Heat transfer fluids with low conductivity comprising hydroxylamine or oxime functional groups, methods for their preparation and their use

Abstract

The present invention relates to a composition having low conductivity comprising a hydroxylamine-containing molecule in combination with a yellow metal corrosion inhibitor, such as a triazole, where the weight ratio of the yellow metal corrosion inhibitor to the hydroxylamine-containing molecule is from 1: 20 to 20: 1; and wherein the composition has an electrical conductivity at 25 DEG C of less than 200 [mu] S / cm. These compositions can be effective to provide ferruginous metal corrosion inhibition and maintain low conductivity in low conductivity heat transfer fluids that do not significantly change with aging. They are therefore particularly useful as heat transfer fluids, for example in fuel cell units or battery electric vehicles. The invention further relates to a method for preparing said composition and to the use of said composition.

Description

Technical Field

[0001] The present invention relates to compositions having low electrical conductivity, which compositions comprise a combination of hydroxylamine-containing molecules and yellow metal corrosion inhibitors such as triazoles, and are particularly useful as heat transfer fluids, for example in fuel cell units or battery electric vehicles. The present invention further relates to a method for preparing said compositions and to uses employing said compositions. Background Art

[0002] Heat transfer fluids are widely used in heat exchange systems associated with internal combustion engines, solar systems, fuel cell units, electric motors, generators, electronic devices, etc.

[0003] Historically, water has been the preferred base fluid considering heat transfer characteristics. In many applications, antifreeze characteristics are required, and in such cases, base fluids consisting of water mixed with freezing point depressants such as alcohols, diols or salts are employed. Additives present in the heat transfer fluid can be used to obtain various functions such as (further) lowering the freezing point, improving heat exchange characteristics, inhibiting corrosion, etc. Since heat transfer fluids are in continuous contact with metal components (aluminum alloys, cast iron, steel, copper, brass, solder, etc.), they almost always contain one or more corrosion inhibitors.

[0004] A fuel cell unit is an electrochemical cell unit in which stored chemical energy is converted into electrical energy by the controlled oxidation of a fuel. The relatively low pollutant production compared to combustion engines makes fuel cell units an attractive alternative in applications such as automobiles and power plants. In most applications, several electrochemical cell units are stacked in series to form a so-called fuel cell unit stack, allowing for the generation of a higher voltage. The heat generated by the fuel cell unit stack can be removed by flowing a coolant through channels formed by bipolar plates.

[0005] The potential difference between the positive and negative ends of a fuel cell unit stack may cause a shunt current to flow through the coolant, thereby reducing the voltage of the fuel cell unit. In addition to the detrimental voltage loss, the shunt current also causes additional problems such as corrosion of the separator near the positive end of the fuel cell unit stack. Therefore, coolants for electrical applications such as fuel cell units need to have low electrical conductivity (i.e., high resistance) and be able to maintain this conductivity throughout the entire service life of the coolant.

[0006] Most known heat transfer fluids (e.g., coolants) are designed for internal combustion engines and are not suitable for electrical applications such as fuel cell units, batteries or power electronics because they (i) have high electrical conductivity, or (ii) become significantly more conductive especially when aging at elevated temperatures. The increase in electrical conductivity upon aging is usually attributed to the formation of ionic compounds due to the degradation of alcohols, especially diols, which are often used as base fluids, due to the degradation of additives, due to metal corrosion and / or due to impurities in the cooling circuit.

[0007] Therefore, in recent years, there has been increasing interest in developing heat transfer fluids suitable for use in electrical applications such as fuel cell units.

[0008] Among the metals and alloys found in cooling systems, iron and steel are the most reactive in the formation of acids, while light metals and alloys such as aluminum are significantly less reactive. In fact, the low-conductivity water-glycol coolants of the prior art do not provide sufficient protection against cast iron corrosion, and most known corrosion inhibitors result in high conductivity or are substantially ineffective in preventing the corrosion of ferrous metals, even when used in large amounts. This is a burden for system designers as they need to avoid the presence of any ferrous metals at all costs. There is a need for a corrosion inhibitor that is effective in inhibiting corrosion in a wide variety of metals, and particularly ferrous materials, and ideally has long-term stability and no other harmful or restrictive properties.

[0009] EP 1775339A1 describes a heat transfer fluid comprising hydroxylamine and its salts and a variety of corrosion inhibitors including phenols and triazoles.

[0010] US 4689201A describes a heat transfer fluid comprising hydroxylamine, tannins, salts of Group II metals, amines, and triazoles.

[0011] It is an object of the present invention to provide a heat transfer fluid that is capable of maintaining a low conductivity when aging in the presence of ferrous metals, such as when aging at elevated temperatures.

[0012] It is an object of the present invention to provide a heat transfer fluid that is capable of providing protection against ferrous metal corrosion in low-conductivity applications, such as in cooling electrical systems, particularly fuel cell units, batteries, or power electronics. Summary of the Invention

[0013] The inventors of the present invention have unexpectedly found that a specific combination of compounds according to formula (I) when used appropriately in the correct ratio in combination with known yellow metal corrosion inhibitors such as triazoles can effectively provide iron metal corrosion inhibition in heat transfer fluids with low conductivity. In addition, these mixtures maintain a low conductivity that does not change significantly with aging. As shown in the appended examples, no such iron metal corrosion inhibition was found when the compounds according to formula (I) or the yellow metal corrosion inhibitors such as triazoles were used alone or in ratios outside the claimed scope. Similarly, this effect was not observed with conventional amines. Without wishing to be bound by any theory, the inventors of the present invention believe that the N-OH (hydroxylamine) functional group contained in the compounds according to formula (I) is crucial for its functioning in combination with corrosion inhibitors such as triazoles. One or more objects of the present invention are achieved by the various aspects of the present invention described herein.

[0014] Accordingly, in a first aspect of the present invention, there is provided a composition comprising a base fluid, a first corrosion inhibitor, and a compound according to formula (I) wherein X is nitrogen such that the compound according to formula (I) is a hydroxylamine, or X is imine such that the compound according to formula (I) is an oxime; wherein R 1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl, or tolyl; and wherein R 2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl, or tolyl; or R 1 and R 2 are linked and together form a C2-C6 alkanediyl linked to X to form a 3- to 7-membered ring; and wherein the base fluid consists of water, an alcohol, or a mixture thereof; wherein the first corrosion inhibitor is selected from the group consisting of triazoles, thiazoles, triazines, diazoles, and combinations thereof; wherein the weight ratio of the first corrosion inhibitor to the compound according to formula (I) is from 1:20 to 20:1; and wherein the composition has a conductivity at 25 °C of less than 200 μS / cm.

[0015] In a preferred embodiment, the composition of the present invention is provided in the form of a ready-to-use composition.

[0016] In a preferred embodiment, the composition of the present invention is provided in the form of a concentrate for preparing the ready-to-use composition described herein.

[0017] In another aspect, the present invention provides a kit for preparing the ready-to-use composition described herein.

[0018] In another aspect, the present invention provides a method for preparing the composition described herein.

[0019] In another aspect, the present invention provides a method for preparing the ready-to-use composition described herein from a concentrate.

[0020] In another aspect, the present invention provides a method for preparing the ready-to-use composition described herein from a kit.

[0021] In another aspect, the present invention provides a method of exchanging heat, the method comprising: a. generating heat in: an electrical system, preferably an electrical system selected from the group consisting of: a solar system, a fuel cell unit, an electric motor, a generator, a battery, a telephone transmitting station, a power electronic device, a radio and television broadcasting station, a relay station, an electric heating or cooling device, preferably a fuel cell unit, a battery or a power electronic device; b. contacting the composition according to the present invention, preferably the ready-to-use composition, with the system of step a; c. transferring the heat from the system to the composition; d. passing the composition through a heat exchanger; and e. transferring the heat out of the composition.

[0022] In another aspect, the present invention provides the use of a compound according to formula (I) as a corrosion inhibitor for ferrous metals or cast iron, preferably as a corrosion inhibitor for ferrous metals or cast iron in a heat transfer fluid having a conductivity at 25 °C of less than 200 μS / cm, more preferably as a corrosion inhibitor for ferrous metals or cast iron in a heat transfer fluid having a conductivity at 25 °C of less than 100 μS / cm and comprising a first corrosion inhibitor selected from the group consisting of triazoles, thiazoles, triazines, diazoles and combinations thereof. Detailed Description

[0023] As used herein, the expression "comprise" and its variants, such as "comprises" and "comprising", should be interpreted in an open, inclusive sense, meaning that the described embodiments include the recited features, but do not exclude the presence of other features, provided that they do not render the embodiments infeasible.

[0024] As used herein, the phrases "one embodiment", "a specific embodiment", "an embodiment", etc. shall be construed to mean that the specific features, structures, or characteristics described in connection with that embodiment are included in at least one embodiment. Thus, the appearances of such phrases throughout this specification are not necessarily all referring to the same embodiment. Further, in one or more embodiments, the specific features, structures, or characteristics may be combined in any suitable manner. For example, certain features of the present disclosure described in the context of separate embodiments are also contemplated to be combined explicitly in a single embodiment.

[0025] Unless the context clearly dictates otherwise, the singular forms "a / an" and "the" as used herein shall be construed to include plural referents. It should also be noted that, unless the context clearly dictates otherwise, the term "or" is generally employed in its broadest sense, i.e., meaning "and / or".

[0026] As used herein, the term "alkyl" includes straight-chain, branched-chain, and cyclic alkyl groups.

[0027] As used herein, the term "tolyltriazole" refers to any methylbenzotriazole isomer. Preferably, the term refers to CAS 29385-43-1, which is a commercial mixture composed of approximately equal amounts of 4- and 5-methylbenzotriazole with minor amounts of their corresponding 7- and 6-methyl tautomers.

[0028] Reference is made to the substance, component, or ingredient that exists prior to first contact, blending, or mixing with one or more other substances, components, or ingredients in accordance with the present disclosure. The substance, component, or ingredient may acquire an identity, property, or characteristic through a chemical reaction or transformation during the process of contact, blending, or mixing (if carried out in accordance with the present disclosure using the common sense and ordinary skills of an ordinary chemist). Unless otherwise explicitly indicated, the definition of the substance, component, or ingredient and its relative amounts pertains to the composition prepared when the components are first contacted.

[0029] The conductivity as referred to herein is preferably measured in accordance with ASTM D1125 (2014) using a Radiometer Copenhagen CDC745-9 conductivity cell and a Radiometer Copenhagen temperature sensor T201 with a Radiometer Copenhagen CDM210 conductivity meter.

[0030] In a first aspect, the present invention provides a composition comprising a base liquid, a first corrosion inhibitor, and a compound according to formula (I) wherein X is nitrogen such that the compound according to formula (I) is a hydroxylamine, or X is an imine such that the compound according to formula (I) is an oxime; wherein R 1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; or R 1 and R 2 are linked and together form a C2-C6 alkanediyl linked to X to form a 3- to 7-membered ring; and wherein the base liquid consists of water, an alcohol or a mixture thereof; wherein the first corrosion inhibitor is selected from the group consisting of triazoles, thiazoles, triazines, diazoles and combinations thereof; wherein the weight ratio of the first corrosion inhibitor to the compound according to formula (I) is from 1:20 to 20:1; and wherein the composition has a conductivity at 25 °C of less than 200 μS / cm.

[0031] According to the invention, the weight ratio of the first corrosion inhibitor to the compound according to formula (I) is determined based on the total amount of the first corrosion inhibitor and the total amount of the compound according to formula (I) in the composition. Since two or more different first corrosion inhibitors can be used and two or more different compounds according to formula (I) can be used, it logically follows that in such embodiments, the weights of all the first corrosion inhibitors and all the compounds according to formula (I) should be considered to determine their relative weights.

[0032] As will be understood by those skilled in the art, when R 1 and R 2 are linked and together form a C2-C6 alkanediyl linked to X to form a 3- to 7-membered ring, if X is nitrogen, the resulting ring will be a heterocycle containing one nitrogen atom.

[0033] Preferably provided is a composition according to the invention, wherein R 1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; More preferably wherein R 1Selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 Selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; More preferably wherein R 1 Selected from C1-C6 alkyl or C5-C6 cycloalkyl; and wherein R 2 Selected from C1-C6 alkyl or C5-C6 cycloalkyl. Wherein the compound according to formula (I) is a composition of the hydroxylamine according to formula (Ia)

[0034] In a preferred embodiment of the present invention, there is provided a composition as described herein, wherein X in the compound according to formula (I) is nitrogen, such that the compound according to formula (I) is the hydroxylamine according to formula (Ia): wherein R 1 Selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 Selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; or R 1 and R 2 are linked and together form a C2-C6 alkanediyl linked to the nitrogen of formula (Ia) to form a 3- to 7-membered ring.

[0035] Preferred embodiments of the present invention wherein X in the compound according to formula (I) is nitrogen, such that the compound according to formula (I) is the hydroxylamine according to formula (Ia), are those wherein R 1 Selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 Selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; More preferably wherein R 1 Selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 Selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; More preferably, wherein R 1 is selected from C1-C6 alkyl or C5-C6 cycloalkyl; and wherein R 2 is selected from C1-C6 alkyl or C5-C6 cycloalkyl.

[0036] Highly preferred embodiments of the present invention in which X in the compound according to formula (I) is nitrogen such that the compound according to formula (I) is a hydroxylamine according to formula (Ia) are those in which R 1 is selected from C1-C4 alkyl; and wherein R 2 is selected from C1-C4 alkyl; Preferably, wherein R 1 is selected from C1-C2 alkyl; and wherein R 2 is selected from C1-C2 alkyl.

[0037] The most preferred embodiments of the present invention in which X in the compound according to formula (I) is nitrogen such that the compound according to formula (I) is a hydroxylamine according to formula (Ia) are those in which the compound according to formula (I) is N,N-diethylhydroxylamine.

[0038] In some embodiments of the present invention in which X in the compound according to formula (I) is nitrogen such that the compound according to formula (I) is a hydroxylamine according to formula (Ia), R 1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl, and R 2 is hydrogen. In the composition wherein the compound according to formula (I) is an oxime according to formula (Ib)

[0039] In a preferred embodiment of the present invention, there is provided a composition as described herein, wherein X in the compound according to formula (I) is an imine such that the compound according to formula (I) is an oxime according to formula (Ib): wherein R 1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; or R1 and R 2 are connected and together form a C2-C6 alkanediyl that is connected to the oxime carbon of formula (Ib) to form a 3- to 7-membered ring.

[0040] The inventors of the present invention believe that the stereochemistry of the oximes according to formula (Ib) is not particularly limited, and both E and Z stereoisomers can be used in the compositions of the present invention. The wavy bond in formula (Ib) is used to indicate either E or Z stereochemistry.

[0041] Preferred embodiments of the present invention in which X in the compound according to formula (I) is an imine such that the compound according to formula (I) is an oxime according to formula (Ib) are those in which R 1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; More preferably, wherein R 1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; More preferably, wherein R 1 is selected from C1-C6 alkyl or C5-C6 cycloalkyl; and wherein R 2 is selected from C1-C6 alkyl or C5-C6 cycloalkyl.

[0042] Highly preferred embodiments of the present invention in which X in the compound according to formula (I) is an imine such that the compound according to formula (I) is an oxime according to formula (Ib) are those in which R 1 is selected from C1-C4 alkyl; and wherein R 2 is selected from C1-C4 alkyl; Preferably, wherein R 1 is selected from C1-C2 alkyl; and wherein R 2 is selected from C1-C2 alkyl.

[0043] A most preferred embodiment of the present invention in which X in the compound according to formula (I) is an imine such that the compound according to formula (I) is an oxime according to formula (Ib) is those in which the compound according to formula (I) is methyl ethyl ketoxime.

[0044] In some embodiments of the present invention in which X in the compound according to formula (I) is an imine such that the compound according to formula (I) is an oxime according to formula (Ib), R 1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl, and R 2 is hydrogen.

[0045] In some embodiments of the present invention in which X in the compound according to formula (I) is an imine such that the compound according to formula (I) is an oxime according to formula (Ib), R 1 and R 2 are linked and together form a C5-C6 alkanediyl linked to the oxime carbon of formula (Ib) to form a 6- to 7-membered ring. First corrosion inhibitor

[0046] The composition of the present invention comprises a first corrosion inhibitor selected from the group consisting of triazoles, thiazoles, triazines, diazoles and combinations thereof, preferably selected from the group consisting of triazoles, thiazoles, triazines and combinations thereof, more preferably selected from the group consisting of triazoles and thiazoles. Such corrosion inhibitors are known to those skilled in the art as "yellow" corrosion inhibitors because they are known to inhibit the corrosion of metals such as copper, brass and their alloys.

[0047] The first corrosion inhibitor may be provided in the form of a salt (especially a sodium salt, potassium salt or amine salt), provided that the maximum conductivity of the composition should be considered. Suitable amine salts include salts of amines having the formula NRR'R", where R, R' and R" are each independently selected from H, C1-C6 alkyl, C1-C6 hydroxyalkyl. Such amines are preferably tertiary amines. The first corrosion inhibitor is preferably provided in free base form.

[0048] In a preferred embodiment of the present invention, the first corrosion inhibitor is selected from 1,2,3-triazole, 1,2,4-triazole and combinations thereof.

[0049] In a preferred embodiment of the present invention, the first corrosion inhibitor is selected from 1,2,4-triazole, 4H-1,2,4-triazole, 4-amino-1,2,4-triazole, 3-amino-1,2,4-triazole, 1,2,4-triazole-3-thiol, 3-amino-1,2,4-triazole-5-thiol, 3,5-diamino-1,2,4-triazole, 1H-1,2,3-triazole, benzotriazole, 2-mercaptobenzothiazole, tolyltriazole, 2-[2-hydroxyethyl-[(4-methylbenzotriazol-1-yl)methyl]amino]ethanol, 2-[2-hydroxyethyl-[(benzotriazolyl)methyl]amino]ethanol, (2-benzothiazolylthio)acetic acid, 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]imino]bisethanol, N,N-bis(2-ethylhexyl)-methyl-1H-benzotriazol-1-methanamine, and combinations thereof, more preferably selected from benzotriazole, tolyltriazole, 2-mercaptobenzothiazole, and combinations thereof.

[0050] In some embodiments of the present invention, the first corrosion inhibitor is a thiazole selected from the following: 4,4'-(4(ethane-1,2-diylbis(oxy))bis(4-phenylene)dithiazol-2-amine, 2-(acetyl-ethoxycarbonyl-methylene)-3-phenyl-4-(phenylhydrazono)-1,3-thiazolidin-5-one, 2-amino-4-(4-chlorophenyl)-thiazole, 2-methoxy-1,3-thiazole, 4-(4-methylphenyl)-2-thiazolamine, 2-amino-4-methyl-thiazole, 2-salicylideneamino-4-phenylthiazole, 4-[1-aza-2-(phenyl)vinyl]-3-phenyl-2-thioxo(1,3-thiazolin-5-yl), 4-(4-methylphenyl)-2-thiazolamine, 2-amino-4-methyl-thiazole, 2-amino-thiazole, 2,2'-disulfidobis(benzothiazole), and combinations thereof.

[0051] In some embodiments of the present invention, the first corrosion inhibitor is a triazine selected from the following: 1,2,3-triazine, 1,2,4-triazine, 1,3,5-triazine, 6-methyl-5-[m-nitrostyryl]-3-mercapto-1,2,4-triazine, 2,4,6-tris(2-pyridyl)-1,3,5-triazine, and combinations thereof.

[0052] In other embodiments of the present invention, the first corrosion inhibitor is not selected from N,N',N"-tris-(2-hydroxypropyl) hexahydrotriazine, N,N′,N″-tris(2-hydroxyethyl) hexahydrotriazine, 2,2′,2″-(hexahydro-1,3,5-triazine-1,3,5-triyl)-triethanol or α,α′,α″-trimethyl-1,3,5-triazine-1,3,5-(2H,4H,6H) triethanol. Preferably, the first corrosion inhibitor is not selected from hexahydrotriazine. In other embodiments of the present invention, the first corrosion inhibitor is not selected from triazine. In highly preferred embodiments of the present invention, the composition of the present invention is substantially free of N,N',N"-tris-(2-hydroxypropyl) hexahydrotriazine, N,N',N"-tris(2-hydroxyethyl) hexahydrotriazine, 2,2′,2″-(hexahydro-1,3,5-triazine-1,3,5-triyl)-triethanol and α,α′,α″-trimethyl-1,3,5-triazine-1,3,5-(2H,4H,6H) triethanol. More preferably, the composition of the present invention is substantially free of triazine.

[0053] In some embodiments of the present invention, the first corrosion inhibitor is a diazole selected from the following: pyrazole, 4-nitropyrazole, 4-sulfonylpyrazole.

[0054] In a preferred embodiment of the present invention, the first corrosion inhibitor is selected from compounds according to general formulas (IIa), (IIb) and / or (IIc): wherein R 1 represents one, two or three substituents on the six-membered ring, each substituent independently selected from C1-C 11 alkyl, amine, methoxy, ethoxy, Cl or Br; wherein X is selected from nitrogen or a C-H group; and wherein R 2 is selected from hydrogen, mercapto (-SH) or C1-C 11 alkyl, preferably methyl or ethyl; Preferably wherein R 1 represents one, two or three substituents on the six-membered ring, each substituent independently selected from C1-C6 alkyl, amine, methoxy, ethoxy, Cl or Br; wherein X is selected from nitrogen or a C-H group; and wherein R 2 is selected from hydrogen, mercapto (-SH) or C1-C6 alkyl, preferably methyl or ethyl. The relative amounts of the compound having formula (I) and the first corrosion inhibitor

[0055] As previously explained herein, and as shown in the appended examples, the inventors of the present invention have found that when used in accordance with the present invention, i.e., when employing the relative amounts described herein, the compounds according to formula (I) and the first corrosion inhibitor exhibit a beneficial and unexpected synergistic behavior in the form of iron-based metal corrosion inhibition (without significant conductivity generation upon aging).

[0056] According to a preferred embodiment of the present invention, the weight ratio of the first corrosion inhibitor to the compound according to formula (I) is from 1:20 to 10:1, preferably from 1:10 to 10:1, more preferably from 1:5 to 5:1, and most preferably from 1:3.33 to 2.5:1. Base liquid

[0057] According to the present invention, the base liquid consists of water or an alcohol or a mixture thereof. As will be understood by those skilled in the art, the alcohol of the base liquid is different from the compound according to formula (I). Preferably, the alcohol is a compound composed only of C, H, and O atoms.

[0058] In a preferred embodiment of the present invention, the alcohol is selected from the group consisting of: monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, monopropylene glycol, 1,3 - propanediol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, methanol, ethanol, propanol, butanol, tetrahydrofurfuryl alcohol, ethoxylated furfuryl alcohol, dimethyl ether of glycerol, sorbitol, 1,2,6 - hexanetriol, trimethylolpropane, methoxyethanol, glycerol, and mixtures thereof, preferably selected from the group consisting of: monoethylene glycol, monopropylene glycol, 1,3 - propanediol, glycerol, and mixtures thereof.

[0059] In a preferred embodiment of the present invention, the base liquid consists of 30 - 70 wt.% (by weight of the base liquid) of water and 30 - 70 wt.% (by weight of the base liquid) of an alcohol. The total amount of water and alcohol is always 100 wt.% (by weight of the base liquid).

[0060] As used herein, "monoethylene glycol" shall be construed to mean "ethane - 1,2 - diol" and may be interchangeably referred to as "MEG".

[0061] As used herein, "monopropylene glycol" shall be construed to mean "propane - 1,2 - diol" and may be interchangeably referred to as "MPG".

[0062] As used herein, the term "glycerol" means "propane - 1,2,3 - triol" and is synonymous with glycerin.

[0063] In a preferred embodiment of the present invention, the base fluid consists of the following: water, monoethylene glycol, monopropylene glycol, 1,3 - propanediol, glycerol, or mixtures thereof. As will be explained elsewhere herein, ready - to - use heat transfer fluids typically contain mixtures of water and alcohols as described herein. However, in some embodiments, particularly in cases where concentrates are provided, only water or only alcohol may be used.

[0064] In a preferred embodiment of the present invention, the base fluid consists of water and an alcohol, where the alcohol is present in an amount of 10 - 99.5 wt.% (based on the weight of the base fluid), preferably 10 - 80 wt.%, more preferably 30 - 70 wt.%. In a specific embodiment, the alcohol is present in an amount within the range of 33 - 60 wt.% (based on the weight of the base fluid). In a preferred embodiment of the present invention, the base fluid consists of 30 - 70 wt.% (based on the weight of the base fluid) of water and 30 - 70 wt.% (based on the total weight of the base fluid) of an alcohol selected from the group consisting of monoethylene glycol, diethylene glycol, monopropylene glycol, 1,3 - propanediol, glycerol, and mixtures thereof.

[0065] In an embodiment of the present invention, the base fluid contains more than 50 wt.%, preferably more than 70 wt.%, more preferably more than 85 wt.% of water (based on the weight of the base fluid).

[0066] In an embodiment of the present invention, the base fluid contains more than 50 wt.% of monoethylene glycol (based on the weight of the base fluid), preferably more than 70 wt.%, more preferably more than 85 wt.%, most preferably more than 95 wt.% of monoethylene glycol.

[0067] In an embodiment of the present invention, the base fluid contains more than 50 wt.% of monopropylene glycol (based on the weight of the base fluid), preferably more than 70 wt.%, more preferably more than 85 wt.%, most preferably more than 95 wt.% of monopropylene glycol.

[0068] In an embodiment of the present invention, the base fluid contains more than 50 wt.% of 1,3 - propanediol (based on the weight of the base fluid), preferably more than 70 wt.%, more preferably more than 85 wt.%, most preferably more than 95 wt.% of 1,3 - propanediol.

[0069] In an embodiment of the present invention, the base fluid contains more than 50 wt.% of glycerol (based on the weight of the base fluid), preferably more than 70 wt.%, more preferably more than 85 wt.%, most preferably more than 95 wt.% of glycerol.

[0070] In a preferred embodiment of the present invention, there is provided a composition as described herein, wherein the composition contains more than 78 wt.% (based on the total weight of the composition) of the base fluid, more preferably more than 85 wt.%, even more preferably more than 90 wt.%, still more preferably more than 95 wt.% or more than 98 wt.% of the base fluid.

[0071] As will be understood by those skilled in the art, the base liquid is typically added to the composition in an 'adequate amount'. In embodiments of the present invention, the composition comprises less than 99.9 wt.% of the base liquid (based on the total weight of the composition), such as less than 99.8 wt.%, less than 99.5 wt.% or less than 99 wt.%, less than 98 wt.%, less than 97 wt.%, less than 96 wt.%, less than 95 wt.%, less than 94 wt.%, less than 93 wt.%, less than 92 wt.%, less than 91 wt.%, less than 90 wt.%, less than 89 wt.%, less than 88 wt.%, less than 87 wt.%, less than 86 wt.%, less than 85 wt.%, less than 84 wt.%, less than 83 wt.%, less than 82 wt.%, or less than 81 wt.% of the base liquid.

[0072] In a preferred embodiment of the present invention, there is provided a composition as described herein, wherein the composition comprises less than 99.9 wt.%, or less than 99.5 wt.%, or less than 99 wt.% of the base liquid (based on the total weight of the composition). pH

[0073] In a preferred embodiment of the present invention, there is provided a composition as defined herein, wherein the composition has a pH in the range of 5 - 9, preferably in the range of 6 - 8.5, more preferably in the range of 6 - 8. Enhancing additive

[0074] The inventors of the present invention have found that when used as a heat transfer fluid, particularly when considering corrosion inhibition (such as iron metal corrosion inhibition) and the ability to maintain low conductivity during aging in the presence of metals at elevated temperatures, or when allowing a reduction in the amount of the compound according to formula (I) used while maintaining the same performance, the inclusion of certain additional additives in the compositions of the present invention can particularly improve one or more properties of the composition. Such particularly preferred additives (referred to herein as 'enhancing additives') include nonionic polymers, amines, phenols, dioxo - aromatic compounds, and nonionic surfactants.

[0075] In a preferred embodiment of the present invention, the composition described herein further comprises a nonionic polymer selected from the group consisting of: polyvinylpyrrolidone, polyvinyl alcohol, polyalkylene oxide, polysiloxane, C1 - C 18 alkyl or alkenyl ethers of polyalkylene oxide, C1 - C 18 alkyl or alkenyl esters of polyalkylene oxide, alkoxylated C1 - C 18Alkyl or alkenyl amines, polyvinyl acetate, its copolymers and combinations thereof, preferably nonionic polymers selected from polyvinylpyrrolidone. The nonionic polymer preferably has a weight average molecular weight M in the range of 100 to 5,000,000 g / mol, preferably 500 to 2,500,000 g / mol w . The polyalkylene oxide is preferably selected from polyethylene oxide, polypropylene oxide, polybutylene oxide and copolymers thereof. The polyvinylpyrrolidone can be selected from polyvinylpyrrolidone homopolymers and polyvinylpyrrolidone copolymers, preferably polyvinylpyrrolidone homopolymers. Examples of suitable polyvinylpyrrolidone copolymers include polymers of a combination of N-vinylpyrrolidone with at least one other monomer selected from: styrene, vinyl acetate, ethylene, propylene, tetrafluoroethylene, methyl methacrylate, vinyl chloride and ethylene oxide. In such embodiments, the percentage of N-vinylpyrrolidone monomers is at least 10%, more preferably at least 25%, such as at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% based on the total number of monomers in the polyvinylpyrrolidone copolymer. Preferred polyvinylpyrrolidone copolymers that can be applied in the compositions according to the invention include copolymers of N-vinylpyrrolidone and vinyl acetate, wherein the percentage of N-vinylpyrrolidone monomers is at least 25% based on the total number of monomers in the polyvinylpyrrolidone copolymer; the hydrolyzed form of the copolymer of N-vinylpyrrolidone and vinyl acetate, wherein the percentage of N-vinylpyrrolidone monomers is at least 10% based on the total number of monomers in the polyvinylpyrrolidone copolymer; and copolymers of N-vinylpyrrolidone and N-vinylcaprolactam, wherein the percentage of N-vinylpyrrolidone monomers is at least 40% based on the total number of monomers in the polyvinylpyrrolidone copolymer. The polyvinylpyrrolidone, preferably the polyvinylpyrrolidone homopolymer, preferably has a weight average molecular weight M in the range of 100 to 5,000,000 g / mol, preferably 500 to 2,500,000 g / mol w . As will be understood by those skilled in the art, the weight average molecule is the weight fraction of the molecules in a polymer sample and provides an average of the molecular masses of the individual macromolecules in the polymer sample. The weight average molecular weight as defined herein is determined using the following equation: Those skilled in the art are aware of different techniques for determining the weight-average molecular weight of polymers with different chain lengths. The weight-average molecular weight and the corresponding measurement method are typically indicated on the product data sheet of the polymer under consideration. In a specific embodiment of the present invention, polyvinylpyrrolidone, preferably polyvinylpyrrolidone homopolymer, has a weight-average molecular weight in the range of from 3,000 to 2,500,000 g / mol, preferably in the range of from 5,000 to 2,250,000 g / mol, more preferably in the range of from 7,500 to 2,000,000 g / mol, and even more preferably in the range of from 8,000 to 1,800,000 g / mol. Polyvinylpyrrolidone that can be suitably used as an additive can be purchased from commercial suppliers such as BASF, Sigma-Aldrich, or Nippon Shokubai. Examples of commercially available polyvinylpyrrolidone are Luvitec K17 (M W = 9,000 g / mol), Luvitec K30 (M W = 50,000 g / mol), Luvitec K90 (M W = 1,400,000 g / mol), and PVP K30. In an embodiment of the present invention, there is provided a composition as defined herein, wherein the composition comprises a non-ionic polymer as an additional additive in an amount of more than 0.001 wt.% (based on the total weight of the composition), preferably more than 0.005 wt.%, preferably more than 0.01 wt.% and / or less than 10 wt.%, preferably less than 5 wt.%, preferably less than 3 wt.%.

[0076] In a preferred embodiment of the present invention, the composition described herein further comprises an amine, wherein the amine does not contain an N-hydroxyamine (N-OH) functional group. The amine is preferably selected from molecules composed of atoms C, N, H and optionally O, containing 1 to 10 C atoms, containing one or more amine functional groups and optionally containing one or more hydroxyl or ether functional groups, wherein the amine does not contain an N-hydroxyamine (N-OH) functional group, and preferably wherein the amine does not contain other functional groups except one or more amine functional groups and optionally one or more hydroxyl or ether functional groups. In a preferred embodiment, the amine is selected from the group consisting of: methylamine, dimethylamine, trimethylamine, ethylamine, isopropylamine, tributylamine, triethylamine, 2-dimethylaminoethanol, 2-diethylaminoethanol, monoethanolamine, 2-amino-2-methyl-1-propanol, ethoxylated octylamine, diisopropylamine, 2-dibutylaminoethanol, 2-dipropylaminoethanol, triethanolamine, tris(isopropanol)amine, ethylenediamine, piperadine, morpholine, pyrrolidine, piperazine, diisopropyl-methylamine, 1,4-diazabicyclo[2.2.2]octane, quinuclidine, ethanolamine, diethanolamine, benzylamine, cyclohexylamine, hexylamine, dicyclohexylamine, isobutanolamine, dihydroxyethylamine, 3-methoxypropylamine, p,p-dioctylaniline, monooctyldiphenylamine, phenyl-1-naphthylamine, phenyl-2-naphthylamine, alkylphenyl-1-naphthylmethylamine, alkyl-phenyl-2-naphthylmethyl-amine, alkoxylated C1-C 22 hydrocarbylamines (especially ethoxylated octylamine such as 2-EO-octylamine) and combinations thereof. In an embodiment of the present invention, there is provided a composition as defined herein, wherein the composition comprises an amine as an additional additive in an amount of more than 0.001 wt.% (based on the total weight of the composition), preferably more than 0.005 wt.%, preferably more than 0.01 wt.% and / or less than 10 wt.%, preferably less than 5 wt.%, preferably less than 3 wt.%.

[0077] In an embodiment of the present invention, the composition described herein further comprises an aromatic alcohol selected from phenol, pyrogallol, gallic acid, gallic acid esters and combinations thereof. The phenol is preferably selected from phenols optionally having 0, 1, 2 or 3 substituents independently selected from amino, C1-C6 alkyl. Examples of suitable and preferred phenols include 2-aminophenol, 4-aminophenol, 2-amino-4-methylphenol, 2,6-ditert-butylmethylphenol, 4,4'-methylenebis(2,6-di-tert-butylphenol) and 4-amino-3-methylphenol. Examples of suitable and preferred gallic acid esters include C1-C of gallic acid esters 12Alkyl esters. In embodiments of the present invention, there are provided compositions as defined herein, wherein the composition comprises an aromatic alcohol as an additional additive in an amount of more than 0.001 wt.% (based on the total weight of the composition), preferably more than 0.005 wt.%, preferably more than 0.01 wt.% and / or less than 10 wt.%, preferably less than 5 wt.%, preferably less than 3 wt.%.

[0078] In embodiments of the present invention, the compositions described herein further comprise a dioxo-aromatic compound selected from benzoquinone, naphthoquinone, hydroquinone and catechol. The dioxo-aromatic compound is preferably selected from 1,4-benzoquinone, 1,2-benzoquinone, 1,2-naphthoquinone, 1,4-naphthoquinone, 1,4-dihydroxybenzene and 1,2-dihydroxybenzene optionally having 0, 1 or 2 substituents independently selected from amino, C1-C6 alkyl, sulfonic acid. In embodiments of the present invention, there are provided compositions as defined herein, wherein the composition comprises a dioxo-aromatic compound as an additional additive in an amount of more than 0.001 wt.% (based on the total weight of the composition), preferably more than 0.005 wt.%, preferably more than 0.01 wt.% and / or less than 10 wt.%, preferably less than 5 wt.%, preferably less than 3 wt.%.

[0079] In embodiments of the present invention, the compositions described herein further comprise a secondary antioxidant selected from thiols, thioethers and thioesters, such as those selected from: methyl mercaptan, ethyl mercaptan, n-propyl mercaptan, 2-propenyl mercaptan, butane mercaptan, tert-butyl mercaptan, benzenethiol, thioacetic acid, dimercaptosuccinic acid, glutathione, cysteine, methyl thionobenzoate, dimethyl sulfide, methyl phenyl sulfide, 4-ethylthio-2-methylpent-2-ene, dimethyl sulfide, diethyl sulfide, diphenyl sulfide, phenyl 4-piperidyl sulfide and thiodiglycol.

[0080] In embodiments of the present invention, the compositions described herein further comprise a nonionic surfactant. The nonionic surfactant is preferably selected from the group consisting of: · Fatty acid esters, such as sorbitan fatty acid esters; · Polyalkylene glycols; · Polyalkylene glycol esters; · Copolymers and block copolymers of ethylene oxide and propylene oxide; · Polyoxyalkylene derivatives of sorbitan fatty acid esters; and · Alkoxylated alcohol ethers.

[0081] In an embodiment of the present invention, there is provided a composition as defined herein, wherein the composition comprises a nonionic surfactant as an additional additive in an amount of more than 0.001 wt.% (based on the total weight of the composition), preferably more than 0.005 wt.%, preferably more than 0.01 wt.% and / or less than 10 wt.%, preferably less than 5 wt.%, preferably less than 3 wt.%. Additional additive

[0082] As will be understood by those skilled in the art, based on the teachings presented herein, the compositions according to the present invention may comprise one or more additional additives other than the enhancing additives described above, as is conventional in the art. Determining how much of a particular additive can be added such that the conductivity of the resulting composition complies with the present invention is within the routine capabilities of a person of ordinary skill in the art. As will be understood by those skilled in the art, nonionic additional additives are preferred. The coolant composition comprises a base fluid in a defined amount, a compound according to formula (I), a first corrosion inhibitor, and optional enhancing additives selected from nonionic polymers, amines, phenols, dioxo-aromatic compounds, and nonionic surfactants as previously described herein. Thus, the one or more additional additives are different from the base fluid, the compound according to formula (I), the first corrosion inhibitor, and the optional enhancing additives selected from nonionic polymers, amines, phenols, dioxo-aromatic compounds, and nonionic surfactants as described herein.

[0083] Examples of such additional additives include, but are not limited to, surfactants (such as dispersants, detergents), chelating agents, dyes, biocides, liquid dielectrics, antioxidants, antiwear agents, pH regulators, wetting agents, bittering agents, and antifoaming agents. In a preferred embodiment, the composition of the present invention further comprises one or more additional additives in an amount in the range of 0.001 - 10 wt.% (based on the total weight of the composition), preferably 0.01 - 5 wt.%.

[0084] As will be understood by those skilled in the art, based on the teachings presented herein, the compositions according to the present invention may comprise one or more additives, as is conventional in the art. Determining how much of a particular additive can be added such that the conductivity of the resulting composition complies with the present invention is within the routine capabilities of a person of ordinary skill in the art.

[0085] In a preferred embodiment, the composition of the present invention further comprises one or more additives selected from the group consisting of polyolefins, silicone oils, mineral oils, silicates, aliphatic monocarboxylic acids, aliphatic dicarboxylic acids, aliphatic tricarboxylic acids, molybdates, nitrates, nitrites, phosphonates, and phosphates. In a preferred embodiment, the composition of the present invention further comprises one or more of the said additives in an amount in the range of 0.001 - 10 wt.% (based on the total weight of the composition), preferably 0.01 - 5 wt.%.

[0086] In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises an antifoaming agent. Preferably, the antifoaming agent is selected from the group consisting of: polyolefins, or silicone polymers (such as 3D silicone polymers) or silicone oils. In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises an antifoaming agent in an amount of more than 0.001 wt.% (based on the total weight of the composition), preferably more than 0.005 wt.%, preferably more than 0.01 wt.% and / or less than 10 wt.%, preferably less than 5 wt.%, preferably less than 3 wt.%.

[0087] In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises an antioxidant. Preferably, the antioxidant is selected from the group consisting of: aromatic amines such as p,p-dioctylaniline, monooctyldiphenylamine, phenothiazine, 3,7-dioctylphenothiazine, phenyl-1-naphthylamine, phenyl-2-naphthylamine, alkylphenyl-1-naphthylmethylamine and alkyl-phenyl-2-naphthylmethyl-amine, and sulfur-containing compounds such as dithiophosphates, phosphites, sulfides and dithiometal salts such as benzothiazole, stannous dialkyldithiophosphate and zinc dialkyldithiophosphate. In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises an antioxidant in an amount exceeding 0.001 wt.% (based on the total weight of the composition), preferably exceeding 0.005 wt.%, preferably exceeding 0.01 wt.% and / or less than 10 wt.%, preferably less than 5 wt.%, preferably less than 3 wt.%.

[0088] In certain embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises a liquid dielectric. Preferred liquid dielectrics are mineral oils, silicone oils and mixtures thereof. In certain embodiments of the present invention, the composition provided herein comprises more than 0.0001 wt.% (based on the total weight of the composition), preferably more than 0.001 wt.%, preferably more than 0.01 wt.% and / or less than 10 wt.%, preferably less than 5 wt.%, preferably less than 3 wt.% of the liquid dielectric.

[0089] In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises an anionic surfactant, such as an anionic surfactant of the following: salts of compounds represented by R-X; wherein X represents a sulfate group, a phosphate group, a sulfonate group or a carboxylate group, preferably a sulfate group; and wherein R is selected from: - branched or straight-chain C5-C 24 alkyl; - branched or straight-chain mono-unsaturated C5-C 24 alkenyl; - A branched or straight-chain polyunsaturated C5-C 24 alkenyl; - An alkylbenzene group containing C8-C 15 alkyl; - An alkenylbenzene group containing C8-C 15 alkenyl; - An alkylnaphthalene group containing C3-C 15 alkyl; - An alkenylnaphthalene group containing C3-C 15 alkenyl; - An alkylphenol group containing C8-C 15 alkyl; and - An alkenylphenol group containing C8-C 15 alkenyl. In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition comprises the anionic surfactant in an amount of more than 0.001 wt.% (based on the total weight of the composition), preferably more than 0.005 wt.%, preferably more than 0.01 wt.% and / or less than 10 wt.%, preferably less than 5 wt.%, preferably less than 3 wt.%.

[0090] In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises a corrosion inhibitor selected from the group consisting of: aromatic carboxylates, aliphatic monocarboxylates, aliphatic dicarboxylates, aliphatic tricarboxylates, molybdates and phosphates. As will be understood by those skilled in the art, the carboxylates mentioned herein are typically provided in the form of the free acid neutralized in situ.

[0091] In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises an aliphatic monocarboxylate, preferably an aliphatic monocarboxylate selected from the group consisting of C4-C 12 aliphatic monocarboxylates, in an amount of more than 50 ppm (by weight), preferably more than 100 ppm, preferably more than 500 ppm and / or less than 5000 ppm, preferably less than 2500 ppm, preferably less than 1000 ppm. The amount of the carboxylate mentioned herein is calculated based on the weight of the carboxylate anion (excluding the weight of the cation).

[0092] In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises an aliphatic dicarboxylate, preferably an aliphatic dicarboxylate selected from the group consisting of C6-C 16Aliphatic dicarboxylates of the group consisting of aliphatic dicarboxylates, in an amount of more than 50 ppm (by weight), preferably more than 100 ppm, preferably more than 500 ppm and / or less than 5000 ppm, preferably less than 2500 ppm, preferably less than 1000 ppm. The amount of carboxylate mentioned herein is calculated based on the weight of the carboxylate anion (excluding the weight of the cation).

[0093] In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises an aliphatic tricarboxylate, preferably an aliphatic tricarboxylate selected from the group consisting of C7-C 18 Aliphatic tricarboxylates of the group consisting of aliphatic tricarboxylates, in an amount of more than 50 ppm (by weight), preferably more than 100 ppm, preferably more than 500 ppm and / or less than 5000 ppm, preferably less than 2500 ppm, preferably less than 1000 ppm. The amount of carboxylate mentioned herein is calculated based on the weight of the carboxylate anion (excluding the weight of the cation).

[0094] In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises an aromatic carboxylate, preferably an aromatic carboxylate selected from the group consisting of benzoates, benzene-1,2-dicarboxylates, benzene-1,2,3-tricarboxylates, benzene-1,2,4-tricarboxylates, benzene-1,4-dicarboxylates and combinations thereof, in an amount of more than 50 ppm (by weight), preferably more than 100 ppm, preferably more than 500 ppm and / or less than 5000 ppm, preferably less than 2500 ppm, preferably less than 1000 ppm. The amount of carboxylate mentioned herein is calculated based on the weight of the carboxylate anion (excluding the weight of the cation).

[0095] In embodiments of the present invention, there is provided a composition as defined herein, wherein the composition further comprises a corrosion inhibitor which is a molybdate, preferably an inorganic molybdate, in an amount of more than 1 ppm (by weight) of molybdate, preferably more than 10 ppm, preferably more than 100 ppm of molybdate and / or less than 10000 ppm, preferably less than 1000 ppm, preferably less than 500 ppm. If the molybdate is employed in the form of a salt, the amount of molybdate as used in this document refers to the amount of the molybdate anion (i.e., excluding the weight of the cation counterion).

[0096] In an embodiment of the present invention, a composition as defined herein is provided, wherein the composition further comprises a corrosion inhibitor that is a phosphate, preferably an inorganic phosphate, in an amount of more than 10 ppm (by weight) of phosphate, preferably more than 250 ppm, preferably more than 1000 ppm of phosphate and / or less than 10000 ppm, preferably less than 5000 ppm, preferably less than 2500 ppm. If the phosphate is employed in the form of a salt, the amount of phosphate as used herein refers to the amount of phosphate anions (i.e., excluding the weight of the cation counterions).

[0097] In an embodiment of the present invention, a composition as defined herein is provided, wherein the composition further comprises a corrosion inhibitor that is a silicate, in an amount of more than 1 ppm Si (by weight), preferably more than 10 ppm Si, preferably more than 100 ppm Si and / or less than 10000 ppm, preferably less than 1000 ppm, preferably less than 500 ppm. The silicate corrosion inhibitor is preferably selected from the group consisting of: inorganic silicates (such as sodium metasilicate), organic silicates (such as Si(R 1 ) n (OR 2 ) 4-n , where R 1 and R 2 are each independently a C1 to C6 alkyl or phenyl, and where n is 0, 1, 2 or 3) or silica (SiO2) nanoparticles (such as silica nanoparticles having a volume median diameter (Dv50) in the range of 10 - 200 nm).

[0098] In an embodiment of the present invention, a composition as defined herein is provided, wherein the composition further comprises a nitrate, preferably an inorganic nitrate, in an amount of more than 1 ppm (based on the total weight of the composition) of nitrate, preferably more than 10 ppm, preferably more than 100 ppm of nitrate and / or less than 10000 ppm, preferably less than 1000 ppm, preferably less than 500 ppm. If the nitrate is employed in the form of a salt, the amount of nitrate as used in this document refers to the amount of nitrate anions (i.e., excluding the weight of the cation counterions).

[0099] In an embodiment of the present invention, a composition as defined herein is provided, wherein the composition further comprises a nitrite, preferably an inorganic nitrite, in an amount of more than 1 ppm (based on the total weight of the composition) of nitrite, preferably more than 10 ppm, preferably more than 100 ppm of nitrite and / or less than 10000 ppm, preferably less than 1000 ppm, preferably less than 500 ppm. If the nitrite is employed in the form of a salt, the amount of nitrite as used in this document refers to the amount of nitrite anions (i.e., excluding the weight of the cation counterions).

[0100] In an embodiment of the present invention, there is provided a composition as defined herein, wherein the composition further comprises a phosphonate, preferably an inorganic phosphonate, in an amount of more than 10 ppm (by total weight of the composition) phosphonate, preferably more than 250 ppm, preferably more than 1000 ppm phosphonate and / or less than 10000 ppm, preferably less than 5000 ppm, preferably less than 2500 ppm. If the phosphonate is employed in the form of a salt, the amount of phosphonate as used in this document refers to the amount of phosphonate anion (i.e., excluding the weight of the cation counterion). Conductivity

[0101] In an embodiment of the present invention, there is provided a coolant composition as described herein, having a conductivity as described elsewhere herein, measured according to ASTM D1125 (2014) using a Radiometer Copenhagen CDC745 conductivity cell and a Radiometer Copenhagen temperature sensor T201 with a Radiometer Copenhagen CDM210 conductivity meter.

[0102] In an embodiment of the present invention, there is provided a composition as described herein, having a conductivity at 25 °C of less than 50 μS / cm, preferably less than 25 μS / cm, after aging at 60 °C for 14 days. In an embodiment of the present invention, there is provided a composition as described herein, having a conductivity at 25 °C of less than 50 μS / cm, preferably less than 25 μS / cm, after undergoing a 14-day, 60 °C glassware corrosion test according to ASTM D1384 (2019), wherein the ASTM D1384 (2019) protocol is applied using deionized water instead of the corrosive water specified in the standard, and wherein a 50 vol% dilution is applied instead of the 33 vol% specified in the standard.

[0103] In embodiments of the present invention, there is provided a coolant composition as described herein, which comprises an alcohol as described herein, wherein after aging for 14 days at 60 °C, the concentration of glycolate and / or the concentration of formate is less than 30 ppm (w / w based on the total weight of the composition), preferably less than 10 ppm, wherein the concentration of glycolate and the concentration of formate are determined by ion chromatography. In embodiments of the present invention, there is provided a coolant composition as described herein, which comprises an alcohol as described herein, wherein after undergoing a 14-day, 60 °C glassware corrosion test according to ASTM D1384 (2019), the concentration of glycolate and / or the concentration of formate is less than 30 ppm (w / w based on the total weight of the composition), preferably less than 10 ppm, wherein the ASTM D1384 (2019) protocol is applied using deionized water instead of the corrosive water specified in the standard, and wherein a 50 vol% dilution is applied instead of the 33 vol% specified in the standard, and wherein the concentration of glycolate and the concentration of formate are determined by ion chromatography. Corrosion inhibition

[0104] As explained throughout this document, the compositions according to the invention exhibit low conductivity but provide excellent iron corrosion protection, and these two properties are maintained even when aged at elevated temperatures. Thus, in embodiments of the present invention, there is provided a composition as described herein, wherein a cast iron UNS F10007 specimen immersed in the composition exhibits a weight loss of less than 20 mg, preferably less than 10 mg, preferably less than 2 mg after undergoing a 14-day, 60 °C glassware corrosion test according to ASTM D1384 (2019), wherein the ASTM D1384 (2019) protocol is applied using deionized water instead of the corrosive water specified in the standard, and wherein a 50 vol% dilution is applied instead of the 33 vol% specified in the standard. Ready-to-use composition

[0105] In highly preferred embodiments of the present invention, there is provided a composition as described herein in the form of a ready-to-use composition, · wherein the concentration of the compound according to formula (I) is in the range of 0.01 - 1 wt.% (based on the total weight of the ready-to-use composition), preferably in the range of 0.05 - 0.5 wt.%, more preferably in the range of 0.06 - 0.2 wt.%; · wherein the concentration of the first corrosion inhibitor is in the range of 0.01 - 1 wt.% (based on the total weight of the ready-to-use composition), preferably in the range of 0.025 - 0.5 wt.%, more preferably in the range of 0.06 - 0.15 wt.%; and · wherein the ready-to-use composition comprises more than 90 wt.% (based on the total weight of the ready-to-use composition), preferably more than 95 wt.%, preferably more than 98 wt.%, preferably more than 98.5 wt.% of the base liquid.

[0106] In highly preferred embodiments, the ready-to-use compositions described herein are heat transfer fluids, preferably heat transfer fluids suitable for use in solar systems, fuel cell units, electric motors, generators, batteries, battery electric vehicles, power electronics or electronic devices, most preferably heat transfer fluids suitable for use in fuel cell units or power electronics.

[0107] In preferred embodiments, there is provided a ready-to-use composition as described herein, wherein the base liquid consists of water and an alcohol, and the alcohol is preferably an alcohol selected from the group consisting of: monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, monopropylene glycol, 1,3 - propanediol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, methanol, ethanol, propanol, butanol, tetrahydrofurfuryl alcohol, ethoxylated furfuryl alcohol, dimethyl ether of glycerol, sorbitol, 1,2,6 - hexanetriol, trimethylolpropane, methoxyethanol and glycerol, preferably an alcohol selected from the group consisting of: monoethylene glycol, monopropylene glycol, 1,3 - propanediol, glycerol or mixtures thereof; and wherein the amount of the alcohol is preferably in the range of 10 - 80 wt.% (based on the total weight of the composition), preferably 30 - 70 wt.%. In a specific embodiment, the amount of the alcohol is in the range of 10 - 55 wt.% (based on the total weight of the composition).

[0108] In all embodiments of the ready-to-use composition, it is preferred that the concentration of the first corrosion inhibitor is less than 1000 ppm w / w (based on the total weight of the composition). Concentrate

[0109] In a preferred embodiment of the present invention, the compositions described herein are provided in the form of a concentrate. The concentrate is suitable as a starting material for preparing the ready-to-use compositions described herein.

[0110] In preferred embodiments, the concentrate is suitable for preparing the ready-to-use compositions described herein by adding only water and / or an alcohol; preferably adding only water, monoethylene glycol, monopropylene glycol, diethylene glycol, 1,3 - propanediol and / or glycerol; most preferably adding water. In highly preferred embodiments, the concentrate is suitable for preparing the ready-to-use composition by adding only water (i.e., the ready-to-use compositions described herein can be prepared from the concentrate without the need to add other ingredients).

[0111] In some embodiments of the present invention, the heat transfer fluid compositions described herein are provided in the form of a concentrate, · wherein the base liquid consists of water or a mixture of water and an alcohol, and the alcohol is preferably an alcohol selected from the group consisting of: monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, monopropylene glycol, 1,3 - propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, methanol, ethanol, propanol, butanol, tetrahydrofurfuryl alcohol, ethoxylated furfuryl alcohol, dimethyl ether of glycerol, sorbitol, 1,2,6 - hexanetriol, trimethylolpropane, methoxyethanol, and glycerol, preferably an alcohol selected from the group consisting of: monoethylene glycol, monopropylene glycol, 1,3 - propylene glycol, glycerol, or a mixture thereof; · wherein the concentration of the compound according to formula (I) is in the range of 1.01 - 25 wt.% (based on the total weight of the concentrate composition), preferably in the range of 5 - 20 wt.%, more preferably in the range of 5 - 15 wt.%; · wherein the concentration of the first corrosion inhibitor is in the range of 1.01 - 25 wt.% (based on the total weight of the concentrate composition), preferably in the range of 5 - 20 wt.%, more preferably in the range of 5 - 15 wt.%; and · wherein the concentrate composition contains at least 40 wt.% (based on the total weight of the concentrate composition) of the base liquid and less than 98 wt.% (based on the total weight of the concentrate composition), preferably less than 95 wt.%, preferably less than 90 wt.%, preferably less than 85 wt.%, preferably less than 80 wt.% of the base liquid.

[0112] In some embodiments of the present invention, the heat transfer fluid composition as described herein is provided in the form of a concentrate, · wherein the base liquid consists of an alcohol, and the alcohol is preferably an alcohol selected from the group consisting of: monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, monopropylene glycol, 1,3 - propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, methanol, ethanol, propanol, butanol, tetrahydrofurfuryl alcohol, ethoxylated furfuryl alcohol, dimethyl ether of glycerol, sorbitol, 1,2,6 - hexanetriol, trimethylolpropane, methoxyethanol, and glycerol, preferably an alcohol selected from the group consisting of: monoethylene glycol, monopropylene glycol, 1,3 - propylene glycol, glycerol, or a mixture thereof; · wherein the concentration of the compound according to formula (I) is in the range of 1.01 - 25 wt.% (based on the total weight of the concentrate composition), preferably in the range of 5 - 25 wt.%, more preferably in the range of 10 - 25 wt.%; · wherein the concentration of the first corrosion inhibitor is in the range of 1.01 - 25 wt.% (based on the total weight of the concentrate composition), preferably in the range of 5 - 25 wt.%, more preferably in the range of 10 - 25 wt.%; · wherein the concentrate composition comprises at least 40 wt.% (based on the total weight of the concentrate composition) of the base fluid and less than 98 wt.% (based on the total weight of the concentrate composition), preferably less than 95 wt.%, preferably less than 90 wt.%, preferably less than 85 wt.%, preferably less than 80 wt.% of the base fluid.

[0113] In some embodiments of the present invention, the heat transfer fluid composition as described herein is provided in the form of a concentrate. · wherein the base fluid consists of water or a mixture of water and an alcohol, and the alcohol is preferably an alcohol selected from the group consisting of: monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, monopropylene glycol, 1,3 - propanediol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, methanol, ethanol, propanol, butanol, tetrahydrofurfuryl alcohol, ethoxylated furfuryl alcohol, dimethyl ether of glycerol, sorbitol, 1,2,6 - hexanetriol, trimethylolpropane, methoxyethanol, and glycerol, preferably an alcohol selected from the group consisting of: monoethylene glycol, monopropylene glycol, 1,3 - propanediol, glycerol, or a mixture thereof; · wherein the concentration of the compound according to formula (I) is in the range of 1.01 - 25 wt.% (based on the total weight of the concentrate composition), preferably in the range of 3 - 15 wt.%, more preferably in the range of 3 - 10 wt.%; · wherein the concentration of the first corrosion inhibitor is in the range of 1.01 - 25 wt.% (based on the total weight of the concentrate composition), preferably in the range of 3 - 15 wt.%, more preferably in the range of 3 - 10 wt.%; · wherein the composition further comprises the non - ionic polymer as described above in an amount of 1 - 25 wt.% (based on the total weight of the concentrate composition), preferably 3 - 20 wt.%, more preferably 5 - 15 wt.%; and · wherein the concentrate composition comprises at least 40 wt.% (based on the total weight of the concentrate composition) of the base fluid and less than 98 wt.% (based on the total weight of the concentrate composition), preferably less than 95 wt.%, preferably less than 90 wt.%, preferably less than 85 wt.%, preferably less than 80 wt.% of the base fluid.

[0114] In some embodiments of the present invention, the heat transfer fluid composition as described herein is provided in the form of a concentrate. · wherein the base liquid consists of an alcohol, which is preferably an alcohol selected from the group consisting of: monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, monopropylene glycol, 1,3 - propanediol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, methanol, ethanol, propanol, butanol, tetrahydrofurfuryl alcohol, ethoxylated furfuryl alcohol, dimethyl ether of glycerol, sorbitol, 1,2,6 - hexanetriol, trimethylolpropane, methoxyethanol and glycerol, preferably an alcohol selected from the group consisting of: monoethylene glycol, monopropylene glycol, 1,3 - propanediol, glycerol or a mixture thereof; · wherein the concentration of the compound according to formula (I) is in the range of 1.01 - 25 wt.% (based on the total weight of the concentrate composition), preferably in the range of 5 - 25 wt.%, more preferably in the range of 5 - 20 wt.%; · wherein the concentration of the first corrosion inhibitor is in the range of 1.01 - 25 wt.% (based on the total weight of the concentrate composition), preferably in the range of 5 - 25 wt.%, more preferably in the range of 5 - 20 wt.%; · wherein the composition further comprises a non - ionic polymer as described above, in an amount of 1 - 25 wt.% (based on the total weight of the concentrate composition), preferably 3 - 20 wt.%, more preferably 5 - 15 wt.%; and · wherein the concentrate composition comprises at least 40 wt.% (based on the total weight of the concentrate composition) of the base liquid and comprises less than 98 wt.% (based on the total weight of the concentrate composition), preferably less than 95 wt.%, preferably less than 90 wt.%, preferably less than 85 wt.%, preferably less than 80 wt.% of the base liquid. Preparation method

[0115] In another aspect of the present invention, there is provided a method for preparing a composition as defined herein, the method comprising the following steps: (i) providing a base liquid as described herein; (ii) providing a compound according to formula (I) as described herein; (iii) providing a first corrosion inhibitor as described herein, which is selected from the group consisting of: triazoles, thiazoles, triazines, diazoles and combinations thereof; (iv) optionally providing one or more enhancing additives or additional additives as described herein; and (v) combining the base liquid of step (i), the compound having formula (I) of step (ii) and the first corrosion inhibitor of step (iii) with optionally the additional additives of step (iv) such that the weight ratio of the first corrosion inhibitor to the compound according to formula (I) is from 1:20 to 20:1.

[0116] According to the present invention, the order of addition of the compounds is not particularly limited.

[0117] In another aspect of the present invention, there is provided a method for preparing a ready-to-use composition as defined herein, the method comprising the steps of: (i) providing a concentrate as defined herein; (ii) providing water, an alcohol or a mixture thereof; (iii) optionally providing one or more enhancing additives or additional additives as described herein; and (iv) combining the concentrate of step (i) with the water, alcohol or mixture thereof of step (ii) and the optional additional additives of step (iii) to obtain a ready-to-use composition.

[0118] The alcohol of step (ii) is as described above. In a highly preferred embodiment, the alcohol of step (ii) is selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol and combinations thereof.

[0119] In a preferred embodiment, step (ii) comprises providing more than 50 wt.% (based on the weight of the concentrate) of water, an alcohol or a mixture thereof, preferably more than 100 wt.%, more than 150 wt.%, more than 200 wt.% or more than 500 wt.% of water, an alcohol or a mixture thereof. Kit of multiple components

[0120] In another aspect of the present invention, there is provided a kit for preparing a composition as defined herein, preferably a ready-to-use composition, the kit comprising (i) a first container containing a first solution of a compound of formula (I) as described herein in water, an alcohol (as described herein) or a mixture thereof, preferably in water, monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol or a mixture thereof, more preferably in water, monoethylene glycol or a mixture thereof, most preferably in water; and (ii) a second container containing a second solution of a first corrosion inhibitor as described herein in water, an alcohol or a mixture thereof, preferably in water, monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol or a mixture thereof, more preferably in water, monoethylene glycol or a mixture thereof, most preferably in monoethylene glycol; and wherein the concentration of the compound of formula (I) in the first container is preferably in the range of 1.01 - 25 wt.% (based on the total weight of the first solution), preferably in the range of 5 - 20 wt.%, more preferably in the range of 5 - 15 wt.%; The concentration of the first corrosion inhibitor in the second container is preferably in the range of 1.01 - 25 wt.% (based on the total weight of the second solution), more preferably in the range of 5 - 20 wt.%, and even more preferably in the range of 5 - 15 wt.%.

[0121] In an embodiment, the kit further includes instructions for combining the first and second containers with water, an alcohol (as described herein), or a mixture thereof to obtain a composition according to the present invention that exhibits improved corrosion inhibition.

[0122] In another aspect of the present invention, there is provided a method for preparing a composition as defined herein, preferably a ready-to-use composition, the method comprising the following steps: (i) providing a kit as defined herein, which includes a first container as defined herein and a second container as defined herein; (ii) providing water, an alcohol (as described herein), or a mixture thereof; (iii) optionally providing an enhancing additive or additional additives as defined herein; and (iv) combining the first container of the kit provided in step (i) with the second container of the kit provided in step (i), the water, alcohol, or mixture thereof of step (ii), and the optional additional additives of step (iii) to obtain a ready-to-use composition.

[0123] In an embodiment of the present invention, there is provided a method for preparing a composition as defined herein, preferably a ready-to-use composition, the method consisting of the following steps: (i) providing a kit as defined herein, which includes a first container as defined herein and a second container as defined herein; (ii) providing water, an alcohol, or a mixture thereof; (iii) combining the first container of the kit provided in step (i) with the second container of the kit provided in step (i) and the water, alcohol, or mixture thereof of step (ii) to obtain a ready-to-use composition.

[0124] In a highly preferred embodiment, the alcohol of step (ii) is selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3 - propanediol, and combinations thereof.

[0125] According to the present invention, the order of addition of the components is not particularly limited.

[0126] In a preferred embodiment, step (ii) includes providing more than 50 wt.% (based on the combined weight of the first and second solutions) of water, an alcohol, or a mixture thereof, preferably more than 100 wt.%, more than 150 wt.%, more than 200 wt.%, or more than 500 wt.%. Use and method of the composition as a heat transfer fluid

[0127] In another aspect of the present invention, there is provided the use of the composition provided herein, preferably the ready-to-use composition, as a heat transfer fluid, preferably as a heat transfer fluid in an internal combustion engine, a solar system, a fuel cell unit, an electric motor, a generator, a battery, a battery electric vehicle or an electronic device, and most preferably as a heat transfer fluid in an internal combustion engine.

[0128] In another aspect of the present invention, there is provided a method for inhibiting corrosion, which comprises bringing the composition provided herein, preferably the ready-to-use composition, into contact with a metal surface. In a preferred embodiment, the metal surface comprises aluminum, brass, steel, iron or copper and alloys thereof, especially iron or alloys thereof.

[0129] In another aspect of the present invention, there are provided an internal combustion engine, a solar system, a fuel cell unit, an electric motor, a generator or an electronic device comprising the composition described herein, preferably the ready-to-use composition.

[0130] In another aspect of the present invention, there is provided the use of the compound according to formula (I) described herein as a corrosion inhibitor for ferrous metal or cast iron, preferably as a corrosion inhibitor for ferrous metal or cast iron in a heat transfer fluid having a conductivity at 25 °C of less than 200 μS / cm, and more preferably as a corrosion inhibitor for ferrous metal or cast iron in a heat transfer fluid having a conductivity at 25 °C of less than 100 μS / cm and comprising a first corrosion inhibitor described herein.

[0131] In another aspect of the present invention, there is provided a method for exchanging heat, which comprises:[[]] a. generating heat in: an electrical system, preferably an electrical system selected from the group consisting of: a solar system, a fuel cell unit, an electric motor, a generator, a battery, a telephone transmitting station, power electronics, a radio and television broadcasting station, a relay station, an electric heating or cooling device, preferably a fuel cell unit, a battery or power electronics; b. bringing the composition described herein, preferably the ready-to-use composition described herein, into contact with the system of step a; c. transferring the heat from the system to the composition; d. passing the composition through a heat exchanger; and e. transferring the heat from the composition. Examples

[0132] Conductivity was measured according to ASTM D1125 (2014) using a Radiometer Copenhagen CDC745-9 conductivity cell, a Radiometer Copenhagen temperature sensor T201, and a Radiometer Copenhagen CDM210 conductivity meter.

[0133] The concentrations of glycolate and formate in the aging composition were determined by ion chromatography. Example 1: Oven Test

[0134] Cast iron specimens were polished with sandpaper, rinsed with ultrapure water (UPW) and acetone, dried at 100 °C for 1 h, and weighed (fresh specimens). The specimens were added to a bottle, and 100 mL of the composition described in Table 1 was added to the bottle. Subsequently, the bottle was placed in an oven at the desired temperature. After 14 days, the bottle was removed from the oven, and the conductivity and pH of the aging composition were measured. All specimens were gently cleaned with water and a soft brush, dried, and weighed. Finally, all specimens were chemically cleaned by treatment with scouring powder. The specimens were further cleaned with water and a soft brush (specimens CC), dried at 100 °C for 1 h, and weighed. The weight change of the cast iron UNS F10007 specimens due to aging was determined using the following formula: Δm (mg) = mass of fresh specimen (mg) - mass of specimen CC (mg)

[0135] The compositions tested are summarized in Table 1. All values are in wt.%. Table 1 1 K90PVP as a 20 wt.% aqueous solution (weight-average molecular weight M W = 1,400,000 g / mol)

[0136] Table 2 shows the corrosion inhibition and conductivity results when the compositions in Table 1 were aged at a temperature of 60 °C according to the procedure outlined above. Example 2 was tested at 40 °C.

[0137] Without wishing to be bound by theory, the inventors believe that both a compound according to formula (I) and a first corrosion inhibitor selected from the group consisting of triazoles, thiazoles, triazines, diazoles and combinations thereof are required to simultaneously prevent corrosion of ferrous materials while maintaining low conductivity. As can be seen from Examples 1 and 2, when both compounds are present, the pH, conductivity and corrosion of the ferrous material remain stable. However, in Comparative Examples 3 and 4 in which the first corrosion inhibitor was absent, the pH and conductivity increased significantly. In Comparative Example 5 in which only the first corrosion inhibitor was present but the compound according to formula (I) was absent, corrosion of the ferrous metal was not avoided. Comparative Example 6 demonstrates that the effects observed in the compositions of the present invention cannot be reproduced with another oxygen scavenger such as sodium sulfite. Table 2 1 The negative sign indicates weight gain

[0138] Table 3 shows the performance of the composition of Example 1 when aged at different temperatures according to the procedure outlined above.

[0139] As can be observed from Table 3, a synergistic effect of the heat transfer fluid comprising a compound according to formula (I) and a corrosion inhibitor can be observed over a wide temperature range. Table 3 Example 1 Example 1 Example 1 Aging Temperature Room Temperature 40℃ 60℃ pH 7.3 7.2 7.3 Glycolate (ppm) 0 1 2 Formate (ppm) 1 2 3 Conductivity (μS / cm) 14.6 13.0 12.3 Example 2: Oven Test

[0140] The compositions in Table 4 were tested according to the procedure of Example 1 (all values in wt.%). The results (60 °C data) are shown in Table 5. Table 4 1 K90 PVP as a 20 wt.% aqueous solution (weight average molecular weight M W = 1,400,000 g / mol) 2 K17 PVP as a 20 wt.% aqueous solution (weight average molecular weight M W = 9,000 g / mol) Table 5 Example 3: Glassware Corrosion Test

[0141] The glassware corrosion test was carried out according to the modified ASTM D1384 (2019) test procedure. The first modification was the use of a second aluminum specimen in the specimen set. The specimen set used consisted of copper UNS C11000 - brass gasket - brass UNS C26000 - Teflon gasket - steel UNS G10200 - steel gasket - cast iron UNS F10007 - steel gasket - aluminum Al 319.1 - steel gasket - aluminum AlSi10Mg(a)(T6). The temperature applied was 60 °C. The second modification was the use of the compositions listed in Table 6, which means that no diluent with corrosive water as specified in the standard was applied. After 14 days, the bottles were removed from the oven and the conductivity and pH of the aged compositions were measured. The specimen cleaning procedure and weight change were carried out and obtained by the methods described in ASTM D1384 (2019). The test compositions are shown in Table 6. The results are shown in Table 7. Table 6 1 As a 20 wt.% aqueous solution of PVP (weight-average molecular weight M W = 9,000 g / mol) Table 7 Example 4: Concentrate Formulation

[0142] The concentrate formulations were studied by dissolving high concentrations of the compound according to formula (I), the first corrosion inhibitor, and an optional non-ionic polymer in different base fluids. Tests were carried out using diethylhydroxylamine (DEHA), tolyltriazole, and polyvinylpyrrolidone.

[0143] It was found feasible to have concentrations of the compound according to formula (I) and the first corrosion inhibitor up to 25 wt.%. In the presence of an additional non-ionic polymer, concentrations of up to 20 wt.% of each component were feasible. When using water as the base fluid, the solubility was mainly limited by the solubility of tolyltriazole and could be below 20 wt.%, depending on the concentration of the other components.

Claims

1. A composition comprising a base liquid, a first corrosion inhibitor, and a compound according to formula (I) wherein X is nitrogen such that the compound according to formula (I) is a hydroxylamine, or X is imine such that the compound according to formula (I) is an oxime; wherein R 1 selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; or R 1 and R 2 are linked and together form a C2-C6 alkanediyl linked to X to form a 3- to 7-membered ring; wherein the base liquid consists of water or alcohol or a mixture thereof; wherein the first corrosion inhibitor is selected from the group consisting of triazoles, thiazoles, triazines, diazoles, and combinations thereof; wherein the weight ratio of the first corrosion inhibitor to the compound according to formula (I) is from 1:20 to 20:1; wherein the composition has a conductivity at 25 °C of less than 200 μS / cm as measured according to ASTM D1125 (2014); and wherein the first corrosion inhibitor is not selected from N,N',N"-tris-(2-hydroxypropyl)hexahydrotriazine, N,N′,N″-tris(2-hydroxyethyl)hexahydrotriazine, 2,2′,2″-(hexahydro-1,3,5-triazine-1,3,5-triyl)-triethanol, or α,α′,α″-trimethyl-1,3,5-triazine-1,3,5-(2H,4H,6H)triethanol.

2. The composition according to claim 1, wherein, The first corrosion inhibitor is not selected from triazines.

3. The composition according to claim 1 or 2, wherein X in the compound according to formula (I) is nitrogen such that the compound according to formula (I) is a hydroxylamine according to formula (Ia): wherein R 1 selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; or R 1 and R 2 are linked and together form a C2-C6 alkanediyl that is linked to the nitrogen of formula (Ia) to form a 3- to 7-membered ring; Preferably, wherein R 1 and R 2 are each independently selected from the group consisting of methyl, ethyl, propyl, butyl and phenyl, more preferably wherein R 1 and R 2 are the same and are selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, butyl and phenyl, even more preferably R 1 and R 2 are both ethyl.

4. The composition according to any one of claims 1 - 3, wherein, The first corrosion inhibitor is selected from 1,2,4-triazole, 4H-1,2,4-triazole, 4-amino-1,2,4-triazole, 3-amino-1,2,4-triazole, 1,2,4-triazole-3-thiol, 3-amino-1,2,4-triazole-5-thiol, 3,5-diamino-1,2,4-triazole, 1H-1,2,3-triazole, benzotriazole, 2-mercaptobenzothiazole, tolyltriazole, 2-[2-hydroxyethyl-[(4-methylbenzotriazol-1-yl)methyl]amino]ethanol, 2-[2-hydroxyethyl-[(benzotriazolyl)methyl]amino]ethanol, and combinations thereof, more preferably selected from benzotriazole, tolyltriazole, 2-mercaptobenzothiazole, and combinations thereof.

5. The composition according to any one of claims 1-4, which further comprises a nonionic polymer, preferably a nonionic polymer selected from the group consisting of: polyvinylpyrrolidone, polyvinyl alcohol, polyalkylene oxide, C1-C 18 alkyl or alkenyl ethers of polyalkylene oxide, C1-C 18 alkyl or alkenyl esters of polyalkylene oxide, polysiloxane, alkoxylated C1-C 18 alkyl or alkenyl amines, polyvinyl acetate, copolymers thereof and combinations thereof, preferably a nonionic polymer selected from polyvinylpyrrolidone.

6. The composition according to any one of claims 1-5, wherein, The composition has a conductivity at 25 °C of less than 75 μS / cm, preferably less than 50 μS / cm, more preferably less than 25 μS / cm.

7. The composition according to any one of claims 1-6, wherein The alcohol is selected from the group consisting of monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, monopropylene glycol, 1,3-propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, methanol, ethanol, propanol, butanol, tetrahydrofurfuryl alcohol, ethoxylated furfuryl alcohol, dimethyl ether of glycerol, sorbitol, 1,2,6-hexanetriol, trimethylolpropane, methoxyethanol, glycerol, and mixtures thereof, preferably selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propylene glycol, glycerol, and mixtures thereof.

8. The composition according to any one of claims 1-7, wherein, The base liquid consists of 30-70 wt.% (by weight of the base liquid) of water and 30-70 wt.% (by weight of the base liquid) of the alcohol.

9. The composition according to any one of claims 1-8, further comprising one or more additional additives selected from the following · an amine, wherein the amine does not contain an N-hydroxyamine (N-OH) functional group, preferably an amine selected from molecules composed of atoms C, N, H and optionally O, containing 1 to 10 C atoms, containing one or more amine functional groups and optionally containing one or more hydroxyl or ether functional groups, wherein the amine does not contain an N-hydroxyamine (N-OH) functional group, and preferably wherein the amine does not contain other functional groups except the one or more amine functional groups and optionally one or more hydroxyl or ether functional groups; · an aromatic alcohol, the aromatic alcohol selected from phenol, pyrogallol, gallic acid, gallic acid esters and combinations thereof; · a dioxo-aromatic compound, the dioxo-aromatic compound selected from benzoquinone, naphthoquinone, hydroquinone and catechol; · a co-antioxidant, the co-antioxidant selected from thiols, thioethers and thioesters; and / or · a non-ionic surfactant.

10. The composition according to any one of claims 1-9, provided in the form of a ready-to-use composition, · wherein the concentration of the compound according to formula (I) is in the range of 0.01-1 wt.% (based on the total weight of the ready-to-use composition), preferably in the range of 0.05-0.5 wt.%, more preferably in the range of 0.06-0.2 wt.%; · wherein the concentration of the first corrosion inhibitor is in the range of 0.01-1 wt.% (based on the total weight of the ready-to-use composition), preferably in the range of 0.025-0.5 wt.%, more preferably in the range of 0.06-0.15 wt.%; and · wherein the ready-to-use composition contains more than 90 wt.% (based on the total weight of the ready-to-use composition), preferably more than 95 wt.%, preferably more than 98 wt.%, preferably more than 98.5 wt.% of the base liquid.

11. The composition according to claim 10, wherein, The pH of the composition is in the range of 5-9, preferably in the range of 6-8.5, more preferably in the range of 6-8.

12. The composition according to claim 10 or 11, wherein The base liquid consists of 30-70 wt.% (based on the total weight of the base liquid) of water and 30-70 wt% (based on the total weight of the base liquid) of an alcohol, the alcohol selected from the group consisting of monoethylene glycol, diethylene glycol, monopropylene glycol, 1,3-propylene glycol, glycerol and mixtures thereof.

13. The composition according to any one of claims 1-9, provided in the form of a concentrate, the concentrate being suitable for preparing a ready-to-use composition according to any one of claims 10-12 by adding only water and / or an alcohol; preferably adding only water, monoethylene glycol, diethylene glycol, monopropylene glycol, 1,3-propylene glycol and / or glycerol; most preferably adding only water.

14. A method of exchanging heat, the method comprising: a. generating heat in: an electrical system, preferably an electrical system selected from the group consisting of: a solar system, a fuel cell unit, an electric motor, a generator, a battery, a telephone transmitting station, power electronics, a radio and television broadcasting station, a relay station, an electric heating or cooling device, preferably a fuel cell unit, a battery or power electronics; b. contacting the composition according to any one of claims 1-13, preferably the ready-to-use composition according to claims 10 to 12, with the system of step a; c. transferring heat from the system to the composition; d. passing the composition through a heat exchanger; and e. transferring heat out of the composition.

15. Use of a compound of formula (I), wherein X is nitrogen such that the compound of formula (I) is a hydroxylamine, or X is imine such that the compound of formula (I) is an oxime; wherein R 1 selected from C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; and wherein R 2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, phenyl, benzyl or tolyl; or R 1 and R 2 are connected and together form a C2-C6 alkanediyl connected to X to form a 3- to 7-membered ring; the compound as a corrosion inhibitor for ferrous metals or cast iron in a heat transfer fluid, the heat transfer fluid having a conductivity at 25 °C of less than 100 μS / cm and comprising a first corrosion inhibitor selected from the group consisting of triazoles, thiazoles, triazines, diazoles and combinations thereof, wherein the first corrosion inhibitor is not selected from N,N',N"-tris(2-hydroxypropyl)hexahydro-1,3,5-triazine, N,N′,N″-tris(2-hydroxyethyl)hexahydro-1,3,5-triazine, 2,2′,2″-(hexahydro-1,3,5-triazine-1,3,5-triyl)-triethanol or α,α′,α″-trimethyl-1,3,5-triazine-1,3,5-(2H,4H,6H)triethanol.

16. Use of the composition according to any one of claims 1-13, preferably the ready-to-use composition according to claims 10 to 12, as a heat transfer fluid.

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