HYDROLYZED POLYACRYLAMIDE MIXTURE AS YIELD IMPROVER OF STARCH

摘要

PURPOSE: To improve the yield of a starch by adding a specific mixture of a relatively low-molecular weight acrylic acid/acrylamide type polymer with a relatively high-molecular weight acrylic acid/acrylamide type polymer to an aqueous papermaking stock. CONSTITUTION: This hydrolyzed polyacrylamide blend obtained by blending (A) a polymer (salt) containing about 5 to about 50 wt.% of acrylic acid or methacrylic acid and about 50 to about 95 wt.% of acrylamide or methacrylamide and having about 2,000,000 to about 8,000,000 viscosity-average molecular weight with (B) a polymer (salt) containing about 5 to about 50 wt.% of acrylic acid or methacrylic acid and about 50 to about 95 wt.% of acrylamide or methacrylamide and having about 10,000,000 to about 20,000,000 viscosity- average molecular weight in about (95:5) to about (5:95), preferably about (95:5) to about (40:60) weight ratio of the components (A) : (B) is added to an aqueous papermaking stock during papermaking.