METHOD FOR RAPID ACTIVATION AND TREATMENT FOR ACTIVATION OF CHROME CATALYSTS FOR PRODUCTION OF POLYETHYLENES WITH HIGH MELT FLOW RATE Russian patent published in 2024 - IPC C08F110/02 C08F4/24 

FIELD: catalytic chemistry.

SUBSTANCE: method is proposed for activating a chromium catalyst on a substrate, including: a) heating the chromium catalyst on a substrate in an inert atmosphere to a first temperature (T¹) at a first temperature change rate (RR¹), where this first temperature T¹ is from 500 to 1000°C and the indicated first rate of change of temperature (RR¹) is more than 1°C/min and less than 5°C/min; b) maintaining the chromium catalyst at a first temperature in an inert atmosphere for a first holding period (tH1), wherein this first holding period (tH1) is less than 15 hours and more than 15 minutes; c) bringing the chromium catalyst to a second temperature (T²) in an inert atmosphere at a second temperature change rate (RR²), where the temperature T² is in the range of 25°C below T¹ to temperature at 500°C is lower than T1 or equal to T1^, followed by exposure of the chromium catalyst to an oxidizing atmosphere; d) maintaining the chromium catalyst at a second temperature in an oxidizing atmosphere for a second holding period (tH2), wherein this second holding period (tH2) is less than 1 hour and more than 30 seconds; and e) cooling the chromium catalyst to a temperature below a second temperature in an inert atmosphere, an oxidizing atmosphere, or any sequential combination of an inert atmosphere and an oxidizing atmosphere during a cooling period (t^C) to provide an activated chromium catalyst. A method for polymerizing olefins is also proposed.

EFFECT: reduction in the total duration of the activation cycle, a decrease in the activation temperature and the production of catalysts that have the desired activity and provide polymers with the desired properties.

15 cl, 16 dwg, 8 tbl, 30 ex