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:
Nov. 24, 1998
Filed:
Aug. 27, 1997
NOF Corporation, Tokyo, JP;
Abstract
A process for producing a polyoxyalkylenecarboxylic acid which comprises: (A) a step of obtaining a salt of a polyoxyalkylenecarboxylic acid by reacting a polyoxyalkylene compound having hydroxyl group at one or both ends of the molecule with a salt of a halogenated acetic acid or a salt of a halogenated propionic acid in an amount of 4 to 50 mol per 1 mol of the polyoxyalkylene compound and an alkali metal hydroxide in an amount of 8 to 70 mol per 1 mol of the polyoxyalkylene compound in the presence of an organic solvent at 80.degree. to 150.degree. C.; (B) a step of converting the obtained salt of a polyoxyalkylenecarboxylic acid into the polyoxyalkylenecarboxylic acid by adjusting pH of the reaction mixture obtained in step (A) to 3 or less by adding an inorganic acid; (C) a step of removing byproducts and the like by washing the obtained solution containing the polyoxyalkylenecarboxylic acid with an aqueous solution of an inorganic salt; and (D) a step of removing the organic solvent and water at a decreased pressure at 50.degree. to 120.degree. C. and removing precipitated salts by filtration. A high purity, high molecular weight polyoxyalkylenecarboxylic acid which contains only small amounts of unreacted starting materials or byproducts can easily be obtained.