GLYCOL-BASED HEAT TRANSFER FLUID COMPRISING ORGANIC CARBOXYLIC ACID OR A SALT THEREOF, METHODS FOR ITS PREPARATIONS AND USES THEREOF

Abstract

The present invention relates to glycol-based heat transfer fluids exhibiting corrosion inhibition and comprising more than 5% by weight (of the total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol, or combinations thereof; and more than 1% by weight (of the total weight of the composition) of a short-chain organic carboxylic acid or salt thereof selected from the group consisting of C2 organic carboxylic acids or salts thereof, C3 organic carboxylic acids or salts thereof, and combinations thereof; wherein the combined amount of glycol and the short-chain organic carboxylic acid or salt thereof is more than 15% by weight (of the total weight of the composition).The invention also relates to concentrates for the preparation of these heat transfer fluids, to methods for the preparation of these heat transfer fluids, and to the methods and uses employing these heat transfer fluids.

Description

GLYCOL-BASED HEAT TRANSFER FLUID COMPRISING ORGANIC CARBOXYLIC ACID OR A SALT THEREOF, METHODS FOR ITS PREPARATIONS AND USES THEREOF rp j Lnn / zznz / E / Yi FIELD OF INVENTION The present invention relates to glycol-based heat transfer fluids comprising an organic carboxylic acid or a salt thereof. The invention further relates to concentrates for preparing these heat transfer fluids, methods for preparing these heat transfer fluids, and methods and uses of these heat transfer fluids. BACKGROUND OF THE INVENTION Heat transfer fluids are widely used in heat exchange systems associated with internal combustion engines, solar thermal systems, fuel cells, electric motors, generators, electronic equipment, and similar applications. Heat transfer fluids generally consist of a base fluid and one or more additives. Historically, water has been the preferred base fluid for heat transfer. In many applications, antifreeze properties are required, and a base fluid consisting of water mixed with freezing point depressants such as alcohols, glycols, or salts is used. Because alcohols or glycols used as freezing point depressants will affect the properties of the heat transfer fluid (e.g., density, kinematic viscosity, thermal conductivity, heat capacity) differently than when salts are used as freezing point depressants, two distinct classes of heat transfer fluids have emerged: alcohol / glycol-free and alcohol / glycol-containing heat transfer fluids. Water and glycol mixtures are the most widely used base fluids because these mixtures are relatively stable, compatible with the elastomers and plastics used in modern heat exchange systems, provide cost-effective freeze and boil protection, and can be formulated with a variety of corrosion inhibitors to provide the specific corrosion protection required for particular heat exchange systems. Heat transfer fluids generally contain additional additives that can be used to achieve a variety of functionalities, such as improving heat exchange properties, inhibiting corrosion, etc. Since heat transfer fluids are in continuous contact with metal parts, such as aluminum alloys, cast iron, steel, copper, brass, solder, etc., they almost always contain one or more corrosion inhibitors. The ability of carboxylic acids to inhibit corrosion in automotive cooling systems was first reported over 60 years ago. Aromatic carboxylic acids, such as benzoic acid and its derivatives, have been extensively studied and are used in Europe as corrosion inhibitors in commercial coolants. Coolants comprising only organic acid corrosion inhibitors, sometimes known as OAT (organic acid technology) coolants, exhibit low depletion rates, resulting in extended coolant life, and are often more environmentally responsible than coolants that rely on inorganic salts for corrosion inhibition. Recent research efforts have focused on long-chain aliphatic organic carboxylates. Aliphatic carboxylic acids comprising six or more carbon atoms have been found to act as corrosion inhibitors, although there is considerable variation in performance depending on the acid and substrate. For example, US2007 / 0152191 discloses the use of C10-C12 dicarboxylic acids as corrosion inhibitors. Known heat transfer fluids that employ organic carboxylate corrosion inhibitors, such as OAT heat transfer fluids, exhibit several disadvantages. For example, they are based on the corrosion inhibition of Ce and higher carboxylates, such as Cs or C10 carboxylates, which are generally expensive. Additionally, the application of many higher carboxylates is limited or cannot be fully utilized due to their low solubility in water / glycol. An object of the present invention is to provide improved glycol-based heat transfer fluids. An additional object of the present invention is to provide glycol-based heat transfer fluids comprising reduced amounts of long-chain organic carboxylate, such as Ce organic carboxylate or higher, while possessing comparable or improved aluminum alloy corrosion inhibition. An additional object of the present invention is to provide glycol-based heat transfer fluids that have extended service life compared to known glycol-based heat transfer fluids, such as known glycol-based heat transfer fluids containing organic carboxylates of Ce or higher. BRIEF DESCRIPTION OF THE INVENTION The present inventors have surprisingly found that one or more of these objectives can be achieved by employing a composition comprising - more than 5% by weight (in the total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol or combinations thereof; and rp j Lnn / zznz / B / Yi - more than 1% by weight (in total weight of the composition) of a short-chain organic carboxylic acid or a salt thereof selected from the group consisting of C2 organic carboxylic acids or salts thereof, C3 organic carboxylic acids or salts thereof and combinations thereof; where the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is more than 15% by weight (in total weight of the composition). As will be shown in the accompanying examples, it was surprisingly found that glycol-based compositions comprising large amounts of short-chain carboxylic acid, such as more than 1 wt%, preferably more than 2 wt%, of a short-chain organic carboxylic acid or a salt thereof, exhibit remarkable corrosion inhibition on metal substrates such as aluminum. Furthermore, according to preferred embodiments of the invention, the present inventors have found that a glycol-based composition comprising a short-chain organic carboxylic acid or a salt thereof exhibits a sudden, non-linear increase in corrosion inhibition after increasing the concentration of the short-chain organic carboxylic acid or a salt thereof. In the art, short-chain organic carboxylates are not known to exhibit significant corrosion protection. Short-chain organic carboxylates have been investigated as freezing point depressants in glycol-free heat transfer fluids. For example, US2007 / 158612 discloses glycol-free heat transfer compositions comprising a C3 organic carboxylate freezing point depressant and a Ce-Cie organic acid salt corrosion inhibitor. It shall be understood by those skilled in the art, in view of the present disclosure, that the compositions according to the present invention effectively allow the provision of heat transfer fluids or refrigerants that require less or even no additional additives and / or that are capable of maintaining metal corrosion inhibition for longer periods of time than comparable compositions known in the art. Therefore, in a first aspect, the invention provides compositions comprising - more than 5% by weight (of the total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol or combinations thereof; and - more than 1% by weight (in total weight of the composition) of a short-chain organic carboxylic acid or a salt thereof selected from the group consisting of C2 organic carboxylic acids or salts thereof, C3 organic carboxylic acids or salts thereof and combinations thereof; where the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is more than 15% by weight (in total weight of the composition). rp j Lnn / zznz / B / Yi In preferred embodiments, the compositions of the invention are provided in the form of ready-to-use compositions. In preferred embodiments, the compositions of the invention are provided in the form of concentrates for preparing the ready-to-use compositions described herein. Another aspect of the invention relates to a method for preparing the compositions described herein. Another aspect of the invention relates to a method for preparing the ready-to-use compositions described herein from a concentrate. Another aspect of the invention relates to corresponding uses of the compositions, preferably the ready-to-use compositions described herein. Yet another aspect of the invention relates to the use of a carboxylic acid selected from the group consisting of C2 organic carboxylic acids or salts thereof, C3 organic carboxylic acids or salts thereof, and combinations thereof, preferably selected from the group consisting of propionic acid and salts thereof, acetic acid and salts thereof, and combinations thereof; to increase the corrosion inhibition of a composition comprising more than 5% by weight (in total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol, or combinations thereof; preferably to increase the pitting corrosion potential, more preferably to increase the pitting corrosion potential of aluminum. According to preferred embodiments of the invention, the pitting corrosion potential as referred to herein is measured by rapid cyclic potentiokinetic polarization (RCP) sweep. In highly preferred embodiments of the invention, the pitting corrosion potential as referred to herein is measured by rapid cyclic potentiokinetic polarization (RCP) scanning in accordance with the method described in the publications of CEBELCOR (Centre Belge d'Etude de la Corrosion) Rapports Techniques, vol. 147, RT 272 (August 1984). This method comprises altering the potential of a stagnant, epoxy-encrusted, rod-shaped aluminum working electrode (alloy AIMgSi0.5) having a polished working surface (using 600 grit silicon carbide polishing paper) of 0.5 cm2 with a scan rate of 0.5 mV / s in 0.5 mV steps versus a solid platinum auxiliary electrode (ref. 6.0330.0040, supplier Metroohm) while immersed in 100 grams of test fluid and employing a solid silver reference electrode (ref. 6.0331).010, supplier Methrohom); record the current density flowing between the working and auxiliary electrodes as a function of the potential difference using a potentiostat (VeraSTAT; AmetekMRScientific Instruments); and identify the pitting corrosion potential Ep by a sudden exponential increase in current density. rp j Lnn / zznz / e / Yii DETAILED DESCRIPTION OF THE INVENTION A first aspect of the invention relates to compositions comprising - more than 5% by weight (of the total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol or combinations thereof; and - more than 1% by weight (in total weight of the composition) of a short-chain organic carboxylic acid or a salt thereof selected from the group consisting of C2 organic carboxylic acids or salts thereof, C3 organic carboxylic acids or salts thereof, and combinations thereof; where the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is more than 15% by weight (in total weight of the composition). Glycol As used herein, the term “monoethylene glycol” means “ethane-1,2-diol”, and may also be referred to as “MEG”. As used herein, the term “monopropylene glycol” means “propane-1,2-diol”, and may also be referred to as “MPG”. As used herein, the term “glycerol” means “propane-1,2,3-triol” and is synonymous with glycerin. In embodiments of the invention, a composition as described herein is provided, wherein the composition comprises more than 5% by weight (of the total weight of the composition) of glycol, such as more than 6% by weight, more than 7% by weight, more than 8% by weight, more than 9% by weight, more than 10% by weight, more than 11% by weight, more than 12% by weight, more than 13% by weight, more than 14% by weight, more than 15% by weight, more than 16% by weight, more than 17% by weight, more than 18% by weight, more than 19% by weight, more than 20% by weight, more than 25% by weight, more than 30% by weight, more than 35% by weight, more than 40% by weight, more than 45% by weight, more than 50% by weight, more than 55% by weight, more than 60% by weight weight, more than 65% by weight or more than 70% by weight of glycol. In preferred embodiments of the invention, a composition as described herein is provided, wherein the composition comprises more than 10% by weight (in total weight of the composition) of glycol, preferably more than 20% by weight, preferably more than 50% by weight. In embodiments of the invention, a composition as described herein is provided, wherein the composition comprises less than 99% by weight (of the total weight of the composition) of glycol, such as less than 98% by weight, less than 97% by weight, less than 96% by weight, less than 95% by weight, less than 94% by weight, less than 93% by weight, less than 92% by weight, less than 91% by weight, less than 90% by weight, less than 89% by weight, less than 88% by weight, less than 87% by weight, less than 86% by weight, less than 85% by weight, less than 84% by weight, less than 83% by weight, less than 82% by weight, less than 81% by weight, less than 80% by weight, less than 75% by weight, less than 70% by weight, less than 65% by weight, less than 60% by weight or less than 55% by weight of glycol. In preferred embodiments of the invention, the glycol is selected from monoethylene glycol, monopropylene glycol, and combinations thereof. In these embodiments, it is preferred that the total amount of glycols other than monoethylene glycol and monopropylene glycol, in particular the total amount of glycerol present in the composition, be less than 5% by weight (of the total weight of the composition), preferably less than 1% by weight, more preferably less than 0.1% by weight, and more preferably about 0% by weight. In these embodiments, the composition is essentially glycerol-free. In particular embodiments of the invention, the low-glycerol embodiments as described herein are provided wherein the short-chain organic carboxylic acid or a salt thereof is selected from the group consisting of C3 organic carboxylic acids or salts thereof as described herein, preferably propionic acid or a salt thereof.Short-chain organic carboxylic acid or salt thereof. In highly preferred embodiments of the invention, the compositions described herein are provided wherein the short-chain organic carboxylic acids or salts thereof described herein are provided in the form of a salt consisting of the carboxylate anion and a cationic counterion. The cationic counterion is preferably selected from the group consisting of an alkaline earth metal cation, an alkali metal cation, an ammonium cation, or combinations thereof, more preferably an alkali metal cation, most preferably sodium or potassium, or combinations thereof. In embodiments of the invention, the ammonium cation is a quaternary ammonium cation represented by the formula (NRR'R''R”')+, wherein R, R', R” and R''” are independently selected from the group of C1-C6 branched or straight alkyls and C1-C1 branched or straight hydroxyalkyls, preferably methyl, ethyl, n-propyl, and isopropyl.In embodiments of the invention, the ammonium cation is a tertiary amine cation represented by the formula (HNRR'R)+ where R, R', and R'' are independently selected from the group of branched or straight C1-C6 alkyls and branched or straight C1-C6 hydroxyalkyls, preferably methyl, ethyl, n-propyl, and isopropyl. In embodiments of the invention, the ammonium cation is a secondary amine cation represented by the formula (H2NRR')+ where R and R' are independently selected from the group of branched or straight C1-C6 alkyls and branched or straight C1-C6 hydroxyalkyls, preferably methyl, ethyl, n-propyl, and isopropyl. If the short-chain organic carboxylic acid or salt thereof is used in the form of a salt, the amount of organic carboxylic acid or salt thereof as used herein refers to the amount of organic carboxylate anion and the cationic counterion (i.e., it includes the weight of the cationic counterion). In embodiments of the invention, the C2 organic carboxylic acid or a salt thereof is selected from the group consisting of acetic acid, oxalic acid, glycolic acid, glyoxylic acid or a salt thereof, or combinations thereof, more preferably potassium acetate or sodium acetate, more preferably potassium acetate. In embodiments of the invention, the C3 organic carboxylic acid or a salt thereof is selected from the group consisting of propionic acid, acrylic acid, propiolic acid, malonic acid, tatronic acid, mesoxalic acid, dihydroxymalonic acid, pyruvic acid, lactic acid, hydracrylic acid, glyceric acid, glycidic acid, 2-aminopropanoic acid or a salt thereof, or combinations thereof; preferably, the C3 organic carboxylic acid or a salt thereof is selected from the group consisting of propionic acid or lactic acid and combinations thereof; more preferably, the C3 organic carboxylic acid or a salt thereof is selected from the group consisting of propionic acid or a salt thereof; more preferably, the C3 organic carboxylic acid or a salt thereof is selected from potassium propionate or sodium propionate; more preferably, the C3 organic carboxylic acid or a salt thereof is selected from potassium propionate. In preferred embodiments, the short-chain organic carboxylic acid or a salt thereof is a C3 organic carboxylic acid or a salt thereof as described herein. In preferred embodiments, the short-chain organic carboxylic acid or a salt thereof is a C2 organic carboxylic acid or a salt thereof as described herein. In embodiments of the invention, a composition as described herein is provided, wherein the composition comprises more than 2% by weight (of the total weight of the composition) of the short-chain organic carboxylic acid or a salt thereof, more than 4% by weight, more than 5% by weight, more than 6% by weight, more than 7% by weight, more than 8% by weight, more than 9% by weight, more than 10% by weight, more than 11% by weight, more than 12% by weight, more than 13% by weight, more than 14% by weight, more than 15% by weight, more than 16% by weight, more than 17% by weight, more than 18% by weight, more than 19% by weight, or more than 20% by weight. In preferred embodiments of the invention, a composition as described herein is provided comprising more than 10% by weight (in total weight of the composition) of the short-chain organic carboxylic acid or salt thereof, preferably more than 15% by weight. In embodiments of the invention, a composition as described herein is provided, wherein the composition comprises less than 50% by weight (in total weight of the composition) of the short-chain organic carboxylic acid or salt thereof, preferably less than 40% by weight, preferably less than 30% by weight. In embodiments of the invention, a composition is provided as described in rp j Lnn / zznz / E / Yi herein, wherein the composition comprises less than 10% by weight (in total weight of the composition) of the short-chain organic carboxylic acid or salt thereof, preferably less than 5% by weight. Combination of glycol and short-chain organic carboxylic acid or salt thereof In embodiments of the invention, a composition as described herein is provided, wherein the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is more than 16% by weight (of the total weight of the composition), more than 17% by weight, more than 18% by weight, more than 19% by weight, more than 20% by weight, more than 25% by weight, more than 30% by weight, more than 35% by weight, more than 40% by weight, or more than 45% by weight. In preferred embodiments of the invention, a composition as described herein is provided, wherein the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is more than 30% by weight (of the total weight of the composition), preferably more than 35% by weight, preferably more than 40% by weight. In embodiments of the invention, a composition as described herein is provided, wherein the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is less than 90% by weight (of the total weight of the composition), preferably less than 80% by weight, preferably less than 70% by weight. In highly preferred embodiments of the invention, a composition as described herein is provided, wherein the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is in the range of 30-70% by weight (in the total weight of the composition), preferably in the range of 35-65% by weight, more preferably in the range of 40-60% by weight. In embodiments of the invention, a composition as described herein is provided, wherein the composition comprises more than 5% by weight (combined weight of glycol and short-chain organic carboxylate) of the short-chain organic carboxylate, more than 6% by weight, more than 7% by weight, more than 8% by weight, more than 9% by weight, more than 10% by weight, more than 11% by weight, more than 12% by weight, more than 13% by weight, more than 14% by weight, more than 15% by weight, more than 16% by weight, more than 17% by weight, more than 18% by weight, more than 19% by weight, more than 20% by weight, more than 25% by weight, more than 30% by weight, or more than 35% by weight of the short-chain organic carboxylic acid or salt thereof. In preferred embodiments of the invention, a composition as described herein is provided, wherein the composition comprises more than 6% by weight (combined weight of glycol and short-chain organic carboxylate) of short-chain organic carboxylic acid or salt thereof, preferably more than 30% by weight. As illustrated in the accompanying examples and explained earlier herein, the inventors have surprisingly found that a glycol-based composition comprising a short-chain organic carboxylic acid or a salt thereof exhibits a sudden, non-linear increase in corrosion inhibition after increasing the concentration of the short-chain organic carboxylic acid or a salt thereof. However, the inventors have also found that extremely high ratios of short-chain organic carboxylic acid to glycol, as employed in particular de-icing fluids, are not required to obtain the enhanced corrosion effect.Accordingly, in embodiments of the invention, a composition as described herein is provided, wherein the composition comprises less than 50% by weight (combined weight of glycol and short-chain organic carboxylate) of the short-chain organic carboxylate, less than 48% by weight, less than 46% by weight, less than 44% by weight, less than 42% by weight, less than 40% by weight, less than 38% by weight, less than 36% by weight, less than 34% by weight, less than 32% by weight, less than 30% by weight, less than 28% by weight, less than 26% by weight, less than 24% by weight, less than 22% by weight, less than 20% by weight, less than 18% by weight, less than 16% by weight, or less than 14% by weight of the short-chain organic carboxylic acid or salt thereof. In preferred embodiments of the invention, a composition as described herein is provided, wherein the composition comprises less than 50% by weight (combined weight of glycol and short-chain organic carboxylate) of short-chain organic carboxylic acid or salt thereof, preferably less than 40% by weight. In highly preferred embodiments of the invention, a composition as described herein is provided, wherein the composition comprises 6-48% by weight (combined weight of glycol and short-chain organic carboxylate) of the short-chain organic carboxylic acid or salt thereof, preferably 7-45% by weight, more preferably 7-40% by weight. Long-chain organic carboxylic acids In certain embodiments of the invention, a composition as described herein is provided, wherein the composition further comprises a long-chain organic carboxylic acid corrosion inhibitor selected from the group consisting of Ce-Cie organic carboxylic acids or salts thereof, preferably Ce-Cu organic carboxylic acids or salts thereof. The preferred Ce-Cie organic carboxylic acids include hexanoic acid, heptanoic acid, isoheptanoic acid, octanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, nonanoic acid, isononanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, neodecanoic acid, cyclohexylbutyl acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and salts thereof. In certain embodiments of the invention, a composition as described herein is provided, wherein the composition further comprises a high carboxylic acid corrosion inhibitor selected from the group consisting of rp j Lnn / zznz / B / Yi - aliphatic C6-C9 monocarboxylic acids and salts thereof, preferably hexanoic acid, heptanoic acid, isoheptanoic acid, octanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, nonanoic acid and salts thereof; - aliphatic C6-C12 dicarboxylic acids and salts thereof, preferably adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid and salts thereof; - aromatic Ce-Cu monocarboxylic acids and salts thereof; preferably benzoic acid, salicylic acid, cinnamic acid, p-hydroxybenzoic acid, gallic acid, vanillic acid, syringic acid, trans-cinnamic acid, p-coumaric acid, caffeic acid, ferulic acid and salts thereof - aromatic Ce-Cu dicarboxylic acids and salts thereof, preferably italic acid, isophthalic acid, terephthalic acid, diphenic acid, 2,6-naphthalenedicarboxylic acid and salts thereof. Without wishing to be limited by any theory, the present inventors believe that these corrosion inhibitors generally do not exhibit any solubility problems at the concentrations commonly employed in glycol-based heat transfer fluids. In certain embodiments of the invention, a composition as described herein is provided, wherein the composition further comprises a long-chain organic carboxylic acid corrosion inhibitor selected from the group consisting of Ce-Cie aliphatic carboxylic acids and salts thereof, preferably Ce-Cu aliphatic dicarboxylic acids and salts thereof, preferably C8-C12 aliphatic dicarboxylic acids and salts thereof, more preferably Cs-Cw aliphatic dicarboxylic acids and salts thereof. In embodiments of the invention, the long-chain organic carboxylic acid corrosion inhibitors described herein are provided in the form of a salt consisting of the carboxylate anion and a cationic counterion. The cationic counterion is preferably selected from the group consisting of an alkaline earth metal cation, an alkali metal cation, an ammonium cation, or combinations thereof, more preferably an alkali metal cation, most preferably sodium or potassium, or combinations thereof. In embodiments of the invention, the ammonium cation is a quaternary ammonium cation represented by the formula (NRR'R''R”')+, where R, R', R” and R”' are independently selected from the group of branched or straight Ci-Ce alkyls and branched or straight Ci-Ce hydroxyalkyls, preferably methyl, ethyl, n-propyl, and isopropyl.In embodiments of the invention, the ammonium cation is a tertiary amine cation represented by the formula (HNRR'R)+ where R, R' and R'' are independently selected from the group of branched or straight alkyl and branched or straight hydroxyalkyl groups, preferably methyl, ethyl, n-propyl and isopropyl. In embodiments of the invention, the ammonium cation is a secondary amine cation represented by the formula (H2NRR')+ where R, and R' are independently selected from the group of branched or straight alkyl and branched or straight hydroxyalkyl groups, preferably methyl, ethyl, n-propyl and isopropyl.If the long-chain organic carboxylic acid or salt thereof is used in the form of a salt, the amount of long-chain organic carboxylic acid or salt thereof as used herein refers to the amount of organic carboxylate anion and cationic counterion (i.e., it includes the weight of the cationic counterion). In preferred embodiments of the invention, a composition as described herein is provided, wherein the composition further comprises more than 0.001% by weight (in total weight of the composition) of the long-chain organic carboxylic acid corrosion inhibitor described herein, preferably more than 0.01% by weight, preferably more than 0.1% by weight of the long-chain organic carboxylic acid corrosion inhibitor. In certain embodiments of the invention, a composition as described herein is provided, wherein the composition comprises less than 5% by weight (in the total weight of the composition) of the long-chain organic carboxylic acid corrosion inhibitor described herein, preferably less than 4% by weight, preferably less than 3% by weight, preferably less than 2% by weight, preferably less than 1% by weight of the long-chain organic carboxylic acid corrosion inhibitor. In preferred embodiments of the invention, a composition as described herein is provided, comprising the long-chain organic carboxylic acid corrosion inhibitor described herein in an amount within the range of 0.01-5% by weight (in the total weight of the composition), preferably in the range of 0.01-2% by weight, preferably in the range of 0.01-1% by weight. In certain embodiments of the invention, a composition as described herein is provided, wherein the composition comprises less than 1% by weight (in the total weight of the composition) of Ce-Cie aliphatic carboxylic acid and salts thereof, preferably less than 0.1% by weight, preferably less than 0.01% by weight, more preferably less than 0.001% by weight. Corrosion inhibition In embodiments of the invention, a composition as described herein is provided which exhibits an aluminum pitting corrosion potential of more than 0 mV, preferably more than 2500 mV when determined by rapid cyclic potentiokinetic polarization (RCP) scanning, preferably employing an AIMgS10.5 alloy working electrode. In highly preferred embodiments of the invention, a composition as described herein is provided which exhibits an aluminum pitting corrosion potential of more than 0 mV, preferably more than 2500 mV when determined according to the method described in the publications of CEBELCOR (Centre Belge d'Etude de la Corrosion) rp j Lnn / zznz / B / Yi Rapports Techniques, vol. 147, RT 272 (August 1984). In highly preferred embodiments of the invention, a composition as described herein is provided which exhibits an aluminum pitting corrosion potential of more than 0 mV, preferably more than 2500 mV when determined by altering the potential of a stagnant, epoxy-embedded, rod-shaped aluminum working electrode (alloy AIMgSi0.5) having a polished working surface (using 600 grit silicon carbide polishing paper) of 0.5 cm2 with a scan rate of 0.5 mV / s in 0.5 mV steps versus a solid platinum auxiliary electrode (ref. 6.0330.0040, supplier Metroohm) while immersed in 100 grams of test fluid and employing a solid silver reference electrode (ref. 6.0331).010, supplier Methrohom); record the current density flowing between the working and auxiliary electrodes as a function of the potential difference using a potentiostat (VeraSTAT; AmetekMRScientific Instruments); and identify the pitting corrosion potential Ep by a sudden exponential increase in current density. As will be understood by those skilled in the art, and as shown in the accompanying examples, depending on the presence and amount of other corrosion inhibitors, the minimum amount of low carboxylic acid or its salt required to achieve an aluminum pitting corrosion potential of more than 0 mV, and preferably more than 2500 mV when determined by rapid cyclic potentiokinetic polarization (RCP) scanning, will vary. It is within the routine capabilities of those skilled in the art, in view of this disclosure, to formulate compositions that exhibit an aluminum pitting corrosion potential of more than 2500 mV when determined by rapid cyclic potentiokinetic polarization (RCP) scanning. Additives In certain embodiments of the invention, the composition as defined herein further comprises one or more additives selected from the group consisting of additional corrosion inhibitors, antioxidants, anti-wear agents, surfactants, and / or antifoaming agents. In this context, additional corrosion inhibitors are to be understood as meaning corrosion inhibitors other than the low- and long-chain organic carboxylic acids and salts thereof described herein. The preferred additional corrosion inhibitors are selected from the group consisting of inorganic corrosion inhibitors, phosphonate corrosion inhibitors, azole corrosion inhibitors, and tlazole corrosion inhibitors. In certain embodiments of the invention, the composition further comprises more than 0.001% by weight (of the total weight of the composition) of the additives, preferably more than 0.01% by weight, preferably more than 0.1% by weight. In preferred embodiments, the composition of the invention further comprises one or more of the additives selected from the group consisting of thioazoles, triazoles, polyolefins, polyalkylene oxides, silicon oils, mineral oils, silicates, molybdates, nitrates, nitrites, phosphonates, and phosphates. In preferred embodiments, the composition of the invention further comprises one or more of the additives in an amount within the range of 0.001–10% by weight (of the total weight of the composition), preferably 0.01–5% by weight. In preferred embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a triazole, a thiazole, or a combination thereof, preferably an aromatic triazole, an aromatic thiazole, or a combination thereof. In preferred embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a corrosion inhibitor in the form of one or more triazoles selected from the group consisting of tolyltriazole, benzotriazole, or combinations thereof. In embodiments of the invention, a composition as defined herein is provided, wherein the composition comprises the triazole or thiazole, in an amount of more than 0.001% by weight (in the total weight of the composition), preferably more than 0.01% by weight, preferably more than 0.1% by weight and / or less than 3% by weight, preferably less than 1% by weight, preferably less than 0.35% by weight. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a defoaming agent. Preferably, the defoaming agent is selected from the group consisting of a polyolefin, a polyalkylene oxide, a silicon polymer (such as a 3D silicon polymer), or a silicon oil. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises the defoaming agent in an amount of more than 0.001% by weight (in the total weight of the composition), preferably more than 0.005% by weight, preferably more than 0.01% by weight and / or less than 1% by weight, preferably less than 0.25% by weight, preferably less than 0.1% by weight. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a corrosion inhibitor in the form of a molybdate, preferably an inorganic molybdate in an amount of more than 1 ppm (by total weight of the composition) 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 molybdate is used in the form of a salt, the amount of molybdate as used herein refers to the amount of molybdate anion (i.e., excluding the weight of the cationic counterion). In embodiments of the invention, a composition as defined in the present rp j Lnn / zznz / E / Yi is provided, wherein the composition further comprises a nitrate, preferably an inorganic nitrate in an amount of more than 1 ppm (by 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 nitrate is used in the form of a salt, the amount of nitrate as used in this document refers to the amount of nitrate anion (i.e., excluding the weight of the cationic counterion). In embodiments of the 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 (by 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 nitrite is used in the form of a salt, the amount of nitrite as used in this document refers to the amount of nitrite anion (i.e., excluding the weight of the cationic counterion). In embodiments of the invention, a composition as defined herein is provided, 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) of phosphonate, preferably more than 250 ppm, preferably more than 1000 ppm of phosphonate and / or less than 10000 ppm, preferably less than 5000 ppm, preferably less than 2500 ppm. If the phosphonate is used 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 cationic counterion). In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a corrosion inhibitor in the form of a phosphate, preferably an inorganic phosphate in an amount of more than 10 ppm (by total weight of the composition) 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 phosphate is used in the form of a salt, the amount of phosphate as used in this document refers to the amount of phosphate anion (i.e., excluding the weight of the cationic counterion). In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a corrosion inhibitor in the form of a silicate, preferably an inorganic silicate, preferably sodium metasilicate in an amount of more than 1 ppm of Si (by total weight of the composition), preferably more than 10 ppm of Si, more preferably more than 100 ppm of Si and / or less than 10000 ppm, preferably less than 1000 ppm, preferably less than 500 ppm. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises an antioxidant. Preferably, the antioxidant is selected from the group consisting of phenols, such as 2,6-di-t-butyl methylphenol and 4,4'-methylene-bis(2,6-di-t-butylphenol); aromatic amines, such as p,p-dioctylphenylamine, monooctyldiphenylamine, phenothiazine, 3,7-dioctylphenothiazine, phenyl-1-naphthylamine, phenyl-2-naphthylamine, alkylphenyl-1-naphthalamines, and alkylphenyl-2-naphthalamines; and sulfur-containing compounds, for example, dithiophosphates, phosphites, sulfides, and dithio-metal salts, such as benzothiazole, tin-dialkyldithiophosphates, and zinc diaryldithiophosphates. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises the antioxidant in an amount of more than 0.001% by weight (in the total weight of the composition), preferably more than 0.005% by weight, preferably more than 0.01% by weight and / or less than 10% by weight, preferably less than 5% by weight, preferably less than 3% by weight. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises an anti-wear agent. Preferably, the anti-wear agent is selected from the group consisting of phosphate esters, phosphites, thiophosphites, for example, zinc dialkyl dithiophosphates, zinc diaryldithiophosphates, tricresyl phosphates, chlorinated waxes, sulfurized greases, and olefins, such as thiodipropionic esters, dialkyl sulfides, dialkyl polysulfides, alkyl mercaptans, dibenzothiophenes, and 2,2'-dithios (benzothiazole); lead compounds, fatty acids, halogen-substituted organosilicon compounds, and halogen-substituted phosphorus compounds. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises the anti-wear agent in an amount of more than 0.001% by weight (in the total weight of the composition), preferably more than 0.005% by weight, preferably more than 0.01% by weight and / or less than 10% by weight, preferably less than 5% by weight, preferably less than 3% by weight. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a surfactant. Preferably, the surfactant is selected from the group consisting of anionic surfactants, such as anionic surfactants that are the salt of a compound represented by RX; 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: - C5-C24 branched or straight chain alkyl groups; rp j Lnn / zznz / E / Yi - C5-C24 mono-unsaturated alkenyl groups of branched or straight chain; - C5-C24 poly-unsaturated alkenyl groups of branched or straight chain; - alkylbenzene groups comprising a C8-C15 alkyl; - alkenylbenzene groups comprising a C8-C15 alkenyl; - alkylnaphthalene groups comprising a C3-C15 alkyl; - alkenylnaphthalene groups comprising a C3-C15 alkenyl; - alkylphenol groups comprising a Cs-Cis alkyl; and - alkenylphenol groups comprising a Ce-Ois alkenyl. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises the surfactant in an amount of more than 0.001% by weight (in the total weight of the composition), preferably more than 0.005% by weight, preferably more than 0.01% by weight and / or less than 10% by weight, preferably less than 5% by weight, preferably less than 3% by weight. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a scale inhibitor. Preferably, the scale inhibitor is selected from the group consisting of chelating agents, threshold precipitation inhibitors, or combinations thereof. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a scale inhibitor that is a chelating agent selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), citric acid, and gluconic acid. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises a scale inhibitor that is a threshold precipitation inhibitor selected from the group consisting of polyphosphates (for example, sodium triphosphate or sodium hexametaphosphate).phosphonates (e.g., aminotrimethylenephosphonic acid (ATMP), ethylenediaminetetramethylenephosphonic acid (EDTMP), diethylenetriaminepentamethylenephosphonic acid (DETPMP), pentaethylenehexamineoctakisethylenephosphonic acid (PEHOMP), 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), 2-phosphonobutane-1,2,4-tricarboxylic acid (2-PBTCA), polyvinylphosphonic acid (PPA), phosphinocarboxylic acids (PCAs) such as poly(phosphinoacrylic) acid (PPCA) or phosphinocarboxylic acid (SPOCA)); polycarboxylic acids and their derivatives (for example, polymers of maleic anhydride, maleic acid, acrylic acid or methacrylic acid; copolymers of these polymers employing an additional monomer such as acrylamide, vinyl sulfonic acid, sulfonated styrene, and itaconic acid;epoxycarboxylic acid polymers such as polyepoxysuccinic acid or amino acid polymers such as polyaspartic acid. In embodiments of the invention, a composition as defined herein is provided, wherein the composition further comprises the scale inhibitor in an amount of rp j Lnn / zznz / B / Yi more than 0.001% by weight (in the total weight of the composition), preferably more than 0.005% by weight, preferably more than 0.01% by weight and / or less than 10% by weight, preferably less than 5% by weight, preferably less than 3% by weight. As will be understood by those skilled in the art, depending on (for example) the intended application, the compositions according to the invention can be formulated and used at various concentrations. Accordingly, the invention is not particularly limited by the maximum concentration of the glycol or the short-chain organic carboxylic acid, or by the concentration of the other additives described herein. Therefore, depending on the intended application, the compositions described herein may be suitable for use as is, or may require dilution with a base fluid prior to use. However, the present inventors have found it particularly advantageous to provide the compositions of the invention in the form of a ready-to-use composition that may be suitable for use as a combustion engine coolant or in the form of a concentrate that is suitable for preparing the ready-to-use composition. Ready-to-use composition In a highly preferred embodiment of the invention, the composition as described herein is provided in the form of a ready-to-use composition wherein the composition further comprises water and wherein - the combined amount of glycol and the short-chain organic carboxylic acid or salt thereof is in the range of 30-70% by weight (of the total weight of the composition), preferably in the range of 35-65% by weight, more preferably in the range of 40-60% by weight; and - the combined amount of water, glycol and short-chain organic carboxylic acid or salt thereof is more than 90% by weight (of the total weight of the composition), preferably more than 95% by weight, preferably more than 98% by weight, and more preferably more than 99% by weight. In preferred embodiments of the invention, the ready-to-use composition is provided, wherein the ready-to-use composition comprises more than 30% by weight (of the total weight of the composition) of water, such as more than 35% by weight, more than 40% by weight, more than 45% by weight, more than 50% by weight, more than 55% by weight, more than 60% by weight, or more than 65% by weight. Preferred combination modes, ready to use Accordingly, in highly preferred embodiments of the invention, a composition comprising: is provided - water - more than 5% by weight (in the total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol or combinations thereof; and - more than 1% by weight (in the total weight of the composition), preferably more than 2% by weight of a short-chain organic carboxylic acid or a salt thereof selected from the group consisting of C2 organic carboxylic acids or salts thereof, C3 organic carboxylic acids or salts thereof and combinations thereof; wherein the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is in the range of 30-70% by weight (in the total weight of the composition), preferably in the range of 35-65% by weight, more preferably in the range of 40-60% by weight; wherein the combined amount of water, glycol, and short-chain organic carboxylic acid or salt thereof is more than 95% by weight (of the total weight of the composition), preferably more than 98% by weight, and more preferably more than 99% by weight; and wherein the glycol is preferably selected from monoethylene glycol, monopropylene glycol, and combinations thereof. In highly preferred embodiments, the composition comprises more than 6% by weight (of the combined weight of the glycol and the short-chain organic carboxylate) of the short-chain organic carboxylic acid or salt thereof, preferably more than 30% by weight. In preferred embodiments of the invention, a composition comprising: - water - more than 5% by weight (of the total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol or combinations thereof; and - more than 1% by weight (of the total weight of the composition), preferably more than 2% by weight, plus preferably more than 10% by weight of a C30 organic carboxylic acid or a salt thereof, preferably propionic acid or a salt thereof, plus preferably potassium propionate; wherein the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is in the range of 30-70% by weight (in the total weight of the composition), preferably in the range of 35-65% by weight, more preferably in the range of 40-60% by weight; wherein the combined amount of water, glycol, and the C3 organic carboxylic acid or a salt thereof is more than 95% by weight (of the total weight of the composition), preferably more than 98% by weight, and more preferably more than 99% by weight; and wherein the glycol is preferably selected from monoethylene glycol, monopropylene glycol, and combinations thereof. In highly preferred embodiments, the composition is provided comprising more than 6% by weight (of the combined weight of the glycol and the short-chain organic carboxylate) of the C3 organic carboxylic acid or a salt thereof, preferably more than 30% by weight. In preferred embodiments of the invention, a composition comprising: - water - more than 5% by weight (of the total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol or combinations thereof; and - more than 1% by weight (of the total weight of the composition), preferably more than 2% by weight, more preferably more than 10% by weight, more preferably more than 15% by weight of a C2 organic carboxylic acid or a salt thereof, preferably acetic acid or a salt thereof, more preferably potassium acetate; wherein the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is in the range of 30-70% by weight (in the total weight of the composition), preferably in the range of 35-65% by weight, more preferably in the range of 40-60% by weight; wherein the combined amount of water, glycol, and C2 organic carboxylic acid or a salt thereof is more than 95% by weight (of the total weight of the composition), preferably more than 98% by weight, and more preferably more than 99% by weight; and wherein the glycol is preferably selected from monoethylene glycol, monopropylene glycol, and combinations thereof. In highly preferred embodiments, the composition comprises more than 6% by weight (of the combined weight of the glycol and the short-chain organic carboxylate) of the C2 organic carboxylic acid or a salt thereof, preferably more than 30% by weight. |dH In preferred embodiments of the invention, a composition is provided, preferably a ready-to-use composition as defined herein, wherein the composition has a pH between 7.5 and 10. Concentrated In another aspect of the invention, a composition as defined herein is provided in the form of a concentrate suitable for preparing the ready-to-use composition described herein above. In preferred embodiments, the concentrate is suitable for preparing the ready-to-use composition described herein by the addition of water and / or alcohol; preferably by the addition of water, monoethylene glycol, monopropylene glycol, 1,3-propanediol, and / or glycerol; more preferably by the addition of water. In highly preferred embodiments, the concentrate is suitable for preparing the ready-to-use composition solely by the addition of water and / or alcohol; preferably solely by the addition of water, monoethylene glycol, monopropylene glycol, 1,3-propanediol, and / or glycerol; more preferably solely by the addition of water (i.e., it is not necessary to add any other ingredients to prepare the ready-to-use composition described herein from the concentrate). In certain embodiments of the invention, the concentrate comprises more than 70% by weight (of the total weight of the concentrate) of a polyalcohol, preferably a polyalcohol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, and glycerol. Preparation methods In another aspect of the invention, a method is provided for preparing a composition as defined herein, comprising the steps of: (i) provide a short-chain organic carboxylic acid or salt thereof as described herein; (i) provide a glycol as described herein; (ii) optionally provide a long-chain organic carboxylic acid or a salt thereof as described herein; (iv) optionally provide additional additives as defined herein; and (v) combine the short-chain organic carboxylic acid or salt thereof from step (i) with the glycol from step (i), the optional high carboxylic acid or salt thereof from step (ii) and the optional additional additives from step (iv) to obtain the composition. According to the invention, the order of addition of the compounds is not particularly limited. In another aspect of the invention, a method is provided for preparing a ready-to-use composition as defined herein, comprising the steps of: (i) provide a concentrate as defined above herein; (ii) provide water, alcohol or a mixture thereof; (ii) optionally provide additional additives as defined herein above; and (iv) combine the concentrate from step (i) with the water, alcohol or a mixture thereof from step (i) and the optional additional additives from step (ii) to obtain the ready-to-use composition. Preferred embodiments provide a method for preparing a ready-to-use composition as defined herein, consisting of the following steps: (i) provide a concentrate as defined above herein; (i) provide water, alcohol or a mixture thereof; (ii) combine the concentrate from step (i) with the water, alcohol or a mixture of these from step (i) to obtain the ready-to-use composition. In highly preferred embodiments, the alcohol in step (i) is selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol, and combinations thereof. In preferred embodiments, step (i) consists of providing water. In preferred embodiments, step (i) comprises providing more than 50% by weight (by weight of concentrate) of water, alcohol or a mixture thereof, preferably more than 100% by weight, more than 150% by weight, more than 200% by weight or more than 350% by weight of water, alcohol or a mixture thereof. Uses / Methods In another aspect of the invention, the use of the composition described above is provided herein, preferably the ready-to-use composition provided herein, as a heat transfer fluid, preferably as a heat transfer fluid in a combustion engine, turbocharger cooler, exhaust gas recovery cooler, brake heat recovery system, solar system, fuel cell, electric motor, generator, battery, battery electric vehicle, or electronic equipment, more preferably as a heat transfer fluid in a combustion engine. In another aspect of the invention, a method for inhibiting corrosion is provided, comprising contacting the composition, preferably the ready-to-use composition provided herein, with a metallic surface. In another aspect of the invention, a combustion engine, a turbocharger cooler, an exhaust gas recovery cooler, a brake heat recovery system, a solar system, a fuel cell, an electric motor, a generator, or electronic equipment comprising the composition, preferably the ready-to-use composition as described herein, is provided. In another aspect of the invention, a method for exchanging heat is provided, comprising: a. generating heat in a selected system of a combustion engine, turbocharger cooler, exhaust gas recovery cooler, brake heat recovery system, solar system, fuel cell, electric motor, generator, battery, battery electric vehicle, or electronic equipment, preferably in a combustion engine; b. bringing into contact a composition as described herein, preferably a ready-to-use composition as described herein, with the system of step a; c. transfer heat from the system to the composition; d. pass the composition through a heat exchanger; and e. transfer heat away from the composition. In another aspect of the invention, the use of a short-chain organic carboxylic acid selected from the group consisting of C2 organic carboxylic acids or salts thereof, C3 organic carboxylic acids or salts thereof, and combinations thereof, preferably selected from the group consisting of propionic acid and salts thereof, acetic acid and salts thereof, and combinations thereof, is provided for increasing the corrosion inhibition of a composition comprising more than 5% by weight (in total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol, or combinations thereof; preferably for increasing the pitting corrosion potential, more preferably for increasing the pitting corrosion potential of aluminum.In preferred embodiments of the invention, a short-chain organic carboxylic acid selected from the group consisting of C2 organic carboxylic acids or salts thereof, C3 organic carboxylic acids or salts thereof, and combinations thereof, preferably selected from the group consisting of propionic acid and salts thereof, acetic acid and salts thereof, and combinations thereof, is used to increase the corrosion inhibition of a composition comprising more than 5% by weight (in total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, and combinations thereof; preferably to increase the pitting corrosion potential, more preferably to increase the pitting corrosion potential of aluminum. Examples All weight percent values ​​in Tables 1-4 are based on the total weight of the composition (unless otherwise stated). The corrosion inhibitor solution consists of 23 weight percent of a mixture of Os and C10 carboxylic acid salts (where the weight percent is calculated based on the organic carboxylate anion (i.e., excluding the weight of the cationic counterion)) in water. The corrosive water comprises 148 milligrams of sodium sulfate, 165 milligrams of sodium chloride, 138 mg of sodium bicarbonate, and 364 mg of calcium chloride dihydrate dissolved in 1 liter of water. The pitting corrosion potential is measured by rapid cyclic potentiokinetic polarization (RCP) scanning according to the method described in the publications of CEBELCOR (Centre Belge d'Etude de la Corrosion) Rapports Techniques, vol. 147, RT 272 (August 1984) described above in the present.A higher Ep value indicates more effective prevention of localized corrosion. rp j Lnn / zznz / B / Yii Table 1: Monoethylene glycol-based samples with potassium propionate Example Monoethylene glycol (% by weight) Potassium propionate (% by weight) Potassium propionate (% by weight*) Corrosion inhibitor solution (% by weight) Deionized water (% by weight) Corrosive water (% by weight) Pitting corrosion potential Ep (mV) A1 30 0 0.0 0 22.5 47.5 -571 A2 22.5 7.5 25.0 0 22.5 47.5 396 A3 15 15.0 50.0 0 22.5 47.5 >2500 A4 7.5 22.5 75.0 0 22.5 47.5 >2500 A5 30 0 0.0 3 19.5 47.5 -270 A6 30 0.8 2.4 3 18.7 47.5 -187 A7 29.3 1.5 4.9 3 18.7 47.5 -82 A9 26.3 3.7 12.5 3 19.5 47.5 >2500 A10 22.5 7.5 25.0 3 19.5 47.5 >2500 A11 15 15.0 50.0 3 19.5 47.5 >2500 A12 7.5 225 75.0 3 19.5 47.5 >2500 rp j Lnn / zznz / B / Yii in combined weight of monoethylene glycol and potassium propionate Table 2: Samples based on monopropylene glycol with potassium propionate (B) Example Monopropylene glycol (% by weight) Potassium propionate (% by weight) Potassium propionate (% by weight*) Corrosion inhibitor solution (% by weight) Deionized water (% by weight) Corrosive water (% by weight) Pitting corrosion potential (mV) B1 30.0 0.0 0.0 0 22.5 47.5 -578 B2 28.5 1.5 5.0 0 22.5 47.5 -194 B3 15.0 15.0 50.0 0 22.5 47.5 >2500 B4 29.3 1.5 4.9 3 18.7 47.5 -157 B5 28.1 2.6 8.5 3 18.7 47.5 >2500 B6 22.5 7.5 25.0 3 19.5 47.5 >2500 combined weight of monopropylene glycol and potassium propionate Table 3: Glycerol-based samples with potassium propionate (C) Sample Glycerol (% by weight) Potassium Propionate (% by weight) Potassium Propionate (% by weight *) Corrosion Inhibitor Solution (% by weight) Deionized Water (% by weight) Corrosive Water (% by weight) Pitting Corrosion Potential (mV) C1 30.0 0.0 0.0 0 22.5 47.5 -658 C2 28.5 1.5 5.0 0 22.5 47.5 -250 C3 27.4 2.6 8.7 0 22.5 47.5 -191 C4 15.0 15.0 50.0 0 22.5 47.5 >2500 C5 29.3 1.5 4.9 3 18.7 47.5 752 C6 28.1 2.6 8.5 3 18.7 47.5 >2500 C7 22.5 7.5 25.0 3 19.5 47.5 >2500 combined weight of glycerol and potassium propionate Table 4: Ethylene glycol-based samples with potassium acetate (D) Sample Monoethylene glycol (% by weight) Potassium acetate (% by weight) Potassium acetate (% by weight *) Corrosion inhibitor solution (% by weight) Deionized water (% by weight) Corrosive water (% by weight) Pitting corrosion potential (mV) D1 38.0 2 5.0 0 30 30 27 D2 35.0 5 12.5 0 30 30 575 D3 30.0 10 25.0 0 30 30 1240 D4 20.0 20 50.0 0 30 30 >2500 by combined weight of monoethylene glycol and potassium acetate

Claims

1. A composition comprising: - more than 5% by weight (in total weight of the composition) of a glycol selected from the group consisting of monoethylene glycol, monopropylene glycol, 1,3-propanediol, glycerol or combinations thereof; and - more than 2% by weight (in total weight of the composition) of a short-chain organic carboxylic acid or a salt thereof selected from the group consisting of C2 organic carboxylic acids or salts thereof, C3 organic carboxylic acids or salts thereof, and combinations thereof; wherein the combined amount of the glycol and the short-chain organic carboxylic acid or salt thereof is more than 15% by weight (in total weight of the composition); wherein the composition exhibits an aluminum pitting corrosion potential of more than 2500 mV when determined by rapid cyclic potentiokinetic polarization (RCP) scanning, preferably employing an AlMgSiO₂ alloy working electrode.5; and wherein the composition further comprises a long-chain organic carboxylic acid corrosion inhibitor selected from the group consisting of Ce-Cie organic carboxylic acids or salts thereof, preferably Ce-Cu organic carboxylic acids or salts thereof.

2. The composition according to claim 1 comprising more than 10% by weight (in the total weight of the composition) of the short-chain organic carboxylic acid or salt thereof, preferably more than 15% by weight.

3. The composition according to claim 1 or 2 comprising more than 6% by weight (combined weight of glycol and short-chain organic carboxylate) of short-chain organic carboxylic acid or salt thereof, preferably more than 30% by weight.

4. The composition according to any of claims 1-3, comprising more than 10% by weight (in total weight of the composition) of glycol, preferably more than 20% by weight, preferably more than 50% by weight.

5. The composition according to any of claims 1-4, further comprising water.

6. The composition according to any of claims 1-5, wherein the short-chain organic carboxylic acid or a salt thereof is a C3 organic carboxylic acid or a salt thereof; preferably a C3 organic carboxylic acid or a salt thereof selected from the group consisting of propionic acid or a salt thereof, acrylic acid or a salt thereof, propiolic acid or a salt thereof, malonic acid or a salt thereof, tatronic acid or a salt thereof, mesoxalic acid or a salt thereof, dihydroxymalonic acid or a salt thereof, pyruvic acid or a salt thereof, lactic acid or a salt thereof, hydracrylic acid or a salt thereof, glyceric acid or a salt thereof, glycidic acid or a salt thereof, or combinations thereof; more preferably a C3 organic carboxylic acid or a salt thereof selected from the group consisting of propionic or lactic acid and combinations thereof;more preferably a C3 organic carboxylic acid or a salt thereof selected from the group consisting of propionic acid or a salt thereof; more preferably potassium propionate.

7. The composition according to any of claims 1-5, wherein the short-chain organic carboxylic acid or a salt thereof is a C2 organic acid or a salt thereof, preferably acetic acid or a salt thereof, oxalic acid or a salt thereof, glyoxylic acid or a salt thereof, or combinations thereof, most preferably potassium acetate.

8. The composition according to any of claims 1-7, wherein the long-chain organic carboxylic acid corrosion inhibitor is selected from the group consisting of - C6-C9 aliphatic monocarboxylic acids and salts thereof; - C6-C12 aliphatic dicarboxylic acids and salts thereof; - Ce-Cu aromatic monocarboxylic acids and salts thereof; and - C6-C14 aromatic dicarboxylic acids and salts thereof.

9. The composition according to any of claims 1-8, wherein the long-chain organic carboxylic acid corrosion inhibitor is selected from the group consisting of Ce-Cie aliphatic carboxylic acids and salts thereof, preferably Ce-Cw aliphatic dicarboxylic acids and salts thereof, preferably C8-C12 aliphatic dicarboxylic acids and salts thereof, more preferably Ce-Cio aliphatic dicarboxylic acids and salts thereof.

10. The composition according to claim 9, comprising less than 0.1% by weight (in total weight of the composition) of Ce-Cw organic carboxylic acids or salts thereof, preferably less than 0.01% by weight.

11. The composition according to any of claims 1-10, further comprising one or more additives selected from the group consisting of additional corrosion inhibitors, antioxidants, anti-wear agents, surfactants, scale inhibitors, antifoaming agents in an amount within the range of 0.001-10% by weight (in the total weight of the composition), preferably within the range of 0.01-5% by weight.

12. The composition according to any of claims 1-11, which is a ready-to-use composition, wherein the composition further comprises water and wherein - the combined amount of glycol and short-chain organic carboxylic acid or salt thereof is in the range of 30-70% by weight (in the total weight of the composition), preferably in the range of 35-65% by weight, more preferably in the range of 40-60% by weight; and - the combined amount of water, glycol and short-chain organic carboxylic acid or salt thereof is more than 95% by weight (in the total weight of the composition), preferably more than 98% by weight, more preferably more than 99% by weight.

13. The composition according to any of claims 1-12, which is a concentrate suitable for preparing the ready-to-use composition according to claim 12.

14. The composition according to claim 13, wherein the concentrate is suitable for preparing the ready-to-use composition according to claim 12 by adding water and / or alcohol, preferably only by adding water, monoethylene glycol, monopropylene glycol, 1,3-propanediol and / or glycerol; more preferably only by adding water.