| 摘要 |
PURPOSE:To obtain the ferromagnetic metal powder applied to audio-appliances and VTS which consists of iron mainly and has the exceedingly improved characteristics by using Fe including P, Si and/or B coated with a coppolycondensate of toluene and methkyl ethyl ketone as a main component. CONSTITUTION:The ferromagnetic metal powder fine particles mainly consisting of iron for this use are manufactured by coating a surface part of the fine particle of needle iron oxyhydroxide with a shape retentive component and subjecting the particles to cleaning, drying, and milling followed by calcination and gas-phase catalytic reduction. For the shape retentive components, the reduced iron powder fine particles preferably include P, Si and/or B within a range of P=0.1-5, Si=0.1-5, B=0.1-5 atomic weight percentage to Fe. If the percentage is under the above range, the copolycondensation performance of toluene and methyl ethyl ketone is low and the effect that the characteristic of deterioration with aging of the ferromagnetic metal powder fine particles is improved is diminished. If the percentage is over the range, the dispersion property during a step of conversion into coating compositions is lowered though the affinity for a binder resin is improved. |
