Corrosion-Inhibiting Compositions

Abstract

The invention relates to a composition comprising a) at least one N-methyl-N-acylglucamine of formula (I), wherein R.sup.1 represents a linear or branched, saturated or unsaturated hydrocarbon chain with 7 to 21 carbon atoms, one or more organic acids of formula (II) and/or the salts thereof, R.sup.2—COOM, wherein R.sup.2 represents a linear or branched alkyl group or a linear or branched mono- or poly-unsaturated alkenyl group with 5 to 29 carbon atoms, and M represents hydrogen or one or more cations, wherein the cations are present in charge-equalizing amounts, and c) one or more alkanolamines of formula (III), wherein NR.sup.1R.sup.2R.sup.3R.sup.1, R.sup.2 and R.sup.3 represent hydrogen, a linear or branched alkyl group with 1 to 4 carbon atoms, a cycloalkyl group with 5 to 7 carbon atoms, a linear or branched hydroxyalkyl group with 2 to 5 carbon atoms and 1 or 2 hydroxy groups or a hydroxyether group with 2 to 6 carbon atoms, with the provision that at least one of the groups is a hydroxyalkyl group or a hydroxyether group.

##STR00001##

Claims

1. A composition comprising a) at least one N-methyl-N-acylglucamine of the formula (I) ##STR00006## where R.sup.1 is a linear or branched, saturated or unsaturated hydrocarbyl chain having 7 to 21 carbon atoms, b) one or more than one organic acids of the formula (II), or salts thereof,
R.sup.2—COOM  (II) where R.sup.2 is a linear or branched alkyl group or a linear or branched, mono- or polyunsaturated alkenyl group having 5 to 29 carbon atoms, and M is hydrogen or one or more cations, where the cations are present in charge-balancing amounts, and c) one or more alkanolamines of the formula (III)
NR.sup.1R.sup.2R.sup.3  (III) where R.sup.1, R.sup.2 and R.sup.3 are hydrogen, a linear or branched alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, a linear or branched hydroxyalkyl group having 2 to 5 carbon atoms and 1 or 2 hydroxyl groups or a hydroxy ether group having 2 to 6 carbon atoms, with the proviso that at least one of the radicals is a hydroxyalkyl group or a hydroxy ether group.

2. The composition as claimed in claim 1, comprising at least one N-methyl-N-acylglucamine of the formula (I) where R.sup.1 is a linear or branched, saturated or unsaturated hydrocarbyl chain having 11 to 17 carbon atoms.

3. The composition as claimed in claim 1, in which the compound of the formula (I) is a mixture of N-methyl-N—C.sub.12-acylglucamine and N-methyl-N—C.sub.14-acylglucamine.

4. The composition as claimed in claim 1, in which the compound of the formula (I) is a mixture of N-methyl-N—C.sub.16-acylglucamine and N-methyl-N—C.sub.18-acylglucamine.

5. The composition as claimed in one or more of claims 1 to 4, comprising one or more organic acids of the formula (II) or salts thereof, in which R.sup.2 comprises 7 to 21 carbon atoms.

6. The composition as claimed in claim 5, comprising one or more organic acids of the formula (II) or salts thereof, in which R.sup.2 comprises 11 to 17 carbon atoms.

7. The composition as claimed in one or more of claims 1 to 4, comprising tall oil fatty acids, rapeseed oil fatty acids and/or soya oil fatty acids or salts thereof as constituent b).

8. The composition as claimed in one or more of claims 1 to 7, in which the alkanolamine which makes up constituent c) is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, diglycolamine, monoisopropanolamine and 2-amino-2-methyl-1-propanol.

9. The composition as claimed in one or more of claims 1 to 8, containing a) 1% to 50% by weight of one or more methylglucamines of the formula (I), b) 0.1% to 23% by weight of at least one organic acid, or salt thereof, of formula (II) and c) 0.05% to 42% by weight of at least one alkanolamine of formula (III).

10. The compositions as claimed in one or more of claims 1 to 9, comprising, as additional component d), one or more constituents selected from one or more emulsifiers, one or more biocides, one or more further corrosion inhibitors, one or more AW additives, one or more EP additives, one or more defoamers, one or more antioxidants, one or more coupling agents, one or more alkali metals or alkaline earth metals, one or more solubilizers, one or more pH regulators, and water.

11. The composition as claimed in one or more of claims 1 to 10, comprising one or more anionic, nonionic, cationic or amphoteric emulsifiers in amounts of 0.5% to 50% by weight, based on the compositions consisting of components a) to d).

12. The composition as claimed in one or more of claims 1 to 11, containing 0.001% to 5% by weight of one or more biocides selected from the group consisting of boric acid, 1,2-benzisothiazol-3-(2H)-one (BIT), 3(2H)-isothiazolone, 2-methyl, methanol [1,2-ethanediylbis(oxy)bis(glyoxal monoethylene acetal)], sodium 2-pyridinethione-1-oxide (sodium pyrithione), 1,3,5-triazine-1,3,5(2H,4H,6H)-triethanol, morpholine, 4,4′-methylenebis(1H,3H,5H)oxazolo[3,4-c]oxazole, 5-ethyl-3,7-dioxa-1-azabicyclo[3.3.0]octane, 3-iodo-2-propynyl butyl carbamate (IPBC).

13. The composition as claimed in one or more of claims 1 to 12, in which M is selected from Li.sup.+, Na.sup.+, K.sup.+, Mg.sup.++, Ca.sup.++, Al.sup.+++, NH.sub.4.sup.+, monoalkylammonium, dialkylammonium, trialkylammonium and/or tetraalkylammonium ions, and in which the alkyl substituents of these ammonium ions are each independently (C.sub.1-C.sub.22)-alkyl radicals.

14. The composition as claimed in claim 13, in which the alkyl substituents bear up to 3 (C.sub.2-C.sub.10)-hydroxyalkyl groups.

15. The composition as claimed in one or more of claims 1 to 14, in which R.sup.1 is an alkyl or alkenyl group.

16. The composition as claimed in one or more of claims 1 to 15, wherein the pH thereof is between 7 and 12.

17. An emulsion concentrate comprising 5% to 40% by weight of a composition as claimed in one or more of claims 1 to 16 and 60% to 95% by weight of one or more oils.

18. The emulsion concentrate as claimed in claim 17, wherein the oil is selected from mineral oils having kinematic viscosities of 5 to 1000 mm.sup.2/s, measured at 40° C., paraffins, isoparaffins, cycloparaffins, aromatic hydrocarbons, poly-alpha-olefins, polyalkylene glycols (PAGs) and ester oils.

Description

EXAMPLES

[0251] All percentages, unless stated otherwise, should be understood to mean percent by weight (% by weight).

[0252] Determination of the corrosion-inhibiting effect of a mixture of N-methyl-N—C.sub.12-acylglucamine and N-methyl-N—C.sub.14-acylglucamine (Glu1) and a mixture of N-methyl-N—C.sub.16-acylglucamine and N-methyl-N—C.sub.18-acylglucamine (Glu2) in the presence of tall oil fatty acid (TOFA), coconut fatty acid (CC) and mono- or di- or triethanolamine on iron.

[0253] A corrosion protection test is conducted in accordance with DIN 51360-2, in which gray iron turnings (GG25 type) on a round filter were wetted with in each case 2% solutions of test formulations 1 to 9 according to table 1 in water having 20 German degrees of hardness (20° dH) for 2 hours each, and the corrosion residues formed on the filter paper were assessed.

[0254] Corrosion is assessed in accordance with DIN 51 360-2 as follows:

0 no corrosion/unchanged
1 traces of corrosion/not more than 3 corrosion marks
2 slight corrosion/not more than 1% of the surface discolored
3 moderate corrosion/not more than 5% of the surface discolored
4 severe corrosion/more than 5% of the surface discolored

TABLE-US-00001 TABLE 1 Test formulations: Component Example [% by weight] 1(C) 2 3(C) 4 5(C) 6 7(C) 8 9(C) Glu1 0 0 0 0 0 0 0 64 0 Glu2 100 64 0 64 0 64 0 0 0 CC 0 0 0 0 0 0 0 15 15 TOFA 0 15 15 15 15 15 15 0 0 Monoethanol- 0 21 21 0 0 0 0 0 0 amine Diethanolamine 0 0 0 21 21 0 0 0 0 Triethanolamine 0 0 0 0 0 21 21 21 21 Propylene glycol 0 0 12.8 0 12.8 0 12.8 0 0 Glycerol 0 0 3.5 0 3.5 0 3.5 0 0 Water 0 0 47.7 0 47.7 0 47.7 0 64 Corrosion 2-3 0 1-2 0 1-2 0 2 0 2 assessment

[0255] Determination of the corrosion-inhibiting action (Glu2) in the presence of tall oil fatty acid and mono- or di- or triethanolamine on aluminum.

[0256] A corrosion protection test is conducted in accordance with EEH1020-AA-1049 with the aluminum alloys AlZnMgCu1.5 and AlMgSi1. 2% test formulations from table 1 were each prepared with water having 20 German degrees of hardness (20° dH), and the test specimens of the abovementioned alloys were each half-immersed in the solutions at 40° C. and left therein for 24 hours. Thereafter, the test specimens are pulled out of the solutions, rinsed with demineralized water and then acetone, and dried. Both the part immersed into the solution (solution) and the exposed part (atmosphere) of the test specimens are assessed according to the criteria mentioned above for DIN 51 360.

TABLE-US-00002 TABLE 2 Test formulations: Component Example [% by weight] 10 11(C) 12 13(C) 14 15(C) Glu2 64 0 64 0 64 0 TOFA 15 15 15 15 15 15 Monoethanolamine 21 21 0 0 0 0 Diethanolamine 0 0 21 21 0 0 Triethanolamine 0 0 0 0 21 21 Propylene glycol 0 12.8 0 12.8 0 12.8 Glycerol 0 3.5 0 3.5 0 3.5 Water 0 47.7 0 47.7 0 47.7

[0257] The results are summarized in table 3.

TABLE-US-00003 TABLE 3 Corrosion of aluminum alloys in the presence of a mixture of N-(test methyl-N-acylglucamine (Glu2), fatty acid and alkanolamines formulation 10, 12 and 14) compared to fatty acid and alkanolamines without N-methyl-N- acylglucamine (test formulations 11, 13 and 15) Example Alloy 10 11(0) 12 13(0) 14 15(0) AlZnMgCu1.5, 1 3 0 1-2 0 1 atmosphere AlZnMgCu1.5 0 0 0 1 0 0 solution AlMgSi1 atmosphere 0-1 3 0-1 2 0-1 2 AlMgSi1 solution 0 0 0 0 0 0