Formaldehyde-free phase change fragrance microcapsule, preparation method and application thereof

Abstract

The application relates to the technical field of microcapsules, in particular to a formaldehyde-free phase-change fragrance microcapsule and a preparation method and application thereof. The preparation method of the formaldehyde-free phase-change fragrance microcapsule provided by the application comprises the following steps: mixing polyaspartic ester, isocyanate, an oil-phase emulsifier, a catalyst and a phase-change material, heating at 60-75 DEG C to obtain an oil-phase solution, and stirring the oil-phase solution at a low speed at 50 DEG C for standby; adding an aqueous fragrance into the oil-phase solution, emulsifying for 3-15 min to obtain an aqueous fragrance W / 0 emulsion; adding the aqueous fragrance W / 0 emulsion into a secondary water-phase emulsifier to perform O / W emulsification, forming a W / O / W multiple emulsion; then adding an ethylenediamine aqueous solution, heating to 70-85 DEG C, and after the reaction is completed, the formaldehyde-free phase-change fragrance microcapsule is obtained. The preparation method of the microcapsule is simple and stable, is suitable for the microencapsulation of most aqueous substances, is simple to operate, is mild and controllable in reaction, and is suitable for large-scale production.

Description

Technical Field

[0001] This application relates to the field of microcapsule technology, and in particular to an aldehyde-free phase change flavor microcapsule, its preparation method, and its application. Background Technology

[0002] Microencapsulation technology refers to the technique of using film-forming materials as shell materials to encapsulate solids, liquids, or gases into tiny particles. The resulting core-shell structure gives microcapsules protective and barrier properties, preventing the core material inside from being affected by the external environment while also preventing it from escaping to the outside.

[0003] Adding fragrance microcapsules to clothing as finishing agents can increase the fragrance content and control fragrance release in time and space. Commercially available fragrance microcapsules typically use melamine-formaldehyde resin as the shell material, and their encapsulation methods are all in-situ polymerization. Encapsulating fragrance microcapsules using this method requires high hydrophilicity / hydrophobicity of the core material itself. Due to the complex composition of fragrances, only a few lipophilic fragrances are suitable for O / W in-situ polymerization encapsulation. Water-based fragrances or perfumes have a short fragrance retention time due to their good water solubility or volatility during daily use. Furthermore, because water-based fragrances have good water solubility, they cannot form oil-in-water emulsions. For the encapsulation of water-based fragrances, W / O or solvent evaporation methods (W / O / W) are mainly used. For example, patent CN114304584A discloses a method for preparing fragrance microcapsules and fragrance microcapsules, using cellulose derivatives to encapsulate water-soluble fragrances, forming an oil-in-water structure. Both the W / O and solvent evaporation methods require the use of large amounts of organic solvents. During large-scale production, the evaporation of organic solvents can cause environmental pollution or high costs associated with the additional oil phase.

[0004] Based on the above analysis, it is essential to provide a method for preparing aldehyde-free phase change flavor microcapsules that does not emit organic solvents. Summary of the Invention

[0005] This application provides a method for preparing aldehyde-free phase change fragrance microcapsules to solve the problem of organic solvents being released into the environment during the encapsulation of water-based fragrances in related technologies.

[0006] In a first aspect, this application provides a method for preparing aldehyde-free phase change flavor microcapsules, comprising the following steps: S101, Preparation of oil phase: Mix polyaspartic acid ester, isocyanate, oil phase emulsifier, catalyst and phase change material, heat at 60-75℃ to obtain oil phase solution, and stir the oil phase solution at 50℃ at low speed for later use. S102, Preparation of primary W / O emulsion of water-based fragrance: Add water-based fragrance and titanium carbide (Ti3C2) to the oil phase solution and emulsify for 3-15 min to obtain water-based fragrance W / O emulsion; S103, Preparation of W / O / W emulsion and microcapsules: Add water-based fragrance W / O emulsion to a secondary aqueous emulsifier for O / W emulsification to form a W / O / W multiple emulsion; then add ethylenediamine aqueous solution, heat to 70-85℃, and react for 2-4 hours to obtain aldehyde-free phase change fragrance microcapsules.

[0007] In some embodiments, the viscosity of the polyaspartic ester is 500–2000 mPa·s and the NH equivalent is 200–300 g / mol.

[0008] In some embodiments, the molar ratio of secondary amine groups to isocyanate in the polyaspartic ester is 0.8 to 1:1. This molar ratio increases the molecular weight of the oil phase, increases its viscosity, and improves its ability to emulsify the primary aqueous phase.

[0009] In some embodiments, the isocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, and hexamethylene diisocyanate trimer.

[0010] In some embodiments, the oil phase emulsifier is one or more selected from Span 80, polyglycerol ricinoleate, silica sol, and β-cyclodextrin solution.

[0011] In some embodiments, the catalyst is one or a mixture of two of organotin catalysts or organobismuth acid catalysts.

[0012] In some embodiments, the phase change material is selected from any one of n-dodecanool, n-tetradecanool, and n-octadecanool.

[0013] In some embodiments, the mass ratio of aqueous fragrance, titanium carbide and oil phase solution is 0.5-0.8:0.2-0.5:1.

[0014] In some embodiments, in step S101, the amount of emulsifier added is 1 to 5% of the mass of the oil phase solution; the amount of catalyst added is 0.5 to 1.5% of the mass of the oil phase solution; and the amount of phase change material added is 10 to 30% of the mass of the oil phase solution.

[0015] In some embodiments, in step S103, the amount of secondary aqueous emulsifier added is 1 to 10% of the mass of the aqueous fragrance W / O emulsion; the amount of ethylenediamine aqueous solution added is 1 to 1.5 times the mass of the aqueous fragrance W / O emulsion.

[0016] In some embodiments, the secondary aqueous emulsifier is one or more of Tween 80, polyvinylpyrrolidone, styrene-maleic anhydride copolymer, and sodium dodecylbenzenesulfonate.

[0017] Secondly, this application also provides formaldehyde-free phase change fragrance microcapsules prepared using the above-mentioned preparation method, wherein the core material of the formaldehyde-free phase change fragrance microcapsules is a mixture of water-based fragrance and titanium carbide, and the shell material of the formaldehyde-free phase change fragrance microcapsules is polyurethane urea.

[0018] Thirdly, this application also provides the application of the aforementioned fragrance microcapsules in textiles.

[0019] The phase change microcapsules obtained in this application have a two-layer shell structure. Considering that the water-based fragrance is protected by the two shells, it is difficult for the microcapsules themselves to release the fragrance. Therefore, a certain amount of phase change material is added to the shell. When the microcapsule comes into contact with the human body, the phase change material melts into a liquid state upon heating, forming pores in the shell and providing a pathway for the release of the water-based fragrance. At room temperature, the release of the water-based fragrance is limited, thus giving the fragrance microcapsules a longer service life.

[0020] The beneficial effects of the technical solution provided in this application include: The preparation method provided in this application uses polyaspartic acid ester as the oil phase, and adds a certain proportion of diisocyanate to the oil phase. Both are completely solidified in the subsequent reaction process, avoiding the release of large amounts of organic solvents into the environment. The microcapsule preparation method provided in this application is simple and stable, and is not only suitable for the microencapsulation of most aqueous substances, but also simple to operate, with mild and controllable reactions, making it suitable for large-scale production. The formaldehyde-free phase change fragrance microcapsules prepared in this application, under the protection of the oil phase polyurethane urea shell material, can be sealed and stored at room temperature without demulsification for 6 to 10 months. When the fragrance microcapsules of this application are added to clothing as a finishing agent, with the assistance of near-infrared laser, bacteria on clothing can be removed within 15 minutes, more preferably within 10 minutes, and more preferably within 8 minutes. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a morphological image of the aldehyde-free phase change fragrance microcapsules prepared in Example 1 of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] This application provides a method for preparing aldehyde-free phase change fragrance microcapsules, which can solve the problem of releasing organic solvents into the environment during the encapsulation of water-based fragrances in related technologies.

[0025] This embodiment provides a method for preparing aldehyde-free phase change flavor microcapsules, including the following steps: Step S101, Preparation of the oil phase: Polyaspartic acid ester, isocyanate, oil phase emulsifier, catalyst, and phase change material are mixed and heated to 60-75°C to obtain an oil phase solution. The oil phase solution is stirred at 50°C at a speed of 50-100 rpm for later use. The amount of oil phase emulsifier added is 1-5% of the mass of the oil phase solution; the amount of catalyst added is 0.5-1.5% of the mass of the oil phase solution; and the amount of phase change material added is 10-30% of the mass of the oil phase solution. Step S102, Preparation of primary water-based fragrance W / O emulsion: Add water-based fragrance and titanium carbide to the oil phase solution and emulsify for 3-15 min to obtain water-based fragrance W / O emulsion; Step S103, Preparation of W / O / W emulsion and microcapsules: The aqueous fragrance W / O emulsion is added to a secondary aqueous emulsifier for O / W emulsification to form a W / O / W multi-emulsion; then an ethylenediamine aqueous solution is added and heated to 70-85℃. After the reaction is completed, aldehyde-free phase change fragrance microcapsules are obtained; the amount of secondary aqueous emulsifier added is 1-10% of the mass of the aqueous fragrance W / O emulsion; the amount of ethylenediamine aqueous solution added is 1-1.5 times the mass of the aqueous fragrance W / O emulsion.

[0026] In the above preparation process, the isocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, and hexamethylene diisocyanate trimer; the oil phase emulsifier is one or more of Span 80, polyglycerol ricinoleate, magnesium hydroxide sol, silica sol, and β-cyclodextrin solution; the catalyst is one or a mixture of two of organotin catalysts or organobismuth acid catalysts; and the secondary aqueous phase emulsifier is one or more of Tween 80, polyvinylpyrrolidone, styrene-maleic anhydride copolymer, and sodium dodecylbenzene sulfonate.

[0027] The viscosity of polyaspartic acid ester is 500–2000 mPa·s, and the NH equivalent is 200–300 g / mol; the molar ratio of secondary amine groups to isocyanate in polyaspartic acid ester is 0.8–1:1; the mass ratio of aqueous fragrance to oil phase solution is 0.5–0.8:1.

[0028] The following detailed description, in conjunction with embodiments, illustrates the aldehyde-free phase change flavor microcapsules 2 provided in this application and their preparation method.

[0029] In the following examples, the water-based fragrance was purchased from Shandong Xinyi Fine Chemical Co., Ltd., and its product name is "Wishing Fairy". Titanium carbide was purchased from Nanjing Mingchang New Material Technology Co., Ltd.

[0030] Example 1 Preparation of the oil phase: Weigh 92g of polyaspartic acid ester with a viscosity of 1000 mPa·s and an NH equivalent of 200 g / mol. While stirring, add 8g of hexamethylene diisocyanate, 5g of polyglycerol ricinoleate, 0.7g of organic bismuth acid catalyst and 16g of n-tetradecanoic acid. After stirring and reacting at 65℃ for 0.5h, the viscosity of the oil phase solution is observed to increase significantly. The oil phase solution is then stirred at 50℃ and 60rpm for later use. Preparation of primary W / O emulsion: 70g of water-based fragrance and 30g of tritiated carbide were added to 100g of oil phase at a speed of 3000rpm and emulsified for 3min to obtain water-based fragrance W / O emulsion; Preparation of secondary W / O / W emulsions and microcapsules: At room temperature, 80g of aqueous fragrance W / O emulsion was added to 140g of 5% (w / w) styrene-maleic anhydride copolymer emulsion for O / W emulsification at 500 rpm to form a W / O / W multiple emulsion; then, 85g of 40% (w / w) ethylenediamine aqueous solution was rapidly added to the reaction system, the temperature was raised to 80℃, and the reaction was carried out for 3 hours before discharge to obtain aldehyde-free phase change fragrance microcapsules with a solid content of about 40%.

[0031] The morphology of the aldehyde-free phase change fragrance microcapsules prepared in Example 1 is shown in the figure. Figure 1 ,from Figure 1 It can be seen that the prepared aldehyde-free phase change flavor microcapsules have a regular morphology.

[0032] The aldehyde-free phase change fragrance microcapsules prepared in Example 1 released water-based fragrance and titanium dicarbide after reaching the phase change temperature of 38.5°C.

[0033] The aldehyde-free phase change fragrance microcapsules prepared in Example 1 were diluted with water to a solid content of 35%, and stored in a sealed container at room temperature. No demulsification occurred within 9 months of storage.

[0034] Example 2 Preparation of the oil phase: Weigh 92g of polyaspartic acid ester with a viscosity of 1800 mPa·s and an NH equivalent of 210 g / mol. While stirring, add 8g of hexamethylene diisocyanate trimer, 4g of polyglycerol ricinoleate, 0.7g of organic bismuth acid catalyst and 25g of n-tetradecanoic acid. After stirring at 70℃ for 0.5h, the viscosity of the oil phase solution is observed to increase significantly. The oil phase solution is then stirred at 50℃ at a speed of 80 rpm for later use. Preparation of primary W / O emulsion: 75g of water-based fragrance and 25g of tritiated carbide were added to 100g of oil phase at a speed of 3000rpm and emulsified for 5min to obtain water-based fragrance W / O emulsion. Preparation of secondary W / O / W emulsions and microcapsules: At room temperature, 80g of aqueous fragrance W / O emulsion was added to 130g of 5% (w / w) styrene-maleic anhydride copolymer emulsion for O / W emulsification at 1000rpm to form a W / O / W multiple emulsion; then, 90g of 40% (w / w) ethylenediamine aqueous solution was rapidly added to the reaction system, the temperature was raised to 70℃, and the reaction was carried out for 2 hours before discharge to obtain aldehyde-free phase change fragrance microcapsules with a solid content of about 40%.

[0035] The aldehyde-free phase change fragrance microcapsules prepared in Example 2 release water-based fragrance and titanium dioxide after reaching the phase change temperature of 45°C.

[0036] The aldehyde-free phase change fragrance microcapsules prepared in Example 2 were diluted with water to a solid content of 35%, and stored in a sealed container at room temperature. No demulsification occurred within 10 months of storage.

[0037] Example 3 Preparation of the oil phase: Weigh 92g of polyaspartic acid ester with a viscosity of 1800 mPa·s and an NH equivalent of 280 g / mol. While stirring, add 8g of hexamethylene diisocyanate, 3g of Span 80, 0.85g of organic bismuth acid catalyst and 22g of n-tetradecanoic acid. After stirring and reacting at 70℃ for 0.5h, the viscosity of the oil phase solution is observed to increase significantly. The oil phase solution is then stirred at 50℃ and 85rpm for later use. Preparation of primary W / O emulsion: 60g of water-based fragrance and 40g of tritiated carbide were added to 100g of oil phase at a speed of 3000rpm and emulsified for 5min to obtain water-based fragrance W / O emulsion. Preparation of secondary W / O / W emulsions and microcapsules: At room temperature, 80g of aqueous fragrance W / O emulsion was added to 110g of 5% Tween 20 emulsion for O / W emulsification at 1000rpm to form a W / O / W multiple emulsion; then, 30g of 40% ethylenediamine aqueous solution was quickly added to the reaction system, the temperature was raised to 70℃, and the reaction was carried out for 2 hours before discharge to obtain aldehyde-free phase change fragrance microcapsules with a solid content of about 40%.

[0038] The aldehyde-free phase change fragrance microcapsules prepared in Example 3 released water-based fragrance and titanium dicarbide after reaching the phase change temperature of 38.5°C.

[0039] The aldehyde-free phase change fragrance microcapsules prepared in Example 3 were diluted with water to a solid content of 35%, and stored in a sealed container at room temperature. No demulsification occurred within 8 months of storage.

[0040] Example 4 Preparation of the oil phase: Weigh 90g of polyaspartic acid ester with a viscosity of 1600 mPa·s and an NH equivalent of 230 g / mol. While stirring, add 10g of hexamethylene diisocyanate trimer, 4g of polyglycerol ricinoleate, 0.9g of organotin catalyst and 28g of n-dodecanool. After stirring at 70℃ for 0.5h, the viscosity of the oil phase solution is observed to increase significantly. The oil phase solution is then stirred at 50℃ at a speed of 90 rpm for later use. Preparation of primary W / O emulsion: 80g of water-based fragrance and 35g of tritiated carbide were added to 100g of oil phase at a speed of 3000rpm and emulsified for 5min to obtain water-based fragrance W / O emulsion. Preparation of secondary W / O / W emulsions and microcapsules: At room temperature, 80g of aqueous fragrance W / O emulsion was added to 125g of 5% (w / w) styrene-maleic anhydride copolymer emulsion for O / W emulsification to form a W / O / W multiple emulsion. Then, 40g of 40% (w / w) ethylenediamine aqueous solution was rapidly added to the reaction system. After heating to 70℃, 10% (w / w) citric acid aqueous solution was added dropwise to adjust the pH to 4.0. After reacting for 2 hours, the product was discharged to obtain fragrance microcapsules with a solid content of about 40%.

[0041] The aldehyde-free phase change fragrance microcapsules prepared in Example 4 released water-based fragrance and titanium dicarbide after reaching the phase change temperature of 22°C.

[0042] The flavor microcapsules prepared in Example 4 were diluted with water to a solid content of 35%, and stored in a sealed container at room temperature. No demulsification occurred within 8 months of storage.

[0043] Example 5 Preparation of the oil phase: Weigh 92g of polyaspartic acid ester with a viscosity of 1500 mPa·s and an NH equivalent of 250 g / mol. While stirring, add 8g of isophorone diisocyanate, 4.5g of polyglycerol ricinoleate, 0.8g of organotin catalyst and 25g of n-octadecyl alcohol. After stirring and reacting at 65℃ for 0.5h, the viscosity of the oil phase solution is observed to increase significantly. The oil phase solution is then stirred at 50℃ and 100rpm for later use. Preparation of primary W / O emulsion: 65g of water-based fragrance and 50g of tritiated carbide were added to 100g of oil phase at a speed of 3000rpm and emulsified for 3min to obtain water-based fragrance W / O emulsion. Preparation of secondary W / O / W emulsions and microcapsules: At room temperature, 80g of aqueous fragrance W / O emulsion was added to 100g of 1% (w / w) styrene-maleic anhydride copolymer emulsion and 40g (w / w) 4% (w / w) polyvinylpyrrolidone (K90) for O / W emulsification to form a W / O / W multiple emulsion; then, 35g of 40% (w / w) ethylenediamine aqueous solution was rapidly added to the reaction system, the temperature was raised to 70℃, and the reaction was carried out for 2 hours before the material was discharged to obtain fragrance microcapsules with a solid content of about 40%.

[0044] The aldehyde-free phase change fragrance microcapsules prepared in Example 5 released water-based fragrance and titanium dicarbide after reaching the phase change temperature of 22.5°C.

[0045] The aldehyde-free phase change fragrance microcapsules prepared in Example 5 were diluted with water to a solid content of 35%, and stored in a sealed container at room temperature. No demulsification occurred within 10 months of storage.

[0046] Comparative Example 1 Preparation of the oil phase: Weigh 92g of polyaspartic acid ester with a viscosity of 1000 mPa·s and an NH equivalent of 200 g / mol. While stirring, add 8g of hexamethylene diisocyanate, 5g of polyglycerol ricinoleate, 0.7g of organic bismuth acid catalyst and 16g of n-tetradecanoic acid. After stirring at 65℃ for 0.5h, the viscosity of the oil phase increased significantly. Preparation of primary W / O emulsion: 70g of water-based fragrance was added to 100g of oil phase at 3000rpm and emulsified for 3min to obtain water-based fragrance W / O emulsion; Preparation of secondary W / O / W emulsion and microcapsules: At room temperature, 140g of 5% (w / w) styrene-maleic anhydride copolymer emulsion was added to 80g of aqueous fragrance W / O emulsion at a rotation speed of 500rpm. After heating to 80℃ and reacting for 3 hours, the product was discharged to obtain fragrance microcapsules with a solid content of about 40%.

[0047] The flavor microcapsules prepared in Comparative Example 1 were diluted with water to a solid content of 35%, and stored in a sealed container at room temperature. After one month of storage, demulsification occurred.

[0048] Comparative Example 2 Preparation of the oil phase: Weigh 92g of polyaspartic acid ester with a viscosity of 1000 mPa·s and an NH equivalent of 200 g / mol. While stirring, add 8g of hexamethylene diisocyanate, 5g of polyglycerol ricinoleate, 0.7g of organic bismuth acid catalyst and 16g of n-tetradecanoic acid. After stirring and reacting at 65℃ for 0.5h, the viscosity of the oil phase solution is observed to increase significantly. The oil phase solution is then stirred at 50℃ and 60rpm for later use. Preparation of primary W / O emulsion: 70g of water-based fragrance was added to 100g of oil phase at 3000rpm and emulsified for 3min to obtain water-based fragrance W / O emulsion; Preparation of secondary W / O / W emulsions and microcapsules: At room temperature, 80g of aqueous fragrance W / O emulsion was added to 140g of 5% (w / w) styrene-maleic anhydride copolymer emulsion for O / W emulsification at 500 rpm to form a W / O / W multiple emulsion; then, 85g of 40% (w / w) ethylenediamine aqueous solution was rapidly added to the reaction system, the temperature was raised to 80℃, and the reaction was carried out for 3 hours before discharge to obtain aldehyde-free phase change fragrance microcapsules with a solid content of about 40%.

[0049] The flavor microcapsules prepared in Comparative Example 1 were diluted with water to a solid content of 35%, and stored in a sealed container at room temperature. After two months of storage, demulsification occurred.

[0050] The fragrance microcapsules prepared in Examples 1-5 and Comparative Examples 1-2 were diluted with water to prepare a suspension with a mass concentration of 30%. Seven pieces of pure cotton fiber with a size of 20cm*20cm were immersed in the suspension. After immersion, they were hung to dry naturally. Then, the dried pure cotton fibers were immersed in a 1*10 cm solution. 6 The cotton fibers were immersed in a solution of Staphylococcus aureus or Candida albicans at a concentration of CFU / mL for 20 minutes. After immersion, the cotton fibers were irradiated with a 780 nm laser. The results of Staphylococcus aureus removal from the cotton fibers are shown in Table 1.

[0051] Table 1: Results of Staphylococcus aureus removal from pure cotton fibers

[0052] As can be seen from the results in Table 1, microcapsules containing titanium dicarbide can remove Staphylococcus aureus from clothing within 15-20 minutes under laser irradiation, demonstrating excellent bactericidal performance.

[0053] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0054] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly specified.

[0055] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing aldehyde-free phase change flavor microcapsules, characterized in that, Includes the following steps: S101, mix polyaspartic acid ester, isocyanate, oil phase emulsifier, catalyst and phase change material, heat at 60-75℃ to obtain oil phase solution, stir the oil phase solution at 50-60℃ for later use. S102, add water-based fragrance and titanium carbide to the oil phase solution and emulsify for 3-15 min to obtain water-based fragrance W / O emulsion; S103, an aqueous fragrance W / O emulsion is added to a secondary aqueous emulsifier for O / W emulsification to form a W / O / W multi-emulsion; then an aqueous ethylenediamine solution is added and heated to 70-85℃. After the reaction is complete, aldehyde-free phase change fragrance microcapsules are obtained.

2. The method for preparing aldehyde-free phase change flavor microcapsules according to claim 1, characterized in that, In step S101, the amount of oil phase emulsifier added is 1 to 5% of the mass of the oil phase solution; the amount of catalyst added is 0.5 to 1.5% of the mass of the oil phase solution; and the amount of phase change material added is 10 to 30% of the mass of the oil phase solution.

3. The method for preparing aldehyde-free phase change flavor microcapsules according to claim 1, characterized in that, The molar ratio of secondary amine groups to isocyanate in the polyaspartic ester is 0.8 to 1:

1.

4. The method for preparing aldehyde-free phase change flavor microcapsules according to claim 1, characterized in that, The isocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, and hexamethylene diisocyanate trimer.

5. The method for preparing aldehyde-free phase change flavor microcapsules according to claim 1, characterized in that, The oil phase emulsifier is one or more of Span 80, polyglycerol ricinoleate, silica sol, and β-cyclodextrin solution; the catalyst is one or a mixture of two of organotin catalysts or organobismuth acid catalysts; the phase change material is one or a mixture of one or more of n-dodecanool, n-tetradecanool, and n-octadecanool.

6. The method for preparing aldehyde-free phase change flavor microcapsules according to claim 1, characterized in that, The mass ratio of water-based fragrance, titanium carbide and oil phase solution is 0.5-0.8:0.2-0.5:

1.

7. The method for preparing aldehyde-free phase change flavor microcapsules according to claim 1, characterized in that, The secondary aqueous emulsifier is one or more of Tween 80, polyvinylpyrrolidone, styrene-maleic anhydride copolymer, and sodium dodecylbenzenesulfonate.

8. The method for preparing aldehyde-free phase change flavor microcapsules according to claim 1, characterized in that, In step S103, the amount of secondary aqueous emulsifier added is 1 to 10% of the mass of the aqueous fragrance W / O emulsion; the amount of ethylenediamine aqueous solution added is 1 to 1.5 times the mass of the aqueous fragrance W / O emulsion.

9. A formaldehyde-free phase change flavor microcapsule, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. The application of the formaldehyde-free phase change fragrance microcapsules of claim 9 in textiles.

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