Composite material capable of continuously releasing negative ions and removing formaldehyde and peculiar smell and having high far infrared emissivity and preparation method thereof

Abstract

The invention relates to a multifunctional environment purification composite material, in particular to a composite material which does not depend on rare earth oxide, can continuously release negative ions and efficiently remove formaldehyde and peculiar smell and has high far infrared emissivity and a preparation method of the composite material. The composite material comprises the following raw materials in percentage by mass: 25-50% of silicon carbide; 20 to 45% of titanium dioxide; 10-25% of zinc oxide; 10-25% of a composite negative ion accelerator; wherein the composite negative ion accelerant is formed by compounding germanium-containing mineral powder or rare earth mineral powder and alkaline earth metal carbonate according to the mass ratio of (0.5-2): 1. Through the synergistic effect of all the components, stable negative ion release (larger than or equal to 5000 ions / cm), high far infrared emissivity (larger than or equal to 0.90) and efficient formaldehyde degradation (the 24-hour removal rate is larger than or equal to 90%) can be achieved at normal temperature and normal pressure. The product has the advantages of easily available raw materials, low cost and simple process, is suitable for various substrates such as coatings, ceramics, plastics, textiles and the like, and has wide application prospects.

Description

Technical Field

[0001] This invention relates to the field of environmental functional materials technology, specifically to a composite material that sustainably releases negative ions, removes formaldehyde and odors, and has high far-infrared emissivity, and its preparation method. Background Technology

[0002] With increasing public awareness of indoor air quality and health, the demand for materials with environmental purification functions is growing. Currently, common photocatalytic materials (such as nano-TiO2) require ultraviolet light to effectively degrade pollutants, and their efficiency decreases significantly in the absence of light or in low-light environments. Furthermore, some materials with negative ion release functions rely on rare earth oxides (such as cerium oxide) as an excitation source, but rare earth resources are scarce, expensive, and their supply chain is uncertain.

[0003] Far-infrared materials, such as silicon carbide and boron nitride, are widely used in health care and physiotherapy due to their excellent thermal radiation properties. However, the functions of a single far-infrared material are limited and cannot meet the diverse needs of environmental purification. In existing technologies, although there have been attempts to combine negative ion release with far-infrared functions, these often suffer from problems such as unstable negative ion release, poor environmental adaptability, limited functionality, or excessively high costs.

[0004] Therefore, developing a low-cost composite material that can efficiently and continuously release negative ions, effectively remove formaldehyde and odors, and has high far-infrared emissivity under conditions of no rare earth dependence, low light or room temperature has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a composite material and its preparation method that is free of rare earth oxides, low in cost, highly adaptable to the environment, and functionally integrated.

[0006] A composite material that sustainably releases negative ions, removes formaldehyde and odors, and possesses high far-infrared emissivity comprises the following raw materials in the indicated mass percentages: silicon carbide 20-40%, boron nitride 10-30%, titanium dioxide 15-30%, zinc oxide 10-25%, and a composite negative ion promoter 10-25%. The composite negative ion promoter is prepared by compounding germanium-containing mineral powder or rare earth mineral powder with alkaline earth metal carbonates at a mass ratio of (0.5-2):1, preferably comprising 30% silicon carbide, 20% boron nitride, 20% titanium dioxide, 15% zinc oxide, and 15% composite negative ion promoter. The composite negative ion promoter is premixed from natural germanium stone powder (or purified rare earth tailings composite powder) and calcium carbonate at a mass ratio of 1:1.

[0007] Furthermore, the silicon carbide has a purity of ≥98% and a particle size D50 of 1-10 μm; the boron nitride has a purity of ≥98% and a particle size D50 of 1-10 μm.

[0008] Furthermore, the titanium dioxide is anatase type, with a purity ≥99% and a particle size D50 of 0.1-1μm; the zinc oxide has a purity ≥99% and a particle size D50 of 0.1-1μm.

[0009] Furthermore, the overall particle size D50 of the composite negative ion promoter is ≤5μm, and its radionuclide limit meets the requirements for Class A materials in GB 6566-2010 "Limits of Radionuclides in Building Materials".

[0010] A method for preparing a composite material as described in any of the above claims, comprising the following steps: S1, Raw material preparation: Weigh each raw material according to the ratio, and premix natural germanium stone powder or purified rare earth tailings composite powder with calcium carbonate at a mass ratio of 1:1 to obtain composite negative ion promoter. S2, Premixing: Add silicon carbide, boron nitride, titanium dioxide, zinc oxide and the composite negative ion promoter obtained in step S1 into a mixer and mix at low speed for 20-30 minutes. S3, Grinding: Transfer the premixed material into a ball mill, use zirconia balls as the grinding medium, the ball-to-material ratio is 2:1, grind at 50 rpm, preferably for 2 hours; S4, Sieving: The ground material is sieved through a 200-mesh sieve to obtain the composite material.

[0011] Furthermore, the mixing in step S2 is carried out using a V-type mixer, with the mixing speed controlled at 20-30 rpm.

[0012] Furthermore, the grinding medium in step S3 is zirconia balls, and the material temperature is controlled to be ≤40℃ during the grinding process through cooling measures.

[0013] The use of a composite material as described in any of the above in the preparation of environmental purification or health care functional articles, said articles including one or more of coatings, paints, inks, ceramics, plastics, leather, wallpaper or textiles.

[0014] Furthermore, when the product is a coating, paint, or ink, the amount of the composite material added is 1-5% of the total mass of the substrate, preferably 1-3%.

[0015] Furthermore, during use, the composite material and the substrate are mechanically mixed at 500-1000 rpm for 10-20 minutes.

[0016] The technical principle of the composite material described in this invention is as follows: High-efficiency far-infrared radiation: The composite far-infrared radiation matrix is ​​composed of silicon carbide and boron nitride. The two work together to provide a high and stable far-infrared emissivity (≥0.90).

[0017] Catalytic Degradation and Electronic Effects: As n-type semiconductors, anatase titanium dioxide and zinc oxide exhibit surface oxygen vacancies and defects that can activate oxygen and water molecules in the air under weak light or at room temperature, catalyzing the oxidation of volatile organic compounds such as formaldehyde and decomposing them into carbon dioxide and water. The two semiconductors synergistically enhance the surface's catalytic activity and electron-donating capacity.

[0018] Continuous and stable release of negative ions: The key lies in the composite negative ion promoter. Natural germanium stone powder or specially treated rare earth tailings powder contains trace amounts of radioactive elements, which can continuously release weak rays (alpha and gamma rays), ionizing air molecules. Calcium carbonate generates static electricity when the material is subjected to thermal stress or friction. These two mechanisms (radioactive ionization and triboelectric charging) work synergistically to ensure the continuous and stable release of negative ions under simple conditions. Porous mineral components (such as zeolite, if present in the tailings composite powder) can also physically adsorb odor molecules.

[0019] Rare earth-free and low cost: By using natural minerals and inexpensive alkaline earth metal salts, the dependence on expensive rare earth elements is completely eliminated, and the cost is significantly reduced while ensuring performance.

[0020] The present invention has the following beneficial effects: Rare earth-free: Completely eliminates dependence on rare earth resources, resulting in a more stable raw material supply chain and significantly reduced costs.

[0021] High performance and multi-functional integration: Under room temperature and low light conditions, the negative ion release is stable at over 5000 ions / cm³, the far-infrared emissivity is ≥0.90, the formaldehyde removal rate is ≥90% in 24 hours, and it also has the function of physical adsorption to remove odors.

[0022] Highly adaptable to the environment: It does not rely entirely on a light source and can maintain high efficiency under a wider range of environmental conditions.

[0023] The process is simple and easy to promote: the preparation process is simple, the equipment requirements are low, and it is suitable for large-scale production.

[0024] Safe and environmentally friendly: The product is non-toxic, and the limits of radioactive nuclides meet the national Class A decoration and renovation material standards, making it safe to use. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and experimental data. It must be noted that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0026] Example 1 Raw material preparation: Weigh the following raw materials by mass percentage: silicon carbide (D50=5μm, 30%), boron nitride (D50=5μm, 20%), anatase titanium dioxide (D50=0.5μm, 20%), and zinc oxide (D50=0.5μm, 15%). Separately weigh natural germanium powder (D50≤5μm) and calcium carbonate (D50≤5μm), and pre-mix them to prepare a composite negative ion promoter (15%).

[0027] Preparation process: S1. Natural germanium stone powder and calcium carbonate are premixed in a small mixer for 10 minutes to prepare a composite negative ion promoter. S2, put all the main ingredients and the premixed composite negative ion promoter into the V-type mixer and mix at 25 rpm for 20 minutes; S3. Transfer the uniformly mixed material into a ball mill, add zirconia balls (ball-to-material ratio 2:1), and grind at 50 rpm for 2 hours, during which the temperature is controlled to be below 40°C by water cooling. S4. After grinding, the material is screened through a 200-mesh vibrating screen, the undersize material is collected, and it is sealed and packaged to obtain the composite material of the present invention.

[0028] Example 2 The method is basically the same as in Example 1, except that the natural germanium stone powder in the composite negative ion promoter is replaced with rare earth tailings composite powder that has been purified and whose radioactivity meets the Class A standard of GB 6566-2010.

[0029] Performance testing Performance tests were performed on the product obtained in Example 1: Negative ion release: According to JG / T 294-2010 standard, the release was tested in a closed chamber and remained stable at 5200 ions / cm³.

[0030] Far-infrared emissivity: According to GB / T 7287-2008 standard, the emissivity was 0.92 when tested at 50℃.

[0031] Formaldehyde removal rate: According to GB / T 18883-2002 standard, the initial formaldehyde concentration in a 1m³ sealed chamber was 1.0±0.1mg / m³, and the sample addition amount was one-third of the bottom area of ​​the test chamber. After 24 hours, the formaldehyde removal rate was 92%.

[0032] Radioactivity: Tested according to GB 6566-2010 standard, internal exposure index IRa=0.6, external exposure index Iγ=0.9, which meets the requirements of Class A materials.

[0033] Safety: Tested according to GB 18582-2020 standard, no excessive heavy metals were detected.

[0034] Application Examples This composite material was added to water-based interior wall latex paint at a ratio of 2% of the total paint mass. After high-speed dispersion (800 rpm, 15 minutes) until uniform, it was applied as a sample using conventional methods. Tests showed that the coated sample had the functions of continuously releasing negative ions, effectively removing formaldehyde, and emitting significant far-infrared radiation.

[0035] Comparative Example 1 The difference between this comparative example and Example 1 is that the composite negative ion promoter does not contain calcium carbonate. Its raw materials consist of the following mass percentages: silicon carbide 30%, boron nitride 20%, titanium dioxide 20%, zinc oxide 15%, and natural germanium powder 15%. That is, the negative ion promoter is composed of only a single mineral powder and does not involve the compounding of alkaline earth metal salts. The preparation process is exactly the same as in Example 1.

[0036] Comparative Example 2 The difference between this comparative example and Example 1 is that silicon carbide and boron nitride in the raw materials are replaced with an equal mass of single alumina ceramic powder. The raw materials consist of the following mass percentages: alumina 50%, titanium dioxide 20%, zinc oxide 15%, and composite negative ion promoter 15%. The preparation process is exactly the same as in Example 1.

[0037] The performance testing methods for the samples in Example 2, Comparative Example 1, and Comparative Example 2 are the same as those in Example 1, and the results are shown in the table below.

[0038] Table 1: Performance Test Data of Examples and Comparative Samples The specific embodiments of the present invention have been described in detail above, but they are merely examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims

1. A composite material that sustainably releases negative ions, removes formaldehyde and odors, and possesses high far-infrared emissivity, characterized in that, The raw materials include the following percentages by mass: silicon carbide 25-50%; titanium dioxide 20-45%; zinc oxide 10-25%; and composite negative ion promoter 10-25%. The composite negative ion promoter is prepared by compounding germanium-containing mineral powder or rare earth mineral powder with alkaline earth metal carbonate at a mass ratio of (0.5-2):

1.

2. The composite material according to claim 1, characterized in that, The silicon carbide has a particle size D50 of 1-10 μm; the boron nitride has a particle size D50 of 1-10 μm.

3. The composite material according to claim 1, characterized in that, The titanium dioxide has a particle size D50 of 0.1-1 μm; the zinc oxide has a particle size D50 of 0.1-1 μm.

4. The composite material according to claim 1, characterized in that, The overall particle size D50 of the composite negative ion promoter is ≤5μm.

5. A method for preparing the composite material according to any one of claims 1-4, characterized in that, Includes the following steps: S1, Raw material preparation: Weigh each raw material according to the ratio, and premix natural germanium stone powder or purified rare earth tailings composite powder with calcium carbonate at a mass ratio of 1:1 to obtain composite negative ion promoter. S2, Premixing: Add silicon carbide, boron nitride, titanium dioxide, zinc oxide and the composite negative ion promoter obtained in step S1 into a mixer and mix at low speed for 20-30 minutes. S3, Grinding: Transfer the premixed material into a ball mill with a ball-to-material ratio of 2:1 and grind it at 50 rpm. S4, Sieving: The ground material is sieved through a 200-mesh sieve to obtain the composite material.

6. The preparation method according to claim 5, characterized in that, The mixing in step S2 is carried out using a V-type mixer, with the mixing speed controlled at 20-30 rpm.

7. The preparation method according to claim 5, characterized in that, The grinding medium in step S3 is zirconia balls, and the material temperature is controlled to be ≤40℃ during the grinding process through cooling measures.

8. The application of the composite material as described in any one of claims 1-4 in the preparation of environmental purification or health care functional products, characterized in that, The products include one or more of the following: coatings, paints, inks, ceramics, plastics, leather, wallpaper, or textiles.

9. The application according to claim 8, characterized in that, When the product is a coating, paint, or ink, the amount of the composite material added is 1-5% of the total mass of the substrate.

10. The application according to claim 8, characterized in that, When using, the composite material and the substrate are mechanically mixed at 500-1000 rpm for 10-20 minutes.

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