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Ferromagnetic powder, coating material and magnetic recording medium using the same

A powder and magnetic technology, which is applied in the field of coating materials and magnetic recording media, can solve problems such as inability to maintain information, poor C/N ratio, loss of media backup function, etc., and achieve the effect of reducing noise and improving C/N ratio

Inactive Publication Date: 2007-03-21
DOWA ELECTRONICS MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

A magnetic recording medium made using particles with a large particle diameter distribution will have a poor C / N ratio and will include particles that are not sufficiently magnetized and therefore unable to retain information, that is, the backup function of the medium may be lost, which has a negative effect on Magnetic recording media is deadly

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0102] Add 3000ml of pure water to a 5000ml beaker, and maintain it at 40°C by a heat regulator. A solution consisting of 500ml of the mixture. Then, 3 equivalents of granular sodium carbonate relative to Fe+Co carbonic acid were directly added to the solution, and the temperature of the solution was adjusted not to exceed ±5°, thus forming a suspension mainly composed of iron carbonate. After aging for 1.5 hours, a hydrogen peroxide solution (30%) that oxidized 20% of the Fe ions was added, causing the formation of iron oxyhydroxide crystal nuclei. The temperature was raised to 65°C, and the oxidation was continued for 1 hour in pure oxygen flowing at 50ml / min. The gas was then switched to nitrogen and aged for 30 minutes.

[0103] Then adjust the temperature to 40° C., and after the temperature stabilizes, add an aqueous solution of aluminum sulfate as Al at a rate of 5.0 g / min within 20 minutes as the iron oxyhydroxide grows. Adjust the dosing amount of the aqueous alumi...

Embodiment 2

[0113] The same conditions as in Example 1 were used, except that in the first nucleation stage, potassium permanganate aqueous solution (0.5 mol / l) was used instead of hydrogen peroxide solution in an amount adjusted to produce an oxidation rate of 20%.

Embodiment 5、7、8

[0115] Using the same conditions as in Example 1, except that in the first stage of crystal nucleation, the average long-axis length of the precursor was changed by adding different amounts of hydrogen peroxide solution, and the amount of Al in solid solution in the particles and the rare earth attached to it were also changed. amount of metal.

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PUM

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Abstract

By providing a magnetic powder composed of particles having a balanced shape and distribution, the particles having a small uniform volume, increased density and reliability of a coating type magnetic recording medium can be obtained. Magnetic powder having Fe as the main component, consisting of particles having a substantially circular or elliptical cross-section perpendicular to the major axis of the particle, wherein the geometric standard deviation indicating the variation of its cross-sectional area is in the range of 1.01 to 3.0 Within, the present invention also relates to magnetic powders, wherein the geometric standard deviation indicating the change in particle volume is in the range of 1.01-4.0, and the geometric standard deviation indicating the change in flatness is in the range of 1.01-2.0.

Description

technical field [0001] The present invention relates to a ferromagnetic powder used in a magnetic layer of a multilayer coating type magnetic recording medium, and to a coating material and a magnetic recording medium using the powder. Background technique [0002] Recording media are becoming increasingly compact and high-capacity. There are various types of recording media other than the conventional Floppy (trademark) Disk (FD), such as compact disc (CD), digital versatile (video) disc (DVD), Compact Flash (trademark) and Memory Stick (trademark), about These, still in development, have helped deliver higher volumes in smaller packages. [0003] One type of magnetic recording medium is a coating type magnetic recording medium prepared by coating magnetic powder on the surface of a film. Although depending on the cost of materials used, the coating type magnetic recording medium has better cost performance than other recording media in terms of capacity, which has led to...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/09G11B5/62
CPCG11B5/714H01F1/09H01F10/007G11B5/70621G11B5/70657G11B5/70647G11B5/70689G11B5/70663H01F1/065Y10T428/2982Y10T428/32
Inventor 正地吉行上山俊彦
Owner DOWA ELECTRONICS MATERIALS CO LTD
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