Abstract: Disclosed is a biaxially oriented polypropylene film substrate free from primer coating, which comprises successively connected affinity layer, core layer and surface layer, said affinity layer comprises 10% to 80% by weight of polypropylene homopolymer, 10% to 80% by weight of polyolefin plastomer and 1% to 10% by weight of anti-adhesion agent; said core layer is polypropylene homopolymer; said surface layer is the same as the affinity layer or a non-coated surface layer that comprises 90% to 99% by weight of polypropylene homopolymer and 1% to 10% by weight of anti-adhesion agent. A film free from primer coating and its preparing method are also provided. The coated film of this invention does not need the process of primer pre-coating, which reduces the relevant equipment costs on one hand and avoids the safety risks when using and restoring solvent type primer on the other.

Abstract: Disclosed is a biaxially oriented polypropylene film substrate free from primer coating, which comprises successively connected affinity layer, core layer and surface layer, said affinity layer comprises 10% to 80% by weight of polypropylene homopolymer, 10% to 80% by weight of polyolefin plastomer and 1% to 10% by weight of anti-adhesion agent; said core layer is polypropylene homopoiymer; said surface layer is the same as the affinity layer or a non-coated surface layer that comprises 90% to 99% by weight of polypropylene homopolymer and 1% to 10% by weight of anti-adhesion agent. A film free from primer coating and its preparing method are also provided. The coated film of this invention does not need the process of primer pre-coating which reduces the relevant equipment costs on one hand and avoids the safety risks when using and restoring solvent type primer on the other.