| 摘要 |
PURPOSE:To provide the title polyester film excellent in thermal dimensional stability, suitable as a base material for flexible printed boards etc., incorporated with a specified amount of inorganic particles with specified size. CONSTITUTION:A polyester resin (e.g. polyethylene terephthalate, polybutylene terephthalate) is incorporated with 1-30wt.% of inorganic particles consisting mainly of calcium silicate >=3 in the ratio d1/d2 (d1 and d2 are the major and minor radii of the primary particles, respectively) and <=7mum in mean size, followed by melt extrusion at 270-330 deg.C and then drawing and heat-setting treatment, thus giving the objective film <=1% in thermal shrinkage at 150 deg.C for 30min. |
