JPH03227903A - Stabilization of pyrethroid compound - Google Patents

Abstract

PURPOSE:To obtain an inexpensive insecticidal/mitcidal agent storable for a long period of time, simplified in its storage process and prevented from decreasing its repellent effect, by carrying a pyrethroid compound on porous silicate compound powder with a size not larger than a specified level to effect stabilization. CONSTITUTION:The objective stabilization can be accomplished by making 1 pt.wt. of a pyrethroid compound adsorb on 0.7-5 pts.wt. of a porous silicate compound powder <=5mum in granular size. Said powder is pref. such a to be produced by a vapor phase process where silicon tetrachloride is hydrolyzed in an oxyhydrogen flame, because of its high oil absorption. Besides the pyrethroid compound and silicate compound powder, at least one of various chemicals (e.g. antioxidant, bactericide, other insecticide/mitcide, antifungal agent, synergist, repellent) can be formulated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for stabilizing pyrethroid compounds useful for household use, epidemic prevention, gardening, etc.

[Prior art]

Conventionally, various drugs have been used as active ingredients in insecticidal and acaricidal compositions for household use, epidemic prevention, and gardening. Examples of insecticides include organic chlorine compounds, organic phosphorous compounds, carbamate compounds, pyrethroid compounds, pyrethroid-like compounds, oxadiazole compounds, and the like.

Examples of acaricides include organic phosphorus compounds, carbamate compounds, pyrethroid compounds, carbinol compounds, and diazo compounds. Among these compounds, compounds with relatively high safety are used for household use, and pyrethroid compounds are representative examples thereof.

These pyrethroid compounds exhibit high insecticidal and acaricidal effects against sanitary pests such as flies, cockroaches, white mites, and house dust mites, but like pyrethroid compounds, their toxicity to humans and livestock is limited by other insecticides or insecticides. Its content is significantly lower than that of acaricides, and it is widely used as an active ingredient in household insecticidal or acaricidal compositions.

However, it has been pointed out that this pyrethroid compound has poor stability due to heat, light, and oxidation by oxygen. Improvements have been made in the addition of compounds, storage of the paste, packaging, dosage form, etc., and it is still used as a household insecticidal or acaricidal composition.

For example, the introduction of halogen into the pyrethroid compound itself,
Addition of antioxidants such as BHA and BIT, addition of rillic acid, tall oil, tung oil or sodium carbonate, potassium carbonate (JP-A-59-20208), inclusion in cyclodext 13 (JP-A-51 No.-81888, JP-A-62
-267203), addition of benzophenone derivatives, triazole derivatives, substituted acrylonitrile compounds, sterically hindered amines, etc. (JP-A-59-39807, JP-A-59-116202), addition of benzoic acid derivatives (JP-A-59-39807, JP-A-59-116202), Many efforts have been made, including adsorption to mineral powder (talc).

On the other hand, silicic acid compound powder has considerable differences in specific volume and purity depending on the manufacturing method such as gas phase method or liquid phase method, and in particular, the product manufactured by the gas phase method is called light silicic anhydride. . This light anhydrous silicic acid is also listed in the Oral Pharmacopoeia, and its uses include dehydrating agents, oil agents, clarifying agents for varnishes, etc., homogeneity and fluidity improvers when added to powders, and the production of fragrances, etc. It can be used as a filtration aid, a thickener for ointments, creams, etc., an emulsion stabilizer for emulsions, an excipient for gunpowder, an abrasive for toothpaste, a bulking agent for toothpaste paste, and a foaming agent. Are known.

It is also known in the field of agrochemicals that zeolite can be used as a crystal precipitation inhibitor on the surface of granules (Japanese Patent Laid-Open No. 1648/1983).

[Problem that the invention seeks to solve]

As mentioned above, many attempts have been made to stabilize pyrethroid compounds, but they are still insufficient.

For example, the addition of antioxidants such as BHA and BHT or adsorption to mineral powder (talc) does not have a sufficient stabilizing effect, and inclusion with cyclodextrin does not have sufficient insecticidal activity. Inclusion is expensive. When a halogen is introduced into the pyrethroid compound itself, stability is improved, but the compound becomes toxic. In addition, the addition of lyrinic acid oil, tall oil, tung oil, sodium carbonate, potassium carbonate, benzophenone derivatives, triazole derivatives, substituted acrylonitrile compounds, sterically hindered amines, and benzoic acid derivatives are limited to the prevention of pyrethroid compounds against light. Very few of them are actually used, as they are only considered from the aspect of stability, and they are not very effective.

[Means to solve the problem]

The present inventors have conducted intensive research to develop an insecticidal and acaricidal composition in which the above-mentioned pyrethroid and ido-based compounds can be stored or used in a stable state, and as a result, they have found that the pyrethroid-based compounds can be retained in the silicate compound powder. discovered that pyrethroid compounds can be stabilized, and completed the present invention.

- That is, the present invention provides a method for stabilizing pyrethroid compounds, characterized in that at least one compound selected from pyrethroid compounds is retained in at least one compound selected from silicate compound powder having a particle size of 5t1m or less. Pertains to.

As the pyrethroid compound according to the present invention, 3-phenoxybenzyl-3-(2,2-dichlorovinyl)-2
, 2-dimethylcyclopropane-1-carboxylate (hereinafter referred to as permethrin), 3-phenoxybenzyl-3-(2-methyl-1-propenyl)-2,2-dimethyl-cyclopropane-1-carboxylate (hereinafter referred to as phenothrin) ), α-cyano-3-phenoxybenzyl-3-(2-methyl-1-propenyl)-2,2-dimethyl-cyclopropane-1-carboxylene-1- (
3-allyl-2-methyl-4oxo-2-cyclopentenyl-3-(2methyl-
1-propenyl)-2,2-dimethylcyclopropane-
1~Carpoxyre+-<hereinafter referred to as allethrin), (
5-Benzyl-3furyl)methyl-3-(2-methyl-
1-propenyl)-2,2-dimethyl-cyclopropane 1-carboxylene-1 (hereinafter referred to as resmethrin),
1-ethynyl-2-methyl-2-pentenyl-2,2-
Dimethyl-3-(2-methyl-1-propenyl)-cyclopropane-1-carboxylate (hereinafter referred to as empenthrin), 3-propargyl-2-methyl-4-oxo-2-cyclopentenyl-3-(2-methyl- 1propenyl)-2,2-dimethyl-cyclopropane-1-carboxylate (hereinafter referred to as prarethrin), [5-(
2-propynyl)-2-furylcomethyl-2,2-dimethyl-3(2-methyl-1-propenyl)-cyclopropane-1-carboxylate (hereinafter referred to as flamethrin), or optical isomers and geometric isomers thereof, Analogs are also exemplified as pyrethroid compounds of the present invention. When these pyrethroid compounds are used in the present invention, at least one or two compounds can be selected from these pyrethroid compounds.

The silicate compound powder according to the present invention is silicon dioxide (particle size 0.001 to 0°20oIHrl, bulk density 0.05 to 0 .13g/7), or hydrated silicon oxide (particle size 51 rrn or less, bulk density 0.15 to 0°25 g/cr(), etc.) produced by a method such as decomposing sodium silicate with hydrochloric acid (liquid phase method), etc. There are various types of silicic acid compounds, but those produced by the vapor phase method are preferable, and the bulk density of silicon dioxide, which is silicate compound powder produced by the vapor phase method, is 0.05 to 1.30 g/rn. ', particle size distribution is 2 to 1.10 nm, oil absorption is 50 to 300 mQ/100
It was g. On the other hand, silicate compound powder produced by the vapor phase method and silicate compound powder produced by the liquid phase method can also be distinguished by their bulk density. silicic acid compound powder manufactured by vapor phase method,
In other words, light anhydrous silicic acid as shown in the Japanese Pharmacopoeia No. 11 is particularly preferred. The stabilization method according to the present invention stably maintains a pyrethroid compound by adsorbing it to the silicic acid compound.

In other words, silicic acid compound powder produced by the gas phase method is preferred because it exhibits high oil absorption. Furthermore, even in powders, etc., the pyrethroid compound held by the carrier is transferred to the silicate compound powder, making it possible to create a stable state. The lower the particle size of the silicic acid compound powder, the stronger the adhesion to the carrier, etc., so the finer the particle size, the better.

Regarding the blending amount of the pyrethroid compound and the silicate compound powder according to the present invention, the silicate compound powder may be used in an amount sufficient to stabilize the pyrethroid compound. It is sufficient that 0.1 part by weight of the silicate compound powder is blended with at least 1 part by weight of the pyrethroid compound. Preferably, 0.5 to 10 parts by weight of silicic anhydride may be blended per 1 part by weight of the pyrethroid compound 8, particularly preferably 0.7 to 5 parts by weight per 1 part by weight of the pyrethroid compound. is desirable.

In addition to the above-mentioned pyrethroid compound and silicate compound powder, various commonly used drugs can be blended into the present invention, and such drugs include antioxidants (BH
T, BHA), insecticides, acaricides, fungicides (benzalkonium chloride, benzethonium chloride, etc.), fungicides, synergists (octachlorodipropyl ether, cinepirin,
biperonyl butoxide, sesax, etc.), repellents (
Examples include N,N-dimethyl-m-toluamide, etc.).

Examples of insecticides or acaricides other than the pyrethroid compounds include organic phosphorus compounds, carbamate compounds, and oxadiazole compounds.

Examples of organic phosphorus compounds include dimethyl-4-nitro-toyl-phosphothiophate, 2,3-sibidro-3-oxo-2-phenyl-6-pyridazinyl-diethylphosphothiophate, and 2,2-dichlorovinyl-dimethyl. Examples include phosphates, carbamate compounds include 1-naphthyl-methylcarbamate, isopropoxyphenyl-methylcarbamate, and oxadiazole compounds include 5-methoxy-3-(2-methoxyphenyl)- An example is 1,3,4-oxadiazolin-2-one. and 2-(4-ethoxyphenyl) as another insecticidal and acaricidal compound.
-2-methylpropyl-3-phenoxybenzyl ether, tetrahydro-5,5 dimethyl-2-pyrimidinone-α-[4-trifluoromethyl-α-(4-triflumethylstyryl)-cinamylidene]hydrazone, isopropyl-11 -Methoxy-3,7,11-1-limethyl-2,4-dodecagenoate, 4-phenoxyphenyl-2-(2-pyridyloxy)propyl ether, and the like.

The present invention can be used not only as a powder and an aquarium, but also as granules and tablets. In order to make each dosage form similar, it is necessary to add various additives depending on the dosage form, use, or manufacturing method.

Additives selected according to each dosage form include carriers, binders, disintegrants, caking agents, viscosity modifiers, dispersants, and adsorbents. Examples of carriers include waxite, shellfish powder, bentonite,
Silica powder, pumice powder, talc, limestone powder, acid clay, clay, algae powder, kaolin, gypsum, calcium carbonate,
Mica powder, colloidal hydrated sodium silicate, etc., binders include starch, polyvinyl alcohol, gelatin, CMC,
Disintegrants such as sodium alginate, nonionic surfactants, anionic surfactants, etc., binders such as xanthan gum, xanfropectin, gum arabic, guar gum, etc., and viscosity modifiers such as liquid paraffin, machine oil, Gear oil, castor oil, silicone oil, heavy oil, cylinder oil, turbine oil, rapeseed oil, bitumen, etc. can be used.

However, in addition to the combination of the pyrethroid compound and silicate compound powder according to the present invention, general adsorbents used such as crystalline cellulose, vermiculite, kaolin, diatomaceous powder, etc.
When adding an insecticide, acaricide, bactericide, fungicide, synergist, or repellent to the composition, it is necessary to devise a manufacturing method. When adsorbing a pyrethroid compound to silicate compound powder, after diluting the pyrethroid compound with an appropriate diluent,
After mixing, the diluent can be removed by air drying or the like if necessary, and as a result, the pyrethroid compound can be adsorbed. As the diluent in this case, common low-boiling organic solvents such as pentane, petroleum ether, hegysanate, benzene, ether, ethyl acetate, acetone, ethanol, methanolacetonitrile, methylene chloride, etc. can be used. Further, if the amount of silicate compound powder is sufficient for the pyrethroid compound, treatments such as dilution and air drying can be omitted.

The dosage form is determined by the intended use and the target pest, and in some cases it is also used as a food poison. In this case, attractants depending on the target pest, such as corn flour, sugar, wheat flour, fish meal, or aggregation pheromones and sex pheromones of the target pest can be used, and in addition to these, fragrances and pigments may be added depending on the purpose.

The present invention can be used as long as it can exterminate insects or mites for which the pyrethroid compound is effective. Insects include agricultural pests, grain storage pests, unpleasant pests, clothing pests,
There are sanitary pests, etc., and the mites are classified into the suborders Mesospiritus, Prospirochlia, and Aspirata. The pyrethroid compounds exemplified in the present invention are particularly effective against grain storage pests 1, nuisance pests, clothing pests, and sanitary pests. Pests include ants, centipedes,
Examples include millipedes, stink bugs, midges, spiders, wasps, etc. Clothing pests include burrs, cutworms, and sanitary pests include fleas, meat flies, gobys. In addition, the above-mentioned middle spiracles, posterior spiracles,
The following are examples of the suborder Asteroides; the suborders Mesospirata include the mites and mites; the suborders the Prospirata include the tick mites and dust mites; Examples include the following.

In addition, the present invention can selectively use the above-mentioned dosage forms and/or drug additions as long as they are effective against insects and/or mites to be exterminated. This shows that selecting a wide variety of chemicals can effectively exert an insecticidal and acaricidal effect in places where multiple species of target insects and/or mites live at the same time, such as in the shade of a house or in an attic.

In the present invention, each dosage form can be selected from those suitable for production, and can be produced by conventionally known methods.

<Examples> The present invention will be explained in more detail with the following examples. However, the following examples are not intended to limit the scope of the invention.

The silicon dioxide used in the following Examples (1 to 5) has a particle size of O9○o5 to 0.11g/a, and a bulk density of 01o5 to 0.13g/a (and the hydrous silicon dioxide has a particle size of 5/f.
less than fi, bulk density 0. 15 to 0.24 g/cm was used. The talc, heavy calcium carbonate, bentonite, clay, and acid clay used as powder carriers in Example 5 were those obtained by sieving through a 300 mesh/inch sieve with a maximum hole diameter of 50 μs.

Example 1 1% by weight of shifuettrin, 1% by weight of silicon dioxide,
0.1% by weight of fragrance and 97.9% by weight of precipitated carbonic acid-15=calcium were sufficiently stirred and mixed to obtain a powder.

Example 2 1 part by weight of resmethrin and 2 parts by weight of silicon dioxide were stirred and mixed. 1.5% by weight of this resmethrin mixture;
2% starch by weight, butylated hydroxytoluene 0.05%
% by weight, 0.5% of chili pepper extract, 0.5% of blue No. 5.
7% by weight and 95.25% by weight of sugar were thoroughly mixed, water was added, the mixture was combined, granulated, dried and sized to obtain granules.

Example 3 1 part by weight of permethrin and 1 part by weight of hydrous silicon oxide were mixed with stirring. This permethrin mixture contains 1.5% by weight, 40% by weight of sugar, 54.8% by weight of starch, 0.5% by weight of capsicum extract and 0.5% by weight of carbon black.
2% by weight was sufficiently stirred and mixed, and the mixture was compressed into a cylindrical shape to obtain tablets.

6 Example 4 The insecticidal and acaricidal composition shown below was prototyped, put into a glass bottle, sealed, and then placed at a room temperature of 40"C (however, compositions No.
After storage for 1 year at 50'C (O-12), the remaining amount of the pyrethroid compound was expressed in weight percent. This weight percentage is expressed as a ratio to the sample composition prepared before storage, and the quantitative determination was performed by gas chromatography after extracting the sample composition with ether using a Soxhlet extractor.

In addition, after removing the silicic acid compound from each composition and storing it under the same conditions for one year at room temperature of 40°C, the remaining amount of the pyrethroid compound was determined (weight percent).
This was used as the comparison area. All compositions are expressed in weight percent.

Composition 1 Allethrin 1.0% Silicon dioxide 1.0% Talc comparative composition 1 Allethrin talc (45IIm) Composition 2 Allethrin hydrated silicon oxide heavy calcium carbonate comparative composition 2 Allethrin heavy calcium carbonate Composition 3 Arethrin talc (45IIm) Silicon dioxide bentonite comparative composition 3 Allethrin bentonite composition 4 98°0% 1, 0% 99, 0% 0, 2% 0, 2% 99, 6% 0, 2% 99, 8% 2, 0% 1, 5% 96, 5% 2, 0% 98, 0% Resmethrin silicon dioxide talc comparative composition 4 Resmethrin talc composition 5 Resmethrin silicon dioxide clay comparative composition 5 Resmethrin clay composition 6 Resmethrin silicon dioxide heavy carbonate Calcium comparison composition 6 Resmethrin 0.4% 0.6% 99°0% 0.4% 99.6% 2.0% 2.0% 96.0% 2.0% 98.0% 0.1% 0.3% 99.6% 1% = 19 Heavy calcium carbonate composition 7 Phenothrin silicon dioxide bentonite comparative composition 7 Phenothrin bentonite composition 8 Phenothrin silicon dioxide heavy calcium carbonate comparative composition 8 Phenothrin heavy calcium carbonate Composition 9 Phenothrin silicon dioxide talc 99,9% 1,0% 0,7% 98,3% 1,0% 99,0% 1,0% 0,7% 98,3% 1,0% 0% 9 1,0% 1,8% 97,2% Comparative composition 9 Phenothrin talc composition 10 Permethrin silicon dioxide talc comparative composition 10 Permethrin talc composition 11 Permethrin silicon dioxide acid clay comparative composition 11 Permethrin acid clay composition 12 Permethrin 1,0% 99,0% 0,1% 0,5% 99,4% 0,1% 99,9% 2,0% 1,2% 96,8% 2,0% 98,0% 6% Silicon dioxide heavy calcium carbonate comparative composition 12 Permethrin heavy calcium carbonate composition 13 Empenthrin silicon dioxide talc comparative composition 13 Empenthrin talc composition 14 Empenthrin silicon dioxide heavy calcium carbonate comparative composition 14 Empenthrin heavy carbonate Calcium 0,6% 98,8% 0,6% 99,4% 0,3% 0,6% 99,2% 0,3% 99,7% 5,0% 3,0% 92,0% 5 , 0% 95, 0% Margin 3 below the test results [Effect] The method of the present invention stabilizes a pyrethroid compound that is low in toxicity and effectively exterminates insects and mites. This not only prevents a decrease in the exterminating effect of pyrethroid compounds, but also makes it possible to simplify packaging and/or storage methods. This has the advantage of producing an insecticide and acaricide that is inexpensive, can be stored for a long period of time, and is effective.

(that's all)

Claims (1)

[Claims] A method for stabilizing a pyrethroid compound, which comprises retaining at least one compound selected from pyrethroid compounds in one or more compounds selected from porous silicate compound powder having a particle size of 5 μm or less.