Alpha-nucleated propylene/ethylene/1-butene terpolymer compositions for blown and cast films

An alpha-nucleated monophasic propylene terpolymer composition (PC), comprising:

• a) a propylene/ethylene/1-butene random terpolymer (PP), having:
• i) an ethylene content (C2), as determined by quantitative 13C-NMR spectroscopy, in the range from 0.75 to 4.0 mol %;
• ii) a 1-butene content (C4), as determined by quantitative 13C-NMR spectroscopy, in the range from 2.0 to 7.5 mol %;
• and
• iii) a content of 2,1-regiodefects, as determined by quantitative 13C-NMR spectroscopy analysis, in the range from 0.1 to 1.5 mol %, and
• b) one or more alpha nucleating agents (NU), wherein at least one of the one or more alpha nucleating agents is a particulate alpha nucleating agent,
• wherein the total amounts of the propylene/ethylene/1-butene random terpolymer (PP) and the one or more alpha nucleating agents (NU) add up to at least 95 wt. % of the total weight of the alpha-nucleated monophasic propylene terpolymer composition (PC),
• wherein the alpha-nucleated monophasic propylene terpolymer composition (PC) has each of the following properties:
• i) a melt flow rate (MFR2), determined according to ISO 1133 at 230° C. at a load of 2.16 kg, in the range from 1.0 to 35 g/10 min;
• ii) a melting temperature, determined according to DSC analysis, in the range from 125 to 140° C.;
• and
• iii) a crystallization temperature, determined according to DSC analysis, in the range from 95 to 115° C.