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.
Patent No.:
Date of Patent:
Aug. 27, 2002
Filed:
Aug. 29, 2000
Applicant:
Inventors:
Kazuhisa Kajihara, Niihama, JP;
Yoshiaki Takeuchi, Niihama, JP;
Assignee:
Sumitomo Chemical Company, Limited, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/738 ;
U.S. Cl.
CPC ...
G11B 5/738 ;
Abstract
The present invention provide a boehmite in which (i) a crystallite diameter in the direction perpendicular to the plane ( ) is about 65 angstrom or longer and (ii) a ratio of a crystallite diameter in the direction perpendicular to the plane ( ) to a crystallite diameter in the direction perpendicular to the plane ( ) is about 1.8 or more. By using the boehmite as a non-magnetic pigment, a base coat layer for magnetic recording medium having an excellent surface smoothness can be obtained.