JP2006167253A - Heating implement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating implement where swelling which occurs after the finish of heating is prevented in the heating implement utilizing heat generated by oxidation of oxidizable metal. <P>SOLUTION: The heating implement 1 is constituted by housing a sheet-like heating material 2 containing the oxidizable metal in a housing 3 provided with a permeable section 3a partially having a water vapor permeability 200 to 2000 g/m<SP>2</SP>×24 hr. The water content of the heating material 2 after heating is 10 to 70 wt.%. The quantity of the oxidizable metal contained in the heating material 2 is 10 to 150 mg/cm<SP>2</SP>per the unit area of the housing. The faces opposing each other of the housing 3 and the sheet-like heating material 2 are partially connected, respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heating tool that uses heat generated by oxidation of an oxidizable metal, and more particularly to a heating tool that is prevented from being swollen after the end of heat generation.

The present applicant has previously proposed a water vapor generator utilizing the oxidation heat generated by an oxidizable metal (see Patent Document 1). This water vapor generating device is suitably used as a facial device for effectively cleaning the facial skin by opening pores with water vapor, or as a steam mask for moistening the throat and nasal mucosa by suction of water vapor. This water vapor generating device is a sheet-like heat generating structure in which an oxidizable metal is contained in a heating element containing portion formed by laminating a breathable sheet having air permeability and a non-breathable sheet having no air permeability. Has a body. The moisture permeability of the moisture permeable sheet in the heating element housing portion is set to a high value of 7000 to 15000 g / m ² · 24 h in view of the above-described use, and thereby a large amount of water vapor of 30 mg or more per 1 cm ² for 15 minutes. Is to be released. Also, the generation of water vapor is completed in a relatively short time of several minutes to one hour. The planar heating element during the generation of water vapor is slightly swollen due to an increase in internal pressure due to the generation of water vapor, but returns to its original flat shape after the generation of water vapor. Therefore, it is not necessary to pay special attention to the swelling of the planar heating element.

  The thing of patent document 2 is known as a heat retention tool aiming at preventing the burst by the internal pressure increase. This heat retaining device is formed by enclosing an inner bag in which a gel-like heat storage material is liquid-tightly enclosed in an outer bag. The sealing portion of the outer bag is provided with a non-adhesive portion and a ventilation portion that communicates the inside and the outside of the outer bag. Thereby, when the inner bag is ruptured, only the expansion gas is discharged to the outside through the ventilation portion while holding the heat storage material inside the outer bag. However, since this heat retaining device does not generate water vapor, it does not relate to an increase in internal pressure due to the generation of water vapor.

International Publication WO03 / 103444 Pamphlet JP 2002-113032 A

  It is an object of the present invention to provide a heating tool that can prevent swelling that occurs after the end of heat generation in a heating tool that uses heat generated by oxidation of an oxidizable metal.

INDUSTRIAL APPLICABILITY The present invention can generate heat by contact with air in a container provided with a breathable portion having a moisture permeability (JIS Z0208, 40 ° C., 90% RH) of 200 to 2000 g / m ² · 24 hr at least in part. Contains heat-generating materials containing oxidizable metals,
The exothermic material has a moisture content of 10 to 70% by weight after completion of exotherm, and the amount of the oxidizable metal contained in the exothermic material is 10 to 150 mg / cm ² per unit area of the container. A sheet-like material,
The object is achieved by providing a heating tool in which the opposing surfaces of the container and the sheet-like heating material are partially joined to each other.

In addition, the present invention can generate heat by contact with air in a container provided with a breathable portion having a moisture permeability (JIS Z0208, 40 ° C., 90% RH) of 200 to 2000 g / m ² · 24 hr at least in part. Contains heat-generating materials containing various oxidizable metals,
The exothermic material has a moisture content of 10 to 70% by weight after completion of exotherm, and the amount of the oxidizable metal contained in the exothermic material is 10 to 150 mg / cm ² per unit area of the container. A sheet-like material,
The container provides a heating tool in which opposing surfaces in a space in which the sheet-like heat generating material is stored are partially joined at a portion inside the peripheral edge.

Furthermore, the present invention can generate heat by contact with air in a container provided with a breathable portion having a moisture permeability (JIS Z0208, 40 ° C., 90% RH) of 200 to 2000 g / m 2 · 24 hr at least in part. Contains heat-generating materials containing oxidizable metals,
The exothermic material has a water content of 10 to 70% by weight after completion of exotherm, and the amount of the oxidizable metal contained in the exothermic material is 20 to 300 mg / cm ² per unit area of the container. A granular mixture,
The container is in the shape of a flat bag, and the container is a heating tool in which opposed faces in a space in which powder is stored are partially joined at a portion inside the peripheral edge. Is to provide.

  According to the present invention, the swelling of the heating tool after the generation of water vapor is effectively prevented, and the appearance impression is prevented from being lowered. Further, it is possible to prevent the user from feeling uneasy.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 shows a perspective view of an embodiment of the heating tool of the present invention. 2 is a cross-sectional view taken along line II-II in FIG. A heating tool 1 shown in FIG. 1 has a flat rectangular shape, and includes a heating sheet 2 as a sheet-shaped heating material and a housing 3 that houses the heating sheet 2. As will be described later, the heat generating sheet 2 is composed of a fiber sheet and is formed slightly smaller than the container 3. The container 3 has a flat bag shape, and a plurality of sheet materials are bonded together to form a hollow bag shape. The container 3 is a breathable part at least part of which has moisture permeability.

  The heat generating sheet 2 can generate heat by contact with air. For this purpose, the heating sheet 2 contains an oxidizable metal, a reaction accelerator, a fibrous material, an electrolyte, and water. When the heat generating sheet 2 comes into contact with air, an oxidation reaction of an oxidizable metal contained in the sheet 2 occurs and heat is generated. The water contained in the heat generating sheet 2 is heated by this heat to become water vapor having a predetermined temperature, and is discharged to the outside through the container 3. The water vapor is released from the breathable portion of the container 3 to the outside.

  The heating tool 1 of the present embodiment is used to give heat accompanied by the generation of water vapor to an object such as a human body (specific uses will be described later). The heating tool 1 of the present embodiment is characterized by a long duration of water vapor generation. It has been found that the heating tool 1 having such characteristics is applied to the lumbar region, shoulders, etc. of the human body to warm these parts, thereby promoting blood circulation throughout the body and increasing the peripheral temperature. It was also found that the temperature increase continued for several tens of minutes after the heating was stopped. In contrast to this, the above-mentioned effect is not observed even when the same part is heated under the same temperature condition with a general disposable body warmer with a small amount of water vapor. When the present inventors examined this reason, it turned out that the heat | fever accompanying generation | occurrence | production of water vapor | steam has high heat conductivity, and can raise the temperature of the deep part of a human body. It is presumed that the temperature in the deep part of the human body increases, thereby stimulating the thermal center, thereby expanding blood vessels and increasing blood flow, and increasing peripheral temperature. Therefore, the heating tool 1 is effective not only for improving the temperature and blood circulation of a part of the human body to which the heating tool 1 is applied, but also for improving the blood circulation of the whole body, increasing the peripheral temperature of the fingertips, and improving the cooling property.

In order to obtain a heating tool having the above-mentioned characteristics, that is, a heating tool having a long duration of water vapor generation, the amount of oxidizable metal used, the moisture content in the heating sheet 2 before heating, the breathable part of the container 3 It is important to control values such as moisture permeability. In the heating tool 1 in which these values are appropriately controlled, when this is applied to the human skin, the release of water vapor with a skin surface temperature of 38 ° C. or higher is preferably 3 hours or longer, more preferably 5 hours or longer. Maintained. Further, the cumulative amount of water vapor released 90 minutes after the heating sheet 2 comes into contact with air is preferably 1.4 to 7.0 mg / cm ² , more preferably 2.2 to 7.0 mg / cm ^2. (This is hereinafter referred to as a water vapor release characteristic). The skin surface temperature refers to the temperature of the skin surface measured by a contact thermometer, for example, a thermocouple.

The cumulative amount of water vapor released in the water vapor release characteristic is measured by the following method.
In a closed system with a volume of 54,000 cm ³ (length 30 cm × width 50 cm × depth 36 cm) at a temperature of 20 ° C. and a humidity of 40% RH, the heating tool 1 is left standing and heated so that water vapor can evaporate. And the humidity of the air in the said closed system is measured with a hygrometer, and the amount of water vapor generated after the start of heat generation is obtained. The integrated value after 90 minutes is taken as the integrated release amount.

  When steam is generated using the heating tool having the above-described water vapor release characteristics and a predetermined time elapses, the temperature of the heating tool gradually decreases, and the amount of water vapor generated decreases. When the time further elapses, the heat generation ends and the generation of water vapor stops. When the heating tool 1 is left as it is, a phenomenon in which the heating tool 1 gradually expands is observed. This phenomenon is a phenomenon that has not been observed in the steam generator described in Patent Document 1 described in the section of the prior art. When the present inventors examined the cause of this phenomenon, this phenomenon does not occur in a steam generator of a type that releases a large amount of water vapor in a short time, but it does not occur for a long time as in the present invention. Was found to be a phenomenon peculiar to the type of sustained release type. The cause of this phenomenon is that the amount of oxidizable metal enumerated above as the main factors for obtaining a heating tool with a long duration of water vapor generation, the moisture content in the heating sheet 2 before heating, and accommodation It has also been found that it is closely related to moisture permeability and the like in the breathable part of the body 3. In particular, it has been found that the moisture content remaining in the heat generating sheet 2 after heat generation is closely related to the moisture permeability in the air-permeable portion of the container 3.

  Specifically, the greater the water content remaining in the heat generating sheet 2 after the end of heat generation, the more noticeably the swelling of the heating tool 1 becomes. In particular, when the moisture content of the heat generating sheet 2 after the heat generation is 10 to 70% by weight, particularly 20 to 70% by weight, the swell of the heating tool 1 becomes remarkable. When the moisture content of the heat generating sheet 2 after heat generation is less than 10% by weight, since the amount of water vapor staying in the container 3 is small, the container 3 does not swell or even if it swells, there is no problem. Level and bulges wither in a short time. The moisture content of the heat generating sheet 2 can be obtained from the remaining heating amount of the heat generating sheet 2. Specifically, the difference between the weight of the heat generating sheet 2 after the end of heat generation and the remaining amount of heating is divided by the weight of the heat generating sheet 2 after the end of heat generation and multiplied by 100 to obtain the moisture content (%) of the heat generating sheet 2 It becomes. The heating conditions are 105 ° C. and 40 minutes. The heating atmosphere is nitrogen gas. The weight of the sample is 3 to 10 g. The term “after heat generation” means the time when the surface temperature of the heat generating sheet 2 becomes room temperature or 30 ° C. or less.

Further, the moisture permeability (JIS Z0208, 40 ° C., 90% RH) of the breathable part in the container 3 is 200 to 2000 g / m ² · 24 hr, particularly 300 to 2000 g / m ² · 24 hr, especially 500 to 1200 g / m ^2. -The swelling of the heating tool 1 is observed when it is 24 hours. When the moisture permeability is 2000 g / m ² · 24 hr or less, the water vapor staying in the container 3 is not sufficiently released to the outside of the container 3, so that swelling occurs, but the desired temperature can be maintained sufficiently. it can. When the moisture permeability is 200 g / m ² · 24 hr or more, the heating tool 1 swells, but a desired water vapor release characteristic can be obtained.

Furthermore, the swelling of the container 3 is also related to the amount of oxidizable metal contained in the heat generating sheet 2. Specifically, the amount of oxidizable metal in the container of 30～600Cm ² is a unit area per 10-150 mg / cm ² of the container, preferably 25~85mg / cm ^2. Although the shape of the container depends on its specific application, a flat bag shape is generally used, and the area of the shape projected onto the maximum surface is defined as the area of the container. When the amount of the oxidizable metal is more than 150 mg / cm ² , the desired temperature is maintained more than necessary, which causes a problem in terms of safety in use. On the other hand, if the amount of the oxidizable metal is less than 10 mg / cm ² , the calorific value is not sufficient and the desired temperature cannot be maintained sufficiently.

The inventors presume that the principle that the heating tool 1 swells is as follows. As shown in FIG. 3A, at least one surface of the container is a moisture permeable sheet. Through this moisture permeable sheet, the gas moves inside and outside due to the partial pressure difference of the gas, and the pressure difference is relaxed. The moisture permeability is as described above, and since the relaxation time has a finite time in this range, it is considered that the following phenomenon occurs. In the heating tool 1 in which the generation of water vapor is completed and the temperature is lowered to around room temperature, a large amount of water that has not been volatilized as water vapor remains in the heat generating sheet 2. Therefore, the water vapor partial pressure Pa _H2O in the container 3 is substantially equal to the saturated water vapor pressure. On the other hand, the water vapor partial pressure Pb _H2O outside the container 3 is usually lower than the saturated water vapor pressure. Apart from the water vapor partial pressure, the air partial pressures Pa _AIR and Pb _AIR in the container 3 are substantially the same with respect to the air partial pressure. That is, Pa _H2O > Pb _H2O and Pa _AIR ≈Pb _AIR . Therefore, when the pressure inside and outside the container 3 is compared, the pressure inside the container 3 is higher by the amount of Pa _H2O -Pb _H2O . As a result, the action of lowering the water vapor partial pressure Pa _H2O in the container 3 works and the container 3 swells. In particular, in an environment where the water vapor partial pressure Pa _H2O outside the container 3 is low, for example, in an environment where the air is dry, such as in winter, a large difference occurs in the water vapor partial pressure inside and outside the container 3. Swelling becomes prominent.

FIG. 3B shows a state where the container 3 is swollen by this action. In this state, the water vapor partial pressure Pa _H2O in the container 3 is reduced by the amount of expansion of the container 3, and substantially coincides with the water vapor partial pressure Pb _H2O outside the container 3. On the other hand, with respect to the air partial pressure, the air partial pressure Pa _AIR in the container 3 is reduced by the amount of expansion of the container 3. There is no change in the air partial pressure Pb _AIR outside the container 3. That is, Pa _H2O ≈Pb _H2O and Pa _AIR <Pb _AIR . Accordingly, the action of balancing the air partial pressure inside and outside the container 3 works, and air is taken into the container 3 from the outside of the container 3.

FIG. 3C shows a state in which air is taken into the housing 3 from the outside of the housing 3. In this state, Pa _H2O ≈Pb _H2O and Pa _AIR ≈Pb _AIR . This condition is temporary and does not last for a long time. The reason is that a large amount of water still remains in the heat generating sheet 2 in the container 3. Specifically, water vapor is generated from the remaining water, and the water vapor partial pressure Pa _H2O in the container 3 rises and becomes higher than the water vapor partial pressure Pb _H2O outside the container 3 (FIG. 3 (d)). As a result, the state returns to the state of Pa _H2O > Pb _H2O and Pa _AIR ≈Pb _AIR , that is, the state shown in FIG. This state change occurs repeatedly, and the heating tool 1 swells to the limit.

  While the heat generating sheet 2 generates heat and water vapor is generated, the water vapor partial pressure in the container 3 rises, but oxygen in the container 3 is consumed by oxidation and the partial pressure is substantially zero. Therefore, the total pressure inside the container 3 is lower than the total pressure outside the container 3, that is, atmospheric pressure (that is, negative pressure), and the heating element 3 does not swell.

  As is clear from the above description, the swelling of the heating tool 1 after the generation of water vapor is caused by the magnitude of the partial pressure of water vapor in the container 3, so that the swelling itself has a health hazard to the human body. Absent. However, since the heating tool 1 swells after use, there is a risk that the user may feel useless anxiety that gas or the like that causes health hazards has been generated. In addition, there is an adverse effect that the impression of appearance is reduced due to the expansion of the heating tool 1. Therefore, in the heating tool 1 of the present embodiment, the following measures are taken to prevent the heating tool 1 from expanding after use.

  In the heating tool 1 of this embodiment, as shown in FIG.1 and FIG.2, the moisture-permeable sheet | seat 3a and the heat generating sheet 2 in the container 3 are joined partially. Further, the hardly moisture permeable sheet 3b and the heat generating sheet 2 are partially joined. Specifically, the moisture-permeable sheet 3a and the heat generating sheet 2 are point-joined at positions J1 and J2 that roughly divide the vertical center line (center line along the long side direction) L shown in FIG. Similarly, the hardly moisture permeable sheet 3b and the heat generating sheet 2 are also point-joined at positions J1 and J2. In FIG. 2, the junction point is denoted by reference numeral 7. Since the moisture-permeable sheet 3a and the hardly moisture-permeable sheet 3b and the heat generating sheet 2 are joined at the joining point 7, even if water vapor is generated from the heating tool 1 after the heat generation is finished, the swelling is prevented. As a result of the study by the present inventors, the moisture-permeable sheet 3a, the hardly moisture-permeable sheet 3b, and the heat generating sheet 2 are prevented from being swelled by merely spot-bonding with a very small joining area of only two places as in the present embodiment. It turned out to be sufficient. This is because the partial pressure of water vapor when the heating tool 1 starts to expand due to water vapor is small.

It is preferable that the bonding area of each bonding portion 7 is at least 0.7 mm ² or more, particularly 1 mm ² or more, since the swelling of the heating tool 1 can be reliably prevented. Although there is no restriction | limiting in particular in the upper limit of a joining area, When the joining area is too large, it exists in the tendency for the softness | flexibility of the heat generating tool 1 to be lost. In addition, the exothermic reaction may be inhibited. Furthermore, the cost of joining becomes high and it is not economical. For these reasons, the upper limit of the bonding area of each bonding portion 7 is preferably 500 mm ² , particularly 100 mm ² . Moreover, the sum total of the junction area of the junction part 7 is 0.005 to 13%, especially 0.008 to 1.5% with respect to the area (area in plan view) of the heating tool 1 excluding the peripheral junction part. It is preferable that

  From the viewpoint of effectively preventing the heating tool 1 from bulging, the bonding strength at the joint 7 is preferably 60 gf or more, particularly preferably 100 gf or more. The adhesive strength is measured using a tensile tester. The tensile speed is 100 mm / min.

  There is no restriction | limiting in particular in the joining means of the moisture-permeable sheet | seat 3a and the heat generating sheet 2, All means which can join both reliably can be used. A simple means includes bonding with an adhesive. In this case, as described above, since the heat generating sheet 2 contains a large amount of moisture, it is preferable that the adhesive to be used has high water resistance. As such an adhesive, for example, a hot melt pressure-sensitive adhesive can be used.

  As shown in FIG. 2, the container 3 is flat because the peripheral edges of the moisture permeable sheet 3 a and the hardly permeable or non-permeable sheet (hereinafter collectively referred to as a hardly permeable sheet) 3 b are joined to each other. It is formed in a bag shape. That is, one side of the container 3 has the moisture-permeable sheet 3a, and the other side has the hardly moisture-permeable sheet 3b. The moisture permeable sheet 3a allows water vapor generated from the heat generating sheet 2 to pass through. However, the hardly moisture-permeable sheet 3b is difficult to pass water vapor or not. That is, water vapor is released to the outside only from one side of the container 3, that is, the moisture permeable sheet 3 a side.

Area of the moisture vapor permeable sheet 3a except for the junction of the perimeter, depending on the specific application of the heating tool 1 generally 30～600Cm ^2, in particular 40～400Cm ^2, it is preferred that especially 48~250c ■.

  As the moisture permeable sheet 3a, a film that allows water vapor and air to permeate but hardly permeates water is used. Examples of the moisture permeable sheet include a fine pore type formed by kneading and stretching calcium carbonate, and a paper making type by rolling fibers. The fine pore type is mainly used for reasons such as denseness, content leakage prevention, and temperature control. Examples of the microporous moisture permeable sheet include a polyolefin film having micropores. Since the water vapor is released to the outside through the moisture permeable sheet 3a as described above, the heating tool 1 of the present embodiment is mounted so that the moisture permeable sheet 3a side faces the human body. Therefore, from the viewpoint of enhancing the wearing feeling, as shown in FIGS. 1 and 2, a non-woven fabric 3c, which is a sheet material having a good texture, is disposed on the outer surface of the moisture-permeable sheet 3a. Accordingly, the nonwoven fabric 3c faces the body when the heating tool 1 is used. The moisture-permeable sheet 3a and the nonwoven fabric 3c may be joined at their peripheral edges, or may be partially bonded within the sheet surface.

  On the other hand, as the hardly moisture-permeable sheet 3b, a film that hardly allows water vapor and water to pass therethrough, for example, a polyolefin film or a polyester film that does not have micropores is used. As shown in FIG. 2, a nonwoven fabric 3d is laminated on the outer surface of the moisture-impermeable sheet 3b in order to enhance the texture of the heating tool 1. An adhesive layer (not shown) may be formed on the outer surface of the nonwoven fabric 3d as necessary. In that case, the adhesive layer is protected with a protective release paper (not shown) until the heating tool 1 is used.

  As described above, the heat generating sheet 2 includes an oxidizable metal, a reaction accelerator, a fibrous material, and an electrolyte, and is in a water-containing state. Specifically, the heat generating sheet 2 of the present embodiment is configured by containing an electrolyte aqueous solution in a molded sheet containing an oxidizable metal, a reaction accelerator, and a fibrous material. As a result of studies by the present inventors, among these various materials, materials that greatly affect the water vapor release characteristics of the heating tool 1 are oxidizable metals, reaction accelerators, and fibrous materials contained in the molded sheet. There was found. Specifically, the amount of the oxidizable metal contained in the molded sheet is preferably 60 to 90% by weight, more preferably 70 to 85% by weight, and the amount of the reaction accelerator is preferably 5 to 25% by weight, more preferably. It is important that the amount of the fibrous material is 8 to 15% by weight, preferably 5 to 35% by weight, and more preferably 8 to 20% by weight. If the amount of these materials is in the above range, desired water vapor release characteristics and temperature duration can be expected. As will be described later, since the molded sheet is preferably obtained by papermaking, it contains 5% by weight or less of moisture in the state after the drying step in the papermaking process.

  The weight ratio of the reaction accelerator and the fibrous material to the oxidizable metal also affects the water vapor release characteristics of the heating tool 1. Specifically, in the heat generating sheet 2, the weight ratio of the reaction accelerator to the oxidizable metal is preferably 0.08 to 0.3, and more preferably 0.11 to 0.25. The weight ratio of the fibrous material to the oxidizable metal is preferably 0.08 to 0.43, more preferably 0.09 to 0.29. Within these ranges, it is easy to improve the skin surface temperature to 38 ° C. or higher and to obtain a desired amount of water vapor, and after opening the pillow bag containing the heating tool 1, to the target temperature. It is easy to provide water vapor at an appropriate temperature for 3 hours or longer.

  Other important factors that affect the water vapor release characteristics of the heating tool 1 include the concentration of the aqueous electrolyte solution in the heating sheet 2 and the amount of the aqueous electrolyte solution added. Specifically, the concentration of the aqueous electrolyte solution in the heat generating sheet 2 is preferably 1 to 15% by weight, more preferably 2 to 10% by weight. If the concentration of the aqueous electrolyte solution is within this range, an economically desired temperature can be obtained. The electrolyte aqueous solution is preferably added in an amount of 30 to 80 parts by weight, more preferably 40 to 70 parts by weight, based on 100 parts by weight of the molded sheet. Within this range, the desired temperature can be maintained and a water vapor generation amount can be obtained.

  In order to make the heat generation characteristic of the heat generation sheet 2 desirable, it is also preferable to use a plurality of heat generation sheets 2 in a stacked manner. In this case, in order to prevent the positional deviation between the heat generating sheets 2 during use of the heat generating tool 1, it is preferable to integrate the heat generating sheets 2 by embossing. Further, it is possible to prevent the positional deviation from occurring by making the above-described holes and cuts in the heat generating sheet 2.

  The details of each material included in the heat generating sheet 2 will be described. Examples of the oxidizable metal include powders and fibers of iron, aluminum, zinc, manganese, magnesium, calcium, and the like. Among these, iron powder is preferably used in terms of handleability, safety, and manufacturing cost. When the oxidizable metal is a powder, the particle size is preferably 0.1 to 300 μm because the fixing property to the fibrous material and the control of the reaction are good. For the same reason, it is also preferable to use a material having a particle size of 0.1 to 150 μm containing 50% by weight or more.

  As the reaction accelerator, it is preferable to use a reaction accelerator that functions as a water retention agent and also has a function as an oxygen retention / supply agent for the oxidizable metal. For example, activated carbon (coconut shell charcoal, charcoal powder, calendar bituminous coal, peat, lignite), carbon black, acetylene black, graphite, zeolite, perlite, vermiculite, silica and the like can be mentioned. Among these, activated carbon is preferably used because it has water retention ability, oxygen supply ability, and catalytic ability. The particle size of the reaction accelerator is preferably 0.1 to 500 μm from the viewpoint that it can effectively contact the oxidizable metal. For the same reason, it is also preferable to use a material containing 50% by weight or more of 0.1 to 200 μm.

  As the fibrous material, a natural or synthetic fibrous material can be used without any particular limitation. Examples of natural fibers include cotton, kabok, wood pulp, non-wood pulp, peanut protein fiber, corn protein fiber, soy protein fiber, mannan fiber, rubber fiber, hemp, manila hemp, sisal hemp, New Zealand hemp, rabu hemp, Plant fibers such as eggplant, igusa and straw are listed. Further, animal fibers such as wool, goat hair, mohair, cashmere, alkapa, Angola, camel, vicuuna, silk, feathers, down, feather, algin fiber, chitin fiber, and casein fiber can be mentioned. Furthermore, mineral fibers, such as asbestos, are mentioned. On the other hand, examples of the synthetic fibrous material include semi-synthetic fibers such as rayon, viscose rayon, cupra, acetate, triacetate, oxide acetate, promix, chlorinated rubber, and hydrochloric acid rubber. Moreover, synthetic polymer fibers such as polyester such as nylon, aramid, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, and polyethylene terephthalate, polyacrylonitrile, acrylic, polyethylene, polypropylene, polystyrene, and polyurethane can be used. Furthermore, metal fiber, carbon fiber, glass fiber, etc. can also be used. Moreover, the collection | recovery reuse goods of these fibers can also be used. Among these, wood pulp, cotton, and polyester are preferably used from the viewpoints of fixability with an oxidizable metal and a reaction accelerator, flexibility of the heat generating sheet 2, oxygen permeability, production cost, and the like. The fibrous material preferably has an average fiber length of 0.1 to 50 mm, particularly 0.2 to 20 mm, from the viewpoint of securing the strength of the heat generating sheet 2 and the water dispersibility of the fibrous material.

  The fibrous material preferably has a CSF (Canadian standard drainage test method JIS P8121) of 600 ml or less, more preferably 450 ml or less. Thereby, the fixing property between the fibrous material and the oxidizable metal becomes good, and the heat generating property of the heat generating sheet 2 can be made good. Moreover, it becomes easy to adjust the tearing length described later within a range described later, and as a result, the oxidizable metal can be removed from the heat generating sheet 2 and the mechanical strength of the heat generating sheet 2 can be appropriately maintained. it can. The lower the CSF of the fibrous material, the better. However, when only normal pulp fiber is used as a fibrous material and papermaking is performed as a raw material, when the component ratio other than the fibrous material is low, if the CSF is less than 100 ml, the drainage tends to deteriorate, and dehydration Becomes difficult to obtain a heat-generating sheet having a uniform thickness. Also, molding defects such as blister breakage may occur during drying. On the other hand, in the heat generating sheet 2, since the ratio of components other than the fibrous material is relatively high, the heat generating sheet 2 having good drainage and uniform thickness can be obtained. Moreover, since the fibril increases as the CSF decreases, the fixability between the fibrous material and components other than the fibrous material is improved, and a high sheet strength can be obtained. Adjustment of the CSF of the fibrous material can be performed by a beating process or the like. CSF may be adjusted by mixing low and high CSF fibers.

  Examples of the electrolyte include alkali metal, alkaline earth metal or transition metal sulfates, halides, and the like. Among these, chlorides of alkali metals, alkaline earth metals or transition metals are preferably used from the viewpoint of excellent chemical stability and production cost, especially sodium chloride, potassium chloride, calcium chloride, magnesium chloride, ferrous chloride. Ferric chloride is preferably used.

  Additives usually used in papermaking, such as a flocculant, a sizing agent, a colorant, a paper strength enhancer, a yield improver, a filler, a thickener, a pH control agent, a bulking agent, etc. A thing can also be added without a restriction | limiting in particular.

  There is no restriction | limiting in particular in the manufacturing method of the heat generating sheet 2. FIG. Since the exothermic sheet is formed by adding an aqueous electrolyte solution to a molded sheet containing an oxidizable metal, a reaction accelerator and a fibrous material, it first contains an oxidizable metal, a reaction accelerator and a fibrous material. A heat generating sheet is obtained by forming a molded sheet and adding an aqueous electrolyte solution to the molded sheet. For the production of the molded sheet, for example, a wet papermaking method described in Japanese Patent Application Laid-Open No. 2003-102761 or an extrusion method using a die coater according to the previous application of the present applicant can be used. In particular, it is preferable to use a wet papermaking method from the viewpoint of manufacturing cost and productivity. When performing the wet papermaking method, a circular paper machine, a long paper machine, a short paper machine, a twin wire paper machine, or the like can be used. The slurry used for papermaking contains an oxidizable metal, a reaction accelerator, a fibrous material, and water, and its concentration is 0.05 to 10% by weight, particularly 0.1 to 2% by weight. Is preferred.

  From the point which maintains the form after papermaking, and the point which maintains mechanical strength, the molded sheet obtained by papermaking has a moisture content (weight moisture content, the same shall apply hereinafter) until 70% or less, particularly 60% or less. It is preferable to dehydrate. Examples of the method for dewatering the formed sheet after papermaking include dewatering by suction, a method of dehydrating by blowing pressurized air, a method of dehydrating by pressing with a pressure roll or a pressure plate, and the like.

  The dehydrated molded sheet is preferably dried by heat drying. The heating and drying temperature is preferably 60 to 300 ° C, particularly 80 to 250 ° C. The moisture content of the molded sheet after drying is more preferably 20% or less, particularly 10% or less. The dehydration and / or drying of the molded sheet is preferably performed in an inert gas atmosphere from the viewpoint of suppressing oxidation of the oxidizable metal. However, since the molded sheet does not contain an electrolyte serving as an oxidation aid, it can be molded in a normal air atmosphere as necessary. This is advantageous because the production equipment can be simplified. The molded sheet after drying contains an oxidizable metal, a reaction accelerator and a fibrous material, preferably 60 to 90% by weight of the oxidizable metal, more preferably 70 to 85% by weight, and a reaction accelerator. 5 to 25% by weight, more preferably 8 to 15% by weight, and 5 to 35% by weight, more preferably 8 to 20% by weight of fibrous material.

The molded sheet thus obtained (that is, the exothermic sheet 2 in a state before being hydrated) has a thickness of 0.1 mm to 2 mm, particularly 0.15 to 1.5 mm. It is preferable in that the molded sheet becomes flexible while maintaining the desired strength, and the heating tool 1 can be easily fitted to the application site of the body. Molded sheet for the same reason, it is preferable that the basis weight of 10 to 1000 g / m ^2, more preferably from 50~600g / m ^2, and still more preferably from 100 to 500 g / m ^2.

The molded sheets may be used by overlapping a plurality of sheets as they are, or may be used by stacking a plurality of molded sheets folded and folded. The weight ratio of the molded sheet with respect to the area of the heating tool 1 is preferably 0.03 g / cm ^{2 to} 0.17 g from the viewpoint that desired temperature sustainability can be achieved, fit is good, and manufacturing problems are unlikely to occur. / cm ^2, more preferably from ^{0.06g / cm 2 ~0.14g / cm 2} . For the same reason, the ratio of the weight per unit area of the oxidizable metal is preferably ^{0.02g / cm 2 ~0.14g / cm 2} , more preferably 0.04g / cm ² ~0.12g / cm ² .

  Further, the molded sheet has a breaking length (JIS P8113, hereinafter referred to as a value measured by this method when referred to as the breaking length) of 200 to 4000 m, particularly 200 to 3000 m, when the heating tool 1 is used. This is preferable from the viewpoint of preventing the oxidizable metal from falling off the sheet and maintaining the flexibility of the molded sheet. A molded sheet having such a tearing length can be easily obtained by using the fibrous material having the CSF described above.

  The molded sheet thus obtained contains an aqueous electrolyte solution to obtain a heat generating sheet 2. This step is preferably performed in an inert gas atmosphere such as nitrogen or argon. In order to contain the electrolyte aqueous solution, for example, a method by directly discharging from a nozzle, a spray coating method, a method of coating with a brush, a method of immersing in an electrolyte aqueous solution, a gravure coating method, a reverse coating method, a doctor blade method and the like can be mentioned. . The concentration of the electrolyte in the aqueous electrolyte solution and the applied amount of the aqueous electrolyte solution are adjusted so that the amount of the electrolyte and the water content in the resulting heat generating sheet 2 are in the ranges described above.

The obtained heat generating sheet 2 is housed in the housing 3 to form the heat generating tool 1. The heating tool 1 is preferably sealed in a packaging bag made of an oxygen-barrier material to form a packaging bag containing a heating tool as the final product. When the heating tool 1 is used, by removing the heating tool 1 from the packaging bag, the oxidizable metal contained in the heating tool 1 reacts with oxygen in the air, heat generation starts and water vapor is generated. As an oxygen barrier material, for example, its oxygen permeability coefficient (ASTM D3985) is 10 cm ³ · mm / (m ² · d · MPa) or less, particularly 2 cm ³ · mm / (m ² · d · MPa) or less. Such a thing is preferable. Specific examples include ethylene-vinyl alcohol copolymer and polyacrylonitrile.

  For example, the heating tool 1 of the present embodiment is used by being worn on the waist or shoulders of a human body, thereby improving blood circulation of the whole body or increasing peripheral temperature of fingertips and the like. An example of the usage pattern of the heating tool 1 is shown in FIG. The heating tool 1 is used by being fixed to a belt-like fitter 5 for body wearing. The center of the fitter 5 is wide, and is slightly narrower toward each tip. A pocket (not shown) for housing the heating tool 1 is formed at the center of the fitter 5. One end portion is provided with a fastening portion such as a hook-and-loop fastener. The fastening part is fastened to the other tip part. The fitter 5 is formed of a stretchable material in consideration of fit to the user's body.

  When using the heating tool 1, first, the heating tool 1 is accommodated in the pocket of the fitter 5. At this time, the moisture permeable film side in the heating tool 1, that is, the side having air permeability and moisture permeability is set to face the user's body. Then, as shown in FIG. 5, the fitter 5 is wound around the waist so that the heating tool 1 contacts the waist of the user. The both ends of the fitter 5 are overlapped on the user's abdomen, and a fastener attached to one tip is fastened to the other tip to fix the fitter 5. Since the contact surface to the user in the heating tool 1 is composed of the non-woven fabric 3c (see FIG. 2) which is a sheet material having a good texture, the user is not uncomfortable during wearing. Thus, the desired effect is exhibited by giving water vapor | steam of predetermined temperature to a user for predetermined time (for example, about 3 to 5 hours).

  Specifically, when the heating tool 1 is attached to the human body, not only the surface temperature of the application site but also the deep temperature of the human body can be increased. As a result, the blood flow throughout the body increases and the temperature at the application site increases, as well as the peripheral temperature of the fingertips and the like. In addition, there is an effect of keeping the peripheral temperature warm. Therefore, the heating tool 1 has effects such as blood circulation promotion, muscle fatigue, muscle stiffness and muscle pain relief, coldness relief, and neuralgia relief. Furthermore, the heating tool 1 is soft and fits the application site of the body, and does not feel uncomfortable.

  The deep part temperature is considered to be a temperature corresponding to a tissue temperature having a depth of 10 mm from the epidermis. When the rise in the deep part temperature is 0.2 ° C. or less, the surface temperature rise of the fingertip is not remarkably confirmed, whereas when the rise in the deep part temperature is 0.3 ° C. or more, the rise or maintenance of the fingertip surface temperature is confirmed. . In addition, regarding the warming of the fingertips and the warming of the whole body, an increase in the deep temperature is not realized at 0.2 ° C. or less, but is noticeable when the increase in the deep temperature is 0.3 ° C. or more.

  Next, second to fourth embodiments of the present invention will be described with reference to FIGS. Regarding the points that are not particularly described with respect to these embodiments, the description of the above-described embodiments is applied as appropriate. 6 to 8, the same members as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  The heating tool 1 of the embodiment shown in FIG. 6 is different from the heating tool of the embodiment described above in that the moisture-permeable sheet 3a and the hardly moisture-permeable sheet 3b and the heating sheet 2 are not joined. Instead of this, in the present embodiment, the opposing surfaces in the space in which the heat generating sheet 2 is accommodated are partially joined to each other at a site inside the peripheral portion of the accommodating body 3. Specifically, the central portion of the heat generating sheet 2 is cut out to form a circular hole 2a, and the moisture permeable sheet 3a and the hardly moisture permeable sheet 3b facing each other through the hole 2a are mutually connected at the joint point 7. It is point joined. According to the present embodiment, in addition to preventing the heating tool 1 from being swollen, the positional deviation of the heat generating sheet 2 is more difficult to occur than in the previously described embodiment.

  In the heating tool 1 of the embodiment shown in FIG. 7, the moisture-permeable sheet 3 a and the hardly moisture-permeable sheet 3 b are joined to each other in the same manner as the heating tool of the embodiment shown in FIG. 6. The difference between the present embodiment and the embodiment shown in FIG. 6 is that the heat generating sheet used in the present embodiment has a size obtained by dividing the heat generating sheet of the embodiment shown in FIG. 6 into four parts. It is a point. As shown in FIG. 7, in this embodiment, four small heat generating sheets represented by reference numerals 2a to 2d are used. And between the small exothermic sheet | seats adjacent to each other, the moisture-permeable sheet 3a and the hardly moisture-permeable sheet 3b are point-joined with each other.

  Specifically, the joining point 7a at the position between the adjacent small heating sheets 2a and 2c, the joining point 7b at the position between the small heating sheets 2b and 2d, the joining point 7c at the position between the small heating sheets 2a and 2b, small The moisture permeable sheet 3a and the hardly moisture permeable sheet 3b are spot-joined at four places of the joining point 7d at the position between the heat generating sheets 2c and 2d. Each joining point is located at the center of the length or width of the small heat generating sheet. By disposing each joining point in this way, the positional deviation of each small heat generating sheet is prevented. Furthermore, in the heating tool 1 of this embodiment, since the number of junction points is larger than that of the heating tool described so far, the swelling of the heating tool can be prevented more effectively.

  The heating tool 1 of the embodiment shown in FIG. 8 is different from the heating tool of each embodiment described so far in the heating material. In the heating tool of each embodiment described so far, the heating sheet 2 formed by a wet papermaking method or an extrusion method is used as a heating material containing an oxidizable metal. In the heating tool 1, a granular mixture containing an oxidizable metal, a reaction accelerator, a fibrous material or a water retention agent, an electrolyte and water is used as a heat generating material. In the present embodiment, as shown in FIG. 8, opposed surfaces in a space in which a heat generating material made of a granular mixture is accommodated in a portion inside the peripheral portion of the flat bag-shaped container 3. Partially spot-bonded. Specifically, the moisture-permeable sheet 3a and the hardly moisture-permeable sheet 3b are joined. As a means for joining, the above-described joining using an adhesive or thermal fusion can be used.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the embodiment shown in FIGS. 1 and 2, the moisture permeable sheet 3a and the hardly moisture permeable sheet 3b and the heat generating sheet 2 are joined, but the moisture permeable sheet 3a and the hardly moisture permeable material are limited to the extent that swelling can be prevented. Only one of the sheets 3b and the heat generating sheet 2 may be joined. Further, in the embodiment shown in FIGS. 1 and 2, the position where the moisture permeable sheet 3a and the hardly moisture permeable sheet 3b are joined to the heat generating sheet 2 is the same position, but instead of this, the moisture permeable sheet 3a and the heat generating sheet 3b are heated. The bonding position with the sheet 2 may be shifted from the bonding position between the moisture-impermeable sheet 3 b and the heat generating sheet 2.

  In each of the above embodiments, the sheets are joined to each other by point joining. However, joining is not limited thereto, and may be linear (for example, linear or curved), a combination of point joining and linear joining, or the like. It may be.

  In each of the above-described embodiments, the container 3 is composed of a moisture-permeable sheet 3a and a hardly moisture-permeable sheet 3b bonded together in a bag shape, but instead of this, two moisture-permeable sheets are used. You may use the container which joined the periphery of each and formed in the bag shape. In this case, water vapor is generated from each surface of the container.

  The heating tool of each of the above embodiments is preferably used by being attached to the lumbar region or shoulder of the human body from the viewpoint of an increase in deep temperature, but other parts of the human body such as the neck, shoulder, back, abdomen, You may apply to an elbow, a knee, etc. Furthermore, the present invention may be applied to skin care applications such as facial and body washing, sterilization, and makeup removal. In addition to being worn on the human body, combined with various functional agents such as cleaning / sterilization, sustained release of wax, fragrance, and deodorization, flooring, folding, around the range, house care applications such as ventilation fans, washing of cars, etc. It can also be applied to car care applications such as.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Example 1]
<Slurry blending>
・ Oxidizable metal: iron powder, manufactured by Dowa Iron Mining Co., Ltd., trade name “RKH”, 150 g
-Fibrous material: Pulp fiber (NBKP, manufactured by Schina Co., Ltd., trade name “Skina”, average fiber length = 2.1 mm), 30 g
-Reaction accelerator: activated carbon, manufactured by Nippon Enviro Chemicals Co., Ltd., trade name “Carborafyn”), 20 g
Flocculant: sodium carboxymethyl cellulose (Daiichi Kogyo Seiyaku Co., Ltd., trade name “Serogen” WS-C) 0.5 g, and polyamide epichlorohydrin resin (Seiko PMC Co., Ltd., trade name “WS4020”) 0.5g
・ Water: Industrial water, 99800g

<Paper making conditions>
Using the slurry, paper was made at a line speed of 7 m / min with a slanted short net paper machine to produce a wet shaped sheet.

<Dehydration and drying conditions>
It was sandwiched with felt and dehydrated under pressure, passed through a heating roll at 120 ° C. at a line speed of 7 m / min, and dried until the water content became 5% by weight or less to obtain a molded sheet.

<Electrolytic aqueous solution addition conditions>
After stacking four obtained molded sheets, a predetermined amount of the following electrolyte aqueous solution was impregnated to prepare a heat generating sheet. Table 1 shows the moisture content of the exothermic sheet and the blending ratio of each component in the exothermic sheet.

<Electrolyte>
Electrolyte: Purified salt (NaCl)
Water: Industrial water Electrolyte concentration: 5% by weight

<Containment in container>
1 and FIG. 1 using a moisture-permeable film made of polyethylene containing calcium carbonate (moisture permeability of 800 g / m ² · 24 hr, air permeability of 10000 s / 100 cm ³ ), a low moisture-permeable film made of linear low density polyethylene, and an air-through nonwoven fabric. A rectangular bag-shaped container (120 mm × 100 mm) shown in FIG. The exothermic sheet was accommodated in this. In housing, the moisture permeable film and the hardly moisture permeable film and the heat generating sheet were point-joined at two points with a hot-melt adhesive. The joining position was as shown in FIG. The joint area of each joint was 4.9 cm ² . The bond strength of the joint was 100 gf.

[Example 2]
Using the raw material of the heat generating sheet used in Example 1, a heat generating material made of a granular mixture was obtained without making the raw material. Separately from this, a container similar to the container used in Example 1 was used, and a moisture-permeable film and a hardly moisture-permeable film were point-joined at one location with a hot melt adhesive. The joining position was the center of the sheet. The joint area of the joint was 7.5 cm ² . The bond strength of the joint was 200 gf. The container was then filled with the granular mixture and sealed. In this way, a heating tool was obtained.

[Comparative Example 1]
A heating tool was obtained in the same manner as in Example 1 except that the moisture permeable film and the heat generating sheet were bonded to each other in Example 1.

[Performance evaluation]
About the heating tool obtained by each Example and each comparative example, the water | moisture content of the heat generating sheet after completion | finish of heat_generation | fever was measured by the method described previously. The results are shown in Table 1. Moreover, the swelling of the heating tool after the end of heat generation and the state during heat generation were observed. Furthermore, the maximum reached temperature of the heating tool and the cumulative amount of water vapor released until 180 minutes after contact with air were measured. The results are shown in Table 2. The maximum temperature reached here was measured according to JIS S4100. The maximum temperature is a value measured at the highest point measured by the JIS method. At low temperatures where the maximum temperature is less than 38 ° C., the deep temperature does not increase and the whole body does not warm. On the other hand, if it is 60 ° C. or higher, it is too hot to be used. Moreover, the heating tool was attached to the fitter shown in FIG. 4 and attached to the panel, and the temperature at the waist was measured by the following method.

(Deep temperature measurement)
Under an environment of 20 ° C. and 40% RH, a deep thermometer (core temp CM-210, deep temperature) near the waist (the upper part of the heating tool application site) where the heating tool obtained in the example and the comparative example is mounted Probe PD1, manufactured by Terumo Corporation) was attached. A depth thermometer was mounted in advance before mounting the heating tool, and after confirming that the deep temperature became stable, the heating tool was applied for 60 minutes to measure the depth temperature. The deep temperature measured using the deep temperature probe PD1 is considered to be a temperature corresponding to a tissue temperature 10 mm deep from the epidermis. The deep temperature before application of the heating tool was defined as A, the maximum deep temperature during measurement was defined as B, and BA was defined as the deep temperature rise.

As is apparent from the results shown in Table 2, the heating tool of each example did not swell after the end of heat generation, and no abnormal heat generation occurred during the heat generation. It can also be seen that the maximum temperature reached is 40 ° C. or higher, and the cumulative amount of water vapor released for 3 hours is 400 mg / cm ² or higher. On the other hand, in Comparative Example 1, since the moisture permeable sheet and the heat generating sheet are bonded to each other, the exothermic reaction is hindered.

It is a perspective view which shows one Embodiment of the heat generating tool 1 of this invention. FIG. 2 is a sectional view taken along line II-II in FIG. It is explanatory drawing explaining the principle which the heating tool of this embodiment swells after completion | finish of heat_generation | fever. It is a figure which shows an example of the usage condition of the heat generating tool shown in FIG. It is a figure which shows the use condition of the heat generating tool shown in FIG. It is a figure which shows 2nd Embodiment of the heat generating tool of this invention. It is a figure which shows 3rd Embodiment of the heat generating tool of this invention. It is sectional drawing (FIG. 2 equivalent view) which shows 4th Embodiment of the heating tool of this invention.

Explanation of symbols

1 Heating Tool 2 Heating Sheet 3 Container 5 Belt Fitter 7 Joint

Claims (8)

An oxidizable metal capable of generating heat by contact with air in a container provided with a breathable portion having a moisture permeability (JIS Z0208, 40 ° C., 90% RH) of 200 to 2000 g / m ² · 24 hr at least in part. Contains heat-generating materials,
The exothermic material has a moisture content of 10 to 70% by weight after completion of exotherm, and the amount of the oxidizable metal contained in the exothermic material is 10 to 150 mg / cm ² per unit area of the container. A sheet-like material,
The heating tool in which the mutually opposing surfaces of the container and the sheet-like heating material are partially joined to each other. An oxidizable metal capable of generating heat by contact with air in a container provided with a breathable portion having a moisture permeability (JIS Z0208, 40 ° C., 90% RH) of 200 to 2000 g / m ² · 24 hr at least in part. Contains heat-generating materials,
The exothermic material has a moisture content of 10 to 70% by weight after completion of exotherm, and the amount of the oxidizable metal contained in the exothermic material is 10 to 150 mg / cm ² per unit area of the container. A sheet-like material,
The container is a heating tool in which opposed surfaces in a space in which the sheet-like heat generating material is stored are partially joined at a portion inside the peripheral edge. An oxidizable metal capable of generating heat by contact with air in a container having a breathable portion having a moisture permeability (JIS Z0208, 40 ° C., 90% RH) of 200 to 2000 g / m 2 · 24 hr at least in part. Contains exothermic material,
The exothermic material has a water content of 10 to 70% by weight after completion of exotherm, and the amount of the oxidizable metal contained in the exothermic material is 20 to 300 mg / cm ² per unit area of the container. A granular mixture,
The container is in the shape of a flat bag, and the container is a heating tool in which opposed faces in a space in which powder is stored are partially joined at a portion inside the peripheral edge. . Water vapor generated from the heat generating material is released to the outside of the container through the breathable portion, and the cumulative amount of water vapor released 90 minutes after the heat generating material comes into contact with air is 1.4. It is -7.0 mg / cm < ² >, The heating tool in any one of Claim 1 thru | or 3.   The heating tool according to claim 1 or 2, wherein the heating material is a heating sheet containing an oxidizable metal, a reaction accelerator, a fibrous material, an electrolyte, and water.   The exothermic sheet is a molded sheet containing 60 to 90% by weight of an oxidizable metal, 5 to 25% by weight of a reaction accelerator, and 5 to 35% by weight of a fibrous material, with respect to 100 parts by weight of the molded sheet. The heating tool according to claim 5, wherein 30 to 80 parts by weight of an aqueous electrolyte solution containing 1 to 15% by weight of the electrolyte is contained.   The container is formed into a bag shape by stacking the moisture permeable sheet having the moisture permeability and the hardly moisture permeable or non-moisture permeable sheet and joining the peripheral edges of both sheets to each other. The heating tool according to claim 1, wherein the heat generating material and the moisture-permeable sheet or the hardly moisture-permeable or non-moisture-permeable sheet are partially joined.   The container is formed in a bag shape by stacking the moisture permeable sheet having moisture permeability and the hardly moisture permeable or non-moisture permeable sheet, and joining the peripheral edges of both sheets to each other. The heating tool according to claim 2 or 3, wherein the moisture-permeable or non-moisture-permeable sheet is partially joined.