| abstract |
FIELD: chemistry. n SUBSTANCE: invention relates to polyolefin compositions suitable for the production of pressure pipes. Disclosed is a polyolefin composition, including component A), containing 90.0–99.0 wt. % ethylene-propylene copolymer, in which i) the content of ethylene units is 1.0–8.0 wt. %; (ii) the melting point is 135–155 °C; (iii) the melt flow rate (230 °C / 5 kg ISO 1133) is 0.2 g / 10 min – 3.5 g / 10 min; (iv) the content of xylene-soluble substances at 25 °C is 10.0–4.0 wt%; (v) the polydispersity coefficient (PI) is 3.0–7.0; and component B) containing 1.0–10.0 wt. % ethylene-propylene copolymer comprising 8.0–20.0 wt. % of ethylene units; said copolymer has a melt flow rate (measured at 190 °C with a weight of 2.16 kg) from 0.5 g / 10 min to 5.0 g / 10 min; where the resulting polyolefin composition has a melt flow rate (230 °C / 5 kg ISO 1133) from 0.2 g / 10 min to 4.0 g / 10 min, and the sum A + B is 100. Pipes, sheets and pipelines, obtained from said composition are also disclosed. n EFFECT: technical result is that the obtained pipes and sheet material has high impact strength. n 7 cl, 3 tbl, 1 ex |