Abstract: The present invention provides a process for the oxidative bleaching of wood pulps and for deinking waste paper by means of hydrogen peroxide and a stabilizing agent, wherein, as stabilizing agent, there is used 2-oxo-2-(4-hydroxyphenyl)-acethydroximic acid chloride (N,4-dihydroxy-.alpha.

Abstract: A process for the recovery of fibers by means of flotation de-inking of waste paper which bears ink applied by flexographic printing or xerography, by reducing the paper to fibers in an aqueous medium with the addition of bleaching chemicals and auxiliaries containing peroxide, fatty acids, complexing agent, sodium hydroxide, and an additive based on polyglycol and a phosphoric ester mixture, produces fibers which are free from ink, which are useful as a recyclable material.

Abstract: A process for the oxidative or reductive bleaching of wood pulp, especially in the presence of heavy metal salts, in which a complex former combination containing at least one phosphonic acid, at least one polyhydroxycarboxylic acid and at least one phosphate or salts thereof is added to a wood pulp slurry in an amount of from 0.5 to 50%, based on the dry mass of the wood pulp, and subsequent bleaching is carried out in the presence of a reducing agent. Also provided is a complex former combination for use in the oxidative or reductive bleaching of wood pulp, comprising at least one phosphonic acid, at least one polyhydroxycarboxylic acid and at least one phosphate or salts thereof.

Abstract: The novel, advantageous, and economical process of reclaiming printed waste paper comprises subjecting waste paper to a flotation de-inking process. The degree of whiteness of the reclaimed paper is considerably increased by the addition of specific phosphonic acid compounds to the de-inking bath. Hydroxy carboxylic acids, amino carboxylic acids, polycarboxylic acids as well as magnesium sulfate may also be added to the de-inking bath containing the phosphonic acids.

Abstract: The difficulties encountered in the manufacture of paper, cardboard, and other cellulosic articles, as they are caused by the formation of resinous or pitch deposits on the paper as well as on the paper machines and processing apparatus, are overcome or at least considerably reduced, by the addition of phosphonic acids and more particularly of alkyl, amino or hydroxy alkyl, or cycloalkyl phosphonic acids or their alkali metal salts and of orthophosphoric acid or its alkali metal salts and/or of polyphosphoric acids. If required, amino polycarboxylic acids, hydroxy carboxylic acids, or their alkali metal salts, or alkali metal polyphosphates are also added during processing.