Microcapsule water dispersion

Abstract

The present invention relates to [1] an aqueous microcapsule dispersion including ingredient (A), which is microcapsules each comprising a shell and a core disposed in the shell and including one or more organic compounds, and ingredient (B), which is a surfactant including a quaternary ammonium salt compound represented by general formula (1), the mass ratio of the content of the ingredient (A) to the content of the ingredient (B) [ingredient (A) / ingredient (B)] being 0.1-20, and [2] a dispersant for microcapsules which comprises the surfactant including a quaternary ammonium salt compound represented by general formula (1).

Description

[Technical field]

[0001] The present invention relates to an aqueous dispersion of microcapsules and a dispersant for microcapsules used therein. [Background technology]

[0002] Various microcapsules encapsulating fragrances and bioactive substances have been developed and used in a wide range of business fields, such as cosmetics, pharmaceuticals, general household products, and printing. As a method for producing such microcapsules, chemical methods such as suspension polymerization, mini-emulsion polymerization, emulsion polymerization, precipitation polymerization, dispersion polymerization, interfacial polycondensation, and liquid curing methods; physicochemical methods such as liquid drying, phase inversion emulsification, and coacervation methods; and mechanical methods such as spray drying and heterocoagulation methods are used. In many of the methods for producing the microcapsules, an aqueous dispersion in which the microcapsules are dispersed in an aqueous medium is obtained, and from an industrial point of view, it is desirable to use the obtained aqueous dispersion of microcapsules as it is without performing isolation operations such as filtration and drying. However, the aqueous dispersion of microcapsules has a 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 small compared to the aqueous medium, they will cream over time and lose fluidity, and if the specific gravity of the microcapsules is relatively large, they will sink over time and lose fluidity. Furthermore, aqueous dispersions of microcapsules can suffer from gelation due to physical or chemical changes in the surface of the shell constituting the microcapsules or in the components contained in the aqueous medium, causing the aqueous dispersion to lose its fluidity. Various studies have been conducted to address this issue.

[0003] International Publication No. 2018 / 053356 (Patent Document 1) describes a microcapsule composition containing microcapsules dispersed in an aqueous phase for the purpose of increasing the dispersion stability of the microcapsule composition by the viscosity modifier, and a viscosity modifier, and describes that the viscosity modifier is an acrylate copolymer, a cationic acrylamide copolymer, or a polysaccharide. Japanese Patent Laid-Open No. 2016-113510 (Patent Document 2) describes a thixotropy-imparting agent that contains a fatty acid glyceride having a hydroxyl group in the fatty acyl group, a nonionic surfactant, and water, and optionally contains an anionic surfactant, for the purpose of providing a liquid detergent composition containing a thixotropy-imparting agent that has low viscosity at high shear in order to suppress separation when capsule particles are suspended, and a thixotropy-imparting agent that has high viscosity at low shear. JP 2012-516371 A (Patent Document 3) describes that, for the purpose of preparing an encapsulation body that does not concentrate in a specific region of a fluid, the encapsulation body comprises a core containing a beneficial agent and an outer shell at least partially surrounding the core, and the encapsulation body further comprises a density balancing agent. JP2013-530253A (Patent Document 4) describes a microcapsule in which the density and / or cLogP of the components constituting the fragrance composition contained in the core are within a specific range, with the aim of providing a core-shell type microcapsule that encapsulates a fragrance composition in the core for controlling the delivery and release of fragrances and other beneficial chemical substances.

[0004] JP 2012-501849 A (Patent Document 5) describes an aqueous suspension of microcapsules having a silicate shell, in which an organofunctional silane is used as a colloidal silicate blocking agent, with the aim of improving the stability of the aqueous suspension of microcapsules having a silicate shell. U.S. Patent No. 9,763,861 (Patent Document 6) describes a fluid and stable silica capsule composition that is composed of a silica capsule suspension and an adjuvant, and uses a cationic polymer such as a vinylpyrrolidone / dimethylaminoethyl methacrylate copolymer as the adjuvant. Summary of the Invention

[0005] The present invention contains the following components (A) and (B): 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. Component (A): A microcapsule having a shell and a core containing one or more organic compounds inside the shell. Component (B): A surfactant containing a quaternary ammonium salt compound represented by the following general formula (1):

[0006] [ka] (In general formula (1), R 1 ,R 2 ,R 3 each independently represents an acyl group derived from a fatty acid having 12 to 30 carbon atoms, or a hydrogen atom; R 4 is an alkyl group having 1 to 3 carbon atoms; X - is an anion, where R 1 ,R 2 ,R 3 At least one of the groups is an acyl group derived from a fatty acid having 12 to 30 carbon atoms. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] In the techniques of Patent Documents 1 to 5, the dispersion stability of the microcapsules in the aqueous dispersion was insufficient. In addition, the technology of Patent Document 2 is a technology in which fatty acid glyceride crystals are formed into spherical crystal particles in a water-containing phase by a nonionic surfactant and, optionally, an anionic surfactant, thereby imparting thixotropy to the liquid detergent composition, but the surfactant that constitutes the spherical crystal particles that impart thixotropy may reduce the stability of the encapsulated components of the microcapsules.Therefore, there is a demand for improving the dispersion stability of microcapsules without relying on the action of such a structure that imparts thixotropy. The technology of Patent Document 4 is a technology for controlling the density and / or cLogP of the components constituting the fragrance composition contained in the core of the microcapsule within a specific range, and therefore limits the freedom in designing the composition of the encapsulated components contained in the core. In addition, since the microcapsules may eventually be released into the natural environment, surface modification of silicate shell microcapsules and colloidal silicate particles with organic functional silanes, as in the technology of Patent Document 5, leads to the release of new persistent components into the natural environment. In addition, even if a cationic polymer is used as in Patent Document 6, there is a concern about toxicity to aquatic organisms, and this is not desirable. As described above, although microcapsules are used in a wide range of business fields, there are no fully satisfactory microcapsules in terms of ease of handling as an aqueous dispersion and impact on the natural environment. Therefore, there is a demand for an aqueous dispersion of microcapsules that has a low load on the natural environment, is inhibited from gelling even when stored for a long period of time, and has high dispersion stability in which a decrease in fluidity due to floating or settling is inhibited. The present invention relates to an aqueous dispersion of microcapsules which is excellent in dispersion stability and can be easily handled as an aqueous dispersion while having a low environmental impact, and to a dispersant for microcapsules used therein.

[0008] The present inventors have noted that the use of a surfactant containing a specific quaternary ammonium salt compound as a dispersant for microcapsules improves the dispersion stability of microcapsules in an aqueous dispersion, and have found that it is possible to provide an aqueous dispersion of microcapsules and a dispersant for microcapsules used therein, which have excellent dispersion stability and can achieve both ease of handling as an aqueous dispersion and low environmental impact.

[0009] That is, the present invention relates to the following [1] and [2]. [1] Contains the following components (A) and (B): A microcapsule aqueous dispersion in which 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. Component (A): A microcapsule having a shell and a core containing one or more organic compounds inside the shell. Component (B): A surfactant containing a quaternary ammonium salt compound represented by the following general formula (1):

[0010] [ka] (In general formula (1), R 1 ,R 2 ,R 3 each independently represents an acyl group derived from a fatty acid having 12 to 30 carbon atoms, or a hydrogen atom; R 4 is an alkyl group having 1 to 3 carbon atoms; X - is an anion, where R 1 ,R 2 ,R 3 At least one of the groups is an acyl group derived from a fatty acid having 12 to 30 carbon atoms. [2] A dispersant for microcapsules, comprising a surfactant containing a quaternary ammonium salt compound represented by the following general formula (1):

[0011] [ka] (In general formula (1), R1 ,R 2 ,R 3 each independently represents an acyl group derived from a fatty acid having 12 to 30 carbon atoms, or a hydrogen atom; R 4 is an alkyl group having 1 to 3 carbon atoms; X - is an anion, where R 1 ,R 2 ,R 3 At least one of the groups is an acyl group derived from a fatty acid having 12 to 30 carbon atoms.

[0012] According to the present invention, it is possible to provide an aqueous dispersion of microcapsules, which has excellent dispersion stability and is easy to handle as an aqueous dispersion while having a low environmental impact, and a dispersant for microcapsules used therein.

[0013] [Microcapsule water dispersion] The microcapsule aqueous dispersion of the present invention contains the following components (A) and (B), and 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 0.1 or more and 20 or less. Component (A): A microcapsule having a shell and a core containing one or more organic compounds inside the shell. Component (B): A surfactant containing a quaternary ammonium salt compound represented by the following general formula (1):

[0014] [ka] (In general formula (1), R 1 ,R 2 ,R 3 each independently represents an acyl group derived from a fatty acid having 12 to 30 carbon atoms, or a hydrogen atom; R 4 is an alkyl group having 1 to 3 carbon atoms; X - is an anion, where R 1 ,R 2 ,R 3 At least one of the groups is an acyl group derived from a fatty acid having 12 to 30 carbon atoms.

[0015] The microcapsule aqueous dispersion of the present invention comprises microcapsules, which are component (A), dispersed in an aqueous medium. In the present specification, the term "aqueous medium" refers to a liquid containing at least water, and preferably contains water as the main component. Examples of components other than water that the aqueous medium may contain include aliphatic alcohols having 1 to 4 carbon atoms, ketones having 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. In this specification, "fatty acids having 12 or more carbon atoms" are also referred to as higher fatty acids.

[0016] The reason why the present invention has an effect is not clear, but is thought to be as follows. The quaternary ammonium salt compound represented by the general formula (1) is considered to form minute vesicles in an aqueous medium because it has a hydrophilic portion due to a quaternary ammonium group and a hydrophobic portion due to an acyl group derived from a higher fatty acid in its structure. It is considered that the aggregation of the microcapsules is suppressed by some interaction between the vesicles and the microcapsules in the aqueous dispersion, and as a result, the dispersion stability of the microcapsule aqueous dispersion is improved.

[0017] <Component (A)> Component (A) is a microcapsule having a shell and a core containing one or more organic compounds inside the shell. The shell constituting the microcapsule of component (A) is not particularly limited as long as it can encapsulate a core containing one or more organic compounds. Specific examples of components constituting the shell include silica, organically modified silica, polyvinyl alcohol, polysaccharides, lipids, polyesters such as polylactic acid resins and polyglycolic acid resins, polyacrylate copolymers, polymethacrylate polymers, melamine / formaldehyde resins, polyurethane resins, polyurea resins, polyamide resins, polyimide resins, polystyrene, or combinations thereof. Among them, from the viewpoint of stably enclosing the encapsulated material in the shell, those having a crosslinked structure are preferred, and specific examples thereof include one or more selected from silica, organically modified silica, melamine / formaldehyde resins, polyurethane resins, polyurea resins, polyamide resins, and polyimide resins, and from the viewpoint of reducing the environmental load when released to the external environment, silica is more preferred. That is, component (A) is preferably a microcapsule (silica microcapsule) (hereinafter also referred to as "silica capsule") having a shell containing silica as a constituent component and a core containing one or more organic compounds inside the shell.

[0018] Silica capsules having a shell containing silica as a constituent component can be produced by, for example, (1) a sol-gel reaction using an alkoxysilane as a starting material, (2) a sol-gel reaction using sodium silicate as a starting material, or (3) the formation of a Pickering emulsion using colloidal silica as a starting material.

[0019] (A) Median diameter D of the microcapsules of the component 50is preferably 100 μm or less, more preferably 75 μm or less, even more preferably 50 μm or less, even more preferably 30 μm or less, and even more preferably 10 μm or less, from the viewpoint of improving dispersion stability based on Stokes' equation. And, from the viewpoint of reducing the specific surface area of ​​the microcapsules and improving the retention of the contents in the core, it is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.07 μm or more, even more preferably 0.1 μm or more, even more preferably 0.5 μm or more, and even more preferably 1 μm or more. The median diameter D of component (A) 50 can be measured by the method described in the Examples.

[0020] From the viewpoint of suppressing floating or settling of the microcapsules over time and improving dispersion stability, the difference in specific gravity between the (A) component and the aqueous medium is preferably less than 0.30, more preferably less than 0.20, even more preferably less than 0.15, still more preferably less than 0.10, still more preferably less than 0.05, still more preferably less than 0.01, and still more preferably there is no difference in specific gravity. The specific gravity of component (A) is determined by the specific gravity of the shell and core that constitute component (A), and the mass ratio of the shell to the core.

[0021] 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, even more preferably one or more selected from fragrances, fragrance precursors, oils, antioxidants, and solvents, still more preferably one or more selected from fragrances, fragrance precursors, and oils, and even more preferably one or more selected from fragrances and fragrance precursors. The organic compounds can be appropriately combined depending on the application of the microcapsules.

[0022] Examples of the fragrance precursor include a compound that reacts with water to release a fragrance component, and a compound that reacts with light to release a fragrance component. Examples of compounds that release fragrance components in reaction with water include silicate ester 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 hemiaminal compounds or hydrazone compounds obtained by reacting a carbonyl component derived from a fragrance aldehyde or fragrance ketone with a hydrazine compound. Examples of compounds that release fragrance components in response to light include 2-nitrobenzyl ether compounds having an alkoxy component derived from a fragrance alcohol, α-ketoester compounds having a carbonyl component derived from a fragrance aldehyde or fragrance ketone, coumaric acid ester compounds having an alkoxy component derived from a fragrance alcohol, etc. These fragrance precursors may be used as polymers, such as the reaction product of some carboxy groups of polyacrylic acid with a fragrance alcohol.

[0023] From the viewpoint of dispersion stability of the microcapsules, the organic compound preferably has a suitable hydrophobicity. As an index representing the hydrophilicity or hydrophobicity of the organic compound, the cLogP value, which is the calculated value of the common logarithm "logP" of the partition coefficient P (n-octanol / water) between n-octanol and water, can be used. The cLogP value is "LogP (cLogP)" calculated by the method described in A.Leo Comprehensive Medicinal Chemistry, Vol.4 C.Hansch, P.G.Sammens, JB Taylor and CARamsden, Eds., P.295, Pergamon Press, 1990, and is the cLogP value calculated by the program CLOGP v4.01. When the organic compound is composed of a plurality of components, the cLogP value of the organic compound can be calculated by multiplying the cLogP value of each component by the volume ratio of each component and calculating the sum of the results. The cLogP value of the organic compound is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, still more preferably 4 or more, and is preferably 30 or less, more preferably 20 or less, even more preferably 10 or less.

[0024] <(B) component> The component (B) is a surfactant containing a quaternary ammonium compound represented by the following general formula (1). In the present invention, the component (B) can be used as a dispersant for microcapsules.

[0025] [ka] (In general formula (1), R 1 ,R 2 ,R 3 each independently represents an acyl group derived from a fatty acid having 12 to 30 carbon atoms, or a hydrogen atom; R 4 is an alkyl group having 1 to 3 carbon atoms; X - is an anion, where R 1 ,R 2 ,R 3 At least one of the groups is an acyl group derived from a fatty acid having 12 to 30 carbon atoms.

[0026] In the general formula (1), R 1 , R 2 , R 3 The number of carbon atoms in the acyl group represented by the formula (I) is, independently from the viewpoint of dispersion stability of the microcapsules, 12 or more, preferably 14 or more, more preferably 16 or more, and 30 or less, preferably 28 or less, more preferably 26 or less, and even more preferably 22 or less.

[0027] The acyl group constituting the quaternary ammonium salt compound preferably contains an acyl group derived from a fatty acid containing a carbon-carbon unsaturated bond, from the viewpoint of ease of handling due to the fluidity of the quaternary ammonium salt compound. The carbon-carbon unsaturated bond is preferably a double bond. The amount of the acyl group derived from a fatty acid containing a carbon-carbon unsaturated bond in the total acyl group constituting the quaternary ammonium salt compound is preferably 20% by mass or more, more preferably 40% by mass or more, even more preferably 60% by mass or more, even more preferably 80% by mass or more, and preferably 100% by mass or less, from the viewpoint of improving the dispersion stability of the microcapsule and the retention of the organic compound such as the encapsulated fragrance.

[0028] Examples of the acyl group include acyl groups derived from saturated fatty acids such as lauric acid, tridecylic acid, myristic acid, pentadecylic 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, from the viewpoint of improving the dispersion stability of the microcapsules and the viewpoint of the retention of organic compounds such as encapsulated fragrances, it is preferable to contain one or more acyl groups derived from fatty acids selected from oleic acid, linoleic acid, linolenic acid, lauric acid, myristic acid, palmitic acid, and stearic acid, more preferably to contain one or more acyl groups derived from fatty acids selected from oleic acid, linoleic acid, linolenic acid, lauric acid, and stearic acid, and even more preferably to contain one or more acyl groups derived from fatty acids selected from oleic acid, linoleic acid, and linolenic acid.

[0029] The acyl group preferably contains one or more fatty acid-derived acyl groups selected from oleic acid, linoleic acid, and linolenic acid. This improves the dispersion stability of the microcapsules and also improves the retention of the encapsulated organic compounds, such as fragrances, at high temperatures. From this viewpoint, the total proportion of oleic acid, linoleic acid, and linolenic acid-derived acyl groups in the total acyl groups constituting the quaternary ammonium salt compound is preferably 25% by mass or more, more preferably 30% by mass or more, even more 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, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and preferably 100% by mass or less.

[0030] When the acyl group contains an acyl group derived from oleic acid, the proportion of the acyl group derived from oleic acid among all the acyl groups constituting the quaternary ammonium salt compound is, from the viewpoint of improving the dispersion stability of the microcapsules and from the viewpoint of the retention of the encapsulated organic compounds such as fragrances at high temperatures, preferably 20% by mass or more, more preferably 30% by mass or more, even more 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.

[0031] In the general formula (1), R 4 is preferably a methyl group or an ethyl group, more preferably a methyl group. In the general formula (1), X - is an organic or inorganic anion, and is preferably one or more selected from a halogen ion such as a chlorine ion, an alkyl sulfate ion having from 1 to 3 carbon atoms, and a benzenesulfonate ion which may be substituted with from 1 to 3 alkyl groups having from 1 to 3 carbon atoms, more preferably an alkyl sulfate ion having from 1 to 3 carbon atoms, even more preferably a methyl sulfate ion or an ethyl sulfate ion, and still more preferably a methyl sulfate ion.

[0032] The quaternary ammonium salt compound is a quaternized product of triethanolamine fatty acid ester, and is therefore composed of three different quaternary compounds having an acylation degree of 1, 2, or 3. The average acylation degree of the quaternary ammonium salt compound is preferably 1.3 or more, more preferably 1.5 or more, and is preferably 2.5 or less, more preferably 2.3 or less, from the viewpoint of dispersion stability of the microcapsules. The average acylation degree can be adjusted by the reaction ratio of the fatty acid and triethanolamine, the reaction ratio with the alkylating agent during quaternization, and the reaction conditions.

[0033] The ratio of the quaternary compounds having different degrees of acylation constituting the quaternary ammonium salt compound is preferably as follows, from the viewpoint of the dispersion stability of the microcapsules and the retention of the encapsulated organic compounds such as fragrances at high temperatures. A compound having an acylation degree of 1, i.e., R 1 is an acyl group, and R 2 and R 3 The proportion of compound (b1) in which is a hydrogen atom (hereinafter referred to as "component (b1)") in the total amount of the quaternary ammonium salt compound is preferably 5 mass% or more, more preferably 10 mass% or more, even more preferably 15 mass% or more, and is preferably 45 mass% or less, more preferably 40 mass% or less, even more preferably 35 mass% or less. A compound having an acylation degree of 2, i.e., R 1 and R 2 is an acyl group, and R 3 The proportion of compound (b2) in which is a hydrogen atom (hereinafter referred to as "component (b2)") in the total amount of the quaternary ammonium salt compound is preferably 30 mass% or more, more preferably 35 mass% or more, even more preferably 40 mass% or more, still more preferably 50 mass% or more, and is preferably 75 mass% or less, more preferably 70 mass% or less, even more preferably 65 mass% or less. A compound having an acylation degree of 3, i.e., R 1 , R 2 and R3 The proportion of compound (b3) in which is an acyl group (hereinafter referred to as "component (b3)") in the total amount of the quaternary ammonium salt compound is preferably 5 mass% or more, more preferably 8 mass% or more, even more preferably 10 mass% or more, and is preferably 40 mass% or less, more preferably 30 mass% or less, even more preferably 25 mass% or less.

[0034] The quaternary ammonium salt compound can be obtained by subjecting an esterification reaction product obtained by a method of subjecting a higher fatty acid to a dehydration esterification reaction with triethanolamine, or a method of subjecting a higher fatty acid lower alkyl ester (wherein the lower alkyl is a methyl group, an ethyl group, or a propyl group) to a transesterification reaction with triethanolamine, to a quaternization reaction with an alkylating agent. As the alkylating agent, methyl chloride, dimethyl sulfate, etc. are preferable. In order to obtain a mixture in which the ratios of the components (b1) to (b3) in the quaternary ammonium salt compound satisfy the above-mentioned ranges, it is preferable to subject a mixture of triethanolamine higher fatty acid esters to a quaternization reaction in which a higher fatty acid or a higher fatty acid lower alkyl ester is reacted with 1 mole of triethanolamine in a ratio of preferably 1.3 moles or more, more preferably 1.5 moles or more, and preferably 2.0 moles or less, more preferably 1.95 moles or less. In the case where dimethyl sulfate is used as an alkylating agent, for example, the quaternization reaction is preferably carried out using dimethyl sulfate 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, per equivalent of the amino group of the ester compound.

[0035] The higher fatty acid or the higher fatty acid lower alkyl ester is preferably one having a fatty acid composition obtained by saponifying fats and oils such as beef tallow, palm oil, sunflower oil, soybean oil, rapeseed oil, safflower oil, cottonseed oil, corn oil, olive oil, etc., and from the viewpoint of dispersion stability of the microcapsules, one having a fatty acid composition obtained from beef tallow, palm oil and sunflower oil is more preferable. In addition, since 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, they can be produced, for example, by crystallization as described in JP-A-4-306296, or by a method of distilling methyl esters under reduced pressure as described in JP-A-6-41578, or the like.

[0036] From the viewpoint of maintaining good dispersion stability of the microcapsules even at the temperature when the aqueous dispersion is handled and at the storage temperature of the aqueous dispersion, the quaternary ammonium salt compound is preferably liquid in the range of 20°C or higher and 50°C or lower, more preferably liquid in the range of 15°C or higher and 45°C or lower, even more preferably liquid in the range of 10°C or higher and 40°C or lower, and even more preferably liquid in the range of 10°C or higher and 35°C or lower.

[0037] The component (B) used in the present invention may contain a surfactant other than the quaternary ammonium salt compound, as long as the effect of the present invention is not impaired. Examples of the surfactant include cationic surfactants other than the quaternary ammonium salt compounds, nonionic surfactants, anionic surfactants, and amphoteric surfactants. In the present invention, the content of the quaternary ammonium salt compound in the (B) component is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and preferably 100% by mass or less, still more preferably 100% by mass, from the viewpoint of dispersion stability of the microcapsules. That is, when the (B) component is used as a dispersant for microcapsules, the microcapsule dispersant is preferably composed of the quaternary ammonium salt compound.

[0038] The aqueous dispersion of the present invention may contain other components in addition to the components (A) and (B) as necessary, such as a pH adjuster, a dye, a preservative, an antioxidant, an ultraviolet absorber, a shell surface modifier, an inorganic salt, a thickener, a deposition aid, a rheology adjuster, etc.

[0039] In order to incorporate the aqueous dispersion into various preparations, the aqueous dispersion of the present invention may previously contain, as necessary, fabric softeners, fabric freshening agents, fabric strengthening agents, enzymes, builders, hair conditioning agents, skin conditioning agents, fragrances, clays, zeolites, silicones, and the like, other than the components (A) and (B).

[0040] (Method of producing a microcapsule aqueous dispersion) The method for producing the aqueous dispersion of the present invention is not particularly limited. For example, the aqueous dispersion of the present invention can be produced by mixing a previously prepared aqueous dispersion containing component (A), component (B), and, if necessary, the other components described above, using a known stirring device or the like. 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, from the viewpoint of dispersion stability of the microcapsules and retention of the encapsulated organic compounds such as fragrances, and is preferably 35°C or lower, more preferably 30°C or lower.

[0041] (Composition of microcapsule aqueous dispersion) The content of the (A) component in the aqueous dispersion of the present invention is, from the viewpoint of reducing the viscosity of the aqueous dispersion and improving handleability, 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, and from the viewpoint of facilitating the preparation of a liquid composition or product using the aqueous dispersion, 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.

[0042] The content of component (B) in the aqueous dispersion of the present invention is, from the viewpoints of suppressing aggregation of microcapsules in the aqueous dispersion, reducing the viscosity of the aqueous dispersion, and improving handleability, preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, still more preferably 10% by mass or less, still more preferably 7% by mass or less, still more preferably 5% by mass or less, and still more preferably 4% by mass or less, and from the viewpoint of dispersion stability of the microcapsules, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, still more preferably 1.5% by mass or more, and still more preferably 2% by mass or more.

[0043] 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 simply 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, still more preferably 4 or more, and still more preferably 5 or more, from the viewpoint of the dispersion stability of the microcapsules, and is 20 or less, preferably 15 or less, more preferably 12 or less, even more preferably 10 or less, still more preferably 9 or less, and still more preferably 8 or less, from the viewpoint of the expression of the effects of the organic compound contained in the core of the microcapsules. Therefore, as an example of the conditions, 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, even more preferably 2 or more and 9 or less, even more preferably 2 or more and 8 or less, even more preferably 3 or more and 8 or less, even more preferably 4 or more and 8 or less, and even more preferably 5 or more and 8 or less.

[0044] The content of the quaternary ammonium salt compound in the aqueous dispersion of the present invention is, from the viewpoints of suppressing aggregation of microcapsules in the aqueous dispersion, reducing the viscosity of the aqueous dispersion, and improving handleability, preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, still more preferably 10% by mass or less, still more preferably 7% by mass or less, still more preferably 5% by mass or less, and still more preferably 4% by mass or less, and from the viewpoint of dispersion stability of the microcapsules, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, still more preferably 1.5% by mass or more, and still more preferably 2% by mass or more.

[0045] The content of the quaternary ammonium salt compound relative to the organic compound contained in the core of component (A) in the aqueous dispersion of the present invention is, from the viewpoint of dispersion stability of the microcapsules, 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, and from the viewpoint of efficiency as a microcapsule aqueous dispersion, it 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.

[0046] The viscosity of the microcapsule aqueous dispersion of the present invention at 25°C is preferably 1 mPa·s or more, more preferably 5 mPa·s or more, even more preferably 10 mPa·s or more, and preferably 4,000 mPa·s or less, more preferably 2,000 mPa·s or less, even more preferably 1,000 mPa·s or less, still more preferably 500 mPa·s or less, still more preferably 100 mPa·s or less, still more preferably 50 mPa·s or less, and still more preferably 30 mPa·s or less. The viscosity of the microcapsule aqueous dispersion at 25°C can be measured by the method described in the Examples.

[0047] The microcapsule aqueous dispersion and the microcapsule dispersant of the present invention can be used in various applications, since they are easy to handle and have a low environmental impact. Examples of applications include cosmetics such as milky lotions, cosmetic liquids, skin lotions, beauty essences, creams, gel preparations, hair treatment agents, and quasi-drugs, fiber treatment agents such as detergents, fabric softeners, and anti-wrinkle sprays, sanitary products such as paper diapers, and fragrances, and the microcapsule aqueous dispersion and the microcapsule dispersant of the present invention can be used suitably in the manufacture of these applications.

[0048] The microcapsule aqueous dispersion and the dispersant for microcapsules of the present invention are preferably used by being contained in or blended with a liquid composition such as a detergent composition, a fiber treatment composition, a cosmetic composition, an aroma composition, a deodorant composition, etc. As such compositions, detergent compositions such as powder detergent compositions and liquid detergent compositions; fiber treatment compositions such as softener compositions, etc. are preferred, fiber treatment compositions are more preferred, and softener compositions are even more preferred.

[0049] In relation to the above-mentioned embodiments, the present invention further discloses the following aqueous microcapsule dispersion and dispersant for microcapsules.

[0050] <1> Contains the following components (A) and (B), A microcapsule aqueous dispersion in which 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. Component (A): A microcapsule having a shell and a core containing one or more organic compounds inside the shell. Component (B): A surfactant containing a quaternary ammonium salt compound represented by the following general formula (1): [ka] (In general formula (1), R 1 ,R 2 ,R 3 each independently represents an acyl group derived from a fatty acid having 12 to 30 carbon atoms, or a hydrogen atom; R 4 is an alkyl group having 1 to 3 carbon atoms; X -is an anion, where R 1 ,R 2 ,R 3 At least one of the groups is an acyl group derived from a fatty acid having 12 to 30 carbon atoms.

[0051] <2> The component (A) is a microcapsule having a shell containing silica as a constituent component and a core containing one or more organic compounds inside the shell. <1> The microcapsule aqueous dispersion according to claim 1. <3> The shell constituting the microcapsules of the component (A) is silica. <1> The microcapsule aqueous dispersion according to claim 1. <4> The median diameter D of the microcapsules of the component (A) 50 is preferably 100 μm or less, more preferably 75 μm or less, even more preferably 50 μm or less, still more preferably 30 μm or less, even more preferably 10 μm or less, and is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.07 μm or more, still more preferably 0.1 μm or more, still more preferably 0.5 μm or more, and still more preferably 1 μm or more. <1> ~ <3> 2. The microcapsule aqueous dispersion according to claim 1 .

[0052] <5> The quaternary ammonium salt compound is preferably liquid at a temperature ranging from 20° C. to 50° C., more preferably liquid at a temperature ranging from 15° C. to 45° C., even more preferably liquid at a temperature ranging from 10° C. to 40° C., and even more preferably liquid at a temperature ranging from 10° C. to 35° C. <1> ~ <4> 2. The microcapsule aqueous dispersion according to claim 1 . <6> 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, even more preferably 40% by mass or more, still more preferably 50% by mass or more, still more preferably 60% by mass or more, still more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, and preferably 100% by mass or less; <1> ~ <5> 2. The microcapsule aqueous dispersion according to claim 1 . <7> 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, even more preferably 40% by mass or more, still more preferably 50% by mass or more, still more preferably 60% by mass or more, still more preferably 70% by mass or more, and preferably 100% by mass or less. <1> ~ <6> 2. The microcapsule aqueous dispersion according to claim 1 .

[0053] <8> The content of the component (A) in the microcapsule aqueous dispersion is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, still more preferably 25% by mass or less, and is preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, still more preferably 10% by mass or more, still more preferably 15% by mass or more. <1> ~ <7> 2. The microcapsule aqueous dispersion according to claim 1 . <9> The content of the (B) component in the microcapsule aqueous 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. <1> ~ <8> 2. The microcapsule aqueous dispersion according to claim 1 . <10> 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, even more preferably 20% by mass or less, still more preferably 10% by mass or less, still more preferably 7% by mass or less, still more preferably 5% by mass or less, still more preferably 4% by mass or less, and is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, still more preferably 1.5% by mass or more, still more preferably 2% by mass or more. <1> ~ <9> 2. The microcapsule aqueous dispersion according to claim 1 .

[0054] <11> the mass ratio of the content of the component (A) to the content of the component (B) in the microcapsule aqueous dispersion [component (A) / component (B)] is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, still more preferably 4 or more, still more preferably 5 or more, and is preferably 15 or less, more preferably 12 or less, still more preferably 10 or less, still more preferably 9 or less, still more preferably 8 or less; <1> ~ <10> 2. The microcapsule aqueous dispersion according to claim 1 . <12> The mass ratio of the content of the component (A) to the content of the 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, even more preferably 2 or more and 10 or less, still more preferably 2 or more and 9 or less, still more preferably 2 or more and 8 or less, still more preferably 3 or more and 8 or less, still more preferably 4 or more and 8 or less, and still more preferably 5 or more and 8 or less. <1> ~ <10> 2. The microcapsule aqueous dispersion according to claim 1 .

[0055] <13> The viscosity of the microcapsule aqueous dispersion at 25°C is preferably 1 mPa·s or more, more preferably 5 mPa·s or more, even more preferably 10 mPa·s or more, and is preferably 4,000 mPa·s or less, more preferably 2,000 mPa·s or less, even more preferably 1,000 mPa·s or less, even more preferably 500 mPa·s or less, even more preferably 100 mPa·s or less, even more preferably 50 mPa·s or less, and even more preferably 30 mPa·s or less. <1> ~ <12> 2. The microcapsule aqueous dispersion according to claim 1 .

[0056] <14> the organic compound contained in the core of the component (A) is preferably one or more selected from fragrances; fragrance precursors; oils; antioxidants; antibacterial agents; fertilizers; surface modifiers for fibers, skin, hair, and the like; 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, even more preferably one or more selected from fragrances, fragrance precursors, oils, antioxidants, and solvents, even more preferably one or more selected from fragrances, fragrance precursors, and oils, and even more preferably one or more selected from fragrances and fragrance precursors; <1> ~ <13> 2. The microcapsule aqueous dispersion according to claim 1 . <15> The cLogP value of the organic compound contained in the core of the component (A) is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and even more preferably 4 or more, and is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. <1> ~ <14> 2. The microcapsule aqueous dispersion according to claim 1 .

[0057] <16> Contains the following components (A) and (B), A microcapsule aqueous dispersion in which 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. Component (A): A microcapsule having a shell containing silica as a constituent component and a core containing one or more organic compounds selected from fragrances and fragrance precursors inside the shell. Component (B): A surfactant containing a quaternary ammonium salt compound represented by the following general formula (1): [ka] (In general formula (1), R 1 ,R 2 ,R 3 each independently represents an acyl group derived from a fatty acid having 12 to 30 carbon atoms, or a hydrogen atom; R 4 is an alkyl group having 1 to 3 carbon atoms; X - is an anion, where R 1 ,R 2 ,R 3 At least one of the groups is an acyl group derived from a fatty acid having 12 to 30 carbon atoms.

[0058] <17> The quaternary ammonium salt compound represented by the general formula (1) is liquid at a temperature ranging from 20° C. to 50° C. <16> The microcapsule aqueous dispersion according to claim 1. <18> The cLogP value of the organic compound contained in the core of the component (A) is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and even more preferably 4 or more, and is preferably 30 or less, more preferably 20 or less, and even more preferably 10 or less. <16> or <17> The microcapsule aqueous dispersion according to claim 1.

[0059] <19> The content of the component (A) in the microcapsule aqueous dispersion is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, still more preferably 25% by mass or less, and is preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, still more preferably 10% by mass or more, still more preferably 15% by mass or more. <16> ~ <18> 2. The microcapsule aqueous dispersion according to claim 1 . <20> The content of the (B) component in the microcapsule aqueous 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. <16> ~ <19> 2. The microcapsule aqueous dispersion according to claim 1 . <21> 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, even more preferably 20% by mass or less, still more preferably 10% by mass or less, still more preferably 7% by mass or less, still more preferably 5% by mass or less, still more preferably 4% by mass or less, and is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, still more preferably 1.5% by mass or more, still more preferably 2% by mass or more. <16> ~ <20> 2. The microcapsule aqueous dispersion according to claim 1 .

[0060] <22> the mass ratio of the content of the component (A) to the content of the component (B) in the microcapsule aqueous dispersion [component (A) / component (B)] is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, still more preferably 4 or more, still more preferably 5 or more, and is preferably 15 or less, more preferably 12 or less, still more preferably 10 or less, still more preferably 9 or less, still more preferably 8 or less; <16> ~ <21> 2. The microcapsule aqueous dispersion according to claim 1 . <23> The mass ratio of the content of the component (A) to the content of the 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, even more preferably 2 or more and 10 or less, still more preferably 2 or more and 9 or less, still more preferably 2 or more and 8 or less, still more preferably 3 or more and 8 or less, still more preferably 4 or more and 8 or less, and still more preferably 5 or more and 8 or less. <16> ~ <22> 2. The microcapsule aqueous dispersion according to claim 1 .

[0061] <24> The viscosity of the microcapsule aqueous dispersion at 25°C is preferably 1 mPa·s or more, more preferably 5 mPa·s or more, even more preferably 10 mPa·s or more, and is preferably 4,000 mPa·s or less, more preferably 2,000 mPa·s or less, even more preferably 1,000 mPa·s or less, even more preferably 500 mPa·s or less, even more preferably 100 mPa·s or less, even more preferably 50 mPa·s or less, and even more preferably 30 mPa·s or less. <16> ~ <23> 2. The microcapsule aqueous dispersion according to claim 1 .

[0062] <25> A dispersant for microcapsules, comprising a surfactant containing a quaternary ammonium salt compound represented by the following general formula (1): [ka] (In general formula (1), R 1 ,R 2 ,R 3 each independently represents an acyl group derived from a fatty acid having 12 to 30 carbon atoms, or a hydrogen atom; R 4 is an alkyl group having 1 to 3 carbon atoms; X - is an anion, where R 1 ,R 2 ,R 3 At least one of the groups is an acyl group derived from a fatty acid having 12 to 30 carbon atoms.

[0063] <26> The quaternary ammonium salt compound is preferably liquid at a temperature ranging from 20° C. to 50° C., more preferably liquid at a temperature ranging from 15° C. to 45° C., even more preferably liquid at a temperature ranging from 10° C. to 40° C., and even more preferably liquid at a temperature ranging from 10° C. to 35° C. <25> The dispersant for microcapsules according to claim 1. <27> 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, even more preferably 40% by mass or more, still more preferably 50% by mass or more, still more preferably 60% by mass or more, still more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, and preferably 100% by mass or less; <25> or <26> The dispersant for microcapsules according to claim 1. <28> 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, even more preferably 40% by mass or more, still more preferably 50% by mass or more, still more preferably 60% by mass or more, still more preferably 70% by mass or more, and preferably 100% by mass or less. <25> ~ <27> 2. The dispersant for microcapsules according to claim 1 . EXAMPLES

[0064] Various measurements in the examples and comparative examples were carried out by the following methods. [Median diameter D 50 〕 Median diameter of emulsion droplets D 50 and the median diameter of the microcapsules D 50 was measured using a laser diffraction / scattering particle size distribution analyzer "LA-960" (product name, manufactured by Horiba, Ltd.). A flow cell was used for the measurement, the medium was water, and the refractive index of the dispersoid was set to 1.45-0i. An emulsion or a water dispersion containing microcapsules was added to the flow cell, and measurements were performed at a concentration that showed a transmittance of approximately 90%, and the median diameter D 50asked for.

[0065] [Viscosity of microcapsule aqueous dispersion at 25°C] The viscosity of the microcapsule aqueous dispersion was measured using a B-type viscometer (model: TVB-10, manufactured by Toki Sangyo Co., Ltd.) The spindle used was M3 or M4, the rotation speed was 60 rpm or 6 rpm, and the measurement temperature was 25°C.

[0066] <Model Fragrance> As the organic compound to be 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 as the sum of the cLogP values ​​of all fragrance components contained in the model fragrance multiplied by their volume ratios in the model fragrance.

[0067] [Table 1]

[0068] (Synthesis of Silica Capsules) Synthesis Example 1-1 0.60 g of Coatamin 60W (trade name, Kao Corporation, cetyltrimethylammonium chloride, active content 30% by mass) was diluted with 89.14 g of ion-exchanged water to obtain an aqueous phase component. An oil phase component prepared by mixing 24 g of model fragrance A and 6 g of tetraethoxysilane (hereinafter also referred to as "TEOS") was added to this aqueous phase component, and the mixture was emulsified for 10 minutes at room temperature (about 25°C) using a homomixer (HsiangTai Corporation, model: HM-310) set to a rotation speed of 8,500 rpm to obtain an emulsion. The median diameter D of the emulsified droplets at this time was 50 was 1.1 μm. The pH of the resulting emulsion was then adjusted to 3.8 using a 0.1 N aqueous sodium hydroxide solution, and the emulsion was then transferred to a separable flask equipped with a stirring blade and a cooler. The liquid was stirred at 200 rpm for 24 hours while maintaining the liquid temperature at 30°C, yielding an aqueous dispersion containing microcapsules having a core and a first shell made of model fragrance A. Next, 2.7 g of TEOS was added dropwise to 90.0 g of the obtained aqueous dispersion over 420 minutes. After the addition, stirring was continued for another 17 hours, and then the mixture was cooled to form a second shell encapsulating the first shell, thereby obtaining an aqueous dispersion containing 20.8 mass% of silica capsules (A-1) in which the model fragrance A was encapsulated in amorphous silica. The median diameter D of the silica capsules (A-1) was 1.0 mm. 50 The content of the silica capsules (A-1) in the water dispersion was a calculated value based on the composition at the time of synthesizing the silica capsules.

[0069] Synthesis Example 1-2 0.60g of Coatamin 60W was diluted with 89.14g of ion-exchanged water to obtain an aqueous phase component. An oil phase component prepared by mixing 24g of model fragrance A and 6g of TEOS was added to this aqueous phase component, and the mixture was emulsified for 10 minutes at room temperature (about 25°C) using a homomixer (HsiangTai Co., Ltd., model: HM-310) set at a rotation speed of 8,000 rpm to obtain an emulsion. The median diameter D of the emulsion droplets at this time was 50 was 0.8 μm. The pH of the resulting emulsion was then adjusted to 3.7 using a 1% by weight aqueous sulfuric acid solution, and the emulsion was transferred to a separable flask equipped with a stirring blade and a cooler. The liquid was stirred at 200 rpm for 24 hours while maintaining the liquid temperature at 30°C, to obtain an aqueous dispersion containing 21.4% by weight of silica capsules (A-2) having a core and shell made of model fragrance A. The median diameter D of the silica capsules (A-2) was 50 The content of the silica capsules (A-2) in the aqueous dispersion was a calculated value based on the composition at the time of synthesis of the silica capsules.

[0070] (Synthesis of quaternary ammonium salt compounds) Synthesis Example 2-1 A higher fatty acid having the following composition was subjected to a dehydration esterification reaction with triethanolamine in a ratio of 1.87 moles of higher fatty acid to 1 mole of triethanolamine to obtain an esterification reaction product containing a triethanolamine higher fatty acid ester, which is a precursor of the quaternary ammonium salt compound represented by the general formula (1). The resulting esterification reaction product contained 1 mass % of unreacted fatty acid. The triethanolamine higher fatty acid in the esterification reaction product ester A quaternization reaction was carried out using 0.96 equivalents of dimethyl sulfate per equivalent of the amino group of the above, and after obtaining a quaternized reaction product, a small amount of ethanol was added. (Composition of higher fatty acids) Oleic acid: 80% by weight Linoleic acid: 10% by weight Linolenic acid: 2% by weight Stearic acid: 2% by weight Palmitic acid: 6% by weight The higher fatty acid composition was calculated by analyzing the composition of the higher fatty acids used as the raw material by gas chromatography, and regarding the area percentage of each fatty acid as mass percentage.

[0071] The composition ratio of each component in the resulting quaternary reaction product was analyzed by HPLC, and tetraoctylammonium bromide was used as an internal standard substance to perform quantification. As a result, it was confirmed that the resulting quaternary reaction product contained 66% by mass of quaternary ammonium salt compound (B-1), 15% by mass of ethanol, 17% by mass of unreacted amine salt (as methyl sulfate salt), 1% by mass of unreacted higher fatty acid, a trace amount of triethanolamine quaternary product, and other trace components. In the following general formula (1), R 1 is an acyl group, and R 2 and R 3 is a hydrogen atom, and R 4 is a methyl group, and X - The component (b1-1) in which R is a methyl sulfate ion is present in the quaternary ammonium salt compound (B-1) at 22% by mass, 1 and R 2 is an acyl group, and R 3 is a hydrogen atom, and R 4 is a methyl group, and X - The component (b2-1) in which R is a methyl sulfate ion is 58% by mass in the quaternary ammonium salt compound component (B-1), 1 , R 2 and R3 is an acyl group, and R 4 is a methyl group, and X - The amount of the component (b3-1), which is a methyl sulfate ion, in the quaternary ammonium salt compound component (B-1) was 20 mass %.

[0072] [ka] (In general formula (1), R 1 ,R 2 ,R 3 , and R 4 is the same as above.)

[0073] Synthesis Example 2-2 A higher fatty acid having the following composition was subjected to a dehydration esterification reaction with triethanolamine in a ratio of 1.65 moles of higher fatty acid to 1 mole of triethanolamine to obtain an esterification reaction product containing a triethanolamine higher fatty acid ester, which is a precursor of the quaternary ammonium salt compound represented by the general formula (1). The resulting esterification reaction product contained 5 mass % of unreacted fatty acid. The triethanolamine higher fatty acid in the esterification reaction product ester The quaternization reaction was carried out using 0.96 equivalents of dimethyl sulfate per equivalent of the amino group of the above, and after obtaining the quaternized reaction product, a small amount of ethanol was added. (Composition of higher fatty acids) Palmitic acid: 45% by weight Stearic acid: 25% by weight Oleic acid: 27% by weight Linoleic acid: 3% by weight The higher fatty acid composition was calculated by analyzing the composition of the higher fatty acids used as the raw material by gas chromatography, and regarding the area percentage of each fatty acid as mass percentage.

[0074] The composition ratio of each component in the resulting quaternary reaction product was analyzed by HPLC, and tetraoctylammonium bromide was used as an internal standard substance to determine the amount of the quaternary ammonium salt compound (B-2) in the resulting quaternary reaction product. Among these, in the general formula (1), R 1 is an acyl group, and R 2 and R 3 is a hydrogen atom, and R 4 is a methyl group, and X - The component (b1-2) in which R is a methyl sulfate ion is present in the quaternary ammonium salt compound (B-2) at 23% by mass. 1 and R 2 is an acyl group, and R 3 is a hydrogen atom, and R 4 is a methyl group, and X - The component (b2-2) in which R is a methyl sulfate ion is 49% by mass in the quaternary ammonium salt compound (B-2), 1 , R 2 and R 3 is an acyl group, and R 4 is a methyl group, and X - The (b3-2) component, which is a methyl sulfate ion, accounted for 14 mass % of the quaternary ammonium salt compound (B-2).

[0075] (Production of microcapsule aqueous dispersion) Examples 1 to 6, 8 and Comparative Examples 1 to 11 A microcapsule aqueous dispersion was prepared by mixing component (A) and component (B) as a microcapsule dispersant at 20 to 25° C. so as to obtain the composition shown in Table 2 below. The content of the encapsulated model fragrance A was adjusted to be 13 to 19% by mass. In Comparative Example 1, the component (B) was not added, and the aqueous dispersion containing the silica capsules (A-1) obtained in Synthesis Example 1-1 was used as it was for the evaluation of dispersion stability. In Comparative Example 11, the component (B) was not added, and the aqueous dispersion containing the silica capsules (A-2) obtained in Synthesis Example 1-2 was used as it was for the evaluation of dispersion stability. In Comparative Examples 2 to 5, the polymer dispersant shown in Table 2 was added as the component (B), but since the silica capsules aggregated immediately after the preparation of the aqueous dispersion, the dispersion stability was not evaluated thereafter.

[0076] The polymer dispersants used in the comparative examples in Table 2 are shown below. Hydroxyethyl cellulose: Natrosol 250HHR aqueous solution (active content 1%) (Ashland) Cetyl hydroxycellulose: Polysurf 67 aqueous solution (active content 1%) (Aqualon Group, Hercules Inc.) Polyvinylpyrrolidone: PVP K-30 aqueous solution (active content 30%) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) N-Dimethylaminoethyl methacrylic acid copolymer diethyl sulfate: HC polymer 2 aqueous solution (active content 1%) (Osaka Organic Chemical Industry Ltd.) Polyethylene glycol: PEG13000 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Carboxyvinyl polymer: Carbopol 980 (manufactured by Lubrizol) Polydimethylmethylene piperidinium chloride: Merquat 100 (active content 42%) (manufactured by Lubrizol Japan, Ltd.) Dimethyldiallylammonium chloride / acrylamide copolymer: Mercoat 550 (effective content 9%) (manufactured by Lubrizol Japan, Ltd.)

[0077] Example 7 Synthesis Example 1 -15 g of the aqueous dispersion containing silica capsules (A-1) obtained in 1 was heated to 60° C. and stirred, while 0.28 g of the aqueous dispersion containing quaternary ammonium salt compound (B-2) obtained in Synthesis Example 2-2, which had also been heated to 60° C., was added. By allowing to cool, a microcapsule aqueous dispersion containing 19.7% by mass of component (A) and 4.6% by mass of component (B) was obtained.

[0078] [Evaluation of Viscosity of Microcapsule Aqueous Dispersion] The viscosities at 25°C of the microcapsule aqueous dispersions obtained in Examples 2, 5, and Comparative Example 1 were measured to be 15.7 mPa s, 24.0 mPa s, and 9.8 mPa s, respectively, indicating that all of the aqueous dispersions had very high fluidity.

[0079] [Evaluation of Dispersion Stability of Microcapsules] The aqueous microcapsule dispersions obtained in the examples and comparative examples were stored at room temperature and at 40°C, and the dispersion stability of the silica capsules in the aqueous dispersions was evaluated by observing whether or not the silica capsules gelled, aggregated, floated, or settled. Table 2 shows the number of days during which no gelling, aggregation, floatation, or settlement of the silica capsules was observed.

[0080] [Table 2]

[0081] From Table 2, it can be seen that the microcapsule aqueous dispersions of the Examples have higher dispersion stability than those of the Comparative Examples because they contain a specific quaternary ammonium salt compound. The Comparative Examples contain various polymer dispersants used as thickeners, but do not provide good dispersion stability. Therefore, according to the present invention, the dispersion stability of the microcapsule aqueous dispersion can be improved, and in the case where a synthetic polymer is not used as a thickener, the burden on the environment can be reduced when the microcapsule aqueous dispersion is subsequently applied to various liquid compositions or when the microcapsule aqueous dispersion is disposed of.

[0082] [Evaluation of retention of fragrance components at high temperatures] The microcapsule aqueous dispersions prepared in Example 5 and Comparative Example 1 were filled into screw tubes and then allowed to stand at 50° C. After being left to stand for 8 hours and 32 hours, 20 mg of the microcapsule aqueous dispersions were scooped out and precisely weighed, diluted with 50 g of ion-exchanged water, and then passed through a membrane filter (manufactured by Millipore Corp., product name "Omnipore", model number "JAWP04700") to recover silica capsules on the membrane filter. Furthermore, after washing the silica capsules on the membrane filter with 10 mL of ion-exchanged water and then with 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, and ultrasonic irradiation was performed for 60 minutes using an ultrasonic irradiation device (manufactured by Branson, model "5510") under conditions of an output of 180 W and an oscillation frequency of 42 kHz to elute the fragrance in the silica capsules. This solution was passed through a membrane filter (manufactured by Toyo Roshi Kaisha, Ltd., product name "DISMIC", model "13JP020AN") again, and each fragrance component contained in this solution was measured using gas chromatography, and the amount of fragrance component encapsulated in the silica capsule was determined as α. In addition, 20 mg of the microcapsule aqueous dispersions prepared in Example 5 and Comparative Example 1 before storage at 50°C were weighed out and immersed in 10 mL of methanol, and ultrasonic waves were irradiated for 60 minutes using an ultrasonic irradiation device under conditions of an output of 180 W and an oscillation frequency of 42 kHz to elute the fragrance in the silica capsules. After passing this solution through a membrane filter (manufactured by Toyo Roshi Kaisha, Ltd., product name "DISMIC", model number "13JP020AN"), each fragrance component contained in this solution was measured using gas chromatography, and the amount β of the fragrance component contained in the microcapsule aqueous dispersion was determined. Linalool and tetrahydrolinalool contained in model fragrance A were combined to determine the linalool content, and the retention rate of the linalool content was measured according to the following formula. The evaluation results are shown in Table 3 below. Linalool retention rate (%) = {(amount of linalool contained in silica capsule after storage α) / (amount of linalool contained in microcapsule aqueous dispersion β)} × 100

[0083] [Table 3]

[0084] From Table 3, it can be seen that the microcapsule aqueous dispersions of the Examples are superior in terms of retention of the encapsulated fragrance components at high temperatures compared to those of the Comparative Examples. [Industrial Applicability]

[0085] The microcapsule aqueous dispersion of the present invention can be stored in a state where the dispersion stability of the microcapsules is well maintained. Therefore, the microcapsule aqueous dispersion of the present invention is easy to handle and can be widely used in various products such as laundry products, personal care products, cosmetics, and household liquid products, for imparting various functions, including fragrance, without thickening due to gelation or aggregation. In addition, the (B) component used in the aqueous dispersion can improve the dispersion stability of the microcapsules, and is therefore particularly useful as a dispersant for microcapsules.

Claims

1. Contains the following components (A) and (B), A microcapsule aqueous dispersion in which the mass ratio of the content of the component (A) to the content of the component (B) [component (A) / component (B)] is 3 or more and 20 or less. Component (A): A microcapsule having a shell and a core containing one or more organic compounds inside the shell. Component (B): A surfactant containing a quaternary ammonium salt compound represented by the following general formula (1): 【Chemistry 1】 (In general formula (1), R 1 , R 2 , R 3 each independently represents an acyl group derived from a fatty acid having from 12 to 30 carbon atoms, or a hydrogen atom; R 4 is an alkyl group having 1 to 3 carbon atoms; - is an anion. 1 , R 2 , R 3 At least one of the groups is an acyl group derived from a fatty acid having 12 to 30 carbon atoms.

2. The microcapsule aqueous dispersion according to claim 1 , wherein the quaternary ammonium salt compound is liquid in the range of 10° C. or higher and 40° C. or lower.

3. 3. The microcapsule aqueous dispersion according to claim 1, 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 any one of claims 1 to 3, wherein the proportion of acyl groups derived from oleic acid in all acyl groups constituting the quaternary ammonium salt compound is 50 mass% or more.

5. The microcapsule aqueous dispersion according to any one of claims 1 to 4, wherein the content of the component (B) in the microcapsule aqueous dispersion is 10 mass% or less.

6. The microcapsule aqueous dispersion according to any one of claims 1 to 5, wherein the content of the component (A) in the microcapsule aqueous dispersion is 5% by mass or more and 50% by mass or less.

7. The microcapsule aqueous dispersion according to any one of claims 1 to 6, 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.

8. The microcapsule aqueous dispersion according to any one of claims 1 to 7, wherein the viscosity of the microcapsule aqueous dispersion at 25°C is 1 mPa·s or more and 500 mPa·s or less.

9. The component (A) is a microcapsule having a shell containing silica as a constituent component and a core containing one or more organic compounds inside the shell. The microcapsule aqueous dispersion according to any one of claims 1 to 8.

10. The median diameter D of the microcapsules of the component (A) 50 The microcapsule aqueous dispersion according to any one of claims 1 to 9, wherein the average particle size is 0.1 µm or more and 50 µm or less.

11. The microcapsule aqueous dispersion according to any one of claims 1 to 10, wherein the organic compound is at least one selected from the group consisting of fragrances, fragrance precursors, oils, antioxidants, and solvents.

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