Building materials

Abstract

To provide construction materials that can suppress the occurrence of wet color.SOLUTION: A construction material of the present invention is composed of an inorganic material mainly composed of a hydraulic material, and has a base material layer and a surface layer formed on the surface of the base material layer, wherein only the surface layer contains a needle-shaped reinforcing material, and the needle-shaped reinforcing material contains 1 mass% to 12 mass% of the total solid content of the surface layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to building materials composed of inorganic materials, primarily composed of hydraulic materials. [Background technology]

[0002] In building materials, such as exterior wall coverings, which are composed primarily of inorganic materials with hydraulic properties, reinforcing fibers are sometimes incorporated to increase their strength.

[0003] Patent Document 1 discloses a fiber-reinforced inorganic molded article obtained by adding short-fiber polyolefin, stretched by a drawing and stretching method, as a reinforcing material to a hydraulic material. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 64-52640 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the building material described in Patent Document 1 still lacks sufficient strength in its surface layer. As a result, cracks may form in the surface layer during transportation or construction, and in such cases, water may penetrate through the cracks, potentially causing discoloration due to wetness.

[0006] The objective of the present invention is to provide a building material that can suppress the occurrence of wet discoloration. [Means for solving the problem]

[0007] The building material according to the present invention is a building material composed of an inorganic material mainly composed of cement, which is a hydraulic material, and comprises a base layer and a surface layer formed on the surface of the base layer, wherein needle-shaped reinforcing material is included only in the surface layer. The aforementioned needle-shaped reinforcing material is at least one selected from the group consisting of potassium titanate whiskers, aluminum borate whiskers, carbon whiskers, calcium carbonate whiskers, wollastonite, sepiolite, palygorskite, tobermorite, zinc oxide whiskers, titanium oxide whiskers, glass fibers, and ceramic fibers.The needle-shaped reinforcing material is present in an amount of 1% to 12% by mass relative to the total solid content of the surface layer, efflorescence is irregularly distributed on the surface of the surface layer, and a clear coating film is formed on the surface of the surface layer.

[0008] Another building material according to the present invention is a building material composed of an inorganic material mainly composed of cement, which is a hydraulic material, and comprises a base layer and a surface layer formed on the surface of the base layer, wherein at least the surface layer contains needle-shaped reinforcing material. The aforementioned needle-shaped reinforcing material is at least one selected from the group consisting of potassium titanate whiskers, aluminum borate whiskers, carbon whiskers, calcium carbonate whiskers, wollastonite, sepiolite, palygorskite, tobermorite, zinc oxide whiskers, titanium oxide whiskers, glass fibers, and ceramic fibers. The needle-shaped reinforcing material is present in an amount of 1% to 4% by mass relative to the total solid content of the base layer and the surface layer, efflorescence is irregularly distributed on the surface of the surface layer, and a clear coating film is formed on the surface of the surface layer.

[0009] In the building material according to the present invention, it is preferable that the aspect ratio of the needle-shaped reinforcing material is 3 or more and 20 or less.

[0011] In the building materials according to the present invention, If it comes into contact with rainwater, Outer surface of the inorganic material to , black dotted pattern occurrence It is preferable not to do so. [Effects of the Invention]

[0012] The building material according to the present invention can suppress the occurrence of wet discoloration. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a cross-sectional view showing an example of a building material according to the present invention. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below.

[0015] <First Embodiment> The building material according to the first embodiment is a building material composed of an inorganic material having a hydraulic material as a main component. As shown in FIG. 1, the building material 1 includes a base material layer 11 and a surface layer 12 formed on the surface of the base material layer 11. Although the surface layer 12 is formed on one surface of the base material layer 11 in the building material 1 of FIG. 1, the surface layer 12 may be formed on both surfaces of the base material layer 11.

[0016] The shape of the base material layer 11 is not particularly limited. For example, it is substantially plate-shaped, and the shape in plan view is, for example, square or rectangular.

[0017] The thickness of the base material layer 11 is, for example, 1 mm or more and 50 mm or less, and preferably 10 mm or more and 30 mm or less.

[0018] The surface layer 12 is formed on the surface of the base material layer 11. The shape of the surface layer 12 is not particularly limited. However, when the base material layer 11 is substantially plate-shaped or the like, it is, for example, substantially plate-shaped, substantially sheet-shaped, or the like.

[0019] The thickness of the surface layer 12 is, for example, 0.5 mm or more and 10 mm or less, and preferably 1 mm or more and 5 mm or less.

[0020] The ratio of the thickness of the surface layer 12 to the thickness of the base material layer 11 (surface layer 12 / base material layer 11) is usually 0.01 or more and 1 or less, and preferably 0.05 or more and 0.3 or less.

[0021] The surface layer 12 contains needle-like reinforcing materials. The building material 1 of the first embodiment contains needle-like reinforcing materials only in the surface layer 12, and the base material layer 11 does not contain needle-like reinforcing materials.

[0022] "Needle-shaped reinforcing material" refers to an inorganic substance having a needle-like shape. "Needle-shaped" means a shape in which the length in one direction is sufficiently longer than the length in other directions, and is a concept that includes, for example, whisker-like, fibrous, and rod-like shapes. Examples of needle-shaped reinforcing materials include potassium titanate whiskers, aluminum borate whiskers, carbon whiskers, calcium carbonate whiskers, wollastonite, sepiolite, palygorskite, tobermorite, zinc oxide whiskers, titanium oxide whiskers, glass fibers, and ceramic fibers. Among these, wollastonite is preferred. Building material 1 may contain one or more types of needle-shaped reinforcing materials.

[0023] The aspect ratio of the needle-shaped reinforcing material is preferably 3 or greater, more preferably 5 or greater, and even more preferably 7 or greater. The aspect ratio of the needle-shaped reinforcing material is preferably 20 or less, more preferably 15 or less, and even more preferably 12 or less. The "aspect ratio" of the needle-shaped reinforcing material is the ratio of the length to the thickness of the needle-shaped reinforcing material (length / thickness). A larger aspect ratio of the needle-shaped reinforcing material is preferable, as it becomes more needle-like and increases the bending strength of the building material 1.

[0024] The needle-shaped reinforcing material is contained in an amount of 1% by mass or more and 12% by mass or less relative to the total solid content of the surface layer 12. "Total solid content" refers to all components excluding liquid components such as water. By containing the needle-shaped reinforcing material in the above proportion, the building material 1 can suppress the occurrence of wet discoloration even when in contact with water. The reason why the above effect is achieved by using the above proportion of needle-shaped reinforcing material in the building material 1 is not entirely clear, but it is possible that, for example, by including needle-shaped reinforcing material with excellent tensile properties in a specific proportion, the bending strength of the surface layer 12 is improved, making it less likely to crack during transportation and construction. The proportion of needle-shaped reinforcing material is preferably 1.5% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more. The proportion of needle-shaped reinforcing material is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 6% by mass or less, and particularly preferably 4% by mass or less.

[0025] The base layer 11 and the surface layer 12 can be formed, for example, by curing a molded body made from an inorganic material mainly composed of a hydraulic material.

[0026] In building material 1, it is preferable that efflorescence is present on the surface of the surface layer 12. Efflorescence has a whitish appearance. Furthermore, it is preferable that this efflorescence is distributed irregularly. In this case, the pattern formed by the efflorescence has a natural texture, and it is unlikely that an observer would overlook the fact that this pattern is artificial.

[0027] In building material 1, it is preferable that a clear coating is formed on the surface of the surface layer 12. When a clear coating is formed on the surface of the surface layer 12 of building material 1, the surface of building material 1 can be protected. For example, wear and dirt on the surface of building material 1 can be suppressed. The thickness of the clear coating applied to the surface of the surface layer 12 is preferably 40 μm or more. There is no particular upper limit to this thickness, but for example it is 100 μm or less.

[0028] In building material 1, it is preferable that the outer surface of the inorganic material does not have a black dot pattern. That is, it is preferable that a black dot pattern does not appear on the outer surface of the inorganic material when building material 1 comes into contact with rainwater, etc. This black dot pattern often occurs when building material 1 becomes discolored when wet. The appearance of building material 1 due to the discoloration caused by the wetness is further exacerbated by the appearance of the building material 1 caused by the black dot pattern.

[0029] <Second Embodiment> The building material 1 of the second embodiment has the same configuration as the building material 1 of the first embodiment, but differs in that the needle-shaped reinforcing material is included in at least one of the base layer 11 and the surface layer 12. That is, in the building material 1 of the second embodiment, the needle-shaped reinforcing material may be included in both the base layer 11 and the surface layer 12, in the base layer 11 only, or in the surface layer 12 only.

[0030] In the building material 1 of the second embodiment, the needle-shaped reinforcing material is contained in an amount of 1% by mass or more and 4% by mass or less relative to the total solid content of the base layer 11 and the surface layer 12. The proportion of the needle-shaped reinforcing material is preferably 1.1% by mass or more, more preferably 1.2% by mass or more, and even more preferably 1.3% by mass or more. The proportion of the needle-shaped reinforcing material is preferably 3% by mass or less, more preferably 2.5% by mass or less, even more preferably 2% by mass or less, and particularly preferably 1.8% by mass or less.

[0031] <Methods for manufacturing building materials> Next, we will explain the manufacturing method of building material 1.

[0032] The building material 1 can be manufactured by a manufacturing method comprising, for example, (1) a step of preparing a composition containing a hydraulic material for forming a base layer and a surface layer (hereinafter also referred to as the base layer forming composition and the surface layer forming composition), (2) a step of molding the base layer forming composition to produce an intermediate molded body, (3) a step of spraying the surface layer forming composition onto the intermediate molded body to produce a molded body, and (4) a step of curing and hardening the molded body.

[0033] (1) In the step (composition preparation step), a composition for forming the base layer and a composition for forming the surface layer are prepared. As the composition for forming the base layer, for example, the hydraulic material-containing composition S shown below or a hydraulic material-containing composition S with needle-shaped reinforcing material added can be used, and as the composition for forming the surface layer, for example, a hydraulic material-containing composition S with needle-shaped reinforcing material added can be used.

[0034] The hydraulic material-containing composition S may contain, for example, a hydraulic material, a silica-containing admixture, reinforcing fibers, lightweight aggregate, filler, water, etc. Examples of hydraulic materials include cement, gypsum (hemihydrate gypsum, dihydrate gypsum, etc.), dolomite, etc. Examples of cement include Portland cement (e.g., ordinary, rapid-hardening, ultra-rapid-hardening, moderate-heat, sulfate-resistant and their respective low-alkali forms), various blended cements (e.g., blast furnace cement, silica cement, fly ash cement), white Portland cement, alumina cement, etc. Examples of silica-containing admixtures include having an SiO2 content of 70% by mass or more and a Blaine value of 3000 cm². 2 The material contains at least one component selected from the group consisting of the above-mentioned silica powder, other silica powder, silica powder, blast furnace granulated slag, fly ash, pulp sludge incineration ash, and sludge incineration ash. The reinforcing fibers contain at least one component selected from the group consisting of, for example, pulp, vinylon fibers, polypropylene fibers, and rock wool. The reinforcing fibers may also include fibers obtained by defibrating paper waste materials such as used paper cups. The lightweight aggregate may include perlite, crushed recycled cement products, etc. The bulking agent contains at least one component selected from the group consisting of, for example, mica, talc, and calcium carbonate. The bulking agent preferably contains mica. The average particle size of the mica is preferably in the range of 50 μm or more and less than 150 μm, and the aspect ratio of the mica is preferably in the range of 80 or more and 150 or less.

[0035] In the hydraulic material-containing composition S, per 100 parts by mass of solids, the amount of hydraulic material is, for example, within the range of 25 parts by mass to 45 parts by mass, the amount of silica-containing admixture is, for example, within the range of 15 parts by mass to 67 parts by mass, the amount of reinforcing fibers is, for example, within the range of 4 parts by mass to 10 parts by mass, the amount of lightweight aggregate is, for example, within the range of 0 parts by mass to 30 parts by mass, and the amount of bulking agent is, for example, within the range of 4 parts by mass to 12 parts by mass.

[0036] The ratio of the amount of water to the amount of solids in the base layer forming composition (amount of water / amount of solids) is preferably within the range of 5 / 95 to 30 / 70.

[0037] Furthermore, the ratio of the molar amount of Ca in the hydraulic material-containing composition S to the molar amount of Si (moles of Ca / moles of Si) (C / S) is preferably within the range of 0.5 to 0.9. In other words, it is preferable that the types and amounts of components in the hydraulic material-containing composition S are determined such 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 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.

[0038] The hydraulic material-containing composition S may also contain a decorative material. In this case, the decorative material can constitute part of the pattern on the surface of the building material 1. That is, efflorescence and the decorative material can form a pattern. The decorative material may be an organic or inorganic material. Examples of organic materials include plant fruits or seeds or the shells covering them, as well as carbonized versions of these materials that retain their shape as much as possible, or crushed versions of the carbonized versions. Examples include coffee grounds and carbonized rice husks. Inorganic materials include, for example, crushed glass powder. The decorative material may include, for example, at least one of coffee grounds and crushed glass powder. The amount of decorative material is appropriately determined according to the pattern to be applied to the surface of the building material 1. When the hydraulic material-containing composition S contains an organic material, it is preferable that the hydraulic material-containing composition S further contains a water-repellent agent. In this case, corrosion and deterioration of the organic material can be suppressed, thereby suppressing changes in the pattern.

[0039] The water-repellent agent imparts water repellency to building material 1. Specifically, the water-repellent agent is dispersed within building material 1, thereby suppressing the reaction between acidic liquids (for example, a solution in which acidic components from the air are dissolved in water droplets such as rainwater) and the components of building material 1. Because the water-repellent agent is added to building material 1, even if an acidic liquid adheres to building material 1, the water-repellent effect derived from the water-repellent agent makes it even more difficult for efflorescence to form, thus making it easier to maintain the efflorescence pattern on building material 1.

[0040] Examples of water-repellent agents include silane-based water-repellent agents. These silane-based water-repellent agents are, for example, alkoxysilane-based water-repellent agents having an alkoxyl group. Alkoxysilane-based water-repellent agents have a medium-chain or long-chain alkyl group as a functional group, and for example, as general formula (1), R n Si(OR1) 4-n …(1) Examples include alkyltrialkskoxysilanes, represented as (where n is an integer from 1 to 3, R represents a medium-chain or long-chain alkyl group, and R1 represents an alkyl group). Furthermore, alkoxysilane-based water repellents are represented by general formula (2), R n Si(OR1) 4-n-m X m …(2) (where n is an integer from 1 to 3, m is an integer from 0 to 2, R represents a medium-chain or long-chain alkyl group, R1 represents an alkyl group, and X represents a hydrolyzable group), etc. Here, suitable examples of medium-chain or long-chain alkyl groups (R) include straight-chain or branched-chain alkyl groups having 4 to 12 carbon atoms. The alkyl group (R1) constituting the alkoxy group (OR1) is, for example, a lower alkyl group having about 1 to 3 carbon atoms. Examples of hydrolyzable groups (X) include alkoxy groups, ester groups, halogen atoms, etc. The amount of water-repellent agent can be in the range of, for example, 0.04 parts by mass or more and 0.12 parts by mass or less per 100 parts by mass of the solid content of the hydraulic material-containing composition S.

[0041] The surface layer forming composition alone, or both the surface layer forming composition and the base layer forming composition, contain needle-shaped reinforcing materials. These compositions can be prepared, for example, by adding needle-shaped reinforcing materials to the aforementioned hydraulic material-containing composition S, but are not limited thereto.

[0042] When needle-shaped reinforcing material is added only to the surface layer forming composition, the proportion of needle-shaped reinforcing material to be added is preferably in the range of 1% by mass or more and 12% by mass or less, and more preferably in the range of 1% by mass or more and 4% by mass or less, relative to the total solid content of the surface layer 12 formed from the surface layer forming composition.

[0043] When needle-shaped reinforcing material is added to both the surface layer forming composition and the base layer forming composition, the proportion of needle-shaped reinforcing material to be added is preferably within the range of 1% by mass or more and 12% by mass or less, relative to the total solid content of the surface layer 12 and base layer 11 formed from the surface layer forming composition and the base layer forming composition.

[0044] The ratio of the amount of water to the total solid content of the surface-forming composition (amount of water / amount of solid content) is preferably within the range of 5 / 95 to 30 / 70.

[0045] (2) In the intermediate molded body manufacturing process, the base material layer forming composition is molded, for example, into a plate to produce an intermediate molded body. The molding method for this is, for example, papermaking, but is not limited to this, and may also be, for example, extrusion molding or casting molding.

[0046] (3) In the process (molded body manufacturing process), a molded body is manufactured by spraying a surface layer forming composition onto the intermediate molded body manufactured in the process (2).

[0047] (4) Before the curing process, the molded body produced in (3) may be subjected to press working. The conditions for press working are, for example, a press pressure of 2.9 MPa or more and 11.8 MPa or less (30 kg / cm²). 2 More than 120kg / cm 2 The following conditions apply: the duration is between 3 seconds and 30 seconds.

[0048] (4) In the process, the molded body produced in (3) process is cured by being subjected to curing. The method of curing is, for example, an autoclave curing method, a steam curing method, a normal temperature curing method, or a combination of two or more of these. In particular, when the method of curing includes a steam curing method, it is easy to generate deposits. In a specific example of the method of curing, first, the molded body is cured by a steam curing method under the conditions of 40°C or higher and 90°C or lower, 90%RH or higher and 100%RH or lower, and 4 hours or longer and 24 hours or shorter, and then cured by an autoclave curing method under the conditions of 140°C or higher and 200°C or lower, and 2 hours or longer and 12 hours or shorter. By curing and hardening the molded body in this way, the building material 1 can be produced.

[0049] (4) In the process, it is preferable that no sealer is applied to the surface of the molded body, or the application amount of the sealer on the surface of the molded body is less than 250 g / m 2 and more preferably less than 200 g / m 2 . In this case, the generation of efflorescence in the building material 1 can be promoted.

[0050] Generally, when manufacturing an inorganic cement board, a sealer is used. The sealer contains, for example, resins such as acrylic resin, vinyl acetate resin, epoxy resin, chlorinated rubber, urethane resin, silicone resin, and fluororesin. The sealer is, for example, an aqueous emulsion, or a solution or dispersion containing an organic solvent. The sealer contains, as necessary, inorganic particles such as heavy calcium carbonate, precipitated calcium carbonate, kaolin, bentonite, sericite, dolomite, talc, clay, aluminum oxide, magnesium oxide, and diatomaceous earth. Such a sealer usually suppresses the generation of efflorescence.

[0051] However, when curing and hardening the molded body as described above, it is preferable that no sealer is applied to the surface of the molded body, or the application amount of the sealer on the surface of the molded body is less than 250 g / m 2 and more preferably less than 200 g / m 2In the following cases, efflorescence formation is not suppressed, i.e., efflorescence is produced. Furthermore, if a sealer is applied to the surface of the molded body, the amount of efflorescence produced can be controlled by adjusting the amount of sealer.

[0052] The manufacturing method for building material 1 may further include a step of applying a clear coating to the surface of building material 1 after steps (1) to (4) to form a clear coating film.

[0053] The manufactured building material 1 comprises a base layer 11 derived from a base layer forming composition and a surface layer 12 derived from a surface layer forming composition.

[0054] The manufacturing method for building material 1 can be carried out more efficiently by using, for example, a traveling belt conveyor to perform each step. [Examples]

[0055] The following are specific embodiments of the present invention.

[0056] A base layer-forming composition and a surface layer-forming composition were prepared by mixing the components shown in Table 1 with water.

[0057] The details of the components shown in Table 1 are as follows: • Cement: Ordinary Portland cement • Silica: Silica powder (Brain: 3600cm²) 2 / g or more) • Fly ash • Mica (40 mesh) • Lightweight aggregate: Crushed material from recovered cement products • Reinforcement fiber: Virgin pulp • Water repellent: Silane-based water repellent (Toray Dow Corning Co., Ltd.'s "Dryseal S") • Wollastonite (Aspect Ratio: 15)

[0058] The building material was manufactured as follows: First, a slurry was prepared by adding water to the base layer forming composition. From this slurry, an unhardened cement board, which would become the base layer, was produced by papermaking. Next, the surface layer forming composition was sprinkled onto the base layer. Then, the composite cement board, comprising the base layer 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 was obtained in which a surface layer was provided on one surface of the base layer.

[0059] <Rating> [Bending strength (N / mm²)] 2 )] Each example of building material was processed into a test specimen measuring 160 mm in length and 40 mm in width. The resulting test specimens were subjected to a three-point bending test under the measurement conditions described below to measure the bending strength of the building material. (Measurement conditions) • Measuring instrument: INSTRON, product name: INSTRON 5566 • Fixture: Indenter radius R=5mm, support radius R=5mm, ratio of distance between supports (L) to specimen thickness (d) (L / d) = 6.3 • Other: The test specimen was set up so that the surface layer 12 was facing downwards, and the test was performed.

[0060] [Wet look] The aforementioned building materials were sprayed with water for 5 minutes to obtain samples for evaluating the wet color. These evaluation samples were visually observed. The wet color of the building materials was evaluated according to the following criteria. ○ (Good): No black spot-like patterns were observed. × (Defective): Black, spot-like patterns were observed.

[0061] [Table 1]

[0062] The results in Table 1 show that the building materials in the example can suppress the occurrence of wet discoloration. The building materials in the comparative example could not suppress the occurrence of wet discoloration. [Explanation of symbols]

[0063] 1. Building materials 11 Base material layer 12 Surface layer

Claims

1. A building material composed of inorganic materials, primarily cement, which is a hydraulic material. It comprises a base layer and a surface layer formed on the surface of the base layer, The aforementioned surface layer contains needle-shaped reinforcing material, The aforementioned needle-shaped reinforcing material is at least one selected from the group consisting of potassium titanate whiskers, aluminum borate whiskers, carbon whiskers, calcium carbonate whiskers, wollastonite, sepiolite, palygorskite, tobermorite, zinc oxide whiskers, titanium oxide whiskers, glass fibers, and ceramic fibers. The needle-shaped reinforcing material is contained in an amount of 1% by mass or more and 12% by mass or less relative to the total solid content of the surface layer. Efflorescence is irregularly distributed on the surface of the aforementioned surface layer. A building material having a clear coating film formed on the surface of the aforementioned surface layer.

2. A building material composed of inorganic materials, primarily cement, which is a hydraulic material. It comprises a base layer and a surface layer formed on the surface of the base layer, At least the surface layer includes needle-shaped reinforcing material, The aforementioned needle-shaped reinforcing material is at least one selected from the group consisting of potassium titanate whiskers, aluminum borate whiskers, carbon whiskers, calcium carbonate whiskers, wollastonite, sepiolite, palygorskite, tobermorite, zinc oxide whiskers, titanium oxide whiskers, glass fibers, and ceramic fibers. The needle-shaped reinforcing material is contained in an amount of 1% by mass or more and 4% by mass or less relative to the total solid content of the base layer and the surface layer. Efflorescence is irregularly distributed on the surface of the aforementioned surface layer. A building material having a clear coating film formed on the surface of the aforementioned surface layer.

3. In claim 1 or 2, A building material in which the aspect ratio of the needle-shaped reinforcing material is 3 or more and 20 or less.

4. In any one of claims 1 to 3, A building material that does not produce black, dot-like patterns on the outer surface of the inorganic material when it comes into contact with rainwater, etc.

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