VERFAHREN ZUM DEINKEN VON BEDRUCKTEM ALTPAPIER

摘要

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.