KR101032219B1 - Method for manufaturing cold-storage material, cold-storage material and ice-pack - Google Patents

Abstract

The present invention relates to a method for preparing a coolant that can be manufactured at low cost by maintaining a cold effect while lowering the freezing point to keep food, beverages, etc. at a low temperature for a long time. Absorbing to obtain a gel-like superabsorbent resin; It relates to a method for producing a coolant comprising a; injecting sodium chloride or sodium chloride aqueous solution to the gel superabsorbent polymer.

Coolant, Sodium Chloride, Ice Pack

Description

TECHNICAL FOR MANUFATURING COLD-STORAGE MATERIAL, COLD-STORAGE MATERIAL AND ICE-PACK

The present invention relates to a method for preparing a coolant that can be manufactured at low cost by maintaining a cold effect while lowering the freezing point to keep food, beverages, etc. at a low temperature for a long time. Absorbing to obtain a gel-like superabsorbent resin; It relates to a method for producing a coolant comprising a; injecting sodium chloride or sodium chloride aqueous solution to the gel superabsorbent polymer.

Super Absorbent Polymer (SAP) is a polymer material that can absorb and retain water of several hundred times to one thousand times its own weight. When water is added, it swells to form a hydrogel. This hydrated gel has a feature that water is not easily released even under pressure from the outside.

On the other hand, in order to keep the inside of the closed container at a low temperature for a certain period of time, it is often used to preserve cold air by using ice or dry ice or to use a coolant in recent years.

In addition, sugars, alcohols and glycols were used to lower the freezing point of the coolant, but in the case of sugars, alcohols and glycols, there was a problem in that the manufacturing cost was increased.

The present invention for solving the above problems is to provide a method for preparing a coolant that can lower the freezing point while maintaining the cold effect using sodium chloride at a low cost.

In addition, the present invention has another object to provide an ice pack that can be stored for a long time at a low temperature in a state that does not lower the freshness of food even in foods such as water.

The present invention for achieving the above object is the step of absorbing water in the superabsorbent resin to obtain a gel-like superabsorbent resin;

It provides a method for producing a coolant comprising the; step of injecting sodium chloride or sodium chloride aqueous solution to the gel-like superabsorbent resin.

In particular, it is preferable to include a step of adding sodium chloride or sodium chloride aqueous solution to the gel-like superabsorbent resin and then stirring.

And the present invention provides an ice pack characterized in that the coolant is produced by the method for producing the coolant, and the coolant is accommodated in the pack.

In particular, the pack is formed of an inner skin forming an accommodation space for accommodating the ice pack coolant, and an outer skin formed of an absorbent material formed outside the inner skin to absorb condensation formed at a temperature difference between the ice pack coolant and the outside air. It is preferable.

Hereinafter, the manufacturing method of the coolant of this invention is demonstrated in detail.

The method for preparing a coolant of the present invention comprises a step of obtaining a gel-absorbent super absorbent resin and a step of adding sodium chloride or an aqueous sodium chloride solution to the gel-absorbent superabsorbent resin.

First, the step of obtaining the gel-like superabsorbent resin is a step of obtaining water-absorbent gel-like superabsorbent by adding water to the superabsorbent polymer.

The superabsorbent polymer is intended to absorb water to exert a cold effect. Starch-based, synthetic resins, cellulose-based resins, and the like may be used, but are not limited thereto. In general, PSA (poly sodium acrylate) is used.

And the amount of water is not significantly limited, such as is determined according to the absorption capacity of the super absorbent polymer.

Next, sodium chloride or aqueous sodium chloride solution is added to the gel-like superabsorbent polymer. When an aqueous sodium chloride or sodium chloride solution is added to the gel-like superabsorbent polymer, a certain amount of water absorbed into the superabsorbent polymer by osmotic pressure is released to dissolve the sodium chloride or sodium chloride solution.

That is, when sodium chloride or sodium chloride aqueous solution is added to the gel-like superabsorbent polymer, a certain amount of water is present in the superabsorbent polymer by the absorbent power of the superabsorbent polymer to maintain the cold retention, and the sodium chloride is released to dissolve the sodium chloride. Or lower the aqueous sodium chloride solution and lower the aqueous sodium chloride solution.

On the other hand, if the superabsorbent resin is not absorbed into the superabsorbent resin first, but the superabsorbent resin is added to the aqueous sodium chloride solution in which sodium chloride is dissolved in the water, the superabsorbent resin does not absorb the sodium chloride aqueous solution and thus has a cold effect. There is a problem that is not good.

However, first, water is added to the superabsorbent resin to obtain a gel-like superabsorbent resin, and then mixing sodium chloride or sodium chloride aqueous solution has the advantage of lowering the freezing point while maintaining the cooling effect.

In addition, the osmotic phenomenon between the sodium chloride or sodium chloride aqueous solution and the gel-like superabsorbent polymer may occur rapidly, and the stirring may be performed using a stirrer to improve productivity.

Thus, the coolant produced by the manufacturing method can lower the freezing point while maintaining the cooling effect, it is possible to keep the temperature of food, beverages and the like in a low temperature state for a long time.

In addition, the present invention provides an ice pack in which the coolant is accommodated in a pack.

In particular, the pack consists of an inner skin forming an accommodating space for accommodating the ice pack coolant, and an outer skin formed of an absorbent material formed outside the inner skin to absorb condensation formed at a temperature difference between the ice pack coolant and the outside air. .

Thus, since the outer shell of the pack is made of an absorbent material capable of absorbing condensation formed at a temperature difference, there is an advantage that it can be used conveniently even without laying paper, cloth, etc., even in the case of food, which is weak in water.

As the material of the outer shell, a paper, a nonwoven fabric, a woven fabric or the like excellent in water absorption can be used.

The present invention can produce a coolant that can lower the freezing point while maintaining the cold effect, it is possible to keep food, beverages and the like at a low temperature for a long time there is an effect that can be widely used for long-distance delivery such as courier.

In addition, by forming an outer shell made of an absorbent material capable of absorbing condensation formed at a temperature difference in the pack containing the ice pack coolant, the food can be stored at low temperature for a long time without degrading the freshness of the food even in foods that are weak in water. It has an effect.

Hereinafter, the manufacturing method of the coolant of the present invention will be described in more detail with reference to Examples. The scope of the present invention is not limited to the following Examples.

Example 1

1000 g of water was added to 9 g of PSA (poly sodium acrylate), a super absorbent polymer of K company, to obtain a gel super absorbent resin, and 30 g of sodium chloride was mixed to prepare a coolant according to Example 1.

[Example 2]

1000 ml of water was added to 9 g of PSA (poly sodium acrylate), a super absorbent resin of K company, to obtain a gel super absorbent resin, and 100 ml of sodium chloride aqueous solution having a concentration of 10% was mixed to prepare a coolant according to Example 2.

Comparative Example 1

As Comparative Example 1, a gelled ice pack obtained by absorbing water into a super absorbent polymer was commercially available.

Comparative Example 2

First, an aqueous sodium chloride solution obtained by dissolving 30 g of sodium chloride in 1000 ml of water was obtained. And 9 g of PSA (poly sodium acrylate), a super absorbent polymer of K Company, was added to the aqueous sodium chloride solution to prepare a coolant of Comparative Example 2.

As described above, the presence or absence of precipitates, the degree of freezing point drop, and the cold storage properties of the coolants of Examples 1, 2 and Comparative Example 2 were tested. The results are shown in Table 1 below.

First, the presence or absence of sediment according to the time elapsed after leaving the coolant of Examples 1 and 2 and Comparative Example 2 prepared for 12 hours according to whether or not the sediment occurred with the naked eye. If not, it is indicated by 'x'.

The degree of freezing point drop was evaluated by measuring the temperature after freezing the coolant of Examples 1, 2 and Comparative Example 1 in the freezer compartment.

The cold insulation was evaluated by measuring the time required until the temperature reaches 5 ℃ after leaving each of the coolants tested in the degree of gas freezing drop in an unsealed room of 24 ℃.

[Table 1] Measurement result of sediment occurrence, freezing point and time taken to reach 5 ℃

Precipitation freezing point 5 ℃ Required Time (min) Example 1 × -18 ℃ 450 Example 2 × -15 ℃ 425 Comparative Example 2 ○ -18 ℃ 330

As in Table 1, in the case of Examples 1 and 2, the precipitate of the high synthetic resin did not occur, but in the case of Comparative Example 1, the precipitate occurred. In the case of the freezing point, all dropped, but the time required to reach 5 ℃ in Comparative Example 1 was short as 330 minutes, but in the case of Examples 1 and 2 was measured to 425 minutes or more. That is, in the case of Comparative Example 1 was not good cold retention, in the case of Examples 1 and 2 it was confirmed that the freezing point can be lowered while maintaining the cold retention.

And when used in the courier, 3.5kg frozen in the state of putting the coolant of Example 1 and Comparative Examples 1 and 2 into three 350 × 500 × 120㎜ styrofoam boxes to determine the preservation of food over time After putting the oysters were packaged and left at room temperature. The temperature in the styrofoam box after 10 hours, 24 hours, and 30 hours was measured, and after 30 hours, the state of the frozen oyster ratio was checked. Is shown in Table 2.

[Table 2] Experimental Results of Temperature and Product Preservation State in Styrofoam Boxes with Time

Temperature (℃) Product Preservation Status freezing point 10 hours 24 hours 30 hours Example 1 -18 -10 -4 -One ○ Comparative Example 1 -8 -One 5 15 × Comparative Example 2 -18 -6 2 10 ×

As in Table 2, in the case of Example 1, the packaged free oyster ratio was good even after 30 hours had elapsed, but in Comparative Examples 1 and 2, it was poor. As described above, in Example 1, the freezing effect was excellent as well as the freezing point drop effect.

Claims (5)

Absorbing water into the superabsorbent resin to obtain a gel-like superabsorbent resin; Injecting sodium chloride or aqueous sodium chloride solution into the gel-like superabsorbent polymer; And adding a sodium chloride or sodium chloride aqueous solution to the gel-like superabsorbent resin, followed by stirring. delete delete delete delete