Heating tool

Abstract

To provide a technique capable of easily controlling a temperature on a tip end of a protrusion, without changing a shape and a size of the protrusion.SOLUTION: A heat generation tool 1 of the invention is configured so that, in a cross sectional view along a thickness direction Z1 of the heat generation tool 1, when a portion of an inner face 11 of a protrusion 10 being provided closer to a first surface 1a side by 10% of a thickness of a heat generation part 70, from a portion corresponding to a tip end 10e of the protrusion 10 on the heat generation part 70, is a first portion 80, an area obtained by dividing a plane view area of the whole heat generation part 70 in viewing the heat generation part 70 from the first sheet 2 side, with the number of the protrusion 10, is 8 times or greater of a superficial area from a portion corresponding to the tip end 10e of the protrusion 10 on the inner face 11 of the protrusion 10 to the first portion 80.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] The heating tool disclosed in Patent Document 1 has protrusions formed on its surface. The hollow space inside the protrusions is filled with a heat-generating material. The heating tool is then fixed to a desired part of a living body so that the protrusions on the surface come into contact with the desired part, thereby applying pressure to the desired part from the protrusions and stimulating the part with the heat of the heat-generating material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-175857 Summary of the Invention [Problem to be solved by the invention]

[0004] The temperature of the tip of the protrusion of such a heating tool depends on the shape and size of the protrusion. Here, it is conceivable to control the temperature of the tip of the protrusion by changing the shape and size of the protrusion and adjusting the amount of heat-generating material filled in the hollow space inside the protrusion. However, depending on the application of the heating tool, it may not be possible to change the shape and size of the protrusion. Therefore, for such a heating tool, a configuration is desired that allows the temperature of the tip of the protrusion to be easily controlled without changing the shape and size of the protrusion.

[0005] An object of the present invention is to provide a heating tool that can easily control the temperature of the tip of a projection without changing the shape or size of the projection. [Means for solving the problem]

[0006] The present invention is a heating tool including a first sheet forming a first surface and a second sheet forming a second surface located on the opposite side to the first surface. In one embodiment of the heating tool of the present invention, the second sheet has one or more hollow protrusions, parts of which protrude in a direction away from the first sheet. In one embodiment of the heating tool of the present invention, the hollow protrusion forms a hollow portion that is a part of the filling portion. In one embodiment of the heating tool of the present invention, the hollow portion is a space located on the inner surface of the second sheet facing the first sheet and defined by the inner surfaces of the protrusions. In one embodiment of the heating tool of the present invention, a heating portion is provided between the first sheet and the second sheet and formed by a heating material filled at least in the hollow portion. In one embodiment of the heating tool of the present invention, when viewed in a cross-section along the thickness direction of the heating tool, if the first portion is the portion of the inner surface of the protrusion that is located 10% of the thickness of the heating portion from the portion corresponding to the tip of the protrusion on the heating portion toward the first surface, the area obtained by dividing the planar area of ​​the entire heating portion when viewed from the first sheet side by the number of protrusions is at least 8 times the surface area from the portion corresponding to the tip of the protrusion on the inner surface of the protrusion to the first portion. Other features, advantages and embodiments of the present invention are described below. [Effects of the Invention]

[0007] According to the heating tool of the present invention, the temperature of the tip of the projection can be easily controlled without changing the shape or size of the projection. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view of a first embodiment of the heating tool of the present invention, as viewed from the outer surface side of the second sheet. [Figure 2] FIG. 2 is a plan view of the heating tool shown in FIG. [Figure 3]FIG. 3 is a cross-sectional view schematically showing a cross section taken along line II in FIG. 2 (a cross section along the thickness direction of the heating tool). [Figure 4] FIG. 4 is a partially enlarged cross-sectional view of the heating tool shown in FIG. [Figure 5] 5 is a cross-sectional view schematically showing the hollow portion and the molding space portion of the heating tool shown in FIG. [Figure 6] FIG. 6 is a plan view showing a second embodiment of the heating tool of the present invention. [Figure 7] FIG. 7 is a cross-sectional view schematically showing a cross section taken along line II-II in FIG. 6 (a cross section along the thickness direction of the heating tool). [Figure 8] FIG. 8 is a plan view showing a third embodiment of the heating tool of the present invention. [Figure 9] FIG. 9 is a cross-sectional view schematically showing a cross section taken along line III-III in FIG. 8 (a cross section along the thickness direction of the heating tool). [Figure 10] FIG. 10 is a cross-sectional view schematically showing a cross section taken along line IV-IV in FIG. 8 (a cross section along the thickness direction of the heating tool). [Figure 11] FIG. 11 is a partially enlarged cross-sectional view showing a fourth embodiment of the heating tool of the present invention. [Figure 12] FIG. 12 is a partially enlarged cross-sectional view showing another embodiment of the heating tool of the present invention. [Figure 13] FIG. 13 is a partially enlarged cross-sectional view showing another embodiment of the heating tool of the present invention. [Figure 14] FIG. 14 is a partially enlarged cross-sectional view showing another embodiment of the heating tool of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described below based on preferred embodiments with reference to the drawings. In the following description of the drawings, the same or similar parts are designated by the same or similar reference numerals. The drawings are basically schematic, and the ratios of the dimensions may differ from those of the actual ones.

[0010] The heating tool 1 of the present invention is applied to various living bodies including the human body, and is used by being applied directly or indirectly to the surface of the target such as the skin.

[0011] The heating tool 1 of the present invention includes a first sheet 2 and a second sheet 3, and is typically a sheet-like heating tool. The first sheet 2 forms a first surface 1a of the heating tool 1. The second sheet 3 forms a second surface 1b located on the opposite side of the heating tool 1 from the first surface 1a. The second surface 1b is the front surface that is positioned relatively close to the object of application when the heating tool 1 is in use. The first surface 1a is the back surface that is positioned relatively far from the object of application when the heating tool 1 is in use. The first sheet 2 and the second sheet 3 are typically rectangular sheets in plan view, examples of which are shown in Figures 1 and 2.

[0012] The surface of the first sheet 2 that forms the first surface 1a of the heating tool 1 is the outer surface 2a of the first sheet 2 opposite the second sheet 3. The surface opposite the outer surface 2a of the first sheet 2 is the inner surface 2b of the first sheet 2 facing the second sheet 3. The surface of the second sheet 3 that forms the second surface 1b of the heating tool 1 is the outer surface 3a of the second sheet 3 facing the first sheet 2. The surface opposite the outer surface 3a of the second sheet 3 is the inner surface 3b of the second sheet 3 facing the first sheet 2. An example of this is shown in Figure 4.

[0013] The materials for the first sheet 2 and the second sheet 3 are not particularly limited, and examples thereof include fiber sheets such as woven fabric, nonwoven fabric, and paper; resin films; and composite sheets in which two or more of these sheets and films are laminated together. The resin films include breathable films, such as porous films, and non-breathable films. Each of the sheets 2 and 3 may have a single-layer structure consisting of a single sheet, or a laminate structure consisting of multiple sheets. It is preferable that at least one of the sheets 2, 3 be breathable in order to easily control the heat generation of the heat generating material 71 (heat generating portion 70) (described later) included in the heating tool 1. From the same viewpoint, it is preferable that at least one of the sheets 2, 3 be moisture permeable. Water vapor generated by the heat generation of the heat generating material 71 passes through the moisture permeable first sheet 2 and / or second sheet 3 and is released to the outside. The second sheet 3 may be, for example, a composite sheet formed by laminating a nonwoven fabric, a resin film, and another nonwoven fabric in this order. The first sheet 2 may be, for example, a composite sheet of paper and a resin film. When both sheets 2 and 3 are composite sheets of such a fiber sheet (breathable sheet) and a resin film, if the resin film is breathable, the sheets 2 and 3 may be breathable, and if the resin film is non-breathable, the sheets 2 and 3 may be non-breathable.

[0014] The first sheet 2 and the second sheet 3 are typically joined to each other at their peripheral edges. Specifically, the peripheral edge of the first sheet 2 and the peripheral edge of the second sheet 3 overlap with their respective thickness directions aligned. The inner surface 2b of the first sheet 2 located at the peripheral edge of the first sheet 2 and the inner surface 3b of the second sheet 3 located at the peripheral edge of the second sheet 3 are joined to each other by known joining means, for example, fusion bonding or adhesive. Thus, a joint 4 between the first sheet 2 and the second sheet 3 is formed at the peripheral edge of the heating tool 1. In this case, the peripheral edge of the first sheet 2 is a first joint 5 that forms the joint 4 of the heating tool 1. The peripheral edge of the second sheet 3 is a second joint 6 that forms the joint 4 of the heating tool 1. Thus, the joint 4 is the region where the first joint 5 of the first sheet 2 and the second joint 6 of the second sheet 3 are joined while overlapping each other. The thickness direction of the first joint portion 5 of the first sheet 2 and the thickness direction of the second joint portion 6 of the second sheet 3 are the thickness direction Z1 of the heating tool 1.

[0015] The second sheet 3 preferably has hollow protrusions 10 that protrude from a part of the second sheet 3 in a direction away from the first sheet 2. The heating tool 1 preferably has two or more protrusions 10. Therefore, the second sheet 3 preferably has two or more protrusions 10. An example of this is shown in Figs. 1 to 3. In the present invention, the number of protrusions 10 is not particularly limited and may be, for example, 1. Therefore, the second sheet 3 has one or two or more hollow protrusions 10.

[0016] The heating tool 1 preferably further includes a hollow molding section 20. The molding section 20 is preferably spaced apart from the first sheet 2 with a portion of the second sheet 3 continuing to each of the protrusions 10, and is preferably located closer to the first sheet 2 than the tip 10e of each of the protrusions 10.

[0017] The molded portion 20 typically has a side wall 21 and a bottom wall 22 . The side wall 21 is a portion of the second sheet 3 that protrudes from the inner peripheral edge of the second joint 6 of the second sheet 3 toward the opposite side to the first sheet 2. The side wall 21 of the shaping portion 20 preferably extends from the inner peripheral edge of the second joint 6 in the thickness direction Z1 of the heating tool 1. The side wall 21 of the shaping portion 20 preferably extends along the inner peripheral edge of the second joint 6 in a plan view. A specific example of the side wall 21 is a quadrangular ring in a plan view.

[0018] The bottom wall 22 is a portion that connects the side walls 21 of the molding portion 20 in the second sheet 3 to each of the protrusions 10. The bottom wall 22 typically extends from the peripheral edge of the side wall 21 on the opposite side from the second joint 6 in a direction perpendicular to the thickness direction Z1 of the heating tool 1. The bottom wall 22 is preferably flat. The inner surface of the bottom wall 22 is preferably continuous with the inner surface of the side wall 21. The bottom wall 22 is preferably located inside the second joint 6 in a planar view of the second sheet 3. The bottom wall 22 is preferably surrounded by the second joint 6 in a planar view of the second sheet 3. The inner surfaces of the side walls 21 and the bottom wall 22 are preferably located on the inner surface 3b side of the second sheet 3 that faces the first sheet 2, and form the inner surface 24 of the molding portion 20. A specific example of the bottom wall 22 is rectangular in a planar view.

[0019] The thickness direction of the shaped portion 20 coincides with the thickness direction Z1 of the heating tool 1. The thickness of the shaped portion 20 is the length of the shaped portion 20 that protrudes from the second joint 6. The length of the shaped portion 20 that protrudes from the second joint 6 is the height H1 of the shaped portion 20 (see FIG. 3).

[0020] It is preferable that each protrusion 10 protrudes from the bottom wall 22 of the molding portion 20 in a direction away from the first sheet 2. It is preferable that the inner surface 11 of each protrusion 10 is continuous with the inner surface of the bottom wall 22 of the molding portion 20. The protrusion direction of each protrusion 10 from the bottom wall 22 of the molding portion 20 coincides with the thickness direction Z1 of the heating tool 1. When two or more protrusions 10 are provided, it is preferable that each of the protrusions 10 has the same shape and size. It is preferable that each of the protrusions 10 is arranged in a position on the second sheet 3 that is more inward than the side wall 21 of the molded portion 20 when the second sheet 3 is viewed from above. The arrangement of the multiple protrusions 10 is not particularly limited, and can be, for example, a square lattice arrangement. Each protrusion 10 typically has a shape that tapers toward the tip (as it moves away from the first sheet 2). The tip of each protrusion 10 may not be sharp, but may have a rounded shape. The multiple protrusions 10 provided on the heating tool 1 may differ from each other in shape and / or size. The figure shows an example of an embodiment having the above-described configuration and including five protrusions 10. When the second sheet 3 is viewed from above, the five protrusions 10 are arranged in a staggered pattern on the inside of the side wall 21 of the molding portion 20 on the second sheet 3.

[0021] Preferably, the hollow protrusions 10 form hollow portions 40 that are part of the filling portion 30. The hollow portions 40 are located on the inner surface 3b side of the second sheet 3 that faces the first sheet 2, and are spaces defined by the inner surfaces 11 of the protrusions 10. Therefore, the hollow portions 40 are spaces located inside the protrusions 10. An example of this is shown in FIG. In the example shown in FIG. 1, the filling section 30 has five hollow sections 40.

[0022] It is preferable that the filling section 30 further has a molding space section 50 that communicates with each hollow section 40. The molding space section 50 is located on the inner surface 3b side of the second sheet 3 that faces the first sheet 2, and is a space defined by the inner surface 24 of the molding section 20. The thickness direction of the molding space section 50 is the direction in which the side wall 21 of the molding section 20 extends, and coincides with the thickness direction Z1 of the heating tool 1. In a configuration in which the molding section 20 has side walls 21 and a bottom wall 22, the molding space 50 is a space surrounded by the inner surfaces of the side walls 21 of the molding section 20. The molding space 50 is located closer to the first sheet 2 than a plane passing through the inner surface of the bottom wall 22 of the molding section 20. Therefore, the total length of the molding space 50 in the thickness direction Z1 is the length from the inner peripheral edge of the second joint portion 6 of the second sheet 3 on the inner surface of the side walls 21 of the molding section 20 to the inner surface of the bottom wall 22. An example of this is shown in Figures 4 and 5. In Figure 5, the regions of each hollow section 40 and molding space section 50 are shown with different hatching. As shown here, the boundary between each hollow section 40 and molding space section 50 is an imaginary plane VL that passes through a plane that passes through the inner surface of the bottom wall 22 of the molding section 20. The region on the first sheet 2 side of the imaginary plane VL is the molding space section 50, and the region on the opposite side of the imaginary plane VL from the first sheet 2 is the hollow section 40. Note that the thicknesses of the first sheet 2 and the second sheet 3 are exaggerated for convenience of illustration. In the example shown in FIGS. 1 to 5, the molding space 50 has a constant overall length W1 in a plan view (see FIG. 3) in the thickness direction thereof.

[0023] It is preferable that the molding space 50 overlaps the entire hollow portion 40 when viewed from the first sheet 2 side. Typically, the planar area of ​​the opening on the first sheet 2 side of the molding space 50 when viewed from the first sheet 2 side is larger than the planar area of ​​the opening on the first sheet 2 side of each hollow portion 40 when viewed from the first sheet 2 side.

[0024] It is preferable that the molding section 20 is configured such that a portion of the second sheet 3 is spaced from the first sheet 2 so that the molding space 50 communicates with the hollow sections 40 defined by the inner surfaces 11 of each protrusion 10. Therefore, when there are multiple protrusions 10, it is preferable that the molding section 20 is configured such that a portion of the second sheet 3 is spaced from the first sheet 2 so that the molding space 50 communicates with at least two of the hollow sections 40 defined by the inner surfaces 11 of each protrusion 10. An example of this is shown in Figures 3 and 4. The filling section 30 is a space between the first sheet 2 and the second sheet 3. The filling section 30 is partitioned by the first sheet 2 and the second sheet 3.

[0025] The heating tool 1 typically includes a heating section 70. The heating section 70 is formed by a heating material 71 filled in the filling section 30. The heating section 70 is preferably formed between the first sheet 2 and the second sheet 3 by the heating material 71 filled in at least each hollow section 40. The heating material 71 is more preferably filled in each hollow section 40 and the molding space section 50, and may also be filled in a first sheet space section 91 described below. The heating section 70 is typically present in an area of ​​the heating tool 1 that is more inward than the joining section 4. Each hollow portion 40 and molding space portion 50 is not filled with the fibers that make up the second sheet 3. The filled portion 30 refers to a space that has the heat-generating material 71 inside. The filled portion 30 is called a "filled portion" even if it is not filled with the heat-generating material 71. An example of this is shown in Figures 2 to 4. In Figure 2, the region where the heat generating portion 70 exists is shown schematically by dot hatching. In Figures 3 and 4, the heat generating portion 70 is shown by dot hatching.

[0026] The heating tool 1 is typically sealed and housed in a packaging material before use. When the packaging material is opened, oxygen contained in the outside air is preferably supplied to the heating material 71 via the first sheet 2 or the second sheet 3, causing the heating material 71 to generate heat. Details of the heating material 71 will be described later.

[0027] In the heating tool of the present invention, the amount of heat-generating material 71 filled between the first sheet 2 and the second sheet 3 may be within 100% of the total volume of the hollow portion 40 and the molding space portion 50. In this case, the partition portion 60 that separates the filling portion 30 in the first sheet 2 (the portion that overlaps with the filling portion 30 in the first sheet 2 in a plan view) does not bulge in a direction away from the second sheet 3. The amount of heat generating material 71 filled into each hollow portion 40 is preferably 100% of the volume of each hollow portion 40, from the viewpoint of stabilizing the heat generating characteristics. The amount of the heat generating material 71 filled into the molding space 50 is preferably 10% or more of the volume of the molding space 50. When the filling amount of the heat-generating material 71 is 100% of the total volume of the hollow portion 40 and the molding space portion 50, the first sheet 2 will be flat as a whole. Therefore, the first sheet 2 may be flat with substantially no irregularities. An example of this is shown in Figures 3 and 4.

[0028] When viewed in a cross section along the thickness direction Z1 of the heating tool 1, the first portion 80 is the portion of the inner surface 11 of each protrusion 10 that is located 10% of the thickness of the heating portion 70 toward the first surface 1a from the portion corresponding to the tip 10e of each protrusion 10 in the heating portion 70. In this case, it is preferable that the area obtained by dividing the planar area of ​​the entire heat generating portion 70 when viewed from the first sheet 2 side by the number of protrusions 10 is at least eight times the surface area from the portion on the inner surface 11 of the protrusion 10 corresponding to the tip 10e of the protrusion 10 to the first portion 80. In detail, if the planar area of ​​the entire heat generating portion 70 when viewed from the first sheet 2 side (the base end side of the protrusion 10) (hereinafter also referred to as the "heat generating portion base end side area") is "A", the number of protrusions 10 is "B", and the surface area from the portion on the inner surface 11 of the protrusion 10 corresponding to the tip 10e of the protrusion 10 to the first portion 80 (hereinafter also referred to as the "protrusion tip inner surface area") is "C", then this can be expressed by the following formula (1). A / B / C≧8 (1) In the embodiment shown in Figure 4, in a cross-sectional view along the thickness direction Z1 of the heating tool 1, an area of ​​10% of the thickness of the heating part 70 from the portion corresponding to the tip 10e of each protrusion 10 in the heating part 70 is shown hatched. The surface area of ​​the inner surface of the protrusion tip does not include the area of ​​the horizontal plane in the first section 80. In terms of the hatched portion in Figure 4, the horizontal portion at the top of the figure is not included in the surface area of ​​the inner surface of the protrusion tip, and only the arc portion located at the bottom of the figure is included.

[0029] The "protrusions" in "number of protrusions B" in formula (1), i.e., the protrusions according to the present invention, are assumed to be in a heating tool with a thickness that varies partially. In other words, the protrusions according to the present invention are present in a heating tool that has a mixture of relatively thick and relatively thin portions. In such a heating tool with a thickness that varies partially, at least some of the relatively thick portions are protrusions according to the present invention. Specifically, it is assumed that the portions of the heating tool where the second sheet protrudes in the direction away from the first sheet (hereinafter also referred to as "protrusions") include a mixture of portions whose thickness is 70% or more of the maximum thickness of the heating tool (hereinafter also referred to as "high protrusions") and portions whose thickness is less than 70% of the maximum thickness (hereinafter also referred to as "low protrusions"). Some (tip side) or all of the high protrusions are protrusions according to the present invention. In other words, the high protrusions are "protrusions including protrusions," and the low protrusions are "protrusions without protrusions." Taking the heating tool 1 shown in FIG. 3 as an example, the convex portion of the heating tool 1, formed by the second sheet 3 protruding in the direction away from the first sheet 2, is a mixture of a first portion (a portion consisting of only the shaped portion 20) having a height, i.e., thickness, H1, and a second portion (a portion where the shaped portion 20 and the protrusion 10 overlap in the thickness direction Z1) having a thickness of H1+H2. At least the second portion is the high convex portion having a thickness of 70% or more of the maximum thickness of the heating tool 1, and is a "convex portion including a protrusion." Of the second portion (high convex portion), the tip end side (the portion on the second sheet 3 side, having a height H2) is the protrusion 10, and the base end side (the portion on the first sheet 2 side, having a height H1) is the shaped portion 20. Meanwhile, whether or not the first portion includes the protrusion according to the present invention is determined by the thickness of the first portion. That is, when the thickness of the first portion is less than 70% of the maximum thickness of the heating tool 1, it is the low convex portion that does not include the protrusions according to the present invention, and when the thickness of the first portion is 70% or more of the maximum thickness of the heating tool 1, it is the high convex portion that includes the protrusions according to the present invention. The thickness of each portion of the heating tool, including the maximum thickness, is measured by the following method.

[0030] (Method for measuring the thickness of the heating tool) With a constant load applied to the heating tool, the thickness of a predetermined measurement target portion (for example, the high convex portion) is measured. Specifically, a constant pressure thickness measuring instrument PG-20J manufactured by Teclock Corporation is used to measure the thickness of the measurement target portion of the heating tool using a φ5 mm measuring probe at a pressure load of 44 gf on the heating tool.

[0031] One of the main functions of the protrusions 10 is to apply pressure stimulation to the target of the heating tool 1. For example, when applying the heating tool 1 to the human body, by applying the protrusions 10 toward the user's skin, the application site can be stimulated by the heat of the heating section 70 as well as pressure from the protrusions 10, and similar to acupuncture and moxibustion, the meridians and acupuncture points of the human body can be stimulated by heat and pressure. The heating tool 1 can be an acupuncture patch. The term "acupuncture patch" as used here refers to a device that is fixed to the human body and can have the same effect as acupuncture treatment on a fixed site on the human body.

[0032] The temperature of the tip 10e of the protrusion 10 of such a heating tool 1 depends on the shape and size of the protrusion 10. Here, it is conceivable to control the temperature of the tip 10e of the protrusion 10 by changing the shape and size of the protrusion 10 and adjusting the amount of heat-generating material 71 filled in the hollow portion 40 inside the protrusion 10. However, depending on the application of the heating tool 1, it may not be possible to change the shape and size of the protrusion 10.

[0033] Therefore, in the heating tool 1 of the present invention, it is preferable that the area A obtained by dividing the base end area of ​​the heating portion by the number B of protrusions 10 is equal to or greater than a predetermined lower limit relative to the inner surface area C of the protrusion tips. For example, it is preferable that the above-mentioned formula (1) "A / B / C≧8" is satisfied. This ensures that the base end area A of the heating portion can be maximized. Therefore, the amount of heat-generating material 71 filled between the first sheet 2 and the second sheet 3 can be adjusted regardless of the shape or size of the protrusions 10. Specifically, for example, by providing a molding section 20 (molding space section 50) without changing the shape and size of the protrusions 10 (hollow section 40) from the current product, A / B / C can be set to or greater than a predetermined lower limit. As a result, the amount of oxygen contained in the outside air supplied to the heat-generating material 71 through the first sheet 2 can be adjusted, and the temperature of the tips 10e of the protrusions 10 can be easily controlled without changing the shape or size of the protrusions 10. In particular, when the heating tool 1 is an acupuncture patch, the required shape and size are within a specific range, and temperature adjustment can be performed within that constraint.

[0034] As described above, the inner surface area C of the protrusion tip is the surface area from the portion of the inner surface 11 of the protrusion 10 corresponding to the tip 10e of the protrusion 10 to the first portion 80, which is a position on the first surface 1a side away by a distance equivalent to 10% of the thickness of the heat generating part 70. This portion of the protrusion 10 from the tip 10e to the first portion 80 typically corresponds to the portion that comes into contact with the user's skin when the heating tool 1 is used in a normal manner, that is, when the heating tool 1 is used so that the side of the second sheet 3 on which the protrusions 10 are formed comes into contact with the user's skin. It is preferable that the formula (1) is satisfied and the ratio of the planar area (A / B) of the side of the heat generating portion 70 opposite the tip of the protrusion 10 (the base end side) to the internal surface area C of the protrusion tip is equal to or greater than a predetermined lower limit. This means that the shape of the heat generating portion 70 filled in the filling portion 30 (hollow portion 40, molding space portion 50) is such that the planar area of ​​the base end (first sheet 2 side) of the protrusion 10 is extremely larger than that of the tip of the protrusion 10. A heat generating tool 1 having a heat generating portion 70 of such a shape can be filled with a relatively large amount of heat generating material 71 compared to conventional heat generating tools that do not satisfy the formula (1) above. Furthermore, if the first sheet 2 is breathable, the base end of the heat generating part 70, which has a relatively large area in a plan view, will be located near the breathable first sheet 2. This increases the amount of oxygen flowing into the heat generating part 70 compared to conventional methods. This allows the heating tool 1 to have excellent heat generating properties and to easily control the temperature of the tips 10e of the protrusions 10. Furthermore, if the heat generating material 71 constituting the heat generating part 70 contains a water-retaining material such as a water-absorbent polymer, the amount of oxygen flowing into the heat generating part 70 is also affected by the density of the water-retaining material. For example, if the area of ​​the base end of the heat generating part 70 is relatively small and the formula (1) is not satisfied, and the water-retaining material is biased toward the base end side of the heat generating part 70 (the side of the first sheet 2), as in the configuration shown in Figure 14 described below, there is a concern that the biased water-retaining material will hinder the flow of oxygen into the heat generating part 70. In contrast, the present invention eliminates such concerns by satisfying the formula (1), and excellent heat generation characteristics can be exhibited even when the water-retaining material is biased toward the base end side of the heat generating part 70.

[0035] In order to ensure that the effect achieved by formula (1) is more reliably achieved, the value of "A / B / C" is preferably 9 or more, and more preferably 10 or more. Furthermore, there is no particular upper limit to the value of "A / B / C", but from the viewpoint of keeping the temperature of the tip 10e of the projection 10 at a temperature that will not cause burns, it is preferably 50 or less, more preferably 40 or less.

[0036] Assuming that the formula (1) is established, it is preferable to set the values ​​of A, B, and C in the formula (1) in the following ranges. The base end area A of the heat generating part is preferably 400 mm 2 More than 500mm, preferably 2 That's all. In addition, A is preferably 2000 mm from the viewpoint of stabilizing the heat generation characteristics. 2 Less than or equal to 1500 mm, preferably 2 The following is the result. The number B of protrusions 10 provided on the heating tool 1 is preferably 2 or more, more preferably 3 or more, from the viewpoint of successfully stimulating the acupoints. Furthermore, from the viewpoint of successfully stimulating the acupoints, B is preferably 10 or less, more preferably 8 or less. The inner surface area C of the tip of the projection is preferably 7 mm 2 More than 8mm, preferably 2 That's all. Also, C is preferably 50 mm from the viewpoint of stimulating the acupoints in an appropriate range. 2 Less than 40mm, preferably 2 The following is the result.

[0037] In order to ensure that the effect achieved by formula (1) is achieved more reliably, the height H2 of the projections 10 (see FIG. 3) is preferably 2 mm or more, and more preferably 3 mm or more. Furthermore, from the viewpoint of ease of use due to the size and weight of the heating tool 1 during use, the height H2 of the projections 10 is preferably 15 mm or less, and more preferably 10 mm or less. The height H2 of each protrusion 10 is the length of protrusion from the outer surface of the bottom wall 22 of the molding portion 20. The height H2 of each protrusion 10 can also be said to be the thickness of each protrusion 10.

[0038] It is preferable that the filling section 30 further has a molding space section 50 that communicates with the hollow section 40. This makes it easier to ensure that the planar area of ​​the entire heat generating section 70, when viewed from the first sheet 2 side, is as large as possible, compared to when the filling section 30 does not have the molding space section 50.

[0039] It is preferable that the molding space 50 is filled with the heat generating material 71 in an amount equal to or greater than the above-mentioned lower limit relative to the volume of the molding space 50. In this way, the filling portion 30 is filled with the minimum amount of heat generating material 71 required to ensure that the planar area of ​​the entire heat generating portion 70 when viewed from the first sheet 2 side is as large as possible. In order to ensure that such an effect is achieved even more reliably, the ratio of the heat-generating material 71 to the volume of the molding space 50 is preferably 20% or more, and more preferably 30% or more. The practical upper limit of the ratio is 100% or less.

[0040] In the molding section 20, it is preferable that a portion of the second sheet 3 is separated from the first sheet 2 so that the molding space 50 communicates with at least two of the hollow sections 40 defined by the inner surfaces 11 of each protrusion 10. This allows the portions of the heat-generating section 70 formed by the heat-generating material 71 filled in at least two of the hollow sections 40 to be connected to each other by the portion formed by the heat-generating material 71 filled in the molding space 50. This makes it possible to more easily control the temperature of the tip 10e of each protrusion 10. The height H1 (see FIG. 3) of the molded portion 20 is preferably 0.5 mm or more, and more preferably 1 mm or more, from the viewpoint of ensuring that the molded portion 20 exerts its effect more reliably. Furthermore, the height H1 of the molded portion 20 is preferably 5 mm or less, and more preferably 4 mm or less, from the viewpoint of maintaining an appropriate heat generation temperature.

[0041] The molding space 50 overlaps with the entire hollow sections 40 when viewed from the first sheet 2 side, and the planar area of ​​the opening on the first sheet 2 side of the molding space 50 when viewed from the first sheet 2 side (hereinafter also referred to as "area 50S") is preferably larger than the planar area of ​​the opening on the first sheet 2 side of each hollow section 40 when viewed from the first sheet 2 side (hereinafter also referred to as "area 40S"). This makes it easier to ensure that the planar area of ​​the entire heat generating section 70 when viewed from the first sheet 2 side is as large as possible. In order to ensure that such an effect is achieved more reliably, the ratio of area 50S to area 40S, as area 40S / area 50S, is preferably 0.1 or more, and more preferably 0.2 or more, assuming that area 50S > area 40S. In order to ensure that such an effect is exhibited more reliably, the ratio is preferably 0.9 or less, and more preferably 0.8 or less. The area of ​​50S is preferably 400mm from the viewpoint of successfully demonstrating the heat generating characteristics. 2 More than 500mm, preferably 2 That's all. In addition, the area of ​​50S is preferably 3600mm from the viewpoint of ease of use. 2 Less than or equal to 2500 mm, preferably 2 The following is the result. The area of ​​40S is preferably 100mm² from the viewpoint of improving thermal conductivity. 2 More than 150mm, preferably 2 That's all. In addition, the area of ​​40S is preferably 2000mm from the viewpoint of successfully demonstrating the heat generating characteristics. 2 Less than or equal to 1500 mm, preferably 2 The following is the result.

[0042] The heat generating material 71 will now be described. The heat generating material 71 typically contains an oxidizable metal, a water-retaining material, and an electrolyte, and generates heat by utilizing heat generated by an oxidation reaction between the oxidizable metal and oxygen in the air. It is preferable that the heat generating material 71 further contains water. The heat generating material 71 exists as a slurry containing water inside the heating tool 1, and the electrolyte in the heat generating material 71, which is a slurry, is in a state of being dissolved in the water in the heat generating material 71. The water content in the heat generating material 71 is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, based on the total mass of the heat generating material 71.

[0043] The oxidizable metal contained in the heat generating material 71 can be any of those used as heat generating materials in this type of heating tool 1 without any particular restrictions, such as iron, aluminum, zinc, manganese, magnesium, calcium, etc., and these can be used alone or in combination of two or more. The content of the oxidizable metal in the heat generating material 71 is preferably 10% by mass or more, more preferably 20% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, relative to the total mass of the heat generating material 71.

[0044] The water retention material contained in the heat generating material 71 is used for the purpose of retaining water contained in the heat generating material 71. In addition to water retention ability, the water retention material may also have oxygen supply ability (catalytic ability) to retain oxygen supplied to the oxidizable metal and supply the oxygen to the oxidizable metal. The type of water retention material is not particularly limited, and may be an organic material or an inorganic material, and one type may be used alone or two or more types may be used in combination. Examples of organic water-retaining materials include water-absorbent polymers, which are preferably capable of absorbing and retaining pure water at a mass of at least five times their own weight, such as starch, cross-linked carboxymethyl cellulose, polymers or copolymers of acrylic acid or alkali metal acrylates, polyacrylic acid and its salts, and polyacrylate graft polymers. Examples of inorganic water-retaining materials include activated carbon (coconut shell charcoal, charcoal powder, bicarbonate coal, peat, lignite), carbon black, acetylene black, graphite, zeolite, perlite, vermiculite, silica, cancrinite, and fluorite. The shape of the water-retaining material is not particularly limited, and may be, for example, fibrous, but from the viewpoint of forming effective contact with the oxidizable metal and improving heat-generating properties, particulate is preferred. Particularly preferred as the water-retaining material is a particulate water-absorbent polymer. The content of the water-retaining material in the heat generating material 71 is preferably 0.5% by mass or more, more preferably 1% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, relative to the total mass of the heat generating material 71.

[0045] The electrolyte contained in the heat generating material 71 is used to increase the reaction efficiency of the oxidizable metal and promote the reaction to sustain the oxidation reaction. By using the electrolyte, the oxide film on the oxidizable metal can be destroyed, promoting the oxidation reaction. Examples of the electrolyte include one or more selected from sulfates and chlorides of alkali metals and alkaline earth metals. Among them, it is preferable to use one or more selected from various chlorides such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, ferrous chloride, and ferric chloride, and sodium sulfate, in view of excellent conductivity, chemical stability, and production costs. The content of the electrolyte in the heat generating material 71 is preferably 0.5 mass % or more, more preferably 1 mass % or more, and preferably 30 mass % or less, more preferably 20 mass % or less, relative to the total mass of the heat generating material 71.

[0046] The heat generating material 71 may contain other components in addition to the above-mentioned components (oxidizable metal, water-retaining material, electrolyte, and water). For example, from the viewpoint of improving the handleability of the heat generating material 71 during the manufacturing of the heating tool 1, the heat generating material 71 may contain a thickener, a flocculant, a surfactant, or the like as the other components.

[0047] The manufacturing method of the heating tool 1 typically includes the steps of deforming the second sheet 3 to form the protrusions 10 or a laminated structure of the protrusions 10 and the molded portions 20 on one side of the second sheet 3, then applying the heat-generating material 71 to the other side of the second sheet 3, and then overlapping the first sheet 2 on the other side of the second sheet 3 and joining them by a joining means such as fusion or adhesive. The deformation of the second sheet 3 to form the protrusions 10 and the molded portions 20 can be carried out by a press process that involves heat. The heating tool of the present invention can also be manufactured by the method described in Patent Document 1.

[0048] The heating tool of the present invention may have protrusions with shapes different from those described above. Examples of such shapes are shown in Figures 6 and 7. In Figure 6, the area where the heating part exists is schematically shown by dot hatching, and in Figure 7, the heating part is also shown by dot hatching.

[0049] Each of the protrusions 10A of the heating tool 1A may be conical. When there are a plurality of protrusions 10A, it is preferable that each of the protrusions 10A has the same shape and size. Each protrusion 10A preferably protrudes from the bottom wall 22 of the molding section 20 in a direction away from the first sheet 2. The inner surface 11A of each protrusion 10A is preferably continuous with the inner surface of the bottom wall 22 of the molding section 20. The direction in which each protrusion 10A protrudes from the bottom wall 22 of the molding section 20 coincides with the thickness direction Z1 of the heating tool 1A. Each protrusion 10A typically has a shape that tapers toward the tip (as it moves away from the first sheet 2). Each protrusion 10A may not have a rounded shape, but may have a sharp tip as shown in the figure. The shape of each protrusion 10A may also be a cone shape such as an elliptical cone or an oblong cone; or a truncated cone shape such as a circular truncated elliptical cone or an oblong cone.

[0050] In the heating tool of the present invention, the projections and molded portions may have shapes different from those described above. Examples of such shapes are shown in Figures 8, 9, and 10. In Figure 8, the area where the heating portion exists is shown schematically with dot hatching, and in Figures 9 and 10, the heating portion is also shown with dot hatching.

[0051] The second sheet 3 of the heating tool 1B preferably has hollow protrusions 10B that protrude in a direction away from the first sheet 2. The heating tool 1B preferably has two or more protrusions 10B. When there are multiple protrusions 10B, it is preferable that each of the protrusions 10B has the same shape and size. 8 and 9 show an example in which five protrusions 10B are provided. In this example, the five protrusions 10B are arranged in a houndstooth pattern when the second sheet 3 is viewed from above. Specifically, one of the five protrusions 10B is arranged in the center of the second sheet 3. The remaining four of the five protrusions 10B are arranged at the four corners of the second sheet 3. Each protrusion 10B typically has a shape that tapers toward the tip (as it moves away from the first sheet 2). The tip of each protrusion 10B may not be sharp, but may have a rounded shape.

[0052] Furthermore, it is preferable that the heating tool 1B further comprises a hollow connecting portion 25. It is preferable that the heating tool 1B comprises a plurality of connecting portions 25. When the heating tool 1B has a plurality of connecting portions 25, each connecting portion 25 is spaced from the first sheet 2 with a portion of the second sheet 3 continuing to the protrusion 10B, and is located closer to the first sheet 2 than the tip 10e of each protrusion 10B. The inner surface 25a of the connecting portion 25 is continuous with the inner surface 11B of the protrusion 10B. The inner surface 11B of the protrusion 10B defines the hollow portion 40B. In other words, the connecting portion 25 corresponds to a portion of the molded portion 20B. 8 and 9 show an example having four connecting portions 25. In this example, each connecting portion 25 extends linearly to connect the protrusion 10B located in the center of the second sheet 3 to one of the protrusions 10B located at each of the four corners of the second sheet 3. Therefore, when the second sheet 3 is viewed in plan, each connecting portion 25 extends radially from the protrusion 10B located in the center of the second sheet 3. An example in which each connecting portion 25 is semi-cylindrical is shown in Figure 10. The thickness direction of each connecting portion 25 coincides with the thickness direction Z1 of the heating tool 1B. The thickness of each connecting portion 25 is the length of protrusion of each connecting portion 25 from the first sheet 2. The space defined by the inner surface 25a of each connecting portion 25 forms part of the molding space portion 50B. Therefore, each connecting portion 25 forms part of the molding portion 20B. In a cross-sectional view along the thickness direction Z1 of the heating tool 1B, each protrusion 10B protrudes from the outer surface 25b of the connecting portion 25 toward the opposite side to the first sheet 2. In the second sheet 3, the portions that are continuous with each protrusion 10B and are closer to the first sheet 2 than the outer surface 25b of the connecting portion 25 are part of the molding portion 20B that defines a part of the molding space 50B. Therefore, in the second sheet 3, the portions that are continuous with each protrusion 10B and are closer to the first sheet 2 than the outer surface 25b of the connecting portion 25, and each connecting portion 25, form the molding portion 20B. The inner surface of the second sheet 3 that forms the molding portion 20B defines the molding space 50B. Each hollow portion 40B and the molding space 50B form the filling portion 30B.

[0053] Of the convex portions of the heating tool 1B formed by the second sheet 3 protruding in the direction away from the first sheet 2, the portions other than the connecting portion 25 are the high convex portions (convex portions including protrusions) whose thickness measured by the above method is 70% or more of the maximum thickness of the heating tool 1B. The tip end side of the high convex portion is protrusion 10B, which is an example of a protrusion according to the present invention, and the base end side of the high convex portion is part of the molded portion 20. On the other hand, the thickness of the connecting portion 25 measured by the above method is less than 70% of the maximum thickness of the heating tool 1B, so it is the low convex portion (convex portion not including protrusions) and is not a protrusion according to the present invention.

[0054] The shaped portions 20B each protrude from the outer surface of the second joint 6 in a direction away from the first sheet 2. The thickness direction of the shaped portions 20B coincides with the thickness direction Z1 of the heating tool 1B. The thickness of the shaped portions 20B is the protruding length of the shaped portions 20B from the second joint 6. The protruding length of the shaped portions 20B from the second joint 6 is the height H21 of the shaped portions 20B.

[0055] In a cross-sectional view taken along the thickness direction Z1 of the heating tool 1B, the direction in which each connecting portion 25 of each protrusion 10B protrudes from the outer surface 25b of each protrusion 10B coincides with the thickness direction Z1 of the heating tool 1B. In a cross-sectional view taken along the thickness direction Z1 of the heating tool 1B, the protrusion length of each connecting portion 25 of each protrusion 10B from the outer surface 25b is the height H22 of each protrusion 10B. The height H22 of each protrusion 10B can be set to a range similar to the height H2 of the protrusion 10 of the first embodiment. Furthermore, the height H21 of the molding portion 20B can be set to a range similar to the height H1 of the molding portion 20 of the first embodiment.

[0056] In the heating tool 1C of the present invention, the partitioning section 60 that defines the filling section 30 in the first sheet 2 may bulge in a direction away from the second sheet 3. The filling section 30 preferably has a first sheet space 91 located on the inner surface 2b side of the first sheet 2 facing the second sheet 3 and defined by the inner surface 60a of the partitioning section 60, and a second sheet space 92 located on the inner surface 3b side of the second sheet 3 facing the first sheet 2 and including at least a hollow section 40. An example of this is shown in Figure 11, where the heating section 70 is indicated by dot hatching.

[0057] It is preferable that the second sheet 3, while defining the filling section 30, be spaced from the partition section 60 to define a first sheet space 91, except for the section forming the protrusion 10A. Therefore, the first sheet space 91 can also be considered a hollow molding section formed by a portion of the second sheet 3 that is spaced from the first sheet 2 while continuing to the protrusion 10A, and that is located closer to the first sheet 2 than the tip 10e of the protrusion 10A. Therefore, the first sheet space 91 can also be considered a molding space that is located on the inner surface 3b of the second sheet 3 that faces the first sheet 2, and is a space defined by the inner surface of the molding section.

[0058] 11, the second sheet space 92 is formed by the hollow portion 40. However, for example, as shown in FIG. 12, the filling section 30 may have a configuration in which the filling section 30 has the hollow portion 40 and the molding space 50, and further has a first sheet space 91. In this case, the second sheet space 92 is formed by the hollow portion 40 and the molding space 50.

[0059] The amount of heat generating material 71 filled between the first sheet 2 and the second sheet 3 exceeds 100% of the volume of the second sheet space 92, and the heat generating material 71 may also be filled in the first sheet space 91. The amount of heat generating material 71 filled in the first sheet space 91 may be 100% of the volume of the first sheet space 91. In this way, by having the volume of the heat generating material 71 account for 100% or more of the volume of the first sheet space 91, it is possible to sufficiently fill the filling portion 30 with the heat generating material 71 required to maximize the planar area of ​​the entire heat generating portion 70 when viewed from the first sheet 2 side.

[0060] In the heating tool of the present invention, the molding section 20D may have a cone shape that protrudes from the inner peripheral edge of the second joint 6 of the second sheet 3 toward the opposite side from the first sheet 2. The molding section 20D preferably has an inclined wall that slopes inward from the inner peripheral edge of the second joint 6 of the second sheet 3 toward the protrusion 10A. The filling section 30 preferably further includes a molding space 50D located on the inner surface 3b of the second sheet 3 that faces the first sheet 2 and defined by the inner surface 24D of the molding section 20D. The molding space 50D has a diameter (length indicated by symbol W1 in FIG. 3 ) that decreases from the first surface 1a toward the second surface 1b. In other words, the diameter of the molding space 50D in a plan view gradually decreases from the first surface 1a toward the second surface 1b. Even with this configuration, it is possible to ensure that the planar area of ​​the entire heat generating portion 70 is as large as possible when viewed from the side of the first sheet 2. An example of this is shown in Figure 13, where the heat generating portion is indicated by dot hatching.

[0061] As shown in Fig. 14, the heating tool of the present invention may have particulate water-absorbent polymer 95, which is a water-retaining material, disposed in the first sheet space 91 described in the fourth embodiment. The water-absorbent polymer 95 is disposed on the first sheet 2 side of the oxidizable metal 96 that constitutes part of the heat-generating material 71. In other words, the water-absorbent polymer 95 may be biased toward the first sheet 2 side in the filling section 30. This increases the contact area between the water-absorbent polymer 95 and the oxidizable metal 96, making it possible to easily control the temperature of the tip 10e of the protrusion 10 without changing the shape or size of the protrusion 10. In the present invention, the water-retaining material may be uniformly dispersed in the heat generating portion 70 together with the other heat generating materials 71 .

[0062] A method for measuring the dimensions and volume of each part of various heating tools, including the heating tool of the present invention, typically includes a disassembly step and a measurement step. Such a measurement method will be explained below using the measurement of the dimensions and volume of each part of the heating tool 1 described above as an example. First, the joint 4 between the first sheet 2 and the second sheet 3 is cut, and the first sheet 2 is peeled off from the second sheet 3 (disassembly step). If the first sheet 2 and the second sheet 3 are joined with a hot melt adhesive, they are cold sprayed to harden the adhesive before being peeled off. If sheets other than the first sheet 2 and the second sheet 3 are laminated, the respective sheets are peeled off in the same manner. Next, the dimensions of each part of the second sheet 3 and the heat generating material 71 contained on its inner surface 3b side are measured in the following order, and the volume is calculated (measurement step). Note that the following measurement order is merely an example, and the measurement order is not particularly limited and can be set as desired.

[0063] In the measurement step, first, the base end side area A of the heat generating portion is measured. Specifically, a measuring instrument such as a scale or calipers is used to measure the across length (unit: mm) of the entire heat generating portion 70 (heat generating material 71) when viewed from the first sheet 2 side (the base end side of the protrusions 10). The area A is calculated using this measurement value. The "across length" here refers to the length of a portion necessary to calculate the area of ​​the object to be measured; for example, if the shape of the object to be measured in plan view is circular, it is the diameter, and if it is rectangular, it is both the vertical length and the horizontal length.

[0064] In the measurement process, the volume of the bulging portion of the heat generating material 71 (heat generating portion 70) or the volume of the portion of the hollow portion 40 or molding space portion 50 that does not contain the heat generating material 71 (hereinafter also referred to as the "space not containing the heat generating material") is measured. Specifically, the second sheet 3 containing the heat generating material 71 is visually observed from the side with the tips 10e of the protrusions 10 positioned at the lowest position. The presence or absence of a bulge of the heat generating material 71 from the top surface of the second sheet 3 (the portion of the inner surface 3b of the second sheet 3 that was in contact with the first sheet 2 to form the joint 4) is confirmed. If a bulge of the heat generating material 71 is confirmed, then the length across and height (unit: mm) of the bottom of the bulge is measured using a measuring instrument such as a scale or calipers. The volume of the bulge (unit: mm) is calculated using the following formula (1): 3 The "area of ​​the base of the bulging portion of the heat-generating material" in the following formula (1) is calculated in a conventional manner using the length across the base of the bulging portion. Volume of the bulging part of the heat generating material = base area of ​​the bulging part of the heat generating material × height ... (1) On the other hand, if the bulging portion of the heat generating material 71 cannot be confirmed, in other words, if the proportion of the heat generating material 71 in the volume of the hollow portion 40 or molding space portion 50 of the second sheet 3 is 100% or less, the following procedure is carried out. Using a measuring instrument such as a scale or calipers, the length of each portion of the space not containing the heat generating material in the hollow portion 40 or molding space portion 50 is measured, specifically, for example, the across length (diameter, vertical length, horizontal length, etc.) and height (unit: mm) of the opening of the space not containing the heat generating material. The volume (unit: mm) of the space not containing the heat generating material is calculated using the following formula (2): 3The "area of ​​the opening of the space not containing the heat generating material" in the following formula (2) is calculated in a conventional manner using the across length of the opening of the space not containing the heat generating material. Volume of the space not containing the heat-generating material = Area of ​​the opening of the space not containing the heat-generating material × Height ... (2)

[0065] The aforementioned "proportion of the volume of the heat-generating material 71 to the volume of the first sheet space portion 91" can be calculated from the volume of the bulging portion of the heat-generating material 71 and the volume of the first sheet space portion 91. The volume of the first sheet space portion 91 is set to be equal to the volume of the bulging portion of the heat-generating material 71. In other words, if there is a bulging portion of the heat-generating material 71, the proportion of the volume of the heat-generating material 71 to the volume of the first sheet space portion 91 is 100%.

[0066] Next, in the measuring step, the volumes of the hollow portion 40 and the molding space portion 50 are measured. Specifically, the heat-generating material 71 is removed from the second sheet 3, and a measuring instrument such as a scale or calipers is used to measure the across length (diameter, vertical length, horizontal length, etc.) of the opening of the molding space portion 50 on the first sheet 2 side and the opening of the hollow portion 40 on the first sheet 2 side. Using these measurements, the area 50S of the molding space portion 50 and the area 40S of the hollow portion 40 are calculated in a conventional manner, and the depths (unit: mm) of the hollow portion 40 and the molding space portion 50 are measured. The volume (unit: mm) of the hollow portion 40 or the molding space portion 50 is calculated using the following formula (3) or (4): 3 ) is calculated. Volume of the hollow part = Area 40S × Depth of the hollow part … (3) Volume of the molding space = Area 50S × Depth of the middle molding space ... (4) In addition, when measuring the diameter W1 (see Figure 3) of the molding space 50 in a plan view to calculate the area 50S, it is possible to confirm whether the length W1 is constant over the entire thickness direction of the molding space 50.

[0067] The aforementioned "amount of heat generating material 71 filled into the hollow portion 40" and "amount of heat generating material 71 filled into the molding space portion 50" can be calculated from the volume of the hollow portion 40 or the volume of the molding space portion 50 and the volume of the space not containing the heat generating material, respectively.

[0068] Next, in the measuring step, the height (thickness) H1 of the molded portion 20 and the height (thickness) H2 of the protrusion 10 (see FIG. 3) are measured using a measuring device. The measuring device used is a constant pressure thickness measuring device PG-20J manufactured by Teclock Corporation. The sum of height H1 and height H2 (H1 + H2) can be calculated by subtracting the thickness of the first sheet 2 from the thickness (maximum thickness) of the heating tool 1. The thickness of the heating tool 1 is measured using the above-mentioned method. The thickness of the first sheet 2 is measured using the constant pressure thickness measuring device PG-20J, with the first sheet 2 peeled off in the disassembly step as the measurement object, and is measured using a φ5 mm measuring probe at a pressure load of 44 gf.

[0069] Next in the measurement step, the inner surface area C of the protrusion tip is measured. Specifically, a hardening resin is poured into the hollow portion 40 of the second sheet 3 to create a replica of the hollow portion 40. Using this replica as the measurement object, the inner surface area C of the protrusion tip, i.e., the "surface area from the portion of the inner surface 11 of the protrusion 10 corresponding to the tip 10e of the protrusion 10 to the first portion 80" (see Figure 4), is measured. When measuring this surface area, a measuring instrument such as a scale or calipers is used to measure the across length of each portion, but if this is difficult, the surface of the replica to be measured is photographed with a microscope or the like, and the surface area is calculated from the photographed image.

[0070] While the present invention has been described above based on its preferred embodiments, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the present invention. Furthermore, all parts of the above-described embodiments can be used interchangeably as appropriate without departing from the spirit of the present invention.

[0071] The following supplementary notes are further disclosed regarding the above-described embodiments of the present invention. <1> a first sheet forming a first surface; a second sheet forming a second surface located on the opposite side to the first surface, the second sheet has one or more hollow protrusions, parts of which protrude in a direction away from the first sheet; The hollow protrusion forms a hollow portion that is a part of the filling portion, the hollow portion is a space located on the inner surface of the second sheet facing the first sheet and defined by the inner surface of the protrusion, a heat generating portion formed between the first sheet and the second sheet and made of a heat generating material filled at least in the hollow portion; In a cross-sectional view along the thickness direction of the heating tool, a portion of the inner surface of the protrusion located 10% of the thickness of the heating part from a portion corresponding to the tip of the protrusion on the heating part toward the first surface is defined as a first portion. A heating tool in which the planar area (A) of the entire heating portion when viewed from the first sheet side divided by the number of protrusions (B) is 8 times or more the surface area (C) from the portion on the inner surface of the protrusion corresponding to the tip of the protrusion to the first portion (i.e., A / B / C≧8). <2> the area (A) of the entire heat generating portion in plan view when viewed from the first sheet side divided by the number (B) of the protrusions is 9 times or more, preferably 10 times or more, the surface area (C) from the portion corresponding to the tip of the protrusion on the inner surface of the protrusion to the first portion; <1> The heating tool described in <3> the area (A) of the entire heat generating portion in plan view when viewed from the first sheet side divided by the number (B) of the protrusions is 50 times or less, preferably 40 times or less, the surface area (C) from the portion on the inner surface of the protrusion corresponding to the tip of the protrusion to the first portion; <1> or <2> The heating tool described in

[0072] <4> a hollow molding portion formed such that a portion of the second sheet is spaced from the first sheet while continuing to the protrusion and is located closer to the first sheet than the tip of the protrusion; the filling section further has a molding space section communicating with the hollow section, The molding space portion is located on the inner surface side of the second sheet on the side of the first sheet, and is a space defined by the inner surface of the molding portion. <1> ~ <3> A heating tool according to any one of the preceding claims. <5> The molding portion has a side wall and a bottom wall. <4> The heating tool described in <6> The height (H1, H21) of the molding portion is 0.5 mm or more, preferably 1 mm or more. <4> or <5> The heating tool described in <7> The height (H1, H21) of the molding portion is 5 mm or less, preferably 4 mm or less. <4> ~ <6> A heating tool according to any one of the preceding claims. <8> The molding space is filled with the heat-generating material in an amount of 10% or more, preferably 20% or more, more preferably 30% or more of the volume of the molding space. <4> ~ <7> A heating tool according to any one of the preceding claims. <9> The ratio of the heat generating material to the volume of the molding space is 100% or less. <4> ~ <8> A heating tool according to any one of the preceding claims. <10> Two or more of the protrusions are provided, The molding portion is formed by separating a part of the second sheet from the first sheet so that the molding space portion communicates with at least two of the hollow portions defined by the inner surfaces of the protrusions. <4> ~ <9> A heating tool according to any one of the preceding claims. <11> the molding space portion overlaps the entire hollow portion when viewed from the first sheet side, a planar area of ​​the opening of the molding space portion on the first sheet side when viewed from the first sheet side is larger than a planar area of ​​the opening of the hollow portion on the first sheet side when viewed from the first sheet side; <4> ~ <10> A heating tool according to any one of the preceding claims. <12> a ratio of a plan view area (50S) of the opening on the first sheet side of the molding space portion when viewed from the first sheet side to a plan view area (40S) of the opening on the first sheet side of the hollow portion when viewed from the first sheet side, expressed as the latter (40S) / the former (50S), is 0.1 or more, preferably 0.2 or more; <4> ~ <11> A heating tool according to any one of the preceding claims. <13> a ratio of a plan view area (50S) of the opening on the first sheet side of the molding space portion when viewed from the first sheet side to a plan view area (40S) of the opening on the first sheet side of the hollow portion when viewed from the first sheet side, expressed as the latter (40S) / the former (50S), is 0.9 or less, preferably 0.8 or less; <4> ~ <12> A heating tool according to any one of the preceding claims. <14> The molding space has a width in a plan view that is constant over the entire thickness of the molding space, or has a portion that decreases from the first surface side toward the second surface side. <4> ~ <13> A heating tool according to any one of the preceding claims. <15> a partition portion of the first sheet that partitions the filling portion does not bulge in a direction away from the second sheet; <4> ~ <14> A heating tool according to any one of the preceding claims. <16> a partition portion of the first sheet that partitions the filling portion bulges in a direction away from the second sheet, the filling portion is located on the inner surface of the first sheet on the second sheet side, and further includes a first sheet space portion defined by the inner surface of the partition portion, The heat generating material filled between the first sheet and the second sheet is filled in the hollow portion, the molding space portion, and the first sheet space portion. <4> ~ <14> A heating tool according to any one of the preceding claims. <17> The amount of the heat generating material filled in the first seat space is 100% of the volume of the first seat space. <16> The heating tool described in

[0073] <18> a partition portion of the first sheet that partitions the filling portion does not bulge in a direction away from the second sheet; <1> ~ <3> A heating tool according to any one of the preceding claims. <19> a partition portion of the first sheet that partitions the filling portion bulges in a direction away from the second sheet, the filling portion is located on the inner surface of the first sheet on the second sheet side, and further includes a first sheet space portion defined by the inner surface of the partition portion, The heat generating material filled between the first sheet and the second sheet is filled in the hollow portion and the first sheet space portion. <1> ~ <3> A heating tool according to any one of the preceding claims. <20> The amount of the heat generating material filled in the hollow portion is 100% of the volume of the hollow portion. <1> ~ <19> A heating tool according to any one of the preceding claims. <21> The inside of the filling portion is not filled with fibers that constitute the second sheet. <1> ~ <20> A heating tool according to any one of the preceding claims. <22> The filling portion is a space having the heat-generating material therein. <1> ~ <21> A heating tool according to any one of the preceding claims. <23> At least one of the first sheet and the second sheet is breathable. <1> ~ <22> A heating tool according to any one of the preceding claims. <24> At least one of the first sheet and the second sheet is moisture permeable. <1> ~ <23> A heating tool according to any one of the preceding claims. <25> The protrusion is a part (tip side) or the whole of a high convex portion (high convex portion) of the heating tool, which is a convex portion formed by the second sheet protruding in a direction away from the first sheet, and the thickness of the convex portion is 70% or more of the maximum thickness of the heating tool. <1> ~ <24> A heating tool according to any one of the preceding claims. <26> The height (H2, H22) of the protrusions is preferably 2 mm or more, more preferably 3 mm or more. <1> ~ <25> A heating tool according to any one of the preceding claims. <27> The height (H2, H22) of the protrusions is 15 mm or less, preferably 10 mm or less. <1> ~ <26> A heating tool according to any one of the preceding claims. <28> the heat generating material includes a water-retaining material, and the water-retaining material is biased toward the first sheet side in the filling portion; <1> ~ <27> A heating tool according to any one of the preceding claims. <29> The heating tool is sealed and housed in a packaging material before use. <1> ~ <28> A heating tool according to any one of the preceding claims. <30> The heating tool is an acupuncture patch. <1> ~ <29> A heating tool according to any one of the preceding claims. [Example]

[0074] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0075] [Examples 1 to 4, Comparative Example 1] Heating tools corresponding to the shapes of the illustrated examples were manufactured as Examples 1 to 4. Furthermore, a heating tool having the same configuration as Example 4 except for the amount of heat-generating material filled was manufactured as a comparative heating tool. The amount of heat-generating material filled and the dimensions of each part of the heating tools of each example and comparative example are shown in Table 1 below. In the heating tools of each Example and Comparative Example, the following materials were used as the first sheet and second sheet. Iron powder was used as the oxidizable metal in the heat-generating material, and activated carbon and a water-absorbent polymer were used as the water-retaining material. In the filling section (the space between the first and second sheets) of the heating tools of each Example and Comparative Example, the water-absorbent polymer was biased toward the first sheet, and the heat-generating materials other than the water-absorbent polymer (iron powder, electrolyte, activated carbon) were placed in a mixed state in the remaining part of the filling section (see Figure 14). First sheet (breathable sheet): Porous film with calcium carbonate dispersed in polyethylene (PE) film (thickness 240 μm, basis weight 125 g / m 2 ). Second sheet (non-breathable sheet): A three-layer composite sheet in which a first nonwoven fabric, a resin film, and a second nonwoven fabric are laminated in this order from the first sheet. The first nonwoven fabric is a nonwoven fabric (basis weight 70 g / m) made of polyethylene terephthalate (PET) fibers. 2 ), the resin film is a PE film (thickness 80 μm), and the second nonwoven fabric is a nonwoven fabric made of PET fiber (basis weight 150 g / m 2 ). In Examples 1 and 2, the diameter W1 of the molding space 50 in a plan view was constant over the entire thickness direction of the molding space 50. In Example 3, as shown in Figures 9 and 10, the diameter W1 of the molding space 50B in a plan view (the length indicated by symbol W1 in Figure 3) had a portion that decreased from the first surface 1a side toward the second surface 1b side. The partitioning portion 60 in the first sheet 2 that separates the filling portions 30, 30B did not bulge in the direction away from the second sheet 3 in Examples 1 to 3, but bulged in Example 4. In Example 4, the heat generating material 71 was filled in the hollow portion 40 and the first sheet space portion 91. The amount of heat generating material 71 filled in the first sheet space portion 91 was 100% of the volume of the first sheet space portion 91.

[0076] For each of the heating tools of the Examples and Comparative Examples, the temperature of the tip of the projections, the skin temperature, and the warmth sensation were measured and evaluated by the following methods. The results are shown in Table 1 below.

[0077] <Method for measuring the temperature at the tip of the protrusion> The heating tool to be measured was placed in an environment with an ambient temperature of 23°C and a relative humidity of 50%RH to initiate an oxidation reaction of the heat-generating material contained in the heating tool, and the maximum temperature reached in Examples and Comparative Examples, T1 (°C), was measured using a thermometer in accordance with the method of JIS S 4100:2007. A K-type thermocouple was used as the temperature measurement sensor, and the sensor was brought into contact with the tip of each of the multiple protrusions contained in the heating tool to measure the heat generation temperature. The average of the maximum temperatures of the multiple protrusions was taken as the tip temperature of the heating tool's protrusions.

[0078] <How to measure skin temperature> The heating tool to be evaluated was fixed to the skin of the calf of a human body, and the temperature of the skin where the heating tool was fixed was measured. Specifically, a thermometer (a data logger with a thermistor, Nikkiso Thermo Co., Ltd. LT-8) was fixed to the skin of the calf of the subject with surgical tape, and the heating tool to be evaluated was placed at the fixed position of the thermometer so that the protruding side (second sheet side) of the heating tool was in contact with the skin around the thermometer, and with socks worn over it, the skin temperature was measured with the thermometer for 25 minutes from the start of heating of the heating tool. If the maximum skin temperature (maximum skin temperature) during this 25-minute period was in the range of 37-42°C, the heating tool was highly evaluated as an acupuncture patch.

[0079] <How to evaluate warmth> During the above-mentioned <Skin temperature measurement method>, the subjects were asked to evaluate the warmth of the area where the heating tool was attached (calf) according to the following evaluation criteria, with "4" being the highest rating. (Evaluation criteria for warmth) 1: No change 2: Feeling a slight warmth 3: Slightly warm 4: Warm

[0080] [Table 1]

[0081] As shown in Table 1, in each example, the formula (1) "A / B / C≧8" was satisfied, and therefore the temperature of the tip of the projections and the skin temperature were within the appropriate range, and the warmth was highly rated compared to Comparative Example 1, where this formula was not satisfied. [Explanation of symbols]

[0082] 1, 1A, 1B, 1C Heating tool 1a 1st page 1b 2nd side 2. Sheet 1 3. Second Sheet 3b Inner surface 10,10A,10B protrusion 10e tip 24,24D inner surface 30,30B Filling section 40,40B Hollow part 60 Compartment 60a inner surface 70 Heat generating part 71 Heat-generating materials 80 Part 1

Claims

1. a first sheet forming a first surface; a second sheet forming a second surface located on the opposite side to the first surface, The first sheet is breathable, a space between the first sheet and the second sheet is a filling portion; the second sheet has one or more hollow protrusions, parts of which protrude in a direction away from the first sheet; The hollow protrusion forms a hollow portion that is a part of the filling portion, the hollow portion is a space located on the inner surface of the second sheet facing the first sheet and defined by the inner surface of the protrusion, a hollow molding portion formed such that a portion of the second sheet is spaced from the first sheet while continuing to the protrusion and is located closer to the first sheet than the tip of the protrusion; The molding portion has a side wall and a bottom wall, the side wall is a portion of the second sheet that protrudes from an inner peripheral edge of a peripheral portion of the second sheet toward an opposite side to the first sheet, the bottom wall is a portion of the second sheet that connects the side wall and the protrusion, and extends in a direction perpendicular to a thickness direction of the heating tool, the filling portion has a molding space portion communicating with the hollow portion, the molding space portion is located on the inner surface side of the second sheet on the side of the first sheet, and is a space defined by the inner surface of the molding portion, a heat generating portion formed between the first sheet and the second sheet and made of a heat generating material filled at least in the hollow portion, In a cross-sectional view along the thickness direction of the heating tool, a portion of the inner surface of the protrusion located 10% of the thickness of the heating part from a portion corresponding to the tip of the protrusion on the heating part toward the first surface is defined as a first portion. an area obtained by dividing a planar view area of ​​the entire heat generating portion when viewed from the first sheet side by the number of the protrusions is eight times or more a surface area from a portion on the inner surface of the protrusion corresponding to the tip of the protrusion to the first portion, a partition portion of the first sheet that partitions the filling portion bulges in a direction away from the second sheet, the filling section further includes a first sheet space section located on the inner surface of the first sheet facing the second sheet and defined by the inner surface of the partition section, and a second sheet space section located on the inner surface of the second sheet facing the first sheet and including the hollow section and the molding space section, the heat generating material filled between the first sheet and the second sheet is filled in the first sheet space and the second sheet space, the amount of the heat-generating material filled in the second seat space exceeds 100% of the volume of the second seat space, the heat-generating material includes an oxidizable metal, a water-retaining material, an electrolyte, and water; The heating tool, wherein the water-retaining material includes a particulate water-absorbent polymer, the particulate water-absorbent polymer being disposed in the first sheet space and biased toward the first sheet.

2. The content of the oxidizable metal in the heat generating material is 10% by mass or more and 80% by mass or less relative to the total mass of the heat generating material, The content of the water retention material in the heat generating material is 0.5% by mass or more and 30% by mass or less with respect to the total mass of the heat generating material, The content of the electrolyte in the heat generating material is 0.5 mass % or more and 30 mass % or less with respect to the total mass of the heat generating material, The heating tool according to claim 1 , wherein the content of the water in the heat generating material is 5% by mass or more and 80% by mass or less with respect to the total mass of the heat generating material.

3. A heating tool as described in claim 1 or 2, wherein the height of the molded portion is 0.5 mm or more and 5 mm or less.

4. Two or more of the protrusions are provided, A heating tool as described in any one of claims 1 to 3, wherein the molding portion is formed by separating a portion of the second sheet from the first sheet so that the molding space portion is connected to at least two of the hollow portions defined by the inner surfaces of each of the protrusions.

5. the molding space portion overlaps the entire hollow portion when viewed from the first sheet side, A heating tool as described in any one of claims 1 to 4, wherein the planar area of ​​the opening on the first sheet side in the molding space portion when viewed from the first sheet side is larger than the planar area of ​​the opening on the first sheet side in the hollow portion when viewed from the first sheet side.

6. A heating tool as described in any one of claims 1 to 5, wherein the diameter of the molding space in a planar view is constant over the entire thickness direction of the molding space, or has a portion that decreases as it moves from the first surface side to the second surface side.

7. A heating device as described in any one of claims 1 to 6, which is an acupuncture patch that is fixed to the human body (excluding those that are used in a state where they are placed along the top surface of the sole of footwear).

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