JP2006001794A - Moisture absorbing/releasing building material and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture absorbing/releasing building material excellent in moisture absorbing/releasing performance which is a porous body and containing calcium silicate and zeolite provided with moisture absorbing/releasing nature, and to provide a method for producing the building material. <P>SOLUTION: This moisture absorbing/releasing building material comprises pulverized matter of calcium silicate hardened body and zeolite, where the content of the pulverized matter of calcium silicate hardened body is 1-50 mass% of the total mass, and the content of zeolite is 1-50 mass% of the total mass. Such a building material can be simply produced by forming a mixture comprising pulverized matter of calcium silicate hardened body, zeolite and water into a predetermined shape as a raw material formed body, and hardening the raw material formed body by conducting hydrothermal reaction into a hardened body. Alternatively, a photocatalytic layer may be formed by applying a photocatalyst to the surface of the hardened body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a moisture-absorbing / releasing building material containing a pulverized calcium silicate cured product and zeolite, and a method for producing the building material.

  Calcium silicate, which is a porous material, is known as an incombustible material, and since it is a lightweight and thermally stable substance, it is molded into molded products of various shapes and has a building material with adsorption performance. Widely used as a thermal insulation material. In general, this calcium silicate can be synthesized by room temperature curing or steam curing, but it is advantageous in terms of strength and dimensional stability to be performed under hydrothermal conditions. Also, a hydrothermal reaction is required in order to cause the siliceous raw material and the calcareous raw material to react to crystallize calcium silicate.

  In addition, moisture-absorbing / releasing building materials (moisture-absorbing building materials) formulated with porous zeolite are known to suppress humidity conditioning and condensation by the moisture absorbing / releasing action in indoor and other building spaces. ing. As building materials containing such zeolite, humidity-controlled building materials obtained by blending zeolite and a setting hardening material (for example, Patent Document 1), and zeolite subjected to high-temperature activation treatment to have a humidity-controlling action There has been provided a humidity-controllable building material having antibacterial and antifungal properties using a powder or granule of zeolite formed by supporting metal ions as a main material (for example, Patent Document 2).

Japanese Patent Laid-Open No. 3-93662 JP-A-3-109244

  On the other hand, the calcium silicate molded body is generally a molded body (cured body) obtained by curing a mixture of silicate raw material, calcareous raw material, cement and the like mixed with water by a hydrothermal reaction or the like. When zeolite is contained in such a mixture and zeolite is made to exist in the calcium silicate molded body, in addition to the zeolite not being well dispersed in the molded body, the molded body is often not sufficiently cured. . Moreover, since the obtained molded object cannot express a desired moisture absorption / release performance, improvement has been demanded.

  Accordingly, an object of the present invention is to provide a moisture-absorbing / releasing building material excellent in moisture-absorbing / releasing performance, and a method for producing the building material, comprising calcium silicate and zeolite that are porous and have moisture-absorbing / releasing properties. It is to provide.

  In order to solve the above-mentioned problems, the moisture-absorbing and releasing building material of the present invention contains a pulverized product of calcium silicate cured product and zeolite, and the content of the pulverized product of the calcium silicate cured product is 1 to 1 in total. It is 50 mass%, The content rate of the said zeolite is 1-50 mass% of the whole, It is characterized by the above-mentioned.

This hygroscopic building material of the present invention is a porous body and employs a structure in which a pulverized calcium silicate cured product having moisture absorbing / releasing performance and zeolite are blended at a specific content.
Therefore, since the calcium silicate is in a state of a pulverized product obtained by pulverizing a cured product that has been previously cured, it is mixed with a porous zeolite having moisture absorption / release performance and cured to form a molded product. It is a building material with excellent moisture absorption and release performance.
In other words, the moisture-absorbing / releasing building material of the present invention contains the hardened calcium silicate in the form of a pulverized product, so that in addition to the moisture-absorbing / releasing performance inherent in calcium silicate and zeolite, An effect similar to that obtained by adding crystals can be expected, and the formation of calcium silicate crystals in the hydrothermal reaction can be promoted. For this reason, it is possible to provide a moisture-absorbing / releasing building material that has been hardened, and the use of this pulverized material also increases the apparent bulk, so that more air holes can be formed. Performance can be maintained at a high level.

Furthermore, since calcium silicate and zeolite, which are constituent materials of the moisture-absorbing / releasing building material of the present invention, are incombustible materials, the building material has excellent moisture-absorbing performance and incombustibility.
And since the hygroscopic building material of this invention can mix | blend the ground material of a calcium silicate hardened | cured material, it can use effectively recycled materials, such as a building waste material, and can respond also to an environmental problem effectively. it can.

In the moisture-absorbing / releasing building material of the present invention, the total content of the pulverized calcium silicate and the zeolite content is preferably 50% by mass or more.
According to this invention, since the total amount of the pulverized product of calcium silicate and zeolite contained in the entire hygroscopic building material is in a specific range, the hygroscopic material (pulverized calcium silicate cured product) Compound and zeolite) in a well-balanced manner, it becomes a moisture-absorbing / releasing building material with even better moisture-absorbing / releasing properties.

In the hygroscopic building material of the present invention, it is preferable that the weight ratio of the ground calcium silicate pulverized product to the zeolite is pulverized product / zeolite = 1/6 to 6/1.
According to the present invention, since the ratio (weight ratio) between the pulverized product of calcium silicate and zeolite is in a specific range, for example, if the ratio of the pulverized product is increased within such a range, the non-combustible building material In addition to improving the performance, it can respond to environmental problems more effectively. On the other hand, if the ratio of zeolite is increased, the adsorption performance of building materials can be improved.

The hygroscopic building material of the present invention preferably has a photocatalytic layer formed on the surface.
According to the present invention, since the photocatalyst layer is formed on the surface of the moisture absorbing / releasing building material, the moisture absorbing / releasing building material is provided with functions such as deodorizing action and antibacterial action by adsorption and decomposition of odor. Can do.

The manufacturing method of the hygroscopic building material of the present invention includes a pulverized product of a cured calcium silicate having a content rate of 1 to 50% by mass of the entire building material, and a content rate of 1 to 50% by mass of the entire building material. And a step of forming the mixture containing zeolite into a predetermined shape to form a raw material molded body, and a step of curing the raw material molded body by hydrothermal reaction to form a cured body.
Since the manufacturing method of the moisture-absorbing / releasing building material of the present invention employs such a predetermined process to manufacture the moisture-absorbing / releasing building material, a pulverized product of a predetermined amount of the hardened calcium silicate and It is possible to efficiently provide a moisture-absorbing / releasing building material excellent in moisture-absorbing / releasing performance by containing zeolite.

In the method for producing a hygroscopic building material of the present invention, it is preferable that a photocatalyst layer is formed by applying a photocatalyst to the surface of the cured body after the hydrothermal reaction.
According to the present invention, since the photocatalyst is applied to the surface of the cured body after the hydrothermal reaction, the moisture absorbing / releasing building material in which the photocatalyst layer is firmly formed on the surface is suitably used. It can be provided.

  The hygroscopic building material of the present invention contains calcium silicate hardened material and zeolite as essential constituent materials, but the ground material of the calcium silicate hardened material constituting the hygroscopic building material of the present invention and As the calcium silicate cured body, for example, made of calcium silicate, the shape is plate-like, block-like, tile-like, fiber-reinforced cement board such as crafted material, ceramic siding, autoclaved lightweight lightweight concrete (ALC), A hardened body having a predetermined shape such as cement roof tile can be used as appropriate. In addition, for example, calcium silicate is obtained by curing a raw material molded body obtained by molding a mixture containing cement, a siliceous raw material, a calcareous raw material, and water into a predetermined shape so as to cause a hydrothermal reaction or the like under predetermined conditions. You may use as a hardening body.

  The means for obtaining a pulverized product by pulverizing the calcium silicate cured product is not particularly limited, and conventionally known means can be used. For example, various kinds of mill pulverization such as a rod mill, a ball mill, and a vibration mill can be used. By the pulverization means, a pulverized product of the calcium silicate cured product can be efficiently obtained. In the present invention, by using the pulverized product of the calcium silicate hardened body as an essential constituent material, the apparent bulk is increased, more air holes can be formed, and the moisture absorption / release performance is improved.

  In the hygroscopic building material of the present invention, the content of the pulverized product of the calcium silicate hardened body is 1 to 50% by mass and 20 to 40% by mass with respect to the entire hygroscopic building material. preferable. When the content of the pulverized product is within the above range, the moisture absorbing / releasing performance of the moisture absorbing / releasing building material is excellent, and the moldability of the moisture absorbing / releasing building material is also good. On the other hand, if the content of the pulverized product is less than 1% by mass, it is impossible to expect a desired effect as moisture absorption / release performance. The moldability of wet building materials may be reduced, leading to increased costs.

  There is no restriction | limiting in particular in the shape of the ground material of a calcium-silicate hardened | cured material, It can be set as various shapes, such as a particle form and a powder form. The average particle size (D50%) of the pulverized product is generally preferably about 1 to 100 μm, particularly preferably about 1 to 20 μm.

  As the zeolite constituting the hygroscopic building material of the present invention, either natural zeolite or synthetic zeolite can be used, or a mixture thereof may be used. Synthetic zeolites are generally roughly classified into adsorption / catalyst use, detergent use, and the like, but there is no problem even if any of these is used.

  In the hygroscopic building material of the present invention, the content of the zeolite is 1 to 50% by mass, preferably 20 to 40% by mass with respect to the entire hygroscopic building material. When the content of zeolite is within such a range, the moisture absorbing / releasing performance of the moisture absorbing / releasing building material is excellent, and the mechanical strength of the moisture absorbing / releasing building material can be maintained in a good state. On the other hand, if the zeolite content is less than 1% by mass, a desired effect cannot be expected as moisture absorption / release performance, as in the case of the pulverized calcium silicate cured product described above. When it exceeds mass%, the bending strength of the moisture-absorbing / releasing building material is lowered.

  The shape of the zeolite is not particularly limited, and can be various shapes such as particles and powders. The average particle diameter (D50%) of zeolite is generally preferably about 1 to 100 μm, and particularly preferably about 1 to 20 μm.

  In the hygroscopic building material of the present invention, it is preferable that the total content of the pulverized calcium silicate and the zeolite content is 50% by mass or more of the entire hygroscopic building material, It is especially preferable that it is 60 mass% or more. Since the total content of the pulverized product and zeolite is 50% by mass or more, it is expected to further improve the moisture absorption / release properties of the resulting moisture-absorbing / releasing building materials by blending materials with excellent moisture absorption / release properties in a balanced manner. it can.

  In the moisture-absorbing / releasing building material of the present invention, the weight ratio of the pulverized product of calcium silicate cured product to zeolite is preferably pulverized product / zeolite = 1/6 to 6/1. More preferably, it is 3 to 3/2. If the ratio of the ground calcium silicate pulverized material is relatively high within such a weight ratio, the nonflammability of the building material can be improved, and more building material waste can be contained, which is also effective for environmental problems. Can respond. On the other hand, if the proportion of zeolite is relatively high, the adsorption performance of the building material can be improved.

In addition to the above essential components, the hygroscopic building material of the present invention may contain the following materials (hereinafter also referred to as “arbitrary materials”).
First, the siliceous raw material refers to a raw material containing silicic acid (SiO ₂ ), for example, mineral fine powder such as quartzite, quartz sand, diatomaceous earth, white clay, perlite, synthetic powder such as white carbon, fly ash, Dust such as silica fume can be used.

  As the calcareous raw material, quick lime, powdered slaked lime obtained by dry digestion of quick lime, slurry-like slaked lime (lime milk) obtained by wet digestion of quick lime with a large amount of water, and the like can be used.

  In addition, cement can also be mixed as a constituent material of moisture-absorbing and releasing building materials, and it is preferable to use Portland cement as the cement material. Portland cements such as heat Portland cement, sulfate resistant Portland cement, low heat Portland cement, low alkali type Portland cement and the like can be mentioned. Moreover, you may use the mixed cement which mixed blast furnace slag, fly ash, and the siliceous mixed material with respect to this Portland cement. When cement is mixed, a hardening accelerator such as sodium silicate may be added to promote cement hydration.

Moreover, as a constituent material, a fiber reinforcing material may be added as necessary. By adding a fiber reinforcing material, the mechanical strength of the building material can be further improved.
Examples of the fiber reinforcing material that can be used include cellulose fiber, polypropylene fiber, aramid fiber, glass fiber, carbon fiber, silicon carbide fiber, stainless steel fiber, etc., and cellulose fiber includes softwood bleached kraft pulp (NBKP), One or more of hardwood bleached kraft pulp (LBKP) may be used. These fiber reinforcing materials can be added in an amount of about 1 to 10% by mass with respect to the entire raw material molded body, and these fiber reinforcing materials can be added to the raw material molded body produced before curing by a predetermined mixing means. What is necessary is just to mix and disperse | distribute uniformly.

In addition, to the moisture-absorbing / releasing building material of the present invention, arbitrary components such as polymer binders, wood chips, glass beads, etc. may be appropriately added to the mixture as long as the effects of the present invention are not hindered. Good.
Furthermore, an admixture may be added. For example, a conventionally known admixture added to a building material having calcium silicate as a constituent material, such as a weight reducing material such as pearlite or a resin balloon, can be appropriately added. .

In order to produce the moisture-absorbing / releasing building material of the present invention, a mixture obtained by mixing the above-mentioned essential materials (pulverized calcium silicate and zeolite) and optional materials with water is formed into a predetermined shape. As the raw material molded body, this raw material molded body is preferably cured by hydrothermal reaction to obtain a cured body.
Here, the raw material molded body can be obtained as follows. That is, an essential material and an optional material are mixed at a predetermined ratio, and then an appropriate amount of water is added to obtain a mixture. As a molding method using the mixture as a molded body, a known molding method such as papermaking, dewatering press molding, or extrusion molding can be used.

  When papermaking or dehydration press molding is used as the molding method, a large amount of water is mixed with the constituent material to form a slurry, and then the constituent material may be molded under arbitrary conditions. In addition, when carrying out papermaking molding or dehydration press molding, a flocculant may be added at the time of molding, and thus the moldability can be improved by adding the flocculant at the time of molding. .

  In the case of extrusion molding as a molding method, a small amount of water and a cellulose-based extrusion aid may be mixed, and mixed and stirred to form a clay-like kneaded material under arbitrary molding conditions. Here, since extrusion molding is a molding method with little unevenness due to the difference in specific gravity of each raw material, not only flat plates but also moldings that are rich in design as building materials such as peripheral edges, parting edges, window frames, etc. can be formed. .

  Next, the raw material molded body is cured using a hydrothermal reaction to make the raw material molded body a cured body. This hydrothermal reaction can be performed using an autoclave. The conditions for the hydrothermal reaction are not particularly limited, but the temperature may be about 105 to 180 ° C. and may be about 1 to 18 hours. Thus, by performing a hydrothermal reaction with respect to a raw material molded object, a raw material molded object will be hardened | cured efficiently and a building material with favorable mechanical strength can be obtained.

  And it is preferable to dry-process the hardening body in which the hydrothermal reaction was performed as needed. Here, the conditions for the drying treatment may be appropriately determined depending on the moisture content of the cured body.

  According to the moisture-absorbing / releasing building material of the present invention, since it contains a predetermined amount of pulverized hardened calcium silicate and zeolite, calcium silicate, which is a porous body having moisture-absorbing / releasing performance, In the state of a pulverized product obtained by pulverizing a pre-cured cured body, this is also mixed with a porous zeolite having moisture absorption / release performance and cured, so that the building material has excellent moisture absorption / release performance. Become.

  In other words, in addition to the moisture absorption / release performance of calcium silicate and zeolite, the resulting moisture-absorbing / releasing building material has the same effect as blending seed crystals, because the hardened calcium silicate is blended in the form of a pulverized product. Therefore, it is possible to promote the formation of calcium silicate crystals in the hydrothermal reaction, and thus it is possible to provide a moisture-absorbing / releasing building material that is firmly cured. Moreover, since the apparent bulkiness is increased by using the pulverized product of the calcium silicate cured product, more air holes can be formed, so that the moisture absorption / release performance can be maintained at a high level.

Furthermore, since calcium silicate and zeolite, which are constituent materials of the moisture-absorbing / releasing building material of the present invention, are incombustible materials, the building material has excellent moisture-absorbing performance and incombustibility.
And since the hygroscopic building material of this invention can mix | blend the ground material of a calcium silicate hardened | cured material, it can use effectively recycled materials, such as a building waste material, and can respond also to an environmental problem effectively. it can.

  The moisture-absorbing / releasing building material is a raw material obtained by molding a mixture containing a ground calcium silicate, zeolite, and optional materials, if necessary, into a predetermined shape. By producing a molded body and hydrolyzing the raw material molded body so as to be cured to obtain a cured body, it is possible to provide a moisture absorbing / releasing building material that suitably enjoys the above-described effects.

  And the moisture-absorbing / releasing building material thus obtained has good moisture-absorbing / releasing performance. For example, wall materials and ceiling materials in highly airtight houses, stores, libraries, museums, etc. It becomes a building material applicable as a constituent material.

In the hygroscopic building material of the present invention, a photocatalyst layer may be formed by applying a photocatalyst to the surface of the cured body after the hydrothermal reaction.
Here, as the photocatalyst used, titanium oxide (TiO ₂ ), zinc oxide (ZnO), iron oxide (Fe ₂ O ₃ ), or the like can be used. A substance having a photocatalytic function such as antimony oxide (SnO ₂ ) or tungsten oxide (WO ₃ ) may be used.

And there is no restriction | limiting in particular as a coating method of these photocatalysts, It can apply | coat using conventionally well-known coating methods, such as spray coating and roll coating.
In addition, when the photocatalyst is applied in this manner, the photocatalyst layer is firmly formed on the surface of the cured calcium silicate by drying at a temperature of 40 to 150 ° C. for 1 to 6 hours if necessary. Become.

  In this way, by applying the photocatalyst to the surface of the cured body after the hydrothermal reaction to form the photocatalyst layer, in addition to the effects exhibited by the moisture absorbing / releasing building material of the present invention described above, Functions such as deodorizing action and antibacterial action by adsorption and decomposition of odor can be suitably imparted to the building materials to be produced.

The aspect described above shows one aspect of the present invention, and the present invention is not limited to the above-described embodiment, and is within the scope of achieving the object and effect of the present invention. Needless to say, modifications and improvements are included in the content of the present invention. In addition, specific configurations, means, and the like in carrying out the present invention may be other configurations, means, and the like as long as the objects and effects of the present invention can be achieved.
For example, in the hydrothermal reaction in manufacturing the moisture absorbing / releasing building material of the present invention described above, a resin material that does not decompose within the temperature of the hydrothermal reaction, for example, a resin material such as polyvinyl alcohol is used in the present invention. It can also add in the range which does not prevent an effect, and can aim at the improvement of the intensity | strength of the hygroscopic building material obtained by this.
In addition, specific configurations, means, and the like in the implementation of the present invention may be other configurations as long as the object of the present invention can be achieved.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, this invention is not limited to the content of the Example.

[Example 1]
Production of hygroscopic building materials (1):
In accordance with the following procedures (1) to (3), a plate-like moisture-absorbing / releasing building material was produced.

(1) Production of pulverized product of calcium silicate cured product:
First, using a hard calcium silicate plate (ply silica NAS: Kamishima Chemical Co., Ltd., specific gravity 0.8) as a hardened calcium silicate, a commercially available dry mill: pore diameter 1.7 mm), the average particle size is 5 The pulverized product of calcified calcium silicate was obtained by pulverizing to ˜15 μm.

(2) Production of raw material compact:
The ground product of the hardened calcium silicate obtained in (1), the building material base material, cement, silica sand, bentonite, diatomaceous earth, reinforcing fiber material (organic fiber, inorganic fiber), and these and water are represented. After mixing according to the configuration of 1 to obtain a mixed material, the mixture was kneaded for 10 minutes with a commercially available mortar mixer at a stirring speed of 50 rpm to obtain a kneaded product having fluidity. Details of the raw materials used are shown below.

(Raw materials used)
Cement: Normal Portland cement Silica sand: SiO ₂ content 97.8% by mass
(Blaine specific surface area 5000 cm ² / g)
Diatomaceous earth powder: SiO ₂ content of 88.5 wt%
(Average particle size 30μm)
Zeolite: Natural zeolite (average particle size 15μm)
Organic fiber: Conifer bleached kraft pulp (NBKP)
(Fiber length 3.5mm, fiber diameter 65μm)
Inorganic fiber: Alkali resistant glass fiber
(Fiber length 13mm, fiber diameter 18μm)

  Next, the obtained kneaded product was molded into a length of 340 mm × width of 340 mm × thickness of 10 mm using a commercially available dehydration molding machine to obtain a plate-shaped raw material molded body.

(3) Curing of the molded body by hydrothermal reaction using an autoclave (formation of a cured body):
The obtained plate-shaped raw material molded body was cured by hydrothermal reaction for 10 hours at a pressure of 0.37 MPa and a temperature of 140 ° C. using a commercially available autoclave to obtain a cured body. Furthermore, this hardened | cured material was dried at 120 degreeC for 12 hours, and the plate-shaped moisture absorption / release building material of this invention was obtained. The dried moisture-absorbing raw building materials did not show any abnormal appearance such as warpage or cracks.

[Comparative Example 1]
In Example 1, a plate-like hygroscopic building material was produced using the method of Example 1, except that the same amount of bentonite was used instead of zeolite. No abnormal appearance such as warpage or cracks was found in the moisture-absorbing and releasing building materials after drying. Details of the raw materials used are shown below. Bentonite is known as a porous material and is also known to have moisture absorption / release performance.

(Raw materials used)
Cement: Normal Portland cement Silica sand: SiO ₂ content 97.8% by mass
(Blaine specific surface area 5000 cm ² / g)
Bentonite: Ca-bentonite (average particle size 15 μm)
Diatomaceous earth powder: SiO ₂ content 88.5% by mass
(Average particle size 30μm)
Organic fiber: Conifer bleached kraft pulp (NBKP)
(Fiber length 3.5mm, fiber diameter 65μm)
Inorganic fiber: Alkali resistant glass fiber
(Fiber length 13mm, fiber diameter 18μm)

(Raw material composition)

[Test Example 1]
The hygroscopic building materials obtained in Example 1 and Comparative Example 1 were evaluated by measuring bulk specific gravity, bending strength, and water absorption rate in order to confirm the performance as a hygroscopic building material. Of these measurement items, bulk specific gravity and water absorption were measured by a method based on JIS A5430. The bending strength was measured by a method based on JIS A1408. The results are shown in Table 2.

(Result)

  As can be seen from Table 2, the moisture-absorbing / releasing building material obtained in Example 1 that was fully cured was blended with the same amount of bentonite instead of zeolite in terms of properties such as bulk specific gravity, bending strength, and water absorption. It was not inferior to the hygroscopic building material of Comparative Example 1 as a product. Therefore, it has been confirmed that even if the ground calcium silicate product and zeolite are used as constituent materials, it is possible to exhibit practical mechanical properties comparable to conventional products.

[Test Example 2]
Hygroscopic performance evaluation (1):
The moisture absorbing / releasing performance of the moisture absorbing / releasing building materials obtained in Example 1 and Comparative Example 1 was measured and evaluated by a method based on the building material test center standard (JSTM H 6302).
Specifically, a sample obtained by cutting a plate-like moisture-absorbing / releasing building material into a 100 mm square is placed in a thermo-hygrostat set at a temperature of 30 ° C. and a humidity of 53% RH, and cured until a predetermined mass is reached. Then, the constant weight was measured in that state (Condition 1).

Next, after the constant weight, the sample was taken out from the constant temperature and humidity chamber, and 5 surfaces other than the surface were sealed with aluminum tape, and then held in a constant temperature and humidity chamber set at a temperature of 30 ° C. and a humidity of 75% RH for 24 hours. (Condition 2).
Then, after 24 hours, the temperature was maintained in a constant temperature and humidity chamber set at 30 ° C. and humidity 53% RH (condition 3). The condition 1 to condition 3 are defined as one cycle, and the moisture absorption / release amount with respect to the elapsed time (the value obtained by subtracting the constant weight from the weight of the sample at the time of measurement is converted into a value per 1 m ² ) is plotted and plotted. . The results are shown in FIG.

  Note that the measurement is performed after 1 hour, 2 hours, 4 hours, 8 hours, and 24 hours have elapsed from the start of condition 2, with the start of condition 2 set to 0. 4 hours, 8 hours, and 24 hours later (25 hours, 26 hours, 28 hours, 32 hours, and 48 hours after the start of Condition 2).

  As can be seen from the results in FIG. 1, the moisture-absorbing / releasing building materials of Example 1 and Comparative Example 1 suitably absorb moisture under condition 2 where the humidity is high, and suitably absorb moisture under condition 3 where the humidity is relatively low. The moisture absorption / release performance was good. Further, as can be seen from FIG. 1, the hygroscopic building material of Example 1 containing a predetermined amount of zeolite, which is a porous body, has better hygroscopic properties than the hygroscopic building material of Comparative Example 1 containing bentonite. It was.

[Example 2]
Manufacture of hygroscopic building materials with photocatalyst layer:
Photocatalyst (PAO-115 :( Ltd.) photocatalyst Institute) on the surface of the obtained plate-like building material in Example 1 (cured product) was spray-coated so that 35 ml / ^{m 2,} at 50 ° C. The hygroscopic building material of Example 2 was produced by drying for 1 hour and forming a photocatalytic layer on the surface.

[Test Example 3]
Moisture absorption / release performance evaluation (2):
The moisture absorbing / releasing performance of the moisture absorbing / releasing building material of Example 2 obtained in this manner was measured and evaluated in the same manner as in Test Example 2. The results are shown in FIG.

  Comparing the results of FIG. 1 and FIG. 2 described above, the moisture absorption / release performance of Example 2 in which the photocatalyst layer was formed on the surface and Example 1 in which the photocatalyst layer was not formed was almost the same. From this, it was confirmed that even if the photocatalyst layer was formed on the surface of the moisture-absorbing / releasing building material of the present invention, the moisture-absorbing / releasing performance was not affected.

[Test Example 4]
Evaluation of photocatalytic performance (confirmation of resolution of acetaldehyde):
The plate-shaped building material obtained in Example 2 and having a photocatalytic layer formed on the surface was cut into a size of 100 mm × 100 mm to obtain a sample. This sample was placed in a 1.05 liter plastic circulation container, and 3 μl of acetaldehyde was injected into the container, and then 15 W × 5 light sources and an ultraviolet intensity of 1.5 mW / cm ² BL (black light) Was used to measure the concentration change of acetaldehyde in the container over time using gas chromatography. The results are shown in FIG.

  As can be seen from the results in FIG. 3, the acetaldehyde concentration in the container decreased with the passage of time, and it was confirmed that the plate-shaped building material of Example 2 having a photocatalytic layer on the surface had acetaldehyde resolution. did it.

  The moisture-absorbing / releasing building material of the present invention is, for example, a moisture-absorbing / releasing building material that can be advantageously used as a constituent material such as a wall material or a ceiling material in an airtight house, store, library, museum or the like. Can be suitably provided.

It is the graph which showed the relationship between the elapsed time in Experiment 2, and the moisture absorption / release amount. 10 is a graph showing the relationship between the elapsed time and the moisture absorption / release amount in Test Example 3. It is the graph which showed the relationship of the time passage in Test Example 4 and the density | concentration change of the acetaldehyde in a container.

Claims (6)

Contains pulverized calcium silicate and zeolite,
The content of the pulverized product of the cured calcium silicate is 1 to 50% by mass of the whole,
A moisture-absorbing / releasing building material characterized in that the content of zeolite is 1 to 50% by mass of the whole. In the moisture-absorbing / releasing building material according to claim 1,
A moisture-absorbing / releasing building material, wherein the total content of the pulverized calcium silicate and the zeolite is 50% by mass or more. In the hygroscopic building material according to claim 1 or 2,
A hygroscopic building material characterized in that the weight ratio of the pulverized product of the calcium silicate cured product and the zeolite is pulverized product / zeolite = 1/6 to 6/1. In the moisture-absorbing / releasing building material according to any one of claims 1 to 3,
A hygroscopic building material characterized in that a photocatalytic layer is formed on the surface. A mixture containing a pulverized calcium silicate having a content of 1 to 50% by mass of the entire building material and a mixture containing zeolite having a content of 1 to 50% by mass of the entire building material is formed into a predetermined shape. A step of forming a raw material molded body;
The raw material compact is cured by hydrothermal reaction to obtain a cured product,
A method for producing a moisture-absorbing / releasing building material, comprising: In the manufacturing method of the hygroscopic building material of Claim 5,
After the hydrothermal reaction, a photocatalyst is applied to the surface of the cured body to form a photocatalyst layer.

Images