Microcapsules

Abstract

A core-shell microcapsule comprising c) an inner shell encapsulating a benefit agent; and d) a shell of a cross-linked polysaccharide; the crosslinking is achieved by means of at least one low-functional (meth) acrylate compound. The resulting core-shell microcapsules have a reduced content of material derived from non-renewable sources.

Description

[0001] The present disclosure relates to an encapsulated composition comprising at least one core - shell microcapsule. The present disclosure also relates to a method for preparing such an encapsulated composition and its use for enhancing the performance of a benefit agent in a consumer product.

[0002] It is known to incorporate encapsulated benefit agents into consumer products such as home care, personal care, and fabric care products. Examples of benefit agents include fragrances, cosmetic agents, food ingredients, nutraceuticals, pharmaceuticals, and matrix enhancers.

[0003] Particularly suitable microcapsules for delivering such benefit agents are core - shell microcapsules, where the core typically contains the benefit agent and the shell is impermeable or partially impermeable to the benefit agent. Generally, these microcapsules are used in aqueous media and the encapsulated benefit agent is hydrophobic. A wide selection of shell materials can be used, provided that the shell material is impermeable or partially impermeable to the encapsulated benefit agent.

[0004] Benefit agents are encapsulated for a variety of reasons. Microcapsules can isolate and protect these materials from the external suspending medium such as the consumer product base, in which they may be incompatible or unstable. They are also used to assist in depositing the benefit agent on a substrate such as skin or hair, or in the case of fragrance ingredients, also on fabrics or hard household surfaces. They can also serve as a means of controlling the spatial and temporal release of the benefit agent.

[0005] A variety of encapsulation media and benefit agents suitable for preparing encapsulated compositions have been proposed in the prior art. Such encapsulation media include synthetic resins made from polyamides, polyureas, polyurethanes, polyacrylates, melamine - derived resins, or mixtures thereof. It has been found that aminoplast capsules, particularly melamine - formaldehyde capsules, are particularly good.

[0006] There is an increasing need to provide microcapsules with a reduced proportion of materials obtained from non - renewable resources such as synthetic petrochemicals. However, it has been found difficult to provide such capsules that can encapsulate with high encapsulation efficiency and are sufficiently impermeable to the benefit agent during storage.

[0007] There is now provided a core - shell microcapsule comprising:

[0008] (a) an inner shell encapsulating a benefit agent; and

[0009] (b) an outer shell of cross - linked polysaccharide;

[0010] Cross - linking is achieved by means of at least one low - functionality (meth)acrylate compound.

[0011] "Beneficial agent" means any substance that, when added to a product, can improve the consumer's perception of the product or can enhance the product's function in an application. Typical beneficial agents include fragrance ingredients, flavoring ingredients, cosmetic ingredients, bioactive agents (such as fungicides, insect repellents, and pheromones), matrix enhancers (such as polysiloxanes and brighteners), enzymes (such as lipases and proteases), dyes, pigments, and nutraceuticals.

[0012] The inner shell of the microcapsule encapsulating the beneficial agent can be made of any suitable material. This will naturally depend on the nature of the beneficial agent and the desired end use. It can be a natural material such as gelatin, or it can be one of many synthetic materials known in the art and used as capsule wall formers. Typical examples include (meth)acrylates, aminoplast resins such as melamine - formaldehyde and urea - formaldehyde, and polyureas. Specific embodiments of the inner shell are further detailed below.

[0013] The polysaccharide can be selected from any polysaccharide capable of cross - reacting with a linking agent molecule, which is a low - functionality (meth)acrylate compound, as will be further described below. Such polysaccharides are those containing uronic acid units, i.e., where CH2OH has been oxidized to form a COOH group. In a specific embodiment, the polysaccharide contains hexuronic acid units. Polysaccharides having uronic acid units, especially hexuronic acid units, are widely available in nature.

[0014] The hexuronic acid unit can be selected from galacturonic acid units, glucuronic acid units, especially 4 - O - methyl - glucuronic acid units, guluronic acid units, and mannuronic acid units.

[0015] The polysaccharide containing carboxylic acid groups can be branched. The branched polysaccharide containing carboxylic acid groups has the advantage of forming a more compact network structure than a linear polysaccharide, and thus can be beneficial for the impermeability of the encapsulating shell, resulting in reduced leakage and higher encapsulation efficiency.

[0016] The carboxylic acid groups can be present partly in the form of the corresponding methyl esters. The percentage of carboxylic acid groups present in the form of the corresponding methyl esters can be from 3% to 95%, preferably from 4% to 75%, more preferably from 5 to 50%. Alternatively, the percentage of carboxylic acid groups present in the form of the corresponding methyl esters can be less than 50%.

[0017] In the context of the present disclosure, a polysaccharide containing carboxylic acid groups, where 50% or more are present in the form of the corresponding methyl esters, is called "high - methoxylated". A polysaccharide containing carboxylic acid groups, where less than 50% are present in the form of the corresponding methyl esters, is called "low - methoxylated".

[0018] The carboxylic acid groups can be present at least partly in the form of the corresponding carboxylates, especially the carboxylates of sodium, potassium, magnesium, or calcium.

[0019] In an alternative embodiment of the present disclosure, the carboxylic acid groups may be present at least in part in the form of complexes with species selected from zirconium species, titanium species and boron species, where the species are in particular oxides.

[0020] Without being bound by any theory, it is postulated that the presence of carboxylates or complexes in the polysaccharides limits their solubility in water and thus promotes the formation of the capsule shell. In addition, the polyvalent metal species may promote intermolecular crosslinking, which can also improve the properties of the encapsulating shell.

[0021] The linker molecules are selected from low-functional acrylate or methacrylate compounds, and they may be selected from any such compounds having a plurality of ethylenically unsaturated terminal double bonds, typically 2-6, especially 2-4, such bonds. While any such compounds may be used, specific examples are as follows:

[0022] 3: 3-(acryloyloxy)-2-hydroxypropyl methacrylate

[0023] 15: ethylene glycol dimethacrylate

[0024] 16: 1,3-butanediol dimethacrylate

[0025] 17: 1,3,5-triacryloylhexahydro-1,3,5-triazine

[0026] 18: tris(2-acryloyloxyethyl) isocyanurate

[0027] 19: pentaerythritol tetraacrylate

[0028]

[0029] In a specific embodiment, the inner shell is formed by the reaction between an aminosilane and a polyfunctional diisocyanate.

[0030] The aminosilane may be selected from compounds of formula (I).

[0031]

[0032] where R 1 , R 2 and R 3 are each independently a C1-C4 straight or branched alkyl or alkenyl residue, in particular methyl or ethyl, and R 4 is a C1-C 12 , preferably a C1-C4 straight or branched alkyl or alkenyl residue, which contains an amine functional group, in particular a primary, secondary or tertiary amine.

[0033] When the functional group is a primary amine, it may be a terminal primary amine. R4 It is preferably a C1-C8, and even more preferably a C1-C4 straight-chain terminal primary aminoalkyl residue. Specific aminosilanes of this category are selected from aminomethyltriethoxysilane, 2-aminoethyltriethoxysilane, 3-aminopropyltriethoxysilane, 4-aminobutyltriethoxysilane, 5-aminopentyltriethoxysilane, 6-aminohexyltriethoxysilane, 7-aminoheptyltriethoxysilane, and 8-aminooctyltriethoxysilane.

[0034] Without being bound by any theory, it is presumed that the silane groups condense with each other to form a silica network structure at the liquid-liquid interface, which additionally stabilizes this interface.

[0035] The aminosilane can be a bipodal aminosilane. "Bipodal aminosilane" refers to a molecule containing at least one amino group and two residues, each of which carries at least one alkoxysilane moiety.

[0036] In a specific embodiment of the present disclosure, the at least one bipodal aminosilane has the formula (II).

[0037] (O-R 4 ) (3-f) (R 3 ) f Si-R 2 -X-R 2 -Si(O-R 4 ) (3-f) (R 3 ) f

[0038] Formula (II)

[0039] In the above formula (II), X represents -NR 1 -, -NR 1 -CH2-NR 1 -, -NR 1 -CH2-CH2-NR 1 -, -NR 1 -CO-NR 1 - or

[0040]

[0041] In the above formula (II), R 1 each independently represents H, CH3 or C2H5. R 2 each independently represents a straight-chain or branched-chain alkylene having 1 to 6 carbon atoms. R 3 each independently represents a straight-chain or branched-chain alkyl having 1 to 4 carbon atoms. R 4Each independently represents H or a straight-chain or branched alkyl group having 1 to 4 carbon atoms. f represents 0, 1 or 2.

[0042] Compared with conventional silanes, bidentate aminosilanes are particularly beneficial for forming a stable oil-water interface.

[0043] Examples of bidentate aminosilanes include, but are not limited to, bis(3-(triethoxysilyl)propyl)amine, N,N'-bis(3-(trimethoxysilyl)propyl)urea, bis(3-(methyldiethoxysilyl)propyl)amine, N,N'-bis(3-(trimethoxysilyl)propyl)ethane-1,2-diamine, bis(3-(methyldimethoxysilyl)propyl)-N-methylamine and N,N'-bis(3-(triethoxysilyl)propyl)piperazine.

[0044] The bidentate aminosilane can be a secondary aminosilane. Using a secondary bidentate aminosilane in place of a primary aminosilane reduces the reactivity of the polymer stabilizer towards electrophilic species, especially aldehydes. Thus, beneficial agents containing high levels of aldehydes can be encapsulated with a lower tendency for adverse interactions between the core-forming material and the shell-forming material.

[0045] In one specific embodiment, the secondary bidentate aminosilane is bis(3-(triethoxysilyl)propyl)amine. This particular secondary aminosilane has the advantage of releasing ethanol rather than the more toxic and less desirable methanol during the polycondensation of the ethoxysilyl groups.

[0046] Other aminosilanes can also be used in combination with the above-mentioned bidentate aminosilanes, especially the aminosilanes described above.

[0047] The weight ratio of the aminosilane to the polymeric surfactant can be from 0.1 to 1.1, especially from 0.2 to 0.9, even more especially from 0.3 to 0.7, for example 0.5.

[0048] The polyfunctional isocyanate can be selected from alkyl, cycloaliphatic, aromatic and alkylaromatic, as well as anion-modified polyfunctional isocyanates, having two or more (e.g., 3, 4, 5, etc.) isocyanate groups in one molecule.

[0049] Preferably, at least one polyfunctional isocyanate is an aromatic or alkylaromatic polyfunctional isocyanate, and the alkylaromatic polyfunctional isocyanate preferably has a methyl isocyanate group attached to the aromatic ring. Compared with alkyl and cycloaliphatic polyfunctional isocyanates, both aromatic and methyl isocyanate-substituted aromatic polyfunctional isocyanates have excellent reactivity. Among them, tris(2-ethylpropane-1,2,3-triyl tris((3-(isocyanatomethyl)phenyl)carbamate)) is particularly preferred because of its tridentate nature that is conducive to the formation of intermolecular crosslinks and because of its intermediate reactivity that is conducive to the uniformity of the network structure. This alkylaromatic polyfunctional isocyanate is commercially available under the trade name Takenate TM D-100N (sold by Mitsui) or the trade name Desmodur TM Quix175 (sold by Covestro).

[0050] In a specific embodiment, the initial inner shell is stabilized in a suspension in an aqueous phase by a polymer stabilizer. Such stabilizers are described in International Publication WO2020 / 233887 but will also be further described below.

[0051] The polymer stabilizer is formed by the combination of a polymer surfactant and at least one aminosilane. "Polymer surfactant" refers to a polysaccharide or a mixture containing at least one polysaccharide, which has the property of reducing the interfacial tension between the oil phase and the water phase when dissolved in one or both of the oil phase and the water phase.

[0052] In a specific embodiment of the present disclosure, the polymer stabilizer is formed by the combination of pectin and bis(3-(triethoxysilyl)propyl)amine. Preferably, the polymer stabilizer is formed by the combination of pectin, bis(3-(triethoxysilyl)propyl)amine and tris(2-ethylpropane-1,2,3-triyl tris((3-(isocyanatomethyl)phenyl)carbamate)). These combinations of natural polymer surfactants and bidentate secondary aminosilanes provide particularly favorable interfacial stability and release characteristics. The stable interface is sufficient to be impermeable to effectively encapsulate at least one beneficial agent contained in the core. The polymer stabilizer effectively forms a shell encapsulating at least one fragrance ingredient contained in the core.

[0053] The core-shell microcapsules of the present disclosure generally have a volume average size (d50) of 1 to 100 μm, preferably 5 to 50 μm, and even more preferably 10 to 30 μm.

[0054] In another aspect, the present disclosure relates to encapsulated compositions, particularly the compositions as described above. The encapsulated composition comprises at least one core-shell microcapsule. The at least one core-shell microcapsule comprises a core and a shell surrounding the core, the core comprising at least one beneficial agent. The shell comprises a polymer stabilizer formed by the combination of a polymeric surfactant and at least one aminosilane. The shell further comprises a polysaccharide, preferably a polysaccharide comprising β(1→4)-linked monosaccharide units, even more preferably a cellulose derivative, particularly a cellulose derivative selected from hydroxyethyl cellulose, hydroxypropyl methyl cellulose, cellulose acetate and carboxymethyl cellulose, preferably hydroxyethyl cellulose.

[0055] To avoid any doubt, the polymer stabilizer referred to in the previous paragraph need not be a polysaccharide containing a carboxylic acid group. If the polymer stabilizer referred to in the previous paragraph is a polysaccharide containing a carboxylic acid group, the polysaccharide additionally comprised in the shell is a further polysaccharide.

[0056] It has been found that the polymer stabilizer is a relevant factor in the balance between microcapsule stability and fragrance leakage during storage and fragrance release under use conditions. In particular, the importance of providing additional stabilization of the oil-water interface has been recognized. The polymer stabilizer thus provides a stable platform which allows the addition of additional shell material and / or shell precursors to form a new encapsulated fragrance composition. More particularly, the addition of a polysaccharide, preferably a polysaccharide comprising β(1→4)-linked monosaccharide units, even more preferably a cellulose derivative results in highly sustainable microcapsules with excellent release characteristics.

[0057] The polysaccharide can be deposited on the outer surface of the capsule shell formed by the polymer stabilizer. This forms a multi-layer shell having at least one layer of polymer stabilizer and one layer of polysaccharide. It can improve the impermeability of the encapsulating shell by increasing the amount of encapsulating material.

[0058] To avoid any ambiguity, the present disclosure is in no way limited to a shell having clearly defined discrete layers, although this is a possible embodiment. More particularly, these layers can also be gradual and not discrete. On the other hand, and at the other extreme, the shell can even be substantially homogeneous.

[0059] The polysaccharide can react with unreacted isocyanate groups and increase the density of the cross-linked shell. But the polysaccharide can also interact with the polymer stabilizer by physical forces, physical interactions such as hydrogen bonding, ionic interactions, hydrophobic interactions or electron transfer interactions.

[0060] The shell additionally comprising a polysaccharide can be further stabilized with a stabilizer. Preferably, the stabilizer comprises at least two carboxylic acid groups. Even more preferably, the stabilizer is selected from citric acid, benzene-1,3,5-tricarboxylic acid, 2,5-furandicarboxylic acid, itaconic acid, poly(itaconic acid) and combinations thereof.

[0061] Another aspect of the present disclosure relates to a method for preparing an encapsulated composition, particularly an encapsulated composition as described above. The method comprises the following steps:

[0062] a) Providing a polymeric surfactant;

[0063] b) Providing an aqueous phase;

[0064] c) Dissolving or dispersing the polymeric surfactant in the aqueous phase;

[0065] d) Providing at least one aminosilane;

[0066] e) Providing an oil phase comprising at least one beneficial agent;

[0067] f) Optionally: dissolving the at least one aminosilane in the oil phase;

[0068] g) Emulsifying the oil phase and the aqueous phase in the presence of both the polymeric surfactant and the aminosilane to form an emulsion of oil droplets in the aqueous phase;

[0069] h) Causing the at least one aminosilane and the polymeric surfactant to form a shell at the oil-water interface of the emulsified oil droplets, thereby forming a slurry of microcapsules;

[0070] i) Adding a polysaccharide to the microcapsule slurry formed in step h), preferably a polysaccharide comprising β(1→4)-linked monosaccharide units, even more preferably a cellulose derivative, particularly a cellulose derivative selected from hydroxyethyl cellulose, hydroxypropyl methyl cellulose, cellulose acetate, and carboxymethyl cellulose, preferably hydroxyethyl cellulose.

[0071] j) Crosslinking the polysaccharide with an oligo-acrylate / methacrylate.

[0072] The oil-in-water emulsion has the advantage of providing multiple droplets that can serve as templates for shell formation, where the shell is constructed around each of these droplets. In addition, the droplet size distribution in the emulsion can be controlled by controlling the emulsification conditions, such as the stirring speed and the agitator geometry. As a result, a plurality of microcapsules with a controlled average size and size distribution are obtained, where the oil phase is encapsulated and thereby forms the core of the microcapsules.

[0073] In a variant of step i), instead of adding all of the polysaccharide in this step, some of the polysaccharide can be added in step g), which will thus be incorporated into the shell formed by the aminosilane / polymeric surfactant shell, and then the oligo-acrylate / methacrylate reacts with both the polysaccharide in the shell and the polysaccharide added in step i).

[0074] Regarding step h), the formation of the polymer stabilizer is preferably initiated by adjusting the pH to a range of 4.0 to 7.5, depending on the polymeric surfactant. For highly methoxylated pectin, the optimal pH range is 6.5 ± 0.5, for alginate it is 7.0 ± 0.5, while for low-methoxylated pectin and gum arabic, the optimal pH range is 4.5 ± 0.5.

[0075] The temperature is preferably maintained at room temperature for at least 1 hour and then increased to at least 60 °C, preferably at least 70 °C, more preferably at least 80 °C, but not exceeding 90 °C, such as 85 °C. Under these conditions, the formation of the shell is well controlled, which means that optimal stability of the interface is obtained.

[0076] The stirring speed and geometry of a suitable stirrer can be selected to obtain the desired average droplet size and droplet size distribution. The present disclosure is characterized in that the polymer stabilizer has sufficient interfacial activity and is capable of promoting the formation of dispersed oil droplets with the desired droplet size.

[0077] In the method of the present disclosure, a one-liter vessel equipped with a turbine or a crossbeam stirrer with inclined beams such as a Mig stirrer and having a stirrer diameter to reactor diameter ratio of 0.6 to 0.8 can be used. Microcapsules can be formed in such a reactor at a stirring speed of about 100 to about 1200 rpm, more particularly about 600 to 1000 rpm, which have a volume average size (d50) of 30 microns or less, more particularly 20 microns or less. Preferably, a Mig stirrer operating at a speed of 850 + / - 50 rpm is used. However, those skilled in the art will readily understand that such stirring conditions can vary depending on the size and batch size of the reactor, the exact geometry of the stirrer, and the ratio of the stirrer diameter to the reactor diameter. For example, for a Mig stirrer with a stirrer to reactor diameter ratio of 0.5 to 0.9 and a slurry volume range of 0.5 to 8 tons, the preferred stirring speed in the context of the present disclosure is 150 rpm to 50 rpm.

[0078] In a specific embodiment of the present disclosure, the weight ratio of the aminosilane to the polymeric surfactant in the emulsion is set in the range of 0.1 to 1.1, more particularly 0.2 to 0.9, still more particularly 0.3 to 0.7, such as 0.35 or 0.65.

[0079] In a specific embodiment of the present disclosure, the weight ratio of the shell material to the oil in the emulsion is set in the range of 0.01 to 0.5, more particularly 0.025 to 0.4, even more particularly 0.05 to 0.3.

[0080] The encapsulated composition obtainable by the methods mentioned above can be used as such or, as described in optional step i) above, a polysaccharide, preferably a polysaccharide comprising β(1→4)-linked monosaccharide units, even more preferably a cellulose derivative, in particular a cellulose derivative selected from hydroxyethylcellulose, hydroxypropylmethylcellulose, cellulose acetate and carboxymethylcellulose, preferably hydroxyethylcellulose-based, can be added to the microcapsule shell formed in step h).

[0081] After formation of the microcapsules, the encapsulated composition is generally cooled to room temperature. Before, during or after cooling, the encapsulated composition can be further processed. Further processing can include treating the composition with an antimicrobial preservative, which is well known in the art. Further processing can also include adding a suspending aid, such as a hydrocolloid suspending aid, to assist the stable physical dispersion of the microcapsules and prevent any creaming or coalescence. Any additional aids conventional in the art can also be added during further processing.

[0082] According to the method of the present disclosure, if desired, the core-shell microcapsules can be further coated with a functional coating. The functional coating can coat the microcapsule shell completely or only partially. Whether the functional coating is charged or uncharged, its main purpose is to change the surface properties of the microcapsules to achieve a desired effect, such as enhancing the deposition of the microcapsules on a treated surface such as a fabric, human skin or hair. The functional coating can be post-coated onto the already formed microcapsules, or they can be physically incorporated into the microcapsule shell during the shell formation process. They can be attached to the shell by physical forces, physical interactions such as hydrogen bonding, ionic interactions, hydrophobic interactions, electron transfer interactions, or they can be covalently bonded to the shell.

[0083] The at least one beneficial agent can be at least one fragrance ingredient. The at least one fragrance ingredient can be selected from ADOXAL TM (2,6,10-trimethylundec-9-enal); AGRUMEX TM (2-(tert-butyl)cyclohexyl acetate); decanal C10 (decanal); aldehyde C11MOA (2-methyldecanal); undecenal C11 (undec-10-enal); undecanal C110 (undecanal); laur aldehyde C12 (dodecanal); aldehyde C12MNA PURE (2-methylundecanal); aldehyde ISOC 11 ((E)-undec-9-enal); tangerine aldehyde 10% / TEC ((E)-dodec-2-enal); allyl pentyl glycolate (allyl 2-(isopentoxy)acetate); allyl cyclohexanepropionate (allyl 3-cyclohexanepropionate); allyl heptanoate (allyl heptanoate); AMBER CORE TM (1-((2-(tert-butyl)cyclohexyl)oxy)butan-2-ol); AMBERMAXTM (1,3,4,5,6,7 - hexahydro - β,1,1,5,5 - pentamethyl - 2H - 2,4a - methano - naphthalen - 8 - ethanol); amyl salicylate (pentyl 2 - hydroxybenzoate); avermectin (1 - (3,3 - dimethylcyclohexyl) ethyl formate); BELAMBRE TM ((1R,2S,4R) - 2'-isopropyl - 1,7,7 - trimethylspiro[bicyclo[2.2.1]heptane - 2,4'-[1,3]dioxane]); BIGARYL (8 - (sec - butyl) - 5,6,7,8 - tetrahydroquinoline); BOISAMBRENE FORTE TM ((ethoxymethoxy)cyclododecane); BOISIRIS TM ((1S,2R,5R) - 2 - ethoxy - 2,6,6 - trimethyl - 9 - methylenebicyclo[3.3.1]nonane); bornyl acetate ((2S,4S) - 1,7,7 - trimethylbicyclo[2.2.1]hept - 2 - yl acetate); butyl butyryl lactate (1 - butoxy - 1 - oxopropan - 2 - yl butanoate); p - tert - butylcyclohexyl acetate (4 - (tert - butyl)cyclohexyl acetate); caryophyllene ((Z) - 4,11,11 - trimethyl - 8 - methylenebicyclo[7.2.0]undec - 4 - ene); CASHMERAN TM (1,1,2,3,3 - pentamethyl - 2,3,6,7 - tetrahydro - 1H - indene - 4(5H) - one); CASSYRANE TM (5 - tert - butyl - 2 - methyl - 5 - propyl - 2H - furan); citral (CITRAL) ((E) - 3,7 - dimethylocta - 2,6 - dienal); CITRAL LEMAROME TM N ((E) - 3,7 - dimethylocta - 2,6 - dienal); CITRATHAL TM R ((Z) - 1,1 - diethoxy - 3,7 - dimethylocta - 2,6 - diene); citronellal (3,7 - dimethyloct - 6 - enal); citronellol (3,7 - dimethyloct - 6 - en - 1 - ol); citronellyl acetate (3,7 - dimethyloct - 6 - en - 1 - yl acetate); citronellyl formate (3,7 - dimethyloct - 6 - en - 1 - yl formate); citronellonitrile (3,7 - dimethyloct - 6 - enitrile); citronellyl propionate (3,7 - dimethyloct - 6 - en - 1 - yl propionate); lauronitrile (dodecanenitrile); coronalol (4 - cyclohexyl - 2 - methylbutan - 2 - ol); COSMONE TM((Z)-3-Methylcyclotetradec-5-enone); Heliotropin (3-(4-Isopropylphenyl)-2-methylpropanal); Allyl cyclohexylglycolate (2-(Cyclohexyloxy)acetic acid allyl ester); Cyclohexyl salicylate (2-Hydroxybenzoic acid cyclohexyl ester); CYCLOMYRAL (8,8-Dimethyl-1,2,3,4,5,6,7,8-octahydronaphthalene-2-carbaldehyde); Damascenone ((E)-1-(2,6,6-Trimethylcyclohex-1,3-dien-1-yl)but-2-en-1-one); Alpha-Damascenone ((E)-1-(2,6,6-Trimethylcyclohex-2-en-1-yl)but-2-en-1-one); Delta-Damascenone ((E)-1-(2,6,6-Trimethylcyclohex-3-en-1-yl)but-2-en-1-one); (E)-Dec-4-enal; 2-Pentylcyclopentanone (DELPHONE) (2-Pentylcyclohexanone); Dihydroanethole (1-(1-(3,3-Dimethylcyclohexyl)ethyl)3-ethyl malonate); Dihydrojasmone (3-Methyl-2-pentylcyclopent-2-enone); Dimethylbenzylcarbinol (2-Methyl-1-phenylpropan-2-ol); Dimethylbenzylmethyl acetate (2-Methyl-1-phenylpropan-2-yl acetate); Dimethylbenzylmethyl butyrate (2-Methyl-1-phenylpropan-2-yl butyrate); Dimethyloctenone (4,7-Dimethyloct-6-en-3-one); Dimethylheptanol (2,6-Dimethylheptan-2-ol); DIPENTENE (1-Methyl-4-(prop-1-en-2-yl)cyclohex-1-ene); DUPICAL TM ((E)-4-((3aS,7aS)-Hexahydro-1H-4,7-methanoinden-5(6H)-ylidene)butanal); Ebony alcohol ((E)-3-Methyl-5-(2,2,3-trimethylcyclopent-3-en-1-yl)pent-4-en-2-ol); Ethyl hexanoate (Ethyl hexanoate); Ethyl octanoate (Ethyl octanoate); Ethyl linalool ((E)-3,7-Dimethylnona-1,6-dien-3-ol); Ethyl linalyl acetate (Acetic acid (Z)-3,7-dimethylnona-1,6-dien-3-yl ester); Ethyl heptanoate (Ethyl heptanoate); Ethyl crocetin (Ethyl 2,6,6-trimethylcyclohex-1,3-diene-1-carboxylate); Cineole ((1s,4s)-1,3,3-Trimethyl-2-oxabicyclo[2.2.2]octane); Isobornyl acetate (Acetic acid (2S)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl ester); Isoborneol ((1S,2R,4R)-1,3,3-Trimethylbicyclo[2.2.1]hept-2-ol); FIXOLIDE TM (1-(3,5,5,6,8,8-Hexamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)ethanone); FLORALOZONE TM(3-(4-Ethylphenyl)-2,2-dimethylpropanal); Florhydral (3-(3-Isopropylphenyl)butanal); FLOROCYCLENE TM ((3aR,6S,7aS)-3a,4,5,6,7,7a-Hexahydro-1H-4,7-methanoinden-6-yl propionate); FLOROPAL TM (2,4,6-Trimethyl-4-phenyl-1,3-dioxane); FRESKOMENTHE TM (2-(sec-Butyl)cyclohexanone); Fructose ester ((3aS,4S,7R,7aS)-Octahydro-1H-4,7-methanoinden-3a-carboxylic acid ethyl ester); Fructonitrile (2-Methyldecanenitrile); Gerponone (1-(3,3-Dimethylcyclohex-1-en-1-yl)penta-4-en-1-one); Anisic ester (Isobutyric acid (3aR,6S,7aS)-3a,4,5,6,7,7a-hexahydro-1H-4,7-methanoinden-6-yl ester); Geraniol ((E)-3,7-Dimethylocta-2,6-dien-1-ol); Synthetic geranyl acetate (Acetic acid (E)-3,7-dimethylocta-2,6-dien-1-yl ester); Geranyl isobutyrate (Isobutyric acid (E)-3,7-dimethylocta-2,6-dien-1-yl ester); Khavone (Ethyl 2-ethyl-6,6-dimethylcyclohex-2-ene-carboxylate); Cyclopentadecenolide ((E)-Oxacyclohexadecen-12-one); Methyl dihydrojasmonate (Methyl 3-oxo-2-pentylcyclopentaneacetate); HERBANATE TM ((2S)-Ethyl 3-isopropylbicyclo[2.2.1]hept-5-ene-2-carboxylate); cis-3-Hexenyl butyrate (Butyric acid (Z)-hex-3-en-1-yl ester); Hexyl cinnamaldehyde ((E)-2-Benzylideneoctanal); Hexyl isobutyrate (Hexyl isobutyrate); Hexyl salicylate (2-Hydroxybenzoic acid hexyl ester); INDOFLOR TM (4,4a,5,9b-Tetrahydroindeno[1,2-d][1,3]dioxin); beta-Ionone ((E)-4-(2,6,6-Trimethylcyclohex-1-en-1-yl)but-3-en-2-one); alpha-Ionone ((E)-4-(2,6,6-Trimethylcyclohex-2-en-1-yl)but-3-en-2-one); alpha-Irisone ((E)-4-(2,5,6,6-Tetramethylcyclohex-2-en-1-yl)but-3-en-2-one); Ambroxan (1-(2,3,8,8-Tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalen-2-yl)ethanone); ISOCYCLOCITRAL (2,4,6-Trimethylcyclohex-3-enecarbaldehyde); Isoamyl acetate (Acetic acid 3,5,5-trimethylhexyl ester); Isopropyl 2-methylbutyrate (Isopropyl 2-methylbutyrate); ISORALDEINETM 70 ((E)-3-Methyl-4-(2,6,6-trimethylcyclohex-2-en-1-yl)but-3-en-2-one); JASMACYCLENE TM ((3aR,6S,7aS)-3a,4,5,6,7,7a-Hexahydro-1H-4,7-methanoinden-6-yl acetate); cis-Jasmone ((Z)-3-Methyl-2-(pent-2-en-1-yl)cyclopent-2-enone); KARANAL TM (5-(sec-Butyl)-2-(2,4-dimethylcyclohex-3-en-1-yl)-5-methyl-1,3-dioxane); Homofarnesene ((Z)-3,4,5,6,6-Pentamethylhept-3-en-2-one); Leaf alcohol acetal ((Z)-1-(1-Ethoxyethoxy)hex-3-ene); LEMONILE TM ((2E,6Z)-3,7-Dimethylnon-2,6-dienenitrile); LIFFAROME TM GIV ((Z)-Hex-3-en-1-yl methyl carbonate); LILIAL TM (3-(4-(tert-Butyl)phenyl)-2-methylpropanal); Linalool (3,7-Dimethyloct-1,6-dien-3-ol); Linalyl acetate (3,7-Dimethyloct-1,6-dien-3-yl acetate); MAHONIAL TM ((4E)-9-Hydroxy-5,9-dimethyldec-4-enal); Maltol isobutyrate (2-Methyl-4-oxo-4H-pyran-3-yl isobutyrate); Matricin (Ethyl 2-methylvalerate); Melonal (2,6-Dimethylhept-5-enal); Menthol (2-Isopropyl-5-methylcyclohexanol); Menthone (2-Isopropyl-5-methylcyclohexanone); Methyl cedryl ketone (1-((1S,8aS)-1,4,4,6-Tetramethyl-2,3,3a,4,5,8-hexahydro-1H-5,8a-methanoazulen-7-yl)ethanone); Methyl nonyl ketone (Undecan-2-one); Methyl octyn carbonate (Methyl non-2-ynoate); Pomarose (6,6-Dimethoxy-2,5,5-trimethylhex-2-ene); Citronellal (4-(4-Methylpent-3-en-1-yl)cyclohex-3-enecarbaldehyde); Nectaron (2-(2-(4-Methylcyclohex-3-en-1-yl)propyl)cyclopentanone); NEOBERGAMATE TM FORTE (2-Methyl-6-methyleneoct-7-en-2-yl acetate); NEOFOLIONE TM ((E)-Methyl non-2-enoate); NEROLIDYLE TM((Z)-3,7,11-Trimethyldodeca-1,6,10-trien-3-yl acetate); Nerol acetate HC ((Z)-3,7-Dimethylocta-2,6-dien-1-yl acetate); Nonanoldo (6,8-Dimethylnonan-2-ol); (Z)-Non-6-enal; NYMPHEAL TM (3-(4-Isobutyl-2-methylphenyl)propanal); ORIVONE TM (4-(tert-Pentyl)cyclohexanone); PARADISAMIDE TM (2-Ethyl-N-methyl-N-(m-tolyl)butanamide); Geranyl pyran (2-Methyl-4-methylene-6-phenyltetrahydro-2H-pyran); PEONILE TM (2-Cyclohexylidene-2-phenylacetonitrile); PETALIA TM (2-Cyclohexylidene-2-(o-tolyl)acetonitrile); PIVAROSE TM (2,2-Dimethyl-2-phenylethyl propionate); PRECYCLEMONE TM B (1-Methyl-4-(4-methylpent-3-en-1-yl)cyclohex-3-enecarbaldehyde); PYRALONE TM (6-(sec-Butyl)quinoline); RADJANOL TM SUPER ((E)-2-Ethyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)but-2-en-1-ol); Raspberry ketone (N112) (4-(4-Hydroxyphenyl)butan-2-one); RHUBAFURANE TM (2,2,5-Trimethyl-5-pentylcyclopentanone); Crystal rose (2,2,2-Trichloro-1-phenylethyl acetate); 9-Decenol (Dec-9-en-1-ol); ROSYFOLIA ((1-Methyl-2-(5-methylhex-4-en-2-yl)cyclopropyl)-methanol); ROSYRANE TM SUPER (4-Methylene-2-phenyltetrahydro-2H-pyran); SERENOLIDE (2-(1-(3,3-Dimethylcyclohexyl)ethoxy)-2-methylpropyl cyclopropanecarboxylate); SILVIAL TM (3-(4-Isobutylphenyl)-2-methylpropanal); SPIROGALBANONE TM (1-(Spiro[4.5]dec-6-en-7-yl)penta-4-en-1-one); STEMONE TM ((E)-5-Methylheptan-3-one oxime); SUPERMUGUET TM ((E)-6-Ethyl-3-methyloct-6-en-1-ol); SYLKOLIDE TM((E)-2-((3,5-dimethylhex-3-en-2-yl)oxy)-2-methylpropyl cyclopropanecarboxylate); terpinolene (1-methyl-4-propan-2-ylcyclohexa-1,4-diene); terpinene (1-methyl-4-(prop-2-enylidene)cyclohex-1-ene); terpinyl acetate (2-(4-methylcyclohex-3-en-1-yl)prop-2-yl acetate); tetrahydrolinalool (3,7-dimethyloctan-3-ol); tetrahydrogeraniol (2,6-dimethyloctan-2-ol); tibetan musk (oxacyclohexadecan-2-one); tridec-2-enenitrile ((E)-tridec-2-enenitrile); methyl decenol ((E)-4-methyldec-3-en-5-ol); VELOUTONE TM (2,2,5-trimethyl-5-pentylcyclopentanone); VIRIDINE TM ((2,2-dimethoxyethyl)benzene); ZINARINE TM (2-(2,4-dimethylcyclohexyl)pyridine); and mixtures thereof.

[0084] A complete list of perfume ingredients that can be encapsulated according to the present disclosure can be found in perfume literature, such as "Perfume & Flavor Chemicals", S. Arctander, Allured Publishing, 2000.

[0085] The at least one beneficial agent may also be a cosmetic ingredient. Preferably, the cosmetic ingredient has a calculated octanol / water partition coefficient (ClogP) of 1.5 or greater, more preferably 3 or greater. Alternatively, preferably the ClogP of the cosmetic ingredient is from 2 to 7.

[0086] Particularly useful cosmetic ingredients may be selected from emollients, smoothing agents, hydrating agents, smoothing and soothing agents, decorative agents, anti-aging agents, draining agents, reshaping agents, skin leveling 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, and exfoliating agents.

[0087] Particularly useful cosmetic ingredients include, but are not limited to, hydrophobic polymers such as alkyl dimethicone, polymethylsilsesquioxane, polyethylene, polyisobutene, styrene-ethylene-styrene and styrene-butene-styrene block copolymers, mineral oils such as hydrogenated isoparaffins, polysiloxanes, vegetable oils such as argan oil, jojoba oil, aloe oil, fatty acids and fatty alcohols and their esters, glycolipids, phospholipids, sphingolipids such as ceramides, sterols and steroids, terpenes, sesquiterpenes, triterpenes and their derivatives, essential oils such as Arnica oil, Artemisia oil, Bark tree oil, birch leaf oil, Calendula oil, cinnamon oil, Echinacea oil, eucalyptus oil, ginseng oil, jujube oil, Helianthus 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 and Yucca oil.

[0088] The resulting encapsulated composition in the form of a microcapsule slurry suspended in an aqueous suspension medium can be incorporated into a consumer product base as such. However, if desired, the slurry can be dried to provide the encapsulated composition in dry powder form. Drying of the microcapsule slurry is conventional and can be carried out according to techniques known in the art, such as spray drying, evaporation, freeze drying or using desiccants. Typically, as is conventional in the art, the dried microcapsules are dispersed or suspended in a suitable powder, such as powdered silica, which can act as a filler or flow aid. Such a suitable powder can be added to the encapsulated composition before, during or after the drying step.

[0089] Another aspect of the present disclosure relates to an encapsulated composition obtainable by any of the methods described above.

[0090] A further aspect of the present disclosure relates to the use of the encapsulated composition as described above in enhancing the performance of a beneficial agent in a consumer product.

[0091] The present disclosure also relates to a consumer product comprising the encapsulated composition as described above. The consumer product can be selected from fabric care detergents and conditioners, hair care conditioners, shampoos, heavy-duty liquid detergents, hard surface cleaners, detergent powders, soaps, body gels and skin care products, particularly fabric softeners and hair conditioners.

[0092] The encapsulated compositions of the present disclosure are particularly useful when used as fragrance delivery carriers in consumer products that require optimal fragrance benefits, i.e., the microcapsules adhere well to the substrate to which they are applied. Such consumer products include shampoos and conditioners, as well as fabric treatment products such as laundry detergents and conditioners.

[0093] Another aspect of the present disclosure relates to a polymer stabilizer formed by the combination of a polymeric surfactant with at least one aminosilane, particularly an aminosilane as described above. The polymeric surfactant includes a polysaccharide containing a carboxylic acid group and particularly a polymeric surfactant as described above.

[0094] Yet another aspect of the present disclosure relates to the use of the polymer stabilizer as described above in the encapsulation of beneficial agents. The polymer stabilizer stabilizes the oil / water interface and thus provides a template for the preparation of encapsulated fragrance and / or cosmetic compositions.

[0095] The present disclosure also relates to a method of enhancing the performance of a beneficial agent in a consumer product, the method being carried out by adding an encapsulated composition according to the present disclosure.

[0096] In addition, the present disclosure relates to a method of encapsulating a beneficial agent, wherein the polymer stabilizer as described above stabilizes and encapsulates oil droplets in an oil-in-water emulsion, and wherein the oil phase contains at least one beneficial agent

[0097] The present disclosure is further described by the following examples, which describe specific embodiments and should not be construed as limiting in any way.

[0098] Example 1

[0099] General Preparation

[0100] In a 100 g reactor equipped with a mechanical overhead stirrer, at ambient temperature and with gentle stirring, 11.5 g of fragrance (Part I) was combined with 0.7 g of bis(3-(triethoxysilyl)propyl)amine (CAS 13497-18-2) and 0.5 g of Takenate TMMix with D110N (polymer of 2-ethyl-2-(hydroxymethyl)-1,3-propanediol and bis(isocyanatomethyl)-cyclohexatriene (CAS 51852-81-4)). While stirring, further add 27 g of fragrance to this mixture, and then carefully add 66 g of water with stirring stopped. Restart stirring to produce an emulsion, and add 1.35 g of powdered pectin (Roeper APA104 high-methoxyl) to it. Then raise the temperature to 45 °C for 30 minutes and hold for 2 h, then further raise the temperature to 55 °C and hold at this temperature for 1 h. Increase the heating again to 85 °C, and at 70 °C, add 0.3 g of trimellitic acid in powder form. At 85 °C, add 2.3 g of starch (HiCap TM 100), 0.4 g of binder acrylate (selected from those shown below), and 60 μL of free radical initiator (selected from those shown below) as a 4 mass% aqueous solution. After 30 minutes, add another 60 μL of free radical initiator solution, and raise the temperature to 90 °C and hold at this temperature for 1 h 30 minutes.

[0101] Stop heating, and gradually cool the reaction mixture to room temperature.

[0102] The initiators used are as follows:

[0103]

[0104] The binder molecules are as follows:

[0105]

[0106] The specific combinations used in the general preparation are as follows:

[0107]

[0108] The result of these preparations is a slurry of fragrance-containing microcapsules with a size range of 5 - 50 μm. Typical characterizations subsequently carried out include measurement of size distribution by light diffraction, solid content residue when dried at 120 °C, fragrance extraction upon capsule impregnation dispersed in a liquid softener base at 37 °C, and determination of polymer residue in the liquid phase by size exclusion chromatography.

[0109] Evaluation of fragrance stability in fabric softeners

[0110] Test the stability of the capsules prepared as above in an unperfumed liquid fabric softener base (“LFS”). Add each capsule sample at 0.5 to 1.0 wt% of the capsule slurry to the LFS sample and incorporate by stirring at room temperature for 10 minutes. Immediately after incorporation into the base (t0) and after 5 days of immersion at a temperature of 37 °C (t5), visually evaluate the mechanical integrity and perfume content of the samples using a microscope at magnifications of 4x and 10x. Compare the change in capsule shape between t0 and t5, especially the change in the perfume content in the capsules, to obtain their stability. Visually determine the amount of perfume still encapsulated in the capsules by image analysis. The visual determination of the perfume still encapsulated is within ±5% of the value determined by the gas chromatography (GC-MS) method (after appropriate extraction of the perfume from the sample).

[0111] The results are shown in the table below.

[0112]

[0113] *Liquid fabric softener, 5 days at 37 °C;

[0114] Grading description:

[0115] Pass = retain more than 60% perfume;

[0116] Fail = more than 60% perfume extracted into the base.

[0117] n.d. = not determined.

[0118] Measure the proportion of polymer incorporated into the capsule shell (as a percentage of the total polymer used) by the proportion of free (unreacted) polymer in the continuous medium.

Claims

1. A core-shell microcapsule, comprising: a) an inner shell encapsulating a beneficial agent; and b) an outer shell of a crosslinked polysaccharide; The crosslinking is achieved by means of at least one low-functional (meth)acrylate compound.

2. The core-shell capsule according to claim 1, wherein the polysaccharide comprises uronic acid units.

3. The core-shell capsule according to claim 2, wherein the uronic acid units are hexuronic acid units, especially hexuronic acid units selected from galacturonic acid units and glucuronic acid units, more especially 4-O-methyl-glucuronic acid units, guluronic acid units and mannuronic acid units.

4. The core-shell capsule according to claim 1, wherein the low-functional (meth)acrylate compound is selected from 3-(acryloyloxy)-2-hydroxypropyl methacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,3,5-triacryloylhexahydro-1,3,5-triazine, tris(2-acryloyloxyethyl) isocyanurate and pentaerythritol tetraacrylate.

5. The core-shell capsule according to claim 1, wherein the inner shell is formed by the reaction between a silane and a polyfunctional diisocyanate.

6. The core-shell capsule according to claim 1, wherein the initial shell is stabilized in an aqueous suspension by a polymer stabilizer which is a product of a polymer surfactant and an aminosilane, the polymer surfactant comprising a polysaccharide or a mixture comprising at least one polysaccharide which has the property of reducing the interfacial tension between the oil phase and the water phase when dissolved in one or both of the oil phase and the water phase.

7. The core-shell capsule according to claim 6, wherein the polymer stabilizer is formed by the combination of pectin with bis(3-(triethoxysilyl)propyl)amine or with a mixture of bis(3-(triethoxysilyl)propyl)amine and tris((3-(isocyanatomethyl)phenyl)carbamate)2-ethylpropane-1,2,3-triyl ester.

8. A method for preparing an encapsulated composition, especially an encapsulated composition as described above, the method comprising the following steps: (a) providing a polymer surfactant; (b) providing an aqueous phase; (c) dissolving or dispersing the polymer surfactant in the aqueous phase; (d) providing at least one aminosilane; (e) providing an oil phase comprising at least one beneficial agent; (f) optionally: dissolving the at least one aminosilane in the oil phase; (g) emulsifying the oil phase and the aqueous phase in the presence of both the polymer surfactant and the aminosilane to form an emulsion of oil droplets in the aqueous phase; (h) forming a shell at the oil-water interface of the emulsified oil droplets by the at least one aminosilane and the polymer surfactant, thereby forming a slurry of microcapsules; (i) adding a polysaccharide, preferably a polysaccharide comprising β(1→4)-linked monosaccharide units, even more preferably a cellulose derivative, especially a cellulose derivative selected from hydroxyethyl cellulose, hydroxypropyl methyl cellulose, cellulose acetate and carboxymethyl cellulose, preferably hydroxyethyl cellulose, to the microcapsule slurry formed in step h); (j) Crosslink the polysaccharide with oligo-acrylate / methacrylate.

Images