SK287136B6 - Reusable heat pack, method for the manufacture thereof and process for the preparation of mixture for use in the reusable heat pack - Google Patents

Abstract

The reusable heat pack comprising a soft sealed plastic bag containing a mixture of super cooled supersaturated recrystalizable solution of inorganic substance, alcohol, chemical compound additives, and means to trigger recrystallization of super cooled supersaturated recrystalizable solution of inorganic substance. It is described method for the manufacture of such reusable heat pack and the process for the preparation of mixture for use in the reusable heat pack

Description

Technical field

The present invention relates to a reusable heater. The present invention also relates to a trigger device for a heater. The invention also relates to a supercooled supersaturated recrystallizable solution for use in a heating element and in the process for its preparation.

BACKGROUND OF THE INVENTION

The use of heating and cooling in many applications has been accomplished by a number of different techniques depending on the specific need. For example, people suffering from muscle pain commonly use rubber pockets filled with hot boiling water to relieve pain. In the case of head injuries, the prescription of ice is normally the first aid. In the case of high fever, a common household remedy was to apply a rag soaked in cold water to the forehead to lower the temperature. People on recreational trips often carry packaged food or even carry a cooking appliance and raw materials, food cooking material. Another need for warm energy is in remote areas where accessibility of fuels is not possible or can be very expensive. Therefore, to overcome all these difficult situations, it is necessary to design methods and means for generating heat in an economical manner and preferably without the use of conventional fuels. In response to this need, a device called a heater has been developed in the last 15 years. The main principle underlying the heater is to use heat generated as a result of initiating a chemical reaction between two or more chemicals or initiating the initiation of crystallization of a super-cooled chemical solution. In the context of the present invention, this is the second aspect mentioned.

Several warming materials are available on the market, such as hot water bags, portable electric pocket heaters or battery heaters. Although in the case of hot water bags, the hot water that is poured into the bag can be obtained either by using fuel or electricity. Further, the heat of the water bag does not last long enough to give any noticeable effect. In the case of an electric pocket heater, a permanent source of electricity is required. This limits the use of such a heating device to only those places where electricity is available, i. j. only inside. In the case of a battery heater, regular battery charging and replacement when discharged is required. In all these cases, the further disadvantage is the limited use and the need for protective measures in the case of electric heaters.

An unconventional heater was disclosed in US Patent 4,532,110 (1985). In this discovery, thermal energy is generated by the triggering action of the supercooled saturated sodium acetate solution. Start-up is performed by a specially adapted device. The entire composition of the trigger mechanism and the supercooled solution is in a plastic container made of PVC, polyurethane or the like. A disadvantage of the present invention is that the trigger mechanism used to initiate crystallization of the super-cooled sodium acetate solution must have a protective layer of gold or silver to prevent corrosion due to contact with the chemical. This is not desirable since the material for producing the trigger mechanism is already an expensive CuBe alloy. Furthermore, the PVC heater material has a very limited shelf life due to the necessary leaching of chloride ions due to the presence of a sodium salt solution. This disadvantage also occurs in the other inventions mentioned, as well as in US patents 4,572,158; 5,058,563 and 5,205,278. Another disadvantage of the aforementioned inventions, with the exception of 5,058,563, is that the supercooled solution tends to flow to one side causing uneven heating, making it difficult to use the heater by adjusting the body contours for individual applications prior to initiating crystallization and resulting heat generation.

In US Patent 5,058,563 an additive was used to induce gelatinization during crystallization. Gelatinization helps to maintain the desired density of the solution and thus uniformity of heat throughout the portion used. The gelling material used in said solution is a water-soluble hydroethylcellulose polymer. Although this material provides the advantage of gelatinizing the solution, it is unstable, thereby preventing reuse of the heater.

US Patent 5,843,145 discloses a reusable heating element wherein a mixture of three gel forming components is maintained within the plastic bag. This reusable heater requires external heating or cooling means for the device to be of useful use. In the case of heating use, the heater is placed in a microwave or any other heater to activate the heater. It is desirable that the temperature of the body be maintained for a sufficiently long period of time, thereby applying its use as a heating element. Due to the fact that the body needs external heating devices, the present invention is disadvantageous in its application as a heating element. This is largely due to the fact that the invention states that the pretreatment of the body must take place within a period of typically two hours. This is, as disclosed, disadvantageous in practical emergency situations and also in remote areas where heating devices such as microwave ovens may not be available.

JP 58180575 discloses a cooling body inside with a composition comprising inter alia aniline chloride. But in the present invention, the composition behaves as an endothermic material where, when the material dissolves in water, it absorbs heat and produces a cooling effect.

The present invention avoids the disadvantages of the prior art inventions.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a heater which avoids the disadvantages already mentioned.

It is a further object of the invention to provide a heater having a service life of at least six months.

Another object of the present invention is to provide a heater that can be recycled at least a hundred times.

Another object of the present invention is to provide a heater with a heat retention for at least two hours.

It is another object of the present invention to provide a heater useful for therapeutic applications.

Therefore, the present invention provides a reusable heater comprising a soft-sealed plastic bag comprising a mixture of a supercooled supercoatable recrystallizable solution of an inorganic substance, an alcohol, a chemical additive, and a means for initiating the recrystallization of a supercooled supercoatable recrystallizable solution of an inorganic substance.

In an embodiment of the invention, the plastic bag is made of polypropylene or polyvinyl chloride.

In another embodiment of the invention, the inorganic substance is selected from sodium acetate and calcium nitrate.

In another embodiment of the present invention, the supercooled, super-saturated, recrystallizable inorganic substance solution is prepared in good quality water.

In another embodiment of the invention, good quality water is public water free of bacteria or distilled water.

In another embodiment of the present invention, the alcohol is selected from ethylene glycol and glycerol.

In another embodiment of the present invention, the chemical additive comprises an organic amine.

In another embodiment of the invention, the organic amine comprises aniline.

In another embodiment of the invention, the supercooled supersaturated recrystallizable solution comprises a 50-70 wt. %, ethylene glycol 1 - 10 wt. %, aniline 10-20 wt. % and water 10-29 wt. %.

In another embodiment of the present invention, the means for initiating recrystallization comprises a mechanical device selected from the group comprising a crocodile clip and a switching pin.

In another embodiment of the present invention, the trigger means material comprises a non-corrosive material.

In another embodiment of the invention, the non-corrosive triggering material comprises stainless steel.

In another embodiment of the invention, the heater has a lifetime of at least six months.

In another embodiment of the invention, the heater may be recycled for at least 100 cycles.

In another embodiment of the present invention, the heater retains heat for at least two hours.

In another embodiment of the present invention, the heater is used for therapeutic applications, heating the body at high altitudes.

The invention also relates to a process for preparing a reusable heater, said process comprising preparing a hydrated solution of an inorganic substance in water, adding alcohol to the solution and thoroughly mixing, adding aniline and thoroughly mixing the resulting mixture, storing the mixture in a soft sealed plastic bag; adding a trigger.

The present invention also relates to a composition for use in reusable heaters, said composition comprising a solution of an inorganic substance in water, an alcohol and aniline.

In one embodiment of the invention, the composition comprises a 50-70 wt. %, ethylene glycol 1-10 wt. %, aniline 10-20 wt. % and water 10-29 wt. %.

The invention relates to a process for preparing a composition for use in reusable heaters, said process comprising preparing a hydrated solution of an inorganic substance in water, adding alcohol to the solution and thoroughly mixing, adding aniline, and thoroughly mixing the resulting mixture.

The composition of the invention for use in a reusable heater is a synergistic admixture with properties above the aggregation and below the aggregation of the properties of the individual components and is not a simple admixture.

DETAILED DESCRIPTION OF THE INVENTION

First, a hydrated solution of preferably sodium acetate of preferred purity in plain water was prepared by mixing 500-700 g in 0.1-0.3 liters of water. This solution was prepared by thoroughly mixing sodium acetate in water. To this was added a polyhydric alcohol and preferably ethylene glycol. This mixture was stirred vigorously and another additive, preferably aniline, was added thereto, and the resulting mixture was vigorously stirred. The addition of the polyhydric alcohol is intended to ensure the smoothness of the recrystallized super-cooled saturated sodium acetate solution. This is achieved by controlled viscosity growth of the resulting mixture after crystallization due to the triggering action by mechanical devices. The use of aniline in the heater body mixture increases the heater body life and also gives the heater body a unique property of recyclability. After the mixture is prepared, it is poured into a plastic bag with a preferred size of 100 mm ² made of a thin film of polyvinyl chloride (PVC). The use of aniline as an additive provides the desired property of preventing leaching of the plastic material and thereby increasing the durability. The stainless steel crocodile clip is inserted into the heating element and then finally sealed from the open end. The heater is now prepared, with a typical, but not limited, content of hydrated sodium acetate salt of 50 wt. %, ethylene glycol 1 wt. % aniline 20 wt. % and water 29 wt. %. Recrystallization activity was initiated by gently pressing the crocodile clip and releasing it immediately. Recrystallization was performed and heat was immediately generated throughout the heating element. The heater can readily adapt to and heat the body portion. The body temperature was 45 ° C higher than ambient temperature and was maintained for about two to three hours depending on the size of the heater.

In the case of a typical therapeutic application, upon activation of the body, this is wrapped in a towel and applied to the patient. The body was cooled to ambient temperature for about four hours. The body was reactivated by storing in hot water, resulting in melting of the crystallized body content and then removal from the hot water and cooling to ambient temperature. In this way, the body was prepared for reuse.

The principle underlying the invention is that the formation of a hydrated salt leads to a heat-absorbing endothermic reaction. When crystallization is performed by the trigger action, the heat of crystallization is released into the container, thereby heating the outer surface of the container. This makes the device useful for any application. The temperature that can be achieved by the heating device can be determined by the amount of supercooled supersaturated hydrated salt solution. Thus, the life of the device will also be adapted to a correspondingly increasing amount of aniline or any of the other additives such as hydroxides or carbonates.

The novelty of the present invention resides in a heater that is reusable, has a long service life and can be recycled.

The novelty of the heater is due to the inventive step of adding hydroxides, carbonates or amines to the recrystallizable mixture.

In the embodiments, the heater is produced by first dissolving the hydrated sodium acetate salt in water. To this was added ethylene glycol. After thorough mixing, aniline was added. The mixture was again thoroughly mixed and then poured into a PVC plastic bag. A stainless steel crocodile clip was used as a trigger and was placed in the bag, then the whole kit was sealed.

The following examples are intended to be illustrative only and should not be construed as limiting the scope of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

The heater contained a hydrated sodium acetate salt of 50 wt. %, ethylene glycol 1 wt. %, aniline 20 wt. % and water 29 wt. %. The trigger action was performed by pressing the clamp 3 times. Crystallization resulted in an immediate temperature rise to 75 ° C. The cooling of the body to ambient temperature took about four hours.

Example 2

The heater contained a hydrated sodium acetate salt of 60 wt. %, ethylene glycol 4 wt. %, aniline 15 wt. % and water 21 wt. %. The trigger action was performed by pressing the clamp 3 times. Crystallization resulted in an immediate temperature rise to 65 ° C. The cooling of the body to ambient temperature took about four hours.

Example 3

The heater contained a hydrated sodium acetate salt of 70 wt. %, ethylene glycol 6 wt. %, aniline 10 wt. % and water 14 wt. %. The trigger action was performed by pressing the clamp 3 times. Crystallization resulted in an immediate temperature rise to 75 ° C. The cooling of the body to ambient temperature took about four hours.

Example 4

The heater contained a hydrated sodium acetate salt of 70 wt. %, ethylene glycol 10 wt. %, aniline 10 wt. % and water 10 wt. %. The trigger action was performed by pressing the clamp 3 times. Crystallization resulted in an immediate temperature rise to 70 ° C. The cooling of the body to ambient temperature took about four hours.

Table 1

entry Percentage of materials by weight Sodium acetate 50 60 70 70 ethylene glycol 1 4 6 10 aniline 20 15 10 10 Water 29 21 14 10 heater temperature in ° C 75 65 75 70

The main advantages of the present invention are:

1. It is easy to produce from generally accessible chemicals of adequate purity.

2. The heater may be stored for at least six months.

3. The body can easily be laid on any contour as it retains flexibility even after recrystallization.

Claims (14)

PATENT REQUIREMENTS in that plastics, anortics, super- What is claimed is: 1. A reusable heater comprising a soft sealed plastic bag comprising a mixture of a supercooled supersaturated recrystallizable solution of an inorganic substance, an alcohol, aniline, and a means for initiating the recrystallization of a supercooled supersaturated recrystallizable solution of an inorganic substance. The reusable heating element according to claim 1, wherein the metal bag is made of polypropylene or polyvinyl chloride. The reusable heating element according to claim 1, wherein the ganic substance is selected from sodium acetate and calcium nitrate. The reusable heating element according to claim 1, characterized in that the cooled supersaturated recrystallizable solution of the inorganic substance is prepared from substantially pure water. 5. The reusable heating element of claim 4, wherein the substantially pure water comprises public water-free water or distilled water. The reusable heating element of claim 1, wherein the alcohol is selected from ethylene glycol and glycerol. The reusable heating element according to claim 1, wherein the supercooled supercoatable recrystallizable solution comprises a mixture of hydrated sodium acetate salt 50-70 wt. %, ethylene glycol 1-10 wt. %, aniline 10-20 wt. % and water 10-29 wt. %. The reusable heating element of claim 1, wherein the means for initiating recrystallization comprises a mechanical device selected from the group comprising a crocodile clip and a switching pin. The reusable heating element of claim 1, wherein the trigger means comprises a non-corrosive material. The reusable heating element according to claim 1, characterized in that the birthing material for the trigger means comprises stainless steel. 11. A supercooled supercoatable recrystallizable solution for use in a heater, comprising a mixture of a solution of an inorganic substance, an alcohol and aniline. 12. The supercooled supercoatable recrystallizable solution of claim 11 comprising a 50-70 wt. %, ethylene glycol 10 wt. %, aniline 10-20 wt. % and water 10-29 wt. %. 13. A process for preparing a composition for use in a re-use heater, comprising preparing a hydrated solution of an inorganic substance in water, mixing the alcohol thoroughly, adding aniline, and mixing the resulting mixture thoroughly. 14. A method for producing a reusable heater comprising preparing a hydrated solution of an inorganic substance in water, adding alcohol to the solution and mixing thoroughly, adding aniline, and mixing the resulting mixture thoroughly, placing the mixture in a soft mix sealed plastic bag and a trigger is added.