PURPOSE: To provide the base for photographic paper which has an excellent resolution and is hardly damaged by bending by providing a concn. gradient in the content concn. of pigments in such a manner that the concn. is low in a resin layer on a raw paper side and is high in the outermost layer.
CONSTITUTION: The plural resin layers essentially consisting of polyester are laminated on the emulsion coating side surface of the raw paper. The concn. gradient is so provided in the content concn. of the pigments in the coating layers laminated with plural sheets in such a manner that the concn. is low in the resin layer on the raw paper side and is high in the outermost layer. Particularly, titanium dioxide is used for the pigments and is so incorporated into the above-mentioned layers in such a manner that the concn. of the pigments in the resin layers exclusive of the outermost layer is 10wt.% and the pigment concn. in the resin layer of the outermost layer is ≥10wt.%. The polyester is particularly preferably polyethylene terepthalate and while the resin layers may be the polyester resin alone, the mixing of this resin with other resins is equally well. Powders of titanium dioxide, barium sulfate, zinc oxidize, talc, calcium carbonate, silicon oxide, solid soln. thereof, etc., are usable as the pigments.
MIYOSHI TAKAHITO
TADA SUGIHIKO
