METHOD OF GAS-PHASE POLYMERISATION OF OLEFINS Russian patent published in 2009 - IPC C08F2/01 C08F2/34 C08F10/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of gas-phase polymerisation of one or more alpha-olefins in the presence of a catalyst system. The method involves: a) bringing one or more of the said alpha-olefins into continuous contact with the said catalyst system in a pre-polymerisation reactor, in which reaction takes place in a liquid medium at temperature ranging from 23° to 50°C; b) continuous feeding of a pre-polymer, obtained from stage a), into a gas-phase reactor which has interconnected polymerisation zones, in which growing polymer particles flow upstream through the first ascending polymerisation zone in conditions of stable fluidisation or transportation, come out of the said ascending polymerisation zone and enter the second descending polymerisation zone, through which they flow downstream under gravitational force, come out of the said descending polymerisation zone and then enter the said ascending polymerisation zone again; in which the pre-polymer, obtained at stage a), continuously enter the ascending polymerisation zone, characterised by speed of upward-flowing gases of over 3.0 m/s.

EFFECT: use of the invention improves size distribution of polyolefin particles.

13 cl, 1 dwg, 1 tbl, 6 ex