ANTI-FREEZE ANTI-CORROSION CONCENTRATES

Abstract

The present invention relates to antifreeze/anticorrosive concentrates, to processes for production of such concentrates from superconcentrates, to aqueous coolant compositions made from these concentrates and to the use thereof.

Claims

1. An antifreeze/anticorrosive concentrate, comprising 1% to 10% by weight, based on a total amount of the concentrate, of a mixture of 30-100% by weight of ##STR00016## 0-40% by weight of ##STR00017## and 0-30% by weight of ##STR00018## wherein n is a positive integer from 1 to 5 and may be the same or different for each of (Ia), (Ib) and (Ic), with the proviso that a sum total of the amounts of (Ia), (Ib) and (Ic) in the mixture is always 100% by weight.

2. The antifreeze/anticorrosive concentrate of claim 1, comprising 2% to 8% by weight, based on the total amount of the concentrate, of the mixture.

3. The antifreeze/anticorrosive concentrate of claim 1, wherein n is a positive integer from 1 to 4.

4. The antifreeze/anticorrosive concentrate of claim 1, further comprising at least one of the following: (a) up to 5% by weight of one or more alkali metal, ammonium or substituted ammonium salt of an aliphatic, cycloaliphatic or aromatic monocarboxylic acid having 3 to 16 carbon atoms; (b) up to 5% by weight of one or more alkali metal, ammonium or substituted ammonium salt of an aliphatic or aromatic di- or tricarboxylic acid having 3 to 21 carbon atoms; (c) up to 1% by weight of one or more alkali metal borates, alkali metal phosphates, alkali metal silicates, alkali metal nitrites, alkali metal or alkaline earth metal nitrates, alkali metal molybdates or alkali metal or alkaline earth metal fluorides; (d) up to 5% by weight of one or more aliphatic, cycloaliphatic or aromatic amines which have 2 to 15 carbon atoms and may additionally comprise ether oxygen atoms or hydroxyl groups; (e) up to 5% by weight of one or more mono- or polycyclic, unsaturated or partly unsaturated heterocycles which have 4 to 10 carbon atoms and may be benzofused and/or may bear additional functional groups; (f) up to 5% by weight of one or more tetra(C.sub.1-C.sub.8-alkoxy)silanes (tetra-C.sub.1-C.sub.8-alkyl orthosilicates); (g) up to 10% by weight of one or more carboxamides or sulfonamides; (h) up to 1% by weight of 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, wherein each amount is based on the total amount of the concentrate.

5. The antifreeze/anticorrosive concentrate of claim 1, comprising, in addition to the mixture, 0.01% to 5% by weight, based on the total amount of the concentrate, of at least one corrosion inhibitor.

6. The antifreeze/anticorrosive concentrate of claim 1, wherein a pH of the concentrate is in a range of from 4 to 11.

7. An antifreeze/anticorrosive concentrate, comprising 1% to 10%, based on a total amount of the concentrate, of a mixture of 30-100% by weight of ##STR00019## 0-40% by weight of ##STR00020## and 0-30% by weight of ##STR00021## wherein n is a positive integer from 1 to 5 and may be the same or different for each of (Ia), (Ib) and (Ic), with the proviso that a sum total of the amounts of (Ia), (Ib) and (Ic) in the mixture is always 100% by weight, 0.01% to 5% by weight of at least one of the following corrosion inhibitor compounds (a) to (g); (a) one or more alkali metal, ammonium or substituted ammonium salt of an aliphatic, cycloaliphatic or aromatic monocarboxylic acid having 3 to 16 carbon atoms; (b) one or more alkali metal, ammonium or substituted ammonium salt of an aliphatic or aromatic di- or tricarboxylic acid having 3 to 21 carbon atoms; (c) one or more alkali metal borates, alkali metal phosphates, alkali metal silicates, alkali metal nitrites, alkali metal or alkaline earth metal nitrates, alkali metal molybdates or alkali metal or alkaline earth metal fluorides; (d) one or more aliphatic, cycloaliphatic or aromatic amines which have 2 to 15 carbon atoms and may additionally comprise ether oxygen atoms or hydroxyl groups; (e) one or more mono- or polycyclic, unsaturated or partly unsaturated heterocycles which have 4 to 10 carbon atoms and may be benzofused and/or may bear additional functional groups; (f) one or more tetra(C.sub.1-C.sub.8-alkoxy)silanes (tetra-C.sub.1-C.sub.8-alkyl orthosilicates); (g) one or more carboxamides or sulfonamides; optionally at least one compound effective as a hard water stabilizer, defoamer or bitter substance, and the difference from 100% by weight, based on the total amount of the concentrate, of at least one alcohol.

8. The antifreeze/anticorrosive concentrate of claim 1, additionally comprising 0.01% to 5% by weight, based on the total amount of the concentrate, of at least one corrosion inhibitor other than (Ia), (Ib) and (Ic).

9. The antifreeze/anticorrosive concentrate of claim 1, consisting of the mixture, 0.01% to 5% by weight, based on the total amount of the concentrate, of at least one corrosion inhibitor other than (Ia), (Ib) and (Ic), optionally one or more further typical ingredients of antifreeze/anticorrosive concentrates, and the difference from 100% by weight, based on the total amount of the concentrate, of at least one alcohol as an antifreeze component.

10. A superconcentrate for an antifreeze/anticorrosive concentrate, consisting of 5% to 40% by weight, based on a total amount of the superconcentrate, of a mixture of 30-100% by weight of ##STR00022## 0-40% by weight of ##STR00023## and 0-30% by weight of ##STR00024## wherein n is a positive integer from 1 to 5 and may be the same or different for each of (Ia), (Ib) and (Ic), with the proviso that a sum total of the amounts of (Ia), (Ib) and (Ic) in the mixture is always 100% by weight; 0.05% to 30% by weight of at least one of the following corrosion inhibitor compounds (a) to (g): (a) one or more alkali metal, ammonium or substituted ammonium salt of an aliphatic, cycloaliphatic or aromatic monocarboxylic acid having 3 to 16 carbon atoms; (b) one or more alkali metal, ammonium or substituted ammonium salt of an aliphatic or aromatic di- or tricarboxylic acid having 3 to 21 carbon atoms; (c) one or more alkali metal borates, alkali metal phosphates, alkali metal silicates, alkali metal nitrites, alkali metal or alkaline earth metal nitrates, alkali metal molybdates or alkali metal or alkaline earth metal fluorides; (d) one or more aliphatic, cycloaliphatic or aromatic amines which have 2 to 15 carbon atoms and may additionally comprise ether oxygen atoms or hydroxyl groups; (e) one or more mono- or polycyclic, unsaturated or partly unsaturated heterocycles which have 4 to 10 carbon atoms and may be benzofused and/or may bear additional functional groups; (f) one or more tetra(C.sub.1-C.sub.8-alkoxy)silanes (tetra-C.sub.1-C.sub.8-alkyl orthosilicates); (g) one or more carboxamides or sulfonamides; and optionally at least one compound effective as a hard water stabilizer, defoamer or bitter substance.

11. A process for producing an antifreeze/anticorrosive concentrate, the process comprising mixing the antifreeze superconcentrate of claim 10 with an antifreeze component selected from the group consisting of ethylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol, hexapropylene glycol, 1,3-propylene glycol, glycerol, monomethyl-, -ethyl-, -propyl- and -butyl ethers of ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol, to obtain a mixture, wherein an amount of the antifreeze component in the mixture is 10% to 50% by weight, based on a total amount of the mixture.

12. An aqueous coolant composition, comprising 10% to 90% by weight of the antifreeze/anticorrosive concentrate of claim 1.

13. A process for producing a coolant composition, the process comprising mixing the antifreeze/anticorrosive concentrate of claim 1 with water.

14. A process of protecting water from frost and simultaneously protecting a metal housing of a vessel comprising water from corrosion, the process comprising contacting the water and/or metal housing with the coolant composition of claim 12.

Description

EXAMPLES

[0086] The invention is elucidated in the examples which follow, but without restricting it thereto.

SYNTHESIS EXAMPLES: COMPOUND (IA) FROM (IC)

Gas Chromatography Analysis

[0087] The oxydiol (1) used in the examples and the reaction product obtained were each analyzed by gas chromatography for their organic components. The procedure for this purpose was as follows: [0088] Gas chromatograph: Agilent 7890B [0089] Column: Rxi-1 ms (length 30 m, 0.25 mm (ID), 0.25 m (film) [0090] Temperature program: 3 minutes at 60 C., heating from 60 C. to 290 C. at 5 C./min, 12 minutes at 290 C. [0091] Sample preparation: The catalyst was filtered off and the water was removed. 50 mg of the anhydrous mixture were then mixed with 1 mL of MSTFA (N-methyl-N-(trimethylsilyl)trifluoroacetamide) and heated to 80 C. for 1 hour, and the sample is injected into the gas chromatograph.

Example 1: 2.5 Mol % of Pt Based on (Ic)

[0092] 200 g of pulverulent catalyst having 5% by weight of platinum on activated carbon, corresponding to 10 g or 0.0513 mol of Pt (source: Sigma-Aldrich), were charged into a 4 liter glass reactor and stirred together with 957 g of water at 1000 rpm. Subsequently, 410 g of oxydiol (I) with the distribution shown in the table below and an average molar mass of 200 g/mol were added, the mixture was equilibrated to 60 C., and 50 L/h of oxygen were passed through the reaction mixture with further stirring. The molar ratio of Pt to oxydiol (1) was thus 0.025, and the concentration of water in the liquid phase was 70% by weight. Since no base had been added, the initial pH was 6.9. After 27 hours, full conversion had been attained. The feed of oxygen was ended, and the reaction mixture was cooled down and discharged from the glass reactor. The reaction mixture had a pH of 1.5. It was filtered through a D4 glass freight and the filtercake was washed three times with 200 mL each time of warm water. The filtrate was then concentrated on a rotary evaporator at 45 C. at a pressure down to 10 mbar. 280 g of product mixture with the composition shown in the table below were obtained. The analyses of the organic components were each effected by gas chromatography. The water content was determined by Karl Fischer titration.

Reactant Distribution (by Gas Chromatography):

[0093]

TABLE-US-00001 (lc) n = 0 n = 1 n = 2 n = 3 n = 4 n = 5 n = 6 n = 7 [GC 4.9 23.9 31.0 22.1 11.2 4.5 1.4 0.3 area%]

Product Distribution (by Gas Chromatography):

[0094]

TABLE-US-00002 (Ia) n = 0 n = 1 n = 2 n = 3 n = 4 [GC area %] 26.6 31.1 24.7 11.3 1.9 Glycolic acid 4.5 [GC area %] Water 7 [% by wt.]

[0095] The product (Ia) also contains 4.5 area % of hydroxyacetic acid.

Example 2: 1 Mol % of Pt Based on (Ic)

[0096] 78 g of pulverulent catalyst of the same type as in example 1, having 5% by weight of platinum on activated carbon, corresponding to 3.9 g or 0.020 mol of Pt (source: Sigma-Aldrich), were charged into a 4 liter glass reactor and stirred together with 957 g of water at 1000 rpm. Subsequently, analogous to example 1, 410 g of oxydiol (I) with the distribution shown in the table below and an average molar mass of 200 g/mol were added, the mixture was equilibrated to 60 C., and 50 L/h of oxygen were passed through the reaction mixture with further stirring. The molar ratio of Pt to oxydiol (I) was thus 0.0098, and the concentration of water in the liquid phase was 70% by weight. Since no base had been added, the initial pH was 6.9. After 67 hours, full conversion had been attained. The feed of oxygen was ended, and the reaction mixture was cooled down and discharged from the glass reactor. The reaction mixture likewise had a pH of 1.5. It was filtered through a D4 glass freight and the filtercake was washed three times with 200 mL each time of warm water. The filtrate was then concentrated on a rotary evaporator at 45 C. at a pressure down to 10 mbar. 436 g of product mixture with the composition shown in the table below were obtained. The analyses of the organic components were each effected by gas chromatography. The water content was determined by Karl Fischer titration.

Reactant Distribution (by Gas Chromatography):

[0097]

TABLE-US-00003 (lc) n = 0 n = 1 n = 2 n = 3 n = 4 n = 5 n = 6 n = 7 [GC 4.9 23.9 31.0 22.1 11.2 4.5 1.4 0.3 area%]

Product Distribution (by Gas Chromatography):

[0098]

TABLE-US-00004 (Ia) n = 0 n = 1 n = 2 n = 3 n = 4 [GC area %] 12.3 29.2 32.5 19.6 5.8 Glycolic acid 0.3 [GC area %] Water 4.9 [% by wt.]

Example 3

[0099] The catalyst was isolated by filtration at the end of the previous experiment and reused under the experimental conditions specified above. The results were comparable: 464 g of compound (Ia) were obtained with a product composition as follows:

TABLE-US-00005 (Ia) n = 0 n = 1 n = 2 n = 3 n = 4 [GC area %] 11.0 29.0 33.0 20.0 6.0 Glycolic acid 0.8 [GC area %] Water 6.8 [% by wt.]

[0100] The results were also comparable in the case of another recovery and reuse. 467 g of compound (Ia) were obtained with a product distribution as follows:

TABLE-US-00006 (Ia) n = 0 n = 1 n = 2 n = 3 n = 4 [GC area %] 11.1 28.5 33.0 20.5 6.3 Glycolic acid 0.7 [GC area %] Water 7.3 [% by wt.]

Example 4: 2.5 Mol % of Pt Based on (Ic)

[0101] The catalyst (16 g) (Pt/C from Sigma-Aldrich, 10% by weight of platinum on activated carbon) was introduced into a 250 mL glass reactor and stirred together with 114 g of water at 1000 rpm. 49 g of compound (Ic) (n=1) (triethylene glycol from Sigma-Aldrich) were added, the mixture was equilibrated to 60 C. and 80 L/h of oxygen were passed through the reaction mixture. After 21 hours, full conversion was attained, and the mixture was cooled down, discharged and filtered through a D4 glass suction filter. The filtercake was washed with 300 mL of warm water in each case. The filtrate was concentrated on a rotary evaporator at 45 C. at a pressure down to 10 mbar. 48 g of compound (Ia) (n=1) were obtained.

USE EXAMPLES

[0102] The corrosion tests which follow were conducted to ASTM D 4340. This standard test serves to determine the propensity of aluminum or aluminum alloys to corrosion in cooling devices for internal combustion engines. The standard apparatus used for this purpose simulates the aluminum-containing hot internal surface of a cooling circuit of an internal combustion engine. An aluminum test plate is heated from below while it is in contact with the cooling fluid to be tested. The test temperature is 135 C. On conclusion of the test, after the fixed test duration of 168 hours, the plate is assessed visually for corrosion and the change in weight is determined by weighing. Removal of material by corrosion is determined in accordance with ASTM D1384 to be 33% in dilution with water.

Composition of the Test Fluids

[0103]

TABLE-US-00007 Feedstocks Fluid 1 Fluid 2 Fluid 3 Monoethylene glycol 90.96 Other inhibitors (total) 0.95 Phosphoric acid (75% 0.15 by weight in water) Sebacic acid 3.0 Triethylene glycol diacid 3.0 (formula (Ia), n = 1) from example 4 Polyethylene glycol 3.0 diacid (formula (Ia), n = 2) from example 2 Tolutriazole 0.15 Commercial silicate 400 ppm by weight Standard hard water 0.15 stabilizer Denatonium benzoate 0.01 Standard defoamer 0.01 Potassium hydroxide 4.19 (48% by weight in water)

[0104] The additions, by contrast, resulted in the following physical data in accordance with ASTM D1384 (without aqueous dilution with ASTM water to 33% by volume):

TABLE-US-00008 Fluid 1 Fluid 2 Fluid 3 pH, before test 8.2 8.21 10.12 pH, after test 7.7 7.16 8.78

[0105] The following corrosion rates were determined to ASTM 4340 (specific change in mass with etching blank mg/cm.sup.2):

TABLE-US-00009 Fluid 1 Fluid 2 Fluid 3 Copper F-CU 0.05 0.08 0.08 Soft solder L - PbSn30 BASF 0.12 0.11 0.17 Brass Ms - 63 0.08 0.14 0.14 Steel H - II 0.01 0.00 0.08 Gray cast iron GG - 25 0.02 0.04 0.02 Cast aluminum G - AlSi6Cu4 0.1 0.13 0.13