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:
Jul. 10, 1984
Filed:
Aug. 31, 1982
Applicant:
Inventors:
Assignees:
Agency of Industrial Science & Technology, Tokyo, JP;
Ministry of International Trade & Industry, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
C01G / ; C09C / ;
U.S. Cl.
CPC ...
423633 ; 106304 ;
Abstract
Yellow iron oxide crystals having lengths in the range of 100 to 1000 nm and a major axis/motor axis length ratio in the range of 1.5 to 4.5 are produced by adding an aqueous ferric salt solution to an aqueous alkali solution, causing the two solutions to react with each other at a temperature in the range of -5.degree. to 30.degree. C. thereby inducing precipitation of iron hydroxide, allowing the precipitate to age, then subjecting the aged precipitate to a hydrothermal treatment thereby producing crystals and, when necessary, further allowing the crystals to grow.