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:
Dec. 15, 1998
Filed:
Jul. 19, 1996
Applicant:
Inventor:
Wing Sum Kwan, Deerfield, IL (US);
Assignee:
Videojet Systems International, Inc., Wood Dale, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09C / ;
U.S. Cl.
CPC ...
106460 ; 106456 ; 106457 ; 106459 ; 106499 ; 252 6256 ; 252 6259 ; 428 / ;
Abstract
A method for making magnetic ink compositions is disclosed. The magnetic particles used in the ink are prepared from an aqueous slurry. A surface derivatizing agent is added to the slurry to render the magnetic pigment particles hydrophobic. The particles then sink to the bottom of the slurry, and the bulk water is then removed. After air drying, dry magnetic pigment particles are provided. The particles will be hydrophobic, and thus will have superior resistance to water as compared to previously known magnetic pigment particles. Magnetic ink compositions are formulated from the magnetic particles.