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:
Mar. 21, 1995
Filed:
Aug. 11, 1993
Edward G Zey, Corpus Christi, TX (US);
Olan S Fruchey, Corpus Christi, TX (US);
Thomas H Shockley, Corpus Christi, TX (US);
Joe S Trevino, Corpus Christi, TX (US);
B Frank Wood, Corpus Christi, TX (US);
Daniel D Lindley, Portland, TX (US);
Hoechst Celanese Corporation, Somerville, NJ (US);
Abstract
A method is provided for purifying crude N-acetyl-para-aminophenol (APAP) containing color bodies or their precursors, the method comprising: a) forming a solution of the crude APAP; and b) subsequently contacting the solution with substoichiometric quantifies of an acetylating agent for a sufficient period of time to convert said color bodies or their precursors to substantially non-color bodies/stable, colorless substances; said quantities of acetylating agent provided is such that substantially none of the APAP is converted to other compounds.