Aminomethylphosphonic acid and polymaleic anhydride combinations for treating corrosion

Claim 1

A method of inhibiting corrosion of low carbon steel in an aqueous system comprising the step of treating said system with from 1.0 to 300 parts per million by weight of the total aqueous content of said system, of a corrosion inhibiting composition comprising (1) one or more aminomethylphosphonic acid compounds; and (2) one or more polymers selected from the group consisting of homopolymers, and random copolymers with acrylamide, of polymaleic anhydride and amine adducts of polymaleic anhydride selected from the group consisting of: (a) polymers having recurring units of the formula: ##STR14## wherein M.sup.⊕ may be H.sup.⊕, alkali metal cation, or quaternary ammonium cation of the formula: ##STR15## wherein for all of the above formulas, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to ten carbon atoms, and substituted alkyl of from one to ten carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; and wherein n is an integer of from 2 to 100; and (b) polymers having recurring units of the formula: ##STR16## wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to ten carbon atoms, and substituted alkyl of from one to ten carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; wherein p is an integer of from 1 to 6; wherein m is an integer of from 2 to 100; and wherein n is an integer of from 2 to about 100, provided that, n not equal to m, the lesser of m or n is multiplied by a factor such that n=m; wherein the polymaleic anhydride and amine adducts of polymaleic anhydride have a weight average molecular weight of from about 200 to about 10,000; and wherein the weight ratio of aminomethylphosphonic acid to polymer is from 10:1 to 1:10.

Claim 2

A method of inhibiting corrosion of low carbon steel in an aqueous system comprising the step of treating said system with from 1.0 to 300 parts per million by weight of the total aqueous content of said system, of a corrosion inhibiting composition comprising (1) one or more aminomethylphosphonic acid compounds; and (2) one or more polymers selected from the group consisting of homopolymers, and random copolymers with acrylamide, of polymaleic anhydride and amine adducts of polymaleic anhydride selected from the group consisting of: (a) polymers having recurring units of the formula: ##STR14## wherein M.sup.⊕ may be H.sup.⊕, alkali metal cation, or quaternary ammonium cation of the formula: ##STR15## wherein for all of the above formulas, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to ten carbon atoms, and substituted alkyl of from one to ten carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; and wherein n is an integer of from 2 to 100; and (b) polymers having recurring units of the formula: ##STR16## wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to ten carbon atoms, and substituted alkyl of from one to ten carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; wherein p is an integer of from 1 to 6; wherein m is an integer of from 2 to 100; and wherein n is an integer of from 2 to about 100, provided that, n not equal to m, the lesser of m or n is multiplied by a factor such that n=m; wherein the polymaleic anhydride and amine adducts of polymaleic anhydride have a weight average molecular weight of from about 200 to about 10,000; and wherein the weight ratio of aminomethylphosphonic acid to polymer is from 10:1 to 1:10.

Claim 6

A method of inhibiting corrosion of low carbon steel in an aqueous system comprising the step of treating said system with from 1.0 to 300 parts per million by weight of the total aqueous content of said system, of a corrosion inhibiting composition comprising (1) one or more aminomethylphosphonic acid compounds (2) one or more polymers selected from the group consisting of homopolymers, and random copolymers with acrylamide, of polymaleic anhydride and amine adducts of polymaleic anhydride selected from the group consisting of: (a) polymers having recurring units of the formula: ##STR20## wherein M.sup.⊕ may be H.sup.⊕, alkali metal cation, or quaternary ammonium cation of the formula: ##STR21## wherein for all of the above formulas, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to ten carbon atoms, and substituted alkyl of from one to ten carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; and wherein n is an integer of from 2 to 100; and (b) polymers having recurring units of the formula: ##STR22## wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to ten carbon atoms, and substituted alkyl of from one to ten carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; wherein p is an integer of from 1 to 6; wherein m is an integer of from 2 to 100; and wherein n is an integer of from 2 to about 100, provided that, n not equal to m, the lesser of m or n is multiplied by a factor such that n=m; wherein the polymaleic anhydride and amine adducts of polymaleic anhydride have a weight average molecular weight of from about 200 to about 10,000; and wherein the weight ratio of aminomethylphosphonic acid to polymer is from 10:1 to 1:10; and (3) zinc; wherein the weight ratio of the combined aminomethylphosphonic acid and polymer components to the zinc component is from 1:5 to 50:1.

Claim 7

A method of inhibiting corrosion of low carbon steel in an aqueous system comprising the step of treating said system with from 1.0 to 300 parts per million by weight of the total aqueous content of said system, of a corrosion inhibiting composition comprising (1) one or more aminomethylphosphonic acid compounds (2) one or more polymers selected from the group consisting of homopolymers, and random copolymers with acrylamide, of polymaleic anhydride and amine adducts of polymaleic anhydride selected from the group consisting of: (a) polymers having recurring units of the formula: ##STR20## wherein M.sup.⊕ may be H.sup.⊕, alkali metal cation, or quaternary ammonium cation of the formula: ##STR21## wherein for all of the above formulas, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to ten carbon atoms, and substituted alkyl of from one to ten carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; and wherein n is an integer of from 2 to 100; and (b) polymers having recurring units of the formula: ##STR22## wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, alkyl of from one to ten carbon atoms, and substituted alkyl of from one to ten carbon atoms, where the substituent is hydroxyl; carbonyl; and carboxylic acid groups, and alkali metal ion and ammonium salts thereof; wherein p is an integer of from 1 to 6; wherein m is an integer of from 2 to 100; and wherein n is an integer of from 2 to about 100, provided that, n not equal to m, the lesser of m or n is multiplied by a factor such that n=m; wherein the polymaleic anhydride and amine adducts of polymaleic anhydride have a weight average molecular weight of from about 200 to about 10,000; and wherein the weight ratio of aminomethylphosphonic acid to polymer is from 10:1 to 1:10; and (3) zinc; wherein the weight ratio of the combined aminomethylphosphonic acid and polymer components to the zinc component is from 1:5 to 50:1.