EP1652909B2 - Corrosion-inhibiting agent for functional fluids, water-miscible lubricating concentrate and its use. - Google Patents

Description

The present invention relates to a functional fluid corrosion inhibitor, a water-miscible water-based functional fluid-containing concentrate containing this corrosion inhibitor, and the use thereof.

Due to their low flammability and their low environmental risk, water-based functional fluids are increasingly gaining in interest. These functional fluids are liquids used as lubricants, abrasives, coolants and lubricants for metal forming and metal cutting, and more particularly as hydraulic fluids, namely, hydraulic fluids. These water-based functional fluids are also referred to as HFA fluids or HFA hydraulic fluids. Such HFA hydraulic fluids are used in particular in the hydraulic longwall mining systems. They are prepared on site by mixing from 1 to 20% by weight of a water-miscible concentrate containing the necessary active ingredients with correspondingly 99 to 80% by weight of water. The concentrates may contain as lubricants, synthetic products or those based on mineral oil. Depending on the composition of the water-miscible concentrate, the HFA hydraulic fluid obtained is either an emulsion (HFAE), including a microemulsion, with mineral or synthetic oil, or solutions (HFAS). Such HFA hydraulic fluids have the viscosity of water and can be used in a temperature range of + 5 ° C to + 55 ° C.

If such a water-based functional fluid, or HFA hydraulic fluid, does not ensure sufficient corrosion protection, this leads to the formation of corrosion on the material surfaces in contact with this functional fluid, namely the hydraulic devices. This can be caused in particular pitting, trough corrosion, cratering or even the deposition of coating-forming corrosion products. Since such corrosion especially in the use of HFA hydraulic fluid in large hydraulic systems, such as in the longwall mining, must be prevented, these water-based functional fluids contain corrosion inhibitors and other auxiliaries, such as animal, vegetable, mineral and / or synthetic oils, fats , Oil or fat components as lubricants, fatty alcohols, biocides, fungicides, complexing agents, heavy metal inhibitors, nonionic or anionic emulsifiers, dispersants and defoamers.

From the EP 1 174 489 A1 For example, there is known a process for preparing water-based cutting fluids containing an oil phase, an aqueous phase, a bactericide or fungicide, and high pressure components. As anticorrosive and / or bacteriostatic agents, these cutting fluids may contain organic acids such as sebacic acid.

From the DE 198 33 894 A1 is a water-miscible coolant concentrate known which contains natural or synthetic mineral oils, emulsifiers, solubilizers, preservatives, metal inhibitors and other conventional additives and having a pH of less than 7.7 for the purpose of ensuring skin compatibility. As corrosion inhibitor, this concentrate may contain reaction products of boric acid with primary or tertiary alkanolamines, ethoxylated or propoxylated fatty acids or fatty acid alkanolamides, phosphoric acid esters, triazoles of the thiadiazoles either alone or in combination. Although it is stated in this document that a water-mixed cooling lubricant can be produced with these concentrates, whose pH is as close to the neutral point and still does not lead to rusting of metal parts that have been processed with an aqueous solution of the coolant, these assets Concentrates and the functional fluids produced therewith based on water, especially with regard to their corrosion effect unsatisfactory. In particular, these waterborne coolants, when in contact with metal surfaces for extended periods of time, such as when used in hydraulic equipment, can result in corrosion of the exposed metal surfaces, particularly by pitting and the deposition of undesirable deposits.

EP-A-591 771 describes lubricant compositions for metal forming comprising as lubricating component an ethoxylated fatty amine or amide, an amine or amide salt, a Imidazolinsalz, a polyalkylene glycol or lanolin, as a film-forming component one or more vinyl or acrylic polymers, cellulose ethers, fatty alcohols or waxes and anticorrosive a mixture of mono and dicarboxylic acids, a fatty acid ethanolamide or a glycol derivative.

US-A-4391722 describes an aqueous hydraulic fluid containing a 0.15 wt .-% C21-Alkyldiethanolamid, 0.1 wt .-% benzoic acid and 0.2% by weight of an alcohol and a concentrate containing C21 diethanolamide, 0.2% ethanol and 2% benzoic acid.

DE-A-4323909 describes a composition of an oil / water emulsion containing an oil component, an emulsifier, a co-emulsifier (fatty alcohols), and water and an aqueous solution containing salts of aliphatic mono- or dicarboxylic acids, benzenecarboxylic acids or Arylsulfonaminocarbonsauren as a corrosion inhibitor.

The object of the present invention is now a corrosion inhibitor for functional fluids to improve the corrosion protection performance of such HFA fluids, namely HFA hydraulic fluids for hydraulic systems, without affecting the other requirements for such a functional fluid, in such a way that their use in large-volume and extremely costly hydraulic equipment, as described in Mining becomes possible becomes possible.

It has surprisingly been found that it is possible with a combination of at least three different corrosion protection additives known per se, to improve the corrosion protection behavior of such HFA hydraulic fluids in unexpectedly strong extent, so that not only the pitting, the trough corrosion and cratering, but also the deposition of scale-forming corrosion products observed when using conventional HFA fluids in the crevice corrosion test described below in accordance with DSK Standard N 762 830 can be completely avoided.

The invention therefore provides the corrosion inhibitor according to the main claim. The subclaims relate to preferred embodiments of this subject of the invention, a water-miscible water-based functional concentrate containing this corrosion inhibitor, preferred embodiments of this concentrate and its use for the preparation of a lubricant, an abrasive, a hydraulic fluid or a water-based cooling lubricant for metal forming and metal cutting.

One embodiment of the invention therefore relates to a functional fluid corrosion inhibitor comprising 5 to 80% by weight of at least one fatty acid alkanolamide based on saturated or unsaturated fatty acids having 10 to 20 carbon atoms, 5 to 80% by weight of at least one alcohol having 2 to 14 carbon atoms selected from the group consisting of isopropanol, n-butanol, butyldiglycol, hexylene glycol, butyltriglycol, benzyl alcohol and phenoxyethanol and from 5 to 80% by weight of at least one aromatic monocarboxylic acid or an aliphatic dicarboxylic acid having from 10 to 12 carbon atoms selected from sebacic acid, undecanedioic acid, Dodecanedioic acid and p-tert-butylbenzoic acid group, wherein the sum of these ingredients is 100 wt .-% and the wt .-% based on the weight of the corrosion inhibitor.

It has been found in comparative tests, which are illustrated in the following examples and comparative examples, that only when the anticorrosion agent contains the three specified necessary ingredients and the aromatic monocarboxylic acid or aliphatic dicarboxylic acid, the undesirable corrosion can be completely avoided, for example in the presence of an aliphatic monocarboxylic acid having 10 carbon atoms, such as neodecanoic acid, the occurrence of solid deposits and line corrosion can not be avoided. This result is undoubtedly surprising and unexpected to those skilled in the art.

Preferably, the corrosion inhibitor according to the invention contains from 25 to 60% by weight of the at least one fatty acid alkanolamide, from 15 to 25% by weight of the at least one alcohol with from 20 to 50% by weight of the at least one aromatic monocarboxylic acid or aliphatic dicarboxylic acid of the type defined above.

Preferred fatty acid alkanolamides in the corrosion inhibitor according to the invention are those based on saturated or unsaturated fatty acids having 12 to 18 carbon atoms and alkanolamines having 2 to 6 carbon atoms, namely monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, monoisopropanolamine, 2-amino-2-methyl-1 propanol, 2-amino-2-ethyl-1,3-propanediol and / or diglycolamine, which is also referred to as 2-aminoethoxyethanol or ethylene glycol 2-aminoethyl ether.

Fatty acid alkanolamides which are particularly preferred according to the invention are coconut fatty acid alkanolamides and tall oil fatty acid monoalkanolamides, such as coconut fatty acid monoethanolamide, coconut fatty acid monopropanolamide, tall oil fatty acid monoethanolamide and tall oil fatty acid monopropanolamide and in particular also reaction products of coconut fatty acid, coconut oil, tall oil fatty acid and / or tall oil and diglycolamine.

The aromatic monocarboxylic acid or aliphatic dicarboxylic acid used according to the invention as the third essential constituent of the corrosion inhibitor is selected from the group consisting of sebacic acid, undecanedioic acid, dodecanedioic acid and p-tert-butylbenzoic acid. Mixtures of these acids have proven to be particularly favorable, in particular mixtures of undecanedioic acid and dodecanedioic acid in a weight ratio of 3: 1 to 1: 3 and in particular 1: 1.

A further subject matter of the invention is a water-miscible concentrate for water-based functional fluids and in particular for HFA hydraulic fluids containing animal, vegetable, mineral and / or synthetic oils, fats, oil or fat components as lubricants, fatty alcohols, biocides, fungicides, complexing agents, Contains heavy metal inhibitors, nonionic or anionic emulsifiers, dispersants, defoamers, corrosion inhibitors and water and conventional additives as the remainder and contains as essential ingredient of the invention 2 to 20 wt .-%, preferably 5 to 15 wt .-% of the above-defined corrosion inhibitor, wherein the weight percent are based on the weight of the water-miscible concentrate.

According to a preferred embodiment, the water-miscible concentrate contains 1 to 12% by weight, more preferably 2 to 8% by weight, of at least one fatty acid alkanolamide based on saturated or unsaturated Fatty acids having 10 to 20 carbon atoms, 1 to 8 wt.% At least, more preferably 1.5 to 5 wt.% Of the alcohol having 2 to 14 carbon atoms and 1 to 8 wt.%, More preferably 1 to 5 wt. the aromatic monocarboxylic acid or aliphatic dicarboxylic acid having 10 to 12 carbon atoms.

Advantageously, the water-miscible concentrate contains a fatty acid alkanolamide based on saturated or unsaturated fatty acids having 12 to 18 carbon atoms and alkanolamines having 2 to 6 carbon atoms, wherein as alkanolamines monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, monoisopropanolamine, 2-amino-2-methyl 1-propanol, 2-amino-2-ethyl-1,3-propanediol and diglycolamine are particularly preferred. Even more preferably, the concentrate contains, as fatty acid alkanolamide, a coconut fatty acid monoalkanolamide and / or tall oil fatty acid monoalkanolamide, especially coconut fatty acid monoethanolamide, coconut fatty acid monopropanolamide, tall oil fatty acid monoethanolamide and / or tall fatty acid monopropanolamide, according to a further preferred embodiment as fatty acid alkanolamide a reaction product of coconut fatty acid, coconut oil, tall oil fatty acid and / or tall oil and diglycolamine.

The concentrate contains as alcohol isopropanol, n-butanol, butyl diglycol, hexylene glycol, butyl triglycol, benzyl alcohol and phenoxyethanol, these alcohols can be used individually or in the form of any mixtures.

The water-miscible concentrate contains as aromatic monocarboxylic acid or aliphatic dicarboxylic acid sebacic acid, undecanedioic acid, dodecanedioic acid or p-tert-butylbenzoic acid, which acids can be used individually or in the form of mixtures. Here, mixtures of undecanedioic acid and dodecanedioic acid in weight ratios of 3: 1 to 1: 3 and in particular of 1: 1 are particularly preferred. These mixtures have proven to be particularly advantageous with regard to the corrosion protection effect.

According to another preferred embodiment, the water-miscible concentrate according to the invention may contain from 0.5 to 3% by weight of a biocidal compound selected from biocidal quaternary ammonium compounds, guanidine derivatives, O- or N-formals, O- or N-acetals, isothiazolines, isothiazolinones, aliphatic amines or diamines, 3-iodo-2-propynyl butylearbamate, bis (3-aminopropyl) dodecylamine, and mixtures thereof. As a fungicide or bactericide, the concentrate may contain 0.5 to 3% by weight of a fungicidal pyridine derivative, preferably pyrithione or a pyrithione derivative such as 2-pyridinethiol-1-oxide sodium salt.

As a complexing agent, the concentrate according to the invention may contain 0.5 to 5 wt .-% ethylenediaminetetraacetic acid or its alkali metal or ammonium salts, sodium citrate, sodium gluconate, N, N'-disalicylidene and / or derivatives thereof.

According to a further advantageous embodiment, the water-miscible concentrate according to the invention contains 1 to 8 wt .-%, more preferably 2 to 5 wt .-% of a phosphoric acid esters such as Ethylhexylphosphorsäure, phosphonic, Diaminoxethylat, Triaminoxethylat, Alkylimidazolinen, Polyaminnaphthensäureamiden, synthetic or natural sulfonates, such as petroleum sulfonates , p-tert-butylbenzoic acid, tricarboxylic acids, neodecanoic acid, 5- or 6-carboxy-4-hyl-2-hexene-1-octanoic acid, saturated or unsaturated fatty acids, ethoxylated or propoxylated fatty acids and fatty acid alkanolamides, thiadiazole compounds, and mixtures thereof of additional anticorrosion agent selected.

Furthermore, 3 to 25 wt .-% of a reaction product of boric acid and primary or tertiary alkanolamines may be contained in the water-miscible concentrate according to the invention as additional corrosion protection.

The concentrate according to the invention can furthermore contain 0.05 to 1.5% by weight of benzotriazole and / or toluyltriazole and / or derivatives thereof as heavy metal inhibitor.

According to the invention, the water-miscible concentrate contains as animal, vegetable, mineral and / or synthetic lubricant 3 to 70 wt .-% of a natural or synthetic mineral oil, 2 to 40 wt .-% of an ester oil, which are conventional synthetic ester oils to those skilled in the art, 1 to 6 wt .-% of a phosphated and / or ethoxylated alcohol and / or 2 to 35 wt .-% of a polyalkylene glycol and / or polyvinylpyrrolidone, with the proviso that this lubricant 10 to 70 wt. -% of the water-miscible concentrate.

As defoamer, the concentrate may contain from 0.05 to 1% by weight of a siloxane compound, while as emulsifier from 1 to 5% by weight of oleoyl sarcoside are preferred. As a dispersant, 0.2 to 5 wt .-% of an acrylic polymer salt, in particular a salt of a poly (meth) acrylic acid may be contained in the concentrate.

According to a preferred embodiment, the water-miscible concentrate after dilution with water to a concentrate content of 1 to 20 wt .-%, based on the resulting functional liquid, a pH of 8.4 to 9.8, preferably 9.0 to 9.5 on.

According to a further embodiment, the invention relates to the use of the above-defined water-miscible concentrate for the production of a lubricant, an abrasive, a hydraulic fluid or a water-based cooling lubricant for metal forming and metal cutting by mixing from 1 to 20% by weight, preferably 2 to 5% by weight of the above-defined water-miscible concentrate, having 99 to 80 Wt .-%, preferably 99 to 95 wt .-% water. Under non-cutting metal forming in the context of the inventive use deep drawing. Cold extrusion or rolling, while the metal cutting operations include turning, milling, drilling and grinding of metals.

It has surprisingly been found that the water-miscible concentrate according to the invention even when mixed with water having a hardness of 3 ° dH to 42 ° dH at a concentrate content of 2% HFA hydraulic fluid results in the form of emulsions, even after 600 hours at a temperature of 50 ° C are absolutely stable.

The corrosion inhibitor of the invention is prepared by simply mixing the ingredients. The water-miscible concentrate of the present invention is prepared by first introducing the water-soluble or water-dispersible ingredients into water, then dissolving or dispersing the oil-soluble ingredients in the oil component, and then slowly adding the hydrous mixture to the mineral oil mixture.

The following examples serve to further illustrate the invention.

In the examples and the comparative examples, the corrosion protection effect achieved with the anticorrosion agent according to the invention is determined by means of the crevice corrosion test, in accordance with DSK standard N 762 830. The method of corrosion testing by means of this crevice corrosion test is published in Glückauf 138 (2002) No. 5, pages 208-212. The method consists in that the pressure fluid or hydraulic fluid to be tested in a defined punch unit (piston-cylinder) is stored under purely static conditions for 21 days at a humidity of 95% and a test temperature of 35 ° C. The gap region is formed between the cylinder inner surface and a bronze part located on the piston. On the bronze part, a commercially available sealing ring is mounted. After a contact time with the liquid to be tested for 21 days, the stamp unit is dismantled and examined the gap area on the cylinder inner surface with respect to a corrosion formation. In this crevice corrosion test shows that inadequate corrosion protection in addition to a pitting and cratering also deposit-like, very different color corrosion products are deposited in the gap area on the cylinder surface. If these deposits are found in the gap area of the sealing ring on the cylinder surface, they are usually also found on the sealing ring surface and the bronze surface. In particular, smaller particles collect on the sealing lip, which are responsible for a linear corrosion in the circumferential direction of the cylinder surface. With regard to the definition of the term "crevice corrosion", reference should be made to the standard DIN EN ISO 8044-3.17.

Examples 1 to 5 and Comparative Examples A to E

Water-mixable concentrates are first prepared from the constituents indicated in the following Tables 1 to 3, which are then mixed in a ratio of 2 parts by weight concentrate with 98 parts by weight of water, to form a HFA hydraulic fluid, which is examined in the above-mentioned crevice corrosion test.

For the preparation of the water-mixable concentrates, water is initially introduced, after which potassium hydroxide is added and dissolved with stirring. Subsequently, the particular acids used, such as sebacic acid, dodecanedioic acid, undecanedioic acid or in Comparative Example E neodecanoic acid added, and it is stirred at a temperature of 50 ° C until the pH of the mixture is 7. Subsequently, sodium citrate and monoethanolamine are added and the mixture is allowed to cool with stirring to 25 ° C.

A portion of the aliphatic hydrocarbon lubricant (50%) is heated in a separate vessel and then the fatty acid alkanolamides, sodium petroleum sulfonate is added with stirring and then the remaining aliphatic hydrocarbon followed by the remaining ingredients. The mixture is then thoroughly mixed and, with stirring, the water-containing mixture obtained in the first stage is added to the aliphatic hydrocarbon-based mixture. This gives a light brown, clear, slightly viscous concentrate, which is then mixed with water to form a water-based functional fluid (HFA hydraulic fluid) containing 2 wt .-% of the concentrate and 98 wt .-% water. This HFA hydraulic fluid is introduced into the gap area of the stamp unit for the crevice corrosion test and statically stored for 21 days at a humidity of 95% and a temperature of 35 ° C. After opening the stamp unit and removing the HFA-Hydaulikflüssigkeit contained therein, the tester is examined with regard to the sludge in the bottom area of the outer tube, in the gap area and bronze piston area and deposits before cleaning in the inner tube and the outer tube and on tarnish after cleaning in the inner tube and in the outer tube and on solid deposits on the inner surface of the cylinder and in the gap region of the cylinder and on the surface of the bronze piston examined.

As indicated in Tables 1 to 3 below, the HFA hydraulic fluids of the present invention do not give rise to any corrosion effects, while the products of Comparative Examples A to E do not pass the corrosion test according to DSK Standard N 762 830, since both deposits are present the cleaning on the cylinder notice, as well as solid deposits in the gap region of the cylinder and a line-shaped corrosion in the circumferential direction in the gap region of the cylinder. Table 1 example 1 Comparison A Example 2 Comparison B ingredients Wt .-% Wt .-% Wt .-% Wt .-% water 28.0 31.6 28.0 32.0 Totuyltriazol / benzotriazole 0.5 0.5 0.5 0.5 Fettalkoholpolyglykolether 3.6 3.6 3.6 3.6 Oleoylsarkosid 1.8 1.8 1.8 1.8 hexahydrotriazine 1.2 1.2 1.2 1.2 aliphatic. Hydrocarbon boiling range <200 ° C (BNS 4) 42.8 42.8 42.8 42.8 Synthetic sodium petrol sulfonate 1.8 1.8 1.8 1.8 potassium hydroxide 1.3 1.3 1.3 sodium citrate 0.9 0.9 0.9 0.9 Triethanolamine pure Oleyl ether carboxylic acid 5 EO 1.8 1.8 1.8 1.8 5-, 6-carboxy-4-hexyl-2-cyclohexene-1-octanoic acid Polysiloxane defoamers 0.25 0.25 0.25 0.25 Monoethanolamine 2.6 2.6 2.6 2.6 tall oil fatty acid 2-ethylhexyl phosphoric acid 3 Iodine 2Propinylbutylcarbamat 0.35 0.35 0.35 0.35 Bis (3-aminopropyl) dodecyl-amine 0.5 0.5 0.5 0.5 Kokosfettsäurealkanolamid 3.0 3.0 Tallölfettsäurealkanolamid 6.3 6.3 3.3 3.3 n-butanol 0.9 0.9 0.9 benzyl alcohol 2.7 2.7 2.7 diglycol sebacic dodecanedioic 1.35 1.35 1.35 undecanoic 1.35 1.35 1.35 Neodecanoic acid (C ₁₀ monocarboxylic acid) total 100.00 100.00 100.00 100.00 pH after dilution 9.3 8.8 9.2 9.4 Crevice corrosion test according to DSK N 762 830 no corrosion Deposits in the cylinder, solid deposits, line corrosion no corrosion Deposits in the cylinder, solid deposits, line corrosion Table 2 Example 3 Comparison C Example 4 Comparison D ingredients Wt .-% Wt .-% Wt .-% Wt .-% water 25.7 30.1 59.0 62.5 Tolyltriazole / benzotriazole 0.2 0.2 0.2 0.2 Fettalkoholpolyglykolether 3.6 3.6 3.0 3.0 Oleoylsarkosid 1.8 1.8 1.0 1.0 hexahydrotriazine 0.5 0.5 1.0 1.0 aliphatic. Hydrocarbon boiling range <200 ° C (BNS 4) 42.8 42.8 13.0 13.0 Synthetic Sodium Petroleum Sulphate 1.8 1.8 1.0 1.0 potassium hydroxide 1.0 1.0 1.0 1.0 sodium citrate 0.9 0.9 1.0 1.0 Triethanolamine pure Oleyl ether carboxylic acid 5 EO 1.8 1.8 2.0 2.0 5-, 6-carboxy-4-hexyl-2-cyclohexene-1-octanoic acid 0.75 0.75 Polysiloxane defoamers 0.25 0.25 0.5 0.5 Monoethanolamine 4.3 4.3 3.8 3.8 Tallöliettsäure 0.8 0.8 2-ethylhexyl phosphoric acid 2.0 2.0 3.0 3.0 3 Iodine 2Propinylbutylcarbamat Bis (3-aminopropyl) -dodecyl-amine 0.5 0.5 Koltosfettsäurealkanolamid 5.0 5.0 5.0 5.0 Tallölfeftsäurealkanolamid n-butanol 0.9 1.0 benzyl alcohol 2.5 2.5 diglycol 1.0 sebacic 1.0 1.0 dodecanedioic 1.0 1.0 undecanoic 1.0 1.0 1.0 1.0 Neodecanoic acid (C ₁₀ monocarboxylic acid) total 100.00 100.00 100.0 100.0 pH after dilution 9.40 9.40 9.2 8.6 Crevice corrosion test according to DSK N 762 830 no corrosion Deposits in the cylinder, solid deposits, line corrosion no corrosion Deposits in the cylinder, solid deposits, line corrosion Table 3 Example 5 Comparison E ingredients Wt .-% Wt .-% water 61.5 61.5 Tolyltriazole / benzotriazole 0.2 0.2 Fettalkoholpolyglykolether 3.0 3.0 Oleoylsarkosid 1.0 1.0 hexahydrotriazine 1.0 1.0 aliphatic. Hydrocarbon boiling range <200 ° C (BNS 4) 13.0 13.0 Synthetic sodium petrol sulfonate 1.0 1.0 potassium hydroxide 1.0 1.0 sodium citrate 1.0 1.0 Triethanolamine pure 2.0 2.0 Oleyl ether carboxylic acid 5 EO 2.0 2.0 5-, 6-carboxy-4-hexyl-2-cyclohexene-1-octanoic acid Polysiloxane defoamers 0.5 0.5 Monoethanolamine 0.3 0.3 tall oil fatty acid 2-ethylhexyl phosphoric acid 3 Iodine 2Propinylbutylcarbamat Bis (3-aminopropyl) dodecylamine kokosfettsäurealkanolamid 5.0 5.0 Tallölfettsänrealkanolamid n-butanol 1.0 1.0 benzyl alcohol 1.5 1.5 diglycol 3.0 3.0 sebacic dodecanedioic 1.0 undecanoic 1.0 Neodecanoic acid (C ₁₀ monocarboxylic acid) 2.0 total 100.00 100.00 pH after dilution 8.9 9.0 Crevice corrosion test according to DSK N 762 830 no corrosion Deposits in the cylinder, solid deposits, line corrosion

In particular, Comparative Example E reveals that a water-based hydraulic fluid containing neodecanoic acid, ie a C ₁₀ monocarboxylic acid, develops considerable corrosive effects and consequently unsuitable for use as HFA hydraulic fluid, while the anticorrosion agent according to the invention and the HFA hydraulic fluid containing it , which differs from the product of the prior art by the inventive selection of the particular aliphatic dicarboxylic acids, shows no corrosion effect and is readily suitable for use in, for example, hydraulic longwall mining systems.

This result of the abrupt improvement of the corrosion protection effect by the combination according to the invention of the defined fatty acid alkanolamide, the defined alcohol and the defined aromatic monocarboxylic acid or the defined aliphatic dicarboxylic acids, has been surprising and was not to be expected in any way.

Claims (27)

1. Corrosion protectant for functional fluids, comprising 5 to 80 weight % of at least one fatty acid alkanolamide based on saturated or unsaturated fatty acids with 10 to 20 carbon atoms, 5 to 80 weight % of at least one alcohol with 2 to 14 carbon atoms selected from the group comprising isopropanol, n-butanol, butyl diglycol, hexylene glycol, butyl triglycol, benzyl alcohol, and phenoxyethanol, and 5 to 80 weight % of at least one aromatic monocarboxylic acid or an aliphatic dicarboxylic acid with 10 to 12 carbon atoms selected from the group comprising sebacic acid, undecanedioic acid, dodecanedioic acid, and p-tert-butylbenzoic acid, where the sum of these components is 100 weight % and the weight % is relative to the weight of the corrosion protectant.
2. Corrosion protectant as in claim 1, characterized in that it contains 25 to 60 weight % of at least one fatty acid alkanolamide, 15 to 25 weight % of at least one alcohol, and 20 to 50 weight % of at least one aromatic monocarboxylic acid or aliphatic dicarboxylic acid, and the sum of these components is 100 weight %.
3. Corrosion protectant as in claim 1 or 2, characterized in that it contains fatty acid alkanolamides based on saturated or unsaturated fatty acids with 12 to 18 carbon atoms and alkanolamines with 2 to 6 carbon atoms.
4. Corrosion protectant as in claim 3, characterized in that it contains fatty acid alkanolamides based on saturated or unsaturated fatty acids with 12 to 18 carbon atoms and monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, monoisopropanolamine, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1,3-propandiol and/or diglycolamine.
5. Corrosion protectant as in claim 4, characterized in that it contains coco fatty acid monoalkanolamide and/or tall oil fatty acid monoalkanolamide as the fatty acid alkanolamide.
6. Corrosion protectant as in claim 5, characterized in that it contains a reaction product of coco fatty acid, coconut oil, tall oil fatty acid, and/or tall oil and diglycolamine as the fatty acid alkanolamide.
7. Corrosion protectant as in claim 5, characterized in that it contains coco fatty acid monoethanolamide, coco fatty acid monopropanolamide, tall oil fatty acid monoethanolamide and/or tall oil fatty acid monopropanolamide as the fatty acid alkanolamide.
8. Water-soluble concentrate for aqueous functional fluids containing animal, vegetable, mineral, and/or synthetic oils, fats, oil or fat components as a lubricant, fatty alcohols, biocides, fungicides, complexing agents, heavy metal inhibitors, nonionic or anionic emulsifiers, dispergents, anti-foaming agents, corrosion protectant, and water, and typical additives as a remainder, characterized in that it contains as a corrosion protectant 2 to 20 weight %, preferably 5 to 15 weight %, of the corrosion protectant as in one of the claims 1 through 7, and the weight % is relative to the weight of the concentrate.
9. Concentrate as in claim 8, characterized in that it contains 1 to 12 weight % of at least one fatty acid alkanolamide based on saturated or unsaturated fatty acids with 10 to 20 carbon atoms, 1 to 8 weight % of at least one alcohol with 2 to 14 carbon atoms, and 1 to 8 weight % of at least one aromatic monocarboxylic acid or aliphatic dicarboxylic acid with 10 to 12 carbon atoms.
10. Concentrate as in claim 9, characterized in that it contains 2 to 8 weight % of at least one fatty acid alkanolamide, 1.5 to 5 weight % of at least one alcohol, and 1 to 5 weight % of at least one aromatic monocarboxylic acid or aliphatic dicarboxylic acid.
11. Concentrate as in at least one of the claims 8 through 10, characterized in that it contains fatty acid alkanolamides based on saturated or unsaturated fatty acids with 12 to 18 carbon atoms and alkanolamines with 2 to 6 carbon atoms.
12. Concentrate as in claim 11, characterized in that it contains fatty acid alkanolamides based on saturated or unsaturated fatty acids with 12 to 18 carbon atoms and monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, monoisopropanolamine, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1,3-propandiol and/or diglycolamine.
13. Concentrate as in claim 11, characterized in that it contains coco fatty acid monoalkanolamide and/or tall oil fatty acid monoalkanolamide as the fatty acid alkanolamide.
14. Concentrate as in claim 13, characterized in that it contains a reaction product of coco fatty acid, coconut oil, tall oil fatty acid, and/or tall oil and diglycolamine as the fatty acid alkanolamide.
15. Concentrate as in claim 13, characterized in that it contains coco fatty acid monoethanolamide, coco fatty acid monopropanolamide, tall oil fatty acid monoethanolamide and/or tall oil fatty acid monopropanolamide as the fatty acid alkanolamide.
16. Concentrate as in at least one of the claims 8 to 15, characterized in that it contains 0.5 to 3 weight % of a biocidal compound that is selected from biocidal quaternary ammonium compounds, guanidine derivates, O- or N-formals, O- or N-acetals, isothiazolines, isothiazolinones, aliphatic amines or diamines, 3-iodine-2-propinyl-butyl carbamate, bis(3-aminopropyl)-dodecylamine and mixtures thereof.
17. Concentrate as in at least one of the claims 8 to 16, characterized in that it contains 0.5 to 3 weight % of a fungicidal pyridine derivate, preferably pyrithion or a pyrithion derivate such as 2-pyridinthiol-1-oxide sodium salt as a fungicide or bactericide.
18. Concentrate as in at least one of the claims 8 to 17, characterized in that it contains 0.5 to 5 weight % of ethylenediaminetetraacetic acid or its alkali or ammonium salts, sodium citrate, sodium gluconate, N,N'-disalicylidene, and/or derivates of them as a complexing agent.
19. Concentrate as in at least one of the claims 8 to 18, characterized in that it contains 1 to 8 weight %, preferably 2 to 5 weight % of an additional corrosion protectant selected from phosphoric acid esters, such as ethylhexylphosphoric acid, phosphonic acid derivatives, diamine oxethylate, triamine oxethylate, alkylimidazolines, polyaminenaphthalenic acid amides, synthetic or natural sulfonates, such as petroleum sulfonates, p-tert-butyl benzoic acid, tricarboxylic acids, neodecanoic acids, 5 or 6-carboxy-4-hexyl-2-hexene-1-octane acid, saturated or unsaturated fatty acids, ethoxylated or propoxylated fatty acids and fatty acid alkanolamides, thiadiazole compounds, and mixtures of these.
20. Concentrate as in at least one of the claims 8 to 19, characterized in that it contains 3 to 25 weight % of a reaction product from boric acid and primary or tertiary alkanolamines as an additional corrosion protectant.
21. Concentrate as in at least one of the claims 8 to 20, characterized in that it contains 0.05 to 1.5 weight % benzotriazole and/or toluyltriazole and/or derivatives thereof as a heavy metal inhibitor.
22. Concentrate as in at least one of the claims 8 to 21, characterized in that it contains 3 to 70 weight % of a natural or synthetic mineral oil; 2 to 40 weight % of an ester oil; 1 to 6 weight % of a phospated and/or ethyloxylated alcohol and/or 2 to 35 weight % of a polyalkylene glycol and/or polyvinylpyrrolidone as an animal, vegetable, mineral, and/or synthetic lubricant, with the requirement that this lubricant makes up 10 to 70 weight % of the concentrate.
23. Concentrate as in at least one of the claims 8 to 22, characterized in that it contains 0.05 to 1 weight % of a siloxane compound as a defoamer.
24. Concentrate as in at least one of the claims 8 to 23, characterized in that it contains 1 to 5 weight % oleoylsarcoside and/or ethoxylated oleylethercarboxylic acid as an emulsifier.
25. Concentrate as in at least one of the claims 8 to 24, characterized in that it contains 0.2 to 5 weight % of an acrylic polymer salt as a dispersant, in particular a salt of a poly(meth)acrylic acid.
26. Concentrate as in at least one of the claims 8 to 25, characterized in that it has a pH value of 8.4 to 9.8, preferably 9.0 to 9.5, after diluting with water to a concentration of 1 to 20 weight % relative to the functional fluid obtained.
27. Use of the water-soluble concentrate as in at least one of the claims 8 through 26 for the manufacture of a lubricant, an abrasive, a hydraulic fluid, and a coolant/lubricant on an aqueous basis for metal forming and metal cutting, by mixing from 1 to 20 weight % with 99 to 80 weight % of water.