JP2003206479A - Exothermic molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a readily handleable exothermic molded product having a high mechanical strength. <P>SOLUTION: This exothermic molded product comprises at least oxidizable metal powder, an electrolyte, a water holding agent, thermoplastic fibers and water. The exothermic molded product has a network structure in which the thermoplastic fibers are mutually fused in the interior thereof. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exothermic molded body utilizing heat generated by an oxidation reaction between oxygen in the air and an oxidizable metal powder, and a method for producing the same.

[0002]

2. Description of the Related Art As a conventional technique relating to a method for producing a heat-generating molded body utilizing the heat generated by the oxidation reaction between oxygen in the air and the oxidizable metal powder, there is, for example, Japanese Patent Laid-Open No. The technique described in Japanese Patent Publication No. 20121253 is known.

This technique involves suspending fibrous substances in water,
An oxidizable metal such as iron powder, activated carbon as a water retention agent, electrolyte as a reaction aid, and the like are added to a raw material slurry, paper is made from the raw material slurry, suction-dewatered, and then pressed to have a water content of 5 to 65 wt%. The heat-generating molded body is manufactured by dehydration molding into a sheet-like shape.

For this reason, the exothermic moldings obtained have weak bonds between the compositions and low mechanical strength, and are difficult to handle when subsequent processing is required. .

Accordingly, it is an object of the present invention to provide a heat-generating molded article having high mechanical strength and easy to handle, and a method for producing the same.

[0006]

The present invention is a heat-generating molded article containing at least an oxidizable metal powder, an electrolyte, a water retention agent, thermoplastic fibers and water, in which the thermoplastic fibers are fused together. The object is achieved by providing a heat-generating molded article having the above-mentioned network structure.

In the present invention, an intermediate compact is made from a raw material composition containing at least an oxidizable metal powder, a water retention agent, a thermoplastic fiber and water in a paper making step, and the intermediate compact is then made into the thermoplastic fiber. By providing a method for producing a heat-generating molded body in which an electrolyte is contained in the intermediate molded body, after heating the thermoplastic fibers to fuse the thermoplastic fibers to each other to form a network structure thereof, It has been achieved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described based on its preferred embodiments with reference to the drawings.

The heat-generating molded article of the present invention contains at least an oxidizable metal powder, an electrolyte, a water retention agent, a thermoplastic fiber and water.

As the oxidizable metal powder, any oxidizable metal powder that has been conventionally used in this type of exothermic molding can be used without particular limitation. As the oxidizable metal powder, for example, iron powder, aluminum powder, zinc powder,
Examples thereof include manganese powder, magnesium powder, calcium powder and the like. Among these, iron powder is preferably used from the viewpoints of handleability, safety and manufacturing cost. The oxidizable metal powder has a fixability to the thermoplastic fiber or a fibrous material described later,
From the viewpoint of good control of the reaction, it is preferable to use particles having a particle size (hereinafter, referred to as a particle size, the maximum length in the form of powder) of 0.1 to 300 μm, and a particle size of 0.1 to 300 μm. It is more preferable to use the one containing 50 μm or more of 150 μm.

The content of the oxidizable metal powder in the exothermic molding excluding water is preferably 10 to 90% by weight, more preferably 30 to 80% by weight. If it is less than 10% by weight, the temperature of the exothermic molded body obtained may not rise to a level higher than that felt by a person touching it with a fingertip or the like. In some cases, an oxide film such as oxidizable metal powder is formed and air permeability is impaired, and as a result, the reaction does not easily occur inside the exothermic molded body, the exothermic temperature cannot be raised, or the exothermic time is shortened. Further, since the thermoplastic fibers forming the sheet-shaped heat-generating molded article, the fibrous material described later, and the adhesive component are reduced, mechanical strength such as bending strength and tensile strength may decrease.

As the above-mentioned electrolyte, any of the electrolytes conventionally used in this kind of exothermic molded article can be used without particular limitation. Examples of the electrolyte include sulfates, carbonates of alkali metals, alkaline earth metals, or heavy metals,
Examples thereof include chlorides and hydroxides. Of these, various chlorides such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, and iron chloride (first and second) are preferably used because of their excellent conductivity, chemical stability, and production cost.

The amount of the electrolyte compounded in the exothermic molded body is preferably 0.5 to 30% by weight, and more preferably 3 to 25% by weight, based on the weight ratio of water in the exothermic molded body to be obtained. preferable. If it is less than 0.5% by weight, the oxidative reaction of the exothermic molded body to be obtained may be suppressed, and if it exceeds 30% by weight, excess electrolyte is deposited and the air permeability of the exothermic molded article obtained is impaired. There are cases.

As the water retention agent, a water retention agent conventionally used in this kind of exothermic molding can be used without particular limitation. The water retention agent not only functions as a water retention agent, but also has a function as an oxygen retention / supply agent to the oxidizable metal powder. Examples of the water-retaining agent include activated carbon (coconut shell charcoal, charcoal powder, calcareous charcoal, peat, lignite), carbon black, acetylene black, graphite, zeolite, perlite, vermiculite, silica, and the like. Activated carbon is preferably used in terms of its ability, oxygen supply ability and catalytic ability. It is preferable to use a water retention agent having a particle size of 0.1 to 500 μm from the viewpoint that an effective contact state with the oxidizable metal powder can be formed.
It is more preferable to use one containing 0.1 to 200 μm of 50% by weight or more.

The content of the water retention agent after removing water from the exothermic molded body is preferably 0.5 to 60% by weight, more preferably 1 to 50% by weight. 0.
If it is less than 5% by weight, the oxidizable metal powder may not be able to accumulate water in a heat-generating molded body that can obtain the water necessary for sustaining the reaction to the extent that the temperature rises above the human body temperature due to the oxidation reaction. When the content is more than weight%, the heat capacity of the obtained exothermic molded body with respect to the calorific value becomes large, the rise in exothermic temperature becomes small, and it may not be possible to feel when a person is warm.

The thermoplastic fibers include high density polyethylene, medium density polyethylene, low density polyethylene, polyolefin such as polypropylene, polyester, vinylidene chloride, polyvinyl alcohol or vinyl acetate, or a single fiber such as a copolymer or modified product thereof. Alternatively, a composite fiber having a core-sheath structure having these resin components in the sheath can be used. Among these, polyolefins and modified polyesters are preferably used in terms of the adhesive strength between fibers, the ease of forming a three-dimensional network structure by fusing fibers together, and the melting point lower than the ignition point of pulp fibers. The thermoplastic fiber has a thickness of 0.1 to 1
It is preferable to use the one of 00 dtex, and 0.5 to
It is more preferable to use the one with 50 dtex. If the wire diameter of the thermoplastic fiber is too thin, the mechanical strength of the fiber itself will be low, so the mechanical strength of the resulting exothermic molded article may be low, and if it is too thick, a three-dimensional network structure will be formed. In some cases, the required amount of fibers becomes large, the thermoplastic fibers are melted during molding and cover the surface of the surrounding oxidizable metal powder, and the exothermicity of the exothermic molded body obtained is reduced. The thermoplastic fibers have an average fiber length of 0.1 to
It is preferable to use a 100 mm one, and 1 to 50 m
It is more preferable to use m. If the fiber length is too short, it becomes difficult for the thermoplastic fibers to come into contact with each other, so that the thermoplastic fibers may not be melt-bonded to each other, and the mechanical strength of the exothermic molded article may not be obtained sufficiently. If it is too much, it becomes difficult to uniformly disperse the thermoplastic fibers in the resulting exothermic molding, and the mechanical strength of the exothermic molding may be reduced.

The blending amount of the thermoplastic fiber in the exothermic molding is preferably 0.1 to 50% by weight,
It is more preferably 0.5 to 30% by weight. When the blending amount of the thermoplastic fibers is less than 0.1% by weight, it becomes difficult for the thermoplastic fibers to come into contact with each other, so that the thermoplastic fibers are not melt-bonded to each other, and the mechanical strength of the exothermic molded article is sufficient. If it exceeds 50% by weight,
The surface of many oxidizable metal powders (powder to generate heat) may be covered with the melted thermoplastic fibers, and the oxidation reaction may be hindered, resulting in deterioration of heat generation of the heat-generating molded body obtained.

The heat-generating molded article of the present invention has a network structure in which the thermoplastic fibers are fused together. The mechanical strength can be enhanced by having a network structure in which the fiber molded bodies are fused to each other inside the molded body.
Further, the oxidizable metal powder on the surface of the thermoplastic fiber,
In addition to the water retention agent, the adhesion of the fibrous material described below and the removal thereof due to being retained in the mesh structure, the oxidizable metal powder retained in the mesh structure, The water retention agent and the fibrous material can also be prevented from falling off by the oxidizable metal powder adhered to the surface of the thermoplastic fiber, the water retention agent and the fibrous material. The mesh structure is 3
It has a dimensional structure. The network structure means a state in which most of the thermoplastic fibers are bonded to other thermoplastic fibers at at least two points on the surface thereof.

It is preferable that the exothermic molded article contains the following natural or synthetic fibrous substances in addition to the thermoplastic fibers. By including the fibrous material, the oxidizable metal powder and the water retention agent can be held in the surface and in the gaps generated by the entanglement of the thermoplastic fibers and the fibrous material to suppress the dropout. While you can
By fixing the oxidizable metal powder and the water retention agent on the surface of the thermoplastic fiber by physical bonding or electrical bonding, it is possible to obtain a double drop-off preventing effect. Examples of the fibrous material include plant fibers (cotton, cabot, wood pulp, non-wood pulp, peanut protein fiber, corn protein fiber, soy protein fiber, mannan fiber, rubber fiber, hemp, and Manila hemp as natural fiber materials. ,
Sisal, New Zealand hemp, Rafu, palm, igusa, straw, etc.), animal fiber (wool, goat hair, mohair, cashmere, alcapa, angora, camel, vicuna, etc.)
Silk, feathers, down, feathers, algin fibers, chitin fibers, casein fibers, etc.) and mineral fibers (asbestos, etc.) can be mentioned. Mix, chlorinated rubber, hydrochloric acid rubber, etc.), metal fiber, carbon fiber,
Glass fiber etc. are mentioned. Also, these recovered and reused products can be used. And, among these, wood pulp and cotton are preferable from the viewpoints of fixability with the powder contained in the raw material composition, flexibility of the resulting exothermic molded article, oxygen permeability due to the presence of voids, production cost, and the like. Used. The fibrous material has an average fiber length of 0.1 to 50.
mm is preferably used, and 0.2 to 20 mm
It is more preferable to use the above. If the fiber length is too short, mechanical strength such as bending strength and tensile strength of the obtained heat-generating molded body may not be sufficiently secured, and if the fiber length is too long, the fibrous material is uniformly dispersed in the heat-generating molded body. It may become difficult to obtain uniform mechanical strength.

The blending amount of the fibrous material in the exothermic molding is preferably 2 to 80% by weight, more preferably 5 to 50% by weight. If it is less than 2% by weight, the effect of preventing the oxidizable metal powder and the water retention agent from falling off may be reduced, and if it exceeds 80% by weight, the heat capacity of the heat-generating molded article with respect to the calorific value becomes large and the temperature rise is small. May be.

Further, the above-mentioned exothermic molded body is made of paper such as a sizing agent, a coloring agent, a paper strength enhancer, a retention improver, a filler, a thickener, a pH control agent and a bulking agent, if necessary, during the papermaking. Additives usually used in the papermaking can be added without particular limitation. The blending amount of the additive in the raw material composition can be appropriately set according to the additive to be added.

The heat-generating molded article of the present invention preferably has a water content (weight water content, the same applies hereinafter) of 5 to 70%,
It is more preferably 10 to 60%. Water content is 5%
If the water content is less than the above value, the water required for sustaining the oxidation reaction cannot be secured, and the oxidation reaction may be terminated in the middle. If the water content exceeds 70%, the heat capacity of the heat generating molded body with respect to the heat generation amount is large. Therefore, the rise in heat generation temperature may be small.

The heat-generating molded article of the present invention has an ultimate heat temperature of 30 to 150 ° C., which is measured by the method described in Examples below.

The shape of the heat-generating molded article of the present invention is not particularly limited, and for example, it has a three-dimensional three-dimensional shape such as a sheet shape, a cup shape, a bowl shape, and a bottle shape. . And, for example, in the case of a sheet shape, the thickness is 0.1 to 20 m from the viewpoint of easy post-processing.
It is preferably m, and more preferably 0.2 to 10 mm. Further, when the exothermic molded body of the present invention has a sheet-like shape, the basis weight thereof is preferably 30 to 5000, and more preferably 50 to 1000 g / m ² .

When the exothermic molded article of the present invention has a sheet-like shape, for example, the tensile strength at a basis weight of 300 g / m ² measured by the method of an embodiment described later is 1.5 N or more. .

Next, an embodiment of the method for manufacturing the exothermic molded body of the present invention will be described.

In the present invention, first, a raw material composition containing at least an oxidizable metal powder, a water retention agent, thermoplastic fibers and water is prepared, and an intermediate molded body is made from the raw material composition in a paper making step. As the oxidizable metal powder, the water retention agent, and the thermoplastic fiber, those used for the exothermic molding of the invention are used. In addition, the raw material composition includes additives such as a sizing agent, a colorant, a paper strength enhancer, a retention improver, a filler, a thickener, a pH control agent, and a bulking agent, which are usually used in the papermaking of paper. Can be added without particular limitation. The blending amount of the additive in the raw material composition can be appropriately set according to the additive to be added.

Next, the raw material composition is paper-made to form an intermediate molded body having a predetermined shape. The papermaking method of the intermediate molded body is
Conventional papermaking methods used for papermaking of molded products in various forms such as sheet form and three-dimensional form can be used without particular limitation. As the papermaking method, for example, in the case where the intermediate molded body is formed into a sheet, a papermaking method using a continuous papermaking type cylinder paper machine, fourdrinier paper machine, shortdrinier paper machine, twin wire paper machine, etc. , A handmade method which is a batch-type papermaking method, and when the intermediate molded body has a three-dimensional shape, for example, Japanese Patent No. 3155522 (page 2, line 4, line 17 to page 4, line 8, line 23). ), The so-called core papermaking method described in, for example, Japanese Patent No. 3155503 (page 2, line 4, line 4 to page 4, line 7, line 6), for example, patent 30.
No. 72088 (Page 2, line 4, line 4 to page 3, line 5 43)
The so-called underwater bonding method, etc. In the papermaking process, the fibrous material can be further kneaded with the surface of the molded product.

The intermediate molded article preferably has a water content (weight water content, hereinafter the same) of 70% or less, from the viewpoint of maintaining the shape after papermaking (shape retention) and maintaining mechanical strength.
It is more preferable to dehydrate it to 60% or less. The dehydration method of the intermediate molded body can be appropriately selected according to the form of the intermediate molded body and the papermaking method. As the dehydration method, for example, when the intermediate molded body is a sheet-shaped molded body, in addition to dehydration by suction, dehydration by blowing pressurized air, dehydration by pressurizing with a pressure roll or a pressure plate. And the like, and in the case where the intermediate molded body is a molded body obtained by using a papermaking mold, a method of dewatering by blowing pressurized air or the like to the intermediate molded body formed into a papermaking mold, Examples of the dehydration method include a method of pressing an intermediate molded body formed in the papermaking mold against the inner surface of the papermaking mold to dehydrate it.

In the present invention, the intermediate molded article containing the thermoplastic fiber is heated to a temperature not lower than the melting temperature of the thermoplastic fiber to form the three-dimensional network structure of the thermoplastic fiber as described above, and the intermediate molding is performed. In addition to increasing the mechanical strength of the body, the oxidizable metal powder, the water retention agent, the fibrous material and the like are retained on the surface of the thermoplastic fiber and in the mesh structure to prevent the oxidizable metal powder from falling off. By positively heating and drying an intermediate molded body containing a metal powder (having heat reactivity in an oxidizing atmosphere) to separate its water content,
While adjusting to a predetermined water content in a short time, to suppress the oxidation of the oxidizable metal powder during the manufacturing process, and to enhance the carrying power of the oxidizable metal powder to the fibrous material after drying. From the viewpoint of suppressing the falling off, it is preferable to dry the intermediate molded body after papermaking of the intermediate molded body and before incorporating an electrolyte described later (after dehydration in the case of including the dehydration step described above).

The heating and drying temperature of the intermediate compact in the drying step is preferably 90 to 300 ° C., and 100 to 100 ° C.
More preferably, it is 200 ° C. When the heating and drying temperature of the intermediate molded body is lower than 90 ° C., the moisture is dried and
The oxidative reaction of the oxidizable metal powder may be promoted, which may cause a decrease in exothermicity. If the temperature exceeds 300 ° C., the performance of the water retention agent or the like may be deteriorated, and the exothermic effect of the exothermic molded article may decrease. is there.

The water content of the intermediate molded product after drying is 5
It is preferably 0% or less, and more preferably 30% or less. If the water content exceeds 50%, the thermoplastic fibers may not be sufficiently melt-bonded to each other, and the resulting heating element may not have sufficient mechanical strength. The method for drying the intermediate molded body can be appropriately selected depending on the form of the intermediate molded body, the method for treating the intermediate molded body before drying, the water content before drying, the water content after drying, and the like. Examples of the drying method include contacting with a heating structure (heating element), spraying of heated air or steam (superheated steam), vacuum drying, electromagnetic wave heating, electric heating, and the like. It can also be carried out at the same time in combination with the aforementioned dehydration method.

In the present invention, the molding of the intermediate compact is
It is preferable to carry out the molding in an inert gas atmosphere, but since the intermediate molded body does not contain an electrolyte serving as an oxidation aid as described above, the molding can be carried out in a normal air atmosphere as necessary. Therefore, the manufacturing equipment can be simplified. Also, if necessary, trimming
It is also possible to perform processing such as changing the form by processing.

Next, an electrolyte is contained in the intermediate compact. The step of incorporating the electrolyte is preferably performed in an atmosphere of an inert gas such as nitrogen or argon. As the electrolyte to be contained in the intermediate molded body, a usual one which has been conventionally used for this type of heat-generating molded body can be used without particular limitation. As the electrolyte, for example, the electrolyte preferably used in the exothermic molding of the present invention is used.

The method of incorporating the electrolyte into the intermediate molded body can be appropriately set depending on the treatment method of the intermediate molded body after papermaking, the water content, the form and the like. Examples of the method include a method of impregnating the intermediate compact with an electrolyte solution having a predetermined concentration of the electrolyte, a method of adding a solid electrolyte having a predetermined particle size to the intermediate compact, and the like. Among these, the method of impregnating with an electrolytic solution of a predetermined concentration is preferably used because the electrolyte can be uniformly contained in the intermediate molded body and the water content can be adjusted at the same time.

When the above-mentioned electrolyte is impregnated with the electrolytic solution into the intermediate compact, the impregnation method can be appropriately selected depending on the form of the intermediate compact and the water content. Examples of the impregnation method include a method of spray-coating the electrolytic solution on the intermediate molded body, a method of coating with a brush, a method of dipping in the electrolytic solution, a gravure coating method, a reverse coating method, a doctor blade method and the like. Among these, the spray coating method is preferable from the viewpoint that the electrolyte can be uniformly distributed, it is simple, and the equipment cost is relatively low.

After the electrolyte is contained in the intermediate molded body as described above, the water content can be adjusted and stabilized if necessary to obtain a heat-generating molded body. Then, it can be processed into a predetermined size by performing trimming, lamination, and the like, if necessary.

In the present invention, an intermediate molded body is made from the raw material composition in a papermaking step, and the intermediate molded body is heated to a temperature not lower than the melting temperature of the thermoplastic fibers to fuse the thermoplastic fibers to each other. After the network structure is formed, the intermediate molded body is made to contain an electrolyte, so that the resulting exothermic molded body has high mechanical strength and suppresses the oxidizable metal powder, the water retention agent and the like from falling off. It is possible and easy to handle.

Further, as described above, since the raw material composition does not contain an electrolyte serving as an oxidation aid, the concentration of ions in the suspension is lowered, so that the material composition in the raw material composition is reduced. The dispersibility of the oxidizing metal powder is improved.
Then, by substantially contacting the oxidizable metal powder and the fibrous substance in the slurry preparation step, the oxidizable metal powder is uniformly fixed on the surface of the fibrous substance, and the heat generation characteristics of the heat-generating molded body obtained. Is improved.

Furthermore, it is possible to easily control the electrolytic mass to be contained in the exothermic molded body and the water content of the exothermic molded body, and to suppress the oxidation of the oxidizable metal during the manufacturing process as much as possible, so that good exothermic characteristics can be obtained. It is possible to obtain an exothermic molded body having.

The exothermic molded body thus obtained can be further coated with a coating layer having oxygen permeability. The coating layer may have oxygen permeability over its entire surface or may partially have oxygen permeability. The coating layer may be used without particular limitation as long as it has oxygen permeability. The coating layer is, for example, paper, non-woven fabric,
It can be provided by laminating a multi-microporous membrane, a resin film having fine pores, or the like, or can be provided by impregnating a synthetic resin paint, an emulsion paint or the like into a heat-generating molded body. Then, the obtained exothermic molded article is provided by being accommodated in a non-oxygen permeable, non-moisture permeable packaging bag or the like in order to avoid contact with oxygen before use.

The present invention is not limited to the above-described embodiment, but can be modified as appropriate without departing from the spirit of the present invention.

As described above, the exothermic molded body of the present invention is preferably manufactured by previously molding the intermediate molded body and adding the electrolyte to the intermediate molded body in advance. A molded body is made from an electrolyte-added product, dehydrated if necessary, and then dried by heating to a temperature equal to or higher than the melting point of the thermoplastic fibers, and the thermoplastic fibers are fused to form a network structure thereof. You can also

[0044]

[Examples] Exothermic molded bodies were prepared as in the following Examples 1 to 5 and Comparative Example 1 or 2, and
The tensile strength was measured as described below and the strength was examined. The results are shown in Table 1 together with the blending (parts by weight) of the thermoplastic fiber and the water content.

Example 1 <Raw material composition blending> Oxidizable metal powder: iron powder (average particle size 45 μm), 4.5
g thermoplastic fiber: fiber having a core-sheath structure (core: polyester (melting point 200 ° C. or higher), sheath: modified polyester (melting point 220 ° C.), average fiber length 1.3 mm, average fiber thickness 2.2 dtex), 0.08 g Fibrous substance: pulp fiber (average fiber length 1.3 mm), 0.
08 g Water retention agent: Activated carbon (average particle size 40 μm), 2.25 g Water: Distilled water, 500 ml <Electrolyte> Electrolyte: NaCl Water: Distilled water Electrolyte concentration: 10 wt% <Papermaking conditions> A slurry made of the above raw material composition Diameter 1
It was deposited on a 100 mesh net using a 70 mm Buchner funnel. <Dehydration conditions> Subsequent to the papermaking process, suction dewatering was performed for 1 minute using the Buchner funnel to obtain a molded product having a water content of about 70%. <Drying conditions> The obtained molded body is pressed for 60 seconds with a pressing die at a temperature of 200 ° C. and a pressure of 1.96 MPa to form a sheet-shaped intermediate molding having a three-dimensional network structure of the thermoplastic fiber therein. A body (a water content reached in the almost completely dried state of about 5%) was obtained. <Form of Intermediate Molded Product> The obtained intermediate molded product had a thickness of 0.3 to 0.7 mm and a basis weight of 250 to 350 g / m ² .

[Example 2] In the blending of the raw material composition of Example 1, the blending amount of the thermoplastic fiber was 0.38 g (about 5
An intermediate compact was produced in the same manner as in Example 1 except that

[Example 3] In the compounding of the raw material composition of Example 1, the compounding amount of the thermoplastic fiber was 0.75 g (about 1
An intermediate molded body was produced in the same manner as in Example 1 except that it was set to 0 times.

Example 4 The intermediate compact obtained in Example 3 was cut into a size of 140 mm × 15 mm, the weight of the intermediate compact was 100 parts by weight, and the electrolyte content was 60 parts by weight.
The above electrolyte solution was sprayed and impregnated in a nitrogen atmosphere so that the water content was 37.5% to produce a heat-generating molded body.

[Example 5] In the compounding of the raw material composition of Example 1, the compounding amount of the thermoplastic fiber was 1.5 g (about 20%).
An intermediate compact was produced in the same manner as in Example 1 except that

Comparative Example 1 The raw material composition of Example 1 was mixed except that the thermoplastic fiber was 0 g and the fibrous material was 0.7 g.
An intermediate molded body was produced in the same manner as in Example 1.

[Comparative Example 2] An intermediate molded body was prepared in the same manner as in Example 3 except that the three-dimensional network structure was not formed by setting the drying conditions to the melting point of the thermoplastic fiber or less (80 ° C), and the intermediate As in Example 4, the molded body was sprayed and impregnated with the above electrolytic solution to prepare a heat-generating molded body.

[Measurement of Tensile Strength] From the obtained exothermic molded body, length 140 mm × width 15 m according to JIS-P8113.
Cut out a test piece of m and put it on a tensile tester with a chuck interval of 10
It was mounted at 0 mm and the maximum tensile strength was measured at a tensile speed of 20 mm / min.

[0053]

[Table 1]

The intermediate compacts and exothermic compacts obtained in Examples 1 to 5 had high tensile strength of 2.5 to 35N. On the other hand, in the intermediate molded body and the exothermic molded body obtained in Comparative Examples 1 and 2, the thermoplastic fibers are not contained, or even if they are contained, the three-dimensional network structure is formed by fusion of the fibers. Its tensile strength is 0.5
It was as low as ~ 1.5N.

[0055]

According to the present invention, there is provided a heat-generating molded article having high mechanical strength and easy to handle, and a method for producing the same.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kunio Matsui             Kao Stock Exchange 2606, Akabane, Kai-cho, Haga-gun, Tochigi Prefecture             Company research institute F-term (reference) 4C099 AA01 JA04 LA15 LA16

Claims (4)

[Claims] 1. At least an oxidizable metal powder, an electrolyte,
What is claimed is: 1. A heat-generating molded article containing a water retention agent, thermoplastic fibers, and water, and having a network structure in which the thermoplastic fibers are fused to each other. 2. The exothermic molding according to claim 1, which contains pulp fibers. 3. At least an oxidizable metal powder, a water retention agent,
An intermediate molded body is made from a raw material composition containing a thermoplastic fiber and water in a papermaking step, and then the intermediate molded body is heated to a temperature above the melting temperature of the thermoplastic fiber to fuse the thermoplastic fibers to each other. A method for producing a heat-generating molded body, wherein an electrolyte is contained in the intermediate molded body after forming a network structure. 4. The method for producing a heat-generating molded body according to claim 3, wherein the intermediate molded body is impregnated with an electrolytic solution of the electrolyte.