METHOD OF POLYMERISING OLEFINS Russian patent published in 2015 - IPC C08F10/00 C08F4/24 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of polymerising at least one alpha-olefin containing 2-12 carbon atoms in the presence of a supported chromium oxide-based catalyst. The supported chromium oxide-based catalyst is a titanium-modified supported chromium oxide-based catalyst. The chromium oxide-based catalyst is supported on a heat-resistant oxide. The titanium-modified supported chromium oxide-based catalyst is subjected to two-step heat treatment, where: (1) the first step includes heating the catalyst in an inert atmosphere to 600-900°C, holding the catalyst for 8 hours or less in the inert atmosphere at 600-900°C; and (2) the second step includes treating the catalyst obtained at step (1) in an oxidative atmosphere at 400-700°C for 2-10 hours. The maximum temperature at step 2 is always lower than the maximum temperature at step 1, wherein the difference between maximum temperature at step 1 and the maximum temperature at step 2 is 50-250°C. The catalyst is not prepared using a method for combined gelling and includes depositing a titanium compound on a support by adding and/or impregnation.

EFFECT: method enables to obtain a polymer product with desirable properties and achieve high catalyst activity.

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