Heating element for feet

Abstract

To provide a temperature control method for a heating surface, and a heating element capable of not only controlling temperature distribution in the heating surface of a heating element for feet, but also suppressing movement of a heating material to one side.SOLUTION: A temperature control method for a heating surface 6 is a temperature control method for controlling the temperature distribution of the heating surface 6 in a heating element 1. The heating element 1 includes a heating material 4 and a bag body 2 in which the heating material 4 is encapsulated, and which includes the heating surface 6 at least on one surface. The temperature control method for the heating surface 6 prevents conduction of heat from outside a partitioning part 51 to inside the partitioning part 51 by the partitioning part 51 surrounding one range in the heating surface 6 viewed from the front, and controls the temperature distribution of the heating surface 6.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention provides a foot heating On the body Regarding. [Background technology]

[0002] Patent Document 1 discloses a conventional heating element. The heating element described in Patent Document 1 includes a heat-generating composition (heat-generating material) that generates heat upon contact with air, and a storage bag (bag) that stores the heat-generating composition. The storage bag is formed into a bag shape by sealing the outer edges of two sheets of material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-354 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in cold outdoor environments in winter, such as when working in the fields, at the market, or on snowy mountains, the feet get cold, so the heating element described in Patent Document 1 is sometimes placed between the foot and the shoe.

[0005] However, in the heating element described in Patent Document 1, when the temperature distribution of the heating surface is examined, a high-temperature region is formed in the center when viewed from the front. On the other hand, by positioning the high-temperature region of a foot heating element in a desired location, it is expected that the applications of heating elements will be further expanded, for example, by targeting the toes (fingers). However, no technology for positioning the high-temperature region in a desired location is known. On the other hand, because a foot heating element is sandwiched between the foot and the inner surface of the shoe, it is not desirable for this high-temperature region to have a localized high temperature rise.

[0006] Furthermore, the heating element described in Patent Document 1, when placed between the foot and shoe, sways significantly during walking, which causes the heating material to easily shift to one side inside the bag. This is problematic.

[0007] The present invention provides a foot heating element that can control the temperature distribution of the heating surface of the foot heating element and can prevent the heating material from being unevenly distributed. Body The purpose is to provide. [Means for solving the problem]

[0008] A temperature control method for a heating surface of a foot heating element according to one aspect of the present invention is a temperature control method for controlling the temperature distribution of the heating surface of a foot heating element placed between a user's foot and a shoe. The foot heating element includes a heating material and a bag that encloses the heating material and has a heating surface on at least one side. When viewed from the front, a compartment that surrounds one area of ​​the heating surface prevents heat conduction from the outside of the compartment toward the inside of the compartment, thereby controlling the temperature distribution of the heating surface.

[0009] In addition, in the temperature control method for the heating surface of the foot heating element, it is preferable that the partition, when viewed from the front, prevents heat conduction from the outside of the partition to the inside of the partition by excluding the heat-generating material.

[0010] In addition, in the method for controlling the temperature of the heat generating surface of the foot heating element, it is preferable that the heat generating material is also excluded from the inside part of the partition section when viewed from the front.

[0011] Furthermore, in the temperature control method for the heating surface of the heating element for the feet, it is preferable that the bag body has a front sheet portion and a back sheet portion, and the partition portion is formed by joining the front sheet portion and the back sheet portion, thereby configuring to exclude the heat-generating material.

[0012] In addition, in the temperature control method for the heat generating surface, it is preferable that the entire surface of the portion (inner portion) inside the partition portion is formed by joining the front sheet portion and the back sheet portion.

[0013] In the method for controlling the temperature of the heating surface of the feet heating element, it is preferable to control the temperature distribution of the heating surface by changing the size or shape of the partitioned portion.

[0014] A foot heating element according to one aspect of the present invention is a foot heating element to be placed between a user's foot and a shoe. The foot heating element includes a heat-generating material and a bag containing the heat-generating material and having a heat-generating surface on one side. The bag has a partition that surrounds one area of ​​the heat-generating surface and prevents heat from being conducted from the outside to the inside.

[0015] Furthermore, in the heating element for the feet, it is preferable that the bag body has a front sheet portion and a back sheet portion, and the partition portion is formed by excluding the heat-generating material from between the front sheet portion and the back sheet portion.

[0016] In addition, it is preferable that the heat-generating material is also excluded from the inside of the partition section when viewed from the front of the foot heating element.

[0017] Furthermore, in the heating element for the feet, it is preferable that the bag body has a front sheet portion and a back sheet portion, and the partition portion is formed by joining the front sheet portion and the back sheet portion, thereby being configured to exclude the heat-generating material.

[0018] In addition, in the heating element for feet, it is preferable that the entire surface of the portion (inner portion) inside the partition portion is formed by joining the front sheet portion and the back sheet portion. [Effects of the Invention]

[0019] The temperature control method for the heating surface of the foot heating element and the foot heating element of the above-mentioned aspect of the present invention have the advantage of being able to lower the maximum temperature on the heating surface, suppress localized high temperature increases, and suppress uneven distribution of the heating material. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a cross-sectional view of a heating element for feet according to one embodiment of the present invention in use. [Figure 2] FIG. 2 is a front view of the above-mentioned foot heating element. [Figure 3] Fig. 3(A) is a cross-sectional view taken along the line AA in Fig. 2. Fig. 3(B) is a bottom view of the same heating element for feet. [Figure 4] Fig. 4(A) is a front view of a heat generating element according to Example 1. Fig. 4(B) is a front view of a heat generating element according to Example 2. Fig. 4(C) is a front view of a heat generating element according to Example 3. [Figure 5] FIG. 5 is a diagram showing temperature distributions according to Examples 1, 2, and 3 and the comparative example. [Figure 6] FIG. 6 is a graph showing the temperature distributions according to Examples 1, 2, and 3 and the comparative example. [Figure 7] 7A is a front view of a heat generating element according to Example 4. FIG. 7B is a front view of a heat generating element according to Example 5. FIG. [Figure 8] FIG. 8 is a diagram showing the temperature distributions according to Examples 4 and 5 and the comparative example. [Figure 9] FIG. 9 is a graph showing the temperature distributions according to Examples 4 and 5 and the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0021] (1) Implementation form The temperature control method for the heating surface of the feet heating element 1 according to this embodiment (hereinafter, may be simply referred to as the "temperature control method") and the feet heating element 1 will be described in detail below.

[0022] As shown in Fig. 1, the foot heating element 1 according to this embodiment is placed between a user's foot 7 and a shoe 8. In this embodiment, it is placed between the toe-side portion of the sole 71 of the user's foot and the toe-side portion of the insole 81 of the shoe 8. Examples of the shoe 8 include, but are not limited to, athletic shoes, sneakers, shoes, leather shoes, rubber boots, boots (including long boots), slippers, etc. Furthermore, the "user's foot 7" here refers to a foot wearing socks, stockings, tights, etc., or a bare foot.

[0023] When used to warm the feet, the foot heating element 1 is typically designed so that its heat temperature is between 25°C and 50°C in a 20°C environment, and preferably between 30°C and 45°C (the temperature measurement method conforms to the foot warmer temperature measurement method of the Body Warmer Industry Association).

[0024] In the following description, first, a method for controlling the temperature of the heating surface 6 of the feet heating element 1 will be described, and then the feet heating element 1 to which this temperature control method is applied will be described in detail.

[0025] (1.1) Temperature control method The temperature control method according to this embodiment is, for example, a method for controlling the temperature distribution of the heat generating surface 6 of a foot heating element 1 as shown in Fig. 2. This foot heating element 1 comprises a heat generating material 4 (Fig. 3(A)) and a bag 2 that has the heat generating surface 6 and encloses the heat generating material 4.

[0026] 2, a partition 51 (preferably a heat-generating material removal section 5) is formed somewhere on the heat-generating surface 6, thereby preventing heat conduction from the outside to the inside of the partition 51 and controlling the temperature distribution on the heat-generating surface 6. The partition 51 according to this embodiment is formed by the outer periphery of the heat-generating material removal section 5 formed somewhere on the heat-generating surface 6.

[0027] The heat-generating material removal section 5 is a section where the heat-generating material 4 has been removed and is therefore not present, as viewed from the front. The outer periphery of the heat-generating material removal section 5 (i.e., the partition section 51) prevents heat conduction from the outside of the heat-generating material removal section 5 (the heat-generating material 4 side) to the inside of the heat-generating material removal section 5. In other words, in the heat-generating element 1 according to this embodiment, heat conduction from the heat-generating material 4 toward the inside of the partition section 51 is blocked, so heat generation in the heat-generating material removal section 5 of the heat-generating surface 6 is suppressed. The heat-generating material removal section 5 according to this embodiment may be located anywhere on the heat-generating surface 6, and may be formed, for example, at a position overlapping with the centroid 9 (center) of the heat-generating surface 6, or at a position away from the centroid 9 of the heat-generating surface 6.

[0028] For example, when attempting to lower the maximum temperature to a predetermined temperature and increase the area of ​​the high-temperature region including the lowered maximum temperature for a heat-generating surface 6 that does not have a partition 51 formed therein, a partition 51 (heat-generating material removal section 5) of a predetermined size (area) can be formed in the center of the heat-generating surface 6 (this will be referred to as the reference heat-generating surface 6 and the reference partition 51 (reference heat-generating material removal section 5)). Here, the "center of the heat-generating surface 6" refers to an area including the centroid 9 of the heat-generating surface 6 when viewed from the front (viewed in a direction perpendicular to the heat-generating surface 6) (hereinafter referred to as the front view). When attempting to further lower the maximum temperature for this reference heat-generating surface 6, the partition 51 (heat-generating material removal section 5) is designed to be larger than the reference partition 51 (reference heat-generating material removal section 5). On the other hand, when preventing the maximum temperature from dropping to the same level as that of the reference heat-generating surface 6, the partition 51 (heat-generating material removal section 5) can be designed to be smaller than the reference partition 51 (heat-generating material removal section 5).

[0029] Furthermore, when attempting to lower the maximum temperature to a predetermined temperature and move the position of the high temperature zone including the lowered maximum temperature on a heat-generating surface on which no heat-generating material removal section 5 is formed, it is sufficient to form partition section 51 (heat-generating material removal section 5) at a position away from centroid 9 of heat-generating surface 6. When attempting to adjust the area of ​​the high temperature zone on this heat-generating surface 6 while maintaining the position of the high temperature zone, it is sufficient to adjust the size or shape of partition section 51 (area or shape of heat-generating material removal section 5).

[0030] Thus, in the temperature control method according to this embodiment, by forming the partition 51 so as to surround the centroid 9, the maximum temperature can be lowered compared to a heat-generating surface without the partition 51, and the area of ​​the high-temperature region including the lowered maximum temperature can be increased, thereby improving the uniformity of the temperature distribution. Also, by changing the size or shape of the partition 51, the maximum temperature can be adjusted while keeping the area of ​​the high-temperature region approximately the same. Furthermore, the position of the high-temperature region can be adjusted by the position of the partition 51 (heat-generating material removal section 5). In short, according to the temperature control method according to this embodiment, the temperature distribution of the heat-generating surface 6 can be controlled.

[0031] The "high temperature range" in this disclosure refers to a temperature range of the heat generating surface that is equal to or higher than (maximum temperature -5°C) and equal to or lower than the maximum temperature.

[0032] (1.2) Heating element for feet The foot heating element 1 according to this embodiment can provide heat to a part of the foot 7 in contact with the bag 2 by generating heat from the heat generating material 4, thereby providing a warming effect to the foot 7. The foot heating element 1 according to this embodiment is, for example, a disposable warmer, and uses the reaction heat generated when an oxidation reaction occurs in the heat generating material 4 as a heat source. Before use, the foot heating element 1 according to this embodiment is, for example, housed in an airtight outer bag (not shown) that does not allow air to pass through. However, the foot heating element 1 according to the present disclosure is not limited to a disposable warmer, and may be, for example, a heating appliance in which the heat generating material 4 generates heat by irradiating the foot heating element 1 with microwaves in a microwave oven or the like.

[0033] The feet heating element 1 according to this embodiment has a heating surface 6 on the surface of the bag body 2. In the present disclosure, the "heating surface 6" refers to the surface of the bag body 2 that is surrounded by an outer periphery that forms a space for storing the heat generating material 4. In the feet heating element 1 according to this embodiment, the heating surface 6 is the main surface of the approximately rectangular bag body 2 that is surrounded by an edge 31 (the outer periphery that forms the space for storing the heat generating material 4) described below, and the feet heating element 1 has a pair of heating surfaces 6 on the front and back. The front view and back view of the heating element 1 are from the direction in which the heating surface 6 is viewed from the front.

[0034] The size of the heating surface 6 is determined appropriately depending on the area to which a thermal effect is to be applied. For example, a foot heating element 1 having a relatively large heating surface 6 is appropriate for use on the sole 71 of the foot. For example, a foot heating element 1 having a normal-sized heating surface 6 is appropriate for use on a relatively narrow area such as the instep, side, heel, or ankle of the foot 7. However, this is merely an example, and a foot heating element 1 having a large heating surface 6 may also be used on a relatively narrow area, for example.

[0035] (1.2.1) Heat-generating materials The heat generating material 4 is a material that can generate heat, and in this embodiment, is a powdery material that generates heat upon contact with air. The heat generating material 4 is sealed in the bag 2.

[0036] Examples of the heat-generating material 4 include an oxidizable metal, activated carbon, carbon black, a water-retaining agent, a metal salt (e.g., table salt), and water. The oxidizable metal is a metal that generates heat through oxidation reaction, and examples thereof include powder or fiber of one or more types selected from iron, aluminum, zinc, manganese, magnesium, and calcium. Among these, iron powder is preferred from the viewpoints of handleability, safety, production cost, storage stability, and stability. Examples of the iron powder include one or more types selected from reduced iron powder and atomized iron powder. Examples of the water-retaining agent include wood flour, vermiculite, diatomaceous earth, perlite, silica gel, alumina, and water-absorbent resin. The heat-generating material 4 is not particularly limited and may be a composition used in conventional disposable hand warmers.

[0037] Materials other than those that generate heat upon contact with air may also be used as the heat-generating material 4. For example, materials that generate heat upon exposure to microwaves in a microwave oven or the like (for example, ceramic powder such as ferrite, adzuki beans, etc.) may also be used as the heat-generating material 4.

[0038] (1.2.2) Bag body The bag body 2 is formed in a bag shape and has an internal storage space for storing the heat-generating material 4. As shown in Fig. 3(A), the bag body 2 according to this embodiment is formed flat and includes a front sheet portion 21 and a back sheet portion 22. The front sheet portion 21 and the back sheet portion 22 are joined at a joining portion 3 to form the internal storage space of the bag body 2.

[0039] The bag body 2 according to this embodiment has a width and a length as shown in Fig. 2. The bag body 2 according to this embodiment has longitudinal ends formed in an arc shape, but the bag body 2 according to the present disclosure may be formed in any shape, such as a square shape when viewed from the front, a triangular shape when viewed from the front, a polygonal shape with pentagons or more when viewed from the front, a perfect circle when viewed from the front, or an elliptical shape when viewed from the front, and is not limited in shape.

[0040] (1.2.2.1) Front sheet part As shown in FIG. 3(A), the front sheet portion 21 is a sheet-like portion that forms one surface of the bag body 2. The front sheet portion 21 according to this embodiment is made of a single sheet material. The front sheet portion 21 according to this embodiment is flexible. This allows the foot heating element 1 to deform along the user's feet 7.

[0041] From the viewpoints of strength and durability against heat generation by the heat-generating material 4, a resin film is preferably used for the front sheet portion 21 according to this embodiment. A thermoplastic resin is preferably used as the resin for the resin film. Examples of thermoplastic resins include polyethylene, polypropylene, polyester, polyamide, polyurethane, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polycarbonate, and ethylene-vinyl acetate copolymer. These resins may be used alone or in combination of two or more.

[0042] In order to improve the feel on the skin of the foot 7, the front sheet portion 21 preferably has a woven fabric or nonwoven fabric on the outside of the resin film.

[0043] Examples of fiber materials for the woven or nonwoven fabric include natural fibers such as cotton, linen, silk, and paper; semi-synthetic fibers such as rayon and acetate; synthetic fibers such as nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, polyvinyl chloride, and polybutylene terephthalate; and blends of these fibers. Of these, nylon, polyester, and polypropylene are preferred as fiber materials from the viewpoint of providing a pleasant feel to the skin. These fiber materials may be used alone or in combination of two or more. The basis weight of the woven or nonwoven fabric is not particularly limited as long as it is sufficient to prevent leakage of the heat-generating material 4 to the outside of the bag body 2, but an example is 20 g / m 2 More than 70g / m 2 The following is an example:

[0044] However, the front sheet portion 21 does not have to be a laminate of a resin film and a woven or nonwoven fabric, and may be made of a single resin film, or a single woven or nonwoven fabric.

[0045] The front-side sheet portion 21 according to this embodiment is breathable. In this embodiment, the resin film of the front-side sheet portion 21 is a porous resin film or a resin film having a plurality of holes (not shown), so that the front-side sheet portion 21 has a plurality of holes. Therefore, the front-side sheet portion 21 allows ventilation between the inside and outside of the bag body 2 through the plurality of holes. The plurality of holes may be uniformly formed over the entire surface of the front-side sheet portion 21, or may be densely formed in a portion. The diameter of each hole may be any size sufficient to prevent leakage of the heat-generating material 4 through the holes, and is, for example, 0.1 μm to 30 μm. The shape and number of the holes are not particularly limited. The sensible temperature of the feet heating element 1 changes depending on the amount of ventilation through the bag body 2. Therefore, the size, shape, and number of the holes are appropriately determined taking into consideration the sensible temperature of the feet heating element 1 and the degree of prevention of leakage of the heat-generating material 4.

[0046] When a nonwoven fabric is used alone as the front sheet portion 21, the plurality of holes may not be formed.

[0047] The front sheet portion 21 preferably has a certain moisture permeability. The moisture permeability of the front sheet portion 21 is 300 g / (m 2 ·day) or more 1000g / (m 2 ·day) or less, and 400g / (m 2 ·day) or more than 900g / (m 2 However, the moisture permeability of the front sheet portion 21 is not particularly limited.

[0048] (1.2.2.2) Back sheet part The back-side sheet portion 22 is a sheet-like portion that forms the surface of the bag body 2 opposite to the front-side sheet portion 21. The back-side sheet portion 22 according to this embodiment is made of a single sheet material. Like the front-side sheet portion 21, the back-side sheet portion 22 according to this embodiment is flexible.

[0049] The back-side sheet portion 22 is preferably made of a resin film, similar to the front-side sheet portion 21. However, the back-side sheet portion 22 does not need to have the same structure or material as the front-side sheet portion 21. Like the front-side sheet portion 21, the back-side sheet portion 22 is preferably made of a laminate of a resin film and a woven fabric or a nonwoven fabric, but is not limited thereto and may be made of a single resin film, or a single woven fabric or nonwoven fabric.

[0050] The back-side sheet portion 22 according to this embodiment is breathable. As with the front-side sheet portion 21, the back-side sheet portion 22 according to this embodiment has a plurality of holes because the resin film is a porous resin film or a resin film having a plurality of holes (not shown) formed therein. However, the back-side sheet portion 22 does not necessarily have to be breathable and may be non-breathable.

[0051] There are no particular limitations on the thickness of each of the front sheet portion 21 and the back sheet portion 22, but it is preferably 0.1 mm or more and 2.0 mm or less, for example. This makes the foot heating element 1 soft and easy to fit to the soles 71, while also ensuring a certain level of strength that allows it to withstand repeated stepping on by the soles 71.

[0052] The back sheet portion 22 preferably has a certain moisture permeability, similar to the front sheet portion 21. The moisture permeability of the back sheet portion 22 is preferably 300 g / (m 2 ·day) or more 1000g / (m 2 ·day) or less, and 400g / (m 2 ·day) or more than 900g / (m 2 However, the moisture permeability of the back sheet portion 22 is not particularly limited.

[0053] The foot heating element 1 according to this embodiment includes an anti-slip portion 23. The anti-slip portion 23 prevents the foot heating element 1 from shifting position between the user's foot 7 and shoe 8. The anti-slip portion 23 according to this embodiment is composed of a plurality of small protrusions 231 formed on the back sheet portion 22. In this embodiment, the plurality of small protrusions 231 are formed evenly over the entire surface of one side (outer surface) of the back sheet portion 22, but in the present disclosure, they may be formed in at least a partial area.

[0054] The small protrusions 231 are made of, for example, rubber or acrylic resin. However, the non-slip portions 23 may be formed by printing foaming ink having a non-slip function on the back-side sheet portion 22. The non-slip portions 23 may also be formed on the front-side sheet portion 21 instead of the back-side sheet portion 22, or may be formed on both the back-side sheet portion 22 and the front-side sheet portion 21.

[0055] Furthermore, in the foot heating element 1 according to the present disclosure, an adhesive layer may be provided instead of the anti-slip portion 23. The adhesive layer is provided on either the back sheet portion 22 or the front sheet portion 21. This allows the foot heating element 1 to be attached to the user's foot 7 or to the shoe 8 (for example, the insole 81).

[0056] (1.2.2.3) Joints The joint 3 is the portion where the front sheet portion 21 and the back sheet portion 22 are joined. The joint 3 according to this embodiment is formed by welding (heat sealing) a portion of the front sheet portion 21 and a portion of the back sheet portion 22 together. However, the joint 3 does not have to be formed by welding, and may be formed by, for example, adhesion, sewing, crimping, or a combination of these. As shown in FIG. 2 , the joint 3 comprises an edge portion 31 and a middle portion 32.

[0057] The edge 31 is a portion of the joint 3 formed along the outer periphery of the bag body 2, where the outer peripheries of the front sheet portion 21 and the back sheet portion 22 are joined together. The edge 31 according to this embodiment is continuous over the entire periphery of the bag body 2. There are no particular restrictions on the width of the edge 31, but it is preferably, for example, between 1 mm and 10 mm, and more preferably between 3 mm and 7 mm. The edge 31 according to this embodiment is formed to have approximately the same width over its entire length.

[0058] The edge portion 31 according to this embodiment includes a pair of first straight portions 315 formed along the length direction, a second straight portion 316 formed along the width direction, and an arc-shaped portion 317 connecting the pair of first straight portions 315. In this embodiment, the pair of first straight portions 315 are formed in a substantially linear shape and are parallel to each other.

[0059] The intermediate portion 32 is a portion of the joint 3 that is formed inside the edge portion 31 and away from the edge portion 31. The size of the intermediate portion 32 in this embodiment is not particularly limited as long as it is not connected to the edge portion 31 and the heat-generating material 4 is disposed between the intermediate portion 32 and the edge portion 31. In the foot heating element 1 in this embodiment, the intermediate portion 32 constitutes the heat-generating material removal portion 5. The heat-generating material removal portion 5 will be described in detail below in "(1.2.2.4) Heat-generating material removal portion."

[0060] The intermediate portion 32 according to this embodiment is formed in a rectangular shape when viewed from the front, as shown in Fig. 2. However, the intermediate portion 32 according to the present disclosure may also be formed in, for example, a circular shape when viewed from the front, a polygonal shape with pentagons or more sides when viewed from the front, an oval shape (including an ellipse) when viewed from the front, a star shape when viewed from the front, a heart shape when viewed from the front, or the like.

[0061] (1.2.2.4) Heat-generating material removal section The heat-generating material removal section 5 is the portion from which the heat-generating material 4 has been removed when the heat-generating surface 6 is viewed from the front. The heat-generating material removal section 5 according to this embodiment is the portion inside the edge 31 of the bag body 2 where the heat-generating material 4 is not present. As described above, the heat-generating material removal section 5 according to this embodiment is composed of the middle section 32. The outer periphery of the heat-generating material removal section 5 forms the partition section 51, and the presence of the partition section 51 makes it possible to control the temperature distribution of the heat-generating surface 6 in the foot heating element 1.

[0062] The heat-generating material removal section 5 in this embodiment is not limited in shape or size when viewed from the front, but it is preferably, for example, 0.1% to 20% of the area of ​​the heat-generating surface 6 (or the area of ​​each heat-generating surface 6 if there are multiple heat-generating surfaces 6), more preferably 0.25% to 10%, and even more preferably 1% to 5%.

[0063] The heat-generating material removal section 5 includes a partition section 51 and an inner section 52 surrounded by the partition section 51. The partition section 51 is configured to surround a certain area of ​​the heat-generating surface 6 and prevents heat conduction from the outside to the inside of the partition section 51. In this embodiment, the partition section 51 and the inner section 52 are integral and have no visible boundary, but a boundary may also be visible.

[0064] The partition 51 according to this embodiment is a frame-shaped portion formed by joining the front sheet portion 21 and the back sheet portion 22. In the present disclosure, "surrounding a certain area of ​​the heating surface 6" may refer to a closed partition that completely surrounds a certain area on the heating surface 6, or a partially open partition, such as a U-shaped or C-shaped partition. The front sheet portion 21 and the back sheet portion 22 may be joined by, for example, heat sealing, gluing, sewing, or crimping. The partition 51 may be formed by joining the front sheet portion 21 and the back sheet portion 22. Alternatively, the partition 51 may be formed from a tubular member with low thermal conductivity, and the tubular member may be interposed between the front sheet portion 21 and the back sheet portion 22 so as to surround a certain area of ​​the heating surface 6. Alternatively, the partition 51 may be formed from a solid member with low thermal conductivity, and the solid member may be interposed between the front sheet portion 21 and the back sheet portion 22.

[0065] The inner portion 52 is a portion surrounded by the partition portion 51 and is located on the same plane as the partition portion 51. Like the partition portion 51, the inner portion 52 according to this embodiment is formed by joining the front sheet portion 21 and the back sheet portion 22 and is not penetrated in the thickness direction of the heating element 1. The heat-generating material removal portion 5 does not have to be equipped with the inner portion 52, and the bag body 2 may have a through hole in the portion corresponding to the inner portion 52. However, the heating element 1 according to this embodiment is advantageous in that it can prevent the temperature on the heating surface 6 from dropping too much at the heat-generating material removal portion 5 compared to when the inner portion 52 is a through hole.

[0066] Controlling the temperature distribution of the heat-generating surface 6 by using the partitioning section (heat-generating material removal section 5) can be performed, for example, as follows.

[0067] When attempting to lower the maximum temperature to a predetermined temperature and increase the area of ​​the high temperature region including the lowered maximum temperature for the heating surface 6 of a foot heating element that does not have a partition 51 (heat-generating material removal section 5), a heat-generating material removal section 5 (here, intermediate section 32) is provided in the center of the heating surface 6 ("standard heating surface 6" and "standard partition section (heat-generating material removal section 5)").

[0068] When attempting to further reduce the maximum temperature compared to the standard heat-generating surface 6, the partition 51 (heat-generating material removal section 5) is set larger than the standard partition 51 (heat-generating material removal section 5). Here, "setting the partition 51 (heat-generating material removal section 5) larger" means setting the size 5 of the partition 51 (area of ​​the heat-generating material removal section) in front view larger than the standard partition 51 (standard heat-generating material removal section 5).

[0069] If it is desired not to lower the maximum temperature to the standard heat-generating surface 6, the partition 51 (heat-generating material removal section 5) is set smaller than the standard partition 51 (heat-generating material removal section 5). Here, "setting the partition 51 (heat-generating material removal section 5) smaller" means setting the size of the partition 51 (area of ​​the heat-generating material removal section 5) in a front view to be smaller than the standard partition (standard heat-generating material removal section 5).

[0070] Furthermore, when it is desired to lower the maximum temperature of the heat-generating surface 6 and position the high-temperature region toward one end in the lengthwise direction, for example, the partition 51 (heat-generating material removal section 5) may be formed, in the lengthwise direction, closer to the other end than the centroid 9 of the heat-generating surface 6. On the other hand, when it is desired to lower the maximum temperature of the heat-generating surface 6 and position the high-temperature region toward one end in the widthwise direction, for example, the partition 51 (heat-generating material removal section 5) may be formed, in the widthwise direction, closer to the other end than the centroid 9 of the heat-generating surface 6.

[0071] Furthermore, the proportion of the high temperature area to the whole changes depending on the shape or size of the partition section 51 (the shape or area of ​​the heat-generating material removal section 5), so the area of ​​the high temperature area can be adjusted while maintaining the position of the high temperature area.

[0072] In this way, in the heating element 1 according to this embodiment, by forming the partition 51 (heat-generating material removal section 5) to surround the centroid 9 of the heating surface 6 or to surround a certain area of ​​the heating surface 6, it is possible to lower the maximum temperature of the heating surface 6 and suppress local high temperature rises, and also to increase the area of ​​the high-temperature region and improve the uniformity of the temperature distribution. Moreover, by changing the shape or area of ​​the partition 51, it is possible to obtain a target temperature distribution.

[0073] Furthermore, in the foot heating element 1 of this embodiment, the position of the high temperature area can be changed by changing the position of the partition section 51 (heat-generating material removal section 5), so that the maximum temperature on the heating surface 6 can be lowered and the high temperature area can be positioned at the desired position.

[0074] (2) Action and Effects As described above, the temperature control method and foot heating element 1 of this embodiment have a partition 51 that surrounds a certain area of ​​the heating surface 6 when viewed from the front, thereby preventing heat conduction from the outside of the partition 51 to the inside of the partition 51.

[0075] According to this embodiment, the maximum temperature on the heating surface 6 of the foot heating element 1 can be lowered to prevent localized high temperature rises, and the position of the high temperature area can be changed. Therefore, for example, it is possible to position the foot heating element 1 in a convenient location and set the heating surface 6 so that the high temperature area is located in a part of the user's foot 7 that is particularly prone to getting cold. Furthermore, the heating material 4 enclosed in the bag 2 is prevented from moving by the heating material removal section 5. Therefore, in the foot heating element 1 according to this embodiment, the heating material 4 is less likely to become unevenly distributed inside the bag 2.

[0076] Here, by forming partition 51 so as to surround centroid 9 of heat-generating surface 6, the maximum temperature decreases and the high-temperature area increases, making it possible to achieve a more uniform temperature distribution and warm a wider area of ​​the feet. On the other hand, by forming partition 51 in a position biased toward one end of bag body 2 in the length direction, the maximum temperature decreases and the high-temperature area moves from the center of bag body 3 in the length direction, making it possible to warm, for example, the toes (fingers).

[0077] Furthermore, because the partitions 51 are formed by excluding the heat-generating material 4, heat generation in the partitions 51 is suppressed. Therefore, the maximum temperature on the heat-generating surface 6 of the foot heating element 1 can be lowered and the area of ​​the high-temperature region can be increased, and a decrease in the average temperature of the heat-generating surface 6 can be suppressed.

[0078] Furthermore, since the heat-generating material is also removed from the inner portion (inner portion 52) of the partition portion 51, the maximum temperature on the heat-generating surface 6 of the heat-generating element 1 can be further reduced.

[0079] In addition, the partition section 51 is formed by joining the front sheet section 21 and the back sheet section 22 together, thereby eliminating the heat generating material 4. Therefore, the foot heating element 1 can be manufactured efficiently.

[0080] In addition, by changing the size and / or shape of the partitions 51, the temperature distribution of the heat-generating surface 6 can be controlled, and therefore the temperature distribution of the heat-generating surface 6 can be made closer to a target temperature distribution.

[0081] (3) Variations The above embodiment is merely one of various embodiments of the present disclosure. The embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the embodiment are listed below. The modifications described below can be applied in appropriate combinations.

[0082] In the above embodiment, the heat-generating material removal portion 5 is configured with one intermediate portion 32, but may be configured with two or more intermediate portions 32.

[0083] In the above embodiment, the heating surface 6 was rectangular when viewed from the front, but in the present disclosure, the heating surface 6 is not limited to a rectangular shape, and may be formed into, for example, an oval shape (including an ellipse), a heart shape, a polygonal shape with pentagons or more, etc.

[0084] In the above embodiment, the foot heating element 1 is positioned between the sole 71 of the user's foot and the insole 81 of the shoe 8, but in the present disclosure, it may also be positioned between the instep of the foot 7 and the shoe 8, or between the side of the foot 7 and the shoe 8.

[0085] In the present disclosure, expressions including "approximately" such as "approximately rectangular" may be used. For example, "approximately rectangular" means that the shape is substantially rectangular, and includes not only a shape that is strictly rectangular, but also a shape that can be roughly recognized as rectangular. The same applies to other expressions including "approximately".

[0086] Furthermore, in this disclosure, expressions distinguishing between "end" and "end" are used, such as "front end" and "front end." For example, "front end" means a part having a certain range that includes the "front end." The same applies to other expressions that include "end."

[0087] (4) Example The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0088] (4.1) Test 1 In Test 1, a test was conducted to confirm the expected effect of a heating element in which a partition (heat-generating material removal portion) was formed so as to surround the centroid of the heating surface. Heat-generating elements having a heat-generating material removal portion were manufactured as Examples 1 to 3, and a heating element without a heat-generating material removal portion was manufactured as a comparative example. The temperature of the heating surface during heat generation was photographed with a thermograph, and the temperature distributions were compared.

[0089] As shown in Figures 4(A) to 4(C), the heating elements according to Examples 1 to 3 were manufactured with a heating surface formed into a substantially rectangular shape, with a length dimension E (longest part) of the heating surface of 116 mm and a width dimension W of 81 mm. As a comparative example, a heating element was manufactured with a heating surface formed into a substantially rectangular shape, with a length dimension E (longest part) of the heating surface of 116 mm and a width dimension W of 81 mm. For the heating elements according to Examples 1 to 3 and the comparative example, the heating material and the material of the pouch were the same as those in the above embodiment, and all were the same. Furthermore, the amount of heating material in each of Examples 1 to 3 and the comparative example was 37 g, giving them all the same weight.

[0090] For the heat generating element of Example 1, a heat sealed portion was formed as a heat generating material removal portion at the center of the heat generating surface (i.e., at a position E1 = 58 mm, W1 = 40.5 mm) as shown in Fig. 4(A). The heat sealed portion was a square with a side length of H1 = 10 mm.

[0091] As shown in Fig. 4(B), a heat-sealed portion was formed as a heat-generating material removal portion in the center of the heat-generating surface of the heat-generating element according to Example 2. The heat-sealed portion was a square with a side length H2 of 20 mm.

[0092] As shown in Fig. 4(C), a heat-sealed portion was formed as a heat-generating material removal portion in the center of the heat-generating surface of the heat-generating element according to Example 3. The heat-sealed portion was a square with a side length H3 of 30 mm.

[0093] Figure 5 shows the results of thermographic photography of Examples 1, 2, and 3 and the Comparative Example. The area in each temperature range was calculated from the thermographic results, and the relationship between each temperature range and the area ratio to the entire area in that temperature range is shown in Table 1-1. Table 1-2 also shows the area ratio of the high-temperature range (the temperature range between a maximum temperature of -5°C or higher and a maximum temperature of -5°C or lower) extracted from Table 1.

[0094] Table 1-1 is graphed in Figure 6. In the graph, the vertical axis represents the area ratio (%) and the horizontal axis represents the temperature (°C).

[0095] Furthermore, for each of Examples 1, 2, and 3 and the Comparative Example, the maximum temperature was extracted from Table 1-1, and the difference in maximum temperature between the Comparative Example and Examples 1, 2, and 3 was calculated. Furthermore, the average temperature on the heat-generating surface of each of Examples 1, 2, and 3 and the Comparative Example was calculated, and the difference in average temperature between the Comparative Example and Examples 1, 2, and 3 was calculated. The results are shown in Table 1-3. [Table 1-1] [Table 1-2] [Table 1-3]

[0096] As can be seen from Fig. 5, the comparative example has a thick, clear white area in the center of the heating surface, indicating a high temperature, while the heating elements of Examples 1 to 3 have a thinner white area than the comparative example. Furthermore, as can be seen from Tables 1-1 and 1-2 and Fig. 6, the heating elements of Examples 1 to 3 have a maximum temperature on the heating surface that is about 1 to 3°C lower and a high-temperature region area ratio that is about 17 to 25% larger than the comparative example. In other words, the heating elements of Examples 1 to 3 can lower the maximum temperature and increase the area of ​​the high-temperature region on the heating surface compared to the comparative example. In other words, the heating elements of Examples 1 to 3 can lower the maximum temperature to prevent localized high temperature increases, and can also increase the uniformity of the temperature distribution by increasing the area of ​​the high-temperature region that includes the lowered maximum temperature.

[0097] Furthermore, as can be seen from Table 1-2, the maximum temperature of the heating surface of the heating element of Example 3 is lower than that of the heating element of Example 2, and the maximum temperature of the heating surface of the heating element of Example 1 is higher. In other words, it was found that the maximum temperature on the heating surface can be controlled by changing the area of ​​the partition section (heat-generating material removal section).

[0098] Furthermore, as can be seen from Tables 1-3, the heating elements according to Examples 1 and 2 have a maximum temperature difference of 1.3 to 2°C compared to the comparative example, while the average temperature difference is 0.28 to 0.85°C. Furthermore, the heating element according to Example 3 has a maximum temperature difference of 3.5°C compared to the comparative example, while the average temperature difference is 1.72°C. In other words, the heating elements according to Examples 1, 2, and 3 have a smaller decrease in average temperature compared to the comparative example, compared to the comparative example. In other words, by forming a partition section (heat-generating material removal section) in the center of the heating surface, it is possible to lower the maximum temperature while suppressing the decrease in the average temperature of the heating surface.

[0099] (4.2) Test 2 Next, in Test 2, a test was conducted to confirm the effect of a heating element in which a partition portion (heat-generating material removal portion) was formed at a position deviated from the centroid of the heating surface.

[0100] As Examples 4 and 5, a heating element having a heat-generating material removal section was manufactured, and as a comparative example, a heating element without a heat-generating material removal section was manufactured. The temperature of the heating surface during heating was photographed using a thermograph, and the temperature distribution was compared.

[0101] As shown in Figures 7(A) and (B), the heating elements according to Examples 4 and 5 were manufactured with a heating surface formed into a substantially rectangular shape, with a length dimension E (longest part) of the heating surface of 116 mm and a width dimension W of 81 mm. As a comparative example, a heating element was manufactured with a heating surface formed into a substantially rectangular shape, with a length dimension E (longest part) of 116 mm and a width dimension W of 81 mm. In the heating elements according to Examples 4 and 5 and the comparative example, the heating material and the material of the pouch were the same as those in the above embodiment, and all were the same. Furthermore, the amount of heating material in each of Examples 4 and 5 and the comparative example was 37 g, so all had the same weight.

[0102] 7(A), a heat-sealed portion was formed as a heat-generating material removal portion at a position E1=29 mm from one end of the heat-generating surface in the longitudinal direction and W1=40.5 mm, which is the center in the width direction, for the heat-generating element of Example 4. The heat-sealed portion was a square with each side H1=10 mm.

[0103] For the heating element of Example 5, as shown in Fig. 7(B), a heat-sealed portion was formed as a heat-generating material removal portion at a position E1 = 29 mm from one end of the heating surface in the longitudinal direction and W1 = 40.5 mm, which is the center in the width direction. The heat-sealed portion was a square with each side H2 = 20 mm.

[0104] Examples 4 and 5 and the Comparative Example were lined up and photographed using a thermograph, and the results, colored according to the temperature range, are shown in Figure 8. Furthermore, the area in each temperature range was calculated from the results of the thermography, and the relationship between each temperature range and the area ratio in that temperature range to the whole, is shown in Table 2. Furthermore, a graph of Table 2 is shown in Figure 9. In the graph, the vertical axis represents the area ratio (%) and the horizontal axis represents the temperature (°C). [Table 2]

[0105] As can be seen from Figure 8, in the comparative example, the high temperature region spreads to the center, whereas in the heating elements of Examples 4 and 5, the high temperature region is located on the opposite side of the partition section (heat-generating material removal section) from the center of the heating surface in the longitudinal direction. Therefore, it was found that the position of the high temperature region moves depending on the position of the partition section (heat-generating material removal section). Furthermore, as can be seen from the graph in Figure 9 and Table 2, the maximum temperatures of the heating elements of Examples 4 and 5 are lower than those of the comparative example.

[0106] Therefore, the heating elements according to Examples 4 and 5 can reduce the maximum temperature of the heating surface and move the high temperature zone compared to the comparative example. In other words, the heating elements according to Examples 4 and 5 can reduce the maximum temperature, suppress localized high temperature rises, and control the position of the high temperature zone.

[0107] Furthermore, as can be seen from Figure 9, the area of ​​the high temperature region in Example 5 is smaller than that in Example 4. In other words, when Figure 8 is also considered, it was found that the area of ​​the high temperature region on the heat-generating surface can be adjusted by changing the size of the partition section (heat-generating material removal section) while maintaining the position of the high temperature region. [Explanation of symbols]

[0108] 1 Heating element for feet 2 bags 21 Front sheet part 22 Back sheet part 32 Edge (periphery) 4. Heat-generating materials 51 Partition 52 Inner part (inner part of the partition) 6 Heating surface

Claims

[Claim 1] A foot heating element disposed between a user's foot and shoe, A heat generating material; a bag body formed into a bag shape by joining a front sheet portion and a back sheet portion at their edges, which encloses the heat-generating material and has a heat-generating surface on one side; Equipped with a non-penetrating heat-generating material removal portion formed by joining the front-side sheet portion and the back-side sheet portion in one range of the heat-generating surface; the heat-generating material removal portion is located inside the edge portion and away from the edge portion, and the heat-generating material is filled between the edge portion and the heat-generating material removal portion over the entire periphery of the heat-generating material removal portion; and the area of ​​the heat-generating material removal portion is 1% or more and 10% or less of the area of ​​the heat-generating surface, The position of the heat-generating material removal portion is within a range including the centroid, The shape of the heat-generating material removal portion is rectangular in front view, circular in front view, polygonal in front view having pentagons or more, elliptical in front view, star-shaped in front view, or heart-shaped in front view, and Only one heat-generating material removal portion is provided for the heat-generating surface. Heating element for feet.

Images