Hardened body

Abstract

To provide a hardened body capable of improving strength compared with conventional hardened bodies.SOLUTION: A hardened body is constituted of a hardened body of a composition containing, by mass%: 20% or more and 50% or less of slaked lime and / or quick lime, provided that lime-made sand and slaked lime and / or quick lime dissolved in water are excluded; 20% or more and 55% or less of lime-made sand; 2% or more and 15% or less of porous stone powder, provided that zeolite powder and sepiolite powder are excluded; 2% or more and 8% or less of clay that is kibushi clay and / or gairome clay; and 2% or more and 15% or less of a Ca-ion-containing aqueous solution having a Ca ion concentration of 1 to 20 g / L, the ratios of the respective components being selected so as to be 100% in total.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cured product. [Background technology]

[0002] Hardened bodies obtained by hardening specific compositions have been known. For example, Patent Document 1 discloses a technology for using a hardened body of a composition containing slaked lime and / or quicklime, lime-made sand, powder of rhyolitic welded tuff distributed from Takasago City to Kasai City in Hyogo Prefecture, clay, a porous clay mineral (zeolite or sepiolite), and a Ca ion-containing aqueous solution as a humidity-regulating building material. Patent Document 2 discloses a technology for using a hardened body of a composition containing slaked lime and / or quicklime, lime-made sand, porous stone powder not containing powder of rhyolitic welded tuff distributed from Takasago City to Kasai City in Hyogo Prefecture, clay, a porous clay mineral (zeolite or sepiolite), and a Ca ion-containing aqueous solution as a humidity-regulating building material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-146854 [Patent Document 2] Japanese Patent Publication No. 2023-146855 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional hardened body described above is hardened by a specific composition absorbing CO2. Therefore, it is more difficult to increase the strength of this type of hardened body compared to fired products formed by firing ceramic raw materials. Although Patent Documents 1 and 2 state that the strength can be ensured with the conventional hardened body described above, the maximum bending strength in the experimental example of Patent Document 1 was 2.60 N / mm 2 In the experimental example of Patent Document 2, the maximum bending strength was 2.59 N / mm 2Therefore, there is room for further improvement in strength.

[0005] The present invention has been made in view of the above problems, and aims to provide a hardened body that can achieve improved strength compared to conventional hardened bodies. [Means for solving the problem]

[0006] One aspect of the present invention is A hardened body of a composition containing slaked lime and / or quicklime (excluding lime sand and slaked lime and / or quicklime dissolved in water), lime sand, porous stone powder (excluding zeolite powder and sepiolite powder), clay that is kibushi clay and / or gairome clay, and a calcium ion-containing aqueous solution having a calcium ion concentration of 1 to 20 g / L, The composition comprises, in mass %: The slaked lime and / or quicklime: 20% or more and 50% or less, The lime sand: 20% or more and 55% or less, The porous stone powder: 2% or more and 15% or less, The clay: 2% or more and 8% or less, The Ca ion-containing aqueous solution: 2% or more and 15% or less (however, the proportions of each component are selected so that the total is 100%), It is in a hardened body. [Effects of the Invention]

[0007] The cured product is made of the specific composition. Therefore, the cured product can ensure higher bending strength than conventional cured products. Therefore, the cured product can provide a cured product that can achieve improved strength compared to conventional cured products. DETAILED DESCRIPTION OF THE INVENTION

[0008] The cured product of this embodiment will be described in detail. In this disclosure, the lower limit and upper limit of the numerical ranges can be arbitrarily combined (omitted below).

[0009] The hardened body of this embodiment is made of a hardened body of a composition containing slaked lime and / or quicklime, lime sand, porous stone powder, clay, and a Ca ion-containing aqueous solution.

[0010] The hardened body of this embodiment can be produced by press-molding a clay made from the specific composition and drying the resulting pressed body to harden it. Since the specific composition contains clay, the green strength of the pressed body can be ensured. Therefore, the hardened body of this embodiment can be produced without pouring raw materials into a mold or firing it, thereby improving productivity. Furthermore, since the hardened body of this embodiment is made of a hardened body of the specific composition, it can absorb CO2 from the air during production, harden, and immobilize it. Even after the hardened body is formed, it can still absorb a certain amount of CO2 from the air. This is presumably because the specific composition contains a Ca ion-containing aqueous solution, which facilitates CO2 penetration not only onto the surface of the hardened body but also into the interior of the hardened body. This promotes the neutralization of slaked lime and / or quicklime and lime-based sand within the hardened body, thereby accelerating hardening.

[0011] In the specific composition, slaked lime (Ca(OH)2) and / or quicklime (CaO) are important components for hardening by reaction with carbon dioxide in the air. However, the "slaked lime and / or quicklime" in the specific composition does not include lime-made sand or slaked lime and / or quicklime dissolved in water. Therefore, the specific composition requires both "slaked lime and / or quicklime" that is different from lime-made sand and "lime-made sand." Furthermore, the specific composition requires both "slaked lime and / or quicklime" that is different from slaked lime and / or quicklime dissolved in water and a "Ca ion-containing aqueous solution."

[0012] The specific composition may contain either slaked lime or quicklime, or both. Preferably, slaked lime is used from the viewpoints of suppressing heat generation due to reaction with water during preparation of the specific composition, ease of handling, etc. The slaked lime and quicklime may be derived from, for example, limestone, limestone, shells (oyster shells, scallop shells, etc.), coral, etc. The slaked lime and quicklime may be in the form of powder.

[0013] In the specific composition, lime sand refers to a sand-like substance produced when quicklime is produced from limestone. The lime sand can function as a fine aggregate, and the particle size of the lime sand can be, for example, 4 mm or less. For example, lime sand manufactured by Nakayama Lime Industry Co., Ltd. can be obtained from Kawara Kogyo Miyake Co., Ltd.

[0014] In the specific composition, the porous stone powder is a powder of a porous stone material. The porous stone powder is a component useful for imparting moisture absorption and desorption properties and / or deodorizing properties to a cured product of the specific composition. However, the "porous stone powder" in the specific composition does not include zeolite powder or sepiolite powder.

[0015] The porous stone material constituting the porous stone powder is preferably a natural material. Specific examples include natural pumice from Towada Volcano (hereinafter sometimes referred to as Lake Towada pumice), koga stone from Niijima Island in the Izu Islands (hereinafter sometimes referred to as Niijima koga stone), bakuhan stone from Mino Shirakawa in Gifu Prefecture (hereinafter sometimes referred to as Mino Shirakawa bakuhan stone), and rhyolitic welded tuff (e.g., Tatsuyama stone, feldspar, Takamuro stone, etc.) distributed from Takasago City to Kasai City in Hyogo Prefecture. However, the porous stone powder is not limited to these, and various materials can be used as long as they have moisture absorption and desorption properties and / or deodorizing properties. Furthermore, one or more types of porous stone materials can be used in combination.

[0016] In the specific composition, clay is a component necessary for ensuring press moldability of the clay made of the specific composition and for ensuring the green strength of the pressed body. Specifically, the clay is Kibushi clay and / or Gairome clay. Kibushi clay is preferably used as the clay because it has a high alumina content, is sticky, and makes it easy to ensure the green strength of the pressed body.

[0017] In the specific composition, the calcium ion-containing aqueous solution contains at least calcium ions and water. The calcium ion-containing aqueous solution may contain, in addition to calcium ions and water, acids such as acetic acid, citric acid, and formic acid. One or more of these acids may be included. The water is not particularly limited, and may be tap water, ionized water, pure water, distilled water, potable groundwater, or the like.

[0018] It is known that quicklime and slaked lime dissolve in pure water at a weight percentage concentration of about 0.2%. In the above-mentioned specific composition, a Ca ion-containing aqueous solution in which CaO or Ca(OH)2 is dissolved at a concentration of more than 0.2% can be suitably used. For example, a 10% acetic acid aqueous solution can dissolve CaO at a weight percentage concentration of about 3.2% (32 g / L) based on Ca at room temperature. If dissolving CaO or Ca(OH)2 is difficult, sodium bicarbonate (NaHCO3) can be added. In addition to an acetic acid aqueous solution, an acid-containing aqueous solution such as a citric acid aqueous solution or a formic acid aqueous solution may be used to dissolve CaO and / or Ca(OH)2. However, considering the natural environment and dissolving ability, an acetic acid aqueous solution is preferred. The pH of the Ca ion-containing aqueous solution can be adjusted as appropriate. When the calcium ion-containing aqueous solution contains calcium ions, an acid, and water, calcium acetate having needle-like crystals can be produced during hardening of the specific composition, which is advantageous in improving the strength of the hardened body.

[0019] The CaO and / or Ca(OH)2 used to prepare the calcium ion-containing aqueous solution is not limited to specific CaO and / or Ca(OH)2. For example, oyster shell powder calcined at 900°C to 1200°C can be used. Alternatively, shell powder calcined from other shells, such as scallop shells, can be used instead of oyster shells. When the calcium ions in the calcium ion-containing aqueous solution are derived from shells, discarded shells in the fishing industry can be reused as resources, thereby reducing waste. Among the above-mentioned shells, oyster shells are preferred. This is because component analysis of oyster shells reveals that they contain more minerals than other shells, which is thought to have a positive effect on the physical properties and strength of hardened bodies during production. A calcium ion-containing aqueous solution containing calcium ions derived from shells can be obtained, for example, from Seto Shikkui Honpo Co., Ltd. or Kawara Kogyo Miyake Co., Ltd. The calcium ion-containing aqueous solution may be prepared to a predetermined calcium ion concentration from the beginning, or it may be prepared by diluting a stock solution with water.

[0020] The Ca ion concentration in the Ca ion-containing aqueous solution is specifically 1 to 20 g / L. From the viewpoint of improving the strength of the hardened body, the Ca ion concentration in the Ca ion-containing aqueous solution can be preferably 1 to 10 g / L. In this case, if the Ca ion-containing aqueous solution contains acetic acid, it is easy to produce calcium acetate having needle-like crystals, which is advantageous for improving the strength of the hardened body.

[0021] The specific composition may also contain one or more additives such as pigments, etc. Examples of pigments include ink and red iron oxide.

[0022] The specific composition is 20% to 50% slaked lime and / or quicklime, 20% to 55% lime sand, 2% to 15% porous stone powder, 2% to 8% clay, and 2% to 15% calcium ion-containing aqueous solution. The proportions of the above components are selected so that the total is 100%. The proportion of the pigment can be, for example, 0.1% to 5% of the total of the above components (100%). The proportions of the above components are expressed in mass%.

[0023] If the content of slaked lime and / or quicklime in the specific composition is less than 20%, the required amount must be compensated for primarily with lime sand, resulting in an excessive amount of lime sand that can function as aggregate. As a result, the pressed body immediately after press-molding the specific composition will feel very rough, and the green strength of the pressed body will be reduced, making it more prone to deformation and difficult to handle. It will also be difficult to improve the bending strength of the hardened body. Furthermore, since less slaked lime and / or quicklime is used, the CO2 absorption rate of the hardened body will also be reduced. On the other hand, if the content of slaked lime and / or quicklime exceeds 50%, there will be a large amount of dust loss during the formulation of the specific composition, resulting in inconsistent quality of the hardened body. Furthermore, by limiting the content of slaked lime and / or quicklime to 20% or more and 50% or less, the hardened body will tend to be white in color, improving marketability. The lower limit of slaked lime and / or quicklime is preferably 22.5% or more, more preferably 25% or more, even more preferably 27.5% or more, and even more preferably 30% or more, while the upper limit of slaked lime and / or quicklime is preferably 49% or less, more preferably 48% or less, even more preferably 47% or less, and even more preferably 46% or less.

[0024] If the content of lime-based sand in the specific composition falls below 20%, it becomes necessary to compensate for this by mainly using slaked lime and / or quicklime or porous stone powder, resulting in excessive amounts of slaked lime and / or quicklime or excessive amounts of porous stone powder. Excessive amounts of slaked lime and / or quicklime result in increased dust loss during the formulation of the specific composition, leading to inconsistent quality of the hardened body. Excessive amounts of porous stone powder make it difficult to improve the bending strength of the hardened body. Furthermore, since porous stone powder is often not white, it is difficult to achieve a white color for the hardened body. On the other hand, if the content of lime-based sand exceeds 55%, the amount of lime-based sand that can function as aggregate becomes excessive. As a result, the pressed body immediately after press-molding the specific composition will feel very rough, and the green strength of the pressed body will decrease, making it prone to deformation and difficult to handle. It will also be difficult to improve the bending strength of the hardened body. Furthermore, it becomes necessary to use less slaked lime and / or quicklime, which also reduces the CO2 absorption rate of the hardened body. The lower limit of the lime sand is preferably 25% or more, more preferably 27.5% or more, even more preferably 30% or more, even more preferably 32.5% or more, and even more preferably 35% or more. The upper limit of the lime sand is preferably 54% or less, more preferably 53% or less, even more preferably 52% or less, even more preferably 51% or less, and even more preferably 50% or less.

[0025] In the specific composition, the total content of slaked lime and / or quicklime and lime-made sand is preferably 75% or more. In this case, it is possible to enhance the strength improvement effect compared to conventional hardened bodies. The total content of slaked lime and / or quicklime and lime-made sand is more preferably 76% or more, even more preferably 77% or more, even more preferably 78% or more, even more preferably 79% or more, and most preferably 80% or more.

[0026] In the above specific composition, if the porous stone powder content is 2% or less, it becomes difficult to impart humidity control and deodorizing properties to the cured product. On the other hand, if the porous stone powder content exceeds 15%, it becomes difficult to improve the bending strength of the cured product, and since porous stone powder is often not white, it becomes difficult to make the cured product white. The lower limit of the porous stone powder content is preferably 3% or more, more preferably 4% or more, and even more preferably 5% or more. The upper limit of the porous stone powder content is preferably 14% or less, more preferably 13% or less, even more preferably 12% or less, even more preferably 11% or less, and even more preferably 10% or less.

[0027] In the above specific composition, if the clay content is less than 2%, the viscosity of the specific composition decreases, making it difficult to ensure press moldability, and the pressed body tends to crumble easily. On the other hand, if the clay content exceeds 8%, it tends to be difficult to demold the pressed body after press molding the specific composition. The lower limit of the clay content is preferably 2.5% or more, more preferably 3% or more, even more preferably 3.5% or more, and even more preferably 4% or more. The upper limit of the clay content is preferably 7.5% or less, more preferably 7% or less, even more preferably 6.5% or less, and even more preferably 6% or less.

[0028] In the specific composition, if the Ca ion-containing aqueous solution is less than 2%, it becomes difficult to ensure curing by reaction with carbon dioxide, and it tends to be difficult to ensure bending strength. On the other hand, if the Ca ion-containing aqueous solution is more than 15%, the moisture content in the specific composition increases, and when the specific composition is press-molded, the pressed body tends to stick to the mold, which tends to reduce productivity. The lower limit of the Ca ion-containing aqueous solution is preferably 3% or more, more preferably 4% or more, even more preferably 5% or more, and even more preferably 6% or more. The upper limit of the Ca ion-containing aqueous solution is preferably 13% or less, more preferably 12% or less, even more preferably 11% or less, and even more preferably 10% or less.

[0029] The hardened product of this embodiment can be suitably used as, for example, building materials such as tiles, boards, and panels. The hardened product of this embodiment is not limited to these, and can also be used for deodorizers, coasters, purifying agents (for aquariums, etc.), humidity control materials, dehumidifying materials, etc. The shape of the hardened product of this embodiment is not particularly limited, and can be selected appropriately depending on the application of the hardened product.

[0030] As described above, the hardened body of this embodiment is formed by hardening the specific composition. Specifically, the hardened body of this embodiment can be formed by drying and hardening a press-molded body of the specific composition. In other words, the hardened body of this embodiment is not fired. Despite not being fired, the hardened body of this embodiment can maintain higher strength than conventional hardened bodies. The fact that the hardened body has not been fired can be confirmed by X-ray diffraction and thermal analysis. Specifically, the presence of calcium carbonate is confirmed in the hardened body, and thermal analysis of the hardened body is performed to confirm the presence or absence of weight loss due to elimination of adsorbed water up to about 100°C, weight loss due to elimination of water of crystallization up to about 600°C, and weight loss due to elimination of carbon dioxide resulting from decomposition of calcium carbonate up to about 800°C. If weight loss due to elimination of carbon dioxide resulting from decomposition of calcium carbonate is observed, it can be said that the body was not heated to at least a temperature at which calcium carbonate decomposes, i.e., it was not fired.

[0031] The cured body of the present embodiment can be produced as follows, but is not limited to this.

[0032] The method for producing a hardened body of this embodiment includes a clay preparation step, a press molding step, and a drying and hardening step, but does not include a firing step.

[0033] The clay preparation step is a step of preparing a clay consisting of the specific composition containing slaked lime and / or quicklime, lime sand, porous stone powder, clay, and a Ca ion-containing aqueous solution. The clay consisting of the specific composition can be prepared, for example, by blending the components, kneading them in a kneading machine such as a clay mixer, and then finely pulverizing them using a grinder such as a desinter. The moisture content of the specific composition can be approximately 7% to 13% by mass.

[0034] The press molding step is a step of press molding the clay prepared in the clay preparation step to obtain a press-molded body. A dry press molding machine can be suitably used as the press molding machine. The maximum thickness of the press-molded body can be, for example, 8 mm or more and 25 mm or less.

[0035] The drying and curing step is a step in which the press-molded body is dried and cured to form a cured body. The press-molded body may be dried by natural drying or forced drying using a dryer, but forced drying is preferable from the viewpoint of productivity, etc. In this case, the drying temperature may be, for example, about 80°C to 120°C. The drying time may be about 6 hours to 12 hours. The drying atmosphere may be air.

[0036] After the drying and curing step, if necessary, additional steps may be added, such as a step of pulverizing the hardened body to obtain a pulverized product, a step of further classifying the pulverized hardened body, or a step of processing the hardened body by cutting, grinding, hollowing, or the like.

[0037] The method for producing a hardened body of this embodiment described above can produce the hardened body of this embodiment without pouring raw materials into a mold to form it or firing it, thereby improving the productivity of the hardened body. Furthermore, since the specific composition does not contain slag like plaster materials, the method for producing a hardened body of this embodiment is less likely to cause problems when kneading the specific composition, which is advantageous for improving productivity.

[0038] The cured body of the present disclosure will be described in more detail below using experimental examples. (Experimental Example 1) <Raw material preparation> The following raw materials were prepared: Slaked lime (powder) (grain size 0.15 mm or less, manufactured by Nakayama Lime Industry Co., Ltd.) Lime sand (granular sand) (grain size 4.0 mm or less, manufactured by Nakayama Lime Industry Co., Ltd.) ·Porous stone powder Niijima Koga stone (powder) (grain size 1mm or less, manufactured by Marumi Toryo Co., Ltd.) ·clay Kibushi clay (powder) "Particle size 0.5mm or less, desintered elutriated Kibushi clay obtained from Yamada Ceramic Materials Co., Ltd." Zeolite (powder) (particle size 1.25 μm or less, manufactured by Nitto Funka Kogyo Co., Ltd.) Sepiolite (powder) (grain size 150 mesh 0.1 mm or less, manufactured by Omi Mining Co., Ltd.) Ca ion-containing aqueous solution A calcium ion water stock solution derived from oyster shells was obtained from Seto Shikkui Honpo Co., Ltd. The calcium ion water stock solution was prepared by dissolving oyster shell-derived CaO in an acetic acid solution to achieve a calcium ion concentration of 20 g / L. A calcium ion-containing aqueous solution was prepared by mixing the calcium ion water stock solution with distilled water in a mass ratio of 400 L:600 L. The calcium ion-containing aqueous solution derived from oyster shells prepared in this experimental example contained calcium ions derived from oyster shells, water, and acetic acid, and had a calcium ion concentration of 8 g / L.

[0039] <Clay preparation> Each composition was obtained by kneading together slaked lime, lime sand, porous stone powder, clay, zeolite, sepiolite, and a Ca ion-containing aqueous solution in the proportions shown in Table 1. Each of the resulting compositions was pulverized in a de-sinter to obtain each clay made from de-sintered powder.

[0040] Each of the obtained clays was press-molded using a uniaxial pressure dry friction press molding machine to obtain each press-molded body. The outer dimensions of the press-molded body were 75 mm x 75 mm. The thickness of the press-molded body was approximately 9 to 10 mm, and the weight was approximately 85 g to 95 g per piece. The surface of the press-molded body was flat.

[0041] <Formation of hardened body> Each press-molded body removed from the molding die was placed in an airtight container filled with high-concentration CO2 and held there for 24 hours to form a hardened body. In this way, hardened bodies Test Specimens 1 to 7 were obtained. In this experimental example, each hardened body obtained was intended to be an interior tile.

[0042] A commercially available fired humidity-conditioning tile was used as specimen 8. Specimen 8 was used to compare the strength with specimens 1 to 7, which were unfired products.

[0043] <Evaluation> -Bending strength- A three-point bending test (n=3) was performed on each specimen, and the arithmetic mean value of the bending strength measurements was taken as the bending strength. The bending strength measurement span was 65 mm.

[0044] -CO2 concentration- Immediately after press molding, each press-molded piece was placed in a plastic bag to prevent natural CO2 absorption, creating samples (each mass was standardized to approximately 400 g, equivalent to four pieces). A desiccator (material: acrylonitrile-styrene resin, dimensions: 35 cm x 35 cm x 40 cm, container volume: 49 L) was also prepared as an airtight container. Next, a 30 L carbon dioxide gas cylinder (industrial carbon dioxide, purity (v / v%): 99.5%) was used to adjust the CO2 concentration in the room (21 °C) and the desiccator. The sample was then removed from the plastic bag and placed in the desiccator. A CO2 concentration meter (400–5000 ppm, manufactured by Sanwa Supply Co., Ltd.) was used to measure the relationship between the elapsed time from the start of the test and the CO2 concentration in the desiccator. As the sample absorbed CO2, the CO2 concentration in the desiccator decreased over time. Here, the CO2 concentrations at 0 minutes (start of the test), 30 minutes, and 60 minutes were extracted and compared. If the CO2 concentration reached the measurement limit of 400 ppm, which is the limit of the CO2 concentration meter, before 60 minutes had elapsed, the elapsed time at which the CO2 concentration reached 400 ppm was calculated. Note that a CO2 concentration of 400 ppm is the same as that found in nature.

[0045] Table 1 shows the blending ratio of each composition used to prepare each test specimen, as well as the measurement results of bending strength and CO2 concentration.

[0046] [Table 1] Table 1 reveals the following. Specimen 7 simulates a hardened body of the composition specified in Patent Document 2. Specimen 7 contains lime sand and porous stone powder that are not within the ranges specified in this disclosure, and also contains zeolite and sepiolite. Therefore, Specimen 7 had the lowest bending strength of all the experimental examples.

[0047] Furthermore, the content of slaked lime and lime sand in the composition of specimen 1 did not satisfy the ranges specified in the present disclosure. Therefore, although specimen 1 had a higher bending strength than specimen 7, it was unable to achieve a sufficient strength improvement effect.

[0048] In contrast, specimens 2 to 6 were made of cured products of specific compositions defined by the present disclosure. Therefore, specimens 2 to 6 were able to ensure higher bending strength than specimen 7. These results confirmed that specimens 2 to 6 can provide cured products that are capable of improving strength compared to conventional cured products. Therefore, it can be said that the cured product of the present disclosure can provide a cured product that is high in strength and easy to handle.

[0049] Furthermore, unlike specimen 7, specimens 2 to 6 do not require the typical firing process, and therefore do not emit CO2 generated during firing into the natural environment. Furthermore, during the production of the hardened product, CO2 in the air is absorbed, hardened, and immobilized, and even after the product is made, it continues to absorb a certain amount of CO2 from the air. Therefore, the hardened product of the present disclosure can be obtained with a high degree of contribution to the natural environment.

[0050] Furthermore, when comparing specimens 2 to 6, specimens 4 to 6, which have a total content of slaked lime and / or quicklime and lime-made sand of 80% or more, show a particularly large effect in improving strength, and also show a faster CO2 absorption time. Furthermore, when the slaked lime content exceeds 50%, there is a tendency for dust loss to increase during the mixing of the composition. Therefore, when considering factors such as suppressing quality variation in the hardened body due to dust loss and ensuring a better production environment, specimens 4 and 5 can be said to be more preferable hardened bodies than specimen 6.

[0051] (Experimental Example 2) Tiles were produced using the composition formulations of specimens 4 and 5 in Experimental Example 1, each consisting of a cured product. A moisture absorption / desorption test was conducted for each of the resulting tiles in accordance with JIS A1470-1:2014, "Test Methods for Moisture Absorption / Desorption of Building Materials - Part 1: Humidity Response Method." Additionally, ammonia gas and formaldehyde gas adsorption tests were conducted for each of the resulting tiles. Specifically, the adsorption test was conducted by placing each tile in a 10-liter gas collection bag, sealing it, transferring 10 liters of nitrogen gas containing approximately 200 ppm ammonia and approximately 100 ppm formaldehyde into the gas collection bag, and measuring the gas concentrations at regular intervals using a detector tube method.

[0052] As a result, it was confirmed that each tile had moisture absorption and desorption properties, as well as the ability to adsorb ammonia gas and formaldehyde gas.

[0053] Therefore, by combining the results of Experimental Example 2 with those of Experimental Example 1, it can be said that the hardened body of the present disclosure can achieve improved strength compared to conventional hardened bodies, does not emit CO2 during firing, and can continue to absorb a certain amount of CO2 even after production, making it possible to obtain a hardened body that makes a significant contribution to the natural environment and can also contribute to maintaining a clean environment through its humidity control and deodorizing effects.

[0054] The present invention is not limited to the above-described embodiment and experimental examples, and various modifications are possible without departing from the spirit and scope of the present invention. Furthermore, the configurations shown in the above-described embodiment and experimental examples can be combined in any manner.

[0055] The features of the present invention are as follows. Section 1. A hardened body of a composition containing slaked lime and / or quicklime (excluding lime sand and slaked lime and / or quicklime dissolved in water), lime sand, porous stone powder (excluding zeolite powder and sepiolite powder), clay that is kibushi clay and / or gairome clay, and a calcium ion-containing aqueous solution having a calcium ion concentration of 1 to 20 g / L, The composition comprises, in mass %: The slaked lime and / or quicklime: 20% or more and 50% or less, The lime sand: 20% or more and 55% or less, The porous stone powder: 2% or more and 15% or less, The clay: 2% or more and 8% or less, The Ca ion-containing aqueous solution: 2% or more and 15% or less (however, the proportions of each component are selected so that the total is 100%), Hardened body. Section 2. The composition comprises, in mass %: The total content of the slaked lime and / or quicklime and the lime sand is 75% or more. Item 1. The hardened body according to item 1. Section 3. The hardened body is a press-molded body of the composition that is hardened by drying. Item 1 or 2. The cured product according to item 1 or 2. Section 4. The hardened body is not fired. Item 4. The cured product according to any one of items 1 to 3. Section 5 The Ca ion-containing aqueous solution contains Ca ions, an acid, and water. Item 5. The cured product according to any one of items 1 to 4. Section 6. The Ca ions are derived from shells. Item 6. The cured body according to item 5.

Claims

1. A hardened body of a composition containing slaked lime and / or quicklime (excluding lime sand and slaked lime and / or quicklime dissolved in water), lime sand, porous stone powder (excluding zeolite powder and sepiolite powder), clay that is kibushi clay and / or gairome clay, and a calcium ion-containing aqueous solution having a calcium ion concentration of 1 to 20 g / L, The composition comprises, in mass %: The slaked lime and / or quicklime: 20% or more and 50% or less, The lime sand: 20% or more and 55% or less, The porous stone powder: 2% or more and 15% or less, The clay: 2% or more and 8% or less, The Ca ion-containing aqueous solution: 2% or more and 15% or less (however, the proportions of the respective components are selected so that the total is 100%), Hardened body.

2. The composition comprises, in mass %: The total content of the slaked lime and / or quicklime and the lime sand is 75% or more. The cured product according to claim 1.

3. The hardened body is a press-molded body of the composition that is hardened by drying. The cured product according to claim 1 or claim 2.

4. The hardened body is not fired. The cured product according to claim 1 or claim 2.

5. The Ca ion-containing aqueous solution contains Ca ions, an acid, and water. The cured product according to claim 1 or claim 2.

6. The Ca ions are derived from seashells. The cured product according to claim 5.

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