| 摘要 |
PURPOSE:To obtain a heat-shrinkable polyester laminated film which is shrinkable at low temp. and with a uniform shrinking without unevenness of shrinking and exhibits excellent practical heat resistance. CONSTITUTION:A polyester resin A (with a glass transition temp. of 81 deg.C) obtd. from terephthalic acid, ethylene glycol and 1,4-cyclohexane dimethanol, a polyester resin B (with a glass transition temp. of 55 deg.C) obtd. from terephthalic acid, isophthalic acid, ethylene glycol and diethylene glycol and a polyethylene terephthalate resin C (with a glass transition temp. of 75 deg.C) are prepd. These resins are melt-extruded into a five-layered sheet to laminate them by arranging in the order of a layer of the resin A (with a thickness of 15mum)/a layer of the resin B (with a thickness of 35mum)/a layer of the resin C (with a thickness of 20mum)/a layer of the resin B (with a thickness of 35mum)/a layer of the resin A (with a thickness of 15mum). This laminated film is drawn 3-fold in the transverse direction at 85 deg.C to prepare a heat-shrinkable laminated film. This heat- shrinkable laminated film is suitable for a shrinkable label for a PET bottle to which retort sterilization treatment is performed. |
