Microcapsule aqueous dispersion

Abstract

The present invention relates to [1] a microcapsule aqueous dispersion and [2] a dispersant for microcapsules composed of a surfactant containing a quaternary ammonium salt compound represented by the general formula (1), wherein the microcapsule aqueous dispersion contains: (A) a microcapsule having a shell and a core containing one or more organic compounds inside the shell; and (B) a surfactant containing a quaternary ammonium salt compound represented by the general formula (1), wherein the mass ratio of the content of component (A) to the content of component (B) [component (A) / component (B)] is 0.1 or more and 20 or less.

Description

Technical Field

[0001] The present invention relates to a microcapsule aqueous dispersion and a microcapsule dispersant used therefor. Background Art

[0002] Various microcapsules encapsulating fragrances and bioactive substances are being developed and utilized in a wide range of industries, including cosmetics, pharmaceuticals, household goods, and printing. Methods for producing these microcapsules include chemical methods such as suspension polymerization, microemulsion polymerization, emulsion polymerization, precipitation polymerization, dispersion polymerization, interfacial polycondensation, and liquid solidification; physical and chemical methods such as liquid drying, phase inversion emulsification, and coacervation; and mechanical methods such as spray drying and heterogeneous coacervation. Among these microcapsule production methods, many methods produce aqueous dispersions of microcapsules by dispersing them in an aqueous medium. From an industrial perspective, it is desirable to use the resulting aqueous dispersions of microcapsules directly without performing separation operations such as filtration or drying.

[0003] However, aqueous dispersions of microcapsules have the problem of floating or sinking depending on the difference in specific gravity between the microcapsules and the aqueous medium, the viscosity of the aqueous medium, and the particle size and shape of the microcapsules. For example, if the specific gravity of the microcapsules is relatively low relative to the aqueous medium, they will gradually cream and lose fluidity. On the other hand, if the specific gravity of the microcapsules is relatively high, they will gradually sink and lose fluidity.

[0004] Furthermore, aqueous dispersions of microcapsules have the problem of gelation and loss of fluidity due to physical or chemical changes in the surface of the microcapsule shell or components contained in the aqueous medium.

[0005] Various studies have been conducted on this issue.

[0006] International Publication No. 2018 / 053356 (Patent Document 1) describes a microcapsule composition containing microcapsules dispersed in an aqueous phase and a viscosity modifier for the purpose of improving the dispersion stability of the microcapsule composition by using a viscosity modifier. The viscosity modifier is described as an acrylate copolymer, a cationic acrylamide copolymer, or a polysaccharide.

[0007] Japanese Patent Application Laid-Open No. 2016-113510 (Patent Document 2) describes a thixotropy-imparting agent comprising a fatty acid glyceride having a hydroxyl group in an aliphatic acyl group, a nonionic surfactant, and water, and optionally an anionic surfactant, for the purpose of providing a thixotropy-imparting agent having a low viscosity under high shear and a liquid detergent composition containing the thixotropy-imparting agent having a high viscosity under low shear, in order to suppress separation of capsule particles during suspension.

[0008] Japanese Patent Application No. 2012-516371 (Patent Document 3) describes an encapsulation body comprising a core containing a beneficial agent and a shell at least partially surrounding the core, with the purpose of preparing an encapsulation body in a manner that does not concentrate in a specific area of the fluid. The encapsulation body also contains a density balance regulator.

[0009] Japanese Patent Application Publication No. 2013-530253 (Patent Document 4) describes microcapsules in which the density of the components constituting the fragrance composition contained in the core and / or cLogP are within specific ranges, with the purpose of providing core-shell microcapsules containing a fragrance composition in the core for the controlled delivery and release of fragrances and other beneficial chemical substances.

[0010] Japanese Patent Application Publication No. 2012-501849 (Patent Document 5) describes an aqueous suspension of microcapsules having a silicate shell using an organofunctional silane as a colloidal silicate sealant for the purpose of improving the stability of the aqueous suspension of microcapsules having a silicate shell.

[0011] US Patent No. 9,763,861 (Patent Document 6) describes a stable silica capsule composition having fluidity, which comprises a silica capsule suspension and an adjuvant, wherein a cationic polymer such as a vinylpyrrolidone / dimethylaminoethyl methacrylate copolymer is used as the adjuvant. Summary of the Invention

[0012] The present invention relates to a microcapsule aqueous dispersion containing the following components (A) and (B), and

[0013] The mass ratio of the content of the component (A) to the content of the component (B) [component (A) / component (B)] is 0.1 or more and 20 or less.

[0014] Component (A): Microcapsules having a shell and a core containing one or more organic compounds inside the shell

[0015] Component (B): a surfactant comprising a quaternary ammonium salt compound represented by the following general formula (1)

[0016]

[0017] (In general formula (1), R 1 、R 2 、R 3 are each independently an acyl group derived from a fatty acid having 12 or more and 30 or less carbon atoms, or a hydrogen atom, R 4 is an alkyl group having 1 or more and 3 or less carbon atoms, and X- is an anion. 1 、R 2 、R3 At least one of the acyl groups is an acyl group derived from a fatty acid and having 12 to 30 carbon atoms. DETAILED DESCRIPTION

[0018] In the techniques of Patent Documents 1 to 5, the dispersion stability of the microcapsules in the aqueous dispersion is insufficient.

[0019] Furthermore, the technology of Patent Document 2 is a technology that crystallizes fatty acid glycerides in a phase containing water, forming spherical crystals with the aid of a nonionic surfactant and, optionally, an anionic surfactant, thereby imparting thixotropy to a liquid detergent composition. However, this technology sometimes reduces the stability of the components contained in the microcapsules due to the surfactant that forms the spherical crystals that impart thixotropy. Therefore, regardless of the role of the structure imparting thixotropy, it is necessary to improve the dispersion stability of the microcapsules.

[0020] The technology of Patent Document 4 controls the density and / or cLogP of the components constituting the flavor composition contained in the core of the microcapsule within a specific range. Therefore, the degree of freedom in designing the composition of the components contained in the core is limited.

[0021] Furthermore, microcapsules can ultimately be released into the natural environment. Therefore, as in the technique of Patent Document 5, surface modification of silicate-shell microcapsules and colloidal silicate particles using organofunctional silanes results in the release of new, persistent components into the natural environment. Furthermore, even with the use of cationic polymers, as in Patent Document 6, there are concerns about toxicity to aquatic organisms, making this undesirable.

[0022] As mentioned above, although microcapsules are used in a wide range of industrial fields, they are not fully satisfactory from the perspectives of ease of handling as aqueous dispersions and their impact on the natural environment. Therefore, there is a need for aqueous dispersions of microcapsules that have a low environmental impact, inhibit gelation and reduce the loss of fluidity caused by floating or sinking even during long-term storage, and exhibit high dispersion stability.

[0023] The present invention relates to an aqueous dispersion of microcapsules having excellent dispersion stability and achieving both ease of handling as an aqueous dispersion and low environmental load, and a dispersant for microcapsules therefor.

[0024] The present inventors focused on improving the dispersion stability of microcapsules in an aqueous dispersion by using a specific surfactant containing a quaternary ammonium salt compound as a dispersant for microcapsules. They have discovered an aqueous dispersion of microcapsules that is excellent in dispersion stability and can achieve both ease of handling as an aqueous dispersion and low environmental impact, and a dispersant for microcapsules used therein.

[0025] That is, the present invention relates to the following [1] and [2].

[0026] [1] A microcapsule aqueous dispersion comprising the following components (A) and (B), and

[0027] The mass ratio of the content of the component (A) to the content of the component (B) [component (A) / component (B)] is 0.1 or more and 20 or less.

[0028] Component (A): Microcapsules having a shell and a core containing one or more organic compounds inside the shell

[0029] Component (B): a surfactant comprising a quaternary ammonium salt compound represented by the following general formula (1)

[0030]

[0031] (In general formula (1), R 1 、R 2 、R 3 are each independently an acyl group derived from a fatty acid having 12 or more and 30 or less carbon atoms, or a hydrogen atom, R 4 is an alkyl group having 1 or more and 3 or less carbon atoms, and X- is an anion. 1 、R 2 、R 3 At least one of the acyl groups is an acyl group derived from a fatty acid and having 12 to 30 carbon atoms.

[0032] [2] A dispersant for microcapsules, comprising a surfactant containing a quaternary ammonium salt compound represented by the following general formula (1).

[0033]

[0034] (In general formula (1), R 1 、R 2 、R 3 are each independently an acyl group derived from a fatty acid having 12 or more and 30 or less carbon atoms, or a hydrogen atom, R 4 is an alkyl group having 1 or more and 3 or less carbon atoms, and X- is an anion. 1 、R 2 、R 3 At least one of the acyl groups is an acyl group derived from a fatty acid and having 12 to 30 carbon atoms.

[0035] According to the present invention, there can be provided an aqueous dispersion of microcapsules having excellent dispersion stability and achieving both ease of handling as an aqueous dispersion and low environmental load, and a microcapsule dispersant therefor.

[0036] [Microcapsule aqueous dispersion]

[0037] The microcapsule aqueous dispersion of the present invention contains the following components (A) and (B), wherein the mass ratio of the content of component (A) to the content of component (B) [component (A) / component (B)] in the microcapsule aqueous dispersion is 0.1 to 20.

[0038] Component (A): Microcapsules having a shell and a core containing one or more organic compounds inside the shell

[0039] Component (B): a surfactant comprising a quaternary ammonium salt compound represented by the following general formula (1)

[0040]

[0041] (In general formula (1), R 1 、R 2 、R 3 are each independently an acyl group derived from a fatty acid having 12 or more and 30 or less carbon atoms or a hydrogen atom, R 4 is an alkyl group having 1 or more and 3 or less carbon atoms, X - is an anion. 1 、R 2 、R 3 At least one of the acyl groups is an acyl group derived from a fatty acid and having 12 to 30 carbon atoms.

[0042] The microcapsule aqueous dispersion of the present invention is obtained by dispersing microcapsules as the component (A) in an aqueous medium.

[0043] As used herein, an "aqueous medium" refers to a liquid containing at least water, preferably a medium primarily composed of water. Examples of components other than water that may be contained in an aqueous medium include: aliphatic alcohols having from 1 to 4 carbon atoms; ketones having from 3 to 8 carbon atoms; ethers such as ethyl ether, propyl ether, butyl ether, and tetrahydrofuran; and esters such as methyl acetate and ethyl acetate.

[0044] In addition, in this specification, "fatty acids having 12 or more carbon atoms" are referred to as higher fatty acids.

[0045] The reason why the effects of the present invention are obtained has not yet been determined, but is considered to be as follows.

[0046] The quaternary ammonium salt compound represented by the general formula (1) has a hydrophilic portion derived from the quaternary ammonium group and a hydrophobic portion derived from the acyl group of the higher fatty acid in its structure. Therefore, it is believed that it forms microvesicles in an aqueous medium. Moreover, these vesicles interact with the microcapsules in the aqueous dispersion to some extent, thereby suppressing the aggregation of the microcapsules. As a result, it is believed that the dispersion stability of the microcapsule aqueous dispersion is improved.

[0047] <(A)Component>

[0048] The component (A) is a microcapsule having a shell and a core containing one or more organic compounds inside the shell.

[0049] The shell of the microcapsule constituting (A) component is not particularly limited as long as it can inner package the core of the organic compound comprising more than one. As the specific example of the component constituting the shell, can be enumerated: polyesters such as silicon dioxide, organically modified silicon dioxide, polyvinyl alcohol, polysaccharides, lipids, polylactic acid resin, polyglycolic acid resin, polyacrylate copolymers, polymethacrylate polymers, melamine / formaldehyde resin, polyurethane resin, polyurea resin (polyurea resin), polyamide resin, polyimide resin, polystyrene or a combination thereof. Wherein, from the viewpoint of stably closing the inner inclusion in the shell, preferably there is a cross-linked structure, as a specific example, preferably selected from silicon dioxide, organically modified silicon dioxide, melamine / formaldehyde resin, polyurethane resin, polyurea resin, polyamide resin and polyimide resin more than one, from the viewpoint of reducing the environmental load when releasing to the external environment, more preferably silicon dioxide. Specifically, the component (A) is preferably a microcapsule (silica microcapsule) having a shell composed of silica as a constituent component and a core composed of one or more organic compounds inside the shell (hereinafter referred to as "silica capsule").

[0050] Silica capsules having a shell containing silica as a constituent component can be produced by methods such as (1) a sol-gel reaction using alkoxysilane as a starting material, (2) a sol-gel reaction using sodium silicate as a starting material, or (3) formation of a Pickering emulsion using colloidal silica as a starting material.

[0051] Based on Stokes' equation, from the viewpoint of improving dispersion stability, the median particle size D of the microcapsules of component (A) is 50 It is preferably 100 μm or less, more preferably 75 μm or less, further preferably 50 μm or less, further preferably 30 μm or less, and further preferably 10 μm or less. Moreover, from the viewpoint of reducing the specific surface area of the microcapsule and improving the retention of the core's contents, it is preferably 0.01 μm or more, more preferably 0.05 μm or more, further preferably 0.07 μm or more, further preferably 0.1 μm or more, further preferably 0.5 μm or more, and further more preferably 1 μm or more. (A) Median particle size D 50 It can be measured by the method described in the Examples.

[0052] From the viewpoint of suppressing the floating or sinking of the microcapsules over time and improving the dispersion stability, the specific gravity difference between component (A) and the aqueous medium is preferably less than 0.30, more preferably less than 0.20, further preferably less than 0.15, further preferably less than 0.10, further preferably less than 0.05, further more preferably less than 0.01, and further preferably no specific gravity difference.

[0053] The specific gravity of the component (A) is determined based on the specific gravity of the shell and the core constituting the component (A), and the mass ratio of the shell to the core.

[0054] The organic compound contained in the core of component (A) is preferably one or more selected from fragrances; fragrance precursors; oils; antioxidants; antibacterial agents; fertilizers; surface modifiers for fibers, skin, hair, etc.; cooling agents; dyes; pigments; silicones; solvents; and oil-soluble polymers, more preferably one or more selected from fragrances, fragrance precursors, oils, antioxidants, antibacterial agents, fertilizers, surface modifiers, and solvents, further preferably one or more selected from fragrances, fragrance precursors, oils, antioxidants, and solvents, further preferably one or more selected from fragrances, fragrance precursors, and oils, and further preferably one or more selected from fragrances and fragrance precursors.

[0055] The above-mentioned organic compounds can be appropriately combined according to the use of the microcapsules.

[0056] Examples of the fragrance precursor include compounds that react with water to release fragrance components and compounds that react with light to release fragrance components.

[0057] Examples of compounds that react with water to release fragrance components include silicate compounds having an alkoxy component derived from a fragrance alcohol, fatty acid ester compounds having an alkoxy component derived from a fragrance alcohol, acetal compounds or hemiacetal compounds obtained by reacting a carbonyl component derived from a fragrance aldehyde or fragrance ketone with an alcohol compound, Schiff base compounds obtained by reacting a carbonyl component derived from a fragrance aldehyde or fragrance ketone with a primary amine compound, and hemiamine aldehyde compounds or hydrazone compounds obtained by reacting a carbonyl component derived from a fragrance aldehyde or fragrance ketone with a hydrazine compound.

[0058] Examples of compounds that react with light to release fragrance components include 2-nitrobenzyl ether compounds having an alkoxy group derived from fragrance alcohols, α-ketoester compounds having a carbonyl group derived from fragrance aldehydes or fragrance ketones, and coumaric acid ester compounds having an alkoxy group derived from fragrance alcohols. These fragrance precursors can also be used as polymers such as reaction products of some carboxyl groups of polyacrylic acid and fragrance alcohols.

[0059] From the perspective of microcapsule dispersion stability, the organic compound preferably has appropriate hydrophobicity. As an indicator of the hydrophilicity or hydrophobicity of the organic compound, the calculated value of the common logarithm "logP" of the partition coefficient P (n-octanol / water) between n-octanol and water, i.e., the cLogP value, can be used. The cLogP value is "LogP (cLogP)" calculated using the method described in A. Leo, "Comprehensive Medicinal Chemistry", Vol. 4, C. Hansch, P.G. Sammens, J.B. Taylor and C.A. Ramsden, Eds., p. 295, Pergamon Press, 1990. The cLogP value is calculated using the program CLOGP v4.01.

[0060] When the organic compound is composed of a plurality of components, the cLogP value of the organic compound can be obtained by multiplying the cLogP value of each component by the volume ratio of each component and taking the sum of the multiplied values.

[0061] The cLogP value of the organic compound is preferably 1 or greater, more preferably 2 or greater, further preferably 3 or greater, and further preferably 4 or greater, and is preferably 30 or less, more preferably 20 or less, and further preferably 10 or less.

[0062] <(B) Ingredient>

[0063] The component (B) is a surfactant composed of a quaternary ammonium compound represented by the following general formula (1).

[0064] In the present invention, the component (B) can be used as a dispersant for microcapsules.

[0065]

[0066] (In general formula (1), R 1 、R 2 、R 3 are each independently an acyl group derived from a fatty acid having 12 or more and 30 or less carbon atoms, or a hydrogen atom, R 4 is an alkyl group having 1 or more and 3 or less carbon atoms, X - is an anion. 1 、R 2 、R 3 At least one of the groups is an acyl group derived from a fatty acid and having 12 to 30 carbon atoms.

[0067] In the above general formula (1), from the viewpoint of dispersion stability of microcapsules, R 1 、R 2、R 3 The number of carbon atoms of the acyl groups represented is independently 12 or more, preferably 14 or more, more preferably 16 or more, and is 30 or less, preferably 28 or less, more preferably 26 or less, and further preferably 22 or less.

[0068] From the viewpoint of the handling easiness that has fluidity and produces of this quaternary ammonium salt compound, the acyl group that constitutes above-mentioned quaternary ammonium salt compound preferably comprises the acyl group that is derived from the fatty acid that comprises carbon-carbon unsaturated bond.This carbon-carbon unsaturated bond is preferably two bonds.From the viewpoint of the dispersion stability that improves microcapsule and the retentive viewpoint of organic compounds such as the spices of inner bag, the amount that is derived from the fatty acid that comprises carbon-carbon unsaturated bond in the whole acyl groups that constitute above-mentioned quaternary ammonium salt compound is preferably more than 20 quality %, more preferably more than 40 quality %, further be preferably more than 60 quality %, more further be preferably more than 80 quality %, and, be preferably below 100 quality %.

[0069] Examples of the acyl group include acyl groups derived from saturated fatty acids such as lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, and dimethyloctanoic acid; and acyl groups derived from unsaturated fatty acids such as dodecenoic acid, tetradecenoic acid, hexadecenoic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid, and elaidic acid. Among these compounds, from the viewpoint of improving the dispersion stability of the microcapsules and the retention of organic compounds such as the encapsulated fragrance, it is preferred that the compound contain an acyl group derived from one or more fatty acids selected from oleic acid, linoleic acid, linolenic acid, lauric acid, myristic acid, palmitic acid, and stearic acid, more preferably contain an acyl group derived from one or more fatty acids selected from oleic acid, linoleic acid, linolenic acid, lauric acid, and stearic acid, and even more preferably contain an acyl group derived from one or more fatty acids selected from oleic acid, linoleic acid, and linolenic acid.

[0070] Above-mentioned acyl group preferably comprises the acyl group that is derived from the fatty acid of more than one being selected from oleic acid, linoleic acid and linolenic acid.Thus, can improve the dispersion stability of microcapsule, and also improve the conservatism of organic compounds such as the spices of inner bag at high temperature.From this viewpoint, the total ratio of the acyl group that is derived from oleic acid, linoleic acid and linolenic acid in whole acyl groups of constituting above-mentioned quaternary ammonium salt compound is preferably more than 25 mass %, more preferably more than 30 mass %, further preferably more than 40 mass %, more further preferably more than 50 mass %, more further preferably more than 60 mass %, further more preferably more than 70 mass %, further more preferably more than 80 mass %, more further preferably more than 90 mass %, and, preferably below 100 mass %.

[0071] When the acyl group includes an acyl group derived from oleic acid, from the viewpoint of improving the dispersion stability of the microcapsules and the retention of organic compounds such as perfumes contained therein at high temperatures, the proportion of the acyl group derived from oleic acid in all the acyl groups constituting the quaternary ammonium salt compound is preferably 20% by mass or more, more preferably 30% by mass or more, further preferably 40% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, still more preferably 70% by mass or more, and preferably 100% by mass or less.

[0072] In the above general formula (1), R 4 It is preferably a methyl group or an ethyl group, and more preferably a methyl group.

[0073] In the above general formula (1), X - It is an organic or inorganic anion, preferably one or more selected from halogen ions such as chloride ions, alkyl sulfate ions having 1 to 3 carbon atoms, and benzenesulfonate ions in which 1 to 3 alkyl groups having 1 to 3 carbon atoms may be substituted, more preferably alkyl sulfate ions having 1 to 3 carbon atoms, further preferably methyl sulfate ions or ethyl sulfate ions, and even more preferably methyl sulfate ions.

[0074] The quaternary ammonium salt compound is a quaternary compound of triethanolamine fatty acid ester, and therefore is composed of three different quaternary ammonium compounds with an acylation degree of 1, 2 or 3.

[0075] From the perspective of microcapsule dispersion stability, the average degree of acylation of the quaternary ammonium salt compound is preferably 1.3 or greater, more preferably 1.5 or greater, and preferably 2.5 or less, more preferably 2.3 or less. The average degree of acylation can be adjusted by the reaction ratio of the fatty acid to triethanolamine, the reaction ratio with the alkylating agent during quaternization, and the reaction conditions.

[0076] From the viewpoint of dispersion stability of microcapsules and retention of encapsulated organic compounds such as fragrances at high temperatures, the ratios of the quaternary ammonium compounds having different degrees of acylation constituting the quaternary ammonium salt compound are preferably the following ratios.

[0077] The compound with an acylation degree of 1, that is, R in the general formula (1) 1 is acyl, R 2 and R 3 The proportion of the compound (b1) which is a hydrogen atom (hereinafter referred to as "component (b1)") in the total amount of the above-mentioned quaternary ammonium salt compound is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, and is preferably 45% by mass or less, more preferably 40% by mass or less, further preferably 35% by mass or less.

[0078] The compound with an acylation degree of 2, that is, R in the general formula (1) 1 and R 2 is acyl, R 3 The proportion of the compound (b2) which is a hydrogen atom (hereinafter referred to as "component (b2)") in the total amount of the above-mentioned quaternary ammonium salt compound is preferably 30% by mass or more, more preferably 35% by mass or more, further preferably 40% by mass or more, further preferably 50% by mass or more, and preferably 75% by mass or less, more preferably 70% by mass or less, further preferably 65% by mass or less.

[0079] The compound with an acylation degree of 3, that is, R in the general formula (1) 1 、R 2 and R 3 The proportion of the acyl compound (b3) (hereinafter referred to as "component (b3)") in the total amount of the above-mentioned quaternary ammonium salt compound is preferably 5% by mass or more, more preferably 8% by mass or more, further preferably 10% by mass or more, and is preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 25% by mass or less.

[0080] The quaternary ammonium salt compound can be obtained by subjecting a higher fatty acid to a dehydration esterification reaction with triethanolamine, or a higher fatty acid lower alkyl ester (lower alkyl is methyl, ethyl, or propyl) to an ester exchange reaction with triethanolamine, to a quaternization reaction using an alkylating agent. The alkylating agent is preferably methyl chloride, dimethylsulfuric acid, or the like.

[0081] In order to obtain a mixture in which the ratio of components (b1) to (b3) in the above-mentioned quaternary ammonium salt compound satisfies the above-mentioned range, it is preferred that, for example, a mixture of triethanolamine higher fatty acid esters obtained as follows is subjected to a quaternization reaction, wherein the mixture of triethanolamine higher fatty acid esters is obtained by reacting a higher fatty acid or a higher fatty acid lower alkyl ester in an amount of preferably 1.3 mol or more, more preferably 1.5 mol or more, and preferably 2.0 mol or less, more preferably 1.95 mol or less, relative to 1 mol of triethanolamine.

[0082] In the case of using dimethylsulfate as the alkylating agent, for example, the quaternization reaction is carried out in an amount of preferably 0.9 equivalents or more, more preferably 0.95 equivalents or more, and preferably 1.1 equivalents or less, more preferably 0.99 equivalents or less, relative to 1 equivalent of the amino group of the ester compound.

[0083] The higher fatty acid or higher fatty acid lower alkyl ester is preferably a compound composed of fatty acids obtained by saponifying fats and oils such as beef tallow, palm oil, sunflower oil, soybean oil, rapeseed oil, safflower oil, cottonseed oil, corn oil, and olive oil. From the viewpoint of the dispersion stability of the microcapsules, a compound composed of fatty acids obtained from beef tallow, palm oil, and sunflower oil is more preferred.

[0084] In addition, these higher fatty acids or higher fatty acid lower alkyl esters contain a large amount of alkenyl groups having two or more carbon-carbon unsaturated bonds, and therefore can be produced by, for example, crystallization as described in Japanese Patent Laid-Open No. 4-306296 or by vacuum distillation of methyl esters as described in Japanese Patent Laid-Open No. 6-41578.

[0085] From the viewpoint of maintaining good dispersion stability of the microcapsules even at the temperature during the treatment of the aqueous dispersion and the storage temperature of the aqueous dispersion, the quaternary ammonium salt compound is preferably a liquid in the range of 20°C to 50°C, more preferably a liquid in the range of 15°C to 45°C, further preferably a liquid in the range of 10°C to 40°C, and even more preferably a liquid in the range of 10°C to 35°C.

[0086] (B) component used in the present invention can also comprise the surfactant other than the above-mentioned quaternary ammonium salt compound in the scope that does not hinder the effect of the present invention.As this surfactant, can enumerate: cationic surfactant, nonionic surfactant, anionic surfactant and amphoteric surfactant other than the above-mentioned quaternary ammonium salt compound.

[0087] In the present invention, from the viewpoint of dispersion stability of the microcapsules, the content of the quaternary ammonium salt compound in component (B) is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less, even more preferably 100% by mass. That is, when component (B) is used as a dispersant for microcapsules, the microcapsule dispersant is preferably composed of the quaternary ammonium salt compound.

[0088] The aqueous dispersion of the present invention may contain other components in addition to component (A) and component (B) as needed. Examples of such other components include pH adjusters, pigments, preservatives, antioxidants, ultraviolet absorbers, shell surface modifiers, inorganic salts, thickeners, deposition aids, and rheology modifiers.

[0089] The aqueous dispersion of the present invention may contain, as necessary, a fabric softener, a fabric freshener, a fabric strengthening agent, an enzyme, a builder, a hair conditioner, a skin conditioner, a fragrance, clay, zeolite, silicone, etc., in addition to components (A) and (B), in order to incorporate the aqueous dispersion into various preparations.

[0090] (Method for producing microcapsule aqueous dispersion)

[0091] The method for producing the aqueous dispersion of the present invention is not particularly limited, and can be produced, for example, by mixing a previously prepared aqueous dispersion containing the component (A), the component (B), and, if necessary, the other components described above using a known stirring apparatus or the like.

[0092] From the viewpoint of the dispersion stability of the microcapsules and the retention of organic compounds such as encapsulated fragrances, the mixing temperature of the aqueous dispersion containing component (A) and component (B) is preferably 15°C or higher, more preferably 20°C or higher, and preferably 35°C or lower, more preferably 30°C or lower.

[0093] (Composition of Microcapsule Aqueous Dispersion)

[0094] From the viewpoint of reducing the viscosity of the aqueous dispersion and improving the handleability, the content of component (A) in the aqueous dispersion of the present invention is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and even more preferably 25% by mass or less. Furthermore, from the viewpoint of facilitating the preparation of a liquid composition or product using the aqueous dispersion, the content of component (A) is preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, even more preferably 10% by mass or more, and even more preferably 15% by mass or more.

[0095] From the viewpoint of suppressing aggregation of microcapsules in the aqueous dispersion, reducing the viscosity of the aqueous dispersion, and improving handleability, the content of component (B) in the aqueous dispersion of the present invention is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 7% by mass or less, even more preferably 5% by mass or less, and even more preferably 4% by mass or less. Furthermore, from the viewpoint of dispersion stability of the microcapsules, the content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 1.5% by mass or more, and even more preferably 2% by mass or more.

[0096] From the viewpoint of dispersion stability of the microcapsules, the mass ratio of the content of component (A) to the content of component (B) in the aqueous dispersion of the present invention [component (A) / component (B)] (hereinafter also referred to as "mass ratio [component (A) / component (B)]") is 0.1 or more, preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, even more preferably 4 or more, and even more preferably 5 or more. Furthermore, from the viewpoint of exerting the effect of the organic compound contained in the core of the microcapsule, it is 20 or less, preferably 15 or less, more preferably 12 or less, even more preferably 10 or less, even more preferably 9 or less, and even more preferably 8 or less.

[0097] Therefore, as an example of a condition, the mass ratio [component (A) / component (B)] is preferably 1 or more and 15 or less, more preferably 2 or more and 12 or less, further preferably 2 or more and 10 or less, further preferably 2 or more and 9 or less, further preferably 2 or more and 8 or less, further more preferably 3 or more and 8 or less, further more preferably 4 or more and 8 or less, and still further preferably 5 or more and 8 or less.

[0098] From the viewpoint of suppressing the aggregation of microcapsules in the aqueous dispersion, reducing the viscosity of the aqueous dispersion, and improving the handleability, the content of the quaternary ammonium salt compound in the aqueous dispersion of the present invention is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 7% by mass or less, even more preferably 5% by mass or less, and even more preferably 4% by mass or less. Furthermore, from the viewpoint of the dispersion stability of the microcapsules, the content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 1.5% by mass or more, and even more preferably 2% by mass or more.

[0099] From the viewpoint of dispersion stability of the microcapsules, the content of the quaternary ammonium salt compound in the aqueous dispersion of the present invention relative to the organic compound contained in the core of component (A) is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, even more preferably 3% by mass or more, even more preferably 5% by mass or more, and even more preferably 10% by mass or more. Furthermore, from the viewpoint of effectiveness as an aqueous microcapsule dispersion, the content is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, and even more preferably 20% by mass or less.

[0100] The viscosity of the aqueous microcapsule dispersion of the present invention at 25°C is preferably 1 mPa·s or higher, more preferably 5 mPa·s or higher, and even more preferably 10 mPa·s or higher. Furthermore, it is preferably 4,000 mPa·s or lower, more preferably 2,000 mPa·s or lower, even more preferably 1,000 mPa·s or lower, even more preferably 500 mPa·s or lower, even more preferably 100 mPa·s or lower, even more preferably 50 mPa·s or lower, and even more preferably 30 mPa·s or lower. The viscosity of the aqueous microcapsule dispersion at 25°C can be measured by the method described in the Examples.

[0101] The microcapsule aqueous dispersion and microcapsule dispersant of the present invention achieve both ease of handling and low environmental impact, and therefore can be used in a variety of applications. Examples of such applications include emulsions, cosmetic lotions, toners, serums, creams, gel preparations, hair treatments, quasi-drugs and other fragrances, detergents, softeners, anti-wrinkle sprays and other fiber treatments, sanitary products such as disposable diapers, and fragrances, and can be suitably used in the production of products for these applications.

[0102] The aqueous microcapsule dispersion and microcapsule dispersant of the present invention are preferably incorporated into or used in liquid compositions such as detergent compositions, fiber treatment compositions, cosmetic compositions, fragrance compositions, and deodorant compositions. Such compositions are preferably detergent compositions such as powder detergent compositions and liquid detergent compositions; and fiber treatment compositions such as softener compositions. More preferably, they are fiber treatment compositions, and even more preferably, they are softener compositions.

[0103] Regarding the above-mentioned embodiment, the present invention further discloses the following microcapsule aqueous dispersion and microcapsule dispersant.

[0104] <1> A microcapsule aqueous dispersion comprising the following components (A) and (B), wherein the mass ratio of the content of component (A) to the content of component (B) [component (A) / component (B)] is 0.1 to 20.

[0105] Component (A): Microcapsules having a shell and a core containing one or more organic compounds within the shell

[0106] Component (B): a surfactant comprising a quaternary ammonium salt compound represented by the following general formula (1)

[0107]

[0108] (In general formula (1), R 1 、R 2 、R 3 are each independently an acyl group derived from a fatty acid having 12 or more and 30 or less carbon atoms, or a hydrogen atom, R 4 is an alkyl group having 1 or more and 3 or less carbon atoms, X - is an anion. 1 、R 2 、R 3 At least one of the acyl groups is an acyl group derived from a fatty acid and having 12 to 30 carbon atoms.

[0109] <2> The aqueous microcapsule dispersion according to <1> above, wherein the component (A) is a microcapsule having a shell composed of silica as a constituent component and a core containing one or more organic compounds within the shell.

[0110] <3> The aqueous microcapsule dispersion according to <1> above, wherein the shell of the microcapsule constituting the component (A) is silicon dioxide.

[0111] <4> The aqueous microcapsule dispersion according to any one of <1> to <3>, wherein the median particle size D of the microcapsules of the component (A) is 50 It is preferably less than 100 μm, more preferably less than 75 μm, further preferably less than 50 μm, further preferably less than 30 μm, further preferably less than 10 μm, and preferably greater than 0.01 μm, more preferably greater than 0.05 μm, further preferably greater than 0.07 μm, further preferably greater than 0.1 μm, further preferably greater than 0.5 μm, and further more preferably greater than 1 μm.

[0112] <5> The microcapsule aqueous dispersion according to any one of <1> to <4>, wherein the quaternary ammonium salt compound is preferably liquid in the range of 20°C to 50°C, more preferably in the range of 15°C to 45°C, further preferably in the range of 10°C to 40°C, and even more preferably in the range of 10°C to 35°C.

[0113] <6> The aqueous microcapsule dispersion according to any one of <1> to <5> above, wherein the total proportion of acyl groups derived from oleic acid, linoleic acid, and linolenic acid in all acyl groups constituting the quaternary ammonium salt compound is preferably 25% by mass or more, more preferably 30% by mass or more, further preferably 40% by mass or more, further preferably 50% by mass or more, further preferably 60% by mass or more, further more preferably 70% by mass or more, further more preferably 80% by mass or more, still further preferably 90% by mass or more, and preferably 100% by mass or less.

[0114] <7> The microcapsule aqueous dispersion according to any one of <1> to <6> above, wherein the proportion of acyl groups derived from oleic acid in all acyl groups constituting the quaternary ammonium salt compound is preferably 20% by mass or more, more preferably 30% by mass or more, further preferably 40% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 70% by mass or more, and preferably 100% by mass or less.

[0115] <8> The microcapsule aqueous dispersion according to any one of <1> to <7> above, wherein the content of the above-mentioned component (A) in the microcapsule aqueous dispersion is preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, further preferably 25% by mass or less, and is preferably 3% by mass or more, more preferably 5% by mass or more, further preferably 8% by mass or more, further preferably 10% by mass or more, and further preferably 15% by mass or more.

[0116] <9> The aqueous microcapsule dispersion according to any one of <1> to <8>, wherein the content of the component (B) in the aqueous microcapsule dispersion is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 7% by mass or less, even more preferably 5% by mass or less, even more preferably 4% by mass or less, and preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 1.5% by mass or more, even more preferably 2% by mass or more, and 10% by mass or less.

[0117] <10> The microcapsule aqueous dispersion according to any one of <1> to <9>, wherein the content of the quaternary ammonium salt compound in the microcapsule aqueous dispersion is preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, further preferably 10% by mass or less, further preferably 7% by mass or less, further more preferably 5% by mass or less, further more preferably 4% by mass or less, and preferably 0.1% by mass or more, more preferably 0.5% by mass or more, further preferably 1% by mass or more, further preferably 1.5% by mass or more, further preferably 2% by mass or more.

[0118] <11> The microcapsule aqueous dispersion according to any one of <1> to <10> above, wherein the mass ratio of the content of component (A) to the content of component (B) in the microcapsule aqueous dispersion [component (A) / component (B)] is preferably 1 or more, more preferably 2 or more, further preferably 3 or more, further preferably 4 or more, further preferably 5 or more, and preferably 15 or less, more preferably 12 or less, further preferably 10 or less, further preferably 9 or less, and further preferably 8 or less.

[0119] <12> The microcapsule aqueous dispersion according to any one of <1> to <10> above, wherein the mass ratio of the content of component (A) to the content of component (B) in the microcapsule aqueous dispersion [component (A) / component (B)] is preferably 1 or more and 15 or less, more preferably 2 or more and 12 or less, further preferably 2 or more and 10 or less, further preferably 2 or more and 9 or less, further preferably 2 or more and 8 or less, further more preferably 3 or more and 8 or less, further more preferably 4 or more and 8 or less, and even more preferably 5 or more and 8 or less.

[0120] <13> The microcapsule aqueous dispersion according to any one of <1> to <12> above, wherein the viscosity of the microcapsule aqueous dispersion at 25°C is preferably 1 mPa·s or more, more preferably 5 mPa·s or more, further preferably 10 mPa·s or more, and preferably 4,000 mPa·s or less, more preferably 2,000 mPa·s or less, further preferably 1,000 mPa·s or less, further preferably 500 mPa·s or less, further preferably 100 mPa·s or less, further more preferably 50 mPa·s or less, and further more preferably 30 mPa·s or less.

[0121] <14> The microcapsule aqueous dispersion according to any one of <1> to <13>, wherein the organic compound contained in the core of the above-mentioned component (A) is preferably one or more selected from the group consisting of fragrances; fragrance precursors; oils; antioxidants; antibacterial agents; fertilizers; surface modifiers for fibers, skin, and hair; cooling agents; dyes; pigments; silicones; solvents; and oil-soluble polymers, more preferably one or more selected from the group consisting of fragrances, fragrance precursors, oils, antioxidants, antibacterial agents, fertilizers, surface modifiers, and solvents, further preferably one or more selected from the group consisting of fragrances, fragrance precursors, oils, antioxidants, and solvents, further preferably one or more selected from the group consisting of fragrances, fragrance precursors and oils, and even more preferably one or more selected from the group consisting of fragrances and fragrance precursors.

[0122] <15> The microcapsule aqueous dispersion according to any one of <1> to <14>, wherein the cLogP value of the organic compound contained in the core of the above-mentioned component (A) is preferably 1 or more, more preferably 2 or more, further preferably 3 or more, further preferably 4 or more, and is preferably 30 or less, more preferably 20 or less, and further preferably 10 or less.

[0123] <16> A microcapsule aqueous dispersion comprising the following components (A) and (B), wherein the mass ratio of the content of component (A) to the content of component (B) [component (A) / component (B)] is 0.1 to 20.

[0124] Component (A): A microcapsule having a shell composed of silicon dioxide as a constituent component and a core containing one or more organic compounds selected from fragrances and fragrance precursors within the shell.

[0125] Component (B): a surfactant comprising a quaternary ammonium salt compound represented by the following general formula (1)

[0126]

[0127] (In general formula (1), R 1 、R 2 、R 3 are each independently an acyl group derived from a fatty acid having 12 or more and 30 or less carbon atoms or a hydrogen atom, R 4 is an alkyl group having 1 or more and 3 or less carbon atoms, X - is an anion. 1 、R 2 、R 3 At least one of the groups is an acyl group derived from a fatty acid and having 12 to 30 carbon atoms.

[0128] <17> The microcapsule aqueous dispersion according to <16>, wherein the quaternary ammonium salt compound represented by the general formula (1) is liquid in the range of 20°C to 50°C.

[0129] <18> The microcapsule aqueous dispersion according to <16> or <17>, wherein the cLogP value of the organic compound contained in the core of the above-mentioned component (A) is preferably 1 or more, more preferably 2 or more, further preferably 3 or more, further preferably 4 or more, and is preferably 30 or less, more preferably 20 or less, and further preferably 10 or less.

[0130] <19> The microcapsule aqueous dispersion according to any one of <16> to <18>, wherein the content of the above-mentioned component (A) in the microcapsule aqueous dispersion is preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, further preferably 25% by mass or less, and preferably 3% by mass or more, more preferably 5% by mass or more, further preferably 8% by mass or more, further preferably 10% by mass or more, and further preferably 15% by mass or more.

[0131] <20> The aqueous microcapsule dispersion according to any one of <16> to <19>, wherein the content of the component (B) in the aqueous microcapsule dispersion is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 7% by mass or less, even more preferably 5% by mass or less, even more preferably 4% by mass or less, and preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 1.5% by mass or more, even more preferably 2% by mass or more, and 10% by mass or less.

[0132] <21> The microcapsule aqueous dispersion according to any one of <16> to <20>, wherein the content of the quaternary ammonium salt compound in the microcapsule aqueous dispersion is preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, further preferably 10% by mass or less, further preferably 7% by mass or less, further more preferably 5% by mass or less, further more preferably 4% by mass or less, and preferably 0.1% by mass or more, more preferably 0.5% by mass or more, further preferably 1% by mass or more, further preferably 1.5% by mass or more, further preferably 2% by mass or more.

[0133] <22> The microcapsule aqueous dispersion according to any one of <16> to <21> above, wherein the mass ratio of the content of component (A) in the microcapsule aqueous dispersion to the content of component (B) [component (A) / component (B)] is preferably 1 or more, more preferably 2 or more, further preferably 3 or more, further preferably 4 or more, further preferably 5 or more, and preferably 15 or less, more preferably 12 or less, further preferably 10 or less, further preferably 9 or less, and further preferably 8 or less.

[0134] <23> The microcapsule aqueous dispersion according to any one of <16> to <22> above, wherein the mass ratio of the content of component (A) in the microcapsule aqueous dispersion to the content of component (B) [component (A) / component (B)] is preferably 1 or more and 15 or less, more preferably 2 or more and 12 or less, further preferably 2 or more and 10 or less, further preferably 2 or more and 9 or less, further preferably 2 or more and 8 or less, further more preferably 3 or more and 8 or less, further more preferably 4 or more and 8 or less, and still further preferably 5 or more and 8 or less.

[0135] <24> The microcapsule aqueous dispersion according to any one of <16> to <23> above, wherein the viscosity of the microcapsule aqueous dispersion at 25°C is preferably 1 mPa·s or more, more preferably 5 mPa·s or more, further preferably 10 mPa·s or more, and preferably 4,000 mPa·s or less, more preferably 2,000 mPa·s or less, further preferably 1,000 mPa·s or less, further preferably 500 mPa·s or less, further preferably 100 mPa·s or less, further more preferably 50 mPa·s or less, and further more preferably 30 mPa·s or less.

[0136] <25> A dispersant for microcapsules, comprising a surfactant containing a quaternary ammonium salt compound represented by the following general formula (1).

[0137]

[0138] (In general formula (1), R 1 、R 2 、R 3 are each independently an acyl group derived from a fatty acid having 12 or more and 30 or less carbon atoms, or a hydrogen atom, R 4 is an alkyl group having 1 or more and 3 or less carbon atoms, X - is an anion. 1 、R 2 、R 3 At least one of the acyl groups is an acyl group derived from a fatty acid and having 12 to 30 carbon atoms.

[0139] <26> The microcapsule dispersant according to <25>, wherein the quaternary ammonium salt compound is preferably liquid in the range of 20°C to 50°C, more preferably liquid in the range of 15°C to 45°C, further preferably liquid in the range of 10°C to 40°C, and even more preferably liquid in the range of 10°C to 35°C.

[0140] <27> The dispersant for microcapsules according to <25> or <26>, wherein the total proportion of acyl groups derived from oleic acid, linoleic acid, and linolenic acid in all acyl groups constituting the quaternary ammonium salt compound is preferably 25% by mass or more, more preferably 30% by mass or more, further preferably 40% by mass or more, further preferably 50% by mass or more, further preferably 60% by mass or more, further more preferably 70% by mass or more, further more preferably 80% by mass or more, still further preferably 90% by mass or more, and preferably 100% by mass or less.

[0141] <28> The dispersant for microcapsules according to any one of <25> to <27>, wherein the proportion of acyl groups derived from oleic acid in all acyl groups constituting the quaternary ammonium salt compound is preferably 20% by mass or more, more preferably 30% by mass or more, further preferably 40% by mass or more, further preferably 50% by mass or more, further preferably 60% by mass or more, further more preferably 70% by mass or more, and preferably 100% by mass or less.

[0142] Example

[0143] Various measurements in Examples and Comparative Examples were performed by the following methods.

[0144] [Median particle size D 50 ]

[0145] Median particle size D of emulsion droplets 50 and the median particle size D of the microcapsules 50 The measurement was performed using a laser diffraction / scattering particle size distribution analyzer "LA-960" (trade name, manufactured by Horiba, Ltd.). A flow cell was used for the measurement, and water was used as the medium. The refractive index of the dispersion medium was set to 1.45-0i. An aqueous dispersion containing an emulsion or microcapsules was added to the flow cell, and the measurement was performed at a concentration with a transmittance of approximately 90%. The median particle size D was determined based on volume. 50 .

[0146] [Viscosity of microcapsule aqueous dispersion at 25°C]

[0147] The viscosity of the microcapsule aqueous dispersion was measured using a Brookfield viscometer (model: TVB-10, manufactured by Toki Sangyo Co., Ltd.) using an M3 or M4 rotor at a rotation speed of 60 rpm or 6 rpm, and a measurement temperature of 25°C.

[0148] <Model spices>

[0149] As the organic compound encapsulated in the microcapsules, model fragrance A (volume average cLogP: 3.8, specific gravity: 0.88) having the composition shown in Table 1 was used. The volume average cLogP value of the model fragrance was calculated by multiplying the cLogP values of all fragrance components contained in the model fragrance by their volume ratios in the model fragrance, and summing these values.

[0150] [Table 1]

[0151] Table 1: Model Fragrance A

[0152]

[0153] (Synthesis of Silica Capsules)

[0154] Synthesis example 1-1

[0155] 0.60 g of QUARTAMIN 60W (trade name, manufactured by Kao Corporation, cetyltrimethylammonium chloride, 30% active ingredient by mass) was diluted with 89.14 g of ion-exchanged water to obtain an aqueous phase component. To this aqueous phase component, an oil phase component prepared by mixing 24 g of model fragrance A and 6 g of tetraethoxysilane (hereinafter referred to as "TEOS") was added. The mixture was emulsified at room temperature (approximately 25°C) for 10 minutes using a homomixer (manufactured by HsiangTai Co., Ltd., model: HM-310) set at 8,500 rpm to obtain an emulsion. The median particle size D of the emulsion droplets at this time was 1.5 wt %. 50 It is 1.1μm.

[0156] The resulting emulsion was then adjusted to a pH of 3.8 using a 0.1N aqueous sodium hydroxide solution and then transferred to a separable flask equipped with a stirring blade and a cooler. The solution was stirred at 200 rpm for 24 hours while maintaining the liquid temperature at 30°C. This yielded an aqueous dispersion of microcapsules having a core composed of model fragrance A and a first shell.

[0157] Next, 2.7 g of TEOS was added dropwise to 90.0 g of the resulting aqueous dispersion over 420 minutes. After the addition, stirring was continued for a further 17 hours, followed by cooling, to obtain an aqueous dispersion containing 20.8% by mass of silica capsules (A-1), wherein the silica capsules (A-1) formed a second shell enclosing the first shell and contained the model fragrance A within the amorphous silica. The median particle size D of the silica capsules (A-1) was 50 The content of the silica capsules (A-1) in the aqueous dispersion is a calculated value obtained from the blending composition during the synthesis of the silica capsules.

[0158] Synthesis example 1-2

[0159] 0.60 g of Quartamin 60W was diluted with 89.14 g of ion-exchanged water to obtain an aqueous phase. To this aqueous phase, an oil phase prepared by mixing 24 g of model fragrance A and 6 g of TEOS was added. The mixture was emulsified at room temperature (approximately 25°C) for 10 minutes using a homomixer (manufactured by HsiangTai Co., Ltd., model: HM-310) set at 8,000 rpm to obtain an emulsion. The median diameter D of the emulsion droplets at this time was 1.3 %. 50 0.8μm.

[0160] Next, the pH of the obtained emulsion was adjusted to 3.7 using a 1% by mass aqueous sulfuric acid solution, and then transferred to a separable flask equipped with a stirring blade and a cooler. The liquid temperature was maintained at 30°C and stirred at 200 rpm for 24 hours to obtain an aqueous dispersion containing 21.4% by mass of silica capsules (A-2) having a core and a shell composed of the model fragrance A. The median particle size D of the silica capsules (A-2) was 21.4%. 50 The content of the silica capsules (A-2) in the aqueous dispersion is a calculated value obtained from the blending composition when the silica capsules were synthesized.

[0161] (Synthesis of Quaternary Ammonium Salt Compounds)

[0162] Synthesis example 2-1

[0163] A higher fatty acid having the following composition and triethanolamine were subjected to a dehydration esterification reaction at a ratio of 1.87 mol of the higher fatty acid to 1 mol of triethanolamine to obtain an esterification reaction product containing triethanolamine higher fatty acid ester, which is a precursor of the quaternary ammonium salt compound represented by the above general formula (1).

[0164] The obtained esterification reaction product contained 1% by mass of unreacted fatty acid.

[0165] A quaternization reaction was carried out using 0.96 equivalents of dimethylsulfuric acid per equivalent of the amino group of the triethanolamine higher fatty acid ester in the esterification reaction product to obtain a quaternized reaction product, and then a small amount of ethanol was added.

[0166] (Composition of higher fatty acids)

[0167] Oleic acid: 80 mass%

[0168] Linoleic acid: 10% by mass

[0169] Linolenic acid: 2% by mass

[0170] Stearic acid: 2% by mass

[0171] Palmitic acid: 6% by mass

[0172] The higher fatty acid composition was calculated by analyzing the composition of the higher fatty acids used in the raw materials by gas chromatography and regarding the area % of each fatty acid as mass %.

[0173] The resulting quaternized reaction product was analyzed for the compositional ratio of each component by HPLC, using tetraoctylammonium bromide as an internal standard for quantification. The results confirmed that the resulting quaternized reaction product contained 66% by mass of the quaternary ammonium salt compound (B-1), 15% by mass of ethanol, 17% by mass of unreacted amine salt (as methyl sulfate), 1% by mass of unreacted higher fatty acid, a trace amount of triethanolamine quaternary compound, and other trace components.

[0174] In the following general formula (1), R 1 is acyl, R 2 and R 3 is a hydrogen atom, R 4 is methyl, X - The component (b1-1) which is methylsulfate ion accounts for 22% by mass in the quaternary ammonium salt compound (B-1); in the following general formula (1), R 1 and R 2 is acyl, R 3 is a hydrogen atom, R 4 is methyl, X - The component (b2-1) which is methylsulfate ion accounts for 58% by mass of the quaternary ammonium salt compound (B-1); in the following general formula (1), R 1 、R 2 and R 3 is acyl, R 4 is methyl, X - The component (b3-1) which is methylsulfate ion accounts for 20 mass % in the quaternary ammonium salt compound (B-1).

[0175]

[0176] (In general formula (1), R 1 、R 2 、R 3 , and R 4 Same as above.)

[0177] Synthesis example 2-2

[0178] A higher fatty acid having the following composition and triethanolamine were subjected to a dehydration esterification reaction at a ratio of 1.65 mol of the higher fatty acid to 1 mol of triethanolamine to obtain an esterification reaction product containing triethanolamine higher fatty acid ester, which is a precursor of the quaternary ammonium salt compound represented by the above general formula (1).

[0179] The obtained esterification reaction product contained 5% by mass of unreacted fatty acid.

[0180] A quaternization reaction was carried out using 0.96 equivalents of dimethylsulfuric acid per equivalent of the amino group of the triethanolamine higher fatty acid ester in the esterification reaction product to obtain a quaternized reaction product, and then a small amount of ethanol was added.

[0181] (Composition of higher fatty acids)

[0182] Palmitic acid: 45% by mass

[0183] Stearic acid: 25% by mass

[0184] Oleic acid: 27% by mass

[0185] Linoleic acid: 3% by mass

[0186] The higher fatty acid composition was calculated by analyzing the composition of the higher fatty acids used in the raw materials by gas chromatography and regarding the area % of each fatty acid as mass %.

[0187] The composition ratio of each component of the obtained quaternary reaction product was analyzed by HPLC and quantified using tetraoctylammonium bromide as an internal standard substance. As a result, it was confirmed that the obtained quaternary reaction product contained 86% by mass of the quaternary ammonium salt compound (B-2).

[0188] In the above general formula (1), R 1 is acyl, R 2 and R 3 is a hydrogen atom, R 4 is methyl, X - The component (b1-2) which is methylsulfate ion accounts for 23% by mass in the quaternary ammonium salt compound (B-2); in the above general formula (1), R 1 and R 2 is acyl, R 3 is a hydrogen atom, R 4 is methyl, X -The component (b2-2) which is methylsulfate ion accounts for 49% by mass in the quaternary ammonium salt compound (B-2); in the above general formula (1), R 1 、R 2 and R 3 is acyl, R 4 is methyl, X - The component (b3-2) which is methylsulfate ion accounts for 14% by mass in the quaternary ammonium salt compound (B-2).

[0189] (Manufacturing of Microcapsule Aqueous Dispersion)

[0190] Examples 1 to 6, 8 and Comparative Examples 1 to 11

[0191] A microcapsule aqueous dispersion was prepared by mixing component (A) and component (B) as a microcapsule dispersant at 20-25° C. to obtain the composition shown in Table 2. The content of the encapsulated model fragrance A was 13-19% by mass.

[0192] In Comparative Example 1, the aqueous dispersion containing silica capsules (A-1) obtained in Synthesis Example 1-1 was used directly for dispersion stability evaluation without adding component (B). In Comparative Example 11, the aqueous dispersion containing silica capsules (A-2) obtained in Synthesis Example 1-2 was used directly for dispersion stability evaluation without adding component (B). In Comparative Examples 2 to 5, the polymer dispersants listed in Table 2 were added as component (B). However, aggregation of the silica capsules occurred immediately after the aqueous dispersion was prepared, and therefore, subsequent dispersion stability evaluation was not performed.

[0193] The polymer dispersants used in the comparative examples in Table 2 are shown below.

[0194] Hydroxyethylcellulose: Natrosol 250HHR aqueous solution (active ingredient 1%) (manufactured by Ashland)

[0195] Cetyl hydroxycellulose: Polysurf 67 aqueous solution (active ingredient 1%) (manufactured by Aqualon Group, Hercules Inc.)

[0196] Polyvinylpyrrolidone: PVP K-30 aqueous solution (active ingredient 30%) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0197] N-dimethylaminoethyl methacrylic acid copolymer diethylsulfate: HC polymer 2 aqueous solution (active ingredient 1%) (manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[0198] Polyethylene glycol: PEG13000 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0199] Carboxyvinyl polymer: Carbopol 980 (manufactured by Lubrizol Corporation)

[0200] Polydimethylmethylenepiperidinium chloride: Merquat 100 (active ingredient 42%) (manufactured by Lubrizol Japan Ltd.)

[0201] Dimethyldiallylammonium chloride / acrylamide copolymer: Merquat 550 (active ingredient 9%) (manufactured by Lubrizol Japan Ltd.)

[0202] Example 7

[0203] 5 g of the aqueous dispersion containing silica capsules (A-1) obtained in Synthesis Example 1-1 was heated to 60° C. and stirred, and 0.28 g of the aqueous dispersion containing the quaternary ammonium salt compound (B-2) obtained in Synthesis Example 2-2, also heated to 60° C., was added. The mixture was allowed to cool naturally to obtain an aqueous dispersion of microcapsules containing 19.7% by mass of component (A) and 4.6% by mass of component (B).

[0204] [Evaluation of Viscosity of Microcapsule Aqueous Dispersion]

[0205] The viscosities of the microcapsule aqueous dispersions obtained in Example 2, Example 5, and Comparative Example 1 at 25°C were measured to be 15.7 mPa·s, 24.0 mPa·s, and 9.8 mPa·s, respectively, indicating that all of them were aqueous dispersions with very high fluidity.

[0206] [Evaluation of dispersion stability of microcapsules]

[0207] The aqueous microcapsule dispersions obtained in the Examples and Comparative Examples were stored at room temperature and 40°C, and the presence or absence of gelation, aggregation, floating, or sinking of the silica capsules was observed to evaluate the dispersion stability of the silica capsules in the aqueous dispersions. Table 2 shows the number of days during which no gelation, aggregation, floating, or sinking of the silica capsules was observed.

[0208]

[0209] As shown in Table 2, the microcapsule aqueous dispersions of the Examples contain specific quaternary ammonium salt compounds and therefore have high dispersion stability compared to the microcapsule aqueous dispersions of the Comparative Examples. In addition, the Comparative Examples contain various polymeric dispersants used as thickeners, but good dispersion stability was not obtained.

[0210] Therefore, according to the present invention, the dispersion stability of the microcapsule aqueous dispersion can be improved, and therefore, without using a synthetic polymer as a thickener, the dispersion can be applied to various subsequent liquid compositions or the environmental load at the time of disposal can be reduced.

[0211] [Evaluation of the retention of fragrance ingredients at high temperatures]

[0212] The aqueous microcapsule dispersions prepared in Example 5 and Comparative Example 1 were sealed in spiral tubes and allowed to stand at 50°C. After standing for 8 hours and 32 hours, the aqueous microcapsule dispersions were collected and accurately weighed to 20 mg. The mixture was diluted with 50 g of ion-exchanged water and passed through a membrane filter (manufactured by Millipore, product name "Omnipore", model "JAWP04700") to recover the silica capsules on the membrane filter.

[0213] Separately, after washing silica capsules on a membrane filter with 10 mL of ion-exchanged water and then 10 mL of hexane, the silica capsules were immersed in 10 mL of methanol containing tridecane at a concentration of 10 μg / mL as an internal standard. Ultrasonic waves were then irradiated for 60 minutes using an ultrasonic irradiation device (Branson, Model "5510") at an output of 180 W and an oscillation frequency of 42 kHz to dissolve the fragrance within the silica capsules. This solution was then passed through a membrane filter (Toyo Roshi Co., Ltd., product name "DISMIC," model "13JP020AN"), and the fragrance components contained in this solution were measured by gas chromatography. This was used as the amount of fragrance components encapsulated in the silica capsules, α.

[0214] Separately, 20 mg of the microcapsule aqueous dispersion prepared in Example 5 and Comparative Example 1 before storage at 50°C was accurately weighed and immersed in 10 mL of methanol. Ultrasonic waves were then irradiated for 60 minutes using an ultrasonic irradiation device at an output of 180 W and an oscillation frequency of 42 kHz to dissolve the fragrance within the silica capsules. This solution was passed through a membrane filter (Toyo Roshi Co., Ltd., product name "DISMIC," model number "13JP020AN"), and the fragrance components contained in the solution were measured by gas chromatography. This was used as the fragrance component amount β contained in the microcapsule aqueous dispersion.

[0215] Linalool and tetrahydrolinalool contained in the model fragrance A were totaled and defined as linalools, and the retention rate of linalools was measured according to the following formula. The evaluation results are shown in Table 3 below.

[0216] Linalool retention rate (%) = {(amount of linalool encapsulated in silica capsules after storage α) / (amount of linalool contained in microcapsule aqueous dispersion β)}×100

[0217] [Table 3]

[0218]

[0219] As shown in Table 3, the microcapsule aqueous dispersions of Examples are superior in retaining the encapsulated fragrance component at high temperatures compared to the microcapsule aqueous dispersions of Comparative Examples.

[0220] Industrial applicability

[0221] The microcapsule aqueous dispersion of the present invention can be stored while maintaining the dispersion stability of the microcapsules. Therefore, the microcapsule aqueous dispersion of the present invention can be used to impart various functionalities, such as fragrances for laundry products, personal care products, cosmetics, and household liquid products, without causing gelation or viscosity increase due to aggregation. It is easy to handle and can be widely used. Furthermore, component (B) used in this aqueous dispersion can improve the dispersion stability of the microcapsules, making it particularly useful as a dispersant for microcapsules.

Claims

1. A microcapsule aqueous dispersion, wherein: Contains the following components (A) and (B), wherein the content of component (A) is 5% by mass or more and 50% by mass or less, and The mass ratio of the content of the component (A) to the content of the component (B), (A) component / (B component), is 3 or more and 20 or less, The median particle size D of the microcapsules of the component (A) 50 is 0.1 μm or more and 50 μm or less, The viscosity of the microcapsule aqueous dispersion at 25° C. is 1 mPa·s or more and 500 mPa·s or less. (A) Component: a microcapsule having a shell and a core containing one or more organic compounds within the shell, wherein the shell contains silicon dioxide as a constituent component; Component (B): a surfactant comprising a quaternary ammonium salt compound represented by the following general formula (1), In the general formula (1), R 1 、R 2 、R 3 are each independently an acyl group derived from a fatty acid having 12 or more and 22 or less carbon atoms or a hydrogen atom, R 4 is an alkyl group having 1 or more and 3 or less carbon atoms, X - is an alkyl sulfate ion having 1 or more and 3 or less carbon atoms, wherein R 1 、R 2 、R 3 At least one of them is an acyl group derived from a fatty acid and having 12 to 22 carbon atoms.

2. The microcapsule aqueous dispersion according to claim 1, wherein The quaternary ammonium salt compound is liquid in a temperature range of 10° C. to 40° C.

3. The microcapsule aqueous dispersion according to claim 1 or 2, wherein The total proportion of acyl groups derived from oleic acid, linoleic acid, and linolenic acid in all acyl groups constituting the quaternary ammonium salt compound is 60% by mass or more and 100% by mass or less.

4. The microcapsule aqueous dispersion according to claim 1 or 2, wherein The ratio of the acyl groups derived from oleic acid in all the acyl groups constituting the quaternary ammonium salt compound is 50% by mass or more.

5. The microcapsule aqueous dispersion according to claim 1 or 2, wherein The content of the component (B) in the microcapsule aqueous dispersion is 10% by mass or less.

6. The microcapsule aqueous dispersion according to claim 1 or 2, wherein The content of the quaternary ammonium salt compound in the microcapsule aqueous dispersion is 0.1% by mass or more and 10% by mass or less.

7. The microcapsule aqueous dispersion according to claim 1 or 2, wherein The viscosity of the microcapsule aqueous dispersion at 25° C. is 5 mPa·s or more and 100 mPa·s or less.

8. The microcapsule aqueous dispersion according to claim 1 or 2, wherein The median particle size D of the microcapsules of the component (A) 50 It is 0.5 μm or more and 30 μm or less.

9. The microcapsule aqueous dispersion according to claim 1 or 2, wherein The organic compound is one or more selected from the group consisting of fragrances, fragrance precursors, oils, antioxidants, and solvents.

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