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:
Jun. 09, 2000
Young-sam Kim, Pusan, KR;
Katsuto Nakatsuka, Taihaku-ku, Sendai-shi, Miyagi 982-0252, JP;
Toyohisa Fujita, Akita, JP;
Takafumi Atarashi, Tokyo, JP;
Other;
Abstract
A magnetic fluid and a process for producing the same are provided. The magnetic fluid is an excellent fluid which mightily and precisely actuates by the action of an external magnetic field so that its viscosity can be significantly increased and be easily and precisely controlled by regulating the external magnetic field applied thereto. The magnetic fluid is also excellent in the unsusceptibility to oxidation and dispersibility of the particles and has a sufficiently wide viscosity range. The magnetic fluid comprises magnetic metal particles coated with an oxidation-preventive film stably dispersed in a solvent, wherein the dispersion conditions are maintained, and the process for producing the fluid comprises forming an oxide film on the surface of raw oxide particles of magnetic metal particles, reducing the raw oxide particles coated with the oxide film to obtain magnetic metal particles coated with an oxidation-preventive film, and stably dispersing the magnetic metal particles coated with an oxidation-preventive film in a solvent.