Inorganic board

Abstract

To provide an inorganic board having low water absorption.SOLUTION: An inorganic board comprises a substrate 2, and a filler part 3 and a water-repellent part 4 exposed on a rear face of the substrate 2. The filler part 3 inhibits water-repellent agent from impregnating into the substrate 2, the water-repellent part 4 can be easily held on the rear face of the substrate 2, impregnation of moisture into the substrate 2 is reduced due to water repellency by the water-repellent part 4, and an inorganic board having low water absorption is obtained.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention generally relates to an inorganic plate, and more particularly to an inorganic plate containing a cured product of cement.

Background Art

[0002] Patent Document 1 describes a ceramic decorative board. This decorative board contains titanium oxide-coated mica in the outermost surface gloss layer of a decorative layer formed on at least one surface of a ceramic substrate. When forming the decorative layer, an impregnating sealer is applied to the surface of the ceramic substrate, and then a decorative layer paint is applied. Also, on the back surface of the ceramic substrate, the same impregnating sealer (back sealer) as described above is applied to improve waterproofness (see paragraph 0035).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, the moisture absorbed by the ceramic substrate is difficult to be discharged to the outside by the back sealer, and there is a case that is not preferable in terms of freeze damage resistance.

[0005] The present invention has been made in view of the above reasons, and an object thereof is to provide an inorganic plate having low water absorption.

Means for Solving the Problems

[0006] The inorganic plate according to one aspect of the present invention includes a base material, and a caulking portion and a water repellent portion exposed on the back surface of the base material.

Effects of the Invention

[0007] According to the present invention, the caulking part makes it difficult for the water-repellent part to be impregnated into the base material, making it easier for the water-repellent part to be retained on the back surface of the base material. The water-repellent property of the water-repellent part reduces the impregnation of moisture into the base material, and an inorganic plate with low water absorption can be obtained.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0009] (Embodiment) The inorganic plate 1 according to the present embodiment includes a base material 2, a caulking part 3 and a water-repellent part 4 exposed on the back surface of the base material 2. That is, part or all of the caulking part 3 is present on the back surface of the base material 2. Similarly, part or all of the water-repellent part 4 is present on the back surface of the base material 2. That is, as shown in FIG. 1, on the back surface of the base material 2, the caulking part 3 and the water-repellent part 4 are formed in an island shape (patchy).

[0010] The base material 2 is preferably a cement base material. The cement base material is a ceramic base material containing a cured product of cement. In this case, compared with a wooden plate or a metal plate, the base material 2 has a large number of fine voids, and the voids open to the back surface of the base material 2. Therefore, the caulking agent described later is easily impregnated into the base material 2 from the back surface, and it becomes difficult to form the caulking part 3 in a film shape.

[0011] As the above cement, known cements such as Portland cement, blast furnace cement, alumina cement, fly ash cement, etc. are used. Only one kind of the above-listed cements may be included, or two or more kinds may be included. In addition to the cured product of cement, the base material 2 may contain reinforcing fibers. Examples of the reinforcing fibers include natural fibers such as pulp fibers, synthetic fibers such as vinylon and polypropylene, and inorganic fibers such as glass fibers, rock wool, and carbon fibers. Only one kind of the above-listed reinforcing fibers may be included, or two or more kinds may be included. The base material 2 may further contain inorganic powders such as wood chips, wollastonite, mica, calcium carbonate, waste material powders of fiber-reinforced cement boards and gypsum boards, silica, silica powder, resin beads, lightweight aggregates, etc.

[0012] The base material 2 can be formed into a rectangular plate shape. The thickness of the base material 2 is not particularly limited, but considering its use as a building material for the inorganic board 1, it is preferably 3 to 40 mm. In addition, uneven patterns may be formed on the surface of the base material 2. Also, a decorative layer formed of a coating film of enamel paint and clear paint, etc. may be provided on the surface of the base material 2. Further, male and female joints may be formed at the ends of the base material 2. Note that the surface of the base material 2 means one of the two surfaces orthogonal to the thickness direction of the base material 2. When the inorganic board 1 is a building material, the surface of the base material 2 is constructed facing the outdoor side (outside). The back surface of the base material 2 is the surface on the opposite side of the above surface, meaning the other of the two surfaces orthogonal to the thickness direction of the base material 2. When the inorganic board 1 is a building material, the back surface of the base material 2 is constructed facing the indoor side (inside).

[0013] The base material 2 can be formed into a desired shape by a casting method, an extrusion method, a papermaking method, etc. using a molding material containing cement. In addition to cement, the above materials such as reinforcing fibers can be blended in the molding material, and further, water, a water reducing agent, a thickening agent, and other additives can be blended. The blending ratio and mixing method of each material constituting the molding material are not particularly limited and can be appropriately set according to the physical properties and intended use required for the base material 2 to be manufactured. Also, after forming the molding material into a flat plate, press molding may be performed on its surface to form uneven patterns.

[0014] After the base material 2 forms the above-mentioned molding material into a desired shape, it can be cured by curing. For curing, steam curing, autoclave curing, etc. can be performed. Further, after curing, male fruits and female fruits can be formed by cutting or the like, and a decorative layer can be formed by painting.

[0015] And, the inorganic plate 1 according to the present embodiment is provided with a caulking portion 3 and a water repellent portion 4 exposed on the back surface of the base material 2. Here, "exposed" means a state in which a part or all of the caulking portion 3 and the water repellent portion 4 are present on the back surface of the base material 2. Therefore, a state in which a part of the caulking portion 3 and the water repellent portion 4 is internal to the base material 2 and the other part of the caulking portion 3 and the water repellent portion 4 is present on the back surface of the base material 2 is also included.

[0016] The caulking portion 3 is formed of a solid content (vehicle) contained in the caulking agent. The caulking agent is a paint (sealer paint) containing a solid content and a solvent, and the caulking portion 3 can be formed by applying the caulking agent to the back surface of the base material 2, drying it, and curing it as necessary. Since the caulking agent is liquid, when it is applied to the back surface of the base material 2, a part of it is impregnated into the base material 2. That is, since the base material 2 has a large number of voids that open on the back surface, a part of the caulking agent penetrates into the voids and the other part remains on the back surface. In such a state, since the caulking agent applied to the base material 2 dries and the caulking portion 3 is formed, the caulking portion 3 is not formed as a coating film with a uniform thickness.

[0017] When applying the caulking agent to the back surface of the base material 2, a known coating method can be adopted. For example, it can be applied by means such as spraying, roll coater, curtain coater, and brush. The coating amount of the caulking agent varies depending on the components and concentration of the solid content contained in the caulking agent. For example, it can be 3 to 100 g / m 2 Thereby, the effect of making it difficult for the water repellent agent described later to impregnate the base material 2 is easily obtained.

[0018] The caulking agent preferably contains an acrylic emulsion-based paint. Thereby, the caulking portion 3 containing an acrylic polymer can be formed, and the effect of making it difficult for the water repellent agent described later to impregnate the base material 2 is easily obtained. The acrylic emulsion-based paint is a paint containing a low molecular weight acrylic resin in a solvent in an emulsion state. And as the caulking agent, in addition to the acrylic emulsion, a sealer paint in which additives such as pigments, extender pigments, dispersants, and defoamers are stirred and dispersed in a solvent such as water can be used.

[0019] The water repellent portion 4 is formed of the solid content (vehicle) contained in the water repellent agent. The water repellent agent is a paint (water repellent paint) containing a solid content and a solvent. By applying the water repellent agent to the back surface of the base material 2, drying it, and, if necessary, curing it, the water repellent portion 4 can be formed. Here, before applying the water repellent agent to the back surface of the base material 2, the caulking portion 3 is formed on the back surface of the base material 2. That is, the water repellent agent is applied to the back surface of the base material 2 on which the caulking portion 3 is formed. Since the water repellent agent is liquid, when it is applied to the back surface of the base material 2, a part of it is impregnated into the base material 2. That is, since the base material 2 has a large number of voids opening to the back surface, a part of the water repellent agent penetrates into the voids and the other part remains on the back surface. On the other hand, the voids communicating with the back surface of the base material 2 are not completely filled with the caulking portion 3. When there is a hollow portion in the base material 2, the hollow portion communicates with the voids communicating with the back surface, and the air in the hollow portion can flow out to the outside of the base material 2. In such a state, since the water repellent agent applied to the base material 2 dries to form the water repellent portion 4, the water repellent portion 4 is not formed as a coating film with a uniform thickness. That is, the caulking portion 3 and the water repellent portion 4 are formed in an island shape (patchy shape), and the air from the hollow portion of the base material 2 can flow. Also, when applying the water repellent agent, since the caulking portion 3 is formed on the back surface of the base material 2 and is exposed, the impregnation amount of the water repellent agent into the base material 2 is less than that when there is no caulking portion 3. Therefore, the water repellency of the back surface of the inorganic plate 1 can be improved by the water repellent portion 4 exposed on the back surface of the base material 2, and the waterproofness of the inorganic plate 1 can be enhanced.

[0020] When applying the water repellent to the back surface of the base material 2, a known coating method can be adopted. For example, it can be applied by means such as spraying, roll coater, curtain coater, brush, etc. The coating amount of the water repellent varies depending on the components and concentration of the solid content contained in the water repellent. For example, it can be 10~100 g / m 2 This makes it easier to obtain the water repellent effect by the water repellent part 4.

[0021] The water repellent preferably contains a silane-based water repellent. Thereby, it is easy to obtain the effect that the water repellent part 4 containing the polymerized aqueous silane compound can be formed and the water repellency can be improved. The silane-based water repellent is a paint containing an aqueous silane compound such as alkylalkoxysilane.

[0022] The inorganic board 1 according to the present embodiment preferably has a contact angle of water on the back surface of 80° or more and 150° or less. When the contact angle of water is 80° or more and 150° or less, the water absorption from the back surface of the base material 2 is reduced, and the freeze damage resistance is improved. For example, in an environmental test assuming a cold region, the ratio of water absorption, which is the freeze damage index, is lowered, and the water repellent is also effective in improving the freeze damage resistance like the waterproof sealer. Specifically, compared with an inorganic board that is not freeze damage resistant (an inorganic board that does not use a water repellent), the water absorption rate can be reduced by about 20~40% in this embodiment.

[0023] When only the water repellent is applied to the back surface of the base material 2, the water repellent easily penetrates into the base material 2 from the back surface and is difficult to remain on the back surface, and it is difficult to form the water repellent part 4 exposed on the back surface of the base material 2. Therefore, the inorganic board 1 according to the present embodiment forms a blocking part 3 on the back surface of the base material 2 before applying the water repellent. Therefore, it becomes difficult for the water repellent to penetrate into the base material 2 from the back surface, it is easy to retain the water repellent on the back surface of the base material 2, and it is easy to form the water repellent part 4 exposed on the back surface of the base material 2.

[0024] Conventionally, inorganic plates deployed in cold regions use a base material with hollow holes. In this case, in order to enhance freeze damage resistance, a highly waterproof back surface sealer coating is applied to prevent water permeation from the back surface of the base material. Therefore, in an environmental test assuming a cold region, the water absorption rate of the base material, which is the cause of freeze damage, is low, and it has a high freeze damage resistance specification. However, as the waterproofness of the back surface increases, the moisture permeability of the base material decreases. Therefore, when the temperature of the base material rises during construction, the air in the hollow holes expands, and when placing the sealant, pressure is applied to the sealant because the air escapes through small openings before it dries. For these reasons, as the performance required for the back surface of the inorganic plate, the water absorption rate of the base material is low and the moisture permeability is high. And in the inorganic plate according to this embodiment, even when the base material 2 has hollow holes, the moisture permeability from the back surface of the base material becomes high, preventing the volume expansion of the air in the hollow holes, so that it becomes difficult for pressure to be applied to the sealant.

Example

[0025] (Example 1) As the base material, a cement base material (Neo Rock base material manufactured by Caymu Co., Ltd.) was used. As a caulking agent for the back surface of the base material, an acrylic emulsion-based paint was used. The caulking agent was applied to the back surface of the base material at a coating amount of 5 g / m 2 . After drying the applied caulking agent to form a caulked portion, as a water repellent for the back surface of the base material, a silane-based water repellent (manufactured by BASF Japan Ltd.) was used. The water repellent was diluted with water to 4000% of the stock solution and then applied to the back surface of the base material at a coating amount of 13 g / m 2 . The applied water repellent was dried to form a water repellent portion. The inorganic plate was formed in this way.

[0026] (Example 2) As the caulking agent, a product with an increased solid content of the caulking agent in Example 1 was used. The caulking agent was diluted with 20% water of the stock solution and then applied to the back surface of the base material at a coating amount of 13 g / m 2 . Except for the above, an inorganic plate was formed in the same manner as in Example 1.

[0027] (Comparative Example 1) In Example 1, the caulking portion and the water-repellent portion were not formed. That is, the back surface of the base material was left in its initial state. (Comparative Example 2) In Example 1, the caulking portion was not formed. On the back surface of the base material, after diluting the same water-repellent agent as in Example 1 with water to 1000%, it was applied to the back surface of the base material at a coating amount of 4 g / m 2 . The applied water-repellent agent was dried to form a water-repellent portion. In this way, an inorganic board was formed.

[0028] (Comparative Example 3) In Comparative Example 2, an inorganic board was formed in the same manner except that the water-repellent agent was diluted with water to 2000%.

[0029] (Comparative Example 4) In Comparative Example 2, an inorganic board was formed in the same manner except that the water-repellent agent was diluted with water to 4000%.

[0030] (Measurement of water absorption rate) The water absorption rate by the freeze damage resistance test was measured. The results are shown in FIG. 2. In FIG. 2, in addition to the examples and comparative examples, the water absorption rates of Reference Examples 1 to 4 are also shown. Reference Examples 1 and 2 are inorganic boards of ordinary products (not freeze damage resistant specifications). Reference Examples 3 and 4 are inorganic boards of freeze damage resistant specifications.

[0031] Examples 1 and 2 had a lower water absorption rate than Comparative Examples 1 to 4.

[0032]

Table 1

[0033] According to the first aspect, the caulking portion 3 makes it difficult for the water-repellent agent to impregnate into the base material 2, and makes it easier for the water-repellent portion 4 to be retained on the back surface of the base material 2. Due to the water repellency of the water-repellent portion 4, the impregnation of moisture into the base material 2 is reduced, and there is an advantage that an inorganic board with low water absorption can be obtained.

[0034] In the second aspect, for the inorganic plate 1, in the first aspect, on the back surface, the caulking part 3 and the water repellent part 4 are formed in an island shape.

[0035] According to the second aspect, the caulking part 3 makes it difficult for the water repellent agent to impregnate into the base material 2, and makes it easier for the water repellent part 4 to be retained on the back surface of the base material 2. Due to the water repellency of the water repellent part 4, the impregnation of moisture into the base material 2 is reduced, and there is an advantage that an inorganic plate with low water absorption can be obtained.

[0036] In the third aspect, for the inorganic plate 1, in the first or second aspect, the contact angle of water on the back surface is 80° or more and 150° or less.

[0037] According to the third aspect, there is an advantage that an inorganic plate with low water absorption can be easily obtained.

[0038] In the fourth aspect, for the inorganic plate 1, in the first or second aspect, the base material 2 is a cement base material.

[0039] According to the fourth aspect, even if the cement base material into which water easily penetrates is the base material 2, there is an advantage that an inorganic plate with low water absorption can be easily obtained.

[0040] In the fifth aspect, for the inorganic plate 1, in the first or second aspect, the caulking part 3 is formed of a caulking agent containing an acrylic emulsion-based paint. The water repellent part 4 is formed of a water repellent agent containing a silane-based water repellent agent. According to the fifth aspect, there is an advantage that an inorganic plate with lower water absorption can be easily obtained.

Explanation of reference numerals

[0041] 1 Inorganic plate 2 Base material 3 Caulking part 4 Water repellent part

Claims

1. An inorganic board comprising a base material, a caulking portion and a water-repellent portion exposed on the back surface of the base material.

2. The inorganic board according to claim 1, wherein the caulking portion and the water-repellent portion are formed in an island shape on the back surface.

3. The inorganic board according to claim 1 or 2, wherein the contact angle of water on the back surface is 80° or more and 150° or less.

4. The inorganic board according to claim 1 or 2, wherein the base material is a cement base material.

5. The caulking portion is formed of a caulking agent containing an acrylic emulsion-based paint, and the water-repellent portion is formed of a water-repellent agent containing a silane-based water-repellent agent. The inorganic board according to claim 1 or 2.

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