ASTERISK-BRANCHED DIENE RUBBER Russian patent published in 2022 - IPC C08C19/40 C08C19/44 C08F236/04 C08L55/02 C08L9/00 

FIELD: chemistry.

SUBSTANCE: group of inventions relates to asterisk-branched diene rubber, a method for the manufacture of such rubber, and its inclusion in high impact polystyrene (hereinafter – HIPS) and acrylonitrile-butadiene-styrene (hereinafter – ABS) polymers. Asterisk-branched diene rubber is characterized by a vinyl content measured on polymer film, using IR spectroscopy with Fourier transform of less than 15 wt. % of the total weight of rubber, Mooney ML 1+4 viscosity at 100°C, determined according to ASTM D1646 (1999) standard, from 30 to 80 MU, a solution viscosity in the range from 30 to 60 mPa·s, determined at a rubber concentration in styrene of 5 wt. %, using a B type viscometer placed in thermostat at 25°C, low rubber discoloration expressed by APHA number, determined in 5% solution in styrene according to DIN EN ISO 6271, of less than 100, and a value of the ration of the Mooney viscosity to the solution viscosity of more than 1.0. A method for the production of asterisk-branched diene rubber is also described, including polymerization of at least one conjugated diene monomer with the formation of diene polymer, and interaction of diene polymer with a combination agent corresponding to the formula (I) R₁-R₂-Si-(R₃)₃ (I), where R₁ is a glycidoxy group, R₂ is optionally substituted C₁-C₈ alkylene optionally containing one or several oxygen atoms, and R₃ is C₁-C₈ alkoxy group. At the same time, a method for the production of HIPS or ABS includes grafting to asterisk-branched diene rubber of a polystyrene part for obtaining HIPS or a part in the form of styrene-acrylonitrile copolymer for obtaining ABS.

EFFECT: provision of asterisk-branched diene rubbers with a higher value of the ratio of the Mooney viscosity and the solution viscosity (MV/SV) with obtaining high surface gloss and preservation of high impact resistance, and with reduced relative discoloration for HIPS or ABS resin containing this asterisk-shaped diene polymer compared to such HIPS or ABS resin containing cross-linked diene rubber obtained using a halogen-containing combination agent.

12 cl, 1 tbl, 8 ex