| 摘要 |
PURPOSE:To obtain a multilayer heat shrinkable film having excellent heat shrinkability at low temperatures, excellent heat shrinking package adaptability temperature range, preferable slipperiness, optical properties, and excellent melt sealability by providing a shielding layer between an outermost layer and a core layer. CONSTITUTION:There is obtained a tubular coextruded multilayer unoriented original sheet having both outermost layers made of crystalline polypropylene resin having 135-150 deg.C of melting point, a core layer made of normal chain low density polyethylene resin having 0.890-0.910g/cm<3> of density and 60-80 deg.C of Vicat softening point, a shielding layer made of a resin composition in which the crystalline polypropylene resin used for both the outermost layers and the polyethylene resin used as the core layer are mixed by weight in a range of 2:1-3:1, and a structure of the outermost layer, the shielding layer, the core layer, the shielding layer and the outermost layer. The thickness of the shielding layer ranges from 1-30% of the whole thickness, and the melt flow index (MI) of the crystalline polypropylene resin is higher than that of the low density polypropylene resin. Lubricant and antiblocking agent are added to the outermost layers and the same lubricant as that of both the outermost layers is added to the core layer and the shielding layer. |
