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. 28, 2000
Filed:
Jun. 29, 1999
Applicant:
Inventors:
Kevin P Cusack, East Greenbush, NY (US);
Kwang Kim, Schenectady, NY (US);
Dennis L Edie, Delmar, NY (US);
Benjamin S Tennyson, Saratoga Springs, NY (US);
Assignee:
BASF Corporation, Southfield, MI (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
562 59 ; 562 43 ; 562 67 ; 564250 ; 564279 ; 568306 ; 568438 ;
Abstract
The present invention provides a method of purifying an aqueous dye solution having an aldehyde and/or ketone impurity including a step of reacting the impurity with a hydrazine derivative, forming a water-insoluble hydrazone compound. The hydrazone compound is then removed from the solution to form a dye having an increased purity.