Patent · US Expired

Preparation of oxide magnetic material

US5951937A · kind A · utility

11Cited by
5References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 3, 1997
Grant dateSep 14, 1999
Priority date
Expiry dateDec 3, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01F1/344
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

The method of the invention uses a molding slurry containing a particulate oxide magnetic material and water and having a dispersant added thereto. The dispersant is an organic compound having a hydroxyl group and a carboxyl group or a neutralized salt thereof or a lactone thereof, an organic compound having a hydroxymethylcarbonyl group, or an organic compound having an enol form hydroxyl group dissociable as an acid or a neutralized salt thereof. The organic compound has 3 to 20 carbon atoms, with the hydroxyl group being attached to at least 50% of carbon atoms other than the carbon atom forming a double bond with an oxygen atom. Citric acid or a neutralized salt thereof is also useful as the dispersant. The addition of the dispersant facilitates the wetting of the particulate oxide magnetic material with water and improves the dispersion of primary particles and a degree of orientation upon molding.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.