TWI853866B - Uses of foot warmers and air inhalation release materials - Google Patents

Abstract

The present invention provides a foot warmer that can effectively warm the soles of the feet when placed in shoes (especially boots with poor air permeability, etc.) without improving the air permeability of the inner bag.

The foot warmer has: an air-inhaling and releasing material disposed on the insole of the shoe; and a heating element of a heating composition that generates heat by contact with air, which is enclosed in a breathable inner bag and is disposed between the sole of the user's foot and the air-inhaling and releasing material; and the air-inhaling and releasing material can contain air inside and can be deformed to inhale and/or release air.

Description

Uses of foot warmers and air inhalation release materials

Invention Field

The present invention relates to a foot warmer that is placed in shoes and provides a warm feeling to the soles of the user’s feet.

Background technology

As we all know, disposable heat packs are used to keep the body warm. They are frequently used due to their portability, safety, convenience, and low price.

A general disposable heat pack, such as that shown in Patent Document 1, is a heat-generating composition that generates heat by contact with air and is enclosed in a breathable inner bag. By rubbing the disposable heat pack in the hand, the air will be in roughly uniform contact with the heat-generating composition in the inner bag, causing the heat-generating composition to generate heat, and the warming effect is exerted by this heating principle. The disposable heat pack can control the heating temperature by adjusting the amount of air in contact with the heat-generating composition. For example, when a synthetic resin film is used as the material of the inner bag, small holes are provided in the synthetic resin film in order to give the inner bag air permeability, and the amount of air in contact with the heat-generating composition can be adjusted according to the size and number of the small holes.

Prior art literature

Patent Literature

[Patent Document 1] Japanese Patent Publication No. 5-208031

Summary of invention

For example, in the cold winter outdoor environment such as farm work, markets, and snowy mountains, it is common to put disposable hand warmers between the soles of the feet and the insoles of the shoes to warm the toes because the feet are cold. However, the heating temperature of disposable hand warmers decreases as the temperature of the environment in which they are used decreases. In addition, the shoes (especially long boots, leather shoes, and thigh boots) have poor air permeability and the amount of air in contact with the heating composition in the inner bag is small, so the heating composition cannot heat well. Therefore, it is a reality that even if disposable hand warmers are used, the soles of the feet cannot be effectively warmed.

In contrast, in order to make the exothermic composition in the inner bag heat at a higher temperature, the air permeability of the inner bag is improved so that more air can come into contact with the exothermic composition. However, when the size and number of the small holes in the inner bag are increased, there is the problem of the exothermic composition leaking out of the inner bag. In addition, when the air permeability of the inner bag is improved, a lot of air can come into contact with the exothermic composition even when the disposable hand warmer is not in use (for example, when the user takes off shoes, etc.), causing the exothermic composition to overheat, which can also shorten the life of the disposable hand warmer.

This invention is developed with the above-mentioned issues in mind, with the purpose of providing a foot warmer that can effectively warm the soles of the feet when placed in shoes, especially boots, leather shoes, and long boots with poor air permeability, without improving the air permeability of the inner bag.

The first form of the present invention is related to a foot warmer. The foot warmer of the present invention is arranged between the sole of the user's foot and the insole of the shoe, and is characterized by having: a heating element of a heat-generating composition that generates heat by contact with air is enclosed in a breathable inner bag, and an air intake and release material that can contain air inside and can be deformed to absorb and/or release air.

The foot warmer of the present invention preferably has the air intake and release material that absorbs and releases air by compression deformation or expansion deformation.

In addition, in the foot warmer of the present invention, the aforementioned air intake and release material is preferably a three-dimensional woven fabric.

In addition, in the foot warmer of the present invention, the aforementioned air intake and release material preferably has a net structure or a honeycomb structure.

In addition, in the foot warmer of the present invention, the air intake and release material is arranged on the insole of the shoe, and the heating element is preferably arranged between the sole of the user and the air intake and release material.

In addition, in the foot warmer of the present invention, it is preferred that the aforementioned air intake and release material constitutes the insole of the shoe.

In addition, in the foot heating element of the present invention, the size of the aforementioned air intake and release material is preferably larger than the aforementioned heating element when viewed from above.

In addition, in the foot warmer of the present invention, it is preferred that the air intake and release material is integrated with the inner bag of the heating element.

The second form of the present invention is related to the use of air inhalation and release materials. The use of the air inhalation and release material of the present invention is to improve the air supply to the heating element. The aforementioned heating element is a heating element of a heating composition that generates heat by contact with air in a breathable inner bag, and is a heating element for warming the soles of the user's feet in the shoes. The aforementioned air inhalation and release material can contain air inside and can be deformed to inhale and/or release air.

The purpose of the air-inhaling and releasing material of the present invention is preferably to form the insole of a shoe.

According to the present invention, when a user steps on the heating element with the sole of the foot while wearing shoes, the air intake and release material is deformed by the external force applied from the sole of the foot, and the air inside is released to the outside and/or the air outside is taken in. In this way, the heat-generating composition in the inner bag of the heating element is in contact with more air, so that the heat-generating composition heats well. Therefore, since the heating temperature of the heating element can be greatly increased, even if the ambient temperature of the heating element is low, the high heating temperature can effectively give a warm feeling to the sole of the foot.

1: Warm parts

2: Heat generating body

3: Pyrogenic composition

4: Inner pocket

5: Air inhalation release material

10: Soles of feet

11: Shoes

12: Insole

40: Sheet 1

41: Sheet 2

42: Fever part

43:Joint part

44: Adhesive layer

45: small protrusion

46: Foaming ink

50: Three-dimensional knitted fabric

51: Sponge

Figure 1 is an exploded three-dimensional diagram of the foot heating element of this embodiment.

Figure 2 is a three-dimensional diagram of the state where the foot heating element of this embodiment is arranged on the insole of the shoe.

Figure 3 is a cross-sectional view showing the use of the foot heating element of this embodiment.

Figure 4 is a plan view (A), a cross-sectional view (B) along the line X1-X1, and a plan view of a modified example of the heating element of Figure 1.

Figure 5 is a plan view of the air intake and release material in Figure 1.

Figure 6 is a three-dimensional diagram of the air intake and release material of a modified example.

Figure 7 is a cross-sectional view showing the state of the foot heating element before use in another embodiment.

Figure 8 is a plan view of the heating element of a modified example.

Figure 9 is a temperature change graph showing the heating temperature of the heating element.

Figure 10 is a temperature change graph showing the heating temperature of the heating element.

The form used to implement the invention

The following is an explanation of the implementation form of the foot warmer of the present invention with reference to the drawings. As shown in Figures 1 to 3, the foot warmer 1 is arranged between the sole of the user 10 and the inner sole 12 of the shoe 11, and is equipped with: a heating element 2 and an air inhalation and release material 5. The foot warmer 1 is placed in the shoe 11, and is particularly suitable for users of shoes 11 with very poor air permeability such as long boots, leather shoes, and long boots. In this implementation form, when the foot warmer 1 is used, the air inhalation and release material 5 is arranged on the inner sole 12 of the shoe 11, and the heating element 2 is arranged between the sole 10 of the user and the air inhalation and release material 5, and the heating element 2 is used to give a warm feeling to the sole 10. Below, each component of the foot warmer 1 is described in detail.

First, as shown in FIG. 4 , the heat generating element 2 includes: a heat generating composition 3 that generates heat by contact with air, and an inner bag 4 that encloses the heat generating composition 3. The inner bag 4 is breathable, and the heat generating composition 3 is brought into contact with air in the inner bag 4 by allowing air to flow inside and outside the inner bag 4, thereby generating heat. For example, the heat generating element 2 can be a disposable heat pack, and the heat generating element 2 is stored in an airtight outer bag (not shown) before use.

The pyrophoric composition 3 is a composition that generates heat by contact with air. The pyrophoric composition 3 can be any composition that generates heat by contact with air, and examples thereof include compositions containing appropriate amounts of oxidizable metals, activated carbon, carbon black, water retaining agents (wood powder, vermiculite, diatomaceous earth, pearlite, silica gel, alum, water-absorbing resin, etc.), metal salts (salt, etc.), and water. The oxidizable metal is a metal that generates heat energy in an oxidation reaction, and examples thereof include powders or fibers of one or more selected from iron, aluminum, zinc, manganese, magnesium, and calcium. Among them, iron powder is preferred from the viewpoints of usability, safety, manufacturing cost, storage, and stability. As for the iron powder, for example, one or more selected from reduced iron powder and atomized iron powder can be cited. As for the exothermic composition 3, a known composition that has been used in disposable heat packs can be used.

The inner bag 4 is configured as a flat bag having a front surface and a back surface, and has a space inside that can accommodate the heat-generating composition 3. Although the outer shape of the inner bag 4 is not particularly limited, it is preferably a shape corresponding to a portion of the sole or the entire shape. In this embodiment, since the heat-generating body 2 is arranged on a portion of the toe side of the sole, it is horseshoe-shaped when viewed from above as shown in FIG. 4 (A). In addition, the outer shape of the inner bag 4 is not limited to a horseshoe shape, and can be configured in various shapes such as a rectangle or other polygonal shape, a circle, an ellipse, etc.

In this embodiment, the inner bag 4 is formed into a bag shape by overlapping two first sheets 40 and second sheets 41 of the same shape forming the front and back sides, and sealing (joining) or thermally joining (heat sealing) the outer periphery using a known adhesive to cover the entire periphery. Alternatively, it is also possible to form a bag shape by bending and overlapping a sheet and then sealing (joining) or thermally joining (heat sealing) the outer periphery using an adhesive. The portion of the heat generating body 2 that is enclosed by the heat generating composition 3 of the inner bag 4, that is, the portion excluding the joint portion 43 of the two sheets 40 and 41 at the outer periphery, constitutes the heat generating portion 42.

The two sheets 40 and 41 constituting the inner bag 4 are flexible by being in close contact with the sole of the foot. Although the raw materials of the two sheets 40 and 41 are not particularly limited, it is preferred to use a resin film when considering strength or durability against heat generated by the heat-generating composition 3.

Although the resin used for the resin film is not particularly limited, it is preferred to use a thermoplastic resin. As for the thermoplastic resin, polyethylene, polypropylene, polyester, polyamide, polyurethane, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polycarbonate, ethylene-vinyl acetate copolymer, etc. can be exemplified, but polyethylene, polypropylene, and ethylene-vinyl acetate copolymer can be exemplified as preferred. These resins can be used alone or in combination of two or more.

Furthermore, the two sheets 40 and 41 are preferably formed by laminating a resin film layer with a breathable woven or non-woven fabric when considering good skin touch to the sole. In this case, the resin film is arranged on the inner side of the heat-generating composition 3, and the woven or non-woven fabric is arranged on the outer side.

As for the fiber raw materials of woven or non-woven fabrics, natural fibers such as cotton, linen, silk, and paper can be exemplified; semi-synthetic fibers such as spunlace and acetate; synthetic fibers such as nylon, vinyl, polyester, acrylic, polyethylene, polypropylene, polyvinyl chloride, and polybutylene terephthalate; and mixed fibers of these fibers. Among them, from the perspective of good skin touch, nylon, polyester, and polypropylene can be exemplified as fiber raw materials, and nylon and polyester are more preferred. These fiber raw materials may be used alone or in combination of two or more. The unit area weight of the woven or nonwoven fabric is not particularly limited as long as it can prevent the exothermic composition 3 from leaking out of the inner bag 4, but is preferably in the range of 20 g/ ^m2 to 70 g/ ^m2 .

Although the thickness of the two sheets 40 and 41 is not particularly limited, the smaller the thickness, the softer the inner bag 4 will be and the easier it will fit the sole of the foot. On the other hand, if the thickness becomes too small, the strength of the inner bag 4 will be reduced, so it is better to be between 0.1 mm and 2.0 mm.

The first sheet 40 on one side (the air intake and release material 5 side) of the two sheets 40 and 41 may be breathable, and the second sheet 41 on the other side (the sole side) may be breathable or non-breathable.

The resin film used for the first air-permeable sheet 40 is a porous resin film or a resin film with a plurality of perforations (not shown) formed by a needle to ensure air permeability. The air is connected to the inside and outside of the inner bag 4 through a plurality of small holes and contacts the pyrophoric composition 3, so that the pyrophoric composition 3 generates heat. The small holes may be formed in the entire area of the resin film or in a part of the area. In addition, the size of the small holes is not particularly limited as long as it can prevent the pyrophoric composition 3 from leaking out of the inner bag 4. The shape and number of the small holes are also not particularly limited. The size, shape, and number of the small holes can be appropriately set after considering the heating temperature of the pyrophoric composition 3 during use in response to the air permeability of the inner bag 4. On the other hand, the resin film used for the second non-breathable sheet 41 is not a porous film, nor is it a non-breathable resin film with perforations (not shown) formed in the non-breathable case.

Furthermore, when the heating element 2 is used for the purpose of warming the feet, its heating temperature is usually set to be above 25°C and below 45°C in a 20° environment, preferably above 30°C and below 40°C (the temperature measurement method is based on the foot temperature measurement method of the Heat Pack Industry Association).

The moisture permeability of the inner bag 4 is not particularly limited, but is preferably 300 g/m ² ˙ day or more and 700 g/m ² ˙ day or less, and more preferably 400 g/m ² ˙ day or more and 650 g/m ² ˙ day or less.

When the inner bag 4 is in use, the first air-permeable sheet 40 is arranged on the air-intake-release material 5 toward the air-intake-release material 5. By implementing anti-slip on the entire area or at least a part of the outer surface of the first sheet 40 of the inner bag 4, the inner bag 4 and the air-intake-release material 5 can be integrated, making it difficult for the inner bag 4 to shift relative to the air-intake-release material 5 during use.

The anti-slip effect is achieved by uniformly arranging a plurality of small protrusions 45 made of, for example, rubber or acrylic resin to cover the entire area or substantially the entire area of the outer side of the first sheet 40 of the inner bag 4, as shown in Fig. 4 (A) and (B). Alternatively, the anti-slip effect is achieved by printing a foaming ink 46 having an anti-slip effect on the entire area or substantially the entire area of the outer side of the first sheet 40 of the inner bag 4, as shown in Fig. 4 (C).

Furthermore, the method of integrating the inner bag 4 and the air inhalation and release material 5 is not limited to the above-mentioned anti-slip method. For example, an adhesive layer (not shown) is formed by applying an acrylic adhesive, a urethane adhesive, a silicone adhesive, a rubber adhesive, a rosin adhesive, etc. to the outer peripheral portion 43 of the inner bag 4 other than the heat-generating portion 42, and the inner bag 4 and the air inhalation and release material 5 are bonded and integrated by the adhesive layer. As long as it is a method that can make the inner bag 4 difficult to shift for the air inhalation and release material 5, various methods can be used.

Secondly, the air intake and release material 5 is used to increase the air supply to the heating body in order to warm the sole of the user's foot in the shoe. As shown in FIG. 5 or FIG. 6, the air intake and release material 5 has a space inside that can contain air, and releases the air in the aforementioned space to the outside and/or absorbs the external air into the aforementioned space by deformation. In this embodiment, the air intake and release material 5 releases the internal air to the outside as it contracts and deforms, and absorbs the external air into the inside as it expands. The air intake and release material 5 may be one that repeatedly compresses and expands each time according to the action of an external force to inhale and release air, but it is better to have elasticity so that it can return to its original shape when the external force disappears. Thus, once the air inside is released to the outside (or the air outside is sucked inside) due to the contraction deformation (or compression deformation) caused by the application of external force, it can automatically expand and recover (or shrink and recover) according to the removal of the external force, and the air outside is sucked inside (the air inside is released to the outside). In addition, in terms of elasticity, as long as the air intake and release material 5 that is deformed by the application of external force can return to its original shape, it does not necessarily need to return to its original shape completely. In addition, it is better for the air intake and release material 5 to be easy to deform and further have softness.

As for the air intake and release material 5, for example, as shown in Figures 1 to 3 and 5, a three-dimensional woven fabric 50 with a specific thickness can be used. The three-dimensional woven fabric 50 has elasticity and breathability, and has a structure that can contain air inside. As it contracts and deforms, the air in the aforementioned space is released to the outside, and as it expands and deforms, the external air is sucked into the aforementioned space. Because the three-dimensional woven fabric 50 has elasticity, the three-dimensional woven fabric 50 that is deformed (contracted or expanded) by the external force applied from the sole of the foot can automatically restore (expand or contract) as the external force is removed.

As for the three-dimensional woven fabric 50, for example, a double woven fabric using synthetic fibers such as polyester, nylon, polypropylene, and polyethylene, or a three-dimensional mesh structure using a thermoplastic resin can be cited. The three-dimensional mesh structure is formed by forming a plurality of lines composed of a thermoplastic elastic resin into irregular loops, and at least a portion of the line joints are welded. As for the thermoplastic elastic resin forming the three-dimensional mesh structure, polyester-based, polyolefin-based, polyurethane-based thermoplastic resin elastomers can be exemplified.

Although the three-dimensional woven fabric 50 is not particularly limited, it is preferably a mesh structure or a honeycomb structure (a honeycomb structure in FIG. 5 ). The air intake and release material 5 has a mesh structure or a honeycomb structure, which can improve the air permeability of the air intake and release material 5. Since good air circulation is created inside and outside the air intake and release material 5, the shoe will not be stuffy and can maintain a comfortable feeling. In addition, the mesh structure or the honeycomb structure can gently stimulate the sole of the foot.

In addition, as for the air intake and release material 5, for example, a porous body with a specific thickness can be preferably used. The aforementioned space porous body is a structure having a space with small holes, cracks, gaps, etc. inside, and contains air in the aforementioned space. With the contraction deformation, the air in the aforementioned space is released to the outside, and with the expansion deformation, the external air is sucked into the aforementioned space. Since the porous body has elasticity, the porous body that is deformed (contracted or expanded) by the application of external force can be automatically restored (expanded or contracted) as the external force is removed.

As for the elastic porous body, for example, as shown in FIG6 , a sponge 51 is preferred. As for the sponge 51, various sponges can be used, such as synthetic sponges with synthetic resins such as urethane resin and melamine resin as the main raw materials, natural sponges with natural materials such as sponges and cellulose as the main raw materials, and rubber sponges with rubber materials such as synthetic rubber and natural rubber as the main raw materials. Among them, urethane sponges are preferred. In addition to plugging fine pores, urethane sponges are soft and have high elasticity (recovery), and can be sold at a low price in the market.

The size of the air intake and release material 5 when viewed from above is not particularly limited, but it is preferably a size that can cover the heating element 2 in a manner that can supply the air contained inside to the entire heating element 2. In addition, by making the size of the air intake and release material 5 larger than the heating element 2 when viewed from above, the air intake and release material 5 is easy to contact with the air, and it is suitable because it is easy to cause the above-mentioned air circulation.

Although the shape of the air intake and release material 5 is not particularly limited, it is preferred that the air intake and release material 5 be used as an insole of a shoe and present a shape similar to the overall shape of the sole (the same shape or a similar shape). In this way, the elasticity of the air intake and release material 5 can not only make the comfort of the shoe good, but also the air contained in the air intake and release material 5 can improve the heat preservation between the insole and the sole. In addition, the shape of the air intake and release material 5 is not limited to this, and can be formed into various shapes such as horseshoe shape, rectangular shape or other polygonal shape, circular shape, ellipse shape, etc.

It is better to implement anti-slip in the entire area or a part of the area of the side of the air intake and release material 5 that contacts the insole. In this way, the air intake and release material 5 is integrated with the insole, and it is difficult to shift in the shoe during use.

Furthermore, the air intake and release material 5 is not necessarily limited to a porous body such as a three-dimensional woven fabric 50 or a sponge 51. For example, as for the air intake and release material 5, a hollow body such as a bag or a box having elasticity may also be used. The hollow body is a structure having a space inside and at least one communication port connecting the aforementioned space with the outside. Air exists in the aforementioned space, and the air in the aforementioned space is released to the outside through the communication port by contraction and deformation, and the air outside is sucked into the aforementioned space by expansion and deformation. Since the hollow body has elasticity, the hollow body that is deformed (contracted or expanded) by the application of external force can automatically restore (expand or contract) as the external force is removed. The elastic hollow body can be formed using rubber material or synthetic resin material.

In the above embodiment, the air intake and release material 5 is configured to maintain an expanded state at normal times, and to contract by applying an external force to release the internal air to the outside, and to expand by removing the external force to absorb the external air into the inside, but it is not limited to this. Although it is configured to maintain a flat and deflated state at normal times, it is also possible to expand by applying an external force to absorb the external air into the inside, and to contract by removing the external force to release the internal air to the outside.

Next, the method of using the foot heating element 1 constructed as above is described. First, as shown in Figures 1 to 3, the air intake and release material 5 is arranged on the inner sole 12 of the shoe 11. Next, the heating element 2 is taken out from the outer bag (not shown), and the heating element 2 is placed into the shoe 11 with the first sheet 40 of the inner bag 4 facing downward, so that the heating element 2 is arranged on the air intake and release material 5 and on the toe side of the shoe 11.

Next, when the user wears the shoe 11 and steps on the heating element 2 with the sole 10, the air intake and release material 5 under the heating element 2 is deformed (e.g., contracted) by the external force applied from the sole 10, thereby releasing the air in the air intake and release material 5 to the outside. At this time, the air released from the air intake and release material 5 contacts the heating composition 3 in the inner bag 4 through the first sheet 40 of the inner bag 4 of the heating element 2. Furthermore, when the user lifts his foot, the air intake and release material 5 is deformed (e.g., expanded) to return to its original shape because the external force from the sole 10 is eliminated, thereby sucking the air in the shoe 11 into the air intake and release material 5. By repeatedly lifting and lowering the foot while walking, a large amount of air comes into contact with the heat-generating composition 3 in the inner bag 4, so that the heat-generating composition 3 can generate heat well. Therefore, since the heating temperature of the heating element 2 can be greatly increased, even when the ambient temperature of the heating element 2 is low, the sole 10 can be effectively warmed by the high heating temperature.

On the other hand, when the heating element 2 is not in use (for example, when the shoes 11 are taken off), only the air corresponding to the air permeability of the inner bag 4 is allowed to pass through the inner bag 4 and contact the heating element 3, so the heating of the heating element 3 can be suppressed, and the heating temperature of the heating element 2 will not be greatly increased, and the heating element 2 will not become high temperature.

In this way, in the above-mentioned foot warmer 1, the heating temperature of the heating element 2 can be increased even in the shoe 11 with poor air permeability. During the non-use time, the heating temperature of the heating element 2 can be suppressed from excessively rising, so the life of the heating element 2 will not be shortened, and the sole 10 of the user's foot can be effectively warmed.

Furthermore, when the foot warmer 1 is constructed as described above, the heating temperature of the heating element 2 can be increased without increasing the air permeability of the inner bag 4 of the heating element 2, so it is not necessary to increase the size or number of the small holes provided in the synthetic resin film constituting the inner bag 4, thereby preventing the exothermic composition 3 in the inner bag 4 from leaking out of the inner bag 4.

Although the above description is directed to a heating element of one embodiment of the present invention, the heating element of the present invention is not limited to the heating element of the above embodiment, and various changes can be made as long as they do not deviate from the purpose of the present invention.

For example, although the foot warmer 1 of the above-mentioned embodiment integrates the heating element 2 with the air inhalation and release material 5, the heating element 2 may not be integrated with the air inhalation and release material 5. In this case, as shown in FIG. 7, the inner bag 4 of the heating element 2 is provided with an adhesive layer 44 by applying an adhesive such as an acrylic adhesive, a urethane adhesive, a silicone adhesive, a rubber adhesive, or a rosin on the entire area or at least a part of the outer surface of the first breathable sheet 40 facing the air inhalation and release material 5 and the second sheet 41 on the opposite side.

Next, when in use, as shown in FIG. 7 , after the heating element 2 is adhered to the toe side of the user's sole 10 using the adhesive layer 44 of the inner bag 4, the user wears the shoe 11 so that the heating element 2 fixed to the sole 10 is arranged on the air intake and release material 5 arranged on the inner sole 12 of the shoe 11. In this embodiment, as in the above-mentioned embodiment, the air intake and release material 5 is used to inhale and release air by repeatedly lifting and lowering the foot according to walking, etc., so that a large amount of air contacts the heat-generating composition 3 in the inner bag 4, and the heat-generating composition 3 can be effectively heated. Therefore, because the heating temperature of the heating element 2 can be greatly increased, even if the ambient temperature of the heating element 2 is low, a good warm feeling can be given by using the high heating temperature.

In addition, although the above-mentioned embodiment of the foot heating element 1 arranges the heating element 2 on a part of the sole on the toe side, it can also be arranged on other parts of the sole, or even arranged on the entire sole. When the heating element 2 is arranged on the entire sole, as shown in FIG8 , the inner bag 4 of the heating element 2 can be arranged in a shape similar to the overall shape of the sole (the same shape or a similar shape).

In addition, the above-mentioned embodiment of the foot heating element 1 is to arrange the air intake and release material 5 on the inner sole 12 of the shoe 11, and arrange the heating element 2 between the user's sole 10 and the air intake and release material 5. However, it is not limited to this, and the heating element 2 is arranged on the inner sole 12 of the shoe 11, and the air intake and release material 5 is arranged on the heating element 2, so that it is located between the user's sole 10 and the heating element 2.

In addition, although the foot warmer 1 of the above-mentioned embodiment makes the heating element 2 and the air intake and release material 5 as separate independent components, the air intake and release material 5 can be packaged together with the heat-generating composition 3 inside the inner bag 4. In addition, when the first breathable sheet 40 of the inner bag 4 is formed by a laminate of a resin film and a woven or non-woven fabric, the air intake and release material 5 can be interposed between the woven or non-woven fabric and the resin film.

Furthermore, in the above-mentioned embodiment, although the inner bag 4 has one heat-generating portion 42, it is also possible to divide the heat-generating portion 42 into multiple portions.

[Implementation example]

The following is a description of the embodiments of the present invention. In addition, the present invention is not limited to the following embodiments.

As Example 1, a heat-generating composition containing 53% iron powder, 12% activated carbon, 2.6% vermiculite, 2.5% water-absorbing resin, 1.6% salt, and 28.3% water was packed in a breathable inner bag with a horseshoe shape in such a way that the filling volume became ^10.5cm3 (equivalent to 13g) with respect to the inner bag volume of ^31.5cm3 , thereby manufacturing a heat-generating body. The inner bag was formed by stacking two sheets of nylon nonwoven fabric and polyethylene resin film. In addition, as an air inhalation and release material, a three-dimensional woven fabric ("air˙net" manufactured by UNITIKA TECHNOS.LTD.) large enough to be used as an insole of a shoe was used. A shoe-pad type three-dimensional knitted fabric is arranged on a rubber boot insole, and a heating element is arranged on the shoe-pad type three-dimensional knitted fabric and on the toe side of the boot insole.

After attaching a temperature sensor with tape to the side of the inner bag of the heating element that contacts the insole-type three-dimensional knitted fabric, wear the boots in an environment with a temperature of 5°C and walk for 15 minutes while measuring the heating temperature of the heating element. The measurement results are shown in Figure 9. In addition, as a comparative example, wear the boots without configuring the insole-type three-dimensional knitted fabric on the inner sole of the rubber boots and only configure the heating element on the toe side. The measurement results of measuring the heating temperature of the heating element while walking for 15 minutes in an environment with a temperature of 5°C are also shown in Figure 9.

It can be clearly seen from Figure 9 that the heating temperature of the heating element of the embodiment is greatly increased compared with the comparative example. It can be confirmed that the heating temperature of the heating element in the embodiment is increased by more than 10°C compared with the comparative example. Therefore, it can be known that the heating element of the present invention can achieve a good heating effect by a high heating temperature even when the ambient temperature of the heating element is low.

In addition, for Example 1, the inner bag of the heating element is formed into a shape larger than the insole-type three-dimensional knitted fabric, and the same test is carried out in a state where the insole-type three-dimensional knitted fabric and the heat-generating composition are packed together in the inner bag of the heating element. It is confirmed that the same result can be obtained as when the insole-type three-dimensional knitted fabric is arranged on the outside of the inner bag of the heating element.

Next, as Example 2, a heat-generating composition comprising 53% iron powder, 12% activated carbon, 2.6% vermiculite, 2.5% water-absorbing resin, 1.6% salt, and 28.3% water was packed in a breathable inner bag having a rectangular shape when viewed from above, so that the filling volume was 66.902 cm ^{3 (} equivalent to 56.9 g) with respect to the inner bag volume of 166.39 cm ³ , thereby manufacturing a heat-generating body. The inner bag was formed by stacking two sheets of nylon nonwoven fabric and polyethylene resin film. As the air intake and release material, a urethane sponge ("CUT SPONGE HARD SR01-4585 (urethane foam)" from KOHNAN SHOJI CO., LTD., the import distributor) having a size (width×length×thickness) of 60 mm×80 mm×10 mm was used.

After attaching a temperature sensor to the air-permeable sheet of the two sheets constituting the inner bag of the heating element with adhesive tape, the heating element is held in the hand while the urethane sponge is in contact with the sheet in a manner that covers the temperature sensor. The heating element and the urethane sponge are rubbed together for 15 minutes at a rate of 5 seconds per time in an environment of 20℃±1℃ and 55% to 70% humidity. The heating element and the urethane sponge are then placed on the hand without rubbing for 20 minutes. After that, the heating element and the urethane sponge are rubbed for 15 minutes at a rate of 5 seconds per time while measuring the heating temperature of the heating element. The measurement results are shown in Figure 10.

It can be clearly seen from Figure 10 that when the heating element and the urethane sponge are not rubbed and not used, the heating temperature of the heating element drops to about 40°C. Although Figure 10 shows the change in the heating temperature of the heating element when the heating element and the urethane sponge are rubbed by hand, it can be inferred that the heating temperature of the heating element will reach the same level when the heating element and the urethane sponge are stepped on with the soles of the feet. Therefore, it can be seen that the heating element of the present invention will not significantly increase the heating temperature of the heating element when not in use, and the heating element will not always be at a high temperature.

In addition, for Example 2, when the same test was conducted in a state where the urethane sponge was packaged together with the exothermic composition in the inner bag of the heating element, it was confirmed that the same result could be obtained as when the urethane sponge was arranged on the outer side of the inner bag of the heating element.

1: Warm parts

2: Heat generating body

3: Pyrogenic composition

4: Inner pocket

50(5): Three-dimensional woven fabric (air inhalation and release material)

11: Shoes

12: Insole

Claims (4)

A foot warmer is disposed between the sole of the user and the insole of the shoe, and comprises: a heating element, which is a heating composition that generates heat by contacting with air and is enclosed in an air-permeable inner bag; and an air-inhaling and releasing material, which can contain air inside and deform to inhale and/or release air; the air-inhaling and releasing material constitutes the insole of the shoe disposed on the insole of the shoe, the heating element is disposed between the sole of the user and the air-inhaling and releasing material constituting the insole, the air-inhaling and releasing material inhales and releases air by compression deformation and expansion deformation, the air-inhaling and releasing material is a three-dimensional woven fabric with a net structure, and the air-inhaling and releasing material uses synthetic fiber yarns containing polyester. As in claim 1, the foot heating element, wherein the size of the air intake and release material is larger than the heating element when viewed from above. As in claim 1 or 2, the foot heating element, wherein the air intake and release material is integrated with the inner bag of the heating element. A use of an air inhalation and release material, which is used to improve the air supply to a heating element, wherein the heating element is a heating composition that generates heat by contacting with air and is enclosed in an air-permeable inner bag, and is used to warm the soles of the user's feet in the shoe, wherein the air inhalation and release material can contain air inside and can be deformed to inhale and/or release air, wherein the air inhalation and release material can be used ... The air intake and release material constitutes the insole of the shoe arranged on the insole of the shoe, the heating element is arranged between the sole of the user and the air intake and release material constituting the insole, the air intake and release material inhales and releases air by compression deformation and expansion deformation, the air intake and release material is a three-dimensional woven fabric with a net structure, and the air intake and release material uses synthetic fiber yarn containing polyester.

Images