JP5339888B2 - Exothermic molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat generating molded body which has excellent strength, wherein a problem of a conventional technique based on using powder as it is improved while keeping excellent heat generating characteristics of a conventional pulverized heat generating body. <P>SOLUTION: The heat generating molded body contains: a heat generating material which generates heat by reacting with water; and a fluorine-based resin, wherein, more specifically, the content of the heat generating material is 20-99 wt.% and the content of the fluorine-based resin is 80-1 wt.%, based on 100 wt.% of the sum total of the heat generating material and the fluorine-based resin. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an exothermic molded body that generates heat by reacting with water.

  Conventionally, calcium oxide is known as a heating element that generates heat by reacting with water (for example, Patent Document 1). As a further improvement, a mixture of calcium oxide and aluminum is known (for example, Patent Documents 2 to 5). The heating elements of Patent Documents 2 to 5 cause calcium oxide and water to react with each other and generate heat, and cause calcium hydroxide and aluminum generated by this reaction to generate heat, and heat articles such as foods. A sufficient calorific value can be obtained in a short time. In particular, Patent Document 3 states that after the reaction, the temperature reaches about 100 ° C. in about 30 seconds, and this temperature can be maintained for 20 minutes or more. And using this exothermic reaction, sake and ekiben are warmed outdoors, and cooked retort food is reheated.

  The conventional heating element (especially Patent Documents 2 to 5) contains powder of an active ingredient containing calcium oxide and aluminum in an inner bag such as a nonwoven fabric, and in contact with water together with the inner bag during use, penetrates into the inner bag. The generated water reacts with the active ingredients to generate heat. This heating element has the advantage that since the active ingredient is powder, it can be easily brought into contact with water and easily heated.

  However, the conventional heating element has a problem in that the powder leaks from the inner bag before use and during heat generation because the active ingredient is powder. When used for heating foods and the like, the leaked powder may be mixed into the foods, and such a situation needs to be avoided. In addition, hydrogen gas is by-produced during the exothermic reaction. Moreover, since water vapor is generated due to heat generation, these gas components expand the inside of the bag and suppress the invasion of water that is about to enter the bag in an attempt to be ejected from a fine hole in the bag. In addition, since the powder is filled in the bag expanded during heat generation and then solidifies, it is necessary to secure a space for accommodating the heat generating element with a margin. Moreover, the operation | work which accommodates the powder of an active ingredient in an inner bag from the beginning is troublesome.

  Therefore, it is conceivable that the active ingredient powder is not used as it is, but is processed into a molded body. However, even if the molded body is simply processed, the contact area between water and the active ingredient decreases, resulting in heat generation. There is a problem that the reaction cannot be obtained quickly and sufficiently. Patent Document 6 proposes an exothermic molded body mainly composed of calcium oxide, in which the porosity, strength, water permeability, and the like are set in specific ranges (particularly in the claims), When forming a compact by selecting the particle size and molding pressure of the heat generating material, the strength tends to be insufficient when considering the porosity and water permeability, and further improvement is necessary to achieve both strength and heat generation efficiency. is there.

Accordingly, there is a demand for the development of a heat-generating molded body having good strength that improves the problems of the prior art based on using powder as it is while maintaining the excellent heat generation characteristics of the conventional powder-like heat generating body.
Japanese Utility Model Publication No. 1-158485 Japanese Patent No. 3467729 Japanese Patent No. 4008490 JP 2007-63404 A Japanese Patent Laid-Open No. 2007-131589 JP-A-4-168190

  An object of the present invention is to provide an exothermic molded body having good strength, which has improved the problems of the prior art based on the use of powder as it is while maintaining the excellent heat generation characteristics of the conventional powdery heating element. And

  As a result of intensive studies to achieve the above object, the present inventor has found that the above object can be achieved when a heat generating material that generates heat by reacting with water and a specific resin component are used in combination. It came to be completed.

That is, this invention relates to the following exothermic molded object.
1. An exothermic molded body containing a heat generating material that generates heat by reacting with water and a fluororesin,
Heating material comprises a mixture of calcium oxide and aluminum,
When the total amount of the heat generating material and the fluororesin is 100% by weight, the content of the heat generating material is 20 to 99% by weight, and the content of the fluororesin is 80 to 1% by weight.
Exothermic molded body.
2 . The heat generation according to claim 1 , wherein the fluororesin is at least one selected from the group consisting of polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, and an ethylene-tetrafluoroethylene copolymer. Molded product.
3 . The exothermic molded article according to claim 1 , wherein the fluororesin is fibrillated polytetrafluoroethylene.
4 . The exothermic molded object according to any one of claims 1 to 3 , wherein a process for increasing a surface area is performed.
5 . The exothermic molded object according to any one of claims 1 to 4 , which is in a pellet form.
6 . The exothermic molded object according to any one of claims 1 to 4 , which is in a sheet form.

  The exothermic molded article of the present invention is characterized by containing a heat generating material that generates heat by reacting with water and a fluororesin.

  Since the exothermic molded body of the present invention having the above characteristics is formed into a molded body by using a fluorine resin as a binder component, it is possible to prevent the powder of the active ingredient from leaking before use and during heat generation. Yes. In addition, since the fluororesin is easily fibrillated by the shearing force when forming the molded body, the heat-generating material is not coated, and the fibrillated thread-like fluororesin is point-bonded to the heat-generating material. Even after making into a body, it is difficult to interfere with the contact between the active ingredient and water, the heat generation characteristics can be kept high, and a high-strength molded body that does not fall off can be obtained. Furthermore, since it is a molded body, it is not necessary to be housed in an inner bag and the expansion during heat generation is suppressed, so that the space for housing the heat generating body can be suppressed to a minimum volume.

  The exothermic material used in the present invention is not limited as long as it reacts with water and generates heat. For example, at least one of calcium oxide, a mixture of calcium oxide and aluminum, soda lime, magnesium-iron alloy and the like can be used. Can be mentioned. Among these heat generating materials, a mixture of calcium oxide and aluminum is particularly preferable.

  The average particle size of the heat generating material is not limited, but is preferably about 5 to 200 μm, more preferably about 10 to 100 μm.

  The specific surface area of the heat generating material is not limited. For example, calcium oxide generally used for a desiccant or one having a larger specific surface area can be used. By using calcium oxide having a large specific surface area, the heat generation characteristics can be improved.

  The fluororesin used in the present invention is preferably one that acts as a binder and easily fibrillates by a shearing force when forming a molded body when the molded body containing the heat generating material is formed. For example, when forming a molded body by extrusion molding, the shearing force can be adjusted by changing the molding pressure, the cross-sectional area ratio between the nozzle and the cylinder, and the like. Moreover, when forming a molded object by press molding, a shear force can be adjusted by changing a press pressure. Examples of such a fluororesin include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene, polyvinylidene fluoride, and an ethylene-tetrafluoroethylene copolymer. Among these, PTFE is particularly preferable because it can be easily fibrillated.

  The mixing ratio of the heat generating material and the fluororesin is not limited, but when the total amount of the heat generating material and the fluororesin is 100% by weight, the content of the heat generating material is 20 to 99% by weight, and the fluororesin The content of is preferably 80 to 1% by weight. Further, it is more preferable that the content of the heat generating material is 60 to 99% by weight and the content of the fluororesin is 40 to 1% by weight. Furthermore, the content of the heat generating material is more preferably 80 to 97% by weight, and the content of the fluororesin is more preferably 20 to 3% by weight.

  Since the fluororesin has low surface free energy and water repellency, excessive blending may hinder the contact between the heat generating material and water. Therefore, as described above, the total amount of the heat generating material and the fluororesin is set to 100. The content of the fluororesin is preferably set to 80% by weight or less, more preferably 40% by weight or less as the weight%.

  In the exothermic molded article of the present invention, other components may be used in combination with the above components. For example, calcium sulfate, ferrous sulfate, magnesium chloride, sodium sulfite, sodium phosphate, sodium carbonate and the like can be blended. Although these content is not limited, it is preferable to set it as 5-10 weight part with respect to 100 weight part of said heat-generating materials.

  The exothermic molded body of the present invention can be obtained by mixing and molding the above components. At the time of molding, a molding aid may be used in combination so that the molding can be easily performed. Examples thereof include hydrocarbon compounds such as isoparaffin, glycol compounds such as propylene glycol, and oily compounds such as silicone.

  The amount of the molding aid used is not limited, and may be appropriately adjusted according to the type of molding aid used together. The molding method is not limited as long as it can be molded into a desired shape such as extrusion molding or press molding. In extrusion molding, the molding pressure and the cross-sectional area ratio of the nozzle and cylinder are appropriately set according to the mixing ratio of the raw materials used, and in press molding, the share and molding pressure when mixing the raw materials used are appropriately set.

  The shape of the exothermic molded body of the present invention may be any shape suitable for the heating element, and examples thereof include a pellet shape, a coin shape, and a sheet shape. When processing into these shapes, the thickness is preferably set to about 0.1 to 10 mm. When the thickness is less than 0.1 mm, the number of sheets to be used increases and the area of the sheet becomes extremely large, which is not preferable. The sheet can be produced by rolling a mixture of used raw materials by biaxial stretching or calendering. Moreover, the pellet form and the coin form can be produced by using those prepared by extrusion molding or press molding, or by pulverizing or punching a sheet.

  Moreover, it is preferable that the surface of the heating element is processed to increase the surface area. For example, the surface area can be easily increased by providing an uneven shape on the surface, or providing holes or cuts. Furthermore, if the degree of porosity is changed within a range in which the strength of the molded body can be maintained, the degree of moisture absorption can be adjusted, so the degree of heat generation can be adjusted. Those with sharp heat generation are suitable for heat generation applications, and those with moderate heat generation are suitable for heat insulation applications.

  The exothermic molded body of the present invention, for example, when processing food such as ekiben, accommodates the exothermic molded body of the present invention and water in the lowermost part of the outer container so that they come into contact with each other during use. Set and contain food to be heated on the inner lid. And the exothermic molded object of this invention and water contact and react at the time of use, heat_generation | fever arises, and a foodstuff is heated. The heating time and the amount of heat generated can be appropriately adjusted by adjusting the type of heat generating material used and the size of the molded body. Moreover, it can be used not only for heating foods but also for heat-retaining materials and for aromatherapy materials (heating fragrances).

  Since the exothermic molded body of the present invention is formed into a molded body by using a fluororesin as a binder component, the active ingredient powder is prevented from leaking before use and during heat generation. In addition, since the fluororesin is easily fibrillated by the shearing force when forming the molded body, the heat-generating material is not coated, and the fibrillated thread-like fluororesin is point-bonded to the heat-generating material. Even after making into a body, it is difficult to interfere with the contact between the active ingredient and water, the heat generation characteristics can be kept high, and a high-strength molded body that does not fall off can be obtained. Furthermore, since it is a molded body, it is not necessary to be housed in an inner bag and the expansion during heat generation is suppressed, so that the space for housing the heat generating body can be suppressed to a minimum volume.

  Hereinafter, the present invention will be described with reference to examples and comparative examples. However, the present invention is not limited to the examples.

Examples 1-20
Calcium oxide (calcined product of calcium hydroxide “Karmyu Mesox” (registered trademark) manufactured by Yoshizawa Lime Industry) with respect to 100 parts by weight of aluminum (product name “VA-235”, manufactured by Yamaishi Metal, average particle size 40-50 μm) 50 parts by weight, sodium carbonate (product name “soda lime”, manufactured by Tokuyama, average particle size 100 μm) 37.5 parts by weight and magnesium chloride (product name “magnesium chloride”, manufactured by Maruyasu Sangyo, average particle size 66 μm) 5.25 weights The parts were mixed to obtain a heat generating material.

  Mixing proportions shown in Table 1 below include binder: PTFE (product name “F-201” manufactured by Daikin Industries) and molding aid: hydrocarbon compound (product name “Iso-H M” (registered trademark), manufactured by ExxonMobil)) as the heat generating material. To form a coin-shaped or sheet-shaped molded body (heat generating agent). The diameter of the coin-shaped molded body was 23 mm (the same applies to the following examples).

  The thickness of the molded body and the presence or absence of surface irregularities (holes) were as shown in Table 1 below.

[In Table 1, the double amount and the triple amount indicate the water content with respect to the exothermic agent.]
(Fever test)
A container having a double structure was prepared, and the exothermic agent (18 g each of exothermic agent weight) and twice or three times the amount of water were added to the lower stage, and 200 g of 20 ° C. water was added to the upper stage of the container. The temperature change of the water in the upper stage was monitored. The graph which shows the result of a heat_generation | fever test is shown in FIGS.

  As is apparent from FIGS. 2 to 5, although all of Examples 1 to 20 have different degrees of temperature rise, all of them have risen in temperature (higher rises to 70 ° C. or more) and are used as heating or heat retaining means. You can see that it can be used.

(Expansion coefficient test)
The thickness of the heat generating agent (before heat generation) is as shown in Table 1. The expansion coefficient was examined by measuring the thickness of the heat generating agent (after heat generation) measured immediately after the end of the heat generation test. The expansion coefficient is shown in Table 5 below.

Examples 21-23
100 parts by weight of calcium oxide (product name “Volmic”, made by Yue Mining Co., Ltd., average particle size 31 μm) was used as a heat generating material.

  Mixing ratios shown in Table 3 below include binder: PTFE (product name “F-201” manufactured by Daikin Industries) and molding aid: hydrocarbon compound (product name “Iso-H M” (registered trademark), manufactured by ExxonMobil)) as the heat generating material. To obtain a coin-shaped molded body (exothermic agent).

  The thickness of the molded body and the presence or absence of surface irregularities (holes) were as shown in Table 3 below.

  As in Examples 1 to 20, an exothermic test and an expansion rate test were performed. A graph showing the results of the heat generation test is shown in FIG. As is clear from the results of FIG. 7, although all of Examples 21 to 23 have different temperature rises, they all have a temperature rise (higher ones rise to about 70 ° C.) and are used as heating or heat retaining means. I understand that I can do it. It can be seen that even when calcium oxide is used as the heat generating material, it can be used as a heating means by increasing the weight (g) of the heat generating agent.

  The results of the expansion coefficient test are shown in Table 5 below. As is apparent from Table 5, it can be seen that the exothermic molded body of the present invention has an extremely low expansion rate compared to the conventional product even when the heat generating material is calcium oxide. It can be seen that the heat generation rate increases as the proportion of the active ingredient increases and the thickness of the heating element decreases.

Examples 24 and 25
(Example 24)
A coin-shaped molded body was produced in the same manner as in Example 4 except that no molding aid was used.

The coin-shaped molded bodies (diameter: 23 mm) produced in the Examples were not deformed at all even when a load of 10 kg was applied to the bottom or upper circular portion, and maintained excellent strength.
(Example 25)
A molded body was produced in the same manner as in Example 4 except that a 5 mm square pellet-shaped molded body was used instead of the coin-shaped molded body.

  Exothermic tests were performed on the molded bodies (exothermic agents) of Examples 24 and 25 in the same manner as in Examples 1-20. A graph showing the results of the heat generation test is shown in FIG. As is apparent from the results of FIG. 8, it can be seen that the pellets can be used as heating or heat retaining means. Moreover, it turns out that it can be used as a heating or heat retention means, without using a shaping | molding adjuvant.

Comparative Examples 1-3
As shown in Table 4 below, each example described in each patent document was reexamined to produce a conventional powdery heat generating agent (a mode in which the heat generating agent was housed in an inner bag).

  As in Examples 1 to 20, an exothermic test and an expansion rate test were performed. A graph showing the results of the heat generation test is shown in FIG. As is apparent from the example of the present application such as FIG. 2 and the results of FIG. 6, it can be seen that the exothermic molded article of the present invention is comparable to the exothermic characteristics as compared with the conventional powdered exothermic agent.

  The results of the expansion coefficient test are shown in Table 5 below. As is apparent from Table 5, it can be seen that the exothermic molded body of the present invention has an extremely low expansion rate compared to the conventional product. When the content of the active ingredient is large, the expansion of the thickness becomes relatively large, but the expansion can be suppressed by drilling. It can be seen that the heating rate increases as the proportion of the active ingredient increases and the thickness of the heating element decreases.

  In addition, as can be seen from Table 4 as a result of the expansion coefficient test, the example maintains the shape as a molded body before and after heat generation. On the other hand, since Comparative Examples 1 to 3 have a form in which the heat generating agent is housed in the inner bag, the heat generating agent itself cannot maintain the shape without the inner bag after the heat generation. Also in Comparative Example 4, the shape as a molded body can be maintained before heat generation, but the heat generating agent is dispersed in water and cannot retain the shape after heat generation. It turns out that this invention is excellent also in the surface of the shape retention performance before and behind heat_generation | fever.

Comparative Example 4
An exothermic molded body was produced in the same manner as in Example 1 except that polyethylene glycol (PEG, non-fluorine resin) was used instead of PTFE, and no hydrocarbon-based molding aid was added.

  PEG is a hydrophilic resin and generates heat because of its good water permeability. However, since PEG dissolves in water, the molded body could not retain its shape, and the exothermic material after heat generation was dispersed in water.

(A) It is a schematic diagram (an example) of a coin-like exothermic molded object. (B) It is a schematic diagram (an example) of the coin-like exothermic molded object which provided the small hole in the surface. It is a figure which shows the result of the heat_generation | fever test of Examples 1-8. It is a figure which shows the result of the heat_generation | fever test of Examples 9-14. It is a figure which shows the result of the heat_generation | fever test of Example 15 and 16. It is a figure which shows the result of the heat_generation | fever test of Examples 17-20. It is a figure which shows the result of the heat_generation | fever test of Comparative Examples 1-3. It is a figure which shows the result of the heat_generation | fever test of Examples 21-23. It is a figure which shows the result of the heat_generation | fever test of Example 24,25.

Claims (6)

An exothermic molded body containing a heat generating material that generates heat by reacting with water and a fluororesin,
Heating material comprises a mixture of calcium oxide and aluminum,
When the total amount of the heat generating material and the fluororesin is 100% by weight, the content of the heat generating material is 20 to 99% by weight, and the content of the fluororesin is 80 to 1% by weight.
Exothermic molded body. The heat generation according to claim 1 , wherein the fluororesin is at least one selected from the group consisting of polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, and an ethylene-tetrafluoroethylene copolymer. Molded product. The exothermic molded article according to claim 1 , wherein the fluororesin is fibrillated polytetrafluoroethylene. The exothermic molded object according to any one of claims 1 to 3 , wherein a process for increasing a surface area is performed. The exothermic molded object according to any one of claims 1 to 4 , which is in a pellet form. The exothermic molded object according to any one of claims 1 to 4 , which is in a sheet form.

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