METHOD OF BLEACHING CELLULOSE PULP (ITS VERSION), BIODEGRADABLE CHELATION AGENT FOR BLEACHING CELLULOSE PULP WITH HYDROGEN PEROXIDE, AND METHOD OF REMOVING PRINTER'S INK FROM CELLULOSE PULP Russian patent published in 1999 - IPC

FIELD: pulp- and-paper industry. SUBSTANCE: cellulose pulp is bleached with hydrogen peroxide in presence of effective amount of at least one biodegradable 1-aminoalkane-1,1-diphosphonate chelation agent with general formula I: (I), wherein R₁ is hydrogen atom; R₂, and R₃ the same or different, hydrogen, C₁-C₂₂-alkyl, C₅-C₆-cycloalkyl, hydroxy-C₁-C₁₀-alkyl, carboxyalkyl with up to 10 carbon atoms, and, together with nitrogen, piperidine, pyrrolidine, or morpholine groups; and X is hydrogen atom, alkali metal, or ammonium. Pulp can be preliminarily treated with sufficient amount of compound I and then with hydrogen peroxide. Printer's ink is removed from pulp also using compound I. EFFECT: enhanced activity of bleaching solution and improved environmental condition. 10 cl, 17 dwg, 4 tbl, 9 ex