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. 14, 2000
Filed:
Apr. 08, 1999
Thanikavelu Manimaran, Baton Rouge, LA (US);
Richard A Holub, Baton Rouge, LA (US);
Randall S Barton, Baton Rouge, LA (US);
Albemarle Corporation, Richmond, VA (US);
Abstract
Bisphenol-A or preferably, a mixture of bisphenol-A and underbrominated bisphenol-A, is brominated in a liquid phase reaction medium in which tetrabromobisphenol-A is relatively insoluble, using a stoichiometric deficiency of bromine to thereby form in the reaction mass a precipitate (i.e., a solids phase) composed of 50-95 wt % of tetrabromobisphenol-A and 50-5 wt % of underbrominated bisphenol-A. The precipitate is separated from the reaction mass, preferably during the bromination, and tetrabromobisphenol-A is recovered from the precipitate. Preferably underbrominated bisphenol-A is recycled as feed to the bromination. The process technology of this invention has the capability of producing high quality tetrabromobisphenol-A (high purity, good color, low ionic halide content) with efficient raw material utilization, minimized waste product formation, and minimized waste disposal costs.