| abstract |
Dilute aqueous alkaline solutions of hydrogen peroxide obtained by diluting and adding alkali to a concentrated acid solution of hydrogen peroxide and adding an aminopolyalkylene phosphonic acid compound as a stabilizer may exhibit improved stability if sufficient time is allowed between the addition of the stabilizer and the formation of the dilute alkaline solution to allow the stabilizer to transform into a more active derivative. Preferably, the stabilizer introduced is cyclohexane-1,2-diaminotetrakis (methylene phosphonic acid), and the dilute solution has a pH of 8.5 to 9.5, and contains pyrophosphate and/or sodium bicarbonate as a buffer. at least a part of which may be added, before dilution, to the concentrated solution of hydrogen peroxide. |