| 摘要 |
PURPOSE: To obtain a polyester support having good flatness hard to generate a winding habit curl at the time of heat treatment and free from the coating irregularity of an emulsifier by taking up a biaxially oriented polyester film in a roll form while always specifying the thickness layer of air interposed between film layers and heat-treating the roll-shaped taken-up product at specific temp. CONSTITUTION: A biaxially oriented polyester film is taken up in a roll form while the thickness layer of air interposed between film layers is always set to 1.5-10μm and the roll shaped taken-up product is heat-treated at 95-120 deg.C. Further, a technique increasing the amt. of air between the support layers in the roll is effective in order to remove the stress generated during heat treatment and, more pref., the thickness of an air layer is 2-8μm, further pref., it is 2.5-5μm. In the case of polyethylene-2,6-naphthalate, Tg is 120 deg.C and heat treatment temp. is pref. 100-115 deg.C, further pref., 105-115 deg.C. |
