Hydroxamic acid containing polymers used as corrosion inhibitors
AssigneeNalco Chemical Company
InventorsDodd W. Fong, Binaifer S. Khambatta
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Abstract
A method of inhibiting corrosion of iron and steel alloys in contact with industrial waters is claimed. The method comprises treating said waters with an effective corrosion inhibiting amount of a water soluble polymer having an average molecular weight ranging from about 2,000 to about 50,000, said polymer containing at least four mole percent of a hydroxamic acid mer unit.
Claims11
A method of inhibiting corrosion of iron and steel alloys in contact with industrial waters containing hardness ions the method comprising the step of:
- adding to said waters a corrosion inhibiting amount of water soluble polymer having from about 4.0 to about 30 mole percent of hydroxamic acid mer unit having the structure:
- ##STR7## wherein R is selected from the group consisting of H, CH.sub.3 and mixtures thereof, and from about 40 to about 96 mole percent acrylic acid mer unit, and wherein the polymer has a molecular weight ranging from about 2000 to about 50,000.
A method of inhibiting corrosion of iron and steel alloys in contact with industrial waters containing hardness ions, which method comprises the step of treating said hardness ion containing waters with a combination of the following polymers:
- a. water soluble scale inhibiting polymers having a molecular weight between 1,000-50,000 and containing carboxylate functionality, the polymers being free of hydroxamic acid functional groups, the polymers being comprised of mer units having the structure:
- ##STR9## wherein R is H, CH.sub.3, or mixtures thereof;
- B is H, --CO.sub.2 H, --CH.sub.2 CO.sub.2 H or mixtures thereof;
- and
- b. a water soluble polymer having a molecular weight between 2,000-50,000 and containing from about 4.0 to about 30 mole percent of a hydroxamic acid mer unit having the structure:
- ##STR10## wherein R is chosen from the group H, CH.sub.3, and mixtures thereof, and from about 40 to about 96 mole percent acrylic acid mer unit;
- and
- wherein the weight ratio of the two polymers is between about 10:1 to about 1:10.
Dependencies are inferred from the claim text.