Thermochromic salt-based construction material

Abstract

The application discloses a temperature-sensing color-changing salt-based building material, which is characterized by comprising the following components: sea salt, PVA, light calcium, talcum powder, inorganic temperature-sensing color-changing powder or organic temperature-sensing color-changing powder. The temperature-sensing color-changing salt-based building material is characterized by comprising a salt-based building material made of temperature-sensing color-changing powder. The temperature-sensing color-changing salt-based building material has the advantages of simple preparation process, low cost, convenient construction, good cold and hot hardness, good wear resistance and weather resistance, and the function of reducing building energy consumption in winter and summer. The material can overcome the shortcomings of poor weather resistance and short service life of the temperature-sensing color-changing salt-based building material, and has the functions of environmental protection and sustainable temperature-sensing color-changing energy saving and consumption reduction.

Description

A thermochromic salt-based building material Technical Field

[0001] This invention relates to the field of novel sensing building materials, and in particular to a temperature-sensitive color-changing salt-based building material. Background Technology

[0002] Thermochromic salt-based building materials are special salt-based building materials that use color changes to indicate the surface temperature and distribution of a building. Under certain conditions, when a specific temperature is reached, a certain color change will occur, thus visually representing the temperature of the building environment. Thermochromic ceramic coatings are now widely used for surface coating of products such as kitchen utensils. CN101538427A discloses a thermochromic material, which includes a film-forming base, a thermochromic pigment, and a color-changing additive. The film-forming base is acrylic, epoxy, or polyester resin. The thermochromic material is applied to the outer wall of an electric kettle, and the kettle displays different colors according to different temperatures during heating. CN101487601A discloses a thermochromic microwave oven door panel. The inner side of the door panel is coated with a thermochromic ink screen print. When the temperature of the door panel rises, a pattern will appear on the door panel to remind the user.

[0003] Thermochromic salt-based building materials exhibit a light color at high temperatures, maximizing sunlight reflection and reducing the building's absorption of solar radiation during hot summer weather, thus effectively lowering the building's interior temperature. At low temperatures, they exhibit a dark color, maximizing sunlight absorption and increasing the building's absorption of solar radiation during cold winter weather, thus effectively raising the building's interior temperature. These materials can regulate building temperature while reducing the building's cooling (heating) load, achieving intelligent interaction between the building and its environment. Currently, thermochromic ceramic coatings are beginning to be used in kitchenware, experiencing rapid development due to their safety advantages. Ceramic coatings are a new type of water-based inorganic coating, with nano-inorganic compounds as the main component and water as the dispersion medium. After application, they are typically cured by low-temperature heating to form a film with properties similar to ceramics; they possess numerous advantages such as high temperature resistance, high hardness, weather resistance, environmental friendliness, rich colors, and easy application. CN102370432A and CN102407638A both disclose an apparatus in which a base surface is covered with a sol-gel coating, a functional coating comprising a thermochromic pigment is coated on the sol-gel coating, and a transparent finishing layer is coated on the functional coating; the thermochromic pigment comprises a core containing a semiconductor thermochromic pigment and a robust, transparent and continuous encapsulation; the thermochromic pigment exhibits a reversible color change within a thermal color change region with an amplitude not exceeding 40 degrees Celsius.

[0004] However, the thermochromic powder used in thermochromic salt-based building materials has poor weather resistance and is prone to fading and powdering, resulting in a short service life for thermochromic salt-based building materials and limiting their widespread application in exterior walls.

[0005] Simultaneously addressing building energy conservation in both summer and winter has broad application prospects for improving the comfort of the living environment and reducing building energy consumption. Traditional high-reflectivity building materials only focus on reducing cooling load in summer; however, these materials can increase building heating load in cold winters, which is detrimental to building energy conservation in hot-summer and cold-winter regions. Therefore, accelerating the research and development of a new type of green building material with superior comprehensive performance is imperative. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a thermochromic salt-based building material that can improve the service temperature of organic thermochromic powders.

[0007] Another objective of this invention is to provide a temperature-sensitive color-changing wall coating. This coating has a simple preparation process, does not require multiple layers, and has good cold and hot hardness, wear resistance, and temperature-sensitive color-changing function.

[0008] According to the technical solution provided by the present invention, the thermochromic salt-based building material is characterized by comprising the following components, in parts by weight: 100 parts sea salt, 0.5 parts PVA, 5-45 parts filler, 50-100 parts organosilane, 0.3-1 part catalyst, 30-40 parts heat-resistant color powder, 15-45 parts inorganic thermochromic powder or 5-35 parts organic thermochromic powder; the preparation method is as follows: first, 100 parts by weight of sea salt, the prescribed amount of inorganic or organic thermochromic powder, the prescribed amount of heat-resistant color powder, and the prescribed amount of filler are mixed together as mixture A; then, the prescribed amount of PVA, the prescribed amount of organosilane, and the prescribed amount of catalyst are mixed evenly as mixture B; then, mixture B is added to the dispersed mixture A, allowed to stand for 2.5 hours, and finally filtered through a 100-150 mesh filter to obtain the thermochromic salt-based building material.

[0009] In one specific embodiment, the organosilane is selected from one or more combinations of methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and phenyltrimethoxysilane.

[0010] In one specific embodiment, it further includes 5 to 10 parts of other organosilanes, wherein the other organosilanes are tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, or combinations thereof, in parts by weight.

[0011] In one specific embodiment, the catalyst is formic acid, acetic acid, hydrochloric acid, citric acid, methyl formate, ethyl acetoacetate, maleic anhydride, or a combination thereof.

[0012] In one specific embodiment, the heat-resistant pigment is an inorganic pigment of various colors.

[0013] In one specific embodiment, it further includes 30 to 50 parts of filler, in parts by weight; the filler is talc, light calcium carbonate, plant fiber, kaolin, mica powder or a combination thereof.

[0014] In one specific embodiment, the inorganic thermochromic powder is selected from Bi2O3, BiVO4, WO3, CeO2, In2O3 or Fe2O3; the organic thermochromic powder is selected from fluorane, spirocyclic pyran, bisanthrone, Schiff base or triphenylmethane thermochromic powder.

[0015] The thermochromic wall of the present invention is characterized in that it comprises a wall made of thermochromic salt-based building materials and a transparent topcoat applied to the surface of the wall.

[0016] The application of the thermochromic salt-based building material described above is characterized by including walls made of salt-based building material using the above-mentioned thermochromic salt-based building material, or transparent topcoat applied to the surface of the walls.

[0017] The thermochromic salt-based building material provided by this invention has a simple preparation process, low cost, and convenient construction; the resulting thermochromic wall has good cold and hot hardness and wear resistance, and can change color according to temperature changes; at the same time, it can improve the service temperature of organic thermochromic powders, and can be used normally within 30 minutes at 50℃. Attached Figure Description

[0018] Figure 1 is a diagram showing the effect of testing the hardness of the wall material after drying in Embodiment 4 of the present invention.

[0019] Figure 2 is a diagram showing the effect of testing the hardness of the wall material after drying in Embodiment 5 of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments.

[0021] The sea salt described in this invention primarily serves to increase the strength and hardness of the building wall network. The sea salt can be processed using a crusher and filter plugs. If the mesh size of the sea salt is too low, the resulting building wall will have poor support, excessive fluidity, and poor workability due to the large amount of sea salt dissolved in water. If the mesh size of the sea salt is too high, the adhesion of the salt-based building materials will be weak, and the wall surface will be rough. In the embodiments of this invention, the mesh size of the sea salt is 70-80 mesh.

[0022] The organosilane described in this invention is methyltrimethoxysilane or methyltriethoxysilane, with methyltrimethoxysilane being preferred. In addition to the aforementioned organosilane, 5 to 10 parts by weight of other organosilanes such as tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, or combinations thereof may be added to adjust the hardness or softness of the wall material. The organosilane can form an adhesive with PVA. If the amount of organosilane used is too high, during the baking process, dehydration or excessive methanol or ethanol will cause significant shrinkage of the wall material, making it prone to cracking. If the amount of organosilane used is too low, poor adhesion to the substrate will result in easy detachment.

[0023] The catalyst described in this invention is formic acid, acetic acid, hydrochloric acid, citric acid, methyl formate, ethyl acetoacetate, maleic anhydride, or a combination thereof. The catalyst accelerates the hydrolysis rate of organosilanes and the reaction rate between the hydrolysate of organosilanes and PVA. If the amount of catalyst is too high, the pH value of the reaction between organosilanes and PVA will be below 4.0. If the amount of catalyst is too low, the pH value of the reaction between organosilanes and PVA will be above 6.5. Both excessively high and insufficient amounts of catalyst will result in poor adhesion between the building wall and the substrate, and may even lead to pulverization of the wall.

[0024] The inorganic and organic thermochromic powders described in this invention are commercially available thermochromic powders, both of which are reversible thermochromic substances with an average diameter of 1–10 μm.

[0025] Inorganic thermochromic powders are generally Bi2O3, BiVO4, WO3, CeO2, In2O3 or Fe2O3.

[0026] Organic thermochromic powders are generally thermochromic powders of the following types: fluorane, spirocyclic pyran, bisanthrone, Schiff base, or triphenylmethane.

[0027] In this invention, inorganic or organic thermochromic powders can be further encapsulated within a protective layer to form microencapsulated thermochromic powders. The protective layer is a transparent outer shell, approximately 0.2–0.5 μm thick, that is neither soluble nor meltable, protecting the internal thermochromic powders from corrosion by other chemical substances. In the embodiments of this invention, the microencapsulated inorganic or organic thermochromic powders are commercially available products. For example, inorganic thermochromic powders can be encapsulated with materials such as SiO2; organic thermochromic powders can be encapsulated with materials such as acrylic resin, ABS resin, acetal resin, polyamide, vinyl chloride resin, polycarbonate, polyphenylene ether, polybutylene terephthalate, polyimide, polyethylene, polypropylene, and polystyrene.

[0028] In this invention, 30 to 40 parts by weight of heat-resistant color powder can be further added to the basic building materials. Mixing the heat-resistant color powder with thermochromic powder can yield a wider variety of color combinations. The heat-resistant color powder can be various colors of inorganic color powder, such as white powder like titanium dioxide or zinc sulfide; black powder like cobalt copper manganese oxide, copper manganese oxide, copper manganese iron oxide, or iron oxide; yellow powder like titanium yellow; green powder like cobalt green or chromium oxide green; blue powder like cobalt chromium aluminum oxide, etc. The color powder can be used alone or in mixtures.

[0029] In this invention, 30 to 50 parts by weight of filler can be further added to the salt-based building material. The filler can be talc, light calcium carbonate, plant fiber, kaolin, mica powder, or a combination thereof. The filler is preferably talc, light calcium carbonate, plant fiber, or a combination thereof. The filler increases the scratch resistance of the salt-based building material. If the filler content is too high, the wall will have low gloss, poor appearance, and poor adhesion to the substrate. Due to insufficient adhesion, the wall surface is prone to cracking and peeling. If the filler content is too low, it will affect wear resistance and scratch resistance. This invention preferably uses a suitable filler addition ratio to ensure good adhesion to the substrate while maintaining hardness, wear resistance, and scratch resistance. The filler particle size used in this invention is between 0.05 μm and 30 μm. If the filler particle size is too large, it will cause a rough wall surface, resulting in low gloss after spraying the salt-based building material, affecting appearance and non-stick properties. If the particle size of the filler is too small, the filler will absorb a large amount of oil, resulting in high viscosity of the base building material and affecting the spraying operability.

[0030] Preparation method of thermochromic salt-based building materials:

[0031] This invention provides a method for manufacturing a thermochromic salt-based building material. First, sea salt and inorganic or organic thermochromic powder and filler are mixed together as mixture A. Then, PVA, organosilane and catalyst are mixed evenly as mixture B. Then, mixture B is added to the dispersed mixture A. Finally, the mixture is filtered through a 100-150 mesh filter to obtain the salt-based building material of this invention.

[0032] When further heat-resistant color powder and filler are added to the salt-based building material, sea salt, thermochromic powder, heat-resistant color powder and filler can be mixed together as mixture A; then PVA, organosilane and catalyst can be mixed evenly as mixture B; then mixture B can be added to the dispersed mixture A, and finally filtered with a 100-150 mesh filter to obtain the salt-based building material of the present invention.

[0033] Preparation method of thermochromic coating:

[0034] This invention also provides a thermochromic wall, comprising a wall made of the aforementioned salt-based building material, wherein a coating, also a salt-based building material, may be applied to the surface of the wall. The preparation method of the thermochromic wall is as follows: first, the surface of the substrate is sandblasted, roughened, and degreased; then, the salt-based building material is sprayed onto the surface of the substrate, followed by baking at 30°C for 2 minutes, then baking at 50°C for 10-15 minutes, and finally cooling at room temperature.

[0035] The aforementioned thermochromic coating can be applied to the walls of residential buildings, medical spaces, and other similar applications.

[0036] The names and sources of the drugs used in this invention are listed below, but are not limited to the listed drugs:

[0037] (1) Inorganic thermochromic powders: Bi2O3 (pale yellow at room temperature), BiVO4 (yellow at room temperature).

[0038] (2) Organic thermochromic powder: Thermochromic powder (microencapsulated, fluorane) sold by Shenzhen Biochrom Technology Co., Ltd.

[0039] The weight percentages described in the following examples can be in grams or kilograms.

[0040] Example 1:

[0041] First, 100 parts by weight of sea salt (from Fujian Quanzhou Port Yaoyao Co., Ltd.), 15 parts by weight of thermochromic powder Bi2O3, 30 parts by weight of titanium dioxide, and 5 parts by weight of talc are mixed together as mixture A. Then, 0.5 parts by weight of PVA and 0.6 parts by weight of acetic acid are mixed evenly as mixture B. Then, mixture B is added to the dispersed mixture A, and the mixture is allowed to stand for 2 hours. Finally, it is filtered through a 100-150 mesh filter to obtain the thermochromic salt-based building material of the present invention.

[0042] Example 2:

[0043] First, 100 parts by weight of sea salt (from Fujian Quanzhou Port Yaoyao Co., Ltd.), 15 parts by weight of thermochromic powder BiVO4, 30 parts by weight of titanium dioxide, and 5 parts by weight of talc are mixed together as mixture A. Then, 0.5 parts by weight of PVA, 50 parts by weight of methyltrimethoxysilane, and 0.3 parts by weight of formic acid are mixed evenly as mixture B. Then, mixture B is added to the dispersed mixture A, and the mixture is allowed to stand for 1.5 hours. Finally, it is filtered through a 100-15 mesh filter to obtain the thermochromic salt-based building material of the present invention.

[0044] Example 3:

[0045] First, 100 parts by weight of sea salt (from Fujian Quanzhou Port Yaoyao Co., Ltd.), 5 parts by weight of thermochromic powder (microencapsulated, fluorane), 30 parts by weight of titanium dioxide, and 5 parts by weight of light calcium carbonate are mixed together as mixture A. Then, 0.5 parts by weight of PVA, 50 parts by weight of methyltriethoxysilane, and 1 part by weight of formic acid are mixed evenly as mixture B. Then, mixture B is added to the dispersed mixture A, and the mixture is allowed to stand for 1 hour. Finally, it is filtered through a 100-150 mesh filter to obtain the thermochromic salt-based building material of the present invention.

[0046] Example 4:

[0047] First, 100 parts by weight of sea salt (Fujian Quanzhou Port Yaoyao Co., Ltd.), 10 parts by weight of thermochromic powder (microencapsulated, fluorane, Jinhua Lijin Technology Co., Ltd.), 40 parts by weight of titanium dioxide, and 5 parts by weight of light calcium carbonate are mixed together as mixture A. Then, 0.5 parts by weight of PVA, 70 parts by weight of methyltrimethoxysilane, 10 parts by weight of phenyltrimethoxysilane, and 0.8 parts by weight of acetic acid are mixed evenly as mixture B. Then, mixture B is added to the dispersed mixture A, and the mixture is allowed to stand for 2.5 hours. Finally, it is filtered through a 100-150 mesh filter to obtain the thermochromic salt-based building material of the present invention.

[0048] Example 5:

[0049] First, 100 parts by weight of sea salt (Fujian Quanzhou Port Yaoyao Co., Ltd.), 35 parts by weight of thermochromic powder (microencapsulated, fluorane, Jinhua Lijin Technology Co., Ltd.), and 5 parts by weight of talc are mixed together as mixture A. Then, 0.5 parts by weight of PVA, 100 parts by weight of methyltrimethoxysilane, and 0.7 parts by weight of acetic acid are mixed evenly as mixture B. Then, mixture B is added to the dispersed mixture A, and the mixture is allowed to stand for 3 hours. Finally, it is filtered through a 100-150 mesh filter to obtain the thermochromic salt-based building material of the present invention.

[0050] The thermochromic salt-based building material obtained in any of Examples 1 to 5 is sprayed onto the surface of a substrate, then baked at 30°C for 1 minute, then baked at 50°C for 10 to 15 minutes, and finally cooled at room temperature to obtain a coating.

[0051] Comparative Example 1:

[0052] First, 100 parts by weight of sea salt (from Fujian Quanzhou Port Yaoyao Co., Ltd.), 15 parts by weight of thermochromic powder Bi2O3, 30 parts by weight of titanium dioxide, and 5 parts by weight of talc are mixed together as mixture A. Then, 0.5 parts by weight of PVA and 0.6 parts by weight of acetic acid are mixed evenly as mixture B. Then, mixture B is added to the dispersed mixture A, and the mixture is allowed to stand for 2 hours. Finally, it is filtered through a 100-150 mesh filter to obtain the thermochromic salt-based building material of the present invention.

[0053] The substrate surface was sandblasted, roughened, and degreased; then the basic building material prepared in Comparative Example 1 was sprayed onto the substrate surface, baked at 30°C for 2 minutes, then baked at 50°C for 10-15 minutes, and finally cooled at room temperature to obtain the coating.

[0054] Table 1 is a comparison table of the performance of coatings prepared by the coatings described in Examples 1-5 and Comparative Example 1.

[0055]

[0056] Figures 1 and 2 show the hardness tests of the wall materials after drying in Examples 4 and 5, respectively. It can be seen that the wall materials have high hardness and high viscosity, and remain in block form after being broken.

[0057] As can be seen from Table 1 and Figures 1 and 2, the coatings of Examples 1 to 5 of the present invention have good cold and hot hardness, adhesion and wear resistance, and have a thermochromic function. Compared with the coating material of Comparative Example 1, the coating material obtained by the present invention can improve the service temperature of organic thermochromic powders and can be used normally within 30 minutes at 50°C.

[0058] The measurement methods for each performance component are as follows:

[0059] (1) Coating hardness test: Tested according to the method described in standard ASTM D 3363.

[0060] (2) Viscosity test:

[0061] Attach the product to the substrate, keeping the product's weight and contact area with the substrate constant. Slowly change the tilt angle of the substrate relative to the horizontal plane and observe the displacement of the product at each tilt angle. A good tilt angle is 60°–80°, and a better angle is 80°–90°.

[0062] (3) Abrasion resistance test:

[0063] The product was placed on a DuPont abrasion tester, and a pressure of 4.9 kg was applied. A small amount of detergent and water were added, and a 3M-7447# scouring pad was used. The scouring pad was replaced every 250 cycles. The test was terminated when 10 strips of the substrate showed white residue, and the total number of cycles was calculated.

[0064] (4) Heat resistance test:

[0065] Place the sample in an oven at 50°C and bake for 30 minutes. Remove and cool the sample. Observe whether the coating material of the sample can recover its original color. OK indicates that it can be recovered, and F indicates that it cannot be recovered.

[0066] Although the present invention has been disclosed above with reference to several preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make any modifications and refinements without departing from the spirit and scope of the present invention.

Claims

1. A thermochromic salt-based building material, characterized in that, The product comprises the following components, in parts by weight: 100 parts sea salt, 0.5 parts PVA, 5-45 parts filler, 50-100 parts organosilane, 0.3-1 part catalyst, 30-40 parts heat-resistant color powder, and 15-45 parts inorganic thermochromic powder or 5-35 parts organic thermochromic powder. The preparation method is as follows: First, mix 100 parts by weight of sea salt, the specified amount of inorganic or organic thermochromic powder, the specified amount of heat-resistant color powder, and the specified amount of filler together as mixture A. Then, mix the specified amounts of PVA, organosilane, and catalyst evenly to form mixture B. Finally, add mixture B to the pre-dispersed mixture A. The mixture is left to stand for 2.5 hours, and then filtered through a 100-150 mesh filter to obtain the thermochromic salt-based building material. The organosilane is selected from one or more combinations of methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and phenyltrimethoxysilane. The catalyst is selected from one or more combinations of formic acid, acetic acid, hydrochloric acid, citric acid, and maleic anhydride.

2. The thermochromic salt-based building material as described in claim 1, characterized in that: The heat-resistant pigment is an inorganic pigment.

3. The thermochromic salt-based building material as described in claim 1, characterized in that... The filler is selected from one or more of the following: talc, light calcium carbonate, plant fiber, kaolin, and mica powder.

4. The thermochromic salt-based building material as described in claim 1, characterized in that... Inorganic thermochromic powders are selected from Bi2O3, BiVO4, WO3, CeO2, In2O3 or Fe2O3; organic thermochromic powders are selected from fluorane, spirocyclic pyran, bisanthrone, Schiff base or triphenylmethane thermochromic powders.

5. The application of a thermochromic salt-based building material according to any one of claims 1-4, characterized in that, This includes walls made of salt-based building materials using any one of the thermochromic salt-based building materials described in claims 1-4, or transparent topcoats applied to the surface of walls.

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