SUSPENSION POLYMERISATION METHOD Russian patent published in 2013 - IPC C08F10/02 C08F2/00 C08L23/06 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing multimodal polyethylene. The method is carried out in at least two reactors which are connected in series, where 20-80 wt % of a high-molecular weight polymer is obtained in a suspension in a first reactor and 20-80 wt % of a low-molecular weight polymer is obtained in a suspension in a second reactor. The ratio of the average effective concentration of substance in the reactor of the low-molecular weight product to the average effective concentration of substance in the reactor of the high-molecular weight product is 0.25-1.5. The average effective concentration of substance in each reactor is defined as output of polyethylene obtained in the reactor (kg PE/h)/[concentration of ethylene in the reactor (mol %) × dwell time in the reactor (h) × rate of feeding catalyst into the reactor (g/h)]. The dwell time is defined as the mass of the polymer in the reactor (kg)/rate of removal of the polymer from the reactor (kg/h). The volume of the second reactor is at least 10%, preferably at least 30%, and even more preferably at least 50%, greater than the volume of the first reactor. The ratio of the length to the diameter of the first reactor L/D(1) is greater than that of the second reactor L/D(2), and is preferably greater by at least 20%.

EFFECT: method of producing multimodal polyethylene in two reactors with optimum ratio of dimensions.

15 cl, 1 tbl, 1 ex