PROPYLENE POLYMERS WITH IMPROVED PROPERTIES Russian patent published in 2006 - IPC C08F110/06 C08F297/08 C08F10/06 C08K3/00 C08K5/20 C08K5/09 C08K5/3415 C08K5/3417 C08K5/3437 

FIELD: chemistry of polymers.

SUBSTANCE: invention relates to mixtures of propylene polymers with improved properties comprising propylene polymers and seed charge-forming agents of crystallization wherein propylene polymers are represented by propylene homopolymers with melt indices from 0.05 to 15 g/10 min at 230°C/2.16 kg or propylene block-copolymers comprising from 90.0 to 99.9 wt.-% of propylene links and from 0.1 to 10 wt.-% of α-olefin links with 2 or 4-18 carbon atoms, melt indices from 0.05 to 20 g/10 min at 230°C/2.16 kg or their mixtures wherein propylene homopolymers or propylene block-copolymers are represented by propylene polymers with seed charge-forming agents of crystallization in β-form. Propylene homopolymers with seed charge-forming agents of crystallization in β-form have value IRτ ≥0.98, elasticity modulus at stretching ≥1500 MPa at +23°C and impact viscosity by Sharpy ≥3 kJ/m² at -20°C with incision and propylene block-copolymers with seed charge-forming agents of crystallization in β-form have value IRτ of propylene homopolymer block ≥0.98, elasticity modulus at stretching ≥1100 MPa at +23°C and impact viscosity by Sharpy ≥6 kJ/m² at -20°C with incision. Also, invention discloses a method for preparing mixtures of propylene polymers with seed charge-forming agents of crystallization in β-form that involves propylene homopolymers or propylene copolymers in melt with 0.0001-2.0 wt.-% of seed charge-forming agents of crystallization in β-form at temperatures in the range from 175 to 250°C. Such mixtures of propylene polymers are characterized by the presence of high rigidity and good resistance against impact charges and can be used in making the molded articles for pipeline nets, such pipes, fittings, man holes and so on.

EFFECT: improved and valuable properties of polymers.

5 cl, 5 ex