JP2005170956A - Method for producing microencapsulated agrochemical - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method for microencapsulation of a solid agrochemical active ingredient hardly soluble in organic solvents and solid at normal temperature. <P>SOLUTION: The method comprises suspending the agrochemical active ingredient solid at normal temperature in a water-immiscible liquid, dispersing the obtained suspension in water as droplets, and forming a film around the droplets. The method also comprises suspending the agrochemical active ingredient in a water-immiscible liquid of ≤5% agrochemical active ingredient solubility so that the solid concentration is ≤45 wt.%, adding a film forming material of the microcapsule in the obtained suspension, dispersing the obtained product in water as droplets, and forming the film on the outer periphery of the droplets. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for microencapsulating an agrochemical active ingredient that is solid at room temperature.

  Conventionally, it is known that an agrochemical active ingredient with various characteristics can be obtained by microencapsulating an agrochemical active ingredient. Generally, an organic solvent is used to microencapsulate a solid agrochemical active ingredient. As a liquid material dissolved in a water-immiscible liquid such as the above, a microencapsulation method is used in which the liquid material is dispersed as droplets in water and a film is formed around the droplets.

  However, with such a method, it is difficult to microencapsulate a solid agrochemical active ingredient that is hardly soluble in an organic solvent or the like.

The present invention can be easily microencapsulated even in a solid agrochemical active ingredient that is sparingly soluble in an organic solvent or the like, and a suspension obtained by suspending a solid agrochemical active ingredient in a water-immiscible liquid at room temperature The present invention provides a method for producing a microencapsulated agricultural chemical in which a liquid is dispersed as droplets in water and a film is then formed around the droplets.
Further, in the production method, when the solid agrochemical active ingredient is suspended in the water-immiscible liquid, the solid content concentration is adjusted to 45% by weight or less, which is more advantageous in producing the microencapsulated agrochemical. Become.

  Since the pesticidal active ingredient used in the present invention must be suspended in a water-immiscible liquid, it is solid at room temperature, preferably has a melting point of 50 ° C. or higher, and is a water-immiscible liquid such as an organic solvent. Those that can be dispersed without dissolving are used. Of course, even if it is a pesticidal active ingredient easily soluble in a certain organic solvent, the manufacturing method of this invention can be implemented by selecting and disperse | distributing the kind of water immiscible liquid suitably.

Specific examples of the pesticidal active ingredient used in the present invention include methoxadiazone {5-methoxy-3- (2-methoxyphenyl) -1,3,4-oxadiazol-2 (3H) -one}, diniconazole {( E) -1- (2,4-Dichlorophenyl) -4,4-dimethyl-2- (1H-1,2,4-triazol-1-yl) pent-1-en-3-ol}, procymidone {N -(3,5-dichlorophenyl) -1,2-dimethylcyclopropane-1,2-dicarboximide}, oxophosphoric acid {5-ethyl-5,8-dihydro-8-oxo [4,5-g] quinoline -7-carboxylic acid}, bromobutide {2-bromo-N- (α, α-dimethylbenzyl) -3,3-dimethylbutanamide}, full microlac-pentyl {pentyl 2-chloro 4-fluoro-5- (3,4,5,6-tetrahydrophthalimide) phenoxyacetate}, uniconazole {(E) -1- (4-chlorophenyl) -4,4-dimethyl-2- (1H-1,2, , 4-triazol-1-yl) pent-1-en-3-ol}, tetramethrin {3,4,5,6-tetrahydrophthalimidomethyl chrysanthemate}, resmethrin {5-benzyl-3-furylmethyl chrysante Mart}, dioxabenzophos {2-methoxy-4H-benzo-1,3,2-dioxaphospholine-2-sulfide}, xylylcarb {3,4-xylylmethylcarbamate}, tolcrofosmethyl {O- (2 , 6-dichloro-4-methylphenyl) O, O-dimethylphosphorothioate}, dimethoate {O, O-dimethyl Le S- methylcarbamoylmethyl phosphorodithioate}, diethofencarb {isopropyl 3
, 4-diethoxycarbanilate} and the like.

  The water-immiscible liquid used in the present invention is appropriately selected depending on the type of the pesticidal active ingredient, and can be appropriately dispersed without dissolving the pesticidal active ingredient. For example, aliphatic carbonization such as trimethylpentane is used. Hydrogen, aromatic hydrocarbons such as phenylxylyl ethane, alcohols such as hexanol and octanol, ketones such as diisobutyl ketone, esters such as 2-ethylhexyl acetate, dibutyl maleate, diisodecyl adipate, 2-ethylhexyl Examples include ethers such as ether, mineral oils such as machine oil, vegetable oils such as cottonseed oil, and mixtures thereof. The solubility of the agrochemical active ingredient in the water-immiscible liquid is preferably 5% by weight or less.

Below, the manufacturing method of the general this invention is demonstrated in detail.
First, a pesticidal active ingredient is pulverized in a water-immiscible liquid to obtain a suspension, or a pulverized pesticidal active ingredient is dispersed in a water-immiscible liquid to obtain a suspension. When pulverizing active ingredients of agricultural chemicals in a water-immiscible liquid to obtain a suspension, Attritor (Mitsui Miike Chemical), Dino Mill (Shinmaru Enterprises), Colloid Mill (Special Machine Industries) A wet mill such as a pearl mill (manufactured by Serizawa Tekko) is used. In addition, when a pulverized agricultural chemical active ingredient is dispersed in a water-immiscible liquid to obtain a suspension, dry pulverization such as an atomizer (Fuji Powdal) or a jet ohmizer (Seishin Enterprise) is used. Machine is used.

  When obtaining a suspension as described above, as an auxiliary agent, fatty acid soap, ether carboxylate, salt of condensate of higher fatty acid and amino acid, higher alkyl sulfonate, α-olefin sulfonate, higher Sulfonates of fatty acid esters, dialkylsulfosuccinates, sulfonates of higher fatty acid amides, alkylaryl sulfonates, higher alcohol sulfates, alkyl ether sulfates, alkylaryl ether sulfates, higher fatty acid esters Formalin condensation of anionic surfactants such as sulfates, sulfates of higher fatty acid alkylolamides, sulfated oils, phosphates, polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl phenols Stuff, Nonionic surfactants such as reoxyethylene fatty acid esters, polyoxyethylenated oils, polyoxyethylenated waxes, polyhydric alcohol esters, polyoxyethylene polyoxypropylene block copolymers, silicic anhydride, organically modified montmorillonites, etc. A thickener or the like may be added.

  When the obtained suspension is dispersed as droplets in water, a stirrer such as a propeller stirrer, a turbine type stirrer, or a high-speed shear mixer is used, and the suspension is usually dispersed as fine droplets. The particle size of the microcapsules obtained can be adjusted by changing the stirring conditions at this time, and the microcapsule membrane obtained can be adjusted by adjusting the amount of the film-forming substance used thereafter. The thickness can be adjusted.

When dispersing the suspension droplets in water, it is preferable to add a dispersant in advance in water. Dispersants used include gelatin, gum arabic, casein, dextrin, pectin, sodium alginate, methylcellulose, ethylcellulose, sodium carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium polyacrylate, polyvinyl alcohol, polyvinylpyrrolidone, carboxyvinyl polymer Water-soluble polymers such as fatty acid soaps, ether carboxylic acids, ether carboxylates, salts of condensates of higher fatty acids and amino acids, higher alkyl sulfonates, α-olefin sulfonates, sulfonates of higher fatty acid esters , Dialkyl sulfosuccinate, sulfonate of higher fatty acid amide, alkyl aryl sulfonate, higher alcohol sulfate, alkyl ether sulfate Anionic surfactants such as ester salts, alkylaryl ether sulfates, higher fatty acid esters, higher fatty acid alkylolamide sulfates, sulfated oils, phosphate ester salts, alkylamine salts, polyamines or Amino acid fatty acid derivative amine salt, alkyl quaternary ammonium salt, cyclic quaternary ammonium salt, quaternary ammonium salt having hydroxyl group, quaternary ammonium salt having ether bond, carboxylic acid type, sulfuric acid Amphoteric surfactants such as ester type, sulfonic acid type and phosphate ester type, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene alkylphenol formalin condensate, polyoxyethylene fatty acid ester, polyoxyethylene Nonionic surfactants such as xyethylenated fats and oils, polyhydric alcohol esters, polyoxyethylene polyoxypropylene block copolymers and the like can be mentioned.

In order to form a film around the droplet, a normal microencapsulation method such as an interfacial polymerization method or an in-situ polymerization method is used.
In order to perform the microencapsulation method by the interfacial polymerization method, a polyvalent isocyanate (for example, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, Range isocyanate, toluene diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, polymethylene polyphenyl diisocyanate), polyvalent carboxylic acid chlorides (eg sebacic acid dichloride, adipic acid dichloride, azelaic acid dichloride, terephthalic acid The microcapsule film-forming raw material such as dichloride, trimesic acid dichloride), polyvalent sulfonyl chloride (for example, benzenesulfonyl dichloride), etc. is added, and it is necessary in water to disperse the liquid droplets of the suspension. Add water-soluble film-forming materials such as polyhydric alcohols (eg, ethylene glycol, butanediol, hexanediol) and polyamines (eg, ethylenediamine, hexamethylenediamine, phenylenediamine, diethylenetriamine, triethylenetetramine, piperazine) Keep it. The film forming reaction is usually carried out in a temperature range of 0 to 80 ° C., preferably 40 to 80 ° C., for about 0.5 to 48 hours, and a catalyst can be used to accelerate the reaction. In this way, films of polyurethane, polyurea, polyamide, polyester, polysulfonate, polysulfonamide and the like are formed.

  In order to perform microencapsulation by in-situ polymerization, water-soluble prepolymers such as aminoplast, urea formalin condensate, and melamine formalin condensate are previously added to the water in which the suspension droplets are dispersed. Under stirring, it can be carried out usually by heating within a range of 40 to 80 ° C. and holding for about 0.5 to 48 hours.

The microencapsulated pesticide slurry produced in this way can be used as a pesticide as it is, but usually as an aqueous suspension to which a thickener, antifreeze, preservative, specific gravity adjuster, etc. are added. used. As thickeners, natural polysaccharides such as xanthan gum, rhamzan gum, locust bean gum, carrageenan, and welant gum, synthetic polymers such as sodium polyacrylate, semi-synthetic polymers such as carboxymethylcellulose, aluminum magnesium silicate, smectite, bentonite, Examples thereof include mineral powders such as hectorite and dry silica, and alumina sol. Examples of the antifreezing agent include propylene glycol. Examples of the preservative include p-hydroxybenzoic acid ester and salicylic acid derivative. Specific gravity regulators include water-soluble salts such as sodium sulfate and water-soluble fertilizers such as urea.
Moreover, it can also be used as a powdery preparation by a technique such as spray drying.

  The content of the pesticidal active ingredient when formulated into an aqueous suspension or powder preparation is usually 0.1 to 40% by weight of the whole preparation, and in the case of an aqueous suspension, usually 0.1 to 40% by weight. 20% by weight.

Production Example 1
100 g of diniconazole was added to a mixed solution of 100 g of phenylxylylethane and 100 g of diisodecyl adipate, and pulverized with a bead mill to obtain a suspension having a solid content of about 31% by weight. To this, 25 g of Sumidur L-75 (Sumitomo Bayer Urethane aromatic isocyanate) was added to 500 g of water containing 30 g of gum arabic and 20 g of ethylene glycol. K. The mixture was stirred at room temperature with an auto homomixer (a homogenizer manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain fine droplets. Next, by stirring at 60 ° C. for 24 hours, a slurry in which diniconazole suspended in a mixed liquid of phenylxylylethane and diisodecyl adipate was microencapsulated with a polyurethane film was obtained.
To this slurry, 175 g of water containing 1 g of xanthan gum and 5 g of aluminum magnesium silicate was added to obtain a 10% by weight diniconazole composition.

Production Example 2
50 g of bromobutide was added to 200 g of phenylxylylethane and pulverized with a bead mill to obtain a suspension having a solid content of about 19% by weight. To this, 10 g of Sumidur L-75 was added to 500 g of water containing 30 g of gum arabic and 20 g of ethylene glycol. K. The mixture was stirred at room temperature with an auto homomixer to obtain fine droplets. Next, by stirring at 60 ° C. for 24 hours, a slurry in which bromobutide suspended in phenylxylylethane was microencapsulated with a polyurethane film was obtained.
To this slurry, 240 g of water containing 1 g of xanthan gum and 5 g of aluminum magnesium silicate was added to obtain a 5% by weight bromobutide composition.

Production Example 3
100 g of diniconazole was added to a mixed solution of 100 g of phenylxylylethane and 100 g of diisodecyl adipate, and pulverized with a bead mill to obtain a suspension having a solid content of about 31% by weight. To this, 25 g of Sumidur L-75 was added to 490 g of water containing 30 g of gum arabic. K. The mixture was stirred at room temperature with an auto homomixer to obtain fine droplets. Next, by stirring at 60 ° C. for 24 hours, a slurry was obtained in which diniconazole suspended in a mixed liquid of phenylxylylethane and diisodecyl adipate was microencapsulated with a polyurea film.
To this slurry, 185 g of water containing 1 g of xanthan gum and 5 g of aluminum magnesium silicate was added to obtain a 10% by weight diniconazole composition.

Production Example 4
100 g of procymidone was added to 200 g of diisodecyl adipate and finely pulverized with a bead mill to obtain a suspension having a solid content of about 30% by weight. To this, 25 g of Sumidur L-75 was added to 325 g of water containing 30 g of gum arabic and 20 g of ethylene glycol. K. The mixture was stirred at room temperature with an auto homomixer to obtain fine droplets. Next, by stirring at 60 ° C. for 24 hours, a slurry in which procymidone suspended in diisodecyl adipate was microencapsulated with a polyurethane film was obtained.
To this slurry, 350 g of water containing 1 g of xanthan gum and 5 g of aluminum magnesium silicate was added to obtain a 10% by weight procymidone composition.

Production Example 5
100 g of diniconazole was added to a mixed solution of 150 g of phenylxylylethane and 50 g of diisodecyl adipate and finely pulverized with a bead mill to obtain a suspension having a solid content concentration of about 32% by weight. To this, 50 g of Sumidur L-75 was added to 530 g of water containing 30 g of gum arabic and 30 g of ethylene glycol. K. The mixture was stirred at room temperature with an auto homomixer to obtain fine droplets. Next, by stirring at 60 ° C. for 24 hours, a slurry in which diniconazole suspended in a mixed liquid of phenylxylylethane and diisodecyl adipate was microencapsulated with a polyurethane film was obtained.
120 g of water containing 1 g of xanthan gum and 5 g of aluminum magnesium silicate was added to this slurry to obtain a 10% by weight diniconazole composition.

Production Example 6
To a mixture of 100 g of phenylxylylethane and 100 g of diisodecyl adipate, 100 g of procimidone was added and pulverized with a bead mill to obtain a suspension having a solid content concentration of about 30% by weight. To this, 25 g of Sumidur L-75 was added to 500 g of water containing 15 g of polyvinyl alcohol and 20 g of ethylene glycol. K. The mixture was stirred at room temperature with an auto homomixer to obtain fine droplets. Next, by stirring at 60 ° C. for 24 hours, a slurry in which procymidone suspended in a mixed liquid of phenylxylylethane and diisodecyl adipate was microencapsulated with a polyurethane film was obtained.
To this slurry, 175 g of water containing 1 g of xanthan gum and 5 g of aluminum magnesium silicate was added to obtain a 10% by weight procymidone composition.

  According to the microencapsulated agricultural chemical production method of the present invention, even a solid agricultural chemical active ingredient hardly soluble in an organic solvent or the like can be easily microencapsulated.

Claims (11)

Suspend an agrochemical active ingredient that is solid at room temperature in a water-immiscible liquid, add the microcapsule film-forming raw material to the resulting suspension, disperse it as droplets in water, A method for producing a microencapsulated pesticide, comprising forming a film around the periphery. A pesticidal active ingredient that is solid at room temperature is suspended in a water-immiscible liquid so that the solid content concentration is 45% by weight or less. A method for producing a microencapsulated pesticide, characterized in that the film is dispersed as droplets and then a film is formed around the droplets. Suspend an agrochemical active ingredient that is solid at room temperature in a water-immiscible liquid, add polyisocyanate to the resulting suspension, disperse it in water as droplets, and then around the droplets A method for producing a microencapsulated pesticide, comprising forming a film. Suspend an agrochemical active ingredient that is solid at room temperature in a water-immiscible liquid so that the solids concentration is 45% by weight or less, add polyisocyanate to the resulting suspension, and liquid this in water. A method for producing a microencapsulated pesticide, comprising dispersing as a droplet and then forming a film around the droplet. Suspend an agrochemical active ingredient that is solid at room temperature in a water-immiscible liquid, add polyisocyanate to the resulting suspension, and disperse it as a droplet in water to which polyhydric alcohol has been added. Then, a method for producing a microencapsulated pesticide, wherein a polyurethane film is formed around the droplets within a temperature range of 40 to 80 ° C. Suspend an agrochemical active ingredient that is solid at room temperature in a water-immiscible liquid so that the solid concentration is 45% by weight or less, add polyisocyanate to the resulting suspension, A method for producing a microencapsulated pesticide, which comprises dispersing as a droplet in added water at room temperature, and then forming a polyurethane film around the droplet within a temperature range of 40 to 80 ° C. Suspend an agrochemical active ingredient that is solid at room temperature in a water-immiscible liquid so that the solid concentration is 45% by weight or less, add polyisocyanate to the resulting suspension, and add ethylene glycol to this suspension A method for producing a microencapsulated pesticide, comprising dispersing in water at room temperature as droplets and then forming a polyurethane film around the droplets within a temperature range of 40 to 80 ° C. A pesticide active ingredient that is solid at room temperature, the solubility of the pesticide active ingredient is 5% by weight or less, aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, ketones, esters, ethers, mineral oils, Suspended in a water-immiscible liquid selected from vegetable oils and mixtures thereof and containing esters so that the solid concentration is 45% by weight or less, and the resulting suspension forms a microcapsule film. A method for producing a microencapsulated pesticide, which comprises adding a raw material, dispersing it in water as droplets, and then forming a film around the droplet. The water-immiscible liquid is selected from aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, ketones, esters, ethers, mineral oils, vegetable oils and mixtures thereof, and the esters are 25% by weight or more. The method for producing a microencapsulated agricultural chemical according to claim 8, wherein the liquid is contained. The microencapsulation according to claim 8, wherein the water-immiscible liquid is a liquid selected from aromatic hydrocarbons, esters, and mixtures thereof and containing 25% by weight or more of esters. A method for producing agricultural chemicals. The method for producing a microencapsulated pesticide according to any one of claims 8 to 10, wherein the microcapsule film-forming raw material is a polyvalent isocyanate.