METHOD FOR PRODUCING PAPER AND AGENT FOR IMPROVING YIELD

摘要

A method for producing paper, characterized in that it comprises adding a silica sol which is prepared by the reaction of an aqueous sodium silicate solution with a mineral acid and has, at a SiO2 concentration [C] of 15 to 50 g/L and at 25˚C, a viscosity of 0.12 x [C] mPa . s or more and 15 mPa . s or less, and a cationic compound and/or amphoteric compound to a pulp slurry, followed by mixing, and subjecting the resulting mixture to a paper making process. The method allows the improvement of the yield in a paper making process.