JP2003265513A - Exothermic body and warming material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exothermic body and a warming material in which the problem caused by the warping of the exothermic body caused during using the warming material is solved and comfortable fitted feeling and constant warming effect are obtained during use and in which peripheral part is peeled and the warming material can be used without being peeled off. <P>SOLUTION: The exothermic body comprises an exothermic composition which can be exothermic in contact with air and a bag material for storing the exothermic composition. The bag material has a surface for facing external atmosphere, and a surface for facing an object to be mounted. The surface facing external atmosphere has gas permeability, the shrinkage of a sheet of a surface facing the object to be mounted is larger than that of a sheet of the surface facing external atmosphere. The warming material includes an exothermic body and a means for mounting the exothermic body. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating element including a heating element and a mounting means such as an adhesive portion, and is particularly applicable to various parts of the human body and used for a long time. Even if it relates to a heating element and a heating material that can obtain a good fit.

[0002]

2. Description of the Related Art A heating element consisting of a breathable bag containing a heat-generating composition that generates heat when contacted with air is a chronic body due to various causes such as stiff shoulders, neuralgia, muscle aches and the like. As a medical device to reduce pain,
In addition, it is generally widely used as a warming warmth. Such a heating element is often used as a heating material having an adhesive layer on one surface of a bag and applied to the skin or clothes so that the heating element can be easily attached to a human body or clothes. In addition, recently, a heating material that uses such a heating element in combination with a drug is a drug that sends the drug from the skin to the affected area.
It is also being developed as an element of the delivery system. Furthermore, a heating material for applying to the face for the purpose of beauty and reducing eye fatigue has been developed, and the application of such heating material tends to expand more and more.

Generally, a bag material for a heating element has air-permeable fine pores of a micron unit produced by kneading and molding a thermoplastic resin such as polyolefin and a fine particle size filler and stretching the mixture. A porous film is used on one side, that is, the side facing the outside air. A resin film such as polyethylene is usually used on the other surface, that is, the surface facing the mounting target.

However, in the bag material conventionally used for such a heating element / heating material, there is a phenomenon that the peripheral portion of the heating element / heating material warps in the direction away from the skin or clothes with time during use. Occur. Therefore, there is a problem that the fit is gradually lost to the wearer, causing a feeling of strangeness and instability, the peripheral portion of the heating material is flipped over and caught on clothes, and the heating material is peeled off. Also,
In particular, in the case of a heating material that is applied to the face for cosmetic purposes, etc., the application site is relatively small and the surface is undulated. There was a problem that became difficult. Further, since the heat is radiated from the portion away from the wearer due to the warp of the peripheral edge, the stability of the skin temperature is lost, the heating effect is reduced, and the purpose of the heating material may not be sufficiently achieved.

Therefore, the present invention solves the problem caused by such warpage of the heating element during the use of the heating material, and provides a comfortable fit and a constant heating effect throughout the use, and the peripheral portion An object of the present invention is to provide a heating element and a heating material that can be used without curling up or peeling off the heating material.

[0006]

The inventor has found that the cause of the above-mentioned warping of the heating element is due to the heat generation of the heat-generating composition.
It has been found that the sheet constituting the surface of the bag material in contact with the outside air contracts, while the sheet constituting the surface in contact with the skin or clothes does not contract or rather stretches. Then, by properly selecting the sheets constituting both sides of the bag material and balancing the contraction of both sheets during heat generation, it was found that the problems caused by such warpage can be solved, and the present invention has been completed. .

That is, the heating element of the present invention is a heating element composed of a heating composition capable of generating heat by contacting with air, and a bag material containing the heating composition, wherein the bag material is the outside air. The sheet has a surface facing each other and a surface facing the mounting object, the surface facing the outside air has air permeability, and the contraction rate of the sheet forming the surface facing the mounting object constitutes the surface facing the outside air. It is a bag material that has a larger shrinkage rate of the sheet,
Is characterized by.

In the heating element of the present invention, the contraction rate of the sheet forming the surface facing the object to be mounted is higher than the contraction rate of the sheet forming the surface facing the outside air. Does not warp in the direction of the object to be worn and the peripheral edge of the heating element does not turn outward, but it further adheres to the object to be worn over time and the fit may be improved.

Further, the present invention provides a heating material including the heating element described above and means for mounting the heating element. The means for mounting the heating element is preferably an adhesive portion provided on the surface of the heating element facing the outside air or the surface facing the mounting target.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the heating element of the present invention, the sheet constituting the surface of the bag material facing the object to be mounted and the sheet constituting the surface facing the outside air are appropriately selected depending on the relative shrinkage ratio with respect to each other. To be selected.

The shrinkage ratio here is a heat shrinkage ratio,
The dimensional change rate after heating the sheet before heating the sheet at a constant temperature for a certain period of time. That is, contraction rate (%) =
[(Dimension of sheet before heating)-(Dimension of sheet after heating) / Dimension of sheet before heating] * 100. Shrinkage is measured in a thermostat without tension on the sheet.
It is carried out by placing it in a static state under conditions of 50 ° C., relative humidity of 90% and heating time of 1 hour, and measuring the dimensions of the sheet after heating with a caliper and comparing them.
For example, vertical direction (MD) 100 mm × horizontal direction (TD) 1
Sheet dimensions of 00 mm may be measured. Alternatively,
In the case of a sheet that has the property of curling by heating,
It is also possible to draw a square having a length of 100 mm and a width of 100 mm on a sheet having a length of 200 mm and a width of 200 mm, and measure the size of the square. When the size of the sheet (or square) to be measured is 100 mm square, the size difference (mm) before and after heating is the numerical value of the shrinkage rate (%), which is convenient, and therefore 100 mm is normally used. However, since there is no substantial difference in shrinkage rate when measured with other sizes, the size is not limited to 100 mm square. For the purposes of the present invention, shrinkage is defined by the machine direction (MD) and the transverse direction (T
When the contraction rate is different in D), the larger contraction rate is used as a reference.

The term "shrinkage rate of the sheet" used in the present specification means a heating element or a heating element regardless of whether the sheet is a monolayer film, a laminated film, a composite sheet with a covering material such as a nonwoven fabric, or the like. The shrinkage rate of the entire sheet when used as a bag material. Therefore, when the sheet has an adhesive portion when used in a heating material, the shrinkage rate of the sheet is the shrinkage rate measured in the state including the adhesive portion.

In the bag material of the present invention, the sheet constituting the surface facing the outside air is a breathable sheet,
The contraction rate may be smaller than the contraction rate of the sheet forming the surface facing the attachment target.

The shrinkage rate of the sheet constituting the surface facing the outside air is usually about 0% to 2%. The closer the shrinkage rate is to 0, the more preferable, for example, 0% to 1.5% is preferable, further 0% to 1%, and particularly 0% to 0.5% is preferable.

As the bag material sheet having air permeability, a single layer or laminated porous film or sheet is generally used. As the resin constituting the film, polyethylene,
Polypropylene, polyester, polyamide, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride,
Polyurethane, polystyrene, ethylene-vinyl acetate copolymer, polycarbonate, hydrochloric acid rubber and the like are preferably used alone or in combination, and appropriate ventilation is performed according to the required heat generation amount, temperature, heat-generating composition used, etc. The degree can be appropriately selected. Of these, linear low-density polyethylene is most preferable from the viewpoint of workability and the like. The thickness of the breathable film is usually preferably about 20 μm to 1 mm.

The film as described above may be laminated with a covering material such as a non-woven fabric. Usually, as a covering material,
Examples thereof include those containing artificial fibers such as nylon, vinylon, polyester, rayon, acetate, acrylic, polyethylene, polypropylene and polyvinyl chloride, and natural fibers such as cotton, hemp and silk. The basis weight of non-woven fabric is usually 20 to 1
It is about 00 g / m ² .

Particularly, a breathable sheet in which a nonwoven fabric such as nylon fiber is laminated on a thermoplastic synthetic resin film is generally used.

The air permeability of the air-permeable bag material sheet is about 200 as measured by the Gurley method (JIS P-8117).
0 to about 60,000 seconds / 100 cc is preferable, about 1
Particularly preferred is 50,000 to about 50,000 seconds / 100 cc. The moisture permeability of the bag material sheet is determined by the Lissi method (JIS K
-7129A method) 200-1000 g /
It is preferably in the range of (m ² · 24 hr), particularly preferably 300 to 600 g / (m ² · 24 hr).
If the air permeability is lower or the water vapor permeability is lower than these ranges, the calorific value is likely to be insufficient, while if the air permeability is high or the water vapor permeability is high, the maximum temperature of the heating element becomes too high and the human body is burned. This is because there is a risk of incurring.

The sheet forming the surface facing the outside air preferably has a concealing property. This is because the exothermic composition is generally black, and if it has no concealing property, the exothermic composition is visible from the outside and does not look good. Further, when the heating element of the present invention is used as a heating material for medical treatment and cosmetics, a bag material sheet or film,
It is preferably colored white to give a feeling of cleanliness. As the color pigment, either an organic pigment or an inorganic pigment can be used, but an inorganic pigment is preferable. Examples of the inorganic pigments include titanium oxide, calcium carbonate, talc, alumina and barium sulfate.

The sheet constituting the surface facing the object to be mounted may have a shrinkage ratio larger than that of the sheet constituting the surface facing the outside air. In order to achieve the object of the present invention, the difference in shrinkage ratio may be about 0.5%, but if it is 1% or more, it is more preferable in terms of improving fit. However, if the shrinkage ratio is too large, the heating element may be excessively deformed, and on the contrary, there is a possibility that the heating object may not be stably attached to the object to be mounted. Therefore, the contraction rate of the sheet constituting the surface facing the mounting target is 1 to 40 in terms of the fit property to the mounting target.
The range is preferably%, more preferably 1 to 30%, still more preferably 2 to 20%, most preferably 2 to 10%.

The method for producing a film or sheet having such a desired shrinkage ratio is known to those skilled in the art. For example,
Various stretched films are used as the heat-shrinkable film. The commonly used heat-shrinkable stretched film is a single-layer or laminated non-breathable film. Stretching
It may be uniaxially stretched or biaxially stretched, but preferably biaxially stretched.

Since the surface facing the object to be mounted has low air permeability or substantially non-air permeability when attached to the object, the sheet constituting this surface is a sheet having the above-mentioned air permeability. It may be present, but it may be a non-breathable sheet.

The non-breathable film is a film that is substantially impermeable to oxygen, and includes, for example, polyolefins such as polyethylene, polypropylene and polybutadiene, PET,
Polyvinyl chloride, polyvinylidene chloride, polyester,
A material made of polyether, polysulfone, or polyamide and having a thickness of about 20 μm to 1 mm is preferably used. The film as described above may be laminated with a covering material such as a non-woven fabric. Usually, examples of the covering material include those containing artificial fibers such as nylon, vinylon, polyester, rayon, acetate, acrylic, polyethylene, polypropylene and polyvinyl chloride, and natural fibers such as cotton, hemp and silk. The basis weight of the non-woven fabric is usually 20 to 100 g / m ^2.
It is a degree.

Further, it is preferable that the sheet forming the surface facing the object to be attached has a concealing property for the same reason as that of the sheet forming the surface facing the outside air. Therefore, the sheet that constitutes the surface facing the mounting target also
It is preferably a colored sheet or film as described above.

The sheet constituting the surface facing the object to be mounted may be a laminated film for the purpose of improving heat sealability or film strength. In this case, a layer that is capable of improving the heat-sealing property on the inside of the bag and is in contact with the heat-generating composition, that is, a layer (sealant layer) made of the same or similar resin as the sheet constituting the surface facing the outside air
Those having are preferred. For example, when the sheet forming the surface facing the outside air is a polyethylene-based porous film, the surface contacting the heat-generating composition of the sheet forming the surface facing the attachment target preferably contains polyethylene as a resin, and at low temperature. From the viewpoint of heat-sealing property, it is particularly preferable to include polyethylene produced using a metallocene catalyst.

From the above points, in the present invention, as the sheet constituting the surface facing the object to be attached, a stretched film or a sheet containing the same, preferably a stretched porous film or a sheet containing the same is suitable. Used for. The stretched porous film is preferable because the pores are closed by heating and the shrinkage rate is appropriately increased. Particularly preferred is a white or milky white olefin-based (particularly polyethylene-based) stretched porous laminated film, particularly a laminated film containing a metallocene-based linear low-density polyethylene non-permeable film as a sealant, and a composite sheet of the same and a nonwoven fabric. Can be mentioned.

The bag material constituting the heating element of the present invention may be provided with means for mounting the heating element, for example, an adhesive portion. When the heating element has such mounting means or other additional elements, it is referred to herein as "heat material".

In the present specification, the "adhesive portion" means a portion having an adhesive force sufficient to at least temporarily attach the heating element or the heating material to the object to be attached. The adhesive part is, for example, a part obtained by applying and forming a pressure-sensitive adhesive for application to clothes or the like in a layer having a certain thickness (for example, a layer of an acrylic pressure-sensitive adhesive, a thread of a pressure-sensitive adhesive containing a hot-melt polymer substance). A layer formed by the body or a layer formed by a mixture of a foam of a pressure-sensitive adhesive containing a hot-melt type polymeric substance and a filamentous material), a poultice layer portion for direct attachment to the body, etc. To do. The thickness of the adhesive portion is not particularly limited, but is usually 5 to 1500 μm, preferably 10 to 1000 μm.

The adhesive portion is generally provided on the surface facing the object to be attached. In this case, the adhesive portion may be provided over the entire surface or may be provided partially. When the heating element is used by being attached to clothes or the like, the adhesive portion may be provided on the surface facing the outside air. In this case, the heating element is attached to the inside of the clothing or the like (that is, the surface facing the wearing target such as the clothing). Since the surface of the heating element facing the mounting target is not fixed to the mounting target but is in close contact with it, the inflow of air or oxygen required for heat generation needs to be secured on the side where the adhesive portion is provided. Therefore, when the adhesive portion is provided on the surface facing the outside air, the adhesive portion needs to be partial to such an extent that the air permeability necessary for heat generation is secured on the surface.

The presence of the adhesive portion may act to increase the shrinkage rate of the sheet depending on the composition and / or the configuration such as the thickness thereof. When it is provided on the facing surfaces, it is preferably partial. To make it partial, for example, the adhesive may be applied in stripes, dots, or the like.

A layer of a hydrophobic pressure-sensitive adhesive is generally used mainly for sticking to clothes or the like. As the adhesive,
An acrylic pressure-sensitive adhesive (two-component reaction type) containing a copolymer of an acrylic monomer and a functional group-containing monomer as a main component is generally used.

Examples of hydrophobic pressure-sensitive adhesives for application to the skin and the like include rubber-type pressure-sensitive adhesives containing a styrene block polymer, a tackifier and a softening agent as main components. As the styrene block polymer, styrene-ethylene-butylene-styrene block copolymer (SEBS),
Styrene-isoprene-styrene block copolymer (S
IS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), and other rubber-based adhesives,
Examples thereof include acrylic adhesives and adhesives containing a hot melt type polymer substance. These pressure-sensitive adhesives may optionally contain other components such as other pressure-sensitive adhesives, tackifiers, softeners, tackiness improvers, antioxidants, fillers, stabilizers, pigments,
An adhesion modifier, an adhesion improver, a colorant, a defoaming agent, a thickener, a modifier, an antifungal agent, an antibacterial agent, a bactericidal agent, a deodorant or a deodorant and the like may be appropriately blended. Examples of tackifiers include petroleum resin-based and rosin resin-based tackifiers. Examples of the softening agent include process oil and plasticizer.

For application to the skin or the like, a hydrophilic adhesive portion (so-called gel layer) is also used. From the viewpoint of heat conduction to the skin and sweat absorption, the hydrophilic adhesive portion preferably contains 30 to 70% by weight of water with the weight of the adhesive portion being 100%. Such an adhesive portion is known as a poultice layer in a hot poultice, and for example, as a base material, polyvinyl alcohol, glycerin, sorbitol; carboxymethyl cellulose (CMC), sodium polyacrylate, water-absorbent resin, zeolite-based material. Inorganic water absorbing agents such as, kaolin, bentonite, talc, gelatin, titanium oxide; various crosslinking agents, surfactants such as sorbitan monolaurate, ethyl paraoxybenzoate, and the like. If necessary, a softening agent, a pressure-sensitive adhesive, etc. may be contained. Furthermore, the adhesive portion, which is such a poultice layer, can hold poultices containing pharmaceutically effective ingredients such as water or poultice liquid, poultice paste and the like. The drug used here is not particularly limited as long as it is transdermally absorbable, and specifically, for example, a skin stimulant, an analgesic / anti-inflammatory agent, a central nervous system agent (sleep sedative, anti-inflammatory agent, anti-inflammatory agent). Epilepsy agent, neuropsychiatric agent), diuretic, antihypertensive, coronary vasodilator, antitussive expectorant, antihistamine, antiarrhythmic agent, cardiotonic agent, corticosteroid,
Examples include local anesthetics. These medicinal components may be used alone or in admixture of two or more if necessary.

In the bag material constituting the heating element of the present invention, a desired release paper or release film can be further provided outside the adhesive portion. As the release film, a polyethylene terephthalate film or a polypropylene film alone or those coated with silicon are generally used.

The heating element of the present invention is used in the bag material as described above.
It can be manufactured by containing an exothermic composition that generates heat upon contact with air. Methods for producing such exothermic compositions and heating elements are well known. The exothermic composition used for the heating element of the present invention may be any conventionally known one as long as it generates heat in the presence of air (oxygen). Generally, metal powder such as iron powder and water that generate heat due to oxidation reaction and water are essential components, activated carbon, inorganic chlorides such as salt and potassium chloride, and water-absorbing polymers, vermiculite, sawdust,
A composition containing a water retention agent such as a silica-based substance is used. For example, if the weight of the exothermic composition is 100%, iron 3
5-80% by weight, activated carbon 1-10% by weight, chloride 1-1
It may include 0% by weight, 5 to 45% by weight of water, and 1 to 45% by weight of a water retention agent. The exothermic composition is generally a powder (including granules), but may be formed into a sheet by means such as containing alcohol or pressurizing (for example, JP-A 2000-60886, WO 00 / 1362
6).

For the heating element, for example, such a heat-generating composition is sandwiched between a sheet forming a surface facing the object to be mounted and a sheet forming a surface facing the outside air, and the peripheral portion is sealed by thermocompression bonding. Manufactured by. It can also be manufactured by laminating by further providing a layer made of a hot-melting agent on the periphery of both sheets.

The heating element of the present invention may further include, as a heating material, together with the adhesive portion or in place of the adhesive portion, an additional component such as a mounting means such as a band-shaped sheet member. . The heating element or the heating material of the present invention is usually stored in a bag that is substantially impermeable to oxygen until it is used after production until it is stored.

[0038]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Preparation of exothermic composition Iron powder (55.0 parts), activated carbon (7.0 parts), NaCl
(2.0 parts), water (29.9 parts), and Sunfresh S
T571 (manufactured by Sanyo Kasei) (3.0 parts) and vermiculite (3.1 parts) were mixed by stirring to prepare a heat-generating composition.
This exothermic composition was used in the production of each heating element in the following Examples and Comparative Examples.

Example 1 A sheet (A) facing an object to be mounted was manufactured as follows. Linear low density polyethylene [Density: 0.921g
/ Cm ³ , MI: 1 g / 10 min] 32 parts by weight, branched low-density polyethylene [density: 0.919 g / cm ³ , M
I: 2 g / 10 min] 5 parts by weight, calcium carbonate (average particle size 1.2 μm, fatty acid treatment) 60 parts by weight, ester plasticizer 3 parts by weight are mixed in a tumbler mixer, and then twin-screw kneading extrusion The mixture was uniformly kneaded at 220 ° C. using a machine and processed into pellets. Using an extruder equipped with a circular die, the pellets were subjected to melt film formation at 200 ° C., and then a line speed of 20 m at a draw ratio of 2.7 times between a preheating roll heated to 60 ° C. and a drawing roll. The film was uniaxially stretched in the machine direction (MD) at 1 / min to obtain a 40 μm thick porous opalescent film. Metallocene-based linear low-density polyethylene [density: 0.906 g /
cm ³ , MI: 11.0 g / 10 min] is extrusion-laminated to a thickness of 20 μm, and a shrinkable opalescent film
A sheet (A) that is (non-breathable) was obtained.

A pressure-sensitive adhesive (acrylic two-component liquid) was applied to the porous opalescent film side of the two-layer film of the above-mentioned porous opalescent film and metallocene-based polyethylene, and release paper was provided thereon.

The sheet (B) facing the outside air was manufactured as follows. Linear low density polyethylene [Density:
0.921 g / cm ³ , MI: 1 g / 10 min] 41 parts by weight, branched low-density polyethylene [density: 0.919 g
/ Cm ³ , MI: 2 g / 10 min] 10 parts by weight, calcium carbonate (average particle size 1.2 μm, fatty acid treatment) 45 parts by weight, ester plasticizer 4 parts by weight are mixed in a tumbler mixer, and then mixed. 220 ° C using a shaft type kneading extruder
Was evenly kneaded and processed into pellets. The pellets were heated to 200 ° C using an extruder equipped with a circular die.
At the line speed of 2 times at a draw ratio of 2.0 times between the preheating roll heated to 60 ° C. and the draw roll after melt film formation in
It was uniaxially stretched in the machine direction at 0 m / min to obtain a porous film having a thickness of 35 μm. To this porous film, a nylon nonwoven fabric is coated with a commonly used hot melt agent,
(Breathability) A sheet (B) was obtained.

Each of these two types of composite sheets (A) and (B) is cut into a size of 130 × 100 mm, and the polyethylene film surface of the sheet (B) facing the outside air and the metallocene of the sheet (A) facing the object to be mounted. The surface of the polyethylene film was placed inside, and the periphery was heat-sealed with a width of about 5 mm, leaving a part of the periphery, and laminated to form a bag.
30 g of the exothermic composition was placed in this bag, and the remaining unsealed portion was heat-sealed to encapsulate the exothermic composition to obtain a heating material 1.

Example 2 A sheet (A) facing an object to be attached was manufactured as follows. Linear low density polyethylene [Density: 0.921g
/ Cm ³ , MI: 1 g / 10 min] 27 parts by weight, ethylene butene copolymer polyethylene [density: 0.880 g /
cm ³ , MI: 3.6 g / 10 min] 10 parts by weight, calcium carbonate (average particle size 1.2 μm, fatty acid treatment) 60
2 parts by weight and 3 parts by weight of ester plasticizer were mixed in a tumbler mixer, and then mixed using a twin-screw kneading extruder.
The mixture was uniformly kneaded at 0 ° C. and processed into pellets. Using an extruder equipped with a circular die, the pellets were
After melt film formation at 80 ° C., it was uniaxially stretched in the machine direction at a line speed of 20 m / min at a draw ratio of 2.5 times between a preheating roll heated to 60 ° C. and a stretching roll, and a thickness of 35 μm.
To obtain a porous opalescent film. In the same manner as in Example 1, a metallocene-based linear low-density polyethylene [density: 0.906 g / cm ³ , MI: 11.0 g was added to this porous opalescent film.
/ 10 min] to a thickness of 20 μm by extrusion lamination, and a shrinkable opalescent film (non-breathable) sheet (A)
After that, a pressure-sensitive adhesive (acrylic two-component liquid) was applied on the porous opalescent film side, and a release paper was provided thereon.

The seat (B) facing the outside air is the same as in the first embodiment.
The same one was used.

Using these two kinds of composite sheets, the exothermic composition was enclosed in the same manner as in Example 1 to obtain a heating material 2.

Comparative Example 1 A sheet (A) facing an object to be attached was manufactured as follows. Linear low density polyethylene [Density: 0.925g
/ Cm ³ , MI: 0.8 g / 10 min] 93 parts by weight and titanium oxide 7 parts by weight were mixed in a tumbler mixer, and then 190 using an extruder equipped with a circular die.
Melt film formation was performed at 0 ° C. to obtain a film (non-stretched, non-porous) having a thickness of 60 μm. On this film, as a sealant film, a metallocene-based linear low-density polyethylene [density: 0.906 g / cm ³ , MI: 11.0 g / 1
0 minutes] Using an extruder, a thickness of 20 at 280 ° C.
A film having a thickness of 80 μm was obtained by extruding a film having a thickness of μm. An adhesive (acrylic two-component liquid) was applied to this film in the same manner as in Example 1, and release paper was provided thereon.

The same sheet as in Example 1 was used as the sheet facing the outside air.

Using these two types of composite sheets, the exothermic composition was enclosed in the same manner as in Example 1 to obtain a heating material 3.

Test Example 1 The shrinkage rate of each of the sheets of Examples 1 and 2 and Comparative Example 1 was measured. Specifically, each sheet is 200m
A m-square piece was prepared, and a square of 100 mm square was drawn on each to prepare a sample. These samples
Without tension on the sheet, the sheet was left standing and heated in a thermostat at a temperature of 50 ° C, a relative humidity of 90%, and a heating time of 1 hour.
Measure the horizontal dimension with calipers and measure it before heating (100 m
The shrinkage rate was calculated by comparing with m). The shrinkage rate of the sheet (A) facing the attachment target was measured in a state similar to that during use of the heating element, that is, after the sheet (A) was coated with the adhesive and the release paper was not included. Similarly, a sample in which a 50 mm square is drawn on a 100 mm square sheet is also prepared,
The shrinkage rate of these was also measured.

Further, as a reference, for the sheet (A) facing the object to be mounted, the sample before applying the adhesive is also measured, and is generally used as the sheet constituting the surface (B) facing the outside air. The shrinkage rate was similarly measured for two commercially available sheets (having no adhesive portion).

The results are shown in Table 1.

[Table 1] Shrinkage: Numerical value is the average of 5 measurements in the MD direction. The shrinkage in the TD direction was zero for all sheets.

Test Example 2 The occurrence of warpage in the heating materials 1 to 3 when the exothermic composition was caused to generate heat was evaluated. Specifically, each heating material is fixed at one end with a clip in a state where the release paper is removed, and the temperature (2
(1 ℃) in the air, generate heat in this state, and measure the surface temperature of the surface side facing the mounting object,
The occurrence of warpage was visually evaluated. Maximum surface temperature is 34-3
The temperature was 7 ° C., and this temperature lasted for about 5.5 to 6.5 hours. The warp was determined 15 minutes and 1 hour after the maximum temperature was reached.

The results are shown in Table 2.

[Table 2] Warp: (-) = no warp; (+) = slightly warp; (++) = considerably warp

Test Example 3 Using the bag materials of Examples 1 and 2 and Comparative Example 1, a heating material was produced as described above. However, the adhesive portion was produced by applying JM6038 manufactured by Nippon Fuller Co., Ltd. in an amount of 30 g / m ² . These heating materials (heating materials 1 ′, 2 ′, and 3 ′, respectively) were used for four test subjects (A to
It was attached to the upper arm of D), and the skin temperature and duration of the skin located below the center of the heating element were measured. Maximum skin temperature is 38
The temperature was -40 ° C, and the duration was about 5.5 to 6.5 hours. In addition, each subject was asked to rate the usability in three grades of 1 (not good), 2 (tolerable to use), and 3 (good), and to arbitrarily comment the reason for the rating.

Table 3 shows the evaluation results.

[Table 3]

From the above results, the heating element of the present invention is more closely adhered to the human body than the heating element using the conventional bag material,
It was found to be excellent in overall usability.

[0058]

EFFECTS OF THE INVENTION According to the present invention, the peripheral portion of the heating element warps in the direction away from the skin or clothes with time during use, so that the wearer gradually loses a feeling of fit, and feels uncomfortable or unstable. There is no problem with conventional heating elements and heating materials such as heat treatment, heat effect reduction, and exfoliation of the heating element, and heat generation suitable for being applied to the human body or face especially for medical purposes or cosmetic purposes. A body and its bag material are provided. That is, the heating element and the heating material of the present invention do not warp in the direction away from the wearing target during use, but rather adhere more closely to the wearing target, and provide a comfortable fit and a constant heating effect throughout use. It can be used without peeling off the heating element.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yutaka Kawai             5-8 Mitsuyacho, Nagahama-shi, Shiga Mitsubishi Plastics             Nagahama Factory Co., Ltd. F-term (reference) 4C099 AA01 CA19 GA03 JA04 LA01                       LA08 LA15

Claims (5)

[Claims] 1. A heating element comprising a heat-generating composition capable of generating heat upon contact with air, and a bag material containing the heat-generating composition, wherein the bag material is attached to a surface facing the outside air and an object to be attached. The sheet having a surface facing each other, the surface facing the outside air is breathable, and the shrinkage rate of the sheet forming the surface facing the attachment target is greater than the shrinkage rate of the sheet forming the surface facing the outside air. Heating element characterized by. 2. The heating element according to claim 1, wherein the sheet constituting the surface facing the attachment target is a stretched porous film or a sheet including the stretched porous film. 3. A heating material including the heating element according to claim 1 and a means for mounting the heating element. 4. The heating material according to claim 3, wherein the means for mounting the heating element is an adhesive portion provided on a surface of the heating element facing the outside air or a surface facing the mounting object. 5. The heating material according to claim 4, wherein the adhesive portion is a layer of a hydrophobic adhesive or a layer of a hydrophilic poultice.