Water-repellent material, water-repellent paint, method for producing water-repellent concrete, method for preventing generation of mold, method for preventing rusting, and method for producing water-repellent material
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- 东新 一三
- Filing Date
- 2023-02-10
- Publication Date
- 2026-07-07
AI Technical Summary
Existing water repellent compositions using purified compounds are expensive, and there is a need for a cost-effective method to produce water-repellent materials using waste materials.
A method involving the mixing and baking of burned rice husks with silicone oil to create a water-repellent material, which is then incorporated into paints and concrete compositions.
The method produces a durable, cost-effective water-repellent material that effectively prevents water penetration and mold growth, and prevents rust on structures and metal surfaces.
Abstract
Description
[Technical field]
[0001] The present invention relates to a method for producing a water-repellent material, a method for producing a water-repellent paint, a method for producing water-repellent concrete, a mold prevention method, a rust prevention method, and a water-repellent material. [Background technology]
[0002] A liquid water repellent containing silicone oil is known, as described in Patent Document 1. The water repellent material in Patent Document 1 is said to be a liquid water repellent composition containing silicone oil and paraffin oil or low molecular weight hydrocarbon resin having a separation index for silicone oil of 0.4 or less. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Publication No. 115988 / 1988 Summary of the Invention [Problem to be solved by the invention]
[0004] In the case of a water repellent agent mainly composed of a purified compound as in Patent Document 1, the cost of producing the raw material of the water repellent composition is expensive, and the cost of the water repellent composition tends to be high. If waste materials are used as the raw material of the water repellent material, the cost required for producing the water repellent material can be reduced, but there is no such disclosure in Patent Document 1.
[0005] The present invention aims to provide a water-repellent material using rice husks, which are waste materials, a method for producing the water-repellent material, a method for producing a water-repellent paint containing the water-repellent material, a method for producing water-repellent concrete containing the water-repellent material, a mold prevention method using the water-repellent material, and a rust prevention method using the water-repellent material. [Means for solving the problem]
[0006] The above-mentioned problems are solved by a method for producing a water-repellent material, which includes a step of mixing burned rice husks with silicone oil, and a step of burning the mixture of rice husks and silicone oil to obtain a water-repellent burned product.
[0007] The above-mentioned problems are solved by a method for producing a water-repellent material, which includes a step of burning rice husks, a step of mixing the burned rice husks with silicone oil, and a step of burning the mixture of rice husks and silicone oil to obtain a water-repellent burned product.
[0008] The above-mentioned problems are solved by a method for producing a water-repellent paint, which includes a step of mixing the water-repellent material with the paint.
[0009] The above-mentioned problems are solved by a method for producing water-repellent concrete, which includes a step of mixing the water-repellent material with a concrete composition.
[0010] The above-mentioned problems are solved by an antifungal method in which the water-repellent coating material is applied to a structure to prevent the growth of mold on the structure.
[0011] The above problems are solved by a rust prevention method in which the water-repellent paint is applied to a metal material to prevent rusting.
[0012] The above problems are solved by a water-repellent material containing burned rice husks and silicone oil.
[0013] In the method for producing a water-repellent material, the temperature for firing the mixture may be 500 to 900° C. In the method for producing a water-repellent paint, the amount of the water-repellent material may be 0.5 to 6 mass % of the mass of the paint, based on the mass of the paint before the water-repellent material is mixed in. In the method for producing a water-repellent concrete, the amount of the water-repellent material may be 0.5 to 6 mass % of the mass of the cement, based on the mass of the cement mixed in the concrete composition. Effect of the Invention
[0014] According to the present invention, it is possible to provide a water-repellent material using rice husks, which are waste materials, a method for manufacturing the water-repellent material, a method for manufacturing a water-repellent paint containing the water-repellent material, a method for manufacturing water-repellent concrete containing the water-repellent material, a mold prevention method using the water-repellent material, and a rust prevention method using the water-repellent material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Preferred embodiments of the present invention will be described below. The embodiments described below are merely limited examples of the present invention, and the technical scope of the present invention is not limited to the exemplified embodiments.
[0016] The manufacturing method of the water-repellent material of this embodiment includes the steps of calcining rice husks, mixing the calcined rice husks with silicone oil, and calcining the mixture of rice husks and silicone oil to obtain a water-repellent calcined product.
[0017] Rice husks are the outer skin of unhulled rice grains. From the viewpoint of cost, the unhulled rice grains that are discharged as industrial waste when the outer skin is removed from rice can be suitably used. Rice is a silicic acid plant and actively absorbs silicic acid from the soil. The absorbed silicic acid is accumulated in high concentrations in the rice husks.
[0018] In the step of burning the rice husks, the rice husks are burned by an appropriate method. When burning the rice husks, it is preferable to heat the rice husks to a degree that the color of the rice husks changes to black under conditions where oxygen is supplied to cause complete combustion. The temperature when burning the rice husks is, for example, 500 to 900°C. By burning the rice husks, a black burned product containing a high content of silica (SiO2) is obtained. The content of silica contained in the black burned product is, for example, 90 to 98 mass%. In addition, by burning the rice husks, the rice husks become porous. Silica has excellent chemical resistance and heat resistance, and is not easily altered. For this reason, when mixed with silicone oil and burned, it becomes a water-repellent material with excellent durability, which is not easily affected by, for example, acid rain or chemicals. By supporting silicone oil on the burned product of rice husks mainly composed of silica, which has excellent durability, the silicone oil itself is not easily decomposed or altered, and the water-repellent effect is sustained for a long period of time.
[0019] In the step of mixing the burned rice husks with silicone oil, the burned rice husks and silicone oil are preferably mixed in a ratio of 4 to 200 parts by mass of silicone oil per 100 parts by mass of the burned rice husks. The amount of silicone oil is more preferably 4 to 50 parts by mass, and more preferably 4 to 15 parts by mass. In this step, the silicone oil is supported on the rice husks. When the burned rice husks, which are mainly composed of silica, are mixed with the silicone oil, they are compatible with each other and can be blended uniformly.
[0020] The silicone oil may be a commercially available product having a contact angle with a water droplet of 40 degrees or more according to the sessile drop method of JIS R3257:1999. The contact angle is more preferably 90° C. or more. The upper limit of the contact angle is not particularly limited, but may be, for example, 160° C. or less, or 150° C. or less. Examples of silicone oils include those containing a polymer having a siloxane bond in the main chain as an active ingredient.
[0021] In the step of obtaining a water-repellent burned product by burning the mixture of rice husks and silicone oil, the mixture of the burned rice husks and silicone oil is burned. When burning the rice husks, it is preferable to heat the rice husks to a degree that the color of the rice husks changes to white under conditions in which oxygen is supplied to cause complete combustion. The temperature when burning the rice husks is preferably, for example, 500 to 900°C.
[0022] The white fired product obtained by the above method has water repellency. For example, if it is mixed with a concrete composition, a water repellent concrete molded product can be obtained. Also, if it is mixed with a paint, a water repellent paint can be obtained.
[0023] The concrete molded product having the above-mentioned water repellency is water repellent in itself. Therefore, if the concrete molded product is used to construct a structure installed outdoors, such as an exterior wall, it is possible to effectively prevent mold from growing in the structure by preventing water from penetrating into the concrete molded product. In addition, if the concrete molded product has reinforcing bars, it is possible to effectively prevent corrosion of the reinforcing bars. Examples of the structure include exterior walls, stairs, flower beds, gateposts, slopes, inner walls of tunnels, and pedestals.
[0024] The composition of the concrete composition is not particularly limited, and may be any composition containing cement, aggregate, and water. A surfactant may be added to facilitate mixing of the water repellent with the composition. The amount of the water repellent added to the concrete composition is preferably 0.5 to 6 mass% of the mass of the cement based on the mass of the cement added to the cement composition. A surfactant may be added to the concrete composition.
[0025] If the above-mentioned water-repellent paint is applied to the surface of a structure installed outdoors, it is possible to effectively prevent mold from growing on the structure by preventing water from penetrating into the interior of the structure. Also, if the above-mentioned water-repellent paint is applied to the bottom of a ship, it is possible to effectively prevent barnacles, algae, and the like from attaching to the bottom of the ship.
[0026] The above-mentioned water-repellent paint can be applied to the surface of a metal material to prevent rusting of the metal material. Examples of metal materials include fences, playground equipment, and other items that are made of metal and prone to corrosion.
[0027] The paint is not particularly limited, and the above-mentioned water repellent material can be blended into both oil-based paint and water-based paint. The amount of the water repellent material blended into the paint is preferably 0.5 to 6 mass % of the mass of the paint based on the mass of the paint before blending the water repellent material. The paint is preferably one in which the synthetic resin component hardens as the solvent evaporates. The paint may contain a surfactant. EXAMPLES
[0028] The present invention will be described in more detail below with reference to examples. The examples shown below are merely limited examples, and the technical scope of the present invention should not be limited to the examples shown below.
[0029] [Example 1] The rice ears were threshed and dried, and the unhulled rice was hulled using a rice huller. 50 kg of rice husks were obtained by hulling. 50 kg of rice husks were burned in a rotary kiln at 700°C for 1 hour under oxygen supply conditions, and 1 kg of black burned material was obtained.
[0030] 1 kg of the above-mentioned baked product was mixed with 100 g of commercially available silicone oil (Shin-Etsu Chemical Co., Ltd. KF-99). The mixture was baked at 700°C for 1 hour using a rotary kiln to obtain a white baked water-repellent material. The water-repellent material was in the form of powder or granules.
[0031] The water-repellent material of Example 1 was placed in a container and a few milliliters of water was dropped onto it. It was confirmed that the water droplets dropped onto the powdered water-repellent material turned into beads, demonstrating a water-repellent effect.
[0032] [Example 2] 100 g of cement, 875 g of sand, and 25 g of water were mixed to obtain 1 kg of concrete composition. 25 g of the water repellent material obtained by the method of Example 1 and 6 g of a surfactant were added to the concrete composition and mixed.
[0033] The above mixture was poured into a formwork and cured for 30 days to obtain a concrete block according to Example 2.
[0034] [Comparative Example 1] A concrete block was manufactured in the same manner as in Example 2, except that in the above concrete composition, 25 g of the above-mentioned commercially available silicone oil was mixed in place of the water-repellent material obtained by the method of Example 1.
[0035] [Water immersion test] The concrete block was immersed in a sufficient amount of water and left to stand for one week. After one week had passed, the concrete block was pulled out, broken, and visually inspected to see if water had seeped into the interior of the concrete block.
[0036] It was confirmed that in the concrete block manufactured by the method of Example 2, water did not seep into the inside of the concrete block.
[0037] In the concrete block according to Comparative Example 1 prepared for comparison, water was slightly seeped into the concrete after immersing it in water for one week. It was confirmed that the longer the concrete block was immersed in water, the greater the degree of water penetration. From this, it was confirmed that when silicone oil was added, the water repellency tends not to last for a long time.
[0038] [Mold growth] The concrete block according to the above-mentioned Example 2 was left in the shade outdoors and visually inspected for the occurrence of mold growth. Due to the strong water repellency of the concrete block according to Example 2, water did not penetrate the concrete block, and no mold growth occurred.
[0039] In the concrete block according to Comparative Example 1 prepared for comparison, it was confirmed that a small amount of water penetrated into the inside of the concrete block, and a small amount of mold was generated. It was confirmed that the longer the concrete block was left outdoors, the more the degree of mold growth tended to increase. From this, it was confirmed that when silicone oil was blended, the mold prevention performance tended not to be sustained for a long time.
[0040] [Example 3] 150 g of the water repellent material obtained by the method of Example 1 was added to 4 liters of a commercially available oil-based paint and thoroughly stirred to obtain a paint.
[0041] [Comparative Example 2] A coating material was obtained in the same manner as in Example 3, except that 150 g of silicone oil similar to that described above was used instead of the water repellent material.
[0042] [Mold growth] The paint according to Example 3 was applied to a commercially available concrete block using a brush. The concrete block was left in the shade outdoors and visually inspected for mold growth. In the concrete block to which the paint according to Example 3 was applied, water did not penetrate the concrete block due to the strong water repellency, and no mold was generated.
[0043] In the concrete block coated with the paint according to Comparative Example 2 prepared for comparison, it was confirmed that a small amount of water penetrated into the inside of the concrete block, and a small amount of mold was generated. It was confirmed that the longer the concrete block was left outdoors, the more the degree of mold growth tended to increase. From this, it was confirmed that when silicone oil was added, the mold prevention performance tended not to be sustained for a long time.
Claims
1. The process involves mixing the burnt rice husks with silicone oil, A method for producing a water-repellent material, comprising the step of firing a mixture of rice husks and silicone oil to obtain a water-repellent fired product.
2. The process of burning rice husks, The process involves mixing the burnt rice husks with silicone oil, A method for producing a water-repellent material, comprising the step of firing a mixture of rice husks and silicone oil to obtain a water-repellent fired product.
3. The method for producing a water-repellent material according to claim 1 or 2, wherein the temperature at which the mixture is fired is 500 to 900°C.
4. A method for producing a water-repellent coating, comprising the step of mixing the water-repellent material described in claim 1 or 2 with a coating.
5. The method for producing a water-repellent paint according to claim 4, wherein the amount of the water-repellent material is 0.5 to 6% by mass of the paint, based on the mass of the paint before the water-repellent material is added.
6. A method for producing water-repellent concrete, comprising the step of mixing the water-repellent material described in claim 1 or 2 with a concrete composition.
7. The method for producing water-repellent concrete according to claim 6, wherein the amount of the water-repellent material is 0.5 to 6% by mass of the concrete composition, based on the mass of the concrete composition before the addition of the water-repellent material.
8. A method for preventing mold growth on a structure by applying the water-repellent paint of claim 4 to the structure.
9. A rust prevention method comprising applying the water-repellent paint of claim 4 to a metal material to prevent rust formation.
10. A water-repellent material containing calcined rice husks and silicone oil.