| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat-shrinkable polyester-based film which is rich in the design property of an iridescent metallic glossiness which reflects the light of a specified wavelength, and in addition, wherein fracture in a label forming process is hard to occur because the breaking extension in the orthogonal direction to the main shrinking direction is high, and which has heat-shrinkability for enabling the film to be pasted on a container such as a PET bottle. SOLUTION: This heat-shrinkable polyester-based film includes an alternately laminated body (I) for which a first layer including a polyester (A) having an ethylene terephthalate as the major component, and a second layer including a polyester (B) having an ethylene-2,6-naphthalenedicarboxylate as the major component are alternately laminated in a range from 25 layers to 1,001 layers. (i) Either one of the first layer and the second layer has a low crystal structure. (ii) The breaking extension in both directions of the main contraction direction and its orthogonal direction is 50% or higher. (iii) The thermal shrinking rate after being let for 10 seconds in warm water at 80°C is 30% or higher in the main contraction direction, and is 0% or higher and less than 10% in the absolute value in the orthogonal direction to the main contraction direction. (iv) The total of the layer thickness of the polyester layer having the ethylene terephthalate as the major component to the total film thickness is from 80% to 96%. Also, (v) the heat-shrinkable polyester-based film has at least one reflective peak of 25% or higher reflection factor in the reflection factor curve of a range of 400 to 800 nm wavelength. COPYRIGHT: (C)2010,JPO&INPIT |
