JP7083769B2 - Dispersion - Google Patents

Description

The present invention relates to dispersions.

By using each drug such as an insect repellent, a pesticide, a fragrance, and a deodorant as a microcapsule encapsulated in a wall material, the expected effect can be maintained for a long period of time. Therefore, various such microcapsules have been studied.

Examples of applications for such microcapsules include various spraying agents. Typical sprays containing microcapsules include, for example, microcapsules and water-containing dispersions, which may also contain alcohol. The reason for using water is that it is highly safe as a medium for handling microcapsules, and it is widely used as a solvent in the production of microcapsules, and the spray agent is produced as it is without being removed even after the production of microcapsules. ..

The spray agent is, for example, a solvent or a dispersion medium (in the present specification, "solvent") so that the aqueous dispersion of the microcapsules obtained at the time of manufacturing the microcapsules has an appropriate concentration as the spray agent. It is manufactured by diluting with (see Patent Document 1). As the solvent at the time of dilution, for example, water, alcohol, a mixture thereof, or the like is used. The reason for using alcohol is that a spraying agent having high drying property after spraying can be obtained. As a solvent, a spray agent containing not only water but also alcohol having a boiling point lower than that of water is easier to dry after spraying and is superior in usability.

Japanese Unexamined Patent Publication No. 2012-217960

However, in the dispersion obtained by diluting with a solvent, there is a problem that microcapsules may aggregate during storage and redispersion may become difficult. As a method of suppressing the aggregation of microcapsules, a method of adding a surfactant to the dispersion is known. However, in that case, in order to obtain a sufficient aggregation inhibitory effect, it is necessary to use a large amount of a surfactant, and the concentration of microcapsules in the dispersion cannot be increased. Will be low.

An object of the present invention is to provide a dispersion containing microcapsules and a solvent, suppressing aggregation of microcapsules during storage, and facilitating redispersion of microcapsules after storage.

The present invention is a dispersion, wherein the dispersion contains microcapsules, water, a monohydric alcohol and cellulose nanofibers, and in the dispersion, the cellulose nanofibers with respect to the content of the monohydric alcohol. Provided is a dispersion having a content ratio of 0.015% by mass or more.
In the dispersion of the present invention, it is preferable that the constituent component of the wall material of the microcapsules is polyurea.

According to the present invention, there is provided a dispersion containing microcapsules and a solvent, which suppresses aggregation of microcapsules during storage and facilitates redispersion of microcapsules after storage.

<< Dispersion >>
The dispersion according to one embodiment of the present invention contains microcapsules, water, monohydric alcohol and cellulose nanofibers (sometimes abbreviated as "CNF" in the present specification), and in the above dispersion, The ratio of the content of the cellulose nanofibers (CNF) to the content of the monohydric alcohol is 0.015% by mass or more.
The dispersion of the present embodiment can be produced, for example, by adding alcohol or a mixture of alcohol and water (mixed solvent) to the aqueous dispersion of microcapsules to dilute the aqueous dispersion. The method for producing the dispersion of the present embodiment will be described in detail later.
In the dispersion of the present embodiment, the ratio of the content of CNF to the content of monovalent alcohol is 0.015% by mass or more, so that the aggregation of microcapsules is suppressed in the dispersion during storage. The microcapsules can be easily redispersed in the dispersion after storage.

In the present specification, as described above, the property of suppressing the aggregation of microcapsules in the dispersion during storage is referred to as “aggregation inhibitory”, and the microcapsules can be redispersed in the dispersion after storage. The property is referred to as "redispersability".

<Water>
The water contained in the dispersion may be, for example, blended alone or as a mixture with other components at the time of producing the dispersion.
For example, the water contained in the dispersion may be used in the production of the microcapsules and then brought into the dispersion as it is without being removed.

The water content of the dispersion may be appropriately adjusted according to the use of the dispersion, and is not particularly limited.
For example, when the dispersion is used as a spraying agent, the ratio of the water content to the total mass of the dispersion ([amount of water in the dispersion (parts by mass)] / [of the dispersion] Total mass (parts by mass)] × 100) is preferably 10 to 80% by mass, more preferably 20 to 60% by mass.

<Monohydric alcohol>
The monohydric alcohol used in this embodiment is not particularly limited as long as it is a compound having a structure in which one hydrogen atom (-H) in an aliphatic hydrocarbon is substituted with a hydroxyl group (-OH), and is known. It can be anything.

The monohydric alcohol is, for example, a compound having a structure in which one hydrogen atom in a saturated aliphatic hydrocarbon is substituted with a hydroxyl group (monohydroxylated saturated aliphatic hydrocarbon), and unsaturated aliphatic hydrocarbons. It may be any of a compound having a structure in which one hydrogen atom is substituted with a hydroxyl group (monohydroxylated unsaturated aliphatic hydrocarbon).

The carbon number of the monohydric alcohol is not particularly limited as long as the monohydric alcohol is liquid at room temperature, but is preferably 1 to 5, more preferably 1 to 4, and 2 to 3. Is even more preferable.
In addition, in this specification, "normal temperature" means a temperature which is not particularly cooled or heated, that is, a normal temperature, and examples thereof include a temperature of 15 to 25 ° C.

The boiling point of the monohydric alcohol is not particularly limited, but is preferably 99 ° C. or lower.

Preferred monohydric alcohols include, for example, ethanol, 1-propanol, 2-propanol and the like.

The monohydric alcohol contained in the dispersion may be only one kind, may be two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily adjusted.

The amount of the monohydric alcohol in the dispersion may be appropriately selected depending on the intended purpose, and is not particularly limited.
For example, when the dispersion is used as a spraying agent and used for drying the dispersion, the content of the monovalent alcohol in the dispersion is 0.2 to 0.2 with respect to the content of water. It is 10 times by mass (in other words, the value of [content of monovalent alcohol of dispersion (parts by mass)] / [content of water of dispersion (parts by mass)] is 0.2 to 10). Is preferable, 0.3 to 5 times by mass is more preferable, and 0.4 to 2 times by mass is further preferable. When the content of the monohydric alcohol is at least the lower limit value, it becomes easier to dry the dispersion. When the content of the monohydric alcohol is not more than the upper limit, the excessive use of the monohydric alcohol is suppressed.

<Cellulose Nanofiber (CNF)>
The CNF used in this embodiment is not particularly limited and may be a known one.
More specifically, the CNF includes, for example, cellulose or a derivative thereof, which is a microfibril or an aggregate of microfibrils having a fiber width of 3 to 200 nm.

Examples of the CNF include deflated cellulose nanofibers (deflated CNF) and TEMPO oxidized cellulose nanofibers (TEMPO oxidized CNF).
The defibrated CNF is manufactured by having a step of obtaining a cellulose nanofiber dispersion liquid (CNF dispersion liquid) by performing a defibration treatment on a cellulose nanofiber precursor (CNF precursor) in a dispersion medium such as water. CNF manufactured by the method.
TEMPO Oxidized CNF is a CNF obtained by a chemical denaturation method of cellulose catalyzed by 2,2,6,6-tetramethyl-1-piperidinyloxy, radical (TEMPO).

The CNF precursor is a cellulose that has not been defibrated, and is composed of, for example, an aggregate of microfibrils.
As the CNF precursor, for example, cellulose oxide, that is, one in which a carboxy group is introduced into at least a part of the glucopyranose ring in the cellulose molecule by the oxidation treatment of cellulose may be used.

The cellulose source (raw material containing cellulose) for obtaining the CNF precursor is not particularly limited as long as it contains cellulose, and may be cellulose itself.
Examples of the cellulose source include those containing naturally-derived cellulose having a crystalline structure of cellulose I, and more specifically, for example, various wood pulps, non-wood pulps, bacterial celluloses, waste paper pulps, cottons, and baronia. Examples thereof include cellulose and squirrel cellulose.
Various commercially available products such as cellulose powder and microcrystalline cellulose powder can also be used as a cellulose source.

The method for defibrating the CNF precursor is not particularly limited. As a specific method of defibration treatment, for example, an ultrasonic homogenizer, a low-pressure homogenizer, a high-pressure homogenizer, a counter-collision homogenizer, an ultra-high pressure homogenizer, a ball mill, a planetary mill, a high-speed rotary mixer, a grinding machine, or the like was used. Examples thereof include a mechanical defibration treatment method (in this specification, a CNF obtained by performing a mechanical defibration treatment method is referred to as “mechanical defibration CNF”).
The fact that the treated product obtained by the defibration treatment of the CNF precursor is CNF can be confirmed by observing the fibers of the treated product using, for example, an atomic force microscope (AFM).

When the mechanically defibrated CNF is used in the present embodiment, the aggregation inhibitory property and redispersity of the dispersion are higher and the viscosity of the dispersion is lower than when the TEMPO oxidized CNF is used. , The properties tend to be more favorable.

The CNF contained in the dispersion may be only one kind, may be two or more kinds, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily adjusted.

In the dispersion, the ratio of the content of CNF to the content of monovalent alcohol ([CNF content of dispersion (parts by mass)] / [content of monovalent alcohol of dispersion (parts by mass)] × 100) is 0.015% by mass or more, preferably 0.02% by mass or more, for example, 0.1% by mass or more, 0.2% by mass or more, 0.5% by mass or more, and 1 It may be any of mass% or more. When the ratio is at least the lower limit value, the aggregation inhibitory property and the redispersible property of the dispersion are enhanced.

In the dispersion, the upper limit of the ratio of the content of CNF to the content of monohydric alcohol is not particularly limited. For example, the ratio may be 3% by mass or less so that the viscosity of the dispersion does not become excessively high.

The ratio can be appropriately adjusted within a range set by arbitrarily combining any of the above-mentioned lower limit values and upper limit values. For example, in one embodiment, the ratio is preferably 0.015 to 3% by mass, more preferably 0.02 to 3% by mass, and for example, 0.1 to 3% by mass, 0. It may be any of 2 to 3% by mass, 0.5 to 3% by mass, and 1 to 3% by mass.

<Microcapsules>
The microcapsules used in this embodiment are configured by encapsulating a core substance by a wall material.
In the microcapsules, the constituent component of the wall material (in this specification, it may be abbreviated as "wall material component") and the core substance are not particularly limited, and are arbitrarily selected according to the purpose. can.

[Core substance]
The core substance may be, for example, either an organic compound or an inorganic compound, but is preferably an organic compound.
Examples of the core substance include insect repellents, insecticides, pesticides, fragrances, deodorants, pharmaceuticals, fungicides, and other chemical reactants. The chemical reaction agent inhibits the action of the chemical substance by reacting with a specific chemical substance, and can be used as an insect repellent, a pesticide, a fragrance, a deodorant, a pharmaceutical or a bactericidal agent. It is an ingredient that does not apply.
The core substance is preferably a component suitable for using the dispersion as a spray agent, and more preferably, for example, an insect repellent, an insecticide, a pesticide, a fragrance or a deodorant.

(Insect repellent)
The insect repellent can be arbitrarily selected depending on the intended purpose, and is not particularly limited.
The amount of the insect repellent dissolved in 1 L of water at any temperature of 15 to 25 ° C. is preferably 15 g or less, for example.

The insect repellent is preferably liquid at room temperature.

Examples of the insect repellent include N, N-diethyl-3-methylbenzamide (also known as N, N-diethyl-m-toluamide, DEET) and 1- (1-methylpropoxycarbonyl) -2- (2-hydroxy). Ethyl) piperidine (also known as icaridin) and the like can be mentioned.

In the microcapsules, the core substance contained in the wall material may be only one kind, may be two or more kinds, and when there are two or more kinds, the combination and the ratio thereof shall be. It can be selected arbitrarily.

[Wall material, wall material component]
The wall material component (component of the wall material) is not particularly limited as long as it has a film-forming ability, but is preferably a polycondensate, and more preferably an oligomer or a polymer.

Preferred wall material components include, for example, polyurea, polyurethane, polyamide and the like. All of these can be formed by a known method and are suitable for forming by the interfacial polycondensation method described later.
As used herein, the term "polyurea" means an oligomer or polymer having a bond (urea bond) represented by the formula "-NH-C (= O) -NH-", and for example, as a raw material compound, 2 It is obtained by subjecting an isocyanate compound having two or more isocyanate groups and an amine compound having two or more amino groups to a polycondensation reaction.
"Polyurethane" means an oligomer or polymer having a bond (urethane bond) represented by the formula "-NH-C (= O) -O-", and for example, as a raw material compound, two or more isocyanate groups. It is obtained by subjecting an isocyanate compound having two or more hydroxyl groups (-OH) to a polycondensation reaction with the hydroxy compound having two or more hydroxyl groups (-OH).
The "polyamide" means an oligomer or polymer having a bond (amide bond) represented by the formula "-NH-C (= O)-", and for example, as a raw material compound, two or more carboxy groups (-). A carboxylic acid having C (= O) -OH), or a carboxylic acid chloride in which one or more carboxy groups thereof are replaced with a chlorocarbonyl group (-C (= O) -Cl) and two. It is obtained by subjecting the above amine compounds having an amino group to a polycondensation reaction.

The wall material component of the microcapsules is preferably polyurea. By using such microcapsules, the aggregation inhibitory property and redispersibility of the dispersion are further enhanced.

<Other ingredients>
The dispersion may contain microcapsules, water, monohydric alcohol, and other components that do not fall under any of CNF, as long as the effects of the present invention are not impaired.
The other components are not particularly limited and can be arbitrarily selected depending on the method for producing the dispersion and the purpose of use.
The other components may be those used in the production of the microcapsules and then brought into the dispersion as they are without being removed.

The other components contained in the dispersion may be only one kind, two or more kinds, and when two or more kinds, the combination and ratio thereof can be arbitrarily adjusted.

Examples of the other component include a solvent that does not correspond to any of water and a monohydric alcohol; an emulsifier and the like.

Among the other components, examples of the solvent include organic solvents other than monohydric alcohols.
The organic solvent may be either a hydrophilic solvent or a hydrophobic solvent.
Examples of the organic solvent include alcohols other than monohydric alcohols (that is, polyhydric alcohols such as dihydric alcohols), amides, nitriles, ketones, esters, ethers, hydrocarbons, halogenated hydrocarbons, and phenols (phenolic). Compounds having a hydroxyl group), carbon sulfide, carboxylic acid and the like can be mentioned.

Among the other components, known emulsifiers can be mentioned.
Examples of the emulsifier include alkylbenzene sulfonates such as polyvinyl alcohol, carboxymethyl cellulose, ethyl cellulose, methyl cellulose, casein, gum arabic, gelatin, funnel oil, sodium benzenesulfonate, sodium dodecylbenzenesulfonate, and polyoxyethylene sulfate. Examples thereof include ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, poly (meth) acrylic acid and the like.
In addition, in this specification, "(meth) acrylic acid" is a concept including both "acrylic acid" and "methacrylic acid".

The total content of the microcapsules, water, monohydric alcohol, and CNF of the dispersion may be appropriately adjusted according to the use of the dispersion, and is not particularly limited.
For example, in the dispersion, the ratio of the total content of microcapsules, water, monovalent alcohol, and CNF to the total mass of the dispersion ([Microcapsules in the dispersion, water, and monovalent]. The total amount of alcohol and CNF (parts by mass)] / [total mass of dispersion (parts by mass)] × 100) is preferably 80% by mass or more, for example, 90% by mass or more, 95% by mass. It may be any of% or more, 97% by mass or more, and 99% by mass or more. When the ratio is at least the lower limit value, the aggregation inhibitory property and the redispersible property of the dispersion become higher.
In other words, in the dispersion, the ratio of the content of the other component to the total mass of the dispersion ([amount of the other component in the dispersion (parts by mass)] / [total mass of the dispersion (mass)). Part)] × 100) is preferably 20% by mass or less, and may be, for example, 10% by mass or less, 5% by mass or less, 3% by mass or less, or 1% by mass or less.

In the dispersion, the ratio of the total content of the microcapsules, water, monohydric alcohol, and CNF to the total mass of the dispersion may be 100 mass or less.

The thickness of the film or layer of the wall material is not particularly limited and may be, for example, 50 to 1000 nm.

The average particle size of the microcapsules is not particularly limited. For example, the average particle size may be any of 0.5 to 20 μm, 0.5 to 16 μm, 0.5 to 13 μm, 0.5 to 10 μm, 1 to 7 μm, and 1.5 to 4 μm.

As used herein, the term "average particle size" means the medium diameter of a volume particle size distribution measured with a particle size distribution meter for particles, unless otherwise specified.

The microcapsules can be made to have sustained release properties that gradually release the contained insect repellent to the outside over time. Such microcapsules can sustain the action of the insect repellent for a long period of time and are suitable as, for example, an insect repellent.

Hereinafter, an example of microcapsules (hereinafter referred to as “microcapsules (A)”) composed of polyurea as a constituent component of a wall material and an insect repellent as a core substance will be described in detail.

○ Microcapsules (A)
The microcapsules (A) contain a polycondensate of an isocyanate compound and an amine compound (that is, polyurea) as a constituent component of the wall material, and the wall material contains an insect repellent, and the isocyanate compound is polymethylene. It includes polyphenylpolyisocyanate (in this specification, may be referred to as "polymeric MDI") and a diisocyanate modified product having an isocyanate group content of 20% by mass or more.
The microcapsules (A) are highly safe because melamine resin, which requires the use of formaldehyde, is not the main constituent of the wall material. Further, in the microcapsules (A), the amount of the insect repellent contained in the microcapsules (A) is increased by selecting a specific range of polyurea as the wall material component.

As used herein, the term "isocyanate compound" means a compound having an isocyanate group (-NCO).
In the present specification, the modified isocyanate group in the diisocyanate modified product described later is not included in the isocyanate group.
In the present specification, the "isocyanate group content of the isocyanate compound" means the amount of the isocyanate group contained in one molecule of the isocyanate compound, and is calculated by the following formula.
[Isocyanate group content of isocyanate compound (% by mass)] = [Amount of isocyanate groups in 1 mol of isocyanate compound (parts by mass)] / [Molecular weight of isocyanate compound] × 100

In the present specification, unless otherwise specified, the description of a mere "diisocyanate modified product" means the above-mentioned diisocyanate modified product having an NCO content of 20% by mass or more.

In the microcapsules (A), the constituent component (wall material component) of the wall material is only a polycondensate of an amine compound and the above-mentioned specific range of isocyanate compounds, that is, a specific range of polyurea, or this. Polyurea such as is the main ingredient. As described above, the microcapsules (A) are highly safe because the melamine resin, which requires the use of formaldehyde, is not used as the main constituent component of the wall material.
Further, in the microcapsules (A), the amount of the insect repellent contained in the microcapsules (A) is increased by selecting the polyurea in a specific range as described above.

[Wall material]
The thickness of the film or layer of the wall material is not particularly limited and may be, for example, 50 to 1000 nm.

[Isocyanate compound]
The isocyanate compound, which is a raw material for producing the microcapsules (A), contains a polypeptide MDI and the diisocyanate modified product.
The isocyanate compound contains a polypeptide MDI and the diisocyanate modified product as main components, and may contain only the polypeptide MDI and the diisocyanate modified product, and the polypeptide MDI and the diisocyanate modified product may be contained as long as the effects of the present invention are not impaired. Means and other isocyanates that do not fall under any of these and have two or more isocyanate groups in one molecule (in this specification, may be abbreviated as "other isocyanates"). , May be included.
When only the polypeptide MDI and the diisocyanate modified product are used as the isocyanate compound, the wall material component is a structural unit derived from the polypeptide MDI and a structural unit derived from the diisocyanate modified product as the structural unit derived from the isocyanate compound. And only have. On the other hand, when a polypeptide MDI, the diisocyanate modified product, and the other isocyanate are used as the isocyanate compound, the wall material component is a constituent unit derived from the polypeptide MDI and the constituent unit derived from the isocyanate compound. It has a structural unit derived from a diisocyanate modified product and a structural unit derived from the other isocyanate.

The polypeptide MDI and the diisocyanate modified product form the wall material component constituting the microcapsules (A) by a polycondensation reaction with the amine compound.
That is, the wall material component more specifically has both a polycondensation structure of a polypeptide MDI and an amine compound and a polycondensation structure of a diisocyanate modified product and an amine compound.
When the other isocyanate is used, the other isocyanate may form the wall material component by the polycondensation reaction with the amine compound. Therefore, the wall material component is the above two types of polycondensation. In addition to the structure, it may also have a polycondensation structure of the other isocyanate and an amine compound. However, even in this case, the main structure of the wall material component is a polycondensation structure of the polypeptide MDI and the amine compound, and a polycondensation structure of the diisocyanate modified product and the amine compound.

(Polymeric MDI)
Polymeric MDI is represented by the following general formula (P1).

（式中、ｎは０以上の整数である。）

(In the formula, n is an integer greater than or equal to 0.)

In the general formula (P1), n may be an integer of 0 or more, and may be, for example, 0 to 100.

The NCO content of the polypeptide MDI can be adjusted as appropriate, but is preferably 30 to 32% by mass, more preferably 30.5 to 32% by mass.

Polymeric MDI is liquid at room temperature, and its viscosity at 25 ° C. is not particularly limited, but is preferably 150 to 250 mPa · s.

There are a plurality of types of polypeptide MDI depending on the number of n.
The polypeptide MDI (in other words, the structural unit derived from the polypeptide MDI of the wall material component) used at the time of forming the wall material component may be only one type, two or more types, or two or more types. If so, their combinations and ratios can be arbitrarily selected.

(Diisocyanate modified product)
The NCO content of the diisocyanate modified product is 20% by mass or more.
The NCO content of the diisocyanate modified product is, for example, 22% by mass or more, or 24% by mass or more, in that microcapsules (A) having a large amount of insect repellent can be produced more stably. You may.

The upper limit of the NCO content of the diisocyanate modified product is not particularly limited. For example, the NCO content of the diisocyanate modified product may be 28% by mass or less in that the microcapsules (A) can be produced more stably.

The NCO content of the diisocyanate modified product can be appropriately adjusted within a range set by arbitrarily combining any of the above-mentioned lower limit values and upper limit values. For example, in one embodiment, the NCO content may be any of 20-28% by weight, 22-28% by weight, and 24-28% by weight.

The diisocyanate modified product is not particularly limited as long as its NCO content is 20% by mass or more.
The modified diisocyanate may be either a modified aliphatic diisocyanate or a modified aromatic diisocyanate.
As used herein, the term "aliphatic diisocyanate" means a diisocyanate having an aliphatic group and no aromatic group. Further, the "aromatic diisocyanate" is a diisocyanate having an aromatic group and no aliphatic group, or a diisocyanate having both an aromatic group and an aliphatic group, that is, a diisocyanate having at least an aromatic group. Means.

The aliphatic group in the aliphatic diisocyanate may be linear, branched or cyclic.
In the present specification, a cyclic aliphatic group may be referred to as an "aliphatic cyclic group". The cyclic aliphatic group (aliphatic cyclic group) may have a cyclic structure and may not have a chain-like (that is, linear or branched chain-like) structure, and may have a cyclic structure and a chain-like structure. They may have both structures, i.e., they have at least a cyclic structure. The aliphatic cyclic group may be either monocyclic or polycyclic.
The aromatic group in the aromatic diisocyanate may be either monocyclic or polycyclic.

The diisocyanate modified product is preferably an aliphatic diisocyanate modified product, and more preferably an aliphatic diisocyanate modified product having a linear aliphatic group.
Examples of such a diisocyanate modified product include a pentamethylene diisocyanate (may be abbreviated as “PDI” in the present specification) modified product and a hexamethylene diisocyanate (abbreviated as “HDI” in the present specification). (May be) Examples include denatured substances.

The diisocyanate modified product may be referred to as, for example, a biuret modified product of diisocyanate, an isocyanurate modified product, or a trimethylolpropane adduct modified product (in the present specification, a “TMP adduct modified product” or a “TMP adduct product”. ), And allophanate modified product and the like.
In this specification, for example, "diisocyanate biuret modified product" may be referred to as "diisocyanate-biuret modified product". The same applies to the other diisocyanate modified products.

More specifically, examples of the diisocyanate modified product include an isocyanurate modified product of PDI, a biuret modified product of HDI, and an isocyanurate modified product of HDI.

The diisocyanate modified product (in other words, the structural unit derived from the diisocyanate modified product of the wall material component) used at the time of forming the wall material component may be only one type or two or more types. When there are two or more kinds, the combination and the ratio thereof can be arbitrarily selected.

The diisocyanate modified product used at the time of forming the wall material component is preferably one or more selected from the group consisting of PDI modified products and HDI modified products, and is preferably an isocyanurate modified product of PDI and biuret modified products of HDI. More preferably, it is one or more selected from the group consisting of the body and the isocyanurate denatured product of HDI.
In other words, the wall material component is one or more selected from the group consisting of the constituent unit derived from the PDI modified product and the constituent unit derived from the HDI modified product as the constituent unit derived from the diisocyanate modified product. One selected from the group consisting of a structural unit derived from an isocyanurate modified product of PDI, a structural unit derived from a biuret modified product of HDI, and a structural unit derived from an isocyanurate modified product of HDI. Or it is more preferable to have two or more kinds.

(Other isocyanates)
The other isocyanate is not particularly limited as long as it has two or more isocyanate groups in one molecule and does not fall under any of the polypeptide MDI and the diisocyanate modified product.

In the wall material component, the ratio of the number of the constituent units derived from the other isocyanates to the total number of the constituent units derived from the polypeptide MDI, the constituent units derived from the diisocyanate modified product, and the constituent units derived from the other isocyanates. ([Number of structural units derived from the other isocyanate in the wall material component] / ([Number of structural units derived from polypeptide MDI in the wall material component] + [Constituent unit derived from the diisocyanate modified product in the wall material component] ] + [Number of the other isocyanate-derived constituent units in the wall material component] × 100) is preferably 10% or less, more preferably 5% or less, and 3% or less. It is more preferably 1% or less, and more preferably 1% or less. When the ratio is not more than the upper limit, a microcapsule (A) having a larger amount of the insect repellent is obtained.

[Amine compound]
The amine compound is not particularly limited as long as it has two or more amino groups in one molecule.
In the present specification, unless otherwise specified, the description of a mere "amine compound" means such a compound having two or more amino groups.

The number of amino groups contained in one molecule of the amine compound is not particularly limited as long as it is 2 or more, but is preferably 2 to 6, more preferably 2 to 5, and 2 to 5. It is more preferably 4 pieces, and particularly preferably 2 or 3 pieces.

The amine compound preferably has no isocyanate group or a hydroxyl group, and more preferably has neither an isocyanate group nor a hydroxyl group.

The amine compound is preferably an organic polyvalent amine compound.
The organic polyvalent amine compound may be linear, branched or cyclic, but is preferably linear or branched.

Preferred organic polyvalent amine compounds are, for example, aliphatic polyvalent amine compounds having a structure in which two or more hydrogen atoms (-H) of an aliphatic hydrocarbon are substituted with an amino group (-NH ₂ ). The NH-substituted aliphatic polyvalent structure having a structure in which one or more methylene groups ( _-CH2- ) of the aliphatic polyvalent amine compound are substituted with a group represented by the formula "-NH-". Examples include amine compounds.

In the aliphatic polyvalent amine compound, the bonding position of the amino group is not particularly limited, and may be bonded to a carbon atom at the end of the main chain or side chain, or may be bonded to a carbon atom at the end of the main chain or side chain, or the non-terminal of the main chain or side chain. It may be bonded to the carbon atom of the part.
In the aliphatic polyvalent amine compound, it is preferable that two or more amino groups are not bonded to the same carbon atom.
As used herein, the term "main chain" means a chain of chains existing in a molecule having the largest number of atoms forming the chain skeleton. "Side chain" means a chain of chain skeletons present in a molecule that does not fall under the backbone.

The aliphatic polyvalent amine compound preferably has an amino group bonded to a carbon atom at at least one or both ends of the main chain, and an amino group bonded to a carbon atom at at least both ends of the main chain. Such a substance is more preferable, and examples thereof include an aliphatic diamine compound in which an amino group is bonded to a carbon atom at both ends of the main chain.

Preferred examples of the aliphatic polyvalent amine compound include 1,3-diaminopropane (NH ₂ -CH ₂ CH ₂ CH ₂ -NH ₂ ) and the like.

In the NH-substituted aliphatic polyvalent amine compound, the position of the methylene group substituted with the group represented by the formula "-NH-" is not particularly limited, but is adjacent to the carbon atom to which the amino group is bonded. It is preferably a non-methylene group.
In the NH-substituted aliphatic polyvalent amine compound, the number of methylene groups substituted with the group represented by the formula "-NH-" varies depending on the carbon number of the amine compound, and is, for example, 1 to 4. It may be 1 to 3 or 1 to 2.

Preferred NH-substituted aliphatic polyvalent amine compounds include, for example, diethylenetriamine ( _{NH2-CH 2 CH 2-NH-CH 2 CH 2-NH 2 ) , N , N'} -bis (3-aminopropyl). Ethylenediamine (NH ₂ -CH ₂ CH ₂ CH ₂ -NH-CH ₂ CH ₂ -NH-CH ₂ CH ₂ CH ₂ -NH ₂ ) and the like can be mentioned.

The amine compound used at the time of forming the wall material component (in other words, the structural unit derived from the amine compound contained in the wall material component) may be only one kind or two or more kinds. In the case of species or more, their combinations and ratios can be arbitrarily selected.

The wall material component may contain only a polycondensate (polyurea) of the isocyanate compound and an amine compound, or the polycondensate and other polycondensates as long as the effects of the present invention are not impaired. It may contain one or both of oligomers and polymers.

The other oligomers and polymers contained in the wall material component may be of only one type, may be of two or more types, and when there are two or more types, the combination and ratio thereof may be determined. It can be selected arbitrarily.

In the microcapsule (A), the ratio of the total content of the other oligomers and polymers in the wall material component to the total mass of the wall material component ([the other in the wall material component in the microcapsule (A)). Total content of oligomers and polymers (parts by mass)] / [total mass of wall material components in microcapsules (A) (parts by mass)] x 100) is preferably 5% by mass or less, preferably 3% by mass. It is more preferably 1% by mass or less, and particularly preferably 1% by mass or less.
In other words, in the microcapsules (A), the ratio of the content of the polycondensate in the wall material component to the total mass of the wall material component ([the polycondensation in the wall material component in the microcapsules (A)). Content of substance (parts by mass)] / [total mass of wall material components (parts by mass) in microcapsules (A)] × 100) is preferably 95% by mass or more, preferably 97% by mass or more. It is more preferable, and it is particularly preferable that it is 99% by mass or more.
When these ratios are in such a range, microcapsules (A) having a larger amount of insect repellent included can be obtained.

<Insect repellent>
The insect repellent in the microcapsules (A) is the same as described above.

The average particle size of the microcapsules (A) is not particularly limited, but is preferably 3 μm or more, more preferably 4 μm or more, further preferably 5 μm or more, and for example, 8 μm or more and 10 μm or more. It may be either. The microcapsules (A) having the average particle size equal to or larger than the lower limit are advantageous in that the amount of the insect repellent contained is larger.

The upper limit of the average particle size of the microcapsules (A) is not particularly limited. For example, the microcapsules (A) having an average particle size of 16 μm or less can be more easily produced.

The average particle size of the microcapsules (A) can be appropriately adjusted within a range set by arbitrarily combining any of the above-mentioned lower limit values and upper limit values. For example, in one embodiment, the average particle size of the microcapsules (A) is preferably 3 to 16 μm, more preferably 4 to 16 μm, even more preferably 5 to 16 μm, for example, 8 It may be any of ~ 16 μm and 10 ~ 16 μm.

The degree of inclusion of the insect repellent in the microcapsules (A) can be determined, for example, by the inclusion rate of the insect repellent in the microcapsules calculated by the following formula.
[Encapsulation rate of insect repellent in microcapsules (% by mass)] = [Contents of insect repellent in microcapsules (parts by mass)] / [Amount of insect repellent used in manufacturing microcapsules (parts by mass)] × 100

The encapsulation rate of the insect repellent in the microcapsules (A) is preferably 75% by mass or more, more preferably 80% by mass or more, and for example, 82.5% by mass or more and 85% by mass or more. It may be either.

The upper limit of the inclusion rate is 100% by mass. For example, microcapsules having an encapsulation rate of 93% by mass or less can be more easily produced.

Usually, in a microcapsule having a large amount of a core substance, its shape is close to a true sphere and its particle size (average particle size) is large. The microcapsules (A) have such characteristics, and the amount of the insect repellent, which is the core substance, is large.
For example, the shape of microcapsules can be observed using a scanning electron microscope (SEM).

<< Manufacturing method of microcapsules (A) >>
The microcapsules (A) can be produced by subjecting the isocyanate compound and the amine compound to a polycondensation reaction in the presence of an insect repellent.

In the present embodiment, by selecting a combination of the polypeptide MDI and the diisocyanate modified product as the reaction target of the amine compound, that is, the isocyanate compound, the microcapsules (A) having a large amount of the insect repellent are included. Is obtained.
Polymeric MDI has a relatively high reactivity with an amine compound and can be used for forming a wall material component, but easily reacts with a component other than the intended one, and reacts with, for example, a compound having a hydroxyl group (-OH) or the like. easy. Examples of such compounds include emulsifiers. Therefore, when the majority of the isocyanate compound is a polypeptide MDI or the isocyanate compound is only a polypeptide MDI, side reactions during the polycondensation reaction are not suppressed, and the target microcapsules (A) are obtained almost or completely. I can't.
On the other hand, in the present embodiment, the reactivity between the isocyanate compound and the amine compound is adjusted by using the diisocyanate modified product having lower reactivity than the polypeptide MDI in addition to the polypeptide MDI, and as a result, the reactivity is adjusted. It is presumed that the desired microcapsules (A) can be obtained in high yield.

At the time of the polycondensation reaction, other components that do not correspond to any of the isocyanate compound (polymeric MDI, the diisocyanate modified product, the other isocyanate) and the amine compound may be used.
Examples of the other components include solvents, emulsifiers and the like.
For example, polycondensation can be performed as interfacial polycondensation by performing a polycondensation reaction in the coexistence of water and a hydrophobic component.

Among the other components, examples of the solvent include water, an organic solvent and the like.
The organic solvent may be either a hydrophilic solvent or a hydrophobic solvent, but a hydrophobic solvent is preferable.
Examples of the hydrophobic solvent include alcohols, amides, nitriles, ketones, esters, ethers, hydrocarbons, halogenated hydrocarbons, phenols (compounds having a phenolic hydroxyl group), carbon sulfide, carboxylic acids and the like.

Among the other components, known emulsifiers can be mentioned.
Examples of the emulsifier include alkylbenzene sulfonates such as polyvinyl alcohol, carboxymethyl cellulose, ethyl cellulose, methyl cellulose, casein, gum arabic, gelatin, funnel oil, sodium benzenesulfonate, sodium dodecylbenzenesulfonate, and polyoxyethylene sulfate. Examples thereof include ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, poly (meth) acrylic acid and the like.

The emulsifier is preferably polyvinyl alcohol in that the emulsified state of the reaction solution during the polycondensation reaction is better and the microcapsules (A) can be more easily produced.

The insect repellent, polypeptide MDI, the diisocyanate modified product, the other isocyanate, the amine compound, and the other components used in the polycondensation reaction may be only one kind or two or more kinds. There may be two or more kinds, and the combination and the ratio thereof can be arbitrarily selected.

At the time of the polycondensation reaction, the total amount of the polypeptide MDI and the diisocyanate modified product used is preferably 20 to 55 parts by mass and 25 to 50 parts by mass with respect to 100 parts by mass of the insect repellent. More preferably, it is more preferably 30 to 45 parts by mass. When the total amount used is at least the lower limit, the microcapsules (A) having a large amount of the insect repellent contained can be produced more stably. When the total amount used is not more than the upper limit, the excessive use of the polypeptide MDI or the diisocyanate modified product is suppressed.

At the time of the polycondensation reaction, the ratio of the amount of the diisocyanate modified product used to the amount of the polypeptide MDI is preferably 100 to 450% by mass, more preferably 140 to 400% by mass, and 180 to 180. It is more preferably 350% by mass. When the ratio is in such a range, the microcapsules (A) having a large amount of the insect repellent contained can be produced more stably.

At the time of the polycondensation reaction, the total amount of the polypeptide MDI and the diisocyanate modified product and the amount of the amine compound used are [the number of moles of amino groups in the amine compound]: [polymeric MDI and the diisocyanate modified product. The molar ratio of [total number of moles of isocyanate groups] is preferably 10:90 to 60:40, more preferably 20:80 to 40:60. When the number of moles of amino groups in the amine compound is set to be smaller than the total number of moles of isocyanate groups in the polypeptide MDI and the diisocyanate modified product, higher quality microcapsules (A) can be obtained.

The amount of the other components used during the polycondensation reaction can be appropriately adjusted according to the type.
For example, when the other component is a solvent, the amount of the other component (solvent) used is the total amount of the insect repellent, the polypeptide MDI, the diisocyanate modified product, the other isocyanate, and the amine compound. It is preferably 100 to 250 parts by mass with respect to 100 parts by mass, and may be, for example, 100 to 210 parts by mass or 100 to 170 parts by mass.

For example, when the other component is an emulsifier, the amount of the emulsifier used is 4 to 100 parts by mass based on 100 parts by mass of the total amount of the polypeptide MDI, the diisocyanate modified product, the other isocyanate, and the amine compound. It is preferably 25 parts by mass, more preferably 7 to 20 parts by mass, and particularly preferably 10 to 15 parts by mass. When the amount used is at least the lower limit, the emulsified state of the reaction solution at the time of the polycondensation reaction becomes better. When the amount used is not more than the upper limit, overuse of the emulsifier is suppressed.

For example, when the other component is a component that does not correspond to any of the solvent and the emulsifier, the amount of the other component used is the insect repellent, the polypeptide MDI, the diisocyanate modified product, the other component. The total amount of the isocyanate and the amine compound used is preferably 10 parts by mass or less, preferably 5 parts by mass or less, or 1 part by mass or less.

The temperature at which the polycondensation reaction is carried out (that is, the reaction temperature) is not particularly limited, but is preferably 60 to 110 ° C, more preferably 65 to 100 ° C, and particularly preferably 70 to 90 ° C. preferable.

The time for performing the polycondensation reaction (that is, the reaction time) is preferably 0.5 to 5 hours, more preferably 1 to 4 hours, and particularly preferably 1.5 to 3 hours.

After the polycondensation reaction, for example, the microcapsules (A) are obtained as a dispersion such as an aqueous dispersion.

The obtained microcapsules (A) may be used as they are for the intended purpose, or may be used for the intended purpose after being post-treated, purified, etc. by a known method as needed. It may be used for the intended purpose after removing the dispersion medium.

When the solvent other than water is used during the polycondensation reaction, the wall material may contain this solvent in addition to the insect repellent in the obtained microcapsules (A). Further, depending on the conditions of the polycondensation reaction, the wall material may contain other components in addition to the insect repellent and the solvent.

The solvent and other components contained in the wall material may be of only one kind, may be two or more kinds, and when there are two or more kinds, the combination and ratio thereof shall be. It can be selected arbitrarily.

The amount of the insect repellent, the solvent and other components contained in the microcapsules (A) can be adjusted according to the production conditions of the microcapsules (A).

The rotation speed of the stirring means during the polycondensation reaction (in other words, the stirring speed of the reaction solution) may be, for example, either 300 to 900 rpm or 400 to 700 rpm.
For example, when the amount of the insect repellent used in the polycondensation reaction is 50 to 200 g, such a stirring speed is particularly suitable. However, the amount of the insect repellent used is not limited to these.

As an example of a more specific method for producing the microcapsule (A), for example, a second solution containing water and an emulsifier contains a polypeptide MDI, the diisocyanate modified product, and an insect repellent. A step of adding a solution to obtain an emulsified solution (in this specification, it may be abbreviated as "emulsifying step"), and a third solution containing water and an amine compound are added to the emulsified solution to add weight. A production method having a step of performing a condensation reaction (in this specification, it may be abbreviated as "hypercondensation step") (in this specification, it may be referred to as "manufacturing method (I)"). Can be mentioned. However, the method for producing the microcapsules (A) is not limited to this production method (I).
Hereinafter, the manufacturing method (I) will be described.

<Emulsification process>
In the emulsification step of the production method (I), the second solution is added to the first solution to obtain an emulsified solution.

[First solution]
The first solution contains water and an emulsifier, and, if necessary, contains water and the other components that do not fall under any of the emulsifiers, as long as the effects of the present invention are not impaired. You may.

The emulsifier and other components used in the preparation of the first solution may be only one kind or two or more kinds, respectively, and when there are two or more kinds, the combination and the ratio thereof shall be. It can be selected arbitrarily.

The ratio of the content of the emulsifier to the total mass of the first solution (that is, the concentration of the emulsifier in the first solution) is not particularly limited, but is preferably 1 to 15% by mass, preferably 2 to 8% by mass. Is more preferable.

When the first solution contains the other component, the content of the other component can be appropriately adjusted according to the purpose.

The first solution is obtained by blending water, an emulsifier, and, if necessary, the other components.
The first solution is preferably prepared by adding an emulsifier to water. When the other components are used, the timing of addition and the target to be added can be appropriately adjusted according to the type of the other components.
When preparing the first solution, for example, after blending all the components, the mixture is heated and stirred at preferably 80 to 100 ° C., preferably 0.5 to 3 hours, and then cooled to a room temperature of 27 ° C. or lower. Thereby, the first solution may be prepared.

[Second solution]
The second solution contains a polypeptide MDI, the diisocyanate modified product, an insect repellent, and, if necessary, the other isocyanate, and further, to the extent that the effects of the present invention are not impaired. It may contain the other component which does not correspond to any of the components (polymeric MDI, the diisocyanate modified product, the insect repellent, the other isocyanate).

The polypeptide MDI, the diisocyanate modified product, the insect repellent, the other isocyanate, and the other components used in the preparation of the second solution may be only one kind or two or more kinds, respectively. When there are two or more kinds, the combination and the ratio thereof can be arbitrarily selected.

In the production method (I), the total content of the polypeptide MDI and the diisocyanate modified product in the second solution is preferably 20 to 55 parts by mass with respect to 100 parts by mass of the insect repellent. It is more preferably to 50 parts by mass, and further preferably 30 to 45 parts by mass.

In the production method (I), the ratio of the content of the diisocyanate modified product to the content of the polypeptide MDI in the second solution is preferably 100 to 450% by mass, preferably 140 to 400% by mass. Is more preferable, and 180 to 350% by mass is further preferable.

Examples of the other component in the second solution include a solvent.
By using the solvent, the solubility of the contained component can be adjusted in the second solution.
Examples of the solvent in the second solution include water, an organic solvent, and the like, and the organic solvent is the same as that described above.

When the second solution contains the other isocyanate or the other component, the content of these components can be appropriately adjusted according to the purpose.

The second solution is obtained by blending a polypeptide MDI, the diisocyanate denaturant, an insect repellent,, if necessary, the other isocyanate, and, if necessary, the other component.
When the insect repellent is liquid at room temperature, the second solution contains the insect repellent with a polypeptide MDI, the diisocyanate modified product,, if necessary, the other isocyanate, and, if necessary, other components. It is preferable to prepare by adding.
When preparing the second solution, for example, from the blending of raw materials (polymeric MDI, the diisocyanate modified product, the insect repellent, other isocyanates, other components) to stirring after blending all the components, preferably 15 It can be carried out at ~ 28 ° C. The stirring time after blending all the components may be, for example, 1 to 60 minutes.

In the emulsification step, when the second solution is added to the first solution, the second solution may be added all at once or dropped.

In the emulsification step, for example, from the initial step of adding the second solution to the first solution to stirring after the addition can be performed at preferably 15 to 28 ° C. The stirring time after adding the second solution to the first solution may be, for example, 1 to 60 minutes.

In the emulsification step, the second solution is added to the first solution and the obtained mixed solution is stirred, so that when the emulsion is obtained, the stirring rate of the mixed solution is adjusted to microncapsulate. The particle size (average particle size) of the capsule (A) can be adjusted. More specifically, the slower the stirring speed, the larger the particle size of the microcapsules (A), and the faster the stirring speed, the smaller the particle size of the microcapsules (A).

The stirring speed of the mixed liquid (in other words, the rotation speed of the stirring means) when obtaining the emulsion may be, for example, either 300 to 1000 rpm or 400 to 800 rpm.
For example, when the amount of the insect repellent used at the time of emulsification is 50 to 200 g, such a stirring speed is particularly suitable. However, the amount of the insect repellent used is not limited to these.

<Polycondensation process>
In the polycondensation step, the third solution is added to the emulsified solution obtained in the emulsification step to carry out a polycondensation reaction.

[Third solution]
The third solution contains water and an amine compound, and may contain the other components other than water, if necessary, as long as the effects of the present invention are not impaired.

The amine compound and other components used in the preparation of the third solution may be only one kind or two or more kinds, respectively, and when they are two or more kinds, the combination and ratio thereof are , Can be selected arbitrarily.

The ratio of the content of the amine compound to the total mass of the third solution (that is, the concentration of the amine compound in the third solution) is not particularly limited, but is preferably 5 to 40% by mass, preferably 10 to 30. More preferably, it is by mass.

In the production method (I), the amount of the emulsifier in the first solution, the amount of the polypeptide MDI and the diisocyanate modified product in the second solution, and the amount of the amine compound in the third solution have been described above. The amounts of the first solution, the second solution, and the third solution may be adjusted so as to be related to each other.

When the third solution contains the other component, the content of the other component can be appropriately adjusted according to the purpose.

The third solution is obtained by blending water, an amine compound, and, if necessary, the other components.
The third solution may be prepared, for example, by adding water to the amine compound, or by adding the amine compound to water. When the other components are used, the timing of addition and the target to be added can be appropriately adjusted according to the type of the other components.
At the time of preparation of the third solution, for example, the third solution may be prepared by mixing all the components and then stirring at preferably 15 to 28 ° C., preferably 1 to 60 minutes.

In the polycondensation step, when the third solution is added to the emulsion, the third solution may be added all at once or dropped.

In the production method (I), in the polycondensation step, the reaction temperature, the reaction time, and the stirring speed of the reaction solution are set to the above-described reaction temperature, reaction time, and reaction solution for performing the polycondensation reaction. It is preferable to set the stirring speed.

In the production method (I), the microcapsules (A) are obtained as an aqueous dispersion by performing the polycondensation step.

The microcapsules (A) have a sustained release property that gradually releases the contained insect repellent to the outside with time, regardless of the manufacturing method thereof. Therefore, the microcapsules (A) can sustain the action of the insect repellent for a long period of time.

The microcapsules (A) are suitable, for example, as an insect repellent.
For example, a liquid insect repellent can be obtained by preparing a liquid composition containing microcapsules (A) or by using the product of the polycondensation reaction obtained by the above-mentioned production method as it is. Further, by applying these liquid insect repellents and drying them, a layered (for example, film-shaped) insect repellent can be obtained.
Further, by preparing a resin composition containing the microcapsules and molding the resin composition, a solid insect repellent such as a sheet can be obtained.

The reason why the aggregation of microcapsules is suppressed in the dispersion during storage is not clear, but it is presumed as follows.
That is, the microcapsules are initially in a well-dispersed state in the dispersion. This is brought about by sufficient mixing of the dispersion, which may be more stable, for example, if the dispersion contains some component other than microcapsules, such as an emulsifier. ..
However, during storage of the dispersion, the microcapsules tend to be unevenly distributed, for example, they tend to settle. In that case, the microcapsules that were initially well dispersed will be aggregated. This is because monohydric alcohol affects some factors that suppressed the aggregation of microcapsules. For example, even if the aggregation of microcapsules is initially suppressed by some component such as an emulsifier, the aggregation of microcapsules progresses by the action of monohydric alcohol on such components.
On the other hand, since the dispersion of the present embodiment contains a specific amount of CNF, the influence (action) of the monohydric alcohol is reduced, and as a result, in the dispersion during storage, Even if the microcapsules settle, it is presumed that the progress of aggregation is suppressed.
It is presumed that the suppression of the aggregation of the microcapsules in this way further facilitates the redispersion of the microcapsules in the dispersion after storage.
The dispersion of the present embodiment exhibits the above-mentioned excellent effects, for example, regardless of the timing of blending the monohydric alcohol in the production process thereof.

<< Manufacturing method of dispersion >>
The dispersion contains microcapsules, water, a monohydric alcohol, CNF, and, if necessary, the other components, and at this time, the amount of CNF to be added to the amount of monohydric alcohol to be added. By setting the ratio to 0.015% by mass or more and dispersing the formulation. Can be manufactured.
When blending microcapsules, water, monohydric alcohol, CNF and the other ingredients, these blended ingredients may be added individually or in whole in whole, or in small portions or in small amounts. Alternatively, it may be added in divided portions. Further, as the compounding component, the whole amount may be added all at once as a mixture in which two or more kinds thereof are mixed, or a part or the whole amount may be added little by little or in divided portions.

The method of mixing the ingredients is not particularly limited, and the method of mixing by rotating a stirrer or a stirring blade or the like; a method of mixing using a mixer, a three-roll roll, a kneader or a bead mill or the like; A known method such as a method may be appropriately selected.

The temperature in each step until the dispersion is obtained is not particularly limited as long as each compounding component is not deteriorated, and may be, for example, 5 to 50 ° C.
The time for dispersing the formulation is not particularly limited, and may be, for example, 5 minutes to 2 hours.

The microcapsules may be obtained as an aqueous dispersion (a state of being dispersed in the coexistence of water), for example, when formed by an interfacial polycondensation method. In that case, the aqueous dispersion may be used as a mixture of microcapsules, water, and, if necessary, the other components, to produce the dispersion. When the interfacial polycondensation method is adopted as the method for forming microcapsules, examples of the other preferable components include the solvent and emulsifier.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the examples shown below.

<Additives>
The additives used in the production of the dispersion are shown below.

[Example 1]
<< Manufacturing of dispersion >>
<Manufacturing of microcapsules>
Polyvinyl alcohol ("PVA420" manufactured by Kuraray Co., Ltd.) (5.6 g) is added to distilled water (174.4 g), stirred at 90 ° C. for 1 hour to form a solution, and cooled to 25 ° C. to obtain polyvinyl alcohol. An aqueous solution (corresponding to the first solution) was obtained.
Separately, DEET (insect repellent) (100 g), Polymeric MDI (Tosoh's "Millionate MR-200") (10 g) and HDI-Biuret modified product (Mitsui Chemicals'"TakenateD-165N") (25 g) ) Was added and stirred at 25 ° C. to obtain a mixed solution (corresponding to the second solution) in which all of these components were dissolved.
Separately, distilled water (30 g) was added to diethylenetriamine (7.5 g), and the mixture was stirred at 25 ° C. to obtain an aqueous diethylenetriamine solution (corresponding to the third solution).
An emulsified solution was obtained by adding the entire amount of the mixed solution to the total amount of the polyvinyl alcohol aqueous solution and stirring at 25 ° C. for 3 minutes (corresponding to the emulsification step).
Interfacial polycondensation was performed by adding the entire amount of the diethylenetriamine aqueous solution to the total amount of the obtained emulsion and stirring the reaction solution at 80 ° C. for 2 hours (corresponding to the polycondensation step).
As described above, a microcapsule containing a polycondensate of diethylenetriamine, a polypeptide MDI and an HDI-biuret modified product as a wall material component and DEET as a core substance (insect repellent) contained in the wall material is obtained as an aqueous dispersion. rice field.

<Manufacturing of dispersion>
The aqueous dispersion (100 g) of the microcapsules obtained above was added to the container.
Then, distilled water (100 g) and ethanol (100 g) were further added to this container.
Next, the mechanical defibration CNF (0.3 g, 0.03 g as the mechanical defibration CNF itself) was further added to this container as an additive, and the mixture was stirred at 25 ° C. for 10 minutes to obtain the desired dispersion. I got a body.
In the obtained dispersion, the content of monohydric alcohol was 0.62% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol was 0.03. It was% by mass.

<< Evaluation of dispersion >>
<Evaluation of aggregation inhibitory and redispersible>
The dispersion (30 g) obtained above was immediately measured in a glass bottle with a lid at room temperature and sealed.
Then, the glass bottle with a lid containing this dispersion was left to stand at 40 ° C. for 1 day.
Next, the glass bottle with a lid was placed in an environment of 25 ° C. and allowed to stand until the temperature of the enclosed dispersion reached 25 ° C.
Then, immediately turn the lidded glass bottle upside down, turn the lidded glass bottle over, and then perform this operation once more (that is, perform the operation of flipping the lidded glass bottle twice in a row). The dispersion inside the above was mixed (hereinafter referred to as "inversion mixing"). Then, the state of the enclosed dispersion was observed.
Visually observe whether the above-mentioned dispersion after inversion mixing is in the same good dispersion state as the dispersion immediately after production, and if it is in a good dispersion state, further inversion mixing is performed. If it was not performed and the dispersion state was not good, inversion mixing was repeated until the dispersion state was good. Table 2 shows the number of overturning miscibility required at this time. It can be judged that the smaller the number of inversion miscibility is, the better the aggregation inhibitory property and the redispersible property of the dispersion are.

<< Manufacture and evaluation of dispersion >>
[Example 2]
Except for the point that the product addition amount of the mechanical defibration CNF was 1.5 g instead of 0.3 g (that is, the addition amount of the mechanical defibration CNF itself was 0.15 g instead of 0.03 g). The dispersion was produced in the same manner as in Example 1.
In the obtained dispersion, the content of monohydric alcohol was 0.62% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol was 0.15. It was% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Example 3]
Example 1 except that the product addition amount of the mechanically defibrated CNF was 3 g instead of 0.3 g (that is, the added amount of the mechanical defibrated CNF itself was 0.3 g instead of 0.03 g). The dispersion was produced in the same manner as in the case of.
In the obtained dispersion, the content of monohydric alcohol is 0.61% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol is 0.3. It was% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Example 4]
In the case of Example 1, except that the product addition amount of the mechanically defibrated CNF was 20 g instead of 0.3 g (that is, the added amount of the mechanical defibrated CNF itself was 2 g instead of 0.03 g). The dispersion was produced in the same manner as above.
In the obtained dispersion, the content of monohydric alcohol is 0.56% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol is 2% by mass. Met.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Example 5]
The dispersion was produced by the same method as in Example 1 except that 2-propanol (100 g) was used instead of ethanol (100 g).
In the obtained dispersion, the content of monohydric alcohol was 0.62% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol was 0.03. It was% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Example 6]
The point that 2-propanol (100 g) was used instead of ethanol (100 g) and the amount of the mechanical defibrated CNF added to the product was 1.5 g instead of 0.3 g (that is, the addition of the mechanical defibrated CNF itself). The dispersion was produced by the same method as in Example 1 except that the amount was 0.15 g instead of 0.03 g).
In the obtained dispersion, the content of monohydric alcohol was 0.62% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol was 0.15. It was% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Example 7]
Except for the fact that the TEMPO-oxidized CNF (7.5 g, 0.15 g as the TEMPO-oxidized CNF itself) was used in place of the mechanically defibrated CNF (0.3 g, 0.03 g as the mechanical defibrated CNF itself). Dispersions were produced in the same manner as in Example 1.
In the obtained dispersion, the content of monohydric alcohol was 0.59% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol was 0.15. It was% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Example 8]
Example 1 except that the TEMPO-oxidized CNF (15 g, 0.3 g as the TEMPO-oxidized CNF itself) was used instead of the mechanically defibrated CNF (0.3 g, 0.03 g as the mechanical defibrated CNF itself). The dispersion was produced in the same manner as in the case of.
In the obtained dispersion, the content of monohydric alcohol is 0.57% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol is 0.3. It was% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Comparative Example 1]
The dispersion was produced by the same method as in Example 1 except that the mechanical defibration CNF (0.3 g, 0.03 g as the mechanical defibration CNF itself) was not used.
In the obtained dispersion, the content of monohydric alcohol is 0.62% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol is 0% by mass. Met.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Comparative Example 2]
Except for the point that the product addition amount of the mechanical defibration CNF was changed to 0.05 g instead of 0.3 g (that is, the addition amount of the mechanical defibration CNF itself was set to 0.005 g instead of 0.03 g). The dispersion was produced in the same manner as in Example 1.
In the obtained dispersion, the content of monohydric alcohol was 0.62% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol was 0.005. It was% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Comparative Example 3]
Except for the point that the product addition amount of the mechanical defibration CNF was 0.1 g instead of 0.3 g (that is, the addition amount of the mechanical defibration CNF itself was 0.01 g instead of 0.03 g). The dispersion was produced in the same manner as in Example 1.
In the obtained dispersion, the content of monohydric alcohol is 0.62% by mass with respect to the content of water, and the ratio of the content of CNF to the content of monohydric alcohol is 0.01. It was% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Comparative Example 4]
This was carried out except that the polyoxyethylene alkyl ether (25 g, 15 g as the polyoxyethylene alkyl ether itself) was used instead of the mechanical defibrated CNF (0.3 g, 0.03 g as the mechanical defibrated CNF itself). The dispersion was produced in the same manner as in Example 1.
In the obtained dispersion, the content of monohydric alcohol was 0.58 times by mass with respect to the content of water, and the ratio of the content of polyoxyethylene alkyl ether to the content of monohydric alcohol was , 15% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Comparative Example 5]
This was carried out except that the polyoxyethylene alkyl ether (50 g, 30 g as the polyoxyethylene alkyl ether itself) was used instead of the mechanical defibrated CNF (0.3 g, 0.03 g as the mechanical defibrated CNF itself). The dispersion was produced in the same manner as in Example 1.
In the obtained dispersion, the content of monohydric alcohol is 0.55% by mass with respect to the content of water, and the ratio of the content of polyoxyethylene alkyl ether to the content of monohydric alcohol is , 30% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

[Comparative Example 6]
This was carried out except that the polyoxyethylene alkyl ether (75 g, 45 g as the polyoxyethylene alkyl ether itself) was used instead of the mechanical defibrated CNF (0.3 g, 0.03 g as the mechanical defibrated CNF itself). The dispersion was produced in the same manner as in Example 1.
In the obtained dispersion, the content of monohydric alcohol is 0.52% by mass with respect to the content of water, and the ratio of the content of polyoxyethylene alkyl ether to the content of monohydric alcohol is , 45% by mass.
The obtained dispersion was evaluated by the same method as in Example 1. The results are shown in Table 2.

As is clear from the above results, in Examples 1 to 8, the number of overturning mixings was 10 times or less (4 to 10 times), and the dispersion was easily redispersed after being statically stored at 40 ° C. for 1 day. Met. In Examples 1 to 8, the dispersion after static storage was merely settled at the bottom of the glass bottle and did not aggregate. As described above, the dispersions of Examples 1 to 8 had high aggregation inhibitory and redispersible properties.
In the dispersions of Examples 1 to 8, the ratio of the CNF content to the monohydric alcohol content was 0.03% by mass or more (0.03 to 2% by mass).

On the other hand, in Comparative Example 1, even if the inversion mixing was performed 100 times, the dispersion after standing still storage at 40 ° C. for 1 day could not be redispersed. In Comparative Example 1, the dispersion after static storage was highly aggregated inside the glass bottle. This was because the dispersion of Comparative Example 1 did not contain CNF.

In Comparative Examples 2 and 3, the number of inversion mixing was 20 times or more (20 times, 40 times), and it was not easy to redisperse the dispersion after standing still at 40 ° C. for 1 day. In Comparative Examples 2 and 3, the dispersion after static storage was moderately agglomerated inside the glass bottle. This is because, in the dispersions of Comparative Examples 2 and 3, the ratio of the CNF content to the monovalent alcohol content was 0.01% by mass or less (0.01% by mass, 0.005% by mass). This was because the CNF content was relatively low.

In Comparative Examples 4 to 5, as in the case of Comparative Example 1, even if the inversion mixing was performed 100 times, the dispersion after standing still storage at 40 ° C. for 1 day could not be redispersed. In Comparative Examples 4 to 5, the dispersion after static storage was highly aggregated inside the glass bottle. This was because the dispersions of Comparative Examples 4 to 5 contained a considerably large amount of polyoxyethylene alkyl ether as a surfactant, but did not contain CNF.

In Comparative Example 6, the number of inversion mixing was 50 times, and it was not easy to redisperse the dispersion after standing still at 40 ° C. for 1 day. In Comparative Example 6, the dispersion after static storage was relatively highly aggregated inside the glass bottle. This is because the dispersion of Comparative Example 6 contained polyoxyethylene alkyl ether as a surfactant, and the content thereof was higher than that of Comparative Examples 4 to 5, but it did not contain CNF. there were.

INDUSTRIAL APPLICABILITY The present invention can be used as a spray agent containing microcapsules containing each agent such as an insect repellent, an insecticide, a pesticide, a fragrance, and a deodorant.

Claims (2)

It ’s a dispersion,
The dispersion contains microcapsules, water, monohydric alcohols and cellulose nanofibers.
In the dispersion, the ratio of the content of the cellulose nanofibers to the content of the monohydric alcohol is 0.015% by mass or more. The dispersion according to claim 1, wherein the component of the wall material of the microcapsules is polyurea.