| 摘要 |
Cellulosic textile materials are bleached in a solution of a chlorite which has been activated by means of a multivalent metal or alloy or insoluble compound thereof which is in contact with the chlorite, the extent or time of contact of the activator with the chlorite solution being capable of regulation. Suitable metals are chromium, iron, cobalt, nickel, copper and manganese. In order to prevent uncontrollable activation of the chlorite by the metal of which the container is made, the metal is polarized by known electrical methods, e.g. a protecting metal which is more electropositive than the metal of the container may be introduced into the chlorite solution, and an electrical connection made between the two metals. In a modification, the protecting metal is in a separate vessel which is in hydraulic connection with the bleaching vessel. Other modifications are described in which the activating metal or compound is in a separate vessel and the chlorite solution is circulated through the bleaching vessel and the vessel containing the activator; in which the protecting metal is enclosed within a porous cell in the bleaching vessel; and in which the activator is in the form of a mass, e.g. of cobalt oxide, at the bottom of the vessel.ALSO:The oxidizing power of chlorite solutions is activated by means of a multivalent metal or alloy or insoluble compound thereof which is in contact with the chlorite, the extent or time of contact of the activator with the chlorite solution being capable of regulation. Suitable metals are chromium, iron, cobalt, nickel, copper and manganese. In order to prevent uncontrollable activation of the chlorite by the metal of which the container is made, the metal is polarized by known electrical methods, e.g. a protecting metal which is more electro-positive than the metal of the container may be introduced into the chlorite solution, and an electrical connection made between the two metals. In a modification, the protecting metal is in a separate vessel which is in hydraulic connection with the bleaching vessel. Other modifications are described in which the activating metal or compound is in a separate vessel and the chlorite solution is circulated through the bleaching vessel and the vessel containing the activator; in which the protecting metal is enclosed within a porous cell in the bleaching vessel; and in which the activator is in the form of a mass, e.g. cobalt oxide, at the bottom of the vessel. |
