Blowing quality that shows superior stiffness, transparency and processing behavior

摘要

Extrusion blown film comprising a polypropylene composition, said polypropylene composition comprises a random propylene copolymer (R-PP), a high melt strength polypropylene (HMS-PP) and optionally a clarifier (C), in the that (a) the random propylene copolymer (R-PP) comprises units derived from propylene and at least one other C2 to C20 a-olefin, (b) the high melt strength polypropylene (HMS-PP) has an index of branch g 'of less than 1.0, (c) the clarifier (C) comprises at least one a-nucleating agent (N), and in which in addition (i) the branching index g' of the propylene copolymer at Random (R-PP) is higher than the branching index g 'of the high melt strength polypropylene (HMS-PP), (ii) the melt extrusion blown film and / or the polypropylene composition (a) meets (n) equation (I) Tf-Tc = 30 (I) in which Tf is the melting temperature [ºC] that represents nta more than 50% of the total melting enthalpy Hf of the melt blown film or of the polypropylene composition measured by DSC according to ISO 11357-3; Tc is the crystallization temperature [° C] of the melt extrusion blown film or of the polypropylene composition measured by DSC according to ISO 11357-3; and / or (b) has (n) a melt flow rate MFR2 (230 ° C) measured according to ISO 1133 from 1.0 to 5.5 g / 10 min.