POLYOLEFIN COMPOSITIONS SHOWING HIGH FLOWABILITY Russian patent published in 2007 - IPC C08L23/10 C08L23/16 C08F2/00 C08J5/18 

FIELD: polymer mixtures.

SUBSTANCE: invention provides polyolefin composition used to manufacture films and sheets, in particular films molded from solution, comprising: (A) 15 to 40% crystalline propylene copolymer with at least one α-olefin having general formula H₂C=CHR¹, where R¹ represents hydrogen atom or linear or branched C₂-C₈-alkyl, containing at least 90% propylene and soluble in xylene at ambient temperature to less than 15% by weight, and (B) 60 to 85% elastomer fraction comprising propylene/ethylene copolymer, wherein content of ethylene is 20-35% by weight and which optionally contains 0.5 to 5% diene, exhibiting solubility in xylene at ambient temperature above 45%, intrinsic viscosity of xylene-soluble fraction ranging between 1.0 and 3.0 dL/g, and (2) copolymer of ethylene with at least one α-olefin having general formula H₂C=CHR², where R² represents linear or branched C₂-C₈-alkyl, wherein content of α-olefin is 15-40% by weight and which optionally contains 0.5 to 5% diene, exhibiting solubility in xylene at ambient temperature above 35%, intrinsic viscosity of xylene-soluble fraction ranging between 1.0 and 3.0 dL/g; provided that (1)/(2) weight ratio varies between 1:5 and 5:1. Polyolefin composition according to invention and preferably prepared in at least three-step consecutive polymerization process is characterized by elevated flowability, plasticity, lack of gels, having flexural modulus below 130 MPa, Shore hardness D below 40, and MFR ≥ 1.5 g/10 min.

EFFECT: improved performance characteristics of polyolefin composition.

14 cl, 2 tbl