Heating device

Abstract

To provide a new heating tool capable of exhibiting desired heating characteristics.SOLUTION: The heating tool includes a storage bag 5 that stores a mixture containing an oxidizable metal powder, an oxidation accelerator, and a water retention agent, and a water holder 6 that can supply water to the mixture. At least a part of the storage bag has water permeability, and the mixture absorbs 10 to 210 parts by mass of water per 100 parts by mass of the mixture.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a heating tool. [Background technology]

[0002] Disposable hand warmers are known as body warmers. Disposable hand warmers typically contain an exothermic composition that generates heat in the presence of air (oxygen), and this heat-generating principle is what provides the warming effect. For this reason, the exothermic composition is stored in a non-breathable outer bag to prevent contact with air until use. At the time of use, the exothermic composition can be easily generated by simply removing it from the outer bag. Furthermore, adhesive-type disposable hand warmers, such as those described in Patent Document 1, are easy to use because they can be applied to any location where warmth is desired. Disposable hand warmers are widely used because of their simple usage procedure, portability and safety as a warming device, and low cost.

[0003] However, even when disposable hand warmers are stored in a non-breathable outer bag, problems can arise in that the components that make up the exothermic composition gradually react during storage. This can lead to a decline in heat-generating properties, such as difficulty in generating heat to the desired temperature during use or uneven heat generation, leading to a deterioration in quality. To address this problem, for example, measures have been taken to improve the non-breathable outer bag so as to further block contact between the exothermic composition and air. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-80018 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a new heating tool that can exhibit desired heating characteristics. [Means for solving the problem]

[0006] The present inventors have conducted extensive research to solve the above-mentioned problems and have found that desired heat generation characteristics, such as heat generation temperature, can be obtained by placing a mixture containing an oxidizable metal powder, an oxidation promoter, and a water retention agent in a water-permeable storage bag, separately preparing a water retention device for supplying water to the mixture, bringing the storage bag into contact with the water retention device, supplying water from the water retention device to the mixture in the storage bag, and causing the mixture to absorb 10 to 210 parts by mass of water per 100 parts by mass of the mixture.The present invention was completed based on this finding and through further research.That is, the present invention provides the following inventions.

[0007] Item 1. A storage bag containing a mixture containing an oxidizable metal powder, an oxidation promoter, and a water retention agent, and a water retention device capable of supplying water to the mixture, At least a portion of the storage bag is water permeable, The heating tool, wherein the mixture absorbs 10 to 210 parts by mass of water per 100 parts by mass of the mixture. Item 2. The heating tool according to Item 1, wherein the mixture contains 5% by mass or less of water. Item 3. The heating tool according to Item 1 or 2, wherein the water retaining device is a water-containing body impregnated with water, and water is supplied to the mixture by bringing the water-containing body into contact with the containing bag. Item 4. The heating tool according to any one of Items 1 to 3, further comprising a housing section for housing the water retaining device, for bringing the water retaining device into contact with the storage bag. Item 5. Items 1 to 4, wherein the water retention agent contains a polyacrylate resin having a water absorption rate of 10 seconds or more. 10. A heating tool according to any one of the preceding items. [Effects of the Invention]

[0008] According to the present invention, a new heating tool can be provided that can exhibit desired heat generation characteristics (heat generation temperature, heat generation duration and / or heat generation start time). [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 shows an example of the present heating tool, which includes a storage bag containing a mixing part, a water retaining tool, a storage part for the water retaining tool, and a carrier. [Figure 2] FIG. 2 shows an example of the present heating tool, which includes a storage bag containing a mixing part, a water holder, a storage part for the water holder, and a carrier. [Figure 3] FIG. 3 shows an example of a schematic cross-sectional view of the heating tool shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention relates to a heating tool comprising a storage bag containing a mixture including an oxidizable metal powder, an oxidation promoter, and a water retention agent, and a water retention device capable of supplying water to the mixture, wherein at least a portion of the storage bag is water permeable, and the mixture absorbs 10 to 210 parts by mass of water per 100 parts by mass of the mixture.

[0011] mixture In the heating tool, the mixture contains an oxidizable metal powder, an oxidation promoter, and a water retention agent, and absorbs 10 to 210 parts by mass of water per 100 parts by mass of the mixture.

[0012] ·Oxidizable metal powder The oxidizable metal powder is not limited as long as it is a metal powder that generates heat when oxidized, and examples thereof include iron powder, zinc powder, aluminum powder, magnesium powder, and copper powder, with iron powder being preferred. Examples of iron powder include reduced iron powder, cast iron powder, atomized iron powder, and electrolytic iron powder. The shape of the oxidizable metal powder is also not limited, and examples include powder forms such as powder, granules, and fibers that are commonly used in conventional disposable body warmers. These may be used alone or in combination of two or more.

[0013] The content of the oxidizable metal powder is not limited, but the oxidizable metal powder is, for example, 20 to 80 mass %, preferably 25 to 70 mass %, more preferably 30 to 65 mass % in the mixture.

[0014] Pro-oxidant The pro-oxidant is used for the purpose of promoting the supply of oxygen to the mixture, particularly to the oxidizable metal powder, by taking in air. Examples of pro-oxidants include, but are not limited to, activated carbon, coal, charcoal, bamboo charcoal, graphite, carbon black, graphite, acetylene black, and coffee grounds charcoal. Preferred examples include activated carbon, carbon black, bamboo charcoal, charcoal, and coffee grounds charcoal. The shape of the pro-oxidant is also not limited, and examples include the powder, granules, and fibers used in conventional disposable body warmers. These may be used alone or in combination of two or more.

[0015] The content of the pro-oxidant is not limited, but the pro-oxidant content in the mixture is, for example, 1 to 30 mass %, preferably 3 to 25 mass %, more preferably 5 to 23 mass %.

[0016] ·Water retention agent The water-retaining agent is not limited to the present invention, but examples thereof include porous materials and water-absorbent resins. More specific examples of water-retaining agents include, but are not limited to, natural or synthetic inorganic substances such as vermiculite, perlite, calcium silicate, aluminum silicate, kaolin, talc, smectite, mica, bentonite, calcium carbonate, silica gel, alumina, zeolite, silicon dioxide, and diatomaceous earth, and natural or synthetic organic substances such as pulp, wood flour (sawdust), cotton, polyacrylate resins, polysulfonate resins, maleic anhydride resins, polyacrylamide resins, polyvinyl alcohol resins, polyethylene oxide resins, polyaspartate resins, polyglutamate resins, polyalginate resins, starches, and celluloses.

[0017] Preferred examples of water-retaining agents include vermiculite, perlite, silica gel, diatomaceous earth, aluminum oxide, wood flour (sawdust), and polyacrylate resins. Furthermore, more preferred examples of water-retaining agents include polyacrylate resins, particularly sodium polyacrylate. Preferred examples of polyacrylate resins include polyacrylate resins with a water absorption rate of 10 seconds or more, preferably sodium polyacrylate with a water absorption rate of 10 seconds or more, and more preferably sodium polyacrylate with a water absorption rate of 20 seconds or more. While not limited thereto, preferred examples of water-absorption rates are 10 to 90 seconds, more preferably 20 to 60 seconds. Here, the water absorption rate is measured according to a method in accordance with JIS K7224 (1996). In the present invention, a polyacrylate resin with a water absorption rate of 10 seconds or more refers to the time it takes for 2 g of the polyacrylate resin to absorb 50 g of physiological saline.

[0018] The shape of the moisture retaining agent is not limited, and examples thereof include shapes used in conventional disposable body warmers.

[0019] These may be used alone or in combination of two or more.

[0020] The content of the water retention agent is not limited, but the water retention agent may be present in an amount of 1 to 65 mass %, preferably 5 to 60 mass %, and more preferably 10 to 60 mass % in the mixture.

[0021] The mixture may further contain any other component as necessary, provided that the effects of the present invention are not impaired. Examples of such other components include, but are not limited to, water-soluble salts, water, hydrogen generation inhibitors, thickeners, excipients, surfactants, sequestering agents, and various useful components such as fragrances, warming components, anti-fatigue components, analgesic components, anti-inflammatory components, blood circulation promoting components, cooling (cooling, refreshing) components, and repellent components. The other components may be appropriately selected and used depending on the purpose, and may be used alone or in combination of two or more, and the amounts of the other components may also be appropriately selected.

[0022] Although not limiting the present invention, examples of other components include water-soluble salts. Examples of water-soluble salts include, but are not limited to, chloride salts and sulfide salts of alkali metals such as sodium and potassium, chloride salts and sulfide salts of alkaline earth metals such as calcium and magnesium, and chloride salts and sulfide salts of metals such as iron, copper, aluminum, zinc, nickel, silver, and barium. Preferred examples of water-soluble salts include sodium chloride and potassium chloride. These salts may be used alone or in combination of two or more. When the mixture contains water-soluble salts, their content is not limited as long as the effects of the present invention are obtained. However, the content of the water-soluble salts in the mixture is, for example, 0.1 to 10% by mass, preferably 0.5 to 7% by mass, and more preferably 1 to 5% by mass.

[0023] Although not limiting the present invention, water can be used as an example of another component. Examples of water include distilled water, tap water, ion-exchanged water, pure water, ultrapure water, and industrial water. The content of water is also not limited as long as it does not impair the effects of the present invention. However, the content of water in the mixture is preferably 0 to 5% by mass (5% by mass). Examples include:

[0024] Furthermore, although this does not limit the present invention, when a useful ingredient such as a fragrance is used as the other ingredient, from the viewpoint of more effectively exerting the useful effects attributable to the useful ingredient by the heat generated in the heating tool, it is more preferable that the useful ingredient be an ingredient that can volatilize its useful effects at the temperature at which the mixture generates heat in the presence of oxygen (for example, approximately 38 to 85°C).

[0025] As mentioned above, conventional disposable hand warmers that use an exothermic composition that generates heat in the presence of air (oxygen) are stored in a water-impermeable outer bag to prevent contact with air until use, and generate heat to the desired temperature simply by removing the exothermic composition from the outer bag at the time of use. Unlike conventional heating tools that generate heat to the desired temperature simply by removing the exothermic composition from the outer bag at the time of use, this heating tool exhibits the desired heat generation properties by having the mixture absorb water supplied from a water holder (described below) in an amount of 10 to 210 parts by mass of water per 100 parts by mass of the mixture.

[0026] The mixture can be produced by mixing an oxidizable metal powder, an oxidation promoter, a water-retaining agent, and, if necessary, the other ingredients. The mixture may be prepared in the presence of oxygen, or may be prepared under vacuum or an inert gas atmosphere, and can be produced according to a conventionally known manufacturing procedure for a heating tool. In particular, since this heating tool does not generate heat simply by removing the bag containing the mixture from the outer bag and contacting it with oxygen when in use, the mixture may be prepared in the presence of air (oxygen).

[0027] Thus, in this heating tool, the mixture absorbs 10 to 210 parts by mass of water per 100 parts by mass of the mixture at room temperature (about 15 to 25°C) from the time when water supply to the mixture begins upon contact between the storage bag containing the mixture and the water retainer, thereby exhibiting the desired heat generation characteristics (heat generation temperature, heat generation duration, and / or heat generation onset). Although the present invention is not limited in this respect, the mixture preferably absorbs 10 to 180 parts by mass of water, more preferably 60 to 115 parts by mass of water, per 100 parts by mass of the mixture.

[0028] Furthermore, although the mixture is not limited thereto, from the viewpoint of more efficiently exhibiting the desired heat-generating properties, it is more preferable that the mixture absorbs 10 to 210 parts by mass of water per 100 parts by mass of the mixture at room temperature (approximately 15 to 25°C) within 60 seconds from the start of water supply to the mixture by contacting the storage bag containing the mixture with the water retainer, and it is even more preferable that the mixture absorbs 10 to 180 parts by mass of water, and particularly preferably absorbs 60 to 115 parts by mass of water.

[0029] In order to exhibit the desired heat-generating properties during heat generation, the mixture needs to absorb a predetermined amount of water. Furthermore, in order to exhibit the desired heat-generating properties more efficiently, it is more desirable for the mixture to absorb a predetermined amount of water within a predetermined time after water is supplied. If the mixture absorbs too much or too little water, it becomes difficult to generate heat. Furthermore, even if the amount of water is the same, if the absorption rate is too fast or too slow, it becomes difficult to generate heat efficiently. From this perspective, it is preferable for the mixture to absorb the aforementioned water within 60 seconds from the start of water supply to the mixture through contact between the storage bag containing the mixture and the water retainer, as described above.

[0030] Here, the water absorption capacity of the mixture is calculated by measuring the weight (weight A) of the water-holding device carrying water before contact with the storage bag, and measuring the weight (weight B) of the water-holding device after contact with the storage bag, and subtracting the latter weight (weight B) from the former weight (weight A).

[0031] The ratio of 10 to 210 parts by mass of water per 100 parts by mass of the mixture was determined by subtracting weight B from weight A and calculating the weight of the mixture stored in the storage bag (before contact with the water holder). ) by the weight of the mixture and multiply the value thus obtained by 100. That is, it is calculated by the following formula.

[0032] Water absorption rate per 100 parts by mass of mixture = ((Weight A) - (Weight B)) x 100 / Weight of the mixture contained in the storage bag

[0033] A preferred example of the mixture is a mixture that satisfies the weight B, where B is the weight of the water retaining device measured 60 seconds after water begins to be supplied to the mixture by contact between the storage bag and the water retaining device.

[0034] An example of the mixture, although not limiting the present invention, is a mixture containing 20 to 70 mass% of oxidizable metal powder, 5 to 20 mass% of a pro-oxidant, 10 to 35 mass% of a water-retaining agent, and 0 to 10 mass% of a water-soluble salt. Another example of the mixture, although not limiting the present invention, is preferably a mixture containing 40 to 60 mass% of oxidizable metal powder, 5 to 20 mass% of a pro-oxidant, 15 to 35 mass% of a water-retaining agent, and 0 to 5 mass% of a water-soluble salt. Another example of the mixture, although not limiting the present invention, is preferably a mixture containing 0 to 5 mass% water.

[0035] By placing the mixture obtained in this manner in a storage bag described below, a storage bag containing a mixture containing an oxidizable metal powder, an oxidation promoter, and a water retention agent, which exhibits the desired heat generation properties by absorbing 10 to 210 parts by mass of water per 100 parts by mass of the mixture, can be obtained.

[0036] The amount of the mixture contained in the storage bag is not limited as long as the effects of the present invention can be obtained, and may be appropriately determined based on the size and shape of the storage bag, the purpose of use of the heating tool, the target of application, etc., with reference to conventionally known disposable body warmers, etc. Although not limiting the present invention, an example of the amount of the mixture contained in one storage bag is 4 to 20 g, preferably 8 to 16 g.

[0037] Furthermore, the desired heat generation characteristics of the present heating tool may be determined appropriately depending on the intended use and application of the heating tool, and are not intended to limit the present invention. Examples of the desired heat generation characteristics include a maximum heat generation temperature of the mixture of approximately 38 to 85°C, preferably approximately 40 to 70°C. The present heating tool is not limited in this respect, but examples of the duration of the heat generation temperature of the mixture exceeding 40°C include 10 minutes or more, more preferably 30 minutes or more. The present heating tool is not limited in this respect, but examples of the time it takes for the mixture to reach a heat generation temperature exceeding 40°C (rise time) include 12 minutes or less, more preferably 7 minutes or less, from the time water is added to the mixture. The present heating tool is only required to exhibit the desired heat generation characteristics in at least one of the maximum heat generation temperature, duration, and rise time, and preferably exhibits the desired heat generation characteristics in two, and more preferably three, of these.

[0038] These temperatures and times are determined according to measurements based on JIS S4100 (2007). Specifically, as described in the Examples below, these temperatures and times are determined by measuring the exothermic temperature and time by first attaching and fixing a temperature sensor with tape to the surface of a storage bag containing the mixture opposite the surface that comes into contact with the water retaining device, then contacting the storage bag (the other surface not having the temperature sensor fixed thereto) with the water retaining device, and then placing the storage bag on a wire rack with the opposite surface (the surface with the temperature sensor fixed thereto) facing downward, and measuring the temperature at room temperature (approximately 15 to 25°C). In the Examples below, a temperature sensor that can also measure time is used, and therefore the time can be measured accordingly.

[0039] Although not limiting the present invention, in order to efficiently obtain the desired heat generating characteristics, A preferable example is one in which the above value is satisfied when the water holder is removed 60 seconds after the start of water supply to the mixture due to contact with the holder.

[0040] a storage bag for storing the mixture The mixture is contained in a containing bag, at least a portion of which is water-permeable. Any conventionally known bag can be used as the containing bag, as long as it can contain the mixture, at least a portion of which is water-permeable, prevents leakage of the mixture, and is durable against heat generation as a heating tool.

[0041] Although the storage bag is not a limitation of the present invention, a flat bag is typically used as an example, and it may have any shape, such as a square, triangular, circular, oval, or foot-shaped bag. The mixture is stored in the internal space of the bag.

[0042] In this heating tool, the mixture contained in the storage bag generates heat when water is supplied, so at least a portion of the storage bag is water permeable.

[0043] Examples of the storage bag include, but are not limited to, a storage bag made of a water-permeable resin film, a storage bag made of a water-permeable woven or nonwoven fabric, and a storage bag having a laminated structure in which a water-permeable resin film and a water-permeable woven or nonwoven fabric are laminated together. In the case of a storage bag having such a laminated structure, the water-permeable resin film may be disposed on the inside of the storage bag and the water-permeable woven or nonwoven fabric may be disposed on the outside, or vice versa. Examples of the storage bag include, but are not limited to, water-permeable bags used in conventionally known disposable hand warmers.

[0044] The resin used for the water-permeable resin film is not intended to limit the present invention, but a preferable example is a thermoplastic resin film.

[0045] Examples of thermoplastic resins include polyethylene, polypropylene, polyester, polyamide, polyurethane, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polycarbonate, ethylene-vinyl acetate copolymer, etc., and preferred examples include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, etc. These may be used alone or in combination of two or more.

[0046] The water-permeable resin film has pores at least partially formed therein to ensure water permeability. The pores formed in the resin film are not limited in size, shape, number, or method of forming the pores, as long as they are large enough to allow water to pass through at least from the outside to the inside of the storage bag and prevent the mixture from leaking out of the storage bag. Means for forming pores in a resin film are also conventionally known and can be carried out according to conventional procedures. The water-permeable resin film may be a conventionally known perforated film, porous film, or the like. The term "porous film" is used in the conventional, general sense, and refers to a porous film having a large number of pores in which multiple pores are connected. The pores may be formed uniformly throughout the entire resin film, or may be formed densely in a portion.

[0047] The thickness of the resin film is not limited as long as it can be used as a storage bag, and is preferably 10 to 2000 μm, and more preferably 10 to 1000 μm, for example.

[0048] Examples of water-permeable woven or nonwoven fiber materials include synthetic fibers such as nylon, vinylon, polyester, rayon, acrylic, polyethylene, polypropylene, acetate, polyvinyl chloride, polybutylene terephthalate, and ethylene-vinyl acetate copolymer; natural fibers such as cotton, hemp, silk, and paper; and blends of synthetic and natural fibers. From this viewpoint, preferred examples of the fiber material include nylon, polyester, polypropylene, ethylene-vinyl acetate copolymer, etc., and more preferred examples include nylon, polyester, ethylene-vinyl acetate copolymer, etc. These may be used alone or in combination of two or more.

[0049] The woven or nonwoven fabric is not limited as long as it can pass water at least from the outside to the inside of the storage bag and can prevent the mixture from leaking out of the storage bag, but the basis weight is preferably 25 to 70 g / m 2 is exemplified.

[0050] The thickness of the nonwoven fabric or woven fabric is not limited as long as the effects of the present invention can be obtained, and is preferably 10 to 2000 μm, more preferably 10 to 1000 μm, for example.

[0051] The lamination of the resin film and the woven or nonwoven fabric is not limited as long as the resulting laminate has the strength required for a storage bag and ensures water permeability at least in part. Examples of lamination methods include lamination by thermal bonding, and lamination using an adhesive such as a hot-melt adhesive, an acrylic adhesive, or a urethane adhesive. These laminations may be formed over the entire surface of the storage bag or may be formed only in part, as long as the desired effect is obtained.

[0052] As mentioned above, this heating tool exhibits the desired heat-generating properties by having a predetermined amount of water absorbed into the mixture from the water-holding device through the water-permeable part of the storage bag.Therefore, it is sufficient for at least a part of the storage bag to have water permeability to the extent that a predetermined amount of water can be supplied from the water-holding device to the mixture.

[0053] Furthermore, in this heating tool, the mixture contained in the storage bag generates heat upon contact with air (oxygen). For this reason, at least a portion of the storage bag is breathable. In this way, the mixture contained in the storage bag generates heat upon supply of water and contact with air (oxygen). In the storage bag, the water-permeable portion may also serve as the breathable portion, or the water-permeable portion may be provided separately from the breathable portion. Although this does not limit the present invention, from the viewpoint of facilitating contact between the mixture in the storage bag and air (oxygen) while contacting the water-permeable portion of the storage bag with a water retaining device to supply water to the mixture, a preferred example is that the breathable portion is provided in a portion different from the water-permeable portion with which the water retaining device comes into contact.

[0054] Generally, a water-permeable portion can be said to also have breathability, and therefore the breathable portion of the storage bag may be manufactured in the same manner as the water-permeable portion described above. Also, although a water-permeable portion can be said to also have breathability in this way, the breathable portion of the storage bag is not limited as long as it has breathability that allows air (oxygen) to pass through at least from the outside to the inside of the storage bag, and may be manufactured in the same manner as a storage bag that has breathability in at least a portion thereof.

[0055] When the storage bag has a breathable portion in addition to the water-permeable portion, the breathable portion may be made of, but is not limited to, a breathable resin film, a breathable woven or nonwoven fabric, or a laminated structure in which a breathable resin film is laminated with a breathable woven or nonwoven fabric. In addition, when a laminated structure is provided, a breathable resin film may be placed on the inside of the storage bag and a breathable woven or nonwoven fabric may be placed on the outside, or vice versa. Resin films, woven fabrics, nonwoven fabrics, etc. can be described in the same manner as above, except for being breathable. As such a breathable portion, but is not limited to, the present invention, the resin films, woven fabrics, nonwoven fabrics, etc. that constitute the breathable portion of storage bags used in conventionally known disposable warmers may be used. Illustrated.

[0056] Furthermore, the storage bag is not limited to this, and may have a water-impermeable portion.

[0057] A commercially available bag may be used as the storage bag, and its size is not limited as long as the desired effect can be obtained, and may be appropriately determined depending on the purpose of use of the heating tool, the target of application, etc. Furthermore, the amount of the mixture to be stored in the storage bag may be appropriately determined depending on the size of the storage bag, the purpose of use, the target of application, etc.

[0058] Although not limiting the present invention, an example of the storage bag is a flat bag in which at least a portion of one side of the bag is water-permeable and at least a portion of the other side is breathable. In this case, by bringing a water-holding device that holds water into contact with the water-permeable portion of one side, water can be supplied from the water-holding device to the mixture in the storage bag. Even if this contact causes the water-permeable portion to be covered with the water-holding device and reduces breathability or becomes non-breathable, air (oxygen) can be supplied to the mixture in the storage bag from the breathable portion of the other side, thereby allowing the mixture to be efficiently heated in the heating device.

[0059] When the heating tool is used by being attached to clothing, skin, etc., an adhesive sheet may be provided on the outside of the storage bag to secure the heating tool to clothing, skin, etc. with a releasable force. The adhesive sheet may be provided by any means and in any location on the storage bag as long as the desired heating characteristics are obtained. Examples of such adhesive sheets include the adhesive sheets used in conventionally known stick-on disposable warmers, or direct-attachment adhesive sheets.

[0060] water holder The heating tool includes a water retainer that supplies water to the mixture. The water retainer is capable of retaining water and supplies water to the mixture by contacting the storage bag that contains the mixture and releasing water. More specifically, the water retainer supplies water to the mixture by contacting at least a water-permeable portion of the outside of the storage bag that contains the mixture and releasing water into the storage bag. The mixture absorbs the water thus supplied and generates heat.

[0061] In this heating tool, the water retaining device may be in a state where it retains water or in a state where it does not retain water. The water retaining device only needs to retain water when water is supplied to the mixture, i.e., when the water retaining device is brought into contact with the storage bag. A water retaining device in a state where it retains water can also be called, for example, a water-containing body.

[0062] The water retainer may be used in contact with the entirety of the storage bag, or in contact with only a portion of the bag. From the viewpoint of supplying air (oxygen) to the mixture while allowing the mixture to absorb water, the water retainer is preferably used in contact with only a portion of the storage bag. The contact is not limited as long as 10 to 210 parts by mass of water can be supplied to the mixture per 100 parts by mass of the mixture at room temperature (about 15 to 25°C). Although not limited thereto, the contact can be, for example, by supplying, more preferably, 10 to 180 parts by mass, and even more preferably, 60 to 115 parts by mass of water per 100 parts by mass of the mixture.

[0063] The water retaining device is not limited to this, and its size, shape, material, etc. are not important, and examples thereof include a sheet-like shape and a bag-like shape. Water can be retained in the water retaining device by any means, such as immersion, coating, injection, spraying, etc.

[0064] Although the present invention is not limited thereto, a sheet-shaped water retaining device having a predetermined thickness will be described as an example of the water retaining device. This can be understood by those skilled in the art and can be determined appropriately based on the following explanation.

[0065] The sheet-like water retaining device having a predetermined thickness can be formed in any shape, including square, triangular, circular, oval, and foot-shaped.

[0066] For example, when the storage bag is a flat square and a water retaining device is brought into contact with one water-permeable surface of the bag, for example, one surface of the bag may be brought into contact with a single square sheet-like water retaining device, or two triangular sheet-like water retaining devices arranged in a square may be brought into contact with one surface of the bag, or a circular sheet-like water retaining device may be brought into contact with one surface of the bag. Here, the entire surface of the one surface may be in contact with the water retaining device, or only a portion of the one surface may be in contact with the water retaining device.

[0067] From the viewpoint of efficient heat generation, the shape of the water holder is exemplified as a shape that allows contact with the entire surface of the one side in a shape that is approximately the same as the shape of the entire surface of the one side. That is, if the one side is, for example, rectangular, the water holder is also rectangular; if the one side is, for example, square, the water holder is also square; and if the one side is, for example, circular or elliptical, the water holder is also circular or elliptical. Here, "approximately the same shape" does not necessarily have to be the exact same shape, and minor differences in shape, such as whether or not corners are chamfered, are acceptable.

[0068] From the viewpoint of efficient heat generation, the shape of the water holder is preferably approximately the same as the shape of the one side, particularly the shape of the heat generating area of ​​the one side (the part of the storage bag on the one side where the mixture is present).

[0069] Furthermore, from the perspective of efficient heat generation, the size of the water retaining device is, for example, approximately the same as the size of one side, particularly the size of the heat generating area of ​​that side (the portion of the storage bag on that side where the mixture is present). Here, "approximately the same" means that the size of that side (particularly the heat generating area) and the size of the water retaining device are exactly the same, and also means that one side can be slightly larger than the other. Having these sizes be approximately the same has the advantage of facilitating uniform release of water from the water retaining device to the entire mixture stored in the storage bag, while also preventing water from being released anywhere other than the mixture. Furthermore, covering the heat generating area of ​​the storage bag with the water retaining device prevents the heat generating area of ​​the storage bag from coming into direct contact with the application site when the heating device is applied to the skin, etc., thereby reducing the risk of low-temperature burns.

[0070] The size of the water holder is not limited to this and may be determined appropriately, but from the viewpoint of ease of use, it is preferably 4 to 14 cm in the horizontal direction and 2 to 10 cm in the vertical direction, and more preferably 7 to 11 cm in the horizontal direction and 3 to 6 cm in the vertical direction. In terms of area, it is preferably 8 to 98 cm. 2 is exemplified, and more preferably 25 to 55 cm 2 is exemplified.

[0071] The thickness of the water retaining device is not limited to this and may be determined appropriately, but from the standpoint of ease of use, it is preferably 0.5 to 5 mm, and more preferably 2 to 4 mm, for example.

[0072] The material of the water retaining device is not particularly limited as long as it can retain water and release water into the storage bag in contact with it to supply water to the mixture in the storage bag.

[0073] The water-retaining device can be formed, for example, from a woven or nonwoven fabric using various fiber materials, preferably hydrophilic fibers or blends of hydrophilic and synthetic fibers. The fiber material is not particularly limited, but preferred examples include polyethylene, polypropylene, polyester, rayon, cotton, and pulp, with pulp being a suitable example from the standpoint of flexibility and water retention. The method for producing a water-retaining device made of a fiber material is not particularly limited, but preferably the air-laid method. is exemplified.

[0074] From the viewpoints of productivity, processability, and durability, the water retainer is preferably formed by blending pulp, which is the main component, with heat-fusible fibers such as polyethylene in a predetermined ratio. The blending ratio of pulp to heat-fusible fibers is not particularly limited, but a preferred example is 60:40 to 80:20.

[0075] The water retaining device is not particularly limited in terms of basis weight as long as it can retain the amount of water to be supplied to the storage bag, but it is preferably 50 g / m 2 The above are examples, and 100 g / m 2 The above are examples. If the basis weight is too large, the water retention device becomes hard, and therefore, when the heating device is applied to the skin, the feeling of use during application may be reduced. For this reason, when the water retention device is to be applied to the skin in particular, the basis weight is preferably 50 to 1000 g / m 2 , more preferably 100 to 600 g / m 2 is exemplified.

[0076] The water retainer may have a single-layer or multi-layer structure. While this does not limit the present invention, a preferred example is a three-layer structure in which the aforementioned fiber material is sandwiched between a pair of nonwoven fabrics, from the standpoint of durability and water retention. In this case, the layer sandwiched between the pair of nonwoven fabrics is referred to as the middle layer, and the layers consisting of the pair of nonwoven fabrics are referred to as the end layers. The nonwoven fabrics in the end layers may be made of the same material or different materials. Examples of materials for the nonwoven fabrics in the end layers include hydrophilic fibers, hydrophobic fibers, synthetic fibers, and blends of hydrophilic and synthetic fibers. Examples of hydrophilic fibers include, but are not limited to, preferred examples: rayon and cotton, and more preferably rayon. Making the material hydrophilic facilitates the absorption of water into hydrophilic fibers such as pulp during manufacturing, thereby facilitating manufacturing. Examples of hydrophobic fibers include, but are not limited to, polyesters such as polyethylene, polypropylene, and polyethylene terephthalate, and more preferably polyethylene and polypropylene. Making the material hydrophobic prevents wetting and stickiness. For this reason, for example, when the water retaining device comes into contact with the skin when using the heating tool, or when the heating tool is applied to the skin via the water retaining device, it is preferable to configure the surface of the water retaining device facing the skin using a hydrophobic fiber, and the opposite surface (the surface that comes into contact with the storage bag) using a hydrophilic fiber such as rayon. The basis weight of such a pair of nonwoven fabrics is not particularly limited, but is preferably 20 to 50 g / m 2 The following is an example:

[0077] In addition to woven or nonwoven fabric, the water retaining device can also be formed from a porous body such as a sponge. A porous body has a structure with a continuous network of spaces such as small holes, cracks, and voids inside, and water is retained in these spaces. The sponge is not particularly limited, but examples include synthetic sponges made primarily from synthetic resin materials such as urethane resin and melamine resin, natural sponges made primarily from natural materials such as sea sponge and cellulose, and rubber sponges made primarily from rubber materials such as synthetic rubber and natural rubber.

[0078] Although not particularly limited, the water retaining device is preferably compressible and deformable by the action of an external force. In other words, it is preferable that the water retaining device releases water by forcing the retained water outward through compressive deformation. The water retaining device may release water by naturally seeping out, but by being configured to release water through compressive deformation, water can be reliably released from the water retaining device. Furthermore, it is more preferable that the water retaining device has flexibility that allows it to be easily compressed and deformed. This allows a sufficient amount of water to be released from the water retaining device to generate heat without applying a large force to the water retaining device. Although not particularly limited, preferred examples of water retaining devices that are easily compressible and deformable include sponges such as urethane sponges and stretchable nonwoven fabrics such as "Felibendy" (registered trademark) manufactured by Kuraray Kuraflex Co., Ltd. Furthermore, the water retaining device does not necessarily need to be elastic, but a preferred example of elasticity is that it tends to return to its original shape when an external force is removed. Elasticity refers to the ability of a water retaining device that has been compressively deformed by the application of an external force to return to its original shape. It is sufficient for the material to have this property, and it is not necessarily required that the material completely return to its original shape.

[0079] The water retaining device is not particularly limited, but preferably releases a predetermined amount of water into the storage bag within 60 seconds from the time when the water-carrying water retaining device is brought into contact with the storage bag and the supply of water to the mixture begins. While not limiting the present invention, the water retaining device preferably releases 10 to 210 parts by mass of water into the storage bag per 100 parts by mass of the mixture in the storage bag within 60 seconds from the time when the water retaining device is brought into contact with the storage bag at room temperature (15 to 25°C), more preferably 10 to 180 parts by mass, and even more preferably 60 to 115 parts by mass of water per 100 parts by mass of the mixture. The method for releasing water from the water retaining device into the storage bag is not particularly limited, and water may be released by bringing the water retaining device into contact with the storage bag as described above.

[0080] Although not limited to this, a method of releasing water from the water holder into the storage bag may be, for example, to release the water held in the water holder into the storage bag by allowing it to naturally seep out from the water holder when the water holder is brought into contact with the storage bag.

[0081] In addition, as a method of releasing water from the water holder into the storage bag, for example, the water holder may be pressurized when it is brought into contact with the storage bag, causing it to compress and deform, and the water held by the water holder may be pushed out of the water holder and released into the storage bag.

[0082] Although not limiting the present invention, a preferred method of releasing water is to contact the water retaining device with the storage bag, apply pressure to compress and deform it, and then push out the water held in the water retaining device from the water retaining device, thereby releasing 10 to 210 parts by mass of water per 100 parts by mass of the mixture in the storage bag so that the mixture absorbs it. More preferably, by compressing and deforming the water retaining device in this way and pushing out the water, the aforementioned amount of water is released from the water retaining device into the storage bag.

[0083] Furthermore, although not limiting the present invention, a more preferred method of releasing water from the water retainer to the storage bag is to apply pressure to the water retainer for 60 seconds from the time the water retainer is brought into contact with the storage bag, compressively deforming the water retained by the water retainer, and then extruding the water held by the water retainer from the water retainer, thereby releasing 10 to 210 parts by mass of water from the water retainer to the storage bag per 100 parts by mass of the mixture in the storage bag, and more preferably releasing the aforementioned amount of water from the water retainer to the storage bag. This allows the mixture in the storage bag to receive a predetermined amount of water from the water retainer within a predetermined time with high reliability.

[0084] In this case, the force applied to the water retention device is not particularly limited, but is preferably a force that allows a human hand to comfortably press the water retention device, exemplified by approximately 1800 Pa or more, and preferably approximately 1800 to 6500 Pa. Here, if the water retention device is flexible and easily compressible, such as the above-mentioned sponge or stretchable nonwoven fabric, the force applied to the water retention device may be relatively small, exemplified by approximately 1800 to 3000 Pa. In contrast, if the water retention device is difficult to compress and deform, such as an ordinary nonwoven fabric, the force applied to the water retention device must be relatively large, exemplified by approximately 4000 to 6500 Pa. The force applied when pressurizing the water retention device can be adjusted according to the flexibility of the water retention device so that 10 to 210 parts by mass of water are released into the storage bag per 100 parts by mass of the mixture in the storage bag.

[0085] Here, the amount of water released from the water retaining device to the storage bag is calculated by measuring the weight (weight A) of the water retaining device carrying water before it comes into contact with the storage bag, and measuring the weight (weight B) of the water retaining device after it comes into contact with the storage bag, and subtracting the latter weight (weight B) from the former weight (weight A).

[0086] In addition, the ratio of 10 to 210 parts by mass of water per 100 parts by mass of the mixture is The value obtained by subtracting weight B from A is divided by the weight of the mixture contained in the containment bag (before contact with the water retainer), and the value thus obtained is multiplied by 100. That is, it is calculated using the following formula.

[0087] Emission rate per 100 parts by mass of mixture = ((Weight A) - (Weight B)) x 100 / Weight of the mixture contained in the storage bag

[0088] As a water retaining device, preferably, the weight of the water retaining device measured 60 seconds after the start of supplying water to the mixture by contact between the storage bag and the water retaining device is defined as weight B, and an example of a water retaining device that satisfies the above value is given.

[0089] The amount of water held in the water holder (water holding amount) is not limited as long as it is possible to supply a predetermined amount of water to the storage bag, and may be determined appropriately taking into consideration the amount of the mixture, the desired heating temperature, the application of the heating tool, etc. The amount of water held in the water holder does not limit the present invention, but examples include any amount such as 1 g or more, 3 g or more, 6 to 30 g, or 8 to 25 g.

[0090] In this heating tool, if the water retaining device holds more water than can be absorbed by the mixture, the heat generated by the mixture will cause the water held in the water retaining device to turn into steam, thereby humidifying the area where the heating tool is applied and its surroundings. When capable of humidifying in this way, the heating tool also has humidifying and moisturizing functions, and is therefore useful as a heating tool for humidification and moisturizing.

[0091] The water retainer may remain in contact with the storage bag while the mixture is generating heat, or the water retainer may be removed from the storage bag after the mixture is generating heat. For example, from the viewpoint of preventing low-temperature burns caused by direct contact of the mixture with the skin, etc., or, as described above, from the viewpoint of supplying warm steam emitted from the water retainer that retains water to the application site and its surroundings while the mixture is generating heat, it is preferable to keep the water retainer in contact with the storage bag while the mixture is generating heat.

[0092] Other ingredients may also be added to the water held in the water holder.

[0093] Although not limiting the present invention, an example of another component added to water is salt. An example of water containing salt is 0.1 to 10% by mass of saline solution. In this case, the saline solution is retained in the water retainer. For example, salt may be added to water from the viewpoint of further suppressing uneven heat generation.

[0094] In addition, as another component, polyols can be exemplified, but are not limited to the present invention. Examples of polyols include, but are not limited to, glycerin, dipropylene glycol, 1,3-butylene glycol, propylene glycol, sorbitol, 1,2-pentanediol, 1,2-hexanediol, etc., and more preferably glycerin from the viewpoint of safety. In addition to these, preservatives such as methylparaben and phenoxyethanol, moisturizers such as hyaluronate and betaine, plant extracts, water-soluble thickeners such as xanthan gum, hydroxypropylmethylcellulose (HPMC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), agar, guar gum, and carrageenan, fragrances such as eucalyptus and mint, and surfactants (nonionic surfactants, amphoteric surfactants, anionic surfactants) that solubilize fragrances, etc., can be added as appropriate.

[0095] The water retaining device is preferably stored in a bag made of an impermeable aluminum laminate film, aluminum vapor-deposited PET film, transparent (silica) vapor-deposited PET film, or the like, until it is brought into contact with the storage bag.

[0096] Heating tool The heating tool comprises the mixture, the containing bag, and the water retaining device. In the heating tool, the mixture is contained in the containing bag.

[0097] This heating tool generates heat in the presence of air (oxygen) by bringing the water-permeable portion of the storage bag into contact with the water retaining device that retains water, and the mixture stored in the storage bag absorbs the water retained by the water retaining device. Therefore, this contact may be carried out when the heating tool is in use.

[0098] The heating tool may further include a storage section for storing the water retaining device and / or the storage bag, so that the water retaining device and the storage bag come into contact with each other. The storage section may store only one of the water retaining device and the storage bag, or may store both, and preferably stores the water retaining device.

[0099] To explain one example of such a storage section, although this does not limit the present invention, the storage section may be provided on the outside of the storage bag (for example, on one side that is water-permeable), and in this case, the water retention device may be stored in the storage section, causing the water retention device to come into contact with that side of the storage bag and generate heat. Although this does not limit the present invention, for example, the shape and size of the storage section are not particularly limited as long as it is possible to store the water retention device therein, and a preferred example is that it is formed to have the same shape and size as the storage bag.

[0100] Although this does not limit the present invention, a storage section may be provided in a part of the water retaining device, and in this case, the water retaining device and the storage bag may be brought into contact by storing one side of the storage bag that is water-permeable in the storage section facing the water retaining device.

[0101] Although not limiting the present invention, if the heating tool has a storage section that can store both the water retaining device and the storage bag, both the water retaining device and the storage bag can be stored in the storage section, and the water retaining device and the storage bag can be brought into contact in this stored state.

[0102] Although not limiting the present invention, if the heating tool has a storage section that can store both the water retaining device and the storage bag, and a partition is provided within the storage section to create a compartment structure that can store the water retaining device and the storage bag separately, the water retaining device and the storage bag can be stored in each compartment, and the water retaining device and the storage bag can be brought into contact when stored in this manner.

[0103] When the water retaining device and the storage bag are not in direct contact as described above but are in contact via a partition or the like, water is supplied from the water retaining device to the storage bag through the contact area. From this point of view, at least a portion of the partition at the contact area has water permeability that allows water to be supplied from the water retaining device to the storage bag. As a result, water is supplied from the water retaining device to the storage bag, and the mixture generates heat. Contact, heat generation, water permeability, etc. are explained in the same manner as above.

[0104] Although this does not limit the present invention, the storage section may be either moisture-impermeable or moisture-permeable, but from the perspective of humidifying the application site of this heating tool and its surroundings, it is preferable that at least a portion of the storage section, preferably the entire area that is applied to the skin, etc., be moisture-permeable.

[0105] Examples of such moisture-permeable storage parts include storage parts made of moisture-permeable resin film, storage parts made of moisture-permeable woven or nonwoven fabric, and laminates of moisture-permeable resin film and moisture-permeable woven or nonwoven fabric. When this heating tool is applied to the skin and consideration is given to the feel on the skin, it is preferable to use woven or nonwoven fabric so that the woven or nonwoven fabric comes into contact with the skin. The resin, woven or nonwoven fabric used in the resin film of the storage part The fiber material of the fabric is not limited as long as it has moisture permeability.

[0106] The moisture-permeable resin film of the storage section has pores in at least a portion thereof to ensure moisture permeability. The pores are not particularly limited in size, shape, or number, as long as they allow vapor to pass through. Resin films having pores are conventionally known, and examples include resin films and porous films having a large number of perforations. The pores may be uniformly present throughout the entire resin film, or may be densely present in a portion. The basis weight of the moisture-permeable woven or nonwoven fabric of the storage section is also not particularly limited, as long as it allows vapor to pass through.

[0107] The thickness of the storage section is not particularly limited, and the moisture permeability of the storage section is also not particularly limited as long as it allows hot steam emitted from the water holder to pass through. The moisture permeability of the storage section is appropriately set depending on the number and size of holes in the resin film that constitutes the storage section, the basis weight of the woven or nonwoven fabric, etc. The storage section may be breathable.

[0108] The heating tool may contain one or more bags containing the mixture as long as it can generate heat as described above. Also, the heating tool may contain one or more water retainers.

[0109] Furthermore, without limiting the present invention, the storage bag may be attached to any carrier, and the carrier may be provided with a storage section for storing the water retaining device, and the water retaining device may be stored in the storage section, and the water retaining device and the storage bag may be brought into contact in this stored state.

[0110] Although the present invention is not limited thereto, examples of using such a carrier include the masks shown in FIGS.

[0111] 1 to 3 show a mask 1, which comprises a main body portion 2 that covers part of the wearer's face (the area under the eyes, particularly the nose and mouth) when worn, a pair of ear loops 3 for holding the main body portion 2 on the wearer's face, a storage bag 5 that stores a mixture 4 (shown in FIG. 3), a water holder 6 that holds water that can be supplied to the mixture 4, and a storage portion 7 that stores the water holder 6 and brings it into contact with the storage bag 5. An opening 70 is formed in the storage portion 7, and the opening 70 is a portion for inserting the water holder 6 into the space within the opening. By storing the water holder 6 in the storage portion 7 through the opening 70, the water holder 6 can be brought into contact with the storage bag 5 while retaining the water holder 6. The mixture 4 in the storage bag 5 receives a supply of water from the water holder 6 that is in contact with the storage bag 5 and generates heat by coming into contact with air.

[0112] Although not limiting the present invention, the storage bag 5 can also heat the water retaining device 6 in contact with the storage bag 5 by the heat generated by the mixture 4. If the water retaining device 6 holds more water than is necessary to heat the mixture 4, hot steam will be emitted from the water retaining device 6 when the mask 1 is worn. Figure 1 shows an example of the mask 1, but this also aids in understanding the explanation of the storage section of this heating device other than the mask.

[0113] When the water retaining device, the storage bag and / or the carrier has a storage section, the storage section can be attached, for example, by joining the storage section to a part of the water retaining device, the storage bag and / or the carrier by means of adhesive, welding (thermal welding, ultrasonic welding, etc.), sewing, or other methods.

[0114] The heating tool can be used for any purpose, including as a heat retaining device, a thermal therapy device, a mask, an eye mask, etc. Furthermore, for example, if the mixture, the storage bag, and / or the water retaining device contain an analgesic component as an active ingredient, the heating tool can be said to have an analgesic effect (analgesic tool), and if it contains an ingredient with an anti-inflammatory effect, an anti-blood circulation effect, etc., the heating tool can be said to have an anti-inflammatory effect (analgesic tool), respectively. The heating tool may also be referred to as one having an inflammation-suppressing effect (an inflammation-suppressing tool), one having a blood circulation-promoting effect (a blood circulation-promoting tool), etc. Furthermore, when emitting steam derived from the water retained in the water retainer, the heating tool may be used as a humidifier, moisturizer, etc., and in this case, is useful for humidifying and moisturizing the application site and its surroundings. Although not limiting the present invention, when the heating tool is used, for example, as a mask that emits steam, it can be referred to as a mask that humidifies the throat and nose with steam, and when used as an eye mask that emits steam, it can be referred to as a mask that humidifies the eyes with steam.

[0115] In order to facilitate the carrying of the heating tool, the heating tool may be housed in any breathable and / or non-breathable outer bag, etc. Such outer bags, etc. are conventionally known.

[0116] According to the present invention, the desired heat generation characteristics (heat generation temperature, heat generation duration, and / or heat generation onset) can be exhibited simply by bringing the water retention device, which holds water, into contact with the storage bag containing the mixture. Also, according to the present invention, the desired heat generation characteristics can be exhibited simply by bringing the water retention device into contact with the storage bag once. [Example]

[0117] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0118] Preparation of the mixture Mixtures (Examples 1 to 8, Comparative Examples 1 and 2) were obtained by mixing oxidizable metal powder, an oxidation promoter, a water-retaining agent, and water-soluble salts according to the compositions shown in Table 1. In the table, the content of the mixture is expressed in weight percent. The components are as follows: Oxidizable metal powder: Iron powder (product name Atmel 80AF-2, manufactured by Kobe Steel, Ltd.) Oxidant promoter: activated carbon, synthetic aluminum silicate (trade name Kyoward 700, manufactured by Kyowa Chemical Industry Co., Ltd.) Water-retaining agent: sodium polyacrylate (trade name: Sunfresh K31, manufactured by Sanyo Chemical Industries, Ltd., water absorption speed: 35 seconds), crystalline cellulose 1 (trade name: Comprecel S 101, manufactured by Fushimi Pharmaceutical Co., Ltd.), crystalline cellulose 2 (trade name: Ceolus KG-802, manufactured by Asahi Kasei Corporation) Water-soluble salts: sodium chloride (product name TF-100, manufactured by Salt Kansai Co., Ltd.)

[0119] 12 g of each mixture was placed in a water-permeable bag (50 mm × 80 mm) and sealed to obtain a bag containing the mixture. Because the mixture did not generate heat when in contact with air, it was left as is without being placed in a non-air-permeable bag until it was brought into contact with the water retainer described below.

[0120] Preparation of water holder As a water retaining material, nonwoven fabric (product name: Felibendi 150g / m 2 (Manufactured by Kuraray Kuraflex Co., Ltd., ethylene-vinyl alcohol copolymer, steam jet manufacturing method) was used. Specifically, in Examples 1 to 8 and Comparative Examples 1 and 2, this nonwoven fabric (size: 60 mm x 90 mm) was used as the water retaining device, and in Examples 7 and 8, two sheets of the nonwoven fabric used in Example 1, stacked together, were used as the water retaining device.

[0121] The amount of water absorbed into each water retainer was 2 g for Example 1, 4 g for Example 2, 10 g for Example 3, 11 g for Example 4, 14 g for Example 5, 20 g for Example 6, 22 g for Example 7, 25 g for Example 8, 0.5 g for Comparative Example 1, and 1 g for Comparative Example 2.

[0122] Water supply to the mix from the water holder Water was supplied from the water retainer to the mixture as follows: At room temperature (approximately 15 to 25°C), the water retainer containing the water was placed on one side (the water-permeable side) of the storage bag containing the mixture, and immediately a load of 3.6 kg (approximately 6500 Pa) was applied, followed by leaving the bag to stand for 1 minute.

[0123] The amount of water absorbed by the mixture upon contact was determined by measuring the weight of the water-holding device carrying water (weight before contact) immediately before contact, and then measuring the weight of the water-holding device after leaving it to stand for 1 minute (weight after contact) as described above, subtracting the weight after contact from the weight before contact, and using the resulting value as the amount of water absorbed by the mixture.

[0124] It should be noted that no water was observed to leak out of the storage bag, etc. In other words, all of the water released from the water-containing body was absorbed by the mixture in the storage bag.

[0125] Fever assessment Heat generation was evaluated according to the following procedure. First, a temperature sensor was attached and fixed with tape to the surface of the storage bag containing the mixture opposite the surface that came into contact with the water retaining device. Next, the water retaining device was brought into contact with the storage bag (the other side not attached to the temperature sensor). The storage bag was then placed on a wire rack with the opposite side (the side with the temperature sensor attached) facing downward, and the temperature was measured at room temperature (approximately 15 to 25°C), thereby measuring the heat generation temperature and time. During this process, data was recorded at 5-second intervals using the temperature sensor. After leaving the bag to stand for 1 minute under a load as described above, the water retaining device was removed from the storage bag.

[0126] Next, based on the exothermic temperature and time measured in this manner, the maximum exothermic temperature (maximum exothermic temperature within 3 hours from the application of the load), the duration of the exothermic temperature exceeding 40°C, and the time until the exothermic temperature exceeded 40°C (rise time) were evaluated. Specifically, for the maximum exothermic temperature, a temperature exceeding 40°C was rated as ◯, a temperature exceeding 30°C but below 40°C was rated as △, and a temperature below 30°C was rated as x. For the duration, a temperature exceeding 40°C for 30 minutes or more was rated as ◯, a temperature exceeding 10 minutes but less than 30 minutes was △, and a temperature less than 10 minutes was rated as x. For the rise time, the time required for the temperature to exceed 40°C after the contact was rated as ◯ if it was within 7 minutes, △ if it was more than 7 minutes but within 12 minutes, and x if it was longer than 12 minutes.

[0127] result The results are shown in Table 1.

[0128] [Table 1]

[0129] As is clear from Table 1, in Comparative Examples 1 and 2, which had a low water absorption rate per 100 parts by weight of the mixture, the heat generation (maximum temperature) was low, and the desired heat generation duration and heat generation start time were not observed. In contrast, in Example 1, which had an increased water absorption rate per 100 parts by weight of the mixture, At 8, good heat generation (maximum temperature) was achieved, and the heat generation duration was 10 minutes or more, and the heat generation started within 12 minutes.

[0130] This confirms that good heat generation characteristics can be obtained according to Examples 1 to 8. This also confirms that good heat generation characteristics can be obtained even when the water-containing material is brought into contact with the storage bag during use to cause the mixture in the storage bag to absorb water. [Explanation of symbols]

[0131] 1. Mask 2 Main body 3 Ear hook 4 mixture 5 Storage bag 6 Water retainer 7 Storage section

Claims

[Claim 1] The method comprises: a storage bag containing a mixture containing an oxidizable metal powder, an oxidation promoter, and a water retention agent; and a water retention device capable of supplying water to the mixture. At least a portion of the storage bag is water permeable, The heating tool, wherein the mixture absorbs 10 to 210 parts by mass of water per 100 parts by mass of the mixture.

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