| 摘要 |
Process for the preparation of LLDPE with improved processability by gas phase polymerization performed in two or more reactors, wherein, whatever the order, in one of the reactors a mixture of ethylene and an alpha-olefin CH2=CHR, where R is an alkyl having 1-10 carbon atoms, is polymerized to yield a copolymer containing up to about 20% by mole of the alpha-olefin, and in another reactor a mixture of propylene and an alpha-olefin CH2=CHR', where R' is an alkyl radical having 2-10 carbon atoms, is polymerized to yield a copolymer containing from 5 to 40% by weight of said olefin, in an amount of 5-30% with respect to the total polymer weight and the polymer-catalyst system obtained in the first reactor is fed to the other reactors. |
