FIELD: building materials.
SUBSTANCE: invention relates to a polymer-bitumen composition, which is used in the production of roofing materials. The polymer-bitumen composition for roofing materials includes (A) 61.6-68.6 wt.% of bitumen, (B) 5.5-7.4 wt.% of block copolymer, and (C) 25.9-31.0 wt.% of a mineral filler, where block copolymer is copolymer of conjugated diene and monovinyl aromatic monomer and is characterized by the content of bound monovinyl aromatic monomer from 32 to 39 wt.%, the content of 1,2-links from 20 to 40 wt.% per polymer block of conjugated diene, the content of two-block from 16 to 20 wt.% per 100 wt.% of block copolymer, average molecular weight from 160,000 to 180,000 Da, and glass transition temperature of the elastic block from -88 to -74°C. In this case, block copolymer is represented by the formula (AB)nX (i) and the formula AB (ii), where A is a polymer block of monovinyl aromatic hydrocarbon, B is a polymer block of conjugated diene. Block copolymer of conjugated diene and monovinyl aromatic monomer, which is part of the specified composition, is also described.
EFFECT: provision of a polymer-bitumen composition characterized by a reduced dynamic viscosity, namely, at 170°C, the dynamic viscosity decreases by at least 2000 MPa×s, improved heat resistance – the softening temperature (ring-and-ball method) increases by at least 10°C, and frost resistance – the temperature, at which flexibility remains on R15 beam (according to GOST 2678-94) decreased by 5°C, while penetration remains unchanged.
12 cl, 16 ex, 2 tbl
