LAMINATED FILM AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To enhance tear resistance and mechanical characteristics by selecting polymers constituting the respective layers of a film laminated at least as two layers in its thickness direction from either one of at least two kinds of different thermoplastic resins and providing at least one layer of which the longitudinal refractive index is larger than a lateral refractive index. SOLUTION: The polymers constituting the respective layers of a film laminated in at least two layers in its thickness direction are selected from either one of at least two kinds of different thermoplastic resins. At least one layer wherein a refractive index in a longitudinal direction is larger than that in a lateral direction is provided to the laminated film. Herein, a layer wherein the refractive index in the longitudinbal direction of the laminated film is larger than that in the laterial direction thereof is a layer wherein the refractive index in the flow direction of the film is larger than that in the right-angled direction when the thermoplastic resin constitution that layer is biaxially stretched as a single film. By this constitution, tear strength and mechanical characteristics can be enhanced.