Inorganic coating with air purification function and preparation method thereof

Abstract

The invention discloses an inorganic coating with an air purification function and a preparation method thereof.The inorganic coating is prepared from, by weight, 1-10 parts of modified tourmaline, 10-20 parts of porous materials and 1-5 parts of functional filler, and the modified tourmaline is obtained by grafting polycaprolactone to tourmaline. The tourmaline is modified and grafted with polycaprolactone, so that the dispersity and stability of the tourmaline in the water-based inorganic coating can be improved, particle aggregation is reduced, and the utilization rate of the tourmaline in a system is increased; by adding the porous material, a communication channel can be constructed, and the contact efficiency between air and functional components is enhanced; in conclusion, effective release of the tourmaline air purification function can be achieved, and the inorganic coating is endowed with more efficient, stable and lasting air purification capacity on the basis that the original performance of the inorganic coating is kept.

Description

Technical Field

[0001] The present invention relates to the technical field of functional building materials, and in particular to an inorganic coating with air purification function and a preparation method thereof. Background Art

[0002] In recent years, with increasing awareness of indoor air quality, new building materials with air purification capabilities have garnered widespread attention. Inorganic coatings, due to their excellent weather resistance, fire resistance, and environmental friendliness, have shown broad application prospects in architectural decoration and functional coatings.

[0003] In existing technologies, some inorganic coatings attempt to achieve air purification by adding natural mineral materials such as tourmaline, leveraging their spontaneous polarization properties to generate negative oxygen ions in the environment. However, due to the hydrophobic surface of natural tourmaline, it is difficult to disperse evenly in aqueous systems and is prone to agglomeration, significantly reducing its efficiency in generating active ions.

[0004] Furthermore, most existing inorganic coatings form a dense structure after film formation. While this structure helps improve the coating's water resistance and mechanical strength, it also limits effective contact between air and the functional components, hindering the full effectiveness of tourmaline. Therefore, even when tourmaline is added to a coating, its air purification function often fails to achieve the desired effect. Summary of the Invention

[0005] In view of the above problems, the present invention aims to provide an inorganic coating with air purification function and a preparation method thereof.

[0006] The technical solutions of the present invention are as follows: On the one hand, an inorganic coating with air purification function is provided, which comprises 1-10 parts of modified tourmaline, 10-20 parts of porous material and 1-5 parts of functional filler in parts by weight, wherein the modified tourmaline is obtained by grafting polycaprolactone on tourmaline.

[0007] Preferably, the modified tourmaline is prepared by the following steps: preparing tourmaline, and performing plasma spraying treatment on the tourmaline to obtain functionalized tourmaline; The functionalized tourmaline is dispersed in an aqueous phase and preheated to a target temperature, and then amino-modified nano-polycaprolactone is added to carry out a grafting reaction. After the reaction is completed, vacuum filtration and drying are performed to obtain the modified tourmaline.

[0008] Preferably, the target temperature is 40-80° C. and the reaction time is 1-4 h.

[0009] Preferably, the porous material is any one or more of diatomaceous earth, zeolite powder, and activated carbon.

[0010] Preferably, the functional filler includes any one or more of titanium dioxide, calcium carbonate, and potassium silicate.

[0011] Preferably, the invention further comprises an auxiliary agent, wherein the auxiliary agent is any one or more of a film-forming agent, a defoaming agent, a mildew preventer, and an antioxidant.

[0012] Preferably, the film-forming agent is a styrene-acrylic emulsion or a silicone-modified resin, the defoaming agent is a silicone defoaming agent or a mineral oil defoaming agent, the mildew inhibitor is an isothiazolinone compound, and the antioxidant is a phenolic antioxidant or an amine antioxidant.

[0013] On the other hand, a method for preparing the inorganic coating with air purification function described in any one of the above is also provided, comprising the following steps: S1: mixing the modified tourmaline, the porous material and the solvent, and performing ultrasonic dispersion to obtain a mixed solution; S2: adding a pH adjuster to the mixed solution to adjust the pH of the mixed solution to 7-9; S3: adding a functional filler under ultrasonic stirring conditions and mixing uniformly to obtain the inorganic coating.

[0014] Preferably, in step S2, the pH adjuster is aqueous ammonia or sodium hydroxide solution.

[0015] Preferably, in step S3, after the mixing is uniform, the step further includes adding an auxiliary agent and continuing to mix uniformly.

[0016] The beneficial effects of the present invention are: The present invention improves the dispersibility and stability of tourmaline in water-based inorganic coatings by modifying tourmaline and grafting polycaprolactone, reduces particle agglomeration, and increases its utilization rate in the system; and by adding porous materials, it can utilize them to construct connecting channels and enhance the contact efficiency between air and functional components. In summary, the present invention can effectively release the air purification function of tourmaline, and on the basis of maintaining the original performance of the inorganic coating, give it a more efficient, stable and long-lasting air purification ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is the SEM image of the inorganic coating of Comparative Example 1; Figure 2 This is the SEM image of the inorganic coating of Comparative Example 2; Figure 3 This is the SEM image of the inorganic coating of Example 1. DETAILED DESCRIPTION

[0019] The present invention is further described below with reference to the accompanying drawings and examples. It should be noted that, in the absence of conflict, the embodiments in this application and the technical features in the embodiments can be combined with each other. It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as those commonly understood by those of ordinary skill in the art to which this application belongs. The use of similar words such as "include" or "comprising" in the present invention means that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0020] On the one hand, the present invention provides an inorganic coating with air purification function, which comprises 1-10 parts of modified tourmaline, 10-20 parts of porous material and 1-5 parts of functional filler in parts by weight, wherein the modified tourmaline is obtained by grafting polycaprolactone on tourmaline.

[0021] In the present invention, polycaprolactone is grafted onto tourmaline, which can improve the dispersibility and stability of tourmaline in water-based inorganic coatings, reduce particle agglomeration, and improve its utilization rate in the system; the addition of porous materials can construct a coating system with a rich pore structure, enhance air flowability and the diffusion capacity of negative oxygen ions, thereby comprehensively improving the air purification performance of the coating; in summary, the present invention can achieve the effective release of the air purification function of tourmaline, and on the basis of maintaining the original performance of the inorganic coating, give it a more efficient, stable and lasting air purification ability.

[0022] In a specific embodiment, the modified tourmaline is prepared by the following steps: preparing tourmaline, and performing plasma spraying treatment on the tourmaline to obtain functionalized tourmaline; The functionalized tourmaline is dispersed in an aqueous phase and preheated to a target temperature, and then amino-modified nano-polycaprolactone is added to carry out a grafting reaction. After the reaction is completed, vacuum filtration and drying are performed to obtain the modified tourmaline.

[0023] In the above embodiment, plasma spraying the tourmaline creates a large number of functionalized amino and carboxyl groups on its surface, facilitating the subsequent grafting of polycaprolactone onto the tourmaline. The polycaprolactone not only acts as a dispersant but also forms hydrogen bonds or physical entanglements with the tourmaline silicate matrix through its surface-active groups, thereby enhancing interfacial bonding.

[0024] In a specific embodiment, plasma spraying is performed in a plasma sprayer, which can use plasma as a heat source to heat the powdered material to a molten or semi-molten state and spray it onto the surface of the substrate through a high-speed airflow to form a functional group coating.

[0025] In a specific embodiment, the target temperature is 40-80° C. and the reaction time is 1-4 h.

[0026] In a specific embodiment, the porous material is any one or more of diatomaceous earth, zeolite powder, and activated carbon, and the functional filler includes any one or more of titanium dioxide, calcium carbonate, and potassium silicate.

[0027] In the above embodiment, the porous material can create a large number of micropores and mesoporous structures within the coating, promoting air circulation and pollutant transport, allowing the negative oxygen ions generated by tourmaline to diffuse fully into the air. The titanium dioxide can provide hiding power and whiteness to the inorganic coating, the calcium carbonate can adjust the coating hardness and reduce costs, and the potassium silicate can serve as an inorganic binder.

[0028] In a specific embodiment, the inorganic coating further includes an additive, wherein the additive is any one or more of a film-forming agent, a defoaming agent, a mildewproofing agent, and an antioxidant. Optionally, the film-forming agent is a styrene-acrylic emulsion or a silicone-modified resin, the defoaming agent is a silicone-based defoaming agent or a mineral oil-based defoaming agent, the mildewproofing agent is an isothiazolinone compound, and the antioxidant is a phenolic antioxidant or an aminic antioxidant.

[0029] In a specific embodiment, the auxiliary agent includes, by weight, 1-10 parts of a film-forming agent, 1-10 parts of a defoaming agent, 1-3 parts of a mildew preventer, and 1-5 parts of an antioxidant.

[0030] On the other hand, the present invention also provides a method for preparing the inorganic coating with air purification function described in any one of the above, comprising the following steps: S1: mixing the modified tourmaline, the porous material and the solvent, and performing ultrasonic dispersion to obtain a mixed solution; S2: adding a pH regulator to the mixed solution to adjust the pH of the mixed solution to 7-9; optionally, the pH regulator is ammonia water or sodium hydroxide solution; S3: adding a functional filler under ultrasonic stirring conditions and mixing uniformly to obtain the inorganic coating.

[0031] In the above embodiment, the present invention adjusts the pH of the mixed solution to 7-9. Within this pH range, the interface stability between the modified tourmaline and the porous material is optimal, which is more conducive to maintaining the function in the subsequent coating process.

[0032] In a specific embodiment, in step S3, after the mixing is uniform, the step further includes adding an auxiliary agent and continuing to mix uniformly.

[0033] Example 1 An inorganic coating with air purification function is prepared by the following steps: (1) 10 g of tourmaline powder was added to a plasma sprayer for surface treatment to obtain functionalized tourmaline powder; (2) The functionalized tourmaline powder was added to a 100 mL beaker containing 50 mL of deionized water and subjected to ultrasonic dispersion treatment in an ultrasonic cleaner for 10 min to remove impurities attached to the particle surface and improve its dispersion uniformity in the aqueous phase. It was then transferred to a 250 mL three-necked round-bottom flask, and the three-necked flask was placed in a constant temperature oil bath and heated to 60°C for preheating. After the system temperature stabilized, the condensed water circulation system was turned on and the magnetic stirring device was started to maintain constant temperature and uniform mixing of the system during the reaction; (3) Under continuous stirring, slowly add 2g of amino-nano polycaprolactone (PCL) aqueous dispersion by dropwise addition, and control the dropwise acceleration rate to ensure the stability of the reaction system and avoid agglomeration caused by excessive local concentration. After the addition is completed, continue the reaction at a constant temperature of 60°C for 2h to allow PCL to be fully adsorbed and grafted onto the surface of the tourmaline particles, thereby achieving effective surface functional modification. After the reaction is completed, the resulting mixture is vacuum filtered to remove unbound PCL and reaction by-products, and then the filter cake is transferred to a blast drying oven and dried at 60-80°C to constant weight to finally obtain PCL surface-modified tourmaline; (4) 1000g of porous material (diatomaceous earth), 50g of PCL surface-modified tourmaline, and 5000g of alcohol-water mixed solvent were added to a constant temperature reaction device in sequence. Under the condition of external application of an ultrasonic-assisted dispersion device, the components were fully mixed by high-speed stirring. In this process, the porous material adsorbed the PCL surface-modified tourmaline through its rich pore structure to achieve effective loading. The synergistic effect of ultrasound helped to disperse the porous material and improve the uniform distribution of PCL surface-modified tourmaline on the surface of the porous material, thereby obtaining a stable and well-dispersed "porous material loaded with PCL surface-modified tourmaline" mixed solution; (5) Add an appropriate amount of pH regulator to the above mixed solution to control the pH value of the system within the range of 7 to 9. Continue to add functional fillers, including 100g titanium dioxide, 100g calcium carbonate, and 150g potassium silicate, in sequence under ultrasonic stirring. All components are fully mixed under the combined action of ultrasonic and mechanical stirring to form a homogeneous slurry; (6) Under ultrasonic-assisted stirring conditions, 100 g of film-forming agent, 50 g of defoaming agent, 50 g of mildew inhibitor, and 50 g of antioxidant were further added to improve the coating's workability, durability, and environmental adaptability. All additives were thoroughly stirred until completely dissolved to ensure a uniform and stable system, ultimately obtaining an inorganic coating with air purification function.

[0034] Example 2 Different from Example 1, the porous material added in step (4) of this example is activated carbon.

[0035] Example 3 Different from Example 1, the dosage of each agent in step (4) of this example is 1000 g of porous material, 500 g of PCL surface-modified tourmaline and 5000 g of alcohol-water mixed solvent.

[0036] It should be noted that the above embodiments are only some of the embodiments of the present invention. By changing parameters such as the reagent, dosage, temperature, and time, the inorganic coating with air purification function of the present invention can also be obtained.

[0037] Comparative Example 1 Different from Example 1, this comparative example does not include steps (1) to (3), the tourmaline in step (4) directly adopts the original tourmaline powder in step (1), and no porous material is added in step (4).

[0038] Comparative Example 2 Different from Comparative Example 1, this comparative example further performs an ultrasonic treatment on the inorganic coating after obtaining it in step (6).

[0039] The morphology of the inorganic coatings of Comparative Examples 1-2 and Example 1 was observed using a scanning electron microscope. Figure 1-3 As shown. Figure 1-3 As can be seen, conventional coating surfaces obtained through conventional treatment exhibit significant adhesion and minimal porosity. Ultrasonic treatment increases the surface porosity, but it remains dense. However, the addition of PCL-surface-modified tourmaline and porous materials in the present invention significantly enhances surface dispersion, resulting in a fibrous porous structure. This invention significantly enhances the air purification effect of tourmaline, and the porous structure also promotes air flow.

[0040] It should be noted that the above test examples are only some of the test examples of the present invention. The inorganic coatings obtained in other embodiments of the present invention have similar effects and are all superior to conventional coatings.

[0041] In summary, the present invention not only solves the difficult problem of tourmaline dispersion in coating systems but also optimizes the coating film structure, allowing the functional components to function more efficiently. While maintaining the inherent excellent physical and chemical properties of the inorganic coating, it also imparts a stable and efficient air purification function. Compared with existing technologies, the present invention represents a significant improvement.

[0042] The above description is merely a representative embodiment of the present invention and does not constitute any form of limitation to the present invention. Any technical personnel familiar with the present invention who, without departing from the scope of the technical solution of the present invention, makes some changes or modifications to the embodiments disclosed above using the technical contents disclosed above are equivalent embodiments of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An inorganic coating with air purification function, characterized in that: The invention comprises, by weight, 1-10 parts of modified tourmaline, 10-20 parts of porous material and 1-5 parts of functional filler. The modified tourmaline is obtained by grafting polycaprolactone onto tourmaline.

2. The inorganic coating with air purification function according to claim 1, characterized in that: The modified tourmaline is prepared by the following steps: preparing tourmaline, and performing plasma spraying treatment on the tourmaline to obtain functionalized tourmaline; The functionalized tourmaline is dispersed in an aqueous phase and preheated to a target temperature, and then amino-modified nano-polycaprolactone is added to carry out a grafting reaction. After the reaction is completed, vacuum filtration and drying are performed to obtain the modified tourmaline.

3. The inorganic coating with air purification function according to claim 2, characterized in that: The target temperature is 40-80°C and the reaction time is 1-4h.

4. The inorganic coating with air purification function according to claim 1, characterized in that: The porous material is any one or more of diatomaceous earth, zeolite powder, and activated carbon.

5. The inorganic coating with air purification function according to claim 1, characterized in that: The functional filler includes any one or more of titanium dioxide, calcium carbonate, and potassium silicate.

6. The inorganic coating with air purification function according to any one of claims 1 to 5, characterized in that: The invention also includes auxiliary agents, which are any one or more of film-forming agents, defoaming agents, mildew inhibitors, and antioxidants.

7. The inorganic coating with air purification function according to claim 6, characterized in that: The film-forming agent is a styrene-acrylic emulsion or an organosilicon-modified resin, the defoaming agent is an organosilicon-based defoaming agent or a mineral oil-based defoaming agent, the mildew preventer is an isothiazolinone compound, and the antioxidant is a phenolic antioxidant or an amine antioxidant.

8. The method for preparing an inorganic coating having an air purification function according to any one of claims 1 to 7, wherein: The following steps are involved: S1: mixing the modified tourmaline, the porous material and the solvent, and performing ultrasonic dispersion to obtain a mixed solution; S2: adding a pH adjuster to the mixed solution to adjust the pH of the mixed solution to 7-9; S3: adding a functional filler under ultrasonic stirring conditions and mixing uniformly to obtain the inorganic coating.

9. The method for preparing an inorganic coating having an air purification function according to claim 8, wherein: In step S2, the pH adjuster is ammonia water or sodium hydroxide solution.

10. The method for preparing the inorganic coating with air purification function according to claim 8 or 9, characterized in that: In step S3, after the mixture is uniformly mixed, an auxiliary agent is added and the mixture is further uniformly mixed.

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