BASE FOR PHOTOSENSITIVE MATERIAL, SPOT DETECTING METHOD AND DETECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a base for a photosensitive material formed by coating base paper essentially consisting of natural pulp remarkably suppressed in the tendency to the occurrence of spot trouble to a silver halide photosensitive layer with a resin having film formability, a rapid detecting method and a rapid detecting device. SOLUTION: This base for the photosensitive material is formed by coating the base paper essentially consisting of the natural pulp with the resin having the film formability. The natural pulp contains Kraft pulp. This Kraft pulp is formed by subjecting the natural pulp to vapor decomposition by Kraft method, then to washing treatment in the presence of a defoaming agent and foam suppressing agent in an unbleaching stage after the same and subjecting the washed natural pulp to oxygen deliginification treatment before and after the washing treatment, followed by cleaning treatment. The number of the blackening points by the physical development of the natural Kraft pulp is <=40 pieces per 20 g. The method and device for adding a silver ion solution and developer to a pulp slurry and detecting a dotty fogging cause by the physical development.