Westvaco Corporation

Eugene R Fischer

Paul G Boyd

John A Alford

David E Knox

This invention relates to water-soluble corrosion inhibiting compositions and the method of making the same. Specifically, this invention relates to inhibiting the corrosion of metals, particularly those employed in the production, processing, and transportation of petrochemical products. These water-soluble corrosion inhibiting compositions are created by neutralizing a C.sub.22 tricarboxylic acid with aminoethylethanolamine and a member selected from the group consisting of imidazoline, amidoamine, and combinations thereof. The resulting compositions exhibit excellent film persistency characteristics even when utilized in small amounts.

Water soluble corrosion inhibitors

A corrosion inhibitor with excellent film forming and film persistency characteristics may be produced by first reacting C.sub.18 unsaturated fatty acids with maleic anhydride or fumaric acid to produce the fatty acid Diels-Alder adduct or the fatty acid-ene reaction product. This adduct or reaction product is further reacted in a condensation or hydrolysation reaction with a polyalcohol to form an acid-anhydride ester corrosion inhibitor. The ester may be reacted with amines, metal hydroxides, metal oxides, ammonia, and combinations thereof to neutralize the ester. Surfactants may be added to tailor the inhibitor formulation to meet the specific needs of the user (i.e., the corrosion inhibitor may be formulated to produce an oil-soluble, highly water-dispersible corrosion inhibitor or an oil-dispersible, water-soluble corrosion inhibitor). Suitable carrier solvents may be employed where needed to effectively disperse the corrosion inhibitor formulation.

Acid-anhydride esters as oil field corrosion inhibitors

A corrosion inhibitor with excellent film forming and film persistency characteristics may be produced by first reacting in a condensation reaction a polybasic acid with a polyalcohol to form a partial ester. The partial ester is reacted with imidazoline and/or fatty diamines to salt the ester. If warranted, the salted partial ester may be reacted with a metal hydroxide, a metal oxide, and/or ammonia to further salt the ester. Surfactants may be added to tailor the inhibitor formulation to meet the specific needs of the user (i.e., the corrosion inhibitor may be formulated to produce an oil-soluble, highly water-dispersible corrosion inhibitor or an oil-dispersible, water-soluble corrosion inhibitor). Suitable carrier solvents may be employed where needed to effectively disperse the corrosion inhibitor formulation.

Polybasic acid esters as oil field corrosion inhibitors

An inhibitor formulation including the product obtained by reacting maleic anhydride or fumaric acid with fatty acids containing unsaturation in the presence of a suitable catalyst, such as iodine, clay, or silica, is disclosed to provide improved corrosion inhibition in oil field equipment and piping over conventional dimer/trimier based inhibitor formulations.

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James Island, SC, United States of America

Eugene R Fischer