JP6817015B2 - Manufacturing method of laminated heating element - Google Patents

Description

The present invention relates to a method for producing a laminated heating element having a heating layer.

Conventionally, a laminated heating element in which a heat generating composition is enclosed in a breathable coating material has been widely used for imparting heat to the human body. As a method for producing such a laminated heating element, a method for producing a laminated heating element in which a heating layer is arranged between a first base sheet and a second base sheet is known.

The applicant first applies the heat-generating additive to the first base material sheet, then forms a streak-like recess on the outer surface of the heat-generating additive, and after superimposing the second base material sheet, corresponds to the recess. We have proposed a method for producing a laminated heating element that prevents delamination by sealing the portion and cutting the sealed portion (see Patent Document 1).

Further, the applicant first superimposes the first base sheet and the second base sheet, and then heats and melts the portion corresponding to the uncoated region of the heating element composition to form the first base sheet and the second base sheet. A method for producing a laminated heating element that prevents delamination by joining and cutting a base sheet has been proposed (see Patent Document 2).

JP-A-2015-42457 Japanese Unexamined Patent Publication No. 2014-94038

However, in the method for producing a laminated heating element described in Patent Document 1, since the heat generating composition is scraped off to form recesses after the heat generating composition is applied, the bonding strength is lowered when the heat generating composition cannot be completely scraped off. There is a risk of As described above, the manufacturing method described in Patent Document 1 has room for further improvement.

Further, in the method for producing a laminated heating element described in Patent Document 2, since the fusing member is heated to fusing the first base material sheet and the second base material sheet, the surroundings of the fusing portion are affected by radiant heat and the like. It becomes easy to receive. As described above, there is room for further improvement in the manufacturing method described in Patent Document 2.
It is conceivable to improve the bonding strength by using an adhesive such as hot melt to reduce the bonding strength, but when an adhesive such as hot melt is used, the adhesive such as hot melt is used. When it comes into contact with the heat-generating composition, there is a problem that the heat-generating characteristics of the heat-generating composition deteriorate.

Therefore, an object of the present invention is to provide a method for manufacturing a laminated heating element that can eliminate the above-mentioned drawbacks of the prior art.

The present invention is a method for producing a laminated heating element in which a heat generating layer containing a heat generating composition is arranged between a first base material sheet and a second base material sheet, the first base material sheet and the second base material sheet. One of the base sheet is formed containing heat-sealing fibers, and the heat-generating composition is applied so that an uncoated region is formed on the surface of the strip-shaped first base sheet being conveyed. The coating process of coating along the transport direction and the first base sheet so as to cover the heat generating layer formed on the surface of the first base sheet and on the uncoated region of the first base sheet. In the stacking step of superimposing the strip-shaped second base sheet so as to arrange the two base sheets to obtain a laminated heat generating intermediate, and in the uncoated region of the laminated heat generating intermediate, the uncoated portion is obtained. It is an object of the present invention to provide a method for manufacturing a laminated heating element, which comprises a joining fusing step of fusing at the same time as joining by ultrasonic waves along a work area.

According to the method for producing a laminated heating element of the present invention, it is difficult to cause a decrease in the heat generation characteristics of the heating layer of the laminated heating element while suppressing a decrease in the bonding strength between the first base sheet and the second base sheet. ..

FIG. 1 is a schematic view showing a apparatus for manufacturing a laminated heating element according to a first embodiment, which is a preferred embodiment of the present invention. FIG. 2 is a schematic perspective view showing a main part of the manufacturing apparatus shown in FIG. FIG. 3A is a diagram schematically showing an ultrasonic horn and a receiving roll of a joint fusing portion included in the manufacturing apparatus shown in FIG. 1, and FIG. 3B is a diagram showing an ultrasonic wave shown in FIG. 3A. It is a partial enlarged view which shows the contact part between the tip part of a horn and the groove part of a receiving roll. FIG. 4 is a schematic view showing a apparatus for manufacturing a laminated heating element according to a second embodiment, which is a preferred embodiment of the present invention. FIG. 5 is a diagram schematically showing another form of the joint fusing portion included in the manufacturing apparatus shown in FIG.

Hereinafter, the present invention will be described based on the preferred first embodiment with reference to the drawings.
The production method of the present invention is a method for producing a laminated heating element in which a heat generating layer containing a heat generating composition is arranged between a first base material sheet and a second base material sheet. The laminated heating element 1A manufactured by the method for manufacturing a laminated heating element of the first embodiment is, for example, a heating element provided in a heating element. The heating element is configured by covering the entire laminated heating element 1A with a breathable first covering sheet 7A and a non-breathable second covering sheet 7B, which will be described later. The laminated heating element 1A is made of the same or different materials so as to sandwich the layer containing the heat generating composition 3b (hereinafter, also referred to as "heating layer 3") and the layer of the water retaining material 4b (hereinafter, also referred to as "water retaining layer 4"). The first base sheet 2A and the second base sheet 2B of the above are arranged and configured.

In the present embodiment, the heat generating layer 3 is a water-containing layer having a heat generating composition 3b containing an oxidizing metal, a carbon component, water, and the like and an electrolyte 5b. The heating layer 3 generates heat by utilizing the oxidation reaction of the metal to be oxidized.

As the oxidizable metal constituting the exothermic composition 3b, a metal that generates heat of oxidation reaction is used, and for example, one or more powders selected from iron, aluminum, zinc, manganese, magnesium, and calcium. Examples include fiber. Among them, iron is preferable from the viewpoint of handleability, safety, manufacturing cost, storage stability and stability, and iron powder is particularly preferable. Examples of the iron powder include reduced iron powder and atomized iron powder.

The carbon component constituting the exothermic composition 3b has at least one function of water retention ability, oxygen supply ability, and catalytic ability, and it is preferable that the carbon component has these three functions. As the carbon component, for example, one or more selected from activated carbon, acetylene black, and graphite can be used. Among these, activated carbon is preferably used from the viewpoint of easily adsorbing oxygen when wet and keeping the water content in the laminated heating element 1A constant. More preferably, one or more fine powders or small granules selected from coconut shell coal, wood pulverized coal and pete charcoal are used. Of these, wood pulverized coal is preferable because it is easy to keep the water content of the laminated heating element 1A within a desired range.

In addition to the carbon component, the heat generating composition 3b may contain other components having the same function, that is, water retention ability and the like. Such components include, for example, one or more selected from vermiculite, sawdust and silica gel. When these other components are contained in the heating layer 3, the ratio of the carbon component to the total amount of these other components and the carbon component must be 90% by mass or more to reduce the water content in the laminated heating element 1A. From the viewpoint of control, it is preferably 95% by mass or more, more preferably 98% by mass or more.

The electrolyte 5b contained in the heating layer 3 is used for the purpose of increasing the reaction efficiency of the metal to be oxidized and promoting the reaction to sustain the oxidation reaction. By using the electrolyte 5b, the oxide film of the metal to be oxidized can be destroyed and the oxidation reaction can be promoted. Examples of the electrolyte 5b include one or more selected from alkali metals, sulfates of alkaline earth metals, and chlorides. Among them, it is selected from various chlorides such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, iron 1 chloride, iron 2 chloride, and sodium sulfate because of their excellent conductivity, chemical stability, and production cost. It is preferable to use one type or two or more types.

The water contained in the heating layer 3 is used not only for the oxidation reaction of the metal to be oxidized, but also as a steam source generated by the heat generated by the oxidation reaction of the metal to be oxidized and as a refrigerant for cooling the generated heat to an appropriate temperature. Used. In the laminated heating element 1A manufactured by using the manufacturing apparatus 100A described later, the water retention layer 4 is arranged so as to be in contact with the heating layer 3, and the amount of water contained in the laminated heating element 1A before the reaction is determined. It is important from the viewpoint of controlling the temperature characteristics at the initial stage of heat generation.

The water retention layer 4 is made of a material capable of retaining water. A particularly preferable water-retaining material 4b for the water-retaining layer 4 is a water-absorbent polymer, which has an extremely high water-retaining amount and has a property of discharging water due to changes in heat and salt concentration. In the laminated heating element 1A manufactured by using the manufacturing apparatus 100A described later, in the initial stage of heat generation, the water content of the laminated heating element 1A is set to be slightly high and the heat capacity of the laminated heating element 1A is increased to increase the second base material. The increase in reaction speed due to the free ventilation of the sheet 2B is suppressed. Further, by giving the amount of heat generated by the exothermic reaction to the water in the laminated heating element 1A, the amount of heat is consumed by the temperature rise (sensible heat) of the water. Since the water in the laminated heating element 1A is used in this initial heat generation, the electrolyte concentration in the laminated heating element 1A rises sharply. Due to this, the osmotic pressure inside the water-absorbent polymer decreases, and the water held by the water-absorbent polymer is released. Further, the water-absorbent polymer has a property that water is easily separated when the temperature rises, and water is released from the water-absorbent polymer by the combined action of these two effects.

Either one of the first base material sheet 2A and the second base material sheet 2B is formed containing heat-sealing fibers. In the manufacturing method using the manufacturing apparatus 100A described later, both the first and second base sheet sheets 2A and 2B are heat-sealed from the viewpoint of fusing the sheets at the same time as the bonding by ultrasonic waves in the bonding fusing step. It is preferably formed containing sex fibers.

The heat-sealing fibers include, for example, polyolefin fibers such as polyethylene, polypropylene and polyvinyl alcohol, polyester fibers, polyethylene-polypropylene composite fibers, polyethylene-polyester composite fibers, low melting point polyester-polyester composite fibers, and the fiber surface is hydrophilic. Examples thereof include polyvinyl alcohol-polypropylene composite fibers and polyvinyl alcohol-polyester composite fibers. When a composite fiber is used, either a core-sheath type composite fiber or a side-by-side type composite fiber can be used. Each of these heat-sealing fibers can be used alone, or two or more of them can be mixed and used.

Generally, the heat-sealing fiber preferably has a fiber length of 30 mm to 70 mm, and a fiber diameter of 1.0 dtex to 50 dtex. The ratio of the heat-sealing fiber to the first base material sheet 2A or the second base material sheet 2B is 0.1% by mass or more and 10% by mass or less, particularly 0.5% by mass or more and 5% by mass or less. preferable.

Either one of the first base material sheet 2A and the second base material sheet 2B may contain hydrophilic fibers or the like in addition to the heat-sealing fibers. As the hydrophilic fiber, either a natural fiber or a synthetic fiber can be used. By containing hydrophilic fibers as constituent fibers of the first and second base sheet sheets 2A and 2B, for example, hydrogen bonds are formed with the oxidizing metal powder contained in the heating layer 3 of the laminated heating element 1A. There is an advantage that the shape retention of the heating layer 3 is improved. Further, by containing the hydrophilic fiber, the water absorption or water retention of the first and second base sheets 2A and 2B is improved, and for example, there is an advantage that the water content of the heat generating layer 3 can be easily controlled. .. From these viewpoints, it is preferable to use cellulose fibers as the hydrophilic fibers. As the cellulose fiber, a chemical fiber (synthetic fiber) and a natural fiber can be used.

As the chemical fiber of cellulose, for example, rayon and acetate can be used. On the other hand, examples of natural cellulose fibers include various plant fibers such as wood pulp, non-wood pulp, cotton, hemp, wheat straw, hemp, jute, capoc, palm, and rush. Among these cellulose fibers, it is preferable to use wood pulp from the viewpoint that thick fibers can be easily obtained. The use of thick fibers as the cellulose fibers is advantageous from the viewpoints of water absorption or water retention of the first and second substrate sheets 2A and 2B, retention of the heating layer 3 of the laminated heating element 1A, and the like.

Each of the first and second base material sheets 2A and 2B has a basis weight of preferably 10 g / m ² or more, more preferably 35 g / m ² or more, and preferably 200 g / m ² or less, more preferably 200 g / m ² or less. It is 150 g / m ² or less. By setting the basis weights of the first and second base sheets 2A and 2B within this range, it is possible to sufficiently secure the strength of the first and second base sheets 2A and 2B in a wet state, and also. The water absorption or water retention of the first and second base sheets 2A and 2B can be made suitable. These basis weights are values measured for the first and second base sheets 2A and 2B in a dry state before the heat generating layer 3 is formed on the first and second base sheets 2A and 2B. is there.

Next, the method for manufacturing the laminated heating element of the present invention will be described with reference to FIGS. 1 to 3 by taking the above-mentioned manufacturing method for the laminated heating element 1A as an example. In explaining the method for manufacturing the laminated heating element 1A of the first embodiment, the manufacturing apparatus 100A of the first embodiment will be described first. FIG. 1 schematically shows an embodiment of a manufacturing apparatus (hereinafter, also referred to as “manufacturing apparatus 100A”) used in a method for manufacturing a heating element including the laminated heating element 1A of the first embodiment. In the following description, the transport direction (longitudinal direction of the base sheet) for transporting the sheet by rotating the roller in the circumferential direction is the Y direction, and the direction orthogonal to the Y direction (width direction of the base sheet) is X. The direction and the thickness direction of the sheet to be conveyed will be described as the Z direction.

As shown in FIG. 1, in the manufacturing apparatus 100A of the first embodiment, the coating unit 10 for applying the heat-generating composition coating material to the surface of the first base material sheet 2A from the upstream side to the downstream side. Addition part 20 for forming the water retention layer 4 by spraying the water absorbing polymer which is the water retention material 4b on the heat generation composition 3b after the heat generation composition coating is applied to the first base material sheet 2A in the part 10. The second base material sheet 2B is superposed on the first base material sheet 2A and the spraying portion 30 which sprays the electrolyte 5b on the water retention layer 4 to form the heat generating layer 3, and the first and second base materials are superposed. A pair of continuous elongated laminated heating elements 1Abr and 1Abl formed by the joining fusing portion 40 and the joining fusing portion 40 that flute the sheets 2A and 2B at the same time as joining along the transport direction Y are cut in the width direction X. The cutting portion 50 forming the single-wafer laminated heating elements 1Ar and 1Al, the re-pitch portion 60 for adjusting the interval between the laminated heating elements 1Ar and 1Al adjacent to each other in the transport direction Y in the transport direction Y, and the laminated heating elements 1Ar and 1Al. It is provided with a coating portion 70 that covers the first and second coating sheets 7A and 7B.

In the manufacturing apparatus 100A of the first embodiment, the coating unit 10 includes a die coater 11 for applying the heat-generating composition paint, as shown in FIGS. 1 and 2. The die coater 11 continuously coats the surface of the strip-shaped first base material sheet 2A transported from the raw fabric roll 2Ab in the transport direction Y with the heat-generating composition paint along the transport direction Y. There is. In the manufacturing apparatus 100A, the die coater 11 is adapted to apply the heat-generating composition paint so that an uncoated region is formed on the surface of the first base material sheet 2A. Preferably, uncoated areas 2b1, 2b2, 2b3 in which the heat generating composition paint is not applied are formed on both sides of the first base sheet 2A along the transport direction Y and in the central portion passing through the center in the width direction X. In addition, a pair of heat-generating composition paints juxtaposed in the width direction X are applied to the surface of the first base material sheet 2A.

Although the die coater 11 is used in the manufacturing apparatus 100A of the first embodiment, roller coating, screen printing, roller gravure, knife coating, curtain coater and the like may be used instead of the die coater 11. The exothermic composition paint is pre-prepared by a preparation device (not shown).

The heat-generating composition coating material applied in the coating unit 10 of the manufacturing apparatus 100A does not contain an electrolyte and at least contains an oxidizing metal and water. The electrolyte here means an electrolyte added for the purpose of dissolving the oxide formed on the metal to be oxidized, and does not mean that all the electrolytes are not contained at all. This means that the electrolyte 5b sprayed by the spraying unit 30 is substantially not contained, and when tap water is used as water, the chlorine component and the like contained in the tap water are not the electrolytes referred to here. That is, the electrolyte that cannot impart a constant continuous heat generation state to the laminated heating element 1A is not the electrolyte referred to here.

The heat-generating composition coating material can be prepared, for example, by mixing an oxidizing metal and a carbon component or the like, and then adding water to the mixture until it becomes uniform. Even if the surface of the oxidizing metal is damaged by, for example, a carbon component or the like during the preparation of the heat-generating composition coating material, and oxidation of the oxidizing metal is temporarily generated, the heat-generating composition coating material contains the electrolyte 5b. Since it is not, the oxide film formed by oxidation does not dissolve, and further oxidation is hindered. Therefore, the metal to be oxidized does not substantially oxidize until it comes into contact with the electrolyte. Therefore, the progress of the oxidation reaction during storage of the heat-generating composition paint can be suppressed, and the heat-generating loss can be reduced. Further, since the heat-generating composition paint does not contain the electrolyte 5b, the components of the heat-generating composition paint before and during coating maintain good dispersibility. Further, since the heat-generating composition coating material does not contain the electrolyte 5b, it is possible to suppress corrosion of equipment such as a pipe connecting the adjusting device (not shown) to the die coater 11. From the above, the coating unit 10 does not need any special allowance for blocking the metal to be oxidized from the air.

The heat-generating composition coating material preferably contains 25 parts by mass or more of water, particularly 35 parts by mass or more, and preferably 85 parts by mass or less, particularly 75 parts by mass or less, of water with respect to 100 parts by mass of the metal to be oxidized. .. For example, the heat-generating composition coating material preferably contains 25 parts by mass or more and 85 parts by mass or less of water, particularly 35 parts by mass or more and 75 parts by mass or less, with respect to 100 parts by mass of the metal to be oxidized. The proportion of water contained in the heat-generating composition coating material is preferably 18% by mass or more, particularly preferably 23% by mass or more, and particularly 48% by mass or less, particularly 43, based on the total mass of the heat-generating composition coating material. It is preferably mass% or less. For example, the proportion of water contained in the heat-generating composition coating material is preferably 18% by mass or more and 48% by mass or less, particularly preferably 23% by mass or more and 43% by mass or less.

The viscosity of the heat-generating composition coating material is preferably 500 mPa · s or more, particularly preferably 1000 mPa · s or more, preferably 30,000 mPa · s or less, particularly preferably 15,000 mPa · s or less, and further particularly preferably 10,000 mPa · s at 23 ° C. and 50 RH. -S or less, for example, 500 to 30000 mPa · s, particularly 1000 to 15000 mPa · s, particularly preferably 1000 to 10000 mPa · s. A No. 4 rotor of a B-type viscometer was used for measuring the viscosity. The measurement was performed by rotating the rotor at 6 rpm.

In the manufacturing apparatus 100A of the first embodiment, the addition unit 20 is installed downstream of the coating unit 10 as shown in FIGS. 1 and 2. The addition unit 20 has a water-absorbent polymer spraying device 21. The water-absorbent polymer spraying device 21 is directed toward the layer composed of the pair of heat-generating compositions 3b and 3b after the heat-generating composition paint is applied to the band-shaped first base material sheet 2A being conveyed, and the water-retaining material 4b The water-absorbent polymer is continuously sprayed. In the manufacturing apparatus 100A, the addition unit 20 has a pair of water-absorbing polymer spraying apparatus 21 and 21 juxtaposed in the width direction X. A pair of superabsorbent polymers 3b so that the water-absorbent polymer 2b1, 2b2, 2b3 described above of the first base sheet 2A is not sprayed with the water-absorbent polymer 4b by the pair of water-absorbent polymer spraying devices 21 and 21. , 3b, the water-absorbent polymer which is the water-retaining material 4b can be sprayed only on the layer. The water-absorbent polymer which is the water-retaining material 4b constitutes a heat-generating additive additive.

As the water-absorbent polymer sprayed by the water-absorbent polymer spraying device 21, it is preferable to use a hydrogel material capable of absorbing and retaining 20 times or more of its own weight of pure water and gelling. As the water-absorbent polymer, for example, one in the form of particles can be used. The shape of the particles can be, for example, spherical, lumpy, botryoidal, fibrous or the like. The particle size of the particles is preferably 1 μm or more and 1000 μm or less, particularly preferably 10 μm or more and 500 μm or less. Specific examples of the water-absorbent polymer include starch, crosslinked carboxylmethylated cellulose, a polymer or copolymer of acrylic acid or an alkali metal salt of acrylic acid, polyacrylic acid and its salt, and a polyacrylate graft polymer. Can be mentioned.

Further, the water-absorbent polymer has a retention amount of 3 times or more, particularly 5 times or more of its own weight, with respect to an aqueous solution having the same electrolyte concentration as the concentration of the electrolyte 5b contained in the laminated heating element 1A in the state before the start of the oxidation reaction. It is preferable to have. The reason for this is that the water-absorbent polymer, which is the water-retaining material 4b, retains sufficient moisture before the laminated heating element 1A starts the oxidation reaction, so that the amount of water before the oxidation reaction of the laminated heating element 1A is set small. This is because it becomes easy to supply sufficient water to the laminated heating element 1A after the start of the oxidation reaction.

In the manufacturing apparatus 100A of the first embodiment, the spraying section 30 is installed downstream of the adding section 20 as shown in FIGS. 1 and 2. The spraying unit 30 has an electrolyte spraying device 31. The electrolyte spraying device 31 conveys the electrolyte 5b toward the pair of water retention layers 4 laminated on the layers of the pair of heat generating compositions 3b and 3b coated on the first base sheet 2A being conveyed. It is designed to be continuously sprayed along the direction Y. In the manufacturing apparatus 100A, the spraying unit 30 has a pair of electrolyte spraying devices 31 and 31 juxtaposed in the width direction X. The pair of electrolyte spraying devices 31 and 31 can continuously spray the electrolyte 5b toward the pair of water retention layers 4 and 4 along the transport direction Y. The sprayed electrolyte 5b is immediately or gradually dissolved in the exothermic composition 3b over a predetermined time to form the exothermic layer 3. When the electrolyte 5b is added, other solid components (excluding particles of the metal to be oxidized) such as capsules of the scent component may coexist, but preferably only the electrolyte 5b is added alone. When coexisting, other solid components are preferably blended in the exothermic composition 3b described above. By adding the electrolyte 5b alone, an advantageous effect of improving the dispersibility of the other solid components in the heat generating layer 3 is exhibited. In particular, by spraying the electrolyte 5b in a solid state, the amount of water in the heat generating composition 3b can be reduced, and the amount of water absorbed in the first base sheet 2A can also be reduced, so that the first base material can be reduced. The advantageous effect of being able to reduce the basis weight of the sheet 2A is achieved.
As the electrolyte spraying device 31, for example, a screw feeder, an electromagnetic feeder, an auger type feeder, or the like can be used.

The form of the sprayed electrolyte 5b is not particularly limited. For example, it may be a granular material in which each particle has a visible size. Small particles having a size invisible to the naked eye may be used. From the viewpoint of smooth dissolution in the coated heat-generating composition 3b, it is preferable to spray the electrolyte 5b in the form of a powder (powder) as an aggregate of small particles. As such an electrolyte 5b, for example, it is preferable to spray it in a powder state having an average particle diameter of 50 μm or more and 1000 μm or less, particularly 100 μm or more and 800 μm or less. The average particle size can be measured, for example, by a sieving method using a standard sieve of JIS Z8801.
The electrolyte 5b may be uniformly present in the heating layer 3 by the time the laminated heating element 1A is used.

In the manufacturing apparatus 100A of the first embodiment, the joint fusing portion 40 is installed downstream of the spraying portion 30 as shown in FIGS. 1 and 2. The joint fusing portion 40 is fed from an original roll (not shown) onto the surface of the ultrasonic oscillating device 41 having an ultrasonic horn 43 for oscillating ultrasonic waves and the first base material sheet 2A being conveyed. It has an anvil roll 42 on which two base sheet sheets 2B are overlapped. The anvil roll 42 of the joint fusing portion 40 constitutes a receiving roll that presses the ultrasonic horn 43 of the ultrasonic oscillator 41 via the first and second base material sheets 2A and 2B.

In the manufacturing apparatus 100A of the first embodiment, the ultrasonic horn 43 and the anvil roll 42 of the joint fusing portion 40 sandwich the laminated first and second base sheets 2A and 2B as shown in FIG. The ultrasonic horns 43 are installed facing each other, the ultrasonic horn 43 is installed on the first base sheet 2A side, and the anvil roll 42 of the joint fusing portion 40 is arranged on the second base sheet 2B side. That is, in the joint fusing portion 40 of the manufacturing apparatus 100A, the second base material sheet 2B is overlapped from above the first base material sheet 2A, and the first and second base material sheets are overlapped from below the first base material sheet 2A. The ultrasonic horn 43 is pressed against the anvil roll 42 of the joint fusing portion 40 via 2A and 2B, and the first and second base sheets 2A and 2B are overlapped with each other, and the bonding and fusing by ultrasonic waves are performed. It is supposed to be done at the same time.

In the manufacturing apparatus 100A of the first embodiment shown in FIG. 1, the ultrasonic oscillator 41 includes a power supply (not shown), a drive circuit unit (not shown), a piezoelectric body (not shown), and an electrode (not shown). ), An ultrasonic horn 43, and an elevating mechanism (not shown) for raising and lowering the ultrasonic horn 43. The drive circuit unit (not shown) drives a piezoelectric body (not shown), and a drive circuit unit known as a drive circuit unit used in a general ultrasonic oscillator can be used. The drive circuit unit (not shown) is connected to the piezoelectric body (not shown) by electrodes. The piezoelectric body (not shown) constitutes an ultrasonic oscillator and vibrates the ultrasonic horn 43. The piezoelectric body (not shown) is preferably composed of barium titanate, lead titanate, and lead zirconate titanate, and is particularly composed of a mixture containing PbO, TiO ₂ , and ZrO ₂ as main raw materials. Lead titanate titanate is preferred.

In the manufacturing apparatus 100A of the first embodiment, the ultrasonic horn 43 is formed in a substantially cylindrical shape as shown in FIGS. 1 and 3A. Further, since the ultrasonic horn 43 presses the conveyed first and second base sheets 2A and 2B against the anvil roll 42 of the joining fusing portion 40 and fusing at the same time as joining, FIG. As shown, when viewed from the front, the anvil roll 42 side of the joint fusing portion 40 has a tip portion 44 having a sharp vertical cross section. Further, the tip portion 44 is formed so that the tip shape thereof protrudes toward the anvil roll 42 of the joint fusing portion 40 when viewed from the side surface. Here, the front view of the ultrasonic horn 43 means that the ultrasonic horn 43 is viewed from the upstream side or the downstream side of the overlapped first and second base sheet sheets 2A and 2B in the transport direction Y. .. Further, the side view of the ultrasonic horn 43 means that the ultrasonic horn 43 is viewed from one side of the width direction X of the first and second base sheets 2A and 2B.

The ultrasonic horn 43 is formed of one or more selected from metals such as iron, stainless steel, aluminum, copper, brass, and titanium.

In the manufacturing apparatus 100A of the first embodiment, as shown in FIG. 3A, the ultrasonic horn 43 has the first and second base sheets 2A and 2B overlapped with the uncoated areas 2b1 and 2b1 described above. It has three ultrasonic horns 43, 43, 43 from the viewpoint of fusing along 2b2 and 2b3 at the same time as joining. The three ultrasonic horns 43, 43, 43 are juxtaposed in the width direction X. The ultrasonic horns 43, 43, 43 are arranged at locations corresponding to the uncoated areas 2b1, 2b2, 2b3 of the first and second substrate sheets 2A, 2B that are transported and overlapped.

In the manufacturing apparatus 100A of the first embodiment, the elevating mechanism (not shown) elevates and elevates the ultrasonic horn 43 and presses the ultrasonic horn 43 against the anvil roll 42 of the joint fusing portion 40.

In the manufacturing apparatus 100A of the first embodiment, as shown in FIG. 1, the anvil roll 42 of the joint fusing portion 40 is sandwiched between the first and second base sheets 2A and 2B which are overlapped with the ultrasonic horn 43. It is installed facing each other. The anvil roll 42 of the joint fusing portion 40 is installed on the second base sheet 2B side, and the second base sheet 2B conveyed from the second raw fabric roll (not shown) is used as the first base sheet 2A. Overlay on. The anvil roll 42 of the joint fusing portion 40 is a rotating roller, and in FIG. 1, the first and second base sheets 2A and 2B which are rotated counterclockwise and overlapped are conveyed in the conveying direction Y. ing.

In the manufacturing apparatus 100A of the first embodiment, as shown in FIG. 3A, a groove portion 45 is formed on the anvil roll 42 of the joint fusing portion 40 in the direction along the rotation direction. As shown in FIG. 3B, the groove portion 45 is recessed toward the axial center of the anvil roll 42 of the joint fusing portion 40 when viewed from the front, and is formed by being recessed in a sharp shape in the manufacturing apparatus 100. Has been done. When the tip 44 of the ultrasonic horn 43 is inserted into the groove 45, the groove 45 recessed in a sharp shape does not come into contact with the tip 44t of the tip 44 and only the side surface 44s of the tip 44 does not come into contact with the groove 45. It is formed to the depth of contact. In the manufacturing apparatus 100A, the anvil roll 42 of the joint fusing portion 40 has three groove portions 45, 45, 45 corresponding to the three ultrasonic horns 43, 43, 43.

In the manufacturing apparatus 100A of the first embodiment, the cutting portion 50 is installed downstream of the joining fusing portion 40 as shown in FIGS. 1 and 2. The cutting unit 50 has a cutting device 51. The cutting device 51 includes a rotary die cutter 53 having a cutter blade 52 on its peripheral surface and an anvil roll 54. The cutter blade 52 of the rotary die cutter 53 extends in the width direction X on the roll peripheral surface of the rotary die cutter 53, and is a pair of continuous long laminated heating elements 1Abr and 1Abl juxtaposed in the X direction. It is formed wider than the entire width (length in the X direction).

In the manufacturing apparatus 100A of the first embodiment, the re-pitch portion 60 is installed downstream of the cutting portion 50 as shown in FIG. The re-pitch unit 60 has a flight conveyor 61. The transport speed of the flight conveyor 61 is higher than the peripheral speed of the anvil roll 54 of the cutting section 50 installed in the cutting section 50. The flight conveyor 61 has a plurality of rollers 62 arranged so that the rotation axes are parallel to each other, and an endless belt 63 bridged between the rollers 62. The endless belt 63 is configured to orbit in the arrow direction (counterclockwise direction) in FIG. The orbit of the endless belt 63 has a portion 63a in which the support surface of the object to be transported faces downward in the vertical direction (Z direction). The flight conveyor 61 has a suction box 64 at a position of the downwardly facing portion 63a inside the endless belt 63. Further, the endless belt 63 is provided with a plurality of through holes (not shown) for sucking air from the outside to the inside of the orbit by activating the suction box 64. Further, in the manufacturing apparatus 100A, a sensor (not shown) for detecting defects is arranged at any position upstream of the flight conveyor 61. Then, the sensor can detect defects of a pair of single-wafer laminated heating elements 1Ar and 1Al.

In the manufacturing apparatus 100A of the first embodiment, the covering portion 70 is installed downstream of the re-pitch portion 60 as shown in FIG. The covering portion 70 has an endless belt 71 and an anvil roll 72. The endless belt 71 transfers a pair of single-wafer laminated heating elements 1Ar and 1Al that have passed through the re-pitch portion 60 onto a first covering sheet 7A made of a continuous long object. This transfer is performed by stopping the suction performed through the through hole (not shown) of the endless belt 63 of the re-pitch portion 60 when the pair of single-wafer laminated heating elements 1Ar and 1Al are delivered from the re-pitch portion 60. It is supposed to do. The anvil roll 72 of the covering portion 70 is provided on the downstream side of the re-pitch portion 60 so that the second covering sheet 7B is overlapped with the pair of single-wafer laminated heating elements 1Ar and 1Al conveyed by the endless belt 71. It has become.

Next, the manufacturing method of the first embodiment for manufacturing the laminated heating element 1A using the manufacturing apparatus 100A of the first embodiment described above will be described.

In the manufacturing method of the first embodiment, as shown in FIGS. 1 and 2, heat is generated so that uncoated regions 2b1, 2b2, 2b3 are formed on the surface of the band-shaped first base material sheet 2A being conveyed. A coating step of applying the composition paint along the transport direction Y and a heating layer 3 by spraying the electrolyte 5b on the heat generating composition 3b after the heat generating composition paint is applied to the first base material sheet 2A. And the second base material so as to cover the heat generating layer 3 formed on the surface of the first base material sheet 2A and on the uncoated areas 2b1, 2b2, 2b3 of the first base material sheet 2A. A stacking step of superimposing the strip-shaped second base sheet 2B so that the sheets are arranged to obtain a laminated heat generating intermediate 2C, and super over along the uncoated areas 2b1, 2b2, 2b3 of the laminated heat generating intermediate 2C. It is equipped with a bonding fusing process in which the material is fused at the same time as the bonding by sound wave. Further, the method for producing the laminated heating element 1A of the present embodiment includes an addition step of adding a water-absorbing polymer, which is a heat-generating auxiliary additive, to the heat-generating composition 3b after the coating step.

First, the heat-generating composition paint is applied along the transport direction Y so that the uncoated areas 2b1, 2b2, 2b3 are formed on the surface of the strip-shaped first base material sheet 2A (coating step). In the coating step of the manufacturing method of the first embodiment, as shown in FIGS. 1 and 2, the strip-shaped first base material sheet 2A is unwound from the raw fabric roll 2Ab, and the first base material sheet 2A is transferred to the conveyor 12 In the transport direction Y. When the first base material sheet 2A is conveyed by the conveyor 12 in the transfer direction Y, the heat-generating composition paint is applied to the surface of the first base material sheet 2A being conveyed.

In the manufacturing method of the first embodiment, the coating step is performed by using the die coater 11 of the coating unit 10 as shown in FIGS. 1 and 2. Preferably, in the coating step of the production method of the first embodiment, the heat-generating composition coating material is applied to the surface of the strip-shaped first base material sheet 2A transported from the raw fabric roll 2Ab in the transport direction Y by using the die coater 11. Is continuously coated along the transport direction Y. At this time, using the die coater 11, the uncoated areas 2b1, 2b2, 2b3 in which the heat generating composition paint is not applied to both sides of the first base sheet 2A along the transport direction Y and the central portion passing through the center of the width direction X. The heat-generating composition paint is applied so that As a result, layers composed of the pair of heat generating compositions 3b are continuously formed on the surface of the first base material sheet 2A along the transport direction Y at intervals in the width direction. As described above, in the manufacturing method of the first embodiment, in the coating step, the heat generating composition paint is not applied to both sides of the heat generating layer 3 formed from each heat generating composition 3b along the transport direction Y. Regions 2b1, 2b2, 2b3 are formed. When the first base sheet 2A contains hydrophilic fibers, a part of the water of the heat generating composition 3b coated on the surface of the first base sheet 2A is the first base sheet. It will be absorbed by 2A.

Next, as shown in FIGS. 1 and 2, a water retaining material is placed on a layer composed of a pair of heat generating compositions 3b and 3b formed on the surface of the first base material sheet 2A which is conveyed by the conveyor 12 in the conveying direction Y. The water-absorbent polymer of 4b is sprayed, and the water-absorbent polymer is added onto the layer made of the heat-generating composition 3b (addition step). The water-absorbent polymer constitutes a heating aid additive. In the addition step of the production method of the first embodiment, the pair of water-absorbent polymer spraying devices 21 and 21 is used so that the water-absorbent polymer is not sprayed on the uncoated areas 2b1, 2b2 and 2b3 of the first base sheet 2A. In addition, the water-absorbent polymer is sprayed only on the layer composed of the pair of heat-generating compositions 3b and 3b. As a result, a pair of water-retaining layers 4 and 4 made of a water-absorbing polymer are continuously formed along the transport direction Y on the layer made of the pair of heat-generating compositions 3b and 3b. By providing an addition step of adding the water-absorbent polymer which is the water-retaining material 4b as a step different from the above-mentioned coating step, the water-absorbent polymer is spread over a layer composed of the pair of heat generating compositions 3b in a wide range of setting amounts. It can be added, and the amount of water retained in the water retention layer 4 can be freely controlled.

Next, the electrolyte 5b is sprayed on the coated heat-generating composition 3b to form the heat-generating layer 3 (spraying step). In the spraying step of the manufacturing method of the first embodiment, as shown in FIGS. 1 and 2, the first is transported in the transport direction Y by the conveyor 12 using the pair of electrolyte spraying devices 31 and 31 of the spraying section 30. The pair of electrolytes 5b and 5b are continuously sprayed along the transport direction Y on the pair of water retention layers 4 and 4 formed on the surface of the base sheet 2A. The pair of sprayed electrolytes 5b, 5b are immediately or gradually dissolved in the heat generating composition 3b over a predetermined time to form the heat generating layer 3.

Next, the second base sheet 2B is arranged so as to cover the heat generating layer 3 formed on the surface of the first base sheet 2A and on the uncoated areas 2b1, 2b2, 2b3 of the first base sheet 2A. The strip-shaped second base material sheet 2B is laminated so as to obtain a laminated heat generating intermediate 2C (superimposition step). In the stacking step of the manufacturing method of the first embodiment, as shown in FIGS. 1 and 2, the second base material sheet 2B unwound from the original roll (not shown) is conveyed by the conveyor 12 in the conveying direction Y. The first base material sheet 2A is merged from above and superposed by the anvil roll 42 of the joint fusing portion 40. In the stacking step, by superimposing the second base material sheet 2B on the first base material sheet 2A, the heat generating layer 3 and the water retention layer 4 are sandwiched between the first base material sheet 2A and the second base material sheet 2B. 2C, which is a laminated heat generating intermediate, is obtained.

Next, in the uncoated regions 2b1, 2b2, 2b3 of the laminated heat-generating intermediate 2C, the uncoated regions 2b1, 2b2, 2b3 are ultrasonically fused at the same time as joining (joining fusing step). In the joint fusing step of the manufacturing method of the first embodiment, the uncoated area is used by using the ultrasonic horn 43 installed so as to face each other with the laminated heat generating intermediate 2C sandwiched between them and the anvil roll 42 of the joint fusing portion 40. It is fused along 2b1, 2b2 and 2b3 at the same time as joining.

In the joint fusing step of the manufacturing method of the first embodiment, the ultrasonic horn 43 and the anvil roll 42 of the joint fusing portion 40, which are installed facing each other with the laminated heat generating intermediate 2C sandwiched between them, are used in the joining step. The joint fusing process is performed at the same time. By simultaneously superimposing the first and second base sheets 2A and 2B (forming the laminated heat generating intermediate 2C) and joining and fusing with ultrasonic waves, for example, water such as the above-mentioned heat generating composition 3b can be produced. Bonding and fusing by ultrasonic waves are possible before the transition to the second base material sheet 2B or the like, and the bonding strength between the first base material sheet 2A and the second base material sheet 2B can be improved.

Further, by pressing the ultrasonic horn 43 against the anvil roll 42 of the bonding fusing part 40 via the laminated heat generating intermediate 2C and fusing at the same time as the bonding of the laminated heat generating intermediate 2C, the laminated heat generating intermediate 2C can be bonded and Fusing can be performed locally. Therefore, the length X in the width direction of the portion for joining and fusing in the uncoated areas 2b1, 2b2, 2b3 of the laminated heat-generating intermediate 2C can be shortened, and the uncoated areas 2b1, 2b2, 2b3 can be shortened. It is possible to reduce the decrease in the area of the heat generating layer 3 required for formation. In addition, since the length of the portion for joining and fusing in the width direction X is short, it is difficult for the influence of radiant heat or the like to be exerted on the heat generating layer 3 around the fusing portion, and since no adhesive is used, heat is generated. It is possible to prevent deterioration of the heat generation characteristics of the composition.

In particular, in the manufacturing method of the first embodiment, only the ultrasonic horn 43 in which the tip 44t shape of the tip portion 44 has a sharp vertical cross section when viewed from the front and the side surface 44s of the tip portion 44 are grooved portions. Using the anvil roll 42 of the joint fusing portion 40 having the groove portion 45 formed so as to come into contact with the 45 and not to contact the tip 44t with the groove portion 45, only the side surface 44s of the tip portion is brought into contact with the fusing at the same time as the joining. Therefore, it is possible to prevent the tip 44t of the ultrasonic horn 43 from being worn.

In the manufacturing method of the first embodiment, the tip portions 44 of the three ultrasonic horns 43, 43, 43 are pressed against the three grooves 45, 45, 45 of the anvil roll 42 of the joint fusing portion 40, and the uncoated area is formed. It is fused along 2b1, 2b2 and 2b3 at the same time as joining. As a result, a pair of continuous elongated laminated heating elements 1Abr and 1Abl juxtaposed in the width direction X are formed. Both sides of the elongated laminated heating element 1Abr and 1Abl along the transport direction Y are separately collected as trim tr and tr.
As described above, in the manufacturing method of the first embodiment, a pair of continuous elongated laminated heating elements 1Abr and 1Abl are formed.

Next, in the manufacturing method of the first embodiment, when a pair of continuous elongated laminated heating elements 1Abr and 1Abl are formed, the pair of continuous elongated laminated heating elements 1Abr and 1Abl are conveyed to the cutting portion 50. .. In the cutting portion 50, as shown in FIGS. 1 and 2, a pair of continuous elongated laminated heating elements 1Abr and 1Abl are conveyed between the rotary die cutter 53 and the anvil roll 54 of the cutting portion 50. It is cut with a cutter blade 52 to continuously produce a pair of single-wafer laminated heating elements 1Ar and 1Al. Each of the pair of single-wafer laminated heating elements 1Ar and 1Al becomes a laminated heating element 1A manufactured by the manufacturing method of the first embodiment. The pair of continuous long laminated heating elements 1Abr and 1Abl may be cut by the cutting device 51 so as to extend in the width direction X of each laminated heating element 1Abr and 1Abl. For example, the laminated heating elements 1Abr and 1Abl may be cut. It can be done linearly over the width direction X. Alternatively, the cutting can be performed so that the cutting line draws a curve. In any case, it is preferable to adopt a cutting pattern that does not cause trim by cutting.

Then, for example, a heating element having the laminated heating element 1A may be continuously manufactured by using a pair of single-wafer laminated heating elements 1Ar, 1Al (laminated heating element 1A). In the manufacturing method using the manufacturing apparatus 100 of the first embodiment, when a pair of single-wafer laminated heating elements 1Ar, 1Al are formed, as shown in FIG. 1, a pair of single-wafer laminated heating elements 1Ar, 1Al Is conveyed to the re-pitch section 60. In the re-pitch portion 60, a pair of single-wafer laminated heating elements 1Ar, 1Al are continuously placed on a high-speed flight conveyor 61, and the distance between the laminated heating elements 1Ar, 1Al adjacent to each other in the front-rear direction in the transport direction Y. The laminated heating elements 1Ar and 1Al are rearranged at a predetermined distance. When the distance between the laminated heating elements 1Ar and 1Al adjacent to each other in the front-rear direction in the transport direction Y is widened, the components 63a facing downward are transported. At the downwardly facing portion 63a, a pair of single-wafer laminated heating elements 1Ar and 1Al are supported in a suspended state by sucking from a through hole provided in the endless belt 63, and the endless belt 63 orbits. A pair of single-wafer laminated heating elements 1Ar and 1Al are transported. Then, when a pair of single-wafer laminated heating elements 1Ar and 1Al are being transported in a suspended state, when the defective product detected by the defect detection sensor reaches the discharge point of the portion 63a facing downward. , The suction of air by the suction box 64 at the discharge point is switched to a blowout, the defective product is dropped, and the defective product is discharged from the production line.

Next, when passing through the re-pitch portion 60, the pair of single-wafer laminated heating elements 1Ar and 1Al are conveyed to the covering portion 70. In the covering portion 70, as shown in FIG. 1, a pair of single-wafer laminated heating elements 1Ar and 1Al are conveyed on a second covering sheet 7B made of a continuous long object conveyed by an endless belt 71 in a conveying direction Y. Place intermittently in. Then, the second covering sheet 8B made of a continuous long object is overlapped with the anvil roll 72 of the covering portion 70 so as to cover the entire laminated heating elements 1Ar and 1Al.

Through the above steps, a heating element having a structure in which a pair of single-wafer laminated heating elements 1Ar and 1Al are sandwiched between the first coating sheet 8A and the second coating sheet 8B and made of a continuous long object is formed. .. After that, a heating tool made of a continuous long object is introduced into the sealing portion (not shown) by the endless belt 71. The sealing portion (not shown) includes a first roller (not shown) having a seal convex portion on the peripheral surface and a second roller (not shown) having a seal convex portion on the peripheral surface. In the sealing portion (not shown), the extending portions of the first and second covering sheets 8A and 8B extending from the front, back, left and right of each heating element made of a continuous long object are joined by heat sealing, and each of them is joined. Join so as to surround the heating element 7. In this way, a continuous long heat generating tool in which the pair of heating elements is coated with the first covering sheet 7A and the second covering sheet 7B is manufactured. The heating tool is continuously manufactured by cutting the continuously long heating element between adjacent heating elements in the transport direction Y over the width direction X.

As described above, according to the method for manufacturing the laminated heating element 1A of the first embodiment, the laminated heating intermediate 2C is joined and fractured by ultrasonically joining and fusing the laminated heating intermediate 2C at the same time. It can be done locally. Therefore, the length X in the width direction of the portion for joining and fusing in the uncoated areas 2b1, 2b2, 2b3 of the laminated heat-generating intermediate 2C can be shortened, and the uncoated areas 2b1, 2b2, 2b3 can be shortened. It is possible to reduce the decrease in the area of the heat generating layer 3 required for formation. In addition, since the length of the portion for joining and fusing in the width direction X is short, it is difficult for the influence of radiant heat or the like to be exerted on the heat generating layer 3 around the fusing portion, and since no adhesive is used, heat is generated. It is possible to prevent deterioration of the heat generation characteristics of the composition.

Next, a second embodiment of the method for producing a laminated heating element of the present invention will be described with reference to FIG. In explaining the method for manufacturing the laminated heating element 1B of the second embodiment, the manufacturing apparatus 100B of the second embodiment will be described first. FIG. 4 schematically shows an embodiment of a manufacturing apparatus (hereinafter, also referred to as “manufacturing apparatus 100B”) used in a method for manufacturing a heating element including the laminated heating element 1B of the second embodiment.

The difference between the manufacturing apparatus 100B of the second embodiment and the manufacturing apparatus 100A of the first embodiment will be described. The manufacturing apparatus 100B of the second embodiment is the same as the manufacturing apparatus 100A of the first embodiment except that not particularly described, and the description of the manufacturing apparatus 100 of the laminated heating element 1A of the first embodiment is appropriately applied. ..

In the manufacturing method using the manufacturing apparatus 100A of the first embodiment, the stacking step of superimposing the second base sheet 2B on the first base sheet 2A to obtain the laminated heat generating intermediate 2C and joining the laminated heat generating intermediate 2C. When the joining and fusing step of fusing at the same time was performed at the same time, in the manufacturing method using the manufacturing apparatus 100B of the second embodiment, as shown in FIG. 4, the overlapping step and the joining and fusing step are simultaneously performed. Absent. Therefore, in the manufacturing apparatus 100B of the second embodiment, the superimposing portion 80 for performing the laminating step and the joining fusing portion 40B for performing the joining fusing step are separately provided.

In the manufacturing apparatus 100B of the second embodiment, the overlapping portion 80 is installed downstream of the spraying portion 30 as shown in FIG. The overlapping portion 80 joins the second base material sheet 2B conveyed from the raw fabric roll (not shown) with the first base material sheet 2A conveyed by the conveyor 12 on the surface of the first base material sheet 2A. It has a guide roll 81 to be overlapped with.

In the manufacturing apparatus 100B of the second embodiment, as shown in FIG. 4, a joint fusing portion 40B is installed on the downstream side of the overlapping portion 80. The joint fusing portion 40B includes an ultrasonic horn 43 that oscillates ultrasonic waves, and an anvil roll 42B that is arranged to face the ultrasonic horn 43 with the laminated heat generating intermediate 2C interposed therebetween. The anvil roll 42B of the joint fusing portion 40B of the manufacturing apparatus 100B of the second embodiment is a flat roll having a flat outer peripheral surface unlike the anvil roll 42 of the joint fusing portion 40 of the manufacturing apparatus 100A of the first embodiment. The ultrasonic horn 43 of the joint fusing portion 40B of the manufacturing apparatus 100B of the second embodiment is the same as the ultrasonic horn 43 of the joint fusing portion 40 of the manufacturing apparatus 100A of the first embodiment.

Next, a method of manufacturing the laminated heating element 1B using the manufacturing apparatus 100B of the second embodiment described above will be described. The points not particularly described in the method for manufacturing the laminated heating element 1B of the second embodiment are the same as the method for manufacturing the laminated heating element 1A using the manufacturing apparatus 100A of the first embodiment, and the first embodiment The description of the method for manufacturing the laminated heating element 1A using the manufacturing apparatus 100A is appropriately applied.

As described above, in the manufacturing method using the manufacturing apparatus 100B of the second embodiment, the stacking step and the joining fusing step are not performed at the same time. Further, the method for manufacturing the laminated heating element 1B using the manufacturing apparatus 100B according to the second embodiment includes a joining fusing step after the stacking step. Therefore, in the manufacturing method of the second embodiment, the heat generating layer 3 and the water retaining layer 4 are formed so as to overlap on the surface of the first base material sheet 2A, as in the manufacturing method of the first embodiment. In the manufacturing method of the second embodiment, a superposition step and a joint fusing step will be described in particular.

In the stacking step of the manufacturing method of the second embodiment, as shown in FIG. 4, the second base material sheet 2B unwound from the raw fabric roll (not shown) is conveyed by the conveyor 12 in the conveying direction Y. 1 The base sheet 2A is merged from above and laminated by a guide roll 81 to obtain a laminated heat generating intermediate 2C (superimposition step). In the stacking step, by superimposing the second base material sheet 2B on the first base material sheet 2A, the heat generating layer 3 and the water retention layer 4 are sandwiched between the first base material sheet 2A and the second base material sheet 2B. become.

Next, in the manufacturing method of the second embodiment, the first base sheet 2A and the second base sheet 2B are superposed with the heat generating layer 3 and the water retaining layer 4 sandwiched between them, and then the first base sheet is superposed. The material sheet 2A and the second base material sheet 2B (laminated heat generating intermediate 2C) are conveyed to the joint fusing portion 40B.

In the manufacturing method of the second embodiment, the first base material sheet 2A and the second base material sheet 2B (laminated heat generation intermediate 2C) sandwiching the heat generating layer 3 and the water retention layer 4 are ultrasonically bonded to the joint fusing portion 40B. Fusing at the same time as joining (joining fusing process). The bonding and fusing by ultrasonic waves are performed by the anvil roll 42B and the ultrasonic horn 43 of the bonding fusing portion 40B arranged to face each other with the first and second base sheet sheets 2A and 2B (laminated heat generating intermediate 2C) sandwiched between them. Will be.

In the manufacturing method of the second embodiment, the tip portions 44 of the three ultrasonic horns 43, 43, 43 are pressed against the peripheral surface of the flat anvil roll 42B of the joint fusing portion 40B, and the uncoated areas 2b1, 2b2, It is fused along 2b3 at the same time as joining. As a result, a pair of continuous elongated laminated heating elements 1Bbr and 1Bbl juxtaposed in the width direction X are formed. Both sides of the elongated laminated heating element 1Bbr and 1Bbl along the transport direction Y are separately collected as trim tr and tr.

Next, when a pair of continuous elongated laminated heating elements 1Bbr and 1Bbl are formed, the pair of continuous elongated laminated heating elements 1Bbr and 1Bbl are conveyed to the cutting portion 50. Then, as shown in FIG. 4, a pair of continuous elongated laminated heating elements 1Bbr and 1Bbl are cut by the cutting portion 50 to continuously manufacture a pair of single-wafer laminated heating elements 1Br and 1Bl.

In the manufacturing method of the second embodiment, a pair of single-wafer laminated heating elements 1Br and 1Bl are continuously manufactured by cutting a pair of continuous long laminated heating elements 1Bbr and 1Bbl by a cutting portion 50. Each of the pair of single-wafer laminated heating elements 1Br and 1Bl becomes a laminated heating element 1B manufactured by the manufacturing method of the second embodiment.

In the manufacturing method of the second embodiment, the ultrasonic horn 43 is pressed against the anvil roll 42B of the joint fusing intermediate 40B via the laminated heat-generating intermediate 2C to perform fusing at the same time as the laminated heat-generating intermediate 2C, thereby laminating. The heating intermediate 2C can be joined and fused locally. Therefore, the length X in the width direction of the portion for joining and fusing in the uncoated areas 2b1, 2b2, 2b3 of the laminated heat-generating intermediate 2C can be shortened, and the uncoated areas 2b1, 2b2, 2b3 can be shortened. It is possible to reduce the decrease in the area of the heat generating layer 3 required for formation. In addition, since the length of the portion for joining and fusing in the width direction X is short, it is difficult for the influence of radiant heat or the like to be exerted on the heat generating layer 3 around the fusing portion, and since no adhesive is used, heat is generated. It is possible to prevent deterioration of the heat generation characteristics of the composition.
As described above, according to the method for manufacturing the laminated heating element 1B of the second embodiment, the laminated heating element 1B can be obtained while suppressing a decrease in the bonding strength between the first base sheet 2A and the second base sheet 2B. It is possible to suppress a decrease in the heat generation characteristics of the heat generating layer 3 having the heat generating layer 3.

Although the present invention has been described above based on the preferred first and second embodiments, the present invention is not limited to the first and second embodiments.
For example, the production methods of the first and second embodiments include a spraying step of spraying the electrolyte 5b on the heat generating composition 3b to form the heat generating layer 3, but the spraying step may not be provided. Further, in the production methods of the first and second embodiments, after the coating step of coating the heat generating composition 2b, before the spraying step of spraying the electrolyte 5b on the heat generating composition 3b to form the heat generating layer 3. Although an addition step of adding the water-absorbent polymer (SAP), which is a heat-generating auxiliary additive, to the heat-generating composition 3b is provided, the addition step may be omitted, and the addition step may be provided after the spraying step. Good.

Further, in the first embodiment, when viewed from the front, three ultrasonic horns 43, 43, 43 having a tip portion 44 having a sharp vertical cross section and three groove portions 45, 45, 45 of the joint fusing portion 40 are formed. Although the ultrasonic oscillating device 41 including the anvil roll 42 having the structure has been described, for example, as shown in FIG. 5, three ultrasonic horns 46 having a tip portion 47 having a flat bottom surface when viewed from the front. An ultrasonic oscillator equipped with 46, 46, and a diamond-shaped three receiving rolls 48, 48, 48 when viewed from the front may be used. When the ultrasonic oscillator shown in FIG. 5 is used, for example, when the contact portion between the tip portion 47 of each ultrasonic horn 46 and each receiving roll 48 is worn, the contact portion between the ultrasonic horn 46 and the receiving roll 48 is contacted. It is preferable to use the portion while shifting it in the width direction X, and it is preferable to rotate the receiving roll 48 in the circumferential direction.

Further, for example, in the first and second embodiments, the uncoated region in which the heat generating composition 3b is not applied is applied to both sides of the first base sheet 2A along the transport direction Y and the central portion passing through the center of the width direction X. The heat generating composition 3b was applied so that 2b1, 2b2, 2b3 were formed, but the uncoated area is not limited to the shape of the uncoated area 2b1, 2b2, 2b3 described above.

Further, in the manufacturing method using the manufacturing apparatus 100A of the first embodiment, in the joint fusing step, an anvil having three ultrasonic horns 43, 43, 43 and three groove portions 45, 45, 45 of the joint fusing portion 40. Using the ultrasonic oscillating device 41 provided with the roll 42, the first and second base sheets 2A and 2B are continuously cut in the transport direction Y, and a pair of continuous elongated laminated heating elements 1Abr and 1Abl are formed. Although formed, for example, the ultrasonic horn 43 is received via the first base sheet 2A and the second base sheet 2B that are overlapped with each other, and is intermittently pressed against the anvil roll 42 of the joint fusing portion 40, which is a roll. Joining and fusing by ultrasonic waves may be performed intermittently. When joining and fusing by ultrasonic waves are performed intermittently, a groove 45 formed over the entire circumference of the anvil roll 42 of the joining fusing portion 40 is intermittently provided with a recess in the circumferential direction of the anvil roll 42. It may be changed as follows.

In addition, each of the above embodiments can be appropriately combined without departing from the spirit of the present invention.

1A, 1B Laminated heating element 1Abr, 1Abl, 1Bbr, 1Bbl Pair of continuous long laminated heating elements 1Ar, 1Al, 1Br, 1Bl Pair of single-wafer laminated heating elements 2A 1st base sheet 2b1, 2b2, 2b3 Not yet Coating area 2B 2nd base sheet 2C Laminated heating element 3 Heating layer 3b Heating composition 4 Water retention layer 4b Water retention material 10 Coating part 20 Addition part 21 Water-absorbent polymer spraying device 30 Spraying part 31 Electrolyte spraying device 40 Joint fusing Part 41 Ultrasonic oscillator 42 Anvil roll 43 Ultrasonic horn 44 Tip 44t Tip 44s Side surface

Claims (6)

A method for producing a laminated heating element in which a heat generating layer containing a heat generating composition is arranged between a first base material sheet and a second base material sheet.
Either one of the first base material sheet and the second base material sheet is formed containing heat-sealing fibers.
The paint of the heat-generating composition is continuously applied to the surface of the band-shaped first base material sheet being transported along the transport direction to form a plurality of heat-generating layers and an uncoated region located between the heat-generating layers. And the coating process to form
A band shape so as to cover the heat generating layer formed on the surface of the first base material sheet and to arrange the second base material sheet on the uncoated region of the first base material sheet. A stacking step of superimposing the second base material sheets to obtain a laminated heat-generating intermediate, and
In the uncoated region of the laminated heating intermediate, a joining fusing step of obtaining a plurality of continuous long laminated heating elements by fusing at the same time as joining by ultrasonic waves along the uncoated region.
A method for manufacturing a laminated heating element, comprising a cutting step of cutting a plurality of the laminated heating elements in the width direction to form a single-wafer laminated heating element. The method for manufacturing a laminated heating element according to claim 1, wherein the stacking step and the joining fusing step are performed at the same time. The method for producing a laminated heating element according to claim 1 or 2, wherein in the coating step, the uncoated regions are formed on both sides of the first base sheet along the transport direction. In the joint fusing step, an ultrasonic horn that oscillates ultrasonic waves and a rotating receiving roll are used, and the ultrasonic horn is received via the first base material sheet and the second base material sheet that are overlapped with each other. The method for producing a laminated heating element according to any one of claims 1 to 3, wherein the laminated heating element is pressed against a roll and fused at the same time as bonding by ultrasonic waves. The ultrasonic horn has a tip portion having a sharp vertical cross section.
The method for manufacturing a laminated heating element according to claim 4, wherein the receiving roll has a groove portion having a depth that the tip of the tip portion does not contact and the side surface of the tip portion contacts. The method for producing a laminated heating element according to any one of claims 1 to 5, further comprising an addition step of adding a heat generating aid additive to the heat generating composition after the coating step.