| 摘要 |
PURPOSE:To broaden the extent of dependence of heat shrinkage characteristic on temperature, heighten the strength and at the same time improve the workability of a film by a method wherein the tensile strength, shrinkage temperature and shrinkage gradient are respectively set as for a highly oriented film formed by highly orienting resin, which mainly consists of ethylene copolymer, under the cold state held at an enough low temperature. CONSTITUTION:The title film is a highly oriented ethylene copolymer film containing below-mentioned copolymers A and B. The title film has the tensile strength of 5-16kg/mm<2>, shrinkage temperature at 20% of 85-45 deg.C and shrinkage gradient of 1.3-0.5. The highly oriented film as mentioned above can be made by extruding molten resin composition containing copolymers A and/or B in a tubular form, solidifying the extruded molded material by cooling with liquid refrigerant, for example, or the like, heating when necessary, and cold-drawing the resultant material at the drawing temperature of 20-70 deg.C at the areal draw ratio of 500-3,000%. A copolymer of vinyl ester monomer and ethylene is empolyed as the copolymer A. A copolymer of unsaturated aliphatic carboxylic acid and/or unsaturated aliphatic carboxylic and alkyl ester and ethylene is empolyed as the copolymer B. |
