A composite core-wall microcapsule, its preparation method and application

Abstract

This invention provides a composite core-wall microcapsule, its preparation method, and its application. The composite core-wall microcapsule comprises an oily core material and a polymer wall material coating the outer layer of the oily core material; the polymer wall material includes a polymer emulsifier, polyurethane, and polyurea. This invention provides a novel microcapsule wall material for encapsulating fragrances / cosmetics, enabling it to encapsulate oily core materials containing various aldehyde compounds. The core-wall microcapsules involved incorporate multiple wall materials, and the polymer emulsifiers in the wall materials are tightly linked by covalent bonds, exhibiting higher stability in detergents compared to other polyurethane / polyurea type fragrance microcapsules.

Description

Technical Field

[0001] This invention relates to the field of daily chemical product technology, and in particular to a composite core-wall microcapsule, its preparation method, and its application. Background Technology

[0002] To maintain the stability and functional properties of functional materials in consumer products, especially to address the issue of stable preservation in daily chemical products such as detergents and shower gels, microencapsulation technology is often used. This involves encapsulating functional materials, fragrances, or cosmetic raw materials within the wall material, isolating them from the surrounding environment to avoid chemical and physical reactions and prolong their stability. After the microcapsules are deposited on substrates such as fabrics, hair, and skin, the functional materials are released through friction or other means.

[0003] Furthermore, because microcapsules slow down the volatilization of functional materials and enable more efficient use through targeted release, the amount of functional materials added to these consumer products can be significantly reduced. Additionally, the superior experience gained from using these types of consumer products can reduce the frequency of washing or cosmetic use, thus contributing to the conservation of natural resources.

[0004] Currently, the most widely used fragrance microcapsules in detergents use amino plastic resin wall materials. Although this type of microcapsule has excellent encapsulation properties and friction-release effect for fragrances, this type of wall material exhibits poor encapsulation properties for fragrances with high aldehyde content.

[0005] WO2020 / 233887 discloses a fragrance core-wall microcapsule using the polymer ZeMac 400 as a polymer stabilizer. This microcapsule exhibits fragrance release properties comparable to amino-plastic type resin wall materials, but its stability in detergent products remains unresolved.

[0006] CN105722495A discloses a polyurea or polyurethane capsule composition. These compositions contain a plurality of capsules and a capsule-forming aid, wherein each capsule contains a polyurea or polyurethane wall and an oil core; the polyurea or polyurethane wall is formed from the reaction product of a polyisocyanate and a crosslinking agent in the presence of the capsule-forming aid; and the oil core contains an active substance, but its stability in detergents is poor.

[0007] CN113557082A discloses a microcapsule having: an oil-based core comprising a hydrophobic material; a first material being a coagulation layer comprising a first polyelectrolyte and a second polyelectrolyte, wherein the first polyelectrolyte is selected from proteins, peptides, polysaccharides, or mixtures thereof, and wherein the second polyelectrolyte is composed of components such as gum arabic and xanthan gum; the second material is a polymeric material. The second material is selected from the group consisting of polyurea, polyester, polyurethane, and polyamide, but its stability in detergent products remains unresolved.

[0008] In view of this, the present invention is hereby proposed. Summary of the Invention

[0009] One objective of this invention is to provide a composite core-wall microcapsule, comprising an oily core material and a polymer wall material coating the outer layer of the oily core material; the polymer wall material comprises a polymer emulsifier, polyurethane, and polyurea. This invention achieves a tight bond between the polymer emulsifier, polyurethane, and polyurea, thereby significantly improving the encapsulation properties of the polymer wall material and greatly enhancing its stability in detergent products.

[0010] The second objective of this invention is to provide a method for preparing the composite core-wall microcapsules, the method comprising the following steps: preparing an oil phase containing an oily core material and an aqueous phase containing a polymer emulsifier, respectively, emulsifying and then polycondensing to form a polyurethane and polyurea mixed layer, thereby obtaining the composite core-wall microcapsules.

[0011] A third objective of this invention is the application of the aforementioned composite core-wall microcapsule in the preparation of detergents.

[0012] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0013] In a first aspect, the present invention provides a composite core-wall microcapsule, the composite core-wall microcapsule comprising an oily core material and a polymer wall material coating the outer layer of the oily core material;

[0014] The polymer wall material includes polymer emulsifiers, polyurethane, and polyurea.

[0015] In this invention, the polymer emulsifier, polyurethane, and polyurea are tightly bonded together, thereby greatly improving the encapsulation properties of the polymer wall material and significantly enhancing its stability in detergent products. The core-wall microcapsules are obtained by forming an encapsulating wall around oil droplets dispersed in an aqueous phase as an oil-in-water emulsion. The size of the microcapsules affects their deposition and release performance on substrates such as fabrics, hair, and skin.

[0016] Preferably, the polymer wall material comprises, from the inside out, a polymer emulsifier layer, a polyurethane layer, and a polyurea layer.

[0017] Preferably, the polymer emulsifier comprises polyvinyl alcohol and polysiloxane, wherein the polysiloxane and polyvinyl alcohol are linked by epoxy groups and hydroxyl groups.

[0018] Preferably, the polysiloxane is formed by the condensation polymerization of epoxy-based siloxanes.

[0019] Preferably, the polyurethane is formed by polycondensation of polyvinyl alcohol and polyisocyanate-based compounds.

[0020] Preferably, the polyurea is formed by the condensation polymerization of polyisocyanate-based compounds and amine compounds, or the polyurea is formed by the condensation polymerization of polyisocyanate-based compounds, amine compounds and alcohol compounds.

[0021] Preferably, the polymer wall material comprises, from the inside out, a polysiloxane layer, a polyvinyl alcohol layer, a polyurethane layer, and a polyurea mixed layer.

[0022] In this invention, the polymer emulsifier is formed by combining polyvinyl alcohol and epoxy siloxane. The polysiloxane layer and the polyvinyl alcohol layer are tightly connected through the reaction between epoxy groups and hydroxyl groups. At the same time, polyvinyl alcohol and polyisocyanate compounds polymerize to form polyurethane, and the polyisocyanate compounds further condense with amine compounds to form polyurea. Each layer is tightly connected by chemical bonds, forming a three-layer polymer wall material covering an oily core material microcapsule structure. This further improves the strength of the polymer wall material, thereby achieving tight encapsulation of the core material. The resulting microcapsules can play a very good role in stabilizing the microcapsules and are not easy to leak.

[0023] Preferably, the degree of alcoholysis of the polyvinyl alcohol is 73-99%, for example, it can be 73%, 75%, 80%, 85%, 90%, 95%, 99%, etc., and the molecular weight of the polyvinyl alcohol is 10,000 to 250,000, for example, it can be 10,000, 20,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, 120,000, 130,000, 140,000, 150,000, 160,000, 170,000, 180,000, 190,000, 200,000, 210,000, 220,000, 230,000, 240,000, 250,000, etc.

[0024] In this invention, polyvinyl alcohol is obtained by alcoholysis of polyvinyl acetate, and its degree of alcoholysis refers to the percentage of ethylene alcohol units in the molecular chain to the total number of molecular structural units.

[0025] The degree of hydrolysis of polyvinyl alcohol is preferably 73% to 88%, and more preferably 88%.

[0026] The preferred molecular weight range for polyvinyl alcohol is 14,000 to 205,000, and the even more preferred molecular weight range is 30,000 to 205,000.

[0027] Preferably, the structure of the epoxy-based siloxane is shown in Formula I:

[0028] CH2OCHR1XR2Si(OR3) 3-n (R4) n Formula I

[0029] Wherein, R1 is selected from straight-chain or branched alkyl groups having 1-6 carbon atoms, R2 is selected from straight-chain or branched alkyl groups having 1-6 carbon atoms, R3 is selected from H or straight-chain or branched alkyl groups having 1-4 carbon atoms, R4 is selected from straight-chain or branched alkyl groups having 1-4 carbon atoms, X is selected from O, S, CH2 or C=O, and n is 0, 1 or 2.

[0030] Preferably, the epoxysiloxane is selected from any one or a combination of at least two of (3-glycidylpropoxy)trimethoxysilane, epoxybutyltrimethoxysilane, or 5,6-epoxyhexyltriethoxysilane.

[0031] Preferably, the amine compound is selected from polyamine polymers and / or small molecule polyamines.

[0032] Preferably, the polyamine polymer is selected from polyacetylimine.

[0033] Preferably, the molecular weight of the polyacetylimide is 300-250,000, for example, it can be 300, 1,000, 2,000, 5,000, 8,000, 10,000, 20,000, 30,000, 40,000, 50,000, 60,000, 80,000, 100,000, 120,000, 150,000, 200,000, 250,000, etc.

[0034] Preferably, the small molecule polyamine is a small molecule compound containing two or more amine groups, and is preferably diethylenetriamine and / or triethylenetetramine.

[0035] Preferably, the alcohol compound is a small molecule polyol.

[0036] Preferably, the small molecule polyol is a small molecule compound containing two or more alcohol groups, and is preferably diethanolamine and / or triethanolamine.

[0037] Preferably, the polyisocyanate compound is a compound containing two or more isocyanate groups, and more preferably an anion-modified hexamethylene diisocyanate (HDI). - It may be any one or a combination of at least two of the following: dicyclohexylmethane-4,4'-diisocyanate (HMDI) or isophorone diisocyanate (IPDI).

[0038] Preferably, the mass ratio of the polymer wall material in the outer layer of the oily core material is (2.05-5.05):1, for example, it can be 2.05:1, 2.55:1, 3.05:1, 3.55:1, 4.05:1, 4.55:1, 5.05:1, etc.

[0039] Preferably, the raw materials for preparing the polymer wall material include, by mass percentage:

[0040]

[0041] Based on the total mass of the raw materials used to prepare the polymer wall material as 100%, the content of polyvinyl alcohol is 5-25%, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, etc., preferably 8.6-20.2%.

[0042] Based on the total mass of the raw materials used to prepare the polymer wall material as 100%, the content of the epoxy siloxane is 0.1-15%, for example, it can be 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc., preferably 0.1-12.1%.

[0043] Based on the total mass of the raw materials used to prepare the polymer wall material as 100%, the content of the polyisocyanate compound is 40-70%, for example, it can be 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, etc., preferably 49-69%.

[0044] Based on the total mass of the raw materials used to prepare the polymer wall material as 100%, the content of the amine compound is 5-25%, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, etc., preferably 5.2-21.2%.

[0045] Preferably, the raw materials for preparing the polymer wall material also include amphoteric polymers.

[0046] Preferably, the amphoteric polymer is a quaternary ammonium cationic amphoteric polymer, and more preferably a dimethyl diallyl ammonium chloride-acrylic acid copolymer.

[0047] Preferably, the amount of the amphoteric polymer added accounts for 0-25% of the total mass of the raw materials for preparing the polymer wall material, for example, it can be 0.1%, 0.5%, 1%, 2%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, etc.

[0048] Preferably, the oily core material contains at least one fragrance and / or one cosmetic ingredient.

[0049] Preferably, the fragrance is selected from benzoic acid ester, benzyl acetate, methyl 3-oxo-2-pentylcyclopentaacetate, 4-tert-butylcyclohexyl acetate, 2-methylpropionic acid-2-phenoxyethyl ester, heptanoate-2-propenyl ester, (3-methylbutoxy)-acetic acid-2-propenol ester, linalool acetate, 2-(benzoyl)octanol, 2,6-dimethyl-7-octen-2-ol, 3,7-dimethyl-3-octanol, terpineol, 3,7-dimethyl-6-octen-1- - Alcohols, phenylethanol, (E)-3,7-dimethyl-2,6-octadien-1-ol, (Z)-3,7-dimethyl-2,6-octadien-1-ol, 4-(1,1-dimethylethyl)-α-methyl-phenylpropanal, dodecaldehyde, β-(3,4-methylenedioxy)phenyl-α-methylpropanal, 10-undecenal, α-methyl-4-(1-methylethyl)phenylpropanal, 1-(1,2,3,4,5,6,7,8a-octahydro-2,3, 8,8-Tetramethyl-2-naphthyl)acetone, (R-)1-methyl-4-(1-methylvinyl)cyclohexene, diphenyl ether, (E)-3,7-dimethyl-2,6-octadien-1-ol acetate, benzoate, neroli acetate, 2,6-dimethyl-7-octen-2-ol, (E)-3,7-dimethyl-2,6-octadien-1-ol, 3,7,11,15-tetramethyl-1-hexadecen-3-ol, 1-methyl-2-[( 1,2,2-Trimethylbicyclo[3,1,0]hex-3-yl)methyl]cyclopropylmethanol, β-(3,4-methylenedioxy)phenyl-α-methylpropanal, α-methyl-4-(1-methylethyl)phenylpropanal, 6-pentyl-2H-tetrahydropyran-2-one, 1-[4-(1,1-dimethylethyl)-2,6-dimethyl-3,5-dinitrophenyl]ethyl ketone, 4-methyl anisole, 6,6-dimethyl-2-methylene-bicyclo[3,1,0]1]-Heptane, 1-Methyl-4-(1-Methylethyl)-1,4-cyclohexadiene, α-pinene, 3a,4,5,6,7,7a-hexahydro-4,7-methylene-1H-indene-6-ol propionate, 3a,4,5,6,7,7a-hexahydro-4,7-methylene-1H-indene-5-ol propionate, 2-hydroxybenzoic acid pentyl ester, benzoyl acetate, 2-hydroxybenzoic acid hexyl ester, α-(trichloromethyl)benzyl acetate, 1,1-dimethyl-2-phenylethyl butyrate, 2,4-dihydroxy-3,6-dimethylbenzoate methyl ester, 2-propenylhexanoate, 3,7-dimethyl-1,6-octadien-3-ol, terpineol, 3,7-dimethyl-3-octanol, 3 The following are listed: phenyl-2-propen-1-ol, phenethyl alcohol, 4-(1,1-dimethylethyl)-α-methyl-phenylpropanal, 3-phenyl-2-propenal, 10-undecenal, 1,3-benzodioxacyclopenten-5-carboxaldehyde, undecenal, dodecaaldehyde, 2-(phenylmethylene)octanal, 2H-1-benzopyran-2-one, 1-[4-(1,1-dimethylethyl)-2,6-dimethyl-3,5-dinitrophenyl]ethyl ketone, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopentano[g]-2-benzopyran, or 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane, or a combination of at least two of these.

[0050] Preferably, the cosmetic ingredient has a calculated octanol / water partition coefficient (ClogP) of 1.5 or more (e.g., 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 9, etc.), more preferably 3 or more, and even more preferably 2-7.

[0051] Preferably, the cosmetic ingredients may be selected from any one or a combination of at least two of the following: emollients, smoothing agents, hydrating agents, smoothing and soothing agents, decorative agents, anti-aging agents, drainage agents, reshaping agents, skin smoothing agents, preservatives, antioxidant agents, antibacterial or bacteriostatic agents, cleansing agents, lubricating agents, structuring agents, hair conditioning agents, whitening agents, texturing agents, softening agents, anti-dandruff agents, or exfoliating agents.

[0052] Preferably, the cosmetic ingredients include, but are not limited to, any one or a combination of at least two of the following: alkyl dimethylsiloxane, polymethylsilsesquioxane, polyethylene, polyisobutylene, styrene-vinyl-styrene and styrene-butene-styrene block copolymers; mineral oils such as hydrogenated isoparaffins; silicones; vegetable oils such as argan oil, jojoba oil, aloe vera oil; fatty acids and fatty alcohols and their esters; glycolipids; phospholipids; sphingolipids such as ceramides; sterols and steroids; terpenes, sesquiterpenes, triterpenes and their derivatives; and essential oils such as arnica oil, artemisia oil, bark oil, birch leaf oil, calendula oil, cinnamon oil, echinacea oil, eucalyptus oil, ginseng oil, jujube oil, sunflower oil, jasmine oil, lavender oil, lotus seed oil, perilla oil, rosemary oil, sandalwood oil, tea tree oil, thyme oil, valerian oil, wormwood oil, ylang-ylang oil, or yucca oil.

[0053] In a second aspect, the present invention provides a method for preparing composite core-wall microcapsules as described in the first aspect, the method comprising:

[0054] An oil phase containing an oily core material and an aqueous phase containing a polymer emulsifier were prepared separately, emulsified, and then polycondensed to form a polyurethane and polyurea mixed layer, thus obtaining the composite core wall microcapsules.

[0055] Preferably, the preparation method specifically includes the following steps:

[0056] Preparation of the oil phase: The epoxy siloxane and the oily core material are mixed to obtain the oil phase O;

[0057] Preparation of the aqueous phase: Polyvinyl alcohol and water are mixed to obtain the aqueous phase W;

[0058] Emulsification: The oil phase O and the aqueous phase W are mixed and emulsified to obtain an emulsion;

[0059] Polycondensation: First, the above emulsion is subjected to a polycondensation reaction with a polyisocyanate-based compound, and then to a polycondensation reaction with an amine compound to form a polyurethane and polyurea mixed layer, thus obtaining a composite core wall microcapsule.

[0060] Preferably, the mass ratio of polyvinyl alcohol to water is 1:(10-35), for example, it can be 1:10, 1:12, 1:14, 1:16, 1:18, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:32, 1:35, etc.

[0061] Preferably, the mixing temperature of the oil phase is 10-30℃, for example, it can be 10℃, 12℃, 14℃, 16℃, 18℃, 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, etc.

[0062] Preferably, the temperature of the aqueous phase is 75-85℃, for example, it can be 75℃, 76℃, 78℃, 79℃, 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, etc.

[0063] Preferably, the mixing temperature during emulsification is 60-70°C, for example, it can be 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, etc.

[0064] Preferably, the emulsification is carried out by stirring at a speed of 300-400 rpm, such as 300 rpm, 320 rpm, 340 rpm, 360 rpm, 380 rpm, 400 rpm, etc.

[0065] Preferably, water and / or alkali solution need to be added to the emulsion obtained by emulsification.

[0066] Preferably, the alkaline solution is an aqueous solution of sodium hydroxide, and the solid content of the aqueous solution of sodium hydroxide is 0.5-2%, for example, it can be 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, etc.

[0067] Preferably, the mass ratio of the emulsion, water, and alkali solution is (50-55):(10-30):(0.1-1);

[0068] Among them, "50-55" can be, for example, 50, 51, 52, 53, 54, 55, etc.;

[0069] Among them, "10-30" can be, for example, 10, 15, 20, 25, 30, etc.;

[0070] Among them, "0.1-1" can be, for example, 0.1, 0.2, 0.4, 0.6, 0.8, 1, etc.

[0071] Preferably, the specific process of the polycondensation is as follows: a polyisocyanate compound is added dropwise to the emulsion, and the mixture is stirred for 1-3 hours (e.g., 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc.) at 20-30°C (e.g., 200 rpm, 220 rpm, 240 rpm, 260 rpm, 280 rpm, 300 rpm, etc.); then stirred again at 20-30°C (…). For example, amine compounds can be added dropwise at 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, etc., and then the temperature is raised to 65-75℃ (for example, 65℃, 66℃, 68℃, 70℃, 72℃, 75℃, etc.) and stirred at a speed of 200-300 rpm (for example, 200 rpm, 220 rpm, 240 rpm, 260 rpm, 280 rpm, 300 rpm, etc.) for 1-3 hours (for example, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc.).

[0072] Preferably, the polycondensation process further includes: mixing the reaction solution obtained from the polycondensation with the amphoteric polymer, and stirring at 65-75°C (e.g., 65°C, 66°C, 68°C, 70°C, 72°C, 75°C, etc.) at a speed of 200-300 rpm (e.g., 200 rpm, 220 rpm, 240 rpm, 260 rpm, 280 rpm, 300 rpm, etc.) for 1-3 hours (e.g., 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc.).

[0073] Thirdly, the present invention provides an application of the composite core-wall microcapsules according to the first aspect in the preparation of detergents.

[0074] In this invention, the composite core-wall microcapsules can be added to consumer products, including fabric care detergents and conditioners, hair conditioners, shampoos, heavy-duty liquid detergents, hard surface cleaners, laundry powder, soaps, shower gels, and skin care products.

[0075]

Terminology Explanation

[0076] In the context of this invention, the term "polymer emulsifier" refers to a polymer that, when dissolved in one or both of the oil and aqueous phases, can reduce the interfacial tension between the oil and aqueous phases.

[0077] In the context of this invention, the term "emulsification" refers to the liquid-liquid interface phenomenon in which one liquid can be dispersed into another immiscible liquid under the action of a surfactant.

[0078] In the context of this invention, the term "emulsion" refers to a stable, homogeneous mixture formed by emulsifying two or more immiscible liquids, in which the dispersed phase exists in the form of small droplets within a continuous phase. If, in the presence of a polymer emulsifier, two phases are mixed and stirred to form a homogeneous mixture, but once stirring stops, the two phases exhibit significant stratification, then the homogeneous mixture formed during stirring cannot be called an emulsion and is considered an emulsification failure.

[0079] In this invention, the product of the core-wall microcapsules is in an emulsion state. After adding a polymer emulsifier, an emulsion is formed. If the originally dispersed small droplets in the emulsion attract each other to form large particles during subsequent feeding or reaction, the flowable emulsion becomes a non-flowable solid, which is considered to be an agglomeration and solidification phenomenon, and is regarded as a failure of core-wall microcapsule synthesis.

[0080] In the context of this invention, the term "alkyl" means a saturated aliphatic hydrocarbon group comprising branched and straight chains having a specified number of carbon atoms. For example, "straight-chain or branched alkyl having 1-6 carbon atoms" is defined as a group comprising 1, 2, 3, 4, 5, or 6 carbon atoms in a straight-chain or branched structure. For example, in this invention, the straight-chain or branched alkyl groups having 1-6 carbon atoms are each independently methyl, ethyl, propyl, butyl, pentyl, or hexyl; wherein, propyl is a C3 alkyl group (including isomers, such as n-propyl or isopropyl); butyl is a C4 alkyl group (including isomers, such as n-butyl, sec-butyl, isobutyl, or tert-butyl); pentyl is a C5 alkyl group (including isomers, such as n-pentyl, 1-methyl-butyl, 1-ethyl-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, isopentyl, tert-pentyl, or neopentyl); and hexyl is a C6 alkyl group (including isomers, such as n-hexyl or isohexyl).

[0081] In the context of this invention, the term "epoxysiloxane" refers to a substance containing at least one epoxy group and at least one alkoxysilane group.

[0082] In the context of this invention, the term "formed by means of" refers to the interaction between the polymer emulsifier and the epoxy siloxane, such as electrostatic forces, hydrogen bonds, or covalent bonds, which together reduce the surface tension between the oil phase and the aqueous phase.

[0083] In this invention, the polymer emulsifier is formed by combining the hydroxyl groups of polyvinyl alcohol and the epoxy groups of an epoxy silane in the manner mentioned above, wherein the hydroxyl groups and epoxy groups interact to form covalent bonds.

[0084] Compared with the prior art, the present invention has the following beneficial effects:

[0085] (1) The present invention provides a novel microcapsule wall material for encapsulating fragrances / cosmetics, which enables it to encapsulate an oily core material containing a variety of aldehyde compounds;

[0086] (2) The core-wall microcapsules involved in this invention are composited with a variety of wall materials. The polymer emulsifiers in the wall materials are tightly linked by covalent bonds, and have higher stability in detergents compared with other polyurethane / polyurea fragrance microcapsules. Attached Figure Description

[0087] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0088] Figure 1 This is a schematic diagram of the composite core-wall microcapsule structure provided by the present invention;

[0089] Among them, 1 is an oil-based core material, 2 is a polysiloxane layer, 3 is a polyvinyl alcohol layer, and 4 is a polyurethane and polyurea mixed layer.

[0090] Figure 2 Comparison of infrared spectra of polyvinyl alcohol, (3-glycidylpropoxy)trimethoxysilane, and polymer emulsifier. Detailed Implementation

[0091] Unless otherwise defined herein, the scientific and technical terms used in conjunction with this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0092] Generally, the nomenclature and techniques used in cell and tissue culture, molecular biology, immunology, microbiology, genetics, and protein and nucleic acid chemistry and hybridization, together with those described herein, are those well-known and commonly used in the art. Unless otherwise stated, the methods and techniques of the present invention are generally carried out according to conventional methods well-known in the art and described in various general and more specific references, which are cited and discussed throughout this specification. Enzymatic reactions and purification techniques are carried out according to the manufacturer's instructions, as commonly practiced in the art, or as described herein. The nomenclature, laboratory procedures, and techniques used in analytical chemistry, synthetic organic chemistry, and medical and medicinal chemistry, together with those described herein, are those well-known and commonly used in the art.

[0093] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0094] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0095] The names of raw materials and terms in the following embodiments are compared as follows:

[0096] Compound Abbreviations

[0097] PVA (Polyvinyl alcohol)

[0098] GPTS (3-glycidylpropoxy)trimethoxysilane

[0099] HMDI 4,4'-Dicyclohexylmethane diisocyanate

[0100] HDI - Anion-modified diisocyanate compounds

[0101] IPDI isophorone diisocyanate

[0102] PEI (Polyethyleneimine)

[0103] Figure 1 This is a schematic diagram of the composite core-wall microcapsule structure provided by the present invention; as shown. Figure 1 As shown, the composite core-wall microcapsule includes an oily core material and a polymer wall material covering the outer layer of the oily core material 1; the polymer wall material includes, from the inside out, a polysiloxane layer 2, a polyvinyl alcohol layer 3, and a polyurethane and polyurea mixed layer 4.

[0104] Figure 2 Comparison of infrared spectra of polyvinyl alcohol, (3-glycidylpropoxy)trimethoxysilane, and polymer emulsifiers. Figure 2 As shown, the polymer emulsifier is formed by combining the hydroxyl groups of polyvinyl alcohol and the epoxy groups of an epoxy silane in the manner mentioned above, wherein the hydroxyl and epoxy groups interact to form covalent bonds. Infrared spectroscopy results show that in the polymer emulsifier, the (3-glycidylpropoxy)trimethoxysilane attributable to the raw material has a concentration at 819 cm⁻¹. -1 and 780cm -1The stretching and bending vibration peaks of the ethylene oxide three-membered ring disappeared, while the peaks attributed to polyvinyl alcohol remained unchanged, indicating that the epoxy groups underwent a ring-opening reaction and modified the polyvinyl alcohol. In this invention, after the formation of the polymer emulsifier, the siloxane groups in the polymer emulsifier undergo condensation polymerization to form polysiloxanes. Infrared spectroscopy results show that the polymer emulsifier at 1093 cm⁻¹... -1 1020cm -1 A distinct polysiloxane stretching vibration absorption peak was observed, confirming the polycondensation reaction of the siloxane.

[0105] Examples 1-8

[0106] Examples 1-8 provide composite core-wall microcapsules prepared from different raw materials. Detailed information on the specific amounts of raw materials is shown in Table 1 below (in the examples below, PVA1788 has an average molecular weight of 74800 g / mol and a degree of hydrolysis of 88%, PEI has an average molecular weight of 2000 g / mol, and the fragrance was purchased from Givaudan Flavors & Fragrances, brand name Pure Life 2G):

[0107] Table 1

[0108]

[0109]

[0110] Examples 1-8 above were all prepared by the following method:

[0111] (1) Dissolve the epoxy siloxane in the fragrance / or cosmetic according to the formula amount in Table 1, and stir slowly with a glass rod until the solution is uniform. This is considered as complete dissolution, and the oil phase O is obtained.

[0112] (2) Add polyvinyl alcohol to 25g of hot water at 80℃ and stir slowly with a glass rod until the solution becomes a homogeneous, colorless and transparent solution. This is considered to be completely dissolved, and the aqueous phase W is obtained.

[0113] (3) Cool the aqueous phase W to 65°C, mix the oil phase O with the aqueous phase W and stir with a stirring rod at 350 rpm until a uniform milky white opaque and flowable liquid system is formed, which is called emulsion. Emulsification is considered successful. Then add 15 mL of water and 0.5 g of 1% NaOH aqueous solution.

[0114] (4) Cool to room temperature, add polyisocyanate group compound, stir at 250 rpm and keep for 2 hours;

[0115] (5) Add polyamine polymer (24% polyethyleneimine (PEI) aqueous solution) and / or polyamine small molecules (diethylenetriamine) dropwise at room temperature, then heat to 70°C and maintain for 2 hours;

[0116] (6) Add 0.6g of dimethyl diallyl ammonium chloride / acrylic acid copolymer at 70℃, keep for 2h, cool to room temperature and then discharge.

[0117] Examples 9-14

[0118] The only difference between Examples 9-14 and Example 3 is the degree of alcoholysis and molecular weight of the polyvinyl alcohol. Detailed information on the specific raw material quantities is shown in Table 2 below.

[0119] Table 2

[0120]

[0121]

[0122] Example 15

[0123] This embodiment provides a composite core-wall microcapsule, which differs from Example 3 only in that the small molecule polyamine compound is replaced with an equal mass of 0.6g of diethanolamine, while the other steps are exactly the same as in Example 3.

[0124] Example 16

[0125] This embodiment provides a composite core-wall microcapsule, which differs from Example 3 only in that the small molecule polyamine compound is replaced with an equal mass of 0.6g of triethanolamine, while the other steps are exactly the same as in Example 3.

[0126] Comparative Examples 1-4

[0127] Comparative Examples 1-4 provide composite core-wall microcapsules prepared from different raw materials. Detailed information on the specific raw material usage is shown in Table 3 below:

[0128] Table 3

[0129]

[0130] Comparative Examples 1-4 were prepared using the same methods as Examples 1-8 described above.

[0131] Comparative Examples 5-6

[0132] The only difference between Comparative Examples 5-6 and Example 3 is the degree of alcoholysis and molecular weight of polyvinyl alcohol. Detailed information on the specific raw material dosages is shown in Table 4 below:

[0133] Table 4

[0134]

[0135] Comparative Example 7

[0136] This comparative example provides a method for preparing composite core-wall microcapsules from polyvinylpyrrolidone, the preparation method comprising the following steps:

[0137] (1) Dissolve 2.0g of polyvinylpyrrolidone (PVP) in 50g of deionized water to form an aqueous phase W;

[0138] (2) Dissolve 0.5g of (3-glycidylpropoxy)trimethoxysilane in 25g of fragrance, and stir slowly with a glass rod until the solution is uniform. This is considered as complete dissolution, and the oil phase O is obtained.

[0139] (3) After mixing the oil phase O and the water phase W, stir with a stirring rod at a speed of 350 rpm for 1.5 h and then cool to room temperature.

[0140] (4) Add 2.5g of 4,4'-dicyclohexylmethane diisocyanate (HMDI) and 0.8g of anion-modified diisocyanate compound (HDI-), and stir for 1h;

[0141] (5) Add 2.0 g of 25% polyethyleneimine (PEI) aqueous solution dropwise at room temperature, and heat to 70°C and stir for 2 h;

[0142] (6) Add 0.6g of dimethyl diallyl ammonium chloride / acrylic acid copolymer at 70℃, continue stirring for 2h, cool to room temperature, and discharge.

[0143] Because there are no chemical bonds between polyvinylpyrrolidone and the (3-glycidylpropoxy)trimethoxysilane mixture, the microcapsules obtained in Comparative Example 7 exhibit severe aggregation, with the formation of solid particles that can be observed with the naked eye.

[0144] Test Example 1

[0145] Determining the size of microcapsules

[0146] Test samples: Composite core-wall microcapsules provided in Examples 1-16, and composite core-wall microcapsules provided in Comparative Examples 1-4 and 7;

[0147] Test method:

[0148] (1) Preparation of laundry detergent samples: Each of the above microcapsule samples was diluted with deionized water by one-tenth. 1.5g of the diluted solution was added to 98g of fragrance-free laundry detergent base containing suspending agent. Then 0.5g of the encapsulated fragrance was added to each. The mixture was stirred until the laundry detergent was observed to be uniform in color and free of agglomeration, thus obtaining a series of laundry detergent samples containing core-wall microcapsules.

[0149] (2) Determination of the size and size distribution of microcapsules:

[0150] One specific method for measuring microcapsule size is light scattering. Light scattering measurements can be performed using a Malvern Mastersizer 2000S instrument and Mie scattering theory. Experimentally, a few drops of slurry are added to a degassed circulating water stream connected to a scattering cell. Under these dilution conditions, the angular distribution of scattering intensity is measured and analyzed using Malvern proprietary software included with the instrument to provide the average size and size distribution of the droplets present in the sample. In the case of a unimodal (monodispersive) droplet distribution, percentiles Dv(10), Dv(50), and Dv(90) are used to characterize the droplet size distribution, while Dv(50) corresponds to the median of the distribution and is taken as a measure of the average volumetric size of the microcapsules. In this invention, based on the experience of those skilled in the art, a Dv(50) > 30 μm is considered excessively large for the microcapsule size, and a Dv(50) < 2 μm is considered excessively small for the microcapsule size.

[0151] The specific test results are shown in Table 5 below:

[0152] Table 5

[0153]

[0154]

[0155] As shown in Table 5, the D50 of the microcapsules prepared by this invention is 5-30 μm. For Comparative Example 3, the microcapsule size is too large because the amount of polyvinyl alcohol added is too small. For Comparative Example 4, the microcapsule size is too small because the amount of polyvinyl alcohol added is too large. For Comparative Example 7, the microcapsule size is too large because the product has agglomerated.

[0156] Test Example 2

[0157] Microcapsule release performance test

[0158] Test samples: Composite core-wall microcapsules provided in Examples 1-16, and composite core-wall microcapsules provided in Comparative Examples 1-4 and 7;

[0159] Test Principle: When the core material of the core-wall microcapsule is fragrance, the release performance of the microcapsule can be determined by testing its frictional fragrance release performance. The frictional fragrance release performance of the core-wall microcapsule is evaluated by comparing the fragrance intensity of the sample before and after friction following the use of the consumer product.

[0160] Fragrance intensity was evaluated by a panel of four experts, with a rating range of 1 to 10. A difference of 4 or more in fragrance intensity before and after rubbing was considered excellent fragrance release performance, corresponding to high release performance of the microcapsules. A fragrance intensity less than 4 after rubbing was considered poor fragrance release performance, corresponding to low release performance of the microcapsules.

[0161] The criteria for evaluating fragrances are shown in Table 5 below:

[0162] Table 5

[0163]

[0164]

[0165] The stability of core-wall microcapsules refers to the changes in the appearance of consumer products, such as shower gel and laundry detergent, after the microcapsules are stored in them, as well as the retention of the release performance of the microcapsules. If the appearance of the consumer product does not change, that is, the color of the consumer product remains unchanged, there is no precipitation in the consumer product, and the release performance of the microcapsules in the consumer product still maintains good frictional fragrance release performance, then the stability of the core-wall microcapsules is considered to be high.

[0166] Test method: Dissolve 10g of laundry detergent in 2L of water, add the towel to soak for 15 minutes, rub and wash 10 times, wring dry, rinse twice with 2L of water, and air dry naturally (4h). Then evaluate the fragrance of the towel before and after rubbing.

[0167] The specific test results are shown in Table 6 below:

[0168] Table 6

[0169]

[0170] As shown in Table 6, the composite core-wall microcapsules prepared by this invention exhibit excellent release performance. The fragrance score of the towels rubbed after washing with this invention is above 4, achieving the desired effect in the preferred technical solution. In contrast, samples 3, 4, and 7 all showed poor release performance due to microcapsule sizes that were either too large or too small.

[0171] Test Example 3

[0172] Stability test

[0173] Test samples: Composite core-wall microcapsules provided in Examples 1-16, and composite core-wall microcapsules provided in Comparative Examples 1-4 and 7;

[0174] Test principle: Same as test example 2;

[0175] Test Method: The laundry detergent samples containing the microcapsules were placed at room temperature, 40℃, and 45℃ for 14 days, respectively. After removal, the appearance of all laundry detergents containing microcapsules showed no significant changes. Microcapsule release performance was tested: 10g of laundry detergent was dissolved in 2L of water, and a towel was added and soaked for 15 minutes. The towel was then rubbed and washed 10 times, wrung out, rinsed twice with 2L of water, and air-dried naturally (4 hours). The fragrance intensity of the towel before and after rubbing was then evaluated.

[0176] The specific test results are shown in Table 7 below:

[0177] Table 7

[0178]

[0179]

[0180] As shown in Table 7, the core-wall microcapsules involved in this invention incorporate multiple wall materials. The polymer emulsifiers in the wall materials are tightly linked by covalent bonds, exhibiting higher stability in detergents compared to other polyurethane / polyurea fragrance microcapsules.

[0181] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite core-wall microcapsule, characterized in that, The composite core-wall microcapsule comprises an oily core material and a polymer wall material coating the outer layer of the oily core material; The raw materials for preparing the polymer wall material, by mass percentage, include: 8.6-20.2% polyvinyl alcohol, 0.1-15% epoxy siloxane, 40-70% polyisocyanate compounds, and 5-25% amine compounds; The polymer wall material comprises, from the inside out, a polysiloxane layer, a polyvinyl alcohol layer, a polyurethane layer, and a polyurea mixed layer; The polysiloxane and polyvinyl alcohol are linked by epoxy and hydroxyl groups; The polysiloxane is formed by the condensation polymerization of epoxy-based siloxanes; and the structure of the epoxy-based siloxane is shown in Formula I below: Equation I; Wherein, R1 is selected from straight-chain or branched alkyl groups having 1-6 carbon atoms, R2 is selected from straight-chain or branched alkyl groups having 1-6 carbon atoms, R3 is selected from H or straight-chain or branched alkyl groups having 1-4 carbon atoms, R4 is selected from straight-chain or branched alkyl groups having 1-4 carbon atoms, and X is selected from O, S, CH2, or n is 0, 1, or 2; The degree of alcoholysis of the polyvinyl alcohol is 73-88%, and the molecular weight of the polyvinyl alcohol is 14,000-205,000. The polyurethane is formed by polycondensation of polyvinyl alcohol and polyisocyanate-based compounds. The polyurea is formed by the condensation polymerization of polyisocyanate compounds and amine compounds, or the polyurea is formed by the condensation polymerization of polyisocyanate compounds, amine compounds and alcohol compounds.

2. The composite core-wall microcapsule according to claim 1, characterized in that, The epoxy siloxane is selected from any one or a combination of at least two of (3-glycidylpropoxy)trimethoxysilane, epoxybutyltrimethoxysilane, or 5,6-epoxyhexyltriethoxysilane.

3. The composite core-wall microcapsule according to claim 1, characterized in that, The amine compounds are selected from polyamine polymers and / or small molecule polyamines.

4. The composite core-wall microcapsule according to claim 3, characterized in that, The polyamine polymer is selected from polyacetylimine.

5. The composite core-wall microcapsule according to claim 4, characterized in that, The molecular weight of the polyacetylimide is 300-250,000.

6. The composite core-wall microcapsule according to claim 3, characterized in that, The small molecule polyamine is a small molecule compound containing two or more amine groups.

7. The composite core-wall microcapsule according to claim 6, characterized in that, The small molecule polyamine is diethylenetriamine and / or triethylenetetramine.

8. The composite core-wall microcapsule according to claim 1, characterized in that, The alcohol compounds are small molecule polyols.

9. The composite core-wall microcapsule according to claim 8, characterized in that, The small molecule polyol is a small molecule compound containing two or more alcohol groups.

10. The composite core-wall microcapsule according to claim 9, characterized in that, The small molecule polyol is diethanolamine and / or triethanolamine.

11. The composite core-wall microcapsule according to claim 1, characterized in that, The polyisocyanate group compound is a compound containing two or more isocyanate groups.

12. The composite core-wall microcapsule according to claim 11, characterized in that, The polyisocyanate-based compound is any one or a combination of at least two of the following: anionic modified hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, or isophorone diisocyanate.

13. The composite core-wall microcapsule according to claim 1, characterized in that, The raw materials for preparing the polymer wall material also include amphoteric polymers.

14. The composite core-wall microcapsule according to claim 13, characterized in that, The amphoteric polymer is a quaternary ammonium-based amphoteric polymer with cationic groups.

15. The composite core-wall microcapsule according to claim 14, characterized in that, The amphoteric polymer is a dimethyl diallyl ammonium chloride-acrylic acid copolymer.

16. The composite core-wall microcapsule according to claim 14, characterized in that, The amount of the amphoteric polymer added accounts for 0-25% of the total mass of the raw materials used to prepare the polymer wall material.

17. The composite core-wall microcapsule according to claim 1, characterized in that, The oily core material contains at least one fragrance and / or one cosmetic ingredient.

18. A method for preparing composite core-wall microcapsules according to any one of claims 1-17, characterized in that, The preparation method includes: An oil phase containing an oily core material and an aqueous phase containing a polymer emulsifier were prepared separately, emulsified, and then polycondensed to form a polyurethane and polyurea mixed layer, thus obtaining the composite core wall microcapsules. Specifically, the following steps are included: Preparation of the oil phase: The epoxy siloxane and the oily core material are mixed to obtain the oil phase O; Preparation of the aqueous phase: Polyvinyl alcohol and water are mixed to obtain the aqueous phase W; Emulsification: The oil phase O and the aqueous phase W are mixed and emulsified to obtain an emulsion; Polycondensation: First, the above emulsion is subjected to a polycondensation reaction with a polyisocyanate-based compound, and then to a polycondensation reaction with an amine compound to form a polyurethane and polyurea mixed layer, thus obtaining a composite core wall microcapsule.

19. The method for preparing composite core-wall microcapsules according to claim 18, characterized in that, The mass ratio of polyvinyl alcohol to water is 1:(10-35).

20. The method for preparing composite core-wall microcapsules according to claim 18, characterized in that, The mixing temperature of the oil phase is 10-30℃.

21. The method for preparing composite core-wall microcapsules according to claim 18, characterized in that, The aqueous phase is configured at a temperature of 75-85℃.

22. The method for preparing composite core-wall microcapsules according to claim 18, characterized in that, The mixing temperature during the emulsification process is 60-70℃.

23. The method for preparing the composite core-wall microcapsules according to claim 18, characterized in that, The emulsification is carried out by stirring at a speed of 300-400 rpm.

24. The method for preparing composite core-wall microcapsules according to claim 18, characterized in that, Water and / or alkali solution need to be added to the emulsion obtained by emulsification.

25. The method for preparing composite core-wall microcapsules according to claim 24, characterized in that, The alkaline solution is an aqueous solution of sodium hydroxide, and the solid content of the aqueous solution of sodium hydroxide is 0.5-2%.

26. The method for preparing composite core-wall microcapsules according to claim 24, characterized in that, The mass ratio of the emulsion, water and alkali is (50-55):(10-30):(0.1-1).

27. The method for preparing the composite core-wall microcapsules according to claim 18, characterized in that, The specific process of the polycondensation is as follows: a polyisocyanate compound is added dropwise to the emulsion and stirred at 200-300 rpm for 1-3 h at 20-30°C; then an amine compound is added dropwise at 20-30°C, followed by heating to 65-75°C and stirring at 200-300 rpm for 1-3 h.

28. The method for preparing the composite core-wall microcapsules according to claim 18, characterized in that, The polycondensation process further includes: mixing the reaction solution obtained from the polycondensation with the amphoteric polymer, and stirring at 65-75°C and 200-300 rpm for 1-3 hours.

29. The use of a composite core-wall microcapsule according to any one of claims 1-17 in the preparation of detergents.

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