JP2008114053A - Exothermic body and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exothermic body utilizing an exothermic composition generating heat by touching oxygen in the air which can easily and correctly control exothermic temperature (a heat generation characteristic). <P>SOLUTION: (1) The exothermic composition is an exothermic body contained in a flat permeable bag in which a permeable packaging material, keeping an air hole bored by irradiation with a laser beam, is used for one side or both sides, (2) a sheet-like support body holding the exothermic composition within a vacant space is an exothermic body contained in a flat permeable bag in which a permeable packaging material, keeping the air hole bored by irradiation with the laser beam, is used for one side or both sides, and (3) two or more exothermic cells, in which each of the exothermic compositions is separately arranged, are exothermic bodies contained in the vacant space of the support body consisting of two sheets in which a permeable packaging material, keeping the air hole bored by irradiation with the laser beam, is used for one side or both sides. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heating element and a method for manufacturing the heating element, and more particularly to a heating element and a method for manufacturing the heating element that are extremely excellent in uniformity in size and shape of air holes and that can easily and accurately control the heat generation characteristics.

  Conventionally, an exothermic composition that is mixed with oxidizable metal, activated carbon, inorganic electrolyte, water, water retention agent, etc. and generates heat upon contact with oxygen in the air has many fine holes, needle holes, etc. on one or both sides. What was stored in the air-permeable flat bag which consists of a packaging material which has is used as a disposable body warmer (heating element). Such a disposable warmer is usually further provided with a non-breathable flat bag in order to shield it from outside air and prevent water from evaporating and diffusing outside until it is used. Sealed in a breathable outer bag.

Further, in the disposable body warmer as described above, the exothermic composition is held in a gap of a sheet-like support such as a non-woven fabric and stored in a breathable flat bag so as to prevent the occurrence of misalignment during use. A sheet-like disposable body warmer is also used.
These warmers have heat generation characteristics set according to the part to be used, and various types are commercially available for body use, pocket use, footwear use and the like. Some of these warmers are provided with a pressure-sensitive adhesive layer to facilitate wearing during use.

  In addition, as a disposable body warmer other than the above, there is a body warmer developed for the purpose of fitting and using in bending and extending parts such as elbows and knees. For example, a heat generating part filled with a heat generating agent (heat generating composition) is provided with a disposable hand warmer on a required surface or location of a disposable hand warmer that is divided into a plurality of parts by a seal part, and on the body. A telescopic disposable body warmer adapted to fit can be mentioned.

Japanese Utility Model Publication No.59-178548 Japanese Utility Model Publication No. 60-58125 Japanese Patent Laid-Open No. 3-152894 Japanese Utility Model Publication No. 6-26829 Japanese Utility Model Publication No. 6-61222 JP-T-2001-513394 Special table 2003-509120 gazette

  In the breathable packaging material used for the disposable warmers as described above, as the packaging material in which relatively small ventilation holes are formed, synthetic resin fibers are randomly stacked and heat-pressed to form a large number of micropores. A packaging material or the like in which inorganic substances such as calcium carbonate, silicon dioxide, and aluminum oxide are dispersed in a packaging material, and then extruded into a sheet to form a large number of micropores is used. Moreover, as a packaging material provided with a relatively large ventilation hole, a packaging material or the like in which a needle hole is formed in a plastic film is used.

However, the conventional formation of such fine holes or needle holes does not sufficiently maintain the uniformity of the size and shape of the holes, and the amount of air within the set range is flattened. If it cannot be taken into the breathable bag, the disposable warmer will not warm up sufficiently.If the air is taken into the flat breathable bag beyond the set range, the disposable warmer will become hot. There was an inconvenience that there was a risk of burns. For this reason, a disposable body warmer, in which the exothermic temperature is usually set low, has been manufactured in consideration of safety.
Therefore, the problem to be solved by the present invention is to provide a disposable body warmer (heating element) capable of easily and accurately controlling the heat generation temperature (heat generation characteristics) in the disposable body warmer (heating element) as described above, and a method for manufacturing the same. That is.

  As a result of intensive studies to solve these problems, the inventors of the present invention include a plastic film in which a ventilation hole is formed by irradiating a laser beam as a breathable packaging material used for a disposable body warmer (heating element). It has been found that by using a breathable packaging material made of a laminated sheet, the uniformity of the size and shape of the air holes is greatly improved, and a heating element capable of controlling the heat generation temperature (heat generation characteristics) easily and accurately is obtained. The present invention has reached a heating element and a method for producing the same.

  That is, the present invention uses a breathable packaging material in which a heat generating composition that generates heat upon contact with oxygen in the air forms a vent by irradiating a laminated sheet including a plastic film with a laser beam on one or both sides. The vent or the equivalent circle diameter is 0.005 to 2.0 mm, and the distance from the center of two adjacent vents is 0.1 to 20 mm. The ratio of the area of the vent hole to the total area of the bonded sheet is 0.001 to 5%.

  In addition, the present invention provides a sheet-like support in which a heat generating composition that generates heat upon contact with oxygen in the air is held in the air gap, and forms a ventilation hole by irradiating a laminated sheet including a plastic film with a laser beam. The ventilated packaging material is housed in a flat breathable bag used on one or both sides, and the diameter of the vent or equivalent circle diameter is 0.005 to 2.0 mm, and two adjacent vents The center-to-center distance is 0.1 to 20 mm, and the ratio of the area of the vent hole to the total area of the bonded sheet is 0.001 to 5%.

  In addition, the present invention provides a breathable packaging material in which a plurality of heat generating cells made of a heat generating composition that generates heat upon contact with oxygen in the air form a vent by irradiating a laminated sheet containing a plastic film with laser light. Are accommodated in a gap between two sheets of one or both sides of the support, and the diameter of the vent or the equivalent circle diameter is 0.005 to 2.0 mm. The heating element is characterized in that the distance from the center to the center is 0.1 to 20 mm, and the ratio of the area of the vent hole to the total area of the bonded sheet is 0.001 to 5%.

  In addition, the present invention includes two laminated sheets including a plastic film so that the heat-sealing surfaces are inside each other, and the peripheral portion is heat-fused to form a flat bag, A method of manufacturing a heating element in which a heat generating composition that generates heat upon contact with oxygen in the air is stored in the flat bag, wherein at least one of the two bonding sheets has a wavelength of 0. It is a breathable packaging material in which a ventilation hole is formed by irradiating a laser beam of 1 to 1000 μm and an output of 1 to 1000 w.

  In addition, the present invention includes two laminated sheets including a plastic film so that the heat-sealing surfaces are inside each other, and the peripheral portion is heat-fused to form a flat bag, A method for producing a heating element in which a sheet-like support holding a heating composition that generates heat upon contact with oxygen in the air is contained in the flat bag, comprising two bonded sheets At least one bonded sheet is a breathable packaging material in which vent holes are formed by irradiating a laser beam having a wavelength of 0.1 to 1000 μm and an output of 1 to 1000 w. .

  The present invention also provides a plurality of exothermic cells made of a heat-generating composition that generates heat upon contact with oxygen in the air, and the heat-sealing surfaces of the sheets are in the gap between two laminated sheets including a plastic film. A method of manufacturing a heating element that is laminated so as to be inside and integrally formed by heat fusion, and at least one of the two laminated sheets has a wavelength of 0.1 to 1000 μm. The heating element manufacturing method is characterized by being a breathable packaging material in which vent holes are formed by irradiating a laser beam with an output of 1 to 1000 w.

Since the heat generating body of the present invention uses a breathable packaging material in which air holes are formed by irradiating laser light as the air permeable packaging material, the size and shape uniformity of the air holes are extremely excellent. It is possible to easily and accurately control the heat generation temperature (heat generation characteristics).
In addition, since the heating element of the present invention forms a vent hole by laser light, the pattern of the vent hole can be easily changed by a program. For example, the central portion is made high temperature and the peripheral portion is made low temperature to give a thermal gradient. For example, the size, shape, and arrangement pattern of the air holes formed in the air permeable packaging material can be freely changed.

The heating element of the present invention is applied to a heating element using a heating composition that generates heat upon contact with oxygen in the air. Further, the heating element of the present invention is not limited to the disposable body warmer, and is applied, for example, as a medical heating tool.
Hereinafter, although the heat generating body of this invention is demonstrated in detail based on FIGS. 1-7, this invention is not limited by these. 1, 3, and 5 are cross-sectional views showing examples of the heating element of the present invention, and FIGS. 2, 4, and 6 are respectively non-venting the heating elements of FIGS. 1, 3, and 5. FIG. 7 is a perspective view showing an example of a packaging material used for the heating element of the present invention.

As shown in FIG. 1, the heating element of the first configuration of the present invention includes a breathable packaging material 2 in which a heating composition 1 that generates heat upon contact with oxygen in the air is a laminated sheet including a plastic film. A heating element housed in a flat air-permeable bag used on one side or both sides, and a heating element using a packaging material in which a ventilation hole is formed by irradiating a laser beam as the air-permeable packaging material 2. .
As shown in FIG. 3, the heating element of the second configuration of the present invention has a sheet-like support 4 in which a heating composition 1 that generates heat in contact with oxygen in the air is held in a gap. A heat generating body that is housed in a flat air-permeable bag using one or both sides of a breathable packaging material 2 made of a laminated sheet. It is a heating element using the packaging material which formed.

As shown in FIG. 5, the heating element of the third configuration of the present invention has a plurality of heating cells in which the heating compositions 1 that generate heat when in contact with oxygen in the air are arranged separately, are made of plastic film. A heat generating element that is housed in a gap between a support 5 composed of two sheets using one side or both sides of a breathable packaging material 2 composed of a laminated sheet. It is a heating element using a packaging material that is irradiated to form a vent.
In any configuration, when both surfaces are breathable packaging materials, only one surface may be a packaging material in which vent holes are formed by irradiating laser light.

  As a material of the breathable packaging material used for the heating elements of the first configuration and the second configuration of the present invention, a bonded sheet including a plastic film is used. As these bonded sheets, for example, , (1) heat-fusible component layer / plastic film / heat-fusible component layer / non-woven fabric, or (2) (mixed film of heat-fusible component and plastic component) / bonded sheet made of non-woven fabric be able to. In addition, as a plastic film, the film which consists of 1 or more types chosen from a polyethylene film, a polypropylene film, a polyester film, and a nylon film can be illustrated.

  Moreover, as a material of the air permeable packaging material used for the heating element of the third configuration of the present invention, a laminated sheet including a plastic film is used. As these laminated sheets, for example, (1 ) Heat-fusible plastic component layer / (one or more films selected from plastic film, rubber film, mixed film of plastic component and rubber component) / heat-fusible plastic component layer / non-woven fabric, (2) (heat fusion (3) (mixed film of heat-sealable plastic component and rubber component) / non-woven fabric, or (4) (heat-sealable plastic component and plastic component) Rubber component mixed film) / nonwoven fabric. Examples of the heat-fusible plastic component include thermoplastics such as polyethylene resin, polypropylene resin, vinyl chloride resin, ABS resin, polyethylene terephthalate resin, polyamide resin, and heat-meltable fluororesin. Of these, low density polyethylene resin is preferred. The heat-fusible plastic component layer is a layer containing these heat-fusible plastic components singly or in combination. For example, a layer comprising a low-density polyethylene resin and a polyethylene resin, a low-density polyethylene resin And a layer made of polypropylene resin. Examples of the rubber component include polybutadiene rubber, polyisoprene rubber, styrene-butadiene rubber, polyurethane rubber and the like having butadiene, isoprene, styrene, urethane and the like as monomer components.

In the present invention, in any configuration, these packaging materials are usually irradiated with laser light to form air holes to form a breathable packaging material. For example, a plastic film is irradiated with laser light to pass through. After forming the pores, a breathable nonwoven fabric may be bonded to form a breathable packaging material.
In addition, as the non-breathable packaging material 3 in this invention, the material of the above-mentioned packaging material can be used as it is, without forming a vent hole, for example. In addition, an adhesive layer can be provided on the surface opposite to the heat-sealing surface of the non-breathable packaging material in order to attach the heating element to the body. The adhesive layer is covered with release paper or the like during the period until use.

  In the heating element of the present invention, there is no particular limitation on the method of irradiating the laminated sheet including the plastic film as described above with laser light to form the air holes. For example, a UV laser, a carbon dioxide gas laser or the like is used. Can be used. The laser beam irradiation is usually performed within a wavelength range of 0.1 to 1000 μm and an output of 1 to 1000 w. The shape of the vent is usually circular, but may be oval, triangle, square, rectangle, rhombus, trapezoid, or polygon. Moreover, the magnitude | size of a vent hole is 0.005-2.0 mm in diameter normally, when circular (it converts into the circle | round | yen which has the same area in the case of another shape). The distance from the center of the two adjacent air holes is usually 0.1 to 20 mm. The arrangement of the vent holes is not particularly limited, and for example, it can be formed on the entire surface, the central portion, the peripheral portion, or a part of the bonded sheet. The occupying ratio is 0.001 to 5%. The number of vent holes formed in one bonded sheet is usually 100 to 1,000,000 although it depends on the size of the vent holes and the size of the bonded sheet.

In the heating elements of the first and second configurations of the present invention, the exothermic composition that generates heat upon contact with oxygen in the air includes an oxidizable metal, activated carbon, an inorganic electrolyte, water, and a polymer water retention agent. Etc. are used.
Examples of the oxidizable metal powder include iron powder and aluminum powder, but iron powder is usually used, and reduced iron powder, atomized iron powder, electrolytic iron powder, and the like are used. Activated carbon is used as a water retention agent in addition to a reaction aid, and usually coconut shell charcoal, wood dust charcoal, peat charcoal and the like are used. As the inorganic electrolyte, alkali metal, alkaline earth metal, heavy metal chloride, alkali metal sulfate and the like are preferable, for example, sodium chloride, potassium chloride, calcium chloride, magnesium chloride, ferric chloride, sodium sulfate and the like. Is used. The ratios of these normal components are 20-80 wt% for oxidizable metals, 1-20 wt% for activated carbon, 1-20 wt% for inorganic electrolyte, 5-50 wt% for water, and 1-20 wt% for water retention agent. It is.

  Also in the heating element of the third configuration of the present invention, the same heating composition as described above can be used. However, since a plurality of exothermic cells in which the exothermic compositions are separately arranged must be fixed to the surface of the packaging material as shown in FIG. 5, it is preferably fixed to the surface of the packaging material by coating or printing. In order to be able to do, what contains a thickener besides the said structural component is preferable. The proportions of these normal components are: 20 to 80 wt% for oxidizable metal, 1 to 10 wt% for activated carbon, 1 to 10 wt% for inorganic electrolyte, 5 to 50 wt% for water, and 1 to 10 wt% for water retention agent. The thickener is 0.1 to 10 wt%.

  The heating element according to the first configuration of the present invention usually includes two breathable packaging materials in which a laminated sheet including the above-described plastic film is irradiated with a laser beam to form vent holes, or such a breathable package. The material and the non-breathable packaging material are overlapped so that the heat-sealing surfaces are inside each other, and the periphery is heat-fused to form a bag shape and filled with the exothermic composition as shown in FIG. The heating element is as shown. As shown in FIG. 2, the heating element is further formed into a non-air-permeable flat bag so as to shut off from outside air and prevent water from evaporating and diffusing to the outside during the period until it is used. Sealed.

  In the heating element of the second configuration of the present invention, the sheet-like support in which the heating composition is held in the gap is, for example, after spraying the heat-fusible adhesive powder together with the heating composition on the nonwoven fabric. Further, it is obtained by superimposing the same non-woven fabric as above from above and thermocompression bonding with a mold compressor or the like. The heating element according to the second configuration of the present invention usually includes two sheets of breathable packaging material in which a laminated sheet including the plastic film is irradiated with laser light to form a vent, or such a breathable package. The material and the non-breathable packaging material are overlapped so that the heat-sealing surfaces are inside each other, the periphery is heat-fused and formed into a bag shape, and the sheet-like support is accommodated in the figure. The heating element as shown in FIG. As shown in FIG. 4, the heating element is further formed into a non-breathable flat bag so as to block the outside air during the period until it is used and prevent water from evaporating and diffusing to the outside. Sealed.

  The heating element of the third configuration of the present invention is a heat-sealing of a breathable packaging material in which vent holes are formed by irradiating a laser beam to a laminated sheet containing the aforementioned plastic film, or a non-breathable packaging material. On the surface side surface, the above-mentioned exothermic composition is disposed by coating or printing so as to form a plurality of flat exothermic cells, and a breathable packaging material or non-breathable packaging material similar to the above is further disposed thereon. Then, they are superposed with the heat-sealing surface on the inside, and heat-pressed to form a heating element as shown in FIG. However, at least one of the two packaging materials is a breathable packaging material. As shown in FIG. 6, the heating element is further formed into a non-breathable flat bag so as to block the outside air during the period until it is used and prevent water from evaporating and diffusing to the outside. Sealed.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these.

(Production of breathable packaging materials)
The packaging material is continuously drawn out from a roll wound with a commercially available (mixed film of heat-sealable plastic component and polyethylene) / nonwoven fabric, and the vent is formed by irradiating UV laser to form a vent. Made a packaging material. In this breathable packaging material, uniform circular ventilation holes having a diameter of 0.5 mm were formed on the entire surface at intervals of about 6 mm in length and about 6 mm in width. Further, the breathable packaging material was cut into 100 mm × 150 mm. In addition, as a result of measuring the Gurley air permeability of the air-permeable packaging material, it was 23 seconds / 100 ml.

(Production of heating element)
In a nitrogen gas atmosphere, an exothermic composition was prepared by mixing so that iron powder was 50 w%, activated carbon was 10 w%, sodium chloride (inorganic electrolyte) was 3 wt%, water was 25 wt, and water retention agent was 12 wt. The two breathable packaging materials described above are overlapped so that the heat-sealing surfaces are inside each other, and the periphery is heat-fused to form a bag shape and filled with 40 g of a heat generating composition as shown in FIG. Such a heating element was manufactured. Thereafter, the heating element was sealed in a 130 mm × 180 mm non-breathable flat bag.

(Investigation of variation in heat generation characteristics of heating elements)
100 bags of the heating element as described above were produced and left in a room at 25 ° C. for one day. Next, with respect to these 100 bags of heating elements, the heating elements were taken out from the non-breathable flat bags, and the heat generation characteristics when left on a 25 ° C. indoor cushion were measured to investigate variations. As a result, with regard to the maximum temperature, it was confirmed that the maximum value in 100 bags was 68 ° C., the minimum value was 63 ° C., and the difference was 5 ° C.

(Production of heating element)
In the production of the breathable packaging material of Example 1, the breathable packaging material was prepared in the same manner as in Example 1 except that the diameter of the ventilation hole was 0.1 mm and the interval was changed to about 3 mm in length and about 6 mm in width. Produced. In addition, as a result of measuring the Gurley air permeability of the air-permeable packaging material, it was 32 seconds / 100 ml. This breathable packaging material (100 mm x 150 mm) and the non-breathable packaging material (100 mm x 150 mm) before forming the air holes are overlapped so that the heat-sealing surfaces are inside each other, and the periphery is heated and melted. It was put on and formed into a bag shape and filled with 40 g of the same exothermic composition as in Example 1 to produce a heating element. Thereafter, the heating element was sealed in a 130 mm × 180 mm non-breathable flat bag.

(Investigation of variation in heat generation characteristics of heating elements)
100 bags of the heating element as described above were produced and left in a room at 25 ° C. for one day. Next, with respect to these 100 bags of heating elements, the heating elements were taken out from the non-breathable flat bags, and the heat generation characteristics when left on a 25 ° C. indoor cushion were measured to investigate variations. As a result, with regard to the maximum temperature, it was confirmed that the maximum value in 100 bags was 62 ° C., the minimum value was 58 ° C., and the difference was 4 ° C.

[Comparative Example 1]
(Production of heating element)
In the production of the heating element of Example 1, the same procedure as in Example 1 was used except that a commercially available (mixed film of heat-fusible plastic component and polyethylene) / nonwoven fabric was used as the breathable packaging material. A heating element was produced. As with Example 1, this breathable packaging material had circular vent holes formed of needle holes with a diameter of 0.5 mm formed on the entire surface at intervals of about 6 mm in length and about 6 mm in width. However, observation of the surface with a magnifying glass confirmed that the size and shape of the air holes were more uneven than the air-permeable packaging material of Example 1. Thereafter, the heating element was sealed in a 130 mm × 180 mm non-breathable flat bag.

(Investigation of variation in heat generation characteristics of heating elements)
100 bags of the heating element as described above were produced and left in a room at 25 ° C. for one day. Next, with respect to these 100 bags of heating elements, the heating elements were taken out from the non-breathable flat bags, and the heat generation characteristics when left on a 25 ° C. indoor cushion were measured to investigate variations. As a result, regarding the maximum temperature, it was confirmed that the maximum value in 100 bags was 71 ° C., the minimum value was 59 ° C., and the difference was 12 ° C.

[Comparative Example 2]
(Production of heating element)
In the production of the heating element of Example 2, the same procedure as in Example 2 was used, except that a commercially available (mixed film of heat-sealable plastic component and polyethylene) / nonwoven fabric was used as the breathable packaging material. A heating element was produced. As in Example 2, this breathable packaging material had circular vent holes made of needle holes with a diameter of 0.1 mm formed on the entire surface at intervals of about 3 mm in length and about 6 mm in width. However, observation of the surface with a magnifying glass confirmed that the size and shape of the air holes were more uneven than the air permeable packaging material of Example 2. Thereafter, the heating element was sealed in a 130 mm × 180 mm non-breathable flat bag.

(Investigation of variation in heat generation characteristics of heating elements)
100 bags of the heating element as described above were produced and left in a room at 25 ° C. for one day. Next, with respect to these 100 bags of heating elements, the heating elements were taken out from the non-breathable flat bags, and the heat generation characteristics when left on a 25 ° C. indoor cushion were measured to investigate variations. As a result, with regard to the maximum temperature, it was confirmed that the maximum value in 100 bags was 63 ° C., the minimum value was 50 ° C., and the difference was 13 ° C.

(Production of heating element)
A commercially available non-woven fabric was cut into 80 mm × 130 mm, and under a nitrogen gas atmosphere, 22 g of the same exothermic composition as in Example 1 (excluding water) and ethylene / vinyl acetate copolymer resin powder (heat fusion) After spraying a mixture of adhesive adhesive powder), the same non-woven fabric as above is overlaid, heat-pressed with a mold compressor, etc., and then 8 g of water is sprayed from above to remove the exothermic composition from the gap. A sheet-like support retained inside was obtained. The breathable packaging material (100 mm × 150 mm) manufactured in the same manner as in Example 1 and the non-breathable packaging material (100 mm × 150 mm) before forming the air holes are arranged so that the heat-sealing surfaces are inside each other. Then, the periphery was heated and fused to form a bag, and the sheet-like support was housed to produce a heating element as shown in FIG. Thereafter, the heating element was sealed in a 130 mm × 180 mm non-breathable flat bag.

(Investigation of variation in heat generation characteristics of heating elements)
100 bags of the heating element as described above were produced and left in a room at 25 ° C. for one day. Next, with respect to these 100 bags of heating elements, the heating elements were taken out from the non-breathable flat bags, and the heat generation characteristics when left on a 25 ° C. indoor cushion were measured to investigate variations. As a result, regarding the maximum temperature, it was confirmed that the maximum value in 100 bags was 65 ° C., the minimum value was 60 ° C., and the difference was 5 ° C.

[Comparative Example 3]
(Production of heating element)
In the production of the heating element of Example 3, the same procedure as in Example 3 was used, except that a commercially available (mixed film of heat-sealable plastic component and polyethylene) / nonwoven fabric was used as the breathable packaging material. A heating element was produced. As in Example 3, this breathable packaging material had circular vent holes formed of needle holes with a diameter of 0.5 mm formed on the entire surface at intervals of about 6 mm in length and about 6 mm in width. However, observation of the surface with a magnifying glass confirmed that the size and shape of the air holes were more uneven than the air permeable packaging material of Example 3. Thereafter, the heating element was sealed in a 130 mm × 180 mm non-breathable flat bag.

(Investigation of variation in heat generation characteristics of heating elements)
100 bags of the heating element as described above were produced and left in a room at 25 ° C. for one day. Next, with respect to these 100 bags of heating elements, the heating elements were taken out from the non-breathable flat bags, and the heat generation characteristics when left on a 25 ° C. indoor cushion were measured to investigate variations. As a result, regarding the maximum temperature, it was confirmed that the maximum value in 100 bags was 65 ° C., the minimum value was 54 ° C., and the difference was 11 ° C.

(Production of breathable packaging materials)
Superimposing a commercially available mixed film of heat-fusible plastic component and rubber component and a commercially available non-woven fabric (polyester spunlace), sandwiching both sides with two molds having a repetitive corrugated shape, and heat-sealing As a result, a stretchable bonded packaging material having a heat-sealing surface having a wave-like repeated shape as shown in FIG. 7 was obtained. (It has elasticity in the direction of the arrow in FIG. 7) This bonded packaging material was irradiated with a carbon dioxide gas laser to form a vent hole to produce a breathable packaging material. In this breathable packaging material, uniform circular ventilation holes having a diameter of 0.07 mm were formed on the entire surface at intervals of about 3 mm in length and about 3 mm in width. Further, the breathable packaging material was cut into 100 mm × 150 mm. In addition, as a result of measuring the Gurley air permeability of the air-permeable packaging material, it was 23 seconds / 100 ml.

(Production of heating element)
Under nitrogen gas atmosphere, iron powder 63.1 wt%, activated carbon 3.2 wt%, salt (inorganic electrolyte) 1.9 wt%, water 26.5 wt%, water retention agent 0.6 wt%, thickener 30 g of the coating liquid mixed so as to be 4.7 wt% is applied to the heat-sealing surface side surface of the breathable packaging material in six places, thereby fixing the heat generating cell, and further heat on it. A breathable packaging material similar to that described above was laminated so that the fused surface was on the inside, and heat-pressed to produce a heating element as shown in FIG. Thereafter, the heating element was sealed in a 130 mm × 180 mm non-breathable flat bag.

(Investigation of variation in heat generation characteristics of heating elements)
100 bags of the heating element as described above were produced and left in a room at 25 ° C. for one day. Next, with respect to these 100 bags of heating elements, the heating elements were taken out from the non-breathable flat bags, and the heat generation characteristics when left on a 25 ° C. indoor cushion were measured to investigate variations. As a result, with respect to the maximum temperature, it was confirmed that the maximum value in 100 bags was 53 ° C., the minimum value was 48 ° C., and the difference was 5 ° C.

[Comparative Example 4]
(Production of heating element)
In the production of the heating element of Example 4, a heating element was produced in the same manner as in Example 4 except that a ventilation hole by a needle hole was formed instead of the ventilation hole by irradiation of the carbon dioxide laser. As with Example 4, this breathable packaging material had circular vent holes with a diameter of 0.07 mm formed on the entire surface at intervals of about 3 mm in length and about 3 mm in width. However, observation of the surface with a magnifying glass confirmed that the size and shape of the air holes were more uneven than the air permeable packaging material of Example 4. Thereafter, the heating element was sealed in a 130 mm × 180 mm non-breathable flat bag.

(Investigation of variation in heat generation characteristics of heating elements)
100 bags of the heating element as described above were produced and left in a room at 25 ° C. for one day. Next, with respect to these 100 bags of heating elements, the heating elements were taken out from the non-breathable flat bags, and the heat generation characteristics when left on a 25 ° C. indoor cushion were measured to investigate variations. As a result, with regard to the maximum temperature, it was confirmed that the maximum value in 100 bags was 55 ° C., the minimum value was 42 ° C., and the difference was 13 ° C.

  As described above, it has been clarified that the heating elements of the examples of the present invention have extremely small variations in the heat generation characteristics as compared with the heat generation elements of the comparative examples, and can easily and accurately control the heat generation characteristics.

Sectional drawing which shows the example of the heat generating body of this invention (1st structure) 1 is a perspective view (partially cutaway perspective view) showing an example of a state in which the heating element of FIG. 1 is sealed in a non-breathable flat bag. Sectional drawing which shows the example of the heat generating body of this invention (2nd structure) FIG. 3 is a perspective view (partially cutaway perspective view) showing an example of a state where the heating element of FIG. 3 is sealed in a non-breathable flat bag. Sectional drawing which shows the example of the heat generating body of this invention (3rd structure) FIG. 5 is a perspective view (partially cutaway perspective view) showing an example of a state where the heating element of FIG. 5 is sealed in a non-breathable flat bag. The perspective view which shows an example of the packaging material used for the heat generating body of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exothermic composition 2 Breathable packaging material 3 Non-breathable packaging material 4 Sheet-like support body which hold | maintained exothermic composition in space | gap 5 Support body which sandwiched exothermic cell with two sheets 6 Bonding of flat bag Part 7 Heat-sealing surface consisting of repeated wave shape 8 Nonwoven fabric

Claims (12)

  An exothermic composition that generates heat when in contact with oxygen in the air uses a breathable packaging material that is formed on one or both sides with a breathable packaging material that irradiates a laminated sheet containing a plastic film with laser light. The diameter or equivalent circle diameter of the vent hole is 0.005 to 2.0 mm, the distance from the center of two adjacent vent holes is 0.1 to 20 mm, the vent hole area. The ratio of the total area of the laminated sheet is 0.001 to 5%.   A breathable packaging material in which a sheet-like support holding a heat generating composition that generates heat in contact with oxygen in the air is formed in a gap, and a laminated sheet including a plastic film is irradiated with laser light to form a vent. , Housed in a flat air-permeable bag used on one or both sides, the diameter of the vent or equivalent circle diameter is 0.005 to 2.0 mm, the distance from the center of two adjacent vents to the center Is 0.1 to 20 mm, and the ratio of the area of the vent hole to the total area of the bonded sheet is 0.001 to 5%.   A plurality of exothermic cells made of a heat-generating composition that generates heat when in contact with oxygen in the air is formed on one or both sides with a breathable packaging material in which vent holes are formed by irradiating a laminated sheet containing a plastic film with laser light. It is housed in a gap between the two sheets of the used support, and the diameter of the vent or the equivalent circle diameter is 0.005 to 2.0 mm, and the distance from the center of the two adjacent vents to the center is A heating element, characterized in that a ratio of 0.1 to 20 mm and the area of the vent hole in the total area of the laminated sheet is 0.001 to 5%.   The heating element according to claim 1 or 2, wherein the flat air-permeable bag is further sealed with a non-air-permeable flat bag.   The heating element according to claim 3, wherein the support composed of two sheets is further sealed in a non-breathable flat bag.   The laminated sheet containing the plastic film is either (1) heat-fusible component layer / plastic film / heat-fusible component layer / nonwoven fabric, or (2) (mixed film of heat-fusible component and plastic component) / The heating element according to claim 1 or 2, comprising a nonwoven fabric.   A laminated sheet containing a plastic film is (1) a heat-fusible plastic component layer / (one or more films selected from a plastic film, a rubber film, a plastic component and a mixed film of rubber components) / a heat-fusible plastic. Component layer / nonwoven fabric, (2) (mixed film of heat fusible plastic component and plastic component) / nonwoven fabric, (3) (mixed film of heat fusible plastic component and rubber component) / nonwoven fabric, or (4) The heating element according to claim 3, comprising: (mixed film of heat-fusible plastic component, plastic component, and rubber component) / nonwoven fabric.   The heating element according to claim 1 or 2, wherein the exothermic composition contains an oxidizable metal, activated carbon, an inorganic electrolyte, water, and a polymer water retention agent.   The heating element according to claim 3, wherein the exothermic composition contains an oxidizable metal, activated carbon, an inorganic electrolyte, water, a thickener, and a polymer water retention agent.   Two laminated sheets containing plastic film are laminated so that the heat-sealing surfaces are inside each other, and the peripheral part is heat-fused to form a flat bag and contact with oxygen in the air And a heating element in which the exothermic composition that generates heat is stored in the flat bag, wherein at least one of the two laminated sheets has a wavelength of 0.1 to 1000 μm and an output of 1 A method for producing a heating element, which is a breathable packaging material in which vent holes are formed by irradiating a laser beam of ˜1000 w.   Two laminated sheets containing plastic film are overlapped so that the heat-sealing surfaces are inside each other, and the peripheral part is heat-fused to form a flat bag and contact with oxygen in the air A method for producing a heating element in which a sheet-like support holding an exothermic composition that generates heat in a gap is housed in the flat bag, wherein at least one of two laminated sheets is bonded. The sheet is a breathable packaging material in which a vent is formed by irradiating a laser beam having a wavelength of 0.1 to 1000 μm and an output of 1 to 1000 w.   A plurality of exothermic cells made of a heat generating composition that generates heat upon contact with oxygen in the air are arranged so that the heat-sealing surfaces of the sheets are inside each other in the gap between two bonded sheets including a plastic film. A method of manufacturing a heating element that is integrally formed by superposition and heat fusion, wherein at least one of the two laminated sheets has a wavelength of 0.1 to 1000 μm and an output of 1 to 1000 w. A method for manufacturing a heating element, wherein the heating element is a breathable packaging material in which a ventilation hole is formed by irradiating a laser beam.

Images