| 摘要 |
PURPOSE:To improve the hiding power, the surface gloss and the printability of the film by a method wherein the longitudinal strength and the sum of the Young's moduli in longitudinal and lateral directions of polyolefin film, the optical density and gloss of which are specified, are specified. CONSTITUTION:Of the polyolefin film, of which the optical density is 0.1 or more and the glossiness is 40% or more, its longitudinal strength is made to be 8kg/mm<2> or higher and the sum of its Young's moduli in longitudinal and lateral directions is made to be 250kg/mm<2> or more. Resin, which is prepared by adding 5-50 pts.wt. of methylpentene polymer, the extraction residue of n-heptane of which is 40% or more, to 100 pts.wt. of polypropylene, the isotactic index of which is 80% or more and the intrinsic viscosity of which is 1.2-3.5dl/g, is formed by fusing into the form of sheet or tube and, after that, micro- stretched in the elastic limit at 120 deg.C or lower and further stretched at least uniaxially within the range of 120-170 deg.C. |
