A plant essential oil-containing mildew-proof tablet, its preparation method and application

Abstract

The present invention relates to the field of essential oil sustained release, and discloses a plant essential oil mildew-proof tablet and its preparation method and application. The plant essential oil mildew-proof tablet comprises two epidermal layers and an essential oil sustained release layer disposed between the two epidermal layers. In the present invention, functionalized mesoporous silica is prepared by grafting sodium rosinate and amino-functionalized mesoporous silica, and after loading plant essential oil thereon, it is used as the core material. Then, double-hydroxyl cage-like silsesquioxane is introduced into the main chain of polyurethane to wrap the core material to prepare an essential oil sustained release agent. Then, using lignin as the base material and the essential oil sustained release agent as the active ingredient, an essential oil sustained release layer is prepared. The essential oil sustained release layer prepared by the present invention can achieve the effects of essential oil sustained release and antibacterial and mildew-proof, and has a significant sustained release effect under normal temperature and high temperature conditions, and still maintains a good sustained release effect in a humid environment, greatly prolonging the efficacy period of the material.

Description

Technical Field

[0001] The present invention belongs to the technical field of essential oil sustained release, and particularly relates to a plant essential oil-containing mildew-proof tablet, a preparation method thereof, and an application thereof. Background Art

[0002] Essence and fragrance are important industrial raw materials for various flavoring products and are widely used in industries such as food, beverage, and daily chemical products. As an important component of natural essence and fragrance, essential oil has a wide range of applications, but its application is limited due to its poor stability. Microencapsulation of essential oil is a common means to solve the above problems. Nano-microencapsulation technology is a technology that uses natural or synthetic polymer materials to make materials with a particle size ranging from 1 nm to 100 nm to encapsulate target substances, mainly through nano-composite materials, nano-emulsification, nano-structuring technology, etc. to encapsulate micro-substances. The use of nano-microencapsulation technology can effectively improve the antioxidant capacity, thermal stability, and biological activity of the encapsulated object.

[0003] With the extension of the use time of essential oil, the effective components of essential oil rapidly decrease. Although natural plant essential oil has a certain inhibitory effect on bacteria and fungi, its long-lasting antibacterial and mildew-proof effect is poor, and the wall materials used in the existing microencapsulation technology have high hydrophilicity, and absorb water in a humid environment to form a hydration layer, resulting in a reduction in the long-acting sustained release effect of the material. Summary of the Invention

[0004] To solve the deficiencies mentioned in the above background art, the purpose of the present invention is to provide a plant essential oil-containing mildew-proof tablet, a preparation method thereof, and an application thereof. Functionalized mesoporous silica is prepared by grafting sodium rosinate and amino-functionalized mesoporous silica, and after loading plant essential oil, it is used as the core material. Double-hydroxyl cage-shaped silsesquioxane is introduced into the polyurethane main chain to encapsulate the core material to prepare an essential oil sustained release agent, and then lignin is used as the substrate and the essential oil sustained release agent is used as the active ingredient to prepare an essential oil sustained release layer. The essential oil sustained release agent prepared by the present invention can achieve the effects of essential oil sustained release and antibacterial and mildew-proof, and still maintain a good sustained release effect in a humid environment, greatly extending the efficacy period of the material.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A plant essential oil-containing mildew-proof tablet includes two skin layers and an essential oil sustained release layer disposed between the two skin layers. The preparation method of the essential oil sustained release layer includes the following steps:

[0007] A1: Immerse lignin in a solution containing an essential oil sustained release agent, take it out, and prepare essential oil-modified lignin;

[0008] A2: Make the essential oil-modified lignin into tablets to prepare an essential oil sustained release layer;

[0009] The essential oil sustained-release agent is prepared by using functionalized mesoporous silica loaded with plant essential oil as the core material, and introducing double-hydroxyl cage-like sesquisiloxane into the main chain of polyurethane to wrap the core material. The functionalized mesoporous silica is prepared by grafting sodium rosinate and amino-functionalized mesoporous silica through a chemical reaction.

[0010] Preferably, the epidermis layer is a breathable film; the solution is one or a combination of two of ethanol and deionized water.

[0011] Preferably, the preparation method of the essential oil sustained-release agent comprises the following steps:

[0012] (1) Take ammonia water, deionized water and cetyltrimethylammonium bromide in a reactor, place it under the conditions of 50-65 °C and 200-300 r / min and stir for 2-3 h, then add tetraethyl orthosilicate and continue to stir for 1-3 h. After stirring is completed, dropwise add 3-aminopropyltriethoxysilane and mix for reaction for 6-8 h, place it at 30-35 °C for constant-temperature crystallization for 20-24 h, and after filtration, washing, drying and ethanol extraction to remove the template agent, amino-functionalized mesoporous silica is prepared;

[0013] (2) Take sodium rosinate and dissolve it in hydrochloric acid aqueous solution to adjust the pH value of the system to 5.5-6, add 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide and stir and mix for 20-24 h, then add amino-functionalized mesoporous silica and continue to stir for reaction for 18-24 h. After the reaction is completed, filter and dry to prepare functionalized mesoporous silica;

[0014] (3) Mix functionalized mesoporous silica and plant essential oil and perform ultrasonic treatment, and after filtration and drying, load-type mesoporous silica is prepared;

[0015] (4) Take polyvinylpyrrolidone and dissolve it in deionized water at 80-90 °C, cool to room temperature and add Tween 80 to stir and emulsify, then add load-type mesoporous silica and stir and disperse, then add isophorone diisocyanate, 1,4-butanediol, double-hydroxyl cage-like sesquisiloxane, polypropylene glycol 2000 and triethylenediamine, heat up to 65-80 °C and react for 1-3 h. After the reaction is completed, perform suction filtration, washing and drying to prepare the essential oil sustained-release agent.

[0016] Preferably, in the step (1), the mass fraction of ammonia water is 20-30%, and the addition ratio of ammonia water, deionized water, cetyltrimethylammonium bromide, tetraethyl orthosilicate and 3-aminopropyltriethoxysilane is 150-200 mL:200-300 mL:2-3.2 g:10-15.5 g:3.6-5 g.

[0017] Preferably, in the step (2), the mass ratio of sodium rosinate to aminated mesoporous silica is 7.5 - 10:0.5.

[0018] Preferably, in the step (3), the plant essential oil is one or a combination of more than one of tea tree essential oil, mustard essential oil, cinnamon essential oil, garlic essential oil, citronella essential oil, rose essential oil, mugwort essential oil, peppermint essential oil, lemon essential oil, clove essential oil, lavender essential oil.

[0019] Preferably, in the step (4), the mass ratio of polyvinylpyrrolidone, Tween 80, supported mesoporous silica, isophorone diisocyanate, 1,4 - butanediol, dihydroxycage - type silsesquioxane, polypropylene glycol 2000, and triethylenediamine is 2.5 - 3:2.5 - 3:2.5 - 5:8 - 9.6:0.4 - 0.7:0.2 - 0.6:7 - 10:0.02 - 0.06.

[0020] Preferably, the preparation method of the dihydroxycage - type silsesquioxane in the step (4) includes the following steps:

[0021] ① Take sodium hydroxide, dissolve it with deionized water, add isopropanol solvent, then add phenyltrimethoxysilane and stir to mix. Place it in a nitrogen atmosphere and reflux at 80 - 95 °C for 3 - 5 h, then cool to room temperature and continue stirring and reacting for 10 - 15 h. After the reaction is completed, carry out rotary evaporation and drying to prepare the primary product;

[0022] ② Take the primary product, add tetrahydrofuran solvent and triethylamine, add methyltrichlorosilane and stir to react in a nitrogen atmosphere for 8 - 12 h, then place it in an ice - water bath and add deionized water to dissolve the excess methyltrichlorosilane and by - products. After the reaction is completed, add toluene for extraction and separation to obtain the organic layer, and carry out washing, filtration, rotary evaporation and drying to prepare the dihydroxycage - type silsesquioxane.

[0023] A preparation method of a plant essential oil - containing mildew - proof tablet, which includes the following steps: Set the essential oil slow - release layer between two epidermal layers and press them together.

[0024] An application of a plant essential oil - containing mildew - proof tablet, characterized in that the plant essential oil - containing mildew - proof tablet is applied to the mildew prevention of food preservation, shoes, clothing, luggage, and sofa products.

[0025] The beneficial effects of the present invention:

[0026] The present invention uses plant essential oil as the active ingredient, loads the plant essential oil on a functionalized mesoporous silica carrier to obtain a supported mesoporous silica, and uses the supported mesoporous silica as the core material. Bishydroxycage silsesquioxane is introduced into the polyurethane main chain to wrap the supported mesoporous silica, thereby preparing an essential oil sustained-release agent. Then, using lignin as the base material and the essential oil sustained-release agent as the active ingredient, an essential oil sustained-release layer is prepared. The essential oil sustained-release layer prepared by the present invention can achieve the effects of essential oil sustained release and antibacterial and mildew-proof properties, and still maintain a good sustained-release effect in a humid environment, greatly extending the efficacy period of the material.

[0027] The present invention uses sodium rosinate to react with amino-functionalized mesoporous silica to obtain functionalized mesoporous silica, and uses the functionalized mesoporous silica as a carrier to load plant essential oil. The grafting of sodium rosinate reduces the specific surface area and pore volume of the mesoporous silica, thereby hindering the volatilization of the plant essential oil and prolonging the sustained-release time of the plant essential oil. In addition, the present invention prepares bishydroxycage silsesquioxane and introduces it as a chain extender into the polyurethane main chain to modify the polyurethane. The modified polyurethane is used as the wall material of the supported mesoporous silica, endowing the wall material with excellent heat resistance and hydrophobicity, and having a significant sustained-release effect under normal and high-temperature conditions, further improving the long-term sustained-release antibacterial and mildew-proof effects of the plant essential oil. Specific Embodiments

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] Example 1 A preparation method of bishydroxycage silsesquioxane includes the following steps:

[0030] ① Take 3.2 g of sodium hydroxide, dissolve it in 2.5 mL of deionized water, add 120 mL of isopropanol solvent, then add 24 g of phenyltrimethoxysilane and stir to mix. Place it in a nitrogen atmosphere and reflux at 90 °C for 4 h, then cool to room temperature and continue stirring for 12 h. After the reaction is completed, perform rotary evaporation and drying to prepare a crude product.

[0031] ② Take 5 g of the crude product, add 50 mL of tetrahydrofuran solvent and 1.1 g of triethylamine, add 2.7 g of methyltrichlorosilane and stir to react for 12 h in a nitrogen atmosphere, then place it in an ice-water bath and add 20 mL of deionized water to dissolve the excess methyltrichlorosilane and by-products. After the reaction is completed, add 80 mL of toluene for extraction and separation to obtain an organic layer, which is washed, filtered, rotary evaporated and dried to prepare bishydroxycage silsesquioxane.

[0032] Example 2 A preparation method of an essential oil sustained-release agent comprises the following steps:

[0033] (1) Take 185 mL of ammonia water with a mass fraction of 25%, 250 mL of deionized water, and 2.7 g of cetyltrimethylammonium bromide in a reactor, place it under the conditions of 55 °C and 260 r / min and stir and react for 2 h, then add 13.4 g of tetraethyl orthosilicate and continue to stir for 2 h. After the stirring is completed, add 4.5 g of 3-aminopropyltriethoxysilane and mix and react for 8 h. Place it at 35 °C for constant-temperature crystallization for 24 h. After filtration, washing, drying, and ethanol extraction to remove the template agent, amino-functionalized mesoporous silica is prepared;

[0034] (2) Take 9.3 g of sodium rosinate and dissolve it in 100 mL of hydrochloric acid aqueous solution to adjust the pH value of the system to 5.5. Add 1.1 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.5 g of N-hydroxysuccinimide and stir and mix for 24 h, then add 0.5 g of amino-functionalized mesoporous silica and continue to stir and react for 24 h. After the reaction is completed, filter and dry to prepare functionalized mesoporous silica;

[0035] (3) Take 1.7 g of functionalized mesoporous silica and mix it with 2 mL of mustard essential oil and perform ultrasonic treatment. After filtration and drying, supported mesoporous silica is prepared;

[0036] (4) Take 2.7 g of polyvinylpyrrolidone and dissolve it in deionized water at 85 °C. After cooling to room temperature, add 2.5 g of Tween 80 and stir and emulsify, then add 2.5 g of supported mesoporous silica and stir and disperse. Then add 8.2 g of isophorone diisocyanate, 0.45 g of 1,4-butanediol, 0.2 g of the double-hydroxyl cage-like silsesquioxane prepared in Example 1, 7.1 g of polypropylene glycol 2000, and 0.02 g of triethylenediamine. Heat up to 80 °C and react for 3 h. After the reaction is completed, perform suction filtration, washing, and drying to prepare the essential oil sustained-release agent.

[0037] Example 3 A preparation method of an essential oil sustained-release agent comprises the following steps:

[0038] (1) Take 175 mL of ammonia water with a mass fraction of 30%, 270 mL of deionized water, and 2.5 g of cetyltrimethylammonium bromide in a reactor, place it under the conditions of 55 °C and 245 r / min and stir and react for 2 h, then add 11.8 g of tetraethyl orthosilicate and continue to stir for 2 h. After the stirring is completed, add 4.2 g of 3-aminopropyltriethoxysilane and mix and react for 8 h. Place it at 35 °C for constant-temperature crystallization for 24 h. After filtration, washing, drying, and ethanol extraction to remove the template agent, amino-functionalized mesoporous silica is prepared;

[0039] (2) Dissolve 7.8 g of sodium rosinate in 100 mL of hydrochloric acid aqueous solution to adjust the pH value of the system to 6. Add 1.1 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.6 g of N-hydroxysuccinimide, stir and mix for 24 h. Then add 0.5 g of amino-functionalized mesoporous silica and continue to stir and react for 24 h. After the reaction is completed, filter and dry to prepare functionalized mesoporous silica;

[0040] (3) Take 1.7 g of functionalized mesoporous silica and mix it with 2 mL of mustard essential oil, and perform ultrasonic treatment. After filtration and drying, load-bearing mesoporous silica is prepared;

[0041] (4) Dissolve 2.5 g of polyvinylpyrrolidone in deionized water at 85 °C. After cooling to room temperature, add 2.7 g of Tween 80 and stir to emulsify. Then add 3.6 g of load-bearing mesoporous silica and stir to disperse. Then add 8.9 g of isophorone diisocyanate, 0.5 g of 1,4-butanediol, 0.4 g of the dihydroxycage-like silsesquioxane prepared in Example 1, 8.3 g of polypropylene glycol 2000, and 0.04 g of triethylenediamine. Heat up to 80 °C and react for 3 h. After the reaction is completed, perform suction filtration, washing, and drying to prepare an essential oil sustained-release agent.

[0042] Example 4 A method for preparing an essential oil sustained-release agent includes the following steps:

[0043] (1) Take 200 mL of 20% ammonia water, 220 mL of deionized water, and 3.1 g of cetyltrimethylammonium bromide in a reactor, place it at 65 °C and 255 r / min, stir and react for 2 h. Then add 14.8 g of tetraethyl orthosilicate and continue to stir for 2 h. After stirring is completed, add 4.8 g of 3-aminopropyltriethoxysilane dropwise and mix and react for 8 h. Place it at 35 °C for constant temperature crystallization for 24 h. After filtration, washing, drying, and ethanol extraction to remove the template agent, amino-functionalized mesoporous silica is prepared;

[0044] (2) Dissolve 9.8 g of sodium rosinate in 100 mL of hydrochloric acid aqueous solution to adjust the pH value of the system to 6. Add 1.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.8 g of N-hydroxysuccinimide, stir and mix for 24 h. Then add 0.5 g of amino-functionalized mesoporous silica and continue to stir and react for 24 h. After the reaction is completed, filter and dry to prepare functionalized mesoporous silica;

[0045] (3) Take 1.7 g of functionalized mesoporous silica and mix it with 2 mL of mustard essential oil, and perform ultrasonic treatment. After filtration and drying, load-bearing mesoporous silica is prepared;

[0046] (4) Dissolve 3 g of polyvinylpyrrolidone in deionized water at 85 °C. After cooling to room temperature, add 2.9 g of Tween 80 and stir to emulsify. Then add 4.5 g of supported mesoporous silica and stir to disperse. Next, add 9.6 g of isophorone diisocyanate, 0.7 g of 1,4-butanediol, 0.5 g of the dihydroxycage silsesquioxane prepared in Example 1, 9.3 g of polypropylene glycol 2000, and 0.06 g of triethylenediamine. Heat up to 80 °C and react for 3 h. After the reaction is completed, filter, wash, and dry to prepare the essential oil sustained-release agent.

[0047] Example 5 A plant essential oil mildew-proof tablet contains two epidermal layers and an essential oil sustained-release layer disposed between the two epidermal layers. The preparation method of the essential oil sustained-release layer includes the following steps:

[0048] A1: Immerse lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Example 2, take it out, and prepare the essential oil-modified lignin.

[0049] A2: Make the essential oil-modified lignin into tablets to prepare the essential oil sustained-release layer.

[0050] Example 6 A plant essential oil mildew-proof tablet contains two epidermal layers and an essential oil sustained-release layer disposed between the two epidermal layers. The preparation method of the essential oil sustained-release layer includes the following steps:

[0051] A1: Immerse lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Example 3, take it out, and prepare the essential oil-modified lignin.

[0052] A2: Make the essential oil-modified lignin into tablets to prepare the essential oil sustained-release layer.

[0053] Example 7 A plant essential oil mildew-proof tablet contains two epidermal layers and an essential oil sustained-release layer disposed between the two epidermal layers. The preparation method of the essential oil sustained-release layer includes the following steps:

[0054] A1: Immerse lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Example 4, take it out, and prepare the essential oil-modified lignin.

[0055] A2: Make the essential oil-modified lignin into tablets to prepare the essential oil sustained-release layer.

[0056] Comparative Example 1 The preparation method of an essential oil sustained-release agent includes the following steps:

[0057] (1) Take 185 mL of 25% ammonia water, 250 mL of deionized water, and 2.7 g of cetyltrimethylammonium bromide in a reactor. Stir and react at 55 °C and 260 r / min for 2 h. Then add 13.4 g of tetraethyl orthosilicate and continue stirring for 8 h. Crystallize at room temperature for 24 h. After filtration, washing, and drying, calcine at 550 °C for 5 h and cool to prepare mesoporous silica;

[0058] (2) Take 1.7 g of mesoporous silica and mix it with 2 mL of mustard essential oil and perform ultrasonic treatment. After filtration and drying, prepare supported mesoporous silica;

[0059] (3) Take 2.7 g of polyvinylpyrrolidone and dissolve it in deionized water at 85 °C. After cooling to room temperature, add 2.5 g of Tween 80 and stir to emulsify. Then add 2.5 g of supported mesoporous silica and stir to disperse. Then add 8.2 g of isophorone diisocyanate, 0.45 g of 1,4-butanediol, 0.2 g of the double-hydroxyl cage-like silsesquioxane prepared in Example 1, 7.1 g of polypropylene glycol 2000, and 0.02 g of triethylenediamine. Heat up to 80 °C and react for 3 h. After the reaction is completed, perform suction filtration, washing, and drying to prepare an essential oil sustained-release agent.

[0060] Comparative Example 2 A method for preparing an essential oil sustained-release agent includes the following steps:

[0061] (1) Take 185 mL of 25% ammonia water, 250 mL of deionized water, and 2.7 g of cetyltrimethylammonium bromide in a reactor. Stir and react at 55 °C and 260 r / min for 2 h. Then add 13.4 g of tetraethyl orthosilicate and continue stirring for 2 h. After the stirring is completed, dropwise add 4.5 g of 3-aminopropyltriethoxysilane and mix and react for 8 h. Place it at 35 °C for constant-temperature crystallization for 24 h. After filtration, washing, drying, and ethanol extraction to remove the template agent, prepare amino-functionalized mesoporous silica;

[0062] (2) Take 9.3 g of sodium rosinate and dissolve it in 100 mL of hydrochloric acid aqueous solution to adjust the pH value of the system to 5.5. Add 1.1 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.5 g of N-hydroxysuccinimide and stir and mix for 24 h. Then add 0.5 g of amino-functionalized mesoporous silica and continue stirring and reacting for 24 h. After the reaction is completed, perform filtration and drying to prepare functionalized mesoporous silica;

[0063] (3) Take 1.7 g of functionalized mesoporous silica and mix it with 2 mL of mustard essential oil and perform ultrasonic treatment. After filtration and drying, prepare supported mesoporous silica;

[0064] (4) Take 2.7 g of polyvinylpyrrolidone and dissolve it in deionized water at 85 °C. After cooling to room temperature, add 2.5 g of Tween 80 and stir to emulsify. Then add 2.5 g of supported mesoporous silica and stir to disperse. Next, add 8.2 g of isophorone diisocyanate, 0.45 g of 1,4-butanediol, 7.1 g of polypropylene glycol 2000, and 0.02 g of triethylenediamine. Heat up to 80 °C and react for 3 h. After the reaction is completed, filter, wash, and dry to prepare an essential oil sustained-release agent.

[0065] Comparative Example 3 A method for preparing an essential oil sustained-release agent includes the following steps:

[0066] (1) Take 185 mL of ammonia water with a mass fraction of 25%, 250 mL of deionized water, and 2.7 g of cetyltrimethylammonium bromide in a reactor. Place it under the conditions of 55 °C and 260 r / min and stir to react for 2 h. Then add 13.4 g of tetraethyl orthosilicate and continue to stir for 2 h. After stirring is completed, add 4.5 g of 3-aminopropyltriethoxysilane dropwise and mix to react for 8 h. Place it at 35 °C for constant-temperature crystallization for 24 h. After filtration, washing, drying, and ethanol extraction to remove the template agent, aminated mesoporous silica is prepared.

[0067] (2) Take 9.3 g of sodium rosinate and dissolve it in 100 mL of hydrochloric acid aqueous solution to adjust the pH value of the system to 5.5. Add 1.1 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.5 g of N-hydroxysuccinimide and stir to mix for 24 h. Then add 0.5 g of aminated mesoporous silica and continue to stir to react for 24 h. After the reaction is completed, filter and dry to prepare functionalized mesoporous silica.

[0068] (3) Take 1.7 g of functionalized mesoporous silica and mix it with 2 mL of mustard essential oil and perform ultrasonic treatment. After filtration and drying, an essential oil sustained-release agent is prepared.

[0069] Comparative Example 4 A plant essential oil anti-mildew tablet includes two skin layers and an essential oil sustained-release layer arranged between the two skin layers. The method for preparing the essential oil sustained-release layer includes the following steps:

[0070] A1: Immerse lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Comparative Example 1, take it out, and prepare essential oil-modified lignin.

[0071] A2: Make the essential oil-modified lignin into tablets to prepare the essential oil sustained-release layer.

[0072] Comparative Example 5 A plant essential oil anti-mildew tablet includes two skin layers and an essential oil sustained-release layer arranged between the two skin layers. The method for preparing the essential oil sustained-release layer includes the following steps:

[0073] A1: Immerse lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Comparative Example 2, take it out, and prepare essential oil-modified lignin;

[0074] A2: Make the essential oil-modified lignin into tablets to prepare an essential oil sustained-release layer.

[0075] Comparative Example 6 A plant essential oil anti-mildew tablet, comprising two skin layers and an essential oil sustained-release layer arranged between the two skin layers. The preparation method of the essential oil sustained-release layer includes the following steps:

[0076] A1: Immerse lignin in an ethanol solution containing the essential oil sustained-release agent prepared in Comparative Example 3, take it out, and prepare essential oil-modified lignin;

[0077] A2: Make the essential oil-modified lignin into tablets to prepare an essential oil sustained-release layer.

[0078] Performance detection

[0079] (1) Room temperature sustained-release performance: Evenly spread the essential oil sustained-release agents prepared in Examples 2-4 and Comparative Examples 1-3 on a petri dish, and place it in an open environment at 25 °C (room temperature) for 60 days. Use a TU-1950 type ultraviolet-visible spectrophotometer to measure the content of essential oil in the essential oil sustained-release agent to obtain the essential oil release amount. The data results are shown in Table 1.

[0080] (2) High temperature sustained-release performance: Evenly spread the essential oil sustained-release agents prepared in Examples 2-4 and Comparative Examples 1-3 on a petri dish, and place it in an 80 °C oven for drying for 30 h. Obtain the essential oil release amount through mass change. The data results are shown in Table 1.

[0081] (3) Long-term antibacterial and anti-mildew performance: Place the essential oil sustained-release agents prepared in Examples 2-4 and Comparative Examples 1-3 in humid air at room temperature and a humidity of 80% RH for different days. Use the Oxford cup method to test the antibacterial performance of the essential oil sustained-release agent. Inoculate Aspergillus niger and Trichoderma viride on PDA medium respectively, and place them in a constant temperature and humidity incubator at a temperature of (28 ± 2) °C and a relative humidity of (85 ± 5)% for several days. Wait until the colonies cover the entire medium and then set aside. Place a sterile Oxford cup in the medium, suck 0.1 mL of the 1% essential oil sustained-release agent prepared with 0.9% physiological saline and slowly inject it into the Oxford cup, and transfer it to the constant temperature and humidity incubator for continued cultivation for 7 days. After the solution in the Oxford cup has diffused, measure the diameter of the antibacterial circle. Each group has 5 parallel tests, calculate the mean value, and obtain the data results as shown in Table 1.

[0082] Table 1 Test results of sample performance

[0083]

[0084] As can be seen from the data in Table 1, the essential oil sustained-release agents prepared in Examples 2-4 of the present invention have an essential oil release amount of less than 22% after being placed at room temperature for 60 days, and an essential oil release amount of less than 25% after being treated at 80 °C for 30 hours, indicating that their sustained-release effects are remarkable under normal and high-temperature conditions, and they can still maintain good sustained-release antibacterial and antifungal effects in a humid environment. Among them, in Comparative Example 1, mesoporous silica was used as a carrier to load essential oil, and the measured essential oil sustained-release effect was worse than that in Examples 2-4. The reason is that the mesoporous silica was not amino-functionalized and then grafted with sodium rosinate. In Comparative Example 2, the component of dihydroxycage-like silsesquioxane was not added, and its measured high-temperature essential oil release amount and sustained-release antibacterial and antifungal effects were worse than those in Examples 2-4, indicating that the addition of dihydroxycage-like silsesquioxane can improve the sustained-release effect of plant essential oils in high-temperature and humid environments. In Comparative Example 3, the polyurethane wall material was not prepared, and its measured essential oil sustained-release effect decreased most significantly compared with that in Examples 2-4.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0086] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A plant essential oil mildew-proof tablet, characterized in that, It includes two skin layers and an essential oil slow-release layer disposed between the two skin layers. The preparation method of the essential oil slow-release layer includes the following steps: A1: Immerse lignin in a solution containing an essential oil slow-release agent, take it out, and prepare essential oil-modified lignin; A2: Make the essential oil-modified lignin into tablets to prepare the essential oil slow-release layer; The preparation method of the essential oil slow-release agent includes the following steps: (1) Take ammonia water, deionized water, and cetyltrimethylammonium bromide in a reactor, place it under stirring reaction at 50~65°C and 200~300 r / min for 2~3 h, then add tetraethyl orthosilicate and continue stirring for 1~3 h. After the stirring is completed, add 3-aminopropyltriethoxysilane and mix and react for 6~8 h. Place it at 30~35°C for constant-temperature crystallization for 20~24 h. After filtration, washing, drying, and ethanol extraction to remove the template agent, prepare amino-functionalized mesoporous silica; (2) Take sodium rosinate and dissolve it in hydrochloric acid aqueous solution to adjust the pH value of the system to 5.5~6. Add 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide and stir and mix for 20~24 h. Then add amino-functionalized mesoporous silica and continue stirring and reacting for 18~24 h. After the reaction is completed, filter and dry to prepare functionalized mesoporous silica; (3) Take functionalized mesoporous silica and mix it with plant essential oil and perform ultrasonic treatment. After filtration and drying, prepare supported mesoporous silica; (4) Take polyvinylpyrrolidone and dissolve it in deionized water at 80~90°C. After cooling to room temperature, add Tween 80 and stir to emulsify. Then add supported mesoporous silica and stir to disperse. Then add isophorone diisocyanate, 1,4-butanediol, dihydroxycage-like silsesquioxane, polypropylene glycol 2000, and triethylenediamine, and raise the temperature to 65~80°C for reaction for 1~3 h. After the reaction is completed, perform suction filtration, washing, and drying to prepare the essential oil slow-release agent; The preparation method of the dihydroxycage-like silsesquioxane in the step (4) includes the following steps: ① Take sodium hydroxide and dissolve it in deionized water, add isopropanol solvent, then add phenyltrimethoxysilane and stir and mix. Place it under reflux reaction at 80~95°C in a nitrogen atmosphere for 3~5 h, then cool to room temperature and continue stirring and reacting for 10~15 h. After the reaction is completed, perform rotary evaporation and drying to prepare the crude product; ② Take the crude product and add tetrahydrofuran solvent and triethylamine. Add methyltrichlorosilane and stir and react in a nitrogen atmosphere for 8~12 h. Then place it in an ice-water bath and add deionized water to dissolve the excess methyltrichlorosilane and by-products. After the reaction is completed, add toluene for extraction and separation to obtain the organic layer. After washing, filtering, rotary evaporation, and drying, prepare dihydroxycage-like silsesquioxane.

2. The anti-mildew tablet containing plant essential oil according to claim 1, wherein The skin layer is a breathable membrane; the solution is ethanol.

3. The mildew-proof tablet containing plant essential oil according to claim 1, wherein In the step (1), the mass fraction of ammonia water is 20~30%, and the addition ratio of ammonia water, deionized water, cetyltrimethylammonium bromide, tetraethyl orthosilicate, and 3-aminopropyltriethoxysilane is 150~200 mL: 200~300 mL: 2~3.2 g: 10~15.5 g: 3.6~5 g.

4. The anti-mildew tablet containing plant essential oil according to claim 1, wherein In the step (2), the mass ratio of sodium rosinate to aminated mesoporous silica is 7.5 - 10:0.

5.

5. The anti-mildew tablet containing plant essential oil according to claim 1, characterized in that, In the step (3), the plant essential oil is one or a combination of tea tree essential oil, mustard essential oil, cinnamon essential oil, garlic essential oil, citronella essential oil, rose essential oil, mugwort essential oil, peppermint essential oil, lemon essential oil, clove essential oil, lavender essential oil.

6. The anti-mildew tablet containing plant essential oil according to claim 1, characterized in that, In the step (4), the mass ratio of polyvinylpyrrolidone, Tween 80, supported mesoporous silica, isophorone diisocyanate, 1,4-butanediol, bis-hydroxycage silsesquioxane, polypropylene glycol 2000 and triethylenediamine is 2.5 - 3:2.5 - 3:2.5 - 5:8 - 9.6:0.4 - 0.7:0.2 - 0.6:7 - 10:0.02 - 0.

06.

7. A preparation method of the plant essential oil mildew-proof tablet according to claim 1, characterized in that, It includes the following steps: The essential oil slow-release layer is set between two epidermal layers and made by composite pressing.

8. Use of the plant essential oil mildew-proof tablets according to any one of claims 1 to 7, characterized in that, The plant essential oil-containing mildew-proof tablets are applied to the mildew prevention of food preservation, shoes, clothing, luggage, and sofa products.

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