JPS63259Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a foot heating element, and more particularly to a foot heating element filled with a heat generating composition.

In winter or in a cold environment, a drop in skin temperature is unavoidable and is a contributing factor to illness, and cold feet are particularly likely to be a contributing factor to illness.

The thermal insoles of the various types of shoes currently available on the market are simply thermal insulators, and cannot essentially prevent feet from getting cold, which can contribute to illness and prevent people from getting frostbite. There were still quite a few. For this reason, there has been a movement in the past year or two to put bags containing heat-generating agents on the market as heating elements for foot warming. However, conventional heating elements for foot warming have not been put into practical use due to various drawbacks. In other words, it is essential that at least one of the front and back sides of the bag that stores the exothermic agent is made of a breathable film, and synthetic fibers such as polyamide, polyester, polypropylene, and rayon are used as the breathable film. microporous films that are chemically perforated during or after the production of synthetic resin films such as polyethylene, polypropylene or polyfluorinated ethylene, such as non-woven or woven fabrics made of natural fibers such as NF sheet (Tokuyama Soda Co., Ltd.); (manufactured by Sekisui Chemical Co., Ltd.), Cellpore (manufactured by Sekisui Chemical Co., Ltd.), Gore-Tex (manufactured by Gore, Inc., USA), and other films that are physically perforated after the production of synthetic resin films such as polyethylene or polypropylene.
Conventionally, a film has been used in which a synthetic resin film such as polyethylene or polypropylene is laminated with the above-mentioned woven or nonwoven fabric and physically perforated therein.

However, heating elements for foot warming using these films as bag materials have various drawbacks. In other words, if such a film is used, the fine powder in the exothermic composition may leak out from the gaps between the fibers, or
Moreover, it has poor bursting strength and impact strength, so the film may tear during use, causing the exothermic agent inside the bag to spill out, and it also has the disadvantage that it does not have the thermal adhesive properties of woven or non-woven fabrics made of rayon or natural fibers. However, if a film is used, it has the disadvantages of poor bursting strength and impact strength, the film tears during use and the exothermic agent inside the bag comes out, and it is relatively expensive. When used, the equivalent diameter of the physically perforated ventilation hole is large enough to allow fine powder in the heat-generating composition to leak out. If there is little circulation and the ambient temperature is low, sufficient heat will not be generated. To generate sufficient heat under these conditions, the diameter of the vent holes must be increased and/or the number of holes must be increased significantly, thereby reducing the amount of fine powder in the exothermic composition. There were disadvantages in that leakage further increased, the bursting strength and impact strength of the film further decreased significantly, and the possibility that the film was torn during use and the exothermic agent inside the bag came out was increased.

The object of the present invention is to have sufficient strength for use in shoes, to substantially completely prevent leakage of fine powder, and to provide sufficient airflow for the exothermic composition to generate sufficient heat. To provide a relatively inexpensive heating element for heating feet, which has an air permeability that enables the supply of heat.

In order to achieve the above-mentioned objective, the present inventors conducted extensive research and created a bag using a unique film in which high-density polyethylene fibers were laminated irregularly as a breathable film, heated and pressurized, and the fibers were bonded to each other. We have obtained new knowledge that the drawbacks of conventional foot heating elements can be overcome by using .

That is, in the present invention, at least one of the high-density polyethylene fibers is laminated irregularly and heated and pressurized so that the fibers are bonded to each other, and the air permeability according to the Gurley air permeability test method is 5 to 150 seconds/1. 100 c.c., into a bag that is a film with a maximum pore diameter of substantially 5 to 20 μ by the air-methanol maximum bubble pressure method.
This is a foot warming heating element which contains a heat generating composition that can generate heat in the presence of air.

The bag used in the foot warming heating element of the present invention is made of a film (hereinafter referred to as high density polyethylene fiber laminated film) is used. It is preferable that the fibers be bonded to each other uniformly over the entire surface of the film, and that there are many fusion points between the fibers per unit area.The thickness of the film is usually 1 mm or less, preferably about 0.1 to 0.3 mm. Also, the breathability is 5~
150 seconds/100 c.c. (Gurley air permeability test, JIS-
P8117), and the maximum diameter of the pores in the film is substantially 5 to 20 μm (based on the air-methanol maximum bubble pressure method). The strength is bursting strength 5Kg/cm ²
Above, preferably about 7 to 20 kg/cm ² (according to Müllen bursting strength test method, JIS-P8112) impact strength
400g or more, preferably about 600 to 5000g (according to dart drop method B method, ASTM-D1709), tear strength is 0.2Kg or more in both longitudinal and transverse directions, preferably about 0.3 to 1.5Kg (Elmendorf tear strength test method) , according to JIS-P8116), and the tensile strength is 5 kg/1.5 cm or more in both the longitudinal and transverse directions, preferably about 7 to 23 kg/1.5 cm (according to JIS-P8113).

As a representative example of a high-density polyethylene fiber laminated film that satisfies all of these characteristics, the Tyvek 10 series ("Tyvek" is a trade name of DuPont, USA) such as Tyvek 1073B and Tyvek 1073D are preferably used in practice. . For one side of the bag, a film having substantially no or little air permeability may be used, if desired, and the former is preferably used. Films that have substantially no air permeability include, for example, polyolefins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, thermoplastic resin films such as polyvinyl chloride and polyvinylidene chloride, and such films. A film made by laminating a thermoplastic resin film with a metal foil such as aluminum foil, a film made by vapor-depositing a metal such as aluminum onto the above thermoplastic resin film, or a synthetic resin such as nylon (trade name). A laminated film in which a thermoplastic resin film such as polyolefin and polyvinyl chloride is laminated to a nonwoven fabric made of fibers is preferably used.

Further, a film with low air permeability is a film in which the above-mentioned film having substantially no air permeability is physically or chemically perforated before or after its preparation.

There is no particular restriction on the shape of the foot heating element of the present invention, and in practice, it is usually rectangular, trapezoidal, a shape in which at least one of these straight lines is curved, a semicircular shape, and a sole shape. However, other shapes are possible.
The size does not need to be so large that you feel strange when using it. The thickness may be so long as it does not cause discomfort or difficulty in use, and is practically 2 cm or less, preferably 0.8 cm or less.

The exothermic composition used in the present invention may be any exothermic composition that can generate heat in the presence of air, and in practice, exothermic compositions containing at least iron powder and inorganic salts such as common salt, and at least metal sulfide. Any commonly used exothermic composition, such as an exothermic composition containing a substance, may be used.

The foot heating element of the present invention can be made, for example, as follows. That is, two high-density polyethylene fiber laminated films having substantially the same shape or one high-density polyethylene fiber laminated film and one film with substantially no or low air permeability are stacked on top of each other. The bags are combined and fixed, leaving a part of the peripheral edge, and the heat-generating composition is filled from the unfixed part, and then the unfixed part is fixed to form a foot warming bag.

There are no particular restrictions on the fixing means, but thermal bonding is preferred.

As a bag for the foot heating element of the present invention, one side is made of a high-density polyethylene fiber laminated film and the other side is a film with substantially no air permeability, and both sides are made of a high-density polyethylene fiber laminated film,
Preferably, one side is a bag made of a high-density polyethylene fiber laminated film and the other side is made of a film with low air permeability.

1 and 2 are a plan view and a front view, respectively, of a semicircular foot heating element of the present invention. In other words, the semicircular tiebacks 1073B are almost the same.
(Product name) 1 and laminated non-breathable film 2 made by laminating polyethylene onto a nylon fiber nonwoven fabric.
(not shown in Fig. 1) are placed one on top of the other and the peripheral edge 3 is fixed, and a heat generating composition (not shown in the drawing) is filled in a bag for heating the feet. .

The foot heating element of the present invention is used by being placed inside footwear such as shoes, tabi socks, and slippers. Although it is generally used by placing it on the inner sole of the shoe, it can also be used by inserting the foot heating element into the gap between the foot and the shoe other than the inner sole. In the former case, it is preferable to use it by inserting it into the toe and arch of the foot.

It can also be used by storing it in a foot heating element storage pocket provided in the insole of the shoe.

FIG. 3 is a side view showing how the foot heating element of the present invention is used. In other words, the foot warming heating element 4 is
The high-density polyethylene fiber laminated film side is laid on the sole of the shoe 6 so that it is in contact with the sole 5 of the foot.

Before use, the heating element for foot warming of the present invention must be wrapped in a non-breathable film to prevent contact between the heat generating composition and air and/or moisture.

The heating element for foot warming of the present invention does not break even under the weight of the body weight and kicking force during running, does not leak the heat generating composition, and generates sufficient heat, making it extremely practical for feet. It is a heating element for warming.

[Brief explanation of the drawing]

1 and 2 are a plan view and a front view, respectively, of the foot warming heating element of the present invention. FIG. 3 is a side view showing one mode of use of the foot warming heating element of the present invention. In the drawings, 1... Tyvek 1073B (product name), 2... Non-breathable film, 3... Peripheral part,
4... Heating element for foot warmth, 5... Feet, and 6...
Shoes.

Claims (1)

[Scope of utility model registration request] At least one of the fibers is made of high-density polyethylene fibers laminated irregularly and heated and pressurized so that the fibers are adhered to each other and have an air permeability of 5 to 150 seconds/100 c.c. according to the Gurley air permeability test method. , a heating element for foot warming, comprising a bag which is a film having a maximum diameter of pores of substantially 5 to 20 μm as measured by the air-methanol maximum bubble pressure method, and containing a heat generating composition capable of generating heat in the presence of air. .