PURPOSE: To obtain a supporting body for photographic printing paper suitable for the production of photographic printing paper having high rigidity by adding a specified proportion of fine fibrous cellulose to the source material slurry to make the base paper.
CONSTITUTION: This supporting body for photographic printing paper consists of the base paper essentially comprising pulp and a polyolefin resin to coat the both surfaces of the base paper. The base paper is produced by compounding fine fibrous cellulose having ≥210% water holding property and <0.2mm number average fiber length, by 1-10% of the source material pulp slurry for paper making. If the add amt. of the fine fiberous cellulose is <1%, the effect to improve rigidity is small, while if the compounding proportion exceeds 10%, filtering property for water decreases and the paper making property decreases. In this case, the fine fibrous cellulose added to the pulp slurry contributes increase in the fiber surface area and formation of bonding network among fibers to increase bonds among fibers of the pulp.
SOMA HARUKO
KAMIYA MASAHIRO
