The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jul. 11, 2000

Filed:

Aug. 18, 1997
Applicant:
Inventors:

Yasuyuki Tanaka, Hiroshima, JP;

Hiroko Morii, Hiroshima, JP;

Kazuyuki Hayashi, Hiroshima, JP;

Hiroshi Sumita, Hiroshima, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428403 ; 428329 ; 106415 ; 106456 ; 106459 ;
Abstract

In accordance with the present invention, there are provided non-magnetic black particles composed primarily of Fe and having a hematite structure, which shows an excellent blackness, heat resistance, and dispersibility in a vehicle, and which particles contain manganese in an amount of 5 to 40% by weight based on the weight of the non-magnetic black particles, a soluble sodium salt in an amount of not more than 500 ppm (calculated as Na), and a soluble sulfate in an amount of not more than 200 ppm (calculated as SO.sub.4), and have an average particle size of 0.1 to 10.0 .mu.m and a pH of not less than 5.5.


Find Patent Forward Citations

Loading…