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:
Jun. 29, 1976
Filed:
Mar. 04, 1975
Heinrich Krimm, Krefeld, DT;
Hermann Schnell, Krefeld-Uerdingen, DT;
Hans-Helmut Schwarz, Krefeld, DT;
Bayer Aktiengesellschaft, , DT;
Abstract
A continuous process for the preparation of a bisphenol bischlorocarbonic acid ester, wherein a hydroquinone or a bisphenol dissolved in excess alkali metal hydroxide solution is reacted with 2.5 to 5.0 mol of phosgene (per mol of the dihydroxy compound) which is dissolved in a suitable solvent for the bischlorocarbonic acid ester formed in the reaction at a pH value of at least 12 and a temperature of 0.degree. to 50.degree.C under vigorous mixing of the reactants and unidirectional flow conditions and the organic layer thus obtained is separated wherefrom the bisphenol bischlorocarbonic acid ester is isolated by distillation and/or crystallization.