PURPOSE: To efficiently remove dissolved oxygen even without the coexistence of hydrogen or a hydrogen generating compd. by obtaining a free-oxygen absorber from a chelating resin having a specified chalating group and carrying an easily oxidative metal.
CONSTITUTION: An aminocarboxylic acid compd. is allowed to react with a resin having a carbonyl chloride group or a chloromethyl group to obtain a free-oxygen absorber having an aminocarboxylic group and carrying an easily oxidative metal and/or an aminoalkylene-phosphonic group carrying an easily oxidative metal. A chalating resin, in which an aminocarboxylic group or an aminoalkylene-phosphoric group is bonded to the principal chain of the resin, is preferably used. Copper, iron, nickel, cobalt, tin, zinc, etc., and the compds. of the metals are preferably exemplified as the easily oxidative metal. The salts of the easily oxidative metals with the mineral acids and org. acids such as sulfuric acid, hydrochloric acid and acetic acid are used as the easily oxidative metal compds.
AOI MASAHIRO
TAKAHASHI MIKIKO
