Building materials

Abstract

To provide a construction material capable of exhibiting humidity-controlling ability.SOLUTION: The present invention relates to a construction material that is a cured and hardened product of a molded body made of a composition containing cement, comprising a base material portion and a surface layer portion provided on a surface of the base material portion. The surface layer portion contains a humidity-controlling material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a building material which is a cured and hardened product of a molded article made of a cement-containing composition. [Background technology]

[0002] BACKGROUND ART It has been studied to use inorganic cement boards made from cement-containing compositions as interior wall materials and the like by imparting a humidity-regulating function to the boards to produce humidity-regulating building materials.

[0003] Patent Document 1 discloses a method for manufacturing a humidity-regulating building material in which a slurry of cement material containing silica gel is layered on a making roll, and the formed body is subjected to pressure dehydration to produce a molding, which is then cured and hardened. The humidity-regulating building material is used as a base material, and a moisture-permeable paint is applied to the surface of the base material to form a decorative layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6166965 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the humidity-conditioning building materials described above, the humidity-conditioning material, silica gel, is embedded in the base material, and there is a risk that the humidity-conditioning performance may not be sufficient.

[0006] An object of the present invention is to provide a building material that can exhibit humidity-regulating performance. [Means for solving the problem]

[0007] The building material according to the present invention is a cured and hardened product of a molded body made of a cement-containing composition, and comprises a base material and a surface layer provided on the surface of the base material, and the surface layer contains a humidity-regulating material. In a moisture absorption / desorption test in accordance with JIS A 1470-1, the moisture release amount was 20 g / m when the relative humidity range was 50% to 75% and the cycle of relative humidity was repeated four times in the order of 50%, 75%, and 50%. 2 As described above, efflorescence is present on the surface of the surface layer portion.

[0008] In the building material according to the present invention, the humidity-conditioning material includes a porous material, The porous material preferably has a moisture absorption and desorption amount of 11 mg / g or more in a moisture absorption and desorption test in accordance with JIS A 1470-1. [Effects of the Invention]

[0011] The building material according to the present invention can exhibit humidity control performance because the humidity control material is unevenly distributed on the surface. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a building material according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described below.

[0014] The building material according to this embodiment is a cured and hardened product of a molded body made of a cement-containing composition. As shown in Fig. 1, the building material 1 comprises a base material 2 and a surface layer 3 provided on the surface of the base material 2. The base material 2 and the surface layer 3 can be formed, for example, by curing and hardening a molded body made of a cement-containing composition.

[0015] The shape of the substrate 2 is not particularly limited, but may be, for example, a substantially plate-like shape, and the shape in plan view may be, for example, a square or rectangular shape.

[0016] The surface layer 3 is provided on the surface of the base material 2. When the base material 2 is substantially plate-shaped or the like, the surface layer 3 may be provided on one surface or both surfaces of the base material 2. The shape of the surface layer 3 is not particularly limited, but when the base material 2 is substantially plate-shaped or the like, it may be, for example, substantially plate-shaped or substantially sheet-shaped.

[0017] The ratio of the dimension of the surface layer 3 to the dimension of the base 2 in the direction perpendicular to the surface of the base 2 (surface layer 3 / base 2) is usually 0.1 or more and 0.2 or less, and preferably 0.14 or more and 0.16 or less.

[0018] The surface layer 3 contains a humidity-regulating material. The humidity-regulating material is unevenly distributed on the surface layer 3, which is the surface of the building material 1, and therefore the building material 1 is able to exhibit humidity-regulating performance. The humidity-regulating material has, for example, a moisture absorption function and a moisture release function, and is a material that can regulate the humidity in the space in which the building material 1 is installed by absorbing water vapor when the humidity is high and releasing water vapor when the humidity is low.

[0019] Humidity-regulating materials include, for example: Volcanic eruptions or weathered products such as Shirasu (white sand, Shirasu), allophane, and imogolite, Porous minerals such as diatomaceous earth, siliceous shale, and sepiolite, Porous materials such as B-type silica gel and zeolite, Charcoal such as bamboo charcoal Porous materials composed of Clay minerals such as attapulgite, montmorillonite (activated clay), bentonite, halloysite, and clay Examples include:

[0020] Volcanic ejecta used as humidity-regulating material are deposits formed when pyroclastic material ejected from the crater during volcanic activity falls to the ground surface, and are classified by atmospheric sorting as they move away from the crater. They are also called volcanic fall products, volcanic debris, pyroclastic fall deposits, fall pumice, etc. Shirasu includes Osumi pumice fall, which is widely deposited in the Osumi Peninsula region of Kagoshima Prefecture, and includes Akabora (Osumi pumice fall (red)) and Yellowbora (Osumi pumice fall (yellow)).

[0021] There are two types of silica gel: type A and type B. Type A silica gel will not release moisture unless it is heated after absorbing it, whereas type B silica gel will absorb and release moisture at room temperature, adsorbing moisture under high humidity conditions and releasing moisture under low humidity conditions.

[0022] The humidity-conditioning material preferably includes a porous material made of volcanic ejecta or its weathered products, and more preferably includes a porous material made of weathered volcanic ejecta. Such humidity-conditioning materials are relatively inexpensive, available in large quantities, and can be suitably used as materials with excellent humidity-conditioning properties.

[0023] The porous material preferably has a moisture absorption and desorption amount of 11 mg / g or more in a moisture absorption and desorption test in accordance with JIS A 1470-1. When the porous material has an absorption and desorption amount of the above value or more, the building material 1 can have further improved humidity control performance.

[0024] The proportion of the humidity-conditioning material in the surface layer portion 3 is preferably 20% by mass or more. In this case, humidity-conditioning performance can be further improved. The upper limit of the proportion of the humidity-conditioning material is not particularly limited, but is, for example, 30% by mass or less.

[0025] The humidity-conditioning material may be contained in the base material portion 2 in addition to the surface layer portion 3, for example.

[0026] In the building material 1, it is preferable that efflorescence is present on the surface of the surface layer 3. If the surface layer 3 contains a humidity-conditioning material that retains moisture during curing, causing efflorescence to be present on the surface of the surface layer 3, the occurrence of efflorescence can be suppressed, the efflorescence pattern can be controlled, and an area capable of humidity control can be secured. The humidity-conditioning material is preferably evenly scattered over the entire surface of the surface layer 3. This allows a natural-looking efflorescence pattern to appear. Furthermore, it is preferable that the humidity-conditioning material is exposed on the surface of the surface layer 3; more specifically, it is preferable that a portion of the humidity-conditioning material is buried in the surface layer 3 while a portion is exposed on the surface of the surface layer 3. This allows the humidity-conditioning material to be fixed to the surface layer 3 while facilitating moisture absorption and release from the external space, allowing the building material 1 to maintain humidity control over a long period of time.

[0027] The surface of the building material 1 may be clear coated. When a clear coating is applied to the surface of the building material 1, the surface of the building material 1 can be protected. This can, for example, prevent wear and dirt on the surface of the building material 1. The thickness of the clear coating applied to the surface of the surface layer 3 is preferably 40 μm or less. In this case, the humidity-regulating performance of the building material 1 can be better maintained. The lower limit of this thickness is not particularly limited, but is, for example, 10 μm or more.

[0028] In a moisture absorption / desorption test in accordance with JIS A 1470-1, Building Material 1 desorbs moisture at a rate of 20 g / m2 when the relative humidity range is 50% to 75% and the cycle of 50%, 75%, and 50% is repeated four times. 2 It is preferable that the moisture release rate is equal to or greater than this value. This moisture release rate is, for example, a value for the surface of the surface layer 3 of the building material 1. When the building material 1 has this moisture release rate equal to or greater than this value, it can be suitably used as a humidity-regulating building material. There is no particular restriction on the upper limit of this moisture release rate, but it can be, for example, 32.5 g / m 2 The following is the result.

[0029] Next, a method for manufacturing the building material 1 will be described.

[0030] The building material 1 can be produced by a production method including, for example, the steps of: (1) preparing a composition containing cement for a base material portion and a surface layer portion (hereinafter also referred to as a cement composition for a base material portion and a cement composition for a surface layer portion); (2) molding the cement composition for a base material portion to produce an intermediate molded body; (3) spraying the cement composition for a surface layer portion onto the intermediate molded body to produce a molded body; and (4) curing and hardening the molded body.

[0031] In step (1) (composition preparation step), a cement composition for a base material and a cement composition for a surface layer are prepared. As the cement composition for a base material, for example, the following cement composition S can be used, and as the cement composition for a surface layer, for example, a composition obtained by adding a humidity-controlling material to the cement composition S can be used.

[0032] The cement composition S may contain, for example, cement, a silica-containing admixture, reinforcing fibers, lightweight aggregate, an extender, water, etc. The silica-containing admixture may have, for example, an SiO2 content of 70 mass% or more and a Blaine value of 3000 cm 2 The composite material contains at least one component selected from the group consisting of the above silica powder, other silica powders, silica powder, granulated blast furnace slag, fly ash, pulp sludge incineration ash, and sludge incineration ash. The reinforcing fiber contains at least one component selected from the group consisting of pulp, vinylon fiber, polypropylene fiber, and rock wool. The reinforcing fiber may contain fibers obtained by defibrating paper waste materials such as used paper cups. The lightweight aggregate may contain perlite, crushed recycled cement products, etc. The bulking material contains at least one component selected from the group consisting of mica, wollastonite, vermiculite, talc, and calcium carbonate. The bulking material preferably contains mica. The average particle size of the mica is preferably in the range of 50 μm to less than 150 μm, and the aspect ratio of the mica is preferably in the range of 80 to 150.

[0033] For 100 parts by mass of solids in the cement composition S, the amount of cement is, for example, in the range of 25 parts by mass to 45 parts by mass, the amount of silica-containing admixture is, for example, in the range of 15 parts by mass to 67 parts by mass, the amount of reinforcing fiber is, for example, in the range of 4 parts by mass to 10 parts by mass, the amount of lightweight aggregate is, for example, in the range of 0 parts by mass to 30 parts by mass, and the amount of extender is, for example, in the range of 4 parts by mass to 12 parts by mass.

[0034] The ratio of the amount of water to the amount of solids in the cement composition for the base material (amount of water / amount of solids) is preferably within the range of 5 / 95 or more and 30 / 70 or less.

[0035] Furthermore, the ratio of the molar amount of Ca in the cement composition S to the molar amount of Si in the cement composition S (molar amount of Ca / molar amount of Si) is preferably within the range of 0.5 to 0.9. In other words, it is preferable to determine the types and amounts of the components in the cement composition S so that the ratio of the molar amount of Ca to the molar amount of Si is within the range of 0.5 to 0.9. When the ratio of the molar amount of Ca in the building material 1 to the molar amount of Si in the building material 1 is within the range of 0.5 to 0.9, an appropriate amount of efflorescence can be easily generated on the surface of the building material 1.

[0036] The cement composition S may contain a decorative material. In this case, the decorative material can form part of the pattern on the surface of the building material 1. That is, the efflorescence and the decorative material can form the pattern. The decorative material may be an organic or inorganic material. Examples of organic materials include plant fruits or seeds, or the shells that cover them, as well as carbonized materials that retain their shape as much as possible, and pulverized carbonized materials, such as coffee bean grounds and carbonized rice husks. Examples of inorganic materials include crushed glass powder. The decorative material includes, for example, at least one of coffee bean grounds and crushed glass powder. The amount of decorative material is appropriately determined depending on the pattern to be imparted to the surface of the building material 1. When the cement composition S contains an organic material, it is preferable that the cement composition S further contain a water repellent. In this case, corrosion and deterioration of the organic material can be suppressed, thereby suppressing changes to the pattern.

[0037] The cement composition for the surface layer portion contains a humidity-conditioning material. The cement composition for the surface layer portion can be prepared, for example, by adding a humidity-conditioning material to the cement composition S described above, but is not limited thereto.

[0038] The ratio of the humidity control material to be added is preferably 20% by mass or more relative to the surface layer portion 3 formed from the cement composition for the surface layer portion. The upper limit of the ratio of the humidity control material is, for example, 30% by mass or less.

[0039] The ratio of the amount of water to the amount of solids in the cement composition for the surface layer portion (amount of water / amount of solids) is preferably within the range of 0 or more and 1 / 2 or less.

[0040] In step (2) (step of preparing an intermediate molded body), the cement composition for the base material is molded into, for example, a plate to prepare an intermediate molded body. The molding method for this purpose is, for example, a papermaking method, but is not limited thereto, and may also be, for example, an extrusion molding method or a cast molding method.

[0041] In the step (3) (molded body preparation step), a cement composition for a surface layer is spread on the intermediate molded body prepared in the step (2) to prepare a molded body.

[0042] Before the step (4) (curing step), the molded body produced in the step (3) may be subjected to press working. The press working conditions are, for example, a press pressure of 2.9 MPa or more and 11.8 MPa or less (30 kg / cm 2 More than 120kg / cm 2 The pressing time is 3 seconds or more and 30 seconds or less. It is preferable that the surface of the compact is not smoothed by this pressing, and that the humidity-conditioning material appears on the surface of the surface layer 3 and is not buried in the surface layer 3.

[0043] In step (4), the molded body produced in step (3) is cured to harden it. The curing method can be, for example, autoclave curing, steam curing, room temperature curing, or a combination of two or more of these. Steam curing is particularly likely to produce precipitates. In one specific example of the curing method, the molded body is first cured by steam curing under conditions of 40°C to 90°C, 90% RH to 100% RH, and 4 hours to 24 hours, and then cured by autoclave curing under conditions of 140°C to 200°C and 2 hours to 12 hours. By curing and hardening the molded body in this manner, the building material 1 can be produced.

[0044] In step (4), no sealer is applied to the surface of the molded body, or the amount of sealer applied to the surface of the molded body is 250 g / m 2 Preferably less than 200 g / m2 It is more preferable that the temperature is below 100°C. In this case, the generation of efflorescence in the building material 1 can be promoted.

[0045] Generally, sealers are used in the production of inorganic cement boards. Sealers contain resins such as acrylic resins, vinyl acetate resins, epoxy resins, chlorinated rubbers, urethane resins, silicone resins, and fluororesins. Sealers are, for example, aqueous emulsions or solutions or dispersions containing organic solvents. Sealers optionally contain inorganic particles such as ground calcium carbonate, precipitated calcium carbonate, kaolin, bentonite, sericite, dolomite, talc, clay, aluminum oxide, magnesium oxide, and diatomaceous earth. Such sealers usually suppress the generation of efflorescence.

[0046] However, as mentioned above, when the molded body is cured and hardened, the sealer is not applied to the surface of the molded body, or the amount of sealer applied to the surface of the molded body is 250 g / m 2 less than 200 g / m 2 If the temperature is below this range, the generation of efflorescence will not be suppressed, i.e., efflorescence will be generated. Furthermore, if a sealer is applied to the surface of the molded body, the amount of efflorescence generated can be controlled by adjusting the amount of sealer. In the building material 1 according to the present invention, the surface layer 3 contains a humidity-conditioning material, which retains moisture during curing, thereby suppressing the generation of efflorescence and allowing for more appropriate control of the efflorescence pattern.

[0047] The method for manufacturing the building material 1 may further include a step of applying a clear coating to the surface of the building material 1 after steps (1) to (4).

[0048] The manufactured building material 1 comprises a base portion 2 derived from the cement composition for the base portion, and a surface layer portion 3 derived from the cement composition for the surface layer portion.

[0049] The manufacturing method of the building material 1 can be carried out more efficiently by using, for example, a moving belt conveyor or the like to carry out each step. [Example]

[0050] Specific examples of the present invention will be presented below.

[0051] The components shown in Table 1 were mixed with water to prepare a cement composition for the base layer and a cement composition for the surface layer.

[0052] The details of the components shown in Table 1 are as follows: · Cement: Ordinary Portland cement. - Silica-containing admixtures: silica powder (7000 Blaine) and JIS fly ash. ·Lightweight aggregate: crushed recycled cement products. · Bulking agent: Mica. Reinforcement fiber: virgin pulp. Humidity-conditioning material A: Humidity-conditioning Shirasu (moisture absorption / desorption amount in moisture absorption / desorption test: 11 mg / g)

[0053] The building material was manufactured as follows. First, water was added to the cement composition for the base material to prepare a slurry. An unhardened cement board to serve as the base material was manufactured from this slurry by a papermaking method. Next, the cement composition for the surface layer was spread on the base material. Next, the composite cement board comprising the base material and the surface layer was cured and hardened to produce the building material. A clear coating was applied to this building material. As a result, a building material (coated board) was obtained in which the surface layer was provided on one surface of the base material.

[0054] A moisture absorption and desorption test was conducted in accordance with JIS A 1470-1 (2002) (Test methods for moisture absorption and desorption of building materials - Part 1: Humidity response method), and the amount of moisture released was measured after four cycles of relative humidity changes of 50%, 75%, and 50% were repeated in the range of 50% to 75%. This moisture absorption and desorption test was conducted with aluminum tape blocking moisture from all surfaces except the surface of the building material, which is the moisture absorption and desorption surface. The moisture conditioning performance of the building material was evaluated when the measured moisture release amount was 20 g / m 2In the above cases, the condition can be evaluated as good.

[0055] [Table 1]

[0056] As can be seen from the results in Table 1, the building material of Example 1 can exhibit sufficient humidity control performance. [Explanation of symbols]

[0057] 1. Building materials 2 Base material part 3 Surface layer

Claims

1. A building material that is a cured and hardened product of a molded body made of a cement-containing composition, A substrate portion; a surface layer portion provided on the surface of the base material portion; Equipped with the surface layer portion contains a humidity-conditioning material, In a moisture absorption / desorption test in accordance with JIS A 1470-1, the moisture release amount is 20 g / m 2 or more when the relative humidity range is 50% or more and 75% or less, and the relative humidity is cycled four times in the order of 50%, 75%, and 50%, Efflorescence is present on the surface of the surface layer portion. Building materials.

2. The humidity-conditioning material includes a porous material, and the porous material has a moisture absorption and desorption amount of 11 mg / g or more in a moisture absorption and desorption test in accordance with JIS A 1470-1. The building material according to claim 1.

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