| 摘要 |
PURPOSE:To provide the titled oriented film imparted with flame-retardancy while maintaining the characteristic features of transparency, mechanical strength, electrical properties, higher order processability, etc., by specifying the amount of elemental phosphorus in a bifunctional phosphorus compound bonded to a main chain of a linear polyester through an ester bond. CONSTITUTION:The objective film can be produced by (1) compounding (A) a dicarboxylic acid component (e.g. terephthalic acid) and (B) a glycol component (e.g. ethylene glycol) with (C) a bifunctional phosphorus compound of formula (R1 is 1-18C hydrocarbon group; R2 and R3 are 1-18C hydrocarbon group, etc.) (e.g. dimethyl phenylphosphonate) at an amount of 0.03-0.48wt% based on whole polyester in terms of elemental phosphorus, copolymerizing the components and forming the copolymer to an oriented film having a thickness of preferably 1-500mum and a plane-orientation birefringence of >=0.1. |
