WO2020194910A1

WO2020194910A1 - Microcapsules, microcapsule composition, softener, and detergent

Info

Publication number: WO2020194910A1
Application number: PCT/JP2019/048975
Authority: WO
Inventors: 加藤　進也; 田中　智史; 優樹中川
Original assignee: 富士フイルム株式会社
Priority date: 2019-03-28
Filing date: 2019-12-13
Publication date: 2020-10-01

Abstract

Microcapsules each comprising a core and a shell with which the core has been enclosed, wherein the shell has a covalent crosslinked structure derived from a reaction between a polysaccharide and a crosslinking agent and has a thickness less than 2 μm.

Description

Microcapsules, microcapsule compositions, fabric softeners and detergents

The present disclosure relates to microcapsules, microcapsule compositions, fabric softeners, and detergents.

In recent years, microcapsules have the property of being able to contain and protect functional materials such as fragrances, dyes, heat storage materials, and pharmaceutical ingredients, or having the property of releasing functional materials in response to external stimuli. For this reason, it is attracting attention as it has the potential to create new value.

In the form of containing the fragrance in the microcapsules, for example, by mixing the microcapsules containing the fragrance (hereinafter, also referred to as the fragrance capsule) with the softener, the fragrance can be given to the clothes after washing. That is, when clothes are washed with a softener, the fragrance capsules contained in the softener adhere to the clothes, and when the attached fragrance capsules are destroyed by an external stimulus such as pressure, the contained fragrance is released. , Can produce a fragrance. In recent years, shell materials used in perfume capsules are mainly composed of reaction products of aldehydes and amines (for example, melamine formaldehyde resin).

However, recently, from the viewpoint of environment and safety to the human body, it is being considered to use biological materials instead of petroleum-based raw materials. The materials used for the production of microcapsules are no exception, and there is an increasing demand for the use of biological substances instead of petroleum-based raw materials for the formation of shells (so-called capsule walls) in the form of microcapsules.

For example, as a method for producing microcapsules using a plant-derived material, a method for producing microcapsules using a fragrance as a core material and a polysaccharide (for example, hydroxypropylmethyl cellulose) and dextrin as a material used for forming a shell is disclosed. (For example, see JP-A-2017-176907).
Also disclosed is a core / multi-layer shell capsule system with multi-layer microcapsules comprising an outer shell formed by adding glutaraldehyde to gelatin as an outer shell material and an inner shell formed of polyurea (eg,). See Patent No. 6250055).
Further, a microcapsule having a microcapsule wall membrane containing hydroxypropyl cellulose bridge-bonded with an oil-soluble polyfunctional isocyanate is disclosed (see, for example, Japanese Patent Application Laid-Open No. 54-426).
In addition to the above, an aqueous composition containing a water-soluble polymer substance such as hydroxypropylmethylcellulose is added to a water-insoluble organic medium to emulsify and disperse the aqueous phase in the oil phase, and an aromatic polyisocyanate is added thereto to form a capsule. (For example, see JP-A-2-293401).

As described above, various techniques for producing microcapsules using materials derived from plants or animals have been studied, but especially in the coexistence of polar substances, the barrier of the shell portion containing the inclusions forming the core portion. There is a problem that the function is deteriorated and the inclusion cannot be stably held in the shell portion. To solve this problem, it is desirable that the shell portion of the microcapsules has a thick film, but if the shell portion has a thickness of 2 μm or more, the release property of the inclusions tends to be impaired. ..
Japanese Patent Application Laid-Open No. 2017-176907, Japanese Patent No. 6250055, Japanese Patent Application Laid-Open No. 54-426, and Japanese Patent Application Laid-Open No. 2-29341 do not disclose the case where the shell portion is a thin film of less than 2 μm. It is not even planned to balance the morphological stability of microcapsules (eg, storage stability) with the release of inclusions in the presence of polar substances. Therefore, in the inventions described in Japanese Patent Application Laid-Open No. 2017-176907, Japanese Patent No. 6250055, Japanese Patent Application Laid-Open No. 54-426, and Japanese Patent Application Laid-Open No. 2-293401, the microcapsules containing the desired inclusions are used. In the usage mode where application is desired, it is difficult to use in an environment where polar substances coexist, and the expected effect of use cannot always be expected.

The present disclosure has been made in view of the above.
According to one embodiment of the present disclosure, microcapsules having an excellent storage stability in the coexistence of polar substances are provided while the shell portion is made into a thin film.
According to another embodiment of the present disclosure, there is provided a microcapsule composition in which the core material contained in the shell portion is stably held in the shell portion, and a softener and a detergent.

The present disclosure includes the following aspects.
<1> A core portion and a shell portion containing the core portion are included, and the shell portion has a covalently bonded cross-linked structure derived from the reaction of a polysaccharide and a cross-linking agent, and has a thickness of less than 2 μm. It is a microcapsule.
<2> The microcapsule according to <1>, wherein the cross-linking agent is at least one isocyanate compound selected from a trifunctional or higher functional aliphatic isocyanate compound and a bifunctional aliphatic isocyanate compound.
<3> The microcapsule according to <1> or <2>, wherein the polysaccharide is at least one selected from the group consisting of a cellulose compound, dextrin, gum arabic, gum arabic, and guar gum.
<4> The microcapsule according to any one of <1> to <3>, wherein the polysaccharide contains at least one selected from the group consisting of hydroxypropyl cellulose and hydroxypropyl methyl cellulose.

<5> The microcapsule according to any one of <1> to <4>, wherein the shell portion further contains a polyphenol compound.
<6> The microcapsules according to <5>, wherein the content of the polyphenol compound is 5% by mass or more with respect to the total mass of the shell portion.
<7> The microcapsule according to any one of <1> to <6>, wherein the content ratio of the structural portion derived from the cross-linking agent is 4% by mass or more with respect to the total mass of the shell portion.
<8> A microcapsule composition containing the microcapsule according to any one of <1> to <7> and a solvent.
<9> A softener containing the microcapsules according to any one of <1> to <7>.
<10> A detergent containing the microcapsules according to any one of <1> to <7>.

According to one embodiment of the present invention, microcapsules having an excellent storage stability in the coexistence of polar substances are provided while the shell portion is made into a thin film.
According to another embodiment of the present invention, there is provided a microcapsule composition in which the core material contained in the shell portion is stably held in the shell, and a softener and a detergent.

Hereinafter, the microcapsules of the present disclosure, microcapsule compositions using the same, and softeners and detergents will be described in detail.
The description of the constituent elements relating to the embodiments of the present disclosure may be based on the typical embodiments of the present disclosure, but the present disclosure is not limited to such embodiments.

In the present specification, the numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.

Further, in the present disclosure, the amount of each component in the composition or layer is the amount of the above-mentioned plurality of substances existing in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means the total amount.
In the present disclosure, "% by mass" is synonymous with "% by weight" and "parts by weight" is synonymous with "parts by weight".
Further, in the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.

In the present specification, the "shell portion" refers to the outer shell forming the particles of the microcapsules, and refers to the so-called capsule wall. Further, the "core portion" is also referred to as a "core portion" and refers to a portion included by the shell portion.
In the present specification, the material for forming the shell portion is referred to as "shell material" or "wall material", and the component contained in the core portion is referred to as "core material" or "inclusion".
Further, in the present disclosure, the “inclusion” refers to a state in which a target object (that is, an inclusion) is covered with a shell portion of a microcapsule and confined.

<Microcapsules>
The microcapsules of the present disclosure have a structure including a core portion and a shell portion containing the core portion, and the shell portion has a covalently bonded cross-linked structure derived from the reaction between the polysaccharide and the cross-linking agent. It has and has a thickness of less than 2 μm.

The microcapsules of the present disclosure have a covalently cross-linked structure in which the shell portion of the microcapsules is derived from the reaction between a polysaccharide and a cross-linking agent, so that even a thin film having a thickness of less than 2 μm is polar. The core material (inclusion) forming the core portion can be stably held in the shell portion in a usage environment coexisting with a substance, and the storage stability is excellent.

The reason why the microcapsules of the present disclosure exert the above-mentioned effects is not always clear, but it is presumed as follows.
Conventionally, various techniques for producing microcapsules using materials derived from plants or animals have been studied. However, in the inventions described in JP-A-2017-176907, Patent No. 6250055, JP-A-54-426 and JP-A-2-293401, all of them are used in an environment where polar substances can coexist. Then, the barrier function for holding the core material (that is, the inclusion) that forms the core part contained in the shell of the microcapsule is lowered, and the core material cannot be stably held in the shell. is there. Such a situation becomes more remarkable as the thickness of the shell (that is, the thickness of the capsule wall) becomes thinner, and it becomes difficult to secure the barrier function when the thickness is set to, for example, less than 2 μm according to a desired purpose.
For example, fabric softeners or laundry detergents often contain polar substances such as cationic surfactants or anionic surfactants. For example, when microcapsules containing fragrance are mixed with a softener or laundry detergent, it is presumed that the polarity of the surfactant affects the ionic bonding of the shell of the microcapsules. As a result, it is considered that the shape of the capsule cannot be stably maintained.
In the present disclosure, a covalent cross-linking structure derived from the reaction between a polysaccharide and a cross-linking agent is introduced into the shell portion while making the thickness of the shell portion less than 2 μm. That is, a cross-linking agent is introduced into the polymer in the shell to form a covalent bond between the polymer and the cross-linking agent, and a covalent cross-linking structure is introduced. As a result, in a usage mode applied to an environment in which a polar substance is present, stability can be ensured even in a microcapsule having a structure in which the thickness (wall thickness) of the shell portion is thin (<2 μm), and the core material is stably in the shell portion. Microcapsules encapsulated in can be provided. That is, in the microcapsules of the present disclosure, the shell portion is thinned and the shape of the capsule is stabilized.

In the following, the shell part that forms the microcapsule will be described first, and then the core part will be described.

(Shell part)
The microcapsules of the present disclosure include a core material forming a core portion and have a shell portion which is an outer shell for forming capsule particles.
The shell portion in the present disclosure may contain a polymer such as polyurethane, polyurea, polyester, or polyether as the shell material forming the shell portion.

-Covalent bridge structure-
The shell portion has a covalently bonded cross-linked structure derived from the reaction between the polysaccharide and the cross-linking agent.
The shell portion is polymerized by the reaction between the plurality of hydroxyl groups of the polysaccharide and the plurality of crosslinkable groups having reactivity with the hydroxyl groups in the crosslinking agent, and a covalently bonded crosslinked structure is formed. It can be obtained by.
Examples of the crosslinkable group include an isocyanate group, a carboxy group, and an epoxy group.
As the covalently bonded crosslinked structure, a crosslinked structure by a urethane bond, a crosslinked structure by an ester bond, and a crosslinked structure by an ether bond are preferable structures.

The crosslinked structure by urethane bond is a structure formed by the reaction of a polysaccharide and an isocyanate compound.
The crosslinked structure by the ester bond is a structure formed by the reaction of the polysaccharide and the carboxylic acid halide (preferably acid chloride).
The crosslinked structure by the ether bond is a structure formed by the reaction of the polysaccharide and the epoxy compound.
Among the above, the core material (for example,) which is excellent in storage stability even in the coexistence of a polar ionic surfactant, maintains the shape of the capsule stably, and is subjected to an external force (for example, scraping). In terms of good release property (for example, fragrance intensity when fragrance is contained), an embodiment having a crosslinked structure by urethane bond is preferable, and it is also referred to as a polyfunctional isocyanate compound (hereinafter, also referred to as "polyisocyanate"). ) Is more preferable. That is, when the shell material in the present disclosure contains polyurethane or polyurea, it is preferably obtained by using polyisocyanate from the viewpoint of storage stability.

Confirmation that the shell portion of the microcapsule has a covalently bonded crosslinked structure can be performed by the following method.
First, the prepared microcapsule aqueous dispersion is centrifuged to separate the microcapsules from the solution. The separated microcapsules are added to dimethyl sulfoxide (DMSO) (1% by mass to 5% by mass based on DMSO) to prepare a DMSO mixture. Then, when the DMSO mixture containing the microcapsules becomes opaque or the swelling of the microcapsules can be confirmed, it is determined that the shell of the microcapsules has a crosslinked structure. When the microcapsules are dissolved and the DMSO mixture becomes transparent, it is assumed that the shell of the microcapsules does not have a crosslinked structure. Confirmation that the DMSO mixture is opaque is visually confirmed, and confirmation that the microcapsules are swollen is performed by observation with an optical microscope.
By the above method, it is also determined that the crosslinked structure is covalent.

Further, the thickness of the shell portion in the present disclosure is less than 2 μm.
The microcapsules of the present disclosure can stably maintain the shape of the capsule even if the thickness of the shell portion is less than 2 μm, and are excellent in storage stability. As a result, when an external force such as scratching is applied, it is possible to stably release the amount of core material planned from the intended stage.
The thickness (wall thickness) of the shell portion (wall) is preferably 1.5 μm or less, more preferably 1.0 μm or less, and further preferably 0.5 μm or less. Further, since the microcapsules in the present disclosure have a crosslinked structure and easily retain their shape, the lower limit of the thickness of the shell portion may be appropriately selected within a manufacturable range, and may be, for example, 0.1 μm.

The thickness (wall thickness) of the shell portion (wall) is an average value obtained by calculating the individual wall thickness (μm) of the five microcapsules with a scanning electron microscope (SEM) and averaging them.
Specifically, the microcapsule solution is applied onto an arbitrary support and dried to form a coating film. A cross-sectional section of the obtained coating film is prepared, and the cross section is observed using an SEM. Arbitrary 5 microcapsules are selected, the cross sections of the individual microcapsules are observed, the wall thickness is measured, and the average value is calculated.

-Polysaccharide-
The polysaccharides in the present disclosure are, for example, a group consisting of mannan, glucan, glucomannan, xyloglucan, cellulose compounds, dextrin, dextran, arabic gum, kitansan gum, guar gum, galactomannan, carrageenan, pectin, alginic acid, chitosan and mixtures thereof. You can choose more.
Gelatin is not included in the polysaccharides in the present disclosure.

Examples of the cellulose compound include hydroxyalkyl cellulose and carboxyalkyl cellulose.
The hydroxyalkyl cellulose preferably has 1 to 8 carbon atoms at the alkyl moiety, and more preferably 1 to 4 carbon atoms at the alkyl moiety. Examples of hydroxyalkyl cellulose include hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), and hydroxypropyl methylcellulose (HPMC).
The carboxyalkyl cellulose preferably has 1 to 4 carbon atoms at the alkyl moiety, and more preferably 1 to 2 carbon atoms at the alkyl moiety. Examples of carboxyalkyl cellulose include carboxymethyl cellulose (CMC).

Of the above, the preferred polysaccharide is at least one selected from the group consisting of cellulose compounds, dextrins, gum arabic, gum arabic, and guar gum in that the morphology of the capsule can be stably maintained and the storage stability is excellent. The polysaccharide is more preferably a cellulose compound, and even more preferably at least one selected from the group consisting of hydroxypropyl cellulose and hydroxypropyl methyl cellulose.

The shell portion in the present disclosure may be one using two or more kinds of polysaccharides. The shell portion includes, as two or more kinds of polysaccharides, a polysaccharide having a linear structure and a polysaccharide having a branched structure, in that it is easy to maintain the morphology of the capsule more stably and to enhance the storage stability. It may be a combination mode.

The polysaccharide having a linear structure is preferably a cellulose compound.
The polysaccharide having a branched structure is preferably dextrin, gum arabic, kitansan gum, or guar gum.
In the present disclosure, a more preferred polysaccharide is a combination of two or more polysaccharides, including at least one of the cellulose compounds and at least one selected from the group consisting of dextrin, gum arabic, kitansan gum, and guar gum. A more preferred polysaccharide is a combination of at least one cellulose compound and two or more polysaccharides, including dextrin.

In the embodiment in which at least one of the cellulose compounds and two or more kinds of polysaccharides including dextrin are used as the polysaccharide, the ratio of the total amount of the cellulose compounds to the amount of dextrin (cellulose compound: dextrin) is 10: 80 to 20:50 is preferable.

The content ratio of the structural portion derived from the polysaccharide in the shell portion is preferably 50% by mass to 95% by mass, more preferably 70% by mass to 95% by mass, and 80% by mass from the viewpoint of fracture strength and fracture deformation rate. -90% by mass is more preferable.
The "structural portion derived from a polysaccharide" refers to a structural unit formed by reacting a polysaccharide with a cross-linking agent.

-Crosslinking agent-
Examples of the cross-linking agent in the present disclosure include isocyanate compounds, carboxylic acid halides, epoxy compounds, and acid anhydrides. When the cross-linking agent reacts with the polysaccharide, a polymer having a cross-linked structure can be obtained as a shell material.

[Isocyanate compound]
The isocyanate compound in the present disclosure is preferably a polyfunctional isocyanate compound (polyisocyanate) from the viewpoint of forming a crosslinked structure.
Polyisocyanates include aromatic polyisocyanates and aliphatic polyisocyanates. As the polyisocyanate, either a bifunctional polyisocyanate or a trifunctional or higher functional polyisocyanate may be used.
Further, the polyurethane or polyurea in the present disclosure may include polyurethane polyurea.

The polyurethane and polyurea in the present disclosure are preferably polymers having a structural portion derived from an aromatic polyisocyanate and a structural portion derived from an aliphatic polyisocyanate. The "structural portion" refers to a structural unit formed by a urethane reaction or a urea reaction.

-2-Functional isocyanate compound-
When the shell material forming the shell portion is polyurethane or polyurea, it is preferable to have a structural portion derived from a bifunctional isocyanate compound. That is, polyurethane or polyurea, which is a shell material forming the shell portion, has at least one structural portion selected from a structural portion derived from a bifunctional aliphatic isocyanate compound and a structural portion derived from a bifunctional aromatic isocyanate compound. It is preferable to have.
The structural portion derived from the bifunctional aliphatic isocyanate compound refers to a structural portion formed by urethanizing or ureaizing the bifunctional aliphatic isocyanate compound.
The structural portion derived from the bifunctional aromatic isocyanate compound refers to the structural portion formed by urethanizing or ureaizing the bifunctional aromatic isocyanate compound.

Examples of the bifunctional aliphatic isocyanate compound include trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, cyclohexylene-1,2-diisocyanate, and cyclohexylene-1, 3-Diisocyanate, cyclohexylene-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,4-bis (isocyanatemethyl) cyclohexane and 1,3-bis (isocyanatemethyl) cyclohexane, isophorone diisocyanate, and lysine Examples thereof include diisocyanate and hydride xylylene diisocyanate.

Examples of the bifunctional aromatic isocyanate compound include m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, naphthalene-1,4-diisocyanate, and methylene diphenyl-4. , 4'-diisocyanate, 3,3'-dimethoxy-biphenyldiisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, 4-chloro Examples thereof include xylylene-1,3-diisocyanate, 2-methylxylylene-1,3-diisocyanate, 4,4′-diphenylpropanediisocyanate, and 4,4′-diphenylhexafluoropropanediisocyanate.

Isocyanate compounds are described in the "Polyurethane Resin Handbook" (edited by Keiji Iwata, published by Nikkan Kogyo Shimbun (1987)).

The total mass of the shell material of at least one structure selected from a structure derived from a bifunctional isocyanate compound, that is, a structure derived from a bifunctional aliphatic isocyanate compound and a structure derived from a bifunctional aromatic isocyanate compound. The proportion of the total mass is preferably 0.1% by mass to 5% by mass, more preferably 0.5% by mass to 3% by mass, and 0.5% by mass to 1.5% by mass. It is more preferably%.
When the proportion of the structure derived from the bifunctional isocyanate compound is 0.1% by mass or more, a portion having a short distance between the cross-linking points is partially present in the shell. Therefore, it is presumed that there is a portion in the shell that is vulnerable to strain against pressure and easily cracked when pressure is applied, and the fracture deformation rate can be further reduced. Further, when the proportion of the structure derived from the bifunctional isocyanate compound is 5% by mass or less, the same effect as described above can be obtained satisfactorily.

-3 Functional or higher functional isocyanate compounds-
When the shell material forming the shell portion is polyurethane or polyurea, it is preferable to have a structural portion derived from a trifunctional or higher functional isocyanate compound. By having a structural portion derived from a trifunctional or higher functional isocyanate compound, the crosslink density can be increased and the flexibility of the shell portion can be increased.
The structural portion derived from a trifunctional or higher functional isocyanate compound refers to a structural portion formed by urethanizing or ureaizing a trifunctional or higher functional isocyanate compound.

Examples of the trifunctional or higher functional aliphatic isocyanate compound include a bifunctional aliphatic isocyanate compound (a compound having two isocyanate groups in the molecule) and a compound having three or more active hydrogen groups in the molecule (for example, trifunctional or higher). Polyisocyanate compound (adduct type) having trifunctional or higher functionality as an adduct compound (additive) with the polyol of trifunctional or higher functional polyamine or trifunctional or higher functional polythiol), and trimeric of difunctional aliphatic isocyanate compound (trimeric). Biuret type or isocyanurate type) can be mentioned.

As the adduct-type trifunctional or higher functional isocyanate compound, a commercially available product on the market may be used. Examples of commercially available products include Takenate (registered trademark) D-120N (isocyanate value = 3.5 mmol / g), D-140N, and D-160N (all manufactured by Mitsui Chemicals, Inc.), Sumijour (registered trademark). HT (Bayer Co., Ltd.), Coronate (registered trademark) HL, and HX (Tosoh Co., Ltd.), Duranate P301-75E (Asahi Kasei Co., Ltd.), and Burnock (registered trademark) DN-950 (DIC Corporation) Can be mentioned.
Among them, as the adduct-type trifunctional or higher functional isocyanate compound, the Takenate (registered trademark) series manufactured by Mitsui Chemicals, Inc. (for example, Takenate D-110N, D-120N, D-140N, and D-160N) is more preferable.

As the isocyanurate-type trifunctional or higher functional isocyanate compound, a commercially available product on the market may be used. Examples of commercially available products include Takenate (registered trademark) D-127N, D-170N, D-170HN, D-172N, and D-177N (manufactured by Mitsui Chemicals, Inc.); Sumijour N3300, Death Module (registered trademark). N3600, N3900, and Z4470BA (manufactured by Bayer Co., Ltd.); Coronate (registered trademark) HK (manufactured by Tosoh Corporation); Duranate (registered trademark) TPA-100, and TKA-100 (manufactured by Asahi Kasei Corporation); and Barnock (Registered trademark) DN-980 (manufactured by DIC Co., Ltd.) can be mentioned.

As the biuret-type trifunctional or higher functional isocyanate compound, a commercially available product on the market may be used. Examples of commercially available products include, for example, Takenate (registered trademark) D-165N and NP1200 (manufactured by Mitsui Chemicals, Inc.); Death Module (registered trademark) N3200A (manufactured by Bayer Co., Ltd.); and Duranate (registered trademark) 24A-. 100 and 22A-75P (manufactured by Asahi Kasei Corporation) can be mentioned.

Specific examples of the trifunctional or higher functional aromatic isocyanate compound include 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate or an adduct of hexamethylene diisocyanate and trimethylolpropane (adduct), biuret and isocyanate. Nurate form is mentioned.
Commercially available products marketed as trifunctional or higher functional aromatic isocyanate compounds may be used. Examples of commercially available products include Burnock® D-750 and D-800 (manufactured by DIC Co., Ltd.); Takenate® D-102, D-103, D-103H, D-103M2, D- 110N and Olester® P49-75S (all manufactured by Mitsui Chemicals, Inc.); Death Module® L75, IL-135-BA, and HL-BA; Sumijour® E-21 -1 (manufactured by Bayer Co., Ltd.); and Coronate (registered trademark) L, L-55, and L-55E (manufactured by Tosoh Corporation).

The ratio of the structural portion derived from the trifunctional or higher functional isocyanate compound to the total mass of the shell material is preferably 5% by mass to 30% by mass, more preferably 5% by mass to 20% by mass, and 5% by mass to 10% by mass. % Is more preferable. When the proportion of the structural portion derived from the trifunctional or higher functional isocyanate compound is 5% by mass or more, the shell can be formed satisfactorily. Further, when the proportion of the structural portion derived from the trifunctional or higher functional isocyanate compound is 30% by mass or less, the shell is more easily destroyed by the pressure, and the core material (for example, fragrance) is released (for example, when fragrance is contained). Fragrance intensity) can be improved.

The trifunctional or higher functional isocyanate compound in the present disclosure preferably contains at least one selected from the group consisting of a trifunctional or higher functional aliphatic isocyanate compound and a trifunctional or higher functional aromatic isocyanate compound, and is preferably a trifunctional or higher functional aliphatic isocyanate compound. Is more preferable to be contained alone.

When the trifunctional or higher functional isocyanate compound contains at least one selected from the group consisting of the trifunctional or higher functional aliphatic isocyanate compound and the trifunctional or higher functional aromatic isocyanate compound, it is derived from the trifunctional or higher functional isocyanate compound in the shell material. The ratio of the content of the structural portion derived from the trifunctional or higher functional aromatic isocyanate compound to the total content of the structural portion to be subjected is preferably 0% by mass or more and less than 50% by mass on a mass basis.
When the ratio of the content of the structural portion derived from the trifunctional or higher functional isocyanate compound to the total content of the structural portion derived from the trifunctional or higher functional isocyanate compound in the shell material is within the above range, the fracture deformation occurs. Since the rate can be made smaller, the fragrance intensity is excellent. Further, the ratio of the content of the structural portion derived from the trifunctional or higher functional isocyanate compound to the total content of the structural portion derived from the trifunctional or higher functional isocyanate compound in the shell material is less than 50% by mass on a mass basis. By being present, the strength of the shell can be better maintained.
From the same viewpoint as above, the ratio of the content of the structural portion derived from the trifunctional or higher functional isocyanate compound to the total content of the structural portion derived from the trifunctional or higher functional isocyanate compound in the shell material is based on the mass. It is more preferably 0% by mass to 40% by mass, and further preferably 0% by mass to 20% by mass.

When the trifunctional or higher functional isocyanate compound is a trifunctional or higher functional aliphatic isocyanate compound, the breaking deformation rate and breaking strength are increased, and the core material (for example, fragrance) is released (for example, fragrance intensity when fragrance is contained). From the viewpoint of balancing with the above, the ratio of the content of the structural part derived from the trifunctional or higher aliphatic isocyanate compound to the total content of the structural portion derived from the trifunctional or higher functional isocyanate compound in the shell material is based on the mass. The content is preferably 60% by mass to 100% by mass, more preferably 80% by mass to 100% by mass.

In the microcapsules of the present disclosure, the ratio of the content of the structural portion derived from the bifunctional isocyanate compound to the content of the structural portion derived from the trifunctional or higher functional isocyanate compound in the shell material is 5/95 to 5/95 on a mass basis. It is preferably 20/80.
When the ratio of the content of the structural portion derived from the bifunctional isocyanate compound to the content of the structural portion derived from the trifunctional or higher functional isocyanate compound in the shell material is 5/95 or more on a mass basis, the inside of the shell There are some parts where the distance between the cross-linking points is short. Therefore, it is presumed that there is a portion in the shell that is vulnerable to strain against pressure and easily cracked when pressure is applied, and the fracture deformation rate can be further reduced. As a result, it is possible to improve the release property (for example, fragrance intensity when fragrance is contained) of the core material (for example, fragrance) when an external force (scratch) is applied.
The same as above, when the ratio of the content of the structural portion derived from the bifunctional isocyanate compound to the content of the structural portion derived from the trifunctional or higher functional isocyanate compound in the shell material is 20/80 or less on a mass basis. The effect of is good. In addition, the strength of the shell can be better maintained.
From the above viewpoint, the ratio of the content of the structural portion derived from the bifunctional isocyanate compound to the content of the structural portion derived from the trifunctional or higher functional isocyanate compound in the shell material is 7/93 to 20 / on a mass basis. 80 is preferable, and 10/90 to 20/80 is more preferable.

The isocyanate compound used as a cross-linking agent for the shell portion in the present disclosure is preferably at least one polyisocyanate selected from a trifunctional or higher functional aliphatic isocyanate compound and a bifunctional aliphatic isocyanate compound.

[Epoxy compound]
Epoxy compounds are compounds that have a glycidyl group in the molecule. From the viewpoint of obtaining a polymer having a crosslinked structure as a shell material, the epoxy compound is preferably a compound having two or more glycidyl groups in the molecule.

Examples of the epoxy compound include 4,4'-meirenbis (N, N-diglycidyl aniline), glycerin triglycidyl ether, bisphenol A diglycidyl ether, neopentyl glycol diglycidyl ether, triglycidyl isocyanurate, 4,4. '-(9-Fluorenylidene) bis (1,2-epoxy-3-phenoxypropane), sorbitol polyglycidyl ether (for example, Denacol series manufactured by Nagase ChemteX Corporation (eg Denacol EX-612), pentaerythritol) Polyglycidyl ether (eg, Denacol series manufactured by Nagase ChemteX Corporation (eg Denacol EX-411), and trimethylpropane polyglycidyl ether (eg, Denacol series manufactured by Nagase ChemteX Corporation (eg, Denacol EX)). -321) can be mentioned.
Further, as the epoxy compound, a commercially available product on the market may be used.

[Carboxylic acid halide]
The carboxylic acid halide is a compound represented by R-COX (X: halogen atom). Carboxylic acid halides include carboxylic acid chlorides and carboxylic acid bromides. From the viewpoint of obtaining a polymer having a crosslinked structure as a shell material, the carboxylic acid halide is preferably a compound having two or more -COX groups in the molecule.

Examples of the carboxyl chloride (also referred to as acid chloride) include adipoil chloride, azelaic acid chloride, suberoyl chloride, sebacoil chloride, succinate chloride, 4,4'-biphenyldicarbonyl chloride, and isophthaloyl. Examples thereof include chloride and terephthaloyl chloride.
Further, as the carboxylic acid halide, a commercially available product on the market may be used.

The content ratio of the structural portion derived from the cross-linking agent is preferably in the range of 3% by mass or more with respect to the total mass of the shell portion. The content of the cross-linking agent better retains the morphology of the microcapsules in the presence of polar substances and balances the breaking strength with the release of the core material (eg, the fragrance strength when the core material contains a fragrance). From the viewpoint, 4% by mass or more is more preferable, 4% by mass to 15% by mass is further preferable, and 4% by mass to 10% by mass is particularly preferable.
The “structural portion derived from the cross-linking agent” refers to a structural unit formed by reacting a polysaccharide with a cross-linking agent.

-Polyphenol compound-
The shell portion in the present disclosure preferably further contains a polyphenol compound.
The inclusion of the polyphenol compound in the shell makes it easier to maintain the shape of the capsule better.

Examples of the polyphenol compound include green tea polyphenol (for example, catechin), anthocyanin, cacao polyphenol, rutin, curcumin, ferulic acid, and proanthocyanidin.

Further, as the polyphenol compound, a commercially available product on the market may be used. Examples of commercially available products include the Sunfood (registered trademark) series (eg, Sunfood 100 and Sunfood CD), which are tea extracts from Mitsubishi Chemical Foods Co., Ltd., and the sugar cane extract from Mitsui Sugar Co., Ltd. (eg,). MSX-100 (J)) can be mentioned.

The content of the polyphenol compound is preferably in the range of 3% by mass or more with respect to the total mass of the shell portion. The content of the polyphenol compound is preferably 5% by mass or more, more preferably 6% by mass or more, still more preferably 9% by mass or more, from the viewpoint of facilitating better retention of the morphology of the microcapsules in the presence of a polar substance. ..

In the microcapsules of the present disclosure, the ratio of the components constituting the shell portion to the total mass of the core portion and the components constituting the shell portion is preferably 15% by mass or less.
The ratio of the components constituting the shell portion in the microcapsules to the total mass of the core portion and the components constituting the shell portion is adjusted by the mass ratio of the core material component and the shell material component when manufacturing the microcapsules. be able to.
The shell material forming the shell portion in the present invention preferably has polyurethane or polyurea having a structure derived from polyisocyanate.

The median diameter (D50) of the volume standard of the microcapsules is preferably 0.1 μm to 100 μm.
When the median diameter (D50) is 0.1 μm or more, it is possible to prevent the microcapsules from entering the fine voids and becoming difficult to crack. When the median diameter (D50) is 100 μm or less, deterioration of adhesiveness can be prevented.
From the above viewpoint, the median diameter (D50) of the volume standard of the microcapsules is more preferably 1 μm to 70 μm, and even more preferably 5 μm to 50 μm. The median diameter of the volume standard of microcapsules can be controlled, for example, by changing the dispersion conditions.
Volume of microcapsules The standard median diameter (D50) is the volume of particles on the large diameter side and the small diameter side when the entire microcapsule is divided into two with the particle diameter at which the cumulative volume is 50% as a threshold. The diameter at which the total is equal. The median diameter of the volume standard of microcapsules is measured using Microtrack MT3300EXII (manufactured by Nikkiso Co., Ltd.).

(Core part)
The microcapsules of the present disclosure contain a desired component as a core material in the shell portion described above. The core material is a material forming the core portion contained in the shell portion.

The core material is not particularly limited, and a desired component may be selected, and examples thereof include fragrances, solvents (oil components), phase transition materials (for example, paraffin and liquid crystal materials), and ultraviolet absorbers. Be done.

When the microcapsules contain fragrance as the core material, the fragrance is released from the microcapsules due to rubbing of clothes, rubbing of hair, etc., and the fragrance can be perceived. Since the microcapsules of the present disclosure are excellent in storage stability, it is expected that the expected amount of fragrance will be released.

-Fragrance-
Examples of fragrances include synthetic fragrances, natural essential oils, and natural fragrances described in "Patent Office, Well-known Conventional Technology Collection (Fragrance), Part III, Cosmetic Fragrances, pp. 49-103, published on June 15, 2001". And animal and plant extracts, suitable ones can be appropriately selected and used.
Specific fragrances include pinene, milsen, camphene, monoterpenes (eg R-limonene and D-limonene), sesquitelpen such as sedren, cariophyllene, longifolene, 1,3,5-undecatorien, α- Synthetic fragrances such as amilcinnamylaldehyde, dihydrojasmon, methylionone, α-damascon, acetylsedrene, methyl dihydrojasmonate, cyclopentadecanolide; Can be mentioned.
The content of the fragrance with respect to the total mass of the core material is preferably 20% by mass to 100% by mass, more preferably 30% by mass to 95% by mass, still more preferably 40% by mass to 85% by mass.

-solvent-
The core material may contain a solvent as an oil component.
Examples of the solvent include tri (capryl capric acid) glyceryl (eg, glycerin fatty acid ester such as polyglycerol octacaprate (for example, Saracos (registered trademark) HG-8 manufactured by Nisshin Oillio Group Co., Ltd.), myristic acid. Fatty acid ester compounds such as isopropyl, alkylnaphthalene compounds such as diisopropylnaphthalene, diarylalkane compounds such as 1-phenyl-1-xsilylethane, alkylbiphenyl compounds such as isopropylbiphenyl, triarylmethane compounds, alkylbenzene compounds, Aromatic hydrocarbons such as benzylnaphthalene compounds, diarylalkylene compounds, arylindane compounds; aliphatic hydrocarbons such as dibutylphthalate and isoparaffin; camellia oil, soybean oil, corn oil, cottonseed oil, rapeseed oil, olive oil, palm oil , Natural animal and vegetable oils such as castor oil and fish oil; and high boiling point distillates of natural compounds such as mineral oils.
The content of the solvent in the core material is preferably less than 50% by mass, more preferably 40% by mass or less, still more preferably 30% by mass or less, based on the total mass of the core material.

-Auxiliary solvent-
If necessary, the core material may contain an auxiliary solvent as an oil phase component for increasing the solubility of the wall material in the oil phase during the production of microcapsules. The auxiliary solvent does not include the above solvent. Further, since the viscosity of the oil phase is changed by containing the auxiliary solvent and the degree of shearing in emulsification is changed, the coefficient of variation can be adjusted.
Examples of the auxiliary solvent include a ketone compound such as methyl ethyl ketone, an ester compound such as ethyl acetate, and an alcohol compound such as isopropyl alcohol. Preferably, the co-solvent has a boiling point of 130 ° C. or lower.
The content of the auxiliary solvent in the core material is preferably less than 50% by mass, more preferably less than 30% by mass, still more preferably less than 20% by mass, based on the total mass of the core material.

-Additive-
Additives such as UV absorbers, light stabilizers, antioxidants, waxes, or odor suppressants can be encapsulated in microcapsules, if desired.
The content of the additive can be, for example, 0% by mass to 20% by mass, preferably 1% by mass to 15% by mass, and more preferably 5% by mass to 10% by mass with respect to the total mass of the core material. ..

～ Manufacturing method of microcapsules ～
The microcapsules of the present disclosure can be produced by a known method, for example, by the production method shown below. However, the present disclosure is not limited to the following methods.

The microcapsules of the present disclosure use an oil phase containing a solvent, a cross-linking agent (for example, an isocyanate compound) which is a part of the shell material, and a core material (for example, an inclusion such as a fragrance) in another part of the shell material. A step of preparing an emulsified solution by dispersing in an aqueous phase containing a certain polysaccharide (emulsification step) and a core material forming a shell portion by polymerizing a shell material at the interface between the oil phase and the aqueous phase to form a core portion. It can be produced by a method having a step of forming microcapsules (encapsulation step) containing the above.

It is preferable that the polysaccharide is contained in the aqueous phase in advance and further added after the emulsification step.
By further adding the polysaccharide after the emulsification step, the breaking strength and breaking deformation rate of the microcapsules can be further improved. The polysaccharide further added after the emulsification step may be a polysaccharide of the same type (for example, HPC) as the polysaccharide (for example, HPMC) previously contained in the aqueous phase, or a polysaccharide previously contained in the aqueous phase. It may be a different type of polysaccharide (for example, dextrin that is not cellulosic) from the saccharide (for example, HPMC).

[Emulsification process]
In the emulsification step, the oil phase containing the solvent, the cross-linking agent (eg, isocyanate compound) that is part of the shell material, and optionally the core material (eg, inclusions such as fragrance) is added to the other part of the shell material. An emulsion can be prepared by dispersing in an aqueous phase containing the polysaccharide.
The inclusion of the solvent in the oil phase enhances the monodispersity of the microcapsules.

~ Emulsified liquid ~
The emulsion in the present disclosure can be prepared by dispersing an oil phase containing a solvent and a part of the shell material in an aqueous phase containing another part of the shell material. The above-mentioned polysaccharides are used as another part of the shell material. Since the polysaccharide also functions as an emulsifier, it is not necessary to further include an emulsifier in the aqueous phase in addition to the polysaccharide in the present disclosure, but an emulsifier described later may be further used in addition to the polysaccharide in the present disclosure.

(Oil phase)
The oil phase in the present disclosure contains at least a solvent and a cross-linking agent forming a part of the shell material, and may contain other components such as a fragrance, an auxiliary solvent, and an additive, if necessary. Details of fragrances, co-solvents, and additives are as described in the section on microcapsules described above.

-solvent-
The solvent that can be used in the production method in the present disclosure is as described in the section of microcapsules described above.

-Part of shell material (crosslinking agent)-
A cross-linking agent is included as part of the shell material in the present disclosure. Since the details of the cross-linking agent are as described above, the description thereof is omitted here.
The content of the cross-linking agent in the oil phase is preferably 1% by mass to 20% by mass, more preferably 1% by mass to 10% by mass, based on the total mass of the oil phase.
The concentration of the cross-linking agent can be appropriately adjusted in consideration of the size of the microcapsules, the wall thickness and the like.

(Water phase)
The aqueous phase in the present disclosure contains at least an aqueous solvent and polysaccharides that form another part of the shell material.

-Aqueous medium-
Examples of the aqueous medium of the present disclosure include water and alcohol, and ion-exchanged water can be used.
The content of the aqueous medium in the aqueous phase is preferably 20% by mass to 80% by mass, preferably 30% by mass to 70% by mass, based on the total mass of the emulsion obtained by emulsifying and dispersing the oil phase in the aqueous phase. Is more preferable, and 40% by mass to 60% by mass is further preferable.

-Other parts of shell material (polysaccharides)-
Since the polysaccharides are as described above, the description thereof is omitted here.
As the emulsifier, in addition to the polysaccharide, a dispersant, a surfactant, or a combination thereof may be used.
Examples of the dispersant include polyvinyl alcohol and its modified products (for example, anionic modified polyvinyl alcohol), polyacrylic acid amide and its derivatives, ethylene-vinyl acetate copolymer, styrene-maleic anhydride copolymer, and ethylene-maleic anhydride. Acid copolymers, isobutylene-maleic anhydride copolymers, polyvinylpyrrolidone, ethylene-acrylic acid copolymers, vinyl acetate-acrylic acid copolymers, casein, gelatin, starch derivatives, sodium alginate and the like can be mentioned. , Polyvinyl alcohol is preferable.
It is preferable that the dispersant does not react with the shell material or is extremely difficult to react. For example, a dispersant having a reactive amino group in a molecular chain such as gelatin should be treated in advance to lose its reactivity. Is preferable.

Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. The surfactant may be used alone or in combination of two or more.

The nonionic surfactant is not particularly limited, and conventionally known surfactants can be used.
Examples of the nonionic surfactant include a polyoxyethylene alkyl ether compound, a polyoxyethylene alkyl phenyl ether compound, a polyoxyethylene polystyryl phenyl ether compound, a polyoxyethylene polyoxy propylene alkyl ether compound, and a glycerin fatty acid moiety. Ester compounds, sorbitan fatty acid partial ester compounds, pentaerythritol fatty acid partial ester compounds, propylene glycol mono fatty acid ester compounds, sucrose fatty acid partial ester compounds, polyoxyethylene sorbitan fatty acid partial ester compounds, polyoxyethylene sorbitol fatty acids Partial ester compounds, polyethylene glycol fatty acid ester compounds, polyglycerin fatty acid partial ester compounds, polyoxyethylene hydrogenated castor oil compounds, polyoxyethylene glycerin fatty acid partial ester compounds, fatty acid diethanolamide compounds, N, N-bis- Examples thereof include 2-hydroxyalkylamine compounds, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides, polyethylene glycols, and copolymers of polyethylene glycol and polypropylene glycol.

The anionic surfactant is not particularly limited, and conventionally known surfactants can be used.
Examples of anionic surfactants include fatty acid salts, avietates, hydroxyalcan sulfonates, alkane sulfonates, dialkyl sulfosulfonic acid ester salts, linear alkylbenzene sulfonates, branched chain alkylbenzene sulfonates, and alkylnaphthalene. Sulfonate, alkylphenoxypolyoxyethylene propyl sulfonate, polyoxyethylene alkyl sulfophenyl ether salt, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonate, sulfuric acid Chemical beef fat oil, sulfate of fatty acid alkyl ester, alkyl sulfate, polyoxyethylene alkyl ether sulfate, fatty acid monoglyceride sulfate, polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene styrylphenyl ether sulfate Salt, alkyl sulfonic acid ester salt, polyoxyethylene alkyl ether sulfonic acid ester salt, polyoxyethylene alkyl phenyl ether sulfonic acid ester salt, partial saponified product of styrene-maleic anhydride copolymer, olefin-maleic anhydride copolymer Examples thereof include a partial saponified product of the above, a naphthalene sulfonate formalin condensate, a salt of an alkylpolyoxyalkylene sulfoalkyl ether, and a salt of an alkenylpolyoxyalkylene sulfoalkyl ether.

The cationic surfactant is not particularly limited, and conventionally known ones can be used.
Examples of cationic surfactants include alkylamine salts, quaternary ammonium salts (eg, hexadecyltrimethylammonium chloride), polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.

The amphoteric surfactant is not particularly limited, and conventionally known surfactants can be used.
Amphoteric surfactants include, for example, carboxybetaine, aminocarboxylic acid, sulfobetaine, aminosulfate ester, and imitazoline.

The concentration of the polysaccharide is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 10% by mass, still more preferably 1% by mass to 5% by mass, based on the total mass of the aqueous phase.
The concentration of the emulsifier other than the polysaccharide is preferably 0% by mass to 20% by mass with respect to the total mass of the emulsion.

The aqueous phase may contain other components such as an ultraviolet absorber, an antioxidant, and a preservative, if necessary. When other components are contained, the content of the other components is preferably more than 0% by mass and 20% by mass or less, more preferably more than 0.1% by mass and 10% by mass or less, based on the total mass of the aqueous phase. ..

(Distributed)
Dispersion means that the oil phase is dispersed as oil droplets in the aqueous phase (that is, emulsification). Dispersion can be carried out using commonly used means for dispersing the oil and aqueous phases, such as homogenizers, menton gorries, ultrasonic dispersers, dissolvers, keddy mills, or other known dispersers.

The mixing ratio of the oil phase to the aqueous phase (oil phase / aqueous phase; based on mass) is preferably 0.03 to 1.5, more preferably 0.05 to 1.2, and further 0.1 to 1.0. preferable. When the mixing ratio is within the above range, the viscosity can be maintained at an appropriate level, the production suitability is excellent, and the stability of the emulsion is excellent.

[Encapsulation process]
The method for producing microcapsules of the present disclosure includes a step of polymerizing a shell material at an interface between an oil phase and an aqueous phase to form a shell to form microcapsules containing a solvent. As a result, microcapsules containing the oil phase component in the shell are formed.

(polymerization)
Polymerization is a step of polymerizing the shell material contained in the oil phase in the emulsion at the interface with the aqueous phase, whereby a shell is formed. The polymerization is preferably carried out under heating. The reaction temperature in the polymerization is usually preferably 40 ° C to 100 ° C, more preferably 50 ° C to 80 ° C. The polymerization reaction time is usually preferably 0.5 hours to 10 hours, more preferably 1 hour to 5 hours. The higher the polymerization temperature, the shorter the polymerization time, but when using a shell material that may decompose at high temperatures, it is desirable to select a polymerization initiator that acts at low temperatures and polymerize at a relatively low temperature. ..

In order to prevent the agglomeration of the microcapsules during the polymerization step, it is preferable to further add an aqueous solution (for example, water or an aqueous acetic acid solution) to reduce the collision probability between the microcapsules, and sufficient stirring may be performed. preferable. A dispersant for preventing aggregation may be added again during the polymerization step. Further, if necessary, a charge regulator such as niglosin or any other auxiliary agent can be added. These auxiliary agents can be added in the shell forming step or any step.

～ Physical properties of microcapsules ～
-Fracture deformation rate-
The microcapsules of the present disclosure preferably have a fracture deformation rate of 55% or less.
The fracture deformation rate refers to the minimum deformation rate of the microcapsules at the fracture point. As a result, deformation when breaking the microcapsules can be suppressed, so that the microcapsules can be broken with a small pressure. For example, when the microcapsules contain a fragrance as a core material, the contained fragrance is satisfactorily released even on the fiber to which the microcapsules are attached. As a result, the scent intensity is greatly improved.
From the above viewpoint, the fracture deformation rate is preferably 45% or less, and more preferably 35% or less.
Further, the fracture deformation rate is preferably 5% or more so that the microcapsules are selectively destroyed when a required pressure is applied.

The fracture deformation rate is the displacement of the microcapsules when the microcapsule particles are broken, which is determined by the method used for measuring the fracture strength described later (the indenter used for measuring the fracture strength comes into contact with the microcapsules and then the microcapsules. It is a value calculated as a value obtained by gradually dividing (the distance traveled before the destruction of the particles) by the average value of the diameters of 50 particles before being deformed by applying pressure, and converting it into a percentage.

-destruction strength-
The microcapsules of the present disclosure preferably have a breaking strength of 20 MPa or less.
This makes it possible to break the microcapsules with less pressure. For example, when the microcapsules contain a fragrance as a core material, the contained fragrance is satisfactorily released. As a result, the scent intensity is further improved.
From the above viewpoint, the breaking strength of the microcapsules of the present disclosure is more preferably 15 MPa or less, further preferably 10 MPa or less, and particularly preferably 6 MPa or less.

The breaking strength of the microcapsules is a value measured by the following method.
A few drops of the microcapsule water dispersion diluted with ion-exchanged water are added dropwise to the preparation and dried.
Next, the value calculated by dividing the fracture force of the particles by the cross section of the particles is obtained.
The destructive power of particles is described in "Mechanical Properties of Melamine-Formaldehyde microcapsules" by Zhang, Z., Sun, G, J. Microencapsulation magazine, vol.18, no.5, 593-602, 2001. It can be measured using the above method.
For 50 particles, the value calculated by dividing the breaking force of the particles by the cross section of the particles is obtained, and the above values of the 50 particles are averaged to obtain the breaking strength (MPa).
The unit of the destructive force of the particles is N (Newton), and the cross section of the particles is calculated by πr ² (r is the radius of the microcapsule particles before being deformed by applying pressure). Can be done.

<Microcapsule composition>
The microcapsule composition of the present disclosure contains the above-mentioned microcapsules of the present disclosure and a solvent.

-solvent-
As the solvent, an aqueous solvent is preferable.
Since the microcapsule composition contains a solvent, the microcapsule composition can be easily blended when used for various purposes. Examples of the aqueous solvent include water and alcohol.
The content of the solvent in the microcapsule composition can be appropriately selected depending on the purpose or application.

-Dispersion medium-
The microcapsule composition can contain a dispersion medium other than the above solvent for dispersing the microcapsules. Since the microcapsule composition contains a dispersion medium, the microcapsule composition can be easily blended when used for various purposes.
The dispersion medium here can be appropriately selected according to the intended use of the composition, and is preferably a liquid component that does not affect the shell material of the microcapsules. Preferred dispersion mediums include viscosity modifiers or stabilizers.
The content of the dispersion medium in the microcapsule composition may be appropriately selected depending on the purpose or application.

-Other ingredients-
The microcapsule composition can contain other components in addition to the microcapsules, solvent and dispersion medium.
The other components are not particularly limited and may be appropriately selected depending on the purpose or necessity. Other components include, for example, surfactants, cross-linking agents, lubricants, UV absorbers, antioxidants, and antistatic agents.

<Softener, detergent>
The microcapsules of the present disclosure can be used in a variety of applications, particularly suitable for applications exposed to environments in the presence of polar substances, such as fabric softeners, laundry detergents, hair care, and day care. ..

The softener of the present disclosure contains the microcapsules of the present disclosure described above, and may further contain a solvent. If the softener further contains a solvent, the softener is an example of a microcapsule composition.
The detergent of the present disclosure contains the microcapsules of the present disclosure described above, and may further contain a solvent. If the detergent further contains a solvent, the detergent is an example of a microcapsule composition.

(Washing composition)
-Clothing softener-
The microcapsule composition of the present disclosure can be made into a fabric softener by including a fragrance as a core material, for example. Thereby, the microcapsule composition of the present disclosure can be applied as a laundry composition.
In the microcapsule composition which is the softener for clothing of the present disclosure, the microcapsules contained in the microcapsule composition are adsorbed on the fibers of the clothing by immersing the clothing in the microcapsule composition, dehydrating and drying. It gets into the fine voids between the fibers and is retained by the clothing. Therefore, the clothing is provided with functions such as flexibility and antistatic property, and by including the microcapsules containing the core material, the core material can be released at a desired time.

When a garment treated with the garment softener of the present disclosure is worn, the core material is stably contained in the microcapsules, so that a soft comfort can be obtained. Further, even after a lapse of time, the core material can be released by applying stress to the microcapsules by rubbing clothes or the like and causing the microcapsules to collapse. In addition, the microcapsules can be disintegrated and the core material can be released by wearing clothes and acting without applying any particular stress.

The fabric softener preferably contains 0.3% by mass to 3% by mass of microcapsules in the total amount of the microcapsule composition.
The garment softener of the present disclosure may further contain known components contained in the garment softener, for example, components such as an antifoaming agent and a coloring material. The dispersion medium used in the fabric softener is preferably water such as ion-exchanged water.

-Laundry detergent-
Similar to the above, the microcapsule composition of the present disclosure can be made into a detergent for clothing by including, for example, a fragrance as a core material. Thereby, the microcapsule composition of the present disclosure can be applied as a laundry detergent.

(Hair care composition)
The microcapsule composition containing the microcapsules and the dispersion medium (solvent) of the microcapsules in the present disclosure can be directly applied to the hair care composition.
As the use of the hair care composition, it can be arbitrarily applied to hair cosmetics such as conditioners, conditioners, and hair styling products.
When applied to hair, the microcapsule composition of the present disclosure, which is a hair cosmetic, causes the microcapsules to adhere to the hair, and when the hair is rubbed or combed, the microcapsules collapse due to stress, and the core material is used. Can be released.

In the case of liquid hair cosmetics, it is preferable to fill the spray container because the microcapsules can be stably stored for a longer period of time.
When the hair cosmetic is applied to the hair by spraying, the dispersion medium and the microcapsules adhere to the hair. Then, for example, by massaging the scalp, stress is applied to the microcapsules, so that the microcapsules disintegrate and the core material can be attached to the hair.
The microcapsule composition of the present disclosure, which is a hair cosmetic, can optionally contain a known component that can be contained in the hair cosmetic.
Known ingredients that can be included in hair cosmetics include aqueous media such as alcohol, oils, surfactants as cleaning or dispersing ingredients, active ingredients that penetrate the skin, coloring materials, and fragrances.

(Day care composition)
The microcapsule composition of the present disclosure can be applied to a day care composition such as a cosmetic sheet or a diaper containing, for example, a support and the above-mentioned microcapsule composition of the present disclosure impregnated in the support. ..
The support is not particularly limited as long as it can retain the liquid component. The support is preferably a fiber aggregate having voids inside such as a non-woven fabric or a woven cloth, or a porous body such as a sponge sheet.
By impregnating the support with the microcapsule composition of the present disclosure, the microcapsules can be disintegrated and the core material can be released at any time by pressing the support against the skin and rubbing it. In addition, the microcapsule composition can be used as a skin cleaning sheet by containing a cleaning component such as a surfactant.
Day care compositions such as cosmetic sheets and diapers are preferably packaged in a water-impermeable packaging material in order to stably hold the microcapsule composition from the viewpoint of long-lasting effect.

As described above, the microcapsule composition of the present disclosure can be applied to various uses because the core material can be released at an arbitrary timing at a required timing. The above-mentioned uses are an example thereof, and the uses of the microcapsule composition of the present disclosure are not limited to the above description.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded.

(Example 1)
As a solvent, 10.5 parts by mass of Saracos (registered trademark) HG-8 (manufactured by Nisshin Oillio Group Co., Ltd .; glycerin fatty acid ester), 31.5 parts by mass of D-limonene (manufactured by Yasuhara Chemical Co., Ltd .; fragrance), and shell material. 1.74 parts by mass of Takenate (registered trademark) D-160N (manufactured by Mitsui Chemicals, Inc., hexamethylene diisocyanate trimethylolpropane adduct; cross-linking agent), which is a trifunctional aliphatic isocyanate compound, is stirred and mixed to obtain oil. Got a phase.

Further, a 2.0% by mass aqueous solution (hereinafter referred to as HPMC aqueous solution) of Metrose® 60SH50 (Shin-Etsu Chemical Co., Ltd., hydroxypropylmethylcellulose (HPMC); polysaccharide) was prepared and used as an aqueous phase.

In a state where 180 parts by mass of the HPMC aqueous solution (aqueous phase) was heated to 40 ° C., 43.74 parts by mass of the above oil phase was added and dispersed to generate an emulsion. Then, 60.0 parts by mass of a 25.0% by mass aqueous solution of Sandec # 180 (Sanwa Cornstarch Co., Ltd., dextrin; polysaccharide) was added to the produced emulsion, and the mixture was heated to 60 ° C. and stirred for 20 minutes. Then, 8.0 parts by mass of a 25.0% by mass aqueous solution of Sunfood (registered trademark) 100 (Mitsubishi Chemical Foods Co., Ltd .; polyphenol compound), which is a tea extract, was added, and the mixture was stirred at 60 ° C. for 1 hour and heated. It was stopped and stirring was continued overnight.
As described above, a microcapsule aqueous dispersion (microcapsule composition) was obtained.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 21.2% by mass.

It was confirmed by the following method that the microcapsules had a crosslinked structure.
The water dispersion of microcapsules was centrifuged to separate the microcapsules from the solution. The separated microcapsules were mixed with dimethyl sulfoxide (DMSO) (5% by mass) to prepare a DMSO mixture. When the DMSO mixture became opaque or the swelling of the microcapsules was confirmed, it was judged that the microcapsules had a crosslinked structure. On the other hand, when the microcapsules were dissolved and the DMSO mixture became transparent, it was determined that the shell of the microcapsules did not have a crosslinked structure. The presence or absence of opacity and swelling in the DMSO mixed solution was confirmed by visual observation and optical microscope observation.

As a result, it was confirmed that the microcapsules of the microcapsule water dispersion had a crosslinked structure in the shell part because the DMSO mixture became opaque.

The thickness of the shell portion of the microcapsules was 0.25 μm. The thickness of the shell portion was determined by calculating the thickness (μm) of each shell portion of the five microcapsules with a scanning electron microscope (SEM) and averaging them.
The volume-based median diameter (D50) of the microcapsules in the obtained aqueous dispersion of microcapsules was 35 μm. The volume-based median diameter was measured by Microtrack MT3300EXII (manufactured by Nikkiso Co., Ltd.).

(Evaluation)
The following evaluations were performed on the obtained microcapsules. The evaluation results are shown in Table 1.

(1) Morphological observation The microcapsules remaining in the softener were confirmed by the following procedure.
1.0 part by mass of the obtained microcapsule water dispersion was diluted with water to an unscented softener (Ultra Downy Free & Gentle, manufactured by Proctor & Gamble Japan Co., Ltd.) 49.0 parts by mass. (Fragrance-free softener: water = 9:40 [mass ratio]) was mixed to prepare a microcapsule composition. After dropping a few drops of the prepared microcapsule composition onto a preparation and drying it, the microcapsules (100 pieces) were observed with a metallurgical microscope (Eclipse LV100D, manufactured by Nikon Corporation) and evaluated according to the following evaluation criteria.
<Evaluation criteria>
A: In the softener, all 100 capsules maintained their capsule shape.
B: In the softener, 90% or more and less than 100% of the microcapsules maintained the capsule shape.
C: In the softener, 50% or more and less than 90% of the microcapsules maintained the capsule shape.
D: In the softener, more than 0% and less than 50% of microcapsules maintained the capsule shape.
E: No microcapsules could be confirmed in the softener (microcapsules disappeared).

(2) Fracture strength and fracture deformation rate The fracture strength and fracture deformation rate of microcapsules were measured by the following methods.
-2.1 Fracture strength-
Microcapsule water dispersion 1.0 parts by mass, 10.0 parts by mass of water, and fragrance-free softener (Ultra Downy Free & Gentle, manufactured by Proctor & Gamble Japan Co., Ltd.) diluted with water. A microcapsule composition was prepared by mixing 9.0 parts by mass (fragrance-free softener: water = 9:10 [mass ratio]). A few drops of the prepared microcapsule composition were added dropwise to the preparation and dried.
Next, the method described in “Mechanical Properties of Melamine-Formaldehyde microcapsules” by J. Microencapsulation (vol. 18, No. 5, 593-602, Zhang, Z., Sun, G (published in 2001)). The rupture force of the particles was measured based on, and the value calculated by dividing the measured rupture force of each particle (unit: N (Newton)) by the cross-sectional area of the corresponding particle was obtained. , 50 particles were obtained, and the average value of the obtained values was taken as the breaking strength (MPa).
The cross section of the particles is a value calculated by πr ² (r is the radius of the microcapsule particles before being deformed by applying pressure, and π is the circumference ratio (= 3.14)). Is.

-2.2 Fracture deformation rate-
The deformation rate of the microcapsules deformed by the measurement of the breaking strength was calculated from the following formula.
Fracture deformation rate (%) = displacement at break (μm) / measured microcapsule diameter (μm) x 100

(3) Fragrance intensity 1.0% by mass of the obtained microcapsule water dispersion in terms of fragrance, and a fragrance-free softener containing a cationic surfactant and water (ULTRA Downy, manufactured by Proctor & Gamble Japan Co., Ltd.) ) 99% by mass was mixed to prepare a microcapsule composition.
Next, 5 parts by mass of the microcapsule composition and 995 parts by mass of water were mixed, and the obtained mixed solution was sprayed 5 times on a cotton towel (35 cm × 35 cm) by spraying 5 times in a 25 ° C. 60% RH environment for 24 hours. It was dried to prepare a sample for evaluation.
After rubbing the obtained evaluation sample (cotton towel) 5 times, we asked 10 evaluators to evaluate the intensity of the generated scent, and scored it in 6 stages according to the following evaluation criteria, and averaged the value. (Rounded to an integer) was calculated and used as an index to evaluate the scent.
The evaluation criteria indicate that the scent intensity increases as the score increases from 0 point (weak scent intensity), and 5 points (strong scent intensity) is the highest evaluation. The evaluation is within a practically acceptable range of 2 points or more.
The evaluation results are shown in Table 1.
<Evaluation criteria>
0: I can't feel the scent at all.
1: A slight scent can be felt, but almost no scent is felt.
2: You can feel a weak scent.
3: You can feel the scent.
4: You can clearly feel the scent.
5: You can feel a strong scent.

(Example 2)
In Example 1, 60.0 parts by mass of a 25.0% by mass aqueous solution of Sandec # 180 (dextrin) was not added to the produced emulsion, and the composition was adjusted as shown in Table 1, as in Example 1. A microcapsule aqueous dispersion was obtained, and further measurement and evaluation were performed.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 8.6% by mass.
Further, by the same method as in Example 1, it was confirmed that the shell portion of the microcapsules had a crosslinked structure because the DMSO mixed solution was opaque.
The results of measurement and evaluation are shown in Table 1.

(Examples 3 to 5)
In Example 1, dextrin (60.0 parts by mass of a 25.0% by mass aqueous solution of Sandec # 180) added to the produced emulsion was replaced with the polysaccharide shown in Table 1, except that the dextrin was replaced with that of Example 1. Similarly, a microcapsule aqueous dispersion was obtained, and further measurement and evaluation were performed.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 6.0% by mass.
Further, by the same method as in Example 1, it was confirmed that the shell portion of the microcapsules had a crosslinked structure because the DMSO mixed solution was opaque.
The results of measurement and evaluation are shown in Table 1.

(Example 6)
Except that the 2.0% by mass aqueous solution of Metrose 60SH50 (HPMC) used as the polysaccharide in Example 1 was replaced with HPC (hydroxypropyl cellulose, Fujifilm Wako Pure Chemical Industries, Ltd .; polysaccharide) shown in Table 1. Obtained a microcapsule aqueous dispersion in the same manner as in Example 1, and further measured and evaluated it.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 20.8% by mass.
Further, by the same method as in Example 1, it was confirmed that the shell portion of the microcapsules had a crosslinked structure because the DMSO mixed solution was opaque.
The results of measurement and evaluation are shown in Table 1.

(Example 7)
In Example 1, Takenate D-160N used as a cross-linking agent was replaced with Takenate D-160N (trifunctional aliphatic isocyanate compound) and hexamethylene diisocyanate (bifunctional aliphatic isocyanate compound; HDI). Except for this, a microcapsule aqueous dispersion was obtained, and further measured and evaluated in the same manner as in Example 1.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 20.8% by mass.
Further, by the same method as in Example 1, it was confirmed that the shell portion of the microcapsules had a crosslinked structure because the DMSO mixed solution was opaque.
The results of measurement and evaluation are shown in Table 1.

(Example 8)
In Example 2, Takenate D-160N used as a cross-linking agent was replaced with Takenate D-160N (trifunctional aliphatic isocyanate compound) and hexamethylene diisocyanate (bifunctional aliphatic isocyanate compound; HDI). Except for this, a microcapsule aqueous dispersion was obtained, and further measured and evaluated in the same manner as in Example 2.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 8.6% by mass.
Further, by the same method as in Example 1, it was confirmed that the shell portion of the microcapsules had a crosslinked structure because the DMSO mixed solution was opaque.
The results of measurement and evaluation are shown in Table 1.

(Examples 9 to 10)
In Example 1, a microcapsule aqueous dispersion was obtained, measured and evaluated in the same manner as in Example 1 except that the thickness of the shell of the microcapsules was changed as shown in Table 1.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 20.8% by mass.
Further, by the same method as in Example 1, it was confirmed that the shell portion of the microcapsules had a crosslinked structure because the DMSO mixed solution was opaque.
The results of measurement and evaluation are shown in Table 1.

(Examples 11 to 13)
In Example 1, the amount of the tea extract (polyphenol compound) was changed as shown in Table 1, and the composition of other components was adjusted as shown in Table 1, as in Example 1. A microcapsule aqueous dispersion was obtained, and further measurement and evaluation were performed.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 20.8% by mass.
Further, in the microcapsules, the DMSO mixture was opaque in Examples 11 to 12 and swelled in Example 13 by the same method as in Example 1, confirming that the shell portion has a crosslinked structure. Was done.
The results of measurement and evaluation are shown in Table 1.

(Example 14)
In Example 1, a microcapsule aqueous dispersion was obtained, and further measured and evaluated in the same manner as in Example 1 except that the types of polysaccharides were changed as shown in Table 1.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 5.0% by mass.
Further, since the microcapsules were swollen by the same method as in Example 1, it was confirmed that the shell portion had a crosslinked structure.
The results of measurement and evaluation are shown in Table 1.

(Examples 15 to 18)
Same as in Example 1 except that the amount of Takenate D-160N used as the cross-linking agent was changed as shown in Table 1 and the other component compositions were adjusted as shown in Table 1. In addition, a microcapsule aqueous dispersion was obtained, and further measurement and evaluation were performed.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 20.8% by mass.
Further, by the same method as in Example 1, it was confirmed that the shell portion of the microcapsules had a crosslinked structure because the DMSO mixed solution was opaque.
The results of measurement and evaluation are shown in Table 1.

(Examples 19 to 20)
In Example 1, a microcapsule aqueous dispersion was obtained, and further measured and evaluated in the same manner as in Example 1, except that the type of the cross-linking agent was changed as shown in Table 1.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 18.0% by mass.
Further, since the microcapsules were swollen by the same method as in Example 1, it was confirmed that the shell portion had a crosslinked structure.
The results of measurement and evaluation are shown in Table 1.

(Comparative Example 1)
In Example 1, a microcapsule aqueous dispersion was obtained, measured and evaluated in the same manner as in Example 1 except that the thickness of the shell of the microcapsules was changed as shown in Table 1.
The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 20.8% by mass.
Further, by the same method as in Example 1, it was confirmed that the shell portion of the microcapsules had a crosslinked structure because the DMSO mixed solution was opaque.
The results of measurement and evaluation are shown in Table 1.

(Comparative Example 2)
In Example 1, the type of the cross-linking agent was changed as shown in Table 1, and after adding Sunfood (registered trademark) 100, which is a tea extract, tannic acid (Fujifilm Wako Pure Chemical Industries, Ltd.) 5 A microcapsule aqueous dispersion was obtained, and further measured and evaluated in the same manner as in Example 1 except that 16.0 g of a% mass aqueous solution was added. The solid content of the microcapsules in the obtained aqueous dispersion of microcapsules was 21.0% by mass.
Further, since the microcapsules were made transparent by the same method as in Example 1, it was confirmed that the shell portion did not have a crosslinked structure.
The results of measurement and evaluation are shown in Table 1.

The details of the components listed in Table 1 are as follows.
・ Polysaccharides:
HPMC: Metrose (registered trademark) 60SH50, Shin-Etsu Chemical Co., Ltd., Hydroxypropyl Methyl Cellulose HPC: Hydroxypropyl Cellulose, Fujifilm Wako Pure Chemical Industries, Ltd. Dextrin: Sandec # 180 (Sanwa Stardust Industry Co., Ltd.)
Gum arabic: Fujifilm Wako Pure Chemical Industries, Ltd. Kitan Sun Gum: Xanthan Gum, Tokyo Kasei Kogyo Co., Ltd. Guar gum: Fujifilm Wako Pure Chemical Industries, Ltd.
D-160N: Trifunctional aliphatic isocyanate compound (Takenate (registered trademark) D-160N, Mitsui Chemicals, Inc., hexamethylene diisocyanate trimethylolpropane adduct)
HDI: Bifunctional aliphatic isocyanate compound (Tokyo Chemical Industry Co., Ltd., hexamethylene diisocyanate)
Tannic acid: Fujifilm Wako Pure Chemical Industries, Ltd. Epoxy: 4,4'-Meilenbis (N, N-diglycidylaniline), Tokyo Chemical Industry Co., Ltd. Acid chloride: Adipoil chloride, Tokyo Chemical Industry Co., Ltd. Polyphenol compound:
Tea extract: Sunfood (registered trademark) 100, Mitsubishi Chemical Foods Co., Ltd.

As shown in Table 1 above, in Examples 1 to 20, the morphology of the capsule was well maintained in the presence of a polar ionic surfactant, even though the shell portion was a thin film having a thickness of less than 2 μm. Good results were also obtained for the scent intensity released when an external force (scratch) was applied, and all the microcapsules were excellent in storage stability.
In particular, when an isocyanate compound was used as the cross-linking agent, it was more excellent in terms of capsule morphology and storage stability.

Comparing Example 1 and Example 2, the microcapsules of Example 1 in which two kinds of linear polysaccharides and branched polysaccharides are used in combination are compared with those of Example 2 in which only linear polysaccharides are used. It can be seen that the effect of improving the breaking strength of
Comparing Example 1 with Examples 3 to 5 in which the branched polysaccharide is changed from Example 1, dextrin is more effective as the branched polysaccharide in terms of the effect of improving the breaking strength of the microcapsules. It turns out that.
Comparing Example 1 and Example 6, HPMC showed better fracture strength while maintaining scent intensity as compared with HPC.
As is clear from the comparison of Examples 10 to 13, the increase or decrease in the amount of the polyphenol compound affects the shape retention of the microcapsules. From the viewpoint of maintaining good morphology of the microcapsules, the amount of the polyphenol compound is preferably 3% by mass or more, more preferably 5% by mass or more (further, 6% by mass or more, particularly particularly) with respect to the total mass of the shell. It can be seen that it is 9% by mass or more).
Further, as can be seen from the results of Examples 15 to 18, the amount of the cross-linking agent is preferably 3% by mass or more, the morphology of the microcapsules is maintained well, and the breaking strength and the fragrance strength are balanced. From the viewpoint, the range of 4% by mass or more and 10% by mass is more preferable.

On the other hand, in Comparative Example 1 in which the shell thickness exceeded 2 μm, good scent intensity could not be obtained. As in Comparative Example 1, the conventional microcapsules described in JP-A-54-426 and JP-A-2-29341 described above are also considered to have a thick shell portion, and the shell portion is less than 2 μm. It is not clear whether or not the stability of the form of microcapsules (storage stability) and the release property of core materials such as fragrances can be balanced in the coexistence of polar substances when the thin film is formed.
Further, in Comparative Example 2 using tannic acid, since a covalently bonded crosslinked structure could not be obtained, the capsule morphology could not be maintained, resulting in a remarkably low scent intensity.

The entire disclosure of Japanese Patent Application No. 2019-064702 filed on March 28, 2019 is incorporated herein by reference in its entirety. Also, all documents, patent applications and technical standards described herein are to the same extent as if the individual documents, patent applications and technical standards were specifically and individually stated to be incorporated by reference. , Incorporated by reference herein.

Claims

Including the core portion and the shell portion containing the core portion,
The shell portion has a covalently bonded cross-linked structure derived from the reaction of the polysaccharide and the cross-linking agent, and has a thickness of less than 2 μm.
Microcapsules.
The microcapsule according to claim 1, wherein the cross-linking agent is at least one isocyanate compound selected from the group consisting of a trifunctional or higher functional aliphatic isocyanate compound and a bifunctional aliphatic isocyanate compound.
The microcapsule according to claim 1 or 2, wherein the polysaccharide is at least one selected from the group consisting of a cellulose compound, dextrin, gum arabic, gum arabic, and guar gum.
The microcapsule according to any one of claims 1 to 3, wherein the polysaccharide contains at least one selected from the group consisting of hydroxypropyl cellulose and hydroxypropyl methyl cellulose.
The microcapsule according to any one of claims 1 to 4, wherein the shell portion further contains a polyphenol compound.
The microcapsule according to claim 5, wherein the content of the polyphenol compound is 5% by mass or more with respect to the total mass of the shell portion.
The microcapsule according to any one of claims 1 to 6, wherein the content ratio of the structural portion derived from the cross-linking agent is 4% by mass or more with respect to the total mass of the shell portion.
A microcapsule composition containing the microcapsule according to any one of claims 1 to 7 and a solvent.
A softener containing the microcapsules according to any one of claims 1 to 7.
Detergent containing the microcapsules according to any one of claims 1 to 7.