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:
Dec. 06, 1994
Filed:
Sep. 13, 1993
Hubert Seitz, Burgkirchen, DE;
Reinhard Vybiral, Burgkirchen, DE;
Hoechst Aktiengesellschaft, Frankfurt, DE;
Abstract
The process described relates to the preparation of aqueous betaine solutions by reaction of a tertiary amine with an .omega.-monohalocarboxylic acid, preferably monochloroacetic acid, and an alkali metal hydroxide in the presence of water, which solutions are said to be highly pure particularly in respect of the tertiary starting amine and .omega.-monohalocarboxylic acid. This is achieved by first reacting the three reaction components in a certain molar ratio with the aim of obtaining a betaine solution which comprises only a tolerated amount of starting amine. This aqueous betaine solution is then treated with a sulfonating agent, preferably with an alkali metal sulfite, alkali metal pyrosulfite or alkali metal bisulfite, for conversion of the .omega.-monohalocarboxylic acid present into the corresponding sulfocarboxylic acid, which is not troublesome. The process described is simple to carry out and leads to the highly pure aqueous betaine solutions mentioned.