METHOD OF STARCH BINDER PREPARING FOR PAPER MAKING Russian patent published in 1995 - IPC

FIELD: paper production. SUBSTANCE: aqueous suspension of starch is treated with sodium hydroxide. Oxidizing agent, preferably sodium hypochlorite, is added to the mass. Then sodium chloroacetate or chloroacetic acid at concentration 0.01-2.0% of starch mass is added simultaneously with oxidizing agent or later to the mass. Mass is kept at 40-50 C for 25-45 min, and polydimethyldiallylammonium chloride is added. Then neutralization is carried out with sulfur-containing compound taken from the group involving sulfurous acid, sodium sulfite or sodium thiosulfate. Consumption of sulfur-containing compound is 0.003-0.070% of starch mass. Mass is boiled at 85-95 C. Method is used for making of paper of different sorts. EFFECT: improved method of binder preparing. 1 tbl