Long-acting slow-release multifunctional air freshener and preparation method thereof

Abstract

The invention relates to the technical field of daily chemical industry, in particular to a long-acting slow-release multifunctional air freshener and a preparation method thereof. The invention provides a long-acting slow-release multifunctional air freshener. The long-acting slow-release multifunctional air freshener is prepared from composite plant essential oil, a porous mineral carrier, a microcapsule coating material, a forming matrix, an Ag / AgBr / TiO2 composite photocatalyst and functional auxiliary components. According to the present invention, by using the specific mass part of the microcapsule coating material, the porous mineral carrier loaded with the plant essential oil is subjected to the microcapsule coating so as to achieve the slow release of the plant essential oil, such that the aroma can be maintained at the comfortable concentration level for the long time, the air quality can be effectively improved, and the slow-release, multi-functional, safe and environmental protection effects can be provided.

Description

Technical Field

[0001] This invention relates to the field of daily chemical technology, and in particular to a long-lasting, slow-release, multifunctional air freshener and its preparation method. Background Technology

[0002] Air fresheners are everyday chemical products used to improve indoor air odors, typically by releasing aromatic components to mask or neutralize unpleasant smells in the air. Their main components include fragrances, solvents, propellants (aerosol type), and bactericides, and they come in various forms, such as sprays, gels, and solid volatile forms. Air fresheners are widely used in enclosed or semi-enclosed spaces such as homes, hotels, and cars to enhance environmental comfort.

[0003] Currently, there are various types of air fresheners on the market, primarily using fragrance molecules to mask or neutralize indoor odors. However, these products generally suffer from problems such as excessively volatile active ingredients, short-lasting fragrance, limited ingredient range, and potential risks to human health and the environment. Furthermore, existing air freshener products commonly exhibit an "overly strong fragrance" issue during initial use. This problem arises because traditional air fresheners, or products lacking effective slow-release mechanisms, release their volatile aromatic components (such as plant essential oils) too quickly and uncontrollably when the product is turned on or exposed to air. This rapid and concentrated release results in an initially overly strong fragrance, potentially causing severe olfactory stimulation, discomfort, or even dizziness, and also leading to premature depletion of the active ingredients, shortening the product's effective lifespan and fragrance duration.

[0004] In response to the aforementioned technologies, a long-lasting, slow-release, multifunctional air freshener and its preparation method are proposed, aiming to provide a slow-release, efficient, safe, and environmentally friendly air freshener to meet modern consumers' needs for health and sustainability. Summary of the Invention

[0005] To meet the requirements of air fresheners being slow-release, multifunctional, safe, and environmentally friendly, this application provides a long-lasting slow-release multifunctional air freshener and its preparation method.

[0006] In a first aspect, this application provides a long-lasting, sustained-release, multifunctional air freshener, employing the following technical solution: A long-lasting, slow-release, multifunctional air freshener is prepared from the following raw materials in parts by weight: 15-30 parts of compound plant essential oil, 60-75 parts of porous mineral carrier, 1-10 parts of microcapsule coating material 1-10 parts of molding matrix; The compound plant essential oil comprises the following components by weight: 8-15 parts antibacterial essential oil, 5-12 parts aromatic essential oil, 2-6 parts aldehyde-removing essential oil, and 0.5-2 parts vitamin E; wherein the antibacterial essential oil is two or more of tea tree oil, eucalyptus oil, thyme oil, cinnamon oil, and clove bud oil; the aromatic essential oil is two or more of lavender oil, sweet orange oil, Roman chamomile oil, bergamot oil, peppermint oil, and rosemary oil; and the aldehyde-removing aromatic essential oil is two or more of lemon eucalyptus oil, lemongrass oil, cypress oil, fir oil, and bay leaf oil.

[0007] By adopting the above scheme, the components of the long-lasting, slow-release, multifunctional air freshener include a specific mass of microcapsule encapsulation material. By microcapsulating a porous mineral carrier loaded with plant essential oils, the slow release of plant essential oils is achieved, ensuring that the fragrance can be maintained at a comfortable concentration level for a longer period of time, effectively improving air quality.

[0008] By adopting the above-mentioned approach and blending essential oils with different functions (antibacterial, aromatic, and formaldehyde-removing), the product not only provides a pleasant aroma but also actively purifies the air, sterilizes, and removes formaldehyde, thus enhancing its overall effectiveness. The combination of different aromatic essential oils ensures a layered and comfortable fragrance, avoiding olfactory fatigue that may result from a single scent. The addition of formaldehyde-removing essential oils allows the product to specifically decompose harmful substances such as formaldehyde in the air, fundamentally improving air quality rather than merely masking odors. The addition of vitamin E as an essential oil stabilizer effectively inhibits the oxidation and degradation of the essential oils, ensuring their activity and aroma quality during long-term storage and slow-release processes, thereby extending the product's effective lifespan.

[0009] Preferably, the compound plant essential oil has the following composition: the antibacterial essential oil is tea tree oil and eucalyptus oil in a mass ratio of 3:(1-2); the aromatic essential oil is lavender oil and sweet orange oil in a mass ratio of 3:(1-2); and the aldehyde-removing aromatic essential oil is lemon eucalyptus oil and lemongrass oil in a mass ratio of 2:(1-2).

[0010] Preferably, the porous mineral carrier is a mixture of modified zeolite molecular sieve and modified diatomaceous earth in a mass ratio of (6-7):(3-4).

[0011] By adopting the above scheme, the specific carrier combination and modification treatment significantly improved the loading capacity, stability and sustained release effect of essential oils, and achieved synergistic adsorption and stabilization of essential oils, providing a more solid and uniform essential oil loading foundation for subsequent microcapsule encapsulation, and further ensuring the controlled sustained release and persistence of aroma.

[0012] Preferably, the preparation of the modified zeolite molecular sieve includes the following steps: mixing zeolite with a mixed acid solution at a mass ratio of 1:(8-12), adding ammonium fluoride at 0.05-0.15% of the zeolite mass, and stirring at 50-70°C for 2-4 hours; mixing the acid-treated zeolite with an alkaline solution at a mass ratio of 1:(6-10), and treating under ultrasonic assistance for 0.5-1.5 hours; reacting the alkaline-treated zeolite, 3-aminopropyltriethoxysilane, and 95% ethanol at a mass ratio of 1:(0.03-0.05):(5-8) under a nitrogen atmosphere at 80°C for 6 hours; washing and drying at 120°C for 12 hours to obtain the modified zeolite molecular sieve.

[0013] Preferably, the modified zeolite molecular sieve has a specific surface area of ​​650-720 m². 2 / g, pore size distribution is micropores 0.5-1nm, mesopores 2-8nm, essential oil loading is 25-30wt%.

[0014] Preferably, the mixed acid solution is a mixture of 1.5M hydrochloric acid and 0.5M sulfuric acid in a volume ratio of (2-3):1.

[0015] Preferably, the alkaline solution is a 0.5M NaOH solution.

[0016] By adopting the above scheme, the acid-base synergistic modification of zeolite molecular sieves optimizes the adsorption performance. Zeolite molecular sieves themselves have regular pore structure. After acid-base synergistic modification, their pore structure and surface properties are optimized, which can provide a larger specific surface area and a more suitable pore size distribution, accurately matching the size of plant essential oil molecules, thereby achieving efficient and high-capacity essential oil adsorption and stable loading.

[0017] Preferably, the preparation of the modified diatomaceous earth includes the following steps: mixing diatomaceous earth with silane hydrolysate at a mass ratio of 1:(8-12), refluxing at 75°C for 6-8 hours under nitrogen protection, and ultrasonically dispersing at 100W for 2 minutes every 30 minutes during the reaction; washing three times by centrifugation with ethanol, Soxhlet extraction for 24 hours, and vacuum drying at 80°C for 12 hours to obtain the modified diatomaceous earth; Preferably, the diatomaceous earth contains ≥85% SiO2.

[0018] Preferably, the silane hydrolysate is prepared by adding 3-aminopropyltriethoxysilane at a concentration of 2-5 wt% to a 95% ethanol mixed solvent, and adjusting the pH to 4.5 with acetic acid.

[0019] Preferably, the modified diatomaceous earth has a contact angle of 120-135° and an essential oil adsorption capacity of 28-32 wt%.

[0020] By employing the above-mentioned method, surface-silanized diatomaceous earth enhances the stability of essential oils. Diatomaceous earth has a porous structure, but its surface is typically hydrophilic. Through silanization, the surface of diatomaceous earth becomes hydrophobic, which significantly enhances its affinity for organic essential oils, reduces non-specific adsorption and initial rapid volatilization of essential oils on the carrier surface, and improves the loading stability and antioxidant capacity of essential oils. Using modified diatomaceous earth as a carrier to compound with plant essential oils, air fresheners with a fragrance retention time of ≥22 days are prepared.

[0021] Preferably, the microcapsule material is HPMCP, chitosan, genipin and PDMAEMA in a mass ratio of 3:(1.5-2.5):(0.5-1):(1.5-2).

[0022] By adopting the above scheme, this microcapsule system with a specific ratio achieves a balance between humidity-responsive sustained release and long-term stability through the synergistic effect of its components. HPMCP (hydroxypropyl methylcellulose phthalate): the ester bonds hydrolyze when RH>70%, increasing the porosity of the capsule wall; PDMAEMA (polydimethylaminoethyl methacrylate): absorbs water and swells when humidity increases, further expanding the release channels; chitosan: provides the basic framework structure, adsorbing negatively charged essential oil molecules through the positive charge of amino groups; genipin: cross-links with chitosan to form a three-dimensional network, increasing the elongation at break of the capsule wall to 45%; at the same time, chitosan and genipin also have antibacterial properties, integrating antibacterial and sustained release.

[0023] Preferably, the molding matrix includes any one of spray molding matrix, gel molding matrix, or solid molding matrix.

[0024] Preferably, the spray-molded matrix is ​​prepared from the following raw materials in parts by weight: 2-3 parts propylene glycol, 0.5-1 parts PEG-40 hydrogenated castor oil, 1.5-2.5 parts anhydrous ethanol, 2-3 parts methyl propylene glycol, and 1-2 parts C12-15 benzoate.

[0025] By adopting the above scheme, compared with conventional molding matrix, the amount of ethanol used is reduced, and the flammability is reduced by adding methyl propylene glycol; C12-15 benzoate is compounded with PEG-40, and the HLB value is adjusted to 12-14, which enhances emulsification; the reduced amount of propylene glycol combined with C12-15 benzoate eliminates the stickiness.

[0026] Preferably, the gel-forming matrix is ​​prepared from the following raw materials in parts by weight: 1-1.5 parts K-carrageenan, 0.5-0.8 parts agarose, 2-3 parts glycerol, 0.4-0.6 parts xanthan gum, and 0.4-0.8 parts sodium alginate.

[0027] By adopting the above scheme, it has better sustained-release performance, environmental adaptability and safety; K-carrageenan + agarose form a three-dimensional network structure, which delays the release of essential oils through hydrogen bonds and sodium alginate ion cross-linking; xanthan gum enhances the thixotropy of the gel and avoids structural collapse at high temperature (≤50℃); glycerin acts as a humectant to balance the rate of water evaporation of the gel and maintain morphological stability under humidity conditions of 30-70%; the all-natural polysaccharide matrix has no ethanol or organic solvent residues and is suitable for mothers and infants and sensitive environments.

[0028] Preferably, the solid molding matrix is ​​prepared from the following raw materials in parts by weight: 3-4 parts microcrystalline cellulose, 1.2-1.5 parts CMS-Na, 0.6-0.8 parts magnesium stearate, and 0.8-1 parts HPMC.

[0029] By adopting the above scheme, mechanical strength and formability are enhanced. Microcrystalline cellulose and CMS-Na provide high porosity and compressive strength, and tableting is crack-free. HPMC acts as a binder to ensure uniform dispersion of carrier particles and avoid component segregation. CMS-Na (sodium carboxymethyl starch) swells upon contact with water to form a gel layer, achieving humidity-triggered release. The release rate increases by 2 times when RH>60%, adapting to the needs of humid environments. Magnesium stearate reduces hygroscopicity and extends shelf life.

[0030] Preferably, the long-lasting, slow-release, multifunctional air freshener further includes 3-8 parts of an Ag / AgBr / TiO2 composite photocatalyst.

[0031] Preferably, the preparation method of the Ag / AgBr / TiO2 composite photocatalyst includes the following steps: (1) Preparation of TiO2 precursor: Tetrabutyl titanate and anhydrous ethanol were mixed at a volume ratio of 1:(8-12), 0.2M nitric acid was added to adjust the pH to 3.0-4.0, and hydrolyzed at 60℃ for 4 hours to form TiO2 sol; (2) AgBr loading: The TiO2 sol obtained in step (1) was mixed with 0.1M sodium bromide solution at a mass ratio of 1:(0.5-1). After stirring for 30 minutes, 0.01M silver nitrate solution of the same mass as sodium bromide solution was added dropwise. The reaction was carried out in the dark for 2 hours. (3) In-situ reduction of Ag nanoparticles: Add an equal volume of 0.02M ascorbic acid solution to the product of step (2), and react for 1-2 hours under 365nm, 50W ultraviolet light irradiation. + Partially restored to Ag 0 ; (4) Post-treatment: The product was washed three times with deionized water and three times with ethanol, and impurities were removed by centrifugation. The product was calcined at 350-400℃ for 2 hours under nitrogen protection to obtain Ag / AgBr / TiO2 composite photocatalyst with Ag content of 0.5-1.5wt% and AgBr content of 5-8wt%.

[0032] By adopting the above scheme, the composite photocatalyst, containing components with active air purification capabilities, significantly enhances the air purification ability of air fresheners, achieving active degradation of harmful substances. The synergistic effect of the Ag / AgBr / TiO2 tri-components, enhanced by the plasma effect, increases the reaction rate of this photocatalyst by 2 times compared to ordinary photocatalysts. This means it can remove air pollutants faster and more effectively, providing a more rapid air purification effect. TiO2 provides a stable support and UV photocatalytic activity, AgBr generates electron-hole pairs under visible light excitation, Ag nanoparticles act as electron traps to suppress carrier recombination, and the SPR effect enhances the local light field intensity. This solves the three major problems of traditional photocatalysts: the need for UV light, easy deactivation, and high cost, making it particularly suitable for home air purification scenarios with high requirements for safety and long-term effectiveness.

[0033] Preferably, the long-lasting, slow-release, multifunctional air freshener further includes functional auxiliary ingredients, including: Natural antibacterial agent: 0.5-1.5 parts of ε-polylysine; Odor neutralizer: 1-3 parts of β-cyclodextrin carboxymethyl derivative; Antioxidant: 0.3-1 part rosemary extract.

[0034] By adopting the above approach, the functional auxiliary ingredients enhance the product's performance from multiple dimensions through the synergistic effect of multiple components, significantly improving the antibacterial properties, deodorizing efficiency, stability, and controlled-release performance of the long-lasting, slow-release, multifunctional air freshener. ε-Polylysine: Provides additional bio-purification function, is a food-grade antibacterial agent, non-irritating to the skin, and has broad-spectrum antibacterial properties, inhibiting bacteria (G+ / G-) and mold, suppressing the growth of bacteria and mold in the air or on product surfaces. When used with chitosan microcapsules, its antibacterial activity is increased by 40%. β-Cyclodextrin carboxymethyl derivatives actively capture and neutralize various odor molecules, achieving true odor elimination rather than simple masking, enhancing the depth and persistence of air purification. Its mechanism of action is odor neutralization rather than masking, avoiding the nausea of ​​fragrance mixing with odors. Rosemary extract: Replaces synthetic antioxidants such as BHT, protecting the active ingredients in the product (especially plant essential oils and photocatalysts) from oxidative degradation, ensuring their long-term activity and efficacy, extending product shelf life and service life. Rosemary itself has a fresh herbal aroma, synergistically enhancing the fragrance without interfering with the main fragrance notes. This functional auxiliary ingredient system achieves upgraded safety and surpasses similar products in antibacterial, deodorizing, and stability indicators through natural antibacterial, molecular capture, and oxidative protection technologies.

[0035] Secondly, this application provides a method for preparing a long-lasting, sustained-release, multifunctional air freshener, employing the following technical solution: Preparation of S1 compound plant essential oil: Antibacterial essential oil, aromatic essential oil, aldehyde-removing essential oil and stabilizer are mixed in proportion and stirred at 40°C for 30 minutes under light-protected conditions to obtain compound plant essential oil; Pretreatment of S2 porous mineral carrier: After mixing, the porous mineral carrier is ball-milled to 300 mesh; S3 Vacuum-loaded plant essential oil: The composite plant essential oil from step S1 and the porous mineral carrier from step S2 are impregnated at 50-70℃ and -0.1 MPa vacuum for 6-8 hours. S4 Functional Component Combination: Ag / AgBr / TiO2 composite photocatalyst and functional auxiliary components are added to the carrier of essential oil loaded in step S3 to obtain composite functional components; S5 Microcapsule Coating: A coating liquid with a solid content of 5-10% is prepared using microcapsule coating material. The composite functional component from step S4 is placed in a fluidized bed and sprayed with the coating liquid. The weight gain of the coating is controlled at 8-10%, and the coating layer thickness is 1-2 μm to obtain the microcapsule composite functional component. S6 Molding and Processing: The microcapsule composite functional components from step S5 are mixed with the molding matrix and processed into a spray form, gel form, or solid form.

[0036] By employing the above-mentioned approach, and utilizing a combination of porous carriers, photocatalysts, and microcapsules, harmful substances are simultaneously removed and long-lasting fragrance is achieved. Through precise control of process, structure, and performance, vacuum loading ensures high load capacity, fluidized bed coating enables controllable release, and the component ratios are optimized through extensive experimentation. This approach can meet the demands of the consumer upgrade market for air purification products that are more efficient, longer-lasting, and safer.

[0037] Preferably, the S5 microcapsule encapsulation is prepared using the following method: S5a. Dissolve the microcapsule coating material in a coating solvent to prepare a coating solution with a solid content of 5-10%, and filter it through a 400-mesh sieve and vacuum degassing to obtain the coating solution; S5b. The composite functional component obtained in step S4 is placed in a fluidized bed and fluidized under the conditions of inlet air velocity of 1.5-2.5 m / s and material temperature of 35-45℃. S5c. Spray the coating liquid obtained in step S5a into the fluidized bed at a rate of 5-10 mL / min through a two-fluid nozzle, and control the atomizing air pressure to be 0.3-0.5 MPa so that the droplet size is 50-100 μm; S5d. Control the coating process until the composite functional component increases in weight by 8-10%, then fluidize and dry at 40-50℃ for 20-40 minutes to form a dense coating layer with a thickness of 1-2μm.

[0038] Preferably, the coating solvent is a mixture of deionized water, ethanol and glacial acetic acid in a volume ratio of 60:(36-38):(2-4).

[0039] By adopting the above scheme, the "acetic acid-water-ethanol" mixed solvent system synergistically improves solubility. Chitosan is only soluble in acidic aqueous solutions, while HPMCP and PDMAEMA are hydrophobic polymers that are readily soluble in organic solvents such as ethanol. This mixed solvent system ensures the complete dissolution of all coating materials, forming a homogeneous and stable solution. The addition of ethanol provides the solvent system with a moderate evaporation rate, preventing excessively rapid drying at the nozzle and clogging, while also allowing for rapid film formation upon contact with the material in the fluidized bed. Ethanol effectively reduces the surface tension of water, making it easier for the coating liquid to be atomized into fine, uniform droplets, thus achieving uniform coating. Compared to using pure organic solvents (such as acetone and dichloromethane), this system, primarily water-based, significantly reduces flammability and toxicity, better meeting safety and environmental protection requirements. During the subsequent fluidized bed drying process, ethanol and acetic acid are easily removed, leaving no solvent residue in the final product, ensuring safety for human health.

[0040] Preferably, the S6 molding process is carried out into a spray form, the microcapsule composite functional components are mixed with the spray matrix, homogenized and emulsified at 5000 rpm for 10 minutes, filtered and then filled into an aluminum can.

[0041] Preferably, the S6 molding process is to form a gel dosage form by dissolving K-carrageenan, agarose, and sodium alginate in deionized water at 80°C and stirring until completely dissolved. Xanthan gum and glycerin are then added, and the mixture is stirred at 50°C for 30 minutes to obtain a dissolved gel molding matrix. The dissolved gel molding matrix is ​​then mixed with the microcapsule composite functional components at a mass ratio of 6:(3-4) to form a homogeneous colloid, which is then filled into the container. The gel molding matrix is ​​dissolved in deionized water at a mass ratio of 1:10.

[0042] Preferably, the S6 molding process is carried out into a solid dosage form, the microcapsule composite functional components and the solid matrix are mixed at a mass ratio of 7:(3-4), and dry roller pressing is performed on the granules at a pressure of 5MPa.

[0043] By adopting the above scheme, a long-acting, sustained-release, multifunctional air freshener was prepared. It can be processed into a spray form with a particle size ≤50 μm, a spray diffusion angle ≥60°, and a PM2.5 diffusion concentration ≤0.1 mg / m³; into a gel form with a gel weight loss rate <5% at 40℃ and 80% RH (7-day accelerated test); and into a solid form: tablets with a disintegration rate ≤15% after 24 hours in an 80% RH environment, meeting the requirements for humid environments. Through the improvement of dosage form characteristics, it can cover all scenarios from immediate deodorization to long-acting sustained release, and the process parameters are clear, facilitating industrialization.

[0044] In summary, this application has the following beneficial effects: 1. This application presents a long-lasting, slow-release, multifunctional air freshener that, through the compounding of essential oils with different functions (antibacterial, aromatic, and formaldehyde-removing), not only provides a pleasant fragrance but also actively purifies the air, sterilizes, and removes formaldehyde, thus enhancing the product's overall effectiveness. A specific mass fraction of microcapsule encapsulation material, by microencapsulating a porous mineral carrier loaded with plant essential oils, achieves the slow release of the plant essential oils, ensuring that the fragrance can be maintained at a comfortable concentration level for a longer period, effectively improving air quality. This product exhibits slow-release, multifunctional, safe, and environmentally friendly effects.

[0045] 2. This application discloses a method for preparing a long-acting, sustained-release, multifunctional air freshener. The prepared air freshener can be processed into a spray form with a particle size ≤50 μm, a spray diffusion angle ≥60°, and a PM2.5 diffusion concentration ≤0.1 mg / m³; into a gel form with a gel weight loss rate <5% at 40℃ and 75% RH (7-day accelerated test); or into a solid form: tablets with a disintegration rate ≤15% after 24 hours in a RH=90% environment, meeting the requirements for humid environments. Through this improved dosage form, it can cover all scenarios from immediate deodorization to long-acting sustained release, and the process parameters are clearly defined, facilitating industrialization. Detailed Implementation

[0046] The technical solution of this application is further illustrated by specific embodiments below. These specific embodiments do not represent a limitation on the scope of protection of this application. Any non-essential modifications and adjustments made by others based on the concept of this application still fall within the scope of protection of this application.

[0047] Unless otherwise specified, the experimental methods shown in the following examples are conventional methods. All reagents and materials shown are commercially available products.

[0048] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0049] Preparation Example Preparation Example 1: Preparation of Modified Zeolite Molecular Sieves 1 kg of zeolite was mixed with 10 kg of mixed acid solution, and 0.1 kg of ammonium fluoride (based on the mass of the zeolite) was added. The mixture was stirred at 60 °C for 3 hours. 1 kg of acid-treated zeolite was mixed with 8 kg of alkaline solution and treated with ultrasound for 1 hour. 1 kg of alkaline-treated zeolite, 0.04 kg of 3-aminopropyltriethoxysilane, and 6 kg of 95% ethanol were mixed and refluxed at 80 °C for 6 hours under a nitrogen atmosphere. After centrifugation and washing with ethanol, the mixture was dried at 120 °C for 12 hours to obtain the modified zeolite molecular sieve.

[0050] The mixed acid solution is a mixture of 2L of 1.5M hydrochloric acid and 1L of 0.5M sulfuric acid. The 1.5M hydrochloric acid is prepared by measuring 125mL of concentrated hydrochloric acid, making up to 1L with deionized water, and mixing well. The 0.5M sulfuric acid is prepared by measuring 27.78mL of concentrated sulfuric acid, making up to 1L with deionized water, and mixing well under ice bath conditions.

[0051] The alkaline solution is a 0.5M NaOH solution: Weigh 20g NaOH, dilute to 1L with deionized water, and mix well.

[0052] Preparation Example 2: Preparation of Modified Zeolite Molecular Sieves The difference from Preparation Example 1 is as follows: 1 kg of zeolite was mixed with 8 kg of mixed acid solution, and 0.05 kg of ammonium fluoride (based on the mass of the zeolite) was added and stirred at 50°C for 2 hours; the acid-treated zeolite was mixed with 6 kg of alkaline solution and treated with ultrasound for 0.5 hours; 1 kg of alkaline-treated zeolite, 0.03 kg of 3-aminopropyltriethoxysilane, and 5 kg of 95% ethanol were mixed.

[0053] The mixed acid solution is a mixture of 3L of 1.5M hydrochloric acid and 1L of 0.5M sulfuric acid.

[0054] Preparation Example 3: Preparation of Modified Zeolite Molecular Sieves The difference from Preparation Example 1 is as follows: 1 kg of zeolite was mixed with 12 kg of mixed acid solution, and 0.15 kg of ammonium fluoride (by mass of zeolite) was added and stirred at 70°C for 4 hours; the acid-treated zeolite was mixed with 10 kg of alkaline solution and treated with ultrasound for 1.5 hours; 1 kg of alkaline-treated zeolite, 0.05 kg of 3-aminopropyltriethoxysilane, and 8 kg of 95% ethanol were mixed.

[0055] Preparation Example 4: Preparation of Modified Diatomite 1 kg of diatomaceous earth was mixed with 10 kg of silane hydrolysate and refluxed at 75 °C for 7 hours under nitrogen protection, with ultrasonic dispersion at 100 W for 2 minutes every 30 minutes during the reaction. The mixture was then washed three times by centrifugation with ethanol, extracted with Soxhlet for 24 hours, and vacuum dried at 80 °C for 12 hours to obtain modified diatomaceous earth. The silane hydrolysate was prepared by adding 3 kg of 3-aminopropyltriethoxysilane (APTES) to 97 kg of a mixed solvent of 95% ethanol, and adjusting the pH to 4.5 with acetic acid.

[0056] Preparation Example 5: Preparation of Modified Diatomite The difference from Preparation Example 4 is that: 1 kg of diatomaceous earth was mixed with 8 kg of silane hydrolysate and refluxed at 75°C for 6 hours under nitrogen protection; the silane hydrolysate was prepared by adding 2 kg of APTES to 98 kg of 95% ethanol mixed solvent and adjusting the pH to 4.5 with acetic acid.

[0057] Preparation Example 6: Preparation of Modified Diatomite The difference from Preparation Example 4 is that: 1 kg of diatomaceous earth was mixed with 12 kg of silane hydrolysate and refluxed at 75 °C for 8 hours under nitrogen protection; the silane hydrolysate was prepared by adding 5 g of APTES to 95 g of 95% ethanol mixed solvent and adjusting the pH to 4.5 with acetic acid.

[0058] Preparation Example 7: Preparation of Ag / AgBr / TiO2 Composite Photocatalyst (1) Preparation of TiO2 precursor: 1 kg tetrabutyl titanate was mixed with 10 kg anhydrous ethanol, 0.2 M nitric acid was added to adjust the pH to 3.0, and hydrolyzed at 60 °C for 4 hours to form TiO2 sol; (2) AgBr loading: Mix 1 kg TiO2 sol with 0.8 kg 0.1 M sodium bromide solution, stir for 30 minutes, then add 0.8 kg 0.1 M silver nitrate solution dropwise, and react in the dark for 2 hours; (3) In-situ reduction of Ag nanoparticles: Add an equal volume of 0.02M ascorbic acid solution to the product from step (2), and react for 1-2 hours under 365nm, 50W ultraviolet light irradiation. + Partially restored to Ag 0 ; (4) Post-treatment: The product was washed three times each with deionized water and ethanol, and impurities were removed by centrifugation. The product was calcined at 380°C for 2 hours under nitrogen protection to obtain Ag / AgBr / TiO2 composite photocatalyst.

[0059] The 0.2M nitric acid solution: Measure 12.5 mL of concentrated nitric acid, dilute to 1 L with deionized water, stir and cool.

[0060] The 0.1M sodium bromide solution: Weigh 10.29g NaBr, dilute to 1L with deionized water, and store protected from light.

[0061] The 0.1M silver nitrate solution: Weigh 16.99g AgNO3, dilute to 1L with deionized water, and store protected from light.

[0062] The 0.02M ascorbic acid solution: Weigh 3.52 g of ascorbic acid, dilute to 1 L with deionized water, store in a brown bottle and protect with nitrogen gas.

[0063] Preparation Example 8: Preparation of Ag / AgBr / TiO2 Composite Photocatalyst The difference from Preparation Example 7 is that: 1 kg of tetrabutyl titanate was mixed with 8 kg of anhydrous ethanol, and 0.2 M nitric acid was added to adjust the pH to 3.0; 1 kg of TiO2 sol was mixed with 0.5 kg of 0.1 M sodium bromide solution; the reaction was carried out under ultraviolet light irradiation for 1 hour; and the reaction was carried out under nitrogen protection at 350 °C for 2 hours.

[0064] Preparation Example 9: Preparation of Ag / AgBr / TiO2 Composite Photocatalyst The difference from Preparation Example 7 is that: 1 kg of tetrabutyl titanate was mixed with 12 kg of anhydrous ethanol, and 0.2 M nitric acid was added to adjust the pH to 4.0; 1 kg of TiO2 sol was mixed with 1 kg of 0.1 M sodium bromide solution; the reaction was carried out under ultraviolet light irradiation for 2 hours; and the mixture was calcined at 400 °C for 2 hours under nitrogen protection. Example

[0065] Example 1 A method for preparing a long-lasting, sustained-release, multifunctional air freshener, employing the following technical solution: Preparation of S1 compound plant essential oil: Antibacterial essential oil, aromatic essential oil, aldehyde-removing essential oil and stabilizer are mixed in proportion and stirred at 40°C for 30 minutes under light-protected conditions to obtain compound plant essential oil; Pretreatment of S2 porous mineral carrier: After mixing, the porous mineral carrier is ball-milled to 300 mesh; S3 Vacuum-loaded plant essential oil: The composite plant essential oil from step S1 and the porous mineral carrier from step S2 are impregnated at 60°C and -0.1 MPa vacuum for 7 hours. S4 Functional Component Combination: Ag / AgBr / TiO2 composite photocatalyst and functional auxiliary components are added to the carrier of essential oil loaded in step S3 to obtain composite functional components; S5 microcapsule encapsulation: S5a. Dissolve 8 kg of microcapsule coating material in 92 kg of coating solvent, and filter through a 400-mesh sieve and vacuum degassing to obtain the coating solution; S5b. The composite functional component obtained in step S4 is placed in a fluidized bed and fluidized under the conditions of an inlet air velocity of 2 m / s and a material temperature of 40°C. S5c. The coating liquid obtained in step S5a is sprayed into the fluidized bed at a rate of 8 mL / min through a two-fluid nozzle, and the atomizing air pressure is controlled at 0.4 MPa; S5d. Control the encapsulation process until the composite functional component gains 9% weight, then fluidize and dry at 40°C for 30 minutes to obtain the microcapsule composite functional component; S6 Molding Processing: Mix the microcapsule composite functional components from step S5 with the molding matrix, homogenize and emulsify at 5000 rpm for 10 minutes, filter, and then fill into aluminum cans.

[0066] The coating solvent is a mixture of 60 kg of deionized water, 36 kg of ethanol, and 4 kg of glacial acetic acid.

[0067] The aforementioned long-acting, slow-release, multifunctional air freshener is made from the following raw materials: 25 kg of compound plant essential oil, 65 kg of porous mineral carrier, 8 kg of microcapsule coating material, and 8 kg of molding matrix.

[0068] The composition and dosage of the long-acting, sustained-release, multifunctional air freshener are shown in Table 1.

[0069] The modified zeolite molecular sieve was prepared according to the preparation method of Example 1; the modified diatomaceous earth was prepared according to the preparation method of Example 4.

[0070] Example 2 A method for preparing a long-lasting, sustained-release, multifunctional air freshener differs from Example 1 in that: S3 Vacuum-loaded plant essential oil: The composite plant essential oil from step S1 and the porous mineral carrier from step S2 are impregnated at 50°C and -0.1 MPa vacuum for 6 hours. S5 microcapsule encapsulation: S5a. Dissolve 5 kg of microcapsule coating material in 95 kg of coating solvent, and then filter through a 400-mesh sieve and perform vacuum degassing. S5b. The composite functional component obtained in step S4 is placed in a fluidized bed and fluidized under the conditions of an inlet air velocity of 1.5 m / s and a material temperature of 35°C. S5c. The coating liquid obtained in step S5a is sprayed into the fluidized bed at a rate of 5 mL / min through a two-fluid nozzle, and the atomizing air pressure is controlled at 0.3 MPa; S5d. Control the encapsulation process until the composite functional component increases in weight by 8%, then fluidize and dry at 40°C for 20 minutes to obtain the microcapsule composite functional component.

[0071] The coating solvent is a mixture of 60 kg of deionized water, 38 kg of ethanol, and 2 kg of glacial acetic acid.

[0072] The dosage of the ingredients in the long-lasting, slow-release, multifunctional air freshener is shown in Table 1.

[0073] The modified zeolite molecular sieve was prepared according to the method of Preparation Example 2; the modified diatomaceous earth was prepared according to the method of Preparation Example 5.

[0074] Example 3 A method for preparing a long-lasting, sustained-release, multifunctional air freshener differs from Example 1 in that: S3 Vacuum-loaded plant essential oil: The composite plant essential oil from step S1 and the porous mineral carrier from step S2 are impregnated at 70°C and -0.1 MPa vacuum for 8 hours. S5 microcapsule encapsulation: S5a. Dissolve 10 kg of microcapsule coating material in 90 kg of coating solvent, and then filter through a 400-mesh sieve and perform vacuum degassing. S5b. The composite functional component obtained in step S4 is placed in a fluidized bed and fluidized under the conditions of an inlet air velocity of 2.5 m / s and a material temperature of 45°C. S5c. The coating liquid obtained in step S5a is sprayed into the fluidized bed at a rate of 10 mL / min through a two-fluid nozzle, and the atomizing air pressure is controlled at 0.5 MPa to make the droplet size 100 μm. S5d. Control the encapsulation process until the composite functional component gains 10% weight, then fluidize and dry at 50°C for 40 minutes to obtain the microcapsule composite functional component.

[0075] The ingredients and dosages of the long-acting, slow-release, multifunctional air freshener are shown in Table 1.

[0076] The modified zeolite molecular sieve was prepared according to the method of Preparation Example 3; the modified diatomaceous earth was prepared according to the method of Preparation Example 6.

[0077] Example 4 A method for preparing a long-acting, slow-release, multifunctional air freshener differs from Example 1 in that: the compound plant essential oil consists of an antibacterial essential oil made by mixing 9 kg of tea tree oil and 6 kg of eucalyptus oil, an aromatic essential oil made by mixing 9 kg of lavender oil and 6 kg of sweet orange oil, and an aldehyde-removing aromatic essential oil made by mixing 2 kg of lemon eucalyptus oil and 2 kg of lemongrass oil.

[0078] The dosage of the ingredients in the long-lasting, slow-release, multifunctional air freshener is shown in Table 1.

[0079] Examples 5-7 A method for preparing a long-acting, slow-release, multifunctional air freshener differs from Example 1 in that the amounts of the components in the long-acting, slow-release, multifunctional air freshener are shown in Table 1.

[0080] Example 8 A method for preparing a long-acting, sustained-release, multifunctional air freshener differs from Example 5 in that: the S6 molding process is carried out into a gel form, K-carrageenan, agarose, and sodium alginate are dissolved in 55 kg of deionized water at 80°C, stirred until completely dissolved, xanthan gum and glycerin are added and stirred at 50°C for 30 minutes to obtain a dissolved gel molding matrix, 60 kg of the dissolved gel molding matrix and 40 kg of microcapsule composite functional components are mixed to form a homogeneous colloid and then filled.

[0081] The gel-forming matrix is ​​prepared from the following raw materials: 1.2 kg of K-carrageenan, 0.6 kg of agarose, 2.5 kg of glycerol, 0.6 kg of xanthan gum, and 0.6 kg of sodium alginate.

[0082] Example 9 A method for preparing a long-acting, sustained-release, multifunctional air freshener differs from Example 5 in that: the S6 molding process is carried out into a solid dosage form, 70 kg of microcapsule composite functional components are mixed with 30 kg of solid matrix, and dry roller pressing is performed at a pressure of 5 MPa.

[0083] The solid molding matrix is ​​made from the following raw materials: 35 kg of microcrystalline cellulose, 14 kg of CMS-Na, 6.7 kg of magnesium stearate, and 8 kg of HPMC. Comparative Example

[0084] Comparative Example 1 Similar to Example 5, except that the long-lasting, slow-release, multifunctional air freshener does not contain an Ag / AgBr / TiO2 composite photocatalyst.

[0085] Comparative Example 2 Similar to Example 5, except that unmodified common zeolite and diatomaceous earth are used as carriers in the composition of the long-lasting slow-release multifunctional air freshener.

[0086] Comparative Example 3 Similar to Example 5, except that the long-lasting, slow-release, multifunctional air freshener uses a traditional wall material (3 kg of gelatin and 3.5 kg of gum arabic dissolved in 45 kg of 50°C deionized water) as the microcapsule coating material.

[0087] Comparative Example 4 Similar to Example 5, except that the long-lasting, slow-release, multifunctional air freshener contains the following essential oils: 13 kg of tea tree oil, 10 kg of lavender oil, and 2 kg of vitamin E mixed together.

[0088] Comparative Example 5 Similar to Example 5, except that in the composition of the long-lasting, slow-release multifunctional air freshener, chemical preservatives (sodium benzoate 0.2%) and synthetic antioxidants (BHT 0.05%) are used to replace all natural functional auxiliary ingredients.

[0089] Comparative Example 6 Similar to Example 5, except that the microcapsule encapsulation step is omitted in the preparation process, and the essential oil is directly adsorbed onto the carrier and then mixed with the other components.

[0090] Comparative Example 7 Similar to Example 5, except that the vacuum impregnation step is omitted in the preparation process, and the essential oil is loaded by stirring at room temperature and pressure.

[0091] Comparative Example 8 Similar to Example 5, except that the molding matrix does not contain a volatile modifier and the amount of C12-15 benzoate is 0.

[0092] Comparative Example 9 Similar to Example 5, except that the solvent for the microcapsule coating material is replaced with pure water.

[0093] Comparative Example 10 Similar to Example 5, except that the simulated commercially available air freshener (the main components are fragrance, solvent, and propellant, without composite carrier, photocatalyst, or functional ingredients). Performance testing

[0094] 1. Determination of fragrance duration: Spray the test sample evenly into a small beaker for 10 seconds. Place the small beaker in a high temperature and high humidity environment of 28℃ and RH60% and 40℃ and RH80%. Smell the fragrance every 5 minutes to confirm until the fragrance completely dissipates and record the time.

[0095] 2. Antibacterial Rate: Referring to the detection standards for Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa in QB / T 2738-2005 "Evaluation Method for Antibacterial and Bacteriostatic Effects of Daily Chemical Products", the antibacterial and bacteriostatic effects of the long-acting, sustained-release, multifunctional air freshener prepared in the above steps were tested. The colony count on plates with filter paper sheets coated with the air fresheners prepared in the examples and comparative examples was measured, and the sterilization rate was calculated as follows: Sterilization rate (%) = (A1-A2) / A1×100%, where A1 is the average colony count on the filter paper sheet with sterile water, and A2 is the average colony count on the filter paper sheet with the air fresheners prepared in the examples and comparative examples. A sterilization rate ≥90% belongs to grade A1, a sterilization rate between 50-90% belongs to grade A2, and a sterilization rate ≤50% belongs to grade A3.

[0096] 3. Odor masking power test: Spray the sample into a beaker containing 5g of artificial odor source (made from garlic, rotten egg liquid and cigarette butt in a ratio of 5:3:2) for 10s, and judge its masking power by smell. A is completely odorless, B is odor can be smelled, C is odor is obvious, and D is completely unable to mask the odor.

[0097] The test results obtained through the performance tests of Examples 1-9 and Comparative Examples 1-10 are shown in Table 2.

[0098]

[0099] As can be seen from the performance test results in Table 2, Examples 1-4 lack photocatalysts and functional ingredients, and rely solely on the properties of the essential oil itself. Their fragrance retention, antibacterial, and deodorizing abilities are lower than those of Example 5, but their performance is significantly improved compared to the commercially available product of Comparative Example 10. The commercially available ordinary product only relies on alcohol and fragrance to instantly mask the odor, and has no long-lasting, antibacterial, or decomposition functions, resulting in the worst overall performance.

[0100] Examples 5-7 show significant improvements in fragrance retention and antibacterial properties due to the addition of photocatalysts and antibacterial agents. Example 5 demonstrates excellent balance across all indicators, maintaining fragrance for 2.8 days at 28°C and 60% RH, and for 1.5 days at 40°C and 80% RH under high temperature and humidity conditions. It also exhibits a 99% antibacterial rate and an antibacterial grade of A1, effectively masking odors.

[0101] Examples 8-9 show the same antibacterial rate and odor masking power as Example 5. The antibacterial function primarily originates from core components such as ε-polylysine and tea tree oil; the change in dosage form did not affect its antibacterial efficacy. Comparison of fragrance retention time at 28℃ and 60% RH: solid dosage form > gel dosage form > spray dosage form. The solid dosage form, due to its dense compression, releases the fragrance most slowly. The gel dosage form exhibits a synergistic effect of water evaporation and essential oil diffusion, resulting in longer fragrance retention. The spray dosage form initially evaporates quickly. These three different dosage forms are suitable for different scenarios: spray is suitable for proactive and rapid treatment; gel is suitable for continuous space freshening; and solid is suitable for long-lasting effects in enclosed, small spaces.

[0102] Comparative Example 1 lacks Ag / AgBr / TiO2 photocatalyst. It can retain fragrance and has antibacterial properties, but it completely loses the function of chemically decomposing formaldehyde and odors. Although it cannot be smelled, harmful substances are still present.

[0103] Comparative Example 2 used an unmodified carrier, which had extremely poor adsorption and sustained-release capabilities, resulting in a significantly shortened fragrance duration and insufficient odor masking.

[0104] Comparative Example 3 uses traditional gelatin-gum arabic microcapsules, which lack humidity responsiveness, fail rapidly under high temperature and high humidity, and have poor stability.

[0105] Comparative Example 4, which used tea tree oil and lavender oil, had a monotonous and poorly coordinated scent, lacking the multifunctional synergistic effect of compound essential oils, resulting in poor overall performance.

[0106] Comparative Example 5 used chemical preservatives and antioxidants, which had good functional indicators, but introduced VOCs and skin irritation risks, and its safety did not meet the standards.

[0107] Comparative Example 6, without microcapsule encapsulation, resulted in rapid evaporation of the essential oils and a very short fragrance duration, failing to achieve the technical effect of "long-lasting sustained release".

[0108] Comparative Example 7: Without vacuum impregnation, the essential oils were not firmly loaded and were easily desorbed, resulting in rapid evaporation in the early stages and a shorter fragrance duration.

[0109] Comparative Example 8 lacks a volatility regulator (C12-15 benzoyl alcohol), resulting in poorer release stability under high temperature and high humidity conditions.

[0110] Comparative Example 9 used water as the coating solvent, which led to the failure of microcapsule preparation and a comprehensive decline in performance, equivalent to the loss of some functions.

[0111] Compared to commercially available ordinary products, the 10th product only relies on alcohol and fragrance to instantly mask the odor, without any long-lasting, antibacterial, or decomposition functions, and has the worst overall performance.

[0112] The above experimental results show that the long-lasting, sustained-release, multifunctional air freshener prepared in this application contains a specific mass fraction of microcapsule coating material. By microcapsulating a porous mineral carrier loaded with plant essential oils, the sustained release of the plant essential oils is achieved, ensuring that the fragrance can be maintained at a comfortable concentration level for a longer period, effectively improving air quality. The preparation process, through a step-by-step functional design of porous carriers, photocatalysts, and microcapsules, simultaneously achieves the removal of harmful substances and long-lasting fragrance. Precise control of process, structure, and performance, with vacuum loading ensuring high loading capacity and fluidized bed coating achieving controllable release, and the component ratio optimized through extensive experimentation, can meet the demands of the consumer upgrade market for air purification products that are efficient, long-lasting, and safe.

[0113] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the present invention, they are protected by patent law.

Claims

1. A long-lasting, slow-release, multifunctional air freshener, characterized in that, It is made from the following raw materials in parts by weight: 15-30 parts of compound plant essential oil, 60-75 parts of porous mineral carrier, 1-10 parts of microcapsule coating material 1-10 parts of molding matrix; The compound plant essential oil comprises the following components by weight: 8-15 parts antibacterial essential oil, 5-12 parts aromatic essential oil, 2-6 parts aldehyde-removing essential oil, and 0.5-2 parts vitamin E; wherein the antibacterial essential oil is two or more of tea tree oil, eucalyptus oil, thyme oil, cinnamon oil, and clove bud oil; the aromatic essential oil is two or more of lavender oil, sweet orange oil, Roman chamomile oil, bergamot oil, peppermint oil, and rosemary oil; and the aldehyde-removing aromatic essential oil is two or more of lemon eucalyptus oil, lemongrass oil, cypress oil, fir oil, and bay leaf oil.

2. The long-lasting, slow-release, multifunctional air freshener according to claim 1, characterized in that, The compound plant essential oils consist of an antibacterial essential oil made of tea tree oil and eucalyptus oil in a mass ratio of 3:(1-2), an aromatic essential oil made of lavender oil and sweet orange oil in a mass ratio of 3:(1-2), and an aldehyde-removing aromatic essential oil made of lemon eucalyptus oil and lemongrass oil in a mass ratio of 2:(1-2).

3. The long-acting, slow-release, multifunctional air freshener according to claim 1, characterized in that, The porous mineral carrier is a mixture of modified zeolite molecular sieve and modified diatomaceous earth in a mass ratio of (6-7):(3-4).

4. The long-acting, slow-release, multifunctional air freshener according to claim 1, characterized in that, The microcapsule material is HPMCP, chitosan, genipin and PDMAEMA in a mass ratio of 3:(1.5-2.5):(0.5-1):(1.5-2).

5. The long-acting, slow-release, multifunctional air freshener according to claim 1, characterized in that, The molding matrix includes any one of spray molding matrix, gel molding matrix, or solid molding matrix.

6. The long-acting, sustained-release, multifunctional air freshener according to claim 5, characterized in that, The spray-molded matrix is ​​prepared from the following raw materials in parts by weight: 2-3 parts propylene glycol, 0.5-1 part PEG-40 hydrogenated castor oil, 1.5-2.5 parts anhydrous ethanol, 2-3 parts methyl propylene glycol, and 1-2 parts C12-15 benzoate.

7. The long-acting, sustained-release, multifunctional air freshener according to claim 1, characterized in that, It also includes 3-8 parts of Ag / AgBr / TiO2 composite photocatalyst.

8. The long-acting, sustained-release, multifunctional air freshener according to claim 1, characterized in that, It also includes functional auxiliary ingredients, including: Natural antibacterial agent: 0.5-1.5 parts of ε-polylysine; Odor neutralizer: 1-3 parts of β-cyclodextrin carboxymethyl derivative; Antioxidant: 0.3-1 part rosemary extract.

9. A method for preparing a long-acting, sustained-release, multifunctional air freshener as described in any one of claims 1-8, characterized in that, The following technical solution is adopted: Preparation of S1 compound plant essential oil: Antibacterial essential oil, aromatic essential oil, aldehyde-removing essential oil and stabilizer are mixed in proportion and stirred at 40°C for 30 minutes under light-protected conditions to obtain compound plant essential oil; Pretreatment of S2 porous mineral carrier: After mixing, the porous mineral carrier is ball-milled to 300 mesh; S3 Vacuum-loaded plant essential oil: The composite plant essential oil from step S1 and the porous mineral carrier from step S2 are impregnated at 50-70℃ and -0.1 MPa vacuum for 6-8 hours. S4 Functional Component Combination: Ag / AgBr / TiO2 composite photocatalyst and functional auxiliary components are added to the carrier of essential oil loaded in step S3 to obtain composite functional components; S5 Microcapsule Coating: A coating liquid with a solid content of 5-10% is prepared using microcapsule coating material. The composite functional component from step S4 is placed in a fluidized bed and sprayed with the coating liquid. The weight gain of the coating is controlled at 8-10%, and the coating layer thickness is 1-2 μm to obtain the microcapsule composite functional component. S6 Molding and Processing: The microcapsule composite functional components from step S5 are mixed with the molding matrix and processed into a spray form, gel form, or solid form.

10. The method for preparing the long-acting, sustained-release, multifunctional air freshener according to claim 9, characterized in that: The S5 microcapsule encapsulation is prepared using the following method: S5a. Dissolve the microcapsule coating material in a coating solvent to prepare a coating solution with a solid content of 5-10%, and filter it through a 400-mesh sieve and vacuum degassing to obtain the coating solution; S5b. The composite functional component obtained in step S4 is placed in a fluidized bed and fluidized under the conditions of inlet air velocity of 1.5-2.5 m / s and material temperature of 35-45℃. S5c. Spray the coating liquid obtained in step S5a into the fluidized bed at a rate of 5-10 mL / min through a two-fluid nozzle, and control the atomizing air pressure to be 0.3-0.5 MPa so that the droplet size is 50-100 μm; S5d. Control the coating process until the composite functional component increases in weight by 8-10%, then fluidize and dry at 40-50℃ for 20-40 minutes to form a dense coating layer with a thickness of 1-2μm.

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