Corrosion-Reducing Composition and Use Thereof

Abstract

The invention relates to a composition which comprises at least one liquefying agent for a hydraulic composition and at least one aminoalcohol, selected from the group consisting of 2-amino-2-methyl-1-propanol and N-aminopropyl-monomethyl ethanolamine. The invention also relates to the use of said composition for reducing corrosion, especially on steel formwork in precast components or on concrete steel of concrete constructions.

1 . A composition comprising at least one plasticizer for a hydraulically setting composition
 and   at least one amino alcohol selected from the group consisting of 2 amino-2-methyl-1-propanol and N-aminopropylmonomethylethanolamine.   
   
   
       2 . The composition as claimed in  claim 1 , wherein the plasticizer comprises or consists of at least one polycarboxylate, preferably at least one polycarboxylate ether. 
   
   
       3 . The composition as claimed in  claim 2 , wherein the polycarboxylate comprises or consists of at least one polymer A of the formula (I) 
     
       
         
         
             
             
         
       
       where 
       the symbols M each represent, independently of one another, H + , an alkali metal ion, alkaline earth metal ion, divalent or trivalent metal ion, ammonium ion or organic ammonium group, 
       each R is, independently of the others, hydrogen or methyl,
 R 1  and R 2  are each, independently of one another, C 1 -C 20 -alkyl, cycloalkyl, alkylaryl or -[AO] n —R 4 ,
 where A=C 2 -C 4 -alkylene, R 4 =C 1 -C 20 -alkyl, cyclohexyl or 
 alkylaryl and n=2-250, 
 
 R 3  is —NH 2 , —NR 5 R 6 , —OR 7 NR 8 R 9 ,
 where R 5  and R 6  are each, independently of one another, 
 H or a C 1 -C 20 -alkyl, cycloalkyl or alkylaryl or aryl group; 
 or, 
 a hydroxyalkyl group, 
 
 or an
 acetoxyethyl (CH 3 —CO—O—CH 2 —CH 2 —) or 
 hydroxyisopropyl (HO—CH(CH 3 )—CH 2 —) or 
 acetoxyisopropyl group (CH 3 —CO—O—CH(CH 3 )—CH 2 —), 
 
 or R 5  and R 6  together form a ring
 of which the nitrogen of —NR 5 R 6  is part so as to build up a morpholine or imidazoline ring, 
 where R 7  is a C 2 -C 4 -alkylene group, 
 
 and R 8  and R 9  are each, independently of one another, a C 1 -C 20 -alkyl, cycloalkyl, alkylaryl, aryl or hydroxyalkyl group, 
 and a, b, c and d are molar ratios and
     a/b/c/d −=(0.05−0.9)/(0.05−0.95)/(0−0.8)/(0−0.5), 
 
 
       and a+b+c+d=1. 
     
   
   
       4 . The composition as claimed in  claim 3 , wherein n=8-200, particularly preferably n=11-150. 
   
   
       5 . The composition as claimed in  claim 3 , wherein
     a/b/c/d =(0.1−0.9)/(0.1−0.9)/(0−0.5)/(0−0.1), preferably       a/b/c /d=(0.1−0.9)/(0.1−0.9)/(0−0.3)/(0−0.06).   
   
   
       6 . The composition as claimed in  claim 5 , wherein c+d>0. 
   
   
       7 . The composition as claimed in  claim 1 , wherein the plasticizer comprises or consists of at least one polysaccharide, vinylic copolymer or sulfonate, in particular a lignosulfonate, naphthalenesulfonate or melaminesulfonate. 
   
   
       8 . The composition as claimed in  claim 1 , wherein the composition is a dispersion, in particular an aqueous dispersion. 
   
   
       9 . The composition as claimed in  claim 1 , wherein the composition is a solution, in particular an aqueous solution. 
   
   
       10 . The composition as claimed in  claim 1 , wherein the composition additionally contains further additives, preferably a solvent or water. 
   
   
       11 . The composition as claimed in  claim 1 , wherein the proportion of the amino alcohol is from 0.1 to 20% by weight, preferably from 0.5 to 10% by weight, particularly preferably from 1 to 5% by weight, based on the total weight of the composition. 
   
   
       12 . The composition as claimed in  claim 1 , wherein the proportion of the at least one plasticizer is from 10 to 99.9% by weight, preferably from 50 to 95% by weight, more preferably from 80 to 90% by weight, based on the total weight of the composition. 
   
   
       13 . A hydraulically setting composition comprising a composition as claimed in  claim 1  and at least one hydraulically setting binder. 
   
   
       14 . A method of reducing corrosion of steel, comprising:
 utilizing a composition as claimed in  claim 1 .   
   
   
       15 . The method as claimed in  claim 14 , wherein corrosion on steel shuttering of prefabricated elements is reduced. 
   
   
       16 . The method as claimed in  claim 14 , wherein corrosion on reinforcing steel of concrete constructions is reduced. 
   
   
       17 . A method of reducing corrosion on steel shuttering of prefabricated elements, comprising:
 utilizing 2-amino-2-methyl-1-propanol and/or N-aminopropylmonomethylethanolamine.   
   
   
       18 . A method of reducing corrosion on reinforcing steel of concrete constructions, comprising:
 utilizing 2-amino-2-methyl-1-propanol and/or N-aminopropylmonomethylethanolamine.   
   
   
       19 . A process for producing a composition as claimed in  claim 1 , which comprises the step
 a) mixing of the amino alcohol 2-amino-2-methyl-1-propanol or N-aminopropylmonomethylethanolamine and at least one plasticizer.   
   
   
       20 . A method of reducing corrosion on steel shuttering of prefabricated elements or on steel reinforcement of steel-reinforced concrete constructions, wherein a composition as claimed in  claim 1  is added to the fresh concrete and the fresh concrete is brought into contact with the steel. 
   
   
       21 . A concrete construction comprising a composition as claimed in  claim 1 . 
   
   
       22 . A concrete construction as claimed in  claim 21 , wherein the concrete construction is a building work or a component of an above-ground or underground construction, in particular a building, a road, a bridge or a tunnel. 
   
   
       23 . A prefabricated element comprising a composition as claimed  claim 1 .