JP2015117319A - Method and apparatus for producing heat generator, and method for cleaning apparatus for producing heat generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for producing a heat generator, in each of which both of a variation of heat generation characteristics due to concentration irregularity of an electrolyte and corrosion of the apparatus can be suppressed.SOLUTION: The method for producing a heat generator 14 which is obtained by forming a heat generation layer 12 on a base material 11, comprises: a preparation step of throwing metal particles to be oxidized and water in a preparation tank 2 and mixing them therein to prepare a coating raw material liquid; a mixing step of sending a part of the prepared coating raw material liquid to a mixing tank 3, storing the sent liquid temporarily and mixing the stored coating raw material liquid with an electrolyte in the mixing tank 3 to form an electrolyte-containing coating liquid; and an application step of applying the electrolyte-containing coating liquid in the mixing tank 3 to the base material 11. At the mixing step, the amount of the electrolyte-containing coating liquid in the mixing tank 3 is measured by a measurement part arranged in the mixing tank 3, and when the measured amount of the electrolyte-containing coating liquid becomes equal to or smaller than a predetermined amount, a part of the coating raw material liquid is sent to the mixing tank 3 from the preparation tank 2 and the electrolyte is added to the mixing tank 3 by an electrolyte addition unit 4.

Description

  The present invention relates to a method of manufacturing a heating element, a manufacturing apparatus used for the manufacturing method, and a cleaning method of the manufacturing apparatus.

  For example, Patent Document 1 describes a method of manufacturing a heating element using a heating composition as a conventional technique related to a method of manufacturing a heating element using heat generated by an oxidation reaction between oxygen in the air and an oxidizable metal. Has been. This heating element manufacturing method is a method of manufacturing a heating element by laminating an ink-like or cream-like heating composition on a base material sheet as a packaging material. The exothermic composition is prepared by mixing and stirring the activated carbon, the thickener, the surfactant, the pH adjuster, the salt and the iron powder in this order in a mixer, and further stirring and kneading while adding water. The

  Further, in Patent Document 2, an oxidizer having a step of applying an oxidizable metal-containing coating solution containing particles of an oxidizable metal, a carbon component, a thickener, and water to a substrate using a coating apparatus. A method for producing a metal-containing coating is described. In the production method, a thickener solution prepared by dissolving a thickener in water, an oxidizable metal particle, and a carbon component or an aqueous dispersion of a carbon component are charged and mixed in a preparation tank. An oxidizable metal-containing coating solution is prepared. A heating element is obtained by adding an electrolyte aqueous solution containing an electrolyte to the oxidizable metal-containing coating manufactured by the above manufacturing method or by adding the electrolyte as a solid.

  Patent Document 3 describes a method for producing a heat generating composition containing iron powder, a carbon component, a reaction accelerator and moisture as essential components. In this exothermic composition manufacturing method, the exothermic composition-containing components such as iron powder and carbon component are sequentially introduced into a cylindrical body arranged in the lateral direction, and the cylindrical body is provided rotatably. In this method, the contained components are mixed with a screw and conveyed to the next step.

JP-A-9-75388 JP 2013-100470 A International Publication No. 2007/081014

In the production method described in Patent Document 1, when the exothermic composition is formed by stirring and kneading, there is an exothermic suppression effect due to excess water. However, since salt (electrolyte) and iron powder are stirred and kneaded at the same time, the paint attached to the paddle, tank wall, etc. of the kneader tends to cause a violent oxidation reaction by losing moisture. For this reason, the manufacturing equipment must use an expensive material having high corrosion resistance such as titanium, which requires a very expensive equipment investment. In particular, the manufacturing method described in Patent Document 1 is basically a so-called batch type manufacturing method, and it is necessary to increase the tank capacity of the kneader in order to increase production efficiency. Therefore, if an expensive material is used, a very expensive capital investment is required.
Further, in the production method described in Patent Document 1, since salt (electrolyte) and iron powder are stirred and kneaded at the same time, it is not possible to suppress sedimentation or water separation of the exothermic composition and maintain dispersibility of the exothermic composition. Difficult to do.

On the other hand, in the manufacturing method described in Patent Document 2, the coating solution prepared in the preparation tank is applied to the base material without introducing the electrolyte into the preparation tank, and the obtained oxidizable metal-containing application is obtained. Add electrolyte to the object. Thereby, the oxidation of the oxidizable metal particles in the preparation tank by the electrolyte is suppressed as much as possible, and the dispersibility of the oxidizable metal-containing coating liquid is maintained.
In this method, when the electrolyte is added onto the oxidizable metal-containing coating using the electrolyte addition means, it is required to minimize the variation in the addition amount. This is because unevenness in the electrolyte concentration on the substrate is caused by variation in the amount of electrolyte added, and if the unevenness in electrolyte concentration becomes large, there is a possibility that variation in the heat generation characteristics between manufactured heating elements may occur. In particular, when an active ingredient other than the electrolyte is to be added at the same time, the variation tends to increase as the amount added to the coating increases. In this case, there is a possibility that the variation in heat generation characteristics between the heat generating bodies becomes unacceptable or the adhesiveness of the base material is deteriorated. Therefore, it is necessary to remove such a heating element in the manufacturing process.

Moreover, the manufacturing method described in Patent Document 3 is a custom-made method in which an exothermic composition containing a water amount capable of generating heat or a water amount higher than that is prepared at a necessary time by continuously dispersing and feeding components into small compartments. Exothermic compositions can be produced. However, in the case where there is a variation in the input of the sodium chloride aqueous solution (reaction promoter aqueous solution), the production described in Patent Document 2 in that the salt concentration of the exothermic composition discharged from the outlet may vary. It is the same as the method.
Further, in the method of Patent Document 3, although the exothermic composition can be continuously supplied to the next step, when the production line is stopped, the exothermic composition-containing component in the middle of the mixture remains in the cylindrical body, and thus, it has been stopped. When the production line is restarted, it is necessary to perform a so-called end cutting operation in which the exothermic composition-containing component in the cylindrical body is exhausted to empty the cylindrical body. Since this cutting operation requires extra work for producing the exothermic composition, there is still room for improvement in terms of production efficiency.

  Accordingly, the present invention relates to a method for manufacturing a heating element and an apparatus for manufacturing the heating element that can suppress variations in heat generation characteristics caused by uneven electrolyte concentration and can suppress corrosion of the apparatus.

The present invention is a method of manufacturing a heating element including a step of forming a heat generating layer by applying an electrolyte-containing coating solution to a substrate, and applying at least oxidizable metal particles and water to a preparation tank A preparation process for preparing a raw material liquid, and a part of the coating raw material liquid is transferred to a mixing tank and temporarily stored, and the coating raw material liquid and an electrolyte are mixed in the mixing tank to generate an electrolyte-containing coating liquid. And a coating step of coating the electrolyte-containing coating solution in the mixing tank on a substrate,
In the mixing step, the amount of the electrolyte-containing coating liquid in the mixing tank is measured by a measuring unit provided in the mixing tank, and when the amount of the electrolyte-containing coating liquid is equal to or less than a predetermined amount, Provided is a heating element manufacturing method in which a part of a coating raw material liquid is transferred from a preparation tank to the mixing tank, and the electrolyte is added to the mixing tank by an electrolyte adding device.

  Further, the present invention is a heating element manufacturing apparatus for manufacturing a heating element formed by applying the electrolyte-containing coating solution to a substrate, and preparing a coating raw material solution containing at least metal to be oxidized and water A tank, a mixing tank capable of temporarily storing a coating raw material liquid prepared in the preparation tank, an application unit for applying an electrolyte-containing coating liquid in which an electrolyte is added to the coating raw material liquid to an object to be coated, and the preparation tank And a first transfer part that connects the mixing tank and a second transfer part that connects the mixing tank and the application part, and the mixing tank contains the electrolyte in the mixing tank A measuring unit for measuring the amount of the coating liquid, and when the amount of the electrolyte-containing coating liquid measured by the measuring unit is equal to or less than a predetermined amount, a part of the coating raw material liquid is transferred from the preparation tank to the mixing tank; And an electrolyte addition device provided in the coating device More added electrolyte to the mixing tank, to provide a manufacturing apparatus of the heating element.

  According to the present invention, it is possible to suppress variations in heat generation characteristics caused by electrolyte concentration unevenness and to suppress corrosion of the apparatus.

FIG. 1 is an overall configuration diagram of a heating element manufacturing apparatus for forming a heating layer on a substrate according to a preferred embodiment of the heating element manufacturing method of the present invention. FIG. 2 is an overall configuration diagram of a coating apparatus including the coating unit illustrated in FIG. FIG. 3 is a cross-sectional view schematically showing a cross section of a heating element obtained by the manufacturing method shown in FIG. FIG. 4 is a graph showing the time change of the electrolyte supply amount and the electrolyte concentration in the mixing tank in the coating apparatus shown in FIG. 2, and (a) shows the time change of the electrolytic mass supplied from the electrolyte addition apparatus to the mixing tank. (B) is a graph which shows the time change of the electrolyte concentration of the electrolyte containing coating liquid in a mixing tank. FIG. 5 is a graph showing the change over time of the electrolyte concentration of a heating element manufactured by a conventional manufacturing method. 6 is a diagram showing a method of cleaning the mixing tank in the coating apparatus shown in FIG. 2, (a) a diagram showing a water supply step, (b) a diagram showing a stirring step, and (c). FIG. 4 is a diagram showing a discharging process.

  Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. 1 and 2 show an embodiment of a heating element manufacturing apparatus used for carrying out the heating element manufacturing method of the present invention. The method for manufacturing a heating element according to this embodiment includes a step of forming a heat generating layer by applying an electrolyte-containing coating solution to the substrate 11 using the coating apparatus 1 including the coating unit 5. Reference numeral 12 in FIG. 1 indicates a heat generating layer formed by applying the electrolyte-containing coating solution to the substrate 11.

  As shown in FIG. 1, the coating apparatus 1 is a part of a heating element manufacturing apparatus 50 that manufactures a heating element 14 that can generate heat by contact with air. The heating element 14 thus obtained is a flat three-layered sheet-like material in which a heating layer 12 is disposed between two upper and lower sheet-like substrates 11 and 11 (see FIG. 3). As shown in FIG. 1, an electrolyte-containing coating solution is applied to a single substrate 11 to form a heat generating layer 12 to obtain a heat generating intermediate structure 10 having a two-layer structure. Furthermore, by superimposing another sheet of base material 11 on the heat generating layer 12 of the heat generating intermediate structure 10, the heat generating element 14 having the target three-layer structure is obtained.

  As shown in FIG. 2, the coating apparatus 1 includes a preparation tank 2 for preparing a coating raw material liquid, a mixing tank 3 capable of temporarily storing a coating raw material liquid prepared in the preparation tank 2, and a coating in the mixing tank 3 An electrolyte addition device 4 for adding an electrolyte to the raw material liquid, and an application unit 5 for applying the electrolyte-containing application liquid to which the electrolyte is added to an object to be applied are provided. Furthermore, the pipe 20A and the first pump 20B as the first transfer section 20 connecting the preparation tank 2 and the mixing tank 3 and the pipe 21A and the second pump 21B as the second transfer section 21 connecting the mixing tank 3 and the coating section 5 are used. A pump 21B is provided.

The preparation tank 2 is a tank for preparing a coating raw material liquid containing at least oxidizable metal particles and water, and one end of a pipe 20A for transferring the coating raw material liquid in the preparation tank 2 to the mixing tank 3 is connected. Yes. Further, the preparation tank 2 is provided with a coating raw material liquid amount measuring unit 6 for measuring the transfer amount of the coating raw material liquid to the mixing tank 3. The coating raw material liquid amount measuring unit 6 may be used as a means for measuring the amount of raw material of the coating raw material liquid to be supplied to the preparation tank 2.
The transfer amount of the coating raw material liquid to the mixing tank 3 and the input amount of the raw material of the coating raw material liquid are obtained before and after the transfer of the coating raw material liquid or the input of the raw material of the coating raw material liquid obtained using the coating raw material liquid measuring unit 6. It can be determined based on the mass change or volume change of the preparation tank 2 before and after.

The mixing tank 3 temporarily stores the coating raw material liquid prepared in the preparation tank 2, and mixes the coating raw material liquid with the electrolyte added by the electrolyte adding device 4 to generate an electrolyte-containing coating liquid. It is a tank for. As will be described later, the mixing tank 3 is a tank specialized in the function of continuously supplying the electrolyte-containing coating solution to the coating unit 5. From this function, the temporary storage is storage for adding an electrolyte to obtain an electrolyte-containing coating solution having a predetermined concentration, and the electrolyte-containing coating solution in the tank is constantly increased or decreased for continuous supply to the coating unit 5. It is repeating. The temporary storage time is preferably determined by pot life (pot life) T described later.
The mixing tank 3 has one end of a pipe 20 </ b> A that supplies the coating raw material solution prepared in the preparation tank 2 and one end of a pipe 21 </ b> A that transfers the liquid (electrolyte-containing coating liquid) in the mixing tank 3 to the coating unit 5. It is connected. In addition, an addition port (not shown) for adding the electrolyte discharged from the discharge port of the electrolyte addition device 4 to the mixing tank 3 is provided. Furthermore, the mixing tank 3 is provided with a measuring unit 7 for measuring the amount of the electrolyte-containing coating liquid in the mixing tank 3 in order to control the transfer of the coating raw material liquid to the mixing tank 3 and the addition of the electrolyte. The amount of the electrolyte-containing coating solution in the mixing tank 3 can be obtained based on the mass or volume obtained using the measuring unit 7.

  In this embodiment, the electrolyte addition apparatus 4 has a storage part for storing the electrolyte and a discharge port, and discharges the electrolyte in the storage part from the discharge port by a screw feeder. The discharge port and the addition port of the mixing tank 3 communicate with each other, and the discharged electrolyte is added into the mixing tank 3. The electrolyte may be added in the form of a solid (powder) or in the form of an aqueous electrolyte solution. However, the base material is capable of absorbing excess moisture of the electrolyte-containing coating solution, and is also prepared. From the viewpoint of ensuring the fluidity of the coating material solution in the tank 2, it is preferably added in a solid state.

  When adding in the form of an aqueous electrolyte solution, the method of adding the aqueous electrolyte solution is to drop the solution with a nozzle or spray the solution with a spray, etc., but to prevent scattering of the aqueous electrolyte solution to the surroundings or clogging of the electrolyte aqueous solution outlet. From the viewpoint, dropping by a nozzle is preferable. In addition, when the electrolyte is added as a solid, addition by various powder feeders such as a screw feeder is preferably used as a method for adding the solid electrolyte.

  Further, the electrolyte addition device 4 is provided with an electrolytic mass measuring unit 8 for measuring the amount of electrolyte added to the mixing tank 3. The electrolytic mass measuring unit 8 may be used as a means for measuring the amount of electrolyte charged into the storage unit of the electrolyte addition device 4. The amount of electrolyte added to the mixing tank 3 and the amount of electrolyte charged into the reservoir are the mass changes of the electrolyte addition device 4 before and after addition of the electrolyte or before and after addition of the electrolyte, obtained using the electrolytic mass metering unit 8. Or it can obtain | require based on a volume change etc.

  The 1st transfer part 20 has 20A of piping which connects the preparation tank 2 and the mixing tank 3, and the 1st pump 20B for liquid feeding. The coating raw material liquid in the preparation tank 2 is transferred to the mixing tank 3 through the pipe 20A by the first pump 20B. The transfer speed can be adjusted by adjusting the flow rate of the first pump 20B. The first pump 20B is preferably a metering pump because it can suppress pulsation and accurately control the amount transferred to the mixing tank 3, and specifically includes a MONO pump, a gear pump, a rotary pump, a sine pump, and a screw pump. It is done.

  The 2nd transfer part 21 has 21 A of piping which connects the mixing tank 3 and the application | coating part 5, and the 2nd pump 21B for liquid feeding. The electrolyte-containing coating solution in the mixing tank 3 is transferred to the coating unit 5 through the pipe 21A by the second pump 21B. The transfer speed can be adjusted by adjusting the flow rate of the second pump 21B. The second pump 21B is preferably a metering pump because the pulsation can be suppressed and the transfer amount to the application unit 5 can be accurately controlled, and specifically, a mono pump, a gear pump, a rotary pump, a sine pump, and a screw pump can be cited. It is done.

  The preparation tank 2 and the mixing tank 3 are not particularly limited in shape, but have a cylindrical shape in the present embodiment. Each of these tanks includes an anchor blade 9 as a stirring portion inside. The anchor blade 9 is operated by a drive source indicated by reference numeral M in FIG. 2 and agitates the liquid in the tank. Various known stirring means can be used as the stirring unit, and in addition to the anchor blade, for example, a paddle blade, a screw blade, a turbine blade, a propeller blade, a helical ribbon blade, or the like can be used. In addition, depending on the room temperature where the coating apparatus 1 is placed, there is a possibility that the viscosity of the coating material solution and the electrolyte-containing coating solution may change or the components may precipitate. In order to prevent such an inconvenience, it is preferable that the coating apparatus 1 includes a heating unit that can heat the pipes 20A and 20B constituting at least the first transfer unit 20 and the second transfer unit 21, respectively. From the same viewpoint, it is preferable that the coating apparatus 1 has a heating unit capable of heating at least one of the preparation layer 2 and the mixing tank 3.

The mixing tank 3 has a smaller maximum liquid storage than the preparation tank 2. That is, the mixing tank 3 has a smaller volume than the preparation tank 2. The preparation tank 2 is a tank having a very large volume because it is necessary to store a necessary amount of coating raw material liquid in a so-called batch type manufacturing method. Specifically, the maximum storage amount of the coating raw material liquid in the preparation tank 2 is preferably 50 kg or more, and more preferably 100 kg or more. Moreover, 1000 kg or less is preferable and 500 kg or less is more preferable.
On the other hand, the maximum storage amount of the electrolyte-containing coating liquid in the mixing tank 3 is 10 kg or more because a certain amount of electrolyte-containing coating liquid needs to remain in the mixing tank 3 during the mixing of the electrolyte and the coating raw material liquid. Is preferable, and 20 kg or more is more preferable. In addition, when the production of the heating element is stopped, the liquid in the mixing tank 3 can be used up easily, and the time from when the electrolyte is added until it is transferred to the coating unit can be shortened, that is, the storage time of the electrolyte-containing coating liquid is shortened. Therefore, 50 kg or less is preferable, and 40 kg or less is more preferable. Here, the “maximum storage amount” of the mixing tank 3 is not limited to the capacity that can be stored without overflowing the liquid from the mixing tank 3, and when the upper limit value of the amount stored in the mixing tank 3 is set in the manufacturing process. Indicates the upper limit capacity.
The ratio of the maximum storage capacity of the preparation tank 2 to the maximum storage capacity of the mixing tank 3 is preferably 3 or more. If it is less than this value, it will be difficult to achieve the effects of the present invention.

  As the coating unit 5, various known coating means can be used without particular limitation. For example, a die coater, a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, a curtain coater. A slide bead or the like can be used.

  Hereinafter, the coating raw material liquid (the oxidizable metal-containing coating raw material liquid) prepared and used in the heating element manufacturing method of the first embodiment will be described. The coating material liquid contains oxidizable metal particles and water as essential components.

  Examples of the oxidizable metal contained in the coating raw material liquid include iron, aluminum, zinc, manganese, magnesium, calcium, and the like, and these can be used alone or in combination of two or more. . Among these oxidizable metals, iron is particularly preferably used in the present invention. The particle size of the oxidizable metal particles is preferably 0.1 μm or more, more preferably 5 μm or more. And it is preferably 300 μm or less, more preferably 100 μm or less, and particularly preferably 50 μm or less. More specifically, it is preferably 0.1 μm or more and 300 μm or less, more preferably 5 μm or more and 100 μm or less, and particularly preferably 5 μm or more and 50 μm or less. The particle size of the oxidizable metal particles was measured by a wet method using a laser diffraction particle size distribution analyzer (SALD-300V, manufactured by Shimadzu Corporation), and the median diameter was defined as the particle size.

  The coating raw material liquid can contain a carbon component. As the carbon component contained in the coating raw material liquid, one having a function capable of promoting the oxidation reaction between oxygen in the air and the oxidizable metal in the heating element 14 (see FIG. 1) is used. Specifically, in addition to the function as a moisture retention agent, those having a function as an oxygen retention agent and an oxygen supply agent for the oxidizable metal are preferably used. Examples of the carbon component include activated carbon (such as coconut shell charcoal, charcoal powder, calendar bituminous coal, peat, lignite, etc.), carbon black, acetylene black, graphite and the like. One of these may be used alone or two or more of them may be used. It can be used by mixing. These carbon components are usually powders. The particle size of the carbon component particles is preferably 0.1 μm or more, more preferably 1 μm or more. And it is preferably 100 μm or less, more preferably 50 μm or less, and particularly preferably 30 μm or less. More specifically, it is preferably 0.1 μm or more and 100 μm or less, more preferably 1 μm or more and 50 μm or less, and particularly preferably 1 μm or more and 30 μm or less. The particle size of the carbon component particles was measured by a wet method using a laser diffraction particle size distribution analyzer (SALD-300V, manufactured by Shimadzu Corporation), and the median diameter was defined as the particle size.

  The coating raw material liquid can contain a thickener. The thickener contained in the coating raw material liquid is mainly used to suppress sedimentation of oxidizable metal particles and to impart appropriate fluidity to the coating raw material liquid. , Poly (meth) acrylic acid (salt, ester), syrup, seaweed, plant mucilage, microbial mucus, protein, polysaccharide, organic, inorganic, synthetic, etc. An auxiliary agent etc. are mentioned, These 1 type can be used individually or in mixture of 2 or more types. Among these thickeners, polysaccharides, particularly xanthan gum, are particularly preferably used in the present invention. In this embodiment, a solid (powder) thickener is used as the thickener.

  In addition to the above-described various components (oxidizable metal particles, carbon component, thickener and water), the coating raw material liquid may further contain other components as necessary. Examples of other components include a pH adjuster, a surfactant, a water retention agent, and the like. One of these can be used alone, or two or more can be used in combination.

  As the pH adjuster, those capable of adjusting the pH of the coating raw material solution to 10 or more are used, and are appropriately selected in view of the degree of influence on the oxidation reaction of the oxidizable metal particles, which is the main reaction. As the pH adjuster, for example, weakly acidic salts or hydroxides of alkali metals or alkaline earth metals can be used, and more specifically, potassium phosphate salts, sodium phosphate salts and the like can be used. it can. Preferable examples of the pH adjuster include, for example, potassium phosphate salts such as monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, potassium pyrophosphate, potassium tripolyphosphate, and potassium metaphosphate. Can be used alone or in admixture of two or more. The components of these pH adjusters are usually solid (powder) at normal temperature and pressure.

The proportions of the various components in the coating raw material liquid are preferably set as follows from the viewpoints of coating properties, fluidity, and heat generation.
The content of the oxidizable metal particles is preferably 40% by mass or more, more preferably 50% by mass or more, based on the total mass of the coating raw material liquid. And preferably it is 80 mass% or less, More preferably, it is 70 mass% or less. More specifically, it is preferably 40% by mass to 80% by mass, and more preferably 50% by mass to 70% by mass.

  The content of the carbon component is preferably 1% by mass or more, more preferably 3% by mass or more, based on the total mass of the coating raw material liquid. And preferably it is 20 mass% or less, More preferably, it is 10 mass% or less. More specifically, it is preferably 1% by mass or more and 20% by mass or less, and more preferably 3% by mass or more and 10% by mass or less.

  The content of the thickener is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, with respect to the total mass of the coating raw material liquid. And preferably it is 1 mass% or less, More preferably, it is 0.30 mass% or less. More specifically, it is preferably 0.01% by mass or more and 1% by mass or less, and more preferably 0.05% by mass or more and 0.30% by mass or less.

  The water content is preferably 10% by mass or more, more preferably 30% by mass or more, based on the total mass of the coating raw material liquid. And preferably it is 60 mass% or less, More preferably, it is 40 mass% or less. More specifically, it is preferably 10% by mass or more and 60% by mass or less, and more preferably 30% by mass or more and 40% by mass or less.

  As the electrolyte added into the mixing tank 3 by the electrolyte adding device 4, an electrolyte capable of dissolving the oxide formed on the surface of the oxidizable metal particles is used. Examples thereof include alkali metal, alkaline earth metal or transition metal sulfates, carbonates, chlorides or hydroxides. Among these, chlorides of alkali metals, alkaline earth metals or transition metals are preferably used from the viewpoint of excellent conductivity, chemical stability and production cost, and particularly sodium chloride, potassium chloride, calcium chloride, magnesium chloride, chloride. Ferrous and ferric chloride are preferably used. When adding in the state of electrolyte aqueous solution, in electrolyte aqueous solution, electrolyte becomes like this. Preferably it is 3 mass% or more, More preferably, 5 mass% or more is contained. And preferably it is 35 mass% or less, More preferably, it is 30 mass% or less. More specifically, the content is preferably 3% by mass or more and 35% by mass or less, and more preferably 5% by mass or more and 30% by mass or less.

  The electrolyte content (electrolyte concentration) of the electrolyte-containing coating solution in the mixing tank 3 to which the electrolyte is added is from the point of effectively exerting the function as an oxidizing aid, and is based on the total mass of the electrolyte-containing coating solution. Preferably it is 0.1 mass% or more, More preferably, it is 1.0 mass% or more. And from a soluble viewpoint with respect to a coating liquid, Preferably it is 15 mass% or less, More preferably, it is 10 mass% or less. The variation in the electrolyte concentration in one batch is preferably ± 0.5% or less from the viewpoint of performance stability of the exothermic composition to be produced. Here, one batch in the mixing tank 3 refers to an electrolyte-containing coating solution that is used for coating on the substrate after the start of the transfer of the coating raw material solution from the preparation tank 2 to the start of the next transfer. That is.

  In the heating element manufacturing apparatus 50, as shown in FIG. 1, the coating device 1 (the coating unit 5) applies the electrolyte-containing coating solution on one surface of the strip-like base material 11 to form the heating layer 12, thereby forming the belt-like shape. The two-layered heating element intermediate structure 10 is manufactured. This belt-shaped heating element intermediate structure 10 is conveyed in the direction indicated by reference numeral X1 in FIG. 1, and another sheet of base material 11 is superimposed on the heating layer 12 of the heating element intermediate structure 10 to achieve the purpose. Thus, a heating element belt 13 having a three-layer structure is obtained. Thereafter, the heating element strip 13 is passed between a cutter roll 51 and an anvil roll 52 each having a cutter blade on the peripheral surface, and is cut into a predetermined length to form a plurality of single-sheet heating elements 14. The sheet heating element 14 having a three-layer structure thus obtained is conveyed by the conveying belt 53.

As the base material 11, a sheet-like material on which an electrolyte-containing coating solution can be applied is used, and in particular, a material having both properties of water absorption and sheet surface smoothness is preferable. When the water absorption of the base material 11 is high, excessive moisture in the electrolyte-containing coating solution is absorbed by the base material 11 and removed, so that the heat generation characteristics of the heating element 14 are further improved. Examples of the material preferably used as the base material 11 include paper obtained mainly by pulp paper or the like by a wet papermaking method, a fiber sheet containing a superabsorbent polymer and pulp fibers, and a nonwoven fabric mainly containing synthetic fibers. It is done. The basis weight of the substrate 11 is not particularly limited, but is preferably 30 g / m ² or more, more preferably 80 g / m ² or more. And it is preferably 200 g / m ² or less, more preferably 120 g / m ² or less. More specifically, it is preferably 30 g / m ² or more and 200 g / m ² or less, and more preferably 80 g / m ² or more and 120 g / m ² or less.

  The heating element manufacturing method according to the first embodiment of the present invention using the heating element manufacturing apparatus 50 described above includes (1) a preparation step, (2) a mixing step, and (3) a coating step, which will be described below.

(1) Preparation process In the preparation process which is one process of the manufacturing process of a heat generating body, the oxidizable metal particle and water thrown into the preparation tank 2 are stirred by the stirring part 9, and a coating raw material liquid is prepared. In addition to the metal particles to be oxidized and water, a carbon component and a thickener may be added as necessary. The coating material solution prepared in the preparation tank 2 does not contain an electrolyte. The electrolyte here means an electrolyte added for the purpose of dissolving the oxide formed in the particles of the oxidizable metal, and “does not contain electrolyte” means that it does not contain any electrolyte at all. Absent. This means that the electrolyte added in the mixing step to be described later is substantially not included, and the chlorine component contained in the moisture when tap water is used is not the electrolyte referred to here.

Since the coating raw material liquid contains substantially no electrolyte, oxidation of the oxidizable metal powder does not proceed in the preparation tank 2. Therefore, in the preparation process, no special allowance is required for shielding the oxidizable metal powder from the air. Moreover, the progress of the oxidation reaction during storage of the coating raw material liquid can be suppressed, and heat loss can be reduced.
Moreover, since the coating raw material liquid does not contain an electrolyte, the coating raw material liquid in the preparation tank 2 maintains good dispersibility. For example, even if the coating raw material liquid is allowed to stand before coating, the particles of oxidizable metal aggregate in the coating raw material liquid, and the aggregates are unlikely to settle or separate.

  According to the heating element manufacturing method of the present invention, as described above, the coating raw material liquid in the preparation tank 2 is substantially free of an electrolyte. It is difficult to cause an oxidation reaction in the paddle, the wall surface, the pipe 20A, etc. of the preparation tank 2 while the coating raw material liquid is transferred to the mixing tank 3 during manufacturing. Therefore, it is possible to avoid using an expensive material having high corrosion resistance as much as possible in the preparation tank 2 having a very large size.

The pH of the coating raw material solution to be prepared is preferably 10 or more, more preferably 11 or more, from the viewpoint of preventing the growth of bacteria and molds. The pH of the coating material solution can be adjusted using the pH adjuster. For example, a thickener solution is prepared by adding and mixing water, a pH adjuster, and a thickener in this order to the preparation tank 2 under stirring by the stirring unit 9. A coating raw material solution having a pH in a predetermined range is prepared by charging and mixing metals.
In the preparation tank 2, in order to supply the coating raw material liquid in which the oxidizable metal particles having a specific gravity larger than that of the solvent are suitably dispersed in a timely manner, a predetermined amount of the coating raw material liquid is stored while maintaining the dispersion state. Yes. For this reason, unlike the mixing tank 2, a coating raw material liquid is provided by a batch type, without supplying electrolyte.

(2) Mixing step In the mixing step, the coating raw material liquid and the electrolyte transferred from the preparation tank 2 into the mixing tank 3 are stirred and mixed by the stirring unit 9 to generate an electrolyte-containing coating liquid. The coating raw material liquid transferred from the preparation tank 2 in the mixing tank 3 is temporarily stored and mixed with the electrolyte by the stirring unit 9, so that the coating unit 5 is always in a stable state (solid content It is possible to supply an electrolyte-containing coating solution (with no water separation or the like), and a high-quality electrolyte-containing coating can be continuously and stably produced.
Since the mixing tank 3 contains an electrolyte-containing coating solution, it is necessary to use a material with high corrosion resistance. However, since the capacity of the mixing tank 3 is smaller than that of the batch-type preparation tank 2, a material with high corrosion resistance is used as much as possible. Less is enough.

  From the viewpoint of storage stability, the viscosity of the mixed electrolyte-containing coating solution is preferably 1000 mPa · s or more, more preferably 20000 mPa · s or more at 20 ° C. and 60% RH. And it is preferably 100,000 mPa · s or less, more preferably 60000 mPa · s or less. More specifically, it is preferably 1000 mPa · s or more and 100,000 mPa · s or less, and more preferably 20000 mPa · s or more and 60000 mPa · s or less. The viscosity of the electrolyte-containing coating liquid can be adjusted by appropriately adjusting the type and content of the thickener.

The viscosity of the liquid is measured as follows. 100 ml of a measurement target liquid is put into a beaker having an inner diameter of 60 mm, and measurement is performed using a B-type viscometer (Toki Sangyo Co., Ltd.). In measuring the viscosity with a B-type viscometer, the rotor No. 4 is rotated at 6 rpm, after 1 minute, the indicated value is read and converted into a viscosity using a conversion table. The measurement environment is 20 ° C. and 60% RH.
The mixed electrolyte-containing coating solution is transferred to the coating unit 5 and coated on the substrate 11 by a coating process described later.

Since the mixed electrolyte-containing coating liquid is applied to the base material 11 by a coating process described later, the remaining amount of the electrolyte-containing coating liquid in the mixing tank 3 is continuously reduced.
In the mixing step, the storage amount of the electrolyte-containing coating solution in the mixing tank 3 is measured by the measuring unit 7 attached to the mixing tank 3. That is, the measuring unit 7 monitors the remaining amount of the electrolyte-containing coating liquid that is being reduced as needed. The measuring unit 7 can measure the amount of storage (volume) by detecting the liquid level of the electrolyte-containing coating liquid stored in the mixing tank 3, for example. 3 is preferably a scale that measures the mass of the electrolyte-containing coating solution stored in the tube 3.

Further, in the mixing step, when the storage amount of the electrolyte-containing coating liquid in the mixing tank 3 measured in the measuring unit 7 is equal to or less than a predetermined amount, a part of the coating raw material liquid in the preparation tank 2 is mixed with the mixing tank 3. The electrolyte is added into the mixing tank 3 by the electrolyte addition device 4 while being transferred to the inside.
Here, the “predetermined amount” refers to the amount of the electrolyte-containing coating liquid that does not include an empty state (zero) in the mixing tank 3 from the viewpoint of suppressing uneven electrolyte concentration due to the addition of the electrolyte. In the first embodiment, the predetermined amount is preferably 20% or more, more preferably 40% or more of the maximum storage amount of the electrolyte-containing coating solution in the mixing tank 3. Further, it is preferably 90% or less, more preferably 80% or less. The above range is desirable because the variation in the electrolyte concentration in the mixing tank 3 can be reliably suppressed within a predetermined range. That is, dispersion of the electrolyte concentration can be suppressed by adding the electrolyte and the coating raw material liquid for the preparation layer 2 in a state where the electrolyte-containing coating liquid remains in the mixing tank 3. Thus, the “predetermined amount” is a reference mass value for adding the coating material solution and the electrolyte. “Below a predetermined amount” means a reference mass value and a neighboring value lower than the reference mass value, and does not include a case where it is significantly lower than the reference mass value. The standard of the neighborhood value is a range up to a mass value that is 99.5% lower than the “predetermined amount” that is the reference mass value.

  The above-described process will be described in detail. The electrolyte-containing coating solution in the mixing tank 3 is reduced by a coating process described later, and the storage amount in the mixing tank 3 is equal to or less than a predetermined amount (for example, the maximum storage in the mixing tank 3). When the amount reaches 50% or less), the first pump 20B of the first transfer unit 20 is activated to start the transfer of the coating raw material liquid from the preparation tank 2 to the mixing tank 3. In the present embodiment, even while the coating raw material liquid is being transferred from the preparation tank 2 to the mixing tank 3, the electrolyte-containing coating liquid is applied to the substrate 11 by the application process described later. Further, along with the transfer of the coating raw material liquid from the preparation tank 2, the addition of the electrolyte from the electrolyte addition device 4 to the mixing tank 3 is started.

  The stop of the transfer of the coating raw material liquid to the mixing tank 3, that is, the stop of the first pump 20 </ b> B is performed by the coating raw material liquid in the preparation tank 2 measured by the coating raw material liquid amount measuring unit 6 provided in the preparation tank 2. Done on a quantity basis. That is, the transfer of the coating raw material liquid to the mixing tank 3 is stopped when the amount obtained by subtracting the desired transfer amount from the amount of the coating raw material liquid in the preparation tank 2 before the start of transfer is reached. As described above, the reason for controlling the transfer amount of the coating raw material liquid by the coating raw material liquid measuring unit 6 provided in the preparation tank 2 is that the measuring unit 7 provided in the mixing tank 3 has the mixing tank 3 to the coating part. 5 and the addition of the electrolyte from the electrolyte addition device 4 together with the transfer of the coating raw material liquid from the preparation tank 2, the accurate transfer amount of the coating raw material liquid can be measured. It is not possible.

The transfer speed of the coating raw material liquid from the preparation tank 2 to the mixing tank 3, that is, the transfer speed V (kg / min) of the first pump 20B in the first transfer section 20 is preferably 1.5 kg / min or more, more preferably. 5 kg / min or more. Further, it is preferably 50 kg / min or less, more preferably 25 kg / min or less. The above range is desirable from the viewpoint of not emptying the electrolyte-containing coating solution in the mixing tank 3. Moreover, the timing from the start to the stop of the transfer of the coating raw material liquid (from the start to the stop of the first pump 20B) is substantially the same as the timing from the start to the stop of the electrolyte addition in the electrolyte addition device 4 described later It is preferable to adjust the transfer speed V of the first pump 20B. Further, the transfer amount of the coating raw material liquid transferred in one transfer process from the start to the stop of the transfer of the raw material for coating (from the start to the stop of the first pump 20B) is preferably 1 kg from the viewpoint of shortening the transfer time. Above, more preferably 2 kg or more. Further, from the viewpoint of physical properties such as the viscosity of the paint, it is preferably 5 kg or less, more preferably 4 kg or less. This transfer amount is obtained by subtracting the electrolyte-containing coating liquid remaining amount in the mixing tank 3 at the start of coating raw material liquid transfer from the maximum storage capacity of the mixing tank 3 (the predetermined amount is the maximum storage capacity of the mixing tank 3). When it is 20%, the transfer amount is preferably 80% of the maximum storage amount of the mixing tank 3).
The ratio of the transfer amount of the coating raw material liquid transferred in the one transfer process to the amount of the electrolyte-containing coating liquid remaining in the mixing tank 3 immediately before the start of the transfer of the coating raw material liquid is 1: 9-4: A range of 1 is preferable.

  The coating raw material liquid quantity measuring unit 6 can measure the storage amount (volume) by detecting the liquid level of the coating raw material liquid stored in the preparation tank 2, for example, from the viewpoint of good measurement accuracy. A scale that measures the mass of the coating material solution stored in the preparation tank 2 is preferable.

  The electrolyte addition device 4 is also provided with an electrolytic mass measuring unit 8, and the stop of the addition of the electrolyte into the mixing tank 3 is based on the amount of electrolyte in the electrolyte addition device 4 measured by the electrolytic mass measuring unit 8. Done. That is, the addition of the electrolyte to the mixing tank 3 is stopped when the amount obtained by subtracting the desired addition amount from the amount of electrolyte in the electrolyte addition device 4 before the start of addition is reached. The addition rate of the electrolyte is preferably 150 g / min or more, more preferably 500 g / min or more. Further, it is preferably 7.5 kg / min or less, more preferably 4 kg / min or less. The above range is desirable from the viewpoint of suppressing variation in the electrolyte concentration in the mixing tank 3 within a predetermined range. The addition amount of the electrolyte is set according to the transfer amount of the coating raw material liquid from the preparation tank 2 so that the electrolyte concentration of the electrolyte-containing coating liquid in the mixing tank 3 becomes a desired value.

  The electrolytic mass measuring unit 8 can measure the amount of storage (volume) by detecting the surface layer of the electrolyte stored in the storage unit of the electrolyte addition device 4, for example, from the viewpoint of good measurement accuracy, A scale that measures the mass of the electrolyte stored in the storage unit of the electrolyte addition device 4 is preferable.

  Here, the reason why the electrolyte concentration unevenness can be suppressed in the present invention will be described with specific examples. It is assumed that the electrolyte concentration of the electrolyte-containing coating solution in the mixing tank 3 is 10%. When the electrolyte-containing coating liquid in the mixing tank 3 is applied to the base material by the coating process, and the mass of the electrolyte-containing coating liquid in the mixing tank 3 reaches 10 kg as a predetermined amount, 0 is transferred from the preparation tank 2 to the mixing tank 3. Assume that 9 kg of coating raw material liquid is transferred. The electrolyte concentration in the mixing tank 3 can be maintained at 10% by setting the amount of electrolyte added at this time to 0.1 kg. However, the addition amount of the electrolyte addition device may vary. This can occur particularly when a powdered electrolyte is added by a screw feeder. Here, for example, when the amount of electrolyte added is 0.11 kg, an electrolyte-containing coating solution having an electrolyte concentration of 10.9% is supplied into the mixing tank 3. Even in this case, in the present invention, since 10 kg of the electrolyte-containing coating solution remains in the mixing tank 3, the electrolyte concentration in the entire mixing tank 3 becomes 10.08%. That is, the residual electrolyte-containing coating liquid in the mixing tank 3 absorbs the variation in the electrolyte concentration and stabilizes the electrolyte concentration. As described above, when the amount of the electrolyte-containing coating solution in the mixing tank 3 measured by the measuring unit 7 is equal to or less than a predetermined amount, the transfer of the coating raw material liquid to the mixing tank 3 where the electrolyte-containing coating solution remains and the electrolyte By performing the addition, it is possible to effectively suppress uneven electrolyte concentration in the electrolyte-containing coating solution.

Here, the effect of suppressing uneven electrolyte concentration will be described with reference to FIGS. 4 and 5, for example, with respect to the difference from the method of directly adding an electrolyte to a coating applied to a substrate as in Patent Document 2. FIG. 4 is a diagram showing changes in the electrolyte concentration when the coating apparatus 1 in the present embodiment is used. The graph of FIG. 4A is a graph showing the time change of the electrolytic mass supplied from the electrolyte addition device 4 to the mixing tank 3. The graph of FIG. 4B is a graph showing the change over time of the electrolyte concentration of the electrolyte-containing coating solution in the mixing tank 3. On the other hand, FIG. 5 shows an electrolyte concentration when a manufacturing apparatus for manufacturing a heating element by adding an electrolyte to a coated material on a substrate after coating a coating raw material solution not containing an electrolyte as a coating solution is used. It is a figure which shows a nonuniformity, and the graph on the right is a graph which shows the time change of the electrolyte concentration of the coating material on the base material after electrolyte addition.
Even if the electrolyte supply amount is deliberately varied as shown in the graph of FIG. 4A, the variation in the electrolyte concentration of the electrolyte-containing coating solution in the mixing tank is caused by dilution with the remaining electrolyte-containing coating solution. As shown in the graph shown in FIG. On the other hand, in the method shown in FIG. 5, the variation in the electrolyte supply amount leads to the uneven electrolyte concentration of the coated material on the substrate as it is. Thus, in the manufacturing method of this embodiment, since the electrolyte containing coating liquid is continuously produced | generated in the mixing tank 3, electrolyte concentration nonuniformity can be suppressed effectively.

  In addition, as described above, the mixing tank 3 has a smaller volume than the preparation tank 2, and is stored in the preparation tank 2 in one transfer process from the start to the stop of the coating raw material liquid. A part of the coating raw material liquid is transferred to the mixing tank 3. In a mixing tank having a volume that can transfer all of the coating raw material liquid in the batch-type preparation tank 2 in one transfer process, it is difficult to use up the electrolyte-containing coating liquid in the mixing tank 3 at the time of manufacturing the heating element. Thus, if the electrolyte-containing coating solution is held in the mixing tank 3 for a long time, the mixing tank 3 may be corroded. Moreover, since the time which stays in the mixing tank 3 until it transfers to the application part 5 after an electrolyte is added becomes long, separation | sedimentation progresses and there exists a possibility that density | concentration nonuniformity, such as a metal oxide particle, may arise.

In view of the above reasons, the maximum storage amount W of the mixing tank 3 is determined by the consumption rate of the application unit 5, that is, the transfer rate X (kg / min) of the second pump 21B of the second transfer unit 21, and the pot of the electrolyte-containing coating solution It is preferable to be equal to or less than the product of the life (potential time) T (min), that is, W ≦ X × T. Here, the pot life T of the electrolyte-containing coating solution is the time required from immediately after the production of the electrolyte-containing coating solution until it becomes difficult to apply the electrolyte-containing coating solution, that is, the state in which the electrolyte-containing coating solution can be applied. It is time that can be maintained. As described above, due to the fact that this electrolyte-containing coating solution contains metal particles having a large specific gravity, water separation of solids is likely to occur over time, and the pot life is essentially short. That is, the electrolyte-containing coating solution is potentially poor in storage stability, and a viscosity decrease with time can occur.
By maintaining the above relationship of W ≦ X × T, the electrolyte-containing coating liquid in the mixing tank 3 can be kept in a continuously usable state for a longer time without water separation. It is possible to provide a form more suitable for industrial production. In this embodiment, the pot life T of the electrolyte-containing coating solution is preferably 6 hours or more and 12 hours or less.
The pot life T is determined by the change rate of the solid content of the electrolyte-containing coating solution. Water separation proceeds when the electrolyte-containing coating solution is left for a long time. The time during which the solid content of the separated electrolyte-containing coating liquid is not changed by 4% or more compared to the initial solid content is defined as the pot life of the electrolyte-containing coating liquid.

  According to such a method for transferring an electrolyte-containing coating solution, it is possible to always supply an electrolyte-containing coating solution in a stable state immediately after preparation to the coating unit 5 without causing solid separation or the like, It becomes possible to produce a high-quality coating material efficiently and continuously.

(5) Coating step In the coating step, the electrolyte-containing coating solution mixed in the mixing tank 3 is transferred to the coating unit 5 by the second transfer unit 21, and the strip-shaped substrate being conveyed by the coating unit 5 11 is applied to one surface. The application amount of the electrolyte-containing coating solution is not particularly limited as the basis weight in the state of the heat generating layer 12, but is preferably 100 g / m ² or more, more preferably 500 g / m ² or more in terms of solid content. And preferably it is 5000 g / m < ² > or less, More preferably, it is 2500 g / m < ² > or less. More specifically, it is preferably 100 g / m ² or more and 5000 g / m ² or less, more preferably 500 g / m ² or more and 2500 g / m ² or less.

  The transfer rate from the mixing tank 3 to the coating unit 5, that is, the transfer rate X (kg / min) of the second pump 21B of the second transfer unit 21 is preferably 0.3 kg / min or more, more preferably 1.0 kg / min. It is more than min. Further, it is preferably 10 kg / min or less, more preferably 5 kg / min or less. The above range is desirable from the viewpoint that the transfer speed can be set in accordance with the coating amount of the electrolyte-containing coating solution in the coating unit 5.

  The relationship between the transfer speed V (kg / min) of the first pump 20B in the first transfer unit 20 and the transfer speed X (kg / min) of the second pump 21B of the second transfer unit 21 is as follows. It is preferable that the transfer speed V (kg / min) of the first pump 20B is greater than the transfer speed X (kg / min) of the second pump 21B of the second transfer unit 21. By satisfying this condition, the coating raw material liquid is transferred from the preparation tank 2 to the mixing tank 3 even while the coating apparatus is continuously applied to the substrate 11, that is, while being continuously applied by the transfer unit 5. The remaining amount of the electrolyte-containing coating solution in the mixing tank 3 can be increased.

  Conventionally, in this type of coating apparatus, a preparation tank that mixes coating solution raw materials to prepare a coating solution and a coating means that uses the prepared coating solution are directly connected via a pipe. The preparation tank was not only used as a coating liquid preparation tank but also as a coating liquid supply tank. Such an apparatus configuration cannot flexibly cope with temporary stop of the production line or continuous operation during preparation of the coating liquid, and there is room for improvement in terms of production efficiency. In addition, in a conventional coating apparatus in which the preparation tank and the coating means are directly connected, when the production line is stopped, the coating liquid raw material in the middle of preparation remains in the preparation tank. In such a case, a so-called end-cutting operation is required in which the coating solution raw material in the preparation tank is completely discharged to empty the preparation tank. The amount of this cutting operation requires extra work to manufacture the coated material, and there is room for improvement in terms of manufacturing efficiency. In addition, as described above, the electrolyte-containing coating solution is potentially poor in storage stability, and there is a concern about a decrease in viscosity over time. It is desirable from the standpoint of improving production efficiency that it is prepared immediately before use and used up in a relatively short time. However, using a conventional coating apparatus in which a preparation tank and a coating means are directly connected, it is difficult to implement such a desirable usage pattern.

  On the other hand, as in this embodiment, by supplying the coating raw material liquid in the preparation tank 2 to the coating unit 5 via the mixing tank 3, the preparation tank 2 is a preparation tank for the coating raw material liquid. The mixing tank 3 is specialized as a supply tank for the electrolyte-containing coating solution. This division of labor makes it possible to solve the problems such as low production efficiency of the conventional coating apparatus, and to carry out a coating method that handles an oxidizable metal-containing coating solution having a poor storage stability in a more preferable state. That is, it becomes possible to produce a high-quality coated product continuously and stably. Further, since the electrolyte is added to the mixing tank 3 and mixed, the electrolyte concentration unevenness can be suppressed as compared with the method in which the electrolyte is directly added to the base material 11. Further, since the electrolyte is added to the mixing tank 3 having a volume smaller than that of the preparation tank 2, it is possible to minimize the use of expensive materials for preventing corrosion, thereby reducing the cost of capital investment. it can.

  In the heating element manufacturing apparatus 50, as shown in FIG. 1, the coating portion 5 of the coating apparatus 1 applies the electrolyte-containing coating liquid on one surface of the strip-shaped substrate 11 to form the heating layer 12. The heating element intermediate structure 10 which is a two-layer structure coating is manufactured. This strip-shaped coating material 10 is conveyed in the direction shown by the code | symbol X1 in FIG. Then, another one base material 11 is superposed on the heat generating layer 12 of the heat generating intermediate structure 10 to obtain the target three-layered heat generating element 14.

  The heating element 14 thus obtained is used as, for example, a constituent member of a heating tool (not shown). The heating tool is, for example, suitably used for promoting blood circulation throughout the body by wearing it on the waist or shoulder of the human body, suitably used for relaxing by wearing on the eyes, etc. Usually, the heat generating element 14 is disposed between two air permeable sheets (not shown), and the space between the two air permeable sheets is a sealed space in which the heat generating element 14 is accommodated.

Next, the washing | cleaning method which wash | cleans the mixing tank 3 of the manufacturing apparatus of this invention is demonstrated with reference to drawings based on the manufacturing apparatus of this embodiment.
As shown in FIG. 6, in the first embodiment, the mixing tank 3 of the coating apparatus 1 is provided with a faucet 22 as a water supply apparatus for supplying water into the mixing tank 3 (FIG. 6). (See (a)). After the heating element 14 is manufactured, the mixing tank 3 that has used up the electrolyte-containing coating solution is in a state of being easily corroded as described above. First, water is supplied from a faucet into an empty mixing tank 3 that uses up the electrolyte-containing coating solution (water supply step; see FIG. 6A). Next, using the anchor blade 9, the water in the mixing tank 3 is stirred to wash away the electrolyte-containing coating solution adhering to the mixing tank 3 (stirring step; see FIG. 6B). After sufficiently stirring, the water in the mixing tank 3 is discharged using the second pump 21B (discharge step; see FIG. 6 (c)). Through the above steps, the inside of the mixing tank 3 after use can be easily washed.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. The configuration of the coating apparatus is not limited to that shown in FIG. 2. For example, the weighing units provided in the preparation tank 2, the mixing tank 3, and the electrolyte addition apparatus 4 are not limited to scales that measure mass, but are piezoelectric elements. Alternatively, an optical sensor for measuring the surface may be used. Moreover, in the said embodiment, although the transfer part which connects a preparation tank and an application part was piping which connects a preparation tank and an application part, this transfer part is not limited to this, For example, a container transfer means, An automated guided vehicle (AGV) may be used. When the transfer section connecting the preparation tank and the application section is a container transfer means, the liquid in the preparation tank is applied by a transport device such as a belt conveyor or human power in a state of being stored in a portable container (container). Transferred to the department.

  Moreover, the number of the preparation tanks, mixing tanks, and application parts constituting the coating apparatus can be set arbitrarily. For example, by using a coating apparatus having a configuration in which a plurality of mixing tanks are connected to one preparation tank, and a plurality of coating units are connected to each mixing tank on a one-to-one basis, It becomes possible to operate simultaneously. In this case, it is possible to simultaneously manufacture a plurality of types of heating elements having different uses, for example, a heating element for skin mounting and a heating element for eye mounting.

  In addition to the above-described embodiments of the present invention, the following additional notes (heating element manufacturing method, heating element manufacturing apparatus) are disclosed.

<1> A method for manufacturing a heating element, which includes a step of applying an electrolyte-containing coating solution to a substrate to form a heating layer,
A preparation step of preparing a coating raw material liquid by charging and mixing at least oxidizable metal particles and water into a preparation tank;
A part of the coating raw material liquid is transferred to a mixing tank and temporarily stored, and in the mixing tank, the coating raw material liquid and an electrolyte are mixed to generate an electrolyte-containing coating liquid;
A coating step of applying the electrolyte-containing coating solution in the mixing tank to a substrate;
In the mixing step, the amount of the electrolyte-containing coating liquid in the mixing tank is measured by a measuring unit provided in the mixing tank, and when the amount of the electrolyte-containing coating liquid is equal to or less than a predetermined amount, A method for manufacturing a heating element, wherein a part of a coating raw material liquid is transferred from a preparation tank to the mixing tank, and the electrolyte is added to the mixing tank by an electrolyte adding device.

<2> The method for manufacturing a heating element according to <1>, wherein the measuring unit measures the mass of the electrolyte-containing coating solution.
<3> The preparation tank has a coating raw material liquid quantity measuring unit,
In the mixing step, when the amount of the electrolyte-containing coating liquid measured by the measuring unit of the mixing tank is equal to or less than a predetermined amount, the transfer of the coating raw material liquid from the preparation tank to the mixing tank is started, and the coating The method for producing a heating element according to <1> or <2>, wherein the transfer of the coating raw material liquid is stopped based on the amount of the coating raw material liquid measured by the raw material liquid amount measuring unit.

<4> The electrolyte addition device has an electrolytic mass measuring unit,
In the mixing step, when the amount of the electrolyte-containing coating liquid measured by the measuring unit of the mixing tank becomes equal to or less than a predetermined amount, the addition of the electrolyte to the mixing tank is started and measured by the electrolytic mass measuring unit The method for producing a heating element according to any one of <1> to <3>, wherein addition of the electrolyte is stopped based on an amount of the electrolyte to be performed.
<5> The heating element according to any one of <1> to <4>, wherein the predetermined amount is 20% or more and 90 or less of the maximum storage amount of the electrolyte-containing coating liquid in the mixing tank. Manufacturing method.
<6> Between the said preparation tank and the said mixing tank, the 1st transfer part which connects both and transfers the said coating raw material liquid is distribute | arranged, This 1st transfer part is provided with a metering pump, <1> To <5>. The method for producing a heating element according to any one of <5>.

<7> A first transfer unit is provided between the preparation tank and the mixing tank to transfer the coating raw material liquid between the preparation tank and the mixing tank, and between the mixing tank and the coating unit for the electrolyte-containing coating liquid. A second transfer unit that connects the two and transfers the electrolyte-containing coating solution is disposed, and the transfer rate Vkg / min of the coating material solution in the first transfer unit is set to be the electrolyte-containing coating solution in the second transfer unit. The heating element manufacturing method according to any one of <1> to <6>, wherein the heating speed is higher than a transfer rate Xkg / min.
<8> The method for manufacturing a heating element according to any one of <1> to <7>, wherein the mixing tank is a tank having a smaller maximum liquid storage capacity than the preparation tank.
<9> The maximum storage amount of the electrolyte-containing coating solution in the mixing tank is preferably 10 kg or more, more preferably 20 kg or more, and preferably 50 kg or less, more preferably 40 kg or less, from the above <1> to <8> The manufacturing method of the heat generating body of any one.

<10> The maximum storage amount of the coating raw material liquid in the adjustment tank is preferably 50 kg or more, more preferably 100 kg or more, 1000 kg or less, more preferably 500 kg or less, any one of <1> to <9> A method for producing the heating element according to claim 1.
<11> The maximum storage amount W of the mixing tank is equal to or less than the product of the transfer rate X (kg / min) of the second transfer unit and the pot life (pot life) T (min) of the electrolyte-containing coating solution. The method for producing a heating element according to any one of <1> to <10>, wherein
<12> The method for manufacturing a heating element according to any one of <1> to <11>, wherein the electrolyte is added in a solid (powder) state in the mixing step.

<13> The predetermined amount is 20% or more, preferably 40% or more, and 90% or less, preferably 80% or less, of the maximum storage amount of the electrolyte-containing coating solution in the mixing tank 3. The method for manufacturing a heating element according to any one of <1> to <12>.
<14> In the mixing step, the transfer speed X (kg / min) of the second transfer unit that connects the mixing tank and the application unit of the electrolyte-containing coating solution and transfers the electrolyte-containing coating solution is preferably 0.00. 3 kg / min or more, More preferably, it is 1.0 kg / min or more, Preferably it is 10 kg / min or less, More preferably, it is 5 kg / min or less, Any one of said <1> to <13> Method for producing a heating element.

<15> In the preparation step, the transfer speed V of the first transfer unit 20 that connects the preparation tank and the mixing tank and transfers the coating raw material liquid is preferably 1.5 kg / min or more, more preferably 5 kg / The method for producing a heating element according to any one of <1> to <14>, wherein the heating element is min or more, preferably 50 kg / min or less, more preferably 25 kg / min or less.
<16> The electrolyte content (electrolyte concentration) of the electrolyte-containing coating solution in the mixing tank is preferably 0.1% by mass or more, more preferably 1.0%, based on the total mass of the electrolyte-containing coating solution. The method for producing a heating element according to any one of <1> to <15>, wherein the heating element is at least mass%, and preferably at most 15 mass%, more preferably at most 10 mass%.
<17> In the mixing step, the addition rate of the electrolyte is preferably 150 g / min or more, more preferably 500 g / min or more, and preferably 7.5 kg / min or less, more preferably 4 kg / min or less. The method for producing a heating element according to any one of <1> to <16>, wherein

<18> The viscosity of the electrolyte-containing coating solution is preferably 1000 mPa · s or more, more preferably 20000 mPa · s or more, and preferably 100,000 mPa · s or less, more preferably 60000 mPa · s, at 20 ° C. and 60% RH. Hereinafter, more specifically, the heating element according to any one of <1> to <17>, preferably 1000 mPa · s or more and 100,000 mPa · s or less, more preferably 20000 mPa · s or more and 60000 mPa · s or less. Manufacturing method.
<19> The heat generation according to any one of <1> to <18>, wherein the oxidizable metal is one or more selected from the group consisting of iron, aluminum, zinc, manganese, magnesium, and calcium. Body manufacturing method.
<20> The method for manufacturing a heating element according to any one of <1> to <19>, wherein the oxidizable metal is iron.

<21> The particle size of the oxidizable metal particles is preferably 0.1 μm or more, more preferably 5 μm or more, and preferably 300 μm or less, more preferably 100 μm or less, and particularly preferably 50 μm or less. Is preferably 0.1 μm to 300 μm, more preferably 5 μm to 100 μm, and particularly preferably 5 μm to 50 μm, in any one of <1> to <20>.
<22> The method for producing a heating element according to any one of <1> to <21>, wherein the coating raw material liquid includes a carbon component or a thickener.

<23> The content of the oxidizable metal particles is preferably 40% by mass or more, more preferably 50% by mass or more, and preferably 80% by mass or less, based on the total mass of the coating raw material liquid. More preferably, it is 70% by mass or less, more specifically, preferably 40% by mass or more and 80% by mass or less, more preferably 50% by mass or more and 70% by mass or less, and any one of <1> to <22> The manufacturing method of the heat generating body of 1.
<24> The content of the water is preferably 10% by mass or more, more preferably 30% by mass or more, and preferably 60% by mass or less, more preferably 40% by mass with respect to the total mass of the coating raw material liquid. %, More specifically, preferably 10% by mass or more and 60% by mass or less, and more preferably 30% by mass or more and 40% by mass or less, and the heat generation according to any one of <1> to <23>. Body manufacturing method.
<25> The electrolyte is one or more selected from the group consisting of sulfates, carbonates, chlorides, or hydroxides of alkali metals, alkaline earth metals, and transition metals, <1> to <24 The manufacturing method of the heat generating body of any one of>.

<26> The heating element according to any one of <1> to <25>, wherein the electrolyte is at least one selected from the group consisting of chlorides of alkali metals, alkaline earth metals, and transition metals. Manufacturing method.
<27> The electrolyte is one or more selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, magnesium chloride, ferrous chloride and ferric chloride, from the above <1> to <26> The manufacturing method of the heat generating body of any one.
<28> The method for manufacturing a heating element according to any one of <1> to <27>, wherein the electrolyte is sodium chloride.

<29> A heating element manufacturing apparatus for manufacturing a heating element formed by applying an electrolyte-containing coating solution to a substrate,
A preparation tank for preparing a coating raw material liquid containing at least oxidizable metal particles and water, a mixing tank capable of temporarily storing the coating raw material liquid prepared in the preparation tank, and an electrolyte in which an electrolyte is added to the coating raw material liquid A coating apparatus comprising: a coating unit that coats the coating solution to be coated; a first transfer unit that connects the preparation tank and the mixing tank; and a second transfer unit that connects the mixing tank and the coating unit. Have
The mixing tank has a measuring unit for measuring the amount of the electrolyte-containing coating liquid in the mixing tank,
When the amount of the electrolyte-containing coating solution measured by the measuring unit is equal to or less than a predetermined amount, a part of the coating raw material liquid is transferred from the preparation tank to the mixing tank, and the electrolyte provided in the coating apparatus An apparatus for manufacturing a heating element, wherein the electrolyte is added to the mixing tank by an adding device.

<30> The heating unit manufacturing apparatus according to <29>, wherein the measurement unit measures the mass of the electrolyte-containing coating solution.
<31> The preparation tank has a coating raw material liquid quantity measuring unit,
When the amount of the electrolyte-containing coating liquid measured by the measuring unit of the mixing tank is equal to or less than a predetermined amount, the transfer of the coating raw material liquid from the preparation tank to the mixing tank is started, and the coating raw material liquid amount measuring unit The heating element manufacturing apparatus according to <29> or <30>, wherein the transfer of the coating raw material liquid is stopped based on the amount of the coating raw material liquid measured by the above.
<32> The electrolyte adding means has an electrolytic mass measuring section,
When the amount of the electrolyte-containing coating solution measured by the measuring unit of the mixing tank becomes equal to or less than a predetermined amount, the addition of the electrolyte to the mixing tank is started, and the amount of the electrolyte measured by the electrolytic mass measuring unit is started. The heating element manufacturing apparatus according to any one of <29> to <31>, wherein addition of the electrolyte is stopped based on an amount.

<33> The heat generation according to any one of <29> to <32>, wherein the predetermined amount is 20% or more and 90% or less of a maximum storage amount of the electrolyte-containing coating liquid in the mixing tank. Body manufacturing equipment.
<34> The heating device manufacturing apparatus according to any one of <29> to <33>, wherein the first transfer unit includes a metering pump.
<35> From <29> to <34>, the transfer rate Vkg / min of the coating material solution in the first transfer unit is greater than the transfer rate Xkg / min of the electrolyte-containing coating solution in the second transfer unit. The heating device manufacturing apparatus according to any one of the above.

<36> The heating device manufacturing apparatus according to any one of <29> to <35>, wherein the mixing tank is a tank having a maximum liquid storage amount as compared with the preparation tank.
<37> The maximum storage amount of the electrolyte-containing coating solution in the mixing tank is preferably 10 kg or more, more preferably 20 kg or more, and preferably 50 kg or less, more preferably 40 kg or less, from the above <29> to <36> The heating device manufacturing apparatus according to claim 1.
<38> The maximum storage amount of the coating raw material liquid in the adjustment tank is preferably 50 kg or more, more preferably 100 kg or more, 1000 kg or less, more preferably 500 kg or less, any of <29> to <37> The heating element manufacturing apparatus according to claim 1.

<39> The maximum storage amount W of the electrolyte-containing coating solution in the mixing tank is equal to or less than the product of the transfer rate Xkg / min of the second transfer unit and the pot life Tmin that is the pot life of the electrolyte-containing coating solution. The apparatus for manufacturing a heating element according to any one of <29> to <38>.
<40> The heating element manufacturing apparatus according to any one of <29> to <39>, wherein the electrolyte is added in a solid or powder state.

<41> The predetermined amount is 20% or more, preferably 40% or more, and 90% or less, preferably 80% or less of the maximum storage amount of the electrolyte-containing coating solution in the mixing tank 3. The heating element manufacturing apparatus according to any one of <29> to <40>.
<42> The transfer rate Xkg / min of the second transfer unit is preferably 0.3 kg / min or more, more preferably 1.0 kg / min or more, and preferably 10 kg / min or less, more preferably 5 kg. The heating element manufacturing apparatus according to any one of <29> to <41>, which is equal to or less than / min.
<43> The transfer speed V of the first transfer unit 20 is preferably 1.5 kg / min or more, more preferably 5 kg / min or more, and preferably 50 kg / min or less, more preferably 25 kg / min or less. The heating device manufacturing apparatus according to any one of <29> to <42>, wherein:

<44> The electrolyte content (electrolyte concentration) of the electrolyte-containing coating solution in the mixing tank is preferably 0.1% by mass or more, more preferably 1.0%, based on the total mass of the electrolyte-containing coating solution. The apparatus for producing a heating element according to any one of <29> to <43>, wherein the heating element is at least mass%, and preferably at most 15 mass%, more preferably at most 10 mass%.
<45> The addition rate of the electrolyte is preferably 150 g / min or more, more preferably 500 g / min or more, and preferably 7.5 kg / min or less, more preferably 4 kg / min or less. 29> to <44>. The heating element manufacturing apparatus according to any one of <44>.

<46> The mixing tank includes a water supply device that supplies water into the mixing tank, supplies water by the water supply device, and stirs the water by a stirring unit provided in the mixing tank. The apparatus for manufacturing a heating element according to any one of <29> to <45>, wherein the water can be washed by discharging the water by the second transfer unit.
<47> The method for cleaning an apparatus for manufacturing a heating element according to <46>, wherein the step of supplying water by the water supply device, the step of stirring the water by the stirring unit, and the second transfer unit A step of discharging the water.

DESCRIPTION OF SYMBOLS 1 Application | coating apparatus 2 Preparation tank 3 Mixing tank 4 Electrolyte addition apparatus 5 Application | coating part 6 Application | coating raw material liquid quantity measurement part 7 Measurement part 8 Electrolytic mass measurement part 9 Anchor blade 10 Heating body intermediate structure 11 Base material 12 Heating layer 13 Heating body belt shape Body 14 Heating element 20 First transfer part 21 Second transfer part 20A, 21A Pipe 20B First pump 21B Second pump 50 Heating element manufacturing apparatus 51 Cutter roll 52 Anvil roll 53 Conveying belt

Claims (11)

A method for producing a heating element comprising a step of applying an electrolyte-containing coating solution to a substrate to form a heating layer,
A preparation step of preparing a coating raw material liquid by charging and mixing at least oxidizable metal particles and water into a preparation tank;
A part of the coating raw material liquid is transferred to a mixing tank and temporarily stored, and in the mixing tank, the coating raw material liquid and an electrolyte are mixed to generate an electrolyte-containing coating liquid;
A coating step of applying the electrolyte-containing coating solution in the mixing tank to a substrate;
In the mixing step, the amount of the electrolyte-containing coating liquid in the mixing tank is measured by a measuring unit provided in the mixing tank, and when the amount of the electrolyte-containing coating liquid is equal to or less than a predetermined amount, A method for manufacturing a heating element, wherein a part of a coating raw material liquid is transferred from a preparation tank to the mixing tank, and the electrolyte is added to the mixing tank by an electrolyte adding device.   The method of manufacturing a heating element according to claim 1, wherein the measuring unit measures the mass of the electrolyte-containing coating solution. The preparation tank has a coating raw material liquid quantity measuring unit,
In the mixing step, when the amount of the electrolyte-containing coating liquid measured by the measuring unit of the mixing tank is equal to or less than a predetermined amount, the transfer of the coating raw material liquid from the preparation tank to the mixing tank is started, and the coating The manufacturing method of the heat generating body of Claim 1 or 2 which stops the transfer of the said coating raw material liquid based on the quantity of the said coating raw material liquid measured by the raw material liquid quantity measurement part. The electrolyte adding device has an electrolytic mass measuring unit,
In the mixing step, when the amount of the electrolyte-containing coating liquid measured by the measuring unit of the mixing tank becomes equal to or less than a predetermined amount, the addition of the electrolyte to the mixing tank is started and measured by the electrolytic mass measuring unit The method for manufacturing a heating element according to any one of claims 1 to 3, wherein addition of the electrolyte is stopped based on an amount of the electrolyte to be performed.   The heating element manufacturing method according to any one of claims 1 to 4, wherein the predetermined amount is 20% or more and 90% or less of a maximum storage amount of the electrolyte-containing coating liquid in the mixing tank.   The first transfer unit is arranged between the preparation tank and the mixing tank so as to connect the two and transfer the coating raw material liquid, and the first transfer unit includes a metering pump. The manufacturing method of the heat generating body of Claim 1.   A first transfer unit is disposed between the preparation tank and the mixing tank to transfer the coating raw material solution, and is connected between the mixing tank and the application unit for the electrolyte-containing coating solution. A second transfer unit for transferring the electrolyte-containing coating solution is disposed, and the transfer rate Vkg / min of the coating material solution in the first transfer unit is the transfer rate of the electrolyte-containing coating solution in the second transfer unit. The manufacturing method of the heat generating body of any one of Claim 1 to 6 larger than Xkg / min. A heating element manufacturing apparatus for manufacturing a heating element formed by applying an electrolyte-containing coating solution to a substrate,
A preparation tank for preparing a coating raw material liquid containing at least oxidizable metal particles and water, a mixing tank capable of temporarily storing the coating raw material liquid prepared in the preparation tank, and an electrolyte in which an electrolyte is added to the coating raw material liquid A coating apparatus comprising: a coating unit that coats the coating solution to be coated; a first transfer unit that connects the preparation tank and the mixing tank; and a second transfer unit that connects the mixing tank and the coating unit. Have
The mixing tank has a measuring unit for measuring the amount of the electrolyte-containing coating liquid in the mixing tank,
When the amount of the electrolyte-containing coating solution measured by the measuring unit is equal to or less than a predetermined amount, a part of the coating raw material liquid is transferred from the preparation tank to the mixing tank, and the electrolyte provided in the coating apparatus An apparatus for manufacturing a heating element, wherein the electrolyte is added to the mixing tank by an adding device.   The heating element manufacturing apparatus according to claim 8, wherein the predetermined amount is 20% or more and 90% or less of the maximum storage amount of the electrolyte-containing coating liquid in the mixing tank.   The mixing tank has a water supply device that supplies water into the mixing tank, supplies water by the water supply device, and stirs the water by a stirring unit provided in the mixing tank. The heating element manufacturing apparatus according to claim 8, wherein the heat generating element can be cleaned by discharging the water by a transfer unit. 11. The cleaning method for a heating element manufacturing apparatus according to claim 10, wherein the step of supplying water by the water supply device, the step of stirring the water by the stirring unit, and the discharging of the water by the second transfer unit. A cleaning method.

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