PHOTOGRAPHIC SUBSTRATE, METHOD FOR PRODUCING SAME AND HEAT DEVELOPABLE PHOTOSENSITIVE MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material for plate making excellent in dimensional stability even at a high temperature in heat development and excellent also in color reproducibility and suitability to processing and a photographic substrate constituting the photosensitive material. SOLUTION: The photographic substrate is a biaxially oriented polyester substrate using a polyester resin having an intrinsic viscosity of 0.5-0.8 and such metal contents as 100-250 ppm Sb, 30-200 ppm Ca+Mg and 20-100 ppm P. The substrate is conveyed and heat-treated under the conditions of temperature Tp ( deg.C), tension Ts (kg/cm2) and time Tm (min) which satisfy the expressions 6.0<=Q<=7.4 (Q=(Tp/25)+log(TM)) and 1.8<=(Q/Ts)<=5.0 at the same time before it is coated with at least one photographic constituent layer.