A mosquito repellent composition, use and space repellent microcapsule

Abstract

The present invention belongs to the technical field of insect repellent products, and discloses a mosquito repellent composition, use and space repellent microcapsule, the mosquito repellent composition comprises a first repellent component and a second repellent component, the weight ratio of the first repellent component to the second repellent component is 2-5:1-6; the first repellent component is eucalyptus essential oil and / or nutmeg essential oil, and the second repellent component is cinnamon essential oil and / or lemon balm essential oil. The first repellent component composed of eucalyptus essential oil and / or nutmeg essential oil and the second repellent component composed of cinnamon essential oil and / or lemon balm essential oil in the present invention can produce a synergistic effect, effectively improve the degree of binding between the composition and the odor binding protein of mosquitoes, thereby affecting the behavior of mosquitoes and improving the mosquito repellent effect.

Description

Technical Field

[0001] The invention relates to the technical field of insect repellent products, and in particular to a mosquito repellent composition, use and space repellent microcapsule. Background Art

[0002] Mosquitoes can transmit a variety of diseases. For example, Anopheles sinensis can transmit malaria, Culex tritaeniorhynchus and Culex pipiens can transmit Japanese encephalitis, while Aedes aegypti and Aedes albopictus are the transmitters of dengue fever. In addition, some parasites can also be transmitted by mosquitoes, such as filariasis. Secondly, mosquito bites can also cause troubles to people's daily lives, such as affecting sleep, hindering rest and work, etc.

[0003] Due to the health and life problems caused by mosquitoes, a variety of mosquito repellent products are now on the market. The main ingredients of common chemical mosquito repellents are DEET, picaridin and mesitylene, which all have relatively good mosquito repellent effects, but they also have certain toxicity and irritation. People with sensitive skin, wounds and pregnant women and infants should avoid using them.

[0004] Prior art 1: Chinese patent 201911059149.6 discloses a compound mosquito repellent essential oil, application and mosquito repellent, wherein the compound mosquito repellent essential oil contains nepeta oil and peppermint oil, and the mass ratio of nepeta oil to peppermint oil is 1-9:9-1.

[0005] According to paragraph 0025 of the specification of prior art 1: Based on the screening of 12 plant essential oils, the applicant found that the two plant essential oils with the best mosquito repellent effect are nepeta oil and peppermint oil, which show high mosquito repellent activity against Aedes albopictus at different concentrations. The two plant essential oils can be compounded to prepare a nano mosquito repellent ointment with better mosquito repellent effect.

[0006] Prior art 1 uses plant essential oils as mosquito repellent products with the characteristics of low toxicity, low residue, good compatibility with the environment, etc., and prior art 1 discloses that different plant essential oils have different repellent effects on mosquitoes. Based on this, plant essential oil mosquito repellent products should become a hot topic; however, there are relatively few plant essential oil mosquito repellent products on the market, and the main reasons are the following two points:

[0007] (1) There are many types of plant essential oils, and different plant essential oil combinations have different repellent effects on mosquitoes. Therefore, it is a time-consuming and labor-intensive study to find a plant essential oil mosquito repellent composition with a high repellent effect. Therefore, there are relatively few plant essential oil mosquito repellent compositions with excellent repellent effects on the market.

[0008] (2) Essential oils are volatile and have a short-term mosquito repellent effect, so they cannot achieve long-term mosquito repellent effects.

[0009] The technical problem to be solved by the present application is: how to develop a mosquito repellent composition to effectively improve the repellent effect. Summary of the invention

[0010] One of the purposes of the present invention is to provide a mosquito repellent composition, which, through the compounding of specific plant essential oils, starts from the mechanism of affecting mosquito odor binding protein, effectively changes the behavior of mosquitoes and thus achieves an excellent mosquito repellent effect.

[0011] Another object of the present invention is to provide a use of the mosquito repellent composition in preparing a repellent.

[0012] At the same time, the present invention also provides a space repellent microcapsule, which has the advantage of long-acting sustained release, effectively improving the use stability, storage stability and durability of the mosquito repellent effect of the plant essential oil, and the material is non-toxic, has good biocompatibility, and has no irritation or side effects on the human body.

[0013] The present invention further provides a method for preparing space repellent microcapsules. The space repellent microcapsules prepared by the method have stable properties and do not directly contact the skin when used in products in the form of mosquito repellent patches, mosquito repellent bracelets, mosquito repellent fans, etc., but indirectly produce a repellent effect and avoid irritation to the skin.

[0014] To achieve the above-mentioned object, the present invention provides a mosquito repellent composition, comprising a first repellent component and a second repellent component, wherein the weight ratio of the first repellent component to the second repellent component is 2-5:1-6; the first repellent component is eucalyptus essential oil and / or nutmeg essential oil, and the second repellent component is cinnamon essential oil and / or lemon balm essential oil.

[0015] As a preferred technical solution, when the first repellent component is nutmeg essential oil and the second repellent component is lemon balm essential oil, the weight ratio of nutmeg essential oil to lemon balm essential oil is 2-5:1-6.

[0016] As another preferred technical solution, the mosquito repellent composition also includes a third repellent component, which is lemon verbena essential oil, the first repellent component is a combination of eucalyptus essential oil and nutmeg essential oil, and the second repellent component is cinnamon essential oil and lemon balm essential oil; the weight ratio of the eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil, lemon balm essential oil and lemon verbena essential oil is 2:1:3:3:1.

[0017] Generally speaking, repellents work by: (1) interfering with the mosquito's ability to properly find a host; (2) changing the mosquito's movement patterns; or (3) causing death when the mosquito comes into contact with the repellent.

[0018] As for the first mode of action, odorant binding proteins (OBPs) play a crucial role in regulating mosquito behavior.

[0019] OBPs are responsible for connecting the external environment with odorant receptors (ORs); odor molecules from the host first pass through the pore canal of the receptor, and then are bound and dissolved by OBPs; subsequently, the OBP-odorant complex is transported through the receptor lymph and eventually reaches the sensory dendrites to activate membrane-bound ORs. The activated ORs are able to convert chemical signals into electrical signals, which are transmitted from the axons to the central nervous system, triggering corresponding behavioral responses in insects.

[0020] Therefore, the OBP-odorant complex is necessary for the activation of OR. Studies have found that odorant-binding proteins such as AealOBP3 are OBP candidates that may be involved in sensing host odor in Aedes albopictus, and odorant-binding proteins such as CquiOBP are OBPs that sense host odor in Culex quinquefasciatus.

[0021] In the technical scheme of the present invention, essential oils such as eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil, lemon balm essential oil, lemon verbena essential oil, etc. form competitive binding with odor binding proteins such as AealOBP3 or CquiOBP, resulting in the inability of odor binding proteins such as AealOBP3 or CquiOBP to bind to odor molecules emitted by the host, unable to form OBP-odor complexes, and unable to activate odor receptors (ORs), thereby causing the loss or weakening of the ability of Aedes albopictus and Culex pipiens to find hosts.

[0022] Furthermore, the binding abilities of eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil, lemon balm essential oil, lemon verbena essential oil and other essential oils with odor binding proteins such as AealOBP3 or CquiOBP are strong or weak, and the reason is that the binding mechanisms are different. The present invention uses eucalyptus essential oil and / or nutmeg essential oil as the first repellent component and cinnamon essential oil and / or lemon balm essential oil as the second repellent component, and effectively improves the repellent effect of the mosquito repellent composition on Aedes albopictus and Culex pipiens quinquefasciatus through the synergistic compounding of different odor binding protein binding mechanisms.

[0023] Especially when nutmeg essential oil and lemon balm essential oil are combined, the repellent effect on Culex pipiens is significantly improved.

[0024] The present invention also provides a use of the mosquito repellent composition to prepare a repellent.

[0025] Furthermore, the repellent is a space repellent or a contact repellent.

[0026] In addition, the present invention also provides a space repellent microcapsule, which comprises 6-12 parts of core material, 260-1040 parts of wall material and 1-2 parts of cross-linking agent by weight, wherein the core material is the mosquito repellent composition, and the wall material comprises gum arabic, gelatin, N-isopropylacrylamide, N,N-methylenebisacrylamide and deionized water.

[0027] Furthermore, the weight ratio of the gum arabic, gelatin, N-isopropylacrylamide, N,N-methylenebisacrylamide and deionized water is: 0.4-0.8: 0.4-0.8: 4-8: 0.4-0.8: 254.8-1029.6.

[0028] Preferably, the cross-linking agent is at least one of transglutaminase, formaldehyde, glutaraldehyde and genipin.

[0029] The present invention also provides a method for preparing the above-mentioned space repellent microcapsules, comprising the following steps:

[0030] Step 1: Gum arabic, gelatin, N-isopropylacrylamide, N,N-methylenebisacrylamide and deionized water are continuously stirred at 50°C until they are completely dissolved to form a uniform colloidal solution, and the stirring is continued for 1 hour to ensure sufficient mixing, and finally a wall material solution is obtained;

[0031] Step 2: dripping the mosquito repellent composition into the wall material solution, stirring the wall material solution at the same time, until the mosquito repellent composition and the wall material solution are completely mixed and fully emulsified to form a uniform and stable emulsion;

[0032] Step 3: Slowly add 10% acetic acid solution to the emulsion obtained in step 2 at a temperature of 0-5°C to adjust the pH value of the system to 3-4, and then keep warm for 60 minutes to obtain a coagulation system.

[0033] Step 4: maintaining 0-5° C., adding 10% sodium hydroxide solution to adjust the pH value of the coagulation system to 5.8-6.2, adding a cross-linking agent to form a microcapsule dispersion, and then standing the microcapsule dispersion for stratification and centrifugation to obtain a supernatant;

[0034] Step 5: freeze-dry the supernatant to obtain powdered space repellent microcapsules.

[0035] Preferably, stirring is maintained during step 3 and step 4.

[0036] Preferably, the present invention uses gum arabic and gelatin as wall materials to wrap the mosquito repellent composition, and also adds two thermosensitive materials, N-isopropyl acrylamide and N, N-methylene bisacrylamide. When the two thermosensitive materials, N-isopropyl acrylamide and N, N-methylene bisacrylamide, are used to prepare space repellent microcapsules, the following uses can be achieved through their thermosensitive properties:

[0037] When the temperature is higher than 35°C, the wall material of the space repellent microcapsule shrinks, and when the temperature is lower than 35°C, the wall material of the space repellent microcapsule returns to its original state; especially when the space repellent microcapsule is used in a mosquito repellent patch, since the mosquito repellent patch is attached to the human body, the wall material of the space repellent microcapsule will always be in a contracted state, thereby achieving a highly sustained release effect and effectively improving the durability of the mosquito repellent composition.

[0038] Beneficial Effects

[0039] Compared with the prior art, the present invention has at least the following advantages:

[0040] (1) The present invention provides a mosquito repellent composition, wherein a first repellent component composed of eucalyptus essential oil and / or nutmeg essential oil and a second repellent component composed of cinnamon essential oil and / or lemon balm essential oil can produce a synergistic effect, effectively improving the degree of binding between the composition and the odor binding protein of mosquitoes, thereby affecting the behavior of mosquitoes and improving the mosquito repellent effect;

[0041] (2) The present invention further found that compared with eucalyptus essential oil, nutmeg essential oil has a weaker binding degree to the odor binding protein of mosquitoes, but when it is combined with lemon balm essential oil, the synergistic mosquito repellent effect produced is better than that produced by the combination of eucalyptus essential oil and lemon balm essential oil; in particular, the repellent effect produced by it is significantly improved against Culex pipiens quinquefasciatus;

[0042] (3) The present invention provides a spatial repellent microcapsule, which effectively encapsulates a mosquito repellent composition by using a wall material composed of gum arabic, gelatin, N-isopropylacrylamide, N,N-methylenebisacrylamide and deionized water, thereby effectively improving the use stability, storage stability and durability of the mosquito repellent effect of the plant essential oil, effectively solving the problem of the essential oil being easy to volatilize, and achieving a long-lasting slow-release mosquito repellent effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention is further described below in conjunction with the accompanying drawings and embodiments;

[0044] Figure 1 This is the thermal stability test result of Application Example 1 of the present invention;

[0045] Figure 2 is an optical microscope image of Application Example 1 of the present invention;

[0046] Figure 3 It is a scanning electron microscope image of Application Example 1 of the present invention. DETAILED DESCRIPTION

[0047] The present invention will be further described below in conjunction with the embodiments, but it does not constitute any limitation to the present invention. Any limited number of modifications made within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0048] In order to explain the technical content of the present invention in detail, further description is given below in conjunction with the implementation modes.

[0049] A mosquito repellent composition was prepared according to the formula shown in Table 1 for subsequent mosquito repellent effect verification, wherein the eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil, lemon balm essential oil, lemon verbena essential oil, peppermint essential oil, and marjoram essential oil were all purchased from Chongqing Chunziyu Trading Company.

[0050] Unless otherwise specified, the parts are parts by weight.

[0051] Table 1 mosquito repellent composition formula

[0052]

[0053] Performance Testing

[0054] 1. Repellency rate

[0055] 1.1 Aedes albopictus repellency rate

[0056] Test method: Recruit 4 volunteers (two men and two women). Before the test begins, prepare the mosquitoes needed for the test. Catch 5-7 day old female Aedes albopictus mosquitoes that have not sucked blood and put them in a mosquito cage. Do not provide sugar water and starve them for 12 hours in advance in preparation for the experiment. Before the test, wash the hands and arms of the volunteers with clean water and then with 75% ethanol. The volunteers put on the homemade test equipment, which consists of sleeves and gloves. There is a 5×5cm 2 The area is used as the test area, and gloves are put on to protect against mosquito bites. First, during the test, the insect repellent patch is placed in the center of the test area. One arm is used as a blank control, and the other arm is used as an essential oil treatment group. The arm is placed in the mosquito cage for 2 minutes to observe whether there are mosquitoes landing. The test is repeated every 15 minutes. The number of mosquito attacks (the number of mosquitoes landing on the exposed area and the number of mosquitoes trying to bite) is recorded, and the repellency rate of Aedes albopictus is calculated within 1 hour.

[0057] Percentage repellency calculation formula: PR = (Nc-Nt) / Nc×100%

[0058] Nc represents the number of mosquito bites on the blank control hand, and Nt represents the number of mosquito bites on the essential oil treatment group

[0059] 1.2 Repellency rate of Culex pipiens

[0060] Test method: Recruit 4 volunteers (two men and two women). Before the test begins, prepare the mosquitoes needed for the test. Culex pipiens quinquefasciatus female mosquitoes that are 5-7 days old and have not sucked blood are caught in mosquito cages. Sugar water is not provided and they are starved for 12 hours in advance in preparation for the experiment. Before the test, the volunteers' hands and arms are washed with clean water and then with 75% ethanol. The volunteers put on the homemade test equipment, which consists of sleeves and gloves. There is a 5×5cm 2 The area is used as the test area, and gloves are put on to protect against mosquito bites. First, during the test, the insect repellent patch is placed in the center of the test area, one arm is the blank control, and one arm is the essential oil treatment group. Then the arm is inserted into the mosquito cage for 2 minutes to observe whether there are mosquitoes landing. The test is repeated every 15 minutes. The number of mosquito attacks (the number of mosquitoes landing on the exposed parts and the number of mosquitoes trying to bite) is recorded, and the repellency rate of Culex pipiens quinquefasciatus within 1 hour is counted.

[0061] Percentage repellency calculation formula: PR = (Nc-Nt) / Nc×100%

[0062] Nc represents the number of mosquito bites on the blank control hand, and Nt represents the number of mosquito bites on the essential oil treatment group

[0063] The mosquito repellent compositions of Examples 1-8 and Comparative Examples 1-7 were tested for repellency rates of Aedes albopictus and Culex pipiens quinquefasciatus according to the above test method, and the results are shown in Table 2;

[0064] Table 2 Results of the repellent rates of Aedes albopictus and Culex pipiens quinquefasciatus of the mosquito repellent compositions of Examples 1-8 and Comparative Examples 1-7

[0065]

[0066]

[0067] According to the results in Table 2:

[0068] According to the data of Examples 1-8, the technical solution of the present invention has a significant repellent effect on Aedes albopictus and Culex pipiens quinquefasciatus;

[0069] Among them, it should be noted that in the experiment on Aedes albopictus, it was found that adding a certain amount of lemon verbena essential oil to the compound of eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil and lemon balm essential oil can significantly improve the repellent effect of the mosquito repellent composition on Aedes albopictus. Specifically, the repellent rate changes of Aedes albopictus in Examples 1, 7 and 8 at 15min, 30min, 45min and 60min can be seen; according to the data comparison of Example 1 and Example 7, when the same weight portions are used, the repellent effect of Aedes albopictus shown by the compound of eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil and lemon balm essential oil is significantly reduced at 30min, 45min and 60min compared with the technical solution of compounding eucalyptus essential oil and cinnamon essential oil, indicating that eucalyptus essential oil and cinnamon essential oil have better repellent performance on Aedes albopictus, and Example 5 also confirms this speculation to a certain extent;

[0070] However, according to Example 8, after adding lemon verbena essential oil, eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil, lemon balm essential oil and lemon verbena essential oil synergistically enhance the repellent effect of Aedes albopictus, and the technical solution of Example 8 significantly improves the effect in the repellent experiment of Aedes albopictus.

[0071] At the same time, according to the comparison between Example 4 and other embodiments, in the technical scheme of the present invention, for Culex quinquefasciatus, the study found that the compound of nutmeg essential oil and lemon balm essential oil has a more significant repellent effect on Culex quinquefasciatus. It is speculated that this may be because the effective components of nutmeg essential oil and lemon balm essential oil are compounded to produce a synergistic enhancement of the binding force between the mosquito repellent composition and the odor binding proteins of Culex quinquefasciatus such as CquiOBP, thereby interfering with the behavior of mosquitoes to appropriately find hosts and effectively repelling Culex quinquefasciatus;

[0072] Similarly, according to the comparison between Example 8 and Example 7, it is found that the present invention also has some improvement in the repellent effect of Culex quinquefolius by compounding eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil, lemon balm essential oil and lemon verbena essential oil, but according to the data comparison between Example 4 and Comparative Example 7, the compounding of lemon verbena essential oil, nutmeg essential oil and lemon balm essential oil does not produce the effect of synergistically improving the repellent effect of nutmeg essential oil and lemon balm essential oil on Culex quinquefolius. It can be inferred that the improvement of the repellent effect of lemon verbena essential oil on Culex quinquefolius requires the compounding of eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil, lemon balm essential oil and lemon verbena essential oil to reflect a certain synergistic improvement in the repellent effect of Culex quinquefolius;

[0073] However, the repellent effect of Culex quinquefasciatus improved by the technical solution of Example 8 is significantly lower than that of Aedes albopictus; it is speculated that this may be because the combination of eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil, lemon balm essential oil and lemon verbena essential oil synergistically enhances the binding force of the mosquito repellent composition with odor-binding proteins unique to Aedes albopictus, such as AealOBP3, and the synergistic effect exerted significantly improves the repellent effect of Aedes albopictus.

[0074] According to the data comparison between Example 1 and Comparative Example 1, Comparative Example 2, and Comparative Example 6, the data comparison between Example 2 and Comparative Example 3 and Comparative Example 4, and the data comparison between Example 3 and Comparative Example 5 and Comparative Example 6, it can be known that the technical scheme of the present invention using eucalyptus essential oil and / or nutmeg essential oil as the first repellent component, using cinnamon essential oil and / or lemon balm essential oil as the second repellent component, and then compounding the first repellent component with the second repellent component can effectively improve the repellent effect of the mosquito repellent composition on Aedes albopictus and Culex pipiens quinquefasciatus, and the repellent effect that can be produced by replacing other essential oils that also have mosquito repellent effect is significantly reduced compared with the technical scheme of the present invention.

[0075] Application Example 1

[0076] In parts by weight, 10 parts of the mosquito repellent composition of Example 1, 0.6 parts of gum arabic, 0.6 parts of gelatin, 6 parts of N-isopropyl acrylamide, 0.6 parts of N,N-methylenebisacrylamide, 382.2 parts of deionized water and 2 parts of transglutaminase were prepared, and then the space repellent microcapsules were prepared according to the following steps:

[0077] Step 1: Gum arabic, gelatin, N-isopropylacrylamide, N,N-methylenebisacrylamide and deionized water are continuously stirred at 50°C until they are completely dissolved to form a uniform colloidal solution, and the stirring is continued for 1 hour to ensure sufficient mixing, and finally a wall material solution is obtained;

[0078] Step 2: dripping the mosquito repellent composition of Example 1 into the wall material solution, stirring the wall material solution at the same time, until the mosquito repellent composition and the wall material solution are completely mixed and fully emulsified to form a uniform and stable emulsion;

[0079] Step 3: Maintaining stirring, slowly add 10% acetic acid solution to the emulsion obtained in step 2 at a temperature of 0-5°C to adjust the pH value of the system to 3.6, and then keep warm for 60 minutes to obtain a coagulation system.

[0080] Step 4: maintaining stirring, maintaining the temperature at 0-5°C, adding 10% sodium hydroxide solution to adjust the pH value of the coagulation system to 6.0, adding a cross-linking agent to form a microcapsule dispersion, and then standing the microcapsule dispersion for stratification and centrifugation to obtain a supernatant;

[0081] Step 5: freeze-dry the supernatant to obtain powdered space repellent microcapsules.

[0082] It should be noted that, since the pH value is adjusted by adding a solution dropwise in step 3-4, the temperature may fluctuate during the process. In the technical solution of the present invention, the temperature may be maintained at 0-5°C during the adding process of step 3-4.

[0083] Performance Testing

[0084] 1. Mosquito repellent effect test

[0085] Test method: Recruit 4 volunteers. Before the test, prepare the mosquitoes needed for the test. Catch 5-7 day old female Aedes albopictus mosquitoes that have not sucked blood and put them in a mosquito cage. Do not provide sugar water and starve them for 12 hours in advance in preparation for the experiment. Before the test, wash the hands and arms of the volunteers with clean water and then with 75% ethanol. The volunteers put on the homemade test equipment, which consists of sleeves and gloves. There is a 5×5cm 2 The area is used as the test area, and gloves are put on to protect against mosquito bites. First, stick the insect repellent patch in the center of the test area, then put your arm into the mosquito cage for 2 minutes to observe whether there are any mosquitoes landing. Repeat the test every 15 minutes. If any mosquitoes land in the test area, it means that the mosquito repellent patch has lost its mosquito repellent effect. Record the time from the start of the test to the first bite, which is recorded as the full protection time (FPT).

[0086] Preparation method of mosquito repellent patch: The mosquito repellent patch is composed of non-woven fabric, a circular PVC patch with a radius of 1 cm and adhesive backing, release paper and space repellent microcapsules or mosquito repellent composition. 1g of space repellent microcapsules or mosquito repellent composition is evenly applied to the patch, covered with non-woven fabric, glue is applied around the non-woven fabric, and the patch is attached to complete the assembly. When in use, the release paper is torn off and the patch can be attached to any position.

[0087] The space repellent microcapsules obtained in Example 1 and the mosquito repellent composition of Example 1 were prepared into mosquito repellent patches, and tested according to the above test method. The results are shown in Table 3;

[0088] Table 3 Mosquito repellent effect of space repellent microcapsules

[0089] sample Full protection time min Application Example 1 125±7.07 Example 1 60±0.73

[0090] According to the results in Table 3:

[0091] The present invention uses the mosquito repellent composition as a core material, and then wraps the core material with a specific wall material, which can effectively improve the durability of the mosquito repellent effect of the mosquito repellent composition.

[0092] 2. Thermal stability

[0093] Test method: The constant temperature thermal weight loss method was used. The specific steps are as follows: First, accurately weigh and record the initial weight of the space repellent microcapsules obtained in Example 1; then, place them in a 70°C environment for drying for 1 hour, and then accurately weigh and record their weight again; thereafter, repeat this drying and weighing process until the weight of the microcapsules reaches a constant, that is, the weight change between two consecutive weighings is very small or unchanged. Through this method, we can evaluate the thermal weight loss of the microcapsules at different time points, so as to understand their sustained release performance.

[0094] The thermal stability test of the space repellent microcapsules obtained in Example 1 was carried out according to the above test method. The results are as follows: Figure 1 As shown;

[0095] Note: Figure 1 The freeze-dried powder of essential oil microcapsules is the space repellent microcapsules obtained in Application Example 1.

[0096] according to Figure 1 It can be seen that the weight of the space-repellent microcapsules obtained by Example 1 decreases slowly and the curve is gentle; this shows that the space-repellent microcapsule powder is released well, and microencapsulation of essential oils can well slow down the release of essential oils, and drying the microcapsules into powder is more conducive to slowing down the release rate of the microcapsules and thus reducing the loss of the microcapsules.

[0097] 3. Morphological determination

[0098] Test methods: optical microscopy and scanning electron microscopy;

[0099] The space repellent microcapsules obtained in Example 1 were observed by optical microscope and scanning electron microscope. Figure 2 , Figure 3 As shown, Figure 2 The results of microscopic observation are as follows: Figure 3 The results are obtained by scanning electron microscopy.

[0100] Under an optical microscope, the space repellent microcapsules have a round appearance, uniform size, and uniform dispersion; the capsules are filled with uniformly dispersed core materials, and the mosquito repellent composition is clearly visible to be embedded in the space repellent microcapsules.

[0101] Under a scanning electron microscope, the surface of the space-repellent microcapsule has no holes and the structure is intact. The wall material structure is only wrinkled but not completely broken, and the structure remains intact. This shows that the space-repellent microcapsule has good rigidity and good sustained-release performance.

[0102] The embodiments presented herein are only embodiments selected according to the combination of all possible embodiments. The appended claims should not be limited by the embodiments describing the present invention. Some numerical ranges used in the claims include sub-ranges therein, and the changes in these ranges should also be covered by the appended claims.

Claims

1. A mosquito repellent composition for repelling Aedes albopictus, characterized in that: The invention comprises a first repellent component, a second repellent component and a third repellent component, wherein the third repellent component is lemon verbena essential oil, the first repellent component is a combination of eucalyptus essential oil and nutmeg essential oil, and the second repellent component is cinnamon essential oil and lemon balm essential oil; the weight ratio of the eucalyptus essential oil, nutmeg essential oil, cinnamon essential oil, lemon balm essential oil and lemon verbena essential oil is 2:1:3:3:

1.

2. Use of the mosquito repellent composition for repelling Aedes albopictus as claimed in claim 1 to prepare a repellent.

3. Use of the mosquito repellent composition for repelling Aedes albopictus according to claim 2 for preparing a repellent, characterized in that: The repellent is a space repellent or a contact repellent.

4. A space repellent microcapsule for repelling Aedes albopictus, characterized in that: The invention comprises 6-12 parts of core material, 260-1040 parts of wall material and 1-2 parts of cross-linking agent by weight, wherein the core material is the mosquito repellent composition according to claim 1, and the wall material comprises gum arabic, gelatin, N-isopropylacrylamide, N,N-methylenebisacrylamide and deionized water.

5. The space repellent microcapsule for repelling Aedes albopictus according to claim 4, characterized in that: The weight ratio of the gum arabic, gelatin, N-isopropylacrylamide, N,N-methylenebisacrylamide and deionized water is: 0.4~0.8: 0.4~0.8: 4~8: 0.4~0.8: 254.8~1029.

6.

6. The space repellent microcapsule for repelling Aedes albopictus according to claim 5, characterized in that: The cross-linking agent is at least one of transglutaminase, formaldehyde, glutaraldehyde and genipin.

7. A method for preparing a space repellent microcapsule for repelling Aedes albopictus according to any one of claims 4 to 6, characterized in that: The steps include: Step 1: Gum arabic, gelatin, N-isopropylacrylamide, N,N-methylenebisacrylamide and deionized water are continuously stirred at 50°C until they are completely dissolved to form a uniform colloidal solution, and the stirring is continued for 1 hour to ensure sufficient mixing, and finally a wall material solution is obtained; Step 2: at 50° C., drip the mosquito repellent composition into the wall material solution, and stir the wall material solution at the same time, until the mosquito repellent composition and the wall material solution are completely mixed and fully emulsified to form a uniform and stable emulsion; Step 3: slowly add 10% acetic acid solution to the emulsion obtained in step 2 at a temperature of 0-5°C to adjust the pH value of the system to 3-4, and then keep the temperature for 60 minutes to obtain a coagulation system; Step 4: maintaining 0-5°C, adding 10% sodium hydroxide solution to adjust the pH value of the coagulation system to 5.8-6.2, adding a cross-linking agent to form a microcapsule dispersion, and then standing the microcapsule dispersion for stratification and centrifugation to obtain a supernatant; Step 5: freeze-dry the supernatant to obtain powdered space repellent microcapsules.

8. The method for preparing the space repellent microcapsule for repelling Aedes albopictus according to claim 7, characterized in that: Stirring is maintained during steps 3 and 4.

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