JPH0995665A - Coolant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coolant having high temperature-stability and safety and exhibiting excellent cooling performance by holding ammonium nitrate, urea and a specific mixture containing Glauber's salt in a state of preventing the contact of each component and enable the mixing and contacting of the components in use. SOLUTION: The objective coolant contains (A) ammonium nitrate, (B) urea and (C) a mixture of (C1 ) sodium sulfate decahydrate and (C2 ) white carbon in a state to prevent the contact of the components and enable the mixing and contact of the components in use. For example, an inner bag filled with the component B and a second inner bag filled with the component C containing 100 pts.wt. of C1 and 0.01-10 pts.wt. of C2 are sealed in an outer bag filled with the component A. Preferably, the oil absorption of the component C2 is >=200mL/100g.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to coolants and more particularly to waterless coolants.

[0002]

2. Description of the Related Art Conventionally, as a simple cooling material which does not require external energy such as electric power, a cooling agent using a substance having a large heat storage capacity and cooling utilizing heat absorption generated when two or more substances are mixed. Agents and the like are known and are becoming popular as a simple cooling agent for the human body, foods and the like. The former regenerator has the drawback that it must be cooled in advance in a refrigerator or freezer before it is used, which is inconvenient and cannot be used immediately. On the other hand, the latter coolant has an advantage that a cooling effect can be obtained only by mixing two or more kinds of substances without requiring a prior cooling operation.

[0003]

As such a cooling agent, inorganic salts such as inorganic ammonium salts and alkali metal salts, or a mixture thereof with urea and water in combination, or an inorganic salt and crystal water are used. The combination with the salt hydrates that it has is well known. Among them, the one using water has an advantage that the rise of cooling is quick, but since water is used, the blending amount of the main component of the cooling agent becomes small, and the cooling capacity is reduced. On the other hand, a salt hydrate containing water of crystallization has a relatively low cooling effect, and improvement is desired, and none of them is practically satisfactory.

As a countermeasure for this problem, a method using strontium hydroxide octahydrate as a salt hydrate having water of crystallization has been disclosed (Japanese Patent Laid-Open No. 5-78651). This method improves the minimum temperature obtained, but does not satisfy the low temperature maintenance time. Moreover, the pH is strongly alkaline, and if it adheres to the skin, it causes a large amount of damage when it gets into the eye, and it is necessary to improve the safety.

As a method in consideration of safety, a method using sodium metasilicate nonahydrate, sodium sulfate decahydrate, etc. is known. In particular, sodium sulfate decahydrate has been attracting attention due to low temperature maintenance time and the like.

However, sodium sulfate decahydrate has a low transition temperature to an anhydrate, which is as low as 32.4 ° C., and above this temperature, it is dissolved by the water of crystallization liberated, and again falls below this transition temperature. In the case of recrystallization, unlike the crystal shape before recrystallization and dissolution, generally it becomes a large crystal,
Mixability with other components is significantly reduced. For this reason, sodium sulfate decahydrate has serious problems in storability and workability, which is an obstacle to practical use.

Further, as an inorganic salt such as an inorganic ammonium salt or an alkali metal salt used in combination with sodium sulfate decahydrate, or a mixture thereof with urea, a mixture of ammonium nitrate and urea has a cooling performance. Used from. The melting point of the simple substance is 165 ° C. for ammonium nitrate and 132.5 ° C. for urea, which is not a problem for practical use. It has a big problem in storability and workability like a product. Particularly, in the case of a coolant that uses water of crystallization, it is a practical obstacle.

[0008]

In order to solve this problem, the present inventors have a high cooling effect even when used in a high temperature atmosphere of 30 ° C. or higher, and even if the atmospheric temperature rises to 40 ° C. or higher during storage. Preservation did not decrease due to dissolution of crystals, the size of crystals did not change during recrystallization, and intensive research was conducted to obtain a cooling agent with little damage even if it adheres to skin. As a result, it was found that ammonium nitrate and urea were separately sealed, white carbon was mixed with sodium sulfate decahydrate, and a coolant having excellent cooling performance was obtained by mixing these when using, The present invention has been completed.

That is, the present invention is characterized in that a mixture of ammonium nitrate, urea and sodium sulphate decahydrate and white carbon is kept out of contact with each other so that they can be in mixed contact during use. It is an agent.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail. Ammonium nitrate, urea and sodium sulfate used in the present invention 1
The zero hydrate may be industrially used or generally commercially available.

In the present invention, the use ratio of ammonium nitrate / urea / sodium sulfate decahydrate is preferably 1 / (0.5 to 2) / (0.75 to 3) by weight, and 1 /
Although 1 / 1.7 is most preferable in terms of performance, this ratio is not particularly limited.

The white carbon used in the present invention is produced by the following method, but the production method is not particularly limited to these. The method for producing white carbon is roughly classified into a wet method and a dry method. Since the white carbon used in the present invention is desired to be inexpensive in terms of its properties, the one obtained by the wet method is preferable. Generally, the method for producing white carbon by the wet method includes the decomposition of sodium silicate with an acid, the decomposition with an ammonium salt, and the organo method of producing an aerogel from an organogel of another silicate by an autoclave. An example of the required properties of white carbon is the oil absorption of white carbon. This oil absorption is 200 ml / 10
It is preferable to use 0 g or more of white carbon.
When the oil absorption is less than 200 ml / 100 g, the retained amount of the dissolved sodium sulfate decahydrate is limited, and the desired effect of the present invention may not be exhibited.

The amount of white carbon mixed is 0.01 to 100 parts by weight of sodium sulfate decahydrate.
10 parts by weight is preferable, and 0.1 to 1.0 is particularly preferable.
Parts by weight. When the amount of white carbon mixed is lower than this, the powder state cannot be maintained when sodium sulfate decahydrate is used, and large crystals are included when recrystallized, so that the miscibility with other components is high. Markedly reduced. On the other hand, if the amount of white carbon mixed is higher than this, not only the fluidity is lowered, but also the cooling effect is lowered, which is not preferable.

Although such an effect due to the addition of white carbon is not clear, the melted crystal behaves like a powder by being retained on the surface of white carbon, voids, etc.,
It is presumed that when recrystallizing, crystals are similarly formed on the surface of white carbon, voids, and the like, and thus it exhibits suitable behavior.

The coolant of the present invention may be prepared by storing ammonium nitrate, urea, and a mixture of sodium sulfate decahydrate and white carbon in separate containers and taking out and mixing them at the time of use. It is preferable that each of them is stored separately in a bag or a container having an isolation means that can be easily removed such as a pouch or a partition, and stored as a portable coolant. When the coolant is used, the contents are mixed by removing these isolation means by applying pressure, impact or the like, and the cooling is started to serve each cooling purpose.

Therefore, as the most preferable form, one of three types of ammonium nitrate, urea and sodium sulfate decahydrate mixed with white carbon and two inner bags are present in the outer bag. Then, in the two inner bags,
It is preferable that the remaining two kinds are present respectively. At this time, it is preferable to obtain a cooling sensation in a shorter time from the purpose of use, and from this point, ammonium nitrate is particularly preferable as one kind to be directly put into the outer bag.

The material of the bag at this time is such that the outer bag is durable,
It is preferable that the inner bag has no water permeability and good sealing property. For example, the outer bag is stretched polypropylene / aluminum deposited polyethylene / polyethylene-ethylene vinyl acetate laminate or nylon / aluminum deposited polyethylene / low density polyethylene laminate, and the inner bag is laterally stretched. High density polyethylene /
Aluminum / sealant-coated laminate and thin paper / aluminum / transverse-stretched high-density polyethylene are preferable, but not limited thereto.

As described above, it is easily inferred that the bag and the container are damaged by the pressure and impact applied during use, and the contents leak out, so that safety is required. Although the pH of the cooling agent of the present invention varies depending on the respective compounding ratios, it is generally 6 to 8, and the safety thereof is high, and the cooling agent of the present invention is also suitable.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples, but the scope of the present invention is not limited thereto.

Example 1 50 g of sodium sulfate decahydrate (manufactured by Koei Chemical Co., Ltd.) and white carbon (Carplex # 8 manufactured by Shionogi Pharmaceutical Co., Ltd.)
0) A mixture with 0.5 g and 30 g of urea (manufactured by Mitsui Toatsu Chemical Co., Ltd.) were each laterally drawn high density polyethylene (HD-P
E) / aluminum / sealing agent Coat in a small bag made of laminate, and these two types of small bags are filled with 30 g of ammonium nitrate (Ube Industries) expanded polypropylene (OPP) / aluminum-deposited polyethylene / polyethylene-ethylene vinyl acetate (PE) -EVA) A coolant sample was prepared by enclosing it in an outer bag made of laminate and sealing it.

This sample was left in a constant temperature bath at 40 ° C. for 24 hours and then left in a constant temperature bath at 0 ° C. for 24 hours. After leaving this in a constant temperature bath of 30 ° C for 24 hours, at the ambient temperature of 30 ° C, an external impact is applied to this coolant to destroy the polyethylene small bag inside, and then a thermocouple thermometer is attached to the surface of the outer bag. Was attached to measure the minimum temperature and the cooling duration at 10 ° C. or lower. As a result, the minimum temperature was −7.4 ° C. and the cooling duration was 99 minutes, and there was no problem in practical use during storage. The pH of the produced slurry was 6.6.

Example 2 50 g of sodium sulfate decahydrate (manufactured by Koei Chemical Co., Ltd.) and white carbon (Carplex # 8 manufactured by Shionogi Pharmaceutical Co., Ltd.)
0) A mixture with 0.5 g and ammonium nitrate (manufactured by Ube Industries, Ltd.) 30 g are each enclosed in a transversely high-density polyethylene (HD-PE) / aluminum / sealant-coated laminate pouch, and these two pouches are urea. (Mitsui Toatsu Chemical Co., Ltd.) 30 g of drawn polypropylene (OPP) / aluminum-deposited polyethylene / polyethylene-ethylene vinyl acetate (PE-EVA) is stored in an outer bag made of laminate and sealed to prepare a coolant sample. did. The minimum temperature and cooling duration of this sample were measured in the same manner as in Example 1.

As a result, the minimum temperature was −6.0 ° C. and the cooling duration was 79 minutes, and there was no problem in practical use during storage. The pH of the produced slurry was 6.6.

Example 3 The material of the outer bag is nylon (NY) / aluminum deposited polyethylene /
The same procedure as in Example 1 was carried out except that a low density polyethylene (LLD-PE) laminate was used. As a result, the minimum temperature was −7.2 ° C. and the cooling duration was 106 minutes, and there was no problem in practical use during storage. The pH of the produced slurry was 6.6.

Example 4 The same procedure as in Example 1 was carried out except that the material for the inner bag was thin paper / aluminum / transverse stretched high density polyethylene (HD-PE) laminate. As a result, the minimum temperature was −7.2 ° C. and the cooling duration was 100 minutes, and there was no problem in practical use during storage. The pH of the produced slurry was 6.6.

Example 5 Example 1 was repeated except that the amount of white carbon added was 5.0 g. As a result, the lowest temperature was −6.7 ° C. and the cooling duration was 86 minutes, and there was no practical problem during storage. The pH of the produced slurry was 6.6.

Example 6 Example 1 was repeated except that the amount of white carbon added was 1.0 g. As a result, the minimum temperature was −5.5 ° C. and the cooling duration was 80 minutes, and there was no problem in practical use during storage. The pH of the produced slurry was 6.6.

Comparative Example 1 50 g of sodium sulfate decahydrate (manufactured by Koei Chemical Co., Ltd.) and white carbon (Carplex # 8 manufactured by Shionogi Pharmaceutical Co., Ltd.)
0) A mixture of 0.5 g was sealed in a bag of laterally drawn high-density polyethylene (HD-PE) / aluminum / sealant-coated laminate, and this bag was filled with 30 g of ammonium nitrate (manufactured by Ube Industries) and urea (Mitsui Toatsu Chemical). A cooling agent sample was prepared by storing the mixture in an outer bag made of oriented polypropylene (OPP) / aluminum-deposited polyethylene / polyethylene-ethylene vinyl acetate (PE-EVA) laminate together with a mixture with 30 g of the mixture and sealing the mixture. This sample was measured for the minimum temperature and the cooling duration at 10 ° C. or less in the same manner as in Example 1.

As a result, the contents of the outer bag were solidified. In order to avoid damage to the outer bag due to the solidified contents, the inner bag was broken and the contents were forcibly mixed by slowly folding the outer bag, and the minimum temperature and cooling duration were measured. The minimum temperature was -4.3 ° C and the cooling duration was 33 minutes.

During storage, it was found that there were practical problems. The pH of the produced slurry was 6.6.

Comparative Example 2 The procedure of Example 1 was repeated except that the amount of white carbon added was 0 g. As a result, sodium sulfate 10
The contents of the sachet containing the hydrate were solidified. In order to avoid damage to the outer bag due to the solidified contents, the inner bag was broken and the contents were forcibly mixed by slowly folding the outer bag, and the minimum temperature and cooling duration were measured. The minimum temperature was -5.0 ° C and the cooling duration was 42 minutes. During storage, it turned out to be a practical problem.
The pH of the produced slurry was 6.6.

Comparative Example 3 A mixture of 30 g of water and 60 g of strontium hydroxide octahydrate (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) was sealed in a polyethylene pouch, and this pouch was put together with 60 g of ammonium nitrate (produced by Ube Industries) in aluminum laminer. Stored in an outer bag
A coolant sample was prepared by sealing.

This sample was left in a constant temperature bath at 50 ° C. for 24 hours and then in a constant temperature bath at 0 ° C. for 24 hours. After leaving this in a thermostatic bath at 36 ° C for 24 hours, at the ambient temperature of 36 ° C, an impact is externally applied to this coolant to destroy the polyethylene small bag inside, and then the thermocouple thermometer is attached to the surface of the outer bag. Was attached to measure the minimum temperature and the cooling duration at 10 ° C. or lower. As a result, the minimum temperature was −4.2 ° C. and the cooling duration was 16 minutes, and there was no problem in practical use during storage. The pH of the produced slurry was 12.6.

[0034]

The cooling agent of the present invention is composed of ammonium nitrate, urea, and a mixture of sodium sulfate decahydrate and white carbon. By separating each of them, temperature stability is imparted and safety is high. It is intended to provide a coolant having more excellent cooling performance.

Claims (3)

[Claims] 1. A cooling agent, characterized in that a mixture of ammonium nitrate, urea and sodium sulfate decahydrate and white carbon is kept out of contact with each other so that they can be in mixed contact during use. 2. The coolant according to claim 1, wherein an inner bag filled with urea and a mixture of sodium sulfate decahydrate and white carbon is enclosed in the outer bag filled with ammonium nitrate. 3. The coolant according to claim 1, which contains 0.01 to 10.0 parts by weight of white carbon with respect to 100 parts by weight of sodium sulfate decahydrate.