JPS6135966B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for controlling the volatilization of the insecticidal component of an electric mosquito repellent to maintain its efficacy for 8 hours or more. Insecticide or insect repellent in which allethrin is impregnated into an impregnated carrier such as a fibrous, porous synthetic resin or mineral medium, and the carrier is heated to a temperature of 150 to 170°C using an appropriate method such as an electric heater to volatilize the insecticidal component. The method is
For example, it is known from Japanese Patent Publication No. 38-8000 and Japanese Patent Publication No. 41-4477, and has been put into practical use and widely used. These insecticidal methods are used to protect the user from pests during sleep, and it is practically important to maintain insecticidal efficacy for the average human sleeping time, which is 7 to 8 hours. However, these insecticidal methods have the disadvantage that, although the insecticidal ingredients themselves have strong efficacy, they exert their efficacy intensively in the early stage of heating the carrier, and the insecticidal efficacy decreases or becomes completely ineffective in the latter half. There is. This is because the insecticidal component has high vapor pressure and good volatility, so most of it evaporates in the initial stage of heating. Therefore, it is necessary to suppress the volatilization of the insecticidal component to a fixed amount and maintain it constant for 8 to 10 hours. Methods to solve these problems include changing the heating temperature of the impregnated plate to a temperature lower than 150℃,
Alternatively, a method may be considered in which a sustained release agent (volatilization inhibitor) is added to the insecticidal component and impregnated into the carrier. However, the former method of lowering the temperature reduces the ability of the insecticidal component to uniformly diffuse into the room after volatilization, which is not preferable for the expression of insecticidal efficacy.Therefore, the present inventors have developed various methods to eliminate these drawbacks. As a result of studying sustained release agents, we found a very effective sustained release agent, confirmed that it is possible to freely control and control the volatilization of insecticidal components, and completed the present invention. That is, the present invention provides allethrin with N-(2-ethylhexyl)- in an amount of 25 to 100% of the amount of allethrin.
1-isopropyl-4-methylbicyclo(2.
2.2) By blending oct-5-ene-2,3-dicarboximide (hereinafter referred to as cinepirin-500) and impregnating it into a carrier, the volatilization duration of the insecticidal component can be increased to 8 to 10 hours. I found out that it is possible. Insecticides mixed with this controlled-release agent may be impregnated into fibers or porous synthetic resins, or may be absorbed into porous magnetic materials such as bisque, mineral powder materials such as diatomaceous earth, clay, white carbon, etc. It can be used even if you let it. It is also suitable for insecticidal methods in which it is formulated into a paste or cream and volatilized over a heating element. Cinepirin-500, the sustained-release agent of the present invention, is known as a synergist for pyrethroids, but this synergistic effect is known to be excellent in liquid formulations, and it is also used in some mosquito coils. However, it is not used at all in electric mosquito repellent insecticides. That is, Cinepirin-500 exhibits a synergistic effect when blended in an amount equal to or more, preferably twice or more, to the pyrethroid. Therefore, it is possible to use it as a liquid agent, and the temperature at which mosquito coils are heated is the highest.
At temperatures as high as 800℃, it is thought to volatilize sufficiently and act as a synergist for pyrethroids. On the other hand, when using a volatile insecticide such as an electric mosquito repellent, pine impregnated only with allethrin has excellent insecticidal efficacy at the initial stage of heating, but the efficacy decreases over time, and the efficacy remains for 8 to 10 hours. It is difficult to keep it constant. The present inventor has discovered that by blending Cinepirin-500 with this allethrin in an amount of 25 to 100% of the amount of allethrin, the volatilization of allethrin can be kept constant for 8 to 10 hours, and the invention has now been completed. This is not the original synergistic action of the synergist for pyrethroid, but rather the action as a single compound.The amount of allethrin volatilized into the air is suppressed to some extent initially, and it remains almost constant for 8 to 10 hours. This is thought to be due to the fact that it is regulated (acts as a sustained release agent). As mentioned above, in the electric mosquito repellent insecticide containing allethrin as an active ingredient, cinepirin-500, which is one of the synergists for pyrethroids, happened to have the function of a sustained release agent for allethrin. Other synergists for pyrethroids such as octachlorodipropyl ether, N-octylbicycloheptenedicarboximide, β-butoxy-β
-thiocyanodiethyl ether, safroxane,
This is an effect that is not seen at all with sulfoxides and the like. The electric mosquito repellent insecticide of the present invention also contains pyrethroid stabilizers such as dibutylhydroxytoluene (hereinafter referred to as BHT), butylhydroxyanisole (hereinafter referred to as BHT), dibutylhydroquinone (hereinafter referred to as DBH), and an active ingredient detector. As, 1.4-
A preparation containing dibutylaminoanthraquinone, 1,4-diisopropylaminoanthraquinone, etc. can also be prepared. Allethrin, an insecticidal ingredient, has various isomers, including allethrolone ester of d-cis/trans-synthetic acid (hereinafter referred to as d-allethrin),
Products such as d-allethrin ester of d-trans-phenolic acid (hereinafter referred to as d.d-allethrin) are commercially available, and these are also included in the allethrin of the present invention. Next, the sustained release effect of Cinepirin-500 of the present invention will be explained using test examples. Test example Test electric mosquito repellent (amount of ingredients in one piece) A: Allethrin 80 mg, BHT 20 mg B: B allethrin 80 mg, Cinepirin-500 40 mg
BHT20mg C: d-allethrin 40mg, BHT20mg D: d-allethrin 40mg, cinepirin-500 30
mg, BHT20mg The above four types of electric mosquito repellent mats were prepared, placed on a hot plate at 160°C, and the amounts of allethrin and d-allethrin volatilized into the air were measured at 3 hour intervals.

[Table] As shown above, in Mats A and C containing allethrin and d-allethrin alone, a large amount of volatilization occurred during the initial 3 hours, and then rapidly decreased with time, whereas in Mats B and D containing Cinepirin-500, The volatilization of the insecticidal component was observed almost constantly for 9 hours. Furthermore, an insecticidal test was conducted on pines C and D using adults of Culex pipiens, and the falling and turning rates were compared and observed over time. The results are shown below. The above results show that the efficacy of the product without Cinepirin-500 sharply decreases after 4 hours, whereas Mattu D according to the present invention, which contains Cinepirin-500, remains almost the same as the initial level even after 10 hours. This shows that it has become possible to continue to maintain efficiency. Judging from the analysis of the volatile components mentioned above, this is not due to the effect of Cinepirin-500 as a synergist, but rather due to the function of Cinepirin-500 to stabilize the volatilization of allethrin, that is, the function of Cinepirin-500 as a sustained release agent. It is. Examples of the present invention will be shown below. Example 1 Allethrin 8g, Cinepirin-500 2g,
Dissolve 4 g of BHT in hexane to make 100 ml, adsorb 1 ml onto a fiberboard, and dry to obtain an electric mosquito repellent mat. Example 2 d-allethrin 4g, cinepirin-500 2
g, 2 g of BHT and 0.1 g of 1,4-dibutylaminoanthraquinone are dissolved in hexane to make 100 ml, and 1 ml of this is absorbed into a fiberboard and dried to obtain an electric mosquito repellent mat. Example 3 d・d-allethrin 0.2g, cinepirin-500
Add 0.8 g of vaseline to 0.02 g of DBH and 0.02 g of DBH, heat and dissolve, cool, and obtain a paste-like electric mosquito repellent insecticide. Example 4 d-allethrin 4g, cinepirin-500 2
g, 2 g of DBH and 0.1 g of 1,4-diisopropylaminoanthraquinone are dissolved in hexane, and 1 ml of this is adsorbed onto a fiberboard and dried to obtain an electric mosquito repellent mat.

Claims (1)

[Claims] 1 Add N-(2-ethylhexyl)-1-isopropyl-4-methylbicyclo(2.2.2)octo-5- to an electric mosquito repellent insecticide containing allethrin as an active ingredient in an amount of 25 to 100% of the amount of allethrin. en-2・3
- A method for maintaining insecticidal efficacy characterized by incorporating dicarboximide.