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:
Mar. 13, 1984
Filed:
Aug. 11, 1980
Joachim Behnke, Amorbach, DE;
Walter Loffelmann, Erlenbach, DE;
Akzo NV, Arnhem, NL;
Abstract
A method for production of polycarbonate-polyether-blockcopolymers is provided. One or more solutions comprising bisphenol A and polyalkyleneglycol and a phosgene solution are added to a cooled initial reaction medium in a cooled reaction chamber in such a way that the phosgene contacts substantially the reaction partners from the one or more cooled solutions after they have spread in the reaction medium. Preferably the phosgene solution and the one or more solutions are added through tubes ending above the liquid level of the reaction medium such that the solutions added contact only within the stirred reaction mixture the reaction partner. The phosgene is employed in an excess of less than about 10 weight percent of the stochiometrically required weight amount relative to bisphenol A and polyalkyleneglycol. The polymer is useful in the production of membranes for dialysis, ultrafiltration and reverse osmosis.