| 摘要 |
PROBLEM TO BE SOLVED: To improve mechanical characteristics, transparency, curling characteristics and hue balance by forming a laminated film consisting of a surface layer of a specified polymer and a backing layer of a specified polymer and specifying the thicknesses of both the layers, the haze value of the laminated film, the optical density of the film and the degree of curl of the film. SOLUTION: This base film is a laminated film consisting of a 1st layer of a polymer based on polyethylene-2,6-naphthalenedicarboxylate and a 2nd layer of a polymer contg. 0.2-10mol% ethylene-phenylindandicarboxylate units and 99.8-90mol% ethylene-2,6-naphthalenedicarboxylate units. The thickness ratio between both the layers is 1:4 to 4:1 and the total thickness is 40-120μm. The haze value of the laminated film is <=2.0%, the optical density C of the film is >=0.050, the optical density M is >=0.050 and the optical density Y is 0.050-0.065. The degree of curl of the film in the transverse direction is 10-30m<-1> and that in the longitudinal direction is <40m<-1> .
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