CZ20021110A3 - Reusable heat pack, super cooled supersaturated recrystalizable solution, process for the preparation of a mixture for use in reusable heat packs and method for the manufacture of such reusable heat pack - Google Patents

Abstract

The invention discloses a reusable heat pack comprising a soft sealed plastic bag containing a mixture of supercooled supersaturated recrystalizable solution of inorganic substance, alcohol, chemical compound additives, and means to trigger recrystallization of supercooled supersaturated recrystalizable solution of inorganic substance.

Description

Technical field

The present invention relates to a reusable thermal wrap. The present invention further relates to a tool for inducing recrystallization in a thermal wrap. The present invention also relates to a supercooled supersaturated recrystallizable solution usable in a thermal wrap and to a process for its preparation.

BACKGROUND OF THE INVENTION

The use of heating or cooling for many different applications is accomplished in different ways depending on the particular need. For example, people suffering from muscle pain commonly use rubber bags filled with hot boiling water to relieve pain. In the event of a head injury, your doctor will usually recommend the use of ice as first aid. In cases of high fever, it is customary to apply a cloth soaked in cold water to the forehead for home treatment to reduce the temperature. On recreational journeys, people often take packaged food or even carry a cooker and raw food preparation material. Another need for thermal energy is in remote areas where fuel may not be available or can be very expensive. To overcome these difficult situations, it is necessary to explore ways and possibilities of heat generation in an economical way and preferably without the use of conventional fuels. For this purpose, a tool called a thermal wrap has been developed over the last 15 years. The main principle of the heat wrap function is to utilize the heat generated by initiating a chemical reaction between two or more chemical compounds or by inducing crystallization of a supercooled chemical solution. This second aspect is described in the context of the present invention.

Various heating means such as a hot water bag, a portable electric heater or a battery heater are available on the market. However, in the case of a hot water bag, the hot water obtained by either fuel or electrical energy must first be poured into the bag. In addition, the heat provided by the hot water bag does not last long enough to produce any noticeable effect. In the case of electric heaters, a continuous supply of tt ftt ·· ·· • titi titititi • ti titi ti ti · ti ti ti ti ti ti ti ti ti ti ti ti ti ti tititi electric power. The use of such a heating tool is limited only to places where electricity is available, ie indoors only. In the case of battery heaters, charged batteries are required and replaced after discharge. In all these cases, another disadvantage is that the use of these tools is very limited and the safety regulations for handling electric heaters must be taken into account.

A non-standard heat wrap is described in U.S. Patent 4,532,110 (1985). According to the invention, thermal energy is generated by a process of inducing recrystallization in a subcooled saturated sodium acetate solution. The recrystallization is induced by a specially designed tool. The entire recrystallization-inducing device and the supercooled solution are enclosed in a plastic container made of PVC, polyurethane or the like. A disadvantage of the present invention is that the tool used to induce the crystallization of a subcooled sodium acetate solution must have a protective layer of gold or silver to prevent any corrosion caused by the chemical. This is not desirable because the material used for the recrystallization inducing tool is an expensive CuBe alloy. In addition, the PVC material used to produce the heat wrap has a limited lifetime because the presence of the sodium salt solution leads to the inevitable washing of chloride ions. This drawback is also contained in the other inventions described in other patents and patents US 4,572,158, US 5,058,563 and US 5,205,278. Another drawback in these inventions, in addition to US Pat. No. 5,058,563, is that the supercooled solution tends to run down on the one hand, which leads to uneven thermal effects and makes it difficult to use the heat wrap due to the need to adjust the shape of the wrap for a particular application before inducing heat generation.

In U.S. Patent No. 5,843,145, an additive was used to induce a gelling process during crystallization. This gelling helps to maintain the desired solution density and thus uniform heat exposure across the usable surface. The gelling agent used in the present invention is a water-soluble hydroethylcellulose polymer. However, this material, in addition to advantageously allowing the solution to gel, has the disadvantage of instability which makes it impossible to reuse the heat wrap.

U.S. Patent No. 5,843,145 discloses a reusable heat wrap wherein a mixture of the three gel forming components is enclosed in a plastic bag. This reusable thermal wrap requires external heating or cooling for successful use. When used for heating, the heat wrap is placed in a microwave or heated in another way to provide energy. It is claimed that the temperature of the heat wrap is maintained for a sufficiently long time to allow use as a heat wrap. In view of the fact that the wrap requires external heating, it appears to be disadvantageous to use the present invention as a thermal wrap. This is influenced by this to this this to this this * to * this * to * this · to this to this In particular, the invention states that preheating of the wrap must be carried out usually for two hours. This suggests that the wrap is not advantageous for use in practical emergency situations and also in remote areas where heating means such as a microwave cannot be available.

JP 58 180 575 discloses a cooling wrap with a composition comprising inter alia aniline chloride. In the present invention, however, the composition acts as an endothermic material which, when dissolved in water, absorbs heat and thus provides a cooling effect.

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

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a reusable thermal wrap that overcomes the above drawbacks.

It is a further object of the present invention to provide a heat wrap with a lifetime of at least six months.

It is a further object of the present invention to provide a thermal wrap that can be recycled at least a hundred times.

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

Another object of the present invention is also to provide a thermal wrap which can be used for therapeutic purposes.

Summary of the Invention:

Thus, the present invention provides a reusable thermal wrap comprising a soft sealed plastic bag comprising a mixture of a supercooled supersaturable inorganic substance, alcohol, additional chemical compounds, and means for causing recrystallization of a supercooled supersaturated inorganic substance.

According to an embodiment of the present invention, the plastic bag is made of polypropylene or polyvinyl chloride.

According to another embodiment of the present invention, the inorganic substance is selected from the group consisting of sodium acetate and calcium nitrate.

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According to another embodiment of the present invention, the supercooled supersaturated recrystallizable inorganic substance solution is prepared from water of good quality.

According to another embodiment of the present invention, the water of good quality is municipal water free of bacteria or distilled water.

According to another embodiment of the present invention, the alcohol is selected from the group consisting of ethylene glycol and glycerol.

According to another embodiment of the present invention, the additional chemical compound comprises an organic amine.

According to another embodiment of the present invention, the organic amine comprises aniline.

According to another embodiment of the present invention, the supercooled supersaturated recrystallizable solution consists of a mixture of hydrated sodium acetate salt of 50 to 70% by weight, ethylene glycol of 1 to 10% by weight, aniline of 10 to 20% by weight. % and water 10 to 29 wt.

According to another embodiment of the present invention, the means for causing recrystallization comprises a mechanical tool selected from the group consisting of a crocodile clip and a switching pin.

According to another embodiment of the present invention, the material of the recrystallization-inducing means comprises a non-corrosive material.

According to another embodiment of the present invention, the non-corrosive material of the means for causing recrystallization comprises stainless steel.

According to another embodiment of the present invention, the heat wrap has a lifetime of at least six months.

According to another embodiment of the present invention, the heat wrap is capable of being recycled at least 100 times.

According to another embodiment of the present invention, the heat wrap retains heat for at least two hours.

According to another embodiment of the present invention, the heat wrap is used for therapeutic applications, for body heating at high altitudes.

The present invention also relates to a process for producing a reusable heat pack 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, sealing the mixture in a soft sealed plastic bag and inducing recrystallization.

Further, the present invention relates to a composition for use in reusable heat packs comprising a solution of an inorganic substance, an alcohol and aniline.

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According to one embodiment of the present invention, the composition comprises sodium acetate 50 to 70% by weight, ethylene glycol 1 to 10% by weight, aniline 10 to 20% by weight. % and water 10 to 29 wt.

The present invention also relates to a process for preparing a composition for use in reusable heat packs, 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 for use in the reusable heat packs of the present invention is a synergistic composition with properties exceeding the sum of the properties of the individual components and not just a simple composition.

Detailed description of the present invention:

First, a hydrated solution of preferably sodium acetate of preferred purity in ordinary water was prepared by mixing 500 to 700 g in 0.1 to 0.3 L of water. The solution was prepared by thoroughly mixing sodium acetate with water. To this solution was added a polyhydric alcohol and preferably ethylene glycol. This mixture was thoroughly mixed, and then additional chemical compound, and preferably aniline, was added thereto, and the resulting mixture was thoroughly mixed. The addition of a polyhydric alcohol adds smoothness to a recrystallized supercooled saturated sodium acetate solution. This is achieved by a controlled increase in the viscosity of the resulting mixture after recrystallization induced by the mechanical tool. The use of aniline in the thermal wrap adds to the thermal wrap's lifetime and also provides unique heat wrap recycling options. After the mixture is prepared, it is poured into a plastic bag of preferred dimensions of 100 mm ² formed from a thin film of vinyl chloride (PVC) poles. The use of aniline as an additional chemical compound imparts desirable properties to prevent leaching of the plastic material and thus extend the useful life. The stainless steel crocodile clip is then placed in a heat wrap and finally sealed from the open end. The heat pack thus prepared usually contains, but is not limited to, sodium acetate woven salt 50 wt%, ethylene glycol 1 wt%, aniline 20 wt%. and water 29 wt. Recrystallization was induced by gently squeezing the crocodile clamp and releasing it immediately. There was a recrystallization and immediate heat generation along the entire wrap. This heat wrap could easily be shaped to any part of the body and thus heated. The wrap temperature was 45 ° C above room temperature and was maintained for two to three hours depending on the size of the heat wrap.

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In a typical therapeutic application, the wrap is wrapped in a mask after heating and applied to the patient. The wrap is cooled to room temperature in about four hours. The wrap is reactivated by placing it in hot water, which results in the crystalline content of the wrap melting and then removing from the hot water and cooling to room temperature. Then the heat pack was ready for further use.

The principle of the present invention is that the formation of a hydrated salt results in an endothermic heat-absorbing reaction. When crystallization is induced, the heat of crystallization is released into the vessel and the outer surface of the vessel is heated. This suggests the use of this tool for any purpose. The temperature obtainable by heat wrapping can be determined by the amount of supercooled supersaturated hydrated salt solution. Thus, tool life will be affected by increasing the amount of aniline or some other additional chemical compound such as hydroxides or carbonates.

Thus, the novelty of heat wrapping is the inventive step of adding hydroxides, carbonates or amines to the recrystallizable mixture.

In the embodiments of the invention, the heat wrap is produced by first dissolving the hydrated sodium acetate salt in water. Ethylene glycol is then added to this solution. After thorough mixing, aniline is added. The mixture is again thoroughly mixed and then poured into PVC plastic bags. The recrystallization-inducing means comprising a crocodile stainless steel clamp is then inserted into the bag and the whole device is sealed.

The following examples are provided for illustrative purposes only and should not be construed as limiting the scope of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Example 1:

The heat pack contained hydrated sodium acetate salt 50 wt%, ethylene glycol 1 wt%, aniline 20 wt%. and water 29 wt. Recrystallization was induced by triple clamping. Crystallization led to an immediate temperature increase to 75 ° C. The wrap cooled to room temperature in about four hours.

Example 2:

The heat pack contained 60% w / w sodium acetate salt, 4% w / w ethylene glycol, 15% w / w aniline. and water 21 wt. Recrystallization was induced by triple clamping. Crystallization led to an immediate temperature increase to 65 ° C. The wrap cooled to room temperature in about four hours.

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Example 3:

The heat pack contained hydrated sodium acetate salt 70 wt%, ethylene glycol 6 wt%, aniline 10 wt%. and water 14 wt. Recrystallization was induced by triple clamping. Crystallization led to an immediate temperature increase to 75 ° C. The wrap cooled to room temperature in about four hours.

Example 4:

The heat pack contained hydrated sodium acetate salt 70 wt%, ethylene glycol 10 wt%, aniline 10 wt%. and water 10 wt. Recrystallization was induced by triple clamping. Crystallization led to an immediate temperature rise to 70 ° C. The wrap cooled to room temperature in about four hours.

Table 1 shows a summary of the results of the examples.

Table 1:

Substance Weight percentages of substances Sodium acetate 50 60 70 70 Ethylene glycol 1 4 6 10 Aniline 20 May 15 Dec 10 -10 Water 29 21 14 10 Heat wrap temperature ° C 75 65 75 70

The main advantages of the present invention are:

1. Easy production from commonly available medium grade chemicals

2. The heat wrap may be kept for at least six months.

3. The heat wrap can be easily applied to a surface of any shape since it is elastic even after recrystallization.

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Claims (14)

PATENT CLAIMS What is claimed is: 1. A reusable heat pack comprising a soft sealed plastic bag comprising a mixture of a supercooled supersaturable inorganic substance, an alcohol, aniline, and means for causing recrystallization of a supercooled supersaturated inorganic substance. The reusable thermal wrap according to claim 1, wherein the plastic bag is made of polypropylene or polyvinyl chloride. The reusable thermal wrap according to claim 1, wherein the inorganic substance is selected from the group consisting of sodium citrate and calcium nitrate. The reusable thermal wrap according to claim 1, wherein the supercooled supersaturated recrystallizable solution of the inorganic substance is prepared from substantially pure water. 5. A reusable thermal wrap according to claim 4 wherein the substantially pure water is bacterial-free municipal water or distilled water. 6. The reusable thermal wrap of claim 1, wherein the alcohol is selected from the group consisting of ethylene glycol and glycerol. 7. The reusable thermal wrap of claim 1, wherein the supercooled supersaturated recrystallizable solution consists of a mixture of hydrated sodium acetate salt of 50 to 70% by weight, ethylene glycol 1 to 10% by weight, aniline 10 to 20% by weight. % and water 10 to 29 wt. 8. The reusable thermal wrap of claim 1, wherein the means for causing recrystallization comprises a mechanical tool selected from the group consisting of a crocodile clip and a switching pin. φφφφ ·· Φ «« Φ ΦΦ «« ΦΦΦΦ ΦΦ Φ Φ Φ ΦΦΦΦ Φ · Φ · Φ · Φ Φ 9 Φ ΦΦΦ »« ΦΦΦ « ΦΦΦ · Φ ΦΦΦΦ φφ ΦΦΦ ΦΦ ΦΦΦ ΦΦ ΦΦΦΦ 9. The reusable thermal wrap of claim 1, wherein the recrystallization-inducing material comprises a non-corrosive material. 10. The reusable thermal wrap of claim 11, wherein the non-corrosive material of the recrystallisation means comprises stainless steel. 11. A supercooled supersaturable recrystallizable solution usable in a thermal wrap, comprising a mixture of a solution of an inorganic substance, an alcohol and aniline. 12. The supercooled supersaturable recrystallizable solution of claim 11 comprising a mixture of sodium acetate 50 to 70% by weight, ethyl englycol 1 to 10% by weight, aniline 10 to 20% by weight. % and water 10 to 29 wt. 13. A method of preparing a composition for use in reusable heat packs 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. 14. A method of making a reusable heat pack 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, sealing the mixture in a soft sealed plastic bag, and attaching means for causing recrystallization.