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:
May. 25, 1976
Filed:
Mar. 04, 1975
Hugo Vernaleken, Krefeld, DT;
Kurt Weirauch, Krefeld, DT;
Gunther Lenz, Krefeld, DT;
Uwe Hucks, Duisburg, DT;
Bayer Aktiengesellschaft, Leverkusen, DT;
Abstract
A continuous process for the production of a bisphenol bischlorocarbonic acid ester wherein an aqueous solution of a dialkali metal salt of a hydroquinone or a bisphenol is reacted in a pump circulating system with 2.5 to 5.0 mol, per mol of dihydroxy compound of phosgene dissolved in a suitable solvent for the bischlorocarbonic acid ester formed in the reaction under the addition of an alkali metal hydroxide solution to keep the pH-value between 9.0 and 12.0, the organic phase obtained is separated wherefrom the bisphenol bischlorocarbonic acid ester is isolated by distillation and/or crystallisation.