Process for the preparation of alkali metal salts of imidodisulfonic acid
AssigneeHoechst Aktiengesellschaft
InventorHans-Peter Rieck
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Abstract
Ammonium nitrilotrisulfonate can be hydrolyzed, in a solid form or dissolved form, with alkali metal hydroxide to give alkali metal salts of imidodisulfonic acid or a mixture of alkali metal salts of imidodisulfonic acid and nitrilotrisulfonic acid, amidosulfonic acid and sulfuric acid. Ammonium nitrilotrisulfonate is preferably added to an aqueous solution of an alkali metal hydroxide, which contains at least 3 moles of alkali metal hydroxide per mole of ammonium nitrilotrisulfonate to be added.
Claims13
A process for obtaining an alkali metal salt of imidodisulfonic acid which comprises hydrolyzing ammonium nitrilotrisulfonate in the presence of an alkali metal hydroxide.
A process for obtaining an alkali metal salt of imidodisulfonic acid which comprises adding ammonium nitrilotrisulfonate to an aqueous solution having a pH of from 0 to 7, effecting a desired degree of hydrolysis and then adding to the resulting reaction mixture an amount of alkali-metal hydroxide sufficient to increase the pH value to from 7 to 11.
Dependencies are inferred from the claim text.