JPH10114608A - Composition for controlling harmful organism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition with a long-term stable preservability by microencapsulating an organophosphorus-based compound together with an aromatic ester solvent. SOLUTION: This composition is obtained by microencapsulating an organophosphrous-based compound having a melting point of >=15 deg.C together with an aromatic ester solvent through an interfacial polymerization method. The organophosphrous-based compound and the aromatic ester solvent are, e.g., chlorpyriphos and a phthalic diester, respectively. The composition is effective for controlling harmful insects infesting in wood such as termite and power- post beetle. This microencapsulated preparation gets little deteriorative due to a deposition or growth of the crystal and is good in long-term stable preservability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pesticidal composition in which an organic phosphorus compound is microencapsulated.

[0002]

2. Description of the Related Art Pest control compositions in which an organic phosphorus compound, for example, chlorpyrifos, is microencapsulated are used for controlling wood pests.

[0003]

However, pest control agents obtained by microencapsulation of a solid organophosphorus compound at room temperature, such as chlorpyrifos, do not always have good long-term storage stability. There is a problem of deterioration of the preparation due to precipitation and growth of, and its improvement has been demanded.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is intended to provide a pesticidal composition in which an organic phosphorus compound having a melting point of 15 ° C. or more is microencapsulated. An object of the present invention is to provide a pesticidal composition in which an ester solvent is encapsulated in microcapsules together with the organic phosphorus compound.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The organophosphorus compound used in the present invention has a melting point of 15 ° C. or more. Specifically, for example, the following active ingredient compounds of insecticides, fungicides, and herbicides are used. No.

(1) O, O-diethyl O-3,5
6-trichloro-2-pyridyl phosphorothioate {chloropyrifos} (2) O, O-dimethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate {chloropyrifosmethyl} (3) O, O-diethyl O-quinoxaline-2 -Yl phosphorothioate {quinalphos} (4) O- (1,6-dihydro-6-oxo-1-phenylpyridazin-3-yl) O, O-diethyl phosphorothioate {pyridafenthione} (5) O, O-dimethyl S- (N-methylcarbamoylmethyl) dithiophosphate {dimethoate}

(6) S-α-ethoxycarbonylbenzyl O, O-dimethyl phosphorodithioate @ PA
P {(7) S-6-chloro-2,3-dihydro-2-oxobenzoxazol-3-ylmethyl O, O-diethyl phosphorodithioate {phosalon} (8) S-2,3-dihydro-5 -Methoxy-2-oxo-1,3,4-thiadiazol-3-ylmethyl
O, O-dimethyl phosphorodithioate {DMTP} (9) 2-chloro-1- (2,4-dichlorophenyl) vinyl dimethyl phosphate {dimethylvinphos} (10) dimethyl 2,2,2-trichloro-1- Hydroxyethyl phosphonate trichlorfon

(11) O-ethyl O-4-nitrophenyl phenylphosphonothioate {EPN} (12) S-benzyl O, O-diisopropyl phosphorothioate {IBP} (13) O-2,6-dichloro-p- Toril O, O-
Dimethyl phosphorothioate {tolclofosmethyl} (14) O-methyl O-2-nitro-p-tolyl isopropyl phosphoramidothioate {amiproposmethyl}

The aromatic ester solvent used in the present invention is an ester solvent having an aromatic ring structure in a molecule, and is an ester solvent derived from an aromatic acid and / or an aromatic alcohol. Examples of the ester solvent derived from an aromatic acid include phthalic acid diesters such as dibutyl phthalate, dioctyl phthalate, dinonyl phthalate, didecyl phthalate, diundecyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, and dicyclohexyl phthalate , Butyl benzoate, benzoic acid esters such as isoamyl benzoate, methyl salicylate, ethyl salicylate,
And salicylic acid esters such as isoamyl salicylate. Examples of the ester solvent derived from an aromatic alcohol include benzyl esters such as benzyl acetate, benzyl propionate, and benzyl salicylate. Among these aromatic ester solvents, the use of dialkyl phthalate (here, the alkyl groups are the same or different alkyl groups having 1 to 13 carbon atoms) is preferable.

In producing the pesticidal composition of the present invention, the microencapsulation preparation method includes, for example, control of microencapsulation reaction such as conventionally known interfacial polymerization method and in-situ method. An easy method is used. Among them, the interfacial polymerization method is a preferable method for obtaining the pesticidal composition of the present invention because of a wide selection range of the film substance.

In the present invention, examples of the membrane material of the microcapsules include polyurethane, polyurea, polyamide, polyester, polycarbonate, polysulfonate, polysulfonamide, urea formalin condensate,
Examples thereof include melamine urea condensate, phenol formalin condensate, acrylate polymer, methacrylate polymer, vinyl acetate polymer, styrene polymer, divinylbenzene polymer, ethylene dimethacrylate polymer, and the like.

To form a polyurethane film, for example, a polyvalent isocyanate and a polyhydric alcohol may be interfacially polymerized. In the case of a polyurea film, interfacial polymerization of a polyvalent isocyanate and a polyvalent amine or water may be used. "New technology of microencapsulation" by Tamotsu Kondo et al., Such as interfacial polymerization of polyacid chloride and polyamine for polyamide membrane and interfacial polymerization of polyacid chloride and polyhydric alcohol for polyester membrane. Microcapsulation can be carried out by a method known from "Management Development Center Publishing Division, etc."

As one embodiment of the present invention, there is provided a pesticidal composition in which chlorpyrifos is microencapsulated. The pesticidal composition is used for controlling wood pests such as termites and leaf beetles. Particularly suitable. As the microencapsulated composition for controlling pests of chlorpyrifos in wood, the average particle size of the microcapsules is 3
The microcapsules are designed so that the value of (average particle diameter / film thickness) is 30 or more and 200 or less, and the value of (average particle diameter × film thickness) is 20 μm ² or less. Are preferred in terms of enhancing the wood pest control effect and formulation stability.

The average particle size of the microcapsules is, for example,
It can be measured using a Coulter Counter TA-II (manufactured by Nikkaki). The film thickness is given by

(Equation 1) Can be calculated by

When the pesticidal composition of the present invention, in which chlorpyrifos is microencapsulated, is used outdoors on wood, discoloration may be observed at the places where it is sprayed, but the aromatic ring in the membrane material may be discolored. The film material is selected so that the weight% value A of the structure is 40 or less and the ratio of the value of A to the value of (average particle size / film thickness) of the microcapsules is 0 or more and 0.8 or less. This can prevent discoloration. For that purpose, for example, to form a polyurea film or the like by the above interfacial polymerization method, by not increasing the use ratio of a film-forming raw material containing an aromatic ring structure such as phenylenediisocyanate or phenylenediamine, the film What is necessary is just to reduce the weight% value occupied by the aromatic ring structure in the substance. Of course, the weight% value of the aromatic ring structure in the film material may be set to 0 by using a film forming raw material not containing the aromatic ring structure.

The polyvalent isocyanate used for forming the polyurethane film or the polyurea film includes hexamethylene diisocyanate, an adduct of hexamethylene diisocyanate and trimethylolpropane, Biuret condensate of three molecules of isocyanate, adduct of tolylene diisocyanate with trimethylolpropane, isocyanurate condensate of tolylene diisocyanate, isocyanurate condensate of hexamethylene diisocyanate, isocyanurate of isophorone diisocyanate One isocyanate portion of the condensate, hexamethylene diisocyanate, forms an isocyanurate with two molecules of tolylene diisocyanate, and the other isocyanate portion has two molecules of another hexamethylene diisocyanate. Isocyanate prepolymer constituting the isocyanurate with preparative, 4,4'-methylenebis (cyclohexyl isocyanate), the use of such trimethyl hexamethylene diisocyanate are preferred.

When the pesticidal composition of the present invention in which chlorpyrifos is microencapsulated is used for termite control, the pesticidal composition is used in an amount of chlorpyrifos of about 5 to 50 g / m ² under the floor of a house. Spray on soil or concrete surface. When the pesticidal composition is treated with xylem, the amount of chlorpyrifos is 1%.
About 5 g / m ² is sprayed on the xylem surface.

When the pesticidal composition of the present invention, in which chlorpyrifos is microencapsulated, is used for insect control plywood for controlling the bark beetle, the pesticidal composition is used in an amount of chlorpyrifos per m ³ of plywood.
The veneer can be mixed with an adhesive so as to have a weight of about 10 to 1000 g, and then laminated to a veneer, and then subjected to pressure treatment to obtain an insect-resistant plywood. As the adhesive, urea resin, melamine urea, modified phenol resin, alkali phenol resin and the like are used.

The pesticidal composition of the present invention, in which chlorpyrifos is microencapsulated, is effective not only in controlling wood pests but also in controlling unpleasant pests such as ants, kamado, gejigeji, centipede, waradbug, and beetle. In this case, for example, the pesticidal composition of the present invention may be sprayed on the unpleasant pest or the place where the unpleasant pest inhabits in an amount of chlorpyrifos of about 1 to 50 g / m ² .

The pesticidal composition of the present invention can be in various forms such as aqueous suspensions, powders, wettable powders, granules and the like. Often used because of its goodness. The aqueous suspension is prepared, for example, by adding a stabilizer such as a thickener, an antifreezing agent, a preservative, and a specific gravity regulator to a slurry obtained as a result of performing a microencapsulation reaction by an interfacial polymerization method. Is done.

Examples of the thickener include xanthan gum,
Ramzan gum, locust bean gum, carrageenan,
Natural polysaccharides such as welan gum, synthetic polymers such as sodium polyacrylate, semi-synthetic polymers such as carboxymethylcellulose, aluminum magnesium silicate, mineral powder such as smectite, bentonite, hectorite, silica, alumina sol, etc. Examples thereof include substances that exhibit a thickening effect in water, and the content in the pesticidal composition of the present invention is usually 0 to 10% by weight. Examples of the antifreeze include ethylene glycol, propylene glycol, glycerin and the like, and the content in the pesticidal composition of the present invention is usually 0 to 20% by weight.

Examples of the preservative include those used in ordinary pesticide preparations such as parahydroxybenzoate and salicylic acid derivatives. Specific gravity regulators include, for example, aqueous solutions of sodium sulfate and the like. And water-soluble fertilizers such as urea and the like. The content of the organophosphorus compound as the active ingredient in the pesticidal composition of the present invention varies depending on the kind of the active ingredient, the form of the preparation and the like, but is usually 0.5 to 80% by weight, In the case of a suspension, it is usually 0.5 to 50% by weight. The ester solvent used in the present invention is generally used in a proportion of 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, based on 1 part by weight of the organic phosphorus compound as an active ingredient.

[0023]

The present invention will be described in more detail with reference to Production Examples, Comparative Examples and Test Examples. First, a production example will be described. Production Example 1 20 parts by weight of chlorpyrifos, 20 parts by weight of dibutyl phthalate, and Sumidur L-75 (an adduct of trimethylolpropane and tolylene diisocyanate manufactured by Sumitomo Bayer Urethane, molecular weight 656, and three aromatic rings with three benzene rings as molecules) 3.24 parts by weight). 8% by weight
Was added to 150 parts by weight of an aqueous solution containing polyvinyl alcohol and 6% by weight of ethylene glycol, and the mixture was stirred at room temperature using a TK auto homomixer (a homogenizer manufactured by Tokushu Kika Kogyo Co., Ltd.) to be dispersed into fine droplets. Subsequently, the mixture was gently stirred at 60 ° C. for 24 hours to obtain a slurry in which chlorpyrifos was microencapsulated in a polyurethane film. An aqueous solution containing 2 parts by weight of xanthan gum and 4 parts by weight of aluminum magnesium silicate was added to the obtained slurry.
6 parts by weight were added to obtain a pesticidal composition of the present invention containing 5% by weight of chlorpyrifos. The average particle size of the obtained microcapsules is 5.1 μm (Coulter counter TA
-Measured value by type II), the film thickness was 0.05 μm, (average particle size / film thickness) was 102, and (average particle size × film thickness) was 0.26 μm ² . In addition, the weight% value A occupied by the aromatic ring structure in the film material A
Was 28.8%, and the ratio of the value of A to the value of (average particle size / film thickness) was 0.28.

Production Example 2 20 parts by weight of chlorpyrifos, 20 parts by weight of diisodecyl phthalate and Sumidur L-75 (an adduct of trimethylolpropane and tolylene diisocyanate manufactured by Sumitomo Bayer Urethane, molecular weight 656, benzene ring 3 as an aromatic ring) 3.52 parts by weight) were uniformly mixed. This was added to 150 parts by weight of an aqueous solution containing 8% by weight of polyvinyl alcohol and 6% by weight of ethylene glycol, and the mixture was stirred at room temperature using a TK auto homomixer to be dispersed in microdroplets. Subsequently, the mixture was gently stirred at 60 ° C. for 24 hours to obtain a slurry in which chlorpyrifos was microencapsulated in a polyurethane film. To the obtained slurry, 206.48 parts by weight of an aqueous solution containing 2 parts by weight of xanthan gum and 4 parts by weight of aluminum magnesium silicate was added to obtain a pesticidal composition of the present invention containing 5% by weight of chlorpyrifos. The average particle size of the obtained microcapsules is 13.1 μm
(Measured value by Coulter Counter TA-II type), film thickness was 0.14 μm, (average particle diameter / film thickness) was 94, and (average particle diameter × film thickness) was 1.83 μm ² . The weight% value A of the aromatic ring structure in the film material was 28.8%, and the ratio of the value of A to the value of (average particle diameter / film thickness) was 0.31.

Next, a production example of a composition for comparative reference in a test example described later is shown as a comparative example. Comparative Example 1 Sumidur N-75 (a biuret condensate of hexamethylene diisocyanate manufactured by Sumitomo Bayer Urethane, containing no aromatic ring in the molecule) A mixture of 1.92 parts by weight of chlorpyrifos and 20 parts by weight of hexane was heated to 60 ° C. After mixing 20 parts by weight, this was mixed with 8% by weight of polyvinyl alcohol and 6 parts by weight.
The mixture was added to 150 parts by weight of an aqueous solution containing ethylene glycol by weight and stirred at room temperature by using a TK auto-homomixer to be dispersed in microdroplets. Subsequently, the mixture was gently stirred at 60 ° C. for 24 hours to obtain a slurry. In the obtained slurry, 1
208.08 parts by weight of an aqueous solution containing 5 parts by weight of xanthan gum and 5 parts by weight of aluminum magnesium silicate were added to obtain a comparative pesticidal composition containing 5% by weight of chlorpyrifos.

Comparative Example 2 After mixing 0.95 parts by weight of Millionate MR-400 (polyethylene polyphenyl polyisocyanate manufactured by Nippon Polyurethane Industry) and 20 parts by weight of chlorpyrifos to make uniform, 150 parts by weight of an aqueous solution containing 8% by weight of polyvinyl alcohol Parts, and stirred at room temperature using a TK auto homomixer,
Dispersed into microdroplets. Then, the mixture was gently stirred at 60 ° C. for 24 hours to obtain a slurry in which chlorpyrifos was microencapsulated in a polyurea membrane. In the obtained slurry,
229.05 parts by weight of an aqueous solution containing 2 parts by weight of xanthan gum and 4 parts by weight of aluminum magnesium silicate were added to obtain a comparative pesticidal composition containing 5% by weight of chlorpyrifos. The average particle size of the obtained microcapsules is 8.3 μm, the film thickness is 0.1 μm, (average particle size / film thickness).
Was 83, and (average particle size × film thickness) was 0.83 μm ² . The weight% value A occupied by the aromatic ring structure in the film material is 45.6%.
%, And the ratio of the value of A to the value of (average particle diameter / film thickness) is 0.
55.

Test examples are shown below. Test Example 1 The pesticidal composition of the present invention obtained in Production Examples 1 and 2 was used as a 1% by weight water diluent, and the termite termite 10 was prepared.
A sufficient amount (6 ml) was sprayed on the head from a height of 60 cm. 1
The mortality after day was determined and found to be 100% for both compositions.

Test Example 2 The pesticidal composition of the present invention obtained in Production Examples 1 and 2 and the pesticidal composition obtained in Comparative Example 1 were each placed in a polyethylene bottle and placed in a refrigerator (in a refrigerator). (Temperature: about 5 ° C.) for 2 weeks, and then observed under a microscope for each composition. In both compositions of the present invention, no precipitation of crystals was observed, whereas in the composition obtained in Comparative Example 1, precipitation of crystals was observed. The pesticidal composition of the present invention showed no storage of crystals and showed excellent storage stability, whereas the composition obtained in Comparative Example 1 using hexane instead of the aromatic ester solvent. Crystals were observed in the product.

Test Example 3 3 g of the pesticidal composition of the present invention obtained in Production Example 2
Was applied on a glass petri dish, air-dried, and kept at 60 ° C. for 1 week. Next, the amount of the active ingredient (chloropyrifos) remaining on the petri dish was measured by gas chromatography, and the remaining rate of the active ingredient was determined by comparing with the applied amount.
%Met.

Test Example 4 0.8 g each of the pesticidal composition of the present invention obtained in Production Example 1 and the pesticidal composition obtained in Comparative Example 2
Was applied on a filter paper and air-dried and then exposed to sunlight for 3 days. The pest control composition of the present invention obtained in Production Example 1 showed little discoloration, while the pest control composition obtained in Comparative Example 2 showed a clear yellowing.

Test Example 5 The pesticidal composition obtained in Production Example 1 was diluted with water to a concentration of 0.1% by weight, and 6 ml was sprayed on soil. After the sprayed soil was stored at 60 ° C. for a predetermined period, ten termite termites were released into the soil, and the mortality (%) three days later was determined. Table 1 shows the results.

[0032]

[Table 1]

[0033]

Industrial Applicability The pesticidal composition of the present invention is a composition excellent in long-term storage stability with little deterioration of the preparation due to precipitation and growth of crystals.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiro Otsubo 4-2-1 Takashi Takarazuka-shi, Hyogo Sumitomo Chemical Industry Co., Ltd.

Claims (6)

[Claims] 1. A pesticidal composition in which an organic phosphorus compound having a melting point of 15 ° C. or higher is microencapsulated, wherein an aromatic ester solvent is included in the microcapsules together with the organic phosphorus compound. A pesticidal composition comprising: 2. The pesticidal composition according to claim 1, wherein the aromatic ester solvent is a phthalic acid diester. 3. The pesticidal composition according to claim 1, wherein the organophosphorus compound is chlorpyrifos. 4. The pesticidal composition according to claim 3, which is used for controlling wood pests. 5. The microcapsule has an average particle size of 30 μm or less, and a value of (average particle size / film thickness) of 30 to 200 μm.
And the value of (average particle size × film thickness) is 20 μm ²
The pesticidal composition according to claim 4, which is: 6. The weight percentage value A of the aromatic ring structure in the membrane material of the microcapsule is 40 or less, and the ratio of the value of A to the value of (average particle size / film thickness) of the microcapsule is less than 40%. 0
The pesticidal composition according to claim 4 or 5, wherein the composition is 0.8 or less.