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AssigneeToray Industries, Inc.
InventorsYasuyuki Imanishi, Masatoshi Ohkura, Haruki Aono
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The present invention addresses the problem of providing a polypropylene film which is structurally stable to heat in deposition when used for packaging, and has appropriate slipperiness without using an anti-blocking agent or particles, and thus has excellent water vapor barrier properties and oxygen barrier properties, in particular, when a transparent deposited layer is laminated. Moreover, the present invention provides a polypropylene film characterized by having at least two types of layers (A layer and B layer) containing a polypropylene-based resin as a main component, wherein the B layer contains a thermoplastic resin incompatible with a polypropylene-based resin, and when the skewnesses Ssk of the A layer and the B layer, as measured through three-dimensional noncontact surface shape measurement, are Ssk (A) and Ssk (B), respectively, the Ssk (B) is at least 5 and the Ssk (A) is less than 5.
A polypropylene film comprising at least two layers comprising a layer A and a layer B that contain polypropylene based resins as primary components wherein the layer B contains a polymethylpentene based resin having a melting point of 185° C. to 240° C. that is incompatible with the polypropylene based resins and wherein Ssk(B) is 5 or more and Ssk(A) is less than 5 where Ssk(A) and Ssk(B) are the skewness Ssk of the layer A and that of the layer B, respectively, as determined by using a three dimensional noncontact surface profile measuring instrument.
Dependencies are inferred from the claim text.