METHOD OF PRODUCING HETEROPHASE PROPYLENE COPOLYMERS Russian patent published in 2010 - IPC C08F2/00 C08F10/00 B01J8/18 

FIELD: chemistry.

SUBSTANCE: heterophase propylene copolymers are obtained through polymerisation of propylene in the presence of a Ziegler-Natta catalyst or a metallocene-type catalyst and hydrogen as a molecular weight stabiliser. At the first step, gas- or liquid-phase propylene is polymerised in a first reactor optionally together with one or more α-olefine comonomers. A fraction of crystalline polymer having less than 7 wt % solubility in xylene at ambient temperature is obtained. At the second step, the obtained fraction is fed into a second gas-phase reactor, where ethylene is copolymerised with propylene and/or 1-butene and optionally with one or more C₅-C₁₂ α-olefin comonomers. Polymerisation zones in the reactors are connected to each other. Polymer particles growing in the second reactor flow bottom up through the first polymerisation zone with an ascending stream and enters the second polymerisation zone with a descending stream, and then enters the first polymerisation zone again, thereby facilitating circulation of the polymer between polymerisation zones. The fraction of crystalline polymer is fed where the bottom is joined between the first and second polymerisation zones.

EFFECT: invention enables to obtain two distinct fractions of an elastomeric polymer.

9 cl, 2 dwg, 5 tbl, 5 ex