SURFACE TREATING AGENT FOR PAPER AND OFFSET PRINTING PAPER

摘要

PROBLEM TO BE SOLVED: To improve coating suitability of a surface treating agent for paper consisting essentially of colloidal silica and to obtain an offset printing paper having excellent surface adhesiveness, inking properties and opacity. SOLUTION: This surface treating agent for the paper is obtained by adding a viscosity improving agent to a surface treating agent comprising the colloidal silica and regulating the solid concentration to 10 wt.% and the Brookfield viscosity at 25 deg.C to 5-150 mPa.s. Furthermore, the offset printing paper is prepared by forming a coating layer comprising the surface treating agent for the paper consisting essentially of the colloidal silica and the viscosity improving agent on a printing base paper.