JPS6318564B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to insecticides. More specifically, the present invention relates to an insecticide comprising a pyrethroid insecticide that kills mosquitoes and the like, and a heat-generating composition that generates heat upon contact with oxygen.

Pyrethroid insecticides are conventionally known as insecticidal ingredients contained in pyrethrum, and have been used for a long time because they are fast-acting and have low toxicity to humans and livestock. Vaporization into the air through incomplete combustion of incense sticks, etc.
Recently, methods such as volatilization with an electric heater have been widely used.

However, when this insecticide is used for portable purposes such as mountain climbing, camping, etc., or for emergency purposes such as power outages, conventional products cannot be used or may cause inconvenience. For example, mosquito coils require an ignition source, may go out during the process, may come into contact with the human body or kimono, causing burns or burns to clothing, and are inconvenient to handle. Furthermore, methods using electric heaters cannot be used where there is no power source. On the other hand, it has been considered to volatilize the above-mentioned pyrethroid insecticides using other heat sources, but in order to volatilize efficiently and maintain the insecticidal effect, it is necessary to maintain the temperature at a constant temperature for a specified period of time and to easily obtain the heat source. This is necessary.

As a result of various studies on insecticides that do not have these drawbacks, the present inventors found that when a pyrethroid insecticide is used in combination with a certain heating element that generates heat when it comes into contact with oxygen, it becomes an ignition source and The present invention was achieved by discovering that it does not require a power source, can be used anytime and anywhere as long as there is oxygen (air), and has the advantage of having a stable insecticidal effect.

That is, the first invention of the present invention generates heat upon contact with oxygen, and (a) metallic iron, (b) silicic acid and/or
or a sodium silicate hydrate, and (c) a heating element containing a metal halide, and a pyrethroid insecticide; the second invention generates heat upon contact with oxygen; ) Metallic iron, (b) silicic acid and/or sodium silicate hydrate, and (c) metal halide is a layered insecticide in which a heating element layer containing a pyrethroid insecticide layer is laminated.

According to the present invention, by arbitrarily selecting the physicochemical properties such as volatility and efficacy of the pyrethroid insecticide, the composition of the exothermic composition, and the coating material,
To provide a new type of insecticide whose efficacy and sustainability can be arbitrarily controlled according to the purpose and use.

The pyrethroid insecticide, which is one of the components of the insecticide of the present invention, can be either natural or synthetic. Natural pyrethroids are insecticidal ingredients contained in the flowers of pyrethrum (Chrysanthemum cinerariaefolium), and are two types of acids known as pyrethrin, pyrethrin, cinerin, cinerin, diasmoline, and diasmolin, chloric acid, or dicarboxylic acid. (pyreth phosphoric acid) and 3
It is known to be an ester consisting of a species alcohol, cinerolone, pyrethrolone or diasmololone. These are contained in natural pyrethrum extract in a range of about 4% to 35%, and they exhibit excellent insecticidal power against mosquitoes and flies.
In recent years, many structural isomers and analogues of natural products have been known by synthetic methods based on the structures of these natural pyrethroids, and any of them can be used in the insecticide of the present invention. Examples of such synthetic products include allethrin (or pinamine),
It is known as fresthrin, cyclethrin, versulin, dimethrin, phthalthrin (neopinamine), resmethrin (krythron), flamethrin, phenotrin, permethrin, etc., and these are all compounds containing chrysanthemum acid or substituted cyclopropane carboxylic acid and various It consists of an ester with an alcohol, and may also include stereoisomers based on the asymmetric carbon in the cyclopropane ring of the chrysanthemum acid moiety. When these pyrethroid insecticides are natural, they can be used either in the form of a powder obtained by drying pyrethrum flowers or in the form of a pyrethrum extract extracted with an organic solvent or the like. When used as an extract, it may be used as it is, or it may be impregnated with a suitable filler as described below. On the other hand, since synthetic products are usually in a liquid state at room temperature, they can be used as they are like natural extracts, or they can be impregnated with a suitable filler and used in the form of powder or granules.

On the other hand, the heating element used in the present invention generates heat when it comes into contact with oxygen (air), does not require ignition or water injection, has a uniform reaction with oxygen, and has a large calorific value per unit weight. For these reasons, it is a heating element containing (a) metallic iron, (b) silicic acid and/or sodium silicate hydrate, and (c) metal halide.

The metallic iron as component (a) in such a heating element is generally used in the form of fine particles or powder, and particles of usually smaller than 10 meshes, preferably smaller than 50 meshes, particularly preferably smaller than 100 meshes are suitable.

In addition, the metallic iron of component (a) can be used in powder form such as reduced powder, electrolytic powder, spray powder, and ground powder.
The metallic iron does not necessarily have to be of high purity, but may contain impurities as long as the purpose of the present invention is not impaired.

On the other hand, various types of silicic acid and/or sodium silicate hydrate can be used as component (b).
For example, silicic acids represented by the following general formula are known, and any of these can be used as the component (b) of the present invention.

Orthosilicic acid [H ₂ n+2SinO ₃ n+1] Metasilicic acid [H ₂ nSinO ₃ n] Mesosilicic acid [H ₂ n−2SinO ₃ n−1] Parasilicic acid [H ₂ n−4SinO ₃ n−2] In these general formulas, n is Represents a positive number.

Specific examples of such silicic acid include H ₄ SiO ₄ ,
Orthosilicic acid such as HSiO ₇ , HSiO ₇ ; H ₂ SiO ₃ , 2
(H ₂ SiO ₃ ), metasilicic acid such as 3 (H ₂ SiO ₃ );
Examples include meso-silicic acids such as H ₂ SiO and H ₄ Si ₃ O; para-silicic acids such as H ₂ Si ₃ O ₇ . However, the silicic acid (b) of the present invention is not limited to these specific examples.

The silicic acid (b) of the present invention can be prepared by various methods, but the method of preparation does not affect the effectiveness of the composition of the present invention. For example, ortho-silicic acid, meta-silicic acid, and metani-silicic acid are prepared by dehydrating silicic acid gel obtained by treating an alkali silicate with an acid using various drying agents, or by hydrolyzing ortho-silicic acid ethyl ester with alcohol and water. A white colloidal precipitate is formed very gradually, and by slow heating and dehydration, orthosilicic acid of SiO ₂ 2.5H ₂ O and SiO ₂ 2H ₂ O;
Pyrosilicic acid of SiO ₂ .1.5H ₂ O; metasilicic acid of SiO ₂ .H ₂ O; metanisilicic acid of SiO ₂ .0.5H ₂ O can be obtained.

In addition, examples of sodium silicate hydrate include
Na ₂ SiO ₃・9H ₂ O, Na ₂ SiO ₃・5H ₂ O and
These include sodium silicate hydrates such as Na ₂ SiO ₃ .4H ₂ O. However, these intermediate salts are of course not limited to the examples listed here.

Furthermore, this sodium silicate hydrate contains water of crystallization, but is itself a solid. Such a sodium silicate hydrate salt can be produced by various methods, and the method of production is not particularly limited.
For example, silicic acid and soda ash are pulverized and mixed, put into a melting furnace, heated with heavy oil or electric power, and when completely melted into a transparent material, taken out and cooled to solidify. Grind this, put it in an autoclave and dissolve it with pressurized steam, let this solution stand still to let the undissolved matter settle, filter the supernatant liquid, and concentrate the liquid Method: Caustic soda and alkali soluble A method is used, such as placing the silicic acid raw material in an autoclave, inhaling pressurized steam to react, filtering to remove insoluble matter, and placing in a boiling pot to concentrate.

These silicic acid and sodium silicate hydrate can be prepared or commercially available, but they can be powdered and mixed later, or (a) metal powder or (c) halogenated It may be crushed when mixed with metal or (d) filler. Furthermore, the silicic acid and sodium silicate hydrate used in the present invention may contain free water in addition to coordinated water.

As for the silicic acid and sodium silicate hydrate used in the present invention as component (b), either silicic acid or sodium silicate hydrate may be used alone, or both silicic acid and sodium silicate hydrate may be used. .

The exothermic composition of the present invention further contains (c) a metal halide in addition to the components (a) and (b).

As the metal halide (c), various metal chlorides, bromides, and iodides can be used, and examples of the metals include alkali metals, alkaline earth metals,
Transition metals are preferred. (c) Specific examples of metal halides include sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, magnesium chloride, calcium chloride, barium chloride, magnesium bromide, calcium bromide, and bromide. Alkali metal or alkaline earth metal halides such as barium, copper chloride, copper bromide, silver chloride, zinc bromide, and zinc bromide; for example, tin chloride,
Ferrous chloride, ferric chloride, ferrous bromide, ferric bromide
Examples include halides of transition metals such as iron, cobalt chloride, nickel chloride, cobalt bromide, and nickel bromide, as well as aluminum chloride.
The ingredients are not limited to these.

Furthermore, the metal halide (c) can be used either in the form of an anhydrous salt or a hydrated salt.

Alkali metals and alkaline earth metals are particularly preferably used as the metal halide (c) in the present invention, and among these, common salt is one of the preferred metals from the viewpoints of ease, economy, and safety.

Furthermore, in the present invention, by using a filler (d) in combination with components (a), (b), and (c), the oxygen absorption rate can be further controlled. First, it becomes possible to control the oxygen absorption capacity, and the air permeability of the composition can be improved.

Such filler (d) includes (a) itself, (b)
It may be either inorganic or organic as long as it is chemically inert to the component or (c) metal halide. Particularly preferred are those that are inert or poorly soluble in water. Examples of such fillers include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), or silica-alumina (SiO ₂ .Al ₂ O ₃ ), of which various types can be used. For example, alumina is α
-, β- or γ-alumina, and silica-alumina has a wide range of silica to alumina ratios, for example 1:99 to 99:1 by weight.
It may be of. Silica-alumina with a weight ratio of silica to alumina of 5:95 to 95:5, particularly 10:90 to 90:10, is excellent.

In addition to such synthetic silica-aluminas, naturally occurring silica-alumina minerals can also be used. Silica-based materials include silica, silica sand, powdered quartz, and diatomaceous earth, and alumina-based materials include pauxite, alumina minerals such as boehmite (Al ₂ O ₃ H ₂ O), and diaspore (Al ₂ O ₃・H ₂ O), gibbsite (Al ₂ O ₃・3H ₂ O),
These include bayerite, snail rock, and clay.

Furthermore, silica-alumina type materials include feldspar, clay minerals such as kaolin, frog's eye clay, kibushi clay, bentonite (main component Al ₂ O ₃ 4SiO ₂・nH ₂ O), acid clay, waxite (main component pyromite), Fillite;
Al ₂ O ₃・4SiO ₂・H ₂ O), sericite; pyrophyllite, mica (e.g. white unmo), nacrite, detsuite,
Various zeolites such as alumina silicates, montmorillonite, and molecuicolar sieves - 3A,
Various Molecule Collar Thieves such as 5A and 13X belong to these. However, the silica and/or alumina are not limited to those mentioned above.

Furthermore, silica-magnesia can also be used as component (d).

Examples of such silica-magnesia include ores containing silica and magnesia as main components and synthetic silica-magnesia. Examples of such ores include talc, whose main component is hydrated magnesium silicate, olivine (holsterite), indomica asbestos, and diamonite. Furthermore, magnesium metasilicate salts and the like are also included.

Furthermore, if synthetic silica-magnesia contains silica and magnesia, the ratio of silica and magnesia can range within a wide range, for example, 1:99 to 99:1 by weight.
It may be of. Further, it is preferable to use a material having a weight ratio of silica and alumina of 95:5 to 5:95.

In the above silica-magnesia system, for example, magnesia completely free of silica can also be used.

(d) In addition to the above-mentioned silica-alumina and silica-magnesia, activated carbon, alkaline earth metal sulfates such as calcium sulfate, calcium silicate, natural graphite, silica-zirutania, aluminum hydroxide, Examples of component (d) include inorganic powders such as mineral powders such as iron oxide, organic monomers and polymer powders such as cellulose, styrene powder, polyaramid powder, and terephthalic acid. However, component (d) is not limited to only those mentioned above.

The proportion of each component in the heat generating element of the present invention is such that component (a) accounts for 5 to 95%, preferably 10 to 90%, particularly preferably 20 to 80% by weight of the total heat generating composition, and (b) component is 2 to 65%, preferably 5 to 65%;
60%, particularly preferably 10-50%,
Furthermore, component (c) is 0.1 to 40%, preferably 0.5 to 30%.
%, particularly preferably 1 to 20%. (d) If a filler is used, its content is 60% by weight based on the total exothermic composition.
or less, preferably 55% or less, particularly preferably 50%
It is sufficient if the ratio is as follows.

A heating element consisting of the above-mentioned components (a) to (c) or (a) to (d) can be used by mixing them in an appropriate manner. For example, each component (a) to (c) or (a) to (d) is made into fine powder and simply mixed together, a mortar, an agate bowl, a chirai machine, a ball mill, a gear compounder, an internal mixer, etc. It is best to use a mixture of pulverized and mixed ingredients. In the present invention, it is necessary to further mix the exothermic composition with the pyrethroid compound. When the pyrethroid compound is in liquid form, such as natural pyrethrum extract or synthetic pyrethroid, the mixing method is to mix any one of the components (a) to (c) or (a) to (d) of the above heating element, preferably (d) It is also possible to impregnate part or all of the components with a liquid pyrethroid compound directly or diluted in an appropriate solvent, and then uniformly mix (a) to (c) or (a) to (d). However, a liquid pyrethroid compound may be impregnated directly or diluted with a suitable solvent into the exothermic composition that has been uniformly mixed in advance. As such a solvent, highly volatile ketones, alcohols, hydrocarbons, and ethers are preferred. Alternatively, the liquid pyrethroid compound is impregnated or supported on a powdered or granular carrier that is inert with any of the components of the heating element or does not impair its properties as a heating element, and then mixed uniformly with the heating element. It's okay. Such carriers include a wide range of inorganic and organic compounds, too many to enumerate; however, in order to promote the properties of the heating element, compounds included in component (d) of the heating element component may be used. preferable.

Furthermore, in another aspect of the present invention, a pyrethroid insecticide layer is formed by impregnating or supporting the above-mentioned carrier with a pyrethroid-based insecticide, while a layer of the heating element is formed, and the two layers are laminated to form a layered layer. It can also be used as an insecticide. These two types of layers may be stacked one layer at a time, or may be stacked to form multiple layers.

The composition and proportions of the heating element of the invention are preferably selected such that it generates heat on contact with oxygen to a temperature of about 40-150°C, preferably 60-120°C.

In this way, an insecticide consisting of a pyrethroid compound and a heating element is obtained, but the ratio of the pyrethroid compound and heating element to be used is not particularly limited. However, it is undesirable for economic and safety reasons that a large amount of pyrethroid compounds remain after the heating element in an insecticide loses its heat-generating function. used. The actual proportion used varies depending on the insecticidal ability and volatility of the pyrethroid compound used and the performance of the heating element (heating temperature, duration, heat retention, etc.), but it is usually 0.5 per gram of heating element.
gram or less, preferably 0.2 g or less of the pyrethroid compound.

In addition, the insecticide of the present invention includes geraniol, citronellol, hydroxyltronellal, ionone,
A flavoring agent such as linalool may also be included. Like pyrethroid compounds, such fragrances also volatilize in the presence of air or oxygen and exhibit a fragrance.

The mixing of each component of these heating elements and the mixing operation with components containing pyrethroid compounds should be performed in an atmosphere of an inert gas that does not contain oxygen, such as nitrogen or carbon dioxide, or if carried out in air, should be carried out in a very short time. There is a need. When the insecticide obtained by mixing these components comes into contact with air or oxygen, the properties of the heating element components are impaired, so care must be taken.

Also. The mixed powder thus obtained may be further molded into pellets, beads, rods, blocks, or sheets using a tablet molding machine, extrusion molding machine, roll molding machine, or the like. At that time, binders and lubricants that are commonly used in powder molding can also be used. Examples of such binders include starch, carboxymethylcellulose, high molecular weight polymers such as polyvinyl acetate, polyolefin, and polyvinyl alcohol, and examples of lubricants include various stearic acid derivatives.

In this way, a powdered or suitably formed insecticide consisting of a pyrethroid compound and a heating element, or a layered insecticide consisting of layers of each layer is obtained, which is coated at least in part with an oxygen permeable coating. It is necessary to completely wrap the outside with an oxygen-impermeable material to avoid contact with air or oxygen until use. Pesticide efficacy can be controlled not only by the composition of the heating element, but also by choosing the permeability of the oxygen permeable material covering it. For example, if a part of the insecticide is coated with a material with low air permeability, air is supplied at a rate of several cc/min or less per gram of the exothermic composition in the insecticide.
It can be maintained for a long time at a relatively low temperature around 80℃, and if a coating material is selected that can supply air at a rate of about 10c.c./min or more per 1g of exothermic composition, the temperature can be maintained at a relatively low temperature of around 80℃ or around 120℃. At higher temperatures, it generates heat for a relatively short period of time. Therefore, in the former case, the insecticidal effect can be maintained for a long time. On the other hand, in the latter case, a large insecticidal effect can be exerted in a short period of time. Therefore, if oxygen (air) is distributed uniformly within the insecticide, the amount of ventilation per unit weight of the heating element in the insecticide within a unit time is approximately equal to the area of the air-permeable coating material per unit weight. It is calculated by multiplying the amount of air permeability per unit time per unit area of the covering material, so by selecting the covering area of the air permeable covering material per unit heating weight of the insecticide and the air permeability of the covering material. It is possible to obtain an insecticide having an insecticidal effect depending on the purpose and use.

In the insecticide according to the present invention, the above-mentioned (a) to
When using a heating element consisting of components (c) or (a) to (d), it is preferable that the heating element be at least 0.1 cc/min per unit weight, although it depends on the composition of the heating element in the insecticide. In order to achieve an oxygen aeration rate of 0.5cc/min or more,
It is advantageous to choose the permeability and coverage area of the insecticide coating material. In this case, it is expressed in terms of the amount of oxygen permeable, but normally the ratio of oxygen and nitrogen in the air is constant and there is almost no difference in permeability.

The oxygen permeability of such a coating material is defined as the oxygen permeability per unit surface area (1 cm ² ) of the coating material, per unit pressure (1 atm) of oxygen partial pressure difference, and per unit time (1 atm).
It can be expressed as the volume (cc) of oxygen passing per minute), and can be measured using a simple device such as the one below. A permeable material C (with a cross-sectional area of a cm ² ) is placed between a container divided into two parts A and B kept at normal pressure, and part A is filled with a gas (e.g. air) with a constant O ₂ concentration. Alternatively, the oxygen partial pressure in the pure acid reactor is maintained at P atm), while the part B (volume bcm ² ) is initially replaced with nitrogen, and after a certain time (t minutes), the part B is replaced with nitrogen. Measure oxygen concentration. Its concentration is C
%, the air permeability is b x C/100 x 1/a x 1/t x 1/P (ml/cm ²・mi
n・atm).

In the insecticide of the present invention, the oxygen permeability of the coating material can be easily determined in this way, so by selecting the coating area per heating weight of the insecticide as described above, You can control the effectiveness.

For example, the insecticide may be entirely coated with an oxygen-permeable material having a certain level of air permeability, or it may be controlled by partially coating it with an oxygen-impermeable material. The insecticide may be coated with materials having different air permeability to control the amount of air permeable per unit weight of the heating element in the insecticide as a whole.

The oxygen-permeable material may be any material as long as it does not allow the solid components in the insecticide to leak out, has the above-mentioned performance, and at the same time allows the vaporized birethroid compound to pass through, and is subject to material type and thickness. , shape, etc. are not particularly limited. The types of materials include, for example, various polymer films with appropriate pores, paper, woven or non-woven fabrics, and open-cell polymer membranes.If the shape is constant, porous magnetic materials and porous Solid materials such as plastic glass materials can be used. They may be made of polymeric compounds such as polyethylene, polypropylene, nylon, polyester, acetate, polyvinyl alcohol, cellophane, polymethyl methacrylate, acrylic, etc., or may be made of carbon fiber, glass fiber,
Inorganic fibers such as asbestos, natural cellulose such as silk, pulp, etc. can also be used. These membrane materials may be a single material, or two or more of these materials may be combined using an appropriate method.
For example, any material may be used as long as it has the above-mentioned air permeability as a unit by bonding, gluing, sewing, heat-sealing, or other methods.

Further, as part of the coating material, a heat insulating material can be applied around the insecticide to prevent heat radiation and improve volatilization efficiency.

After the insecticide of the present invention has been coated, at least in part, with the breathable material described above, it must be kept under an inert gas such as nitrogen until use. The easiest way to do this is to seal the package using an oxygen-impermeable material. When used, the package can be torn and taken out into the atmosphere to exert its insecticidal effect, but if you want to stop its effect midway through, you can block the air in some way. The method is to immediately seal the insecticide in an oxygen-impermeable container or bag, excluding as much oxygen as possible. When you want to use it again, you can take it out into the atmosphere to restore its effectiveness.

The shape of the insecticide of the present invention can be arbitrarily selected. For example, there are sheet-like shapes, disc-like shapes, column-like shapes, rod-like shapes, cylindrical shapes, spherical shapes, hemispherical shapes, semicylindrical shapes, conical shapes, pyramidal shapes, and the like. There are also ways to use it, such as leaving it still or hanging it.

The present invention will be described in detail below with reference to Examples.

Example 1 Commercially available pyrethroid insecticide Pinamine After impregnating 0.1g with 3.6g of activated carbon, 36g of iron powder,
14.4 g of silicic acid, 10.8 g of sodium silicate nonahydrate, 3.6 g of acid clay, and 3.6 g of salt were mixed in a mortar under a nitrogen atmosphere, and the mixture was poured into a nonwoven fabric (breathable After packing it into a 7.0cc/ ^cm2・mm・atm) bag,
Furthermore, it is wrapped and sealed with a gas barrier film.

Meanwhile, release five Culex mosquitoes into a box measuring 100 cm x 50 cm x 60 cm (length x width x height). When the above-mentioned insecticidal composition was put into the container after tearing the gas barrier film bag, all the mosquitoes fell down and turned upside down after about 20 minutes.

Example 2 Commercially available pyrethroid insecticide Pinamine Soak 0.1g into a cardboard sheet 2mm thick, 35mm long and 22mm wide. On the other hand, 36g of iron powder, 14.4g of silicic acid
g, sodium silicate nonahydrate 10.8 g, acid clay 3.6
g, 3.6 g of salt, and 3.6 g of activated carbon in a mortar under a nitrogen atmosphere, and the mixture was poured into a nonwoven fabric (temperature: 7.0 cc/cm ² min atm) made of polypropylene, polyester, and nylon with a size of 9 cm x 9 cm. After filling the bag, it is further wrapped in gas barrier film and sealed.

Next, the length x width x height used in Example 1 is 100 cm x
Five Culex mosquitoes are placed in a 50 cm x 60 cm box, and the heating element is placed inside the box by tearing off the outer gas barrier film and placing a cardboard sheet impregnated with pinamine on top of the heating element. After about 25 minutes, all of the mosquitoes fell and turned upside down.

Example 3 An insecticidal composition was obtained by using a nonwoven fabric impregnated with 0.05 g of flamethrin and 0.05 g of the antioxidant BHT on one side of a bag to be filled with the exothermic agent according to the formulation of Example 2. This is further wrapped and sealed with a gas barrier film.

On the other hand, 10 house flies are placed in a box measuring 100 cm x 50 cm x 60 cm (length x width x height), and the insecticidal composition is placed inside the box by tearing the gas barrier film. After about 30 minutes, all of the houseflies fell and turned upside down.

Example 4 An insecticidal composition was obtained by using a nonwoven fabric impregnated with 1 g of phenothrin on one side of a bag to be filled with the exothermic agent according to the formulation of Example 2. This is further wrapped and sealed with a gas barrier film.

On the other hand, 10 German cockroaches are released into a box measuring 100 cm x 50 cm x 60 cm in length, width and height, and the insecticidal composition is placed inside the box by tearing the gas barrier film. After about 30 minutes, all of the German cockroaches turned over.

Example 5 The exothermic agent according to the formulation of Example 2 was placed in a 10 cm x 10 cm bag made of nonwoven fabric (breathability 7.0 cc/cm ² , min atm) made of polypropylene, polyester, and nylon, and a bag made of Japanese paper laminated with polyethylene (diameter
0.05 α, α-allethrin (α-trans-chrysanthemum monoester α-allethrin ester) was added to one side of the above non-woven fabric bag. g into an impregnated container to obtain an insecticidal composition. This is further wrapped and sealed with a gas barrier film.

This was tested over time using the following experimental equipment. The device consists of two stacked glass cylinders with a diameter of 20 cm and a height of 43 cm on a stand, and a cylinder with a diameter of 20 cm on top of the cylinders.
cm, stacking glass cylinders 20 cm high. Sandwich 12 meshes of stainless steel wire mesh between the second and third tiers and the third and fourth tiers from the bottom, and an additional 48 to 65 meshes of synthetic fabric between the third and fourth tiers. . 20 Culex mosquitoes are released into the third stage of this device, and the above insecticidal composition is placed on the support stand by tearing the gas barrier film. Observe the number of Culex mosquitoes that fall and turn over over time, and find the time (KT50) for 50% of them to fall. This operation was tested immediately, 2 hours, 4 hours, 6 hours, and 8 hours after the insecticidal composition was removed from the gas barrier bag. As a result, allethrin
Almost the same KT50 as mosquito coil containing 0.6% was obtained from immediately to 8 hours later.

Claims (1)

[Scope of Claims] 1. A heating element and pyrethroid insecticide that generates heat upon contact with oxygen and contains (a) metallic iron, (b) hydrated silicic acid and/or sodium silicate, and (c) metal halide. An insecticide made by mixing. 2. A heating element layer that generates heat upon contact with oxygen and contains (a) metallic iron, (b) silicic acid and/or sodium silicate hydrate, and (c) metal halide, and a pyrethroid insecticide layer are superimposed. layered insecticide.