PROCESS FOR FORMING POLYOLEFINS Russian patent published in 2019 - IPC C08F2/00 C08L23/04 C08L23/08 C08L23/10 

FIELD: chemistry.

SUBSTANCE: invention relates to methods for forming polyolefins and controlling the characteristics of the resulting polyolefins. One or more specific embodiments of these methods generally include introducing an olefin monomer, which is selected from C₂-C₃ olefins, in the first reaction zone under the first polymerization conditions to obtain the first polyolefin; withdrawing a transfer effluent from the first reaction zone, the transfer effluent comprising first polyolefin and unreacted olefin monomer; introducing the transfer effluent, a comonomer selected from C₄-C₈ olefins and additional olefin monomer to a second reaction zone under second polymerization conditions to form a second reactor product; maintaining an essentially constant comonomer:olefin monomer ratio in the second reaction zone; and withdrawing at least a portion of the second reactor product, wherein the second reactor product comprises a bimodal polyolefin.

EFFECT: technical result is an improvement of the operational prediction and control of the monomer concentration in the real-time polymerization method, as well as the preparation of multimodal polyolefins having the desired set of characteristics.

29 cl, 4 dwg, 4 tbl, 1 ex