Polymeric corrosion inhibiter for metal surfaces and the production thereof

Abstract

The invention relates to a polymeric corrosion inhibiter for a metal substrate of formula (R 1 ) a A(R 2 X) b , where a=0-3, b=1-6, A is a bridge structure unit, R 1 is identical to or different from H or an aliphatic, aromatic, olefinic, cyclic, heterocyclic, polycyclic or polyheterocyclic radical, R 2 is identical to or different from a polymeric basic structure, X is identical to or different from a functional group selected from the groups comprising: carboxylic acids; dicarboxylic acids; polycarboxylic acids; carboxylic acid anhydrides; carboxylic acid chlorides; carboxylic sulfonic acids; and also esters, amides and imides of the aforementioned groups, the molar mass of the polymer lies between 200 and 10,000, preferably 400 and 6,000. The invention further relates to the use of a polymeric corrosion inhibiter for the treatment of metal surfaces and to a method for producing a polymeric corrosion inhibiter.

1 . A polymeric corrosion inhibitor for a metallic substrate, said polymeric corrosion inhibitor having the formula:
   (R 1 ) a A(R 2 X) b     wherein
 a=0-3; 
 b=1-6; 
 A is a structural bridging unit; 
 R 1  identically or differently is H or an aliphatic, aromatic, olefinic, cyclic, heterocyclic, polycyclic, or polyheterocyclic radical; 
 R 2  identically or differently is a polymeric parent structure; 
 X identically or differently is a functional group selected from the group consisting of carboxylic acids; dicarboxylic acids; polycarboxylic acids; carboxylic anhydrides; carbonyl chlorides; carbosulfonic acids; and also esters, amides, and imides of the aforementioned groups; and 
 the molar mass of the polymer is between 200 and 10 000. 
   
     
     
         2 .- 15 . (canceled) 
     
     
         16 . The polymeric corrosion inhibitor of  claim 1 , wherein the molar mass of the polymer is between 400 and 6000. 
     
     
         17 . The polymeric corrosion inhibitor of  claim 1 , wherein the polymeric parent structure R 2  has ethoxy (EO); propoxy (PO); butoxy (BO); (CH 2 ) n —NH—(CH 2 ) m  (with n and m from 0 to 10) units; or mixtures of these units. 
     
     
         18 . The polymeric corrosion inhibitor of  claim 1 , wherein the polymeric parent structure R 2  is a homopolymer of ethoxy units; a copolymer based on a mixture of ethoxy and propoxy units; or a homopolymer of propoxy units. 
     
     
         19 . The polymeric corrosion inhibitor of  claim 1 , wherein the parent structure R 2  comprises 3 to 200 monomer units; and/or wherein the index b is subject to the following:
 b=2-6.   
     
     
         20 . The polymeric corrosion inhibitor of  claim 19 , wherein the parent structure R 2  comprises 5 to 100 monomer units. 
     
     
         21 . The polymeric corrosion inhibitor of  claim 19 , wherein b=2-3. 
     
     
         22 . The polymeric corrosion inhibitor of  claim 1 , wherein X identically or differently is a functional group selected from the group consisting of carboxylic acids, dicarboxylic acids, polycarboxylic acids, carboxylic anhydrides, and amides and imides of carboxylic acids, dicarboxylic acids, polycarboxylic acids, and carboxylic anhydrides. 
     
     
         23 . The polymeric corrosion inhibitor of  claim 1 , wherein
   X=—NR′—R″ or —O—R″,
   wherein
 R′=an aliphatic, aromatic, olefinic, cyclic, heterocyclic, polycyclic, or polyheterocyclic radical or a derivatized acyl radical; and 
 R″=H or R′. 
   
     
     
         24 . A method for treating a metal surface, comprising contacting the metal surface with a polymeric corrosion inhibitor of  claim 1 . 
     
     
         25 . The method of  claim 24 , wherein the metal is selected from the group consisting of iron, steel, copper, zinc, magnesium, nickel, titanium, and alloys thereof. 
     
     
         26 . The method of  claim 24 , wherein the metal is selected from the group consisting of aluminum and its alloys. 
     
     
         27 . The method of  claim 24 , wherein the polymeric corrosion inhibitor is applied from a dispersion. 
     
     
         28 . The method of  claim 24 , wherein a polymer layer is applied to the metal surface, said polymer layer having:
 a) a thickness of ≦50 nm, and/or   b) an occupancy rate of the metal surface by the polymer of ≦2.5 mg/m 2 .   
     
     
         29 . The method of  claim 28 , wherein said polymer layer has a thickness of ≦30 nm. 
     
     
         30 . The method of  claim 28 , wherein said polymer layer has a thickness of about 10 nm. 
     
     
         31 . The method of  claim 28 , wherein said polymer layer has an occupancy rate of the metal surface by the polymer of ≦1.5 mg/m 2 . 
     
     
         32 . The method of  claim 28 , wherein said polymer layer has an occupancy rate of the metal surface by the polymer of ≦1 mg/m 2 . 
     
     
         33 . A metal workpiece obtainable by a method of  claim 24 . 
     
     
         34 . A method for preparing a polymeric corrosion inhibitor, said method comprising the steps of:
 a) providing a polymer having the formula
   (R 1 ) a A(R 2 Y) b   
   wherein
 a=0-3; 
 b=1-6; 
 A is a structural bridging unit; 
 R 1  identically or differently is H or an aliphatic, aromatic, olefinic, cyclic, heterocyclic, poly-cyclic, or polyheterocyclic radical; 
 R 2  identically or differently is a polymeric parent structure; 
 Y identically or differently is a functional group selected from the group consisting of —OR, —NHR, and —NR 2 , where R identically or differently is H or an aliphatic, aromatic, olefinic, cyclic, heterocyclic, polycyclic, or polyheterocyclic radical; and 
 the molar mass of the polymer is selected such that the molar mass of the polymeric corrosion inhibitor is between 200 and 10,000, 
   and   b) esterifying and/or amidating or imidating the functional group Y with carboxylic acids, dicarboxylic acids, polycarboxylic acids, carboxylic anhydrides, and amides and/or imides of carboxylic acids, dicarboxylic acids, polycarboxylic acids, and carboxylic anhydrides.   
     
     
         35 . The method of  claim 34 , wherein b=2-6. 
     
     
         36 . The method of  claim 34 , wherein b=2-3. 
     
     
         37 . The method of  claim 34 , wherein R is identically H. 
     
     
         38 . The method of  claim 34 , wherein the molar mass of the polymer is selected such that the molar mass of the polymeric corrosion inhibitor is between 400 and 6000. 
     
     
         39 . The method of  claim 34 , wherein the polymeric parent structure R 2  has ethoxy (EO); propoxy (PO); butoxy (BO); (CH 2 ) n —NH—(CH 2 ) m  (with n and m from 0 to 10) units; or mixtures of these units. 
     
     
         40 . The method of  claim 39 , wherein the polymeric parent structure R 2  is a homopolymer of ethoxy units. 
     
     
         41 . The method of  claim 39 , wherein the polymeric parent structure R 2  is a copolymer based on a mixture of ethoxy and propoxy units. 
     
     
         42 . The method of  claim 39 , wherein the polymeric parent structure R 2  is a homopolymer of propoxy units.