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:
Nov. 08, 1983
Filed:
Nov. 18, 1981
Applicant:
Inventors:
Seiji Matsumoto, Sakai, JP;
Tadashi Koga, Osaka, JP;
Kiyoshi Fukai, Izumiotsu, JP;
Hideji Yamamoto, Asahimachi, JP;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01G / ;
U.S. Cl.
CPC ...
423633 ; 423632 ; 423634 ;
Abstract
A method of producing single crystalline, acicular .alpha.-ferric oxide particles of narrow particle size distribution is provided. The method comprises heating an aqueous suspension of ferric hydroxide at temperatures of 100.degree.-250.degree. C. at an alkaline pH in the presence both a water soluble organic or inorganic compound capable of forming complexes with iron as a growth regulating agent and .alpha.-ferric oxide seed crystals of minor axes not larger than 0.4 microns in average in amounts of 0.1-25 mole % in terms of the Fe content thereof in relation to the ferric hydroxide.