| 摘要 |
Chromium dioxide magnetic pigments are stabilized against loss of their magnetic properties by treating them, in aqueous and/or alcoholic suspension, with a block copolymer consisting of siloxane units and alkyleneoxy units of 2 to 4 carbon atoms, the alkyleneoxy units being bonded to the polysiloxane radical by a Si-O-C or Si-C group, in an amount of from 1 to 40% by weight based on the chromium dioxide, after which the latter is separated off and dried at from 50 DEG to 200 DEG C. The stabilized chromium dioxide magnetic pigments may be used for the manufacture of magnetic recording media exhibiting improved stability of the magnetic properties under adverse climatic conditions. |
