METHOD OF PRODUCING ETHYLENE AND VINYL ACETATE COPOLYMERS IN SINGLE-ZONE AUTOCLAVE REACTOR Russian patent published in 2016 - IPC C08F210/02 C08F2/02 

FIELD: chemistry.

SUBSTANCE: described is a method of producing ethylene and vinyl acetate copolymers in a single-zone autoclave reactor with a high-speed mixer. The method comprises feeding a mixture of said comonomers into the reactor; carrying out mass copolymerisation at pressure of 120-250 MPa and high temperature; the copolymerisation reaction is initiated with a solution of a separate organic peroxide or mixtures of peroxides in an organic solvent fed through a pipe into the upper and lower parts of the reactor; maintaining average temperature in the upper part of the reactor at 200-230°C and in the lower part of the reactor at 220-260°C; the dwell time of the peroxide in different parts of the reactor is set based on the condition that the product of the decay constant of the separate peroxide or the additive decay constant of the mixtures of peroxides and the dwell time thereof in the upper part of the reactor is equal to 80-120 and in the lower part of the reactor is equal to 180-220; carrying out two-step separation of the obtained copolymer from the unreacted reaction mixture in high pressure and low pressure recycle systems.

EFFECT: improved elasticity of the copolymer.

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