PRODUCTION OF POLYOLEFIN Russian patent published in 2018 - IPC C08F210/02 C08F4/659 

FIELD: biochemistry.

SUBSTANCE: invention relates to the production of an ethylene polymer in a fluidised bed polymerisation reactor. Method of forming resin particles comprises: forming a catalytic compound, containing bis(n-propylcyclopentadienyl)hafnium-(CH₃)₂, bis(n-propylcyclopentadienyl)hafnium-F₂, bis(n-propyl-cyclopentadienyl)hafnium-Cl₂, or any combination thereof; mixing of the catalytic compound with an activator, containing methylaluminoxane to form a catalyst complex; and combining the catalyst complex with a silica support to form a supported polymerisation catalyst, wherein the supported polymerisation catalyst has a particle size distribution in which 10 % of the particles have a size of less than 17–23 mcm, 50 % of the particles have a size of less than 40–45 mcm and 90 % of the particles have a size of less than 72–77 mcm; reacting the supported polymerisation catalyst with at least ethylene in a gas-phase fluidised bed polymerisation reactor to form resin particles. Resin particles have: an average particle size of the polymer of at least 0.660 mm; particle size distribution with at least 20 % larger than 1 mm in diameter; and the ratio of fluidised bulk density to a settled bulk density (FBD/SBD), of at least 0.570, and the average ratio of fluidised bulk density to a settled bulk density (FBD/SBD) is 4 % higher, than the average FBD/SBD ratio for the resin particles obtained from the catalyst compound, applied to other silica-based supports, when the polymerisation is carried out in the reactor under substantially the same conditions.

EFFECT: technical result is a higher ratio of fluidised bulk density to a settled bulk density while maintaining the desired catalyst efficiency.

8 cl, 13 dwg, 4 tbl