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. 03, 1998
Filed:
Jan. 09, 1997
Frank Ebmeyer, Augsburg, DE;
Harald Haberlein, deceased, late of Neusass, DE;
by Hans Haberlein, heir, Neu-Ulm, DE;
by Jorg Haberlein, heir, Allersberg, DE;
by Mark Haberlein, heir, Freiburg, DE;
Holger Mohn, Gelnhausen-Hailer, DE;
Hoechst Aktiengesellschaft, , DE;
Abstract
The present invention relates to a process for preparing a particularly pure glycolic acid by saponification with chloroacetic acid with an excess of alkali metal hydroxide, with the resulting alkali metal chloride being filtered off, and the 20 to 70% strength by weight glycolic acid solution being subsequently subjected to an electrodialysis at 20.degree. to 40.degree. C. and a cell voltage of 0.5 to 2.5 V per cell pair. The process of the invention permits optimum removal of sodium chloride and chloroacetic acid as necessary for preparing a particularly pure glycolic acid. Other organic acids, nitrogen compounds, aldehydes and salts are not produced in this process and thus do not affect the product quality.