| 摘要 |
PURPOSE:To obtain a master film having high punching sensitivity, no blank and high resolution of an image by molding the film exhibiting specific heating shrinkage stress characteristics by using composition blended with a plurality of thermoplastic polyester resins. CONSTITUTION:A composition containing at least one type of amorphous thermoplastic polyester resin and at least one type of crystalline thermoplastic polyester resin having a melting point of 260 deg.C or lower is stretched to 4-49 times of an area magnification in a temperature (Ts) range represented by a formula I, and heat treated in a temperature (Th) range represented by a formula II. In the formula, the Tg is glass transition temperature ( deg.C) of the composition. It has two or more maximum peaks of heating shrinkage stress of the stretched film having a thickness measured at each temperature of 0.3-15mum in such a manner that at least one of the peaks exist in a temperature range of 65-120 deg.C and at least one exists in a higher temperature range than 120 deg.C. |
