Laminating propylene/1-butene random copolymer composition and composite film using the same

Abstract

A laminating propylene/1-butene random copolymer composition comprising a propylene/1-butene random copolymer and a low-density polyethylene in a specified proportion. With respect to the propylene/1-butene random copolymer, the content of structural units derived from propylene, content of structural units derived from 1-butene, MFR, Mw/Mn and B-value as a parameter indicating the randomness of copolymer monomer chain distribution fall within specified ranges. With respect to the low-density polyethylene, the MFR and density fall within specified ranges. The invention also provides a composite film comprising a substrate film such as a crystalline polypropylene film and, laminated onto at least one side thereof, a resin layer of the above composition having a thickness of 2 to 200 μm. The above composition is excellent in laminate moldability and enables producing a composite film having excellent low-temperature sealing properties, blocking resistance and hot tack. The composite film is characterized by having excellent low-temperature sealing properties, blocking resistance, slip properties and hot tack.

Dependencies are inferred from the claim text.