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. 05, 1986
Filed:
May. 21, 1985
Applicant:
Inventors:
Lucian Borduz, Nashua, NH (US);
Kuldip Raj, Merrimack, NH (US);
Assignee:
Ferrofluidics Corporation, Nashua, NH (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01F / ;
U.S. Cl.
CPC ...
252 6252 ; 252 6251 ; 252 6255 ;
Abstract
A stable ferrofluid composition and the method of preparing and using the ferrofluid composition, such as in a ferrofluid seal apparatus, and which ferrofluid composition comprises: a liquid carrier; ferromagnetic particles sufficient to provide magnetic properties to the ferrofluid dispersed in the liquid carrier; and a dispersing amount of a cationic surfactant to provide a stable ferrofluid composition. The stable ferrofluid compositions have improved electrical conductivity and are useful in sealing computer disc drives and in sputtering apparatus in the semiconductive industry.