Image-forming transfer material including a polyester film

摘要

A polyester film for an image-forming transfer material, wherein a difference DELTA alpha t between the maximum coefficient of thermal expansion and the minimum coefficient of thermal expansion in the film plane is not larger than 1.0x10-5/ DEG C., and the maximum coefficient of thermal expansion alpha tmax is not larger than 2.5x10-5/ DEG C., which can form a high quality color image having less deviation and a high image density.