JP2000060887A - Exothermic composition for throw-away body warmer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exothermic compsn. for throw-away body warmers which ensures the smooth execution of the oxidation of metallic powder and is capable of sustaining a heat generation temp. for long by using active carbon which has large porosity, is porous and has high water-absorbing and holding properties. SOLUTION: The active carbon of the exothermic compsn. for thraw-away body warmers consisting essentially of the metallic powder, such as iron powder, salts, water, active carbon and water-holding agent consists of the carbide formed by using combustibles, porous diatomaceous earth contg. 65 to 97 W/W% silicon oxide (SiO2) or water soluble saccharides as raw materials and subjecting the raw materials to wet process mixing, then forming the mixture to a granular or powder form by firing and pulverizing. At least one kind consisting of natural materials, such as timber, pulp, paper, bamboo, cereal husks (chaff, buckwheat husks, etc.), coconut shells and coffee grounds, having fibrous matter, are used as the combustibles. The compounding ratio of the diatomaceous earth and water-soluble saccharides in the raw materials is preferably a ratio of 5 to 30 V/V% diatomaceous earth and 3 to 20 V/V% water-soluble saccharides to the combustibles.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat-generating composition that generates heat in the presence of air and a disposable body warmer using the same.

[0002]

2. Description of the Related Art A disposable body warmer uses the heat of oxidation of a metal, and its exothermic composition is made of metal powder, salts as reaction aids, water, activated carbon acting as a catalyst, and a water retention agent. Composed of powder. Disposable body warmers are usually manufactured by mixing powder components, adding salt water to retain water, storing in a breathable bag (inner bag), and adding metal powder immediately before sealing to mix. Has been done.
There is also a manufacturing method in which a mixed powder containing salt water and a metal powder are mixed and housed in an inner bag and sealed. Further, this inner bag is commercially available in the state of being hermetically packaged in a bag (outer bag) made of a non-breathable packaging material, and the inner bag is taken out from the outer bag at the time of use.

Japanese Industrial Standard "Disposable Cairo" (J1
The temperature characteristics specified in S S 4100) depend on the size and number of air holes in the inner bag, but the water retention agent of the mixed powder and the activated carbon that acts as a catalyst also play an important role. . If you use a large amount of water retention agent to keep the exothermic temperature for a long time, or if you use an activated carbon with a low porosity, the amount used will increase and the volume of the mixed powder in the inner bag will increase, making it bulky at the time of use. There is a problem that it becomes difficult to use. In addition, mixing and filling during manufacturing become difficult.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to:
By using activated carbon having a large porosity, water absorption, and water retention, the metal powder can be oxidized smoothly and efficiently, and the exothermic temperature can be maintained for a long time, and the volume of the mixed powder becomes small, Mixing during manufacturing,
It is an object of the present invention to provide an exothermic composition that can be easily filled, and thus to provide an inexpensive disposable body warmer that has a small amount of mixed powder in an inner bag and is not bulky at the time of use.

[0005]

In order to achieve the above object, according to the present invention, metal powder such as iron powder, salts, water, activated carbon and a water retention agent (vermiculite, wood powder, diatomaceous earth, hiru stone, water absorption) In a heat-generating composition for a disposable body warmer containing a water-soluble polymer or the like as a main component, the activated carbon contains a combustible substance and a porous diatomaceous earth containing silicon oxide (SiO ₂ ) at 65 to 97 W / W% as a raw material. There is provided a heat-generating composition for a disposable body warmer, which is a charcoal-based material obtained by wet-mixing and then firing and pulverizing the mixture to give a granular or powdery form.

In a preferred embodiment, as the activated carbon, combustibles, diatomaceous earth and water-soluble saccharides are used as essential raw materials, and the raw materials are wet-mixed and then calcined and pulverized to give a granular or powdery charcoal. As the combustible material, wood,
At least one natural product having a fiber quality such as pulp, paper, bamboo, grain shells (rice husks, buckwheat husks, etc.), coconut shells, coffee meal, etc. is used. Further, the blending amount of the diatomaceous earth and the water-soluble saccharide in the raw material is 5 to 30 for the combustible material.
A ratio of V / V% and a water-soluble saccharide of 3 to 20 V / V% is preferable.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-generating composition for a disposable body warmer of the present invention is basically characterized in that a charcoal obtained by wet-mixing a combustible substance and diatomaceous earth, firing and pulverizing the mixture is used as activated carbon. Diatomaceous earth has a structure in which small pores of less than 1 micron (μ) are arranged geometrically, and has a unique porous structure and a chemically stable property of high silicic acid content. When this diatomaceous earth and combustible material are wet-mixed, the surface of the combustible material is covered with diatomaceous earth, whereby the combustible material is kept warm during firing, and an appropriate amount of air is supplied to it, which is then fired and carbonized. In addition, a porous carbide having a fine porosity in the surface layer portion and a porous structure in which the inside is relatively rough can be obtained. Since such a porous carbide is highly water-absorbing and water-retaining, by using it as the activated carbon of the heat-generating composition, the metal powder can be efficiently and smoothly oxidized even if the amount used is relatively small. The exothermic temperature of can be maintained for a long time.

In order to carbonize a combustible material, it is usually necessary to fire it in a reducing atmosphere. When combustibles are burned in an oxidizing atmosphere, they burn to ash, but when wet-mixing porous and fine diatomaceous earth with combustibles, the combustibles are coated with diatomaceous earth and the supply of oxygen is suppressed during firing. . Due to this effect of suppressing oxidation, even if fired in an oxidizing atmosphere, it does not burn but carbonizes. In addition, the yield of carbides in the fired product produced by the addition of diatomaceous earth becomes high. If the ratio of diatomaceous earth to combustibles is too low, it is difficult to coat, and it burns to ash, which reduces the yield of carbides. On the other hand, if this ratio is too high, the amount of inorganic substances increases and the ratio of carbides generated decreases, so that the amount of mixture at the time of preparing the heat-generating composition must be increased. From this point of view, the amount of diatomaceous earth used is 5 to 30 V / V% with respect to combustibles as a guideline, and the coating adjustment is made by appropriately adjusting it according to the type of combustibles used, the amount of water, etc. Just do it.

Another feature of the heat-generating composition for a disposable body warmer of the present invention is to use a charcoal obtained by wet-mixing a combustible substance, diatomaceous earth and a water-soluble saccharide, firing and crushing the activated carbon. When a water-soluble saccharide is allowed to coexist in diatomaceous earth and the surface of a combustible material is coated, the carbonization yield is dramatically improved. This is because the coexistence of water-soluble saccharides with diatomaceous earth suppresses the oxidation of combustible materials. For example, 600-800 ℃
Even if heated for several hours, the combustibles are not oxidized and the carbonized state is maintained, the porous blackening degree of the fired product is increased, and high quality carbides are obtained. If water-soluble saccharides are not mixed, since diatomaceous earth has a high heat retaining property, the burning time of the combustible material lasts, the rate of ashing increases, and the yield of the carbide deteriorates.

If the amount of saccharide added is small, the state of combustible substances covered with diatomaceous earth will deteriorate, and therefore the supply of air will increase and the rate of ashing will increase. On the other hand, if the amount of saccharide added is increased, a porous carbide with a high degree of blackening is obtained,
High cost. From such a point, the amount of saccharides to be added is 3 to 20 V / V% with respect to combustible substances as a standard, and may be appropriately adjusted depending on the type of combustible substances used, the amount of diatomaceous earth, water, etc. Just adjust the coating. By the way, even if the added amount of saccharides is the same, the carbonization yield is improved by increasing the mixing ratio of diatomaceous earth. However, when the content is 30 V / V% or more, the ratio of carbides in the fired product formed becomes low, and the amount of the activated carbon used in preparing the exothermic composition increases, so that 30 V / V
% Or less is preferable.

The above-mentioned wet mixing is to mix a combustible substance and diatomaceous earth or water-soluble saccharides under the condition that water exists, regardless of how the water is supplied. That is, it does not mean simply adding water from the outside to mix, but when the combustible material to be mixed has sufficient water content, this water content is utilized to wet mix with diatomaceous earth or water-soluble saccharides. If the water is insufficient, add new from outside. That is, the water content may be appropriately adjusted according to the desired viscosity of the mixture so that the combustible material can be coated with diatomaceous earth or further with water-soluble saccharides.

As used herein, the term "combustible material" means wood, bamboo, grain shells (rice husks, bran, buckwheat husks, etc.), paper, pulp, coconut shells, coffee meal, etc. Including all. In other words, it means any substance that burns to become a carbon component. The saccharides include polysaccharides, oligosaccharides, monosaccharides, and various substances depending on their molecular weights, but in the present invention, water-soluble saccharides are preferable. Especially, oligosaccharides such as sucrose, maltose and glucose, and monosaccharides are preferable. In addition to adding the sugar itself, the sugar can be used by mixing the sugar with diatomaceous earth in a state of being dissolved in water.

As the diatomaceous earth used in the present invention, silicon oxide (SiO ₂ ) is 65 W / W% or more, preferably 65-
A diatomaceous earth which is obtained by using a porous fine powdery dry product containing 97 W / W% or a crushed dry product as a raw material, adding a small amount of a flux to it, and firing at high temperature is preferable. Diatomaceous earth is in the form of a fine, porous powder and has a structure in which small pores of less than 1 micron (μ) are arranged geometrically, and because of this unique porous structure, it retains heat. The property that fine pores absorb water and expand is important for producing a porous body having a large porosity. If the content ratio of silicon oxide is low, heat retention and absorption of water deteriorate, and good carbides cannot be obtained.

The fired body obtained by the method of the present invention is dried,
Regardless of the firing conditions, it becomes a porous body under all conditions, and the surface layer and internal pores are in communication with each other, and it has properties of extremely high water absorption and water retention. When the drying conditions, the presence or absence of addition of sugars, and the firing conditions, especially the drying conditions are changed, the porosity greatly changes. That is, the combustible material, diatomaceous earth, or a mixture obtained by adding a saccharide thereto is molded into a non-dried product.
When semi-dried and calcined, a carbide having a fine pore structure in the surface layer and a coarse pore structure in the inside, and the pores in the surface layer and the inside are communicated with each other to obtain a porous structure having a high porosity is obtained. Carbides having this structure are extremely rich in water absorption and water retention. This charcoal-based material is made into a granular or powdery form and used as activated carbon of a heat-generating composition for disposable body warmers.

Water is retained in the fine porous diatomaceous earth,
When coated with a dry to semi-dry combustible material and baked, the fine porous diatomaceous earth has excellent heat retention, so the inside is steamed in a heat-retained state, and the surface is porous with a fine pore structure with a fine pore structure. Although a shell is formed, shrinkage due to drying and firing of the inside is prevented by the shell formed in the surface layer portion, so that shrinkage of the entire volume due to firing is suppressed and the inside shrinks.
As a result, the inside has a relatively coarse porous structure, and a carbide having a porous structure with high porosity can be obtained. When diatomaceous earth is used alone as a combustible material coating, since diatomaceous earth has a porous structure, the supply of air is large and the combustible material easily burns completely and the yield of carbides deteriorates. It is solved by adding ~ 20V / V%. A normal dried and baked product has a large volume shrinkage ratio, and it is difficult to obtain a product having a high porosity.

Drying of the molded product can be appropriately selected from non-drying to semi-drying to complete drying. That is, non-drying to semi-drying is preferable for materials having a high porosity, and complete drying is preferable when strength is desired. When completely dried, a molded product having a small porosity and being hard and strong can be obtained. A baking temperature of about 600 to 900 ° C. is sufficient. The firing atmosphere may be either an oxidizing atmosphere or a reducing atmosphere. The carbide used in the present invention has one feature in that it can be produced by oxidation firing. The firing is performed by rapidly heating the inside to a predetermined temperature in a short time of about 2 to 10 minutes using a rotary kiln, and then taking out the fired product and allowing it to cool. The time required for carbonization is about 1 minute for particles having a diameter of 4 to 5 mm and 4 to 5 minutes for particles having a diameter of around 10 mm. In the present invention, since the combustible material is mixed as described above, self-combustion proceeds due to the hydrocarbon component, and fuel supply is small. The fired carbide having a porous structure with high porosity is easily pulverized and easily becomes a carbide for a body warmer of 20 to 200 mesh.

The fired body produced by the method of the present invention is porous and absorbs water well regardless of the drying and firing conditions.
The function of the fired body is not only water absorption and water retention, but the carbonized portion is a porous body with a large specific surface area and also has heat retention, and the carbide powder crushed from this is the most suitable as activated carbon for disposable body warmers. . The calcined carbide is a carbide having a porous structure with a high porosity, and by pulverizing it, it is possible to economically produce a powder of 20 to 250 mesh activated carbon for disposable body warmers.

[0018]

EXAMPLES The present invention will be specifically described below with reference to examples, but it goes without saying that the present invention is not limited to the following examples.

Carbide Production Example 1 Wood chips having a diameter of about 10 mm and diatomaceous earth were mixed in the blending amounts shown in Table 1 below, water was added, and the wood chips were mixed so as to be covered with diatomaceous earth. It was dried and directly placed in a rotary kiln (oxidation firing method) to raise the temperature to 900 ° C. in 2 minutes for firing, and then allowed to cool in the air and cooled. The obtained carbide was a carbide having a porous structure with high porosity. Table 1 also shows the carbide yield of the obtained fired product.

[0020]

[Table 1] As shown in Table 1, regarding the mixing ratio of combustibles (wood chips) and diatomaceous earth, the higher the content of diatomaceous earth, the better the yield. On the other hand, when the content is low, it is difficult to cover the wood chips, And the yield becomes worse. However, if the mixing ratio of the diatomaceous earth becomes too high, the amount of the inorganic substances increases and the ratio of the carbides decreases, so that the mixing ratio in the exothermic composition must be increased. Further, it becomes difficult to crush the carbide. Therefore, the blending ratio of diatomaceous earth is preferably 30 V / V% or less with respect to combustible materials (wood chips).

Carbide Production Example 2 Wood chips having a diameter of about 10 mm, sucrose and diatomaceous earth were mixed in the blending amounts shown in Table 2 below, and water was added to the wood chips so that the wood pieces were covered with the diatomaceous earth and sucrose. After mixing into
It was semi-dried and directly placed in a rotary kiln (oxidation firing method) to raise the temperature to 900 ° C. in 2 minutes for firing, and then allowed to cool in the air and cooled. The obtained carbide was a carbide having a porous structure with high porosity. The carbide yield of the obtained fired product is also shown in Table 2.

[0022]

[Table 2] As shown in Table 2, diatomaceous earth contains water-soluble sugars (sucrose).
If a combustible material (wood chips) is coated with a material that coexists with, the yield of carbide is dramatically improved. Further, when the mixing ratio of diatomaceous earth is increased in the presence of water-soluble saccharides, the yield of carbide is improved. However, the yield does not change significantly even if the mixing ratio of diatomaceous earth is 30 V / V% or more. Also, 30V /
When the content is higher than V%, the amount of inorganic substances increases and the ratio of carbides decreases, so that it becomes necessary to increase the mixing ratio in the heat-generating composition. Further, it becomes difficult to crush the carbide.

Example 1 An exothermic test of an exothermic composition prepared by using the special carbide of the present invention is shown below. This is a comparison of whether the special carbide of the present invention can be used as a raw material for a disposable body warmer or a commonly used activated carbon as a control in an exothermic test. The special carbides of the present invention (Sample No. 7, Sample No. 2) or commonly used activated carbon, vermiculite, diatomaceous earth, water-absorbing polymer (sodium acrylate.
30 g of mixed powder obtained by mixing acrylamide copolymer) at a predetermined ratio, adding brine (10% saline solution) thereto, and stirring the mixture.
Then, 25 g of iron powder was placed in a glass container having an open upper mouth, stirred and mixed, and the exothermic temperature was measured at room temperature of 24 to 25 ° C. The results are shown in Table 3. The formulation of the mixed powder is as follows. Activated carbon 30% Vermiculite 5% Diatomaceous earth 15% Water absorbing polymer 1% Saline 5% Water 44%

[0024]

[Table 3] As shown in Table 3, the product of the present invention had a calorific value equal to or higher than that in the case of using the commonly used activated carbon. Further, the product of the present invention has a heat retaining property and was able to maintain a high temperature for a long time.

[0025]

INDUSTRIAL APPLICABILITY As described above, the activated carbon used in the heat-generating composition for a disposable body warmer of the present invention is a combustible substance and porous diatomaceous earth containing 65 to 97 W / W% of silicon oxide (SiO ₂ ), or further water-soluble. A high-porosity porosity with a fine-pore structure in the surface layer part and a relatively coarse porous structure in the surface part, which is a charcoal-based material obtained by wet-mixing the raw materials with a raw sugar and then firing and pulverizing the raw materials. Since the heat-generating composition has a high quality structure and is highly water-absorbing and water-retaining, the resulting heat-generating composition can smoothly oxidize the metal powder and efficiently maintain the heat-generating temperature for a long time. Further, the volume of the mixed powder can be reduced in the production of the exothermic composition, the mixing and filling at the time of production can be facilitated, and an inexpensive disposable warmer which is not bulky at the time of use and can be used easily can be provided.

Claims (6)

[Claims] 1. A heat-generating composition for a disposable body warmer containing metal powder, salts, water, activated carbon and a water retention agent as main components,
The activated carbon contains flammable materials and silicon oxide (SiO ₂ ) 6
Using a porous diatomaceous earth containing 5 to 97 W / W% as a raw material,
A heat-generating composition for a disposable body warmer, which is a carbide which is obtained by wet-mixing the raw materials and then firing and pulverizing the raw materials to give a granular or powdery form. 2. The activated carbon is made of a combustible material, a porous diatomaceous earth containing silicon oxide (SiO ₂ ) of 65 to 97 W / W%, and a water-soluble saccharide as a raw material, and the raw material is wet-mixed and then calcined. The heat-generating composition for a disposable body warmer according to claim 1, wherein the heat-generating composition is a pulverized and granulated or powdered carbide. 3. The combustible material is wood, pulp, paper, bamboo,
The heat-generating composition for a disposable body warmer according to claim 1 or 2, which is at least one kind of a natural product having a fibrous material such as a grain shell, a palm shell, and a coffee meal. 4. The heat-generating composition for a disposable body warmer according to claim 2, wherein the water-soluble saccharide is at least one kind of a polysaccharide, an oligosaccharide and a monosaccharide. 5. The raw material is diatomaceous earth for combustible substances.
The heat-generating composition for disposable body warmers according to any one of claims 1 to 4, wherein the heat-generating composition is contained in an amount of -30V / V%. 6. The material according to claim 2, wherein the raw material contains a water-soluble saccharide in an amount of 3 to 20 V / V% with respect to a combustible material.
6. The heat-generating composition for a disposable body warmer according to any one of items 1 to 5.