Inhibiting metallic corrosion in aqueous systems

Abstract

The use of polymeric corrosion inhibiting compositions incorporating heterocyclic groups is disclosed. The polymers form a protective barrier on metallic components to aqueous systems and remain substantive on metallic surfaces over a wide pH range. Moreover, the polymers are resistant to oxidizing biocides, and are substantially impervious to repeated or prolonged exposure to corrosive agents.

What is claimed is:  
     
         1 . A process for inhibiting corrosion of metallic components in contact with an aqueous system comprising the step of adding to the system an effective amount of one or more polymers comprising: 
 i) at least one repeating unit selected from a functionalized imide component of Formula Ia, a functionalized amide component of Formula Ib and combinations of Ia and Ib:                          wherein n is 0 or 1; R and R 1  are independently selected from the group consisting of hydrogen, methyl, and C 2 -C 4  alkyl; a heterocycle comprising unsaturated or aromatic heterocycles having one or more hetero atoms selected from the group N, O, S and combinations thereof, the heterocycle chemically bonded to a nitrogen atom via a hetero atom which is part of the heterocycle or a carbon atom of the heterocycle; R 3  is selected from the group consisting of hydrogen, methyl, ethyl, C 3 -C 18  branched and straight chain, alkyl and alkenyl groups; and R 4  is selected from the group consisting of H, CH 3 , C 2 H 5 , C 6 H 5  and C 3 -C 18  branched and straight chain alkyl groups and C 3 -C 18  alkenyl groups;    ii) at least one ethylenically unsaturated monomer component selected from maleic anhydride, itaconic anhydride, cyclohex-4-enyl tetrahydrophthalic anhydride, and monomers of Formula II:    Formula II    CH(R5)=C(R6)(R7)    wherein R 5  is selected from hydrogen, phenyl, methyl, ethyl, C 3 -C 18  branched and straight chain alkyl and alkenyl groups; R 6  is independently selected from hydrogen, methyl, ethyl, phenyl, C 3 -C 18  branched and straight chain alkyl and alkenyl groups, OR 8  and CH 2 OR 8  groups wherein R 8  is acetate, glycidyl, methyl, ethyl, C 3 -C 18  branched and straight chain alkyl and alkenyl groups, and groups having the formula [CH 2 CH(R a )O] m R b  wherein R a  is hydrogen, methyl, ethyl, and phenyl, m is an integer from 1-20 and R b  is independently hydrogen, methyl, ethyl, phenyl and benzyl; and R 7  is independently selected from H, CH 3 , C 2 H 5 , CN, a COR 9  group wherein R 9  is OH, NH 2 , OR 8  group wherein R 8  is a group described previously and a NR c R d  group wherein R c  and R d  are the same group or different groups, are parts of a 5-membered or 6-membered ring system, hydrogen, hydroxymethyl, methoxy methyl, ethyl and C 3 -C 18  branched and straight chain alkyl and alkenyl groups branched and straight chain alkyl and alkenyl groups; and    iii) optionally one or more end groups selected from initiator fragments, chain transfer fragments, solvent fragments and combinations thereof.    
     
     
         2 . The process according to  claim 1 , wherein the weight average molecular weight of the polymer is from 400 to 20,000 and the pH of the aqueous system is from 6 to 10.  
     
     
         3 . The process according to  claim 1 , wherein the amount of polymer added to the aqueous system is from 1 to 500 ppm, based on the weight of the aqueous system.  
     
     
         4 . The process according to  claim 1 , wherein the polymer is added to the aqueous system on a periodic or a continuous basis.  
     
     
         5 . The process according to  claim 1 , wherein the polymer is added to the aqueous system as formulation with one or more additives selected from the group consisting biocidal compositions, corrosion inhibitor compositions known in the art, scale inhibiting compositions, dispersants, defoamers, inert fluorescent tracers and combinations thereof.  
     
     
         6 . The process according to  claim 1 , wherein the polymer comprises a functionalized imide component of Formula 1a selected from succinimide, glutarimide and combinations thereof; wherein the heterocycle is selected from the group consisting of imidazole, thiophene, pyrrole, oxazole, thiazoles and their respective isomers, substituted thiazoles and their respective isomers, pyrazole, tetrazole, pyridine, pyridazine, pyrimidine, pyrazine, triazoles and their respective isomers and combinations thereof; and wherein the ethylenically unsaturated monomer component is selected from the group consisting of maleic anhydride, itaconic anhydride, cyclohex-4-enyl tetrahydrophthalic anhydride, ethylene, propylene, butylene, isobutylene, di-isobutylene, propylene tetramer (C 12 -C 14 ), propylene dimer trimer (C 18 -C 22 ), 1-butene, 1-octene, 1-decene; styrene, α-methyl styrene, hydroxy styrene, styrene sulfonic acid, butadiene; vinyl acetate, vinyl butyrate, vinyl esters, vinyl chloride, vinylidene chloride, stilbene, divinyl benzene, (meth)acrylic acid, C 3 -C 18  (meth)acrylate esters, C 3 -C 18  (meth)acrylamides and (meth)acrylonitrile.  
     
     
         7 . The process according to  claim 1  wherein one or more of the polymers is of formula III:  
       (A)x(B)y(C)z  
       wherein A is an optional end group component selected from initiator fragments, chain transfer fragments, solvent fragments and combinations thereof; wherein B is a functionalized imide component of Formula Ia, a functionalized amide component of Formula Ib and combinations of Ia and Ib; wherein C is an ethylenically unsaturated monomer component selected from maleic anhydride, itaconic anhydride, cyclohex-4-enyl tetrahydrophthalic anhydride, and monomers of Formula II; and wherein x, y, z are integers values chosen such that (y+z)/x is greater than 2.  
     
     
         8 . The polymer according to  claim 7  wherein A is selected from the group consisting of dialkyl peroxides, alkyl hydroperoxides, n-dodecyl isopropyl alcohol, alkyl phosphonates, alkyl phosphites, aryl phosphinic acids, alkyl phosphinic acids, hypophosphites, aldehydes, formates, toluene, xylenes, C 9 -C 10  alkylaromatics, and Aromatic 100; wherein the heterocycle attached to B is selected from the group consisting of imidazole, triazole and their respective isomers, thiophene, pyrrole, oxazole, thiazoles and their respective isomers, pyrazole, substituted thiazoles and their respective isomers, tetrazole, pyridine, pyridazine, pyrimidine, pyrazine, and combinations thereof; and wherein C is selected from the group consisting of maleic anhydride, itaconic anhydride, cyclohex-4-enyl tetrahydrophthalic anhydride, ethylene, propylene, butylene, isobutylene, di-isobutylene, propylene tetramer (C 12 -C 14 ), propylene dimer trimer (C 18 -C 22 ), 1-butene, 1-octene, 1-decene; styrene, cc-methyl styrene, hydroxy styrene, styrene sulfonic acid, butadiene; vinyl acetate, vinyl butyrate, vinyl esters, vinyl chloride, vinylidene chloride, stilbene, divinyl benzene, (meth)acrylic acid, C 3 -C 18  (meth)acrylate esters, C 3 -C 18  (meth)acrylamides and (meth)acrylonitrile.  
     
     
         9 . The process according to  claim 1  wherein one or more of the polymers is of formula IV:  
       Formula IV  
       (A)x(B)y(B′)z  
       wherein A is an end group selected from initiators fragments, chain transfer fragments, solvent fragments and combinations thereof; wherein B is a functionalized imide component of Formula Ia selected from succinimide, glutarimide and combinations thereof; wherein B′ includes at least one unit selected from a functionalized imide component or a functionalized amide component selected from succinimide, glutarimide and combinations thereof, wherein the nitrogen atom of each component of B′ is chemically bonded to a group selected from C 1 -C 18  branched or straight chain alkyl, C 1 -C 18  alkyl or alkenyl substituted aryl, which is in turn chemically bonded to a pendant functional group selected from an amine group, amide group, carboxylic acid group, alcohol group or a group having the formula [CH 2 CH(R a )O] m R b  wherein R a  is hydrogen, methyl, ethyl, and phenyl, m is an integer from 2-20 and R b  is independently hydrogen, methyl, ethyl, phenyl and benzyl; and wherein x, y, z are integers values chosen such that (y+z)/x is greater than 2.  
     
     
         10 . The process according to  claim 9  wherein the group attached to B′ is an C 1 -C 18  branched or straight chain alkyl amine and the pendant heterocycle attached to B is selected from the group consisting of imidazole, triazole and their respective isomers, thiophene, pyrrole, oxazole, thiazoles and their respective isomers, pyrazole, substituted thiazoles and their respective isomers, tetrazole, pyridine, pyridazine, pyrimidine, pyrazine, and combinations thereof.