| 摘要 |
PURPOSE:To provide a polyester film excellent in heat resistance, dimensional stability, etc., by forming a polyethylene 2,6-naphthalate polyester containing a specified diphenyl sulfone derivative as a comonomer into a film and at least uniaxially orienting the film. CONSTITUTION:A polyester is produced by reacting ethylene glycol with 2,6- naphthalenedicarboxylic acid (dialkyl ester) and a compound of the formula (wherein X and Y are each a bivalent organic group) [e.g. bis(p-beta- hydroxyethoxyphenyl) sulfone]. This polyester is formed into a film, which is oriented at least uniaxially to produce a polyester film. The obtained polyester film can be desirably used as especially an industrial heat-resistant film. It is also possible to further introduce polypropylene glycol, terphthalic acid or the like as a comonomer to the polyester. |
