BIAXIALLY ORIENTED POLYESTER FILM FOR THERMAL TRANSFER RIBBON

摘要

A biaxially oriented polyester film for thermal transfer ribbons which comprises a copolyester which is polyethylene 2,6-naphthalate obtained by condensation-polymerizing a dicarboxylic acid ingredient comprising 90 to 99.9 mol% 2,6-naphthalenedicarboxylic acid and 0.1 to 10 mol% isophthalic acid with a diol ingredient comprising 97 to 100 mol% ethylene glycol and 0 to 3 mol% diethylene glycol, characterized in that a melt of the film has an AC volume resistivity of 6x10<8> OMEGA cm or lower and that the film has a coefficient of planar orientation of 0.230 to 0.275 and a density of 1.3450 g/cm<3> or higher.