JP6650363B2 - Cooler - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a cooling device provided with a cooling composition in which a color change upon cooling can be easily visually recognized.

The cool keeping device is widely used for keeping cool of various perishables and at the time of transport, and is usually used repeatedly. Such a cool keeping device is provided with a cool keeping composition having a cool keeping effect, and is constituted by enclosing the cool keeping composition in a heat conductive container.
As the composition for cooling, a composition containing a coloring agent is known so that the presence thereof can be easily recognized from the outside of the cooling tool.For example, a cooling composition colored with a dye is enclosed. There is disclosed a cooler in which the amount of sealing can be easily checked from the outside (see Patent Document 1).

JP-A-2006-97984

  However, even if the cooling composition described in Patent Literature 1 contains a dye in the cooling composition, it is difficult to visually confirm the cooling state, such as the presence or absence of freezing, and to a desired temperature at which cooling can be performed. Until then, there was a problem that the cooling device was sufficiently cooled or it was difficult to visually confirm the cooling state.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a cooler which can easily visually confirm whether a cooling state is a target state.

In order to solve the above-mentioned problems, the present invention is a cooling device provided with a cooling composition containing water, an inorganic salt, a thickener and a pH indicator, wherein the composition for cooling is as the inorganic salt, The following (S1), (S2), (S3) or (S4):
(S1) Combination of phosphate, monohydrogen phosphate, and other inorganic salts that do not fall under any of phosphate, monohydrogen phosphate and dihydrogen phosphate (S2) phosphate And a combination of dihydrogen phosphate and another inorganic salt that does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate (S3) Monohydrogen phosphate and phosphoric acid Combination of dihydrogen salt and other inorganic salts which do not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate (S4) Dihydrogen phosphate, phosphate and phosphoric acid It contains only a combination with other inorganic salts that do not correspond to any of monohydrogen salts and dihydrogen phosphate salts, and the total content of the inorganic salts in the composition for keeping cool is 20 to 35% by mass. Phosphate, monohydrogen phosphate, dihydrogen phosphate of the composition for cooling PH (β1) when all the components other than water and water are replaced by water, and the pH when the components other than the inorganic salt, the thickener and the water other than the water are completely replaced by water. Provided is a cooler that satisfies the relationship represented by the following formula (10) with pH (β2).
11.0 ≦ pH (β1) + pH (β2) ≦ 17.2 (10)

  ADVANTAGE OF THE INVENTION According to this invention, the cooler which can be easily visually recognized whether the cooling state is in the target state is provided.

<< Cooler >>
The cool keeping device of the present invention is a cool keeping device provided with a cold keeping composition containing water, an inorganic salt, a thickener and a pH indicator, wherein the cold keeping composition comprises the following inorganic salt as the following (S1) , (S2), (S3) or (S4):
(S1) Combination of phosphate, monohydrogen phosphate, and other inorganic salts that do not fall under any of phosphate, monohydrogen phosphate and dihydrogen phosphate (S2) phosphate And a combination of dihydrogen phosphate and another inorganic salt that does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate (S3) Monohydrogen phosphate and phosphoric acid Combination of dihydrogen salt and other inorganic salts which do not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate (S4) Dihydrogen phosphate, phosphate and phosphoric acid It contains only a combination with other inorganic salts that do not correspond to any of monohydrogen salts and dihydrogen phosphate salts, and the total content of the inorganic salts in the composition for keeping cool is 20 to 35% by mass. Phosphate, monohydrogen phosphate, dihydrogen phosphate of the composition for cooling PH (β1) when all the components other than water and water are replaced by water, and the pH when the components other than the inorganic salt, the thickener and the water other than the water are completely replaced by water. and pH (β2) satisfy the relationship represented by the following formula (10).
11.0 ≦ pH (β1) + pH (β2) ≦ 17.2 (10)

  In the cooling device, the color of the composition for cooling, which reflects the presence or absence of coloration of the pH indicator, greatly changes before and after freezing of the composition for cooling. This makes it easy to visually recognize whether the cooling device is in a desired state (a state in which the object can be cooled sufficiently). The colors of the composition for cooling before and after freezing do not mainly reflect the colors of the components themselves other than the pH indicator such as the inorganic salt and the thickener.

  The composition for keeping cold contains an inorganic salt and a thickener as components affecting the acidity, but only the above-mentioned (S1), (S2), (S3) or (S4) as an inorganic salt. To limit the total content of the inorganic salt, and among the inorganic salts, focusing on phosphate, monohydrogen phosphate and dihydrogen phosphate, pH (β1 ) And pH (β2) reflecting the acidity of the other inorganic salts and thickeners are limited to a specific range, so that depending on the change in color development of the pH indicator or the presence or absence, It causes a large color change.

The composition for keeping cool is suitable for maintaining the temperature of itself after cooling in a temperature range of, for example, -30 ° C to -25 ° C for a long time. The cooling tool is suitable for keeping the object to be cooled in a temperature range of, for example, -28C to -20C. It can be said that this cold storage temperature is clearly lower than the generally used cold storage temperature of −20 ° C. or higher. When newly designing such a cooling composition, it is necessary to adjust the composition to achieve a lower freezing temperature, but the composition of the cooling composition changes only by the freezing temperature of the cooling composition. It also affects the degree of color change before and after freezing. In other words, even if a new cooling composition is designed with reference to a cooling composition generally used in the past, a lower freezing temperature and a clear color change before and after freezing are simultaneously achieved. It's not easy.
On the other hand, the composition for keeping cool in the present invention achieves a lower freezing temperature and a clear color change before and after freezing at the same time by adopting the above-described limited configuration. is there.

  The cold insulator of the first to fourth embodiments of the cold insulator of the present invention depends on which of the above (S1) to (S4) is selected as the inorganic salt in the composition for cold insulator as follows. are categorized. Hereinafter, the cooler of the present invention will be described for each embodiment.

◎ First Embodiment The cooler according to the first embodiment of the present invention is a cooler provided with a cooler composition containing water, an inorganic salt, a thickener, and a pH indicator, wherein the cooler composition is provided. But, as the inorganic salt,
(S1) It contains only a combination of a phosphate, a monohydrogen phosphate, and another inorganic salt that does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate, The total content of the inorganic salt in the composition for keeping cool is 20 to 35% by mass, and the components of the composition for keeping cool other than phosphate, monohydrogen phosphate, dihydrogen phosphate and water And pH (β2) when all the components other than the inorganic salt, the thickener and the water of the composition for cooling are replaced with water, Satisfy the relationship represented by the following equation (10).
11.0 ≦ pH (β1) + pH (β2) ≦ 17.2 (10)

The composition for keeping cool in the first embodiment does not contain dihydrogen phosphate as the inorganic salt. Accordingly, the composition for cooling according to the first embodiment contains water, an inorganic salt, a thickener and a pH indicator, and as the inorganic salt,
(S1) It contains only a combination of a phosphate, a monohydrogen phosphate, and another inorganic salt that does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate, The total content of the inorganic salt in the composition for keeping cold was 20 to 35% by mass, and the components of the composition for keeping cool except phosphate, monohydrogen phosphate and water were all replaced with water. The following formula (101) is obtained when the pH (β11) in the case and the pH (β21) when all the components other than the inorganic salt, the thickener and the water of the composition for cooling the cold are replaced with water. It can be said that the relationship represented by
11.0 ≦ pH (β11) + pH (β21) ≦ 17.2 (101)

<Inorganic salt>
The inorganic salt in the first embodiment functions as one component of a cold preservative, and the freezing temperature of the composition for cold preservation is determined mainly by its type and amount.
In addition, the inorganic salt does not correspond to the pH indicator, and is a component that precipitates as a crystal or amorphous (amorphous) when the composition for cooling is frozen, and contributes to a color change of the composition for cooling due to precipitation. Things.

  In the present specification, the “acidic inorganic salt” described below means a salt whose aqueous solution is acidic. Similarly, “neutral inorganic salt” means a salt whose aqueous solution shows neutrality, and “basic inorganic salt” means a salt whose aqueous solution shows basicity.

[Phosphate]
The phosphate in the first embodiment is obtained by replacing three hydrogen ions in phosphoric acid (H ₃ PO ₄ ) with a cation, and may be a non-hydrate or a hydrate. It may be a thing.
The phosphate is usually a basic inorganic salt.

Examples of the phosphate in the first embodiment include trisodium phosphate (Na ₃ PO ₄ ), trisodium phosphate dodecahydrate (Na ₃ PO ₄ .12H ₂ O), and tripotassium phosphate (K) ₃ PO ₄₎ tricalcium phosphate metal salts such as; phosphate tribasic ammonium _{((NH 3)} 3 PO ₄₎ such as a three-nonmetal salts and phosphoric acid. of trisodium phosphate _(Na 3 _PO 4), phosphorus Trisodium acid dodecahydrate and tripotassium phosphate (K ₃ PO ₄ ) are preferred.

  The phosphate composition contained in the composition for cooling according to the first embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

[Monohydrogen phosphate]
The monohydrogen phosphate in the first embodiment is obtained by replacing two hydrogen ions in phosphoric acid (H ₃ PO ₄ ) with a cation, and may be a non-hydrate. It may be a hydrate.
The monohydrogen phosphate is usually a basic inorganic salt.

Examples of the monohydrogen phosphate in the first embodiment include phosphorus such as disodium hydrogen phosphate (Na ₂ HPO ₄ ), dipotassium hydrogen phosphate (K ₂ HPO ₄ ), and calcium hydrogen phosphate (CaHPO ₄ ). Non-metallic monohydrogenphosphate salts such as dihydrogen ammonium phosphate ((NH ₄ ) ₂ HPO ₄ ).

  The monohydrogen phosphate salt contained in the composition for keeping cold in the first embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

[Other inorganic salts]
The other inorganic salt in the first embodiment is an inorganic salt that does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate.
The other inorganic salt may be any of an acidic inorganic salt, a neutral inorganic salt, and a basic inorganic salt, and may be a non-hydrate or a hydrate.

Among the other inorganic salts, examples of acidic inorganic salts include, for example, ammonium chloride (NH ₄ Cl), ammonium bromide (NH ₄ Br), ammonium iodide (NH ₄ I), magnesium chloride (MgCl ₂ ), Ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), ammonium nitrate (NH ₄ NO ₃ ), aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), alum (AlK (SO ₄ ) ₂ ), ammonium alum (Al (NH ₄ )) SO ₄ ) ₂ ), calcium nitrate tetrahydrate (Ca (NO ₃ ) ₂ .4H ₂ O), calcium nitrate (Ca (NO ₃ ) ₂ ) and the like.
Among these, the acidic inorganic salt is preferably ammonium chloride, ammonium bromide (NH ₄ Br), or ammonium nitrate.

Among the other inorganic salts, examples of neutral inorganic salts include sodium chloride (NaCl), potassium chloride (KCl), calcium chloride (CaCl ₂ ), sodium sulfate (Na ₂ SO ₄ ), and potassium sulfate (K ₂ SO ₄ ), magnesium sulfate (MgSO ₄ ), sodium nitrate (NaNO ₃ ), potassium nitrate (KNO ₃ ), potassium bromide (KBr), sodium bromide (NaBr), potassium iodide (KI), sodium iodide ( NaI), potassium chlorate (KClO ₃ ), sodium perchlorate (NaClO ₄ ), sodium thiosulfate (Na ₂ S ₂ O ₃ ), and the like.
Among these, the neutral inorganic salt is preferably sodium chloride, potassium chloride, sodium bromide, potassium bromide, or potassium nitrate.

Among the other inorganic salts, basic inorganic salts include, for example, sodium carbonate (Na ₂ CO ₃ ), potassium carbonate (K ₂ CO ₃ ), sodium hydrogen carbonate (NaHCO ₃ ), and potassium hydrogen carbonate (KHCO _3). ), Sodium sulfite (Na ₂ SO ₃ ), borax (Na ₂ B ₄ O ₇ ), and the like.

  The other inorganic salt contained in the composition for keeping cold in the first embodiment may be only one kind, or two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

  The total content of the inorganic salt of the composition for keeping cool in the first embodiment is 20 to 35% by mass, preferably 21 to 34% by mass, more preferably 23 to 32% by mass, It is particularly preferred that it is 24.5 to 30.5% by mass.

  In the composition for keeping cool of the first embodiment, the content of the phosphate is preferably 0.7 to 5.5 times by mass the content of the monohydrogen phosphate, and 0.8 to 5.5 times by mass. It is more preferably 5 times by mass, and particularly preferably 0.9 to 4.5 times by mass.

  In the composition for keeping cold according to the first embodiment, the content of the other inorganic salt is preferably 200 to 2,000 times by mass, and more preferably 220 to 1600 times by mass with respect to the content of monohydrogen phosphate. More preferably, it is particularly preferably 240 to 1200 times by mass.

Before freezing in the first embodiment, preferably in the composition for cooling at 0 ° C. or higher, the dissolved amount of the inorganic salt is preferably as large as possible, and the dissolved amount of the inorganic salt is preferably It is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and may be 100% by mass (total amount).
Further, in the composition for keeping cold after freezing in the first embodiment, it is preferable that the amount of the inorganic salt precipitated is larger, and the amount of the inorganic salt precipitated out of the total amount of the inorganic salt is 90% by mass or more. Is preferably 95% by mass or more, more preferably 98% by mass or more, and may be 100% by mass (total amount).

The pH (β1) in the case where all the components other than the phosphate, monohydrogen phosphate, dihydrogen phosphate and water of the composition for keeping cool in the first embodiment are replaced with water is as described above. It is synonymous with pH (β11) when all the components other than the phosphate, monohydrogen phosphate and water of the composition for cooling are replaced with water.
The pH (β1) (pH (β11)) contains only phosphate and monohydrogenphosphate at the same content (% by mass) as the content (% by mass) in the composition for keeping cool in the first embodiment. PH of the mixture of phosphate and monohydrogen phosphate used in the composition for cooling, which corresponds to the pH of water (eg, an aqueous solution containing phosphate and monohydrogen phosphate). It is what becomes.

  The pH (β1) (pH (β11)) in the first embodiment is preferably a pH at a temperature at which a pH indicator is dissolved in the composition for keeping cold, and the temperature of the mixture is 25 ° C. It is more preferable that the pH is at a certain level.

  The pH (β1) (pH (β11)) in the first embodiment preferably satisfies the relationship of the above formula (10) (the above formula (101)), and is further preferably 8.0 to 12.0. It is more preferably from 8.3 to 11.7, particularly preferably from 8.5 to 11.5.

The pH (β2) of the composition for cooling insulation according to the first embodiment when all the components other than the inorganic salt, the thickener, and water are replaced with water, as described above, is the composition for cooling insulation as described above. The pH (β21) is the same as when the other inorganic salt, thickener and water-containing components are all replaced with water.
The pH (β2) (pH (β21)) contains only the other inorganic salt and the thickener at the same content (% by mass) as the content (% by mass) in the composition for keeping cool in the first embodiment. The pH of the mixture of the other inorganic salt and the thickener used in the cooling composition corresponds to the pH of water (eg, an aqueous solution containing the other inorganic salt and the thickener). It is what becomes.

  The pH (β2) (pH (β21)) in the first embodiment is preferably a pH at a temperature at which a pH indicator is dissolved in the composition for keeping cold, and the temperature of the mixture is 25 ° C. It is more preferable that the pH is at a certain level.

  It is preferable that pH (β2) (pH (β21)) in the first embodiment satisfies the relationship of the above formula (10) (the above formula (102)), and furthermore, 5.0 to 8.0, It is more preferably from 5.2 to 7.3, particularly preferably from 5.5 to 6.6.

In the composition for cold insulation of the first embodiment, the total value of pH (β1) and pH (β2) is the same as the total value of pH (β11) and pH (β21), as described above, and is 11.0 to 17.2 (satisfies the relationship represented by the formula (10)), preferably 11.5 to 17.2, more preferably 12.0 to 17.2, and 12.5. To 17.2, more preferably 13.0 to 17.2, and for example, any of 13.5 to 17.2 and 14.0 to 17.2. .
The total value of the pH (β1) and the pH (β2) can be adjusted by adjusting the type of the compound that affects the pH (β1) or the pH (β2), or the content of the compound in the composition for keeping cool. Can be adjusted. In particular, the total value of pH (β1) and pH (β2) can be easily adjusted by adjusting the ratio between the content of the phosphate and the content of the monohydrogen phosphate in the composition for keeping cool.

<Thickener>
The thickener in the first embodiment is a component that increases the viscosity of the composition for keeping cold and does not correspond to the pH indicator. It is preferable that the thickener in the first embodiment does not precipitate when the composition for cooling is frozen. In the present specification, `` the thickener does not precipitate when the composition for cooling is frozen '' means that when the composition for cooling is frozen, the thickener is solidified in a state of being dissolved in water, It is presumed that the thickener molecules do not aggregate in large quantities and are solidified while being surrounded by water molecules, and it is not a state where a large amount of thickener molecules are aggregated and solidified Guessed.

  The thickener in the first embodiment is not particularly limited, but includes, for example, acrylic polymers (carboxyvinyl polymer, compounds having a polyacrylic acid skeleton) such as polyacrylic acid and sodium polyacrylate; carboxymethylcellulose (CMC) Carboxyalkylcellulose such as sodium carboxymethylcellulose; guar gum; hydroxyalkyl guar gum such as hydroxypropyl guar gum; pectin; xanthan gum; tamarind gum; carrageenan; alkylene glycol such as propylene glycol.

The thickener in the first embodiment is selected from the group consisting of acrylic polymers, carboxyalkyl cellulose, salts of carboxyalkyl cellulose, xanthan gum, guar gum, hydroxyalkyl guar gum, pectin, tamarind gum, carrageenan, and alkylene glycol. It is preferable that the number of species is two or more.
The thickener is more preferably one or more selected from the group consisting of an acrylic polymer, carboxyalkylcellulose, a salt of carboxyalkylcellulose, and hydroxyalkyl guar gum.
By using such a thickener, the composition for keeping cold has a large color change before and after freezing and has better handleability.

  The thickening agent contained in the composition for keeping cold in the first embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  In the composition for keeping cold before and after freezing in the first embodiment, it is preferable that the amount of the thickener that is precipitated is smaller, and the amount of the thickener that is precipitated out of the total amount of the thickener is 10% by mass or less. Is preferably 5% by mass or less, more preferably 2% by mass or less, and particularly preferably 0% by mass (the entire amount is not precipitated).

  The content of the thickener in the composition for keeping cool in the first embodiment is preferably 0.1 to 10% by mass, more preferably 0.3 to 6% by mass, and 0.6 to 3% by mass. It is particularly preferred that the content is mass%.

<PH indicator>
The pH indicator (acid-base indicator) in the first embodiment determines the color of the composition for keeping cool by reflecting the presence or absence of color development. The composition for keeping cold changes its color before and after freezing by containing a pH indicator.

The pH indicator in the first embodiment is not particularly limited, and can be arbitrarily selected according to the purpose.
For example, the pH indicator preferably has a pKa of 4.9 to 8.0.
The pKa of the pH indicator in the present embodiment means a value when the solvent is water and the temperature is 25 ° C., unless otherwise specified.

  The pH indicator has a pH range in which the discoloration is observed, that is, a discoloration range. A pH indicator is present in a solution in a dissociated form and an undissociated form, and a dissociation equilibrium is established between them.The colors exhibited by the dissociated form and the undissociated form are different from each other. In, the equilibrium is significantly biased toward either the dissociated or undissociated form, and only one color is seen. In the discoloration range, the pH indicator is mixed in such an amount that the dissociated form and the undissociated form can be compared, and both colors are mixed (see “Chemical Encyclopedia 39th Edition, September 2006” 15th, Kyoritsu Publishing Co., Ltd.).

  Table 1 illustrates the main pH indicators. Table 1 also shows the pH indicator and its color change range and color change. The “color change (low pH → high pH)” in Table 1 means that when the pH of the liquid containing the pH indicator changes from a specific value to a higher value, the pH indicator changes. For example, “red → yellow” means that the pH indicator changes the color of the liquid from red to yellow in the process of increasing the pH of the liquid.

  The discoloration range (pH) of the pH indicator in the first embodiment is, for example, preferably in the range of 3.0 to 10.5, more preferably in the range of 4.0 to 9.5, Those in the range of 4.5 to 9.0 are particularly preferred.

  The pH indicator contained in the composition for keeping cold in the first embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. However, it is usually preferable to contain only one pH indicator.

  The content of the pH indicator of the composition for keeping cool in the first embodiment is not particularly limited as long as the intended color change of the composition for keeping cool is achieved, but is preferably 1 to 30 ppm, and 5 to 20 ppm. More preferably, there is.

<Other ingredients>
The composition for keeping cool in the first embodiment may contain, in addition to water, an inorganic salt, a thickener, and a pH indicator, other components that do not correspond to these as long as the effects of the present invention are not impaired. . Examples of the other components include solvents other than water; various known additives such as preservatives and surfactants.
The other components contained in the composition for keeping cool in the first embodiment may be only one kind, two or more kinds, and when there are two or more kinds, their combination and ratio can be arbitrarily selected.

[solvent]
The solvent in the first embodiment is preferably capable of dissolving the inorganic salt, the thickener, and the pH indicator, and examples of such a solvent include alcohol.

Water and the solvent function as one component of the cooling agent, and together with the inorganic salt, the freezing temperature of the composition for cooling is determined mainly by their type and amount.
In the cooling composition of the first embodiment, the ratio of the content of the solvent to the total content of water and the solvent is preferably 10% by mass or less, more preferably 5% by mass or less. It is particularly preferred that the content be 2% by mass or less.

[Preservative]
Examples of the preservative in the first embodiment include food preservatives, antioxidants, and the like, and more specifically, sodium pyrithione, parabens (paraoxybenzoate), protamine, organic nitrogen-sulfur compounds, and the like. Is mentioned.

  The content of the preservative of the composition for keeping cool in the first embodiment is not particularly limited, but is preferably 0.02 to 0.5% by mass, and more preferably 0.04 to 0.2% by mass. More preferred.

[Surfactant]
Examples of the surfactant in the first embodiment include known surfactants, and examples thereof include an alkyl sulfate such as sodium dodecyl sulfate; an alkyl carboxylate such as sodium decanoate; and an N-alkyl acrylamide such as N-isopropylacrylamide. Polyoxyethylene dialkyl ethers such as polyoxyethylene octyl dodecyl ether; polyoxyethylene monoalkyl ethers such as polyoxyethylene lauryl ether; and polyoxyethylene monoalkenyl ethers such as polyoxyethylene oleyl ether.

  The composition for keeping cool in the first embodiment is characterized in that the inorganic salt, the water-insoluble component, the total content of components other than water and the solvent (the inorganic salt, the thickener, the pH indicator, and the other components other than the solvent) are contained. The ratio of the total content of the viscosity agent and the pH indicator is preferably 90% by mass or more, more preferably 93% by mass or more, further preferably 96% by mass or more, and more preferably 98% by mass or more. It is particularly preferred that the content be 100% by mass. When the ratio of the total content is equal to or more than the lower limit, the composition for cooling keeps changing color more before and after freezing.

The pH of the composition for keeping cool in the first embodiment is preferably 5.4 to 8.0, more preferably 5.6 to 7.5, and more preferably 5.8 to 7.0. Is particularly preferred.
The composition for cooling according to the first embodiment preferably exhibits a pH in the numerical range at a temperature at which a pH indicator is dissolved in the composition for cooling, and the temperature of the composition for cooling is 25 ° C. Sometimes it is more preferable to show the pH in the above numerical range.
In the present embodiment, the mere description of “pH” with respect to the composition for keeping cool means the pH of the composition for keeping cool, unless otherwise specified.

The composition for keeping cold in the first embodiment is obtained by blending water, the inorganic salt, a thickener, a pH indicator, and if necessary, the other components.
The method of blending the components is not particularly limited, and can be arbitrarily adjusted so that the components are uniformly dissolved or dispersed at a temperature higher than the freezing temperature of the composition for keeping cold.
For example, when compounding each component, all the components may be added and then mixed, or some components may be added sequentially and mixed, or all the components may be added sequentially and mixed. You may.
The mixing method is not particularly limited, a method of mixing by rotating a stirrer or a stirring blade; a method of mixing using a mixer, a three-roll, kneader or a bead mill; a method of mixing by adding ultrasonic waves; What is necessary is just to select suitably from well-known methods.

  The cooling tool according to the first embodiment of the present invention includes the cooling composition. For example, the cooling composition is held by a holding unit such as a container or a bag capable of enclosing a liquid material. It is constituted by doing.

  The material of the holding means is not particularly limited as long as it has transparency such that the color change (discoloration) of the held composition for cooling can be visually recognized, and preferable examples thereof include polyethylene and polypropylene. And the like; synthetic resins such as polyolefins; polyamides; polyesters and the like. Examples of polyethylene include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE).

The material and size of the holding means may be selected in consideration of, for example, the form of the holding means, the holding amount of the composition for cooling, or the color change of the composition for cooling before and after freezing.
For example, in the case of a bag-like holding means, low-density polyethylene is an example of a preferable material of the holding means. In the case of a container-like holding means, an example of a preferable material for the holding means is high-density polyethylene.
For example, the bag-shaped holding means is preferable when it is used as a small one, that is, when the holding amount of the composition for cooling is relatively small. Further, the container-shaped holding means is preferable when it is used as a large one, that is, when the holding amount of the composition for cooling is relatively large.
However, the method of selecting the material and size of the holding means shown here is only an example.

  The material of the holding means is preferably a polyolefin in that it is excellent in low-temperature brittleness resistance, water resistance, chemical resistance and the like.

  The thickness of the flat portion such as a film or sheet in the holding means is not particularly limited, but is preferably 5 to 200 μm.

The flat portion may be composed of a single layer, or may be composed of two or more layers. When the flat portion includes a plurality of layers, the plurality of layers may be the same or different from each other. That is, all the layers may be the same, all the layers may be different, or only some of the layers may be the same. When the plurality of layers are different from each other, the combination of the plurality of layers is not particularly limited. Here, that a plurality of layers are different from each other means that at least one of the material and the thickness of each layer is different from each other.
When the flat portion is composed of a plurality of layers, the total thickness of each layer may be set to the preferable thickness of the flat portion.

The composition for cooling cold in the first embodiment has a large color change before and after freezing, so that the presence or absence of freezing can be easily visually recognized. And this color change of the composition for cooling is visible from the outside of the cooling tool, and thereby, the cooling tool is easily visible whether or not it is sufficiently cooled to the desired temperature. ing.
Further, the composition for cooling the cold, such as repeated freezing and thawing, even if the cooling and heating is repeated, the effect is not impaired, so the cooling tool provided with this is suitable for repeated use. is there.

◎ Second Embodiment The cooler according to the second embodiment of the present invention is a cooler provided with a cooler composition containing water, an inorganic salt, a thickener, and a pH indicator, wherein the cooler composition But, as the inorganic salt,
(S2) a mixture containing only a combination of a phosphate, a dihydrogen phosphate, and another inorganic salt that does not correspond to any of the phosphate, monohydrogen phosphate and dihydrogen phosphate, The total content of the inorganic salt in the composition for keeping cool is 20 to 35% by mass, and the components of the composition for keeping cool other than phosphate, monohydrogen phosphate, dihydrogen phosphate and water And pH (β2) when all the components other than the inorganic salt, the thickener and the water of the composition for cooling are replaced with water, Satisfy the relationship represented by the following equation (10).
11.0 ≦ pH (β1) + pH (β2) ≦ 17.2 (10)

The composition for keeping cool in the second embodiment does not contain monohydrogen phosphate as the inorganic salt. Therefore, the composition for cooling according to the second embodiment contains water, an inorganic salt, a thickener and a pH indicator, and as the inorganic salt,
(S2) a mixture containing only a combination of a phosphate, a dihydrogen phosphate, and another inorganic salt that does not correspond to any of the phosphate, monohydrogen phosphate and dihydrogen phosphate, The total content of the inorganic salt in the composition for keeping cool was 20 to 35% by mass, and the components of the composition for keeping cool except phosphate, dihydrogen phosphate and water were all replaced with water. The following formula (102) is obtained when the pH (β12) in the case and the pH (β22) when all the components other than the inorganic salt, the thickener and the water of the composition for cooling the cold are replaced with water. It can be said that the relationship represented by
11.0 ≦ pH (β12) + pH (β22) ≦ 17.2 (102)

<Inorganic salt>
The inorganic salt in the second embodiment functions as one component of a cold preservative, and the freezing temperature of the composition for cold preservation is determined mainly by its type and amount.
In addition, the inorganic salt does not correspond to the pH indicator, and is a component that precipitates as a crystal or amorphous (amorphous) when the composition for cooling is frozen, and contributes to a color change of the composition for cooling due to precipitation. Things.

[Phosphate]
Examples of the phosphate in the second embodiment include the same phosphates as those in the first embodiment.
For example, the phosphate in the second embodiment is preferably trisodium phosphate, trisodium phosphate dodecahydrate, or tripotassium phosphate.

  The phosphate salt contained in the composition for keeping cold in the second embodiment may be only one kind, two or more kinds, and when there are two or more kinds, their combination and ratio can be arbitrarily selected.

[Dihydrogen phosphate]
The dihydrogen phosphate in the second embodiment is obtained by replacing one hydrogen ion in phosphoric acid (H ₃ PO ₄ ) with a cation, and may be a non-hydrate. It may be a hydrate.
The dihydrogen phosphate is usually an acidic inorganic salt.

Examples of the dihydrogen phosphate in the second embodiment include sodium dihydrogen phosphate (NaH ₂ PO ₄ ), potassium dihydrogen phosphate (KH ₂ PO ₄ ), and calcium dihydrogen phosphate (Ca (H ₂ PO ₄ )). ₄ ) Metal dihydrogen phosphate such as ₂ ); non-metal dihydrogen phosphate such as ammonium dihydrogen phosphate ((NH ₄ ) H ₂ PO ₄ );

  The dihydrogen phosphate salt contained in the composition for keeping cool in the second embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

[Other inorganic salts]
The other inorganic salt in the second embodiment is an inorganic salt that does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate.
The other inorganic salt may be any of an acidic inorganic salt, a neutral inorganic salt, and a basic inorganic salt, and may be a non-hydrate or a hydrate.

Examples of the other inorganic salt in the second embodiment include the same as the other inorganic salt in the first embodiment.
For example, the acidic inorganic salt in the second embodiment is preferably ammonium chloride, ammonium bromide, or ammonium nitrate.
Further, the neutral inorganic salt in the second embodiment is preferably sodium chloride, potassium chloride, sodium bromide, potassium bromide, or potassium nitrate.

  The other inorganic salt contained in the composition for keeping cold in the second embodiment may be only one kind, or two or more kinds, and when there are two or more kinds, their combination and ratio can be arbitrarily selected. .

  The total content of the inorganic salt in the composition for keeping cool in the second embodiment is 20 to 35% by mass, preferably 21 to 34% by mass, more preferably 23 to 32% by mass, The content is particularly preferably 24.5 to 30.5% by mass, and for example, can be any of 24.5 to 28% by mass, 24.5 to 27% by mass, and 24.5 to 26% by mass.

  In the composition for keeping cool of the second embodiment, the content of the phosphate is preferably 1.1 to 11.5 times by mass relative to the content of the dihydrogen phosphate, and 1.2 to 1 times by mass. It is more preferably 11 times by mass, particularly preferably 1.3 to 10.5 times by mass.

  In the composition for keeping cool of the second embodiment, the content of the other inorganic salt is preferably 110 to 2550 times by mass, and more preferably 110 to 2525 times by mass with respect to the content of dihydrogen phosphate. More preferably, it is particularly preferably 110 to 2500 times by mass.

Before freezing in the second embodiment, preferably in the composition for cooling at 0 ° C. or higher, the dissolved amount of the inorganic salt is preferably as large as possible, and the dissolved amount in the total amount of the inorganic salt is preferably It is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and may be 100% by mass (total amount).
In the composition for keeping cold after freezing in the second embodiment, the amount of the inorganic salt precipitated is preferably as large as possible, and the amount of the inorganic salt precipitated out of the total amount of the inorganic salt is 90% by mass or more. Is preferably 95% by mass or more, more preferably 98% by mass or more, and may be 100% by mass (total amount).

The pH (β1) when the components other than the phosphate, monohydrogen phosphate, dihydrogen phosphate and water in the composition for keeping cool in the second embodiment are all replaced with water is as described above. This is synonymous with pH (β12) when all the components other than the phosphate, dihydrogen phosphate and water of the composition for cooling are replaced with water.
pH (β1) (pH (β12)) contains only phosphate and dihydrogen phosphate at the same content (% by mass) as the content (% by mass) in the composition for keeping cool in the second embodiment. PH of water (e.g., an aqueous solution containing phosphate and dihydrogen phosphate), and an index of the acidity of the mixture of phosphate and dihydrogen phosphate used in the composition for keeping cool. It is what becomes.

  The pH (β1) (pH (β12)) in the second embodiment is preferably a pH at a temperature at which a pH indicator is dissolved in the composition for keeping cold, and the temperature of the mixture is 25 ° C. It is more preferable that the pH is at a certain level.

  The pH (β1) (pH (β12)) in the second embodiment satisfies the relationship of the above formula (10), and is preferably 5.8 to 10.9, and more preferably 6.0 to 10.6. Is more preferable, and particularly preferably 6.2 to 10.3.

The pH (β2) of the composition for cooling insulation according to the second embodiment when all the components other than the inorganic salt, the thickener, and water are replaced with water, as described above, is the composition for cooling insulation. The pH (β22) is the same as when the other inorganic salt, thickener and water-containing components are all replaced with water.
The pH (β2) (pH (β22)) contains only the other inorganic salt and the thickener at the same content (% by mass) as the content (% by mass) in the composition for keeping cool in the second embodiment. The pH of the mixture of the other inorganic salt and the thickener used in the cooling composition corresponds to the pH of water (eg, an aqueous solution containing the other inorganic salt and the thickener). It is what becomes.

  The pH (β2) (pH (β22)) in the second embodiment is preferably a pH at a temperature at which a pH indicator is dissolved in the composition for keeping cool, and the temperature of the mixture is 25 ° C. It is more preferable that the pH is at a certain level.

  It is preferable that pH (β2) (pH (β22)) in the second embodiment satisfies the relationship of the above formula (10) (the above formula (102)), and furthermore, is 3.1 to 7.4, It is more preferably from 3.3 to 6.7, particularly preferably from 3.5 to 6.0.

In the composition for keeping cool of the second embodiment, the total value of pH (β1) and pH (β2) is the same as the total value of pH (β12) and pH (β22) as described above, and is 11.0 to 17.2 (satisfies the relationship represented by the formula (10)), preferably 11.0 to 16.9, more preferably 11.0 to 16.6, and 11.0 to 11.0. To 16.3, more preferably 11.0 to 16.0.
The total value of the pH (β1) and the pH (β2) can be adjusted by adjusting the type of the compound that affects the pH (β1) or the pH (β2), or the content of the compound in the composition for keeping cool. Can be adjusted. In particular, the total value of pH (β1) and pH (β2) can be easily adjusted by adjusting the ratio between the content of the phosphate and the content of the dihydrogen phosphate in the composition for keeping cool.

<Thickener>
The thickener in the second embodiment is a component that increases the viscosity of the composition for keeping cold and does not correspond to the pH indicator. It is preferable that the thickener in the second embodiment does not precipitate when the composition for cooling is frozen.

Examples of the thickener in the second embodiment include the same as the thickener in the first embodiment.
As in the case of the first embodiment, the thickener in the second embodiment includes acrylic polymer, carboxyalkylcellulose, a salt of carboxyalkylcellulose, xanthan gum, guar gum, hydroxyalkyl guar gum, pectin, tamarind gum, carrageenan and It is preferable that one or more selected from the group consisting of alkylene glycols.
The thickener is more preferably one or more selected from the group consisting of an acrylic polymer, carboxyalkylcellulose, a salt of carboxyalkylcellulose, and hydroxyalkyl guar gum.
By using such a thickener, the composition for keeping cold has a large color change before and after freezing and has better handleability.

  The thickening agent contained in the composition for keeping cold in the second embodiment may be only one kind, two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  In the composition for keeping cold before and after freezing in the second embodiment, the amount of the thickener that is deposited is preferably as small as possible, and the amount of the thickener that is precipitated out of the total amount of the thickener is 10% by mass or less. Is preferably 5% by mass or less, more preferably 2% by mass or less, and particularly preferably 0% by mass (the entire amount is not precipitated).

  The content of the thickener in the composition for keeping cool in the second embodiment is preferably 0.1 to 10% by mass, more preferably 0.3 to 6% by mass, and 0.6 to 3% by mass. It is particularly preferred that the content is mass%.

<PH indicator>
The pH indicator (acid-base indicator) in the second embodiment determines the color of the composition for keeping cool by reflecting the presence or absence of color development. The composition for keeping cold changes its color before and after freezing by containing a pH indicator.

The pH indicator in the second embodiment is not particularly limited, and can be arbitrarily selected according to the purpose.
For example, the pH indicator preferably has a pKa of 4.9 to 8.0.
The pKa of the pH indicator in the present embodiment means a value when the solvent is water and the temperature is 25 ° C., unless otherwise specified.
Examples of the pH indicator in the second embodiment include the same as the pH indicator in the first embodiment.

  The discoloration range (pH) of the pH indicator in the second embodiment is, for example, preferably in the range of 3.0 to 10.5, more preferably in the range of 4.0 to 9.5, Those in the range of 4.5 to 9.0 are particularly preferred.

  The pH indicator contained in the composition for keeping cold in the second embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. However, it is usually preferable to contain only one pH indicator.

  The content of the pH indicator of the composition for keeping cool in the second embodiment is not particularly limited as long as the intended color change of the composition for keeping cool is achieved, but is preferably 1 to 30 ppm, and 5 to 20 ppm. More preferably, there is.

<Other ingredients>
The composition for keeping cool in the second embodiment may contain, in addition to water, an inorganic salt, a thickener and a pH indicator, other components that do not correspond to these, as long as the effects of the present invention are not impaired. . As the other components, as in the case of the first embodiment, a solvent other than water; various known additives such as a preservative and a surfactant are exemplified.
The other components contained in the composition for keeping cold in the second embodiment may be only one kind, two or more kinds, and when there are two or more kinds, their combination and ratio can be arbitrarily selected.

  The content of the other components of the composition for keeping cool in the second embodiment is the same as the content of the other components of the composition for keeping cool in the first embodiment.

For example, in the composition for keeping cool in the second embodiment, the ratio of the content of the solvent to the total content of water and the solvent is preferably 10% by mass or less, and more preferably 5% by mass or less. It is more preferably at most 2% by mass.
In addition, the content of the preservative of the composition for keeping cool in the second embodiment is not particularly limited, but is preferably 0.02 to 0.5% by mass, and more preferably 0.04 to 0.2% by mass. Is more preferable.
The composition for keeping cool in the second embodiment is characterized in that the inorganic salt, the inorganic salt, The ratio of the total content of the viscosity agent and the pH indicator is preferably 90% by mass or more, more preferably 93% by mass or more, further preferably 96% by mass or more, and more preferably 98% by mass or more. It is particularly preferred that the content be 100% by mass. When the ratio of the total content is equal to or more than the lower limit, the composition for cooling keeps changing color more before and after freezing.

The pH of the composition for keeping cool in the second embodiment is preferably 5.4 to 8.0, more preferably 5.6 to 7.5, and more preferably 5.8 to 7.0. Is particularly preferred.
The composition for keeping cool in the second embodiment preferably shows a pH in the numerical range at a temperature at which a pH indicator is dissolved in the composition for keeping cool, and the temperature of the composition for keeping cool is 25 ° C. Sometimes it is more preferable to show the pH in the above numerical range.
In the present embodiment, the mere description of “pH” with respect to the composition for keeping cool means the pH of the composition for keeping cool, unless otherwise specified.

  The composition for keeping cool in the second embodiment is obtained by the same method as the composition for keeping cool in the above-described first embodiment except that the blending components are different.

The cooling tool according to the second embodiment of the present invention includes the cooling composition, and has the same configuration as the cooling tool according to the above-described first embodiment, except that the cooling composition is different. can do.
The cooler according to the second embodiment of the present invention is obtained by the same method as the cooler according to the above-described first embodiment, except that the composition for cooling is used.

Since the composition for cooling insulation in the second embodiment undergoes a large color change before and after freezing, the presence or absence of freezing can be easily visually recognized. And this color change of the composition for cooling is visible from the outside of the cooling tool, and thereby, the cooling tool is easily visible whether or not it is sufficiently cooled to the desired temperature. ing.
Further, the composition for cooling the cold, such as repeated freezing and thawing, even if the cooling and heating is repeated, the effect is not impaired, so the cooling tool provided with this is suitable for repeated use. is there.

◎ Third Embodiment The cooler according to the third embodiment of the present invention is a cooler provided with a cooler composition containing water, an inorganic salt, a thickener, and a pH indicator, wherein the cooler composition is provided. But, as the inorganic salt,
(S3) It contains only a combination of monohydrogen phosphate, dihydrogen phosphate, and other inorganic salts that do not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate. The total content of the inorganic salt in the composition for keeping cold is 20 to 35% by mass, and the composition for keeping cool, other than phosphate, monohydrogen phosphate, dihydrogen phosphate and water, The pH (β1) when all the components are replaced with water, and the pH (β2) when all the components other than the other inorganic salt, thickener and water of the composition for cooling are replaced with water. Satisfy the relationship represented by the following equation (10).
11.0 ≦ pH (β1) + pH (β2) ≦ 17.2 (10)

The composition for keeping cool in the third embodiment does not contain a phosphate as the inorganic salt. Therefore, the composition for keeping cold in the third embodiment contains water, an inorganic salt, a thickener and a pH indicator, and as the inorganic salt,
(S3) It contains only a combination of monohydrogen phosphate, dihydrogen phosphate, and other inorganic salts that do not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate. The total content of the inorganic salt in the composition for cooling is 20 to 35% by mass, and all components other than monohydrogen phosphate, dihydrogen phosphate and water in the composition for cooling are all contained. The pH (β13) in the case of replacing with water and the pH (β23) in the case of replacing all of the other components other than the inorganic salt, the thickener and the water with water in the composition for keeping cool, are as follows. It can be said that the relationship represented by Expression (103) is satisfied.
11.0 ≦ pH (β13) + pH (β23) ≦ 17.2 (103)

<Inorganic salt>
The inorganic salt according to the third embodiment functions as a component of a cooling agent, and the type and amount of the inorganic salt determine the freezing temperature of the composition for cooling.
In addition, the inorganic salt does not correspond to the pH indicator, and is a component that precipitates as a crystal or amorphous (amorphous) when the composition for cooling is frozen, and contributes to a color change of the composition for cooling due to precipitation. Things.

[Monohydrogen phosphate]
Examples of the monohydrogen phosphate in the third embodiment include the same as the monohydrogen phosphate in the first embodiment.

  The monohydrogen phosphate salt contained in the composition for keeping cool in the third embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

[Dihydrogen phosphate]
Examples of the dihydrogen phosphate in the third embodiment include the same as the dihydrogen phosphate in the second embodiment.

  The dihydrogen phosphate contained in the composition for keeping cool in the third embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

[Other inorganic salts]
The other inorganic salt in the third embodiment is an inorganic salt that does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate.
The other inorganic salt may be any of an acidic inorganic salt, a neutral inorganic salt, and a basic inorganic salt, and may be a non-hydrate or a hydrate.

Examples of the other inorganic salts in the third embodiment include the same as the other inorganic salts in the first embodiment.
For example, the acidic inorganic salt in the third embodiment is preferably ammonium chloride, ammonium bromide, or ammonium nitrate.
Further, the neutral inorganic salt in the third embodiment is preferably sodium chloride, potassium chloride, sodium bromide, potassium bromide, or potassium nitrate.

  The other inorganic salt contained in the composition for keeping cold in the third embodiment may be only one kind, or two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

  The total content of the inorganic salt of the composition for keeping cool in the third embodiment is 20 to 35% by mass, preferably 21 to 34% by mass, more preferably 23 to 32% by mass, The content is particularly preferably 24.5 to 30.5% by mass, and for example, can be any of 24.5 to 28% by mass, 24.5 to 27% by mass, and 24.5 to 26% by mass.

  In the composition for keeping cool of the third embodiment, the content of monohydrogen phosphate is preferably 1.2 to 10 times by mass to the content of dihydrogen phosphate, and 1.4 to 10 times. It is more preferably 8.5 times by mass, and particularly preferably 1.6 to 7 times by mass.

  In the composition for keeping cool according to the third embodiment, the content of the other inorganic salt is preferably 300 to 1500 times by mass, more preferably 350 to 1400 times by mass with respect to the content of dihydrogen phosphate. More preferably, it is particularly preferably 400 to 1300 times by mass.

Before the freezing in the third embodiment, preferably in the composition for cooling at 0 ° C. or higher, the dissolved amount of the inorganic salt is preferably as large as possible, and the dissolved amount in the total amount of the inorganic salt is preferably It is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and may be 100% by mass (total amount).
Further, in the composition for keeping cold after freezing in the third embodiment, the amount of the inorganic salt precipitated is preferably as large as possible, and the amount of the inorganic salt precipitated out of the total amount of the inorganic salt is 90% by mass or more. Is preferably 95% by mass or more, more preferably 98% by mass or more, and may be 100% by mass (total amount).

The pH (β1) when the components other than the phosphate, monohydrogen phosphate, dihydrogen phosphate and water in the composition for cooling insulation in the third embodiment are all replaced with water is as described above. This is synonymous with pH (β13) when all the components other than the monohydrogen phosphate, dihydrogen phosphate and water are replaced with water.
The pH (β1) (pH (β13)) is the same content (% by mass) as the content (% by mass) in the composition for keeping cool in the third embodiment, and only monohydrogen phosphate and dihydrogen phosphate are used. (E.g., an aqueous solution containing monohydrogen phosphate and dihydrogen phosphate), and a mixture of monohydrogen phosphate and dihydrogen phosphate used in the composition for keeping cool. Is an index of the acidity.

  The pH (β1) (pH (β13)) in the third embodiment is preferably a pH at a temperature at which a pH indicator is dissolved in the composition for keeping cold, and the temperature of the mixture is 25 ° C. It is more preferable that the pH is at a certain level.

  It is preferable that pH (β1) (pH (β13)) in the third embodiment satisfies the relationship of the expression (10) (the expression (103)), and furthermore, is 6.5 to 8.3. It is more preferably from 6.7 to 8.0, and particularly preferably from 6.9 to 7.7.

The pH (β2) of the composition for cooling insulation according to the third embodiment when all the components other than the inorganic salt, the thickener, and water are replaced with water, as described above, is the composition for cooling insulation as described above. The pH (β23) is the same as that when all of the other components other than the inorganic salt, thickener and water are replaced with water.
The pH (β2) (pH (β23)) contains only the other inorganic salt and the thickener at the same content (% by mass) as the content (% by mass) in the composition for keeping cool in the third embodiment. The pH of the mixture of the other inorganic salt and the thickener used in the cooling composition corresponds to the pH of water (eg, an aqueous solution containing the other inorganic salt and the thickener). It is what becomes.

  The pH (β2) (pH (β23)) in the third embodiment is preferably a pH at a temperature at which a pH indicator is dissolved in the composition for keeping cool, and the temperature of the mixture is 25 ° C. It is more preferable that the pH is at a certain level.

  The pH (β2) (pH (β23)) in the third embodiment preferably satisfies the relationship of the above formula (10) (the above formula (103)), and is further preferably 4.3 to 8.1, It is more preferably from 4.5 to 7.4, and particularly preferably from 4.7 to 6.7.

In the composition for keeping cool in the third embodiment, the total value of pH (β1) and pH (β2) is the same as the total value of pH (β13) and pH (β23) as described above, and is 11.0 to 17.2 (satisfies the relationship represented by the above formula (10)), preferably 11.3 to 16.5, more preferably 11.6 to 15.5, and 11.8. To 14.5, more preferably 12.0 to 14.0.
The total value of the pH (β1) and the pH (β2) can be adjusted by adjusting the type of the compound that affects the pH (β1) or the pH (β2), or the content of the compound in the composition for keeping cool. Can be adjusted. In particular, by adjusting the ratio between the content of monohydrogen phosphate and the content of dihydrogen phosphate in the composition for keeping cool, the total value of pH (β1) and pH (β2) can be easily adjusted. it can.

<Thickener>
The thickener in the third embodiment is a component that increases the viscosity of the composition for keeping cool and does not correspond to the pH indicator. It is preferable that the thickener in the third embodiment does not precipitate when the composition for cooling is frozen.

Examples of the thickener in the third embodiment include the same as the thickener in the first embodiment.
As in the case of the first embodiment, the thickener in the third embodiment includes an acrylic polymer, carboxyalkyl cellulose, a salt of carboxyalkyl cellulose, xanthan gum, guar gum, hydroxyalkyl guar gum, pectin, tamarind gum, carrageenan and It is preferable that one or more selected from the group consisting of alkylene glycols.
The thickener is more preferably one or more selected from the group consisting of an acrylic polymer, carboxyalkylcellulose, a salt of carboxyalkylcellulose, and hydroxyalkyl guar gum.
By using such a thickener, the composition for keeping cold has a large color change before and after freezing and has better handleability.

  The thickening agent contained in the composition for keeping cold in the third embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and the ratio thereof can be arbitrarily selected.

  In the composition for keeping cold before and after freezing in the third embodiment, the amount of the thickener that is precipitated is preferably as small as possible, and the amount of the thickener that is precipitated out of the total amount of the thickener is 10% by mass or less. Is preferably 5% by mass or less, more preferably 2% by mass or less, and particularly preferably 0% by mass (the entire amount is not precipitated).

  The content of the thickener in the composition for keeping cool in the third embodiment is preferably 0.1 to 10% by mass, more preferably 0.3 to 6% by mass, and 0.6 to 3% by mass. It is particularly preferred that the content is mass%.

<PH indicator>
The pH indicator (acid-base indicator) in the third embodiment determines the color of the composition for keeping cool by reflecting the presence or absence of color development. The composition for keeping cold changes its color before and after freezing by containing a pH indicator.

The pH indicator in the third embodiment is not particularly limited, and can be arbitrarily selected according to the purpose.
For example, the pH indicator preferably has a pKa of 4.9 to 8.0.
The pKa of the pH indicator in the present embodiment means a value when the solvent is water and the temperature is 25 ° C., unless otherwise specified.
Examples of the pH indicator in the third embodiment include the same as the pH indicator in the first embodiment.

  The color change range (pH) of the pH indicator in the third embodiment is, for example, preferably in the range of 3.0 to 10.5, more preferably in the range of 4.0 to 9.5, Those in the range of 4.5 to 9.0 are particularly preferred.

  The pH indicator contained in the composition for keeping cool in the third embodiment may be only one kind, two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily selected. However, it is usually preferable to contain only one pH indicator.

  The content of the pH indicator of the composition for keeping cool in the third embodiment is not particularly limited as long as the intended color change of the composition for keeping cool is achieved, but is preferably 1 to 30 ppm, and 5 to 20 ppm. More preferably, there is.

<Other ingredients>
The composition for keeping cool in the third embodiment may contain, in addition to water, an inorganic salt, a thickener and a pH indicator, other components that do not correspond to these, as long as the effects of the present invention are not impaired. . As the other components, as in the case of the first embodiment, a solvent other than water; various known additives such as a preservative and a surfactant are exemplified.
The other components contained in the composition for keeping cold in the third embodiment may be only one kind, two or more kinds, and when there are two or more kinds, their combination and ratio can be arbitrarily selected.

  The content of the other components of the composition for keeping cool in the third embodiment is the same as the content of the other components of the composition for keeping cool in the first embodiment.

For example, in the composition for keeping cool in the third embodiment, the ratio of the content of the solvent to the total content of water and the solvent is preferably 10% by mass or less, and more preferably 5% by mass or less. It is more preferably at most 2% by mass.
In addition, the content of the preservative of the composition for keeping cool in the third embodiment is not particularly limited, but is preferably 0.02 to 0.5% by mass, and is 0.04 to 0.2% by mass. Is more preferable.
The composition for keeping cool in the third embodiment is characterized in that the inorganic salt, the inorganic salt, The ratio of the total content of the viscosity agent and the pH indicator is preferably 90% by mass or more, more preferably 93% by mass or more, further preferably 96% by mass or more, and more preferably 98% by mass or more. It is particularly preferred that the content be 100% by mass. When the ratio of the total content is equal to or more than the lower limit, the composition for cooling keeps changing color more before and after freezing.

The pH of the composition for keeping cool in the third embodiment is preferably 5.4 to 8.0, more preferably 5.6 to 7.5, and more preferably 5.8 to 7.0. Is particularly preferred.
The composition for keeping cool in the third embodiment preferably shows a pH in the above numerical range at a temperature at which a pH indicator is dissolved in the composition for keeping cool, and the temperature of the composition for keeping cool is 25 ° C. Sometimes it is more preferable to show the pH in the above numerical range.
In the present embodiment, the mere description of “pH” with respect to the composition for keeping cool means the pH of the composition for keeping cool, unless otherwise specified.

  The composition for keeping cool in the third embodiment is obtained by the same method as the composition for keeping cool in the above-described first embodiment except that the blending components are different.

The cooler according to the third embodiment of the present invention includes the cooler composition, and has the same configuration as the cooler according to the above-described first embodiment, except that the cooler composition is different. can do.
The cooler according to the third embodiment of the present invention is obtained by the same method as the cooler according to the above-described first embodiment, except that the composition for cooling is used.

The composition for cooling cold according to the third embodiment has a large color change before and after freezing, so that the presence or absence of freezing can be easily visually recognized. And this color change of the composition for cooling is visible from the outside of the cooling tool, and thereby, the cooling tool is easily visible whether or not it is sufficiently cooled to the desired temperature. ing.
Further, the composition for cooling the cold, such as repeated freezing and thawing, even if the cooling and heating is repeated, the effect is not impaired, so the cooling tool provided with this is suitable for repeated use. is there.

◎ Fourth Embodiment A cooler according to a fourth embodiment of the present invention is a cooler provided with a cooler composition containing water, an inorganic salt, a thickener and a pH indicator, wherein the cooler composition is provided. But, as the inorganic salt,
(S4) The composition for cooling according to the present invention contains only a combination of dihydrogen phosphate and another inorganic salt which does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate. The total content of the inorganic salt is 20 to 35% by mass, and all the components other than the phosphate, monohydrogen phosphate, dihydrogen phosphate and water of the composition for cooling are replaced with water. And the pH (β2) when all the components other than the inorganic salt, the thickener and the water of the composition for cooling are replaced with water, the following formula (10): ).
11.0 ≦ pH (β1) + pH (β2) ≦ 17.2 (10)

The composition for keeping cool in the fourth embodiment does not contain phosphate and monohydrogen phosphate as the inorganic salt. Therefore, the composition for cooling according to the fourth embodiment contains water, an inorganic salt, a thickener and a pH indicator, and as the inorganic salt,
(S4) The composition for cooling according to the present invention contains only a combination of dihydrogen phosphate and another inorganic salt which does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate. The pH (β14) when the total content of the inorganic salt is 20 to 35% by mass, and when the components other than dihydrogen phosphate and water are all replaced with water, PH (β24) when all the components other than the above-mentioned inorganic salt, thickener and water of the composition for cooling are replaced with water, and satisfy the relationship represented by the following formula (104). It can be said that there is.
11.0 ≦ pH (β14) + pH (β24) ≦ 17.2 (104)

<Inorganic salt>
The inorganic salt according to the fourth embodiment functions as one component of a cooling agent, and the freezing temperature of the cooling composition is mainly determined by its type and amount.
In addition, the inorganic salt does not correspond to the pH indicator, and is a component that precipitates as a crystal or amorphous (amorphous) when the composition for cooling is frozen, and contributes to a color change of the composition for cooling due to precipitation. Things.

[Dihydrogen phosphate]
Examples of the dihydrogen phosphate in the fourth embodiment include the same as the dihydrogen phosphate in the second embodiment.

  The dihydrogen phosphate contained in the composition for keeping cool in the fourth embodiment may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

[Other inorganic salts]
The other inorganic salt in the fourth embodiment is an inorganic salt that does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate.
The other inorganic salt may be any of an acidic inorganic salt, a neutral inorganic salt, and a basic inorganic salt, and may be a non-hydrate or a hydrate.

Examples of the other inorganic salt in the fourth embodiment include the same as the other inorganic salt in the first embodiment.
For example, the acidic inorganic salt in the fourth embodiment is preferably ammonium chloride, ammonium bromide, or ammonium nitrate.
Further, the neutral inorganic salt in the fourth embodiment is preferably sodium chloride, potassium chloride, sodium bromide, potassium bromide, or potassium nitrate.

  The other inorganic salt contained in the composition for keeping cold in the fourth embodiment may be only one kind, or two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily selected. .

  The total content of the inorganic salt of the composition for keeping cool in the fourth embodiment is 20 to 35% by mass, preferably 21 to 34% by mass, more preferably 23 to 32% by mass, The content is particularly preferably 24.5 to 30.5% by mass, and for example, can be any of 24.5 to 28% by mass, 24.5 to 27% by mass, and 24.5 to 26% by mass.

  In the composition for keeping cool of the fourth embodiment, the content of the other inorganic salt is preferably 150 to 590 times by mass, more preferably 195 to 550 times by mass, based on the content of dihydrogen phosphate. More preferably, it is particularly preferably 235 to 510 times by mass.

Before the freezing in the fourth embodiment, preferably in the composition for cooling at 0 ° C. or higher, the dissolved amount of the inorganic salt is preferably as large as possible, and the dissolved amount in the total amount of the inorganic salt is preferably It is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and may be 100% by mass (total amount).
Further, in the composition for keeping cold after freezing in the fourth embodiment, it is preferable that the amount of the inorganic salt precipitated is large, and the amount of the inorganic salt precipitated out of the total amount of the inorganic salt is 90% by mass or more. Is preferably 95% by mass or more, more preferably 98% by mass or more, and may be 100% by mass (total amount).

The pH (β1) when the components other than the phosphate, monohydrogen phosphate, dihydrogen phosphate and water in the composition for cooling insulation in the fourth embodiment are all replaced with water is as described above. It is synonymous with pH (β14) when all the components other than dihydrogen phosphate and water of the composition for cooling are replaced with water.
pH (β1) (pH (β14)) is the same content (% by mass) as the content (% by mass) in the composition for keeping cool in the fourth embodiment, and water containing only dihydrogen phosphate (for example, , An aqueous solution containing dihydrogen phosphate), which is an index of the acidity of the dihydrogen phosphate used in the composition for keeping cool.

  The pH (β1) (pH (β14)) in the fourth embodiment is preferably a pH at a temperature at which a pH indicator is dissolved in the composition for keeping cool, and the temperature of the mixture is 25 ° C. It is more preferable that the pH is at a certain level.

  It is preferable that pH (β1) (pH (β14)) in the fourth embodiment satisfies the relationship of the above formula (10) (the above formula (104)), and furthermore, 5.2 to 7.1, It is more preferably 5.4 to 6.8, and particularly preferably 5.6 to 6.5.

The pH (β2) when all the components other than the inorganic salt, the thickener, and the water other than the water in the composition for cooling according to the fourth embodiment are replaced with water, as described above, The same pH (β24) as when the other inorganic salts, thickener and water-containing components are replaced with water.
The pH (β2) (pH (β24)) contains only the other inorganic salt and the thickener at the same content (% by mass) as the content (% by mass) in the composition for keeping cool in the fourth embodiment. The pH of the mixture of the other inorganic salt and the thickener used in the cooling composition corresponds to the pH of water (eg, an aqueous solution containing the other inorganic salt and the thickener). It is what becomes.

  The pH (β2) (pH (β24)) in the fourth embodiment is preferably a pH at a temperature at which a pH indicator is dissolved in the composition for keeping cold, and the temperature of the mixture is 25 ° C. It is more preferable that the pH is at a certain level.

  It is preferable that pH (β2) (pH (β24)) in the fourth embodiment satisfies the relationship of the above formula (10) (the above formula (104)), and furthermore is 4.3 to 8.1, It is more preferably from 4.5 to 7.4, and particularly preferably from 4.7 to 6.7.

In the composition for keeping cool of the fourth embodiment, the total value of pH (β1) and pH (β2) is the same as the total value of pH (β14) and pH (β24) as described above, and is 11.0 to 17.2 (satisfies the relationship represented by the formula (10)), preferably 11.0 to 16.5, more preferably 11.0 to 15.0, and 11.0 to 11.0. To 13.5, more preferably 11.0 to 12.5.
The total value of the pH (β1) and the pH (β2) can be adjusted by adjusting the type of the compound that affects the pH (β1) or the pH (β2), or the content of the compound in the composition for keeping cool. Can be adjusted. In particular, by adjusting the content of dihydrogen phosphate in the composition for keeping cool, the total value of pH (β1) and pH (β2) can be easily adjusted.

<Thickener>
The thickener in the fourth embodiment is a component that increases the viscosity of the composition for keeping cold and does not correspond to the pH indicator. It is preferable that the thickener in the second embodiment does not precipitate when the composition for cooling is frozen.

Examples of the thickener in the fourth embodiment include the same as the thickener in the first embodiment.
As in the case of the first embodiment, the thickener in the fourth embodiment includes acrylic polymer, carboxyalkyl cellulose, a salt of carboxyalkyl cellulose, xanthan gum, guar gum, hydroxyalkyl guar gum, pectin, tamarind gum, carrageenan and It is preferable that one or more selected from the group consisting of alkylene glycols.
The thickener is more preferably one or more selected from the group consisting of an acrylic polymer, carboxyalkylcellulose, a salt of carboxyalkylcellulose, and hydroxyalkyl guar gum.
By using such a thickener, the composition for keeping cold has a large color change before and after freezing and has better handleability.

  The thickening agent contained in the composition for keeping cold in the fourth embodiment may be only one kind, two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily selected.

  In the composition for keeping cold before and after freezing in the fourth embodiment, the amount of the thickener that is precipitated is preferably smaller, and the amount of the thickener that is precipitated out of the total amount of the thickener is 10% by mass or less. Is preferably 5% by mass or less, more preferably 2% by mass or less, and particularly preferably 0% by mass (the entire amount is not precipitated).

  The content of the thickener in the composition for keeping cool in the fourth embodiment is preferably 0.1 to 10% by mass, more preferably 0.3 to 6% by mass, and 0.6 to 3% by mass. It is particularly preferred that the content is mass%.

<PH indicator>
The pH indicator (acid-base indicator) in the fourth embodiment determines the color of the composition for keeping cool by reflecting the presence or absence of color development. The composition for keeping cold changes its color before and after freezing by containing a pH indicator.

The pH indicator in the fourth embodiment is not particularly limited, and can be arbitrarily selected according to the purpose.
For example, the pH indicator preferably has a pKa of 4.9 to 8.0.
The pKa of the pH indicator in the present embodiment means a value when the solvent is water and the temperature is 25 ° C., unless otherwise specified.
Examples of the pH indicator in the fourth embodiment include the same as the pH indicator in the first embodiment.

  The color change range (pH) of the pH indicator in the fourth embodiment is, for example, preferably in the range of 3.0 to 10.5, more preferably in the range of 4.0 to 9.5, Those in the range of 4.5 to 9.0 are particularly preferred.

  The pH indicator contained in the composition for keeping cool in the fourth embodiment may be only one kind, two or more kinds, and when there are two or more kinds, the combination and the ratio thereof can be arbitrarily selected. However, it is usually preferable to contain only one pH indicator.

  The content of the pH indicator of the composition for keeping cool in the fourth embodiment is not particularly limited as long as the intended color change of the composition for keeping cool is achieved, but is preferably 1 to 30 ppm, and 5 to 20 ppm. More preferably, there is.

<Other ingredients>
The composition for keeping cool in the fourth embodiment may contain, in addition to water, an inorganic salt, a thickener and a pH indicator, other components that do not correspond to these, as long as the effects of the present invention are not impaired. . As the other components, as in the case of the first embodiment, a solvent other than water; various known additives such as a preservative and a surfactant are exemplified.
The other components contained in the composition for keeping cold in the fourth embodiment may be only one kind, or two or more kinds, and when there are two or more kinds, their combination and ratio can be arbitrarily selected.

  The content of the other components of the composition for keeping cool in the fourth embodiment is the same as the content of the other components of the composition for keeping cool in the first embodiment.

For example, in the composition for keeping cool in the fourth embodiment, the ratio of the content of the solvent to the total content of water and the solvent is preferably 10% by mass or less, and more preferably 5% by mass or less. It is more preferably at most 2% by mass.
In addition, the content of the preservative of the composition for keeping cool in the fourth embodiment is not particularly limited, but is preferably 0.02 to 0.5% by mass, and is 0.04 to 0.2% by mass. Is more preferable.
The composition for cooling according to the fourth embodiment is characterized in that the inorganic salt, the inorganic salt, The ratio of the total content of the viscosity agent and the pH indicator is preferably 90% by mass or more, more preferably 93% by mass or more, further preferably 96% by mass or more, and more preferably 98% by mass or more. It is particularly preferred that the content be 100% by mass. When the ratio of the total content is equal to or more than the lower limit, the composition for cooling keeps changing color more before and after freezing.

The pH of the composition for keeping cool in the fourth embodiment is preferably from 4.6 to 6.8, more preferably from 4.8 to 6.5, and more preferably from 5.0 to 6.2. Is particularly preferred.
The composition for cooling according to the fourth embodiment preferably exhibits a pH in the numerical range at a temperature at which a pH indicator is dissolved in the composition for cooling, and the temperature of the composition for cooling is 25 ° C. Sometimes it is more preferable to show the pH in the above numerical range.
In the present embodiment, the mere description of “pH” with respect to the composition for keeping cool means the pH of the composition for keeping cool, unless otherwise specified.

  The composition for keeping cool in the fourth embodiment is obtained by the same method as the composition for keeping cool in the above-described first embodiment except that the blending components are different.

The cooling tool according to the fourth embodiment of the present invention includes the cooling composition, and has the same configuration as the cooling tool according to the above-described first embodiment, except that the cooling composition is different. can do.
The cooler according to the fourth embodiment of the present invention is obtained by the same method as the cooler according to the above-described first embodiment, except that the composition for cooling is used.

Since the composition for cooling according to the fourth embodiment undergoes a large color change before and after freezing, the presence or absence of freezing can be easily visually recognized. And this color change of the composition for cooling is visible from the outside of the cooling tool, and thereby, the cooling tool is easily visible whether or not it is sufficiently cooled to the desired temperature. ing.
In addition, the composition for cooling the cold, such as repeated freezing and thawing, even if the cooling and heating are repeated, the effect is not impaired, so a cooling tool equipped with this is suitable for repeated use. is there.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the examples described below. In the following, the unit “ppm” of the content (mixing amount, concentration) of the pH indicator is all based on the mass ratio.

Some of the raw materials used in this example and comparative examples are shown below.
(Thickener)
-HPG (hydroxypropyl guar gum): "Maypro HPG-8111" manufactured by Danisco
・ CMC (sodium carboxymethylcellulose): "Selogen" manufactured by Daiichi Kogyo Seiyaku
-CVP (carboxyvinyl polymer): "Reogic 270" manufactured by Toagosei Co., Ltd.
(PH indicator)
-BCP (bromocresol purple): manufactured by Yoneyama Pharmaceutical Co., Ltd. (pKa = 6.3)
(Preservative)
"Sodium Omagine" manufactured by Sanai Oil Co., Ltd.

[Example 1]
<Manufacture of a composition for cooling and a cooling tool (first embodiment)>
At room temperature (20-25 ° C), water (73.90 parts by mass), BCP, sodium chloride (11.48 parts by mass), potassium chloride (5.74 parts by mass), ammonium chloride (5.74 parts by mass) , Sodium bromide (2.00 parts by mass), trisodium phosphate dodecahydrate (0.10 parts by mass), diammonium hydrogen phosphate (0.05 parts by mass), HPG (0.95 parts by mass) And a preservative (0.05 parts by mass) were mixed and stirred for 1 hour to dissolve these components to obtain a composition for cooling. At this time, the blending amount of BCP was adjusted so that the content in the obtained composition for keeping cold was 10 ppm. Table 2 shows the components and their contents in the composition for keeping cool. In Table 2, trisodium phosphate dodecahydrate is described by omitting water of crystallization (12H ₂ O). In addition, the description of “-” in the column of the blending component means that the component is not blended. These are the same in the following tables.

  Table 6 shows physical properties such as pH (β1), pH (β2), and pH of the composition for keeping cold. The pH (β1), the pH (β2) and the pH of the composition for cooling were all measured with the temperature of the object to be measured at 25 ° C. Table 6 also shows the total content of the inorganic salt in the obtained composition for keeping cold (hereinafter, may be referred to as “(Z1)”). In Table 6, "-" in the column of the physical property means that the physical property has not been measured.

  Next, the obtained composition for cooling insulation was sealed in a bag-like container made of a low-density polyethylene film having a thickness of 5 to 200 μm to obtain a cooling tool of the first embodiment.

<Evaluation of cooling composition>
(Color change)
The obtained composition for keeping cold (cooling tool) was cooled to -35 ° C. During this time, the cooling composition was frozen at a temperature higher than -35C. The change in color of the composition for cooling before and after freezing was visually evaluated according to the following criteria. Table 6 shows the results.

In Table 6, "color change" described in the column of the evaluation result indicates a color change of the composition for cooling insulation before and after freezing. For example, "purple → yellow" indicates the composition for cooling insulation. Means that the color was purple before freezing and yellow after freezing.
：: The color change before and after freezing is large, and it is extremely easy to visually confirm the cooling state.
：: Color change before and after freezing can be determined, and the cooling state can be visually recognized.
X: The color change before and after freezing is unclear, and it is difficult or impossible to visually confirm the cooling state.

<Manufacture of composition for cooling and cooling device (first embodiment), evaluation of composition for cooling>
[Examples 2 to 14]
Except that the components of the composition for keeping cool and the content in the composition for keeping cool were set as shown in Table 2 or Table 3, in the same manner as in Example 1, the composition for keeping cool of the first embodiment and A cooler was manufactured, and the cooler composition was evaluated. Table 6 shows the physical properties and evaluation results of the composition for keeping cold.

<Manufacture of composition for cooling and cooling device (second embodiment), evaluation of composition for cooling>
[Examples 15 to 22]
Except that the components of the composition for keeping cool and the content in the composition for keeping cool were set as shown in Table 3 or Table 4, the composition for keeping cool of the second embodiment and A cooler was manufactured, and the cooler composition was evaluated. Table 6 shows the physical properties and evaluation results of the composition for keeping cold.

<Manufacture of composition for cooling and cooling device (third embodiment), evaluation of composition for cooling>
[Examples 23 to 25]
Except that the components of the composition for keeping cool and the content in the composition for keeping cool were set as shown in Table 4, the composition for keeping cool and the cool keeping tool of the third embodiment were prepared in the same manner as in Example 1. It was manufactured and the composition for cooling was evaluated. Table 6 shows the physical properties and evaluation results of the composition for keeping cold.

<Manufacture of composition for cooling and cooling device (fourth embodiment), evaluation of composition for cooling>
[Examples 26 to 29]
Except that the components of the composition for keeping cool and the content in the composition for keeping cool were set as shown in Table 4, the composition for keeping cool and the cool keeping tool of the fourth embodiment were prepared in the same manner as in Example 1. It was manufactured and the composition for cooling was evaluated. Table 6 shows the physical properties and evaluation results of the composition for keeping cold.

<Manufacture of Comparative Cooling Composition and Cooling Tool, Evaluation of Comparative Cooling Composition>
[Comparative Examples 1 to 8]
Except that the components of the composition for keeping cool and the content in the composition for keeping cool were set as shown in Table 5, the composition for keeping cool and the cool keeping tool were manufactured in the same manner as in Example 1 and used for keeping cool. The composition was evaluated. Table 6 shows the physical properties and evaluation results of the composition for keeping cold.

  As is clear from the above results, the cooler according to the first embodiment (Examples 1 to 14), the cooler according to the second embodiment (Examples 15 to 22), and the cooler according to the third embodiment of the present invention. In the cooling tool (Examples 23 to 25) and the cooling tool according to the fourth embodiment (Examples 26 to 29), the composition for cooling was colored with the pH indicator along with the precipitation of the inorganic salt during freezing. The color clearly changed before and after freezing, reflecting the change in the temperature, and the cooling state could be easily visually recognized.

  On the other hand, in the cooling tools of Comparative Examples 1 to 8, the cooling composition does not satisfy at least the relationship represented by the formula (10), unlike the cooling composition of the above-described example, and the freezing composition does not satisfy the condition. The change in color before and after was unclear, and it was difficult or impossible to visually confirm the cooling state.

  INDUSTRIAL APPLICABILITY The present invention can be used as a cooler for various perishables.

Claims (1)

Water, an inorganic salt, a cooler equipped with a cooler composition containing a thickener and a pH indicator,
The composition for keeping cold is the following (S1), (S2), (S3) or (S4) as the inorganic salt:
(S1) Combination of phosphate, monohydrogen phosphate, and other inorganic salts that do not fall under any of phosphate, monohydrogen phosphate and dihydrogen phosphate (S2) phosphate And a combination of dihydrogen phosphate and another inorganic salt that does not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate (S3) Monohydrogen phosphate and phosphoric acid Combination of dihydrogen salt and other inorganic salts which do not correspond to any of phosphate, monohydrogen phosphate and dihydrogen phosphate (S4) Dihydrogen phosphate, phosphate and phosphoric acid Containing only a combination of monohydrogen salts and other inorganic salts that do not fall under any of the dihydrogen phosphate salts,
The total content of the inorganic salt in the composition for keeping cold is 20 to 35% by mass,
The pH (β1) of the composition for cooling when the components other than the phosphate, monohydrogen phosphate, dihydrogen phosphate and water were all replaced with water, A refrigerating tool, wherein the pH (β2) when all the other components other than the inorganic salt, the thickener and the water are replaced with water satisfies the relationship represented by the following formula (10).
11.0 ≦ pH (β1) + pH (β2) ≦ 17.2 (10)