| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an optical film hardly causing phase difference variation after manufacturing by drawing a master roll film containing polypropylene resin. <P>SOLUTION: According to this method, a long master roll film formed of a resin composition containing polypropylene resin and aliphatic saturated hydrocarbon resin is longitudinally drawn at a temperature Tms within a range of 110-150°C (S10), and subsequently the obtained longitudinally drawn film is horizontally drawn (S20) to manufacture an optical film whose Nz coefficient ranges from 1.2-3. In the step S20, the longitudinally drawn film is kept warm at a temperature Tc for 10-120 seconds (S21), subsequently horizontally drawn at a temperature Tts (S22), and then held at a temperature of 90-150°C for 10-120 seconds and heat fixed (S23). The temperature Tc is equal to or higher than the temperature Tms, and also lower than the temperature Tms+15°C, and the temperature Tts is equal to or higher than the temperature Tms-10°C and also less than the temperature Tms+5°C. <P>COPYRIGHT: (C)2011,JPO&INPIT |
