JPH10292991A - Heating container for heat-storing pack and its heating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a uniform dielectric heating quickly by accommodating a heat-storing pack and a water-retaining material with flexibility where a heat-storing material is built in, sealing them, and at the same time forming them by a heat-resistance material that is subjected to dielectric heating. SOLUTION: As a heating container for a heat-storing pack, it is sufficient if the container has a structure to accommodate the heat-storing pack and a water-retaining material and to be sealed. The heating container can be made of all of heat-resistance materials that are subjected to dielectric heating. However, generally, the heating container may be made of a material where the heating container can be used for a microwave oven, and the material includes polyolefin such as polyethylene, polypropylene, and polymethylpentene, polyester such as polyethylene telephtalete and polybutylene telephtalete, a heat-resistance engineering plastic such as polycarbonate, glass, ceramics, or a combination of them, thus eliminating the need for configuring a heat-storing pack side specially and heating the heat-storing pack safely and quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating container for a heat storage pack and a heating method therefor. More specifically, the present invention relates to a heating container for uniformly and inductively heating a heat storage pack in a short time and a heating method thereof. The heating container of the present invention is for thermotherapy,
Used for keeping food warm.

[0002]

2. Description of the Related Art It has been conventionally proposed to use a heat storage pack in which a flexible plastic is filled with a latent heat storage material such as sodium acetate trihydrate for a thermal treatment device. As a method for heating the heat storage pack, hot water is generally used, but it is often avoided because of the time required and the difficulty in adjusting the temperature at home. Meanwhile, with the spread of microwave ovens,
A method of inductively heating a heat storage pack has been proposed. Dielectric heating is an effective method that allows heating from the inside of the material in a very short time. However, there is a problem to be improved such as breakage of the container due to bumping of water in the film container.

In order to solve this problem, a heat storage device in which a heat storage pack has a double structure and a jacket portion is filled with water (Japanese Patent Laid-Open No. 63-290346) or a heat storage device in which a spacer is inserted between films of a container. (JP-A-63-29
No. 0347) has been proposed.

[0004]

However, the heat storage pack having the double structure has a problem that the pack itself becomes heavy due to the presence of unnecessary moisture. Further, even if the spacer is inserted, there is a problem that uneven melting due to heating occurs. A heat storage material having water of crystallization, such as sodium acetate trihydrate, can be dielectrically heated, but an organic heat storage material, such as paraffin or a fatty acid, has a problem in that it cannot be heated by transmitting microwaves.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a safe heating container for uniformly and indirectly heating a flexible heat storage pack containing a heat storage material therein in a short time, and to provide a heating vessel for heating the same. It is an object of the present invention to provide a method of melting more uniformly for a heat storage material having water and a method of storing heat by dielectric heating for an organic heat storage material having no crystallization water.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the heating container in which a moisture retaining material is present in the vicinity of the heat storage pack is heated by dielectric heating. Melt | dissolved uniformly in a short time, and came to complete this invention.

That is, the gist of the present invention is as follows. 2. A heat storage pack heating container characterized by being formed of a heat-resistant material capable of housing and sealing a heat storage pack and a moisture retaining material and capable of dielectric heating, A method for heating a heat storage pack, wherein the heat storage pack is dielectrically heated after a pack and water are charged and sealed. Hereinafter, the present invention will be described in detail.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

(Heating Container for Heat Storage Pack) The heating container for a heat storage pack of the present invention may have any structure as long as it can store and seal a heat storage pack and a moisture retaining material described later, and can have any shape. The material of the heat storage pack heating container can be used without particular limitation as long as it is a heat-resistant material capable of dielectric heating.For example, those generally determined to be microwaveable can be used.
Polyolefins such as polyethylene, polypropylene and polymethylpentene; polyesters such as polyethylene terephthalate, polybutylene terephthalate and BMC (glass fiber reinforced polyester resin); heat-resistant engineering plastics such as polycarbonate; glass; ceramics; No.

(Thermal Storage Pack) The thermal storage pack used in the present invention is not particularly limited, but it is preferable that the thermal storage material is sealed in a flexible plastic. Here, as the heat storage material, a latent heat storage material is preferable in terms of heat storage amount, and the phase change temperature of the latent heat storage material is preferably 5 ° C. or more and less than 80 ° C., and more preferably 20 ° C. or more and 60 ° C. or less. . When the phase change temperature is less than 5 ° C., the phase change temperature is generally in a molten state at room temperature, there is no need to heat, and the phase change temperature is 8
In order to melt at a temperature of 0 ° C. or higher, it is necessary to heat to 100 ° C. or more. In the heat storage material composition containing water, the internal pressure rises due to evaporation of water, and at a temperature of 100 ° C. or higher, the film becomes soft. It is technically difficult.

Preferred heat storage materials include sodium acetate trihydrate, sodium sulfate decahydrate, calcium chloride hexahydrate,
Sodium pyrophosphate decahydrate, mixed salts of inorganic hydrates such as barium hydroxide hexahydrate and other salts and blended to adjust the melting point, paraffin, polyethylene glycol, and fatty acids are preferred. Trihydrate and sodium sulfate decahydrate are more preferred.

The heat storage material composition includes sodium carbonate, sodium pyrophosphate decahydrate, sodium tetraborate decahydrate, tribasic calcium phosphate, calcium sulfate, aluminum phosphate, silver iodide, and phosphoric acid for preventing supercooling. Supercooling inhibitors such as silver and silver bromide, water-insoluble water-absorbing resins that prevent phase separation, CMC, xanthan gum, guar gum, locust bean gum, phase separation inhibitors such as polyglycerin, sodium alginate, finely divided silica, benzoic acid Preservatives such as sodium and butylhydroxytoluene can be optionally added.

The plastic having flexibility is not particularly limited, but may be a single-layer film and / or sheet of polyethylene, vinyl chloride, etc., gas barrier property, chemical resistance, heat resistance, impact resistance. Examples of the multilayer laminate film and / or sheet composited to improve the water resistance, the film strength and the like include a layer structure of polyethylene / nylon, polypropylene / nylon, polypropylene / polyethylene terephthalate and the like. The thickness of the flexible plastic film and / or sheet is preferably 50 to 500 μm, more preferably 100 to 300 μm, so as to withstand the increase in internal pressure due to evaporation of water inside the container due to microwave heating. If the thickness of the plastic film and / or sheet is less than 50 μm, the film may not be able to withstand an increase in internal pressure during heating and may be easily broken. When the film thickness is 5
When the thickness is larger than 00 μm, the performance of flexibility is easily impaired, and the feeling of use of the heat storage pack deteriorates.

(Moisture Retaining Material) The moisture retaining material used in the present invention retains moisture for heating the heat storage pack by heat transfer during dielectric heating. At this time, a part of the water becomes steam and has an effect of uniformly raising the temperature in the container. The material of the water retaining material is a material that does not melt or deform when heated by a microwave oven, and has only to retain water. Polyester such as polyethylene terephthalate and derivatives thereof, polyolefins such as polyethylene and polypropylene, and natural fibers such as cotton and wool. , Paper, sponge and the like are preferred.

Use forms include nonwoven fabric, woven fabric, fibrous,
Although a superabsorbent polymer is conceivable, it is preferable that the water-absorbing polymer can retain the same amount of water or more as its own weight. Further, since the purpose of the moisture retaining material is to heat the retained moisture and heat the heat storage pack that comes into contact with the moisture retaining material, there is no problem even if the moisture retaining material is filled in the container while retaining the moisture. In addition, the water content of the water retention material is usually 1 to 10 with respect to 100 parts by weight of the heat storage pack.
0 parts by weight, preferably 3 to 50 parts by weight.

The effects of the present invention will be described for the case where the heat storage material is a compound having water of crystallization. When only the heat storage pack is heated in a microwave oven without moisture, a part of the heat storage material is melted. The melted heat storage material composition becomes a liquid, becomes easier to warm than a solid heat storage material composition that is not melted, and the melted liquid is heated preferentially. Thus, the liquid and solid portions remain, and the liquid portion begins to boil, causing damage to the container. In this manner, when heating is performed only with the heat storage pack, heat can be stored only until the solid portion of the heat storage material remains in order to prevent damage to the container, and a shortage of heat storage becomes a problem. When a moisture-retaining material that retains moisture is placed near the heat storage pack, the heat is also heated by the microwave, but the moisture in the moisture-retaining material is quickly heated, and the portion in contact with the container is close to 100 ° C. The temperature rises rapidly until The water in the water holding material is heated to 100 ° C., and the heated water turns into steam to heat the entire inside of the heating vessel. Here, since the temperature of the water retention material is constant at around 100 ° C. of the boiling point of water, the heat storage pack is in an ideal state in which the water is bathed. Heating by heat transfer from the surroundings from the moisture retention material and heating from the inside of the heat storage material by microwaves rapidly and uniformly heat the material.

According to the method of the present invention, a heat storage pack using a material that does not normally react to microwaves, for example, paraffin, polyethylene glycol, fatty acid, or the like, as a heat storage material composition can also be heated by a microwave oven. The principle is the same as that of the heat storage material composition of the compound having water of crystallization, except that heating from the inside of the heat storage material by the microwave is not performed.

[0017] If it is possible to realize a state in which most of the moisture in the moisture retaining material is converted into steam at the end of heating by adjusting the moisture retention amount, the thermal storage pack is almost completely removed when the thermal storage pack is taken out of the heating vessel. There is also a practical advantage that it is hardly wet and there is no need to wipe off water drops with a towel or the like. Furthermore, in order to heat by putting a heat storage pack in a heating container,
Even if the heat storage pack is damaged by heating, there is also a safety advantage that the heat storage material composition does not leak into the microwave oven.

[0018]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited to the following Examples without departing from the scope of the invention.

Example 1 Sodium acetate trihydrate (melting point: 58 ° C .; reagent grade, manufactured by Kishida Chemical Co., Ltd.) was placed in a beaker fixed in a water bath controlled at 70 ° C., and completely melted with stirring. Width 50mm,
A polyester nonwoven fabric (nonwoven fabric K-230 manufactured by Fujibo Co., Ltd.) cut into a length of 100 mm and a thickness of 5 mm was immersed in a beaker in a state of being superposed, and impregnated with the melted sodium acetate trihydrate, and kept at a constant temperature of 23 ° C. It was cooled and solidified on a stainless steel vat in a chamber to obtain a heat storage material. The weight of the two nonwoven fabrics was 2.3 g, and the weight of sodium acetate trihydrate was 63.4 g. This heat storage material is heat-sealed on all sides of a laminate film (Dynalon, trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.) having a thickness of 250 μm, a width of 70 mm,
A heat storage pack having a length of 120 mm was prepared. As a moisture retaining material, a nonwoven fabric made of polyester cut to a width of 50 mm, a length of 100 mm, and a thickness of 5 mm (nonwoven fabric K-
230) was immersed in a beaker filled with water in a state where two sheets were stacked, lightly squeezed, and placed on a heat storage pack. The heat storage pack on which the moisture retaining material was placed was placed in a polypropylene container, covered and sealed. Put this container in a microwave oven and output 2
When heated at 00 W for 2 minutes, the heat storage material was uniformly melted without any hard portion remaining unmelted. As a result of measuring the temperature of the heat storage pack with a digital surface thermometer (manufactured by Anritsu Keiki Co., Ltd .: HL-300), the center was 90 ° C and the side edges were 80 to 90 ° C.
It can be seen that the entire heat storage pack is uniformly heated.

Comparative Example 1 The heat storage pack prepared in Example 1 was placed in a microwave oven and heated at an output of 200 W for 2 minutes. As a result, a hard part where the heat storage material remained unmelted and a liquid part where the heat storage material was completely dissolved were formed. As a result of measuring the temperature of the heat storage pack with a surface thermometer, it was found that the hard portion remaining unmelted was about 50 ° C., and the melted portion was 90 ° C., and there was uneven melting.

Example 2 Polyethylene glycol # 2000 (melting point: 52 ° C .; first class reagent manufactured by Kanto Chemical Co., Ltd.) was placed in a beaker fixed in a water bath controlled at 70 ° C., and completely melted with stirring. Polyester non-woven fabric cut to a width of 70 mm, a length of 100 mm, and a thickness of 3 mm (non-woven fabric KK040 manufactured by Kanebo)
7) was immersed in a beaker and impregnated with the melted polyethylene glycol # 2000, cooled and solidified on a stainless steel vat in a constant temperature room at 23 ° C. to obtain a heat storage material. The weight of the nonwoven fabric was 2.6 g, and the weight of polyethylene glycol # 2000 was 29.0 g. This heat storage material was heat-sealed on all sides of a 250-micron-thick polypropylene laminate film (manufactured by Sumitomo Chemical Co., Ltd.) to obtain a width 9 mm.
A heat storage pack having a length of 5 mm and a length of 140 mm was prepared. As a water retention material, width 70mm, length 90mm, thickness 3mm
The polyester non-woven fabric (non-woven fabric KK0407 manufactured by Kanebo) cut into a beaker filled with water and placed on a heat storage pack. The weight of the nonwoven fabric was 2.2 g, and the retained moisture was 28.0 g. The heat storage pack on which the moisture retaining material was placed was placed in a polypropylene container, covered and sealed. This container was placed in a microwave oven and heated for 6 minutes at an output of 200 W. As a result, the heat storage material was uniformly melted without any remaining hard part. As a result of measuring the surface temperature of the heat storage pack with a digital surface thermometer (manufactured by Anritsu Keiki Co., Ltd .: HL-300), the center is 65 ° C and the side edges are 55 to 65 ° C, and the entire heat storage pack is uniformly heated. You can see that it is.

Comparative Example 2 The heat storage pack prepared in Example 2 was placed in a microwave oven and heated at 200 W for 6 minutes. As a result, a hard portion where the heat storage material remained unmelted and a liquid portion where the heat storage material was completely dissolved were formed. As a result of measuring the temperature of the heat storage pack with a digital surface thermometer, the hard portion remaining unmelted was 42 to 52 ° C., and the melted central portion was 11 ° C.
Melting unevenness was found at 9 ° C.

[0023]

By using the heating container of the present invention,
The heat storage pack can be safely heated in a short time without using a special configuration on the heat storage pack side.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Mitsuo Hashimoto, Inventor 140 Hamakawacho, Takasaki City, Gunma Prefecture (72) Inventor Takeshi Keneda 340-6, Kokuzaiji, Fukaya City, Saitama Prefecture

Claims (6)

[Claims] 1. A heating container for a heat storage pack, comprising a heat-resistant material capable of housing and sealing a heat storage pack and a moisture retaining material and capable of dielectric heating. 2. The heating container for a heat storage pack according to claim 1, further comprising a heat storage pack and / or a moisture retaining material. 3. The heat storage pack has a phase change temperature of 5 to 80 ° C.
The heating container for a heat storage pack according to claim 1 or 2, wherein the latent heat storage material is sealed in a flexible plastic. 4. The latent heat storage material is sodium acetate trihydrate,
The main component is at least one selected from sodium sulfate decahydrate, calcium chloride hexahydrate, sodium pyrophosphate decahydrate, barium hydroxide hexahydrate, paraffin, polyethylene glycol and a fatty acid. 4. The heating container for a heat storage pack according to 3. 5. The moisture retaining material according to claim 1, wherein the moisture retaining material is one selected from nonwoven fabric, cloth, absorbent cotton, sponge, sponge, superabsorbent polymer and water absorbing paper, or a composite material thereof. The heating container for a heat storage pack according to any one of the above. 6. A method for heating a heat storage pack, comprising: charging the heat storage pack and water in the heat storage pack heating container according to claim 1; sealing the heat storage pack and water; and performing dielectric heating on the heat storage pack.