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:
Sep. 21, 1982
Filed:
Sep. 08, 1981
Walter R Demler, Hamburg, NY (US);
Eugene Odin, Williamsville, NY (US);
Buffalo Color Corporation, West Paterson, NJ (US);
Abstract
A method for recovering purified m-hydroxybenzoic acid from crude m-hydroxybenzoic acid alkali metal salt. The method comprises dissolving the crude m-hydroxy benzoic acid alkali metal salt in water at a ratio of between about 13 and 20 milliliters of water per gram of pure m-hydroxybenzoic acid alkali metal salt contained in the crude salt; acidifying the resulting solution to a pH of below 2 with a mineral acid to neutralize all alkali metal hydroxide present and to convert the m-hydroxybenzoic acid alkali metal salt to free m-hydroxybenzoic acid; and cooling the solution to from about 0.degree. C. to about 15.degree. C. for a sufficient time to crystallize purified m-hydroxybenzoic acid from the solution. The method is particularly effective for removing impurities of parahydroxybenzoic acid, alkali metal hydroxide and water soluble inorganic salts.