SOLID REFRIGERANT CONCENTRATES AND THEIR PRODUCTION.

Description

[0001] The present invention describes new coolant concentrates, their production and use.

[0002] Coolants used in mobile or stationary combustion engines, as well as in cooling circuits of electric vehicles or combinations of vehicles with electric and combustion engines by the end user, are generally liquid mixtures of water, glycols, corrosion inhibitors, bases and other components.

[0003] To reduce the volumes to be transported, concentrates are usually sold in which the water content is omitted or significantly reduced. The refrigerants are then prepared by the end user from these concentrates by adding water.

[0004] To further reduce the volumes to be transported, so-called superconcentrates are often produced centrally, in which not only the water but also the glycol content is omitted or significantly reduced. Formulators then use these superconcentrates to produce the final concentrates regionally by blending them with glycols.

[0005] Despite these described concentrations, there is still a need for a further reduction in the volumes to be transported in order to simplify logistics, save transport capacity and reduce the impact of transport on the environment.

[0006] Commercially available are highly concentrated or partially solid coolant additives, also known as supplemental cooling additives (SCAs), which are added by the end user to a coolant already in use to replenish corrosion inhibitors and bases consumed during operation. Due to their concentrated form, they are not capable of replenishing water or glycols in the coolant.

[0007] Such SCAs are described, for example, in US 5643493 or US 6733687.

[0008] German patent DE 3016623 OS describes aqueous mixtures of orthophosphoric acid and dicarboxylic acids that, for example, reduce the corrosion of cast iron and cast aluminum in coolants. These mixtures of compounds, optionally with further additives, can be added to the coolants in the form of a concentrated liquid or a powder mixture.

[0009] US 5643493 describes such SCAs according to which only inorganic compounds are used as corrosion inhibitors, such as phosphates, silicates, borates, nitrites, nitrates, and molybdates. The only organic class of corrosion inhibitors are azoles.

[0010] The organic carboxylic acids commonly used as corrosion inhibitors in modern coolants are not described.

[0011] US 6733687 describes SCAs that can be used as a solid, paste or liquid concentrate and contain aromatic monocarboxylic acids or dicarboxylic acids alongside inorganic components and azoles.

[0012] Nitrites, especially sodium nitrite (NaNO₂), are a mandatory component of SCAs according to US 6733687, acting as an inhibitor against the corrosion of ferrous materials. However, since nitrites exhibit pronounced toxicity, their use should be avoided.

[0013] Typically, nitrites are replaced as inhibitors against the corrosion of ferrous materials by aliphatic monocarboxylic acids, see US 9328278.

[0014] A person skilled in the art who attempts to produce solid mixtures analogous to US 6733687, replacing nitrites with aliphatic monocarboxylic acids, will find that the presence of aliphatic monocarboxylic acids causes the resulting mixtures to be sticky and therefore unsuitable for use in solid applications. Bulk quantities of solid mixtures would clump together and thus not remain free-flowing, significantly hindering storage, transport, and technical application.

[0015] The object of the present invention was therefore to provide solid coolant concentrates that are easily convertible into a stable, solid application form and are nitrite-free, while exhibiting good inhibition of the corrosion of ferrous materials.

[0016] The problem was solved by nitrite-free solid compositions suitable for the production of liquid antifreeze for cooling systems with corrosion protection, containing not more than 10, preferably not more than 7.5 and particularly preferably not more than 5 wt% water (A) not more than 10, preferably not more than 7.5 and particularly preferably not more than 5 wt% alkylene glycol, alkylene glycol monoalkyl ether and glycerol (B), as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the proportion of components inhibitors (C), inorganic bases (D) and other (E) in total, based on the entire composition, is 90 to 95 wt%, the proportion of aliphatic monocarboxylic acids in the entire composition does not exceed 1 wt%, the proportion of nitrites in the entire composition does not exceed 0.25 wt%, and the sum of all components always equals 100 wt%.

[0017] The compositions according to the invention can be easily produced in solid form, are less toxicologically concerning due to the absence of nitrites, and can be easily processed into superconcentrates, concentrates, and coolants.

[0018] Furthermore, they represent the most highly concentrated form of the active components of refrigerants, so that only the smallest possible quantities need to be moved during transport in order to produce superconcentrates, concentrates, and refrigerants decentrally from the compositions according to the invention. This represents a saving in energy or, more generally, in CO₂ equivalents, and thus a reduction in the CO₂ balance. Components (A) Water

[0019] The water used in the present invention should be neutral with a pH value of around 7; it can be demineralized or distilled water, but this is not strictly necessary. To enable the use of hard water, the composition according to the invention generally contains at least one hard water stabilizer (see below). (B) Alkylene glycol, alkylene glycol monoalkyl ethers and glycerin

[0020] Component (B) is responsible for the main freezing point depression in the coolants. It consists of monomeric to tetrameric 1,2-ethylene glycols, 1,2-propylene glycols, or, less frequently, 1,3-propylene glycols, preferably monomeric to trimeric 1,2-ethylene glycols or 1,2-propylene glycols, particularly preferably monomeric or dimeric 1,2-ethylene glycols, and most preferably monomeric 1,2-ethylene glycol, as well as mixtures thereof.

[0021] The alkylene glycol monoalkyl ethers are the mono-C 1 -C 4 -alkyl ethers of the above-mentioned alkylene glycols, preferably the mono methyl, ethyl or n-butyl ethers, particularly preferably the mono methyl or n-butyl ethers and most preferably the mono methyl ethers.

[0022] Furthermore, glycerin or glycerin oligomers are possible components (B).

[0023] Preferred alkylene glycol components or derivatives are in particular monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol and mixtures thereof, but also monopropylene glycol, dipropylene glycol and mixtures thereof, polyglycols, glycol ethers, for example monoethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, monoethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, monoethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether and tetraethylene glycol mono-n-butyl ether, or glycerin, each used alone or as mixtures thereof.

[0024] Particularly preferred are monoethylene glycol alone or mixtures of monoethylene glycol as the main component, i.e., with a content in the mixture of more than 50 wt.%, in particular more than 80 wt.%, especially more than 95 wt.%, with other alkylene glycols or derivatives of alkylene glycols. Inhibitors (C)

[0025] The inhibitors (C) act as corrosion inhibitors against metal corrosion, for example of ferrous materials, aluminium, non-ferrous metals or solder.

[0026] The compositions according to the invention contain (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound. Inorganic inhibitors (C1)

[0027] The inorganic inhibitors (C1) are silicates, borates, nitrates, molybdates, or phosphates, or mixtures thereof, in the form of their free acids or their salts, especially their alkali metal salts, and particularly preferably their sodium or potassium salts. The form in which they are present (protonated or as salts) in the compositions, superconcentrates, concentrates, or coolants depends on the respective pKa value of the compound and the composition, as well as the pH of the respective medium, which is determined by the amount of base (D).

[0028] The inorganic silicates act predominantly as an inhibitor of aluminum corrosion and are mostly used as alkali metal salts or, less frequently, as magnesium, calcium, or aluminum salts, preferably as sodium or potassium salts.

[0029] The silicates are preferably selected from the group consisting of orthosilicates (SiO 4 4-< ), metasilicates (SiO 3 2-< ), and pyrosilicates (Si 2 O 7 6-< ), particularly preferably metasilicates (SiO 3 2-< ), most preferably sodium metasilicate (Na 2 SiO 3 ) or potassium metasilicate (K 2 SiO 3 ), in particular sodium metasilicate (Na 2 SiO 3 ).

[0030] If the solid composition according to the invention contains at least one silicate, in a preferred embodiment at least one silicophosphonate is added in addition to the silicate, as described in the unpublished European patent application with application number 20213979.6 and the filing date of December 15, 2020.

[0031] The silicophosphonate is preferably a compound of the general formula wherein R 5< is a divalent organic residue, preferably a 1,ω-alkylene group with 1 to 6, preferably 1 to 4 carbon atoms, particularly preferably methylene, 1,2-ethylene, 1,2-propylene, 1,3-propylene or 1,4-butylene, very preferably 1,2-ethylene or 1,3-propylene and particularly 1,2-ethylene, R 6< independently of one another hydrogen, C 1 to C 4 alkyl or hydroxy-C 2 to C 4 alkyl, preferably hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl or tert-butyl, 2-hydroxyethyl or 2-hydroxypropyl, particularly preferably hydrogen, methyl, ethyl or propyl, and R 7< is C 1 to C 4 alkyl, preferably methyl, ethyl, n-propyl or n-Butyl, particularly preferably Methyl, Ethyl or n-Butyl, most preferably Methyl or Ethyl and particularly Methyl.

[0032] The silicophosphonates can be used as a free acid or as an alkali metal salt, preferably as a sodium or potassium salt and particularly preferably as a sodium salt.

[0033] The borates are preferably used as sodium tetraborate (borax) or as potassium tetraborate, particularly preferably as sodium tetraborate.

[0034] The nitrates are used as alkali or alkaline earth metal nitrates, preferably as sodium nitrate, potassium nitrate or magnesium nitrate, preferably as sodium nitrate or potassium nitrate, particularly preferably as sodium nitrate.

[0035] The phosphates are used as free acid (H3PO4), as hydrogen phosphate, dihydrogen phosphate or phosphate, preferably as sodium or potassium salt.

[0036] The use of the corresponding diphosphates, triphosphates or oligophosphates is also conceivable, but they are preferably used as monomeric phosphates.

[0037] Preferred is its use as free acid (H3PO4), disodium hydrogen phosphate or trisodium phosphate.

[0038] Preferably, the components (C1) are at least one compound selected from the group consisting of silicates, borates, nitrates or phosphates, and particularly preferably at least one compound selected from the group consisting of silicates, nitrates or phosphates. (C2a) Aromatic monocarboxylic acid

[0039] The optional aromatic monocarboxylic acid is preferably benzoic acid, which can be used as a free acid or, more preferably, in the form of its alkali metal salt, most preferably sodium benzoate.

[0040] In a preferred embodiment of the present invention, no aromatic monocarboxylic acid is present. (C3) Organic dicarboxylic acid containing 4 to 20 carbon atoms

[0041] The organic dicarboxylic acids having 4 to 20 carbon atoms are linear or branched alkandicarboxylic acids, preferably linear alkandicarboxylic acids or alkenedicarboxylic acids, particularly preferably alkandicarboxylic acids, particularly preferably with 5 to 14 and most preferably with 6 to 12 carbon atoms.

[0042] Preferably, the dicarboxylic acids (C3) are selected from the group consisting of succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid (heptanedioic acid), azelaic acid (nonanedioic acid), sebacic acid (decanedioic acid), undecanedioic acid, dodecanedioic acid, as well as alkyl and alkenyl succinic and glutaric acids such as 2-methylbutanedioic acid, 2-ethyl-3-methylbutanedioic acid, 2-ethylpentanedioic acid, 2-dodecylbutanedioic acid, 2-dodecenylbutanedioic acid, 2-phenylbutanedioic acid, 2-(p-methylphenyl)butanedioic acid, 2,2-dimethylbutanedioic acid, 2,3,4-trimethylpentanedioic acid, 2,2,3-trimethylpentanedioic acid, glutaconic acid (pent-2-enedioic acid), itaconic acid, hex-2-enedioic acid, Hex-3-enedioic acid, 5-methyl-hex-2-enedioic acid and 2,3-diemethyl-pent-2-enedioic acid.

[0043] Among these, the dicarboxylic acids having 6 to 12 carbon atoms are preferred, particularly among these the alkandicarboxylic acids having 6 to 12 carbon atoms, and most particularly preferred the linear alkandicarboxylic acids having 6 to 12 carbon atoms.

[0044] Particularly preferred as dicarboxylic acids (D3) are adipic acid, sebacic acid, azelaic acid and dodecanedicarboxylic acid. (C4) Azole compound

[0045] In this document, azole derivatives (C4) are defined as five-membered heterocyclic compounds with 2 or 3 heteroatoms from the nitrogen and sulfur group, which contain no or at most one sulfur atom incorporated into the ring and which may optionally bear an aromatic or saturated six-membered anellant.

[0046] These five-membered heterocyclic compounds (azole derivatives) typically contain as heteroatoms two N atoms and no S atom, 3 N atoms and no S atom, or one N atom and one S atom.

[0047] Preferred groups of the aforementioned azole derivatives are fused imidazoles and fused 1,2,3-triazoles of the general formula or in which the variable R represents hydrogen or a C 1 to C 10 alkyl group, especially methyl or ethyl, and the variable X represents a nitrogen atom or the group CH.

[0048] Typical and preferred examples of azole derivatives of general formula (III) are benzimidazole (X = CH, R = H), benzotriazole (X = N, R = H), and tolutriazole (tolyltriazole) (X = N, R = CH3). A typical example of an azole derivative of general formula (IV) is hydrogenated 1,2,3-tolutriazole (tolyltriazole) (X = N, R = CH3).

[0049] Another preferred group of the aforementioned azole derivatives are benzthiazoles of the general formula (V) in the The variable R has the meaning mentioned above, and the variable R' denotes hydrogen, a C1 to C10 alkyl group, in particular methyl or ethyl, or in particular a mercapto group (-SH). It is conceivable, though less preferred, that R' can also be a carboxyalkyl group of the formula -(CmH2m)-COOR" where m represents a number from 1 to 4 and R" denotes hydrogen or C1 to C10 alkyl, in particular methyl or ethyl, or C6 to C12 aryl. Examples of these are (2-benzothiazolylthio)acetic acid, (2-benzothiazolylthio)acetic acid esters, 3-(2-benzothiazolylthio)propionic acid, or 3-(2-benzothiazolylthio)propionic acid esters. If these compounds are used as acids, they are not among the carboxylic acids excluded according to the invention. A typical example of an azole derivative of the general formula (V) is 2-mercaptobenzthiazole.

[0050] Furthermore, non-fused azole derivatives of the general formula (VI) in which the variables X and Y together denote two nitrogen atoms or one nitrogen atom and a group CH, for example 1H-1,2,4-triazole (X = Y = N) or preferably imidazole (X = N, Y = CH).

[0051] Particularly preferred for the present invention are azole derivatives benzimidazole, benzotriazole, tolutriazole, hydrogenated tolutriazole or mixtures thereof, in particular benzotriazole or tolutriazole, especially tolutriazole.

[0052] The aforementioned azole derivatives are commercially available or can be produced using common methods. Hydrogenated benzotriazoles, such as hydrogenated tolutriazole, are also accessible according to DE-A 1 948 794 and are also commercially available.

[0053] The azoles are preferably selected from the group consisting of benzotriazole, tolutriazole, (2-benzothiazole)acetic acid, 3-(2-benzothiazole)propionic acid and 2-mercaptobenzthiazole. (D) Inorganic base

[0054] The pH value of the antifreeze agents used by the end user is typically in the range of 4 to 11.5, preferably 5 to 10, particularly 6 to 9.

[0055] To adjust this pH value, at least one inorganic base (D) is added at any stage of the manufacturing process of the coolant from a concentrated precursor. The at least one inorganic base can be contained in the composition according to the invention, in the superconcentrate, or in the concentrate, or it can be added during the production of the superconcentrate from the composition according to the invention by mixing with component (A) and / or (B), during the production of the concentrate from the superconcentrate by mixing with component (A) and / or (B), or during the production of the coolant from the concentrate by mixing with component (A) and / or (B).

[0056] Therefore, the compositions according to the invention optionally contain an amount of inorganic base which, upon appropriate dilution in the coolant, adjusts the desired pH value. For this purpose, the compositions according to the invention preferably contain alkali metal hydroxide, particularly preferably solid lithium, sodium, or potassium hydroxide, optionally also in the form of aqueous lithium, sodium, or potassium hydroxide solution.

[0057] Less preferred are carbonates or hydrogen carbonates of lithium, sodium, or potassium.

[0058] Preferred alkali metals are sodium and potassium.

[0059] In a preferred embodiment, at least a portion, and preferably all, of the required inorganic base is already contained in the composition according to the invention. This has the advantage that the base does not need to be added at any subsequent manufacturing stage, thus eliminating the risk of incorrect dosage. Furthermore, the added acids are present in the form of their alkali metal salts, which are generally easier to crystallize, facilitating the formulation of the solid composition according to the invention. (E) Other ingredients selected from the group consisting of hard water stabilizers, defoamers, colourants and bittering agents

[0060] Other common additives in the composition according to the invention may include defoamers (generally in amounts of 0.003 to 0.008 wt.% in the finished diluted coolant) as well as, for reasons of hygiene and safety in case of ingestion, bitter substances (e.g. of the denatonium benzoate type) and dyes.

[0061] Furthermore, the composition may contain one or more hard water stabilizers based on polyacrylic acid, polymaleic acid, acrylic acid-maleic acid copolymers, polyvinylpyrrolidone, polyvinylimidazole, vinylpyrrolidone-vinylimidazole copolymers, and / or copolymers of unsaturated carboxylic acids and olefins. The proportions in the composition are selected so that, after appropriate dilution, the amount in the finished diluted coolant is up to 1% by weight.

[0062] Aliphatic monocarboxylic acids and nitrites are excluded as components of the compositions according to the invention. Their presence is preferably acceptable only to the extent that they are contained as technical or technically induced impurities in the other components, especially in nitrates as component (C1) and dicarboxylic acids (C3). Aliphatic monocarboxylic acids

[0063] The monocarboxylic acids expressly excluded from the compositions according to the invention are organic aliphatic alkanoic or alkenecarboxylic acids. Provided they have sufficient water solubility, these are frequently used in coolants as corrosion inhibitors against the corrosion of ferrous materials.

[0064] Typical examples of such monocarboxylic acids are pentanoic acid, 2,2-dimethylpropanoic acid, hexanoic acid, 2,2-dimethylbutanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, isononanic acid, decanoic acid, undecanoic acid and dodecanoic acid, as well as their isomer mixtures, in particular 2-ethylhexanoic acid and isononanic acid isomer mixtures.

[0065] Such monocarboxylic acids are liquid or have a low melting point, for example of no more than 50 °C, so that no solid compositions can be produced with the free acids, or the resulting compositions would be sticky, become waxy and / or would bake together during storage.

[0066] Since it cannot be ruled out that such monocarboxylic acids may be formed from the aforementioned dicarboxylic acids (C3) contained in the compositions according to the invention by decarboxylation, the compositions according to the invention are considered to be free of these monocarboxylic acids if the proportion of these monocarboxylic acids, which are expressly excluded according to the invention, does not exceed 1 wt% in the compositions according to the invention, for example 0.5 wt%, preferably not more than 0.3 wt%, particularly preferably not more than 0.2 wt%, most preferably not more than 0.1 wt%, and particularly not more than 0.05 wt%. Specifically, no monocarboxylic acids are contained.

[0067] However, a possible, though less preferred, embodiment of the present invention is to use the aliphatic monocarboxylic acids in the form of their alkali metal salts, preferably in the form of their lithium, sodium, or potassium salts, and particularly preferably in the form of their sodium or potassium salts, instead of the free acid, provided that the salts of the aliphatic monocarboxylic acids in question are solid or at least soapy at room temperature (20 °C). In this case, the solid compositions can contain up to 15 wt% of the alkali metal salt of the aliphatic monocarboxylic acids, preferably up to 12.5 wt%, particularly preferably up to 10 wt%, most preferably up to 7.5 wt%, and particularly preferably up to 5 wt%.

[0068] The superconcentrates obtained from such solid compositions by dilution with (A) and / or (B) can accordingly contain up to 10 wt% of the alkali metal salt of the aliphatic monocarboxylic acids, preferably up to 7.5 wt%, particularly preferably up to 5 wt%, most preferably up to 3 wt% and particularly up to 1 wt%.

[0069] The concentrates obtained from such solid compositions by dilution with (A) and / or (B) can accordingly contain up to 5 wt% of the alkali metal salt of the aliphatic monocarboxylic acids, preferably up to 4 wt%, particularly preferably up to 3 wt%, most preferably up to 2 wt% and particularly up to 1 wt%.

[0070] The coolants obtained from such solid compositions by dilution with (A) and / or (B) can accordingly contain up to 3 wt% of the alkali metal salt of the aliphatic monocarboxylic acids, preferably up to 2.5 wt%, particularly preferably up to 2 wt%, most preferably up to 1.5 wt% and particularly up to 1 wt%.

[0071] The amounts of the remaining components (A) to (E), however, remain as described in the compositions obtained from the solid compositions containing little or no aliphatic monocarboxylic acids. Nitrites

[0072] The nitrites excluded from the composition according to the invention are all inorganic salts of nitrite (NO₂-) as well as nitrous acid (HNO₂). Typically, nitrite is used in coolants in the form of sodium nitrite or potassium nitrite, or is converted into these by the inorganic bases (D), so that these particular elements are excluded.

[0073] Since it cannot be ruled out that nitrite may form by reduction in the presence of nitrate as an inhibitor (C1) in the compositions according to the invention, the compositions according to the invention are considered nitrite-free if its proportion in the compositions according to the invention does not exceed 0.2 wt%, preferably not more than 0.15 wt%, particularly preferably not more than 0.1 wt%, and most preferably not more than 0.05 wt%. Specifically, no nitrite is contained. Production

[0074] The compositions according to the invention are produced by mixing the components (A) to (E) in suitable apparatus until a homogeneous mixture is obtained.

[0075] Suitable equipment includes ultrasonic devices, high-pressure homogenizers, and mills such as 2-, 3-, 4-, or 5-roller mills, mini-mills, Henschel mixers, shaking mills, Ang mills, toothed mills, bead mills, attritors, colloid mills, ultrasonic homogenizers, Ultra-Turrax stirrers, and ball mills, especially stirred ball mills. Kneaders with one or two mixing and kneading shafts inside the device are also conceivable, in which axial transport through the device can be achieved by arranging conveying, kneading, and / or mixing elements, such as disc elements, shafts, screws, blades, wipers, or rotors.

[0076] Suitable mixing times have proven to range from 5 minutes to 10 hours, although longer times are also conceivable. A mixing time of 10 minutes to 4 hours is preferred.

[0077] Pressure and temperature conditions during mixing are generally not critical; for example, normal atmospheric pressure has proven suitable. Temperatures in the range of 10°C to 100°C have proven suitable, preferably 20°C to 80°C.

[0078] The homogeneous mixture is optionally, but preferably, sieved after mixing, for example to separate the spheres after sphere grinding, and the ground material is then processed into shaped bodies, preferably pressed, granulated or extruded.

[0079] There are essentially no restrictions regarding the possible geometries of the molded parts. Examples include pellets such as disc-shaped pellets, pills, spheres, scales, platelets, granules, and extrudates such as strands, honeycombs, grids, or hollow bodies.

[0080] Preferably, compression and / or forming can be carried out using a piston press, roller press, compounding, pelletizing, tableting, extrusion, co-extrusion, granulation or a combination of two or more of these methods.

[0081] Pellets and / or tablets are produced in particular.

[0082] It can be advantageous to coat the resulting molded parts after forming to prevent them from sticking together during storage. Such a coating is designed to be water-soluble so that it dissolves during the subsequent production of superconcentrates, concentrates, or coolants. Production of the concentrates

[0083] In this document, coolants, concentrates and superconcentrates are defined according to their composition as follows: Coolant:

[0084] Liquid antifreeze for cooling systems with corrosion protection, containing at least 40 wt% water (A) at least 30 wt% alkylene glycol, alkylene glycol monoalkyl ether and glycerin (B), as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the proportion of components inhibitors (C), inorganic bases (D) and other (E) in total, based on the entire composition, is up to 10, preferably up to 7.5 and particularly preferably up to 5 wt%, the proportion of aliphatic monocarboxylic acids in the entire composition does not exceed 0.2 wt%, the proportion of nitrites in the entire composition does not exceed 0.05 wt% and the sum of all components always equals 100 wt%. concentrate

[0085] Liquid compositions for the preparation of antifreeze agents for cooling systems with corrosion protection properties, containing not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the total proportion of components inhibitors (C), inorganic bases (D) and other (E) in relation to the total composition is 0.01 to 10, preferably 0.5 to 7.5 and particularly preferably 1 to 5 wt%, the proportion of aliphatic monocarboxylic acids in the total composition exceeds 0.4 wt%, the proportion of nitrites in the total composition does not exceed 0.1 wt% and the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B). Super concentrate

[0086] Liquid compositions for the preparation of antifreeze agents for cooling systems with corrosion protection properties, containing not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the proportion of components inhibitors (C), inorganic bases (D) and other (E) in total, based on the total composition, is 0.05 to 30, preferably 1 to 20 and particularly preferably 2 to 10 wt%, the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.6 wt%, the proportion of nitrites in the total composition does not exceed 0.2 wt% and the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B).

[0087] The coolant specification refers to a composition for temperate latitudes, which may differ for extremely hot (higher water content) or extremely cold regions (higher proportion of component (B)).

[0088] An object of the present invention is a method for producing a superconcentrate containing not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the total proportion of components inhibitors (C), inorganic bases (D) and other (E) in relation to the total composition is 0.05 to 30, preferably 1 to 20 and particularly preferably 2 to 10 wt%, the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.6 wt%, the proportion of nitrites in the total composition does not exceed 0.2 wt% and the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B), by combining a solid composition according to the invention with the appropriate amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B).

[0089] Another object of the present invention is a method for producing a concentrate containing not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the total proportion of components inhibitors (C), inorganic bases (D) and other (E) in relation to the total composition is 0.01 to 10, preferably 0.5 to 7.5 and particularly preferably 1 to 5 wt%, the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.4 wt%, the proportion of nitrites in the total composition does not exceed 0.1 wt% and the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B), by first adding to a solid composition according to the invention the appropriate amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B) to obtain a superconcentrate containing not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the total proportion of components inhibitors (C), inorganic bases (D) and other (E) in relation to the total composition is 0.05 to 30, preferably 1 to 20 and particularly preferably 2 to 10 wt%, the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.6 wt%, the proportion of nitrites in the total composition does not exceed 0.2 wt% and the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B), and then, in a second step, adds the corresponding amount of water (A).

[0090] Another object of the present invention is a method for producing a concentrate containing not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the total proportion of components inhibitors (C), inorganic bases (D) and other (E) in relation to the total composition is 0.01 to 10, preferably 0.5 to 7.5 and particularly preferably 1 to 5 wt%, the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.4 wt%, the proportion of nitrites in the total composition does not exceed 0.1 wt% and the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B), by adding to a solid composition according to the invention the appropriate amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B) and the appropriate amount of water (A) in any order.

[0091] Another object of the present invention is a method for producing a coolant comprising at least 40 wt% water (A) at least 30 wt% alkylene glycol, alkylene glycol monoalkyl ether and glycerin (B), as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the proportion of components inhibitors (C), inorganic bases (D) and other (E) in total, based on the entire composition, is up to 10, preferably up to 7.5 and particularly preferably up to 5 wt%, the proportion of aliphatic monocarboxylic acids in the entire composition does not exceed 0.2 wt%, the proportion of nitrites in the entire composition does not exceed 0.05 wt% and the sum of all components always equals 100 wt%, by first adding a solid composition according to the invention with the corresponding amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B) to obtain a superconcentrate containing not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the total proportion of components inhibitors (C), inorganic bases (D) and other (E) in relation to the total composition is 0.05 to 30, preferably 1 to 20 and particularly preferably 2 to 10 wt%, the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.6 wt%, the proportion of nitrites in the total composition does not exceed 0.2 wt% and the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B), and then in a second step adds the corresponding amount of water (A) to it, thus obtaining a concentrate containing not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the total proportion of components inhibitors (C), inorganic bases (D) and other (E) in relation to the total composition is 0.01 to 10, preferably 0.5 to 7.5 and particularly preferably 1 to 5 wt%, the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.4 wt%, the proportion of nitrites in the total composition does not exceed 0.1 wt% and the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B), and then, in a third step, adds the corresponding amount of water (A).

[0092] Another object of the present invention is a method for producing a coolant comprising at least 40 wt% water (A) at least 30 wt% alkylene glycol, alkylene glycol monoalkyl ether and glycerin (B), as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the proportion of components inhibitors (C), inorganic bases (D) and other (E) in total, based on the entire composition, is up to 10, preferably up to 7.5 and particularly preferably up to 5 wt%, the proportion of aliphatic monocarboxylic acids in the entire composition does not exceed 0.2 wt%, the proportion of nitrites in the entire composition does not exceed 0.05 wt% and the sum of all components always equals 100 wt%, by adding, in a first step, to a solid composition according to the invention the appropriate amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B) and the appropriate amount of water (A) in any order, thus obtaining a concentrate containing not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates (C2a) optionally benzoic acid as an aromatic monocarboxylic acid (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms (C4) at least one azole, preferably at least one triazole compound (D) optionally at least one inorganic base (E) at least one other ingredient selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents with the proviso that the total proportion of components inhibitors (C), inorganic bases (D) and other (E) in relation to the total composition is 0.01 to 10, preferably 0.5 to 7.5 and particularly preferably 1 to 5 wt%, the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.4 wt%, the proportion of nitrites in the total composition does not exceed 0.1 wt% and the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B), and then, in a second step, adds the corresponding amount of water (A).

[0093] The mixing and dissolution of the composition according to the invention with alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B) and / or water (A) is generally carried out by energy input via shear energy. This can be achieved, for example, in dynamic mixing devices, i.e., by mixing using a stirrer or by pumping (natural or forced circulation) or pumping with static mixing devices such as static mixers or nozzles in the pumping circuit, by static mixing devices such as static mixers, nozzles, orifices or T-pieces in the inlet of the mixing vessel, or by dynamic mixing devices such as mixing pumps or stirred tanks.

[0094] Preferably, the liquid, i.e., (A) and / or (B), is provided and the solid composition according to the invention is added in a constant stream or in one or more portions.

[0095] The mixing temperature is typically between 10 and 80 °C, preferably between 15 and 70 °C, and particularly preferably between 20 and 60 °C. Of course, mixing can also be carried out at a higher or lower temperature, as long as the components do not decompose under the chosen conditions. However, this generally offers no advantages.

[0096] As explained above, it is possible, during the production of the coolant from the solid composition according to the invention, to add the inorganic base (D) or a part thereof at any step via dilution to the superconcentrate or concentrate in order to adjust the desired pH value in the finished coolant, provided that the solid composition according to the invention does not yet contain the full amount of (D).

[0097] It is an advantage of the present invention that the solid compositions according to the invention are produced centrally, thus only relatively small quantities need to be transported, and these are then mixed regionally by formulators with components (B) to form superconcentrates or with components (A) and (B) to form concentrates.

[0098] This represents a reduction in the quantities transported, since alkylene glycol, alkylene glycol monoalkyl ethers and glycerin (B) are usually widely available and can therefore be easily sourced regionally.

[0099] Thus, a further object of the present invention is a method for reducing the emissions associated with the transport of the product, for example nitrogen oxide and sulfur oxide emissions and in particular carbon dioxide emissions, preferably determined as a carbon footprint or as a life cycle assessment, particularly preferably according to DIN EN ISO 14021, DIN EN ISO 14067, here particularly the 2019-02 edition, DIN EN ISO 14044, here particularly the 2006 + A1:2018 edition and / or DIN EN ISO 14040, here particularly the 2009-11 edition, in which a solid composition according to the invention is produced at a first location and transported from there to a second location, where a superconcentrate and / or concentrate is produced from the solid composition according to the invention by mixing it with alkylene glycol, alkylene glycol monoalkyl ether and glycerin (B).

[0100] For determining the life cycle assessment, DIN EN ISO 14040, especially the 2009-11 edition and / or DIN EN ISO 14044, especially the 2006 + A1:2018 edition, are preferably used as a basis.

[0101] For determining the carbon footprint, DIN EN ISO 14067, especially the 2019-02 edition, is preferably used as a basis.

[0102] A further object of the present invention is a method for reducing emissions, in particular carbon dioxide emissions, preferably determined as a carbon footprint or life cycle assessment, particularly preferably according to DIN EN ISO 14021, DIN EN ISO 14067, here particularly the 2019-02 edition, DIN EN ISO 14044, here particularly the 2006 + A1:2018 edition and / or DIN EN ISO 14040, here particularly the 2009-11 edition, in which a solid composition according to the invention is produced at a first location and transported from there to a second location, where a superconcentrate and / or concentrate is produced from the solid composition according to the invention by mixing it with alkylene glycol, alkylene glycol monoalkyl ether and glycerol (B), and this concentrate is distributed to the end user, who produces a coolant from the concentrate by mixing it with water at a third location.

[0103] It is an advantage of the solid compositions according to the invention that superconcentrates and concentrates can be produced from them, which in turn can be used to produce coolants.

[0104] The smaller quantities to be transported result in a reduction of emissions, especially CO2 emissions, for example determined by the carbon footprint, life cycle assessment or according to DIN EN ISO 14021, DIN EN ISO 14067, especially the 2019-02 edition, DIN EN ISO 14044, especially the 2006 + A1:2018 edition and / or DIN EN ISO 14040, especially the 2009-11 edition.

[0105] A further advantage of the solid compositions according to the invention is that they can be used to produce coolants with good corrosion inhibition of ferrous materials, even though they do not contain either nitrite or free aliphatic monocarboxylic acids, unless their presence is technically necessary. The absence of the mostly liquid or low-melting-point aliphatic monocarboxylic acids makes the solid compositions according to the invention stable for storage. Examples

[0106] Formulations 1 to 3 of the active ingredients of refrigerants containing aliphatic carboxylic acids were prepared for comparison. Subsequently, formulations 4 to 6 according to the invention were prepared, in which the components were kept identical, but the proportions of aliphatic carboxylic acids were replaced by dicarboxylic acids. Thus, the following pairs of formulations were comparable: 1 vs. 4, 2 vs. 5, and 3 vs. 6. Table 1 [Data in % wt] formulation 1 (See) 2 (cf.) 3 (See) 4 5 6 Benztriazole, % 1,55 1,55 Sebacinic acid, % 17,71 43,08 40,85 47,96 51,70 49,00 Borax, % 11,51 11,51 Dodecanedioic acid, % 0,77 0,77 Tolutriazole, % 2,16 2,04 2,16 2,04 2-Ethylhexanoic acid, % 30,25 0 Isononanoic acid, % 8,62 8,15 0 0 2-Benzothiazolyl thioacetic acid, % 2,15 2,04 2,15 2,04 Sodium molybdate dihydrate, % 2,87 4,89 2,87 4,89 Water, % 2,096 1,62 2,096 1,622 Monoethylene glycol, % 2,513 1,95 2,513 1,945 Silicophosponate, % 1,046 0,81 1,046 0,809 Sodium metasilicate pentahydrate, % 2,514 1,95 2,514 1,945 NaOH, % 15,96 15,96 KOH, % 0,67 28,33 31,15 0,67 28,33 31,15 Hard water stabilizer % 0,45 0,216 0,20 0,45 0,216 0,204 Monoethylene glycol, % 8,81 4,095 3,87 8,81 4,095 3,867 Sodium nitrate, % 4,16 4,16 Phosphoric acid 85%, % 2,15 6,80 2,15 6,80 The silicophosphonate used is the compound shown in Table 1, footnote [3] of the unpublished European patent application with application number 20213979.6 and filing date 15 December 2020.

[0107] Tablets were pressed from these formulations using a tablet press equipped with a pressure gauge. The pressure was continuously increased until the yield point (pressure stability) was reached. Furthermore, the tablet was visually inspected and its properties assessed upon removal from the press. Table 2 formulation Condition Pressure, N / m² < Removal from pressing tool 1 (See) crystalline, amorphous areas 10,4 highly adhesive 2 (cf.) crystalline, amorphous areas 11,1 sticks slightly 3 (See) crystalline, amorphous areas 10,8 sticks 4 crystalline 10,9 does not stick 5 crystalline 11,5 does not stick 6 crystalline 11,5 does not stick

[0108] It can be seen that the tablets made from the formulations according to the invention can be produced as crystalline pellets that are easily removable from the pressing tool.

[0109] Furthermore, the tablets made from the formulations according to the invention have a yield strength approximately 0.5 N / m² higher, which demonstrates their improved storability (low clumping during storage). Corrosion examples

[0110] In order to show that coolants obtained from the solid coolant concentrates according to the invention exhibit a comparably good corrosion-inhibiting effect as conventional nitrite-containing and monocarboxylic acid-containing coolants, corrosion tests were carried out in accordance with DIN 51360, Part 2 (July 1981).

[0111] For this purpose, 20% and 40% by volume aqueous solutions of the respective concentrates were prepared. In this case, the concentrates consisted of 90% by weight monoethylene glycol and 10% by weight of the respective components from Table 1.

[0112] Dry grey cast iron chips GG 25 according to DIN 1691 with a chip size of 3 to 6 mm were used as material.

[0113] The corrosion results were assessed by visual inspection according to the following criteria on a five-part rating scale: Degree of corrosion Meaning Description 0 no corrosion unchanged 1 Traces of corrosion at most 3 corrosion marks, none of which has a diameter of more than 1 mm 2 slight corrosion no more than 1% of the surface is discolored, but there are more or larger signs of corrosion than for corrosion grade 1. 3 moderate corrosion over 1%, but not more than 5% of the surface is discolored 4 severe corrosion over 5% of the surface is discolored Table 3 Coolant based on concentration Degree of corrosion Formulation 1 (cf.) 20 3 Formulation 4 20 2 Formulation 4 + 0.25 wt% NaNO₂ 20 2

[0114] At a concentration of 40 vol%, all coolants showed a corrosion level of 0 (zero). Table 4 Coolant based on concentration Degree of corrosion Formulation 2 (cf.) 20 4 Formulation 5 20 4 Formulation 5 + 0.25 wt% NaNO 2 20 3

[0115] At a concentration of 40 vol%, all coolants showed a corrosion level of 0 (zero). Table 5 Coolant based on concentration Degree of corrosion Formulation 3 (cf.) 20 3 Formulation 6 20 3 Formulation 6 + 0.25 wt% NaNO₂ 20 2

[0116] At a concentration of 40 vol%, all coolants showed a corrosion level of 0 (zero).

[0117] The results from Tables 3 to 5 show that, to achieve comparable corrosion protection on ferrous materials, nitrite and aliphatic monocarboxylic acid can be replaced by the compositions according to the invention. A deviation of one degree of corrosion within the limits of measurement accuracy was considered comparable.

Claims

1. Nitrite-free solid compositions suitable for the preparation of liquid antifreeze agents for cooling systems with corrosion-inhibiting action, containing - not more than 10, preferably not more than 7.5 and particularly preferably not more than 5 wt% water (A) - not more than 10, preferably not more than 7.5 and particularly preferably not more than 5 wt% alkylene glycol, alkylene glycol monoalkyl ether and glycerin (B), as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further constituent selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of the components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is 90 to 95 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 1 wt%, - the proportion of nitrites in the total composition does not exceed 0.25 wt%, and - the sum of all components always amounts to 100 wt%.

2. Compositions according to claim 1, characterized in that component (B) is monoethylene glycol.

3. Compositions according to any one of the preceding claims, characterized in that component (C1) is a compound selected from the group consisting of silicates, borates, nitrates or phosphates.

4. Compositions according to any one of the preceding claims, characterized in that no aromatic monocarboxylic acid is present.

5. Compositions according to any one of the preceding claims, characterized in that compound (C3) is a linear alkanedicarboxylic acid having 6 to 12 carbon atoms.

6. Compositions according to any one of claims 1 to 4, characterized in that compound (C3) is selected from the group consisting of succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid (heptanedioic acid), azelaic acid (nonanedioic acid), sebacic acid (decanedioic acid), undecanedioic acid, dodecanedioic acid, as well as alkyl-and alkenylsuccinic acids and -glutaric acids such as 2-methylbutanedioic acid, 2-ethyl-3-methylbutanedioic acid, 2-ethylpentanedioic acid, 2-dodecylbutanedioic acid, 2-dodecenylbutanedioic acid, 2-phenylbutanedioic acid, 2-(p-methylphenyl)butanedioic acid, 2,2-dimethylbutanedioic acid, 2,3,4-trimethylpentanedioic acid, 2,2,3-trimethylpentanedioic acid, glutaconic acid (pent-2-enedioic acid), itaconic acid, hex-2-enedioic acid, hex-3-enedioic acid, 5-methylhex-2-enedioic acid and 2,3-dimethylpent-2-enedioic acid.

7. Compositions according to any one of the preceding claims, characterized in that compound (C4) is selected from the group consisting of benzotriazole, tolyltriazole, (2-benzothiazylthio)acetic acid, 3-(2-benzothiazylthio)propionic acid and 2-mercaptobenzothiazole.

8. Process for the preparation of solid compositions according to any one of the preceding claims by - mixing components (A) to (E) in suitable apparatus over a period of 5 minutes to 10 hours at 10 to 100 °C until a homogeneous mixture is formed, - optional sieving of the homogeneous mixture, and - subsequent processing into shaped bodies.

9. Process for the preparation of a superconcentrate, containing - not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further constituent selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of the components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is 0.05 to 30, preferably 1 to 20 and particularly preferably 2 to 10 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.6 wt%, - the proportion of nitrites in the total composition does not exceed 0.2 wt%, and - the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B), wherein a solid composition according to any one of claims 1 to 7 is combined with the corresponding amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B).

10. Process for the preparation of a concentrate, containing - not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further constituent selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of the components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is 0.01 to 10, preferably 0.5 to 7.5 and particularly preferably 1 to 5 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.4 wt%, - the proportion of nitrites in the total composition does not exceed 0.1 wt%, and - the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B), wherein in a first step a solid composition according to any one of claims 1 to 7 is combined with the corresponding amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B) to obtain a superconcentrate containing - not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further constituent selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of the components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is 0.05 to 30, preferably 1 to 20 and particularly preferably 2 to 10 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.6 wt%, - the proportion of nitrites in the total composition does not exceed 0.2 wt%, and - the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B), and then in a second step the corresponding amount of water (A) is added thereto.

11. Process for the preparation of a concentrate, containing - not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further constituent selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of the components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is 0.01 to 10, preferably 0.5 to 7.5 and particularly preferably 1 to 5 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.4 wt%, - the proportion of nitrites in the total composition does not exceed 0.1 wt% and - the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B), wherein to a solid composition according to any one of claims 1 to 7 the corresponding amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B) and the corresponding amount of water (A) are added in any desired order.

12. Process for the preparation of a coolant, containing - at least 40 wt% water (A) - at least 30 wt% alkylene glycol, alkylene glycol monoalkyl ether and glycerin (B), as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further constituent selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of the components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is up to 10, preferably up to 7.5 and particularly preferably up to 5 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.2 wt%, - the proportion of nitrites in the total composition does not exceed 0.05 wt%, and - the sum of all components always amounts to 100 wt%, wherein in a first step a solid composition according to any one of claims 1 to 7 is combined with the corresponding amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B) to obtain a superconcentrate containing - not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further constituent selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of the components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is 0.05 to 30, preferably 1 to 20 and particularly preferably 2 to 10 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.6 wt%, - the proportion of nitrites in the total composition does not exceed 0.2 wt%, and - the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B), and then in a second step adding the corresponding amount of water (A) to obtain a concentrate containing - not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further component selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is 0.01 to 10, preferably 0.5 to 7.5 and particularly preferably 1 to 5 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.4 wt%, - the proportion of nitrites in the total composition does not exceed 0.1 wt%, and - the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B), and then in a third step adding the corresponding amount of water (A).

13. Process for the preparation of a coolant containing - at least 40 wt% water (A) - at least 30 wt% alkylene glycol, alkylene glycol monoalkyl ether and glycerin (B), as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms having - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further component selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is up to 10, preferably up to 7.5 and particularly preferably up to 5 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.2 wt%, - the proportion of nitrites in the total composition does not exceed 0.05 wt%, and - the sum of all components always equals 100 wt%, wherein in a first step the corresponding amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B) and the corresponding amount of water (A) are added in any order to a solid composition according to one of claims 1 to 7 to obtain a concentrate containing - not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A) as inhibitors (C) - (C1) at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as an aromatic monocarboxylic acid - (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one further component selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents with the proviso that - the proportion of components inhibitors (C), inorganic bases (D) and others (E) in total, based on the total composition, is 0.01 to 10, preferably 0.5 to 7.5 and particularly preferably 1 to 5 wt%, - the proportion of aliphatic monocarboxylic acids in the total composition does not exceed 0.4 wt%, - the proportion of nitrites in the total composition does not exceed 0.1 wt%, and - the remainder to 100 wt% is at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin (B), and then in a second step adding the corresponding amount of water (A).

14. Process for the preparation of superconcentrates, concentrates or coolants according to one of claims 9 to 13 from a solid composition according to one of claims 1 to 7, in which - component (A) and / or (B) is initially charged, - the solid composition according to one of claims 1 to 7 is added, and - mixed by means of energy input through shear energy.

15. Process for reducing emissions, for example nitrogen oxide and sulfur oxide emissions and in particular carbon dioxide emissions, preferably determined as carbon footprint, life cycle assessment or in accordance with DIN EN ISO 14021, DIN EN ISO 14067, in particular the edition 2019-02, DIN EN ISO 14044, in particular the edition 2006 + A 1:2018 and / or DIN EN ISO 14040, in particular the edition 2009-11, wherein a solid composition according to one of claims 1 to 7 is produced at a first location and transported from there to a second location, where a superconcentrate and / or concentrate is produced from the solid composition by mixing with alkylene glycol, alkylene glycol monoalkyl ether and glycerin (B) according to one of claims 9 to 11.