JP5627451B2 - Exothermic composition and heating tool using the same - Google Patents

Description

  The present invention relates to a heating composition and a heating tool using the same.

  As an exothermic composition and a heating tool using the same, for example, there is one described in Patent Document 1.

  In Patent Document 1, an exothermic substance, a water-absorbing polymer and / or a thickener, a carbon component and / or a metal chloride, and water are essential components, and are formed into an ink or cream as a whole. And a heating element in which the ink-like or cream-like exothermic composition and the present ink-like or cream-like exothermic composition are laminated and enclosed in a sheet-like packaging material are described.

JP-A-9-75388

  In a heating element in which a heating composition as described above is laminated and encapsulated in a packaging material, it is important that an appropriate amount of heating composition is uniformly laminated in order to obtain stable heating.

  However, if the viscosity of the exothermic composition becomes too high, the fluidity is insufficient, so that the exothermic composition to be laminated becomes difficult to measure or cannot be stably applied. It may be difficult for objects to be uniformly laminated.

  In this case, there is a method of increasing the water content of the exothermic composition and lowering the viscosity, but although the coating performance is improved, problems such as water separation occur in the exothermic composition, and it can be stably dispersed. Or the heat generation characteristics may deteriorate due to an increase in heat capacity. In this case, in order to obtain a desired exothermic characteristic, there is a method of responding by increasing the number of steps of removing excessive moisture after application of the exothermic composition, but the number of steps may be increased and the process may be complicated. There was room for improvement.

  In view of the above circumstances, the present inventors have conducted extensive studies on the preparation technology of a heat-generating composition having a stable dispersion and heat-generating characteristics while improving the coating performance, and as a result, identified the heat-generating composition. It has been found that the above-mentioned problems can be solved by containing an acid or a salt thereof.

According to the present invention, an exothermic composition containing the following components (A) to (E) is provided.
(A) an oxidizable metal,
(B) carbon component,
(C) thickener,
(D) water,
(E) One or more selected from oxymonocarboxylic acid, polyoxyethylene alkyl ether phosphoric acid, and salts thereof

  Moreover, according to this invention, the heating tool which has a heat generating body formed by laminating | stacking said heat-generating composition on a sheet-like base material is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the exothermic composition with the stable dispersion | distribution of a heat-generating composition and favorable heat-generating characteristic is provided, improving a coating performance.

It is sectional drawing which showed an example of the heat generating tool typically. It is a schematic diagram explaining the heat generating body with which the heat generating tool shown in FIG. 1 is provided. It is a figure explaining an example of the manufacturing method of a heating tool.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

<Heat generation composition>
The present invention includes (A) an oxidizable metal, (B) a carbon component, (C) a thickener, (D) water, (E) an oxymonocarboxylic acid, polyoxyethylene alkyl ether phosphoric acid, And one or more selected from the salts thereof.

  The oxidizable metal of the component (A) is a metal that generates heat of oxidation reaction, for example, iron, aluminum, zinc, manganese, magnesium, calcium, powder or fiber such as a mixed metal in which two or more of these are mixed Is mentioned. Among these, iron powder is preferable from the viewpoints of handleability, safety, manufacturing cost, storage stability, and stability.

  When the oxidizable metal is a powder, the average particle size is preferably 10 to 200 μm, more preferably 20 to 150 μm, from the viewpoint that the oxidation reaction is efficiently performed. The particle size of the oxidizable metal refers to the maximum length in the form of powder, and is measured by classification using a sieve, dynamic light scattering method, laser diffraction method or the like.

  The content of the (A) oxidizable metal in the exothermic composition of the present invention is preferably 15 to 70% by mass, and more preferably 35 to 60% by mass. Thereby, the heat_generation | fever temperature of the heat generating body obtained from the heat-generating composition of this invention can be raised to desired temperature. Here, the content of the iron powder in the exothermic composition can be obtained by an ash content test according to JIS P8128 or a thermogravimetric instrument. In addition, it can be quantified by a vibration sample type magnetization measurement test or the like using the property that magnetization occurs when an external magnetic field is applied.

  The carbon component of the component (B) has water retention ability, oxygen supply ability, and catalytic ability. For example, activated carbon (coconut shell charcoal, charcoal powder, calendar bituminous coal, peat, lignite), carbon black, acetylene Black, graphite or the like can be used. The carbon component is preferably one having an average particle diameter of 3 to 200 μm, more preferably an average particle diameter of 5 to 100 μm, from the viewpoint that an effective contact state with an oxidizable metal can be formed. . The average particle size of the carbon component refers to the maximum length in the form of powder and is measured by a dynamic light scattering method, a laser diffraction method, or the like. The carbon component is preferably used in a powder form, but a form other than the powder form can also be used, for example, a fibrous form can be used.

  As for content of the carbon component of the component (B) in the exothermic composition of this invention, 6-15 mass parts is preferable with respect to 100 mass parts of oxidizable metals of a component (A), and 8-13 mass parts is. More preferred. By doing so, water necessary for sustaining the oxidation reaction can be accumulated in the heating element obtained from the heating composition of the present invention. In addition, since the air permeability of the heating element is sufficiently ensured, a heating element with sufficient oxygen supply and high heating efficiency can be obtained. In addition, since the heat capacity of the heating element with respect to the amount of heat generated can be kept small, the heat generation temperature rises and a desired temperature rise is obtained.

  As the thickener of component (C), a substance that absorbs moisture and increases consistency or imparts thixotropic properties can be used. Alginate such as sodium alginate, gum arabic, gum tragacanth, locust bean gum Polysaccharide thickeners such as guar gum, gum arabic, carrageenan, agar and xanthan gum; starch thickeners such as dextrin, pregelatinized starch and starch for processing; carboxymethylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxymethylcellulose or hydroxy One or a mixture of two or more selected from cellulose derivative thickeners such as propylcellulose; metal soap thickeners such as stearate; mineral thickeners such as bentonite can be used.

  Of these, polysaccharide thickeners are preferable, and xanthan gum is particularly preferable from the viewpoint of salt resistance.

  The content of the thickener of component (C) in the exothermic composition of the present invention is 0.1 to 5 parts by mass, particularly 0.2 to 0.1 parts by mass with respect to 100 parts by mass of the oxidizable metal of component (A). It is preferably 4 parts by mass. By setting it as this range, solid content, such as an oxidizable metal of a component (A) and a carbon component of a component (B), can be disperse | distributed stably. Moreover, thixotropy can be imparted and the coating performance can be further improved.

  The water of the component (D) is only required to disperse at least the oxidizable metal of the component (A) and the carbon component of the component (B), and specifically, the oxidizable property of the component (A). 50-90 mass parts is preferable with respect to 100 mass parts of metals, and 60-80 mass parts is more preferable in order to make exothermic composition into a slurry form and to improve coating property. The water of component (D) functions as a heat source when used in combination with the oxidizable metal of component (A). Moreover, it becomes water vapor | steam by the temperature rise accompanying heat_generation | fever.

  The component (E) oxymonocarboxylic acid is a monocarboxylic acid having a hydroxy group, and specifically, glyceric acid, lactic acid, hydroxybutyric acid, gluconic acid, etc. Glyceric acid, gluconic acid, hydroxybutyric acid and the like, which are oxymonocarboxylic acids having a molecular weight of 100 or more and 300 or less, are preferable from the viewpoint of improving the work performance and not inhibiting the heat generation characteristics. In view of the effect of preventing the problem that hydrogen is generated by reacting with the component (A) while obtaining a stable dispersion effect of the exothermic composition while obtaining a better viscosity reduction effect, Hydroxy monocarboxylic acid salts are preferred. Examples of the counter ion for constituting the salt include alkali metals such as sodium and potassium; alkaline earth metals such as magnesium and calcium. Here, sodium, potassium, magnesium and calcium are preferable from the viewpoint of versatility, and sodium is particularly preferable.

  As the component (E) polyoxyethylene alkyl ether phosphoric acid, the ethylene oxide mass average addition mole number (EO addition mole number) from the point that good viscosity reduction effect is obtained and the heat generation characteristics are not hindered while improving the coating performance. ) Is preferably 0.5 to 15, more preferably 1 to 5.

  The polyoxyethylene alkyl ether phosphoric acid of component (E) preferably has 10 to 22 carbon atoms in the alkyl chain from the viewpoint that a good viscosity reducing effect is obtained and the heat generation characteristics are not impaired while improving the coating performance. ~ 15 is more preferred. In addition, the salt of polyoxyethylene alkyl ether phosphoric acid is preferable from the viewpoint of obtaining a stable dispersion effect of the exothermic composition while obtaining a better viscosity reduction effect. Examples of the counter ion for constituting the salt include alkali metals such as sodium and potassium; alkaline earth metals such as magnesium and calcium; other lithium and amine. Here, sodium, potassium, magnesium and calcium are preferable from the viewpoint of versatility, and sodium is particularly preferable.

  Examples of the component (E) polyoxyethylene alkyl ether phosphoric acid include NIKKOL DDP-2 (di-POE (2) (C12-15) alkyl ether phosphoric acid) and DDP-4 (di-POE (4) (C12). -15) alkyl ether phosphate), DDP-6 (di-POE (6) (C12-15) alkyl ether phosphate), DDP-8 (di-POE (8) (C12-15) alkyl ether phosphate), the same DDP-10 (di-POE (10) (C12-15) alkyl ether phosphate), TDP-2 (tri-POE (2) (C12-15) alkyl ether phosphate), TDP-6 (tri-POE (6 ) (C12-15) alkyl ether phosphoric acid), TDP-8 (tri-POE (8) (C12-15) alkyl ether phosphoric acid), TDP-10 (tri-P) OE (10) (C12-15) alkyl ether phosphoric acid (made by Nikko Chemicals Co., Ltd.) or the like may be used after neutralization with sodium hydroxide, potassium hydroxide or the like, or electro stripper F ( Polyoxyethylene alkyl ether potassium phosphate (manufactured by Kao Corporation) may also be used.

  The content of the component (E) in the exothermic composition of the present invention is preferably 0.1 parts by mass or more and more preferably 2 parts by mass or more with respect to 100 parts by mass of the component (A). By doing so, a good viscosity reducing effect is obtained for the exothermic composition, and the coating performance is improved and the exothermic characteristics are not hindered. Moreover, it is preferable to set it as 8 mass parts or less with respect to 100 mass parts of components (A), and, as for content of a component (E), it is more preferable to set it as 7 mass parts or less. Thereby, good heat generation characteristics can be obtained. In addition, the “heat generation characteristic” in the present specification is measured according to JIS S4100. That is, the ventilation surface (surface with low air permeability in the case of double-sided ventilation) is faced up, the surface is covered with a mesh material (polyester, double raschel fabric having a thickness of 8 mm), and temperature measurement is performed using a thermistor. It can be evaluated by comparing the maximum temperature, and if the maximum temperature is in the range of 40 to 70 ° C., it can be said that the heat generation characteristics are good as a heating tool.

  The exothermic composition of the present invention may further contain a component (F) reaction accelerator.

  The component (F) reaction accelerator is used for the purpose of maintaining the oxidation reaction of the component (A) oxidizable metal in the heating element obtained from the exothermic composition of the present invention. Moreover, by using a component (F) reaction accelerator, the oxide film of a component (A) can be destroyed and an oxidation reaction can be accelerated | stimulated. As the component (F) reaction accelerator, those conventionally used for this type of heating element can be used without particular limitation, and examples thereof include alkali metal, alkaline earth metal sulfate, chloride and the like. . Among them, it is preferable to use various chlorides such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, first ferric chloride, second ferric chloride from the viewpoint of excellent conductivity, chemical stability, and production cost. Sodium is particularly preferred. The content of the component (F) reaction accelerator in the exothermic composition of the present invention is 2 to 12 masses per 100 mass parts of the oxidizable metal of the component (A) from the viewpoint that a sufficient calorific value lasts for a long time. Part.

  The exothermic composition of the present invention may be prepared by mixing all the above-mentioned components at once. However, after mixing the component (A) oxidizable metal and the component (E) in advance, the other components are mixed. May be mixed. In addition, when adding the reaction accelerator of a component (F) to a heat generating body, you may mix simultaneously with the other component in a heat generating composition, but it dissolved in water etc. separately in the heat generating composition after coating. The component (F) may be added by infiltration, spraying or dropping.

  The viscosity of the exothermic composition of the present invention is preferably 5,000 mPa · s or more at 20 ° C., more preferably 7,000 mPa · s or more. This makes it difficult for the solids such as the components (A) and (B) to settle and can be uniformly dispersed in the slurry. The upper limit of the viscosity is preferably 25,000 mPa · s or less, more preferably 20,000 mPa · s or less, and further preferably 19,000 mPa · s or less. Thereby, an exothermic composition can be uniformly apply | coated to a sheet-like base material. In the present invention, the viscosity is a product measured by TOKI SANGYO (VISCOMETER BH type viscometer), using a # 4 rotor, rotating at 6 rpm, using a 100 ml tall beaker, at a measurement temperature of 20 ° C. and after 1 minute. is there.

<Heat tool>
Next, a heating tool including a heating element obtained by applying the above-described heating composition to a sheet-like substrate will be described. FIG. 1 is a schematic cross-sectional view showing an example of a heating tool. As shown in the figure, this heating tool includes a heating element 10 formed by laminating a heating composition on a sheet-like substrate, a ventilation bag 103, and a bag body 104.

  More specifically, in this heating tool, the heating element 10 composed of the heating layer 101 and the absorption layer 102 is put in a ventilation bag 103 having air permeability, and the periphery of the ventilation bag 103 is sealed with a heat seal. A structure surrounded by the bag body 104 is taken. The heating element 10 is a member that generates heat, and the bag body 104 is a member that surrounds the entire heating element and forms the outer surface of the heating tool.

  First, the heating element 10 will be described. FIG. 2 is an enlarged view of the heating element 10 shown in FIG. When the above-described exothermic composition is applied to the sheet-like substrate, the water-soluble component of the exothermic composition is absorbed into the sheet-like substrate to form the absorption layer 102. The heat generating layer 101 is mainly composed of the component (A), the component (B), and the remaining water-soluble component that is not absorbed by the sheet.

  The sheet-like base material may be composed of a fiber sheet including the fiber material 102b, for example. The sheet-like substrate may be composed of a single fiber sheet, or two or more layers may be laminated. The sheet-like substrate may further contain particles 102a of the superabsorbent polymer. FIG. 2 shows an example in which a fiber sheet containing particles 102a of a superabsorbent polymer and a fiber material 102b is used as a sheet-like substrate. When the base sheet contains the superabsorbent polymer particles 102a, the form of the base sheet is (i) a single sheet in which the superabsorbent polymer particles 102a and the fiber material 102b are uniformly mixed. A structure in which the fiber sheet, (ii) the superabsorbent polymer particle 102a is mainly present in a substantially central region in the thickness direction of the base sheet, and the particle 102a is not substantially present on the surface of the base sheet. (Iii) A laminate of two fiber sheets in which superabsorbent polymer particles 102a are arranged between the same or different fiber sheets containing the fiber material 102b. . Especially, it is preferable to use the thing of the form of (ii) or (iii) from a viewpoint that the control of the moisture content of the heat-generating layer 101 can be performed easily.

  As the fiber material 102b, any of hydrophilic fibers and hydrophobic fibers can be used, but hydrophilic fibers are preferably used, and cellulose fibers are more preferably used. As the cellulose fiber, chemical fiber (synthetic fiber) and natural fiber can be used.

  For example, rayon and acetate can be used as the hydrophilic chemical fiber. On the other hand, as natural fibers, various plant fibers, wood pulp, non-wood pulp, cotton, hemp, wheat straw, hemp, jute, kapok, palm, rush and the like can be used. Of these cellulose fibers, wood pulp is preferably used.

  It is preferable that the various hydrophilic fibers have a fiber length of 0.5 to 6 mm, particularly 0.8 to 4 mm.

  In addition to the hydrophilic fiber, the sheet-like base material may be blended with a hydrophobic fiber, particularly a heat-fusible fiber, if necessary. The blending amount of the heat-fusible fiber is preferably 0.1 to 10% by mass, particularly 0.5 to 5% by mass, based on the total amount of fibers in the sheet-like substrate.

  As the superabsorbent polymer particles 102a, it is preferable to use a hydrogel material capable of absorbing and holding a liquid having a weight 20 times or more of its own weight and capable of gelling. Examples of the shape of the superabsorbent polymer particle 102a include a spherical shape, a lump shape, a grape tuft shape, and a fiber shape. The particle diameter of the superabsorbent polymer particles 102a is preferably 1 to 1000 μm, more preferably 10 to 500 μm. The particle diameter of the superabsorbent polymer particles is measured by a dynamic light scattering method, a laser diffraction method, or the like.

  Specific examples of superabsorbent polymers include starch, crosslinked carboxylmethylated cellulose, polymers or copolymers of acrylic acid or alkali metal acrylates, polyacrylic acid and salts thereof, and polyacrylate graft polymers. Is mentioned.

  The proportion of the superabsorbent polymer particles 102a in the sheet-like substrate is preferably 10 to 70% by mass, more preferably 20 to 55% by mass.

The sheet-like base material preferably has a basis weight of 10 to 200 g / m ² , particularly 35 to 150 g / m ² . The basis weight of the superabsorbent polymer particles 102a contained in the sheet-like substrate is preferably 5 to 150 g / m ² , particularly preferably 10 to 100 g / m ² .

  The exothermic layer 101 is formed on the coated surface side by applying the exothermic composition to at least one surface of the sheet-like substrate. The heat generating layer 101 may be provided on one side of the absorption layer 102 or may be provided on both sides. 1-3 show an example in which the heat generating layer 101 is provided on one side. The heat generating layer 101 may be present on the absorbing layer 102 as shown in FIG. 1, or the lower portion of the heat generating layer 101 may be at least partially embedded in the absorbing layer 102 as shown in FIG. That is, even if a part of the solids such as the components (A) and (B) constituting the heat generating layer 101 is supported in a three-dimensional network formed by the fiber material 102b and the superabsorbent polymer particles 102a. Good.

The amount of oxidizable metal component (A) in the heat generating member 10, expressed in the basis weight, the heat generation layer 101 per layer, 100 to 3000 g / ^{m 2,} it is preferred that particularly 200~1500g / ^{m 2.} The amount of the carbon component of the component (B) in the heating element 10 is preferably ⁴ to 80 g / m ² , particularly 8 to 60 g / m ² per layer of the heating layer 101.

  The moisture content before heat generation per heating layer 101 is preferably 5 to 50% by mass, particularly preferably 6 to 40% by mass, and more preferably 10 to 30% by mass. The moisture content of the heat generating layer 101 is determined by taking out the heat generating layer 101 at a portion located above the surface of the absorbing layer 102 (excluding a portion buried in the absorbing layer 102) in a nitrogen environment and measuring its mass. After that, it is obtained by putting in a vacuum oven at 105 ° C. for 2 hours to remove moisture, measuring the mass again, and calculating the water content using the difference mass as the moisture content.

  As described above, since the absorbing layer 102 is also hydrated, the moisture content of the heating element 10 as a whole before heating is preferably 10% by mass or more, and more preferably 20% by mass or more. Thereby, sufficient heat generation characteristics can be obtained. The upper limit of the moisture content in the heating element 10 is preferably 60% by mass or less, particularly preferably 50% by mass or less. By doing so, it is possible to prevent dew condensation from occurring inside the packaging bag 105 (not shown) in the storage environment. When dew condensation occurs, movement of moisture in the exothermic composition occurs, and the exothermic characteristics are adversely affected by changes in the amount of moisture, which is not preferable. The moisture content of the heating element 10 is determined by measuring the mass before heating of the heating element 10 in a nitrogen environment, removing the moisture by placing it in a drying oven at a temperature of 105 ° C. in a vacuum state for 2 hours, It is obtained by measuring and calculating the water content using the difference mass as the water content.

  The ventilation bag 103 is preferably composed of a first cover sheet 103a and a second cover sheet 103b. The first cover sheet 103 a is disposed on the heat generating layer 101 side of the heat generating element 10. The second covering sheet 103b is disposed on the side of the heating element 10 where the heating layer 101 is not formed.

  It is preferable that the first cover sheet 103a and the second cover sheet 103b each have an extended area extending outward from the peripheral edge of the heating element 10 and are joined in each extended area. This joining is preferably a continuous hermetic joining at the periphery. The ventilation bag 103 formed by joining the first cover sheet 103a and the second cover sheet 103b has a space for housing the heating element 10 therein. The heating element 10 is accommodated in this space. The heating element 10 may be fixed to the ventilation bag 103 or may be in an unfixed state.

  Part or all of the first cover sheet 103a has air permeability. The air permeability (JIS P8117) of the first cover sheet is preferably 100 to 50,000 seconds / 100 ml, more preferably 1,000 to 10,000 seconds / 100 ml, and 2,000 to 5,000 seconds / 100 ml. Particularly preferred. As the first covering sheet 103a having such air permeability, for example, a porous sheet made of a synthetic resin having moisture permeability but not water permeability is preferably used. Specifically, a stretched film containing calcium carbonate or the like in polyethylene can be used. When using such a porous sheet, various fiber sheets such as needle punched nonwoven fabric, air-through nonwoven fabric, and spunbonded nonwoven fabric are laminated on the surface of the porous sheet on the outer surface side of the heating tool. The texture of one cover sheet 103a may be enhanced.

  The second cover sheet 103b may be a breathable sheet having a breathability or a non-breathable sheet having no breathability, but has a lower breathability than the first cover sheet 103a. A sheet is preferred.

  When the second covering sheet 103b is made of a non-breathable sheet, various kinds including a nonwoven fabric such as a needle nonwoven fabric or an air-through nonwoven fabric on the surface of a single layer or multilayer synthetic resin film or a film on the outer surface side of the heating tool. A composite sheet obtained by laminating these fiber sheets can be used. For example, a two-layer film composed of a polyethylene film and a polyethylene terephthalate film, a laminate film composed of a polyethylene film and a nonwoven fabric, a laminate film composed of a polyethylene film and a pulp sheet, etc. are used. preferable.

  When the second covering sheet 103b is a breathable sheet, the same thing as the first covering sheet 103a can be used. In this case, the air permeability of the second cover sheet 103b is preferably 6,000 to 150,000 seconds / 100 ml, provided that the air permeability of the first cover sheet 103a is lower than that of the first cover sheet 103a, and is 8,000 to 100, 000 seconds / 100 ml is more preferable. It is particularly preferable that the air permeability of the first cover sheet 103a is 6000 to 13,000 seconds / 100 ml, and the air permeability of the second cover sheet 103b is 8,000 to 20,000 seconds / 100 ml. When the heat generating layer 101 is formed on both surfaces of the water absorbing layer 102, the second cover sheet 103b is also preferably a breathable sheet. In this case, the second cover sheet 103b has a breathability of the first cover sheet 103b. The air permeability of the first covering sheet 103a may be the same as or higher than the air permeability of the first covering sheet 103a.

  The heating element 10 accommodated in the air bag 103 may be one sheet, or may be housed in a multilayer state in which a plurality of sheets are laminated.

  The bag body 104 is preferably composed of a first exterior sheet 104a and a second exterior sheet 104b. The first exterior sheet 104 a is disposed on the heat generating layer 101 side of the heat generating element 10. The second exterior sheet 104b is disposed on the side of the heating element 10 where the heating layer 101 is not formed.

  Similarly to the air bag 103, the bag body 104 also has an extension area extending outward from the periphery of the heating element 10, and the first exterior sheet 104 a and the second exterior sheet 104 b. It is preferable that it is formed by being joined in the exit area. Inside the bag body 104, a space for accommodating the heating element 10 surrounded by the ventilation bag 103 is formed, and the heating element 10 is accommodated in this space. The ventilation bag 103 may be fixed to the bag body 104 or may be unfixed.

  The first and second exterior sheets 104a and 104b are not limited as long as they are various fiber sheets including a nonwoven fabric. For example, a needle punched nonwoven fabric, an air-through nonwoven fabric, a spunbonded nonwoven fabric, or the like can be used.

In the heating tool having the heat generating composition of the present invention, since at least the first covering sheet 103a is made of a breathable sheet and the bag body 104 is a fiber sheet, water vapor from the side on which the first covering sheet 103a is disposed. Can be generated. The amount of water vapor that is released through the first cover sheet 103a and the bag 104, 0.01~0.8mg / (cm ² · min), especially in 0.03~0.4mg / (cm ² · min) Preferably there is. In the case where the second cover sheet 103b is also made of a breathable sheet, water vapor can be generated from the second exterior sheet 104b. Note that the amount of water vapor released through the first covering sheet 103a and the bag body 104 is an upper plate that can be measured up to a unit of 1 mg when the heating tool is brought into contact with air at 20 ° C. and 65% RH to start heat generation. Immediately place the heating tool on the balance, measure the mass for 15 minutes, set the mass at the start of measurement to W _t0 (g), set the mass after 15 minutes to W _t15 (g), and set the steam generation area of the heating tool to S (Cm ² ), the amount of steam generated is calculated from the following formula.
Water vapor release [mg / (cm ² · min)] = {(W _t0 −W _t15 ) × 1000} / 15S

  The bag body 104 may have an adhesive layer formed by applying an adhesive on its outer surface. The pressure-sensitive adhesive layer is used for attaching the heating tool to human skin, clothing, or the like. As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, the same materials as used so far in the technical field including hot melt pressure-sensitive adhesive can be used. From the viewpoint of not impairing the air permeability, it is preferable to provide an adhesive layer on the peripheral portion of the first exterior sheet 104a.

  It continues and demonstrates an example of the manufacturing method of the heating tool mentioned above. FIG. 3 is a diagram for explaining this manufacturing method. First, the exothermic composition 302 according to the present invention is prepared in the coating tank 301. The exothermic composition 302 is stirred by a stirrer 303 to more uniformly disperse components (D) insoluble in water such as component (A) oxidizable metal and component (B) carbon component. Also good.

Next, the heat generating composition 302 is pumped up to the die head 305 by the pump 304. The heated exothermic composition 302 is applied to the sheet-like substrate 306 using the die head 305 while pressing and extruding. At this time, the coating basis weight of the heat generating composition 302 is preferably 150 to 4,600 g / m ² , particularly preferably 300 to 2,200 g / m ² .

  In addition, in FIG. 3, although the coating by die coating was illustrated, the coating method is not limited to this, For example, roll coating, screen printing, roll gravure, knife coding, a curtain coater, etc. are used. You can also.

Moreover, the exothermic composition 302 which does not contain a component (F) may be prepared for the coating tank 301. FIG. In this case, the aqueous solution of (I) component (F) is added to the sheet-like base material 306, and then the exothermic composition 302 not containing the component (F) is applied to the surface to which the component (F) is added. And a method of adding an aqueous solution of the component (F) to the coated surface of the exothermic composition 302 after coating the exothermic composition 302 that does not contain the component (F). In this method, as the method for adding the aqueous solution of component (F), picking or spraying with a nozzle, coating with a brush, die coating, or the like is used, but picking or spraying with a nozzle is preferable. In this case, it is preferable that the component (F) is contained in an aqueous solution of the component (F) to be added in an amount of 3 to 35% by mass, particularly 5 to 30% by mass. The added basis weight of the aqueous solution of the component (F) is preferably 30 to 400 g / m ² , particularly 50 to 300 g / m ² . The component (F) to be added is preferably 2.4 to 12 parts by mass with respect to 100 parts by mass of the oxidizable metal of the component (A).

  After applying the exothermic composition 302 (after applying (II) above, after adding the aqueous solution of the component (F)), suction is performed from the surface of the heating element 10 where the exothermic layer 101 is not formed. Also good. By doing so, the integrity of the absorbing layer 102 and the heat generating layer 101 can be increased. At this time, the suction force in the case of suction is preferably 100 to 10,000 Pa, particularly 500 to 5,000 Pa. The suction force can be measured by attaching a manostar cage to a box in the suction conveyor.

  By the above operation, a continuous long object including the absorbing layer 102 and the heat generating layer 101 is obtained, and the heat generating element 10 is formed by cutting this into an arbitrary size. Thereafter, the first covering sheet 103a made of a continuous long material is disposed on the side on which the heat generating layer 101 is formed while the heating element 10 of each leaf runs in one direction at a predetermined interval, and the other On the side, the second covering sheet 103b made of a continuous long material is disposed. Subsequently, the extension area | region from the heat generating body 10 in the 1st coating sheet 103a and the 2nd coating sheet 103b is joined by a predetermined joining means. The joining is performed outside the left and right side edges and outside the front and rear edges of the heating element 10. Examples of the bonding means include heat fusion, ultrasonic bonding, and adhesion using an adhesive. The obtained continuous long object is cut in the width direction between the adjacent heating elements 10 to obtain the heating element 10 surrounded by the air bag 103.

  Subsequently, the heating element 10 surrounded by the air bag 103 is moved in one direction at a predetermined interval, and the first exterior sheet 104a made of a continuous long material is disposed on the side where the heating layer 101 is formed. At the same time, the second exterior sheet 104b made of a continuous long material is disposed on the other side. Next, the extended areas from the ventilation bag 103 in the first exterior sheet 104a and the second exterior sheet 104b are joined by a predetermined joining means. Joining is performed outside the left and right side edges and outside the front and rear edges of the air bag 103. As a joining means, the same thing as the above-mentioned joining means can be used. The obtained continuous long object is cut across the width direction between the adjacent ventilation bags 103 to obtain a heating tool.

  The obtained heating tool is hermetically housed in a packaging bag (not shown) having oxygen barrier properties in the next step.

  In the above-described method, means for maintaining a non-oxidizing atmosphere may be used as necessary in order to suppress oxidation of the oxidizable metal of component (A) during the production process.

  The heating tool manufactured in this way is applied directly to the human body or applied to clothing, and is suitably used for heating the human body and applying water vapor. Examples of the application site in the human body include the shoulder, neck, eyes, waist, elbow, knee, thigh, lower leg, abdomen, lower abdomen, hands, and soles. Further, in addition to the human body, the present invention is applied to various articles and suitably used for heating and keeping warm. In this case, the first covering sheet 103a side where water vapor is generated is applied toward the portion to be heated.

  In addition, said heat generating body 10 can also be used for the heating tool of the structure other than shown in FIG. 1, and another use.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, in the following examples, “%” is “mass%” and “part” is “part by mass”.

(Examples 1-18, Comparative Examples 1-6)
Exothermic compositions having the compositions shown in Tables 1 to 3 were prepared. In Examples 10-14, the used polyoxyethylene alkyl ether phosphate (Electro Stripper F, manufactured by Kao Corporation) is a potassium salt. (Nafa gluconate used Alfa Aeacr reagent, and hydroxybutyric acid Na used a reagent manufactured by Wako Chemical). For the citric acid used in the comparative examples, Wako Pure Chemical Co., Ltd. reagent grade, and for maleic acid, Wako Pure Chemical Co., Ltd. reagent grade, and iron citrate citrate Wako Pure Chemical Co., Ltd. grade reagent were used.

[viscosity]
The exothermic compositions of Examples 1 to 18 and Comparative Examples 1 to 6 were manufactured by TOKI SANGYO (VISCOMETER BH viscometer), using a # 4 rotor, rotating at 6 rpm, and measuring temperature 20 using a 100 ml tall beaker. The measured value after 1 minute at ° C. was taken as the viscosity. The results are shown in Tables 1-3.

[Paint stability]
The paint stability is shown in Tables 1-3.
A: The dispersibility of the solid content in the exothermic composition is very good.
○: Dispersibility of solid content in the exothermic composition is good.
X: Solid content in the exothermic composition is precipitated, the fluidity is insufficient, and a clay shape is exhibited.

[Heat generation characteristics]
1 was produced using the heat generating compositions of Examples 1 to 18 and Comparative Examples 1 to 6, and the heat generation characteristics were examined in accordance with the evaluation of the heat generation characteristics of (2) below.

(1) Production of heating tool The heating compositions of Examples 1 to 18 and Comparative Examples 1 to 6 were coated on one side of a sheet-like substrate (water absorbent paper or polymer sheet shown below) using a die coating method. . The exothermic composition was applied so that the iron powder per heating tool was 0.9 g (application amount: 1.6-1.7 g). The coating properties are shown in Tables 1 to 3 (◎: coating properties are very good. ○: coating properties are good. ×: coating properties are poor and cannot be applied). Then, it cut | judged in the width direction of a sheet-like base material (5 cm x 5 cm), and salt water (Japanese Pharmacopoeia sodium chloride (made by Otsuka Pharmaceutical Co., Ltd.) 22.4g was ion-exchanged water 77.6g on the coating surface of a heat-generating composition. Diluted with 0.2 g each from the picking nozzle to obtain a heating element 10. The entire heating element 10 obtained was covered with a ventilation bag 103. As the first covering sheet 103a, a ventilation sheet (Kohjin TSF-EU, manufactured by Kojin Co., Ltd., stretched film made of polyethylene and calcium carbonate, air permeability 2000 to 4000 seconds / 100 ml), as the second covering sheet 103b, non- using vent sheet (air-impermeable sheet prepared by laminating a pulp sheet having a basis weight of 40 g / ^m polyethylene film ² and basis weight 30 g / ^{m 2).} As the first exterior sheet 104a and the second exterior sheet 104b, an air-through nonwoven fabric having a basis weight of 30 g / m ² (nonwoven fabric composed of 50% polypropylene and 50% polyethylene, fiber diameter: 1 dtex) is ventilated. The heating element 10 covered with the bag 103 was surrounded to produce a heating tool.

(2) Evaluation of heat generation characteristics A device conforming to JIS S4100 was made, and the heat generation surface (the first covering sheet 103a side) of each of the obtained heating tools was set to the outside, and the non-venting surface (the second covering sheet 103b) The temperature sensor was installed on the measurement surface and fixed to the measurement surface, and the temperature was measured by fixing it to the measurement surface with a mesh material (made of polyester, double raschel fabric having a thickness of 8 mm). After opening, the temperature was measured at intervals of 10 seconds and measured for 40 minutes, and the maximum temperatures were compared. The results are shown in Tables 1-3. When it could not be made with high viscosity, it was indicated with “-” in the table.

  In addition, it shows below about the used sheet-like base material. In Tables 1 to 3, the polymer sheet is indicated as “PS”.

1. Water-absorbing paper Three sheets of paper with a basis weight of 30 g / m ² (pulp 100%) were used in an overlapping manner.

2. A polymer sheet having a basis weight of 100 g / ^{m 2} consisting of a polymer pulp sheet having a basis weight 50 g / ^{m 2} and basis weight 50 g / ^{m 2} of superabsorbent polymer particles. Pulp is a cellulose fiber layer consisting of cross-linked bulky cellulose fiber, softwood bleached kraft pulp and paper strength enhancer (PVA), and a sodium polyacrylate-based superabsorbent at a substantially central region in the thickness direction of this cellulose fiber layer. There are polymer particles (average particle size 340 μm).

  The exothermic composition of Example 1-18 had no water separation or the like, had good coating performance, and could be uniformly applied to a sheet-like substrate. Also, the heat generation characteristics were good results.

  In the exothermic composition of Comparative Example 1-6, the viscosity was too high to be applied to the sheet-like substrate, or even if applied, it was non-uniform.

DESCRIPTION OF SYMBOLS 10 Heat generating body 101 Heat generating layer 102 Absorbing layer 102a Superabsorbent polymer particle 102b Textile material 103 Venting bag 103a First covering sheet 103b Second covering sheet 104 Bag body 104a First exterior sheet 104b Second exterior sheet 301 Coating tank 302 Exothermic composition 303 Stirrer 304 Pump 305 Die head 306 Sheet-like substrate

Claims (9)

An exothermic composition containing the following components (A) to (E).
(A) an oxidizable metal,
(B) carbon component,
(C) thickener,
(D) water and
(E) One or more selected from oxymonocarboxylic acid, polyoxyethylene alkyl ether phosphoric acid, and salts thereof   The exothermic composition according to claim 1, wherein the component (E) is one or more oxymonocarboxylic acids and salts thereof selected from glyceric acid, hydroxybutyric acid, and gluconic acid.   The exothermic composition of Claim 1 or 2 containing 0.1 to 8 mass parts of said component (E) with respect to 100 mass parts of said components (A).   The exothermic composition according to any one of claims 1 to 3, wherein the component (E) is polyoxyethylene alkyl ether phosphoric acid having an EO addition mole number of 0.5 to 15 and a salt thereof.   The exothermic composition according to any one of claims 1 to 4, wherein the component (E) is polyoxyethylene alkyl ether phosphoric acid having an alkyl group having 12 to 15 carbon atoms and a salt thereof.   The exothermic composition according to any one of claims 1 to 5, which is in a slurry form.   A heating tool having a heating element formed by laminating the heating composition according to any one of claims 1 to 6 on a sheet-like substrate.   The heating tool according to claim 7, wherein the sheet-like substrate has a fiber sheet containing particles of a superabsorbent polymer and a fiber material.   The heating element according to claim 7 or 8, wherein the heating element is formed by applying the heating composition to the sheet-like substrate.

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