COPOLYMERS OF ETHYLENE AND AT LEAST ONE OTHER 1-OLEFIN AND SYNTHESIS METHOD THEREOF Russian patent published in 2011 - IPC C08F210/02 C08F210/16 C08F4/22 

FIELD: chemistry.

SUBSTANCE: invention relates to copolymers of ethylene and at least one other 1-olefin, synthesis method thereof and use thereof as blow moulded articles. Described is a copolymer of ethylene and at least one other 1-olefin with density 0.940-0.955 g/cm³, content of vinyl terminal groups greater than 0.5 terminal groups per 1000 carbon atoms, impact resistance under a load a_m measured according to DIN EN ISO 8256 (1997)/1A at -30°C greater than or equal to 145 kJ/m² and content of comonomer side chains per 1000 carbon atoms C_x greater than a value defined by equation I: C_x = 128.7 -134.62 · d'(1), where d' denotes density d of the copolymer in g/cm³. Described is a method of producing said ethylene copolymer via polymerisation of ethylene and at least one other 1-alkene C₃-C₁₂ using a chromium catalyst at temperature 80-125°C and pressure 0.2-20 MPa, where the chromium catalyst is obtained through the following steps: a) obtaining hydrogel containing silicon oxide, b) drying the hydrogel to a state with residual liquid content less than 50 wt % at temperature 200-600°C for at most 300 seconds to form xerogel, c) sieving the xerogel if necessary, d) depositing 0.01-5 wt % chromium salt which can be converted on the xerogel to chromium trioxide through calcination, e) calcination of the solid phase obtained at step (d) at temperature 350-950°C in an oxidative atmosphere. Described also are blow moulded articles made from said ethylene copolymer.

EFFECT: obtaining an ethylene copolymer with the desired hardness and resistance to cracking under external forces and high impact resistance.

17 cl, 1 tbl, 3 ex