JPS63251489A - Cooling medium - Google Patents

Abstract

PURPOSE:To obtain a reclaimable cooling medium which retains its cooling power over a long period of time and is freely changeable in shape in accordance with uses, by incorporating water and a hydrophilic organic solvent that does not freeze under specified low temperature conditions into a powdery or particulate moisture-absorptive polymeric resin, and allowing this mixture to stand. CONSTITUTION:A cooling medium made by incorporating water and a hydrophilic organic solvent that does not freeze even at -30 deg.C (e.g., ethanol or acetone) into a powdery or particulate water-absorptive polymeric resin (e.g., powders having a particle diameter of 10-20mum or particles having a diameter of 2mm or smaller of, e.g., PVA or polyethylene oxide), and allowing this mixture to stand. Since this cooling medium has a persistent stable cooling effect under low temperature conditions and flexibility, it has advantages in that it can be arranged in close contact even with an uneven or curved surface of an object such as a leg part, it can take the shape of a place where it is arranged for placement in a device such as a cold reserving container, and it can assure cooling over a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recyclable refrigerant material that retains cold for a long time and can be freely deformed depending on the usage.

[Prior art] Instead of ice, dry ice, etc., which are conventionally used consumptively for cooling therapy for sprains, fractures, high fevers, etc., or for keeping foods cold, ice can be frozen in advance in a freezer and reused. There are coolant materials that do this. An example of this conventional coolant material is composed of a water-absorbing base material such as polyvinyl alcohol or starch, water and a freezing point depressant such as a boric acid salt, and has a wide range of uses due to its cold retention function at low temperatures.

[Problems to be Solved by the Invention] In the first conventional refrigerant material described above, water is retained in the water-absorbing base material in a swollen state, and is thought to have the effect of enhancing its cold retention effect. This produces a cold preservation effect for a long time of 2 to 3 hours, and the borate and the like contained further lowers the freezing point to maintain a low temperature state.

When this conventional coolant material is used, it is generally stored in a predetermined storage bag, which is then frozen and solidified. This solidified state is a condition for its cold preservation, and its softening means that the cold preservation effect disappears.

As described above, since this conventional refrigerant material is in a completely solidified state, its range of use is limited.For example, when used as an ice pillow, a covering member such as an elastic towel is required around it. Further, in order to use the bag for an irregularly shaped part such as a leg, it is difficult to prepare the above-mentioned storage bag in advance so as to match the circumferential shape of the leg.

There is also a second type of conventional refrigerant that does not freeze, that is, it is flexible, but all of these types of refrigerant have extremely short cooling times of 10 to 15 minutes. It was impractical.

An object of the present invention is to eliminate the drawbacks of the conventional examples described above, and to provide a reusable cooling medium material that can be kept in a stable cold state for a long time and can be freely deformed as necessary. .

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration for the coolant material.

That is, water and a hydrophilic organic solvent that does not cool down even at 30° C. are mixed into a powder or granular material of a water-absorbing polymer resin and allowed to stand still.

The water-absorbing polymer resin of the present invention includes starch, polyvinyl alcohol, vinyl acrylate alcohol copolymer, sodium acrylate polymer, polyethylene oxide, carboxymethylcellulose, polyacrylate-based,
Inbutylene-maleic acid copolymer system, saponified copolymer of vinyl acetate and unsaturated dicarboxylic acid monomer, etc. can be applied, and the particle size of the powder is, for example, 10μ to 200μ, or the particle size of the powder is 10μ to 200μ. For example, the diameter is 2 m
m or less can be applied.

Further, as the hydrophilic organic solvent that does not freeze even at -30°C, lower alcohols such as methanol and ethanol, ketones such as acetone, and ethers such as methyl cellosolve can be used. Both pure water and tap water can be used at room temperature.

In addition, the mixing may be done by first mixing water into powder or granules of water-absorbing polymer resin and then adding a hydrophilic organic solvent, or by mixing water and a hydrophilic organic solvent in advance. This may be mixed into powdered or granular water-absorbing polymer resin.

Further, the standing time corresponds to the time required for water to swell into the water-absorbing polymer resin, and may require 15 minutes to several hours depending on the type of water-absorbing polymer resin to be applied.

Next, the following Experiment 1 illustrates the quantitative relationship between the powdery or granular water-absorbing polymer resin and water.

(Experiment 1) Add tap water to 5 g of polyethylene oxide particles (particle size: 2 mm or less) as a water-absorbing polymer resin (A) 50
ml, (+7) 80 ml, (c) 100 ml, and (d) 150 ml were added at room temperature, respectively, and the swelling state of the granules was examined. In addition, the standing time was 15 minutes for each. The results are shown in Table 1 below.

<Table 1> 1] *The swelling state was determined by the state of swelling due to water absorption of the particles.

In this case, if the swelling state is insufficient like sample (a), the cooling time will be shortened, and if there is excess water between the particles like sample (d), it will freeze during freezing. Because it tends to become stiff overall, test f4 (17
) and (8) later are considered to be optimal.

Next, the quantitative relationship of the hydrophilic organic solvent will be illustrated in Experiment 2 below.

In this experiment 2, the amount of water corresponding to sample (c) in experiment 1 was prepared by mixing tap water and ethanol as a hydrophilic organic solvent at room temperature in advance in the proportions shown in Table 2 below. Then, this mixed solution was mixed into 5 g of polyethylene oxide granules and allowed to swell.

Seal each of these in a plastic bag and
The properties at room temperature (20°C) after being left in a freezer for one day were examined. The results are shown in Table 2 below.

Table 2 * The softness of samples (c) and (d) in the table above was obtained by kneading them by hand.

The results shown in Table 2 above indicate that hydrophilic organic solvents such as ethanol contribute to the flexibility of this coolant material, but increasing the amount thereof shortens the low temperature holding time. Furthermore, the low temperature condition was defined as a case where the surface temperature was around 4°C.

``Function'' Water-absorbing polymer resin absorbs water and swells, exhibiting water-retaining properties. The amount of water absorbed at this time is several tens to hundreds of times greater, and this water acts to enhance the cold retention effect. In addition, when mixed with the powdery or granular water-absorbing polymer resin, it exhibits a thickened state. Further, the hydrophilic organic solvent does not freeze itself, but acts to prevent the water present in and around each particle of the water-absorbing polymer resin in the above-mentioned swollen state from freezing during freezing. Due to these effects,
This cooling medium exhibits a soft viscous state as a whole during freezing, and exhibits a stable cooling effect for a long time at a low temperature of around 4°C. Incidentally, inorganic salts such as borates can also be mixed as freezing point depressants in the present invention.

[Example 1] A mixture of 80 ml of tap water and 5 ml of ethanol was mixed with 5 g of polyethylene oxide granules (particle size: 2 mm or less) at room temperature (20°C) and allowed to stand for 15 minutes to remove the cooling medium. I got the material.

This coolant material was contained in a polyethylene resin storage bag and sealed. Store this sealed refrigerant material in the freezer (-20°C ~
-10°C) for one day.

When this cooled sealed coolant material was rubbed by hand, it quickly became flexible, and when it was left at room temperature, the surface temperature was around 4° C., and it exhibited a stable cooling effect for 2 hours. Or, if the above-mentioned cooled sealed coolant material is touched by hand for about 1 minute at 5-minute intervals, it exhibits a cooling effect for about 1 hour.

[Effects of the Invention] As described above, according to the present invention, a recyclable refrigerant material is provided that exhibits a stable cooling effect at low temperatures for a long period of time and exhibits flexibility during cooling. Because of this, even if the target surface is uneven or curved, such as a leg, it can be placed closely along the surface, and it can also be placed in a device such as a cooler. It has advantages in terms of usage, such as being able to store the coolant material by deforming it depending on the shape of the place where it is placed, and it also has the effect of being able to provide reliable cooling over a long period of time, thereby increasing its range of use. becomes extremely wide.

Procedures Amendment (spontaneous) May 21, 1988 Patent Application No. 85226 of 1988 2, Name of the invention Coolant material 3, Relationship with the person making the amendment Case Applicant: 1-chome Minamihorie, Nishi-ku, Osaka No. 8-3 Riolu Co., Ltd. Representative Shigeo Hosaka 4, Agent Address: 2-23 Hirano-cho, Higashi-ku, Osaka 541 Specification and drawing 6 Contents of amendment (1) The specification will be amended as shown in the attached sheet.

Contents of amendment 1: In the second and third lines of page 1θ of the specification, “...
...Exhibited a cold preservation effect.

[Effects of invention] There is a certain [...Show the cold retention effect.]

[Example 2] Polyethylene oxide granules (particle size: 2 or less) 5
A mixture of 80 ml of tap water and 20 ml of ethanol was mixed with g at room temperature (20° C.) and allowed to stand for 15 minutes to obtain cooling medium material A.

(1) Put 100 g of this coolant material A into an Erlenmeyer flask (100 ml capacity) and store it in a freezer (-40°C).
) for 2 days. Next, this was taken out and placed in a vibrator (37° C.), and the subsequent change in surface temperature of this cooling medium A over time is shown in FIG. 1 by characteristic a.

(2) Furthermore, 100 g of this coolant material A was placed in a plastic bag, and this was stored in a freezer (-40°C) for 2 days. Next, this was taken out and left indoors (25°C), and the subsequent change in surface temperature of this cooling medium A over time was measured using the first method.
The characteristics are already shown in the figure.

(3) In addition, in (2) above, when the refrigerant material A stored in a plastic bag is constantly rubbed by hand indoors (at 25°C) immediately after being taken out from the freezer, the refrigerant material A
The change in surface temperature over time is shown in Figure 1 as characteristic C.

[Example 3] Acrylic acid vinyl alcohol copolymer powder (particle size 1
Coolant material B was obtained by mixing 5 g of 80-29 (lμ) with a mixture of 600 ml of tap water and 250 ml of ethanol at room temperature (20°C) and leaving it for 15 minutes.

This was stored in a freezer (-40°C) for 2 days.

Next, this was taken out and left indoors (25° C.), and the subsequent change over time in the surface temperature of this coolant material B is shown in FIG. 1 by characteristic d.

The properties a to d described above show a cold retention effect for 30 minutes or more even under severe conditions, and for 2 hours or more even when left indoors (25° C.).

[Effect of the invention]" and correct it.

2. On page 10, line 15 of the specification, "...It gets wider." There is a certain [......It becomes wider.

[Brief explanation of drawings]

FIG. 1: A cold storage temperature characteristic diagram using the coolant material according to the present invention. ” he corrected. Above -3=

Claims (3)

[Claims] (1) A cooling medium material obtained by mixing water and a hydrophilic organic solvent that does not freeze even at -30°C with powder or granules of a water-absorbing polymer resin and allowing the mixture to stand. (2) The coolant material according to claim 1, in which the hydrophilic organic solvent is a lower alcohol. (3) The coolant material according to claim 1 or 2, in which an inorganic salt is mixed.