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:
Jun. 05, 1990
Filed:
Feb. 02, 1989
Jeno Pelyva, Fuzfogyartelep, HU;
Csaba Soptei, Veszprem, HU;
Zoltan Kolonics, Balatonalmadi, HU;
Bela Karacsonyi, Budapest, HU;
Sandor Balint, Balatonalmadi, HU;
Janosne Benczik, Balatonalmadi, HU;
Csaba Kayos, Veszprem, HU;
Laszlo Lendvai, Fuzfogyartelep, HU;
Sandor Laszlo, Fuzfogyartelep, HU;
Nitrokemia Ipartelepek, Fuzfogyartelep, HU;
Abstract
The invention relates to the preparation of N-phosphono-methyl-imino-diacetic acid from the calcium salt of imino-diacetic acid in a simplified synthesis. The process comprises in that the imino-diacetic acid calcium salt is heated with concentrated hydrochloric acid in a molar ratio of 2-3:1 at a temperature between 50.degree.-100.degree. C., the obtained imino-diacetic acid hydrogen-chloride is separated then dissolved in water and is reacted with phosphorous acid in a molar ratio of 1.0-1.2:1 calculated for imino-diacetic acid hydrogen chloride and with the aqueous solution of formaldehyde in a molar ratio of 1.0-1.4:1 under stirring, and the obtained product is isolated.