| 摘要 |
A silver halide light sensitive photographic element is disclosed 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 has been formed by drafting a cast resin at a stretch ratio of at least 3.4, tentering at a stretch ratio of at least 3.4, and heat-setting at an actual heat-set temperature of at least 216° C. In accordance with preferred embodiments of the invention, the polyethylene terephthalate film base of the photographic element 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° 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 C., (d) heat-setting the tentered sheet at an actual temperature sensed by the sheet of at least 216° C., and (e) cooling the heat-set sheet without substantial detentering to obtain a stretched, heat-set polyethylene terephthalate film.
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