Patent ID: 6228569
Filing Date: 2001-05-08
Classification: G03C

Abstract:
A silver halide light sensitive photographic element comprising a polyethylene terephthalate film base, at least one light sensitive silver halide-containing emulsion layer, an antihalation undercoat layer, and a process-surviving antistatic backcoat, wherein the polyethylene terephthalate film base is formed by:(a) casting a molten polyethylene terephthalate resin in a machine direction onto a casting surface to form a continuous sheet,(b) drafting the sheet by stretching in the machine direction at a stretch ratio of from 3.4 to 4, and at a temperature ranging from 70 to 130.degree. C.,(c) tentering the sheet in the transverse direction by stretching at a stretch ratio of from 3.4 to 4, and at a temperature ranging from 70 to 130.degree. C.,(d) heat-setting the tentered sheet at an actual temperature sensed by the sheet of at least 216.degree. C., and(e) cooling the heat-set sheet without substantial detentering to obtain a stretched, heat-set polyethylene terephthalate film.