Polypropylene-based copolymer and film comprising the polypropylene-based copolymer

A polypropylene-based copolymer comprising a polymer component comprising 95% by weight or more of a constitutional unit derived from propylene and having a melting point exceeding 155° C. (component A) and a copolymer component of propylene, ethylene and an α-olefin having 4 or more carbon atoms (component B), wherein;

• (i) the content of a fraction soluble in xylene at 20° C. (CXS) of the polypropylene-based copolymer is 4-40% by weight, and
• (ii) the content of the constitutional unit derived from propylene of the fraction soluble in xylene (P) is 30% by weight≦P<70% by weight, the content of the constitutional unit derived from ethylene of the soluble fraction (Q) is 30% by weight<Q≦50% by weight, the content of the constitutional unit derived from an α-olefin having 4 or more carbon atoms of the soluble fraction (R) is 0% by weight<R≦120% by weight, provided that the total of P, Q and R is 100% by weight.