Title:
TITANIUM OXIDE PARTICLE POWDER FOR NONMAGNETIC BASE LAYER OF MAGNETIC RECORDING MEDIUM WHICH USES METAL MAGNETIC PARTICLE POWDER ESSENTIALLY COMPRISING IRON, SUBSTRATE OF MAGNETIC RECORDING MEDIUM HAVING NONMAGNETIC BASE LAYER USING THAT TITANIUM OXIDE POWDER, AND MAGNETIC RECORDING MEDIUM USING THAT SUBSTRATE
Document Type and Number:
Japanese Patent JP3509838
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain a smooth surface of a nonmagnetic base layer and to suppress corrosion of an acicular metal magnetic powder essentially comprising iron in a magnetic recording layer by using a titanium oxide powder having specified physical properties without containing a soluble sodium salt or soluble sulfate.
SOLUTION: This titanium oxide powder has ≤0.3μm average particle size, ≥15m2/g BET specific surface area, ≤230ppm soluble sodium salt calculated as Na, ≤150ppm soluble sulfate calculated as SO4, and pH≥8 of the powder. To remove the sodium salt and the like, the source material of the titanium oxide powder is coarsely pulverized in a dry state, prepared into a slurry and pulverized in a wet state. Then an alkali soln. is added to control the pH to ≥13 at room temp. and the slurry is heat treated at ≥80°C for 30 to ≥120min. After the treatment, the slurry is filtered, washed with water and dried by a normal method to obtain a titanium oxide powder which satisfies the specifications.
Inventors:
Morii, Hiroko
Iwasaki, Keisuke
Hayashi, Kazuyuki
Iwasaki, Keisuke
Hayashi, Kazuyuki
Application Number:
JP35351396A
Publication Date:
March 22, 2004
Filing Date:
December 16, 1996
Export Citation:
Assignee:
TODA KOGYO CORP
International Classes:
C01G23/00; C01G23/04; C01G23/047; C09C1/36; G11B5/73; G11B5/738; (IPC1-7): G11B5/738; C01G23/00; C01G23/04