Method for producing iron oxyhydroxide particle

Abstract

First, a ferrous iron-containing suspension solution is obtained by mixing an aqueous ferrous salt solution and an aqueous alkali solution containing one or two of an alkali carbonate and an alkali hydroxide. Then, an iron oxyhydroxide particle precursor is obtained by blowing an oxygen-containing gas having an oxygen component proportion of 0.5 to 0.8 into the suspension solution thus obtained to oxidize the ferrous iron in the suspension solution at an oxidation rate of 30 to 65% while the suspension solution is being controlled to fall in a temperature range of -5 DEG C. or higher and lower than 10 DEG C. Thereafter, the iron oxyhydroxide particles 2 are produced from the iron oxyhydroxide particle precursor by blowing an oxygen-containing gas into the suspension solution containing the iron oxyhydroxide particle precursor while the suspension solution is being controlled to fall in a temperature range of 20 DEG C. or higher and lower than 45 DEG C.

Description

technical field [0001] The present invention relates to iron oxyhydroxide particles suitable for use as a precursor of magnetic particles for high-density and high-capacity magnetic recording tapes, and in particular to fine iron oxyhydroxide particles having a large axial ratio and a narrow particle size distribution Manufacturing method. Background technique [0002] High-density and high-capacity magnetic recording tapes are increasingly required. As the recording density increases, the bit length or track width becomes smaller. That is, high density can be achieved by improving recording density and track density. However, as the bit length and track width become smaller, the number of magnetic bodies per bit decreases and the SN ratio decreases. Furthermore, if the particle size becomes uneven, the distribution state of the magnetic substance will become uneven, and noise will increase. Therefore, in order to achieve high density, it is necessary to form fine and uni...

AI Technical Summary

Problems solved by technology

Although the oxidation temperature is set at 10° C. or higher, oxidation at this temperature may cause green rust (green rust), which is the core of iron oxyhydroxide, to grow easily, and the iron oxyhydroxide may become too large.

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