POLYPROPYLENE MIXTURE FOR TUBES Russian patent published in 2015 - IPC C08L23/10 C08L23/12 C08F4/64 F16L9/12 

FIELD: chemistry.

SUBSTANCE: invention relates to β-nucleated polypropylene mixtures. Described is a polypropylene mixture for making tubes. The mixture includes a component (A), which is a homo- or copolymer of propylene, obtained using a catalyst system with a single polymerisation centre and having a melt flow rate MFR₂ (230°C) of not more than 0.9 g/10 min, and a component (B), which is a second homo- or copolymer of propylene, obtained using a Ziegler-Natta catalyst and having MFR₂ (230°C) of 0.03-20 g/10 min, which expands molecular weight distribution from the view point of the polydispersity index of the whole composition. The component (A) and/or component (B) and/or composition of the polypropylene mixture are β-nucleated. The mixture has a shear thinning index SHI (0/50), measured according to ISO 6271-10, of 10-85. Also described is the use of the polypropylene mixture to make single-layer tubes or one of the layers of a multilayer tube.

EFFECT: obtaining propylene tubes with high pressure resistance, rigidity and high impact resistance.

14 cl, 6 tbl, 3 ex