Title:
DISPERSED IRON OXIDE MAGNETIC POWDER SLURRY AND METHOD FOR PRODUCING SAME
Document Type and Number:
WIPO Patent Application WO/2022/054571
Kind Code:
A1
Abstract:
[Problem] To provide a method for producing a dispersed iron oxide magnetic powder slurry that exhibits an excellent dispersity even in the weakly acidic region to medium alkaline region. [Solution] A dispersed iron oxide magnetic powder slurry is obtained that exhibits an excellent dispersity and an average secondary particle diameter for ε-type iron oxide of not more than 65 nm as measured using a dynamic light scattering particle size distribution analyzer. The slurry is obtained by adding alkali and a quaternary ammonium salt constituting a first dispersing agent to a slurry that contains ε-type iron oxide particles and bringing the pH at 25°C to at least 11, followed by adding an organic compound and bringing the pH of the slurry at 25°C to at least 4 and less than 11. The organic compound is an organic acid, which constitutes a second dispersing agent and has at least two carboxy groups in the molecule, and in addition to these carboxy groups the organic compound has at least one or two types of the hydroxy group and/or amino group bonded to carbon that does not participate in the carboxy groups.
Inventors:
MIYAMOTO YASUTO (JP)
Application Number:
PCT/JP2021/031037
Publication Date:
March 17, 2022
Filing Date:
August 24, 2021
Export Citation:
Assignee:
DOWA ELECTRONICS MATERIALS CO (JP)
International Classes:
C01G49/00; C01G51/00; G11B5/714; G11B5/842; H01F1/11
Foreign References:
| JP2019175539A | 2019-10-10 | |||
| JP2019001663A | 2019-01-10 |
Attorney, Agent or Firm:
KOMATSU Takashi (JP)
Download PDF: