| 摘要 |
FIELD: polymer production. ^ SUBSTANCE: disclosed is producing a propylene copolymer in a multistage polymerization process including: polymerization of propylene in presence of small amounts of ethylene and catalyst in a first reaction zone comprising at least one suspension reactor to form first polymerization product; and passing the latter to a second reaction zone comprising at least one gas-phase reactor and continuing propylene polymerization in gaseous phase in presence of the first polymerization product, temperature in both suspension and gas-phase reactors being at least 75°C and content of ethylene in the product from at least one of reactors ranging between less than 0.05 and 0.5% by weight. Described is also propylene copolymer obtained in indicated process, which contains ethylene comonomer units in amounts 0.05 to 0.5% by weight and xylene-soluble fractions in amounts 3.0% by weight or less, maximum of the temperature rising elution fractionation thereof corresponding to 120°C or below. Described is further application of thus obtained propylene copolymers as fibers, nonwoven materials, films, and sheets. ^ EFFECT: improved mechanical properties of polymeric material. ^ 26 cl, 4 dwg, 2 tbl, 3 ex |
