JP2008101095A - Exothermic sheet form and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exothermic sheet form which can suppress its own hardening involved in the oxidation reaction progress. <P>SOLUTION: The exothermic sheet form comprises an oxidizable metal, a fibrous material, a water-holding agent, moisture, an electrolyte serving as an oxidation auxiliary, and a thiosulfate; wherein it is preferable that the thiosulfate be contained at 0.5-20 pts.mass based on 100 pts.mass of the oxidizable metal. For this exothermic sheet form, the flexural strength scale factor, the ratio of its flexural strength before exothermic reaction to that after ending exothermic reaction, is 20 or less. This exothermic sheet form is obtained by adding the electrolyte and an aqueous solution of the thiosulfate to an intermediate sheet form comprising the oxidizable metal, the fibrous material and the water-holding agent but containing no electrolyte serving as an oxidation auxiliary. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exothermic papermaking body using heat generated by an oxidation reaction between oxygen in the air and an oxidizable metal and a method for producing the same.

  The exothermic paper making use of the heat generated by the oxidation reaction between oxygen in the air and iron powder, which is an oxidizable metal, causes the iron powder to condense and harden with the progress of the oxidation reaction, resulting in reduced flexibility. Has a problem. In particular, the exothermic paper product having a heat generation time of several hours has a remarkable decrease in flexibility. This is because the oxidation reaction of iron powder proceeds sufficiently. This decrease in flexibility is not preferable because it causes not only a sense of incongruity to the user when the heat-generating paper sheet is worn on the body, but also makes it difficult to efficiently transmit heat to the body.

  As a technology to prevent such a decrease in flexibility, a technology that maintains flexibility even when an oxidation reaction proceeds by using zinc powder instead of iron powder, or a combination of a heat-retaining gel layer and a heat generation layer is flexible. Techniques imparting properties have been proposed (see Patent Documents 1 and 2 below).

  However, the technique disclosed in Patent Document 1 does not disclose a specific numerical value of the effect of suppressing the curing, and is extremely difficult to handle in terms of controlling the amount of heat generated because zinc is used. Since the technology described in Patent Document 2 must provide a water retention gel layer in addition to the heat generation layer, it becomes thicker by the amount of the water retention gel layer, and when it is worn on the body, the wearability becomes worse, Cost is also high.

JP 2001-212167 A JP 2003-135509 A

  The present invention relates to an exothermic papermaking product capable of suppressing curing accompanying the progress of an oxidation reaction and a method for producing the same.

  The present inventors have found that the inclusion of thiosulfate in the exothermic papermaking can suppress the hardening of the exothermic papermaking as the oxidation reaction proceeds, and have completed the present invention.

  The present invention has been made on the basis of the above findings, and provides an exothermic papermaking product containing an oxidizable metal, a water retention agent, moisture, an electrolyte serving as an oxidation aid, and a thiosulfate.

  In addition, the present invention provides an exothermic solution in which an aqueous solution of an electrolyte and an thiosulfate as an oxidation aid is added to an intermediate papermaking body that includes an oxidizable metal, a fibrous material, and a water retention agent and does not contain an electrolyte as an oxidation aid. The manufacturing method of a papermaking body is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the exothermic papermaking body by which hardening accompanying progress of an oxidation reaction is suppressed is provided.

  The present invention will be described below based on preferred embodiments with reference to the drawings.

  The exothermic paper product of this embodiment includes an oxidizable metal, a fibrous material, a water retention agent, moisture, an electrolyte that serves as an oxidation aid, and a thiosulfate.

  As the oxidizable metal in the exothermic paper product, a metal that generates heat of oxidation reaction can be used without any particular limitation. Examples of the oxidizable metal include iron, aluminum, magnesium, copper, and zinc. Among these, it is desirable to use iron powder from the viewpoint of ease of control of the exothermic reaction and cost. Therefore, below, this invention is demonstrated based on embodiment using iron powder as an oxidizable metal.

  The particle diameter of the iron powder used in the present embodiment (hereinafter referred to as the particle diameter in the present specification, the maximum length in the form of the powder, or the average particle diameter measured by a dynamic light scattering method, a laser diffraction method, etc. Is preferably 0.1 to 300 μm, and more preferably 1 to 150 μm. It is preferable for the particle size of the iron powder to be in such a range because the oxidation reaction of the iron powder is performed efficiently. In addition, when the exothermic paper product contains a fibrous material to be described later to form a heat-generating sheet by papermaking, the iron powder used has a particle size because the fixing property to the fibrous material and control of the reaction are good. Is preferably 0.1 to 300 μm, more preferably 0.1 to 150 μm.

  The content of the iron powder in the exothermic paper product is preferably 10 to 95% by mass, and more preferably 30 to 80% by mass. When the content of the iron powder is within such a range, the exothermic temperature of the exothermic papermaking obtained can be raised to a desired temperature. Further, in the case where the exothermic paper sheet is a heat generating sheet described later, the amount of fibrous materials and adhesive components (flocculating agent, etc.) can be suppressed, so that the exothermic paper body has sufficient air permeability. The reaction sufficiently occurs inside the exothermic papermaking body, and the exothermic temperature can be sufficiently increased. Further, the heat generation time can be made sufficiently long, the water supply by a water retention agent described later can be made sufficient, and iron powder is not easily dropped off. Further, since the fibrous material and the adhesive component described later constituting the exothermic papermaking product can be maintained at a certain amount, mechanical strength such as bending strength and tensile strength can be sufficient. Here, the content of the iron powder in the exothermic papermaking product can be obtained by an ash test according to JIS P8128 or a thermogravimetric measuring instrument. In addition, it can be quantified by a vibration sample type magnetization measurement test or the like using the property that magnetization occurs when an external magnetic field is applied.

  The content of the fibrous material in the exothermic papermaking product is preferably 1 to 50% by mass, and more preferably 3 to 40% by mass. When the content of the fibrous material is within such a range, it is possible to sufficiently prevent the components such as iron powder and water retention agent from falling off, and to make the exothermic paper product sufficient when used as a sheet. In addition, it is possible to suppress the heat capacity with respect to the heat generation amount of the exothermic papermaking, to increase the temperature sufficiently, and to ensure the ratio of the components in the exothermic papermaking obtained to some extent, so that the desired It is preferable because sufficient heat generation performance can be obtained.

  The fibrous material preferably has a Canadian Standard Freeness (CSF) of 600 ml or less, and more preferably 450 ml or less. When the amount is 600 ml or less, the fixing property between the fibrous material and the components such as the iron powder and the water retention agent is sufficiently good, the predetermined blending amount can be maintained, and the heat generation performance can be sufficiently exhibited. In addition, a sheet having a uniform thickness is obtained, the fixing between the fibrous material and the component is good, the component is difficult to fall off, and the bond strength derived from the entanglement between the component and the fibrous material or hydrogen bonding Can be given. Further, the mechanical strength such as bending strength and tensile strength can be sufficient, and the workability is also good.

The lower the CSF of the fibrous material, the better. However, in the case of normal pulp fiber-only papermaking, when the component ratio other than the fibrous material is low, the drainage is sufficiently good when the CSF is 100 ml or more, and dehydration. Can be sufficiently performed, and a heat-generating sheet having a uniform thickness is obtained, and blister breakage does not occur during drying, and the moldability is improved. In the present invention, since the ratio of components other than the fibrous material is high, it is possible to obtain a heat generating sheet with good drainage and uniform thickness. Further, since the CSF is lower as the CSF is lower, the fixability between the fibrous material and components other than the fibrous material is improved, and a high sheet strength can be obtained.
Adjustment of the CSF of the fibrous material can be performed by a beating process or the like. CSF may be adjusted by mixing low and high CSF fibers. In addition, CSF can be obtained by measuring by the method shown in JIS P8121 (pulp freeness test method), and is an index representing the degree of water breakage of a fibrous material having a value of 0 or more.

  The fibrous material preferably has a negative (negative) zeta potential. Here, the zeta potential is an apparent potential at the shear plane between the charged particle interface and the solution, and is measured by a streaming potential method, an electrophoresis method or the like. If the zeta potential is negative, the components such as the iron powder and water retention agent are well fixed to the fibrous material, the prescribed blending amount can be maintained, and the heat generation performance is excellent. Mixing a large amount of the components can be suppressed, and the productivity and environmental conservation are not adversely affected.

  The fibrous material preferably has an average fiber length of 0.1 to 50 mm, more preferably 0.2 to 20 mm. By setting the average fiber length in such a range, the obtained exothermic paper product can sufficiently ensure mechanical strength such as bending strength and tensile strength, and the fibrous material layer does not become too dense. The air permeability is good, the oxygen supply is good, and the heat generation is excellent. In addition, since the fibrous material can be uniformly dispersed in the exothermic paper, a uniform mechanical strength can be obtained, and an exothermic paper having a uniform thickness can be obtained. In addition, the fiber spacing does not become too large, and the retention capability of the components such as the iron powder and water retention agent by the fibers is maintained, and the components are difficult to fall off.

  Examples of the fibrous material include, for example, plant fibers (cotton, kabok, wood pulp, non-wood pulp, peanut protein fiber, corn protein fiber, soybean protein fiber, mannan fiber, rubber fiber, hemp, Manila hemp Sisal, New Zealand hemp, Rafu hemp, eggplant, rush, straw, etc.), animal fibers (wool, goat hair, mohair, cashmere, alkapa, Angola, camel, vicuña, silk, feathers, down, feather, algin fiber, chitin Fiber, casein fiber, etc.), mineral fiber (sepiolite, wollastonite, rock wool, etc.), and synthetic fiber materials include, for example, semi-synthetic fibers (acetate, triacetate, oxide acetate, promix, chlorinated rubber, Hydrochloric acid rubber, etc.), metal fibers, carbon fibers, glass fibers, etc. That. Also, polyolefins such as high density polyethylene, medium density polyethylene, low density polyethylene, polypropylene, etc., polyester, polyvinylidene chloride, starch, polyvinyl alcohol or polyvinyl acetate, single fibers such as copolymers or modified products thereof, or these A core-sheath composite fiber having a resin component in the sheath can be used. Among these, polyolefins and modified polyesters are preferably used because they have high adhesive strength between fibers, are easy to form a three-dimensional network structure by fusion of fibers, and have a melting point lower than the ignition point of pulp fibers. Synthetic fibers such as polyolefin having branches are also preferably used because of their good fixability with iron powder and water retention agents. These fibers can be used alone or in combination of two or more. In addition, these fibers can be used in the form of collected and reused. Of these, wood pulp and cotton are preferably used from the viewpoints of fixability of iron powder and water retention agent, flexibility of the resulting exothermic papermaking, oxygen permeability due to the presence of voids, production cost, and the like.

  1-60 mass% is preferable and, as for content of the said water retention agent in an exothermic papermaking body, 3-50 mass% is more preferable. Within such a range, moisture necessary for sustaining the oxidation reaction can be accumulated in the exothermic papermaking. In addition, since the air permeability of the exothermic paper product is sufficiently ensured, the exothermic paper product can be obtained with sufficient oxygen supply and high heat generation efficiency. In addition, since the heat capacity of the exothermic papermaking can be kept small with respect to the heat generation amount obtained, the heat generation temperature rises and a desired temperature rise can be obtained. In addition, when the exothermic paper sheet is a heat generating sheet described later, it is possible to suppress the occurrence of water retention agent drop and the decrease in fibrous materials and adhesive components described later, so that mechanical strength such as bending strength and tensile strength is sufficient. Is obtained.

  As the water retentive agent, a water retentive agent that has been conventionally used in this type of exothermic papermaking can be used without any particular limitation. For example, water-absorbing polymer, wood powder and the like can be mentioned. In addition to acting as a water retention agent, some of the water retention agents also have a function as an oxygen retention / supply agent for iron powder. Examples of the water retention agent include activated carbon (coconut husk charcoal, charcoal powder, calendar bituminous coal, peat, lignite), carbon black, acetylene black, graphite, zeolite, perlite, vermiculite, silica, cancrinite, fluorite and the like. Among these, activated carbon is preferably used because it has water retention ability, oxygen supply ability, and catalytic ability. As the water retention agent, it is preferable to use a powdery material having a particle size of 0.1 to 500 μm from the viewpoint that an effective contact state with iron powder can be formed. It is more preferable to use what is contained above. As the water retention agent, a form other than the powder form as described above can be used. For example, a form of fiber form such as activated carbon fiber can also be used.

  The content of the electrolyte serving as the oxidation aid in the exothermic papermaking body is preferably 0.5 to 30% by mass, more preferably 1 to 25% by mass, based on the mass ratio of water to the exothermic papermaking body. preferable. It is preferable for the content of the electrolyte to fall within such a range because the oxidation reaction of the resulting exothermic papermaking product can proceed sufficiently. Also, the precipitation of the electrolyte hardly occurs, the air permeability of the exothermic paper product is good, the electrolyte necessary for the heat generation function can be secured, sufficient water is supplied to the iron powder, etc., the heat generation performance is excellent, the heat generation It is preferable because the electrolyte can be uniformly mixed in the papermaking body.

  As the electrolyte, an electrolyte that has been conventionally used for this type of exothermic papermaking can be used without particular limitation. Examples of the electrolyte include alkali metal, alkaline earth metal or heavy metal sulfates, carbonates, chlorides or hydroxides. Among these, various chlorides such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, first ferric chloride, second ferric chloride are preferably used from the viewpoint of excellent conductivity, chemical stability, and production cost. These electrolytes can be used alone or in combination of two or more.

  The thiosulfate is 0.5 to 20 masses per 100 mass parts of the oxidizable metal in the exothermic paper product because the thiosulfate can effectively suppress the curing of the exothermic paper product due to condensation accompanying oxidation of the oxidizable metal. It is preferably contained in an amount of 0.5 to 15 parts by mass, more preferably 0.5 to 10 parts by mass.

  Examples of the thiosulfate include thiosulfates such as sodium thiosulfate, potassium thiosulfate, and calcium thiosulfate. Among these, sodium thiosulfate is preferable because it is inexpensive and has high safety.

  The moisture content (mass moisture content, hereinafter the same) of the exothermic paper product is preferably 5 to 80%, and more preferably 10 to 60%. When the moisture content is within such a range, it is possible to sufficiently secure the water necessary for sustaining the oxidation reaction, to prevent the oxidation reaction from being terminated halfway, and to uniformly produce the exothermic paper product. Since moisture can be supplied, uniform heat generation performance can be obtained. When the water content is 80% or less, the heat capacity of the exothermic paper product to be obtained can be kept low, the heat generation temperature can be sufficiently increased, and the air permeability of the exothermic paper product can be sufficiently obtained. Therefore, the heat generation performance is excellent, and shape retention and mechanical strength are sufficiently obtained.

The raw material composition of the exothermic papermaking product is not limited to an oxidizable metal, a water retention agent, moisture, an electrolyte serving as an oxidation aid, and a thiosulfate, and other compositions may be added. For example, when the exothermic paper product is a heat generating sheet described later, a flocculant is preferably added to the exothermic paper product as described later.
In addition, for exothermic paper products, additives usually used for paper making such as sizing agents, colorants, paper strength enhancers, yield improvers, fillers, thickeners, pH control agents, bulking agents, etc. The product can be added without any particular limitation. The addition amount of the additive can be appropriately set according to the additive to be added.

  Next, a method for producing the exothermic papermaking will be described as a preferred embodiment based on a method for producing the exothermic papermaking in a sheet form.

  First, a raw material composition (slurry) containing the oxidizable metal, the fibrous material, the water retention agent and water and not containing the electrolyte and the thiosulfate as an oxidation aid is prepared, and the raw material composition The intermediate papermaking is made from And the exothermic papermaking body is obtained by making the intermediate papermaking body contain the said electrolyte and the said thiosulfate as mentioned later.

The raw material composition of the intermediate papermaking product can contain other components. For example, it is preferable to add the flocculant to the raw material composition. Examples of the flocculant include inorganic flocculants composed of metal salts such as sulfate band, polyaluminum chloride, ferric chloride, polyferric sulfate, and ferrous sulfate; polyacrylamide, sodium polyacrylate, polyacrylamide Mannich modified products, poly (meth) acrylic acid aminoalkyl ester-based, carboxymethylcellulose sodium-based, chitosan-based, starch-based, polyamide epichlorohydrin-based polymer flocculants; dimethyldiallylammonium chloride-based or ethyleneimine-based Organic coagulants such as condensates of alkylene dichloride and polyalkylene polyamines, dicyandiamide / formalin condensates; clay minerals such as montmorillonite and bentonite; silicon dioxide such as colloidal silica or hydrates thereof; hydrous magnesium silicate such as talc And the like. Among these flocculants, anionic colloidal silica, bentonite, etc. from the viewpoint of sheet surface properties, texture formation, moldability improvement, iron powder, fibrous materials, fixability of materials such as water retention agents, paper strength improvement, etc. A combination of cationic and anionic agents such as cationic starch and polyacrylamide, anionic carboxymethylcellulose sodium salt, polyacrylamide and cationic polyamide epichlorohydrin, and polyacrylamide are particularly preferred. Besides these combinations, these flocculants may be used alone or in combination of two or more.

  The addition amount of the flocculant is preferably 0.01 to 5% by mass and more preferably 0.05 to 1% by mass with respect to the solid content of the raw material composition. When the content is 0.01% by mass or more, the agglomeration effect is excellent, and dropping of components such as iron powder, fibrous material, and water retention agent during papermaking can be suppressed, and the raw material composition becomes uniform, and the thickness and composition are uniform. It is excellent in that a heat-generating papermaking product can be obtained. When the addition amount is 5% by mass or less, it is possible to suppress the occurrence of tearing, burning, scorching, etc., sticking to a drying roll during drying, excellent productivity, and maintaining a good potential balance of the raw material composition. This is excellent in that the amount of the component dropped into the white water during papermaking can be suppressed. Further, the oxidation reaction of the exothermic papermaking proceeds, and the storage stability such as exothermic characteristics and strength is excellent.

  The concentration of the raw material composition is preferably 0.05 to 10% by mass, and more preferably 0.1 to 2% by mass. When the concentration is in such a range, a large amount of water is not required, and it is preferable in that an intermediate paper product having a uniform thickness can be formed without requiring a long time for forming the intermediate paper product. Moreover, the dispersion state of the raw material composition is good, the surface property of the finally obtained exothermic paper product is excellent, and this is preferable in that an exothermic paper product having a uniform thickness can be obtained.

Next, the raw material composition is paper-made to produce a sheet-like intermediate paper-making body.
Examples of the papermaking method for the intermediate papermaking include, for example, a papermaking method using a circular papermaking machine, a continuous papermaking machine, a Yankee papermaking machine, a twin-wire papermaking machine, and the like, which are continuous papermaking methods, and a batch papermaking method. Law. Furthermore, an intermediate papermaking product can be formed by multi-layer papermaking using the raw material composition and a composition having a composition different from the raw material composition. In addition, the intermediate paper bodies obtained by papermaking the raw material composition are bonded together in multiple layers, or a sheet-like material obtained from a composition having a composition different from that of the raw material composition is attached to the intermediate paper body. By combining them, an intermediate papermaking product can be formed.

  The intermediate papermaking product is dehydrated until the moisture content (mass moisture content, the same shall apply hereinafter) is 70% or less from the viewpoint of maintaining the shape after papermaking (shape retention) and maintaining the mechanical strength. Is preferable, and it is more preferable to dehydrate it to 60% or less. Examples of the dewatering method of the intermediate papermaking after paper making include dewatering by suction, a method of dehydrating by blowing pressurized air, a method of dehydrating by pressing with a pressure roll or a pressure plate, and the like.

  The intermediate papermaking containing the iron powder (having heat reactivity under normal atmosphere) is actively dried to separate the water, thereby suppressing iron powder oxidation during the production process and long-term storage stability. It is possible to obtain an intermediate papermaking excellent in the above. Furthermore, in addition to the point of increasing the supporting force of iron powder on the fibrous material after drying and suppressing its falling off, it is possible to expect improvement in mechanical strength by adding a hot-melt component and a thermal crosslinking component. It is preferable to dry the intermediate papermaking after the papermaking and before the electrolytic solution of the electrolyte is contained.

  The intermediate papermaking product is preferably dried by heat drying. In this case, the heat drying temperature is preferably 60 to 300 ° C, more preferably 80 to 250 ° C. By setting the heating temperature of the intermediate papermaking to such a temperature range, the drying time can be shortened, so that the oxidation reaction of iron powder accompanying the drying of moisture can be suppressed, and the exothermic deterioration of the resulting exothermic papermaking is reduced. Can be prevented. At the same time, discoloration of the exothermic papermaking due to iron powder oxidation can be prevented. In addition, since the performance deterioration of the water retaining agent can be suppressed, the exothermic effect of the exothermic papermaking can be maintained, and the structure of the exothermic papermaking can be destroyed due to the rapid evaporation of moisture inside the intermediate papermaking. Can be prevented.

  The water content of the intermediate papermaking after drying is preferably 20% or less, and more preferably 10% or less. When the moisture content is 20% or less, excellent long-term storage stability, for example, even when temporarily stored in a wound roll state, moisture does not easily move in the thickness direction of the roll, and heat generation performance and mechanical strength are improved. No change and excellent.

The tear length of the intermediate papermaking after drying is preferably 100 to 4000 m, and more preferably 200 to 3000 m. When the breaking length is within such a range, handling during use, production and operation becomes easy, and since it has appropriate air permeability, the oxidation of iron powder in the exothermic papermaking is significantly accelerated. can do. Here, the breaking length is determined by cutting a test piece 150 mm long × 15 mm wide from the intermediate papermaking, and then mounting the test piece on a tensile tester with a chuck interval of 100 mm according to JIS P8113. It is a value calculated by the following calculation formula after performing a tensile test at min.
Breaking length [m] = (1 / 9.8) × (Tensile strength [N / m]) × 10 ⁶ / (Test piece basis weight [g / m ² ])

The intermediate papermaking after drying that does not contain the electrolyte and the thiosulfate preferably has a basis weight of 10 to 1000 g / m ² , and more preferably 50 to 600 g / m ² . A basis weight in such a range is preferable in that it is light and excellent in feeling of use, and is capable of forming a stable intermediate paper product in terms of productivity and operability.

As for the thickness of the said intermediate papermaking body, it is preferable that it is 0.08-1.2 mm, and it is more preferable that it is 0.1-0.6 mm. When the thickness is within such a range, the exothermic performance, mechanical strength, iron powder, water retention agent, and the like can be well fixed when the exothermic papermaking product is made to contain an electrolyte that serves as an oxidation aid, and is stable. In addition to obtaining a uniform thickness and composition distribution, it becomes difficult to cause destruction of the intermediate papermaking due to the occurrence of pinholes and the like, and productivity and workability are improved. In addition, the bending strength of the exothermic paper can be secured, it is difficult to easily cause brittle fracture, and the flexibility is also good, especially when it is attached to a body part such as the elbow, knee, face, etc. Can be used without any sense of incongruity. In terms of productivity, paper layer formation time and drying time are hardly delayed, operability is good, heat generation performance is good, and workability such as bending is also excellent.
A plurality of the intermediate papermaking products can be used in a stacked manner. By stacking multiple sheets, the required heat generation performance can be easily realized, and at the same time, even if the heat-generating paper sheet is thick, it is possible to obtain a heat-generating paper sheet that has high flexibility and excellent usability. it can.

  The method for drying the intermediate papermaking can be appropriately selected according to the thickness of the intermediate papermaking, the method for treating the intermediate papermaking before drying, the moisture content before drying, the moisture content after drying, and the like. Examples of the drying method include drying methods such as contact with a heating structure (heating element), spraying of heated air or steam (superheated steam), vacuum drying, electromagnetic wave heating, and electric heating. Moreover, it can also implement simultaneously with the above-mentioned dehydration method.

  The intermediate papermaking is preferably formed (dehydrated and dried) in an inert gas atmosphere. However, as described above, the intermediate papermaking does not contain an electrolyte that serves as an oxidizing aid. Molding can also be performed in a normal air atmosphere. For this reason, manufacturing equipment can be simplified. Since the obtained intermediate papermaking product is thin and difficult to break, it can be wound up in a roll shape as necessary.

  The dried intermediate papermaking product can be pierced by creping, slitting, trimming, or needle punching as necessary. Moreover, by making the raw material composition contain a thermoplastic resin component or a hot water decomposing component, it is possible to perform heat sealing and facilitate bonding.

  Next, the electrolyte and the thiosulfate are included in the intermediate papermaking product. There is no particular limitation on the method of including the electrolyte and thiosulfate in the intermediate papermaking body, but considering that both of them are water-soluble, an aqueous solution containing the electrolyte and thiosulfate (hereinafter also referred to as a mixed solution). ) Is preferably prepared and added simultaneously.

The method of containing the electrolyte and thiosulfate in a mixed solution thereof can be appropriately selected according to the method for treating the intermediate papermaking after papermaking, the form such as the thickness of the intermediate papermaking, and the water content. For example, a method of spray-coating a mixed solution of a predetermined concentration onto the intermediate papermaking body, injecting the mixed solution into a part of the intermediate papermaking body with a syringe or the like, and utilizing the capillary phenomenon of the fibrous material Examples include a method of penetrating the whole body, a method of coating with a brush, a method of immersing the intermediate papermaking in the mixed solution, a gravure coating method, a reverse coating method, a doctor blade method, etc. Among these, electrolyte and thiol A spray coating method is preferred because it can distribute the sulfate uniformly, is simple, and requires relatively little equipment cost. In addition, in the case of products with complicated shapes and layer configurations, the concentration of the specified concentration is improved from the viewpoint that productivity is improved, the final finishing can be performed as a separate process, the production flexibility is improved, and the equipment is simplified. A method of injecting the mixed solution with a syringe or the like is preferable. This method of injecting the mixed solution can also be performed after the multilayered sheet-like exothermic papermaking is stored in a predetermined container.

  Since the exothermic papermaking of the present invention is formed by papermaking from a slurry raw material composition, when water-soluble thiosulfate is added to the slurry raw material composition, it flows out of the papermaking net. Considering the amount, a large amount of thiosulfate is required, and further, thiosulfate flows out even during dehydration, which causes a problem in terms of yield and curing suppression effect. In addition, during drying, the added thiosulfate is affected by heat, leading to deterioration of the working environment due to generation of odor and the like.

  On the other hand, as described above, the method of adding the electrolyte and thiosulfate to the intermediate papermaking as a mixed solution does not cause the above-mentioned problems, and allows the thiosulfate to exist uniformly in the intermediate papermaking. Therefore, an exothermic paper product having a good exothermic performance can be obtained. In addition, the amount of thiosulfate added can be quantified and stabilized.

  After the mixed paper is contained in the intermediate paper as described above, the moisture content is adjusted as necessary, and stabilized to obtain a heat-generating paper (heat-generating sheet). If necessary, the sheet can be sandwiched between a moisture permeable sheet and a non-moisture permeable sheet, subjected to a process such as trimming, and processed into a predetermined size. In addition, if necessary, a predetermined process can be performed by sandwiching a heat-generating papermaking sheet between moisture-permeable sheets. In the unused state, the obtained exothermic paper product is provided by being packaged with, for example, an oxygen-impermeable packaging material.

  The exothermic paper product preferably has a thickness of 0.08 to 2.0 mm, more preferably 0.15 to 1.8 mm. When the thickness is 0.08 mm or more, heat generation performance and mechanical strength are sufficient. When the thickness is 2 mm or less, the flexibility is sufficient and the feeling of use is excellent. Here, the thickness of the exothermic paper product can be calculated according to JIS P8118 by measuring five or more points of the exothermic paper product and calculating the average value as the thickness.

Heating papermaking product is preferably a basis weight of one that is 10 to 2000 g / m ^2, and more preferably 50 to 1500 g / m ^2. When the basis weight is 10 g / m ² or more, a stable exothermic papermaking product can be formed. When the basis weight is 2000 g / m ² or less, it is preferable from the viewpoint of use feeling.

  Moreover, the exothermic papermaking body can be used by laminating two or more sheets. The thickness of the laminated exothermic papermaking body is preferably 0.2 to 5 mm, and more preferably 0.5 to 3 mm. When the thickness is 0.2 mm or more, heat generation performance and mechanical strength are sufficient. When the thickness is 5 mm or less, the flexibility of the entire exothermic paper laminate is sufficient, and the usability is excellent.

Preferably the basis weight of the laminated heating papermaking product is 100 to 3000 g / m ^2, and more preferably 200~2500g / m ^2. When the basis weight is in the range of 100 to 3000 g / m ² , the heat generation performance is excellent and the usability at the initial stage of use is also excellent.

The density of the laminated heating papermaking product is preferably from 0.6~3g / cm ^3, more preferably 0.7~2g / cm ^3. When the density is 0.6 g / cm ³ or more, the oxidizable metal and the other components are sufficiently adhered to each other, and good exothermic performance and sufficient strength can be imparted to the exothermic papermaking. Moreover, there is almost no dropout of the constituent components, which is excellent in terms of productivity and workability. When the density is 3 g / cm ³ or less, it is preferable from the viewpoint of flexibility, and it is excellent in feeling of use, and can also be cured when the oxidation reaction proceeds.

  The exothermic papermaking product preferably has a bending strength magnification of 20 or less, more preferably 10 or less, which is the ratio of the bending strength before the exothermic reaction to the bending strength at the end of the exothermic reaction. Here, the bending strength and the bending strength magnification are measured by a measuring method in Examples described later.

  Since the exothermic paper product of the present embodiment contains thiosulfate as described above, curing is suppressed even when oxidation proceeds. In addition, according to the present invention, there is provided an exothermic paper product having a bending strength ratio of 20 or less, which is a ratio of the bending strength before the exothermic reaction and at the end of the exothermic reaction, and when the exothermic paper product is used by being attached to the body. Therefore, the user can efficiently transmit heat to the body without causing the user to feel uncomfortable.

The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present invention.
For example, in the above-described embodiment, the sheet-like exothermic paper product has been described. However, the exothermic paper product of the present invention can also have a three-dimensional shape. For example, after giving a three-dimensional shape to the intermediate paper body made into a sheet shape by press molding or embossing, or after making the intermediate paper body into a three-dimensional shape like a conventionally known pulp mold molded body By adding the electrolyte and thiosulfate, a three-dimensional exothermic paper product can be obtained.

Hereinafter, the exothermic papermaking of the present invention will be described more specifically with reference to examples.
As in Examples 1 and 2 below and Comparative Example 1, intermediate papermaking compositions having a solid content composition shown in Table 1 were prepared. Further, an exothermic papermaking body was produced from the obtained intermediate papermaking body as follows. About the obtained exothermic papermaking body, the bending strength before the oxidation reaction (exothermic reaction) and the bending strength at the end of the oxidation reaction (exothermic reaction) were measured as follows, and the effect of suppressing the curing was evaluated by the maximum bending load. Further, the exothermic paper obtained was examined for exothermic characteristics as follows. The results are shown in Table 2 and FIG.

[Example 1]
<Combination of raw material composition>
Oxidizable metal: Iron powder (particle size 100 μm, Powder Tech Co., Ltd., trade name “NRD-3K”), 80.7% by mass
Fibrous material: Pulp fiber (made by Fletcher Challenge Canada, trade name “Mackenzie”), 9.7% by mass
Water retention agent: activated carbon (particle size 45 μm, (manufactured by Nippon Enviro Chemicals, trade name “Carborafine”)), 9.6% by mass
Water: Industrial water is used. It was added until the solid content concentration became 0.3%.
With respect to 100 parts by mass of the raw material composition, 0.22 parts by mass of a flocculant (carboxymethyl cellulose sodium (Daiichi Kogyo Seiyaku Co., Ltd., trade name “Serogen HE-1500F”), and polyamide epichlorohydrin resin (Japan) PMC product, trade name “WS4020”) 0.8 parts by mass) was added.

<Paper making conditions>
Using the raw material composition, a paper sheet was made by a slanted short net paper machine to prepare a wet molded sheet.

<Drying conditions>
It was sandwiched with felt and dehydrated under pressure, passed through a heating roll at 140 ° C. as it was, and dried until the water content became 5% by mass or less. An intermediate papermaking product having a basis weight of 450 g / m ² was obtained.

[Measurement of powder content]
The powder content and composition ratio of the obtained paper-molded molded body were measured using a thermogravimetric apparatus (TG / DTA6200, manufactured by Seiko Instruments Inc.).

<Preparation of exothermic sheet>
The obtained intermediate papermaking product is cut into 98 mm × 82 mm, and two sheets are laminated. Then, 42 parts by mass of an electrolytic solution containing 5% by mass of sodium chloride is prepared with respect to 100 parts by mass of the laminated intermediate sheet, and 0.5 parts by mass of sodium thiosulfate is mixed and dissolved therein. Thereafter, an electrolytic solution for dissolving the sodium chloride and sodium thiosulfate was injected and added to the laminated intermediate sheet using a syringe, and the whole sheet was infiltrated using capillary action to obtain a heat generating sheet. .
And the following moisture-permeable sheet | seat and the moisture-impermeable sheet | seat were laminated | stacked on the upper and lower sides of said heat generating sheet, the circumference | surroundings of the heat generating sheet were joined by heat seal, and the test body was produced.
Moisture-permeable sheet: microporous sheet made of polyethylene, moisture permeability of 1000 g / (m ² · 24 h)
Non-breathable sheet: Polyethylene sheet

<Measurement of bending strength>
For the test body before heat generation and at the end of the exothermic reaction, both ends of the test body were supported at a span distance of 50 mm, and a load was applied at a crosshead speed of 20 mm / min with a pressing member having a width of 50 mm and a tip radius of 5 mm at the center of the test body. The maximum load was measured and used as the bending strength. Further, the bending strength magnification (= bending strength at the end of exothermic reaction / bending strength before exothermic reaction) was also obtained. The results are shown in Table 2.

<Exothermic reaction evaluation>
The obtained specimen was measured for temperature due to heat generation using a simple temperature measuring device in accordance with JIS S4100. The simple type temperature measuring device is a device in which 6 sheets of 1 mm thick polypropylene sheets, 2 sheets of type 1 gauze prescribed by the Japanese Pharmacopoeia are stacked, and a measuring table whose surface is kept at 35 ° C. is installed horizontally. The test specimen was allowed to stand on the measuring apparatus with the moisture permeable sheet as the bottom surface, and eight sheets of “100% cotton, tex count 5.905 twin yarn” were stacked thereon to evaluate the exothermic reaction.
As a result, the heat generation at 38 ° C. or more continued for 5 hours or more, and the heat generation sheet at the end of the heat generation reaction was oxidized on the entire surface and turned reddish brown. Here, the end of the exothermic reaction was regarded as 12 hours after the start of exotherm. The obtained exothermic characteristics are shown in FIG.

[Example 2]
Except that the amount of sodium thiosulfate used in Example 1 was 1 part by mass as shown in Table 1, an exothermic paper product was prepared in the same manner as in Example 1, and the exothermic characteristics were the same as in Example 1. And the degree of cure inhibition before and after the reaction was examined. The results are shown in Table 2 and FIG.

Example 3
Except that the amount of sodium thiosulfate used in Example 1 was changed to 5 parts by mass as shown in Table 1, a exothermic paper product was prepared in the same manner as in Example 1, and the exothermic characteristics were the same as in Example 1. And the degree of cure inhibition before and after the reaction was examined. The results are shown in Table 2 and FIG.

Example 4
Except that the amount of sodium thiosulfate used in Example 1 was changed to 10 parts by mass as shown in Table 1, a exothermic paper product was prepared in the same manner as in Example 1, and the exothermic characteristics were the same as in Example 1. And the degree of cure inhibition before and after the reaction was examined. The results are shown in Table 2 and FIG.

Example 5
Except that the amount of sodium thiosulfate used in Example 1 was 20 parts by mass as shown in Table 1, a exothermic paper product was prepared in the same manner as in Example 1, and the exothermic characteristics were the same as in Example 1. I investigated. The results are shown in FIG.

[Comparative Example 1]
Exothermic papermaking was prepared in the same manner as in Example 1 except that sodium thiosulfate was not added, and the exothermic characteristics and the degree of curing inhibition before and after the reaction were examined. The results are shown in Table 2 and FIG.

  As shown in Table 2, it was confirmed that the exothermic paper products of the examples had lower bending strength after the oxidation reaction than those of the comparative examples, and the curing was suppressed. In addition, as shown in FIG. 1, it can be confirmed that the exothermic papermaking material of the example can obtain the same exothermic performance as compared with the comparative example up to about 5 parts by mass of sodium thiosulfate. It was. Further, as shown in FIG. 1, it was confirmed that when the content of sodium thiosulfate is about 10 to 20 parts by mass, the maximum temperature is somewhat lowered, but stable heat generation performance can be obtained for a long time. In all the examples, it was also confirmed that the addition of sodium thiosulfate had an effect of suppressing hydrogen generation from the exothermic papermaking during storage.

  The exothermic paper-making body of the present invention is thin and can suppress curing before and after use, and therefore has flexibility and, for example, a wet towel, a steam generator, a pack, etc. Face and body washing, sterilization, moisturizing, makeup remover and other skin care applications, cleaning and sterilization, wax release, aroma, deodorant, etc. It can also be applied to so-called house care applications such as interior goods, around the range, and care for cooking utensils such as ventilation fans, and car care applications such as car washing and waxing. The exothermic papermaking of the present invention can also be used as a steam generator by disposing a moisture permeable surface in a direction in which steam is desired to be generated. By using steam in this way, it is possible to improve the thermal effect and the cleaning effect.

It is a figure which shows the exothermic characteristic of the exothermic papermaking of an Example and a comparative example, (a) is a figure which shows the exothermic characteristic in Examples 1-3, (b) is the exothermic characteristic in Examples 4, 5 and Comparative Example 1. FIG.

Claims (5)

  An exothermic paper product comprising an oxidizable metal, a fibrous material, a water retention agent, moisture, an electrolyte serving as an oxidation aid, and a thiosulfate.   The exothermic papermaking of Claim 1 which contains 0.5-20 mass parts of said thiosulfate with respect to 100 mass parts of oxidizable metals in the said exothermic papermaking.   The exothermic papermaking according to claim 1 or 2, wherein the bending strength magnification, which is the ratio of the bending strength before the exothermic reaction and the bending strength at the end of the exothermic reaction, is 20 or less.   A method for producing an exothermic papermaking, comprising adding an aqueous solution of the electrolyte and thiosulfate to an intermediate papermaking containing an oxidizable metal, a fibrous material, and a water retention agent, and not containing an electrolyte as an oxidation aid.   The manufacturing method of the exothermic papermaking of Claim 4 which adds 0.5-20 mass parts of said thiosulfate with respect to 100 mass parts of oxidizable metals.

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