Solid coolant concentrates and production thereof

Abstract

The present invention describes novel coolant concentrates and the production and use thereof.

Claims

1. A process for producing a concentrate comprising not more than 15% by weight of 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that a total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 0.01% to 10% by weight, a proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 0.4% by weight, a proportion of nitrites in the overall composition does not exceed 0.1% by weight, and the remainder to 100% by weight is at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B), the process comprising: admixing: not more than 10% by weight of water (A), not more than 10% by weight of alkylene glycol, alkylene glycol monoalkyl ethers, 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, to form a solid composition, with the proviso that a total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 90% to 95% by weight, a proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 1% by weight, a proportion of nitrites in the overall composition does not exceed 0.25% by weight, and a sum total of all components is always 100% by weight, admixing the solid composition with an appropriate amount of the at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B), hence obtaining a superconcentrate comprising not more than 15% by weight of 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that the total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 0.05% to 30% by weight, the proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 0.6% by weight, the proportion of nitrites in the overall composition does not exceed 0.2% by weight, and the remainder to 100% by weight is at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B), and then, adding an appropriate amount of water (A), or alkylene glycol, alkylene glycol monoalkyl ether and glycerol (B), or both (A) and (B) thereto.

2. The process according to claim 1, wherein component (B) is monoethylene glycol.

3. The process according to claim 1, wherein component (C1) is a compound selected from the group consisting of silicates, borates, nitrates, and phosphates.

4. The process according to claim 1, wherein no aromatic monocarboxylic acid is present.

5. The process according to claim 1, wherein compound (C3) is a linear alkanedicarboxylic acid having 6 to 12 carbon atoms.

6. The process according to claim 1, wherein 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, alkyl-and alkenylsuccinic acids and -glutaric acids, 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. The process according to claim 1, wherein compound (C4) is selected from the group consisting of benzotriazole, tolyltriazole, (2-benzothiazylthio) acetic acid, 3-(2-benzothiazylthio) propionic acid, and 2-mercaptobenzothiazole.

8. The process according to claim 1, wherein forming the solid composition comprises: mixing components (A) to (E) in a suitable apparatus over a period of 5 minutes to 10 hours at 10 to 100 C., until a homogeneous mixture is formed, optionally, sieving the homogeneous mixture, and subsequently, processing to give shaped bodies.

9. The process for producing the concentrate according to claim 1, which is a superconcentrate, comprising not more than 15% by weight of 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that a total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 0.05% to 30% by weight, a proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 0.6% by weight, a proportion of nitrites in the overall composition does not exceed 0.2% by weight, and the remainder to 100% by weight is at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B), the process comprising: admixing the solid composition with an appropriate amount of the at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B).

10. The process according to claim 1, the process comprising: initially charging component (A) and/or (B), adding the solid composition, and mixing by energy input by shear energy.

11. The process according to claim 1, wherein the composition comprises not more than 5% by weight of the water (A).

12. The process according to claim 1, wherein the composition comprises not more than 5% by weight of the alkylene glycol, alkylene glycol monoalkyl ethers, and glycerol (B).

13. The process according to claim 1, wherein the at least one azole (C4) is at least one triazole compound.

14. A process for producing a concentrate comprising not more than 15% by weight of 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that a total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 0.01% to 10% by weight, a proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 0.4% by weight, a proportion of nitrites in the overall composition does not exceed 0.1% by weight, and the remainder to 100% by weight is at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B), the process comprising: forming a solid composition, adding an appropriate amount of the at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B) and an appropriate amount of water (A) in any sequence to the solid composition, wherein the solid composition is formed by admixing: not more than 10% by weight of water (A), not more than 10% by weight of alkylene glycol, alkylene glycol monoalkyl ethers, 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that a total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 90% to 95% by weight, a proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 1% by weight, a proportion of nitrites in the overall composition does not exceed 0.25% by weight, and a sum total of all components is always 100% by weight.

15. A process for producing a coolant comprising at least 40% by weight of water (A), at least 30% by weight of 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that a total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is up to 10% by weight, a proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 0.2% by weight, a proportion of nitrites in the overall composition does not exceed 0.05% by weight, and a sum total of all components is always 100% by weight, the process comprising: admixing not more than 10% by weight of water (A), not more than 10% by weight of alkylene glycol, alkylene glycol monoalkyl ethers, 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, to form a solid composition, with the proviso that a total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 90% to 95% by weight, a proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 1% by weight, a proportion of nitrites in the overall composition does not exceed 0.25% by weight, and a sum total of all components is always 100% by weight, mixing the solid composition with an appropriate amount of at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B), hence obtaining a superconcentrate comprising not more than 15% by weight of 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that the total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 0.05% to 30% by weight, the proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 0.6% by weight, the proportion of nitrites in the overall composition does not exceed 0.2% by weight, and the remainder to 100% by weight is at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B), and then, adding an appropriate amount of water (A), or alkylene glycol, alkylene glycol monoalkyl ether and glycerol (B), or both (A) and (B) thereto, hence obtaining a concentrate comprising not more than 15% by weight of 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that the total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 0.01% to 10% by weight, the proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 0.4% by weight, the proportion of nitrites in the overall composition does not exceed 0.1% by weight, and the remainder to 100% by weight is at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B), and then, adding an appropriate amount of water (A) thereto, hence obtaining a coolant.

16. The process for producing a coolant according to claim 15, comprising at least 40% by weight of water (A), at least 30% by weight of 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that a total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is up to 10% by weight, a proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 0.2% by weight, a proportion of nitrites in the overall composition does not exceed 0.05% by weight, and a sum total of all components is always 100% by weight, the process comprising: adding an appropriate amount of at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B) and an appropriate amount of water (A) in any sequence to the solid composition, hence obtaining a concentrate comprising not more than 15% by weight of 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 aromatic monocarboxylic acid, (C3) at least one organic dicarboxylic acid having 4 to 20 carbon atoms, (C4) at least one azole, (D) optionally, at least one inorganic base, (E) at least one other constituent selected from the group consisting of hard water stabilizers, defoamers, dyes, and bitter substances, with the proviso that the total proportion of the inhibitor components (C), inorganic base components (D), and other components (E), based on the overall composition, is 0.01% to 10% by weight, the proportion of aliphatic monocarboxylic acids in the overall composition does not exceed 0.4% by weight, the proportion of nitrites in the overall composition does not exceed 0.1% by weight, and the remainder to 100% by weight is at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol (B), and then, adding an appropriate amount of water (A) thereto.

Description

EXAMPLES

(1) Formulations 1 to 3 of the active ingredients of coolants with aliphatic carboxylic acids were produced as a comparison, as opposed to which inventive formulations 4 to 6 were then produced, in which the constituents were each kept the same, but the proportions of the aliphatic carboxylic acids were replaced by dicarboxylic acids. Thus, the following pairs of formulations were comparable with one another: 1 vs, 4, 2 vs. 5 and 3 vs. 6.

(2) TABLE-US-00001 TABLE 1 [figures in % by weight] Formulation 1 (comp) 2 (comp) 3 (comp) 4 5 6 Benzotriazole, % 1.55 1.55 Sebacic acid, % 17.71 43.08 40.85 47.96 51.70 49.00 Borax, % 11.51 11.51 Dodecanedioic acid, % 0.77 0.77 Tolyltriazole, % 2.16 2.04 2.16 2.04 2-Ethylhexanoic acid, % 30.25 0 Isononanoic acid, % 8.62 8.15 0 0 2-Benzothiazolyl- 2.15 2.04 2.15 2.04 thioacetic acid, % 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 Silicophosphonate, % 1.046 0.81 1.046 0.809 Sodium metasilicate 2.514 1.95 2.514 1.945 pentahydrate, % 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 according to table 1, footnote [3] of unpublished European patent application with application number 20213979.6 and filing date Dec. 15, 2020.

(3) These formulations were used to press a tablet in a tableting press with a fitted manometer. The pressure was increased continuously here up to the yield point (constant pressure). In addition, the tableted compact was assessed visually and for its properties on removal from the compression mold.

(4) TABLE-US-00002 TABLE 2 Removal from Pressure, compression Formulation Condition N/m.sup.2 mold 1 (comp) crystalline, amorphous regions 10.4 highly tacky 2 (comp) crystalline, amorphous regions 11.1 slightly tacky 3 (comp) crystalline, amorphous regions 10.8 tacky 4 crystalline 10.9 nontacky 5 crystalline 11.5 nontacky 6 crystalline 11.5 nontacky

(5) It can be seen that the tablets made from the formulations of the invention crystalline compacts can be made, which are easily removable from the compression mold.

(6) Moreover, the tablets made from the formulations of the invention have a yield point which is about 0.5 N/m.sup.2 higher, which shows the improved storability thereof (low caking in the course of storage).

(7) Corrosion Examples

(8) In order to show that coolants obtained from the solid coolant concentrates of the invention have comparably good corrosion-inhibiting action as compared with conventional nitrite-containing and monocarboxylic acid-containing coolants, corrosion experiments according to DIN 51360, Part 2 (July 1981) were carried out.

(9) For this purpose, 20% and 40% by volume aqueous solutions of the respective concentrates were produced. In that case, the concentrates consisted of 90% by weight of monoethylene glycol and 10% by weight of the respective constituents from table 1.

(10) The material used was dry GG 25 gray iron turnings according to DIN 1691 with a turning size of 3 to 6 mm.

(11) The corrosion results were assessed by visual assessment according to the following criteria over a five-grade assessment scale:

(12) TABLE-US-00003 Corrosion level Meaning Description 0 no corrosion unchanged 1 traces of not more than 3 signs of corrosion, none corrosion of which has a diameter of more than 1 mm 2 slight not more than 1% of the surface discolored, corrosion but more or greater signs of corrosion than for corrosion level 1 3 moderate more than 1% but not more than 5% of the corrosion surface discolored 4 severe more than 5% of the surface discolored corrosion

(13) TABLE-US-00004 TABLE 3 Concen- Corrosion Coolant based on tration level Formulation 1 20 3 (comp.) Formulation 4 20 2 Formulation 4 + 20 2 0.25% by weight of NaNO.sub.2

(14) In a concentration of 40% by volume, all coolants showed a corrosion level of 0 (zero).

(15) TABLE-US-00005 TABLE 4 Concen- Corrosion Coolant based on tration level Formulation 2 20 4 (comp.) Formulation 5 20 4 Formulation 5 + 20 3 0.25% by weight of NaNO.sub.2

(16) In a concentration of 40% by volume, all coolants showed a corrosion level of 0 (zero).

(17) TABLE-US-00006 TABLE 5 Concen- Corrosion Coolant based on tration level Formulation 3 20 3 (comp.) Formulation 6 20 3 Formulation 6 + 20 2 0.25% by weight of NaNO.sub.2

(18) In a concentration of 40% by volume, all coolants showed a corrosion level of 0 (zero).

(19) It can be seen from the results from tables 3 to 5 that, in order to achieve comparable protection from corrosion on ferrous materials, nitrite and aliphatic monocarboxylic acid can be replaced by the compositions of the invention. Variance by one corrosion level was assumed here to be comparable within the scope of measurement accuracy.