TREATMENT METHOD OF POLYOLEFIN PARTICLES PRODUCED BY GAS-PHASE POLYMERIZATION Russian patent published in 2016 - IPC C08F6/00 C08F10/00 C08F10/02 C08F2/34 

FIELD: technological processes.

SUBSTANCE: invention relates to a method of treating polyolefin particles produced by gas-phase polymerization of one or several olefins in presence of a catalytic system of polymerization and alkane C₃-C₅ acting as a solvent of polymerization in a gas-phase polymerization reactor. Method involves continuous or periodical dropping of polyolefin particles from the gas-phase polymerization reactor, transfer of the particles to the stage of degassing consisting of three degasifiers. Polyolefin particles in the first degasifier contact with a gaseous flow containing at least 85 mol% of alkane C₃-C₅. Average time of polyolefin particles remaining in the first degasifier is from 5 minutes up to 5 hours. In the second degasifier polyolefin particles are in contact with a flow containing nitrogen and water vapour. Average time of polyolefin particles remaining in the second degasifier is from 5 minutes up to 2 hours. Herewith the contacting is carried out in conditions without condensation of moisture. In the third degasifier polyolefin particles are in contact with a flow of nitrogen. Average time of polyolefin particles being in the third degasifier makes from 5 minutes up to 8 hours. Also described is a method of preparing a polyolefin polymer.

EFFECT: possibility of processing almost all monomers and comonomers simultaneously dropped with polyolefin particles to produce polyolefin products with good organoleptic characteristics without odour.

12 cl, 1 dwg, 1 ex