Warmer

Abstract

To provide a warmer having excellent heat generation characteristics and steam generation amount while suppressing a manufacturing cost.SOLUTION: A warmer 1 includes a heating element 3 comprising powder of an oxidizable metal 3a, powder of a carbon material 3b, and powder of a porous substance 3c excluding the oxidizable metal 3a and the carbon material 3b. The heating element 3 is a sheet-like material. It is preferable for the heating element 3 that a value obtained by multiplying a content mass ratio of water to the oxidizable metal 3a by 100 is 30 or more and 270 or less, a value obtained by multiplying a content mass ratio of the porous substance 3a to the oxidizable metal 3c by 100 is 1 or more and 25 or less, and a value obtained by multiplying a content mass ratio of the porous substance 3c to water by 100 is 1 or more and 30 or less. Preferably, a pore diameter of the porous substance 3c is 0.01 μm or more and 5 μm or less. Preferably, an oil absorption amount of the powder of the porous substance 3c is 300 mL / 100 g or more and 900 mL / 100 g or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Heating devices that utilize heat generated by the oxidation reaction of oxidizable metals are used for various purposes. For example, the present applicant previously proposed a powder-type heating element with a heating layer containing an oxidizable metal, a water absorbent, and water, and a heating device for the eyes equipped with the same (see Patent Document 1). The heating element described in the document contains water, so that water vapor is generated along with the oxidation reaction of the oxidizable metal.

[0003] The applicant also proposed a heating element formed by laminating a heating layer containing an oxidizable metal, a water absorbent, and water, and a water-retaining layer formed from a water-absorbent sheet, and a heating device equipped with the heating element (see Patent Document 2). The heating element described in the document contains water, so that water vapor is generated along with the oxidation reaction of the oxidizable metal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-131088 A [Patent Document 2] US2014 / 373828 A1 Summary of the Invention

[0005] The present invention relates to a heating device. In one embodiment, a heating element is provided that includes a powder of an oxidizable metal, a powder of a carbon material, water, and a powder of a porous substance excluding the oxidizable metal and the carbon material. In one embodiment, the heating element is a sheet-like object. In one embodiment, the heating element has a ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100 [100 × (water / oxidizable metal powder)] of 30 or more and 270 or less.

[0006] The present invention also relates to another heating device. In one embodiment, a heating element is provided that includes a powder of an oxidizable metal, a powder of a carbon material, water, and a powder of a porous substance excluding the oxidizable metal and the carbon material. In one embodiment, the heating element is a sheet-like object. In one embodiment, the heating element has a ratio of the mass content of the porous material powder to the mass content of the oxidizable metal powder multiplied by one hundred [100 × (porous material powder / oxidizable metal powder)] of 1 to 25.

[0007] Furthermore, the present invention relates to still another heating device. In one embodiment, a heating element is provided that includes a powder of an oxidizable metal, a powder of a carbon material, water, and a powder of a porous substance excluding the oxidizable metal and the carbon material. In one embodiment, the heating element is a sheet-like object. In one embodiment, the heating element has a ratio of the mass content of the porous material powder to the mass content of the water multiplied by 100 [100 × (porous material powder / water)] of 1 to 30. Other features of the invention will be apparent from the claims and the following description. [Brief description of the drawings]

[0008] [Figure 1] 1(a) and (b) are cross-sectional views showing the configuration of a heating element in a heating device. [Diagram 2] 2(a) to 2(c) are cross-sectional views showing schematic arrangements of a heat generating element and a water-absorbent resin layer in a heating device. [Diagram 3] FIG. 3 is a cross-sectional view showing a schematic arrangement of a heating element and a water-absorbent resin layer in a heating device. [Figure 4] FIG. 4 is a plan view showing a schematic diagram of one embodiment of the heating device. [Diagram 5] FIG. 5 is an exploded perspective view showing a schematic diagram of the heating device shown in FIG. [Figure 6] FIG. 6 is a schematic diagram of a cross section along the lateral direction, which is the longitudinal direction, of the heating device shown in FIG. [Figure 7] FIG. 7 is a schematic diagram of an enlarged cross section of the heating device shown in FIG. [Figure 8] FIG. 8 is a diagram showing a schematic diagram of the heating device shown in FIG. 4 in use. [Figure 9] FIG. 9 is a plan view showing a schematic view of another embodiment of the heating device. [Figure 10] FIG. 10 is a plan view that shows a schematic diagram of a heating device according to still another embodiment. [Figure 11] FIG. 11 is a perspective view showing a schematic diagram of still another embodiment of the heating device. [Figure 12] FIG. 12 is a schematic diagram of a device for measuring the amount of steam generated from a heating device. Detailed Description of the Invention

[0009] In recent years, in response to the increasing demand for heating devices, techniques for improving heat generation characteristics and increasing the amount of steam generated have been investigated. One method for improving heat generation properties is, for example, to increase the content of oxidizable metals, but this increases the manufacturing costs and the mass of the desired heating device. Furthermore, in the powder-type heating element disclosed in Patent Document 1, the constituent materials of the heating element, such as oxidizable metals, can become unevenly distributed during use, leaving room for improvement in terms of heat generation characteristics and the amount of water vapor generated. Furthermore, the heating element disclosed in Patent Document 2 is in a sheet shape and has improved heat generation properties, but it is desired to further improve the heat generation properties and the amount of water vapor generated while reducing the manufacturing cost.

[0010] The inventors conducted extensive research into improving heat generation characteristics and the amount of water vapor generated, and unexpectedly discovered that by further incorporating a porous material other than an oxidizable metal and a carbon material, it is possible to manufacture a heating device that has good heat generation characteristics and an amount of water vapor generated while keeping manufacturing costs down. In addition, they discovered that by configuring one or more of the content ratio of oxidizable metal to water, the content ratio of oxidizable metal to porous material, and the content ratio of oxidizable metal to porous material to have a specific relationship, it is possible to produce a heating device with excellent heat generation characteristics and water vapor generation by promoting the oxidation reaction of the oxidizable metal while suppressing manufacturing costs.

[0011] Therefore, the present invention relates to a heating device. In one embodiment, the heating device has excellent heat generating properties and water vapor generation while keeping production costs down.

[0012] The present invention will now be described based on its preferred embodiments. In the present specification, when an upper limit or lower limit or upper and lower limits of a numerical value are specified, the upper limit and lower limit values ​​themselves are included. Furthermore, even if not specifically stated, it is understood that all numerical values ​​or numerical ranges below the upper limit or above the lower limit, or within the range of the upper and lower limits, are described. As used herein, "a" and "an" and the like are intended to mean one or more. In light of the following disclosure in this specification, it is understood that various modifications and alterations of the present invention are possible. Therefore, it should be understood that the present invention can be practiced in embodiments not specifically described in this specification within the technical scope based on the description of the claims. The contents of the above-mentioned patent documents and each of the patent documents described below are incorporated in their entirety into this specification as part of the content of this specification.

[0013] The heating device of the present disclosure is used in order to apply heat to an object to be heated by contacting the object with the heating device during use. The object to be heated may be, but is not limited to, the human eyes, mouth, nose and the skin and mucous membranes around them, or the skin and mucous membranes in the throat, face, scalp, neck, arms, shoulders, legs, knees, abdomen, back, waist, buttocks, etc.

[0014] The heating device of the present disclosure may, for example, be in the following forms (a) to (d), but is not limited to these forms. (a) An eye mask in the form of an eye mask configured to be held around the eyes. (b) An attachment form configured to be held on the neck, arm, shoulder, leg, elbow, knee, forehead, abdomen, back or waist. (c) A form of face mask configured to be held over and around the mouth, nose, or across the face. (d) A cup shape configured to be able to contact the mouth, nose and surrounding areas. All disclosures in this specification are applicable to all of the above aspects (a) to (d).

[0015] The heating device of the present disclosure includes a heating element. The heating element preferably contains (1) a powder of an oxidizable metal, (2) a powder of a carbon material, (3) a powder of a porous substance, and (4) water. The oxidizable metal powder has the function of generating heat through an oxidation reaction with oxygen in the air, thereby making it possible to impart heat to an object to be heated. The powder of the carbon material has the function of promoting the oxidation reaction of the oxidizable metal and efficiently generating heat. The powder of the porous substance has the function of increasing the heat generation efficiency by supplying water, which acts as a medium, to the reaction system when the powder of the carbon material promotes the oxidation reaction of the oxidizable metal. In the present disclosure, the porous material contained in the heating element excludes oxidizable metals and carbon materials, meaning that the heating element includes porous materials other than both oxidizable metals and carbon materials. Water has the function of facilitating the generation of an interaction between the powder of the oxidizable metal and the carbon material or the like that serves as a catalyst for the oxidation reaction. The heating element preferably comprises a mixture containing the materials (1) to (4) above.

[0016] The heating element is preferably configured as a sheet. A "sheet-like object" is a thin object that has two opposing surfaces, a small thickness between the surfaces, and is flexible and shape-retaining. The sheet-like material has a thickness of 0.6 mm or more, preferably 0.8 mm or more, and more preferably 1.0 mm or more. The thickness of the sheet-like material is 3.0 mm or less, preferably 2.8 mm or less, and more preferably 2.0 mm or less.

[0017] The heating element constituting the heating device is preferably configured to have the function of reacting with oxygen in the air to generate heat, and generating water vapor heated to a predetermined temperature as a result of this heat generation. In this case, the water contained in the heating element may partially evaporate into water vapor as heat is generated due to the oxidation reaction of the oxidizable metal.

[0018] The heating element may take the following forms (i) and (ii), for example. One embodiment of the heat generating element is (i) a sheet-like object comprising a base sheet and a layer of a heat generating composition provided on one surface of the base sheet. In this case, the heat generating composition is obtained by applying a paste containing a powder of an oxidizable metal, a powder of a carbon material, a powder of a porous substance, and water to one side of a base sheet. In the following description, the form of the heating element of (i) above will also be referred to as a "coating type."

[0019] Another example of the heating element is (ii) a heating element comprising a heat generating composition including a powder of an oxidizable metal, a powder of a carbon material, a powder of a porous material, and water, and preferably further including a fibrous material, which is mixed together and formed into a sheet-like product. In the following description, the heating element of type (ii) above will also be referred to as a "papermaking type."

[0020] The heating element may be used in either form (i) or (ii) as is. Alternatively, a heat generating element in either form (i) or (ii) may be housed in an air-permeable packaging material. It is also preferable that the packaging material is one that does not allow solids to flow in or out. When the heating element is contained within a packaging material, the packaging material is separate from the heating element, i.e., the packaging material does not constitute the heating element.

[0021] The shape of the packaging material is not particularly limited, but it is preferably flat. When forming the packaging material into a flat shape, it is also preferable that the packaging material is formed by laminating together one side of a first sheet material having breathability and the other side of a second sheet material having lower breathability than the first sheet material.

[0022] One embodiment of the heating element described above is shown, for example, in Figures 1(a) and (b). FIG. 1(a) shows an example of a coating type heating element, and FIG. 1(b) shows an example of a paper-made type heating element. In Figures 1(a) and (b), the respective components are shown as a heating element 3, a heating composition 30, a base sheet 31, a powder of an oxidizable metal 3a, a powder of a carbon material 3b, a powder of a porous material 3c, a fibrous material 33 and a packaging material 35.

[0023] It is preferable that the heating element constituting the heating device has a predetermined content ratio for at least one of the content ratios of oxidizable metal and water, the content ratio of oxidizable metal and porous material, and the content ratio of water and porous material.

[0024] In detail, the ratio of the mass content of the water to the mass content of the oxidizable metal powder contained in the heating element multiplied by 100 [100 x (water / oxidizable metal powder)] is preferably 30 or more, more preferably 40 or more, even more preferably 80 or more, and even more preferably 110 or more. In addition, the ratio of the mass content of the water to the mass content of the oxidizable metal powder contained in the heating element multiplied by 100 [100 x (water / oxidizable metal powder)] is preferably 270 or less, more preferably 250 or less, even more preferably 220 or less, and even more preferably 160 or less. In the present disclosure, "the ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100" is calculated by the formula "100 x (mass of water [g] / mass of the oxidizable metal powder [g])". By setting the content ratio of the oxidizable metal and water in this range, even if the content of the oxidizable metal is less than that of conventional heating devices, it is possible to achieve heat generation characteristics equal to or greater than those of conventional heating devices. In addition, it is possible to reduce the manufacturing cost of the heating device. In this disclosure, "reducing manufacturing costs" means being able to reduce the content of oxidizable metals contained in the heating element while improving heat generation characteristics to the same level or higher compared to conventional heating devices.

[0025] It is further preferable that the content ratio of the oxidizable metal powder and water contained in the heating element constituting the heating device is set within a predetermined range according to the form of the heating element. The heating element forms (i) and (ii) above have different manufacturing methods. Also, the heating element forms may be used differently depending on the intended heating device. Therefore, the preferred range of the content ratio of the oxidizable metal powder and water contained in the heating element will be explained below by dividing it into cases according to the form of the heating element.

[0026] In detail, when the heating element is in the form of a coating type, the ratio of the mass content of the water to the mass content of the oxidizable metal powder contained in the heating element multiplied by 100 [100 x (water / oxidizable metal powder)] is preferably 80 or more, more preferably 90 or more, and even more preferably 110 or more. Furthermore, when the heating element is in the form of a coating type, the ratio of the mass content of the water to the mass content of the oxidizable metal powder contained in the heating element multiplied by 100 [100 x (water / oxidizable metal powder)] is preferably 270 or less, more preferably 220 or less, and even more preferably 160 or less. By setting the content ratio of oxidizable metal and water in the application-type heating device as described above, even if the content of oxidizable metal is less than that of conventional heating devices, it is possible to achieve heat generation characteristics that are equal to or better than conventional heating devices. By setting the content of the oxidizable metal and water within a more preferable range, in addition to the excellent heat generating properties described above, it is possible to reduce the manufacturing cost of the heating device. Furthermore, by setting the content of the oxidizable metal and water within a more preferred range, in addition to the excellent heat generating characteristics and reduced manufacturing costs described above, the manufacturing efficiency of the heating device equipped with a heating element can be improved.

[0027] Alternatively, when the heating element is in the form of a paper-making type, the ratio of the mass content of the water to the mass content of the oxidizable metal powder contained in the heating element multiplied by 100 [100 x (water / oxidizable metal powder)] is preferably 30 or more, more preferably 35 or more, and even more preferably 40 or more. Furthermore, when the heating element is in the form of a paper-making type, the ratio of the mass content of the water to the mass content of the oxidizable metal powder contained in the heating element multiplied by 100 [100 × (water / oxidizable metal powder)] is preferably 80 or less, more preferably 70 or less, and even more preferably 60 or less. By setting the content ratio of oxidizable metal and water in the paper-made type, even if the content of oxidizable metal is less than that of conventional heating devices, it is possible to achieve heat generation characteristics that are equal to or better than conventional heating devices. In the paper-made type, by setting the content of oxidizable metal and water within a more preferred range, it is possible to achieve not only the above-mentioned excellent heat generating properties but also to reduce the manufacturing cost of the heating device. Furthermore, by setting the content of oxidizable metal and water in the paper-made type to a more preferred range, in addition to realizing the above-mentioned excellent heat generating properties and reducing manufacturing costs, it is possible to improve the manufacturing efficiency of heating devices equipped with heating elements.

[0028] Examples of the oxidizable metal powder constituting the heating element include powders of iron, aluminum, zinc, manganese, magnesium, calcium, etc. These may be used alone or in combination of two or more. Among these, it is preferable to use metallic iron from the viewpoints of ease of handling, safety, and production costs, that is, iron powder is preferably used. The iron powder may be, for example, one or more types selected from reduced iron powder and atomized iron powder. The oxidizable metal powder constituting the heating element may be an aggregate of metal particles having no pores on the particle surface, or may be an aggregate of porous metal particles.

[0029] The powder of the carbon material constituting the heating element has a function of promoting the oxidation reaction, and specifically, can have one or more functions of an oxygen-holding / supplying material for the oxidizable metal and a catalytic function. Examples of such carbon materials include activated carbon such as coconut shell charcoal, charcoal powder, bicarbonate coal, peat and lignite, carbon black, acetylene black, graphite powder, etc. These may be used alone or in combination of two or more kinds. Among these, activated carbon powder is preferably used as the powder of the carbon material because it has a good balance between oxygen supply ability and catalytic ability.

[0030] As the powder of the porous material constituting the heating element, any material other than the above-mentioned oxidizable metals and carbon materials can be used as the powder. The porous material to be used may be one that has a function of retaining moisture, and is preferably a porous inorganic compound. Specific examples of the porous material include silicon-containing inorganic compounds such as zeolite, silica, vermiculite, perlite, and calcium silicate, which may be used alone or in combination of two or more kinds. The porous materials in the present disclosure exclude diatomaceous earth, that is, it is preferable that the porous material does not contain diatomaceous earth. The porous material may be either anhydrous or hydrated. The pores formed in the porous material may be of the open cell type, closed cell type, or a combination thereof.

[0031] When calcium silicate is used as the porous material, examples of calcium silicate include gyrolite-based compounds, wlastonite-based compounds, tobermorite-based compounds, and calcium silicate hydrate-based compounds, which can be used alone or in combination of two or more.

[0032] In detail, the gyrolite-based compound is gyrolite (Ca 16 (SiO 20 )3(OH)8·14H2O), Truscottite (Ca 14 (SiO 20 )(Si 16 O 38 )8·2H2O), and Z-phase (Ca(Si2O5)·2H2O). Wollastonite-based compounds include necoite (Ca3(SiO 15 )·8H2O), okenite (Ca3(SiO 15 )·6H2O), xonotlite (Ca6(SiO 17 )(OH)2), foshagite (Ca4(Si3O9)(OH)2), and hillebrandite (Ca2(SiO3)(OH)2). The tobermorite-based compounds include 14Å tobermorite (Ca5(SiO 18 H2) 8H2O), 11Å tobermorite (Ca5(SiO 18 H2) 4H2O), and 9Å tobermorite (Ca5(SiO 18 H2)) and quasicrystalline calcium silicate (Ca / Si molar ratio is 0.8 to 2.0). Examples of calcium silicate hydrate compounds include tricalcium silicate hydrate (Ca6(Si2O7)(OH)6) and α-dicalcium silicate hydrate (Ca2(SiO4H)(OH)). The calcium silicate may be a commercially available product, such as Fluorite R (registered trademark), which is a gyrolite-based compound.

[0033] From the viewpoint of obtaining a heating element having a good balance between water retention capacity and water supply capacity and having improved heat generation characteristics due to efficient progress of the oxidation reaction of the oxidizable metal, it is preferable that the porous substance contains the above-mentioned silicon-containing inorganic compound. When the porous material contains a silicon-containing inorganic compound, from the viewpoint of further improving the heat generating properties, the content of the silicon-containing inorganic compound in the porous material is preferably 80 mass% or more, more preferably 90 mass% or more, and even more preferably 100 mass%. From the same viewpoint, it is more preferable that the silicon-containing inorganic compound is one or more of silica and calcium silicate. From the viewpoint of obtaining a heating element having excellent heat generating characteristics and an amount of water vapor generated, it is more preferable that the silicon-containing inorganic compound is calcium silicate. From the viewpoint of obtaining a heating element having even more excellent heat generating properties, it is more preferable to use at least one of gyrolite, xonotlite, and tobermorite as the porous material, and it is even more preferable to use gyrolite.

[0034] Next, another embodiment of the heating element in the heating device will be described. In the following description, components different from the above-described embodiments will be mainly described, and a description of similar components will be omitted. For components not specifically described in this embodiment, the description of the above-described embodiments will be applied as appropriate.

[0035] In this embodiment, the heating element preferably has a predetermined ratio of the mass content of the powder of the porous material to the mass content of the powder of the oxidizable metal. By setting the content ratio of the oxidizable metal and the porous material to a predetermined ratio, even if the content of the oxidizable metal is less than that of conventional heating devices, it is possible to achieve heat generation characteristics equal to or superior to those of conventional heating devices. In addition, it is possible to reduce the manufacturing cost of heating devices equipped with a heating element.

[0036] The heating element in this embodiment preferably contains a powder of an oxidizable metal, a powder of a carbon material, a powder of a porous substance, and water, similarly to the above-described embodiment. In the present embodiment, the heating element is preferably a sheet-like object. The heating element in this embodiment is preferably a coating type or paper type sheet-like material. In addition, the heating element in this embodiment is preferably configured to react with oxygen in the air to generate heat, and to generate water vapor heated to a predetermined temperature as a result of the heat generation.

[0037] In the heating element of this embodiment, the ratio of the mass content of the porous material powder to the mass content of the oxidizable metal powder [100 × (porous material powder / oxidizable metal powder)] is preferably 1 or more, more preferably 3 or more, and even more preferably 5 or more. In addition, the ratio of the mass content of the porous material powder to the mass content of the oxidizable metal powder multiplied by 100 [100 × (porous material powder / oxidizable metal powder)] is preferably 25 or less, more preferably 20 or less, and even more preferably 15 or less. By using such a ratio, the oxidation reaction of the oxidizable metal can be sufficiently and continuously progressed, resulting in a heating device that exhibits excellent heat generating properties. In addition, the manufacturing cost of the heating device can be reduced. In the present disclosure, "the ratio of the mass content of the porous material powder to the mass content of the oxidizable metal powder multiplied by 100" is calculated by the formula "100 x (mass of the porous material powder [g] / mass of the oxidizable metal powder [g])".

[0038] The content ratio of the oxidizable metal and the porous material in the heating element described above is preferably set within a predetermined range depending on the form of the heating device and the desired characteristics and effects to be achieved.

[0039] In detail, for example, when the heating device is in the form of an eye mask and the aim is to reduce manufacturing costs, from the viewpoint of continuously exerting heat generating properties equal to or greater than those of conventional devices, the ratio of the mass content of the porous material powder to the mass content of the oxidizable metal powder multiplied by 100 [100 x (porous material powder / oxidizable metal powder)] is preferably 1 or more, more preferably 3 or more, and even more preferably 5. In addition, in this embodiment, from the viewpoint of efficiently realizing a reduction in manufacturing costs by reducing the content of oxidizable metal compared to conventional heating devices, the ratio of the mass content of the porous material powder to the mass content of the oxidizable metal powder multiplied by 100 [100 x (porous material powder / oxidizable metal powder)] is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

[0040] As another embodiment regarding the content ratio of oxidizable metal and porous material, for example, when the heating device is in the form of an eye mask and the purpose is to increase the amount of water vapor generated, from the viewpoint of continuously exhibiting heat generating characteristics equal to or greater than those of conventional devices, the ratio of the mass content of the oxidizable metal powder to the mass content of the porous material powder multiplied by 100 [100 x (porous material powder / oxidizable metal powder)] is preferably 8 or more, more preferably 10 or more, and even more preferably 12 or more. In the same embodiment, from the viewpoint of facilitating the sustained generation of water vapor and increasing the amount of water vapor generated, the ratio of the mass content of the porous material powder to the mass content of the oxidizable metal powder multiplied by 100 [100 × (porous material powder / oxidizable metal powder)] is preferably 20 or less, more preferably 18 or less, and even more preferably 14 or less.

[0041] As yet another embodiment regarding the content ratio of oxidizable metal and porous material, for example, when the heating device is in the form of a face mask or a cup, from the viewpoint of continuously providing a warm sensation to the heated object even when the heating device is separated from the heated object, the value obtained by multiplying the ratio of the mass content of the oxidizable metal powder to the mass content of the porous material powder by 100 [100 x (porous material powder / oxidizable metal powder)] is preferably 3 or more, more preferably 5 or more, and even more preferably 6 or more. Furthermore, from the viewpoint of facilitating the sustained generation of water vapor and increasing the amount of water vapor generated, the ratio of the mass content of the porous material powder to the mass content of the oxidizable metal powder multiplied by 100 [100 × (porous material powder / oxidizable metal powder)] is preferably 15 or less, more preferably 11 or less, and even more preferably 8 or less.

[0042] Next, still another embodiment of the heating element in the heating device will be described. In the following description, as in the above-described embodiments, components different from the above-described embodiments will be mainly described, and a description of similar components will be omitted. For components not specifically described in this embodiment, the description of the above-described embodiments will be applied as appropriate.

[0043] In the present embodiment, the heating element preferably has a predetermined ratio of the mass content of the porous substance powder to the mass content of the water. By setting the water and porous material at a predetermined content ratio, even if the content of the oxidizable metal is less than that of conventional heating devices, it is possible to achieve heat generation characteristics equal to or superior to conventional heating devices. In addition, it is possible to reduce the manufacturing cost of the heating device.

[0044] The heating element in this embodiment preferably contains a powder of an oxidizable metal, a powder of a carbon material, a powder of a porous substance, and water, similarly to the above-described embodiment. In the present embodiment, the heating element is preferably a sheet-like object. The heating element in this embodiment is preferably a coating type or paper type sheet-like material. In addition, the heating element in this embodiment is preferably configured to react with oxygen in the air to generate heat, and to generate water vapor heated to a predetermined temperature as a result of the heat generation.

[0045] In the heating element of this embodiment, the ratio of the mass content of the porous material powder to the mass content of the water multiplied by 100 [100 x (porous material powder / water)] is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more. In addition, the ratio of the mass content of the porous material powder to the mass content of the water contained in the heating element multiplied by 100 [100 × (porous material powder / water)] is preferably 30 or less, more preferably 20 or less, and even more preferably 15 or less. With this configuration, the pores in the porous material can provide an appropriate balance between the supply of water that promotes the oxidation reaction of the oxidizable metal and the supply of oxygen from the air, so that the oxidation reaction of the oxidizable metal can be sufficiently and sustainably promoted, resulting in a heating device 1 that exhibits excellent heat generating properties. In addition, the manufacturing cost of the heating device can be reduced.

[0046] In the heating element in each of the above-mentioned embodiments, the content ratio of the oxidizable metal to water, the content ratio of the oxidizable metal to the porous material, and the content ratio of the water to the porous material may be such that any one of them satisfies the suitable content ratio, any two of them satisfies the suitable content ratio, or all of them satisfies the suitable content ratio.

[0047] In other words, the heating element may only satisfy the preferred content ratio of the oxidizable metal and water, or may only satisfy the preferred content ratio of the oxidizable metal and porous material, or may only satisfy the preferred content ratio of water and porous material. By having any of the above-mentioned configurations, even if the content of oxidizable metal is reduced compared to conventional heating devices, it is possible to exhibit heat generation characteristics that are equal to or better than conventional heating devices.

[0048] In addition, the heating element may be one that satisfies both a suitable content ratio of the oxidizable metal to water and a suitable content ratio of the oxidizable metal to the porous material, or one that satisfies both a suitable content ratio of the oxidizable metal to water and a suitable content ratio of the water to the porous material, or one that satisfies both a suitable content ratio of the oxidizable metal to water and a suitable content ratio of the water to the porous material. By having any combination of the above-mentioned configurations, it is possible to maintain a good balance between oxygen supply ability and catalytic ability, so that even if the content of oxidizable metal is reduced compared to conventional heating devices, it is possible to exhibit even better heat generation characteristics.

[0049] The heating element may satisfy all of the preferred content ratios of the oxidizable metal and water, the preferred content ratio of the oxidizable metal and porous material, and the preferred content ratio of water and porous material. By creating a heating element that satisfies all of these requirements, the balance between oxygen supply ability and catalytic ability can be maintained even better, and the oxidation reaction of the oxidizable metal can be allowed to proceed sufficiently and sustainably. Therefore, even if the content of the oxidizable metal is reduced compared to conventional heating devices, it is possible to efficiently express heat generation characteristics that are equal to or better than those of conventional devices. In addition, the manufacturing costs of the heating element and the heating device including the heating element can be further reduced. Furthermore, the manufacturing efficiency of the heating element and the heating device including the heating element can be further improved.

[0050] Below, matters that are commonly applied to the above-mentioned embodiments will be described. From the viewpoint of highly productively obtaining a heating device that has excellent heat generating properties and can sustainably exhibit said heat generating properties, the pore diameter D1 of the particles constituting the powder of the porous substance is preferably 0.01 μm or more, more preferably 0.02 μm or more, even more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and even more preferably 0.15 μm or more. The pore diameter D1 of the particles constituting the powder of the porous substance is preferably 5 μm or less, more preferably 1 μm or less, even more preferably 0.8 μm or less, still more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. When calcium silicate is used as the porous material, the pore diameter D1 of the particles is more preferably 0.02 μm or more, further preferably 0.05 μm or more, even more preferably 0.1 μm or more, and further more preferably 0.15 μm or more. When calcium silicate is used as the porous material, the pore diameter D1 of the particles is more preferably 0.8 μm or less, even more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. By setting the pore diameter D1 of the porous material within this range, the moisture held in the powder of the porous material can be efficiently transferred to the oxidizable metal side, thereby further improving the heat generation characteristics. The above-mentioned effects become more pronounced by setting the pore diameter D1 within a more preferable range, and become even more pronounced by setting the pore diameter D1 within an even more preferable range.

[0051] The pore diameter D1 of the above-mentioned porous material can be measured, for example, by the mercury intrusion method specified in JIS R1655. When two or more types of porous substances are blended, the pore diameter D1 is the value measured for the mixture of the porous substances.

[0052] The measurement of pore diameter by the mercury intrusion method specified in JIS R1655 can be carried out, for example, by the following method. First, 0.02 g to 0.1 g of powder of the porous material to be measured is used as a measurement sample, and a measurement cell containing the measurement sample is set in a mercury porosimeter (e.g., Autopore IV9500, manufactured by Micromeritics). The cumulative pore volume V (cm) of the measurement sample is measured as the mercury injection pressure P is increased within a predetermined range. 3 Next, the log differential pore volume (dV / d(log 10 D);cm 3 / g) on ​​the vertical axis to obtain the pore volume distribution. In other words, the pore volume obtained by differentiating the cumulative pore volume V with the logarithm of the pore diameter D is plotted on the vertical axis to obtain the pore volume distribution. D = 4γcosθ / P (A) (γ: surface tension of mercury, θ: contact angle, P: mercury injection pressure)

[0053] The measurement is performed under an environment of 22°C and 65% RH. The surface tension γ of mercury is 480 dyn / cm, the contact angle θ is 140°, and the mercury injection pressure P is in the range of 0 psia (0 MPa) to 60000 psia (413.685 MPa). Based on the distribution curve of the converted pore diameter D obtained under these measurement conditions, the cumulative total value of the converted pore diameters D in the range of 0.0018 μm to 100 μm is defined as the cumulative pore volume V (mL / g), and the median value of the pore diameters in the distribution curve is defined as the pore diameter D1 (μm) of the present disclosure.

[0054] The oil absorption of the powder of the porous substance is preferably 300 mL / 100 g or more, more preferably 350 mL / 100 g or more, and even more preferably 400 mL / 100 g or more. The oil absorption of the powder of the porous substance is preferably 900 mL / 100 g or less, more preferably 800 mL / 100 g or less, and even more preferably 700 mL / 100 g or less. With an oil absorption within this range, the water contained in the heating element is sufficiently retained by the particles of the porous material, and the water retained in the porous material can be transferred more efficiently to the oxidizable metal side, thereby enabling the heat generation characteristics to be sustained and efficiently improved.

[0055] The oil absorption of porous materials can be measured according to JIS K5010-13-2. Specifically, 1 to 5 g of the powder sample to be measured is placed in the center of the measurement plate, and 4 to 5 drops of boiled linseed oil are dropped from a burette onto the center of the sample at a time, and the whole is thoroughly kneaded with a palette knife each time. Dropping of boiled linseed oil and kneading of the sample are repeated, and when the whole sample becomes a hard putty-like mass, one drop of boiled linseed oil is dropped onto the boiled linseed and kneaded. The end point is when one drop of oil is dropped onto the boiled linseed and the sample can be rolled into a spiral shape using a palette knife, and the amount of boiled linseed oil dropped at this time (mL) is read from the scale. However, if the sample cannot be rolled into a spiral shape, the end point is when the sample suddenly becomes soft when one drop of oil is dropped onto the boiled linseed, and the amount of boiled linseed oil dropped at this time (mL) is read from the scale. The amount of powder sample to be used for measurement is determined in accordance with the provisions of JIS K5010-13-2 after a preliminary test is conducted to confirm the approximate value of the oil absorption amount. When two or more types of porous substances are mixed, the oil absorption is measured for the mixture of the porous substances. The amount of dripping (mL) obtained according to the above-mentioned method is converted into an amount per 100 g of the powder sample to be measured, and the oil absorption amount (mL / 100 g) according to the present disclosure is calculated.

[0056] When the powder of the oxidizable metal is composed of particles having pores on the surface, the pore diameter D2 of the particles constituting the powder of the oxidizable metal is preferably smaller than the pore diameter D1 of the powder of the porous material. With this configuration, the difference in capillary force allows the water held by the porous material to be transferred more efficiently to the oxidizable metal side, thereby further improving the heat generation characteristics.

[0057] In detail, the pore diameter D2 of the particles constituting the powder of the oxidizable metal is preferably 0.001 μm or more, more preferably 0.003 μm or more, and even more preferably 0.006 μm or more. The pore diameter D2 of the particles constituting the powder of the oxidizable metal is preferably 0.07 μm or less, more preferably 0.05 μm or less, and even more preferably 0.01 μm or less. By setting the content within this range, the difference in capillary force can efficiently draw the water held by the porous material into the oxidizable metal, thereby further promoting the oxidation reaction of the oxidizable metal and further improving the heat generation characteristics. Such oxidizable metal powders can be prepared, for example, by the method disclosed in EP 3626367 A1.

[0058] The pore diameter D2 of the powder of the oxidizable metal described above can be measured by the following method, for example, the mercury intrusion method specified in JIS R1655. In detail, 0.02 g to 0.1 g of the powder of the oxidizable metal is used as a measurement sample, and a measurement cell containing the measurement sample is set in a mercury porosimeter (e.g., Autopore IV9500, manufactured by Micromeritics), and the cumulative pore volume V (cm) of the measurement sample is measured by increasing the mercury injection pressure P within a predetermined range. 3 Next, the log differential pore volume (dV / d(log 10 D);cm 3 / g) on ​​the vertical axis to obtain the pore volume distribution. In other words, the pore volume obtained by differentiating the cumulative pore volume V with the logarithm of the pore diameter D is plotted on the vertical axis to obtain the pore volume distribution. D = 4γcosθ / P (A) (γ: surface tension of mercury, θ: contact angle, P: mercury injection pressure)

[0059] The measurement is performed under an environment of 22°C and 65% RH. The surface tension γ of mercury is 480 dyn / cm, the contact angle θ is 140°, and the mercury injection pressure P is in the range of 0 psia (0 MPa) to 60000 psia (413.685 MPa). Based on the distribution curve of the converted pore diameter D obtained under these measurement conditions, the cumulative total value of the converted pore diameters D in the range of 0.0018 μm to 100 μm is defined as the cumulative pore volume V (mL / g), and the median value of the pore diameters in the distribution curve is defined as the pore diameter D2 (μm) of the present disclosure.

[0060] From the viewpoint of achieving both continuous generation of water vapor and appropriate progress of the oxidation reaction, it is also preferable to further dispose a water-absorbent resin in or near the heating element. From the viewpoint of achieving both continuous generation of water vapor and moderate progress of the oxidation reaction, as well as preventing unintended dropping off of constituent materials and further improving production efficiency, when a water-absorbent resin is further disposed, it is further preferable that a packaging material is further disposed and a layer containing water-absorbent resin powder is disposed between the heat-generating composition in the heat generating element and the packaging material. The above-mentioned embodiments are applicable to both the coating type and the papermaking type. By further disposing a water-absorbent resin in or near the heating element, it is possible to absorb excess moisture present in the heating element, which in turn makes it possible to efficiently advance the oxidation reaction of the oxidizable metal and improve the heating properties, while at the same time allowing the moisture held in the water-absorbent resin and the heating element to be continuously released as water vapor, providing the user of the heating device with a comfortable feeling of warmth.

[0061] When a water-absorbent resin is further disposed in or near the heating element, one embodiment of the water-absorbent resin is, for example, a form in which a powder of the water-absorbent resin is present by being mixed with each powder of the oxidizable metal, the carbon material, and the porous material of the heating composition in the heating element, and with water. In this case, the powder of the water-absorbent resin constitutes a part of the heating element.

[0062] Alternatively, as another embodiment of the water-absorbent resin, a layer containing a powder of the water-absorbent resin is adjacent to the heating element. In this case, the layer containing the powder of the water-absorbent resin is configured separately from the heating element. Examples of the embodiment in which a layer containing water-absorbent resin powder is adjacent to a heat generating element include (a) an embodiment in which a single layer is formed by sandwiching water-absorbent resin powder between two moisture-permeable sheets, (b) an embodiment in which water-absorbent resin powder is arranged in a single layer in contact with the heat generating composition constituting the heat generating element without any other member, or (c) an embodiment in which a laminated structure in which a first water-absorbent resin layer in which water-absorbent resin powder is arranged adjacent to each other in a layered form and a second water-absorbent resin layer adjacent to the first water-absorbent resin layer and formed by sandwiching water-absorbent resin powder between two moisture-permeable sheets are arranged in the layered structure in which the layered structure is arranged in contact with the heat generating composition constituting the heat generating element without any other member. That is, in any of the above-mentioned cases (a) to (c), it is preferable that a heat-generating composition constituting a heat generating element is disposed between the base sheet and the layer containing the water-absorbent resin powder.

[0063] Alternatively, as yet another embodiment of the water-absorbent resin, a layer containing a powder of the water-absorbent resin is disposed as a base sheet and is adjacent to the heat-generating composition in the heat-generating element. In this case, the powder of the water-absorbent resin constitutes a part of the heat-generating element. The layer containing the water-absorbent resin powder is preferably formed by sandwiching the water-absorbent resin between two moisture-permeable sheets. In this case, it is also preferable that the heat-generating composition in the heat generating element is disposed in contact with the outer surface of one of the moisture-permeable sheets.

[0064] When a layer containing water-absorbent resin powder is disposed as a base sheet, the layer containing water-absorbent resin powder is preferably contained in a packaging material together with the heating element, from the viewpoint of preventing unintended falling off of the constituent materials. When a packaging material is provided, it is also preferable that the packaging material is formed by laminating together one side of a first sheet material having breathability and the other side of a second sheet material having lower breathability than the first sheet material. The packaging material is preferably flat. In the case where the layer containing water-absorbent resin powder is disposed as a base sheet and a packaging material is provided, it is further preferable that the layer containing water-absorbent resin powder and a first sheet material having air permeability in the packaging material are disposed so as to face each other.

[0065] As for the mode of existence of the heat generating element and the water-absorbent resin, one embodiment in which a layer containing a powder of the water-absorbent resin is adjacent to the heat generating element is illustrated in Figs. 2(a) to (c). In all of the embodiments shown in Figures 2(a) to (c), a layer 3L containing powder of a water-absorbent resin 37 (hereinafter, also referred to as a water-absorbent resin layer 3L) is disposed between the heat-generating composition 30 and the packaging material 35 in the heat-generating element 3. Although the heat generating element 3, water-absorbent resin layer 3L, and packaging material 35 shown in Figures 2(a) to (c) are depicted as having different thicknesses overall, this is merely done for the sake of convenience of explanation, and the actual heat generating element 3, water-absorbent resin layer 3L, and packaging material 35 in each of the forms shown in Figures 2(a) to (c) may be the same or different in thickness.

[0066] In detail, when the water-absorbent resin layer 3L is arranged, as shown in Fig. 2(a), the water-absorbent resin layer 3L is preferably formed by sandwiching the water-absorbent resin 37 between two moisture-permeable sheets 38, 38. In this case, it is also preferable that the water-absorbent resin layer 3L is in contact with the heat-generating composition 30 constituting the heat generating element 3 via the moisture-permeable sheet 38. In particular, it is preferable that the heat generating composition 30 constituting the heat generating element 3 is disposed between the base sheet 31 and the water-absorbent resin layer 3L. With this configuration, it is possible to continuously release water vapor while continuously exhibiting excellent heat generating properties, and generate more water vapor than conventional heating devices, so that the heated objects such as the eyes, nose, and throat can be continuously made to feel both a comfortable warmth and moisture. This configuration of the water-absorbent resin layer is advantageous in that, for example, by applying it to a heating device, preferably in the form of an eye mask or a patch, it can provide the user with a continuous sensation of warmth in the application area, such as the user's eyes and the surrounding area, thereby providing comfort to the user.

[0067] Alternatively, as shown in FIG. 2(b), it is also preferable that the water-absorbent resin layer 3L is arranged in a layer shape in which the water-absorbent resin 37 is in contact with the heat-generating composition 30 constituting the heat generating element 3 without any other member therebetween. In particular, it is preferable that the heat generating composition 30 constituting the heat generating element 3 is disposed between the base sheet 31 and the water-absorbent resin layer 3L. This configuration allows the device to generate more water vapor than conventional heating devices, which has the advantage of further increasing the amount of water vapor generated and providing a comfortable sensation of warmth and moisture to the heated objects such as the eyes, nose, mouth, and throat. This configuration of the water-absorbent resin layer is advantageous in that, for example, by applying it to a heating device, preferably in the form of a face mask, it can provide the user with a widespread perception of warmth and moisture in and around the mouth and nose, providing comfort to the user.

[0068] Alternatively, as shown in FIG. 2(c), the water-absorbent resin layer 3L preferably has a laminated structure in which a first water-absorbent resin layer 3s in which a water-absorbent resin 37 is arranged adjacent to the heat-generating composition 30 constituting the heat generating element 3 without any other member therebetween, and a second water-absorbent resin layer 3t adjacent to the first water-absorbent resin layer 3s and formed by sandwiching the water-absorbent resin 37 between two moisture-permeable sheets 38, 38 are arranged. In particular, it is preferable that the heat generating composition 30 constituting the heat generating element 3 is disposed between the base sheet 31 and the water-absorbent resin layer 3L. In the embodiment shown in FIG. 2(c), the water absorbent resin layer 3L has a laminated structure in which a first water absorbent resin layer 3s and a second water absorbent resin layer 3t are arranged in contact with each other. This configuration allows the heat generation reaction of the heating element to proceed efficiently, generating a large amount of water vapor in a relatively short time, allowing the heated objects such as the eyes, nose, mouth, and throat to quickly sense warmth and moisture. This configuration of the water-absorbent resin layer is advantageous in that, for example, when applied to a heating implement, preferably in the form of a cup, it can provide a concentrated sense of warmth and moisture to the user's mouth, nose and surrounding areas in a short period of time.

[0069] Regarding the mode of existence of the heat generating element and the water-absorbent resin, another embodiment in which a layer containing a powder of the water-absorbent resin is adjacent to the heat generating composition in the heat generating element is illustrated in FIG. In the embodiment shown in FIG. 3, a water-absorbent resin layer 3L is disposed between the heat-generating composition 30 and the packaging material 35 in the heat-generating element 3. As shown in FIG. 3, the water-absorbent resin layer 3L is preferably formed by sandwiching a water-absorbent resin 37 between two moisture-permeable sheets 38, 38. 3, the heat generating composition 30 in the heat generating element 3 is preferably disposed in contact with one surface of the moisture permeable sheet 38. In this case, it is also preferable that the water-absorbent resin layer 3L is the base sheet 31 in the heat generating element 3. As shown in FIG. 3, when the water-absorbent resin layer 3L is arranged as a base sheet 31 and a flat packaging material 35 is provided, it is more preferable that the water-absorbent resin layer 3L and a first sheet material having breathability in the packaging material are arranged to face each other. With this configuration, it is possible to continuously release water vapor while continuously exhibiting excellent heat generating properties, and generate more water vapor than conventional heating devices, so that the heated objects such as the eyes, nose, and throat can be continuously made to feel both a comfortable warmth and moisture. This configuration of the water-absorbent resin layer is advantageous in that, for example, by applying it to a heating device, preferably in the form of an eye mask or a patch, it can provide the user with a continuous sensation of warmth in the application area, such as the user's eyes and the surrounding area, thereby providing comfort to the user.

[0070] When the water-absorbent resin layer is disposed adjacent to the heat generating element, the water-absorbent resin layer is preferably configured as a sheet-like material.

[0071] Specific examples of water-absorbent resins include one or more of starch, crosslinked carboxymethylated cellulose, polymers or copolymers of acrylic acid or alkali metal acrylates, polyacrylic acid and its salts, and polyacrylate graft polymers. As the polyacrylate, a sodium salt can be used. The shape of the water-absorbent resin may be spherical, lumpy, grape-cluster-shaped, fibrous, or particles consisting of a combination thereof. The water-absorbent resin is preferably a powder consisting of an aggregate of particles.

[0072] As the moisture permeable sheet, for example, a fiber sheet such as tissue paper, absorbent paper, or nonwoven fabric, or a mesh sheet, etc. can be used. The moisture-permeable sheet preferably has breathability.

[0073] From the viewpoint of obtaining a heating device with good heat generating properties by appropriately controlling the oxidation reaction, the particles constituting the oxidizable metal powder preferably have a particle size of 1 μm or more, more preferably 10 μm or more. From the same viewpoint, the particle size of the particles constituting the powder of the oxidizable metal is preferably 200 μm or less, and more preferably 100 μm or less.

[0074] From the viewpoint of fully exerting the catalytic ability of the oxidation reaction and obtaining a heating device with good heat generating properties, the particle diameter of the particles constituting the powder of the carbon material is preferably 1 μm or more, and more preferably 10 μm or more. From the same viewpoint, the particle size of the particles constituting the powder of the carbon material is preferably 200 μm or less, and more preferably 100 μm or less.

[0075] From the viewpoint of obtaining a heating device with good heat generating properties by appropriately controlling the retention and supply of water, the particle diameter of the particles constituting the powder of the porous substance is preferably 1 μm or more, and more preferably 10 μm or more. From the same viewpoint, the particle size of the particles constituting the powder of the porous material is preferably 200 μm or less, and more preferably 100 μm or less.

[0076] When the water-absorbent resin is used in the form of a powder, the particle size of the particles constituting the powder may be within the range generally used in this technical field.

[0077] The particle size of each of the above-mentioned materials can be, for example, the median diameter measured by a laser diffraction scattering method using a laser diffraction / scattering type particle size distribution measuring device (manufactured by Horiba, Ltd., (model number: LA-950V2)).

[0078] When the heating element is a paper-type sheet-like material containing a fibrous material, the fibrous material may be any natural or synthetic fibrous material without any particular restrictions. Examples of natural fiber materials include plant fibers (cotton, kabak, 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, Ramie, coconut, rush, wheat straw, etc.), animal fibers (wool, goat hair, mohair, cashmere, alcapa, angora, camel, vicuna, silk, feathers, down, feathers, alginate fiber, chitin fiber, casein fiber, etc.), and mineral fibers (asbestos, etc.). These fiber materials can be used alone or in combination. Examples of synthetic fiber materials include semi-synthetic fibers (acetate, triacetate, acetate oxide, promix, chlorinated rubber, rubber hydrochloride, etc.), synthetic polymer fibers (nylon, aramid, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyester such as polyethylene terephthalate, polyacrylonitrile, acrylic, polyethylene, polypropylene, polystyrene, polyurethane, rayon, viscose rayon, cupra, etc.), metal fibers, carbon fibers, glass fibers, etc. These fiber materials can be used alone or in combination. Of these, from the viewpoint of achieving both uniform dispersion of the oxidizable metal and oxygen permeability by ensuring voids, thereby improving heat generation characteristics, it is preferable to use at least one of wood pulp, cotton, and polyester as the fiber material.

[0079] The average fiber length of the fiber material is preferably 0.5 mm or more, and more preferably 2 mm or more. The average fiber length of the fiber material is preferably 10 mm or less, and more preferably 5 mm or less. The average fiber length of a textile material is determined by measuring 50 or more fibers in a textile material, fixing one end of each fiber to a horizontal board and allowing it to hang down under its own weight, and measuring the fiber length using a clamping ruler, or by fixing the fibers on a microscope slide and measuring under a microscope, and taking the arithmetic mean of the measurement results obtained.

[0080] From the viewpoint of facilitating the generation of water vapor accompanying the heat generation of the heating element, it is preferable that the heating element contains an electrolyte. The electrolyte contained in the heating element may be, for example, one or more of a salt of an alkali metal or alkaline earth metal with phosphoric acid or sulfuric acid, or a chloride or hydroxide of an alkali metal or alkaline earth metal. Among these, from the viewpoint of excellent chemical stability and production costs, it is preferable to use one or more of tripotassium phosphate, potassium hydroxide, sodium chloride, and potassium chloride as the electrolyte. The electrolyte may be used, for example, in the form of a powder, or may be used as a liquid dissolved or dispersed in a liquid medium such as water.

[0081] The heating element may be composed only of an oxidizable metal powder, a carbon material powder, a porous substance powder, water, and, if necessary, a fibrous material, or the heating composition may contain other powders other than the oxidizable metal powder, the carbon material powder, and the porous substance powder in addition to various powders, water, and, if necessary, a fibrous material. The other powder may be, for example, one or more of the above-mentioned water-absorbent resins and electrolytes. In order to further improve the heat generation characteristics and amount of water vapor generated, the content of other powders in the heat generating element is preferably 20 mass% or less, and more preferably 10 mass% or less, expressed as the total mass ratio relative to all powders constituting the heat generating element. The total mass ratio of the oxidizable metal powder, the carbon material powder and the porous substance powder to the total powder constituting the heating element is preferably 80 mass% or more, and more preferably 90 mass% or more, from the viewpoint of further improving the heat generation characteristics and the amount of water vapor generated. When a water-absorbent resin is contained as another powder, the mass is based on the mass in an absolutely dry state.

[0082] A heating device having the above-mentioned configuration further contains an oxidizable metal and a porous material other than a carbon material in the sheet-like heating element, and by appropriately setting at least one of the content ratio of the oxidizable metal to water, the content ratio of the oxidizable metal to porous material, and the content ratio of water to porous material, a heating device having excellent heat generation characteristics and a high accumulated sensible heat amount, which is expressed as the integral of temperature and heat generation duration, can be obtained. Furthermore, even if the content of oxidizable metals is reduced compared to conventional heating devices, excellent heat generation properties can be exhibited, so that heating devices with heat generation properties equal to or better than conventional heating devices can be manufactured at reduced costs. Furthermore, by appropriately setting at least one of the content ratios of oxidizable metal and water, the content ratio of oxidizable metal and porous material, and the content ratio of water and porous material in the heating element, a heating device with excellent heat generation characteristics and water vapor generation can be obtained, regardless of the shape of the heating device, while keeping manufacturing costs down.

[0083] In general, the oxidation reaction of an oxidizable metal can be affected by the amount of moisture and oxygen present around the metal powder. In detail, if there is an excessively large amount of moisture around the metal powder, the moisture acts as a barrier making it difficult for the oxidizable metal to come into contact with oxygen, and as a result, the oxidation reaction will not continue or will start slowly. On the other hand, if the amount of moisture around the metal powder is excessively small, the oxidizable metal will be more likely to come into contact with oxygen, but water-mediated interaction with carbon materials, etc., which act as catalysts for the oxidation reaction, will be less likely to occur. As a result, the oxidation reaction will not be sustained sufficiently, making it difficult to achieve the desired heat generation characteristics.

[0084] In this regard, it is presumed that the use of a porous material allows sufficient water to be retained in the pores of the porous material, and that the water retained in the porous material is continuously and appropriately supplied to the oxidizable metal, thereby ensuring the amounts of moisture and oxygen necessary for the continuous progression of the oxidation reaction. In particular, as the oxidation reaction progresses, holes are formed on the surface of the oxidizable metal, making it porous. Therefore, the capillary force generated between the porous material and the oxidizable metal allows water to be continuously supplied from the porous material to the oxidizable metal, so that the oxidation reaction progresses continuously, the heat generation amount is sustained for a long period of time, and the heating device has even better heat generating properties. This becomes more remarkable by using, as the porous substance, preferably the above-mentioned silicon-containing inorganic compound, more preferably calcium silicate, and even more preferably at least one of gyrolite, xonotlite and tobermorite. In addition, due to the enhanced heat generation characteristics, the water contained in the heating element evaporates as heat is generated, and more water vapor is generated than with conventional heating devices, which has the advantage of increasing the amount of water vapor generated and allowing the user of the heating device to experience a comfortable warmth that lasts. Furthermore, the above-mentioned improvements in heat generation characteristics and water vapor generation amount can be easily achieved, regardless of the presence or absence of breathable packaging material or other sheet materials constituting the heating device, or the degree of breathability of the breathable packaging material or other sheet materials constituting the heating device.

[0085] The heating device preferably comprises a main body and a heating element provided in the main body. It is also preferable that the main body has a shape that covers the object to be heated when in use. The heating implement preferably comprises a top sheet located on the side closer to the object to be heated and a back sheet located on the side farther from the object to be heated. In detail, the heating implement preferably comprises a top sheet positioned closer to the user's skin, and a back sheet positioned farther from the user's skin. It is preferable that the main body of the heating implement is constituted by the top sheet and the back sheet. The heating element is preferably held between the top sheet and the back sheet that constitute the main body. It is also preferable that the heating element is held between the top sheet and the back sheet in a state where it is contained in a breathable packaging material. When the packaging material is formed of a first sheet material and a second sheet material, the breathable first sheet material is preferably arranged on the side closer to the heating object, more specifically, on the side closer to the user's skin. In other words, the first sheet material is preferably arranged so as to face the top sheet. When the packaging material is formed of a first sheet material and a second sheet material, the second sheet material, which has lower breathability than the first sheet material, is preferably arranged on the side farther from the heating object, more specifically, on the side farther from the user's skin. In other words, the second sheet material is preferably arranged so as to face the back sheet. It is also preferable that the heating device is adapted to generate steam heated to a predetermined temperature, thereby making it possible to apply heat to the heating target and its surroundings.

[0086] Hereinafter, one embodiment of the heating device will be described with reference to the drawings. 4 to 7 show a heating device in the form of a so-called eye mask as one embodiment of the heating device. That is, the present disclosure encompasses the use of a heating device as an eye mask, as well as a method of using a heating device as an eye mask. In the following description, components different from the above-described embodiments will be mainly described, and similar components will be denoted by the same reference numerals and description thereof will be omitted. For components not specifically described in this embodiment, the above-described description of each configuration will be applied as appropriate.

[0087] The heating device of this embodiment is configured to be held on and around the eyes. This heating device is used to apply heat to the eyes and their surroundings by being placed in contact with both human eyes, which are the object to be heated, during use. The heating device is designed to generate steam heated to a predetermined temperature, thereby making it possible to apply heat to the object to be heated, that is, the eye and its surroundings.

[0088] The heating device of this embodiment preferably comprises a main body portion that is elongated in the horizontal direction and has a shape that covers both eyes of the user when in use, and a heating element provided in the main body portion. It is also preferable that the heating implement of this embodiment is provided with a pair of ear hooks attached to the main body, which make it possible to maintain a state in which both eyes of the user are covered. In the following description of this embodiment, the direction corresponding to the longitudinal direction of the heating implement is also referred to as the horizontal direction, and the direction perpendicular to the horizontal direction is also referred to as the vertical direction. The heating device in this embodiment is illustrated in FIG. 4 as a heating device 1, a main body 2, a heat generating element 3, a horizontal direction X, and a vertical direction Y.

[0089] In the heating device 1 shown in Fig. 4, the ear hooks 4 are provided at both outer end regions in the lateral direction X of the main body 2, and can be turned over outward in the lateral direction X. This allows the ear hooks 4, 4 to be hung on the user's ears, respectively, so that the main body 2 can maintain the state in which both of the user's eyes are covered. From the viewpoint of improving the wearing comfort, the sheet material constituting the ear hook part 4 is preferably a stretchable sheet.

[0090] FIG. 5 shows an exploded perspective view of the heating device 1 of this embodiment. FIG. 6 shows a cross-sectional view of the heating device 1 along the lateral direction X. The main body 2 of the heating device 1 shown in Figures 5 and 6 is flat and includes a top sheet 5 located closer to the user's skin and a back sheet 6 located further away from the user's skin.

[0091] The top sheet 5 constitutes a surface including the areas that come into contact with objects to be heated, such as the human eyes, mouth, and nose, when the heating device 1 is in use. The back sheet 6 is the surface away from the user's skin and forms the outer surface of the heating device 1. That is, in Figures 5 and 6, the upper side of the paper is the side closer to the user's skin, and the lower side of the paper is the side farther from the user's skin.

[0092] The top sheet 5 and the back sheet 6 shown in Figures 5 and 6 are overlapped and bonded to each other with an adhesive 7 such as a hot melt adhesive, so that two heating elements 3, 3 are contained between the two sheets 5, 6 at a distance from each other in the lateral direction X. That is, in this embodiment, the heating element 3 is configured so as to be undetachable from the main body 2 . The heating element 3 is preferably held between a top sheet 5 and a back sheet 6 that constitute the main body 2 . Of the top sheet 5 and the back sheet 6, at least the top sheet 5 is preferably made of a breathable fiber sheet. The fiber sheet is an assembly of constituent fibers that are held in a sheet-like shape by at least one of entanglement, fusion, and adhesion. A detailed description of each of the sheets 5 and 6 will be given later.

[0093] The cross-sectional view of FIG. 6 shows the heating element 3 in a fixed state. As shown in FIG. 6, the heat generating element 3 is preferably formed by bonding a plurality of sheet materials together by heat sealing or the like, and is housed in a packaging material 35 having air permeability. In this case, it is also preferable that the heating element 3 is held between the top sheet 5 and the back sheet 6 in a state where it is contained in a breathable packaging material 35 .

[0094] It is preferable that the packaging material 35 is flat. In this case, it is also preferable that the packaging material 35 is formed by laminating together a first sheet material having air permeability on one side and a second sheet material having lower air permeability than the first sheet material on the other side. When the packaging material 35 is formed of a first sheet material and a second sheet material, the first sheet material having breathability is preferably disposed on the side closest to the user's skin. In other words, the first sheet material is preferably disposed so as to face the top sheet 5. When the packaging material 35 is formed of a first sheet material and a second sheet material, the second sheet material, which has lower breathability than the first sheet material, is preferably disposed on the side farther from the user's skin. In other words, the second sheet material is preferably disposed so as to face the back sheet 6.

[0095] When the heating device 1 is configured to include a packaging material 35, as shown in FIG. 6, it is preferable that the outer surface of the packaging material 35 and the inner surface of the back sheet 6 of the heating device 1 are fixed by adhesive fixing parts 7a, 7a formed by adhesive 7, and that the other surfaces are not fixed to the back sheet 6. In the embodiment shown in FIG. 6, each adhesive fixing part 7a, 7a is provided in the central region in the lateral direction X of the heating device 1, and extends along the longitudinal direction Y of the heating device 1. As shown in FIG. With this configuration, the heating element 3 can be placed with a high degree of fit to the object to be heated when the heating device 1 is in use, and heat can be efficiently applied to the object to be heated.

[0096] Returning to FIG. 5, as shown in the figure, the ear hook portion 4 is preferably made of a sheet material, and an insertion portion 4A extending in the lateral direction X is preferably formed in the sheet material. The insertion portion 4A is a hole through which the ear is passed when the ear hook portion 4 is hung on the ear. Alternatively, the insertion portion 4A may be formed by a through slit or the like through which the ear can pass. As shown in Figures 5 and 7, the ear hook portion 4 is joined to the outer surface of the top sheet 5 of the main body portion 2 at both outer end regions in the horizontal direction X, thereby forming a joining region 9 where the main body portion 2 and the ear hook portion 4 are joined. The joint region 9 also functions as a folding portion when the ear hook portion 4 is turned over around the joint end portion 9s.

[0097] FIG. 7 is a cross-sectional view showing the shape of the joining region 9 in the heating device 1 of this embodiment. The joining region 9 between the main body 2 and the ear hook portion 4 shown in Figures 5 and 7 is preferably continuously joined from the joining end 9s, which is the inner end of the joining region 9 in the horizontal direction X, to the outer end of the main body 2 in the horizontal direction X, and has a substantially semi-elliptical shape. As shown in FIG. 7, the bonding area 9 is preferably formed by bonding the topsheet 5 of the main body 2 and the ear hooking portion 4. It is preferable that the joint region 9 also functions as a folding portion when the ear hook portion 4 is turned inside out, with the joint end portion 9s as an axis. The bonded region 9 shown in FIGS. 5 and 7 is formed by continuous bonding, but may instead be formed by intermittent bonding.

[0098] The heating device 1 in the form of an eye mask shown in Figs. 4 to 7 can be used, for example, as shown in Fig. 8, by utilizing the ear hooks 4 to hold the heating device 1 on the ears. By using the heating device in this way, the steam and heat generated from the heating device 1 can be applied uniformly to the user's eyes and the surrounding area regardless of the user's position (e.g., lying on one's back, sitting, etc.). This is advantageous in that it improves the versatility of the heating device 1 usage.

[0099] Another embodiment of the heating device 1 will be described below with reference to Fig. 9. Fig. 9 shows a heating device having a so-called adhesive form as one embodiment of the heating device. In other words, the present disclosure encompasses the use of the heating device as an adhesive form, as well as a method of using the heating device as an adhesive form. In the following description, components different from the above-described embodiments will be mainly described, and similar components will be denoted by the same reference numerals and description thereof will be omitted. For components not specifically described in this embodiment, the above-described description of each configuration will be applied as appropriate.

[0100] FIG. 9 shows an embodiment of the heating device 1 in a patch form. The heating device 1 of this embodiment preferably comprises a main body 2 having a top sheet 5 which forms the skin-facing surface when in use and a back sheet 6 which forms the non-skin-facing surface when in use, and a heating element 3 provided in the main body 2. The heating element 3 is preferably held between a top sheet 5 and a back sheet 6 that constitute the main body 2 . It is also preferable that the heat generating element 3 is held between the top sheet 5 and the back sheet 6 that constitute the main body 2 in a state where it is contained in a breathable packaging material 35 .

[0101] In this embodiment, the top sheet 5 constituting the skin-facing surface preferably has an adhesive portion 51 provided over a partial region or the entire region of its outer surface. The adhesive part 51 is for holding the heating device 1 to the area where the heat and steam generated from the heating device 1 are to be applied. By providing the adhesive portion 51, the heating device 1 can be attached directly to the user's skin or to the user's clothing, and the heating device 1 can be easily held at a specified part of the body to be heated. In order to allow the adhesive portion to exhibit adhesiveness at a desired timing, a substrate such as a film that covers the adhesive portion may be provided.

[0102] Hereinafter, still another embodiment of the heating device 1 will be described with reference to Fig. 10. Fig. 10 shows a heating device having the form of a so-called face mask as one embodiment of the heating device. Thus, the present disclosure encompasses the use of a heating device as a face mask, as well as a method of using a heating device as a face mask. In the following description, the components different from the above-described embodiments will be mainly described, and the same components will be denoted by the same reference numerals and will not be described. For components not specifically described in this embodiment, the above-described description of each component will be applied as appropriate.

[0103] FIG. 10 shows an embodiment in which the heating device 1 is in the form of a face mask. The heating device 1 of this embodiment preferably comprises a main body 2 that covers at least one of the mouth and nose of the user during use, and a heating element 3 provided in the main body 2. In addition, the heating device 1 of this embodiment preferably has a pair of ear hooks 4 provided on both the left and right ends of the main body 2. The ear hooks make it possible to maintain a state in which at least one of the user's mouth and nose is covered. The ear hook portion 4 in this embodiment is made of a sheet material. It is preferable that an insertion portion 4A is formed in the central region of the ear hook portion 4. The heating element 3 is preferably held between a top sheet 5 and a back sheet 6 that constitute the main body 2 . It is also preferable that the heat generating element 3 is held between the top sheet 5 and the back sheet 6 that constitute the main body 2 in a state where it is contained in a breathable packaging material 35 .

[0104] As shown in FIG. 10, the heating device 1 of this embodiment preferably has a folding line 15 at a position corresponding to the bridge of the user's nose. The folding line 15 in this embodiment is provided in the lateral central region of the main body 2 of the heating device 1. With this configuration, when the heating device 1 in the form of a face mask is used, the folding line 15 acts as a flexible axis and the top sheet 5 can be fitted closely along the convex shape of the nose, reducing the likelihood of gaps occurring between the heating device 1 and the object to be heated, thereby enhancing the heating and humidifying effect. Alternatively, the heating device 1 may be flat and have no folding lines 15 depending on the application. The heating device 1 of this embodiment can be used by utilizing the ear hook portion 4 to hold the heating device 1 on the ear.

[0105] Hereinafter, still another embodiment of the heating device 1 will be described with reference to Fig. 11. Fig. 11 shows a heating device having a so-called cup shape as one embodiment of the heating device. That is, the present disclosure encompasses the use of the heating device in the form of a cup, as well as a method of using the heating device in the form of a cup. In the following description, the components different from the above-described embodiments will be mainly described, and the same components will be denoted by the same reference numerals and will not be described. For components not specifically described in this embodiment, the above-described description of each component will be applied as appropriate.

[0106] FIG. 11 shows an embodiment in which the heating device 1 is in the form of a cup. The heating device 1 of this embodiment preferably comprises a main body 2 that covers at least one of the mouth and nose of the user during use, and a heating element 3 provided in the main body 2. The heating device 1 of this embodiment may or may not have ear hooks that can keep at least one of the user's mouth and nose covered, depending on the application.

[0107] The heating device 1 in this embodiment preferably has a main body 2 in which a first panel portion 21 and a second panel portion 22 having substantially the same shape as the first panel portion 21 are continuously formed, as shown in FIG. In this embodiment, both panel portions 21, 22 are formed in a fan shape, and it is preferable that the tapered portions of both panel portions 21, 22 are configured to be continuous. Both the first panel portion 21 and the second panel portion 22 are composed of a continuous top sheet 5 and a continuous back sheet 6, and it is preferable that the heating element 3 is held between the top sheet 5 and the back sheet 6. It is also preferable that the heat generating element 3 is held between the top sheet 5 and the back sheet 6 that constitute the main body 2 in a state where it is contained in a breathable packaging material 35 .

[0108] The heating device 1 in this embodiment preferably has a boundary line D at the connecting portion between the first panel portion 21 and the second panel portion 22, which serves as a flexible axis along which the main body portion 2 is folded. In this embodiment, it is preferable that the first panel portion 21 and the second panel portion 22 have a shape that is line symmetrical with respect to the boundary line D. In the heating device 1 of this embodiment, the surface sheets 5 are folded around the boundary line D as an axis so that they face each other, and the first side edge 21A of the first panel portion 21 and the first side edge 22A of the second panel portion 22, as well as the second side edge 21B of the first panel portion 21 and the second side edge 22B of the second panel portion 22 are overlapped and joined together. In both panels 21, 22, the third side edge 21C of the first panel 21 and the third side edge 22C of the second panel 22 located on the outside are not joined together to form an opening in the cup shape. This opening is preferably open enough to cover the nose and mouth of the user. This forms a cylindrical cup-shaped heating device with a bottom, with the boundary line D and its vicinity as the bottom. The outer surface of this cup-shaped heating device is formed by the back sheet 6, and the inner surface is formed by the top sheet 5.

[0109] The cup-shaped heating device of this embodiment does not have an ear hook. In this case, it is preferable that the cup-shaped heating device with a bottomed cylindrical shape has a body part with dimensions that can be held by hand. In other words, it is preferable that the cup-shaped heating device has a body part that can be held by hand. When using the cup-shaped heating device, for example, the main body can be grasped by hand and the opening of the cup-shaped heating device can be held near the user's nose and mouth.

[0110] The various sheet materials that can be used for the ear loops, the top sheet and the back sheet, as well as the base sheet, the packaging material and the moisture-permeable sheet can each be independently selected as appropriate taking into consideration their properties such as breathability, moisture permeability, texture, elasticity, strength, and prevention of leakage of the constituent materials of the heat-generating composition. As the sheet material, for example, a fiber sheet such as a nonwoven fabric, a woven fabric, or paper, a resin foam sheet, a metal sheet, or a combination of these may be used. The sheet material may be a single-layer structure made of only one sheet material, whether single-layer or multi-layer, or may be a laminated structure made of two or more kinds of sheet materials superimposed on each other.

[0111] As a sheet material having high air permeability and moisture permeability, a meltblown nonwoven fabric is preferably used. As the sheet material used for the purpose of improving the feel, an air-through nonwoven fabric or a thermal bond nonwoven fabric is preferably used. Examples of sheet materials used for the purpose of exhibiting elasticity include air-through nonwoven fabrics, spunbond nonwoven fabrics, and thermal bond nonwoven fabrics, which contain synthetic fibers such as polyesters such as polyethylene terephthalate, polyethylene, and polypropylene. As the sheet material used for the purpose of imparting strength, a spunbond nonwoven fabric, a spunlace nonwoven fabric, a needle punch nonwoven fabric, a chemically bonded nonwoven fabric, or the like is suitably used. In addition to or instead of the nonwoven fabric described above, a nonwoven fabric that has been surface-treated with silicone, a surfactant, or the like can be used, or a foamed sheet made from a thermoplastic resin such as polyethylene or polyurethane can be used. In addition, these sheet materials can be made by mixing multiple fibers having different fiber raw materials, fiber diameters, degrees of crimp, etc., or by combining multiple sheet materials, so as to achieve desired properties. The ear hook portion, the top sheet and the back sheet, as well as the base sheet, the packaging material and the moisture-permeable sheet may each independently be a single structure consisting of only one sheet material, whether single-layer or multi-layer, or may be a laminated structure consisting of two or more types of sheet materials layered on top of each other.

[0112] As described above, it is preferable to use a fiber sheet for the top sheet. From the viewpoint of improving the manufacturing efficiency of the heating implement, at least one of needle-punched nonwoven fabric, air-through nonwoven fabric, spun-bonded nonwoven fabric, and chemically bonded nonwoven fabric can be preferably used.

[0113] When a fiber sheet such as a nonwoven fabric is used as the top sheet and the back sheet, it is preferable that both the top sheet and the back sheet have air permeability. "Having air permeability" means that the air permeability measured according to JIS P8117:2009 is 10,000 seconds / 100 mL or less. The air permeability measured according to JIS P8117 is the air permeability of 100 mL of air at normal temperature and normal pressure of 6.42 cm. 2 is defined as the time it takes for a

[0114] In detail, the air permeability of the top sheet and the back sheet is preferably 0.01 sec / 100 mL or more, and more preferably 0.03 sec / 100 mL or more, each independently. Air permeability is measured according to JIS P8117: 2009. Small air permeability means that it takes less time for air to pass through, and therefore means that the material has high breathability. By using a surface sheet with such breathability, it is possible to efficiently apply heat and water vapor to the object to be heated, and to efficiently control the oxidation reaction of the oxidizable metal, thereby obtaining a heating device with the desired heat generation characteristics.

[0115] When a packaging material is provided that is breathable and has a first sheet material that is breathable and a second sheet material that is less breathable than the first sheet material, the breathability of the first sheet material that constitutes the packaging material is preferably 20 sec / 100 mL or more, more preferably 30 sec / 100 mL or more, and even more preferably 40 sec / 100 mL or more. The air permeability of the first sheet material is preferably 25,000 sec / 100 mL or less, more preferably 15,000 sec / 100 mL or less, and even more preferably 10,000 sec / 100 mL or less.

[0116] The first sheet material having the above-mentioned breathability can be, for example, a resin film having a plurality of through holes, or a film obtained by uniaxially or biaxially stretching a sheet obtained from a resin composition containing polyethylene and a filler such as calcium carbonate. The breathability can be appropriately changed by adjusting the degree of stretching. A sheet which can be applied to the first sheet material is disclosed, for example, in EP1939240 A1.

[0117] When a breathable packaging material is provided and the packaging material has a first sheet material that is breathable and a second sheet material that is less breathable than the first sheet material, the breathability of the second sheet material that constitutes the packaging material is preferably 10,000 sec / 100 mL or more, and more preferably 25,000 sec / 100 mL or more, and it is even more preferable that it is non-breathable from the viewpoint of expressing sufficient and appropriate heat generating properties and sufficiently applying water vapor to the heated object. "Non-air permeable" means that the air permeability measured in accordance with JIS P8117:2009 is 80,000 seconds / 100 mL or more. As the second sheet material having the above-mentioned breathability, for example, a resin film having fewer through holes than the first sheet material or having no through holes can be used.

[0118] In the case where the packaging material has a breathable packaging material and the packaging material has a first sheet material having breathability and a second sheet material having lower breathability than the first sheet material, the moisture permeability of the first sheet material measured in accordance with JIS Z0208 is preferably 480 g / (m 2 24h) or more, more preferably 720g / (m 2 24h) or more, more preferably 960g / (m 2 24h) or more. The moisture permeability of the first sheet material measured in accordance with JIS Z0208 is preferably 5000 g / (m 2 24h) or less, more preferably 4750g / (m 2 24h) or less, more preferably 4500g / (m 2 24h or less. The moisture permeability of the second sheet material measured in accordance with JIS Z0208 is preferably 480 g / (m 2 24h) or less, preferably 240g / (m 2 ·24h) or less, more preferably 0g / (m 2 24h). By setting the moisture permeability of each of the first sheet material and the second sheet material independently within the above-mentioned ranges, it is possible to exhibit sufficient and appropriate heat generation characteristics and to provide a sufficient amount of water vapor to the object to be heated. As each sheet material that satisfies such moisture permeability, for example, the same sheet materials as explained above regarding the air permeability can be used.

[0119] When a fiber sheet is used as the top sheet, the basis weight of the top sheet is 10 g / m 2 It is preferable that the thickness is 30 g / m or more. 2 More preferably, it is 50 g / m or more. 2 More preferably, it is equal to or greater than this. The surface sheet has a basis weight of 200 g / m 2 It is preferable that the thickness is less than 130 g / m 2 More preferably, it is 100 g / m or less. 2 More preferably, it is equal to or greater than this.

[0120] Furthermore, when a fiber sheet is used as the back sheet, the basis weight of the back sheet is preferably smaller than that of the top sheet from the viewpoints of improving heat retention and printability. In detail, the basis weight of the back sheet is 10 g / m 2 It is preferable that the thickness is 20 g / m or more. 2 More preferably, it is equal to or greater than this. The back sheet has a basis weight of 100 g / m 2 It is preferable that the thickness is less than 80 g / m 2 It is even more preferable that: When the top sheet and the back sheet have a laminated structure, the basis weight of the entire sheet may be within the above-mentioned range.

[0121] The "moisture permeability" of a moisture permeable sheet is defined as the moisture permeability of the sheet measured according to JIS Z0208 of 2000g / (m 2 -24 hours or more. Specifically, the moisture permeability of the moisture permeable sheet is preferably 2000 g / (m2) as measured according to JIS Z0208. 2 24h) or more, more preferably 2500g / (m 2 24h) or more, more preferably 3000g / (m 2 24h) or more. The sheet having the moisture permeability described above can be suitably used as the moisture permeable sheet in the water-absorbent resin layer. When a plurality of moisture permeable sheets are used, the moisture permeability values ​​of the respective moisture permeable sheets may be the same or different.

[0122] When the heating implement has ear hooks, the shape of the ear hooks is not limited to the sheet-like members shown in Figs. 4 and 5, so long as the main body can be fixed to both eyes of the user. For example, instead of ear hooks made of a sheet material, ear hooks made of a string-like material or ear hooks made of a thread-like or band-like material may be used. In order to improve the fit of the heating implement, it is preferable to use an elastic material such as rubber to make the ear hooks 4 stretchable.

[0123] The shape of the heating element in the embodiment of the heating device shown in Figures 4, 9, 10 and 11 has been described as two heating elements held at a distance from each other, but the shape of the heating element is not particularly limited as long as it is capable of imparting a sensation of warmth to the heated object and its surroundings. For example, one heating element having a shape and size capable of covering the object to be heated and its surroundings may be held between the front sheet and the back sheet, or three or more heating elements may be held between the front sheet and the back sheet.

[0124] Further, the heating element shown in Figs. 5 and 6 is only partially fixed in the lateral central region of the heating implement, but the present invention is not limited to this form. For example, the heating element and the back sheet may be joined continuously or intermittently with an adhesive in the lateral central region and in regions other than the central region, or the heating element and the back sheet may be joined by applying adhesive to the entire surface of the back sheet at the position where the heating element is located.

[0125] Although the present invention has been described based on the preferred embodiment, the present invention is not limited to the above embodiment.

[0126] In relation to the above-mentioned embodiment of the present disclosure, the following heating device is further disclosed. <1> A heating element is provided which contains a powder of an oxidizable metal, a powder of a carbon material, water, and a powder of a porous substance other than the oxidizable metal and the carbon material; The heating element is a sheet-like object, The heating element is a heating device in which the ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100 [100 x (water / oxidizable metal powder)] is 30 or more and 270 or less. <2> A heating element is provided which contains a powder of an oxidizable metal, a powder of a carbon material, water, and a powder of a porous substance other than the oxidizable metal and the carbon material; The heating element is a sheet-like object, The heating element is a heating device in which the ratio of the mass content of the porous material powder to the mass content of the oxidizable metal powder multiplied by 100 [100 x (porous material powder / oxidizable metal powder)] is 1 or more and 25 or less. <3> A heating element is provided which contains a powder of an oxidizable metal, a powder of a carbon material, water, and a powder of a porous substance other than the oxidizable metal and the carbon material; The heating element is a sheet-like object, The heating element is a heating device in which the ratio of the mass content of the porous material powder to the mass content of the water multiplied by 100 [100 x (porous material powder / water)] is 1 or greater and 30 or less.

[0127] <4> The heating element has a ratio of the mass content of the powder of the porous material to the mass content of the powder of the oxidizable metal multiplied by one hundred [100×(powder of the porous material / powder of the oxidizable metal)] of preferably 1 or more, more preferably 3 or more, and even more preferably 5 or more. <1> ~ <3> 13. The heating device according to claim 12 . <5> The heating element has a ratio of the mass content of the powder of the porous material to the mass content of the powder of the oxidizable metal multiplied by one hundred [100×(powder of the porous material / powder of the oxidizable metal)] of preferably 25 or less, more preferably 20 or less, and even more preferably 15 or less. <1> ~ <4> 13. The heating device according to claim 12 . <6> The heating element has a ratio of the mass content of the porous material powder to the mass content of the water multiplied by 100 [100×(porous material powder / water)] of preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more. <1> ~ <5> 13. The heating device according to claim 12 . <7> The heating element has a ratio of the mass content of the porous material powder to the mass content of the water multiplied by 100 [100×(porous material powder / water)] of preferably 30 or less, more preferably 20 or less, and even more preferably 15 or less. <1> ~ <6> 13. The heating device according to claim 12 .

[0128] <8> The heating element is contained in a gas-permeable packaging material, A layer containing a water-absorbent resin powder is disposed between the heating element and the packaging material. <1> ~ <7> 13. The heating device according to claim 12 . <9> The water-absorbent resin powder is sandwiched between two moisture-permeable sheets to form the layer. <8> A heating device as described above. <10> The moisture permeability of the moisture permeable sheet measured in accordance with JIS Z0208 is preferably 2000 g / (m 2 24h) or more, more preferably 2500g / (m 2 24h) or more, more preferably 3000g / (m 2 24 hours or more <9> A heating device as described above.

[0129] <11> It is preferable that one surface of the packaging material is constituted by a first sheet material having air permeability, It is preferable that the other surface of the packaging material is made of a second sheet material having lower air permeability than the first sheet material. <8> ~ <10> 13. The heating device according to claim 12 . <12> It is further preferable that the layer containing the water-absorbent resin powder and the first sheet material of the packaging material are disposed so as to face each other. <11> A heating device as described above.

[0130] <13> the heat generating element is a sheet-like object comprising a base sheet and a layer of a heat generating composition provided on one surface of the base sheet, the heating element has a ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100 [100×(water / oxidizable metal powder)] of 80 to 270, The layer of the heat generating composition is obtained from a paste containing a powder of the oxidizable metal, a powder of the carbon material, a powder of the porous substance, and water. <1> ~ <12> 13. The heating device according to any one of claims 1 to 12. <14> The heating element has a ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100 [100×(water / oxidizable metal powder)] of preferably 80 or more, more preferably 90 or more, and even more preferably 110 or more. <13> A heating device as described above. <15> The heating element has a ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100 [100×(water / oxidizable metal powder)] of preferably 270 or less, more preferably 220 or less, and even more preferably 160 or less. <13> or <14> A heating device as described above. <16> The heat generating element comprises a base sheet and a layer of a heat generating composition provided on one surface of the base sheet, the layer of heat generating composition is obtained from a paste containing a powder of the oxidizable metal, a powder of the carbon material, a powder of the porous substance, and water; Further comprising a layer containing a water-absorbent resin powder, The heat generating composition is disposed between the base sheet and the layer containing the water absorbent resin powder. <1> ~ <15> 13. The heating device according to claim 12 . <17> The heat generating element comprises a base sheet and a layer of a heat generating composition provided on one surface of the base sheet, the layer of heat generating composition is obtained from a paste containing a powder of the oxidizable metal, a powder of the carbon material, a powder of the porous substance, and water; Further comprising a layer containing a water-absorbent resin powder, The layer containing the water-absorbent resin powder is disposed as the base sheet. <1> ~ <16> 13. The heating device according to claim 12 .

[0131] <18> the heating element is a sheet-like material obtained by mixing a powder of the oxidizable metal, a powder of the carbon material, a powder of the porous substance, water, and a fibrous material, The heating element has a ratio of the mass of the water to the mass of the oxidizable metal powder multiplied by 100 [100×(water / oxidizable metal powder)] of 30 to 80. <1> ~ <12> 13. The heating device according to claim 12 . <19> The fiber material preferably includes at least one of wood pulp, cotton, and polyester. <18> A heating device as described above. <20> The heating element has a ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100 [100×(water / oxidizable metal powder)] of preferably 30 or more, more preferably 35 or more, and even more preferably 40 or more. <18> or <19> A heating device as described above. <21> The heating element has a ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100 [100×(water / oxidizable metal powder)] of preferably 80 or less, more preferably 70 or less, and even more preferably 60 or less. <18> ~ <20> 13. The heating device according to claim 12 .

[0132] <22> The pore diameter of the porous material is 0.01 μm or more and 5 μm or less. <1> ~ <21> 13. The heating device according to claim 12 . <23> The pore diameter of the porous material is preferably 0.01 μm or more, more preferably 0.02 μm or more, even more preferably 0.05 μm or more, still more preferably 0.1 μm or more, and even more preferably 0.15 μm or more. <1> ~ <22> 13. The heating device according to claim 12 . <24> The pore diameter of the porous material is preferably 5 μm or less, more preferably 1 μm or less, even more preferably 0.8 μm or less, still more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. <1> ~ <23> 13. The heating device according to claim 12 . <25> The porous material is made of a silicon-containing inorganic compound. <1> ~ <24> 13. The heating device according to claim 12 .

[0133] <26> The porous material is made of calcium silicate. <1> ~ <25> 13. The heating device according to claim 12 . <27> The pore diameter of the calcium silicate is 0.02 μm or more and 0.8 μm or less. <26> A heating device as described above. <28> The pore diameter of the calcium silicate is more preferably 0.02 μm or more, even more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and even more preferably 0.15 μm or more. <26> or <27> A heating device as described above. <29> The pore diameter of the calcium silicate is more preferably 0.8 μm or less, even more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. <26> ~ <28> 13. The heating device according to claim 12 .

[0134] <30> The calcium silicate is one or more of a gyrolite-based compound, a wollastonite-based compound, a tobermorite-based compound, and a calcium silicate hydrate-based compound. <26> ~ <29> 13. The heating device according to claim 12 . <31> More preferably, the porous material is one or more of gyrolite, xonotlite, and tobermorite; It is even more preferred that the porous material is gyrolite. <1> ~ <30> 13. The heating device according to claim 12 .

[0135] <32> The oil absorption of the powder of the porous material, as measured in accordance with JIS K5010-13-2, is preferably 300 mL / 100 g or more, more preferably 350 mL / 100 g or more, and even more preferably 400 mL / 100 g or more. <1> ~ <31> 13. The heating device according to claim 12 . <33> The oil absorption of the powder of the porous material, as measured in accordance with JIS K5010-13-2, is preferably 900 mL / 100 g or less, more preferably 800 mL / 100 g or less, and even more preferably 700 mL / 100 g or less. <1> ~ <32> 13. The heating device according to claim 12 . <34> The particle size of the particles constituting the powder of the porous substance is preferably 1 μm or more, more preferably 10 μm or more, The particle size of the particles constituting the powder of the porous material is preferably 200 μm or less, more preferably 100 μm or less. <1> ~ <33> 13. The heating device according to claim 12 .

[0136] <35> The oxidizable metal powder is preferably iron powder, It is more preferable that the iron powder is one or more selected from reduced iron powder and atomized iron powder. <1> ~ <34> 13. The heating device according to claim 12 . <36> the oxidizable metal powder is composed of particles having pores on their surfaces, The pore diameter of the particles constituting the powder of the oxidizable metal is preferably smaller than the pore diameter of the powder of the porous material. <1> ~ <35> 13. The heating device according to claim 12 . <37> The pore diameter of the particles constituting the powder of the oxidizable metal is preferably 0.001 μm or more, more preferably 0.003 μm or more, and even more preferably 0.006 μm or more. The pore diameter of the particles constituting the powder of the oxidizable metal is preferably 0.07 μm or less, more preferably 0.05 μm or less, and even more preferably 0.01 μm or less. <36> A heating device as described above. <38> The particle size of the particles constituting the powder of the oxidizable metal is preferably 1 μm or more, and more preferably 10 μm or more; The particle size of the particles constituting the powder of the oxidizable metal is preferably 200 μm or less, more preferably 100 μm or less. <1> ~ <37> 13. The heating device according to claim 12 . <39> As the powder of the carbon material, activated carbon powder is preferably used. <1> ~ <38> 13. The heating device according to claim 12 . <40> The particle size of the particles constituting the powder of the carbon material is preferably 1 μm or more, more preferably 10 μm or more, The particle diameter of the particles constituting the powder of the carbon material is preferably 200 μm or less, more preferably 100 μm or less. <1> ~ <39> 13. The heating device according to claim 12 . <41> The heating element preferably contains an electrolyte. <1> ~ <40> 13. The heating device according to claim 12 .

[0137] <42> The heating element includes a main body having a shape that covers a heating target when in use, and the heating element is provided in the main body, The main body includes a top sheet located on a side closer to the object to be heated and a back sheet located on a side farther from the object to be heated, The heating element is held between the top sheet and the back sheet. <1> ~ <41> 13. The heating device according to claim 12 . <43> The device comprises a main body having a shape that covers both eyes of a user when in use, the heating element provided in the main body, and a pair of ear hooks that are attached to the main body and can maintain a state in which both eyes of the user are covered by the main body, The main body portion includes a top sheet located on a side closer to the user's skin and a back sheet located on a side farther from the user's skin, The heating element is held between the top sheet and the back sheet. <1> ~ <42> 13. The heating device according to claim 12 . <44> It is preferable that the top sheet has an adhesive portion provided on a part or the entire area of ​​its outer surface. <42> A heating device as described above.

[0138] <45> The device comprises a main body having a shape that covers at least one of a user's mouth and nose when in use, and the heating element provided in the main body, The main body portion includes a top sheet located on a side closer to the user's skin and a back sheet located on a side farther from the user's skin, The heating element is held between the top sheet and the back sheet. <1> ~ <42> 13. The heating device according to claim 12 . <46> The headset further includes a pair of ear hooks that are attached to the main body and can maintain a state in which the main body covers at least one of the mouth and nose of the user. <45> A heating device as described above. <47> The headset does not include a pair of ear hooks that are attached to the main body and can maintain a state in which the main body covers at least one of the mouth and nose of the user, The heating device is configured so that the main body can be held by hand when the heating device is in use. <45> A heating device as described above.

[0139] <48> The air permeability of the top sheet measured in accordance with JIS P8117 is preferably 0.01 sec / 100 mL or more, and more preferably 0.03 sec / 100 mL or more. The air permeability of the back sheet measured in accordance with JIS P8117 is preferably 0.01 sec / 100 mL or more, and more preferably 0.03 sec / 100 mL or more. <42> ~ <47> 13. The heating device according to claim 12 . <49> The surface sheet has a basis weight of 10 g / m 2 It is preferable that the thickness is 30 g / m or more. 2 More preferably, it is 50 g / m or more. 2 It is even more preferable that The surface sheet has a basis weight of 200 g / m 2 It is preferable that the thickness is less than 130 g / m 2 More preferably, it is 100 g / m or less. 2 More preferably, <42> ~ <48> 13. The heating device according to claim 12 . <50> The basis weight of the back sheet is preferably smaller than the basis weight of the top sheet, The basis weight of the back sheet is 10 g / m 2 It is preferable that the thickness is 20 g / m or more. 2 More preferably, The basis weight of the back sheet is 1 g / m 2 It is preferable that the thickness is less than 80 g / m 2 It is more preferable that <42> ~ <49> 13. The heating device according to claim 12 .

[0140] <51> It is preferable that the heating element is held between the top sheet and the back sheet in a state where it is contained in a breathable packaging material. <42> ~ <50> 13. The heating device according to claim 12 . <52> It is preferable that one surface of the packaging material is constituted by a first sheet material having air permeability, It is preferable that the other surface of the packaging material is formed of a second sheet material having lower air permeability than the first sheet material, It is preferable that the first sheet material is disposed so as to face the top sheet, It is preferable that the second sheet material is disposed so as to face the back sheet. <51> A heating device as described above.

[0141] <53> The air permeability of the first sheet material measured in accordance with JIS P8117 is preferably 20 seconds / 100 mL or more, more preferably 30 seconds / 100 mL or more, and even more preferably 40 seconds / 100 mL or more. <11> , <12> , <52> 13. The heating device according to claim 12 . <54> The air permeability of the first sheet material measured in accordance with JIS P8117 is preferably 25,000 sec / 100 mL or less, more preferably 15,000 sec / 100 mL or less, and even more preferably 10,000 sec / 100 mL or less. <11> , <12> , <52> , <53> 13. The heating device according to claim 12 . <55> The air permeability of the second sheet material measured in accordance with JIS P8117 is preferably 10,000 sec / 100 mL or more, more preferably 25,000 sec / 100 mL or more, and further preferably non-air permeable. <11> , <12> , <52> ~ <54> 13. The heating device according to claim 12 .

[0142] <56> The moisture permeability of the first sheet material measured in accordance with JIS Z0208 is preferably 480 g / (m 2 24h) or more, more preferably 720g / (m 2 24h) or more, more preferably 960g / (m 2 24 hours or more <11> , <12> , <52> ~ <55> 13. The heating device according to claim 12 . <57> The moisture permeability of the first sheet material measured in accordance with JIS Z0208 is preferably 5000 g / (m 2 24h) or less, more preferably 4750g / (m 2 24h) or less, more preferably 4500g / (m 2 24 hours or less <11> , <12> , <52> ~ <56> 13. The heating device according to claim 12 . <58> The moisture permeability of the second sheet material measured in accordance with JIS Z0208 is preferably 480 g / (m 2 24h) or less, preferably 240g / (m 2 ·24h) or less, more preferably 0g / (m 2 24h) <11> , <12> , <52> ~ <57> 13. The heating device according to claim 12 . <59> The above-mentioned has a function of generating steam by generating heat. <1> ~ <58> 13. The heating device according to claim 12 .

[0143] <60> The above <1> ~ <59> 2. Use of the heating device according to any one of claims 1 to 11 as an eye mask. <61> The above <1> ~ <59> 2. Use of the heating device according to any one of claims 1 to 11 in the form of an adhesive patch. <62> The above <1> ~ <59> Use of the heating device according to any one of claims 1 to 5 as a face mask. <63> The above <1> ~ <59> 2. Use of the heating device according to any one of claims 1 to 11 as a cup. EXAMPLES

[0144] The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited to such examples. In the tables, blank spaces indicate "non-containing".

[0145] [Examples 1 to 6 and Comparative Example 1] <Paint preparation> Iron powder (RKH3, manufactured by DOWA IP Creation Co., Ltd., particle size: 45 μm) was used as the powder of the oxidizable metal, activated carbon powder (Carborafine, manufactured by Osaka Gas Chemicals Co., Ltd., particle size: 31 μm) was used as the powder of the carbon material, and gyrolite, a gyrolite-based compound of calcium silicate powder (product name: Fluorite R, manufactured by Tomita Pharmaceutical Co., Ltd., particle size: 47 μm, pore diameter D1: 0.18 μm) was used as the powder of the porous material 3c. These raw materials were mixed with water, an electrolyte, and a thickener in the ratios shown in Table 1 below to obtain a paste of an exothermic composition having a viscosity of 5000 mPa·s at 25°C as measured with a B-type viscometer.

[0146] <Preparation of heating element> As the first moisture permeable sheet, a wood pulp paper (basis weight 20 g / m 2 On top of the paper (manufactured by Ino Paper Co., Ltd.), particles of water-absorbent resin (AQUALIC® CA, manufactured by Nippon Shokubai Co., Ltd.) are placed at a basis weight of 50 g / m2 On the water-absorbent resin layer, a wood pulp paper (basis weight 30 g / m2) was applied as a second moisture-permeable sheet. 2 (manufactured by Ino Paper Co., Ltd.) was laminated to obtain a sheet having a water-absorbent resin layer. A polyethylene-laminated tissue paper (manufactured by Nittoku Co., Ltd.) was used as a base sheet, and the above-mentioned paste was applied to one side of the sheet by a die coating method while adjusting the discharge pressure to obtain a sheet-like coated product. The discharge pressure was adjusted so that the basis weight of the paste was the value shown in Table 1. Then, 0.064 g of salt (Otsuka Pharmaceutical Co., Ltd., official sodium chloride) was evenly spread on the paste side, and then a water-absorbent resin sheet was laminated on the paste side to obtain a laminate precursor. The obtained laminate precursor was then cut to a size of 49 mm x 49 mm to obtain a laminate in which a water-absorbent resin layer was disposed on the heat-generating composition side of the coating-type heat generating element. Next, the laminate was sandwiched between a breathable first sheet material (breathability: 1500 sec / 100 mL) and a non-breathable second sheet material, each cut to 63 mm x 63 mm, and the four sides of these sheets were heat-sealed to obtain a heating element housed in a packaging material. This configuration is exemplified in Figure 2(a). The first sheet material in the packaging material was arranged so that its inner surface faced the outer surface of the water-absorbent resin layer sheet, and the second sheet material in the packaging material was arranged so that its inner surface faced the surface of the base sheet. Finally, needle punched nonwoven fabric (80g / m 2 ) and an air-through nonwoven fabric (basis weight 30 g / m 2 The heating element contained in the packaging material was held between the packaging material and a back sheet made of a material such as polyester, to obtain an eye mask-type heating device having the structure illustrated in Figures 4 to 7. The top sheet was arranged so that its inner surface faced the outer surface of the first sheet material in the packaging material. The back sheet was arranged so that its inner surface faced the outer surface of the second sheet material in the packaging material. This heating device was formed to generate steam when heated.

[0147] [Examples 7 and 8] A heating element and a water-absorbent resin layer having the same configuration as in Example 1, and an eye mask-type heating device containing these, were produced, except that a calcium silicate powder different from the calcium silicate powder used in Example 1 was used as the powder of porous material. The calcium silicate powder used in Example 2 was tobermorite, a tobermorite-based compound (manufactured by Nippon Insulation Co., Ltd., product name: tobermorite, particle size: 24 μm, pore diameter D1: 0.62 μm), and the calcium silicate powder used in Example 3 was xonotlite, a wollastonite-based compound (manufactured by Nippon Insulation Co., Ltd., product name: xonotlite, particle size: 47 μm, pore diameter D1: 0.46 μm).

[0148] [Examples 9 to 11 and Comparative Example 2] A heating element, a water-absorbent resin layer, and a heating device were obtained in the same manner as in Example 1, except that the contents of water, oxidizable metal, and porous material in the heating element were changed as shown in Table 1 below.

[0149] [Examples 12 to 13 and Comparative Example 3] As shown in Table 1 below, the contents of water, oxidizable metal, and porous material in the heating element were changed. In addition, the breathable first sheet material constituting the packaging material was changed to one with an air permeability of 60 sec / 100 mL or one with an air permeability of 4000 sec / 100 mL. The first sheet material in the packaging material was disposed so that its inner surface faced the water-absorbent resin layer, and the second sheet material in the packaging material was disposed so that its inner surface faced the base sheet. The top sheet was arranged so that its inner surface faced the outer surface of the first sheet material in the packaging material, and the back sheet was arranged so that its inner surface faced the outer surface of the second sheet material in the packaging material. Other than this, the heat generating element, the water-absorbent resin layer, and the heating device were obtained in the same manner as in Example 1.

[0150] [Example 14 and Comparative Example 4] A mixture containing the oxidizable metal, carbon material, porous substance, and water used in Example 1, as well as pulp fiber (softwood kraft pulp, manufactured by Skeena Corporation, product name "Skeena", average fiber length: 2.1 mm) as a fibrous material, was paper-made into an intermediate molded body, and then an electrolyte was impregnated into the intermediate molded body to form a paper-made type heating element having the raw material ratio shown in Table 1 below. A sheet material with an air permeability of 2500 sec / 100 mL was used as the air permeability material for the packaging material, and a heating device was formed in the same manner as in Example 1. This configuration is illustrated in FIG. 1(b).

[0151] [Example 15 and Comparative Example 5] Crepe paper (manufactured by Daishowa Paper Industries Co., Ltd.) was used as the first moisture permeable sheet. A polyethylene-laminated tissue paper (manufactured by Nittoku Co., Ltd.) was used as a base sheet, and the above-mentioned paste was applied to one side of the sheet by die coating while adjusting the discharge pressure to obtain a sheet-like coated product. The discharge pressure was adjusted so that the basis weight of the paste was the value shown in Table 2. Then, 0.094 g of salt (Otsuka Pharmaceutical Co., Ltd., official sodium chloride) and 0.133 g of water-absorbing polymer (sodium polyacrylate, spherical, average particle size 300 μm, Sunfresh ST-500D*, Sanyo Chemical Industries, Ltd.) were uniformly spread on the paste side, and then crepe paper was laminated on the paste side to obtain a laminate precursor. The obtained laminate precursor was then cut to a size of 49 mm x 49 mm to obtain a laminate in which a water-absorbing resin layer was disposed on the heat-generating composition side of the coating-type heat generating element. Next, the laminate was sandwiched between a breathable first sheet material (breathability: 60 sec / 100 mL) and a non-breathable second sheet material, each cut to 63 mm x 63 mm, and the four sides of these sheets were heat-sealed to obtain a heating element housed in a packaging material. This configuration is exemplified in Figure 3(b). The first sheet material in the packaging material was arranged so that its inner surface faced the outer surface of the water-absorbent resin layer sheet, and the second sheet material in the packaging material was arranged so that its inner surface faced the surface of the base sheet.

[0152] [Example 16 and Comparative Example 6] As the first moisture permeable sheet, a wood pulp paper (basis weight 20 g / m 2 On top of the paper (manufactured by Ino Paper Co., Ltd.), particles of water-absorbent resin (AQUALIC® CA, manufactured by Nippon Shokubai Co., Ltd.) are placed at a basis weight of 50 g / m 2 On the water-absorbent resin layer, a wood pulp paper (basis weight 30 g / m2) was applied as a second moisture-permeable sheet. 2 (manufactured by Ino Paper Co., Ltd.) was laminated to obtain a sheet having a water-absorbent resin layer. A polyethylene-laminated tissue paper (manufactured by Nittoku Co., Ltd.) was used as a base sheet, and the above-mentioned paste was applied to one side of the sheet by die coating while adjusting the discharge pressure to obtain a sheet-like coated product. The discharge pressure was adjusted so that the basis weight of the paste was the value shown in Table 2. Then, 0.169 g of salt (Otsuka Pharmaceutical Co., Ltd., official sodium chloride) and 0.141 g of water-absorbing polymer (sodium polyacrylate, spherical, average particle size 300 μm, Sunfresh ST-500D*, Sanyo Chemical Industries, Ltd.) were uniformly spread on the paste side, and then a water-absorbing resin sheet was laminated on the paste side to obtain a laminate precursor. The obtained laminate precursor was then cut to a size of 49 mm x 49 mm to obtain a laminate in which a water-absorbing resin layer was arranged on the heat-generating composition side of the coating-type heat generating element. Next, the laminate was sandwiched between a breathable first sheet material (breathability: 60 sec / 100 mL) and a non-breathable second sheet material, each cut to 63 mm x 63 mm, and the four sides of these sheets were heat-sealed to obtain a heating element housed in a packaging material. This configuration is exemplified in Figure 3(c). The first sheet material in the packaging material was arranged so that its inner surface faced the outer surface of the water-absorbent resin layer sheet, and the second sheet material in the packaging material was arranged so that its inner surface faced the surface of the base sheet.

[0153] [Measurement of accumulated sensible heat] The accumulated amount of sensible heat in the heating devices of the Examples and Comparative Examples was measured in an environment of room temperature of 20° C. and humidity of 50% RH according to the following method. First, the oxygen barrier bag was opened to select the heating device to be measured, which was sealed in the oxygen barrier bag, and one heating element was removed from the heating device together with its packaging. Next, the first sheet material side of the packaging material for the removed heating element was placed facing outward, and a temperature sensor was installed and fixed in the area of ​​the second sheet material side where the heating element was placed. The temperature sensor was fixed to the measurement surface with a mesh material (polyester, double raschel fabric with a thickness of 8 mm) and a SUS plate (a 500 g perforated plate). The temperature was then measured over time using a measuring device described in JIS S4100 connected to a temperature sensor. The temperature was measured at 10 second intervals starting from the time the oxygen barrier bag was opened, and measurements were continued for a total of 10 minutes or 20 minutes. From the heat generation profile plotted with the measured temperature (℃) on the vertical axis and the measurement time (seconds) on the horizontal axis, the integral value of the measured temperature minus 35℃ was calculated at the time when the temperature was 35℃ or higher, and this was taken as the sensible heat accumulation (℃·10min or ℃·20min). The results are shown in Tables 1 and 2 below.

[0154] [Measurement of water vapor generation amount] The amount of water vapor generated in the heating devices of the Examples and Comparative Examples was measured according to the following method. More specifically, the measurement was performed using an apparatus 100 shown in FIG. First, the oxygen barrier bag was opened for the heating device to be measured, which was sealed and contained within the oxygen barrier bag, and one heating element was removed from the heating device together with its packaging. The removed heating element was placed in the measurement chamber 101 with the first sheet side of the packaging facing outward, and a weight 108 with a metal ball (mass 4.5 g) was placed on top of it. In this state, dehumidified air was allowed to flow from the bottom of the measurement chamber 101, and the difference in absolute humidity before and after the air flow in the measurement chamber 101 was determined from the temperatures and humidities measured by the inlet thermo-hygrometer 104 and the outlet thermo-hygrometer 106. Furthermore, the amount of water vapor released from the heating element was calculated from the air flow rates measured by the inlet flowmeter 105 and the outlet flowmeter 107. The amount of water vapor generated was measured starting from the time when the heating device was removed from the oxygen-blocking bag, and was the total amount of water vapor measured for 10 minutes (mg 10min) and 20 minutes (mg 20min) from that point on. The results are shown in Tables 1 and 2 below.

[0155] [Table 1]

[0156] [Table 2]

[0157] As shown in Tables 1 and 2, the heating devices of the examples contain a powder of a porous material, and are provided with a heating element having a specific relationship between the content ratio of oxidizable metal and water, the content ratio of oxidizable metal and porous material, and the content ratio of oxidizable metal and porous material. As a result, the heating devices have a higher sensible heat accumulation amount and better heat generation characteristics than the heating devices of the comparative examples, even though the heating devices have the same content of oxidizable metal. This also results in a significantly higher amount of water vapor generation. Furthermore, even when the heating element is contained in a packaging material, the heating characteristics and amount of water vapor generation are excellent, regardless of the fiber sheet used. Therefore, it is evident that the heating device of the present disclosure is capable of producing a heating device with excellent heat generating properties at reduced production costs without increasing the content of costly oxidizable metals. [Industrial Applicability]

[0158] The present invention provides a heating device that has excellent heat generating properties and water vapor generation while keeping production costs down.

Claims

1. A heating element is provided which contains a powder of an oxidizable metal, a powder of a carbon material, water, and a powder of a porous material other than the oxidizable metal and the carbon material; The heating element is a sheet-like object, The heating element is a value obtained by multiplying the ratio of the mass content of the water to the mass content of the oxidizable metal powder by 100 [100×(water / oxidizable metal powder)] is 30 or more and 270 or less, a value obtained by multiplying the ratio of the mass content of the powder of the porous material to the mass content of the powder of the oxidizable metal by one hundred [100×(powder of the porous material / powder of the oxidizable metal)] is 1 or more and 25 or less; a value obtained by multiplying the ratio of the mass content of the porous material powder to the mass content of the water by 100 [100 × (porous material powder / water)] is 1 or more and 30 or less; The pore diameter of the porous material is 0.01 μm or more and 5 μm or less, The oil absorption of the powder of the porous substance is 300 mL / 100 g or more and 900 mL / 100 g or less.

2. The heating element is contained in a gas-permeable packaging material, The heating device according to claim 1, wherein a layer containing water-absorbent resin powder is disposed between the heating element and the packaging material.

3. 3. The heating device according to claim 2, wherein the water-absorbent resin powder is sandwiched between two moisture-permeable sheets to form the layer.

4. the heat generating element is a sheet-like object comprising a base sheet and a layer of a heat generating composition provided on one surface of the base sheet, the heating element has a ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100 [100×(water / oxidizable metal powder)] of 80 to 270, The heating device according to any one of claims 1 to 3, wherein the layer of heat-generating composition is obtained from a paste containing a powder of the oxidizable metal, a powder of the carbon material, a powder of the porous substance, and water.

5. the heating element is a sheet-like material obtained by mixing a powder of the oxidizable metal, a powder of the carbon material, a powder of the porous substance, water, and a fibrous material, The heating device according to any one of claims 1 to 4, wherein the ratio of the mass content of the water to the mass content of the oxidizable metal powder multiplied by 100 [100 x (water / oxidizable metal powder)] is 30 or more and 80 or less.

6. The heat generating element comprises a base sheet and a layer of a heat generating composition provided on one surface of the base sheet, the layer of heat generating composition is obtained from a paste containing a powder of the oxidizable metal, a powder of the carbon material, a powder of the porous substance, and water; Further comprising a layer containing a water-absorbent resin powder, The heating device according to any one of claims 1 to 4, wherein the heat-generating composition is disposed between the base sheet and the layer containing the water-absorbent resin powder.

7. The heating device according to any one of claims 1 to 6, wherein the porous material comprises a silicon-containing inorganic compound.

8. The heating device according to claim 7, wherein the porous material is made of calcium silicate.

9. The heating device according to claim 8, wherein the pore diameter of the calcium silicate is 0.02 μm or more and 0.8 μm or less.

10. The device comprises a main body having a shape that covers both eyes of a user when in use, the heating element provided in the main body, and a pair of ear hooks that are attached to the main body and can maintain a state in which both eyes of the user are covered by the main body, The main body portion includes a top sheet located on a side closer to the user's skin and a back sheet located on a side farther from the user's skin, The heating device according to any one of claims 1 to 9, wherein the heating element is held between the top sheet and the back sheet.

11. The heating device according to any one of claims 1 to 10, which has a function of generating steam when heated.

12. A heating element including a powder of an oxidizable metal, a powder of a carbon material, water, and calcium silicate is provided; The heating element is a sheet-like object, The heating element is a value obtained by multiplying the ratio of the mass content of the water to the mass content of the oxidizable metal powder by 100 [100×(water / oxidizable metal powder)] is 30 or more and 270 or less, a value obtained by multiplying the ratio of the mass content of the powder of the porous material to the mass content of the powder of the oxidizable metal by one hundred [100×(powder of the porous material / powder of the oxidizable metal)] is 1 or more and 25 or less; a value obtained by multiplying the ratio of the mass content of the porous material powder to the mass content of the water by 100 [100 × (porous material powder / water)] is 1 or more and 30 or less; The pore diameter of the porous material is 0.01 μm or more and 5 μm or less, The oil absorption of the powder of the porous substance is 300 mL / 100 g or more and 900 mL / 100 g or less.

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