BLOW MOULDED POLYETHYLENE POLYMERS Russian patent published in 2011 - IPC C08F10/02 C08F2/34 C08F4/24 C08F210/02 

FIELD: chemistry.

SUBSTANCE: method involves contact between monomers and particles of a fluidised catalyst in gas phase in the presence of hydrogen gas. The monomers consist of ethylene and optionally at least one non-ethylene monomer. Contact takes place under ethylene partial pressure which is not below 689.5 kPa and polymerisation temperature not higher than 120°C. The ethylene (co)polymer has density of not less than 0.945 g/cm³ and environmental stress-cracking resistance (ESCR index) not less than 1.0. Particles of the catalyst are obtained at activation temperature not higher than 700°C and contain silicon dioxide, chromium and titanium. In another method, the ethylene (co)polymer has die swell between 80% and 100%.

EFFECT: obtaining a polymer with sufficiently high environmental stress-cracking resistance and suitable die swell, while achieving high catalyst efficiency using a gas-phase technique in a fluidised layer.

63 cl, 1 dwg, 2 tbl, 21 ex