WO2020066159A1 - Microcapsule and microcapsule-containing composition - Google Patents

Abstract

A microcapsule that comprises, as a shell material for a shell encapsulating a core therein, a polyurethane or polyurea having a structure derived from a tri- or higher functional isocyanate compound together with a structure derived from a bifunctional aliphatic isocyanate compound and/or a structure derived from a bifunctional aromatic isocyanate compound, wherein: in the shell material, the ratio by mass of the content of the structure moiety derived from the bifunctional isocyanate compound(s) to the content of the structure moiety derived from the trifunctional isocyanate compound is from 5/95 to 20/80; a perfume is contained as a core material; and the break deformation rate is 50% or less, and a microcapsule-containing composition.

Description

Microcapsules and compositions containing microcapsules

The present disclosure relates to microcapsules and compositions containing microcapsules.

In recent years, microcapsules have added new value to customers in terms of encapsulating and protecting functional materials such as fragrances, dyes, heat storage materials, and pharmaceutical ingredients, and releasing functional materials in response to stimuli. Has been attracting attention because of its potential.

す る When the fragrance is encapsulated in the microcapsules, for example, a microcapsule containing the fragrance (hereinafter, also referred to as a fragrance capsule) can be mixed with the softener. When washing clothes using the softener containing the microcapsules, when the microcapsules contained in the softener adhere to the clothes and the pressure or the like is applied and the microcapsules are broken, The contained fragrance is released. Therefore, by encapsulating the fragrance, the fragrance can be held for a certain period of time, and the fragrance due to the fragrance can be generated at a desired time.

JP-T-2009-524723 discloses a composition comprising particles comprising a core material and a wall material surrounding the core material, wherein the particles are at least 0.05, preferably at least 7, more preferably Has a delivery index of at least 70, wherein the composition is a consumer product.

Conventionally, when microcapsules containing a fragrance are adhered to clothes, it has been required to improve the intensity of the scent when the clothes are worn.
Since the composition described in JP-T-2009-524723 is considered not to destroy all microcapsules when microcapsules containing a fragrance are attached to clothes, Perfume is not released, and it is considered that there is room for improvement in fragrance intensity.

A problem to be solved by one embodiment of the present disclosure is to provide a microcapsule and a microcapsule-containing composition having good fragrance intensity.

Means for solving the above problems include the following aspects.
<1> As a shell material of a shell including a core, a polyurethane or polyurea having a structure derived from a trifunctional or more isocyanate compound and a structure derived from a bifunctional isocyanate compound is included, and in the shell material, The ratio of the content of the structure derived from the bifunctional isocyanate compound to the content of the structure derived from the trifunctional or more isocyanate compound is 5/95 to 20/80 on a mass basis, and contains a fragrance as a core material. And microcapsules having a breaking deformation rate of 50% or less.
<2> The microcapsule according to <1>, wherein the fracture deformation rate is 40% or less.
<3> The microcapsule according to <1> or <2>, wherein the fracture deformation rate is 30% or less.
<4> The microcapsule according to any one of <1> to <3>, having a breaking strength of 10 MPa or less.
<5> The microcapsule according to any one of <1> to <4>, having a breaking strength of 6 MPa or less.
<6> The microcapsule according to any one of <1> to <5>, wherein the bifunctional isocyanate compound includes an aromatic isocyanate compound, and the trifunctional or higher functional isocyanate compound includes an aliphatic isocyanate compound. .
<7> In the shell material, the ratio of the content of the structure derived from the bifunctional isocyanate compound to the content of the structure derived from the trifunctional or more isocyanate compound is 7/93 to 20 / 80 is the microcapsule according to any one of <1> to <6>.
<8> The trifunctional or higher functional isocyanate compound includes at least one of a trifunctional or higher functional aliphatic isocyanate compound and a trifunctional or higher functional aromatic isocyanate compound, and is derived from the trifunctional or higher functional isocyanate compound in the shell material. <1> to <7>, wherein the ratio of the content of the structure derived from the trifunctional or higher aromatic isocyanate compound to the total content of the structure is 0% to 87.5% by mass on a mass basis. A microcapsule according to any one of the above.
<9> The microcapsule according to any one of <1> to <8>, wherein the trifunctional or higher functional isocyanate compound includes a trifunctional or higher functional aliphatic isocyanate compound and a trifunctional or higher functional aromatic isocyanate compound. .
<10> The microcapsule according to any one of <1> to <8>, wherein the trifunctional or higher functional isocyanate compound is a trifunctional or higher functional aliphatic isocyanate compound.
<11> The ratio of the content of the structure derived from the trifunctional or more aromatic isocyanate compound to the total content of the structure derived from the trifunctional or more aliphatic isocyanate compound in the shell material is based on mass. The microcapsule according to <8> or <9>, wherein the content is 10% by mass to 40% by mass.
<12> The microcapsule according to any one of <1> to <11>, which has an anionic charge on its surface.
<13> The microcapsule according to any one of <1> to <12>, wherein at least a part of the surface has anion-modified polyvinyl alcohol.
<14> The microcapsule according to any one of <1> to <13>, which is used for laundry, day care, or hair care.
<15> A microcapsule-containing composition containing the microcapsule according to any one of <1> to <14> and an aqueous solvent.

According to one embodiment of the present disclosure, it is possible to provide a microcapsule and a microcapsule-containing composition having good fragrance intensity.

に お い て In this specification, a numerical range indicated by using “to” means a range including numerical values described before and after “to” as a lower limit and an upper limit, respectively. In the numerical ranges described stepwise in the present disclosure, the upper limit or the lower limit described in a certain numerical range may be replaced with the upper limit or the lower limit of another numerical range described in a stepwise manner. Further, in the numerical ranges described in the present disclosure, the upper limit or the lower limit described in a certain numerical range may be replaced with the value shown in the embodiment.

In this specification, the “shell” refers to a wall of a microcapsule (also referred to as a capsule wall), and the “core” refers to a portion included in the shell. In this specification, a material for forming a shell is referred to as a “shell material”, and a component contained in a core is referred to as a “core material”.
In the microcapsule of the present disclosure, “encapsulation” refers to a state in which an object is covered by a shell (capsule wall) of the microcapsule.
The amount of each component in the microcapsule or microcapsule-containing composition of the present disclosure is, unless there is a plurality of substances corresponding to each component in the microcapsule or microcapsule-containing composition, unless otherwise specified, microcapsules or microcapsules. It means the total amount of a plurality of substances present in the capsule-containing composition.

≪Microcapsules≫
The microcapsules of the present disclosure include a polyurethane or polyurea having a structure derived from a trifunctional or more isocyanate compound and a structure derived from a bifunctional isocyanate compound as a shell material of a shell including a core, and The ratio of the content of the structure derived from the bifunctional isocyanate compound to the content of the structure derived from the trifunctional or more isocyanate compound in the shell material is 5/95 to 20/80 on a mass basis, and the core material As a fragrance, and the breaking deformation rate is 50% or less.
Examples of the form of the microcapsule include a microcapsule dispersion, and the microcapsule is preferably in the form of a microcapsule aqueous dispersion in which the microcapsules are dispersed in an aqueous solvent.

The present inventors have found that the strength of the scent can be improved by making the microcapsules easily breakable. The shape of the fibers in clothing is not a plane shape but a linear shape, and if the microcapsules attached to the linear fibers are subjected to pressure enough to break the microcapsules, the fibers themselves move easily. The microcapsules move easily so as to release the applied pressure, and it is difficult to fix the microcapsules on the surface of the linear fibers. As a result, it is presumed that it becomes difficult to apply pressure required for breaking to the microcapsules.

On the other hand, according to the present disclosure, when a microcapsule containing a fragrance is broken on, for example, a fiber, the maximum deformation rate (breaking deformation) of the microcapsule in which the core material is included inside the core without breaking the shell Rate).
It is estimated that the probability of breakage of the microcapsules existing on the fiber increases as the fracture deformation rate decreases. In forming the microcapsules using polyurethane or polyurea, a part of the trifunctional or higher polyisocyanate compound is replaced with a bifunctional isocyanate compound having a structure in which the distance between cross-linking points is short to form a shell material of the microcapsule. Thus, the breaking deformation rate can be reduced.
As a result, the microcapsules are easily broken even on the fiber, and the fragrance contained in the microcapsules can be satisfactorily released.

<Destructive deformation rate>
The microcapsules of the present disclosure have a breaking deformation rate of 50% or less.
The breaking deformation rate refers to the minimum deformation rate of the microcapsule at the breaking point. As a result, the deformation when the microcapsules are broken can be suppressed, so that the microcapsules can be broken with a small pressure, and the fragrance contained therein can be satisfactorily released even on the fiber. As a result, the scent intensity is greatly improved.
From the above viewpoint, the breaking deformation ratio is preferably 40% or less, and more preferably 30% or less.
Further, in order to selectively break when a necessary pressure is applied, the breaking deformation rate is preferably 5% or more.

The breaking deformation rate is determined by the displacement of the microcapsule when the microcapsule particles are broken, which is determined by the method used for measuring the breaking strength described later (the microcapsule is used after the indenter used for measuring the breaking strength contacts the microcapsule). Is a value calculated as a percentage, which is calculated by subtracting the average distance of the diameters of 50 particles before deformation by applying pressure.

<Destruction strength>
The microcapsules of the present disclosure preferably have a breaking strength of 10 MPa or less.
This makes it possible to break down the microcapsules with a smaller pressure, so that the contained fragrance is released well. As a result, the scent intensity is further improved.
From the above viewpoint, the microcapsules of the present disclosure more preferably have a breaking strength of 6 MPa or less.
The lower limit of the breaking strength is not particularly limited, but may be more than 0 MPa or 1 MPa or more.

The breaking strength of the microcapsule can be measured by the following method.
A solution obtained by diluting the aqueous microcapsule dispersion with ion-exchanged water is dropped onto a slide and dried.
Next, a value is calculated by gradually subtracting the rupture force of the particles from the cross-sectional area of the particles.
The destructive power of particles is described in J. Microencapsulation, vol 18, no. 5, pp. 593-602; Zhang, Z .; , Sun, G, "Mechanical Properties of Melamine-Formaldehyde microcapsules".
With respect to 50 particles, a value calculated by gradually reducing the breaking force of the particles by the cross-sectional area of the particles is obtained, and the above values of the 50 particles are averaged and measured as a breaking strength (MPa).
The unit of the breaking force of the particles is N (Newton), and the cross-sectional area of the particles is calculated by πr ² (r is the radius of the microcapsule particles before being deformed by applying pressure). Can be.
The above r is calculated by dividing the median diameter of the volume standard of the microcapsule measured by using Microtrac MT3300EXII (manufactured by Nikkiso Co., Ltd.) by 2. Using the calculated r, the cross-sectional area is determined.

<Shell>
The microcapsule of the present disclosure has a shell that contains a core.
The shell material forming the shell in the present disclosure includes polyurethane or polyurea.
The polyurethane or polyurea in the present disclosure has a structure derived from a trifunctional or more isocyanate compound and a structure derived from a bifunctional isocyanate compound.

The microcapsules of the present disclosure are characterized in that the bifunctional isocyanate compound contains an aromatic isocyanate compound, and the trifunctional or more isocyanate compound contains an aliphatic isocyanate compound, from the viewpoint of reducing the breaking deformation rate and the breaking strength and increasing the fragrance strength. It is preferred to include.

(Trifunctional or higher isocyanate compound)
Polyurethane or polyurea, which is a shell material forming a shell, has a structure derived from a trifunctional or higher functional isocyanate compound. By having a structure derived from a tri- or more functional isocyanate compound, the flexibility of the shell can be increased, and adhesion to an object to be attached such as fiber or hair can be obtained.
The structure derived from a trifunctional or higher functional isocyanate compound refers to a structure formed by urethane or urea conversion of a trifunctional or higher functional isocyanate compound.

Examples of the trifunctional or higher aliphatic aliphatic isocyanate compound include a bifunctional aliphatic isocyanate compound (compound having two isocyanate groups in a molecule) and a compound having three or more active hydrogen groups in a molecule (for example, a trifunctional or higher functional compound). Examples of an adduct (adduct) with a polyol, polyamine or polythiol) include an isocyanate compound having three or more functional groups (adduct type) and a trimer of a bifunctional aliphatic isocyanate compound (biuret type or isocyanurate type). Can be.

As the adduct-type trifunctional or higher isocyanate compound, a commercially available product 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.), Sumidur (registered trademark) HT (manufactured by Bayer Corporation), Coronate (registered trademark) HL, HX (manufactured by Tosoh Corporation), Duranate P301-75E (manufactured by Asahi Kasei Corporation), Vernock (registered trademark) DN-950 (manufactured by DIC Corporation), etc. No.
Among them, Takenate (registered trademark) series (for example, Takenate D-110N, D-120N, D-140N, D-160N, etc.) manufactured by Mitsui Chemicals, Inc. are more preferable as adduct-type isocyanate compounds having three or more functions.

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

As the biuret-type trifunctional or higher isocyanate compound, commercially available products may be used. For example, Takenate (registered trademark) D-165N, NP1200 (manufactured by Mitsui Chemicals, Inc.), Desmodur (registered trademark) N3200A (Manufactured by Bayer Corporation), Duranate (registered trademark) 24A-100, 22A-75P (manufactured by Asahi Kasei Corporation) and the like.

Specific examples of the tri- or higher functional aromatic isocyanate compound include 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate or an adduct of hexamethylene diisocyanate with trimethylolpropane (adduct), biuret or isocyanate. Nurates and the like can be mentioned.
Commercially available products that are marketed as tri- or more functional aromatic isocyanate compounds may be used. Examples of commercially available products include Vernock (registered trademark) D-750, D-800 (manufactured by DIC Corporation), and Takenate (registered trademark). Trademarks) D-102, D-103, D-103H, D-103M2, D-110N, Olestar (registered trademark) P49-75S (all manufactured by Mitsui Chemicals, Inc.), Desmodur (registered trademark) L75, IL -135-BA, HL-BA, Sumidur (registered trademark) E-21-1 (manufactured by Bayer Corporation), Coronate (registered trademark) L, L-55, L-55E (manufactured by Tosoh Corporation) and the like. Can be

The ratio of the structure derived from the trifunctional or higher isocyanate compound to the total mass of the shell material is preferably 80% by mass to 95% by mass, and more preferably 80% by mass to 90% by mass.
When the ratio of the structure derived from the trifunctional or higher isocyanate compound is 80% by mass or more, the shell can be favorably formed. Further, when the proportion of the structure derived from the trifunctional or higher isocyanate compound is 95% by mass or less, the shell is more easily broken by pressure, and more favorable scent intensity can be obtained.

The trifunctional or higher functional isocyanate compound in the present disclosure preferably includes at least one of a trifunctional or higher functional aliphatic isocyanate compound and a trifunctional or higher functional aromatic isocyanate compound, and the trifunctional or higher functional isocyanate compound is a trifunctional or higher functional isocyanate compound. It may contain a group III isocyanate compound and a tri- or more functional aromatic isocyanate compound, or may contain a tri- or more functional aliphatic isocyanate compound alone.

When the trifunctional or higher functional isocyanate compound contains at least one of a trifunctional or higher functional aliphatic isocyanate compound and a trifunctional or higher functional aromatic isocyanate compound, a structural portion derived from the trifunctional or higher functional isocyanate compound in the shell material Is preferably 0% to 87.5% by mass on the basis of mass based on the total content of the above-mentioned trifunctional or higher functional aromatic isocyanate compound.
The ratio of the content of the structural portion derived from the trifunctional or more aromatic isocyanate compound to the total content of the structural portion derived from the trifunctional or more isocyanate compound in the shell material is within the above range. Since the breaking deformation rate can be further reduced, the fragrance intensity is excellent. Further, the ratio of the content of the structural part derived from the aromatic compound having three or more functional groups to the total content of the structural part derived from the trifunctional or more isocyanate compound in the shell material is 87% by mass. When the content is not more than 0.5% by mass, the strength of the shell can be more favorably maintained.
From the same viewpoint as described above, the ratio of the content of the structural part derived from the trifunctional or higher aromatic isocyanate compound to the total content of the structural parts derived from the trifunctional or higher isocyanate compound in the shell material is as follows: It is more preferably from 0% by mass to 56.0% by mass, even more preferably from 0% by mass to 40.0% by mass on a mass basis.

When the trifunctional or higher functional isocyanate compound is a trifunctional or higher functional aliphatic isocyanate compound, from the viewpoint of further reducing the breaking deformation rate and the breaking strength and improving the fragrance strength, the above 3 The ratio of the content of the structure derived from the trifunctional or higher aromatic isocyanate compound to the total content of the structure derived from the functional or higher functional isocyanate compound may be 10% by mass to 40% by mass on a mass basis. preferable.

-Bifunctional isocyanate compound-
Polyurethane or polyurea, which is a shell material forming a shell, has a structure derived from a bifunctional isocyanate compound. That is, the polyurethane or polyurea, which is the shell material forming the shell, has at least one structure selected from a structure derived from a bifunctional aliphatic isocyanate compound and a structure derived from a bifunctional aromatic isocyanate compound.
The structure derived from the bifunctional aliphatic isocyanate compound refers to a structure formed by urethane or urea conversion of the bifunctional aliphatic isocyanate compound.
The structure derived from a bifunctional aromatic isocyanate compound refers to a structure formed by urethane or urea conversion of a 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, cyclohexylene-1, 3-diisocyanate, cyclohexylene-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,4-bis (isocyanatomethyl) cyclohexane and 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, lysine diisocyanate And hydrogenated xylylene diisocyanate.

Examples of the bifunctional aromatic isocyanate compound include m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate and methylene diphenyl-4. 4,4'-diisocyanate, 3,3'-dimethoxy-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, 4-chloro Xylylene-1,3-diisocyanate, 2-methylxylylene-1,3-diisocyanate, 4,4'-diphenylpropane diisocyanate, 4,4'-diphenylhexafluoropropane diisocyanate, etc. It is below.

The isocyanate compound is described in "Polyurethane Resin Handbook" (edited by Keiji Iwata, published by Nikkan Kogyo Shimbun (1987)).

The structure derived from the bifunctional isocyanate compound, that is, at least one structure selected from the structure derived from the bifunctional aliphatic isocyanate compound and the structure derived from the bifunctional aromatic isocyanate compound, The proportion occupied is preferably from 5% by mass to 20% by mass, more preferably from 5% by mass to 15% by mass, even more preferably from 5% by mass to 10% by mass in total mass ratio. .
When the proportion of the structure derived from the bifunctional isocyanate compound is 5% by mass or more, a portion having a short distance between crosslinking points partially exists in the shell. It is presumed that a weakly fragile part is present in the shell, and the fracture deformation rate can be further reduced. Further, when the proportion of the structure derived from the bifunctional isocyanate compound is 20% by mass or less, the same effect as described above can be obtained favorably.

In the microcapsule 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 more isocyanate compound in the shell material is 5/95 to 5/95 on a mass basis. 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 more isocyanate compound in the shell material is 5/95 or more on a mass basis, the content in the shell becomes Since there is a part where the distance between bridging points is short, it is presumed that there is a part in the shell that is vulnerable to strain due to pressure when pressure is applied and that it is susceptible to cracking, and it is possible to further reduce the fracture deformation rate . As a result, the scent intensity can be improved.
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 more isocyanate compound in the shell material is 20/80 or less on a mass basis, the same as described above. Effect is obtained favorably. Further, the strength of the shell can be more favorably maintained.
In view of the above, 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 more isocyanate compound in the shell material is 7/93 to 20 / 80 is preferable, and 7/93 to 15/85 is more preferable.

The thickness (wall thickness) of the shell (wall) of the microcapsule is preferably 0.01 μm to 1 μm. When the wall thickness of the microcapsules is 0.01 μm or more, the microcapsules are prevented from being easily broken, and the core material can be protected in the core until the time when the core material is desired to be released. When the wall thickness of the microcapsule is 1 μm or less, the microcapsule can be given an appropriate degree of fragility, and the core material can be released at a desired time.
From the same viewpoint as above, the wall thickness of the microcapsule is more preferably 0.05 μm to 0.7 μm, and further preferably 0.05 μm to 0.2 μm.

The wall thickness refers to an average value obtained by averaging the individual wall thicknesses (μm) of the five microcapsules by using a scanning electron microscope (SEM).
Specifically, the microcapsule liquid is applied on an arbitrary support and dried to form a coating film. A cross section of the obtained coating film was prepared, the cross section was observed using an SEM, five arbitrary microcapsules were selected, and the cross section of each of the microcapsules was observed to measure the wall thickness. It is obtained by calculating the average value.

<Core>
The microcapsule of the present disclosure has a core encapsulated in a shell, and includes a fragrance as a core material.
When the microcapsules of the present disclosure are used, for example, by adhering to clothes fibers or hairs (hair, etc.), by including a fragrance as a core material, when pressure is applied to the clothes or hairs by rubbing or the like, The capsule is broken and the fragrance is released, and the desired fragrance can be diffused.

(Fragrance)
Examples of the fragrance include synthetic fragrances, natural essential oils, natural fragrances described in "Japan Patent Office, Well-known and Conventional Techniques (Fragrances), Part III, Cosmetic Fragrances, pp. 49-103, issued on June 15, 2001". A suitable one can be appropriately selected from animal and plant extracts and the like.
Examples of the fragrance include monoterpenes such as pinene, myrcene, camphene and R-limonene; sesquiterpenes such as sedren, caryophyllene, and longifolene; , Α-damascon, acetyl cedrene, methyl dihydrojasmonate, cyclopentadecanolide and the like; natural essential oils such as orange essential oil, lemon essential oil, bergamot essential oil, and mandarin essential oil.
The content of the fragrance with respect to the total mass of the core material is preferably 100% by mass to 20% by mass, more preferably 95% by mass to 30% by mass, and still more preferably 85% by mass to 40% by mass.

The core may contain other inclusion components other than the fragrance, and examples of the other inclusion components include a solvent and an auxiliary solvent.

(solvent)
The core may contain a solvent.
Examples of the solvent include fatty acid ester compounds such as glyceryl tri (caprylate / caprate) and isopropyl myristate, alkylnaphthalene compounds such as diisopropylnaphthalene, diarylalkane compounds such as 1-phenyl-1-xylylethane, and isopropylbiphenyl. Aromatic hydrocarbons such as alkylbiphenyl compounds, triarylmethane compounds, alkylbenzene compounds, benzylnaphthalene compounds, diarylalkylene compounds, and arylindane compounds; aliphatic hydrocarbons such as dibutyl phthalate and isoparaffin; Natural animal and vegetable oils such as camellia oil, soybean oil, corn oil, cottonseed oil, rapeseed oil, olive oil, coconut oil, castor oil, fish oil, and the like, and high-boiling fractions of natural products such as mineral oil.
The content of the solvent in the core material is preferably less than 50% by mass, more preferably 40% by mass or less, and most preferably 30% by mass or less based on the total mass of the core material.

(Auxiliary solvent)
The core may contain an auxiliary solvent as an oil phase component from the viewpoint of increasing the solubility of the shell material used in producing the microcapsules in the oil phase. The auxiliary solvent does not include the above solvents.
Examples of the auxiliary solvent include ketone compounds such as methyl ethyl ketone, ester compounds such as ethyl acetate, and alcohol compounds such as isopropyl alcohol. The auxiliary solvent preferably 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, and even more preferably less than 20% by mass based on the total mass of the core material.

(Additive)
The core may contain, in addition to the above components, additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, a wax, and an odor suppressant.
The content of the additive may be within a range that does not impair the effects of the present disclosure, and is preferably 0% to 20% by mass, more preferably 1% to 15% by mass, based on the total mass of the core material. More preferably, the content is 5% by mass to 10% by mass.

<Anion charge>
The microcapsules of the present disclosure preferably have an anionic charge on the surface.
Whether the microcapsules have an anionic charge on the surface can be confirmed by measuring the zeta potential when the microcapsules are dispersed in water. When the zeta potential is negative, it indicates that the surface of the microcapsule is covered with an anionic charge.

The zeta potential of the microcapsules, when dispersed in water, is preferably from -80 meV to -5 meV, more preferably from -80 meV to -11 meV, further preferably from -50 meV to -10 meV. preferable.

“Zeta potential” (z) means the apparent electrostatic potential generated by a charged object in a solution, measured by a special measurement technique. For a detailed discussion of the logical basis and actual relevance of the zeta potential, see, for example, "Colloid \ Science: Zeta \ Potential \ in \ Colloid \ Sciences: Principles \ Applications \ Applications" (Hunter @ Robert, J .; Deb. 1981; p @ 1988). The zeta potential of an object is measured at some distance from the surface of the object and generally does not exceed the electrostatic potential at the surface itself. However, that value can be a good measure of the ability of an object to establish electrostatic interactions with other objects in solution, especially molecules with multiple binding sites.

Zeta potential is a relative measurement and the value tends to depend on the method of measurement. In the present disclosure, the zeta potential is a value measured by the following method.
a. The apparatus uses ELSZ-2000ZS (manufactured by Otsuka Electronics Co., Ltd.).
b. The device settings are as follows.
c. The procedure for preparing the sample is as follows.
(I) The slurry containing the target microcapsules is added to water so as to have a capsule concentration of 0.5% by mass to dilute the slurry. The measurement concentration is adjusted, if necessary, so that the measurement rate is in a preferable range by automatic detection.
(Ii) Measure the zeta potential of the diluted sample without filtering the sample.
(Iii) The filtered slurry is injected into a standard cell unit (manufactured by Otsuka Electronics Co., Ltd.), and the cell is inserted into the device. Set the test temperature to 25 ° C.
(Iv) The measurement is started after the temperature is stabilized (usually after 3 to 5 minutes). Each sample is set to perform five measurements, and the measurement is performed.
d. The zeta potential in the present disclosure is a value measured in units of “mV” as an average of three measurements for each slurry.
Based on the above, the zeta potential of the microcapsule can be measured using ELSZ-2000ZS (manufactured by Otsuka Electronics Co., Ltd.).

The method for imparting an anionic charge to the surface of the microcapsule is not particularly limited. For example, a method of binding an anionic group-imparting agent to a shell, a method of imparting an anionic charge to a surface of a microcapsule using a surface anionizing agent, and the like Is mentioned. Among them, a method of imparting an anionic charge to the surface of the microcapsule using a surface anionizing agent is preferable from the viewpoint of working efficiency.

As a method for bonding an anionic group to the surface of the shell using an anionic group-imparting agent, the following method can be mentioned as an example.
That is, a solvent and a trifunctional aliphatic isocyanate compound and a bifunctional isocyanate compound which are shell materials are stirred and mixed to prepare an oil phase. Subsequently, an aqueous solution containing an anionic group imparting agent (for example, lysine) is prepared as an aqueous phase. The oil phase is added to the prepared aqueous phase, dispersed and emulsified, and the resulting emulsion is heated, stirred, and cooled. After cooling, an aqueous solution of a base (for example, sodium hydroxide) is added to obtain an aqueous dispersion of microcapsules having an anionic group on the surface.
The aqueous solution containing the anionic group imparting agent may be added after the emulsion is formed, or the aqueous solution of the base may be added to the aqueous phase in advance.
In addition, the content of each of the above components can be appropriately changed.

(Anionic group imparting agent)
The anionic group-providing agent is not particularly limited, and examples thereof include lysine, aspartic acid, and glutamic acid (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

The method for imparting an anionic charge to the surface of the microcapsules using a surface anionizing agent is not particularly limited, and for example, a method of forming a protective colloid on the microcapsule surface using a surface anionizing agent is preferable.
The protective colloid refers to a colloid that can impart an anionic charge to the surface of the microcapsule when present on the surface of the microcapsule.

(Surface anionizing agent)
The surface anionizing agent is not particularly limited as long as it can impart an anionic charge to the surface of the microcapsules. Anionic water-soluble polymers (anionic polysaccharides such as anion-modified polyvinyl alcohol, carboxymethyl cellulose, carrageenan, polyacrylic acid) And copolymers of sodium and other monomers, copolymers of sodium polymaleate and other monomers, and anionic surfactants (such as sodium dodecyl sulfate and sodium lauryl sulfate).

マ イ ク ロ The microcapsules in the microcapsule-containing composition of the present disclosure preferably have anion-modified polyvinyl alcohol on at least a part of the surface from the viewpoint of imparting an anionic charge to the surface of the microcapsules.

Examples of a method for forming a protective colloid on the surface of the microcapsule using a surface anionizing agent include the following methods. However, the present disclosure is not limited to the following method.
First, an oil phase is prepared by stirring and mixing a solvent, a trifunctional aliphatic isocyanate compound and a bifunctional isocyanate compound which are shell materials. Subsequently, an aqueous solution containing a surface anionizing agent (for example, anion-modified polyvinyl alcohol) is prepared as an aqueous phase. The oil phase is added to the prepared aqueous phase, dispersed and emulsified, and the resulting emulsion is heated, stirred, and cooled. After cooling, a base (for example, aqueous sodium hydroxide solution) is added to obtain an aqueous dispersion of microcapsules having a protective colloid on the surface.
In addition, the content of each component described above can be appropriately changed.

As the anion-modified polyvinyl alcohol, commercially available products can be used.
Examples of commercially available products include Kuraray Povar KM-618 (manufactured by Kuraray Co., Ltd.), Kuraray Povar KL-318 (manufactured by Kuraray Co., Ltd.), Gosenex L-3266 (manufactured by Nippon Synthetic Chemical Co., Ltd.), and Gosenex T-330 (Japan Synthetic Chemical Co., Ltd.). Above all, from the viewpoint of imparting anionic properties, as the anion-modified polyvinyl alcohol, Kuraray Povar KM-618 and Gohsenex L-3266 are preferable, and Kuraray Povar KM-618 is more preferable.

-Physical properties of microcapsules-
The volume standard median diameter (D50) 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 into minute voids of an attached object (hair, fiber, or the like), thereby preventing the microcapsules from becoming difficult to be broken. When the median diameter (D50) is 100 μm or less, a decrease in adhesion can be prevented.
In view of the above, the volume standard median diameter (D50) of the microcapsules is preferably 1 μm to 70 μm, more preferably 5 μm to 50 μm, and even more preferably 5 μm to 30 μm.
The median diameter of the volume standard of the microcapsules can be controlled by changing the dispersion conditions and the like.
Here, the median diameter of the volume standard of the microcapsule is defined as the volume of the particles on the large diameter side and the small diameter side when the entire microcapsule is divided into two thresholds with the particle diameter at which the cumulative volume becomes 50%. It means the diameter whose sum is equivalent.
In the present disclosure, the median diameter of the volume standard of the microcapsule is measured using Microtrack MT3300EXII (manufactured by Nikkiso Co., Ltd.).

With respect to the microcapsules of the present disclosure, “highly monodisperse” means that the range of the particle size distribution is narrow (that is, there is little variation in particle size), and “low monodispersity” means that the particle size is low. It means that the range of the size distribution is wide (that is, the variation of the particle size is large).
More specifically, the degree of monodispersity of the microcapsules can be expressed using a CV value (coefficient of variation; coefficient of variation). Here, the CV value is a value obtained by the following equation.
CV value (%) = (standard deviation of particle size distribution / volume average particle size) × 100
The lower the CV value, the higher the monodispersity of the microcapsules, and the higher the CV value, the lower the monodispersity of the microcapsules.
In the present disclosure, the volume average particle size and the standard deviation of the particle size distribution (hereinafter, also simply referred to as the standard deviation) are calculated using Microtrack MT3300EXII (manufactured by Nikkiso Co., Ltd.).

For example, “high monodispersity” of microcapsules can also mean that the CV value of the particle size distribution of the microcapsules is preferably 40% or less, more preferably 35% or less. When the CV value is in the above range, the monodispersity of the particle diameter of the microcapsules is high, so that the handling of the microcapsules and the control of the function development are facilitated.

<< composition containing microcapsules >>
The microcapsule-containing composition of the present disclosure contains at least the above-described microcapsules of the present disclosure and an aqueous solvent. The microcapsule-containing composition of the present disclosure, if necessary, preferably further contains a cationic surfactant, an anionic group-providing agent, a surface anionizing agent, and the like. Other components may be contained.

マ イ ク ロ The details of the microcapsules contained in the microcapsule-containing composition of the present disclosure are as described above, and preferred embodiments are also the same.

The content ratio of the microcapsules in the microcapsule-containing composition is not particularly limited, and may be selected according to the purpose or case. % By mass to 50% by mass.

(Aqueous solvent)
Examples of the aqueous solvent include water, water, and alcohol, and ion-exchanged water can be used.
The content ratio of the aqueous solvent in the microcapsule-containing composition is not particularly limited, and may be selected according to the purpose or case. % By mass to 70% by mass.

The microcapsule-containing composition of the present disclosure preferably has an embodiment in which the microcapsules have an anionic charge on the surface and further contain a cationic surfactant.
Thereby, an interaction is obtained between the microcapsules and the cationic surfactant, and a positive charge of the cationic surfactant can be provided around the microcapsules. As a result, it is possible to improve the adhesion of the microcapsule to an attachment target (for example, hair or fiber) having an anionic charge.

(Cationic surfactant)
The microcapsule-containing composition of the present disclosure preferably contains a cationic surfactant when the surface of the microcapsule is provided with an anionic charge. As a result, the anion charge (negative charge) of the microcapsules and the positive charge of the cationic surfactant attract each other through the interaction, so that the positive charge of the cationic surfactant covers the microcapsules. As a result, a positive charge can be generated as a whole capsule, and the positive charge of the microcapsule and the negative charge of the adhered object (for example, fiber or hair) to which the microcapsule adheres are attracted, and the microcapsule with respect to the adhered object Adhesion can be further improved.

The cationic surfactant is not particularly limited, and a conventionally known one can be used. Examples thereof include an alkylamine salt, a quaternary ammonium salt (for example, hexadecyltrimethylammonium chloride), a polyoxyethylene alkylamine salt, and polyethylene. And polyamine derivatives.

As the cationic surfactant, commercially available products may be used. Examples of commercially available products include Cation EQ-01D (NOF Corporation), Cation SF-10 (manufactured by Sanyo Chemical Industry Co., Ltd.), Cation SF-75PA (manufactured by Sanyo Chemical Industry Co., Ltd.), and Adecamine SF-108 (stock (Made by the company ADEKA).

-Dispersion medium-
The microcapsule-containing composition of the present disclosure may include a dispersion medium other than the aqueous solvent.
By further including another dispersion medium in the microcapsule-containing composition, the microcapsules can be easily blended when used for various applications.
Other dispersion media in the microcapsule-containing composition can be appropriately selected depending on the purpose of use of the composition. The other dispersion medium is preferably a liquid component that does not affect the wall material of the microcapsule.
Preferred other dispersion media include a viscosity modifier, a stabilizer and the like.
Note that the content of the dispersion medium in the microcapsule-containing composition of the present disclosure may be appropriately selected depending on the use.

-Other components-
The microcapsule-containing composition of the present disclosure can contain components other than the components described above.
Other components are not particularly limited, and may be appropriately selected depending on the purpose or case. Other components include, for example, surfactants other than the above-mentioned cationic surfactants, crosslinking agents, lubricants, ultraviolet absorbers, antioxidants, antistatic agents and the like.

<Method for producing microcapsules>
The microcapsules of the present disclosure can be manufactured by a known method, for example, the following manufacturing method. However, the present disclosure is not limited to the following method.

The microcapsules according to the present disclosure include a solvent and an oil phase containing a trifunctional or higher functional isocyanate compound and a bifunctional isocyanate compound as a shell material, an emulsifier and (if necessary, an anionic group-providing agent or a surface anionizing agent). A step of preparing an emulsion by dispersing in an aqueous phase containing (an emulsifying step) and a step of forming a shell by polymerizing a shell material at an interface between an oil phase and an aqueous phase to form microcapsules containing a core ( (Encapsulation step).
In addition, the fracture deformation rate in the microcapsule of the present disclosure can be achieved by appropriately adjusting the addition ratio of the trifunctional or more isocyanate compound and the bifunctional isocyanate compound.
The anionic group imparting agent may be added after the emulsification step.

[Emulsification step]
In the emulsification step, a solvent and an oil phase containing a trifunctional isocyanate compound and a bifunctional isocyanate compound as a shell material are converted into an aqueous phase containing an emulsifier and (if necessary, an anionic group-providing agent or a surface anionizing agent). Disperse to prepare an emulsion.
When the oil phase contains a solvent, the monodispersibility of the microcapsules is enhanced.

~ Emulsion ~
The emulsion of the present disclosure can be prepared by dispersing an oil phase containing a solvent and a shell material in an aqueous phase containing an emulsifier.

(Oil phase)
The oil phase in the present disclosure includes at least a solvent and a trifunctional isocyanate compound and a bifunctional isocyanate compound as shell materials, and if necessary, other components such as a fragrance, an auxiliary solvent, and an additive. May be included. The details of the fragrance, the auxiliary solvent, and the additives are as described in the section on the microcapsules described above.

-solvent-
Solvents that can be used in the production method of the present disclosure are as described in the section on microcapsules described above.

－Shell material－
The shell material in the present disclosure includes a trifunctional isocyanate compound and a bifunctional isocyanate compound.
The content of the shell material in the oil phase is preferably more than 0.1% by mass and not more than 20% by mass, more preferably 0.5% by mass to 15% by mass, based on the total mass of the oil phase.
The concentration of the shell material can be appropriately adjusted in consideration of the size, wall thickness, and the like of the microcapsules.

(Aqueous phase)
The aqueous phase in the present disclosure preferably contains at least an aqueous solvent and an emulsifier, and may further contain, for example, an anionic group imparting agent or a surface anionizing agent as a component for imparting an anionic charge to the surface of the microcapsules.

-Aqueous medium-
Examples of the aqueous medium of the present disclosure include water, water, and alcohol, and ion-exchanged water can be used.
The content of the aqueous medium in the aqueous phase is preferably from 20% by mass to 80% by mass, more preferably from 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 preferably 40% by mass to 60% by mass.

-emulsifier-
Emulsifiers include dispersants or surfactants or combinations thereof.
Examples of the dispersing agent include polyvinyl alcohol and modified products thereof (eg, anion-modified polyvinyl alcohol), polyacrylamide and derivatives thereof, ethylene-vinyl acetate copolymer, styrene-maleic anhydride copolymer, ethylene-maleic anhydride. Acid copolymer, isobutylene-maleic anhydride copolymer, polyvinylpyrrolidone, ethylene-acrylic acid copolymer, vinyl acetate-acrylic acid copolymer, carboxymethylcellulose, methylcellulose, casein, gelatin, starch derivatives, gum arabic and alginic acid Sodium and the like can be mentioned, and polyvinyl alcohol is preferable.
It is preferable that the dispersant does not react with the shell material or very hardly reacts.For example, those having a reactive amino group in a molecular chain such as gelatin may be subjected to a treatment for losing reactivity in advance. preferable.

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

The nonionic surfactant is not particularly limited, and a conventionally known nonionic surfactant can be used.
Nonionic surfactants include, for example, polyoxyethylene alkyl ether compounds, polyoxyethylene alkyl phenyl ether compounds, polyoxyethylene polystyryl phenyl ether compounds, polyoxyethylene polyoxypropylene alkyl ether compounds, and glycerin fatty acid moieties. Ester compound, sorbitan fatty acid partial ester compound, pentaerythritol fatty acid partial ester compound, propylene glycol monofatty acid ester compound, sucrose fatty acid partial ester compound, polyoxyethylene sorbitan fatty acid partial ester compound, polyoxyethylene sorbitol fatty acid Partial ester compounds, polyethylene glycol fatty acid ester compounds, polyglycerin fatty acid partial ester compounds, polio Sethylenated castor oil compound, polyoxyethylene glycerin fatty acid partial ester compound, fatty acid diethanolamide compound, N, N-bis-2-hydroxyalkylamine compound, polyoxyethylene alkylamine, triethanolamine fatty acid ester, trialkyl Examples include amine oxide, polyethylene glycol, and a copolymer of polyethylene glycol and polypropylene glycol.

The anionic surfactant is not particularly limited, and a conventionally known anionic surfactant can be used.
Examples of the anionic surfactant include fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts, dialkylsulfosuccinic acid ester salts, linear alkylbenzenesulfonic acid salts, branched alkylbenzenesulfonic acid salts, and alkylnaphthalenes. Sulfonate, alkylphenoxy polyoxyethylene 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 Beef tallow oil, fatty acid alkyl ester sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyls Phenyl ether sulfate, polyoxyethylene styryl phenyl ether sulfate, alkyl phosphate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl phenyl ether phosphate, styrene-maleic anhydride copolymer Saponified product, partially saponified olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensate, salt of alkyl polyoxyalkylene sulfoalkyl ether, salt of alkenyl polyoxyalkylene sulfoalkyl ether, and the like. .

The cationic surfactant is not particularly limited, and a conventionally known cationic surfactant can be used.
Examples of the cationic surfactant include an alkylamine salt, a quaternary ammonium salt (for example, hexadecyltrimethylammonium chloride), a polyoxyethylene alkylamine salt, and a polyethylenepolyamine derivative.

The amphoteric surfactant is not particularly limited, and a conventionally known amphoteric surfactant can be used.
Examples of the amphoteric surfactant include carboxybetaine, aminocarboxylic acid, sulfobetaine, aminosulfate, and imitazoline.

The concentration of the emulsifier is preferably more than 0% by mass and 20% by mass or less, more preferably 0.005% by mass or more and 10% by mass or less, and more preferably 0.01% by mass or more and 10% by mass or less based on the total mass of the emulsifier. More preferably, the content is 1% by mass or more and 5% by mass or less.

-Anionic group imparting agent or surface anionizing agent-
The aqueous phase in the present disclosure preferably contains an anionic group imparting agent or a surface anionizing agent. The details of the anionic group-imparting agent and the surface anionizing agent are as described in the section of the microcapsule described above.
Note that some anionic group-providing agents and surface anionizing agents (for example, anion-modified polyvinyl alcohol) can also be used as an emulsifier described below. When used, an emulsifier described below need not be added.

The content of the anionic group imparting agent in the shell is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 10% by mass, and more preferably 2.5% by mass with respect to the total mass of the shell material. -7% by mass is more preferred.

The content of the surface anionizing agent is preferably 1% by mass to 15% by mass, more preferably 2% by mass to 12% by mass, and still more preferably 4% by mass to 10% by mass based on the total mass of the aqueous phase. .

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 is preferably more than 0% by mass and 20% by mass or less, more preferably more than 0.1% by mass and 15% by mass or less, more preferably more than 1% by mass based on the total mass of the aqueous phase. 10 mass% or less is more preferable.

(dispersion)
Dispersion refers to dispersing (emulsifying) the oil phase of the present disclosure as oil droplets in the aqueous phase of the present disclosure. Dispersion can be performed using a means usually used for dispersing an oil phase and an aqueous phase, for example, a homogenizer, a Menton-Gawley, an ultrasonic disperser, a dissolver, a Keddy mill, or other known dispersing devices.

The mixing ratio of the oil phase to the aqueous phase (oil phase / water phase; mass basis) is preferably 0.1 to 1.5, more preferably 0.2 to 1.2, and 0.4 to 1.0. More preferred. When the mixing ratio is in the range of 0.1 to 1.5, 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 microcapsule manufacturing method of the present disclosure includes a step of forming a shell by polymerizing a shell material at an interface between an oil phase and an aqueous phase to form a microcapsule containing a solvent. Thereby, a microcapsule in which the solvent of the present disclosure is included in the shell is formed.

(polymerization)
The 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 from 40 ° C to 100 ° C, more preferably from 50 ° C to 80 ° C. The reaction time of the polymerization is usually preferably about 0.5 to 10 hours, more preferably about 1 to 5 hours. The higher the polymerization temperature, the shorter the polymerization time, but when using an encapsulating component or shell material that may decompose at high temperature, select a polymerization initiator that works at low temperature and polymerize at relatively low temperature. It is desirable.

In order to prevent aggregation of the microcapsules during the polymerization step, it is preferable to further reduce the probability of collision between the microcapsules by further adding an aqueous solution (for example, water, an aqueous acetic acid solution, etc.), and perform sufficient stirring. Is also preferred. A dispersant for preventing aggregation may be added again during the polymerization step. Furthermore, if necessary, a charge control agent such as nigrosine or any other auxiliary agent can be added. These adjuvants can be added during the formation of the shell or at any time.

-Applications of microcapsules-
The microcapsules of the present disclosure can be used for various applications.
The microcapsules can be applied, for example, to uses such as laundry, hair care, and day care.

-Washing-
The microcapsules of the present disclosure containing a fragrance as a core material in the microcapsules can be used, for example, in the form of a microcapsule-containing composition as a softener for clothing. That is, the microcapsules of the present disclosure are suitable for laundry applications.
By immersing the clothing in the microcapsule-containing composition which is a softener for clothing, dehydrating and drying, the microcapsules contained in the microcapsule-containing composition and, if necessary, the cationic surfactant are adsorbed to the fibers of the clothing. Or retained in the garment by penetrating into fine voids between the fibers. Thereby, flexibility, antistatic property, etc. are provided to the garment. Thus, the microcapsules of the present disclosure, alone or with a cationic surfactant, function as a softener component. In addition, the encapsulated components (such as fragrances) can be released from the microcapsules at a desired time.

When clothing treated with a clothing softener is worn, in addition to soft comfort, the microcapsules stably contain contained components (such as fragrances), so that even after lapse of time, the clothing may be rubbed. By applying stress and disintegrating the microcapsules, the encapsulated components can be released.

The content of the microcapsules in the softener for clothing is preferably 0.3% by mass to 3% by mass based on the total mass of the composition containing microcapsules. When the composition containing microcapsules further contains a cationic surfactant, the content of the cationic surfactant is preferably from 10% by mass to 30% by mass based on the total mass of the composition containing microcapsules. .
In addition, the microcapsule-containing composition can further include a known component (for example, an antifoaming agent, a coloring material, a fragrance, and the like) included in the softener for clothing. Water such as ion-exchanged water is preferred as the dispersion medium used in the softener for clothing.

-hair care-
The microcapsule of the present disclosure and the microcapsule-containing composition containing the microcapsule and the aqueous solvent can be directly applied to hair care applications.
As a hair care application, it can be arbitrarily applied to a hair cosmetic such as a rinse, a conditioner, and a hairdressing agent.
When the microcapsule-containing composition of the present disclosure is applied to hair as a hair cosmetic, the microcapsules adhere to the hair, and when the hair is rubbed or combed, the microcapsules collapse due to stress, and the core material is released. can do.

In the case of a liquid hair cosmetic, the microcapsules can be stably stored for a longer period of time by filling in a spray container, which is preferable.
When the hair cosmetic is applied to the hair by spraying, the dispersion medium and the microcapsules adhere to the hair. Thereafter, the scalp is massaged to apply stress to the microcapsules so that the microcapsules collapse and the core material can be attached to the hair.
The microcapsule-containing composition of the present disclosure, which is a hair cosmetic, may optionally contain known components that can be included in the hair cosmetic.
Known components that can be included in hair cosmetics include aqueous media such as alcohols, oils, surfactants as cleaning or dispersing components, active ingredients that penetrate the skin, coloring materials, and fragrances.

-Day care-
The microcapsules of the present disclosure can be applied to, for example, day care applications (for example, cosmetic sheets, diapers, and the like) including a support and the above-described microcapsule-containing composition impregnated in the support.
When the microcapsule-containing composition contains a cleaning component such as a surfactant, it can be used as a sheet for wiping the skin.

The support is not particularly limited as long as it can hold the liquid component. The support is preferably a nonwoven fabric, a woven fabric, or the like, a fiber aggregate having a void for retaining moisture therein, a porous body such as a sponge sheet, or the like.
By impregnating the support with the microcapsule-containing composition of the present disclosure, the support can be pressed against the skin and rubbed to break the microcapsules and release the encapsulated component (core material) at any time, and Even when no stress is applied, the inclusion components are released spontaneously, so that the effect of releasing the inclusion components can be obtained for a long period of time.
In order to stably hold the microcapsules, cosmetic sheets, diapers and the like are preferably packaged with a water-impermeable packaging material from the viewpoint of sustaining the effect.

As described above, the microcapsules of the present disclosure can release the core material well, and thus can be applied to various uses. The use described above is an example, and the use of the microcapsule of the present disclosure is not limited to the above description.

Hereinafter, embodiments of the present disclosure will be described more specifically with reference to Examples, but the present disclosure is not limited to the following Examples as long as the gist of the present disclosure is not exceeded. Unless otherwise specified, “parts” are based on mass.
In this example, the volume average particle diameter, CV value, breaking deformation ratio and breaking strength of the microcapsules were measured by the methods described above.

(Example 1)
-Preparation of microcapsule-containing composition-
18.2 parts by mass of Saracos (registered trademark) HG-8 (manufactured by Nisshin Oillio Group Co., Ltd.) as a solvent, 54.7 parts by mass of D-limonene as a fragrance (manufactured by Yashara Chemical Co., Ltd .; fragrance), and shell material 3.1 parts by mass of Vernock (registered trademark) D-750 (manufactured by DIC Corporation, tolylene diisocyanate trimethylolpropane adduct), which is a trifunctional aromatic isocyanate compound, and takenate, which is a trifunctional aliphatic isocyanate compound (Registered trademark) D-160N (manufactured by Mitsui Chemicals, Inc., hexamethylene diisocyanate trimethylolpropane adduct) 0.45 parts by mass, and methylene diphenyl-4,4'-diisocyanate (MDI, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 0.67 parts by mass of a bifunctional isocyanate compound). The mixture was stirred and mixed to obtain an oil phase.
Further, a 5.8% by mass aqueous solution of Kuraray Povar (registered trademark) PVA-217E (manufactured by Kuraray Co., Ltd .; PVA), which is a polyvinyl alcohol, was prepared. After adding and dispersing an oil phase to 157 parts by mass of this aqueous solution, the resulting emulsion was heated to 70 ° C. and stirred for 1 hour. Subsequently, after cooling, 3.8 parts by mass of a 10% by mass aqueous solution of sodium hydroxide was added to obtain a microcapsule aqueous dispersion.
The volume-based median diameter (D50) of the obtained microcapsules was 18 μm. The CV value [= (standard deviation / volume average particle size) × 100] of the particle size distribution was 36%. The volume-based median diameter, standard deviation, and volume average particle diameter were measured using Microtrac MT3300EXII (manufactured by Nikkiso Co., Ltd.). The zeta potential of the aqueous microcapsule dispersion was 0 mV. The zeta potential was measured by ELSZ-2000ZS (manufactured by Otsuka Electronics Co., Ltd.). The wall thickness of the microcapsules was 0.12 μm.

1.0 part by mass of the aqueous dispersion of microcapsules obtained above in terms of perfume, and 99 parts by mass of a perfume-free softener containing a cationic surfactant (ULTRA @ Downy, manufactured by Procter & Gamble Japan KK) Was mixed to prepare a microcapsule-containing composition.

(Examples 2 to 10 and Comparative Examples 1 to 4)
The type and mixing ratio of the trifunctional aromatic isocyanate compound, the trifunctional aliphatic isocyanate compound and the bifunctional isocyanate compound, and the type of polyvinyl alcohol were changed as shown in Tables 1 and 2 to prepare a microcapsule aqueous dispersion. A microcapsule-containing composition was prepared in the same manner as in Example 1 except that the composition was obtained. The wall thickness here was the same as in Example 1.

－Evaluation－
(Evaluation 1)
5 parts by weight of the microcapsule-containing composition prepared above and 995 parts by weight of water were mixed, sprayed onto a cotton towel (35 cm × 35 cm) five times by spraying, and dried for 24 hours to prepare a sample for evaluation. .
After the evaluation sample (cotton towel) obtained above was rubbed 5 times, the intensity of the generated fragrance was evaluated by 10 panelists, and the score (0 point (0 fragrance intensity) was divided into 7 levels according to the following evaluation criteria. (Weak) to 6 points (strong scent intensity)), and an average value (rounded to an integer) was obtained for sensory evaluation. The results are shown in Table 1.
-Evaluation criteria-
0: No scent can be felt at all.
1: Smell can be slightly felt, but hardly felt.
2: A weak scent can be felt.
3: Smell can be felt.
4: Smell can be clearly sensed.
5: A strong scent can be felt.
6: A very strong scent can be felt.

(Evaluation 2)
5 parts by mass of the microcapsule-containing composition prepared in Example 7 and Example 10 and 995 parts by mass of water were mixed, and a cotton towel (35 cm × 35 cm) was immersed in the mixture for 20 minutes, squeezed, and dried for 24 hours. A sensory evaluation of the scent intensity was performed in the same manner as in Evaluation 1 above, except that an evaluation sample was prepared, in accordance with the same evaluation criteria as in Evaluation 1 above, taking into account the effect of adhesion to the fiber. The results are shown in Table 2.

 

 

The unit of the mixing ratio in Tables 1 and 2 is parts by mass. The description of “-” in Tables 1 and 2 means that the component is not contained.
Regarding the fracture deformation rate and the fracture strength in Tables 1 and 2, "-" indicates that the microcapsules are brittle, and when the fracture deformation rate and the fracture strength are measured, the microcapsule wall is collapsed. It means there is.

Details of the components in Tables 1 and 2 are as follows.
217E: Kuraray Povar PVA-217E (partially saponified polyvinyl alcohol), Kuraray Co., Ltd. KM-618: Kuraray Povar KM-618 (anion-modified polyvinyl alcohol), Kuraray Co., Ltd. D-750: Barnock D-750 (Torirange) Isocyanate trimethylolpropane adduct; trifunctional or higher aromatic isocyanate compound), DIC D-160N: Takenate D-160N (hexamethylene diisocyanate trimethylolpropane adduct; trifunctional aliphatic isocyanate compound), Mitsui Chemicals, Inc. MDI: Methylene diphenyl-4,4'-diisocyanate (bifunctional aromatic isocyanate compound, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
HDI: Hexamethylene diisocyanate (bifunctional aliphatic isocyanate compound, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

As shown in Tables 1 and 2, Examples 1 to 10 had good fragrance intensity.
Above all, Examples 5 to 10 in which the breaking deformation rate was 30% or less had better fragrance strength than Examples 1 to 4 in which the breaking deformation rate was more than 30%.
Example 7 having a breaking strength of 6 MPa or less had better fragrance strength than Example 5 having a breaking strength of more than 6 MPa.
The trifunctional or higher functional isocyanate compound is a trifunctional or higher functional aliphatic isocyanate compound, and the content of the structural portion derived from the bifunctional isocyanate compound relative to the content of the structural component derived from the trifunctional or higher functional isocyanate compound in the shell material. In Examples 8 and 9 in which the ratio was 7/93 to 20/80 on a mass basis, the fragrance intensity was particularly excellent.
It contains a trifunctional or higher functional aliphatic isocyanate compound and a trifunctional or higher functional aromatic isocyanate compound, and is derived from the trifunctional or higher functional aromatic isocyanate compound with respect to the total content of the structure derived from the trifunctional or higher functional isocyanate compound in the shell material. The ratio of the content of the structure is 10% by mass to 40% by mass on a mass basis, and the structure derived from the bifunctional isocyanate compound with respect to the content of the structural portion derived from the trifunctional or more isocyanate compound in the shell material. Example 7 in which the content ratio of the parts was 7/93 to 20/80 on a mass basis was particularly excellent in fragrance intensity.

The disclosure of Japanese Patent Application No. 2018-185644 filed on September 28, 2018 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned herein are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference. Incorporated herein by reference.

Claims (15)

1. As a shell material for the shell that contains the core,
   A structure derived from a trifunctional or more isocyanate compound,
   A structure derived from a bifunctional isocyanate compound,
   Comprising a polyurethane or polyurea having, and
   The ratio of the content of the structure derived from the bifunctional isocyanate compound to the content of the structure derived from the trifunctional or more isocyanate compound in the shell material is 5/95 to 20/80 on a mass basis,
   Microcapsules containing a fragrance as a core material and having a breaking deformation rate of 50% or less.
2. マ イ ク ロ The microcapsule according to claim 1, wherein the fracture deformation rate is 40% or less.
3. The microcapsule according to claim 1 or 2, wherein the fracture deformation rate is 30% or less.
4. The microcapsule according to any one of claims 1 to 3, wherein the microcapsule has a breaking strength of 10 MPa or less.
5. The microcapsule according to any one of claims 1 to 4, wherein the microcapsule has a breaking strength of 6 MPa or less.
6. The microcapsule according to any one of claims 1 to 5, wherein the bifunctional isocyanate compound includes an aromatic isocyanate compound, and the trifunctional or higher isocyanate compound includes an aliphatic isocyanate compound.
7. The ratio of the content of the structure derived from the bifunctional isocyanate compound to the content of the structure derived from the trifunctional or more isocyanate compound in the shell material is 7/93 to 20/80 on a mass basis. The microcapsule according to any one of claims 1 to 6.
8. The trifunctional or higher functional isocyanate compound includes at least one of a trifunctional or higher functional aliphatic isocyanate compound and a trifunctional or higher functional aromatic isocyanate compound, and the shell material has a total structure derived from the trifunctional or higher functional isocyanate compound. 8. The method according to claim 1, wherein a ratio of the content of the structure derived from the trifunctional or higher aromatic isocyanate compound to the content is 0% by mass to 87.5% by mass on a mass basis. The microcapsule according to the above item.
9. The microcapsule according to any one of claims 1 to 8, wherein the trifunctional or higher functional isocyanate compound includes a trifunctional or higher functional aliphatic isocyanate compound and a trifunctional or higher functional aromatic isocyanate compound.
10. The microcapsule according to any one of claims 1 to 8, wherein the trifunctional or higher functional isocyanate compound is a trifunctional or higher functional aliphatic isocyanate compound.
11. In the shell material, the ratio of the content of the structure derived from the trifunctional or more aromatic isocyanate compound to the total content of the structure derived from the trifunctional or more isocyanate compound is from 10% by mass to The microcapsule according to claim 8 or 9, which is 40% by mass.
12. The microcapsule according to any one of claims 1 to 11, having an anionic charge on the surface.
13. The microcapsule according to any one of claims 1 to 12, wherein the microcapsule has an anion-modified polyvinyl alcohol on at least a part of the surface.
14. The microcapsule according to any one of claims 1 to 13, which is used for washing, day care, or hair care.
15. マ イ ク ロ A microcapsule-containing composition comprising the microcapsule according to any one of claims 1 to 14 and an aqueous solvent.