By forming a polyester film from a polyester resin composition including ketene imine compound represented by the following Formula (1) and polyester, the polyester film having excellent hydrolysis resistance in which volatilization of the ketene imine compound or the ketene compound can be suppressed. In Formula (1), R
1
and R
2
represent an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an aryloxy group, an acyl group, or an aryloxycarbonyl group, and the R
1
—C(═C)—R
2
substructure has a molecular weight of 320 or greater. R
3
represents an alkyl group or an aryl group.
通过从包括以下
化学式(1)所代表的酮
亚胺化合物和聚酯的聚酯
树脂组合物形成聚酯薄膜,可以抑制酮
亚胺化合物或酮
亚胺化合物的挥发,从而获得具有优异耐
水解性的聚酯薄膜。在
化学式(1)中,R1和R2代表烷基基团、芳基团、烷氧基团、烷氧羰基团、
氨基羰基团、芳氧基团、酰基或芳氧羰基团,而R1—C(═C)—R2亚结构的分子量为320或更大。R3代表烷基基团或芳基团。