Patent ID: 11926968

Abstract:
Provided is a method for producing paper that enables to fix an increased amount of starch components contained in papermaking process water to a papermaking raw material (suspended solid: SS) contained in the papermaking process water, and enables (1) enhancement of the strength of paper, (2) reduction in the contamination of the papermaking process water by microorganisms, etc., (3) suppression of the foaming of the papermaking process water, (4) decrease in the load of the waste water treatment, etc. The method comprises a step of adding a polymer having a polyalkylene oxide moiety to papermaking process water containing SS containing a papermaking raw material and unfixed starch. At this time, the concentration of SS contained in the papermaking process water is 100 mg/L or more, the concentration of the unfixed starch is 10 mg/L or more, and the salt viscosity of the polymer is 3 mPa·s or more.