Process for bleaching fibrous material by hydrogen peroxide
AssigneeMitsubishi Gas Chemical Company, Inc.
InventorsMinoru Yotsuya, Kiyoshi Mae, Seikyu Jinnouchi, Toshio Ochiai
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Abstract
A fibrous material is bleached by hydrogen peroxide in a weakly acidic state at a pH of 5-7, and then in a weakly alkaline state at a pH of 8.5-1.1 by adding an alkaline agent to the hydrogen peroxide by one whole charge or continuously after the bleaching in the weakly acidic state and utilizing the remaining hydrogen peroxide. The bleached fibrous material has a soft handling and a high whiteness, and no bleaching unevenness.
Claims14
A process for bleaching a fibrous material by hydrogen peroxide, which comprises bleaching a fibrous material by hydrogen peroxide in a bleaching solution having a weakly acidic state at a pH of 5-7 and at a temperature of 50.degree.-120.degree. C., and then adding an alkaline agent to the bleaching solution by one whole charge or continuously and successively bleaching the fibrous materials at a pH of 8.5-11 by the remaining hydrogen peroxide in a weakly alkaline state.
Dependencies are inferred from the claim text.