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. 07, 2001
Filed:
Jun. 30, 2000
Phillip Montgomery Hudnall, Kingsport, TN (US);
Lucian Boldea, Jonesborough, TN (US);
Eastman Chemical Company, Kingsport, TN (US);
Abstract
The present invention relates to a method of making purified monotertiarybutyl hydroquinone containing less than 0.2% (wt.) of 2,5 ditertiarybutyl hydroquinone. This method includes heating a composition of monotertiarybutyl hydroquinone and 2,5 ditertiarybutyl hydroquinone in a solvent mixture of a polar solvent and a non-polar solvent. During this step, the non-polar solvent is substantially stripped-off and at least part of the 2,5 ditertiarybutyl hydroquinone is solidified, which is separated from the non-solidified composition. The remaining non-solidified composition and polar solvent are mixed with a non-polar solvent of the same type as was previously stripped-off. The polar solvent, which contains the purified monotertiarybutyl hydroquinone, is separated from the non-polar solvent. This purified monotertiarybutyl hydroquinone is separated the from the polar solvent to produce purified monotertiarybutyl hydroquinone containing less than 0.2% (wt.) of 2,5 ditertiarybutyl hydroquinone.