Ferromagnetic powder for magnetic recording and magnetic recording medium

A ferromagnetic technology for magnetic recording, applied in the direction of the magnetic material of the record carrier, etc., can solve the problem of difficult running durability and so on

Active Publication Date: 2019-10-08
FUJIFILM CORP
View PDF15 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, as a result of research, it has been clarified that it is not easy to achieve both excellent electromagnetic conversion chara

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Ferromagnetic powder for magnetic recording and magnetic recording medium
  • Ferromagnetic powder for magnetic recording and magnetic recording medium
  • Ferromagnetic powder for magnetic recording and magnetic recording medium

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0119] [Example 1]

[0120] Weigh SrCO 3 1610g, H 3 BO 3 635g, Fe 2 O 3 1097g, Al(OH) 3 108g, BaCO 3 23g, CaCO 3 34g and Nd 2 O 3 231 g was mixed with a mixer to obtain a raw material mixture.

[0121] In a platinum crucible, the obtained raw material mixture was melted at a melting temperature of 1390°C, and the outflow port provided at the bottom of the crucible was heated while stirring the melt, and the melt was flowed out in a rod shape of about 6 g / sec. The effluent is rolled and quenched with water-cooled twin rolls to produce an amorphous body.

[0122] Put 280g of the produced amorphous body into an electric furnace, raise the temperature to 635°C (crystallization temperature) at a heating rate of 3.5°C / min, and keep the temperature for 5 hours to precipitate hexagonal strontium ferrite particles ( Crystallization).

[0123] Next, the crystallized product obtained above containing hexagonal strontium ferrite particles was coarsely crushed with a mortar, and 1000 g of ...

Example Embodiment

[0124] [Example 2]

[0125] In addition to the Nd used in the preparation of the raw material mixture 2 O 3 Except that the amount was 47 g, a hexagonal strontium ferrite powder was obtained in the same manner as in Example 1.

Example Embodiment

[0126] [Example 3]

[0127] In addition to the Nd used in the preparation of the raw material mixture 2 O 3 Except that the amount was 142 g, a hexagonal strontium ferrite powder was obtained in the same manner as in Example 1.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Specific surface areaaaaaaaaaaa
Step sizeaaaaaaaaaa
Login to view more

Abstract

The invention provides a plate like hexagonal strontium ferrite powder, which is used to produce a magnetic recording medium having electromagnetic conversion characteristics and excellent durability.Provided is a ferromagnetic powder for magnetic recording, in which an activation volume is 800 nm<3> to 1,500 nm<3>, an average plate ratio is 2.0 to 5.0, a rare earth atom content is 0.5 atom % to5.0 atom %, and an aluminum atom content is greater than 10.0 atom % and equal to or smaller than 20.0 atom %, with respect to 100 atom % of iron atom, and the ferromagnetic powder is a plate like hexagonal strontium ferrite powder having a rare earth atom surface layer portion uneven distribution and an aluminum atom surface layer portion uneven distribution, and a magnetic recording medium including this ferromagnetic powder for magnetic recording in a magnetic layer.

Description

technical field [0001] The invention relates to a ferromagnetic powder for magnetic recording and a magnetic recording medium. Background technique [0002] Hexagonal ferrite powder is widely used as a ferromagnetic powder for magnetic recording. Regarding the hexagonal ferrite powder, various proposals for further improving the characteristics have been proposed in recent years (for example, refer to Patent Document 1). [0003] Patent Document 1: Japanese Patent Laid-Open No. 2017-178761 [0004] Patent Document 1 discloses ellipsoid powder, that is, non-plate-shaped hexagonal ferrite powder (Patent Reference 1, claim 1 and paragraph 0013). In addition, in Examples of Patent Document 1, barium ferrite powder and strontium ferrite powder are disclosed as hexagonal ferrite powder. [0005] Regarding the shape of the hexagonal ferrite powder, it is speculated in paragraph 0032 of Patent Document 1 that the hexagonal ferrite powder disclosed in Patent Document 1 is an ellip...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G11B5/706
CPCG11B5/706
Inventor 直井宪次白田雅史
Owner FUJIFILM CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap