other alpha-olefins, copolymer of propylene with 40% of ethylene by weight and copolymer of ethylene with (C4-C10)-alpha-olefins, and to a method for their preparing and articles made of them. Proposed compositions can be easily processed by casting under pressure, and can be used in manufacturing dishware and toys. Compositions possess low turbidity, reduced decolorizing and low content of fraction extracted with organic solvents. Unique balance of technological effectiveness, mechanical and optic properties are attained at the expense that the composition shows the melt flow rate value equal or above 4 g/10 min (230C, 2, 16 kg) and the content of xylene-soluble polymer at room temperature is less 25 wt.-%, and it comprises: 55-90% of homopolymer of crystalline propylene, or copolymer containing up to 15% of ethylene and/or (C4-C10)-alpha-olefin(s); 10-45% of mixture of propylene copolymer with above 15% to below 40% of ethylene (copolymer (a)) and copolymer of ethylene with one or more (C4-C10)-alpha-olefin(s) containing from 10% to 40% of indicated (C4-C10)-alpha-olefin(s) (copolymer (b)) wherein the weight ratio (a)/(b) = from 1:4 to 4:1. ^ EFFECT: improved and valuable properties of compositions. ^ 7 cl, 4 tbl, 13 ex |
