Stable salt-free partially chelated metal compositions and method of preparation
AssigneeThe Dow Chemical Company
InventorDavid A. Wilson
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Abstract
Partially chelated solutions of zinc have been prepared by employing ammonium salts of EDTA together with excess ammonia and dissolving therein an oxide or hydroxide of zinc.
Claims6
A stable, salt-free partially chelated aqueous zinc solution which contains zinc ions, the zinc chelate of an aminopolycarboxylic acid and ammonium hydroxide, at least part of said zinc ions being unchelated.
A process for making a stable partially chelated aqueous solution of zinc ions which comprises (1) providing an aqueous solution of an ammonium salt of an aminopolycarboxylic acid, (2) adding thereto in any sequence a molar excess with respect to the aminopolycarboxylic acid salt of an oxide or hydroxide of zinc, and (3) an excess of ammonium hydroxide.
A process for making a stable, salt-free partially chelated aqueous solution of zinc ions which comprises (1) providing an aqueous solution of an aminopolycarboxylic acid, (2) adding thereto an excess of ammonium hydroxide, and thereafter (3) an oxide or hydroxide of zinc, the zinc being in molar excess with respect to the aminopolycarboxylic acid.
Dependencies are inferred from the claim text.