METHOD OF PREPARING ETHYLENE-OLEFIN COPOLYMERS HAVING HIGHER PROCESSIBILITY, AND COMPOSITION BASED ON LOW- DENSITY LINEAR POLYETHYLENE COPOLYMER AND PROPYLENE IN PARTICLE FORM Russian patent published in 1998 - IPC

FIELD: chemistry of polymers. SUBSTANCE: present invention describes method of preparation of low- density linear polyethylene having higher processibility by gas phase polymerization carried out in two or more reactors. Mixture of ethylene and alpha-olefin CH₂= CHR, wherein R is alkyl containing carbon atoms is polymerized in one of reactors to produce copolymer containing up to about 20 mole % alpha-olefin, and mixture of propylene and alpha-olefin CH₂= CHR wherein R is alkyl having 2-10 carbon atoms to produce copolymer containing from 5 to 40 wt % said olefin in amount of 5-30% of total weight of polymer, polymer-catalyst system prepared in first reactor being admitted into other reactors. Method of preparing said compounds is simple and makes it possible to use the same catalyst in both reactors and maintain higher efficiency in manufacturing film and lower energy consumption. Desired products have lower crystallinity and higher index of melt. EFFECT: more efficient preparation method. 11 cl, 1 dwg, 2 ex, 1 tbl