BLOCK COPOLYMER COMPOSITION AND METHOD FOR ITS PREPARATION Russian patent published in 2022 - IPC C08L53/02 C08L95/00 C08F297/04 C08F212/08 C08F236/10 C08F4/48 C08J3/22 

FIELD: chemical or physical processes.

SUBSTANCE: invention relates to a block-copolymer composition used in polymer-bitumen binders, adhesive compositions, hot melt adhesives, etc. Present invention also relates to a method of producing a block copolymer composition, comprising polymerising a vinyl aromatic hydrocarbon and a conjugated diene, taken in ratio (30–32):(68–70), wt. %, respectively, in a medium of a hydrocarbon solvent, in the presence of an electron-donor additive, an organolithium initiator, post-polymerisation cross-linking using at least two coupling agents of different nature, according to the invention, said at least two coupling agents are selected from silicon-containing compounds of formula R₂SiHal₂, where R is C₁-C₂₀-aliphatic or C₆-C₂₀-aromatic groups, and sulfur-containing compounds having polysulphide groups (-S-)_n in their structure, where n=1–8, and a linker group (-Y-) capable of being substituted with active Li atoms in the polymer chain, selected from C₁-C₂₀-alkyl,C₃-C₂₀-alicyclic, C₃-C₂₀-heterocyclic, C₆-C₂₀-aromatic groups, to obtain a block copolymer composition. In addition, the present invention relates to the obtained block copolymer composition for polymer-bitumen binders, which contains (i) from 8 to 16 wt. % of non-cross-linked block copolymer AB, (ii) from 34 to 87 wt. % of a block copolymer cross-linked with a silicon-containing coupling agent, (iii) from 5 to 50 wt. % of a block copolymer cross-linked with a sulfur-containing coupling agent, and (iv), optionally, functional additives, where A is a monovinyl aromatic hydrocarbon block, B is a conjugated diene block, wherein the content of the bound monovinyl aromatic monomer ranges from 30 to 32 wt. %, conjugated diene — from 68 to 70 wt. %, content of 1,2-vinyl links ranges from 10 to 43 wt. %.

EFFECT: obtaining a block copolymer composition characterized by high content of high molecular weight fraction (Mw), expanded polydispersity, as a result, the obtained block copolymer composition is characterized by improved processability; based on the block copolymer composition, a polymer-bitumen binder (PBB) is obtained, characterized by improved affinity of the polymer to bitumen, an improved set of properties, namely, increased extensibility and maximum tensile force, improved elasticity and increased stability of PBB during thermal aging.

17 cl, 2 tbl