Painting materials and structures containing roof tile chips and magnesia cement

Abstract

To provide a novel coating material that can be coated on an exterior of a structure etc. to impart impact resistance and the like, and a structure coated with the coating material.SOLUTION: The coating material comprises roof tile chips and magnesia cement. A structure has a surface coated with the coating material. Or a structure has an earthen wall coated with the coating material.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a coating material and a structure containing tile chips and magnesia cement.

Background Art

[0002] The earth wall gradually loses its adhesive strength due to aging deterioration, and symptoms such as the earth crumbling and falling occur. The main cause is that the adhesive strength gradually decreases due to the influence of ultraviolet rays and the like, and the earth peels off and falls off with a slight impact. The lifespan of a conventional earth wall is about 10 years because the earth wall cannot be wiped with water, and then the dirt becomes noticeable. In addition to the poor appearance of the wall, the fact that it must be cleaned frequently is a major drawback. As a technique for preventing the earth wall from falling off, for example, Patent Document 1 discloses an earth wall falling-off prevention treatment agent and method.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to extend the lifespan of an earth wall, the strength of the surface coating material of the earth wall is also an important factor. The object of the present invention is to provide a novel coating material that can be applied to the exterior of a structure or the like to impart impact resistance and the like. Another object is to provide a structure coated with the coating material.

Means for Solving the Problems

[0005] As a result of intensive research to solve the above problems, the present inventor has found that the following invention meets the above object, and has arrived at the present invention.

[0006] In other words, the present invention relates to the following invention. <1> A coating material containing roof tile chips and magnesia cement. <2> In the aforementioned coating material, the amount of magnesia cement is 5 to 30 parts by mass per 100 parts by mass of the roof tile chips, <1> The paint materials listed. <3> The aforementioned <1> or <2> A structure whose surface is painted with the paint material described above. <4> The aforementioned <1> or <2> A structure with earthen walls painted with the paint materials described above. [Effects of the Invention]

[0007] According to the present invention, a novel coating material is provided that can be applied to the exterior of a structure to impart impact resistance and other properties. Furthermore, a structure coated with the said coating material is also provided. [Brief explanation of the drawing]

[0008] [Figure 1] This is a photograph of the waste roofing chips used in the experiment. [Figure 2] This image shows a photograph of a test specimen coated with a paint material at 7 days of age during an impact resistance test. [Figure 3] This image shows a photograph of a test specimen coated with a paint material at 28 days of age during an impact resistance test. [Figure 4] This is a schematic diagram of the coating material sample used in the antibacterial activity test. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is just one example (representative example) of an embodiment of the present invention, and the present invention is not limited to the following unless its gist is changed. In this specification, when the expression "~" is used, it is used to mean an expression that includes the numerical value or physical property value before and after it.

[0010] <Painting materials> The present invention relates to a coating material containing tile chips and magnesia cement (hereinafter sometimes referred to as "the coating material of the present invention"). The coating material of the present invention is for coating a structure. For example, by coating the coating material of the present invention on the exterior of an earth wall, the lifespan of a conventional earth wall can be significantly extended. In addition, impact resistance, antibacterial properties, and moisture control properties (hygroscopicity and moisture release properties) can be imparted.

[0011] [Tile chips] The coating material of the present invention contains tile chips. The tile chips are crushed and / or pulverized materials of waste tiles (discarded tiles). Tiles are typically represented by roof tiles, but are not limited to roofing materials and mean all materials obtained by semi-dry firing of clay. The tile chips used in the coating material of the present invention are not limited to crushed and / or pulverized materials of roof tiles, but also include crushed and pulverized materials of tiles other than roof tiles. For example, Tecora (registered trademark) can be used as the tile chips.

[0012] <000007​​​​​​​​​​​​​​​​​​​​​​​​​​The tile chips contained in the coating material of the present invention exhibit weak alkalinity and preferably have a pH of 9 or less.

[0015] In addition, the tile chips contained in the coating material of the present invention preferably contain major elements such as phosphoric acid, calcium, magnesium, and potassium. For example, the tile chips contained in the coating material of the present invention can contain 1 to 3% of P2O5, 35 to 50% of CaO, 1 to 3% of MgO, and 1 to 4% of K2O. By adopting such a composition, when recycling structures or the like to which the coating material has been applied, it can be preferably applied as a supply material for these elements. For example, it is expected to be used as a soil improvement material for agricultural land.

[0016] In addition, the tile chips contained in the coating material of the present invention preferably contain soluble copper, soluble zinc, and hot water-soluble boron within the range of the appropriate amount of healthy soil in Japan or more than that of healthy soil in Japan. By adopting such a composition, it can be used as a supply material for these trace elements. Therefore, when recycling structures or the like to which the coating material has been applied, it is expected to be used as a soil improvement material for agricultural land.

[0017] The tile chips are preferably finely pulverized materials, specifically, preferably having a size of 1 mm or less, 0.5 mm or less, or 0.2 mm or less. For example, those having a size of 0.01 to 1 mm, 0.03 to 0.5 mm, 0.05 to 0.2 mm, etc. can be used.

[0018] [Magnesia cement] The coating material of the present invention contains magnesia cement. The magnesia cement acts as a curing agent. The magnesia cement is a cement obtained by kneading light-burned magnesia (MgO) obtained by burning magnesium carbonate or magnesium hydroxide at 1000°C or lower with a bittern solution (MgCl2 solution) for curing. The curing is due to the formation of an oxychloride salt.

[0019] Unlike calcium derived from limestone, which deteriorates over time, the magnesia cement has the property of increasing in hardness year by year.

[0020] Magnesia cement, compared to Portland cement, has characteristics such as higher strength, stronger adhesion to other materials, antibacterial properties, and resistance to mold growth. It is an air-hardening cement that achieves considerable strength in approximately 20 hours, and continues to harden thereafter. This strength development is achieved when using soil, specifically MgAl(OH) 14 • XH2O and Mg4Al2(OH) 14 Reaction products of magnesium and aluminum, such as 3H2O, have been observed, and these are considered to be factors in the development of strength in good soil (Source: Tetsuji Yamada, 2015).

[0021] The coating material of the present invention may contain components other than roof tile chips, magnesia cement, and water. For example, since magnesia cement has good adhesion to wood, it is presumed to have good compatibility with hemp, bamboo fibers, straw, Japanese paper, sawdust, etc., which can be used as floss, and these may also be included.

[0022] Furthermore, the coating material of the present invention may consist of roof tile chips, magnesia cement, and water. A coating material of the present invention with such a composition can have an excellent balance of impact resistance, crack resistance, ease of adhesion, and antibacterial properties.

[0023] In the coating material of the present invention, the proportion of roof tile chips and magnesia cement can be appropriately set considering impact resistance and other factors, and is not particularly limited. However, for example, 5 to 30 parts by mass, 5 to 25 parts by mass, or 10 to 20 parts by mass of magnesia cement per 100 parts by mass of roof tile chips is preferred. Increasing the amount of roof tile chips improves impact resistance and humidity control, but may also increase the likelihood of cracking.

[0024] The coating material of the present invention is used by mixing roof tile chips, magnesia cement, and water to create a fluid mixture and applying it to surfaces such as earthen walls. The amount of water is adjusted to achieve an appropriate viscosity depending on the application method. For example, the amount of water in the coating material of the present invention is 15-40% by mass or 15-30% by mass.

[0025] <Structure> Furthermore, the present invention relates to a structure on which the above-described coating material of the present invention is applied to the surface. When the coating material of the present invention is applied to the surface of a structure, the coating material of the present invention hardens, and a structure is obtained in which a layer made of the hardened coating material of the present invention is formed on the surface. As shown in the examples described later, the hardened coating material of the present invention has excellent impact resistance, antibacterial properties, and humidity control properties, and these properties can be imparted to the structure.

[0026] As a method for applying the coating material of the present invention, known methods can be used, such as applying it to a wall surface using a spatula or the like.

[0027] While there are no particular limitations on the surface to which the coating material of the present invention is applied, earthen walls are preferred, and a preferred example of the structure of the present invention is a structure comprising earthen walls coated with the coating material of the present invention.

[0028] As described above, the roof tile chips included in the coating material of the present invention utilize those that have the ability to correct the pH value of soil, and those that are rich in plant fertilizer components such as phosphorus, calcium, magnesium, potassium, copper, zinc, and boron. Therefore, the waste material of the cured coating material also contains a large amount of useful fertilizer component magnesium. For this reason, the coating material and the waste material of the cured coating material of the present invention are expected to be useful materials that can be used as soil conditioners and culture soils, which will greatly contribute to food production in Japan in the future. [Examples]

[0029] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless its essence is changed.

[0030] 1-1. Macronutrient properties of waste roof tile chips as plant nutrients We attempted to investigate the macronutrient content of plant materials using "Tecora (registered trademark), fine powder, particle size 1 mm or less" as waste roof tile chips. Figure 1 shows a photograph of the waste roof tile chips used, and Table 1 shows the physicochemical properties of the waste roof tile chips.

[0031] [Table 1]

[0032] As shown in Table 1, when we investigated the content of macronutrients as plant nutrients, we obtained the following results. (1) The pH value showed a slightly alkaline level. This suggests that the material can be used as a soil pH improver. (2) The amount of available phosphorus was slightly lower than that of Japanese black soil field soil. This suggests that it also has the capacity to supply phosphorus. (3) The amount of exchangeable calcium was also slightly higher than that of field soil. This fact suggests that agricultural land has a calcium supply capacity. (4) The amount of exchangeable magnesium was also slightly less than that of field soil. This suggests that it has the ability to supply magnesium, similar to phosphorus. (5) The amount of exchangeable potassium was slightly less than that of field soil. It was estimated to have the capacity to supply agricultural land, similar to phosphorus and magnesium. (6) The bulk density was heavier than that of typical soils, and it was classified as sandy loam.

[0033] The results suggest that the evaluated waste roofing chips can be used not only as a material for correcting soil pH values, but also as a material for supplying macronutrients such as phosphorus, calcium, magnesium, and potassium. Furthermore, the finely powdered waste roof tile chips that were evaluated belonged to the sandy loam soil category. Therefore, this strongly suggests that waste wall plaster can be used as a soil conditioner for agricultural land.

[0034] 1-2. Trace Element Properties of Waste Roof Tile Chips as Plant Nutrients We attempted to investigate the trace element content as plant nutrition using "Tecora (registered trademark), fine powder, particle size 1 mm or less" as waste roof tile chips. Table 2 shows the physicochemical properties of the waste roof tile chips.

[0035] [Table 2]

[0036] As shown in Table 2, when we examined the content of trace elements as plant nutrients, we obtained the following results. (1) The amount of available copper was shown to be extremely high compared to healthy soil in Japan. Therefore, it was estimated that the evaluated waste roof tile chips have the function of being a material for supplying soluble copper to copper-deficient soils. (2) The amount of available zinc was within an appropriate range compared to healthy soil in Japan. Therefore, it was estimated that the evaluated waste roof tile chips function as a material capable of supplying soluble zinc. (3) The amount of readily reducible manganese was considerably lower than that of healthy soil in Japan, unlike the results for soluble copper and soluble zinc. Therefore, the evaluated waste roof tile chips were not found to function as a material capable of supplying readily reducible manganese. (4) The amount of boron available in hydrothermal water was significantly higher than that of healthy soil in Japan. Therefore, the evaluated waste roof tile chips functioned as a material capable of supplying soluble zinc.

[0037] The results suggest that the evaluated waste roofing chips can be used as a source of trace elements such as soluble copper, soluble zinc, and soluble boron. This fact strongly suggests that waste plaster can be used as a soil conditioner for agricultural land.

[0038] 2. Impact resistance of the coating material The impact resistance performance was evaluated assuming that the coating material of the present invention was applied to the surface of an earthen wall used as an interior or exterior material for a building. Earthen walls do not bear the structural forces of the building. Therefore, instead of using a method to obtain quantitative values ​​as with concrete or mortar, a method was chosen to measure the resistance to breakage when something hits it.

[0039] • Evaluation method The measuring instrument [diameter 51mm] conforms to JIS A6909 (architectural finishing coating material). The impact resistance test plate uses a flexible board measuring 300mm (length) x 150mm (width) x 6mm (thickness). The test used a spherical weight W2-500 [mass 533g, diameter 51mm], and the top surface of the test specimen The test will be conducted by free-falling the object from a height of 30 cm. The above-mentioned weight is dropped onto the impact resistance test plate. The evaluation is carried out by visually observing the condition of the test plate, such as 1) cracking, 2) peeling, and 3) deformation. Visual observation is the standard for JIS certification.

[0040] ·test A coating material was prepared by mixing waste roof tile chips (Tecora®, fine powder) and magnesia cement with water. The ratio was 87% waste roof tile chips and 13% magnesium oxide. 260g of water was used per 1kg of the mixture. This was then applied to the surface of a test plate. The coating material (6 mm thick) was tested at 7 days of age (initial solidification stage) and at 28 days of age (stable solidification stage). The test was conducted using two parallel units. The results are summarized in Table 3. Figure 2 shows a photograph of the test specimens coated with the coating material at 7 days of age. Figure 3 shows a photograph of the test specimens coated with the coating material at 28 days of age.

[0041] [Table 3]

[0042] • Seasonal variations The results for the initial solidification stage at 7 days and 28 days showed that (1) cracking, (2) delamination, and (3) significant deformation were not observed at either age. These results clearly demonstrate that the coating material of the present invention solidifies extremely quickly. Since this allows for shorter construction periods, it is expected to offer significant economic advantages.

[0043] • Variation in measured values The results of the two sets of measurements at both ages showed no significant differences, similar to the variations observed between different time periods, including (1) cracking, (2) delamination, and (3) significant deformation. These results suggest that the coating material of the present invention is mixed very homogeneously, resulting in a uniform coating with minimal unevenness.

[0044] ·Conclusion The results of measurements taken at 7 days of age (initial painting stage), 28 days of age (when solidification stabilized), and in double measurements at both ages showed no significant differences in (1) cracking, (2) peeling, or (3) significant deformation. In conclusion, the coating material of the present invention solidifies extremely quickly, mixes very homogeneously, and provides a uniform coating with minimal unevenness.

[0045] 3. Antibacterial properties of paints An antibacterial activity test was conducted on the coating material of the present invention. The antibacterial activity test was performed using the JAS Z 2801 film adhesion method. The pathogen used was Escherichia coli NBRC 3972.

[0046] Characteristics of E. coli used in antibacterial activity tests Escherichia coli (E. coli) is a common and easily handled pathogen in our living environment. E. coli is a Gram-negative bacterium. Gram-negative bacteria tend to be susceptible to inorganic agents. Generally, in unprocessed products, E. coli tends to grow more easily in tests.

[0047] • Experimental method 1) Place 0.4 ml of E. coli solution onto a test specimen (5 cm x 5 cm) in a petri dish, cover with a film (4 cm x 4 cm), and close the petri dish lid. The test will be performed on unprocessed samples and painted material samples. 2) Incubate the petri dish at 35°C and above 90% RH for 24 hours. 3) After 24 hours, add 10 ml of SCDLP medium and wash the test bacteria from the polyethylene film and test piece. 4) Measure the number of bacteria in the wash solution using the agar plate culture method. 5) Calculate the antibacterial activity value according to the following formula. Antibacterial activity value = log "unprocessed sample 1 cm" 2 "Number of viable bacteria after culture" - log "Processed sample 1 cm" 2"Number of viable bacteria after culture" 6) Polyethylene film was used for the processed test specimens. This is because JIS certification specifies the use of polyethylene film as an unprocessed product. Figure 4 is a schematic diagram of the coating material sample used in the test. Using a coating material with the same formulation as for the impact resistance evaluation, a sample with the shape shown in Figure 4 was prepared and evaluated.

[0048] • Method for determining antibacterial activity (effectiveness) The method for determining antibacterial activity (effectiveness) is expressed as "common logarithm of the number of viable cells in the unprocessed product after culture" - "common logarithm of the number of viable cells in the processed product after culture". If there is a difference of 2.0 or more between the two values, it is recognized as a statistically significant difference according to JIS.

[0049] • Antibacterial activity against E. coli Tables 4 to 6 show the results of the antibacterial activity of E. coli.

[0050] [Table 4]

[0051] [Table 5]

[0052] [Table 6]

[0053] The common logarithmic value for the antibacterial effect of E. coli (using unprocessed test strips) was 4.14, and the common logarithmic value after 24 hours was 5.93. The value indicating proliferation is that of the unprocessed product. The antibacterial activity value of the coating material was 6.1, which was more than three times the effective activity value. Therefore, it was clear that the coating material has definite antibacterial activity against E. coli. Since E. coli originates from human and livestock feces, as well as the feces of birds, pet birds, dogs, and cats, it is one of the most common pathogens in human living environments. The high bactericidal effect of the present invention on E. coli was an extremely useful result. In conclusion, the results show that the coating material of the present invention has an extremely strong antibacterial effect against E. coli.

[0054] 4. Moisture absorption test The moisture absorption performance of the coating material of the present invention was investigated. A test specimen (100 mm square) made using a coating material with the same formulation as used for the impact resistance evaluation was brought to equilibrium in a constant temperature and humidity chamber at 25°C and 50%RH. Then, this test specimen was placed in a constant temperature and humidity chamber at 25°C and 90%RH, and the amount of moisture absorbed was measured over 24 hours. Next, it was placed in a constant temperature and humidity chamber at 25°C and 50%RH, and the amount of moisture released was measured. By observing the moisture absorption and release processes of the test specimen under different humidity conditions, both moisture absorption and moisture release properties were confirmed.

[0055] In summary, the coating material of the present invention and the coating applied thereto made the wall plaster more robust and provided impact resistance and high disinfection performance against pathogenic bacteria (E. coli).

[0056] Furthermore, the coating material of the present invention and the coating using it possessed both moisture absorption and moisture release properties. Therefore, wall plaster coated with the coating material of the present invention can be used as having a humidity control function. [Industrial applicability]

[0057] The coating material of the present invention can be used for coating structures such as earthen walls and is industrially useful.

Claims

1. A coating material containing roof tile chips and magnesia cement, In the aforementioned coating material, the amount of magnesia cement is 5 to 30 parts by mass per 100 parts by mass of the roof tile chips. The aforementioned roof tile chips are finely ground Tecora (registered trademark) and are roof tile chips with a particle size of 1 mm or less.

2. A structure having the coating material described in claim 1 applied to its surface.

3. A structure comprising an earthen wall coated with the coating material described in claim 1.

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