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:
Apr. 29, 1997
Filed:
May. 29, 1996
Applicant:
Inventors:
Roger A Mader, Stillwater, MN (US);
William D Ramsden, Afton, MN (US);
Terence D Spawn, West Lakeland Township, MN (US);
Daniel E Saddoris, Hastings, MN (US);
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
544249 ; 564307 ;
Abstract
The present invention provides a novel process for the production of organic solvent soluble squaraine dyes. More specifically, the invention describes how a difficult to prepare tetrahydroxy squaraine intermediate can be prepared in an organic solvent system in the presence of water. This intermediate can then be esterified in pyridine to form the soluble squaraine dye which can then be easily isolated from the reaction mixture. The invention also provides the dyes prepared according to this method.