Slow-release mosquito-repellent mosquito coil and preparation method thereof

Abstract

The present application relates to mosquito and fly control technology field, especially a slow-release type high-efficiency mosquito-repellent mosquito incense and its preparation method, through the synergistic effect of porous slow-release carrier, plant source film forming agent and nano slow-release enhancer, the uniform and persistent release of mosquito-repellent active ingredients is realized, the mosquito-repellent time is significantly prolonged, the problems of traditional mosquito incense, such as fast release in early stage and insufficient effect in later stage, are avoided, at the same time, based on the definite mass ratio compounding, the active ingredients, such as citral, artemisia leaf, menthone, lavender acetate and the like in plant source synergistic extract, and chlorofluorohydrin ester or tetrafluoromethane ester produce significant synergistic mosquito-repellent effect, the instantaneous knockdown and repellent effect are improved, the total amount of chemical ester is reduced, the environmental chemical residue is reduced, the utilization of plant source waste powder realizes resource circulation, the film forming agent and slow-release carrier jointly optimize the uniformity of mosquito incense combustion or volatilization, and stable mosquito-repellent concentration of the product in the whole use cycle is ensured.

Description

Technical Field

[0001] This invention relates to the field of mosquito and fly control technology, and in particular to a slow-release, highly effective mosquito repellent coil and its preparation method. Background Technology

[0002] Mosquito coils are a common household hygiene and insecticidal product, typically made from charcoal powder, plant powder, or similar base materials, with added insecticidal active ingredients, followed by pressing and drying processes. Mosquito coils slowly release their active ingredients through smoldering, creating a sustained mosquito-repelling concentration in the indoor space, thus protecting people from mosquito bites. Traditional mosquito coils mostly use pyrethroid insecticides as their active ingredient, which are highly effective, broad-spectrum, and low in toxicity. In recent years, as consumers have increasingly focused on natural and environmentally friendly products, some mosquito coil manufacturers have begun to incorporate plant-derived extracts to improve the user experience and reduce the amount of chemically synthesized ingredients.

[0003] Existing mosquito coil products suffer from uneven release of active mosquito-repelling ingredients, short duration of mosquito repellency, and unclear synergistic mechanisms between chemical pyrethroids and plant-derived ingredients, making it difficult for products to simultaneously meet the needs of high efficiency, long-lasting effect, and low chemical residue. Summary of the Invention

[0004] The purpose of this invention is to provide a slow-release, high-efficiency mosquito repellent coil and its preparation method, which solves the technical problems in the prior art of uneven release of mosquito repellent active ingredients, short mosquito repellent duration, and unclear synergistic effect mechanism between chemical pyrethroids and plant-derived ingredients, making it difficult for the product to meet the requirements of high efficiency, long-lasting effect and low chemical residue.

[0005] To achieve the above objectives, the present invention provides a slow-release, high-efficiency mosquito repellent coil, comprising: 50-85 parts charcoal powder, 5-25 parts plant-derived waste powder, 5-15 parts porous slow-release carrier, 1-5 parts plant-derived film-forming agent, 2-8 parts binder, 0.04-0.08 parts chlorpyrifos or 0.02-0.05 parts tetrafluoromethrin, 0.5-2 parts plant-derived synergistic extract, 0.5-3 parts natural synergist, and 0.5-2 parts nano-slow-release enhancer;

[0006] The plant-derived synergistic extract is composed of artemisia, peppermint, citral, and lavender, processed via supercritical fluid extraction. The compound essential oil obtained by the extraction process has a raw material mass ratio of 3:1:1:1 for mugwort, peppermint, citral, and lavender.

[0007] The porous sustained-release carrier is natural red zeolite powder that has been acid-modified and then surface-modified with a silane coupling agent. The modification process includes: soaking the natural red zeolite powder in a 0.5-1.5 mol / L hydrochloric acid solution for 2-4 hours, filtering and washing it, calcining and activating it at 300-500℃ for 2-3 hours, and then performing a surface grafting reaction with γ-aminopropyltriethoxysilane in anhydrous ethanol. After drying, modified red zeolite powder is obtained with a particle size of 150-200 mesh and a specific surface area of ​​80-120 m² / g.

[0008] The plant-derived film-forming agent is one or a combination of two of konjac glucomannan and sodium alginate, wherein the mass ratio of konjac glucomannan to sodium alginate is 1:0.5-1:2.

[0009] The natural synergist is one or more of Artemisia argyi extract, citronella oil, and eugenol oil;

[0010] The nano-controlled release enhancer is chitosan nanoparticles or β-cyclodextrin with a particle size of 50-200 nm. The nano-controlled release enhancer, together with the porous controlled release carrier and the plant-derived film-forming agent, forms a multi-level controlled release system. The nano-controlled release enhancer is loaded on the inner surface of the pores of the porous controlled release carrier, and the plant-derived film-forming agent is coated on the outer surface of the porous controlled release carrier.

[0011] Among them, the supercritical fluid of the plant-derived synergistic extract The extraction process parameters are: extraction pressure 20-30 MPa, extraction temperature 35-45℃. Flow rate 20-30 L / h, extraction time 2-4 hours.

[0012] The charcoal powder is a mixture of bamboo charcoal powder and walnut shell charcoal powder in a weight ratio of 1:1 to 2:1.

[0013] The adhesive is a mixture of pregelatinized starch and carboxymethyl cellulose.

[0014] The plant-derived waste powder is obtained by mixing peppermint leaf residue after extracting menthone by steam distillation with Artemisia argyi residue in a weight ratio of 3:1-5:1, and then processing it through a process including low-temperature drying, gradient incineration, tail gas condensation and recovery, and vacuum distillation.

[0015] This invention also provides a preparation method for preparing the slow-release, high-efficiency mosquito repellent as described above.

[0016] include: Natural red zeolite powder was soaked in 0.5-1.5 mol / L hydrochloric acid solution for 2-4 hours, filtered and washed, then calcined and activated at 300-500℃ for 2-3 hours, and then surface grafted with γ-aminopropyltriethoxysilane in anhydrous ethanol. After drying, modified red zeolite powder was obtained. Chitosan nanoparticles or β-cyclodextrin were dispersed in an ethanol-water mixed solvent, and modified red zeolite powder was added. The mixture was stirred at 40-60℃ for 2-4 hours to load the nano-sustained-release reinforcing agent onto the pore surface of the modified red zeolite powder. After filtration and drying, a supported porous sustained-release carrier was obtained. Dissolve chlorpyrifos or tetrafluoromethrin and plant-derived synergistic extracts in an organic solvent, add a supported porous sustained-release carrier, and impregnate at 30-50℃ for 4-8 hours to allow the active ingredients to be adsorbed into the pores of the porous sustained-release carrier. Plant-derived film-forming agents are dissolved in water to form a film-forming solution, which is then mixed with a porous sustained-release carrier loaded with active ingredients. The mixture is stirred to ensure that the film-forming agent is uniformly coated on the outer surface of the carrier, and then dried to obtain sustained-release functional particles. The charcoal powder, plant-derived waste powder, natural synergists, binders and slow-release functional particles are mixed evenly, water is added to make a paste, and the paste is pressed into shape by a mold and dried to obtain the finished mosquito coil.

[0017] This invention discloses a slow-release, high-efficiency mosquito repellent coil and its preparation method. Through the synergistic effect of a porous slow-release carrier, a plant-derived film-forming agent, and a nano-scale slow-release enhancer, it achieves uniform and sustained release of the effective mosquito-repellent ingredients, significantly extending the mosquito-repellent duration and avoiding the problems of excessively rapid release and insufficient efficacy in the later stages found in traditional mosquito coils. Simultaneously, based on a defined mass ratio formulation, the active ingredients such as citral, artemisia, menthone, and lavender acetate in the plant-derived synergistic extract exhibit a significant synergistic mosquito-repellent enhancement effect with chlorpyrifos or tetrafluoromethrin. This not only improves the instantaneous knockdown and repellency effects but also reduces the total amount of chemical pyrethroids used, minimizing environmental chemical residues. Furthermore, the utilization of plant-derived waste powder achieves resource recycling, and the film-forming agent and slow-release carrier jointly optimize the uniformity of mosquito coil combustion or volatilization, ensuring that the product maintains a stable mosquito-repellent concentration throughout its entire usage cycle. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0019] Figure 1 This is a flowchart of the preparation method of the present invention. Detailed Implementation

[0020] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0021] Please refer to Figure 1 , Figure 1 This is a flowchart of the preparation method of the present invention.

[0022] This invention provides a slow-release, high-efficiency mosquito repellent coil, comprising: 50-85 parts charcoal powder, 5-25 parts plant-derived waste powder, 5-15 parts porous slow-release carrier, 1-5 parts plant-derived film-forming agent, 2-8 parts binder, 0.04-0.08 parts chlorpyrifos or 0.02-0.05 parts tetrafluoromethrin, 0.5-2 parts plant-derived synergistic extract, 0.5-3 parts natural synergist, and 0.5-2 parts nano-slow-release enhancer;

[0023] The plant-derived synergistic extract is composed of artemisia, peppermint, citral, and lavender, processed via supercritical fluid extraction. The compound essential oil obtained by the extraction process has a raw material mass ratio of 3:1:1:1 for mugwort, peppermint, citral, and lavender.

[0024] The porous sustained-release carrier is natural red zeolite powder that has been acid-modified and then surface-modified with a silane coupling agent. The modification process includes: soaking the natural red zeolite powder in a 0.5-1.5 mol / L hydrochloric acid solution for 2-4 hours, filtering and washing, calcining and activating it at 300-500℃ for 2-3 hours, and then performing a surface grafting reaction with γ-aminopropyltriethoxysilane in anhydrous ethanol. After drying, modified red zeolite powder is obtained with a particle size of 150-200 mesh and a specific surface area of ​​80-120 m² / g.

[0025] The plant-derived film-forming agent is one or a combination of two of konjac glucomannan and sodium alginate, wherein the mass ratio of konjac glucomannan to sodium alginate is 1:0.5-1:2.

[0026] The natural synergist is one or more of Artemisia argyi extract, citronella oil, and eugenol;

[0027] The nano-controlled release enhancer is chitosan nanoparticles or β-cyclodextrin with a particle size of 50-200 nm. The nano-controlled release enhancer, together with the porous controlled release carrier and the plant-derived film-forming agent, forms a multi-level controlled release system. The nano-controlled release enhancer is loaded on the inner surface of the pores of the porous controlled release carrier, and the plant-derived film-forming agent is coated on the outer surface of the porous controlled release carrier.

[0028] The supercritical fluid of the plant-derived synergistic extract The extraction process parameters are: extraction pressure 20-30 MPa, extraction temperature 35-45℃. Flow rate 20-30 L / h, extraction time 2-4 hours.

[0029] The charcoal powder is a mixture of bamboo charcoal powder and walnut shell charcoal powder in a weight ratio of 1:1 to 2:1;

[0030] The adhesive is a mixture of pregelatinized starch and carboxymethyl cellulose.

[0031] Plant-derived waste powder is obtained by mixing peppermint leaf residue after extracting menthone by steam distillation with Artemisia argyi residue in a weight ratio of 3:1-5:1, and then processing it through steps including low-temperature drying, gradient incineration, tail gas condensation and recovery, and vacuum distillation.

[0032] Example 1: In this example, the preparation method of the slow-release, high-efficiency mosquito repellent coil is as follows:

[0033] Natural red zeolite powder was soaked in 0.5-1.5 mol / L hydrochloric acid solution for 2-4 hours, filtered and washed, then calcined and activated at 300-500℃ for 2-3 hours, and then surface grafted with γ-aminopropyltriethoxysilane in anhydrous ethanol. After drying, modified red zeolite powder was obtained.

[0034] Chitosan nanoparticles or β-cyclodextrin were dispersed in an ethanol-water mixed solvent, and modified red zeolite powder was added. The mixture was stirred at 40-60℃ for 2-4 hours to load 0.5 parts of nano-slow-release reinforcing agent onto the pore surface of the modified red zeolite powder. After filtration and drying, a supported porous slow-release carrier was obtained.

[0035] Dissolve 0.04 parts of chlorfluazuron or 0.02 parts of tetrafluazuron and 0.5 parts of plant-derived synergistic extract in an organic solvent, add 5 parts of a supported porous sustained-release carrier, and impregnate at 30-50℃ for 4-8 hours to allow the active ingredients to be adsorbed into the pores of the porous sustained-release carrier.

[0036] One part of plant-derived film-forming agent was dissolved in water to form a film-forming solution, which was then mixed with a porous sustained-release carrier loaded with active ingredients. The mixture was stirred to ensure that the film-forming agent was uniformly coated on the outer surface of the carrier. After drying, sustained-release functional particles were obtained.

[0037] Mix 50 parts charcoal powder, 5 parts plant-derived waste powder, 0.5 parts natural synergist, 2 parts binder and slow-release functional particles evenly, add water to make a paste, press it into shape with a mold and dry it to obtain the finished mosquito coil.

[0038] Example 2: In this example, the preparation method of the slow-release, high-efficiency mosquito repellent coil is as follows:

[0039] Natural red zeolite powder was soaked in 0.5-1.5 mol / L hydrochloric acid solution for 2-4 hours, filtered and washed, then calcined and activated at 300-500℃ for 2-3 hours, and then surface grafted with γ-aminopropyltriethoxysilane in anhydrous ethanol. After drying, modified red zeolite powder was obtained.

[0040] Chitosan nanoparticles or β-cyclodextrin were dispersed in an ethanol-water mixed solvent, and modified red zeolite powder was added. The mixture was stirred at 40-60℃ for 2-4 hours to load 1.25 parts of nano-slow-release reinforcing agent onto the pore surface of the modified red zeolite powder. After filtration and drying, a supported porous slow-release carrier was obtained.

[0041] Dissolve 0.06 parts of chlorfluazuron or 0.035 parts of tetrafluazuron and 1.25 parts of plant-derived synergistic extract in an organic solvent, add 10 parts of a supported porous sustained-release carrier, and impregnate at 30-50℃ for 4-8 hours to allow the active ingredients to be adsorbed into the pores of the porous sustained-release carrier.

[0042] Three parts of plant-derived film-forming agent were dissolved in water to form a film-forming solution, which was then mixed with a porous sustained-release carrier loaded with active ingredients. The mixture was stirred to ensure that the film-forming agent was uniformly coated on the outer surface of the carrier. After drying, sustained-release functional particles were obtained.

[0043] Mix 68 parts charcoal powder, 15.5 parts plant-derived waste powder, 1.75 parts natural synergist, 5 parts binder and slow-release functional particles evenly, add water to make a paste, press it into shape with a mold, and dry it to obtain the finished mosquito coil.

[0044] Example 3: In this example, the preparation method of the slow-release, high-efficiency mosquito repellent coil is as follows: Natural red zeolite powder was soaked in 0.5-1.5 mol / L hydrochloric acid solution for 2-4 hours, filtered and washed, then calcined and activated at 300-500℃ for 2-3 hours, and then surface grafted with γ-aminopropyltriethoxysilane in anhydrous ethanol. After drying, modified red zeolite powder was obtained. Chitosan nanoparticles or β-cyclodextrin were dispersed in an ethanol-water mixed solvent, and modified red zeolite powder was added. The mixture was stirred at 40-60℃ for 2-4 hours to load 0.5 parts of nano-slow-release reinforcing agent onto the pore surface of the modified red zeolite powder. After filtration and drying, a supported porous slow-release carrier was obtained. Dissolve 0.08 parts of chlorfluazuron or 0.05 parts of tetrafluazuron and 2 parts of plant-derived synergistic extract in an organic solvent, add 15 parts of a supported porous sustained-release carrier, and impregnate at 30-50℃ for 4-8 hours to allow the active ingredients to be adsorbed into the pores of the porous sustained-release carrier. Five parts of plant-derived film-forming agent were dissolved in water to form a film-forming solution, which was then mixed with a porous sustained-release carrier loaded with active ingredients. The mixture was stirred to ensure that the film-forming agent was uniformly coated on the outer surface of the carrier. After drying, sustained-release functional particles were obtained.

[0045] Mix 85 parts charcoal powder, 25 parts plant-derived waste powder, 3 parts natural synergist, 8 parts binder and slow-release functional particles evenly, add water to make a paste, press it into shape with a mold, and dry it to obtain the finished mosquito coil.

[0046] During the impregnation and adsorption process, a stirring speed of 30-60 r / min is maintained, and vacuum degassing is performed for 20-40 minutes in the second half of the adsorption process to enhance the penetration of active ingredients into the deep pores of the carrier.

[0047] Secondly, when the plant-derived film-forming agent is dissolved in water to form a film-forming solution, the mass concentration of the film-forming solution is 1-5%, and glycerol or sorbitol, accounting for 0.5-2% of the mass of the film-forming agent, is added to the film-forming solution as a plasticizer.

[0048] Meanwhile, in the step of obtaining the slow-release functional particles after drying, the drying temperature is 40-60℃, and the particles are dried until the moisture content is ≤5%; before mixing the charcoal powder, plant-derived waste powder, natural synergist, binder and slow-release functional particles evenly, the charcoal powder and plant-derived waste powder are first passed through an 80-120 mesh sieve.

[0049] Furthermore, in the process of molding and drying the mosquito coil to obtain the finished product, the molding pressure is 5-15 MPa, the drying temperature is 50-80℃, and the moisture content of the finished mosquito coil is ≤8%.

[0050] Working Principle: Through the synergistic effect of porous slow-release carriers, plant-derived film-forming agents, and nano-slow-release enhancers, the uniform and sustained release of mosquito-repellent active ingredients is achieved, significantly extending the mosquito-repellent duration and avoiding the problems of traditional mosquito coils where the initial release is too rapid and the later efficacy is insufficient. Simultaneously, based on a clearly defined mass ratio formulation, the active ingredients in the plant-derived synergistic extract, such as citral, artemisia, menthone, and lavender acetate, produce a significant synergistic mosquito-repellent enhancement effect with chlorpyrifos or tetrafluoromethrin, not only improving the instantaneous knockdown and repellency effects but also reducing the total amount of chemical pyrethroids used, thus reducing environmental chemical residues. Furthermore, the utilization of plant-derived waste powder achieves resource recycling, and the film-forming agent and slow-release carrier jointly optimize the uniformity of mosquito coil combustion or volatilization, ensuring that the product maintains a stable mosquito-repellent concentration throughout its entire use cycle.

[0051] The knockdown rate (KT50) of the mosquito coil of this application against Culex pipiens pallens in the first hour after it is lit is 3.2 minutes, KT50 in the sixth hour is 4.1 minutes, and KT50 in the eighth hour is 5.3 minutes. In contrast, the KT50 of ordinary commercially available mosquito coils has risen to 8.7 minutes in the sixth hour and exceeds 12 minutes in the eighth hour.

[0052] The mosquito coil of this invention exhibits a spatial mosquito repellent concentration fluctuation of less than ±12% within an 8-hour usage period, and the total amount of chemical pyrethroids used is reduced by approximately 35%. The addition of plant-derived synergistic extracts enhances the overall mosquito repellent activity by approximately 27%, fully demonstrating its advantages of uniform slow release, high efficiency and long-lasting effect, and low carbon and environmental friendliness.

[0053] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A slow-release, highly effective mosquito repellent coil, characterized in that, It includes: 50-85 parts charcoal powder, 5-25 parts plant-derived waste powder, 5-15 parts porous slow-release carrier, 1-5 parts plant-derived film-forming agent, 2-8 parts binder, 0.04-0.08 parts chlorpyrifos or 0.02-0.05 parts tetrafluoromethrin, 0.5-2 parts plant-derived synergistic extract, 0.5-3 parts natural synergist, and 0.5-2 parts nano slow-release enhancer; The plant-derived synergistic extract is composed of artemisia, peppermint, citral, and lavender, processed via supercritical fluid extraction. The compound essential oil obtained by the extraction process has a raw material mass ratio of 3:1:1:1 for mugwort, peppermint, citral, and lavender.

2. The slow-release, high-efficiency mosquito repellent coil as described in claim 1, characterized in that, The porous sustained-release carrier is natural red zeolite powder that has been acid-modified and then surface-modified with a silane coupling agent. The modification process includes: soaking the natural red zeolite powder in a 0.5-1.5 mol / L hydrochloric acid solution for 2-4 hours, filtering and washing, calcining and activating it at 300-500℃ for 2-3 hours, and then performing a surface grafting reaction with γ-aminopropyltriethoxysilane in anhydrous ethanol. After drying, modified red zeolite powder is obtained with a particle size of 150-200 mesh and a specific surface area of ​​80-120 m² / g. The plant-derived film-forming agent is one or a combination of two of konjac glucomannan and sodium alginate, wherein the mass ratio of konjac glucomannan to sodium alginate is 1:0.5-1:

2.

3. The slow-release, high-efficiency mosquito repellent coil as described in claim 2, characterized in that, The natural synergist is one or more of Artemisia argyi extract, citronella oil, and eugenol; The nano-controlled release enhancer is chitosan nanoparticles or β-cyclodextrin with a particle size of 50-200 nm. The nano-controlled release enhancer, together with the porous controlled release carrier and the plant-derived film-forming agent, forms a multi-level controlled release system. The nano-controlled release enhancer is loaded on the inner surface of the pores of the porous controlled release carrier, and the plant-derived film-forming agent is coated on the outer surface of the porous controlled release carrier.

4. The slow-release, high-efficiency mosquito repellent coil as described in claim 3, characterized in that, The supercritical fluid of the plant-derived synergistic extract The extraction process parameters are: extraction pressure 20-30 MPa, extraction temperature 35-45℃. Flow rate 20-30 L / h, extraction time 2-4 hours.

5. The slow-release, high-efficiency mosquito repellent coil as described in claim 4, characterized in that, The charcoal powder is a mixture of bamboo charcoal powder and walnut shell charcoal powder in a weight ratio of 1:1 to 2:1; The adhesive is a mixture of pregelatinized starch and carboxymethyl cellulose.

6. The slow-release, high-efficiency mosquito repellent coil as described in claim 5, characterized in that, Plant-derived waste powder is obtained by mixing peppermint leaf residue after extracting menthone by steam distillation with Artemisia argyi residue in a weight ratio of 3:1-5:1, and then processing it through steps including low-temperature drying, gradient incineration, tail gas condensation and recovery, and vacuum distillation.

7. A preparation method for preparing the slow-release, high-efficiency mosquito repellent as described in claim 6, characterized in that, include: Natural red zeolite powder was soaked in 0.5-1.5 mol / L hydrochloric acid solution for 2-4 hours, filtered and washed, then calcined and activated at 300-500℃ for 2-3 hours, and then surface grafted with γ-aminopropyltriethoxysilane in anhydrous ethanol. After drying, modified red zeolite powder was obtained. Chitosan nanoparticles or β-cyclodextrin were dispersed in an ethanol-water mixed solvent, and modified red zeolite powder was added. The mixture was stirred at 40-60℃ for 2-4 hours to load the nano-sustained-release reinforcing agent onto the pore surface of the modified red zeolite powder. After filtration and drying, a supported porous sustained-release carrier was obtained. Dissolve chlorpyrifos or tetrafluoromethrin and plant-derived synergistic extracts in an organic solvent, add a supported porous sustained-release carrier, and impregnate at 30-50℃ for 4-8 hours to allow the active ingredients to be adsorbed into the pores of the porous sustained-release carrier. Plant-derived film-forming agents are dissolved in water to form a film-forming solution, which is then mixed with a porous sustained-release carrier loaded with active ingredients. The mixture is stirred to ensure that the film-forming agent is uniformly coated on the outer surface of the carrier, and then dried to obtain sustained-release functional particles. The charcoal powder, plant-derived waste powder, natural synergists, binders and slow-release functional particles are mixed evenly, water is added to make a paste, and the paste is pressed into shape by a mold and dried to obtain the finished mosquito coil.

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