MULTIPLAYER FILM AND APPLICATION THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a film which shows low extensibility even when it is used at high temperature and high tensile strength and mold release properties. SOLUTION: This multilayer film is a three-layer film consisting of a poly 4-methyl-1-pentene resin layer, an adhesive resin layer and a heat-resistant resin layer laminated in that order on the surface side or a five-layer film consisting of the heat-resistant resin layer as a core, on both sides of which the adhesive resin layer and the poly 4-methyl-1-pentene resin layer are laminated. The heat-resistant resin is of such a nature that a heat-deformation temperature which is measured under 4.6 (kg/cm2) load is at lest 130 deg.C and a yield point stress at 140 deg.C is at least 100 (kg/cm2). Especially a polymer alloy is desirably acceptable which is a mixture of non-crystalline resin with at least 130 deg.C glass transition point and a crystalline resin with at least 170 deg.C melt point.