Aromatic microcapsule dispersion and method of making and use thereof

Abstract

The present application relates to a kind of aromatic microcapsule dispersion and its preparation method and application, the preparation method of the aromatic microcapsule dispersion includes the following preparation steps: fragrance, phase change material and beta-cyclodextrin are mixed, and composite core material is obtained;The composite core material is mixed with emulsion dispersion, and core material emulsion is obtained, wherein the emulsion dispersion includes anionic emulsifier and beta-cyclodextrin;And the core material emulsion is mixed with etherified water-soluble amino resin prepolymer, then self-crosslinking reaction is carried out, and the prepared aromatic microcapsule has excellent high-temperature resistance and fragrance slow-release performance, so that aromatic microcapsule can be well applied in fabric finishing agent, cosmetics, odor eliminator and mosquito repellent product etc..

Description

Technical Field

[0001] This invention relates to the field of fragrance technology, and in particular to an aromatic microcapsule dispersion, its preparation method, and its application. Background Technology

[0002] Fragrance is a low molecular weight, highly volatile organic compound. If it is used directly in the dyeing and finishing of fabrics, a large amount of fragrance will evaporate during the high-temperature processing of the fabric, causing the aroma of the fabric to fade or even undergo adverse changes. Therefore, in order to give fabrics a lasting and rich fragrance, microencapsulation technology is usually used to reduce the volatilization of fragrance and improve the stability of fragrance.

[0003] Traditional microencapsulation technology typically uses fragrance as the core material and amino resin, polyacrylate, polyurea, or gum arabic-gelatin as the wall material. It employs interfacial polymerization or in-situ polymerization processes to prepare aromatic microcapsules. Although this enhances the sustained-release performance of fragrance to some extent, the resulting aromatic microcapsules still suffer from rapid fragrance release and short fragrance retention time. In addition, aromatic microcapsules are prone to thermal expansion in high-temperature environments, leading to damage to the capsule wall and loss of fragrance volatilization within the capsule. Summary of the Invention

[0004] Therefore, it is necessary to provide an aromatic microcapsule dispersion, its preparation method, and its application to address the above-mentioned problems. The aromatic microcapsules obtained by the preparation method have excellent temperature resistance and fragrance sustained-release properties, and can be well applied in products such as fabric finishing agents, cosmetics, odor removers, and mosquito repellents.

[0005] This invention provides a method for preparing an aromatic microcapsule dispersion, comprising the following steps:

[0006] A composite core material is obtained by mixing fragrance, phase change material and β-cyclodextrin.

[0007] The composite core material is mixed with an emulsion dispersion to obtain a core material emulsion, wherein the emulsion dispersion comprises an anionic emulsifier and β-cyclodextrin; and

[0008] The core material emulsion is mixed with an etherified water-soluble amino resin prepolymer, and then subjected to a self-crosslinking reaction to obtain an aromatic microcapsule dispersion.

[0009] In one embodiment, the degree of etherification of the etherified water-soluble amino resin prepolymer is 30%-70%.

[0010] In one embodiment, the anionic emulsifier is selected from at least one of sodium styrene-maleic anhydride copolymer, sodium polyacrylate, or sodium carboxymethyl cellulose.

[0011] In one embodiment, in the step of mixing the core material emulsion with the etherified water-soluble amino resin prepolymer, the mass ratio of the composite core material in the core material emulsion to the etherified water-soluble amino resin prepolymer is 1:1-10:1.

[0012] In one embodiment, in the step of mixing the composite core material with the emulsion dispersion, the mass ratio of the anionic emulsifier, β-cyclodextrin and the composite core material is 0.05:0.001:1-0.15:0.05:1.

[0013] In one embodiment, during the step of mixing the flavoring, phase change material, and β-cyclodextrin, the temperature is greater than or equal to the melting point of the phase change material.

[0014] In one embodiment, the phase change material has a melting point of 52°C-72°C, and the phase change material is selected from at least one of paraffin or higher alcohols.

[0015] In one embodiment, in the step of mixing the flavoring, the phase change material and the β-cyclodextrin, the mass ratio of the flavoring, the phase change material and the β-cyclodextrin is 1:0.1:0.01-1:9:0.1.

[0016] In the method for preparing the aromatic microcapsule dispersion provided by this invention, firstly, in the step of mixing fragrance, phase change material, and β-cyclodextrin, the phase change material and β-cyclodextrin can adsorb and encapsulate the fragrance. Compared with free fragrance, the resulting composite core material has good volatility resistance and high temperature resistance. Secondly, in the step of mixing the composite core material with the emulsion dispersion, the β-cyclodextrin in the emulsion dispersion can further adsorb and encapsulate the composite core material on the one hand, and synergistically with the anionic emulsifier on the other hand, so that the composite core material is better emulsified and dispersed. At the same time, the anionic emulsifier coats the surface of the composite core material, forming a core material emulsion with small particle size and stability. Finally, the positively charged etherified water-soluble amino resin prepolymer combines with the anionic emulsifier on the surface of the composite core material and further undergoes a self-crosslinking reaction to form an insoluble and infusible melamine resin microcapsule wall layer, thereby preparing aromatic microcapsules with excellent high temperature resistance and sustained-release performance.

[0017] An aromatic microcapsule dispersion is prepared by the method described above.

[0018] Application of an aromatic microcapsule dispersion as described above in fabric finishing agents, cosmetics, odor removers, and mosquito repellent products.

[0019] The aromatic microcapsule dispersion provided by this invention has excellent high-temperature resistance and fragrance sustained-release properties, enabling it to be widely used in products such as fabric finishing agents, cosmetics, odor removers, and mosquito repellents. In particular, when the aromatic microcapsule dispersion is used in fabric finishing agents, the aromatic microcapsules in the dispersion are not easily damaged during high-temperature processing such as fabric heat setting, thus avoiding fragrance loss and effectively improving the fragrance retention time of the fabric. Detailed Implementation

[0020] The following will further explain the aromatic microcapsule dispersion, its preparation method, and its application provided by the present invention.

[0021] The method for preparing the aromatic microcapsule dispersion provided by the present invention includes the following steps:

[0022] S11, a composite core material is obtained by mixing fragrance, phase change material and β-cyclodextrin;

[0023] S12, mixing the composite core material with the emulsion dispersion to obtain a core material emulsion; and

[0024] S13, the core material emulsion is mixed with the etherified water-soluble amino resin prepolymer, and then a self-crosslinking reaction is carried out to obtain an aromatic microcapsule dispersion.

[0025] In step S11, the phase change material and β-cyclodextrin can adsorb and encapsulate the fragrance. Compared with the free fragrance, the melting point of the resulting composite core material is significantly increased and the volatility is significantly reduced.

[0026] Preferably, the mixing temperature of the fragrance, phase change material, and β-cyclodextrin is higher than the melting point of the phase change material. Further, the mixing temperature of the fragrance, phase change material, and β-cyclodextrin is 5°C-10°C higher than or equal to the melting point of the phase change material, so that the phase change material can melt, thereby better cooperating with β-cyclodextrin to adsorb and encapsulate the fragrance, thereby reducing the volatility of the composite core material and further helping to improve the sustained-release properties of the fragrance microcapsules. Optionally, the temperature in the step of mixing the fragrance, phase change material, and β-cyclodextrin is 60-80°C.

[0027] Optionally, the phase change material has a melting point of 52℃-72℃. In one embodiment, the phase change material is selected from at least one of paraffin wax or higher alcohols, wherein higher alcohols, also known as fatty alcohols, refer to aliphatic primary alcohols containing more than 16 carbon atoms. Specifically, the paraffin wax is selected from at least one of 52# paraffin wax, 54# paraffin wax, 56# paraffin wax, 58# paraffin wax, 60# paraffin wax, 62# paraffin wax, 64# paraffin wax, 66# paraffin wax, 68# paraffin wax, and 70# paraffin wax. Further, the paraffin wax is selected from at least one of semi-refined paraffin wax or fully refined paraffin wax. Preferably, the paraffin wax is selected from 56# fully refined paraffin wax, 58# fully refined paraffin wax, and 60# fully refined paraffin wax, and the higher alcohol is selected from at least one of octadecyl alcohol and didodecyl alcohol, thereby reducing the volatility of the composite core material and improving the fragrance sustained-release performance of the aromatic microcapsules.

[0028] Optionally, the fragrance is selected from hydrophobic fragrances, and further selected from at least one of hydrophobic floral fragrances, hydrophobic fruity fragrances, or hydrophobic herbal fragrances. Specifically, the fragrance is selected from at least one of floral fragrances such as osmanthus, rose, chamomile, cherry blossom, gardenia, and lotus; fruity fragrances such as lemon, orange, cantaloupe, banana, strawberry, and watermelon; or herbal fragrances such as lavender, citronellol, lemon eucalyptus oil, peppermint, aloe vera, and green tea, so as to better meet various fragrance needs.

[0029] β-Cyclodextrin, as a water-soluble nonionic polymer, has a hydrophobic cavity that can effectively absorb fragrances, especially hydrophobic fragrances. β-Cyclodextrin can synergistically enhance the high-temperature resistance of composite core materials with phase change materials.

[0030] To better improve the mixing effect between the components, thereby enhancing the high-temperature resistance of the aromatic microcapsules and the volatility resistance of the fragrance, the mass ratio of fragrance, phase change material and β-cyclodextrin is 1:0.1:0.01-1:9:0.1, preferably 1:0.1:0.02-1:5:0.1.

[0031] In step S12, the emulsifying dispersant includes anionic emulsifier and β-cyclodextrin. β-cyclodextrin in the emulsifying dispersant can further adsorb and encapsulate the composite core material on the one hand, and can synergize with the anionic emulsifier on the other hand, so that the composite core material is better emulsified and dispersed. At the same time, the anionic emulsifier is coated on the surface of the composite core material to form a core material emulsion with small particle size and stability.

[0032] In one embodiment, a portion of the anionic emulsifier may exist freely in the core material emulsion, further enhancing the stability of the prepared aromatic microcapsule dispersion; optionally, the anionic emulsifier is selected from at least one of sodium styrene-maleic anhydride copolymer, sodium polyacrylate, or sodium carboxymethyl cellulose; preferably, the anionic emulsifier is selected from sodium styrene-maleic anhydride copolymer; in one embodiment, the anionic emulsifier is a 20% by mass aqueous solution of sodium styrene-maleic anhydride copolymer.

[0033] To better improve the emulsification and dispersion effect of the composite core material and further enhance the high-temperature resistance and fragrance sustained-release performance of the prepared aromatic microcapsules, the mass ratio of anionic emulsifier, β-cyclodextrin and composite core material in the emulsification dispersion is 0.05:0.001:1-0.15:0.05:1.

[0034] Optionally, in the step of mixing the composite core material with the emulsifying dispersant and water, the mixing temperature is 60℃-80℃. Specifically, a high-speed disperser is used to emulsify and disperse the composite core material, with the dispersion disc rotating at 2000rpm-8000rpm and the emulsification and dispersion time being 10min-50min.

[0035] In one embodiment, the emulsified dispersion can be prepared by the following method, specifically including the following steps:

[0036] Anionic emulsifier, β-cyclodextrin and deionized water are mixed and then heated to 60℃-70℃. After mixing evenly, an emulsion dispersion is obtained.

[0037] In step S13, the positively charged etherified water-soluble amino resin prepolymer combines with the anionic emulsifier on the surface of the composite core material and further undergoes a self-crosslinking reaction to form an insoluble, infusible, and highly crosslinked melamine resin microcapsule wall, thereby preparing aromatic microcapsules with excellent high-temperature resistance and sustained-release properties.

[0038] It should be noted that the degree of etherification refers to the percentage of methoxy groups in the etherified water-soluble amino resin prepolymer molecule compared to the total number of hydroxymethyl groups before etherification. Optionally, the degree of etherification of the etherified water-soluble amino resin prepolymer is 30%-70%. Further, the etherified water-soluble amino resin prepolymer is selected from at least one of methyl etherified melamine-formaldehyde resin, stiffening agent TF-6320, stiffening agent TF-6330, stiffening agent TF-632, or stiffening agent TF-634. Preferably, the etherified water-soluble amino resin prepolymer is selected from stiffening agent TF-6320, which can form a denser, highly cross-linked melamine resin capsule wall, thereby better improving the high-temperature resistance and sustained-release performance of the aromatic microcapsules.

[0039] To better enhance the bonding effect between the composite core material and the water-soluble amino resin prepolymer, and to further improve the high-temperature resistance and sustained-release properties of the aromatic microcapsules, the mass ratio of the composite core material to the water-soluble amino resin prepolymer in the core material emulsion is 1:1-10:1.

[0040] In the step of mixing the core material emulsion with the etherified water-soluble amino resin prepolymer to carry out a self-crosslinking reaction, optionally, the mixing and stirring speed is 500rpm-800rpm, the temperature is 60℃-80℃, and the time is 2h-6h.

[0041] Since the etherified water-soluble amino resin prepolymer contains a small amount of formaldehyde, in order to reduce the formaldehyde content in the aromatic microcapsule dispersion and better improve the safety and environmental performance of the aromatic microcapsule dispersion, hydrogen peroxide and urea are added to the aromatic microcapsule dispersion after the self-crosslinking reaction step to carry out the formaldehyde removal reaction, which effectively removes the formaldehyde in the aromatic microcapsule dispersion and improves the safety and environmental performance of the aromatic microcapsule dispersion.

[0042] In one embodiment, during the formaldehyde removal reaction, the temperature is 60°C-80°C and the time is 1-3 hours, and the free formaldehyde content in the aromatic microcapsule dispersion can be as low as 0.01%-0.05%.

[0043] To better remove formaldehyde from the aromatic microcapsule dispersion, the preferred mass ratio of hydrogen peroxide, urea, and aromatic microcapsule dispersion is 0.005:0.005:1 to 0.05:0.05:1. The hydrogen peroxide has a mass fraction of 30%.

[0044] Therefore, the method for preparing aromatic microcapsule dispersions provided by this invention can easily and efficiently prepare aromatic microcapsule dispersions that are heat-resistant, have excellent sustained-release properties, and are safe and environmentally friendly.

[0045] The present invention also provides an aromatic microcapsule dispersion obtained by the above preparation method.

[0046] The aromatic microcapsule dispersion of the present invention contains aromatic microcapsules with excellent high-temperature resistance and sustained-release properties.

[0047] This invention also provides the application of an aromatic microcapsule dispersion in fabric finishing agents, cosmetics, odor removers, and mosquito repellent products.

[0048] The aromatic microcapsule dispersion provided by this invention has excellent high temperature resistance and sustained release properties, and can be widely used in products such as fabric finishing agents, cosmetics, odor removers and mosquito repellents. In particular, when the aromatic microcapsule dispersion is used to finish fabrics, the aromatic microcapsule fragrance in the dispersion has a high fragrance encapsulation rate and is not easily damaged during high-temperature processing such as fabric heat setting, thus avoiding fragrance loss and effectively improving the fragrance retention time of the fabric.

[0049] In the aromatic microcapsule dispersion of the present invention, the aromatic microcapsules comprise a composite core material and a microcapsule wall layer coating the composite core material. The composite core material has low volatility and high temperature resistance, while the microcapsule wall layer is composed of an insoluble, infusible, highly cross-linked melamine resin and a small amount of polymeric emulsifying dispersant forming a dense outer shell. Thus, the composite core material and the microcapsule wall work synergistically, enabling the rapid weight loss thermal decomposition temperature of the aromatic microcapsules to reach above 330°C, thereby endowing the aromatic microcapsules with excellent high-temperature resistance and sustained-release properties.

[0050] The aromatic microcapsules contain a composite core material comprising fragrance, β-cyclodextrin, and a phase change material, while the outer capsule layer comprises a melamine resin wall, β-cyclodextrin, and an anionic emulsifier. Optionally, the particle size D of the aromatic microcapsules... 90 The range is 1μm-5μm.

[0051] To better control the thickness of the outer capsule layer of the aromatic microcapsule and further improve the high temperature resistance of the aromatic microcapsule, the mass ratio of the composite core material to the microcapsule wall material is 1:1-10:1, preferably 3:1-6:1.

[0052] The following specific examples will further illustrate the aromatic microcapsule dispersion, its preparation method, and its application.

[0053] Example 1

[0054] Mix 10g of peppermint essential oil, 0.5g of β-cyclodextrin and 50g of 58# fully refined paraffin wax evenly, then heat to 65℃ and keep warm for 30 minutes to obtain composite core material.

[0055] 240g of deionized water, 2g of β-cyclodextrin and 30g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%) were mixed, then heated to 65℃ and stirred for 30min to obtain an emulsion dispersion.

[0056] The composite core material was added to the emulsion dispersion, and then emulsified and dispersed at 8000 rpm for 30 minutes using a high-speed dispersion disc to obtain the core material emulsion.

[0057] The core material emulsion was mixed with 20g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 700rpm. After mixing evenly, the mixture was kept at 65℃ and reacted for 5h. Then, 6g of hydrogen peroxide solution (mass fraction of 30%) and 9g of urea were added, and the mixture was kept at 65℃ and reacted for another 2h to obtain an aromatic microcapsule dispersion.

[0058] Example 2

[0059] Mix 10g of peppermint essential oil, 0.5g of β-cyclodextrin and 50g of 58# fully refined paraffin wax evenly, then heat to 65℃ and keep warm for 30 minutes to obtain composite core material.

[0060] 240g of deionized water, 2g of β-cyclodextrin and 30g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%) were mixed, then heated to 65℃ and stirred for 30min to obtain an emulsion dispersion.

[0061] The composite core material was added to the emulsion dispersion, and then emulsified and dispersed at 8000 rpm for 30 minutes using a high-speed dispersion disc to obtain the core material emulsion.

[0062] The core material emulsion was mixed with 9g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 700rpm. After mixing evenly, the mixture was kept at 65℃ and reacted for 5h. Then, 6g of hydrogen peroxide solution (mass fraction of 30%) and 9g of urea were added, and the mixture was kept at 65℃ and reacted for another 2h to obtain an aromatic microcapsule dispersion.

[0063] Example 3

[0064] Mix 10g of peppermint essential oil, 0.5g of β-cyclodextrin, and 50g of docosyl alcohol evenly, then heat to 75℃ and keep warm for 30 minutes to obtain the composite core material.

[0065] 240g of deionized water, 2g of β-cyclodextrin and 30g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%) were mixed, then heated to 75℃ and stirred for 30min to obtain an emulsion dispersion.

[0066] The composite core material was mixed with the emulsion dispersion, and then emulsified and dispersed at 8000 rpm for 30 minutes using a high-speed dispersion disc to obtain the core material emulsion.

[0067] The core material emulsion was mixed with 20g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 700rpm. After mixing evenly, the mixture was kept at 75℃ for 4h. Then, 6g of hydrogen peroxide solution (mass fraction of 30%) and 9g of urea were added, and the mixture was kept at 75℃ for 2h to obtain an aromatic microcapsule dispersion.

[0068] Example 4

[0069] Mix 10g of peppermint essential oil, 0.5g of β-cyclodextrin, and 50g of octadecanol evenly, then heat to 70℃ and keep warm for 30 minutes to obtain the composite core material.

[0070] 240g of deionized water, 2g of β-cyclodextrin and 30g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%) were mixed, then heated to 70℃ and stirred for 30min to obtain an emulsion dispersion.

[0071] The composite core material was mixed with the emulsion dispersion, and then emulsified and dispersed at 8000 rpm for 30 minutes using a high-speed dispersion disc to obtain the core material emulsion.

[0072] The core material emulsion was mixed with 20g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 700rpm. After mixing evenly, the mixture was kept at 70℃ for 4h. Then, 6g of hydrogen peroxide solution (mass fraction of 30%) and 9g of urea were added, and the mixture was kept at 70℃ for 2h to obtain an aromatic microcapsule dispersion.

[0073] Example 5

[0074] Mix 50g of peppermint essential oil, 5g of β-cyclodextrin and 5g of 58# fully refined paraffin wax evenly, then heat to 65℃ and keep warm for 30 minutes to obtain composite core material.

[0075] 240g of deionized water, 2g of β-cyclodextrin and 13.5g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%) were mixed, then heated to 65℃ and stirred for 30min to obtain an emulsion dispersion.

[0076] The composite core material was mixed with the emulsion dispersion, and then emulsified and dispersed at 2000 rpm for 30 minutes using a high-speed dispersion disc to obtain the core material emulsion.

[0077] The core material emulsion was mixed with 8.6g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 800rpm. After mixing evenly, the mixture was kept at 65℃ for 5h. Then, 3g of hydrogen peroxide solution (mass fraction of 30%) and 1.5g of urea were added, and the mixture was kept at 65℃ for 2h to obtain an aromatic microcapsule dispersion.

[0078] Example 6

[0079] Mix 30g of peppermint essential oil, 0.5g of β-cyclodextrin and 30g of 58# fully refined paraffin wax evenly, then heat to 65℃ and keep warm for 30 minutes to obtain composite core material.

[0080] 240g of deionized water, 2g of β-cyclodextrin and 15g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%) were mixed, then heated to 65℃ and stirred for 30min to obtain an emulsion dispersion.

[0081] The composite core material was mixed with the emulsifying dispersant solution, and then emulsified and dispersed at 5000 rpm for 30 minutes using a high-speed dispersing disc to obtain the core material emulsion.

[0082] The core material emulsion was mixed with 15g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 700rpm. After mixing evenly, the mixture was kept at 65℃ for 5h. Then, 3g of hydrogen peroxide solution (mass fraction of 30%) and 3g of urea were added, and the mixture was kept at 65℃ for 2h to obtain an aromatic microcapsule dispersion.

[0083] Example 7

[0084] Mix 30g of peppermint essential oil, 0.5g of β-cyclodextrin and 30g of 58# fully refined paraffin wax evenly, then heat to 65℃ and keep warm for 30 minutes to obtain composite core material.

[0085] 240g of deionized water, 2g of β-cyclodextrin and 15g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%) were mixed, then heated to 65℃ and stirred for 30min to obtain an emulsion dispersion.

[0086] The composite core material was mixed with the emulsifying dispersant solution, and then emulsified and dispersed at 5000 rpm for 30 minutes using a high-speed dispersing disc to obtain the core material emulsion.

[0087] The core material emulsion was mixed with 15g of stiffening agent TF-634 (etherification degree of 65%). The mixing speed was 700rpm. After the mixture was homogeneous, it was kept at 65℃ for 5h. Then, 3g of hydrogen peroxide solution (mass fraction of 30%) and 3g of urea were added, and the reaction was continued at 65℃ for 2h to obtain the aromatic microcapsule dispersion.

[0088] Example 8

[0089] Mix 30g of peppermint essential oil, 1.5g of β-cyclodextrin and 30g of 58# fully refined paraffin wax evenly, then heat to 65℃ and keep warm for 30 minutes to obtain composite core material.

[0090] Mix 240g of deionized water, 2g of β-cyclodextrin and 3g of sodium carboxymethyl cellulose, then heat to 90℃ and stir for 60min to obtain an emulsion dispersion for later use.

[0091] The emulsion dispersion was cooled to 65°C, and the composite core material was added. The mixture was then emulsified and dispersed at 5000 rpm for 30 minutes using a high-speed dispersion disc to obtain the core material emulsion.

[0092] The core material emulsion was mixed with 15g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 700rpm. After mixing evenly, the mixture was kept at 65℃ for 5h. Then, 3g of hydrogen peroxide solution (mass fraction of 30%) and 3g of urea were added, and the mixture was kept at 65℃ for 2h to obtain an aromatic microcapsule dispersion.

[0093] Example 9

[0094] Mix 30g of peppermint essential oil and 30g of 58# fully refined paraffin wax evenly, then heat to 65℃ and keep warm for 30 minutes to obtain composite core material.

[0095] Mix 240g of deionized water and 15g of sodium salt solution of styrene-maleic anhydride copolymer (mass fraction of 20%), then heat to 65℃ and stir for 10 minutes to obtain an emulsified dispersion for later use.

[0096] The composite core material was added to the emulsion dispersion and emulsified and dispersed at 5000 rpm for 30 minutes using a high-speed dispersion disc to obtain the core material emulsion.

[0097] The core material emulsion was mixed with 15g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 700rpm. After mixing evenly, the mixture was kept at 65℃ for 5h. Then, 3g of hydrogen peroxide solution (mass fraction of 30%) and 3g of urea were added, and the mixture was kept at 65℃ for 2h to obtain an aromatic microcapsule dispersion.

[0098] Comparative Example 1

[0099] Mix 10g of lavender fragrance and 50g of octadecane evenly, then heat to 65℃ and keep warm for 30 minutes to obtain the composite core material.

[0100] 240g of deionized water was mixed with 30g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%), and then heated to 65℃. After mixing and stirring for 30min, an emulsion dispersion was obtained.

[0101] The composite core material was mixed with the emulsion dispersion, and then emulsified and dispersed at 8000 rpm for 30 minutes using a high-speed dispersion disc to obtain the core material emulsion.

[0102] The core material emulsion was mixed with 20g of stiffening agent TF-6320 (etherification degree of 45%). The mixing speed was 700rpm. After the mixture was homogeneous, it was kept at 65℃ and reacted for 5h to obtain an aromatic microcapsule dispersion.

[0103] Comparative Example 2

[0104] Mix 10g of lavender essence and 50g of 58# fully refined paraffin wax, then heat to 65℃ and keep warm for 30 minutes to obtain the composite core material.

[0105] 240g of deionized water was mixed with 30g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%), and then heated to 65℃. After mixing and stirring for 30min, an emulsion dispersion was obtained.

[0106] The composite core material was mixed with the emulsion dispersion, and then emulsified and dispersed at 8000 rpm for 30 minutes using a high-speed dispersion disc to obtain the core material emulsion.

[0107] The core material emulsion was mixed with 20g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 700rpm. After mixing evenly, the mixture was kept at 65℃ and reacted for 5h. Then, 6g of hydrogen peroxide solution (mass fraction of 30%) and 9g of urea were added, and the mixture was kept at 65℃ and reacted for another 2h to obtain an aromatic microcapsule dispersion.

[0108] Comparative Example 3

[0109] Mix 240g of deionized water and 30g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%), then heat to 65℃ and stir for 30min to obtain an emulsified dispersion.

[0110] Add 60g of lavender essential oil to the emulsion dispersion, and then use a high-speed dispersion disc to emulsify and disperse at 8000rpm for 30min to obtain the core material emulsion.

[0111] The core material emulsion was mixed with 20g of stiffening agent TF-6320 (etherification degree of 45%). The mixing speed was 700rpm. After the mixture was homogeneous, it was kept at 65℃ and reacted for 5h to obtain an aromatic microcapsule dispersion.

[0112] Comparative Example 4

[0113] Mix 30g of peppermint essential oil, 0.5g of β-cyclodextrin and 30g of octadecane evenly, then heat to 65℃ and keep warm for 30 minutes to obtain the composite core material.

[0114] 240g of deionized water, 2g of β-cyclodextrin and 15g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%) were mixed, then heated to 65℃ and stirred for 30min to obtain an emulsion dispersion.

[0115] The composite core material was mixed with the emulsifying dispersant solution, and then emulsified and dispersed at 5000 rpm for 30 minutes using a high-speed dispersing disc to obtain the core material emulsion.

[0116] The core material emulsion was mixed with 15g of stiffening agent TF-6320 (etherification degree of 45%) at a stirring speed of 700rpm. After mixing evenly, the mixture was kept at 65℃ for 5h. Then, 3g of hydrogen peroxide solution (mass fraction of 30%) and 3g of urea were added, and the mixture was kept at 65℃ for 2h to obtain an aromatic microcapsule dispersion.

[0117] Comparative Example 5

[0118] Mix 30g of peppermint essential oil and 30g of 58# fully refined paraffin wax evenly, then heat to 65℃ and keep warm for 30 minutes to obtain composite core material.

[0119] Mix 240g of deionized water and 15g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%), then heat to 65℃ and stir for 30min to obtain an emulsion dispersion.

[0120] The composite core material was mixed with the emulsifying dispersant liquid and emulsified and dispersed at 5000 rpm for 30 minutes using a high-speed dispersing disc to obtain the core material emulsion.

[0121] Mix 6.5g of melamine with 17.5g of formaldehyde solution (mass fraction 37%) until homogeneous, add 0.04g of liquid alkali (mass fraction 30%) to adjust the pH of the system to 9.2, heat to 79℃, and keep the reaction at this temperature for 50min to obtain water-soluble melamine-formaldehyde resin.

[0122] Water-soluble melamine-formaldehyde resin was slowly added to the core material emulsion, and the mixture was stirred at 700 rpm. After mixing evenly, the mixture was kept at 65°C for 5 hours to obtain an aromatic microcapsule dispersion.

[0123] Comparative Example 6

[0124] Mix 30g of peppermint essential oil and 30g of 58# fully refined paraffin wax evenly, then heat to 65℃ and keep warm for 30 minutes to obtain composite core material.

[0125] Mix 240g of deionized water and 15g of sodium salt aqueous solution of styrene-maleic anhydride copolymer (mass fraction of 20%), then heat to 65℃ and stir for 30min to obtain an emulsion dispersion.

[0126] The composite core material was mixed with the emulsifying dispersant liquid and emulsified and dispersed at 5000 rpm for 30 minutes using a high-speed dispersing disc to obtain the core material emulsion.

[0127] Mix 6.5g of urea with 17.5g of formaldehyde solution (mass fraction 37%) until homogeneous, add 0.04g of liquid alkali (mass fraction 30%) to adjust the pH of the system to 9.0, heat to 82℃, and keep the reaction at this temperature for 60min to obtain water-soluble urea-formaldehyde resin for later use.

[0128] Water-soluble urea-formaldehyde resin was added to the core material emulsion, stirred at 700 rpm, and reacted at 65°C for 5 hours to obtain an aromatic microcapsule dispersion.

[0129] Performance tests were conducted on Examples 1-9 and Comparative Examples 1-6, and the results are shown in Table 1.

[0130] High-temperature resistance test of aromatic microcapsules: Thermogravimetric analysis was used to test the temperature of aromatic microcapsules during rapid weight loss to determine their high-temperature resistance.

[0131] Fragrance retention rate test: The aromatic microcapsule dispersion was dried in a low-temperature vacuum dryer to obtain aromatic microcapsule powder. The aromatic microcapsule powder was placed in a 50℃ oven for 24 hours. The fragrance retention rate of the aromatic microcapsule powder before and after entering the oven was tested by headspace gas chromatography.

[0132] Free formaldehyde content standard: The formaldehyde content is tested using the emulsion formaldehyde content titration test method.

[0133] Aromatic microcapsule particle size: The aromatic microcapsule dispersions of Examples 1-9 and Comparative Examples 1-6 were tested for particle size using a SYMPATEC QICPIC dynamic image analyzer.

[0134] Table 1

[0135]

[0136]

[0137] As can be seen from the experimental data in Table 1, the aromatic microcapsule dispersions prepared under different experimental conditions using different phase change materials and peppermint essential oil as core materials in Examples 1-9, and using partially etherified water-soluble amino resin as microcapsule wall material for coating, showed significant differences in high-temperature resistance and sustained-release performance.

[0138] Comparing Examples 1 and 2, it can be seen that as the mass ratio of the composite core material to the microcapsule wall material increases, the high-temperature resistance of the aromatic microcapsule dispersion decreases, and the fragrance retention rate drops from 91.6% to 83.1%. This indicates that controlling the mass ratio between the composite core material and the microcapsule wall material helps to improve the high-temperature resistance of the aromatic microcapsule dispersion.

[0139] Comparing Examples 1 and 5, it can be seen that when the proportion of 58# fully refined paraffin in the composite core material is reduced, and the amount of sodium salt aqueous solution of styrene-maleic anhydride copolymer is reduced, the particle size of the aromatic microcapsules increases, the fragrance retention rate decreases, and the rapid weight loss temperature decreases. This indicates that controlling the amount of phase change material and anionic emulsifier helps to improve the high temperature resistance and fragrance retention rate of the aromatic microcapsule dispersion.

[0140] Comparing Examples 6 and 9, it can be seen that after adding β-cyclodextrin to the emulsion dispersion, the rapid thermal weight loss temperature and fragrance retention rate of Example 6 are higher than those of Example 9. This indicates that adding β-cyclodextrin to the emulsion dispersion helps to improve the high temperature resistance, sustained release performance and fragrance retention rate of the aromatic microcapsules in the aromatic microcapsule dispersion.

[0141] Compared with Comparative Example 1, Example 1, which uses 58# fully refined paraffin as the phase change material, has a higher rapid thermal weight loss temperature and fragrance retention rate than Comparative Example 1, which uses octadecane as the phase change material. This indicates that using paraffin as the phase change material helps to improve the high-temperature resistance, sustained-release performance, and fragrance retention rate of aromatic microcapsules in the aromatic microcapsule dispersion.

[0142] Comparing Example 6 and Comparative Example 5, Example 6, which uses partially methylated melamine-formaldehyde resin as the wall material of aromatic microcapsules, has similar heat resistance and fragrance retention rate compared to Comparative Example 5, which uses melamine-formaldehyde resin prepolymer. However, the free formaldehyde content of Example 6 is much lower than that of Comparative Example 5, and the safety and environmental protection performance of the aromatic microcapsule dispersion is better. This indicates that using partially methylated melamine-formaldehyde resin as the wall material of aromatic microcapsules helps to better reduce the free formaldehyde content in the aromatic microcapsule dispersion.

[0143] Compared with Comparative Example 6, using melamine-formaldehyde resin as the wall material for aromatic microcapsules resulted in better thermal stability and fragrance retention of the aromatic microcapsule dispersion compared with using urea-formaldehyde resin.

[0144] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0145] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing an aromatic microcapsule dispersion, characterized in that, Includes the following steps: A composite core material is obtained by mixing a fragrance, a phase change material, and β-cyclodextrin, wherein the mass ratio of the fragrance, the phase change material, and the β-cyclodextrin is 1:0.1:0.01-1:9:0.

1. The composite core material is mixed with an emulsion dispersion to obtain a core material emulsion, wherein the emulsion dispersion comprises an anionic emulsifier and β-cyclodextrin, and the mass ratio of the anionic emulsifier, β-cyclodextrin, and the composite core material is 0.05:0.001:1-0.15:0.05:1; and The core material emulsion is mixed with an etherified water-soluble amino resin prepolymer, and then subjected to a self-crosslinking reaction to obtain an aromatic microcapsule dispersion.

2. The method for preparing the aromatic microcapsule dispersion according to claim 1, characterized in that, The degree of etherification of the etherified water-soluble amino resin prepolymer is 30%-70%.

3. The method for preparing the aromatic microcapsule dispersion according to claim 1, characterized in that, The anionic emulsifier is selected from at least one of sodium salt of styrene-maleic anhydride copolymer, sodium salt of polyacrylate, or sodium salt of carboxymethyl cellulose.

4. The method for preparing the aromatic microcapsule dispersion according to claim 1, characterized in that, In the step of mixing the core material emulsion with the etherified water-soluble amino resin prepolymer, the mass ratio of the composite core material in the core material emulsion to the etherified water-soluble amino resin prepolymer is 1:1-10:

1.

5. The method for preparing the aromatic microcapsule dispersion according to any one of claims 1-4, characterized in that, In the step of mixing the fragrance, phase change material, and β-cyclodextrin, the temperature is greater than or equal to the melting point of the phase change material.

6. The method for preparing the aromatic microcapsule dispersion according to claim 5, characterized in that, The phase change material has a melting point of 52℃-72℃, and the phase change material is selected from at least one of paraffin or higher alcohols.

7. An aromatic microcapsule dispersion, characterized in that, It is prepared by the method for preparing aromatic microcapsule dispersion as described in any one of claims 1-6.

8. The application of the aromatic microcapsule dispersion as described in claim 7 in fabric finishing agents, cosmetics, odor removers, and mosquito repellent products.

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