BLOCK COPOLYMER FOR POLYMER-BITUMEN BINDERS, POLYMER-BITUMEN COMPOSITIONS FOR ROAD CONSTRUCTION Russian patent published in 2023 - IPC C08F297/04 C08L95/00 C04B26/26 

FIELD: block copolymers.

SUBSTANCE: block copolymers for polymer-bitumen binders and asphalt mixes for road construction. Three-block styrene-butadiene copolymer of the formula A-B-A is proposed, where A is a polystyrene block, B is a polybutadiene block, which is characterized by a weight average molecular weight of the block copolymer of 70-120 thousand amu, a weight average molecular weight of the first peak Mw₁ 135-185 thousand amu, weight average molecular weight of the second peak Mw₂ 65-85 thousand amu, the content of 1,2-units in the polybutadiene block is not less than 74 wt.%, and the ratio the content of 1,2-units to 1,4-units during the formation of a polybutadiene block changes conically: at a butadiene conversion of 0-10%, the ratio of 1,2- to 1,4-units is from 4.6 to 4.3, and at butadiene conversion of 90-100% is 2.0-3.5, respectively, polymer-bitumen compositions that contain from 2 to 5 wt.% bimodal styrene-butadiene block copolymer and asphalt concrete mixtures obtained using the proposed polymer-bitumen compositions.

EFFECT: improving the properties of the styrene-butadiene block copolymer, increasing its Shore hardness and its Vicat softening point, as well as increasing the manufacturability of polymer-bitumen binders.

8 cl, 3 tbl, 10 ex