PRODUCTION METHOD OF MIDDLE PAPER FOR PHOTOGRAPHIC SUBSTRATE AND PHOTOGRAPHIC SUBSTRATE USING SAID MIDDLE PAPER

摘要

PROBLEM TO BE SOLVED: To reduce the load on drying without impairing smoothness when a natural pulp-base middle paper for photographic substrate is produced and when both faces of the middle paper are coated with a resin having film forming ability to obtain a photographic substrate. SOLUTION: Wet paper is pressed in a paper making machine pressing step using a shoe press in such a way that the water content and density of the wet paper at the outlet of the pressing step satisfy the equations, density (g/ cm3)=-0.012-×water content (%)+1.38 and density (g/cm3)=-0.012×water content (%)+1.44 and wet paper having <=58% water content and <=0.75 g/cm3 density at the outlet of the pressing step is obtained to produce the objective middle paper for a photographic substrate.