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. 02, 2002
Filed:
Jan. 22, 2001
Gadde Ramachandraiah, Gujarat, IN;
Pushpito Kumar Ghosh, Gujarat, IN;
Aditya Shantilal Mehta, Gujarat, IN;
Rajesh Popatlal Pandya, Gujarat, IN;
Ashok Dahyabhai Jethva, Gujarat, IN;
Sanjay Shambhubhai Vaghela, Gujarat, IN;
Sudhindra Nath Misra, Gujarat, IN;
Council of Scientific and Industrial Research, New Delhi, IN;
Abstract
A highly pure and colorless tetrabromobisphenol-A (TBBPA) possessing melting point in the range of 178-182° C. is prepared in yields of 50-70% in first batch and 90-100% when the spent organic layer is recycled. In this method, the corrosive liquid bromine is displaced by sodium bromide/hydrobromic acid as brominating agent. Further, sodium bromate is used as an oxidizing as well as brominating agent to utilize the hydrobromic acid that is produced during the bromination of bisphenol-A (BPA). The reaction is conducted at 10-15° C. in a mixture of methylene chloride-water or carbon tetrachloride-water in the presence of hydrochloric acid and sodium lauryl sulfate. The crystalline product settled at the bottom of the reaction vessel is filtered, washed, dried and weighed. The spent organic layer is recycled in subsequent batches to maximize the overall yield of product recovered directly as solid and to minimize generation of organic effluent.