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. 17, 2002
Filed:
Feb. 27, 2002
Hiroyasu Banba, Yokohama, JP;
Shigeho Tanaka, Yokohama, JP;
Kiyonobu Niwa, Yokohama, JP;
Takakazu Endo, Yokohama, JP;
Mitsubishi Rayon Co., Ltd., Tokyo, JP;
Abstract
Crystals of [S,S]-ethylenediamine-N,N′-disuccinic acid which have a bulk density of 0.45 to 1.2 g/cm , and a process for obtaining these crystals comprising the steps of adjusting an aqueous solution of an [S,S]-ethylenediamine-N,N′-disuccinic acid metal salt to a temperature of 40 to 80° C. and a pH of 1.9 to 4.5, and cooling the solution to a temperature below 40° C. over a period of 0.2 to 10 hours while supplying a mineral acid so as to maintain the pH at 1.9 to 4.5 to precipitate [S,S]-ethylenediamine-N,N′-disuccinic acid in a high yield.