Title:
磁気記録媒体用針状磁性粒子粉末及び該針状磁性粒子粉末を用いた磁気記録媒体
Document Type and Number:
Japanese Patent JP4557102
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain acicular magnetic particle powder used for obtaining a magnetic recording medium having a smooth surface, a lower light transmissivity, a lower surface electric resistance value, a low frictional coefficient and excellent running durability. SOLUTION: An acicular black composite magnetic particle powder for the magnetic recording medium, which has 0.051-0.35 μm average major axis diameter and is formed by using an acicular metal magnetic particle powder consisting essentially of cobalt adhered acicular magnetic iron oxide particle powder or iron as core particle powder, applying an organo-silane compound or polysiloxane formed from alkoxysilane on the particle surface of the core particle powder to form a coating layer and adding >10 pts.wt. and <=40 pts.wt. carbon black to 100 pts.wt. core particle powder to at least a part of the coating layer, is characterized in that the black composite magnetic particle powder has 0.01-0.3 mg/m2 myristic acid adsorption volume.
Inventors:
Kazuyuki Hayashi
Hiroko Morii
Mamoru Kamaki
Yasuyuki Tanaka
Keisuke Iwasaki
Hiroko Morii
Mamoru Kamaki
Yasuyuki Tanaka
Keisuke Iwasaki
Application Number:
JP32415099A
Publication Date:
October 06, 2010
Filing Date:
November 15, 1999
Export Citation:
Assignee:
Toda Kogyo Co., Ltd.
International Classes:
G11B5/712; B22F1/02; C01G49/00; H01F1/11
Domestic Patent References:
| JP3183013A | ||||
| JP49059608A | ||||
| JP59054036A | ||||
| JP6162483A | ||||
| JP9045516A | ||||
| JP9167333A | ||||
| JP10275327A | ||||
| JP10269558A | ||||
| JP11305480A | ||||
| JP4263116A | ||||
| JP9027117A |