A propylene 1-hexene copolymer containing from 5.7 to 7.7% by weight of 1-hexene derived units, based upon the total weight of the propylene 1-hexene copolymer, having:
a) a solubility in xylene at 25° C. ranging from 7.0 wt % to 15.0 wt %, based upon the total weight of the propylene 1-hexene copolymer;
b) a melting temperature, measured by DSC ranging from 143.0° C. to 148.0° C.;
c) a Melt Flow Rate (MFR, measured according to ASTM D 1238, 230° C./2.16 kg) from 3.5 to 8.0 g/10 min.; and
d) a content of 1-hexene derived units in the fraction soluble in xylene at 25° C. ranging from 13.5 wt % to 18.5 wt %, based upon the total weight of the soluble fraction.