JPH10195416A - Antifreezing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inexpensive antifreezing agent for melting ice or snow on loads, etc., not large in affection on environments in comparison with chlorides, etc., and higher in an ice-melting performance than those of conventional acetate-based antifreezing agents. SOLUTION: This antifreezing agent comprises the below-described components (A) and (B) in a weight ratio of 8:2 to 1:9, preferably 5:5 to 3:7. (A) At least one kind of acetate salt antifreezing agent selected from potassium acetate, sodium acetate, calcium acetate, magnesium acetate, calcium.magnesium acetate and calcium.magnesium.potassium acetate, and (B) urea. The antifreezing agent can be used in the form of a solid mixture or an aqueous solution in dependence on uses.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material used for melting snow and ice on roads and bridges in a cold region to melt away or prevent the snow and ice from freezing. In this specification, the agents acting as described above are collectively called "antifreeze agent".

[0002]

2. Description of the Related Art Chloride used for preventing freezing of roads and the like has a problem of salt damage. Accordingly, in recent years, acetate-based antifreezing agents have been used instead. Potassium acetate (KA
C), sodium acetate (SDA), calcium acetate (C
AC), magnesium acetate (MAC), calcium-magnesium acetate (CMA), calcium-magnesium-potassium acetate (CMPA), and the like. -99928) can be recommended as one that realizes high performance at a price similar to that of calcium / magnesium acetate.

[0003] These have the advantage that they do not cause salt damage like chlorides, but they are also more expensive than chlorides, and their melting performance is inferior to chlorides. Despite this, it is not yet widely used. As a compromise, the use of antifreeze, which has been reduced in price by mixing CMA with chloride, may be used, but the use of chloride also has a significant effect on the environment.

[0004] On the other hand, urea is also used as an antifreezing agent. Although urea is not very effective in preventing freezing, it has the advantage that the conductivity of aqueous solutions is significantly lower than that of electrolytes, making it a good choice in areas where it is necessary to prevent effects on the electrical system, typically in railways and airports. Used in

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inexpensive antifreezing agent which does not have a remarkable effect on the environment such as chloride, and has a higher melting performance than acetate-based antifreezing agents. To provide an agent.

[0006]

The antifreezing agent of the present invention for achieving the above object comprises the following components A and B: (A) potassium acetate, sodium acetate, calcium acetate, magnesium acetate, At least one acetate salt selected from the group consisting of calcium magnesium acetate and calcium magnesium potassium potassium, and (B) urea.

Acetate (A) in the cryoprotectant of the present invention
The mixing ratio of urea and urea (B) is not particularly limited, but generally, the range of A: B = 8: 2 to 1: 9 (weight ratio, the same applies hereinafter) is preferable.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The formulation may be solid or liquid. That is, one form of the cryoprotectant of the present invention is a solid mixture of component A and component B.
Another form is a mixed aqueous solution of component A and component B.

In the case of the former solid mixture, the acetate of the component A and the urea of the component B can be used in the form of a composition in which both are homogeneously integrated. It is not necessary to do so, but it is sufficient to use the two components in the form of a mixture of the respective powders, which are sufficiently mixed in the form of powder or particles. This is because both components become homogeneous when dissolved in water when used, and act as described below. However, when mere powder particles are mixed, care must be taken so that the particle size and morphology of both components do not significantly differ so that both components can be evenly dispersed at the time of use. Particularly useful as solid salts for solid mixtures are calcium magnesium acetate and calcium magnesium potassium potassium acetate. When these acetates (A) are used, the mixing ratio with urea (B) is particularly preferably in the range of A: B = 5: 5 to 3: 7.

In forming the latter mixed aqueous solution, it is preferable to use, as the acetate (A), one or more selected from potassium acetate, sodium acetate and magnesium acetate. This is because other complex salts do not completely dissolve and it is difficult to obtain a clear solution. However, complex salts can also be used, as long as they do not depend on the form of use. It is particularly preferable that the mixing ratio of the acetate (A) and the urea (B) is selected in the range of A: B = 5: 5 to 3: 7 by weight. The concentration of the aqueous solution is arbitrary, but is generally the sum of acetate (A) and urea (B),
If the concentration is less than 20%, the effect is poor. On the other hand, if the concentration is higher than 50%, crystals are precipitated at a temperature of -20 ° C or lower. Therefore, it should be selected from the range of 20 to 50%, and particularly preferably 30 to 40%.

As shown in the examples described later, when an aqueous solution is used, a high amount of ice can be obtained in a short time after application. On the other hand, the use of an aqueous solution is nothing more than an increase in the amount of water, so the use of an aqueous solution should be limited to cases where an increase in the amount of water is acceptable at the site.

Hereinafter, acetate and urea used in the antifreezing agent of the present invention are represented by the following symbols. KAC Potassium Acetate SDA Sodium Acetate CAC Calcium Acetate MAC Magnesium Acetate CMA Calcium Magnesium Acetate CMPA Calcium Magnesium Potassium U Urea Thus, for example, "CMA-U" refers to a blend of calcium magnesium acetate and urea.

The antifreezing agent of the present invention in which an acetate and urea are combined naturally has each component having the properties shown as an antifreezing agent. Is over. For example, the antifreezing agent CMA-U or CMPA-U has a rapid effect as a deicing agent and has a long-lasting effect, as is clear from the test results described below. Moreover, although there is no drop in the freezing point, the amount of ice
A or higher than CMPA and U.
This is considered to be due to a synergistic effect of the ice melting performance of CMA or CMPA and the ice melting performance of U.

The aqueous solution of CMA-U or CMPA-U has lower conductivity than the aqueous solution of CMA or CMPA, respectively.

[0015]

EXAMPLES The methods for testing the performance and electric conductivity of the antifreezing agent in the following examples are as follows. (Ice melting ability) 500 ml of water is put into a 500 ml polyethylene beaker, cooled to -5 ° C or -10 ° C, frozen, and the sample is placed on the ice. In the case of a solid sample, 10 g is sprayed, and in the case of a liquid sample, the solid content is equivalent to 10 g.
Pour 5 g. Then, it is allowed to stand in an atmosphere of -5 ° C or -10 ° C, and then, for 10 minutes, 20 minutes, 30 minutes, 60 minutes,
Measure the amount of ice melt at 0 and 180 minutes. (Freezing point) A solid sample was dissolved in water to obtain 1%, 5%, 10%
Prepare solutions with concentrations of%, 15%, 20%, 25% or 30%, put 10 ml each in a test tube and cool with dry ice. The freezing point is defined as the freezing point.

(Electric conductivity)
%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6
%, 0.8%, 1.0%, 2.0%, 3.0%, 4.0
%, 5.0%, 10.0%, 20.0%, 25.0% or 30.0% of the solution at a concentration of 25%.

Example 1 KAC was used as an acetate (A), and U (B) and powder were blended at a weight ratio of 5: 5. This KAC-U deicing agent was tested for its ability to melt ice as described above. For comparison, the same amount of KAC alone (10: 0) and U alone (0:10)
Was also tested. The results are as shown in Table 1 below.

Table 1 KAC-U melting ability Time −5 ° C. −10 ° C. (min) 10: 0 5:50 0:10 10: 0 5:50 0 00 00 00 0 0 0 10 10 19 22 8 22 15 3 20 26 30 11 28 23 7 30 30 31 37 17 17 31 27 10 60 40 47 26 35 30 15 15 120 46 56 33 33 34 34 21 180 51 65 38 38 34 34 The numerical value of the melting temperature at 25-5 ° C is plotted. Thus, a graph shown in FIG. 1 was obtained. KAC-U is K at -5 ° C.
It can be seen that it has better melting ability than AC or U alone.

Example 2 SDA was used as the acetate (A), and it was blended with U (B) at a ratio of 5: 5 in the same manner as in Example 1. The ice melting ability of this SDA-U antifreeze was measured. The results are shown in Table 2 in comparison with the cases of SDA alone (10: 0) and U alone (0:10).

Table 2 SDA-U Melting Capability Time -5 ° C.- 10 ° C. (min) 10: 0 5:50 0:10 10: 0 5:50 0 00 00 00 00 10 20 21 8 The following graph shows the melting ability at 25-10 ° C .: 6 4 3 20 31 28 11 15 14 7 30 30 38 35 17 17 22 23 10 60 51 46 26 35 35 15 15 120 69 56 33 45 37 37 21 180 79 64 38 38 48 41 As shown in FIG. SDA-U is not as good as SDA alone, but shows better performance than the average of urea's ice melting ability.

Example 3 CAC was used as the acetate (A), and was mixed with urea (B) at a ratio of 5: 5 as in Example 1. The ice melting ability of this CAC-U antifreeze was measured. The results are shown in Table 3 in comparison with the cases of CAC alone (10: 0) and urea alone (0:10).

Table 3 CAC-U Melting Capability Time -5 ° C. −10 ° C. (min) 10: 0 5:50 0:10 10: 0 5: 5 0:10 0 0 0 0 0 0 0 0 0 0 10 8 A graph showing the melting ability at 25-5 ° C. is as follows: 0 13 20 07 11 04 47 30 4 12 17 17 16 10 60 21 24 26 3 11 15 120 120 37 39 33 10 18 21 21 180 44 47 38 16 622 5 As shown in FIG. Although CAC-U is affected by the slow-acting effect of CAC, its ability to melt ice after a long period of time is higher than either CAC alone or urea alone.

Example 4 MAC was used as acetate (A), and was mixed with urea (B) at a ratio of 5: 5 as in Example 1. The ice melting ability of this MAC-U antifreeze was measured. The results are shown in Table 4 in comparison with the cases of MAC alone (10: 0) and urea alone (0:10).

Table 4 MAC-U Melting Ability Time -5 ° C.- 10 ° C. (min) 10: 0 5:50 0:10 10: 0 5: 5 0:10 0 0 0 0 0 0 0 0 0 0 0 0 8 8 0 13 20 10 19 11 04 47 30 17 17 25 17 0 8 10 60 28 35 26 26 216 15 120 42 45 33 33 13 26 21 180 52 52 38 38 25 31 25 Ice melting capacity at -5 ° C and -10 ° C Graphs were obtained as shown in FIGS. 4 and 5, respectively. It is relatively fast-acting at -5 ° C, and M
It can be seen that the effect appears earlier than AC, and finally a higher melting ability than either MAC alone or urea alone is obtained.

Example 5 CMA was selected as an acetate, and a granular material of "CMA-100" manufactured by Cryotech was used. This was combined with granular urea and CMA: U = 7: 3.
6: 4, 5: 5, 4: 6, 3: 7 or 2: 8 were blended to obtain 6 types of CMA-U.

These six samples were tested for their ability to melt ice at -5 ° C. The results are shown in Table 5 together with the results for CMA-100 alone and urea alone.

Table 5 Melting ability of CMA-U (−5 ° C.) Time (min) 10: 0 7: 3 6: 4 5: 5 4: 6 3: 7 2: 8 0:10 00 00 00 00 000 10 26 66 88 9 96 88 20 51 12 13 14 16 18 17 17 11 30 11 18 19 20 23 25 25 24 17 60 19 28 30 31 32 36 34 26 120 39 39 45 47 48 49 49 52 483 833 The data in the case of 50 52 54 55 57 60 56 38 4: 6 was plotted to obtain the graph of FIG. The “calculated value” in the figure is the amount of ice melt calculated from the mixing ratio of 4: 6, assuming that CMA-100 and urea each have an additive property between the ice melting capacities independently.

For this 4: 6 sample, -1 was further added.
The ice melting ability at 0 ° C. was measured. The results are as shown in Table 6. Here, the “calculated value” is a value calculated in the same manner as described above, based on the additivity.

Table 6 Melting ability of CMA-U (−10 ° C.) Time (min) 10: 0 4:60:10: Calculated value 0000 00 00 100 2 3 1.8 20 00 67 4 .2 300 0 11 10 6.0 60 0 18 15 9.0 120 8 25 21 15.8 180 15 29 25 21.0 The data in Table 6 are plotted in the graph of FIG.

The following can be understood from the data shown in FIGS. That is, C which is a mixture of CMA-100 and U
MA-U has a greater amount of ice melt than CMA-100 and U,
Having high melting performance exceeding calculated values, and -1
CMA-100, which hardly serves as an antifreezing agent at a low temperature of 0 ° C., is brought out of its ability by mixing with U element. These are considered to be due to a synergistic effect of the ice melting performance of CMA and the ice melting performance of U.

Next, the freezing points of the samples having the mixing ratios of 4: 6 and 3: 7 were measured. Again, for comparison,
The test was performed under the same conditions for CMA-100 and U alone. The results are as shown in Table 7, and there was virtually no drop in the freezing point, but there was some progress over the case of U alone.

Table 7 Concentration (%) of the freezing point (° C.) of CMA-U 10: 0 4: 6 3: 70: 10: 10 1-1 -1 -1 -15 -2-2 -2 -2 10- 4 -3-3 -3 -15 -6 -5 -5 -4 20 -8 -8 -7 -6 -25 -10 -10 -9 -9 30 -14 -13 -12 -11 Compounding ratio 5: 5, 4 : 6 and 3: 7
The conductivity of the aqueous solution was measured. The results are shown in Table 8 below.
And FIG. When CMA-100 alone is compared with CMA-U, the conductivity of CMA-U is lower, and the conductivity tends to decrease as the mixing ratio of U increases. In addition, the conductivity of the aqueous solution of U element is extremely low.

Table 8 Conductivity (25 ° C.) Concentration (%) of CMA-U Aqueous Solution 10: 0 5: 5 4: 6 3: 7 0.10 1.13 0.55 0.44 0.31 0.20 2.03 0.99 0.86 0.67 0.30 2.71 1.43 1.14 0.77 0.40 3.57 1.89 1.49 0.98 0.50 4.30 37 1.92 1.35 0.60 5.19 2.82 2.26 1.56 0.80 6.62 3.49 2.88 2.08 1.00 8.01 4.37 3.43 2 .28 2.00 12.70 6.84 5.83 4.47 3.00 17.10 9.55 7.98 5.93 4.00 20.80 11.90 9.82 7.14 5.00 23.80 13.90 11.90 9.21 10.00 32.90 21.10 18.30 4.50 15.00 35.20 24.80 21.50 17.00 20.00 32.50 25.40 22.50 18.10 25.00 26.70 23.40 21.30 17.90 30. 00 19.90 19.20 17.70 15.20 units dS / m.

Example 6 Lightly burned dolomite was digested,
The molar ratio of Ca (OH) ₂ : Mg (OH) ₂ is 1.44: 1.
00 digested dolomite was obtained. On the other hand, was dissolved K ₂ CO ₃ in an aqueous solution containing CH ₃ COOH exceeding equivalent, was prepared a solution containing an excess of CH ₃ COOH. Both the digested dolomite and the liquid were supplied to an extruder-type reactor having a screw capable of transferring powder or slurry and a stirring paddle and capable of being heated with a jacket, and the resulting paste was observed. Extruded in strands through a dish. The ratio of each component supplied to the reactor was Ca: M
g: K: HA = 4: 3: 3 (equivalent ratio). After leaving the warm strand to dry naturally,
The reaction was completed by placing in air at 150-160 ° C. The reaction product was crushed and sieved to a particle size of 2-5 mm.

The antifreeze agents CMPA and U thus obtained are combined with CMPA: U = 7: 3, 6: 4, 5: 5, 4:
Mix in the ratio of 6,3: 7 or 2: 8, 6 kinds of CM
PA-U was obtained.

The ice melting performance at -5 ° C. was tested on these six types of samples. The results are shown in Table 9 together with the results for CMPA alone and urea alone.

Table 9 Melting Capability of CMPA-U (−5 ° C.) Time (min) 10: 0 7: 3 6: 4 5: 5 4: 6 3: 7 2: 8 0:10 00 00 00 0 0 0 0 10 3 5 6 6 8 10 6 8 20 9 13 14 14 19 19 17 11 30 13 18 19 25 27 27 25 17 60 33 33 38 38 40 41 38 26 120 47 49 49 49 57 56 51 33 180 The data for 57 56 59 58 72 71 58 38 4: 6 were plotted to obtain the graph of FIG. The “calculated value” in the figure is the amount of ice melt calculated in the same manner as described above.

The melting ability at −10 ° C. was further measured for those having a mixing ratio of 4: 6 and 3: 7. The results are as shown in Table 10.

Table 10 Melting ability (−10 ° C.) of CMPA-U Time (minutes) 10: 0 4: 6 3: 70: 100 000 000 10 102 3 4 3 20 4 7 11 7 30 8 12 16 10 60 16 19 26 15 120 25 27 34 21 180 33 35 41 25 The data of Table 10 was plotted to obtain the graph of FIG.

From the data in Table 9 (FIG. 9) and Table 10 (FIG. 10), it can be seen that CMPA-U has a higher amount of ice melt than that of CMPA and urea alone and has a high ice melting performance exceeding the calculated value. I understand.

The freezing point was also measured for those having a mixing ratio of 4: 6 and 3: 7. The results are as shown in Table 11, and, similarly to CMA-U, the freezing point did not decrease.

Table 11 Freezing Point (° C.) Concentration (%) of CMPA-U 10: 0 4: 6 3:70:10 1-1 -1 -1 -1 5-2 -2 -2 -2 10- 4 -4 -4 -3 15 -6 -5 -5 -4 20 -9 -8 -7 -6 -25 -12 -10 -9 930 -16 -16 -14 -12 -11 Mixing ratio 5: 5, 4 : 6 and 3: 7
The conductivity of the aqueous solution was measured. The results are shown in Table 12 and FIG. Compared to CMPA, CMPA-
As in the fifth embodiment, the conductivity of U is lower and the conductivity becomes lower as the mixing ratio of U increases.

Table 12 Conductivity (25 ° C.) Concentration (%) of CMPA-U 10: 0 5: 5 4: 6 3: 7 0.10 1.17 0.57 0.46 0.32 0.20 2 .05 1.00 0.87 0.68 0.30 3.10 1.64 1.30 0.88 0.40 4.06 2.15 1.69 1.12 0.50 4.88 2.69 2.18 1.53 0.60 5.84 3.17 2.54 1.75 0.80 7.73 4.08 3.36 2.43 1.00 9.43 5.15 4.04 2.04. 69 2.00 15.40 8.29 7.07 5.42 3.00 20.60 11.50 9.61 7.14 4.00 25.20 14.40 11.90 8.65 5.00 29 .20 17.10 14.60 11.30 10.00 43.10 27.70 24. 0 19.00 15.00 49.90 35.10 30.50 24.10 20.00 50.20 39.30 34.70 28.00 25.00 46.80 41.00 37.30 31.40 30 .00 42.50 41.10 37.80 32.40 units dS / m.

Example 7 KAC was used as an acetate (A), and a mixture of U (B) at a weight ratio of 5: 5 was dissolved in water to prepare a 40% aqueous solution. This KAC-
The U antifreeze solution was tested for ice melting ability as described above. For comparison, the same amount of KAC alone (1
(0: 0) and U alone (0:10), also in the case of 40% aqueous solutions. The results are shown in Table 13 below.
As shown in FIG.

Table 13 KAC-U (Aqueous Solution) Melting Capability Time −5 ° C. −10 ° C. (min) 10: 0 5:50 0:10 10: 0 5: 5 0:10 0 0 0 0 0 0 0 0 10 37 46 18 40 42 22 22 45 45 54 29 46 49 49 25 30 47 57 33 33 47 50 26 60 55 62 62 41 50 52 30 120 120 61 71 48 52 51 36 180 85 65 80 53 53 49 40 Melting at -5 ° C and -10 ° C The ice performance values were plotted to obtain the graphs shown in FIGS. K
The aqueous solution of AC-U is KAC or U at −5 ° C.
It is evident from FIG. 12 that it has better ice-melting ability than the aqueous solution alone. The ice melting ability at −10 ° C. is not as high as KAC alone, but is better than the average of U melting ability.

Example 8 SDA was used as acetate (A), and a mixture of U (B) at a ratio of 5: 5 was dissolved in water to prepare a 40% aqueous solution. The SDA-U cryoprotectant solution was tested for ice melting ability as described above. The results are shown in Table 14 in comparison with the cases of SDA alone (10: 0) and U alone (0:10).

Table 14 SDA-U (Aqueous Solution) Melting Capability Time −5 ° C. −10 ° C. (min) 10: 0 5:50 0:10 10: 0 5:50 0:10 0 0 0 0 0 0 0 10 39 40 18 39 39 22 22 20 49 51 29 29 49 46 46 25 30 55 57 33 55 55 48 26 60 66 66 66 41 66 49 30 120 84 74 48 84 49 49 36 180 94 82 53 53 94 49 40 Melting at -5 ° C and -10 ° C FIG. 14 and FIG. 15 show a graph of the ice capacity. At −5 ° C., SDA-U is not as good as SDA alone, but shows better performance than the average of U's melting ability.

Example 9 MAC was used as the acetate (A), and a mixture of U (B) at a ratio of 5: 5 was dissolved in water to prepare a 40% aqueous solution. The MAC-U cryoprotectant solution was tested for ice melting ability as described above. The results are shown in Table 15 in comparison with the case of MAC alone (10: 0) and U alone (0:10).

Table 15 Melting ability of MAC-U (aqueous solution) Time −5 ° C. −10 ° C. (min) 10: 0 5:50 0:10 10: 0 5:50 0:10 0 0 0 0 0 0 0 10 23 28 29 23 24 30 20 33 42 36 23 33 30 33 30 40 48 40 23 32 34 60 51 58 49 26 37 38 38 120 65 68 56 36 45 44 180 75 72 72 61 48 48 48 Melting at -5 ° C and -10 ° C The ice capacity was graphed to obtain FIGS. 16 and 17, respectively. At −5 ° C., it was found that both of MAC alone and U alone were superior.

[0050]

According to the present invention, a novel antifreeze comprising a blend of an acetate-based antifreeze and urea is provided. This antifreeze has a higher melting performance than the combination of the melting ability of the conventional acetate-based antifreezing agent and the melting ability of urea, and a synergistic effect is clearly observed. Since the antifreeze of the present invention has a lower conductivity of the aqueous solution than the acetate-based antifreeze, a place such as a railway or an airport facility where entry of the aqueous solution after thawing may affect the electrical system and cause problems. Can also be used.

The production cost of the antifreezing agent of the present invention is not high, as understood from the production method. Since this antifreeze can be used as a solid powder or as an aqueous solution, it can be used properly depending on the application.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows data of an example of an antifreezing agent of the present invention (Example 1) in which its melting ability is compared with that of a known antifreezing agent and urea. The graph shown.

FIG. 2 is a graph showing the same data as in FIG. 1 for one example of the antifreezing agent of the present invention (Example 2), showing the time change of the amount of ice melt at −10 ° C.

FIG. 3 is a graph showing data similar to FIG. 1 and showing a temporal change in the amount of ice melt at −5 ° C. for an example of the antifreezing agent of the present invention (Example 3).

FIG. 4 is a graph showing the same data as in FIG. 1 for one example of the antifreezing agent of the present invention (Example 4), showing the time change of the amount of ice melt at −5 ° C.

FIG. 5 is a graph showing the time change of the amount of ice melt at −10 ° C. for the same example as FIG.

FIG. 6 is a graph showing the same data as in FIG. 1 and showing a temporal change in the amount of ice melt at −5 ° C. for an example of the antifreezing agent of the present invention (Example 5).

FIG. 7 is a graph showing the time change of the amount of ice melt at −10 ° C., for the same example as in FIG. 6;

FIG. 8 shows data obtained by comparing the conductivity of three aqueous solutions having different compositions in one example of the antifreeze of the present invention (Example 5) with that of a known antifreeze, and the relationship between the concentration and the conductivity. A graph showing.

FIG. 9 is a graph showing the same data as in FIG. 1 for one example of the antifreezing agent of the present invention (Example 6), showing the time change of the amount of ice melt at −5 ° C.

FIG. 10 is a graph showing time-dependent changes in the amount of ice melt at −10 ° C. for the same example as in FIG. 9;

FIG. 11 shows data obtained by comparing the conductivity of three aqueous solutions having different compositions in one example of the antifreezing agent of the present invention (Example 6) with that of a known freezing agent. 4 is a graph showing a relationship between electric conductivity.

FIG. 12 is a graph showing the same data as in FIG. 1 for one example of the antifreezing agent of the present invention (Example 7), showing the time change of the amount of ice melt at −5 ° C.

FIG. 13 is a graph showing time-dependent changes in the amount of ice melt at −10 ° C. for the same example as FIG. 12;

FIG. 14 is a graph showing the same data as in FIG. 1 for one example of the antifreezing agent of the present invention (Example 8), showing the time change of the amount of ice melt at −5 ° C.

FIG. 15 is a graph showing the time change of the amount of ice melt at −10 ° C. for the same example as in FIG. 14;

FIG. 16 is a graph showing data similar to FIG. 1 and showing a temporal change in the amount of ice melt at −5 ° C. for an example of the antifreezing agent of the present invention (Example 9).

FIG. 17 is a graph showing the time change of the amount of ice melt at −10 ° C. for the same example as FIG. 16;

Claims (7)

[Claims] An antifreezing agent comprising a solid mixture containing the following components A and B. (A) at least one acetate selected from the group consisting of potassium acetate, sodium acetate, calcium acetate, magnesium acetate, calcium magnesium acetate and calcium magnesium potassium potassium, and (B) urea 2. The antifreezing agent according to claim 1, wherein the mixing ratio of the acetate (A) and the urea (B) is in the range of A: B = 8.2 to 1: 9 by weight. 3. The method according to claim 1, wherein the acetate (A) is calcium / magnesium acetate, and the mixing ratio of the acetate and the urea (B) is in the range of A: B = 5: 5 to 3: 7 by weight. Antifreeze. 4. The method according to claim 1, wherein the acetate (A) is calcium / magnesium / potassium acetate, and its mixing ratio with urea (B) is selected in a range of A: B = 5: 5 to 3: 7 by weight. 1 antifreeze. 5. An antifreezing agent comprising a mixed aqueous solution containing the following components A and B. (A) at least one acetate selected from the group consisting of potassium acetate, sodium acetate, calcium acetate, magnesium acetate, calcium magnesium acetate and calcium magnesium potassium potassium, and (B) urea 6. The acetate (A) is one or two or more kinds selected from potassium acetate, sodium acetate and magnesium acetate, and the compounding ratio with the urea (B) is A: B = 5 by weight. The antifreezing agent according to claim 5, selected in the range of 5 to 3: 7. 7. The concentration of the aqueous solution is in the range of 20 to 50% in total of the acetate (A) and the urea (B).
Or 6 antifreeze.