JP2001198453A - Manufacturing method of microcapsule, and microcapsule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a microcapsule, enabling the use of a film material, to which an in-situ polymerization method cannot be applied. SOLUTION: Two kinds of film materials having low solubility to a dispersion medium are used. One of the two film materials is dispersed in the dispersion medium [a dispersion liquid (a)], and then the other film material is added to the dispersion liquid (a).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a novel microcapsule.

[0002]

2. Description of the Related Art Conventionally, various methods such as an interfacial polymerization method and an in situ polymerization method have been studied and manufactured as a method for producing microcapsules. Among them, it is relatively easy to control particle size and manufacture, and encapsulation can be performed in a short time. In addition, it does not use formalin, which has been taken up due to environmental issues (using melamine resin of In Situ polymerization method, formalin)
Interfacial polymerization is commonly used. The microcapsules formed by this interfacial polymerization method are described in
Japanese Patent Application Publication No. 47-13740 and Japanese Patent Application Publication No. Sho 5-13740 disclose a method for obtaining a capsule having a polyurea wall film by reacting a polyvalent isocyanate with water or amines.
JP-A-2-13508 and JP-A-62-193641 disclose adding and dispersing a hydrophobic liquid in which a polyvalent isocyanate is dissolved in an aqueous solution containing an emulsion stabilizer such as polyvinyl alcohol, A method for obtaining a microcapsule by generating a polyurea resin by an interfacial polymerization reaction in which is added. As an application example of the interfacial polymerization method, JP-A-6-238159 discloses that a solution of a polyisocyanate is dispersed in a poorly water-soluble pesticide in water,
Subsequently, a method for producing an aqueous suspension of microcapsules having a polyurea capsule wall and enclosing a water-immiscible pesticide by reacting the dispersion with a polyamine is disclosed in JP-A-6-3.
At step 62, in a method for producing microcapsules in which a hydrophobic liquid is coated with a polyurea or polyurethane resin by an interfacial polymerization reaction, a hydrophobic liquid obtained by dissolving a polybasic acid halide and a polyvalent isocyanate is converted to an OH group, an NH ₂ group or an NH ₂ group. After adding and dispersing in an aqueous solution of a water-soluble polymer substance having a group, and then adding an alkaline compound,
A method for producing microcapsules, characterized by adding a polyhydric amine or a polyhydric alcohol;
No. 103669 discloses an interfacial polymerization method using a salt or the like. As described above, the interfacial polymerization method has high versatility and is often used, but features of the interfacial polymerization method (O / W type)
The emulsification of a suspension of hydrophobic membrane material and a hydrophobic liquid, in some cases, poorly soluble particles, in water, followed by the addition of a hydrophilic membrane material with stirring, and, in some cases, heating, to provide an interface between oil and water. A microcapsule is obtained by forming a film by a chemical reaction in the above. Therefore, since a chemical reaction occurs at the time of addition of the hydrophilic film material, the film can be formed after adjusting to a desired particle size.

However, a disadvantage of this interfacial polymerization method is that two kinds of film materials having low solubility in a dispersion medium and reacting with each other to form a polymer are used (when the dispersion medium is water, two kinds of film materials are used). When the species is hydrophobic, encapsulation is not possible. There is a method of forming microcapsules by mixing both membrane materials in a hydrophobic solution (In Situ polymerization method)
However, the mainstream method is to form a polymer film by controlling the reaction by adding two kinds of film materials soluble in water around a core substance such as an active ingredient to adjust the pH and the like. It is an essential condition to dissolve in water which is a dispersion medium, and it cannot be used when the film material is hydrophobic. There is also a method of forming a polymer film by adding two kinds of film materials to a hydrophobic liquid. However, since the film is formed quickly, there is a strong possibility that an incomplete film or an aggregate is generated. Therefore, it is difficult to control the particle size and control the production, and this In Situ polymerization method requires a very fine production control using a film material having a low film-forming power, which is not realistic. Therefore,
The interfacial polymerization method which can be added when a reaction film material is desired to react is very advantageous, and a microcapsule production method using two kinds of film materials having low solubility in a dispersion medium by this method is strongly desired. Although it is rare, the solution has not been shown yet. A membrane in which the two membrane materials are both hydrophobic,
For example, a polysiloxane film or the like having excellent weather resistance, light resistance, rain resistance and the like is known in the field of painting and coating. However, a high-temperature treatment (100 ° C.) is required to form a polysiloxane polymer. In most cases, the above process is generally required), and there is a possibility that it will be decomposed at high temperatures. Further, in a reaction at a lower temperature, it is necessary to use, as a catalyst, a substance such as tin which may cause a problem for the environment.
It becomes a problem. The method of microencapsulating the polysiloxane is mainly spray-drying using a water-soluble polymer, and is performed by spray-drying an aqueous emulsion composed of an organopolysiloxane, a water-soluble polymer and a filler (UK patent). No. 892787),
Spray drying an aqueous emulsion of an organopolysiloxane containing polyvinyl alcohol or polyvinylpyrrolidone to produce a powder containing the organopolysiloxane (US Pat. No. 3,210,208), producing a powder redispersible in water by spray drying (EP-A-279373) and a thin-layer drying method (JP-A-5-96151) are disclosed. However, high-temperature treatment (common in the production of capsules of polysiloxane and organopolysiloxane) is disclosed. (100 ° C. or more), spraying or drying in a thin layer is required, and it is not suitable for producing capsules containing active ingredients which are relatively unstable to heat, such as pharmaceuticals and agricultural chemicals. In addition, use with slurries that are the mainstream in the field of agrochemicals is unsuitable. For these reasons, a microcapsule having excellent weather resistance, light resistance, rain resistance, and the like, and having no effect on the active ingredient due to a high-temperature reaction, and a method for producing the same are keenly desired.

[0004]

An object of the present invention is to develop a method for producing microcapsules using a film material having low solubility in a dispersion medium.

[0005]

Means for Solving the Problems The present inventors have intensively studied techniques for responding to the above-mentioned demands, and as a result, have arrived at the present invention. That is, the present invention relates to (1) a method for producing microcapsules carried out in two kinds of film materials and a dispersion medium for the film materials, wherein the first film material of the two kinds of film materials is contained in the dispersion medium. After dispersion (dispersion (a)), a method for producing microcapsules, wherein a second film material is added to dispersion (a);
(2) The method for producing microcapsules according to (1), wherein the second film material is added to the dispersion liquid (a) as a film agent containing a dispersant, (3) the second film material. The method for producing microcapsules according to (1) or (2), wherein the film material is added to the dispersion liquid (a) as a film agent containing a dispersion medium, (4) the second film material Is added to the dispersion liquid (a) in a pre-dispersed state (dispersion liquid (b)), (5) the method for producing microcapsules, (5) the method of preparing the dispersion liquid (b). Viscosity 500 mPa ・ s
(25 ° C.) or lower, the method for producing microcapsules according to (4), wherein (6) the viscosity of the pre-dispersion liquid (a) is
It is less than 500 mPa · s (25 ℃) (1)
(7) The method for producing a microcapsule according to any one of (1) to (5), wherein the dispersion medium is water, and the two kinds of membrane materials are both hydrophobic. (8) The method for producing microcapsules according to any one of (6) and (8), wherein a silane coupling agent and / or a polyvalent reactive silicone oil is used for at least one of the two types of film materials. (9) The method for producing a microcapsule according to any one of (1) to (8), which comprises a core substance, wherein the core substance is an agricultural chemical. , (10) A microcapsule which can be produced by the production method according to any one of (1) to (9).

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention provides a novel method of producing microcapsules in addition to the conventional in situ polymerization method. In particular, the present invention can be applied to a film material that cannot be used in the in situ polymerization method. Provides microcapsules with characteristics that cannot be produced by polymerization

The two kinds of film materials used in the present invention are:
These react with each other to form a microcapsule film. Thus, the two types of film materials that can form the microcapsule film have functional groups (reactive groups) that react with each other. For example, an electrophilic film material having an electrophilic reactive group capable of undergoing a nucleophilic substitution reaction (such as a carbonyl group such as an isocyanate group or an acid halide) and a nucleophilic reactive group (a hydroxyl group or And a nucleophilic film material having an amino group) can be used as two types of film materials. Any type of film material that can form a film by another reaction mode (for example, electrophilic substitution reaction) can be used in the present invention, but two or more reactive groups that react with each other can be used in one molecule. Even if a film material that can form a polymer by itself can react with another film material and obtain a film that is suitable as a macrocapsule film, the two types of the present invention can be used. Can be used as a film material. In addition, a material that generates a reactive group during the production of microcapsules by hydrolysis, thermal decomposition, or the like can also be used as a film material.

In order to form a polymer in a chain reaction, two or more (polyvalent) of these reactive groups are required for each molecule of two kinds of film materials. To form such a film, a film having a network structure is preferred. To form such a film, it is preferable that at least one kind of film material has three or more reactive groups per molecule.

It is also possible to manufacture microcapsules using three types of film materials. For example, in a system for forming microcapsules undergoing nucleophilic substitution reaction reaction mode is the susceptible reactive group to nucleophilic substitution reaction (hereinafter, E ₁ and referred.) And less susceptible reactive group to nucleophilic substitution reaction (hereinafter, referred to as E _2.) a film material having in one molecule (hereinafter, referred to as membrane material a.), the nucleophilic low reactive group (hereinafter, referred to as N _1.) the in one molecule A film material having two or more (hereinafter, referred to as a film material B) is added, E ₁ -N ₁ are first reacted with each other to form a temporary film, and then a reactive group having high nucleophilicity (hereinafter, referred to as N ₂₎ and referred.) a film material having two or more in one molecule (hereinafter, by referred to as the membrane material C.) was added to the reaction of E ₂ -N ₂ together, a film made of a film material A~C It is also possible to obtain microcapsules having the same. The method for producing a microcapsule of the present invention is applicable to any of the reaction between the film material A and the film material B, or the reaction between the film material C and the temporary film as a film material, and includes these. It is.

The reactive group of these film materials is polyamide.
To form -NH₂Forms ClCO- and polyurethane
-NH₂And Cl-CO-O-, -NCO and HO-,
-OH and ClCO- to form polyester, polysul
-NH to form vonamide₂And ClSO₂-, Poly
-NH to form urea₂And COCl₂And H₂N-,-
NCO and H₂N-, forming a polysulfonate-S
O₂Cl and HO-, -OH to form polycarbonate
And COCl₂And HO-, -NCO and HOOC-
However, the present invention is not limited to these.
Here, as a film material having low solubility in a dispersion medium,
When the medium is water, for example, polyurethane or polyurea
Is that if one of the membrane materials is -NCO, the other is H
O-, H ₂N-, etc., and vice versa.
You.

Examples of the film material include a polyvalent isocyanate, a polyvalent reactive silicone oil, a polyvalent amine, a compound having a polyvalent hydroxyl group (a compound having a plurality of hydroxyl groups), and a compound having a polyvalent carboxyl group (a plurality of compounds having a plurality of carboxyl groups). A compound having a carboxyl group).

Specific examples of the polyvalent isocyanate include:
2,4-toluene diisocyanate, 2,6-toluene diisocyanate, methylene-bis- (4-phenyl isocyanate), polymethylene polyphenyl polyisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone Diisocyanates, etc .; these polyvalent isocyanates may be used alone or in combination of two or more. Examples of the polycarboxylic acid chloride include, for example, sebacic acid dichloride, adipic acid dichloride, azelaic acid dichloride, terephthalic acid dichloride, trimesic acid dichloride, and polyvalent sulfonyl chloride, such as benzenesulfonyl dichloride. As a material capable of forming a microcapsule film by reacting with such a film material, a hydrophobic and dissolved in an organic solvent to form a divalent or higher valent reactive group (such as —NH ₂ , —OH, and —COOH). The film material can be exemplified, and two or more kinds can be arbitrarily combined and used.

Specific examples of the polyvalent reactive silicone oil include silicone oils having a reactive group such as an amino group, a hydroxyl group, a carboxyl group or an isocyanate group at the terminal or intermediate part of the polysiloxane. Then, there are the following.

Embedded image Polyvalent reactive silicone oil having a reactive group on the side chain of polysiloxane wherein R represents a reactive group such as an amino group, a hydroxyl group carboxyl group or an isocyanate group.

Embedded image R is a reactive group such as an amino group, a hydroxyl group, a carboxyl group or an isocyanate group. Specifically, amino-modified silicone oils having an amino group introduced into the side chain of polysiloxane, FZ-3705, FZ-3710,
FZ-319 (trade name, manufactured by Nippon Unicar), X-22-161AS, X-22-
161A, X-22-161B, KF-8012 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like have polyaminosiloxanes with amino groups introduced at both ends, and are classified as KF-393, KF-859, KF-860, KF -861, KF-867, KF-869,
KF-8002, KF-8004, KF-8005, KF-858, KF-864, KF-865, KF-86
8, KF-8003 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. In addition, carbinol-modified silicone oils (having a carboxol group introduced into the side chain of polysiloxane: X-22-160AS, KF-600)
1, KF-6002, KF-6003, X-22-4015 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), phenol-modified silicone oil (polysiloxane having a phenol group introduced into its side chain: X-22)
-165B (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)).

Further, specific examples of the polyvalent amine include silane coupling agents A-1120 and A-1122 (trade names, manufactured by Nippon Unicar, H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si (OCH ₃ ) ₃ ), A-1160 (product name,
Manufactured by Nippon Unicar _{Co., H 2 NC 2 H 4 NHC} 3 H 6 Si (OC 2 H 5) 3) , and the like. The polyamine is also preferably an aliphatic polyamine. Specific examples of the aliphatic polyamine include diamine R86 (trade name, manufactured by Kao Corporation, hardened tallow propylene diamine),
Diamine RT (trade name, tallow propylene diamine, manufactured by Kao Corporation), Softex KZ (trade name, Kao Corporation)
And stearylamidomethylpyridinium chloride), p, p'-diaminodiphenylmethane, 4,4-diaminodiphenylether, m-toluylenediamine, tri-n-butylamine, and the like, but are not limited thereto.

Further, specific examples of the compound having a polyvalent hydroxyl group include 1,4-dihydroxynaphthalene, 2,3,5-trimethylhydroquinone, 2-butyl-2-ethyl-1,3-propanediol, and polytetrahydroxynaphthalene. Examples include, but are not limited to, methylene ether glycol and 2,2-bis (4-hydroxyphenyl) hexafluoropropane as a fluorine compound.

Further, specific examples of the compound having a polyvalent carboxyl group include, but are not limited to, phthalic acid, terephthalic acid, and brassic acid.

Further, compounds having two or more of these reactive groups can also be used, for example, 2,4-diaminophenol having both an amino group and a hydroxyl group, and 3,5-diaminobenzene having an amino group and a carboxyl group. Low solubility (1% or less at room temperature) in acid, salicylic acid having hydroxyl group and carboxyl group, and water having amino group and carboxyl group.
Examples include, but are not limited to, amino acids such as L-aspartic acid, L-aspartic acid, DL-leucine, tyrosine, L-cystine, β-benzyl L-aspartate, γ-benzyl L-glutamate, and the like. Not something.

The use ratio of these two kinds of film materials may be near the stoichiometric equivalent in terms of yield, but it is preferable that 1 equivalent of the first film material of the two kinds of film materials be used. The amount of the second film material is 0.1 to 10 equivalents, more preferably 0.2 to 5 equivalents.

Further, in the method for producing a microcapsule of the present invention, the first film material added and dispersed in the dispersion medium may be either of two types of film materials. It can be determined in consideration of the stability of the film material, the properties of the obtained microcapsules, and the like. Note that the second film material is a film material that is not used as the first film material among the two types of film materials.

In the method for producing a microcapsule of the present invention, these two kinds of film materials need to exhibit a dispersion state in a dispersion medium. Even if most of the film material is dissolved in the dispersion medium, the remaining film material may be in a dispersed state in the dispersion medium. In order to improve the microcapsule yield with respect to the amount of the used film material, a material having a low solubility in a dispersion medium is preferable, and a film material having a solubility of 1% by weight or less is preferable. The solubility needs to be determined based on the state of the dispersion medium at the time of the film formation reaction. For example, when the dispersion medium is water, a film material having a solubility in water at 20 ° C. of 1% by weight or less is used. Is preferred.

Next, the dispersion medium used in the method for producing microcapsules of the present invention will be described. The dispersion medium used in the present invention is for dispersing the above-mentioned two kinds of film materials, and is preferably a dispersion medium capable of obtaining a good dispersion state. Further, those that do not dissolve the film material are preferable,
A dispersion medium that exhibits a solubility of 1% by weight (outside ratio) to either of the two types of film materials, preferably to both, is preferable.

As such a dispersion medium, water, an organic solvent, or the like can be used. To lower the solubility of the film material, an organic solvent having a low polarity (hexane Such as aliphatic hydrocarbons and aromatic hydrocarbons such as toluene), and water and highly polar organic solvents are suitable for lipophilic film materials. In addition, fluorocarbons that hardly dissolve organic compounds are also suitable dispersion media.

Further, the solubility of the film material in the dispersion medium varies depending on the physical state of the dispersion medium, the substance added as a solute, and the like. Therefore, it is preferable to adjust these so as to obtain a good dispersion state. . For example, when the dispersing medium is water, a film material whose solubility in water greatly changes depending on pH, temperature, etc., has a water solubility of 1% by weight or less (preferably).
Adjust to H, temperature, etc., dissolve in water 1% by weight (20 ° C)
It is preferable that In addition, the solubility of the film material in water can be suppressed to a low level by adding a metal salt or the like to water to a saturated amount or a nearly saturated amount.

The amount of the dispersion medium to be used for the two kinds of film materials can be determined in consideration of the microcapsule manufacturing process and the like. If the film material is easily dissolved in the dispersion medium, the amount of the dispersion medium to be used is reduced. Is preferred. In order to obtain a good dispersion state, it is preferable to use a dispersant.
Examples of the dispersant include a stabilizer for stabilizing a dispersion state, and a surfactant used as a dispersant when the dispersion medium is water and the film material is a hydrophobic liquid and / or hydrophobic.

Examples of dispersants include gelatin, gum arabic, casein, dextrin, pectin, sodium alginate, methylcellulose, ethylcellulose, sodium carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium polyacrylate, polyvinyl alcohol, polyvinylpyrrolidone and carboxyvinyl. Water-soluble polymers such as polymers, fatty acid soaps, ether carboxylic acids, ether carboxylate salts, salts of condensates of higher fatty acids and amino acids, higher alkyl sulfonates, α-olefin sulfonates, sulfonic acids of higher fatty acid esters Salt, dialkyl sulfosuccinate, sulfonate of higher fatty acid amide, alkylaryl sulfonate, higher alcohol sulfate, alkyl ether Anionic surfactants such as acid ester salts, alkyl aryl ether sulfates, sulfates of higher fatty acid esters, sulfates of higher fatty acid alkylolamides, sulfated oils and phosphate esters, alkylamine salts, polyamines Or an amine salt of an amino alcohol fatty acid derivative, an alkyl quaternary ammonium salt, a cyclic quaternary ammonium salt, a quaternary ammonium salt having a hydroxyl group, a cationic surfactant such as a quaternary ammonium salt having an ether bond, a carboxylic acid type, Sulfate ester type, sulfonic acid type, amphoteric surfactant such as phosphate ester type, polyoxyethylene alkyl ether,
Polyoxyethylene alkyl aryl ether, formalin condensate of polyoxyethylene alkyl phenol,
Examples include nonionic surfactants such as polyoxyethylene fatty acid esters, polyoxyethylenated fats and oils, polyhydric alcohol esters, and polyoxyethylene polyoxypropylene block copolymers. These dispersants may be added in advance to water as a dispersion medium, or may be added to a hydrophobic liquid and / or a hydrophobic film material to make the film material a film material.

In the method for producing microcapsules of the present invention, microcapsules containing various substances as a core substance can be produced. A liquid or solid material having low solubility in the dispersion medium can be used as the core material. The core substance is preferably added when the first film material of the two film materials is dispersed in the dispersion medium. The core material is preferably dispersed in the dispersion medium in such a manner as to be included / dissolved in the first film material. preferable. Therefore, it is preferable that the core material and the first film material have good affinity / compatibility.

The method for producing the novel microcapsules of the present invention will be described. The present invention relates to a method for producing microcapsules performed in a dispersion medium for two kinds of membrane materials and the membrane material,
After dispersing one of the two film materials (first film material) in a dispersion medium (dispersion liquid (a)), adding the other film material (second film material) to dispersion liquid (a) A method for producing a microcapsule characterized by the following.

The dispersion here may be a dispersion state in which the film material, which is a dispersoid, is stably dispersed, and may be a transparent state in a state close to solubilization with a surfactant or the like. It can also be used in a state where substances other than the film material are suspended as fine solid particles.

The particle size of the dispersion is not limited, but preferably the particle size of the primary dispersion in the primary dispersion (dispersion (a)) in which the first film material is dispersed in a dispersion medium. Is preferably smaller than the particle size of the secondary dispersion obtained by further adding the second film material to the dispersion (a) and dispersing the same.

In the above-mentioned production method, when the first film material is dispersed in the dispersion liquid (a), if the dispersion state is poor or it is difficult to control the desired particle size, the dispersant And / or a dispersion medium can be added to the film material and added as a film agent. Thereby, a good dispersion state is obtained.

When the microcapsules microencapsulated by the above-mentioned production method are apt to agglomerate, the second film material is added to the dispersion liquid (a) in a previously dispersed state (dispersion liquid (b)). Can greatly improve the state of aggregation. In this case, the viscosity of the dispersion (b) is 500 mPa · s.
By adjusting the temperature to (25 ° C.) or less, the effect of further preventing aggregation can be obtained. Further, the viscosity of the dispersion (a) is set to 500 mPa · s (25
C)), the same effect can be obtained.

The dispersion medium added to the second film material is as follows:
The dispersion medium in which the first film material is dispersed may be the same or different.

In the production method of the present invention, the dispersion (a)
In the preparation step, it is advantageous to carry out mechanical dispersion, because the particle size of the obtained microcapsules can be adjusted by changing the stirring conditions. One of the two types of film materials having low solubility in the medium is usually dispersed as fine droplets using a high-speed shear mixer such as TK homomixer (manufactured by Tokushu Kika Kogyo). Self-dispersion (self-emulsification) of hydrophobic liquids (active ingredients, etc.) and film materials with low solubility in the dispersion medium
In such a case, it is not necessary to use a high-speed shearing mixer or the like, and it is sufficient to use light stirring. In this case, a desired particle size is obtained by adjusting the amount of the dispersant to be used and the like. The dispersion (b) can be dispersed in the same manner as the dispersion (a).

The microcapsules obtained by the production method of the present invention can be used as a microcapsule slurry without removing the dispersion medium or as a single microcapsule after removing the dispersion medium.

The microcapsule slurry can be used as it is, but usually, a thickener for stabilizing the dispersion system is added. Examples of the thickener include natural polysaccharides such as xanthan gum (xanthan gum) and locust bean gum, magnesium aluminum silicate,
Mineral powder such as bentonite, semi-synthetic polysaccharides such as carboxymethyl cellulose, and synthetic polymers such as polyacrylic acid can be used alone or as a mixture of two or more.
Further, if necessary, an antifreezing agent such as propylene glycol and ethylene glycol, a stabilizer such as BHT, a synergist such as piperonyl butoxide, a fungicide, a coloring agent, a fragrance and the like can be added. . Further, it can be used as a powdery preparation by a method such as spray drying.

In the production method of the present invention, it is possible to use water or a hydrophilic solvent or a hydrophobic solvent as a dispersion medium, but it is more preferable that the dispersion medium is water or a hydrophilic solvent. When the dispersion medium is water or a hydrophilic solvent, a hydrophobic film material can be used. Among them, a polysiloxane and a polyurea can be used by using a silane coupling agent and / or a polyvalent reactive silicone oil. Combination with other polymers has become possible, and it has become possible to create microcapsules that retain the water repellency, light resistance, and weather resistance mainly possessed by silicone, which could not be obtained by conventional microcapsule manufacturing methods. Was.

The microcapsules obtained by the production method of the present invention can be applied to the fields of agricultural chemicals, dyes and the like by using, for example, agricultural chemicals and dyes as core substances. For example, specific examples of applicable pesticides include carbinphos, chlorpyrifos, chlorpyrifosmethyl, cyanofenphos, cyanofos, diazinon, dichlorvos, fenitrothion, fenthion,
Malathion, naled, pirimiphosmethyl, prothiophos, pyridafenthion, salithion, tetrachlorvinphos, trichlorfon, promophos, propetanphos, BPMC, carbaryl, CPMC, ethiophencarb, MPMC, MTMC, promecap, swep,
Propoxer, NAC, XMC, IBP, cypermethrin, cyphenothrin, deltamethrin, fenpropathrin, fenvalerate, cadesrin, permethrin, phenothrin, propulsrin, resmethrin, cyfluthulin, alpha-methrin, tralomethrin, flucithulinate, biphenothrin, Cyhalothrin,
Flumethrin, fencruthrin, cycloprothrin,
Examples include, but are not limited to, fluvalinate, etofenprox, silaneophane, methaldehyde, hexaflumuron, imidacloprid, hydramethylnon, sulfluramide, and the like. In the field of dyes, disperse dyes, cationic dyes (including basic dyes), acid dyes, reactive dyes, direct dyes, and composite dyes can be mentioned. In the pigment field, titanium oxide, iron oxide, zinc oxide, and the like can be used. It can also be used for various inks utilizing pigments and the like, but is not limited thereto.

[0038]

The present invention will be described in more detail with reference to the following Examples (parts are by weight), but the present invention is not limited to only these Examples.

Example 1 A mixture of 100 parts of dodecylbenzene and 324 parts of diazinon and 41.6 parts of polymethylene polyphenyl polyisocyanate as a hydrophobic film material was mixed with Gohsenol AL-06 (trade name, manufactured by Nippon Synthetic Chemical Company, polyvinyl chloride). Addition of 1086.6 parts of a 2% aqueous solution of alcohol) and mixing analyzer 2500 at room temperature (manufactured by Tokushu Kika Kogyo Co., Ltd.)
Was dispersed at 10,000 rpm for 5 minutes to obtain a dispersion liquid (A) of fine droplets. The viscosity was 380 mPa · s (25 ° C). A solution obtained by dissolving 137 parts of the above-mentioned X-22-161AS as a hydrophobic film material in 235 parts of dodecylbenzene, and adding 105 parts of Newcalgen D2112A (trade name, manufactured by Takemoto Yushi Co., Ltd.) as a dispersant thereto. (B) was added to the dispersion (A), and the solution (B) (X-22-161AS) was dispersed. Then, after the mixture became sufficiently uniform, the reaction was carried out at 63 ° C. for 5 hours to obtain a liquid containing the microcapsules of the present invention having a diazinon content of the polysiloxane polyurea film of 15% by weight. Average particle size is 20
μm.

Example 2 MCP was added to 100 parts of dodecylbenzene.
A mixed solution containing 324 parts of BE and 41.6 parts of polymethylene polyphenyl polyisocyanate as a hydrophobic film material is added to 586.6 parts of a 2% aqueous solution of Gohsenol AL-06, and a mixing analyzer 2500 (manufactured by Tokushu Kika Kogyo Co., Ltd.) at room temperature. ) Is dispersed at a rotation speed of 10,000 rpm for 5 minutes.
I got The viscosity was 185 mPa · s (25 ° C). Further, 200 parts of the above-mentioned X-22-165B was previously added as a hydrophobic film material to xylene 163.
The solution containing 20 parts of Newcalgen D2112A (trade name, manufactured by Takemoto Yushi Co., Ltd.) as a dispersant was added to tap water 720
To prepare a dispersion (D). The viscosity of the dispersion liquid (D) was 210 mPa · s (25 ° C.). Next, the dispersion (C)
The dispersion (D) was added to the mixture and stirred until the mixture became sufficiently uniform. Thereafter, the reaction was carried out at 60 ° C. for 5 hours to obtain a liquid containing the microcapsules of the present invention having an MCPBE content of 15% by weight of the polysiloxane polyurethane film. Average particle size is 35
μm.

Example 3 250 parts of diazinon and polymethylene polyphenyl polyisocyanate as a hydrophobic film material
A 40% mixed solution was added to a 2% aqueous solution of Gohsenol AL-06
In addition to 390 parts, the mixture was dispersed at a rotation speed of 10,000 rpm for 5 minutes at room temperature using a mixing analyzer model 2500 (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a dispersion (E) of fine droplets. Viscosity is 200 mPa · s
(25 ° C.). Also, 100 parts of Diamine RT (trade name, tallow propylene diamine, manufactured by Kao Corporation) is dissolved in 100 parts of xylene as a hydrophobic film agent in advance, and Newcalgen D212 (trade name, manufactured by Takemoto Yushi Co., Ltd.) is used as a dispersant. ) 20
The solution (F) to which the solution was added was added to the dispersion (E) to disperse the solution (F). Then, after it is sufficiently uniform, 63
After reacting at ℃ for 5 hours, 50
And 50 parts of a 2% aqueous solution of xanthan gum were added and uniformly mixed to obtain a liquid containing the microcapsules of the present invention having a diazinon content of 25% in the polyurea membrane. The average particle size was 30 μm.

Example 4 A mixed solution consisting of 300 parts of MCPBE and 30 parts of adipic dichloride as a hydrophobic film material was added to 290 parts of a 2% aqueous solution of Gohsenol AL-06, and mixed at room temperature at room temperature with a mixing analyzer 2500 (Tokiki Kagaku Kogyo Co., Ltd.). Liquid dispersion (G) at 10,000 rpm for 5 minutes.
I got The viscosity was 100 mPa · s (25 ° C.). Also, 50 parts of 1,4-dihydroxynaphthalene was previously dissolved in 100 parts of xylene as a hydrophobic film material, and Newcalgen D was used as a dispersant.
A solution containing 20 parts of 2112A (trade name, manufactured by Takemoto Yushi Co., Ltd.) was added to 210 parts of tap water to prepare a dispersion (H). The viscosity of the dispersion (H) was 150 mPa · s (25 ° C.). Next, the dispersion liquid (H) was added to the dispersion liquid (G), and the mixture was stirred until it became sufficiently uniform. Thereafter, the mixture was reacted at 60 ° C. for 5 hours to obtain a liquid containing the microcapsules of the present invention having an MCPBE content of the polyethylene membrane of 15% by weight. Average particle size is 35μm
Met.

Example 5 A mixture of 300 parts of diazinon and 30 parts of KF-860 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) as a hydrophobic film material was mixed with a 2% aqueous solution of Gohsenol AL-06 in 290.
The mixture was dispersed at room temperature for 5 minutes at 10,000 rpm using a mixing analyzer model 2500 (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a dispersion liquid (I) of fine droplets. The viscosity is 200 mPa · s (25
° C). Also, previously dissolved 20 parts of pentamethylene diisocyanate as a hydrophobic film material in 100 parts of xylene,
A solution obtained by adding 50 parts of Newcalgen D2112A (trade name, manufactured by Takemoto Yushi Co., Ltd.) as a dispersant was added to 210 parts of tap water to prepare a dispersion (J). The viscosity of the dispersion (J) is 650 mPa
・ S (25 ° C.). Next, the dispersion liquid (J) was added to the dispersion liquid (I), and the mixture was stirred until it became sufficiently uniform. Thereafter, the mixture was reacted at 60 ° C. for 5 hours to obtain a liquid containing the microcapsules of the present invention having a diazinon content of 30% by weight in the polysiloxane urea film. The average particle size was 45 μm.

[0044]

The method for producing the microcapsules of the present invention and the microcapsules provide a novel production method in addition to the conventional InSitu polymerization method. But can be used, In Situ
A microcapsule production method in which microcapsules having characteristics that cannot be produced by the polymerization method are performed in two kinds of film materials and a dispersion medium for the film materials, and two kinds of film materials having low solubility in the dispersion medium are used. This is made possible by using a method characterized in that one of the two film materials is dispersed in a dispersion medium (dispersion liquid (a)) and the other film material is added to the dispersion liquid (a).

Claims (10)

[Claims] 1. A method for producing microcapsules in two kinds of film materials and a dispersion medium for the film material, wherein the first film agent of the two kinds of film materials is dispersed in a dispersion medium. Dispersion (a)),
A method for producing microcapsules, comprising adding a second film material to the dispersion (a). 2. The method for producing microcapsules according to claim 1, wherein the second film material is added to the dispersion liquid (a) as a film material containing a dispersant. 3. The method for producing microcapsules according to claim 1, wherein the second film material is added to the dispersion (a) as a film agent containing a dispersion medium. 4. The method for producing microcapsules according to claim 3, wherein the second film material is added to the dispersion (a) in a state of being dispersed in advance (dispersion (b)). . 5. The dispersion (b) has a viscosity of 500 mPa · s (25
5. The method for producing microcapsules according to claim 4, wherein the temperature is not higher than (° C). 6. The dispersion (a) having a viscosity of 500 mPa · s (25
C) or less, the method for producing microcapsules according to any one of claims 1 to 5, 7. The method for producing microcapsules according to claim 1, wherein the dispersion medium is water, and the two kinds of film materials are both hydrophobic. 8. The production of microcapsules according to claim 1, wherein a silane coupling agent and / or a polyvalent reactive silicone oil is used for at least one of the two kinds of film materials. Law. 9. The method for producing microcapsules according to claim 1, comprising a core substance, wherein the core substance is an agricultural chemical. 10. A microcapsule which can be produced by the production method according to claim 1.