A multi-layer biaxially oriented polymer film comprising a core layer (CL) and at least one sealing layer (SL), said sealing layer(s) (SL) comprise(s) a propylene copolymer composition (P) having a comonomer content in the range of 3.0 to 8.0 wt.-%, the comonomers are C5 to C12 α-olefins, said propylene copolymer composition (P) comprises a polypropylene (A) and a polypropylene (B) in the weight ratio [(A)/(B)] of 20/80 to 80/20, wherein said polypropylene (A) has a comonomer content of equal or below 4.0 wt.-%, the comonomers are C5 to C12 α-olefins, and said propylene copolymer (B) has a comonomer content of 4.0 to 20.0 wt.-%, the comonomers are C5 to C12 α-olefins.