Patent ID: 7183429
Filing Date: 2007-02-27
Classification: A01N,C05D,C07C

Abstract:
1. Process for the preparation of iminodisuccinic acid ammonium metal salts, comprising: in a first stage, mixing maleic anhydride (MA), alkali metal hydroxide and water in a molar ratio of 2:0–3:5–30 and then metering ammonia into the resulting reaction mixture in a molar ratio of MA:ammonia 2:1.5–8, in order to obtain iminodisuccinic acid ammonium salts of the formula 6 wherein IDA represents iminodisuccinic acid moiety, with x=0.1–4, y=0–3, z=0–3 and m=0–2, in a second stage, reacting the iminodisuccinic acid ammonium salts with metal oxides, metal hydroxides or metal salts or their mixtures to give iminodisuccinic acid ammonium metal salts of the formula 8, in which IDA is the iminodisuccinic acid moiety x=0.1–3.9 y=0–3 z=0–3 m=0.1–2 n=0–6 and Me represents metals of the IInd, IIIrd and IVth main groups and of the Ist to VIIIth subgroups as well as metals of the lanthanide series of the Periodic Table, which can occur in the oxidation states 1, 2, 3 or 4.