JPS6054929B2 - How to maintain the effectiveness of fumigation insecticides - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for sustaining the efficacy of fumigated insecticides.

More specifically, pyrethroid insecticides have an average molecular weight of 2.
It is characterized by containing 00 to 1000 polybutene, and its purpose is to control the volatilization of insecticidal ingredients by fumigation, suppress decomposition, and volatilize insecticidal ingredients efficiently over a long period of time. There are methods that provide long-lasting efficacy. Conventionally, electric fumigation is known as a method of killing insects by fumigation, which involves absorbing a pyrethroid insecticide into an impregnating carrier such as pulp, asbestos, or porous synthetic resin, and then heating the carrier to a temperature of 160 to 18
It is known as an insecticidal method that involves heating at a temperature of 00C to volatilize insecticidal ingredients.

Unlike the methods of using emulsions, oils, aerosols, etc., this insecticidal method effectively volatilizes the insecticidal ingredients over a long period of time by heating, and remains effective for more than 8 hours, which is the average sleeping time of humans. Sustainability is a necessary condition. However, despite the fact that pyrethroid insecticides exhibit excellent fast-acting and insecticidal efficacy,
When used in the fumigation method, that is, electric spray, the insecticidal effect is relatively high at the initial stage of heating, but the drawback is that the effect decreases significantly or becomes ineffective over time.

This is thought to be due to the high vapor pressure of the insecticidal component and its large decomposition due to heat. Therefore, in Denkimonfuku, the volatilization of the insecticidal ingredient should be adjusted so that the insecticidal effect lasts for 8 hours or more, and the decomposition of the insecticidal ingredient due to heat should be controlled, and on the other hand, the decomposition of the insecticidal ingredient during storage should be suppressed. is the biggest problem. In order to solve these problems and obtain an ideal electric pattern, the present inventors conducted extensive research on controlling the volatilization and suppressing the decomposition of insecticidal ingredients, and as a result, we blended polybutene with an average molecular weight of 200 to 1000 into a pyrethroid insecticide. It has been discovered that, as a result, the decomposition of the insecticidal component due to heat is suppressed, its volatilization is efficiently controlled, the insecticidal component can be effectively volatilized over a long period of time, and the insecticidal component has excellent stability over time. This completes the present invention. That is, the method for sustaining the efficacy of a fumigated insecticide according to the present invention is to add a polyb with an average molecular weight of 200 to 1000 to a pyrethroid insecticide.
This is achieved by adding chi. The polybutene used in the fumigation insecticide efficacy sustaining method of the present invention is required to have an average molecular weight in the range of 200 to 1000 in order to obtain the above-mentioned effects.

In the case of blending polybutene with an average molecular weight of 200 or less,
Polybutene volatilizes in a short time, making it difficult to suppress decomposition and control volatilization of the insecticidal component, making it impossible to obtain the desired effect. Furthermore, if polybutene with an average molecular weight of 1000 or more is blended, the volatilization of the insecticidal component will be suppressed too much due to its physical properties, making it unsuitable as a volatilization regulator. In addition, the blending ratio of the above-mentioned polybutene is approximately 25 to 50% by weight based on the insecticidal component, and a practically sufficient effect can be obtained, but it can be adjusted depending on the heating temperature and duration of effect, and it can be blended as appropriate depending on the purpose. It is desirable to determine the amount.

However, if the amount is too small, it will be difficult to suppress the decomposition and control the volatilization of the insecticidal component, making it impossible to obtain the desired effect. Examples of the pyrethroid insecticides used in the present invention include 3-aryl-2-methylcyclopent-2-en-4-one-1-yl-d1sis, trans-chrysanthemate, and 3-aryl-2-methylcyclopentate. 2-ene-4-one-1-yl-d-cis,
Trans-chrysanthemate, d-3-aryl-2-methylcyclopent-2-ene-4-one-1-yl d
-trans-chrysanthemate, 3-phenoxybenzyl-d-cis, trans-chrysanthemate, 3-phenoxybenzyl-d1-cis, trans-3-(2,2
-dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylate, 5-benzyl-3-furylmethyl-dl-cis, trans-chrysanthemate, 2-
Examples include methyl-5-(2-propyl)-3-furylmethyl chrysanthemate.

In carrying out the present invention, at least one of the above-mentioned pyrethroid insecticides and polybutene may be mixed into bulbs, asbestos, porous synthetic resins, glass fibers, cloth, mineral powder materials, porous magnetic materials, etc. It can be used by impregnating it into a porous carrier, or it can be formulated into a paste, cream, tablet, etc.

In addition, other additives effective as volatilization regulators may be added as necessary, such as butyl stearate, butyl oleate,
Butyl palmitate, dibutyl fumarate, dibutyl maleate, isopropyl myristate, diethylene glycol distearate, glycerin monooleate, 2-
Ethylhexyl-P-hydroxybenzoate, methyl acetyl ricinoleate, acetyl tributyl citrate, trioctyl trimellitate, epoxidized soybean oil, di-2-ethylhexyl sebacate, epoxy plasticizer,
A plasticizer such as a polyester plasticizer can also be blended, and a synergist, a decomposition inhibitor, a repellent, etc. can also be blended and used. Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples. Example 1 As an insecticidal ingredient, 3-allyl-2-methylcyclopent-2-en-4-one-1-yl-d-cis, trans-chrysanthemate (hereinafter referred to as pinamine forte) or 3-allyl-2-methylcyclopentane-2- A valve plate (3
An insecticidal mat was prepared by impregnating a 5 cm x 22 CrfL1 (thickness: 0.27 α).

This insecticidal mat was placed on a heating element maintained at a temperature of 16rc, placed in a glass cylinder with a diameter of 15C7r11 and a height of 25an, the top and bottom of which were closed, and heated with electricity for 3, 6 and 9 hours to volatilize the insecticidal ingredients. . At each hour, the insecticidal components floating in the cylinder are allowed to cool and condense and adhere to the wall surface, and this is washed with petroleum ether.The content of the insecticidal components contained in the petroleum ether is determined by gas chromatography. was quantified, and the volatilization rate and decomposition rate were measured. The result is the first
It was as shown in the table. Example 2 A valve plate (3.5 cm
7I1 (thickness: 0.27 cm) to prepare an insecticidal mat.

This insecticidal mat was wrapped in a commercially available mosquito repellent mat wrapping paper and stored at room temperature. After 6 and 12 months, it was extracted using petroleum ether as a solvent, and the change over time in the decomposition rate of the insecticidal component was measured using gas chromatography. Upon investigation, the results shown in Table 2 were obtained. Example 3 A valve plate (3.5α x 2
．． 2C7F! An insecticidal mat was prepared by impregnating it to a thickness of 0.27C77.

When the volatilization rate and decomposition rate of the insecticidal component of this insecticidal mat were measured in the same manner as in Example 1, the results shown in Table 3 were obtained. As is clear from the results shown in Table 3, the duration of efficacy can be adjusted by changing the amount of polybutene blended. Next, about 15 female adults of Chicae mosquito were released into a 16.6 cm cubic glass chamber, and the insecticidal mat prepared as described above was heated with a heating element kept at 167°C to fumigate it, and as time passed, The fall suppression rate was investigated.

The results are shown in the figure. The efficacy is expressed as a relative efficacy with respect to that of a conventional mosquito coil (indicated by a broken line in the figure). As is clear from the figure, when Pinamin Fuorte is used alone, its efficacy decreases rapidly after 6 hours.

On the other hand, when polybutene was blended, a high fall suppression rate was exhibited even after 9 hours had passed, indicating that the insecticidal effect can be effectively exerted over a long period of time.

[Brief explanation of the drawing]

The figure is a graph showing the fall-suppressing effect on Chikaeka in Example 3.

Claims (1)

[Claims] 1 Pyrethroid insecticides with an average molecular weight of 200 to 100
A method for maintaining the efficacy of a fumigation insecticide characterized by blending 0 polybutene.