Water-retentive cement molded body

Abstract

To provide a water-retentive cement molded article that has good water retention, as well as good flexural strength and weather resistance. [Solution] The following components (A), (B), and (C): (A) cement, (B) Calcium silicate granules mainly composed of xonotlite, (C) Organic synthetic fiber raw materials A water-retentive cement molded article containing, The average particle size of component (B) is 10 μm to 100 μm, the content of component (B) is 10 to 70 parts by mass per 100 parts by mass of cement, the content of component (C) is 0.5 to 15 parts by mass per 100 parts by mass of cement, and the bulk density of the water-retentive cement molded body is 0.8 to 1.2 g / cm³. 2 This is a water-retentive cement molded body.

Description

[Technical Field]

[0001] This invention relates to a water-retentive cement molded article. [Background technology]

[0002] In recent years, global warming has caused rising temperatures not only in summer but also from spring to autumn, creating a problem of temperature rise in exterior materials and walls not only in buildings where people live, but also in various facilities, livestock farms, and agricultural equipment. As such, water-retentive cement molded bodies have been developed for use in exterior materials and walls. Water-retentive cement molded bodies suppress the rise in surface temperature by evaporating water absorbed and retained inside from the surface.

[0003] As such a water-retentive cement molded body, a water-retentive cement molded body containing a porous body has been reported, characterized in that, by selecting and using granular material obtained by crushing calcium silicate heat-insulating material using a cutting machine as the porous body, a first capillary portion is formed that connects the surface and interior of the water-retentive cement molded body and retains water in the pF range of pF 2.7 to 4.2, wherein the first capillary portion is formed by a first void which is an internal void of the porous body and a second void which is a void formed between the porous body and the cement gel or between adjacent porous bodies (Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 5336122 [Overview of the project] [Problems that the invention aims to solve]

[0005] The water-retentive cement molded article described in Patent Document 1 has good water retention, but further improvements were desired in terms of durability, weather resistance, and other aspects. [Means for solving the problem]

[0006] Therefore, the inventors conducted various studies to develop a water-retentive cement molded article that has improved durability and weather resistance and high water retention capacity. As a result, they found that by adding specific amounts of calcium silicate granules mainly composed of xonotlite and organic synthetic fibrous raw materials to cement as a material, a water-retentive cement molded article that solves the above problems can be obtained.

[0007] In other words, the present invention provides the following [1] to [3]. [1] The following components (A), (B), and (C): (A) cement, (B) Calcium silicate granules mainly composed of xonotlite, (C) Organic synthetic fiber raw materials A water-retentive cement molded article containing, The average particle size of component (B) is 10 μm to 100 μm. The content of component (B) is 10 to 70 parts by mass per 100 parts by mass of cement. The content of component (C) is 0.5 to 15 parts by mass per 100 parts by mass of cement. The bulk density of the water-retentive cement molded body is 0.8 to 1.2 g / cm³. 2 That is, Water-retentive cement molded body. [2] The water-retentive cement molded article according to claim 1, wherein component (B) is a calcium silicate granular material containing 60% by mass or more of xonotlite. [3] Bending strength is 1 N / mm 2 The water-retentive cement molded article described in [1] or [2] above. [Effects of the Invention]

[0008] The water-retentive cement molded articles of the present invention have excellent water retention, as well as superior bending strength and outdoor durability. Because they are mainly composed of inorganic materials, they have excellent radiant heat insulation properties, and are particularly effective in suppressing temperature rise caused by direct sunlight. They can be used not only as exterior wall materials for buildings and ordinary structures, but also as exterior wall materials for various facilities such as livestock farms and agricultural facilities. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example of a solar radiation testing facility. [Modes for carrying out the invention]

[0010] Terms used herein shall be used in the sense commonly used in the art unless otherwise specified.

[0011] One aspect of the present invention relates to the following components (A), (B), and (C): (A) cement, (B) Calcium silicate granules mainly composed of xonotlite, (C) Organic synthetic fiber raw materials A water-retentive cement molded article containing, The average particle size of component (B) is 10 μm to 100 μm. The content of component (B) is 10 to 70 parts by mass per 100 parts by mass of cement. The content of component (C) is 0.5 to 15 parts by mass per 100 parts by mass of cement. The bulk density of the water-retentive cement molded body is 0.8 to 1.2 g / cm³. 2 That is, It is a water-retentive cement molded product.

[0012] The component (A) used in the present invention is cement. Examples of cement include Portland cement, blast furnace cement, fly ash cement, silica cement, eco-cement, and alumina cement. In addition, ordinary Portland cement and high-early-strength Portland cement can be used as Portland cement.

[0013] Component (B) used in the present invention is a calcium silicate granular material containing xonotlite as the main component. More than 20 types of crystal structures of calcium silicate hydrate are known, and among them, it is preferable in the present invention to use the calcium silicate granular material containing xonotlite as the main component from the viewpoint of obtaining high water retentivity based on its crystal structure. That is, xonotlite has a double chain structure of SiO₄ tetrahedrons and is a needle-like crystal of several micrometers, so it has the effect of retaining a large amount of water and allowing it to evaporate gradually. Here, the main component means containing 60 mass% or more of xonotlite, preferably 70 mass% or more, more preferably 80 mass% or more, and even more preferably 85 mass% or more. Further, it is a calcium silicate granular material, and the average particle diameter is preferably 10 μm to 100 μm, more preferably 15 μm to 90 μm, and even more preferably 20 μm to 80 μm. Here, the average particle diameter can be measured by a centrifugal sedimentation method, a laser diffraction / scattering method, a Coulter method, or the like. From the viewpoint of obtaining high water retentivity, the calcium silicate granular material used in the present invention preferably has an average pore diameter of 10 μm to 100 μm, more preferably 15 μm to 90 μm, and even more preferably 20 μm to 80 μm. Here, the average pore diameter is measured by a laser diffraction / scattering method. From the viewpoint of obtaining high water retentivity and maintaining the low bulk density of the cement molded body, component (B) is preferably contained in the water-retentive cement molded body of the present invention in an amount of 10 parts by mass to 70 parts by mass, more preferably 15 parts by mass to 65 parts by mass, and even more preferably 20 parts by mass to 60 parts by mass, relative to 100 parts by mass of cement.

[0014] Component (C) is an organic synthetic fibrous raw material. Examples of the organic synthetic fibrous raw material include vinylon resin, acrylic resin, polypropylene resin, rayon, and the like. The fiber diameter of these organic synthetic fibrous raw materials is preferably 0.6 to 3.3 decitex from the viewpoints of strength development and porosity of the composite material. From the viewpoint of increasing the bending strength of the cement molded article, component (C) is preferably contained in the water-retentive cement molded article of the present invention in an amount of 0.5 to 15 parts by mass, more preferably 1 to 13 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of cement.

[0015] In addition to the above-mentioned components, the water-retentive cement molded article of the present invention may also contain inert and inexpensive powdered raw materials such as calcium carbonate, silica, and wollastonite.

[0016] The water-retentive cement molded article of the present invention can be manufactured by mixing and kneading the raw materials with water, followed by a molding process, curing, and drying.

[0017] The bulk density of the water-retentive cement molded article of the present invention is 0.8 to 1.2 cm², from the viewpoint of flexural strength, outdoor durability, and water retention. 2 Preferably, 0.85 to 1.15 cm 2 More preferably, 0.9-1.1 cm 2 That is even more preferable. Furthermore, the bending strength of the water-retentive cement molded article of the present invention is 1 N / mm 2 The above is preferable, 3N / mm 2 The above is preferable.

[0018] The water-retentive cement molded body of the present invention not only has excellent water retention properties but also excellent bending strength and outdoor durability, making it useful not only as a general exterior wall material and exterior material but also as an exterior wall material for various facilities such as livestock farms and agricultural facilities. [Examples]

[0019] The present invention will now be described in more detail with reference to examples, but the present invention is not limited in any way to these examples.

[0020] Examples 1-8 and Comparative Examples 1-11 Cement molded bodies were manufactured using the components listed in Tables 1-3, and the temperature changes of the molded bodies were observed through solar radiation tests. Their bending strength and outdoor durability were also investigated. The results are shown in Tables 1 to 3.

[0021] (1) Materials Cement: Ordinary Portland cement manufactured by Taiheiyo Cement Calcium silicate granules: In-house synthesized product Xonotlite: In-house synthesized product using lime and silica stone Tobermorite: In-house synthesized product using lime and silica stone CSH-based crystal: In-house synthesized product using lime and silica stone Concrete: In-house produced product using ordinary Portland cement manufactured by Taiheiyo Cement and silica stone Organic synthetic fibrous raw material: Vinylon RMH-182 manufactured by Kuraray Co., Ltd. Other components: Inorganic filler Wollastonite Other components: Inorganic filler Calcium carbonate (2) Production method of molded body: Press dewatering molding method, vibration press molding method, casting molding, etc. can be used, but the vibration press molding method was used in this specification. (3) Solar radiation test method Using an apparatus as shown in Figure 1, changes in plate temperature were monitored by simulating solar radiation. The heat receiving energy of the specimen is 650W / m 2 The specimen is immersed in water for 24 hours and starts from a water-saturated state. Irradiate continuously for 7 hours and observe the change in plate temperature. (4) Bending strength test The bending strength of the air-dried specimens in a dry state was measured in accordance with JIS A 5430. (5) Outdoor durability test Outdoor durability was judged from the degree of deterioration due to actual exposure and the results of water-water freeze-thaw (refer to JIS A 1148). This test is generally evaluated based on the presence or absence of significant appearance changes such as thickness expansion and material collapse after 30 cycles or more. In the results shown below, samples with no observed appearance change were marked as ○, those with slight changes as △, and those with observed expansion or collapse as ×.

[0022] [Table 1]

[0023] Table 1 shows that using calcium silicate granules with xonotlite as the main component results in good water retention of the cement molded product.

[0024] [Table 2]

[0025] Table 2 shows that incorporating an appropriate amount of organic synthetic fibrous raw materials improves the flexural strength and outdoor durability of cement molded articles (compared to Comparative Examples 8 and 9). It also shows that if the particle size of xonotlite, which is calcium silicate powder, is not within the appropriate range, molding defects and reduced strength are likely to occur (compared to Comparative Examples 6 and 7).

[0026] [Table 3]

[0027] Table 3 shows that when the components constituting calcium silicate are within an appropriate range with xonotlite as the main component, a cement molded article with excellent water retention can be obtained.

Claims

1. The following components (A), (B), and (C): (A) Cement, (B) Calcium silicate granules mainly composed of xonotlite, (C) Organic synthetic fiber raw materials A water-retentive cement molded article containing, The average particle size of component (B) is 10 μm to 100 μm. The content of component (B) is 10 to 70 parts by mass per 100 parts by mass of cement. The content of component (C) is 0.5 to 15 parts by mass per 100 parts by mass of cement. The bulk density of the water-retentive cement molded body is 0.8 to 1.2 g / cm³. ２ That is, Water-retentive cement molded body.

2. The water-retentive cement molded article according to claim 1, wherein component (B) is a calcium silicate granular material containing 60% by mass or more of xonotlite.

3. Bending strength is 1 N / mm ２ The water-retentive cement molded article according to claim 1 or 2.

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