VERFAHREN ZUR HERSTELLUNG VON MAGNETISCHEN, BINDEMITTELHALTIGEN DISPERSIONEN

摘要

This invention relates to the addition of organic boron compounds, prepared by either reacting boric acid with polyhydric alcohols having a total of 5 or more neighbouring OH groups per boron atom and then with polyethylene oxide in a mol ratio of 1:40, based on 1 mol of borate which is obtained, and with a carboxylic acid having from 8 to 22 carbon atoms or reacting boric acid first with polyhydric alcohols having a total of 5 to 11 neighbouring OH groups per boron atoms, and the with a carboxylic acid having from 8 to 22 carbon atoms, said boron compound being added, in a quantity of from 3 to 12, in particular from 3 to 6 parts, by weight, based on 100 parts, by weight, of magnetic pigments, and in particular of metal powders, to the grinding operation of the magnetic pigment dispersion and then processing in a known manner. The necessary degree of dispersion is achieved after a short grinding time compared to known dispersing agents, during which time the pigment particles which are initially lying together are separated into monodisperse individual particles. The favorable effect is expressed by improved alignment values in the finished magnetic tape.